Merge remote-tracking branch 'upstream/master' into fast-swap

48 files changed, 3378 insertions, 3289 deletions

diff --git a/src/libsyntax/Cargo.toml b/src/libsyntax/Cargo.toml
index 0b38f5450b6..82e7cfa0032 100644
--- a/src/libsyntax/Cargo.toml
+++ b/src/libsyntax/Cargo.toml
@@ -10,8 +10,8 @@ crate-type = ["dylib"]
 
 [dependencies]
 serialize = { path = "../libserialize" }
-log = { path = "../liblog" }
-rustc_bitflags = { path = "../librustc_bitflags" }
+log = "0.3"
+bitflags = "0.8"
 syntax_pos = { path = "../libsyntax_pos" }
 rustc_errors = { path = "../librustc_errors" }
 rustc_data_structures = { path = "../librustc_data_structures" }
diff --git a/src/libsyntax/abi.rs b/src/libsyntax/abi.rs
index 30641515a41..ed2eb209906 100644
--- a/src/libsyntax/abi.rs
+++ b/src/libsyntax/abi.rs
@@ -20,6 +20,7 @@ pub enum Abi {
     Stdcall,
     Fastcall,
     Vectorcall,
+    Thiscall,
     Aapcs,
     Win64,
     SysV64,
@@ -55,6 +56,7 @@ const AbiDatas: &'static [AbiData] = &[
     AbiData {abi: Abi::Stdcall, name: "stdcall", generic: false },
     AbiData {abi: Abi::Fastcall, name: "fastcall", generic: false },
     AbiData {abi: Abi::Vectorcall, name: "vectorcall", generic: false},
+    AbiData {abi: Abi::Thiscall, name: "thiscall", generic: false},
     AbiData {abi: Abi::Aapcs, name: "aapcs", generic: false },
     AbiData {abi: Abi::Win64, name: "win64", generic: false },
     AbiData {abi: Abi::SysV64, name: "sysv64", generic: false },
diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 981667337d5..2eb39bc26b5 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -14,78 +14,30 @@ pub use self::TyParamBound::*;
 pub use self::UnsafeSource::*;
 pub use self::ViewPath_::*;
 pub use self::PathParameters::*;
-pub use symbol::Symbol as Name;
+pub use symbol::{Ident, Symbol as Name};
 pub use util::ThinVec;
 
-use syntax_pos::{mk_sp, Span, DUMMY_SP, ExpnId};
+use syntax_pos::{Span, DUMMY_SP};
 use codemap::{respan, Spanned};
 use abi::Abi;
-use ext::hygiene::SyntaxContext;
+use ext::hygiene::{Mark, SyntaxContext};
 use print::pprust;
 use ptr::P;
+use rustc_data_structures::indexed_vec;
 use symbol::{Symbol, keywords};
 use tokenstream::{ThinTokenStream, TokenStream};
 
+use serialize::{self, Encoder, Decoder};
 use std::collections::HashSet;
 use std::fmt;
 use std::rc::Rc;
 use std::u32;
 
-use serialize::{self, Encodable, Decodable, Encoder, Decoder};
-
-/// An identifier contains a Name (index into the interner
-/// table) and a SyntaxContext to track renaming and
-/// macro expansion per Flatt et al., "Macros That Work Together"
-#[derive(Clone, Copy, PartialEq, Eq, Hash)]
-pub struct Ident {
-    pub name: Symbol,
-    pub ctxt: SyntaxContext
-}
-
-impl Ident {
-    pub const fn with_empty_ctxt(name: Name) -> Ident {
-        Ident { name: name, ctxt: SyntaxContext::empty() }
-    }
-
-    /// Maps a string to an identifier with an empty syntax context.
-    pub fn from_str(s: &str) -> Ident {
-        Ident::with_empty_ctxt(Symbol::intern(s))
-    }
-
-    pub fn unhygienize(&self) -> Ident {
-        Ident { name: self.name, ctxt: SyntaxContext::empty() }
-    }
-}
-
-impl fmt::Debug for Ident {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "{}{:?}", self.name, self.ctxt)
-    }
-}
-
-impl fmt::Display for Ident {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        fmt::Display::fmt(&self.name, f)
-    }
-}
-
-impl Encodable for Ident {
-    fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
-        self.name.encode(s)
-    }
-}
-
-impl Decodable for Ident {
-    fn decode<D: Decoder>(d: &mut D) -> Result<Ident, D::Error> {
-        Ok(Ident::with_empty_ctxt(Name::decode(d)?))
-    }
-}
-
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Copy)]
 pub struct Lifetime {
     pub id: NodeId,
     pub span: Span,
-    pub name: Name
+    pub ident: Ident,
 }
 
 impl fmt::Debug for Lifetime {
@@ -116,6 +68,12 @@ pub struct Path {
     pub segments: Vec<PathSegment>,
 }
 
+impl<'a> PartialEq<&'a str> for Path {
+    fn eq(&self, string: &&'a str) -> bool {
+        self.segments.len() == 1 && self.segments[0].identifier.name == *string
+    }
+}
+
 impl fmt::Debug for Path {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         write!(f, "path({})", pprust::path_to_string(self))
@@ -134,7 +92,7 @@ impl Path {
     pub fn from_ident(s: Span, identifier: Ident) -> Path {
         Path {
             span: s,
-            segments: vec![identifier.into()],
+            segments: vec![PathSegment::from_ident(identifier, s)],
         }
     }
 
@@ -159,6 +117,8 @@ impl Path {
 pub struct PathSegment {
     /// The identifier portion of this path segment.
     pub identifier: Ident,
+    /// Span of the segment identifier.
+    pub span: Span,
 
     /// Type/lifetime parameters attached to this path. They come in
     /// two flavors: `Path<A,B,C>` and `Path(A,B) -> C`. Note that
@@ -170,16 +130,14 @@ pub struct PathSegment {
     pub parameters: Option<P<PathParameters>>,
 }
 
-impl From<Ident> for PathSegment {
-    fn from(id: Ident) -> Self {
-        PathSegment { identifier: id, parameters: None }
-    }
-}
-
 impl PathSegment {
+    pub fn from_ident(ident: Ident, span: Span) -> Self {
+        PathSegment { identifier: ident, span: span, parameters: None }
+    }
     pub fn crate_root() -> Self {
         PathSegment {
             identifier: keywords::CrateRoot.ident(),
+            span: DUMMY_SP,
             parameters: None,
         }
     }
@@ -249,6 +207,14 @@ impl NodeId {
     pub fn as_u32(&self) -> u32 {
         self.0
     }
+
+    pub fn placeholder_from_mark(mark: Mark) -> Self {
+        NodeId(mark.as_u32())
+    }
+
+    pub fn placeholder_to_mark(self) -> Mark {
+        Mark::from_u32(self.0)
+    }
 }
 
 impl fmt::Display for NodeId {
@@ -269,6 +235,16 @@ impl serialize::UseSpecializedDecodable for NodeId {
     }
 }
 
+impl indexed_vec::Idx for NodeId {
+    fn new(idx: usize) -> Self {
+        NodeId::new(idx)
+    }
+
+    fn index(self) -> usize {
+        self.as_usize()
+    }
+}
+
 /// Node id used to represent the root of the crate.
 pub const CRATE_NODE_ID: NodeId = NodeId(0);
 
@@ -739,7 +715,7 @@ impl Stmt {
             StmtKind::Mac(mac) => StmtKind::Mac(mac.map(|(mac, _style, attrs)| {
                 (mac, MacStmtStyle::Semicolon, attrs)
             })),
-            node @ _ => node,
+            node => node,
         };
         self
     }
@@ -935,6 +911,8 @@ pub enum ExprKind {
     Closure(CaptureBy, P<FnDecl>, P<Expr>, Span),
     /// A block (`{ ... }`)
     Block(P<Block>),
+    /// A catch block (`catch { ... }`)
+    Catch(P<Block>),
 
     /// An assignment (`a = foo()`)
     Assign(P<Expr>, P<Expr>),
@@ -1041,6 +1019,18 @@ impl Mac_ {
     }
 }
 
+#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
+pub struct MacroDef {
+    pub tokens: ThinTokenStream,
+    pub legacy: bool,
+}
+
+impl MacroDef {
+    pub fn stream(&self) -> TokenStream {
+        self.tokens.clone().into()
+    }
+}
+
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug, Copy)]
 pub enum StrStyle {
     /// A regular string, like `"foo"`
@@ -1098,16 +1088,16 @@ impl LitKind {
     pub fn is_unsuffixed(&self) -> bool {
         match *self {
             // unsuffixed variants
-            LitKind::Str(..) => true,
-            LitKind::ByteStr(..) => true,
-            LitKind::Byte(..) => true,
-            LitKind::Char(..) => true,
-            LitKind::Int(_, LitIntType::Unsuffixed) => true,
-            LitKind::FloatUnsuffixed(..) => true,
+            LitKind::Str(..) |
+            LitKind::ByteStr(..) |
+            LitKind::Byte(..) |
+            LitKind::Char(..) |
+            LitKind::Int(_, LitIntType::Unsuffixed) |
+            LitKind::FloatUnsuffixed(..) |
             LitKind::Bool(..) => true,
             // suffixed variants
-            LitKind::Int(_, LitIntType::Signed(..)) => false,
-            LitKind::Int(_, LitIntType::Unsigned(..)) => false,
+            LitKind::Int(_, LitIntType::Signed(..)) |
+            LitKind::Int(_, LitIntType::Unsigned(..)) |
             LitKind::Float(..) => false,
         }
     }
@@ -1383,6 +1373,8 @@ pub enum TyKind {
     ImplicitSelf,
     // A macro in the type position.
     Mac(Mac),
+    /// Placeholder for a kind that has failed to be defined.
+    Err,
 }
 
 /// Inline assembly dialect.
@@ -1418,7 +1410,7 @@ pub struct InlineAsm {
     pub volatile: bool,
     pub alignstack: bool,
     pub dialect: AsmDialect,
-    pub expn_id: ExpnId,
+    pub ctxt: SyntaxContext,
 }
 
 /// An argument in a function header.
@@ -1455,7 +1447,7 @@ impl Arg {
                     TyKind::Rptr(lt, MutTy{ref ty, mutbl}) if ty.node == TyKind::ImplicitSelf => {
                         Some(respan(self.pat.span, SelfKind::Region(lt, mutbl)))
                     }
-                    _ => Some(respan(mk_sp(self.pat.span.lo, self.ty.span.hi),
+                    _ => Some(respan(self.pat.span.to(self.ty.span),
                                      SelfKind::Explicit(self.ty.clone(), mutbl))),
                 }
             }
@@ -1472,7 +1464,7 @@ impl Arg {
     }
 
     pub fn from_self(eself: ExplicitSelf, eself_ident: SpannedIdent) -> Arg {
-        let span = mk_sp(eself.span.lo, eself_ident.span.hi);
+        let span = eself.span.to(eself_ident.span);
         let infer_ty = P(Ty {
             id: DUMMY_NODE_ID,
             node: TyKind::ImplicitSelf,
@@ -1605,6 +1597,15 @@ pub struct ForeignMod {
     pub items: Vec<ForeignItem>,
 }
 
+/// Global inline assembly
+///
+/// aka module-level assembly or file-scoped assembly
+#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug, Copy)]
+pub struct GlobalAsm {
+    pub asm: Symbol,
+    pub ctxt: SyntaxContext,
+}
+
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub struct EnumDef {
     pub variants: Vec<Variant>,
@@ -1679,7 +1680,8 @@ pub struct AttrId(pub usize);
 pub struct Attribute {
     pub id: AttrId,
     pub style: AttrStyle,
-    pub value: MetaItem,
+    pub path: Path,
+    pub tokens: TokenStream,
     pub is_sugared_doc: bool,
     pub span: Span,
 }
@@ -1707,6 +1709,16 @@ pub struct PolyTraitRef {
     pub span: Span,
 }
 
+impl PolyTraitRef {
+    pub fn new(lifetimes: Vec<LifetimeDef>, path: Path, span: Span) -> Self {
+        PolyTraitRef {
+            bound_lifetimes: lifetimes,
+            trait_ref: TraitRef { path: path, ref_id: DUMMY_NODE_ID },
+            span: span,
+        }
+    }
+}
+
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub enum Visibility {
     Public,
@@ -1821,6 +1833,8 @@ pub enum ItemKind {
     ///
     /// E.g. `extern {}` or `extern "C" {}`
     ForeignMod(ForeignMod),
+    /// Module-level inline assembly (from `global_asm!()`)
+    GlobalAsm(P<GlobalAsm>),
     /// A type alias (`type` or `pub type`).
     ///
     /// E.g. `type Foo = Bar<u8>;`
@@ -1850,6 +1864,7 @@ pub enum ItemKind {
     /// E.g. `impl<A> Foo<A> { .. }` or `impl<A> Trait for Foo<A> { .. }`
     Impl(Unsafety,
              ImplPolarity,
+             Defaultness,
              Generics,
              Option<TraitRef>, // (optional) trait this impl implements
              P<Ty>, // self
@@ -1860,7 +1875,7 @@ pub enum ItemKind {
     Mac(Mac),
 
     /// A macro definition.
-    MacroDef(ThinTokenStream),
+    MacroDef(MacroDef),
 }
 
 impl ItemKind {
@@ -1873,6 +1888,7 @@ impl ItemKind {
             ItemKind::Fn(..) => "function",
             ItemKind::Mod(..) => "module",
             ItemKind::ForeignMod(..) => "foreign module",
+            ItemKind::GlobalAsm(..) => "global asm",
             ItemKind::Ty(..) => "type alias",
             ItemKind::Enum(..) => "enum",
             ItemKind::Struct(..) => "struct",
diff --git a/src/libsyntax/attr.rs b/src/libsyntax/attr.rs
index 096657a6e7a..8e63e219c42 100644
--- a/src/libsyntax/attr.rs
+++ b/src/libsyntax/attr.rs
@@ -15,20 +15,24 @@ pub use self::ReprAttr::*;
 pub use self::IntType::*;
 
 use ast;
-use ast::{AttrId, Attribute, Name};
+use ast::{AttrId, Attribute, Name, Ident};
 use ast::{MetaItem, MetaItemKind, NestedMetaItem, NestedMetaItemKind};
-use ast::{Lit, Expr, Item, Local, Stmt, StmtKind};
-use codemap::{Spanned, spanned, dummy_spanned, mk_sp};
-use syntax_pos::{Span, BytePos, DUMMY_SP};
+use ast::{Lit, LitKind, Expr, ExprKind, Item, Local, Stmt, StmtKind};
+use codemap::{Spanned, respan, dummy_spanned};
+use syntax_pos::{Span, DUMMY_SP};
 use errors::Handler;
 use feature_gate::{Features, GatedCfg};
 use parse::lexer::comments::{doc_comment_style, strip_doc_comment_decoration};
-use parse::ParseSess;
+use parse::parser::Parser;
+use parse::{self, ParseSess, PResult};
+use parse::token::{self, Token};
 use ptr::P;
 use symbol::Symbol;
+use tokenstream::{TokenStream, TokenTree, Delimited};
 use util::ThinVec;
 
 use std::cell::{RefCell, Cell};
+use std::iter;
 
 thread_local! {
     static USED_ATTRS: RefCell<Vec<u64>> = RefCell::new(Vec::new());
@@ -108,7 +112,7 @@ impl NestedMetaItem {
     /// Returns the MetaItem if self is a NestedMetaItemKind::MetaItem.
     pub fn meta_item(&self) -> Option<&MetaItem> {
         match self.node {
-            NestedMetaItemKind::MetaItem(ref item) => Some(&item),
+            NestedMetaItemKind::MetaItem(ref item) => Some(item),
             _ => None
         }
     }
@@ -116,7 +120,7 @@ impl NestedMetaItem {
     /// Returns the Lit if self is a NestedMetaItemKind::Literal.
     pub fn literal(&self) -> Option<&Lit> {
         match self.node {
-            NestedMetaItemKind::Literal(ref lit) => Some(&lit),
+            NestedMetaItemKind::Literal(ref lit) => Some(lit),
             _ => None
         }
     }
@@ -143,6 +147,24 @@ impl NestedMetaItem {
         self.meta_item().and_then(|meta_item| meta_item.value_str())
     }
 
+    /// Returns a name and single literal value tuple of the MetaItem.
+    pub fn name_value_literal(&self) -> Option<(Name, &Lit)> {
+        self.meta_item().and_then(
+            |meta_item| meta_item.meta_item_list().and_then(
+                |meta_item_list| {
+                    if meta_item_list.len() == 1 {
+                        let nested_item = &meta_item_list[0];
+                        if nested_item.is_literal() {
+                            Some((meta_item.name(), nested_item.literal().unwrap()))
+                        } else {
+                            None
+                        }
+                    }
+                    else {
+                        None
+                    }}))
+    }
+
     /// Returns a MetaItem if self is a MetaItem with Kind Word.
     pub fn word(&self) -> Option<&MetaItem> {
         self.meta_item().and_then(|meta_item| if meta_item.is_word() {
@@ -185,26 +207,38 @@ impl NestedMetaItem {
 
 impl Attribute {
     pub fn check_name(&self, name: &str) -> bool {
-        let matches = self.name() == name;
+        let matches = self.path == name;
         if matches {
             mark_used(self);
         }
         matches
     }
 
-    pub fn name(&self) -> Name { self.meta().name() }
+    pub fn name(&self) -> Option<Name> {
+        match self.path.segments.len() {
+            1 => Some(self.path.segments[0].identifier.name),
+            _ => None,
+        }
+    }
 
     pub fn value_str(&self) -> Option<Symbol> {
-        self.meta().value_str()
+        self.meta().and_then(|meta| meta.value_str())
     }
 
-    pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]> {
-        self.meta().meta_item_list()
+    pub fn meta_item_list(&self) -> Option<Vec<NestedMetaItem>> {
+        match self.meta() {
+            Some(MetaItem { node: MetaItemKind::List(list), .. }) => Some(list),
+            _ => None
+        }
     }
 
-    pub fn is_word(&self) -> bool { self.meta().is_word() }
+    pub fn is_word(&self) -> bool {
+        self.path.segments.len() == 1 && self.tokens.is_empty()
+    }
 
-    pub fn span(&self) -> Span { self.meta().span }
+    pub fn span(&self) -> Span {
+        self.span
+    }
 
     pub fn is_meta_item_list(&self) -> bool {
         self.meta_item_list().is_some()
@@ -225,7 +259,7 @@ impl MetaItem {
         match self.node {
             MetaItemKind::NameValue(ref v) => {
                 match v.node {
-                    ast::LitKind::Str(ref s, _) => Some((*s).clone()),
+                    LitKind::Str(ref s, _) => Some(*s),
                     _ => None,
                 }
             },
@@ -264,8 +298,66 @@ impl MetaItem {
 
 impl Attribute {
     /// Extract the MetaItem from inside this Attribute.
-    pub fn meta(&self) -> &MetaItem {
-        &self.value
+    pub fn meta(&self) -> Option<MetaItem> {
+        let mut tokens = self.tokens.trees().peekable();
+        Some(MetaItem {
+            name: match self.path.segments.len() {
+                1 => self.path.segments[0].identifier.name,
+                _ => return None,
+            },
+            node: if let Some(node) = MetaItemKind::from_tokens(&mut tokens) {
+                if tokens.peek().is_some() {
+                    return None;
+                }
+                node
+            } else {
+                return None;
+            },
+            span: self.span,
+        })
+    }
+
+    pub fn parse<'a, T, F>(&self, sess: &'a ParseSess, mut f: F) -> PResult<'a, T>
+        where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>,
+    {
+        let mut parser = Parser::new(sess, self.tokens.clone(), None, false, false);
+        let result = f(&mut parser)?;
+        if parser.token != token::Eof {
+            parser.unexpected()?;
+        }
+        Ok(result)
+    }
+
+    pub fn parse_list<'a, T, F>(&self, sess: &'a ParseSess, mut f: F) -> PResult<'a, Vec<T>>
+        where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>,
+    {
+        if self.tokens.is_empty() {
+            return Ok(Vec::new());
+        }
+        self.parse(sess, |parser| {
+            parser.expect(&token::OpenDelim(token::Paren))?;
+            let mut list = Vec::new();
+            while !parser.eat(&token::CloseDelim(token::Paren)) {
+                list.push(f(parser)?);
+                if !parser.eat(&token::Comma) {
+                   parser.expect(&token::CloseDelim(token::Paren))?;
+                    break
+                }
+            }
+            Ok(list)
+        })
+    }
+
+    pub fn parse_meta<'a>(&self, sess: &'a ParseSess) -> PResult<'a, MetaItem> {
+        if self.path.segments.len() > 1 {
+            sess.span_diagnostic.span_err(self.path.span, "expected ident, found path");
+        }
+
+        Ok(MetaItem {
+            name: self.path.segments.last().unwrap().identifier.name,
+            node: self.parse(sess, |parser| parser.parse_meta_item_kind())?,
+            span: self.span,
+        })
     }
 
     /// Convert self to a normal #[doc="foo"] comment, if it is a
@@ -293,7 +385,7 @@ impl Attribute {
 /* Constructors */
 
 pub fn mk_name_value_item_str(name: Name, value: Symbol) -> MetaItem {
-    let value_lit = dummy_spanned(ast::LitKind::Str(value, ast::StrStyle::Cooked));
+    let value_lit = dummy_spanned(LitKind::Str(value, ast::StrStyle::Cooked));
     mk_spanned_name_value_item(DUMMY_SP, name, value_lit)
 }
 
@@ -348,7 +440,8 @@ pub fn mk_spanned_attr_inner(sp: Span, id: AttrId, item: MetaItem) -> Attribute
     Attribute {
         id: id,
         style: ast::AttrStyle::Inner,
-        value: item,
+        path: ast::Path::from_ident(item.span, ast::Ident::with_empty_ctxt(item.name)),
+        tokens: item.node.tokens(item.span),
         is_sugared_doc: false,
         span: sp,
     }
@@ -365,41 +458,34 @@ pub fn mk_spanned_attr_outer(sp: Span, id: AttrId, item: MetaItem) -> Attribute
     Attribute {
         id: id,
         style: ast::AttrStyle::Outer,
-        value: item,
+        path: ast::Path::from_ident(item.span, ast::Ident::with_empty_ctxt(item.name)),
+        tokens: item.node.tokens(item.span),
         is_sugared_doc: false,
         span: sp,
     }
 }
 
-pub fn mk_sugared_doc_attr(id: AttrId, text: Symbol, lo: BytePos, hi: BytePos)
-                           -> Attribute {
+pub fn mk_sugared_doc_attr(id: AttrId, text: Symbol, span: Span) -> Attribute {
     let style = doc_comment_style(&text.as_str());
-    let lit = spanned(lo, hi, ast::LitKind::Str(text, ast::StrStyle::Cooked));
+    let lit = respan(span, LitKind::Str(text, ast::StrStyle::Cooked));
     Attribute {
         id: id,
         style: style,
-        value: MetaItem {
-            span: mk_sp(lo, hi),
-            name: Symbol::intern("doc"),
-            node: MetaItemKind::NameValue(lit),
-        },
+        path: ast::Path::from_ident(span, ast::Ident::from_str("doc")),
+        tokens: MetaItemKind::NameValue(lit).tokens(span),
         is_sugared_doc: true,
-        span: mk_sp(lo, hi),
+        span: span,
     }
 }
 
 pub fn list_contains_name(items: &[NestedMetaItem], name: &str) -> bool {
-    debug!("attr::list_contains_name (name={})", name);
     items.iter().any(|item| {
-        debug!("  testing: {:?}", item.name());
         item.check_name(name)
     })
 }
 
 pub fn contains_name(attrs: &[Attribute], name: &str) -> bool {
-    debug!("attr::contains_name (name={})", name);
     attrs.iter().any(|item| {
-        debug!("  testing: {}", item.name());
         item.check_name(name)
     })
 }
@@ -425,8 +511,7 @@ pub fn find_export_name_attr(diag: &Handler, attrs: &[Attribute]) -> Option<Symb
             } else {
                 struct_span_err!(diag, attr.span, E0558,
                                  "export_name attribute has invalid format")
-                    .span_label(attr.span,
-                                &format!("did you mean #[export_name=\"*\"]?"))
+                    .span_label(attr.span, "did you mean #[export_name=\"*\"]?")
                     .emit();
                 None
             }
@@ -452,8 +537,14 @@ pub enum InlineAttr {
 /// Determine what `#[inline]` attribute is present in `attrs`, if any.
 pub fn find_inline_attr(diagnostic: Option<&Handler>, attrs: &[Attribute]) -> InlineAttr {
     attrs.iter().fold(InlineAttr::None, |ia, attr| {
-        match attr.value.node {
-            _ if attr.value.name != "inline" => ia,
+        if attr.path != "inline" {
+            return ia;
+        }
+        let meta = match attr.meta() {
+            Some(meta) => meta.node,
+            None => return ia,
+        };
+        match meta {
             MetaItemKind::Word => {
                 mark_used(attr);
                 InlineAttr::Hint
@@ -574,14 +665,15 @@ fn find_stability_generic<'a, I>(diagnostic: &Handler,
     let mut rustc_depr: Option<RustcDeprecation> = None;
 
     'outer: for attr in attrs_iter {
-        let tag = attr.name();
-        if tag != "rustc_deprecated" && tag != "unstable" && tag != "stable" {
+        if attr.path != "rustc_deprecated" && attr.path != "unstable" && attr.path != "stable" {
             continue // not a stability level
         }
 
         mark_used(attr);
 
-        if let Some(metas) = attr.meta_item_list() {
+        let meta = attr.meta();
+        if let Some(MetaItem { node: MetaItemKind::List(ref metas), .. }) = meta {
+            let meta = meta.as_ref().unwrap();
             let get = |meta: &MetaItem, item: &mut Option<Symbol>| {
                 if item.is_some() {
                     handle_errors(diagnostic, meta.span, AttrError::MultipleItem(meta.name()));
@@ -596,7 +688,7 @@ fn find_stability_generic<'a, I>(diagnostic: &Handler,
                 }
             };
 
-            match &*tag.as_str() {
+            match &*meta.name.as_str() {
                 "rustc_deprecated" => {
                     if rustc_depr.is_some() {
                         span_err!(diagnostic, item_sp, E0540,
@@ -772,7 +864,7 @@ fn find_deprecation_generic<'a, I>(diagnostic: &Handler,
     let mut depr: Option<Deprecation> = None;
 
     'outer: for attr in attrs_iter {
-        if attr.name() != "deprecated" {
+        if attr.path != "deprecated" {
             continue
         }
 
@@ -847,8 +939,8 @@ pub fn find_deprecation(diagnostic: &Handler, attrs: &[Attribute],
 /// structure layout, and `packed` to remove padding.
 pub fn find_repr_attrs(diagnostic: &Handler, attr: &Attribute) -> Vec<ReprAttr> {
     let mut acc = Vec::new();
-    match attr.value.node {
-        ast::MetaItemKind::List(ref items) if attr.value.name == "repr" => {
+    if attr.path == "repr" {
+        if let Some(items) = attr.meta_item_list() {
             mark_used(attr);
             for item in items {
                 if !item.is_meta_item() {
@@ -856,6 +948,7 @@ pub fn find_repr_attrs(diagnostic: &Handler, attr: &Attribute) -> Vec<ReprAttr>
                     continue
                 }
 
+                let mut recognised = false;
                 if let Some(mi) = item.word() {
                     let word = &*mi.name().as_str();
                     let hint = match word {
@@ -866,25 +959,46 @@ pub fn find_repr_attrs(diagnostic: &Handler, attr: &Attribute) -> Vec<ReprAttr>
                         _ => match int_type_of_word(word) {
                             Some(ity) => Some(ReprInt(ity)),
                             None => {
-                                // Not a word we recognize
-                                span_err!(diagnostic, item.span, E0552,
-                                          "unrecognized representation hint");
                                 None
                             }
                         }
                     };
 
                     if let Some(h) = hint {
+                        recognised = true;
                         acc.push(h);
                     }
-                } else {
-                    span_err!(diagnostic, item.span, E0553,
-                              "unrecognized enum representation hint");
+                } else if let Some((name, value)) = item.name_value_literal() {
+                    if name == "align" {
+                        recognised = true;
+                        let mut align_error = None;
+                        if let ast::LitKind::Int(align, ast::LitIntType::Unsuffixed) = value.node {
+                            if align.is_power_of_two() {
+                                // rustc::ty::layout::Align restricts align to <= 32768
+                                if align <= 32768 {
+                                    acc.push(ReprAlign(align as u16));
+                                } else {
+                                    align_error = Some("larger than 32768");
+                                }
+                            } else {
+                                align_error = Some("not a power of two");
+                            }
+                        } else {
+                            align_error = Some("not an unsuffixed integer");
+                        }
+                        if let Some(align_error) = align_error {
+                            span_err!(diagnostic, item.span, E0589,
+                                      "invalid `repr(align)` attribute: {}", align_error);
+                        }
+                    }
+                }
+                if !recognised {
+                    // Not a word we recognize
+                    span_err!(diagnostic, item.span, E0552,
+                              "unrecognized representation hint");
                 }
             }
         }
-        // Not a "repr" hint: ignore.
-        _ => { }
     }
     acc
 }
@@ -913,6 +1027,7 @@ pub enum ReprAttr {
     ReprExtern,
     ReprPacked,
     ReprSimd,
+    ReprAlign(u16),
 }
 
 #[derive(Eq, Hash, PartialEq, Debug, RustcEncodable, RustcDecodable, Copy, Clone)]
@@ -931,6 +1046,208 @@ impl IntType {
     }
 }
 
+impl MetaItem {
+    fn tokens(&self) -> TokenStream {
+        let ident = TokenTree::Token(self.span, Token::Ident(Ident::with_empty_ctxt(self.name)));
+        TokenStream::concat(vec![ident.into(), self.node.tokens(self.span)])
+    }
+
+    fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<MetaItem>
+        where I: Iterator<Item = TokenTree>,
+    {
+        let (mut span, name) = match tokens.next() {
+            Some(TokenTree::Token(span, Token::Ident(ident))) => (span, ident.name),
+            Some(TokenTree::Token(_, Token::Interpolated(ref nt))) => match **nt {
+                token::Nonterminal::NtIdent(ident) => (ident.span, ident.node.name),
+                token::Nonterminal::NtMeta(ref meta) => return Some(meta.clone()),
+                _ => return None,
+            },
+            _ => return None,
+        };
+        let node = match MetaItemKind::from_tokens(tokens) {
+            Some(node) => node,
+            _ => return None,
+        };
+        if let Some(last_span) = node.last_span() {
+            span.hi = last_span.hi;
+        }
+        Some(MetaItem { name: name, span: span, node: node })
+    }
+}
+
+impl MetaItemKind {
+    fn last_span(&self) -> Option<Span> {
+        match *self {
+            MetaItemKind::Word => None,
+            MetaItemKind::List(ref list) => list.last().map(NestedMetaItem::span),
+            MetaItemKind::NameValue(ref lit) => Some(lit.span),
+        }
+    }
+
+    pub fn tokens(&self, span: Span) -> TokenStream {
+        match *self {
+            MetaItemKind::Word => TokenStream::empty(),
+            MetaItemKind::NameValue(ref lit) => {
+                TokenStream::concat(vec![TokenTree::Token(span, Token::Eq).into(), lit.tokens()])
+            }
+            MetaItemKind::List(ref list) => {
+                let mut tokens = Vec::new();
+                for (i, item) in list.iter().enumerate() {
+                    if i > 0 {
+                        tokens.push(TokenTree::Token(span, Token::Comma).into());
+                    }
+                    tokens.push(item.node.tokens());
+                }
+                TokenTree::Delimited(span, Delimited {
+                    delim: token::Paren,
+                    tts: TokenStream::concat(tokens).into(),
+                }).into()
+            }
+        }
+    }
+
+    fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<MetaItemKind>
+        where I: Iterator<Item = TokenTree>,
+    {
+        let delimited = match tokens.peek().cloned() {
+            Some(TokenTree::Token(_, token::Eq)) => {
+                tokens.next();
+                return if let Some(TokenTree::Token(span, token)) = tokens.next() {
+                    LitKind::from_token(token)
+                        .map(|lit| MetaItemKind::NameValue(Spanned { node: lit, span: span }))
+                } else {
+                    None
+                };
+            }
+            Some(TokenTree::Delimited(_, ref delimited)) if delimited.delim == token::Paren => {
+                tokens.next();
+                delimited.stream()
+            }
+            _ => return Some(MetaItemKind::Word),
+        };
+
+        let mut tokens = delimited.into_trees().peekable();
+        let mut result = Vec::new();
+        while let Some(..) = tokens.peek() {
+            match NestedMetaItemKind::from_tokens(&mut tokens) {
+                Some(item) => result.push(Spanned { span: item.span(), node: item }),
+                None => return None,
+            }
+            match tokens.next() {
+                None | Some(TokenTree::Token(_, Token::Comma)) => {}
+                _ => return None,
+            }
+        }
+        Some(MetaItemKind::List(result))
+    }
+}
+
+impl NestedMetaItemKind {
+    fn span(&self) -> Span {
+        match *self {
+            NestedMetaItemKind::MetaItem(ref item) => item.span,
+            NestedMetaItemKind::Literal(ref lit) => lit.span,
+        }
+    }
+
+    fn tokens(&self) -> TokenStream {
+        match *self {
+            NestedMetaItemKind::MetaItem(ref item) => item.tokens(),
+            NestedMetaItemKind::Literal(ref lit) => lit.tokens(),
+        }
+    }
+
+    fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<NestedMetaItemKind>
+        where I: Iterator<Item = TokenTree>,
+    {
+        if let Some(TokenTree::Token(span, token)) = tokens.peek().cloned() {
+            if let Some(node) = LitKind::from_token(token) {
+                tokens.next();
+                return Some(NestedMetaItemKind::Literal(Spanned { node: node, span: span }));
+            }
+        }
+
+        MetaItem::from_tokens(tokens).map(NestedMetaItemKind::MetaItem)
+    }
+}
+
+impl Lit {
+    fn tokens(&self) -> TokenStream {
+        TokenTree::Token(self.span, self.node.token()).into()
+    }
+}
+
+impl LitKind {
+    fn token(&self) -> Token {
+        use std::ascii;
+
+        match *self {
+            LitKind::Str(string, ast::StrStyle::Cooked) => {
+                let mut escaped = String::new();
+                for ch in string.as_str().chars() {
+                    escaped.extend(ch.escape_unicode());
+                }
+                Token::Literal(token::Lit::Str_(Symbol::intern(&escaped)), None)
+            }
+            LitKind::Str(string, ast::StrStyle::Raw(n)) => {
+                Token::Literal(token::Lit::StrRaw(string, n), None)
+            }
+            LitKind::ByteStr(ref bytes) => {
+                let string = bytes.iter().cloned().flat_map(ascii::escape_default)
+                    .map(Into::<char>::into).collect::<String>();
+                Token::Literal(token::Lit::ByteStr(Symbol::intern(&string)), None)
+            }
+            LitKind::Byte(byte) => {
+                let string: String = ascii::escape_default(byte).map(Into::<char>::into).collect();
+                Token::Literal(token::Lit::Byte(Symbol::intern(&string)), None)
+            }
+            LitKind::Char(ch) => {
+                let string: String = ch.escape_default().map(Into::<char>::into).collect();
+                Token::Literal(token::Lit::Char(Symbol::intern(&string)), None)
+            }
+            LitKind::Int(n, ty) => {
+                let suffix = match ty {
+                    ast::LitIntType::Unsigned(ty) => Some(Symbol::intern(ty.ty_to_string())),
+                    ast::LitIntType::Signed(ty) => Some(Symbol::intern(ty.ty_to_string())),
+                    ast::LitIntType::Unsuffixed => None,
+                };
+                Token::Literal(token::Lit::Integer(Symbol::intern(&n.to_string())), suffix)
+            }
+            LitKind::Float(symbol, ty) => {
+                Token::Literal(token::Lit::Float(symbol), Some(Symbol::intern(ty.ty_to_string())))
+            }
+            LitKind::FloatUnsuffixed(symbol) => Token::Literal(token::Lit::Float(symbol), None),
+            LitKind::Bool(value) => Token::Ident(Ident::with_empty_ctxt(Symbol::intern(if value {
+                "true"
+            } else {
+                "false"
+            }))),
+        }
+    }
+
+    fn from_token(token: Token) -> Option<LitKind> {
+        match token {
+            Token::Ident(ident) if ident.name == "true" => Some(LitKind::Bool(true)),
+            Token::Ident(ident) if ident.name == "false" => Some(LitKind::Bool(false)),
+            Token::Interpolated(ref nt) => match **nt {
+                token::NtExpr(ref v) => match v.node {
+                    ExprKind::Lit(ref lit) => Some(lit.node.clone()),
+                    _ => None,
+                },
+                _ => None,
+            },
+            Token::Literal(lit, suf) => {
+                let (suffix_illegal, result) = parse::lit_token(lit, suf, None);
+                if suffix_illegal && suf.is_some() {
+                    return None;
+                }
+                result
+            }
+            _ => None,
+        }
+    }
+}
+
 pub trait HasAttrs: Sized {
     fn attrs(&self) -> &[ast::Attribute];
     fn map_attrs<F: FnOnce(Vec<ast::Attribute>) -> Vec<ast::Attribute>>(self, f: F) -> Self;
@@ -945,7 +1262,7 @@ impl<T: HasAttrs> HasAttrs for Spanned<T> {
 
 impl HasAttrs for Vec<Attribute> {
     fn attrs(&self) -> &[Attribute] {
-        &self
+        self
     }
     fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
         f(self)
@@ -954,7 +1271,7 @@ impl HasAttrs for Vec<Attribute> {
 
 impl HasAttrs for ThinVec<Attribute> {
     fn attrs(&self) -> &[Attribute] {
-        &self
+        self
     }
     fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
         f(self.into()).into()
diff --git a/src/libsyntax/codemap.rs b/src/libsyntax/codemap.rs
index 0f4b844b0ea..d32c3ec5f46 100644
--- a/src/libsyntax/codemap.rs
+++ b/src/libsyntax/codemap.rs
@@ -17,54 +17,38 @@
 //! within the CodeMap, which upon request can be converted to line and column
 //! information, source code snippets, etc.
 
+pub use syntax_pos::*;
+pub use syntax_pos::hygiene::{ExpnFormat, ExpnInfo, NameAndSpan};
 pub use self::ExpnFormat::*;
 
-use std::cell::RefCell;
-use std::path::{Path,PathBuf};
+use std::cell::{RefCell, Ref};
+use std::path::{Path, PathBuf};
 use std::rc::Rc;
 
 use std::env;
 use std::fs;
 use std::io::{self, Read};
-pub use syntax_pos::*;
 use errors::CodeMapper;
 
-use ast::Name;
-
 /// Return the span itself if it doesn't come from a macro expansion,
 /// otherwise return the call site span up to the `enclosing_sp` by
 /// following the `expn_info` chain.
-pub fn original_sp(cm: &CodeMap, sp: Span, enclosing_sp: Span) -> Span {
-    let call_site1 = cm.with_expn_info(sp.expn_id, |ei| ei.map(|ei| ei.call_site));
-    let call_site2 = cm.with_expn_info(enclosing_sp.expn_id, |ei| ei.map(|ei| ei.call_site));
+pub fn original_sp(sp: Span, enclosing_sp: Span) -> Span {
+    let call_site1 = sp.ctxt.outer().expn_info().map(|ei| ei.call_site);
+    let call_site2 = enclosing_sp.ctxt.outer().expn_info().map(|ei| ei.call_site);
     match (call_site1, call_site2) {
         (None, _) => sp,
         (Some(call_site1), Some(call_site2)) if call_site1 == call_site2 => sp,
-        (Some(call_site1), _) => original_sp(cm, call_site1, enclosing_sp),
+        (Some(call_site1), _) => original_sp(call_site1, enclosing_sp),
     }
 }
 
-/// The source of expansion.
-#[derive(Clone, Hash, Debug, PartialEq, Eq)]
-pub enum ExpnFormat {
-    /// e.g. #[derive(...)] <item>
-    MacroAttribute(Name),
-    /// e.g. `format!()`
-    MacroBang(Name),
-    /// Desugaring done by the compiler during HIR lowering.
-    CompilerDesugaring(Name)
-}
-
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug, Copy)]
 pub struct Spanned<T> {
     pub node: T,
     pub span: Span,
 }
 
-pub fn spanned<T>(lo: BytePos, hi: BytePos, t: T) -> Spanned<T> {
-    respan(mk_sp(lo, hi), t)
-}
-
 pub fn respan<T>(sp: Span, t: T) -> Spanned<T> {
     Spanned {node: t, span: sp}
 }
@@ -73,47 +57,6 @@ pub fn dummy_spanned<T>(t: T) -> Spanned<T> {
     respan(DUMMY_SP, t)
 }
 
-#[derive(Clone, Hash, Debug)]
-pub struct NameAndSpan {
-    /// The format with which the macro was invoked.
-    pub format: ExpnFormat,
-    /// Whether the macro is allowed to use #[unstable]/feature-gated
-    /// features internally without forcing the whole crate to opt-in
-    /// to them.
-    pub allow_internal_unstable: bool,
-    /// The span of the macro definition itself. The macro may not
-    /// have a sensible definition span (e.g. something defined
-    /// completely inside libsyntax) in which case this is None.
-    pub span: Option<Span>
-}
-
-impl NameAndSpan {
-    pub fn name(&self) -> Name {
-        match self.format {
-            ExpnFormat::MacroAttribute(s) |
-            ExpnFormat::MacroBang(s) |
-            ExpnFormat::CompilerDesugaring(s) => s,
-        }
-    }
-}
-
-/// Extra information for tracking spans of macro and syntax sugar expansion
-#[derive(Hash, Debug)]
-pub struct ExpnInfo {
-    /// The location of the actual macro invocation or syntax sugar , e.g.
-    /// `let x = foo!();` or `if let Some(y) = x {}`
-    ///
-    /// This may recursively refer to other macro invocations, e.g. if
-    /// `foo!()` invoked `bar!()` internally, and there was an
-    /// expression inside `bar!`; the call_site of the expression in
-    /// the expansion would point to the `bar!` invocation; that
-    /// call_site span would have its own ExpnInfo, with the call_site
-    /// pointing to the `foo!` invocation.
-    pub call_site: Span,
-    /// Information about the expansion.
-    pub callee: NameAndSpan
-}
-
 // _____________________________________________________________________________
 // FileMap, MultiByteChar, FileName, FileLines
 //
@@ -160,36 +103,69 @@ impl FileLoader for RealFileLoader {
 //
 
 pub struct CodeMap {
-    pub files: RefCell<Vec<Rc<FileMap>>>,
-    expansions: RefCell<Vec<ExpnInfo>>,
-    file_loader: Box<FileLoader>
+    // The `files` field should not be visible outside of libsyntax so that we
+    // can do proper dependency tracking.
+    pub(super) files: RefCell<Vec<Rc<FileMap>>>,
+    file_loader: Box<FileLoader>,
+    // This is used to apply the file path remapping as specified via
+    // -Zremap-path-prefix to all FileMaps allocated within this CodeMap.
+    path_mapping: FilePathMapping,
+    // The CodeMap will invoke this callback whenever a specific FileMap is
+    // accessed. The callback starts out as a no-op but when the dependency
+    // graph becomes available later during the compilation process, it is
+    // be replaced with something that notifies the dep-tracking system.
+    dep_tracking_callback: RefCell<Box<Fn(&FileMap)>>,
 }
 
 impl CodeMap {
-    pub fn new() -> CodeMap {
+    pub fn new(path_mapping: FilePathMapping) -> CodeMap {
         CodeMap {
             files: RefCell::new(Vec::new()),
-            expansions: RefCell::new(Vec::new()),
-            file_loader: Box::new(RealFileLoader)
+            file_loader: Box::new(RealFileLoader),
+            path_mapping: path_mapping,
+            dep_tracking_callback: RefCell::new(Box::new(|_| {})),
         }
     }
 
-    pub fn with_file_loader(file_loader: Box<FileLoader>) -> CodeMap {
+    pub fn with_file_loader(file_loader: Box<FileLoader>,
+                            path_mapping: FilePathMapping)
+                            -> CodeMap {
         CodeMap {
             files: RefCell::new(Vec::new()),
-            expansions: RefCell::new(Vec::new()),
-            file_loader: file_loader
+            file_loader: file_loader,
+            path_mapping: path_mapping,
+            dep_tracking_callback: RefCell::new(Box::new(|_| {})),
         }
     }
 
+    pub fn path_mapping(&self) -> &FilePathMapping {
+        &self.path_mapping
+    }
+
+    pub fn set_dep_tracking_callback(&self, cb: Box<Fn(&FileMap)>) {
+        *self.dep_tracking_callback.borrow_mut() = cb;
+    }
+
     pub fn file_exists(&self, path: &Path) -> bool {
         self.file_loader.file_exists(path)
     }
 
     pub fn load_file(&self, path: &Path) -> io::Result<Rc<FileMap>> {
         let src = self.file_loader.read_file(path)?;
-        let abs_path = self.file_loader.abs_path(path).map(|p| p.to_str().unwrap().to_string());
-        Ok(self.new_filemap(path.to_str().unwrap().to_string(), abs_path, src))
+        Ok(self.new_filemap(path.to_str().unwrap().to_string(), src))
+    }
+
+    pub fn files(&self) -> Ref<Vec<Rc<FileMap>>> {
+        let files = self.files.borrow();
+        for file in files.iter() {
+            (self.dep_tracking_callback.borrow())(file);
+        }
+        files
+    }
+
+    /// Only use this if you do your own dependency tracking!
+    pub fn files_untracked(&self) -> Ref<Vec<Rc<FileMap>>> {
+        self.files.borrow()
     }
 
     fn next_start_pos(&self) -> usize {
@@ -204,8 +180,7 @@ impl CodeMap {
 
     /// Creates a new filemap without setting its line information. If you don't
     /// intend to set the line information yourself, you should use new_filemap_and_lines.
-    pub fn new_filemap(&self, filename: FileName, abs_path: Option<FileName>,
-                       mut src: String) -> Rc<FileMap> {
+    pub fn new_filemap(&self, filename: FileName, mut src: String) -> Rc<FileMap> {
         let start_pos = self.next_start_pos();
         let mut files = self.files.borrow_mut();
 
@@ -216,9 +191,12 @@ impl CodeMap {
 
         let end_pos = start_pos + src.len();
 
+        let (filename, was_remapped) = self.path_mapping.map_prefix(filename);
+
         let filemap = Rc::new(FileMap {
             name: filename,
-            abs_path: abs_path,
+            name_was_remapped: was_remapped,
+            crate_of_origin: 0,
             src: Some(Rc::new(src)),
             start_pos: Pos::from_usize(start_pos),
             end_pos: Pos::from_usize(end_pos),
@@ -232,11 +210,8 @@ impl CodeMap {
     }
 
     /// Creates a new filemap and sets its line information.
-    pub fn new_filemap_and_lines(&self, filename: &str, abs_path: Option<&str>,
-                                 src: &str) -> Rc<FileMap> {
-        let fm = self.new_filemap(filename.to_string(),
-                                  abs_path.map(|s| s.to_owned()),
-                                  src.to_owned());
+    pub fn new_filemap_and_lines(&self, filename: &str, src: &str) -> Rc<FileMap> {
+        let fm = self.new_filemap(filename.to_string(), src.to_owned());
         let mut byte_pos: u32 = fm.start_pos.0;
         for line in src.lines() {
             // register the start of this line
@@ -255,7 +230,8 @@ impl CodeMap {
     /// information for things inlined from other crates.
     pub fn new_imported_filemap(&self,
                                 filename: FileName,
-                                abs_path: Option<FileName>,
+                                name_was_remapped: bool,
+                                crate_of_origin: u32,
                                 source_len: usize,
                                 mut file_local_lines: Vec<BytePos>,
                                 mut file_local_multibyte_chars: Vec<MultiByteChar>)
@@ -276,7 +252,8 @@ impl CodeMap {
 
         let filemap = Rc::new(FileMap {
             name: filename,
-            abs_path: abs_path,
+            name_was_remapped: name_was_remapped,
+            crate_of_origin: crate_of_origin,
             src: None,
             start_pos: start_pos,
             end_pos: end_pos,
@@ -334,6 +311,8 @@ impl CodeMap {
         let files = self.files.borrow();
         let f = (*files)[idx].clone();
 
+        (self.dep_tracking_callback.borrow())(&f);
+
         match f.lookup_line(pos) {
             Some(line) => Ok(FileMapAndLine { fm: f, line: line }),
             None => Err(f)
@@ -353,14 +332,14 @@ impl CodeMap {
     /// Returns `Some(span)`, a union of the lhs and rhs span.  The lhs must precede the rhs. If
     /// there are gaps between lhs and rhs, the resulting union will cross these gaps.
     /// For this to work, the spans have to be:
-    ///    * the expn_id of both spans much match
+    ///    * the ctxt of both spans much match
     ///    * the lhs span needs to end on the same line the rhs span begins
     ///    * the lhs span must start at or before the rhs span
     pub fn merge_spans(&self, sp_lhs: Span, sp_rhs: Span) -> Option<Span> {
         use std::cmp;
 
         // make sure we're at the same expansion id
-        if sp_lhs.expn_id != sp_rhs.expn_id {
+        if sp_lhs.ctxt != sp_rhs.ctxt {
             return None;
         }
 
@@ -383,7 +362,7 @@ impl CodeMap {
             Some(Span {
                 lo: cmp::min(sp_lhs.lo, sp_rhs.lo),
                 hi: cmp::max(sp_lhs.hi, sp_rhs.hi),
-                expn_id: sp_lhs.expn_id,
+                ctxt: sp_lhs.ctxt,
             })
         } else {
             None
@@ -391,10 +370,6 @@ impl CodeMap {
     }
 
     pub fn span_to_string(&self, sp: Span) -> String {
-        if sp == COMMAND_LINE_SP {
-            return "<command line option>".to_string();
-        }
-
         if self.files.borrow().is_empty() && sp.source_equal(&DUMMY_SP) {
             return "no-location".to_string();
         }
@@ -409,157 +384,6 @@ impl CodeMap {
                         hi.col.to_usize() + 1)).to_string()
     }
 
-    // Returns true if two spans have the same callee
-    // (Assumes the same ExpnFormat implies same callee)
-    fn match_callees(&self, sp_a: &Span, sp_b: &Span) -> bool {
-        let fmt_a = self
-            .with_expn_info(sp_a.expn_id,
-                            |ei| ei.map(|ei| ei.callee.format.clone()));
-
-        let fmt_b = self
-            .with_expn_info(sp_b.expn_id,
-                            |ei| ei.map(|ei| ei.callee.format.clone()));
-        fmt_a == fmt_b
-    }
-
-    /// Returns a formatted string showing the expansion chain of a span
-    ///
-    /// Spans are printed in the following format:
-    ///
-    /// filename:start_line:col: end_line:col
-    /// snippet
-    ///   Callee:
-    ///   Callee span
-    ///   Callsite:
-    ///   Callsite span
-    ///
-    /// Callees and callsites are printed recursively (if available, otherwise header
-    /// and span is omitted), expanding into their own callee/callsite spans.
-    /// Each layer of recursion has an increased indent, and snippets are truncated
-    /// to at most 50 characters. Finally, recursive calls to the same macro are squashed,
-    /// with '...' used to represent any number of recursive calls.
-    pub fn span_to_expanded_string(&self, sp: Span) -> String {
-        self.span_to_expanded_string_internal(sp, "")
-    }
-
-    fn span_to_expanded_string_internal(&self, sp:Span, indent: &str) -> String {
-        let mut indent = indent.to_owned();
-        let mut output = "".to_owned();
-        let span_str = self.span_to_string(sp);
-        let mut span_snip = self.span_to_snippet(sp)
-            .unwrap_or("Snippet unavailable".to_owned());
-
-        // Truncate by code points - in worst case this will be more than 50 characters,
-        // but ensures at least 50 characters and respects byte boundaries.
-        let char_vec: Vec<(usize, char)> = span_snip.char_indices().collect();
-        if char_vec.len() > 50 {
-            span_snip.truncate(char_vec[49].0);
-            span_snip.push_str("...");
-        }
-
-        output.push_str(&format!("{}{}\n{}`{}`\n", indent, span_str, indent, span_snip));
-
-        if sp.expn_id == NO_EXPANSION || sp.expn_id == COMMAND_LINE_EXPN {
-            return output;
-        }
-
-        let mut callee = self.with_expn_info(sp.expn_id,
-                                             |ei| ei.and_then(|ei| ei.callee.span.clone()));
-        let mut callsite = self.with_expn_info(sp.expn_id,
-                                               |ei| ei.map(|ei| ei.call_site.clone()));
-
-        indent.push_str("  ");
-        let mut is_recursive = false;
-
-        while callee.is_some() && self.match_callees(&sp, &callee.unwrap()) {
-            callee = self.with_expn_info(callee.unwrap().expn_id,
-                                         |ei| ei.and_then(|ei| ei.callee.span.clone()));
-            is_recursive = true;
-        }
-        if let Some(span) = callee {
-            output.push_str(&indent);
-            output.push_str("Callee:\n");
-            if is_recursive {
-                output.push_str(&indent);
-                output.push_str("...\n");
-            }
-            output.push_str(&(self.span_to_expanded_string_internal(span, &indent)));
-        }
-
-        is_recursive = false;
-        while callsite.is_some() && self.match_callees(&sp, &callsite.unwrap()) {
-            callsite = self.with_expn_info(callsite.unwrap().expn_id,
-                                           |ei| ei.map(|ei| ei.call_site.clone()));
-            is_recursive = true;
-        }
-        if let Some(span) = callsite {
-            output.push_str(&indent);
-            output.push_str("Callsite:\n");
-            if is_recursive {
-                output.push_str(&indent);
-                output.push_str("...\n");
-            }
-            output.push_str(&(self.span_to_expanded_string_internal(span, &indent)));
-        }
-        output
-    }
-
-    /// Return the source span - this is either the supplied span, or the span for
-    /// the macro callsite that expanded to it.
-    pub fn source_callsite(&self, sp: Span) -> Span {
-        let mut span = sp;
-        // Special case - if a macro is parsed as an argument to another macro, the source
-        // callsite is the first callsite, which is also source-equivalent to the span.
-        let mut first = true;
-        while span.expn_id != NO_EXPANSION && span.expn_id != COMMAND_LINE_EXPN {
-            if let Some(callsite) = self.with_expn_info(span.expn_id,
-                                               |ei| ei.map(|ei| ei.call_site.clone())) {
-                if first && span.source_equal(&callsite) {
-                    if self.lookup_char_pos(span.lo).file.is_real_file() {
-                        return Span { expn_id: NO_EXPANSION, .. span };
-                    }
-                }
-                first = false;
-                span = callsite;
-            }
-            else {
-                break;
-            }
-        }
-        span
-    }
-
-    /// Return the source callee.
-    ///
-    /// Returns None if the supplied span has no expansion trace,
-    /// else returns the NameAndSpan for the macro definition
-    /// corresponding to the source callsite.
-    pub fn source_callee(&self, sp: Span) -> Option<NameAndSpan> {
-        let mut span = sp;
-        // Special case - if a macro is parsed as an argument to another macro, the source
-        // callsite is source-equivalent to the span, and the source callee is the first callee.
-        let mut first = true;
-        while let Some(callsite) = self.with_expn_info(span.expn_id,
-                                            |ei| ei.map(|ei| ei.call_site.clone())) {
-            if first && span.source_equal(&callsite) {
-                if self.lookup_char_pos(span.lo).file.is_real_file() {
-                    return self.with_expn_info(span.expn_id,
-                                               |ei| ei.map(|ei| ei.callee.clone()));
-                }
-            }
-            first = false;
-            if let Some(_) = self.with_expn_info(callsite.expn_id,
-                                                 |ei| ei.map(|ei| ei.call_site.clone())) {
-                span = callsite;
-            }
-            else {
-                return self.with_expn_info(span.expn_id,
-                                           |ei| ei.map(|ei| ei.callee.clone()));
-            }
-        }
-        None
-    }
-
     pub fn span_to_filename(&self, sp: Span) -> FileName {
         self.lookup_char_pos(sp.lo).file.name.to_string()
     }
@@ -656,9 +480,29 @@ impl CodeMap {
         }
     }
 
+    /// Given a `Span`, try to get a shorter span ending before the first occurrence of `c` `char`
+    pub fn span_until_char(&self, sp: Span, c: char) -> Span {
+        match self.span_to_snippet(sp) {
+            Ok(snippet) => {
+                let snippet = snippet.split(c).nth(0).unwrap_or("").trim_right();
+                if !snippet.is_empty() && !snippet.contains('\n') {
+                    Span { hi: BytePos(sp.lo.0 + snippet.len() as u32), ..sp }
+                } else {
+                    sp
+                }
+            }
+            _ => sp,
+        }
+    }
+
+    pub fn def_span(&self, sp: Span) -> Span {
+        self.span_until_char(sp, '{')
+    }
+
     pub fn get_filemap(&self, filename: &str) -> Option<Rc<FileMap>> {
         for fm in self.files.borrow().iter() {
             if filename == fm.name {
+               (self.dep_tracking_callback.borrow())(fm);
                 return Some(fm.clone());
             }
         }
@@ -669,6 +513,7 @@ impl CodeMap {
     pub fn lookup_byte_offset(&self, bpos: BytePos) -> FileMapAndBytePos {
         let idx = self.lookup_filemap_idx(bpos);
         let fm = (*self.files.borrow())[idx].clone();
+        (self.dep_tracking_callback.borrow())(&fm);
         let offset = bpos - fm.start_pos;
         FileMapAndBytePos {fm: fm, pos: offset}
     }
@@ -679,6 +524,8 @@ impl CodeMap {
         let files = self.files.borrow();
         let map = &(*files)[idx];
 
+        (self.dep_tracking_callback.borrow())(map);
+
         // The number of extra bytes due to multibyte chars in the FileMap
         let mut total_extra_bytes = 0;
 
@@ -723,110 +570,8 @@ impl CodeMap {
         return a;
     }
 
-    pub fn record_expansion(&self, expn_info: ExpnInfo) -> ExpnId {
-        let mut expansions = self.expansions.borrow_mut();
-        expansions.push(expn_info);
-        let len = expansions.len();
-        if len > u32::max_value() as usize {
-            panic!("too many ExpnInfo's!");
-        }
-        ExpnId(len as u32 - 1)
-    }
-
-    pub fn with_expn_info<T, F>(&self, id: ExpnId, f: F) -> T where
-        F: FnOnce(Option<&ExpnInfo>) -> T,
-    {
-        match id {
-            NO_EXPANSION | COMMAND_LINE_EXPN => f(None),
-            ExpnId(i) => f(Some(&(*self.expansions.borrow())[i as usize]))
-        }
-    }
-
-    /// Check if a span is "internal" to a macro in which #[unstable]
-    /// items can be used (that is, a macro marked with
-    /// `#[allow_internal_unstable]`).
-    pub fn span_allows_unstable(&self, span: Span) -> bool {
-        debug!("span_allows_unstable(span = {:?})", span);
-        let mut allows_unstable = false;
-        let mut expn_id = span.expn_id;
-        loop {
-            let quit = self.with_expn_info(expn_id, |expninfo| {
-                debug!("span_allows_unstable: expninfo = {:?}", expninfo);
-                expninfo.map_or(/* hit the top level */ true, |info| {
-
-                    let span_comes_from_this_expansion =
-                        info.callee.span.map_or(span.source_equal(&info.call_site), |mac_span| {
-                            mac_span.contains(span)
-                        });
-
-                    debug!("span_allows_unstable: span: {:?} call_site: {:?} callee: {:?}",
-                           (span.lo, span.hi),
-                           (info.call_site.lo, info.call_site.hi),
-                           info.callee.span.map(|x| (x.lo, x.hi)));
-                    debug!("span_allows_unstable: from this expansion? {}, allows unstable? {}",
-                           span_comes_from_this_expansion,
-                           info.callee.allow_internal_unstable);
-                    if span_comes_from_this_expansion {
-                        allows_unstable = info.callee.allow_internal_unstable;
-                        // we've found the right place, stop looking
-                        true
-                    } else {
-                        // not the right place, keep looking
-                        expn_id = info.call_site.expn_id;
-                        false
-                    }
-                })
-            });
-            if quit {
-                break
-            }
-        }
-        debug!("span_allows_unstable? {}", allows_unstable);
-        allows_unstable
-    }
-
     pub fn count_lines(&self) -> usize {
-        self.files.borrow().iter().fold(0, |a, f| a + f.count_lines())
-    }
-
-    pub fn macro_backtrace(&self, span: Span) -> Vec<MacroBacktrace> {
-        let mut prev_span = DUMMY_SP;
-        let mut span = span;
-        let mut result = vec![];
-        loop {
-            let span_name_span = self.with_expn_info(span.expn_id, |expn_info| {
-                expn_info.map(|ei| {
-                    let (pre, post) = match ei.callee.format {
-                        MacroAttribute(..) => ("#[", "]"),
-                        MacroBang(..) => ("", "!"),
-                        CompilerDesugaring(..) => ("desugaring of `", "`"),
-                    };
-                    let macro_decl_name = format!("{}{}{}",
-                                                  pre,
-                                                  ei.callee.name(),
-                                                  post);
-                    let def_site_span = ei.callee.span;
-                    (ei.call_site, macro_decl_name, def_site_span)
-                })
-            });
-
-            match span_name_span {
-                None => break,
-                Some((call_site, macro_decl_name, def_site_span)) => {
-                    // Don't print recursive invocations
-                    if !call_site.source_equal(&prev_span) {
-                        result.push(MacroBacktrace {
-                            call_site: call_site,
-                            macro_decl_name: macro_decl_name,
-                            def_site_span: def_site_span,
-                        });
-                    }
-                    prev_span = span;
-                    span = call_site;
-                }
-            }
-        }
-        result
+        self.files().iter().fold(0, |a, f| a + f.count_lines())
     }
 }
 
@@ -843,14 +588,47 @@ impl CodeMapper for CodeMap {
     fn span_to_filename(&self, sp: Span) -> FileName {
         self.span_to_filename(sp)
     }
-    fn macro_backtrace(&self, span: Span) -> Vec<MacroBacktrace> {
-        self.macro_backtrace(span)
-    }
     fn merge_spans(&self, sp_lhs: Span, sp_rhs: Span) -> Option<Span> {
         self.merge_spans(sp_lhs, sp_rhs)
     }
 }
 
+#[derive(Clone)]
+pub struct FilePathMapping {
+    mapping: Vec<(String, String)>,
+}
+
+impl FilePathMapping {
+    pub fn empty() -> FilePathMapping {
+        FilePathMapping {
+            mapping: vec![]
+        }
+    }
+
+    pub fn new(mapping: Vec<(String, String)>) -> FilePathMapping {
+        FilePathMapping {
+            mapping: mapping
+        }
+    }
+
+    /// Applies any path prefix substitution as defined by the mapping.
+    /// The return value is the remapped path and a boolean indicating whether
+    /// the path was affected by the mapping.
+    pub fn map_prefix(&self, path: String) -> (String, bool) {
+        // NOTE: We are iterating over the mapping entries from last to first
+        //       because entries specified later on the command line should
+        //       take precedence.
+        for &(ref from, ref to) in self.mapping.iter().rev() {
+            if path.starts_with(from) {
+                let mapped = path.replacen(from, to, 1);
+                return (mapped, true);
+            }
+        }
+
+        (path, false)
+    }
+}
+
 // _____________________________________________________________________________
 // Tests
 //
@@ -858,14 +636,12 @@ impl CodeMapper for CodeMap {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use symbol::keywords;
     use std::rc::Rc;
 
     #[test]
     fn t1 () {
-        let cm = CodeMap::new();
+        let cm = CodeMap::new(FilePathMapping::empty());
         let fm = cm.new_filemap("blork.rs".to_string(),
-                                None,
                                 "first line.\nsecond line".to_string());
         fm.next_line(BytePos(0));
         // Test we can get lines with partial line info.
@@ -880,9 +656,8 @@ mod tests {
     #[test]
     #[should_panic]
     fn t2 () {
-        let cm = CodeMap::new();
+        let cm = CodeMap::new(FilePathMapping::empty());
         let fm = cm.new_filemap("blork.rs".to_string(),
-                                None,
                                 "first line.\nsecond line".to_string());
         // TESTING *REALLY* BROKEN BEHAVIOR:
         fm.next_line(BytePos(0));
@@ -891,15 +666,12 @@ mod tests {
     }
 
     fn init_code_map() -> CodeMap {
-        let cm = CodeMap::new();
+        let cm = CodeMap::new(FilePathMapping::empty());
         let fm1 = cm.new_filemap("blork.rs".to_string(),
-                                 None,
                                  "first line.\nsecond line".to_string());
         let fm2 = cm.new_filemap("empty.rs".to_string(),
-                                 None,
                                  "".to_string());
         let fm3 = cm.new_filemap("blork2.rs".to_string(),
-                                 None,
                                  "first line.\nsecond line".to_string());
 
         fm1.next_line(BytePos(0));
@@ -958,14 +730,12 @@ mod tests {
     }
 
     fn init_code_map_mbc() -> CodeMap {
-        let cm = CodeMap::new();
+        let cm = CodeMap::new(FilePathMapping::empty());
         // € is a three byte utf8 char.
         let fm1 =
             cm.new_filemap("blork.rs".to_string(),
-                           None,
                            "fir€st €€€€ line.\nsecond line".to_string());
         let fm2 = cm.new_filemap("blork2.rs".to_string(),
-                                 None,
                                  "first line€€.\n€ second line".to_string());
 
         fm1.next_line(BytePos(0));
@@ -1007,7 +777,7 @@ mod tests {
     fn t7() {
         // Test span_to_lines for a span ending at the end of filemap
         let cm = init_code_map();
-        let span = Span {lo: BytePos(12), hi: BytePos(23), expn_id: NO_EXPANSION};
+        let span = Span {lo: BytePos(12), hi: BytePos(23), ctxt: NO_EXPANSION};
         let file_lines = cm.span_to_lines(span).unwrap();
 
         assert_eq!(file_lines.file.name, "blork.rs");
@@ -1023,17 +793,17 @@ mod tests {
         assert_eq!(input.len(), selection.len());
         let left_index = selection.find('~').unwrap() as u32;
         let right_index = selection.rfind('~').map(|x|x as u32).unwrap_or(left_index);
-        Span { lo: BytePos(left_index), hi: BytePos(right_index + 1), expn_id: NO_EXPANSION }
+        Span { lo: BytePos(left_index), hi: BytePos(right_index + 1), ctxt: NO_EXPANSION }
     }
 
     /// Test span_to_snippet and span_to_lines for a span coverting 3
     /// lines in the middle of a file.
     #[test]
     fn span_to_snippet_and_lines_spanning_multiple_lines() {
-        let cm = CodeMap::new();
+        let cm = CodeMap::new(FilePathMapping::empty());
         let inputtext = "aaaaa\nbbbbBB\nCCC\nDDDDDddddd\neee\n";
         let selection = "     \n    ~~\n~~~\n~~~~~     \n   \n";
-        cm.new_filemap_and_lines("blork.rs", None, inputtext);
+        cm.new_filemap_and_lines("blork.rs", inputtext);
         let span = span_from_selection(inputtext, selection);
 
         // check that we are extracting the text we thought we were extracting
@@ -1053,7 +823,7 @@ mod tests {
     fn t8() {
         // Test span_to_snippet for a span ending at the end of filemap
         let cm = init_code_map();
-        let span = Span {lo: BytePos(12), hi: BytePos(23), expn_id: NO_EXPANSION};
+        let span = Span {lo: BytePos(12), hi: BytePos(23), ctxt: NO_EXPANSION};
         let snippet = cm.span_to_snippet(span);
 
         assert_eq!(snippet, Ok("second line".to_string()));
@@ -1063,73 +833,20 @@ mod tests {
     fn t9() {
         // Test span_to_str for a span ending at the end of filemap
         let cm = init_code_map();
-        let span = Span {lo: BytePos(12), hi: BytePos(23), expn_id: NO_EXPANSION};
+        let span = Span {lo: BytePos(12), hi: BytePos(23), ctxt: NO_EXPANSION};
         let sstr =  cm.span_to_string(span);
 
         assert_eq!(sstr, "blork.rs:2:1: 2:12");
     }
 
-    #[test]
-    fn t10() {
-        // Test span_to_expanded_string works in base case (no expansion)
-        let cm = init_code_map();
-        let span = Span { lo: BytePos(0), hi: BytePos(11), expn_id: NO_EXPANSION };
-        let sstr = cm.span_to_expanded_string(span);
-        assert_eq!(sstr, "blork.rs:1:1: 1:12\n`first line.`\n");
-
-        let span = Span { lo: BytePos(12), hi: BytePos(23), expn_id: NO_EXPANSION };
-        let sstr =  cm.span_to_expanded_string(span);
-        assert_eq!(sstr, "blork.rs:2:1: 2:12\n`second line`\n");
-    }
-
-    #[test]
-    fn t11() {
-        // Test span_to_expanded_string works with expansion
-        let cm = init_code_map();
-        let root = Span { lo: BytePos(0), hi: BytePos(11), expn_id: NO_EXPANSION };
-        let format = ExpnFormat::MacroBang(keywords::Invalid.name());
-        let callee = NameAndSpan { format: format,
-                                   allow_internal_unstable: false,
-                                   span: None };
-
-        let info = ExpnInfo { call_site: root, callee: callee };
-        let id = cm.record_expansion(info);
-        let sp = Span { lo: BytePos(12), hi: BytePos(23), expn_id: id };
-
-        let sstr = cm.span_to_expanded_string(sp);
-        assert_eq!(sstr,
-                   "blork.rs:2:1: 2:12\n`second line`\n  Callsite:\n  \
-                    blork.rs:1:1: 1:12\n  `first line.`\n");
-    }
-
-    /// Test merging two spans on the same line
-    #[test]
-    fn span_merging() {
-        let cm = CodeMap::new();
-        let inputtext  = "bbbb BB bb CCC\n";
-        let selection1 = "     ~~       \n";
-        let selection2 = "           ~~~\n";
-        cm.new_filemap_and_lines("blork.rs", None, inputtext);
-        let span1 = span_from_selection(inputtext, selection1);
-        let span2 = span_from_selection(inputtext, selection2);
-
-        if let Some(sp) = cm.merge_spans(span1, span2) {
-            let sstr = cm.span_to_expanded_string(sp);
-            assert_eq!(sstr, "blork.rs:1:6: 1:15\n`BB bb CCC`\n");
-        }
-        else {
-            assert!(false);
-        }
-    }
-
     /// Test failing to merge two spans on different lines
     #[test]
     fn span_merging_fail() {
-        let cm = CodeMap::new();
+        let cm = CodeMap::new(FilePathMapping::empty());
         let inputtext  = "bbbb BB\ncc CCC\n";
         let selection1 = "     ~~\n      \n";
         let selection2 = "       \n   ~~~\n";
-        cm.new_filemap_and_lines("blork.rs", None, inputtext);
+        cm.new_filemap_and_lines("blork.rs", inputtext);
         let span1 = span_from_selection(inputtext, selection1);
         let span2 = span_from_selection(inputtext, selection2);
 
@@ -1170,7 +887,7 @@ mod tests {
                     let span = Span {
                         lo: BytePos(lo as u32 + file.start_pos.0),
                         hi: BytePos(hi as u32 + file.start_pos.0),
-                        expn_id: NO_EXPANSION,
+                        ctxt: NO_EXPANSION,
                     };
                     assert_eq!(&self.span_to_snippet(span).unwrap()[..],
                             substring);
@@ -1180,82 +897,4 @@ mod tests {
             }
         }
     }
-
-    fn init_expansion_chain(cm: &CodeMap) -> Span {
-        // Creates an expansion chain containing two recursive calls
-        // root -> expA -> expA -> expB -> expB -> end
-        let root = Span { lo: BytePos(0), hi: BytePos(11), expn_id: NO_EXPANSION };
-
-        let format_root = ExpnFormat::MacroBang(keywords::Invalid.name());
-        let callee_root = NameAndSpan { format: format_root,
-                                        allow_internal_unstable: false,
-                                        span: Some(root) };
-
-        let info_a1 = ExpnInfo { call_site: root, callee: callee_root };
-        let id_a1 = cm.record_expansion(info_a1);
-        let span_a1 = Span { lo: BytePos(12), hi: BytePos(23), expn_id: id_a1 };
-
-        let format_a = ExpnFormat::MacroBang(keywords::As.name());
-        let callee_a = NameAndSpan { format: format_a,
-                                      allow_internal_unstable: false,
-                                      span: Some(span_a1) };
-
-        let info_a2 = ExpnInfo { call_site: span_a1, callee: callee_a.clone() };
-        let id_a2 = cm.record_expansion(info_a2);
-        let span_a2 = Span { lo: BytePos(12), hi: BytePos(23), expn_id: id_a2 };
-
-        let info_b1 = ExpnInfo { call_site: span_a2, callee: callee_a };
-        let id_b1 = cm.record_expansion(info_b1);
-        let span_b1 = Span { lo: BytePos(25), hi: BytePos(36), expn_id: id_b1 };
-
-        let format_b = ExpnFormat::MacroBang(keywords::Box.name());
-        let callee_b = NameAndSpan { format: format_b,
-                                     allow_internal_unstable: false,
-                                     span: None };
-
-        let info_b2 = ExpnInfo { call_site: span_b1, callee: callee_b.clone() };
-        let id_b2 = cm.record_expansion(info_b2);
-        let span_b2 = Span { lo: BytePos(25), hi: BytePos(36), expn_id: id_b2 };
-
-        let info_end = ExpnInfo { call_site: span_b2, callee: callee_b };
-        let id_end = cm.record_expansion(info_end);
-        Span { lo: BytePos(37), hi: BytePos(48), expn_id: id_end }
-    }
-
-    #[test]
-    fn t12() {
-        // Test span_to_expanded_string collapses recursive macros and handles
-        // recursive callsite and callee expansions
-        let cm = init_code_map();
-        let end = init_expansion_chain(&cm);
-        let sstr = cm.span_to_expanded_string(end);
-        let res_str =
-r"blork2.rs:2:1: 2:12
-`second line`
-  Callsite:
-  ...
-  blork2.rs:1:1: 1:12
-  `first line.`
-    Callee:
-    blork.rs:2:1: 2:12
-    `second line`
-      Callee:
-      blork.rs:1:1: 1:12
-      `first line.`
-      Callsite:
-      blork.rs:1:1: 1:12
-      `first line.`
-    Callsite:
-    ...
-    blork.rs:2:1: 2:12
-    `second line`
-      Callee:
-      blork.rs:1:1: 1:12
-      `first line.`
-      Callsite:
-      blork.rs:1:1: 1:12
-      `first line.`
-";
-        assert_eq!(sstr, res_str);
-    }
 }
diff --git a/src/libsyntax/config.rs b/src/libsyntax/config.rs
index ea12a31770f..2e98c7d9626 100644
--- a/src/libsyntax/config.rs
+++ b/src/libsyntax/config.rs
@@ -13,9 +13,10 @@ use feature_gate::{feature_err, EXPLAIN_STMT_ATTR_SYNTAX, Features, get_features
 use {fold, attr};
 use ast;
 use codemap::Spanned;
-use parse::ParseSess;
-use ptr::P;
+use parse::{token, ParseSess};
+use syntax_pos::Span;
 
+use ptr::P;
 use util::small_vector::SmallVector;
 
 /// A folder that strips out items that do not belong in the current configuration.
@@ -84,43 +85,33 @@ impl<'a> StripUnconfigured<'a> {
             return Some(attr);
         }
 
-        let attr_list = match attr.meta_item_list() {
-            Some(attr_list) => attr_list,
-            None => {
-                let msg = "expected `#[cfg_attr(<cfg pattern>, <attr>)]`";
-                self.sess.span_diagnostic.span_err(attr.span, msg);
-                return None;
-            }
-        };
-
-        let (cfg, mi) = match (attr_list.len(), attr_list.get(0), attr_list.get(1)) {
-            (2, Some(cfg), Some(mi)) => (cfg, mi),
-            _ => {
-                let msg = "expected `#[cfg_attr(<cfg pattern>, <attr>)]`";
-                self.sess.span_diagnostic.span_err(attr.span, msg);
+        let (cfg, path, tokens, span) = match attr.parse(self.sess, |parser| {
+            parser.expect(&token::OpenDelim(token::Paren))?;
+            let cfg = parser.parse_meta_item()?;
+            parser.expect(&token::Comma)?;
+            let lo = parser.span.lo;
+            let (path, tokens) = parser.parse_path_and_tokens()?;
+            parser.expect(&token::CloseDelim(token::Paren))?;
+            Ok((cfg, path, tokens, Span { lo: lo, ..parser.prev_span }))
+        }) {
+            Ok(result) => result,
+            Err(mut e) => {
+                e.emit();
                 return None;
             }
         };
 
-        use attr::cfg_matches;
-        match (cfg.meta_item(), mi.meta_item()) {
-            (Some(cfg), Some(mi)) =>
-                if cfg_matches(&cfg, self.sess, self.features) {
-                    self.process_cfg_attr(ast::Attribute {
-                        id: attr::mk_attr_id(),
-                        style: attr.style,
-                        value: mi.clone(),
-                        is_sugared_doc: false,
-                        span: mi.span,
-                    })
-                } else {
-                    None
-                },
-            _ => {
-                let msg = "unexpected literal(s) in `#[cfg_attr(<cfg pattern>, <attr>)]`";
-                self.sess.span_diagnostic.span_err(attr.span, msg);
-                None
-            }
+        if attr::cfg_matches(&cfg, self.sess, self.features) {
+            self.process_cfg_attr(ast::Attribute {
+                id: attr::mk_attr_id(),
+                style: attr.style,
+                path: path,
+                tokens: tokens,
+                is_sugared_doc: false,
+                span: span,
+            })
+        } else {
+            None
         }
     }
 
@@ -132,9 +123,12 @@ impl<'a> StripUnconfigured<'a> {
                 return false;
             }
 
-            let mis = match attr.value.node {
-                ast::MetaItemKind::List(ref mis) if is_cfg(&attr) => mis,
-                _ => return true
+            let mis = if !is_cfg(attr) {
+                return true;
+            } else if let Some(mis) = attr.meta_item_list() {
+                mis
+            } else {
+                return true;
             };
 
             if mis.len() != 1 {
@@ -156,7 +150,7 @@ impl<'a> StripUnconfigured<'a> {
         // flag the offending attributes
         for attr in attrs.iter() {
             if !self.features.map(|features| features.stmt_expr_attributes).unwrap_or(true) {
-                let mut err = feature_err(&self.sess,
+                let mut err = feature_err(self.sess,
                                           "stmt_expr_attributes",
                                           attr.span,
                                           GateIssue::Language,
@@ -264,7 +258,7 @@ impl<'a> StripUnconfigured<'a> {
     pub fn configure_struct_expr_field(&mut self, field: ast::Field) -> Option<ast::Field> {
         if !self.features.map(|features| features.struct_field_attributes).unwrap_or(true) {
             if !field.attrs.is_empty() {
-                let mut err = feature_err(&self.sess,
+                let mut err = feature_err(self.sess,
                                           "struct_field_attributes",
                                           field.span,
                                           GateIssue::Language,
@@ -296,7 +290,7 @@ impl<'a> StripUnconfigured<'a> {
         for attr in attrs.iter() {
             if !self.features.map(|features| features.struct_field_attributes).unwrap_or(true) {
                 let mut err = feature_err(
-                    &self.sess,
+                    self.sess,
                     "struct_field_attributes",
                     attr.span,
                     GateIssue::Language,
diff --git a/src/libsyntax/diagnostic_list.rs b/src/libsyntax/diagnostic_list.rs
index 2d59051ec4a..01d1277ea62 100644
--- a/src/libsyntax/diagnostic_list.rs
+++ b/src/libsyntax/diagnostic_list.rs
@@ -287,10 +287,10 @@ register_diagnostics! {
     E0550, // multiple deprecated attributes
     E0551, // incorrect meta item
     E0552, // unrecognized representation hint
-    E0553, // unrecognized enum representation hint
     E0554, // #[feature] may not be used on the [] release channel
     E0555, // malformed feature attribute, expected #![feature(...)]
     E0556, // malformed feature, expected just one word
     E0557, // feature has been removed
     E0584, // file for module `..` found at both .. and ..
+    E0589, // invalid `repr(align)` attribute
 }
diff --git a/src/libsyntax/diagnostics/plugin.rs b/src/libsyntax/diagnostics/plugin.rs
index fe5cb87ad59..2a5de3c7382 100644
--- a/src/libsyntax/diagnostics/plugin.rs
+++ b/src/libsyntax/diagnostics/plugin.rs
@@ -120,7 +120,7 @@ pub fn expand_register_diagnostic<'cx>(ecx: &'cx mut ExtCtxt,
 
         // URLs can be unavoidably longer than the line limit, so we allow them.
         // Allowed format is: `[name]: https://www.rust-lang.org/`
-        let is_url = |l: &str| l.starts_with('[') && l.contains("]:") && l.contains("http");
+        let is_url = |l: &str| l.starts_with("[") && l.contains("]:") && l.contains("http");
 
         if msg.lines().any(|line| line.len() > MAX_DESCRIPTION_WIDTH && !is_url(line)) {
             ecx.span_err(span, &format!(
@@ -177,7 +177,7 @@ pub fn expand_build_diagnostic_array<'cx>(ecx: &'cx mut ExtCtxt,
             if let Err(e) = output_metadata(ecx,
                                             &target_triple,
                                             &crate_name.name.as_str(),
-                                            &diagnostics) {
+                                            diagnostics) {
                 ecx.span_bug(span, &format!(
                     "error writing metadata for triple `{}` and crate `{}`, error: {}, \
                      cause: {:?}",
@@ -206,7 +206,7 @@ pub fn expand_build_diagnostic_array<'cx>(ecx: &'cx mut ExtCtxt,
             (descriptions.len(), ecx.expr_vec(span, descriptions))
         });
 
-    let static_ = ecx.lifetime(span, ecx.name_of("'static"));
+    let static_ = ecx.lifetime(span, Ident::from_str("'static"));
     let ty_str = ecx.ty_rptr(
         span,
         ecx.ty_ident(span, ecx.ident_of("str")),
@@ -227,7 +227,7 @@ pub fn expand_build_diagnostic_array<'cx>(ecx: &'cx mut ExtCtxt,
 
     MacEager::items(SmallVector::many(vec![
         P(ast::Item {
-            ident: name.clone(),
+            ident: *name,
             attrs: Vec::new(),
             id: ast::DUMMY_NODE_ID,
             node: ast::ItemKind::Const(
diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs
index dc7e7673eb0..71dc81c3759 100644
--- a/src/libsyntax/ext/base.rs
+++ b/src/libsyntax/ext/base.rs
@@ -12,11 +12,11 @@ pub use self::SyntaxExtension::{MultiDecorator, MultiModifier, NormalTT, IdentTT
 
 use ast::{self, Attribute, Name, PatKind, MetaItem};
 use attr::HasAttrs;
-use codemap::{self, CodeMap, ExpnInfo, Spanned, respan};
-use syntax_pos::{Span, ExpnId, NO_EXPANSION};
-use errors::{DiagnosticBuilder, FatalError};
+use codemap::{self, CodeMap, Spanned, respan};
+use syntax_pos::{Span, DUMMY_SP};
+use errors::DiagnosticBuilder;
 use ext::expand::{self, Expansion, Invocation};
-use ext::hygiene::Mark;
+use ext::hygiene::{Mark, SyntaxContext};
 use fold::{self, Folder};
 use parse::{self, parser, DirectoryOwnership};
 use parse::token;
@@ -24,6 +24,7 @@ use ptr::P;
 use symbol::Symbol;
 use util::small_vector::SmallVector;
 
+use std::collections::HashMap;
 use std::path::PathBuf;
 use std::rc::Rc;
 use std::default::Default;
@@ -56,6 +57,14 @@ impl HasAttrs for Annotatable {
 }
 
 impl Annotatable {
+    pub fn span(&self) -> Span {
+        match *self {
+            Annotatable::Item(ref item) => item.span,
+            Annotatable::TraitItem(ref trait_item) => trait_item.span,
+            Annotatable::ImplItem(ref impl_item) => impl_item.span,
+        }
+    }
+
     pub fn expect_item(self) -> P<ast::Item> {
         match self {
             Annotatable::Item(i) => i,
@@ -201,7 +210,26 @@ impl<F> TTMacroExpander for F
 {
     fn expand<'cx>(&self, ecx: &'cx mut ExtCtxt, span: Span, input: TokenStream)
                    -> Box<MacResult+'cx> {
-        (*self)(ecx, span, &input.trees().collect::<Vec<_>>())
+        struct AvoidInterpolatedIdents;
+
+        impl Folder for AvoidInterpolatedIdents {
+            fn fold_tt(&mut self, tt: tokenstream::TokenTree) -> tokenstream::TokenTree {
+                if let tokenstream::TokenTree::Token(_, token::Interpolated(ref nt)) = tt {
+                    if let token::NtIdent(ident) = **nt {
+                        return tokenstream::TokenTree::Token(ident.span, token::Ident(ident.node));
+                    }
+                }
+                fold::noop_fold_tt(tt, self)
+            }
+
+            fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
+                fold::noop_fold_mac(mac, self)
+            }
+        }
+
+        let input: Vec<_> =
+            input.trees().map(|tt| AvoidInterpolatedIdents.fold_tt(tt)).collect();
+        (*self)(ecx, span, &input)
     }
 }
 
@@ -507,7 +535,7 @@ pub enum SyntaxExtension {
     ///
     /// The `bool` dictates whether the contents of the macro can
     /// directly use `#[unstable]` things (true == yes).
-    NormalTT(Box<TTMacroExpander>, Option<Span>, bool),
+    NormalTT(Box<TTMacroExpander>, Option<(ast::NodeId, Span)>, bool),
 
     /// A function-like syntax extension that has an extra ident before
     /// the block.
@@ -522,12 +550,16 @@ pub enum SyntaxExtension {
 
     /// An attribute-like procedural macro that derives a builtin trait.
     BuiltinDerive(BuiltinDeriveFn),
+
+    /// A declarative macro, e.g. `macro m() {}`.
+    DeclMacro(Box<TTMacroExpander>, Option<Span> /* definition site span */),
 }
 
 impl SyntaxExtension {
     /// Return which kind of macro calls this syntax extension.
     pub fn kind(&self) -> MacroKind {
         match *self {
+            SyntaxExtension::DeclMacro(..) |
             SyntaxExtension::NormalTT(..) |
             SyntaxExtension::IdentTT(..) |
             SyntaxExtension::ProcMacro(..) =>
@@ -541,6 +573,13 @@ impl SyntaxExtension {
                 MacroKind::Derive,
         }
     }
+
+    pub fn is_modern(&self) -> bool {
+        match *self {
+            SyntaxExtension::DeclMacro(..) => true,
+            _ => false,
+        }
+    }
 }
 
 pub type NamedSyntaxExtension = (Name, SyntaxExtension);
@@ -561,6 +600,7 @@ pub trait Resolver {
                      -> Result<Option<Rc<SyntaxExtension>>, Determinacy>;
     fn resolve_macro(&mut self, scope: Mark, path: &ast::Path, kind: MacroKind, force: bool)
                      -> Result<Rc<SyntaxExtension>, Determinacy>;
+    fn check_unused_macros(&self);
 }
 
 #[derive(Copy, Clone, Debug)]
@@ -590,6 +630,7 @@ impl Resolver for DummyResolver {
                      _force: bool) -> Result<Rc<SyntaxExtension>, Determinacy> {
         Err(Determinacy::Determined)
     }
+    fn check_unused_macros(&self) {}
 }
 
 #[derive(Clone)]
@@ -602,14 +643,13 @@ pub struct ModuleData {
 pub struct ExpansionData {
     pub mark: Mark,
     pub depth: usize,
-    pub backtrace: ExpnId,
     pub module: Rc<ModuleData>,
     pub directory_ownership: DirectoryOwnership,
 }
 
 /// One of these is made during expansion and incrementally updated as we go;
-/// when a macro expansion occurs, the resulting nodes have the backtrace()
-/// -> expn_info of their expansion context stored into their span.
+/// when a macro expansion occurs, the resulting nodes have the `backtrace()
+/// -> expn_info` of their expansion context stored into their span.
 pub struct ExtCtxt<'a> {
     pub parse_sess: &'a parse::ParseSess,
     pub ecfg: expand::ExpansionConfig<'a>,
@@ -617,6 +657,7 @@ pub struct ExtCtxt<'a> {
     pub resolver: &'a mut Resolver,
     pub resolve_err_count: usize,
     pub current_expansion: ExpansionData,
+    pub expansions: HashMap<Span, Vec<String>>,
 }
 
 impl<'a> ExtCtxt<'a> {
@@ -633,10 +674,10 @@ impl<'a> ExtCtxt<'a> {
             current_expansion: ExpansionData {
                 mark: Mark::root(),
                 depth: 0,
-                backtrace: NO_EXPANSION,
                 module: Rc::new(ModuleData { mod_path: Vec::new(), directory: PathBuf::new() }),
                 directory_ownership: DirectoryOwnership::Owned,
             },
+            expansions: HashMap::new(),
         }
     }
 
@@ -658,58 +699,36 @@ impl<'a> ExtCtxt<'a> {
     pub fn parse_sess(&self) -> &'a parse::ParseSess { self.parse_sess }
     pub fn cfg(&self) -> &ast::CrateConfig { &self.parse_sess.config }
     pub fn call_site(&self) -> Span {
-        self.codemap().with_expn_info(self.backtrace(), |ei| match ei {
+        match self.current_expansion.mark.expn_info() {
             Some(expn_info) => expn_info.call_site,
-            None => self.bug("missing top span")
-        })
+            None => DUMMY_SP,
+        }
+    }
+    pub fn backtrace(&self) -> SyntaxContext {
+        SyntaxContext::empty().apply_mark(self.current_expansion.mark)
     }
-    pub fn backtrace(&self) -> ExpnId { self.current_expansion.backtrace }
 
     /// Returns span for the macro which originally caused the current expansion to happen.
     ///
     /// Stops backtracing at include! boundary.
-    pub fn expansion_cause(&self) -> Span {
-        let mut expn_id = self.backtrace();
+    pub fn expansion_cause(&self) -> Option<Span> {
+        let mut ctxt = self.backtrace();
         let mut last_macro = None;
         loop {
-            if self.codemap().with_expn_info(expn_id, |info| {
-                info.map_or(None, |i| {
-                    if i.callee.name() == "include" {
-                        // Stop going up the backtrace once include! is encountered
-                        return None;
-                    }
-                    expn_id = i.call_site.expn_id;
-                    last_macro = Some(i.call_site);
-                    return Some(());
-                })
+            if ctxt.outer().expn_info().map_or(None, |info| {
+                if info.callee.name() == "include" {
+                    // Stop going up the backtrace once include! is encountered
+                    return None;
+                }
+                ctxt = info.call_site.ctxt;
+                last_macro = Some(info.call_site);
+                Some(())
             }).is_none() {
                 break
             }
         }
-        last_macro.expect("missing expansion backtrace")
-    }
-
-    pub fn bt_push(&mut self, ei: ExpnInfo) {
-        if self.current_expansion.depth > self.ecfg.recursion_limit {
-            let suggested_limit = self.ecfg.recursion_limit * 2;
-            let mut err = self.struct_span_fatal(ei.call_site,
-                &format!("recursion limit reached while expanding the macro `{}`",
-                         ei.callee.name()));
-            err.help(&format!(
-                "consider adding a `#![recursion_limit=\"{}\"]` attribute to your crate",
-                suggested_limit));
-            err.emit();
-            panic!(FatalError);
-        }
-
-        let mut call_site = ei.call_site;
-        call_site.expn_id = self.backtrace();
-        self.current_expansion.backtrace = self.codemap().record_expansion(ExpnInfo {
-            call_site: call_site,
-            callee: ei.callee
-        });
+        last_macro
     }
-    pub fn bt_pop(&mut self) {}
 
     pub fn struct_span_warn(&self,
                             sp: Span,
@@ -762,6 +781,15 @@ impl<'a> ExtCtxt<'a> {
     pub fn span_bug(&self, sp: Span, msg: &str) -> ! {
         self.parse_sess.span_diagnostic.span_bug(sp, msg);
     }
+    pub fn trace_macros_diag(&self) {
+        for (sp, notes) in self.expansions.iter() {
+            let mut db = self.parse_sess.span_diagnostic.span_note_diag(*sp, "trace_macro");
+            for note in notes {
+                db.note(note);
+            }
+            db.emit();
+        }
+    }
     pub fn bug(&self, msg: &str) -> ! {
         self.parse_sess.span_diagnostic.bug(msg);
     }
@@ -780,11 +808,15 @@ impl<'a> ExtCtxt<'a> {
             v.push(self.ident_of(s));
         }
         v.extend(components.iter().map(|s| self.ident_of(s)));
-        return v
+        v
     }
     pub fn name_of(&self, st: &str) -> ast::Name {
         Symbol::intern(st)
     }
+
+    pub fn check_unused_macros(&self) {
+        self.resolver.check_unused_macros();
+    }
 }
 
 /// Extract a string literal from the macro expanded version of `expr`,
@@ -792,9 +824,9 @@ impl<'a> ExtCtxt<'a> {
 /// compilation on error, merely emits a non-fatal error and returns None.
 pub fn expr_to_spanned_string(cx: &mut ExtCtxt, expr: P<ast::Expr>, err_msg: &str)
                               -> Option<Spanned<(Symbol, ast::StrStyle)>> {
-    // Update `expr.span`'s expn_id now in case expr is an `include!` macro invocation.
+    // Update `expr.span`'s ctxt now in case expr is an `include!` macro invocation.
     let expr = expr.map(|mut expr| {
-        expr.span.expn_id = cx.backtrace();
+        expr.span.ctxt = expr.span.ctxt.apply_mark(cx.current_expansion.mark);
         expr
     });
 
diff --git a/src/libsyntax/ext/build.rs b/src/libsyntax/ext/build.rs
index f8d4eff80b2..a4580ea3939 100644
--- a/src/libsyntax/ext/build.rs
+++ b/src/libsyntax/ext/build.rs
@@ -38,11 +38,11 @@ pub trait AstBuilder {
 
     fn qpath(&self, self_type: P<ast::Ty>,
              trait_path: ast::Path,
-             ident: ast::Ident)
+             ident: ast::SpannedIdent)
              -> (ast::QSelf, ast::Path);
     fn qpath_all(&self, self_type: P<ast::Ty>,
                 trait_path: ast::Path,
-                ident: ast::Ident,
+                ident: ast::SpannedIdent,
                 lifetimes: Vec<ast::Lifetime>,
                 types: Vec<P<ast::Ty>>,
                 bindings: Vec<ast::TypeBinding>)
@@ -52,7 +52,7 @@ pub trait AstBuilder {
     fn ty_mt(&self, ty: P<ast::Ty>, mutbl: ast::Mutability) -> ast::MutTy;
 
     fn ty(&self, span: Span, ty: ast::TyKind) -> P<ast::Ty>;
-    fn ty_path(&self, ast::Path) -> P<ast::Ty>;
+    fn ty_path(&self, path: ast::Path) -> P<ast::Ty>;
     fn ty_ident(&self, span: Span, idents: ast::Ident) -> P<ast::Ty>;
 
     fn ty_rptr(&self, span: Span,
@@ -76,10 +76,10 @@ pub trait AstBuilder {
     fn trait_ref(&self, path: ast::Path) -> ast::TraitRef;
     fn poly_trait_ref(&self, span: Span, path: ast::Path) -> ast::PolyTraitRef;
     fn typarambound(&self, path: ast::Path) -> ast::TyParamBound;
-    fn lifetime(&self, span: Span, ident: ast::Name) -> ast::Lifetime;
+    fn lifetime(&self, span: Span, ident: ast::Ident) -> ast::Lifetime;
     fn lifetime_def(&self,
                     span: Span,
-                    name: ast::Name,
+                    ident: ast::Ident,
                     attrs: Vec<ast::Attribute>,
                     bounds: Vec<ast::Lifetime>)
                     -> ast::LifetimeDef;
@@ -323,7 +323,7 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
             segments.push(ast::PathSegment::crate_root());
         }
 
-        segments.extend(idents.into_iter().map(Into::into));
+        segments.extend(idents.into_iter().map(|i| ast::PathSegment::from_ident(i, sp)));
         let parameters = if lifetimes.is_empty() && types.is_empty() && bindings.is_empty() {
             None
         } else {
@@ -333,7 +333,11 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
                 bindings: bindings,
             })))
         };
-        segments.push(ast::PathSegment { identifier: last_identifier, parameters: parameters });
+        segments.push(ast::PathSegment {
+            identifier: last_identifier,
+            span: sp,
+            parameters: parameters
+        });
         ast::Path {
             span: sp,
             segments: segments,
@@ -346,7 +350,7 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
     fn qpath(&self,
              self_type: P<ast::Ty>,
              trait_path: ast::Path,
-             ident: ast::Ident)
+             ident: ast::SpannedIdent)
              -> (ast::QSelf, ast::Path) {
         self.qpath_all(self_type, trait_path, ident, vec![], vec![], vec![])
     }
@@ -357,7 +361,7 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
     fn qpath_all(&self,
                  self_type: P<ast::Ty>,
                  trait_path: ast::Path,
-                 ident: ast::Ident,
+                 ident: ast::SpannedIdent,
                  lifetimes: Vec<ast::Lifetime>,
                  types: Vec<P<ast::Ty>>,
                  bindings: Vec<ast::TypeBinding>)
@@ -369,7 +373,8 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
             bindings: bindings,
         };
         path.segments.push(ast::PathSegment {
-            identifier: ident,
+            identifier: ident.node,
+            span: ident.span,
             parameters: Some(P(ast::PathParameters::AngleBracketed(parameters))),
         });
 
@@ -473,19 +478,19 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
         ast::TraitTyParamBound(self.poly_trait_ref(path.span, path), ast::TraitBoundModifier::None)
     }
 
-    fn lifetime(&self, span: Span, name: ast::Name) -> ast::Lifetime {
-        ast::Lifetime { id: ast::DUMMY_NODE_ID, span: span, name: name }
+    fn lifetime(&self, span: Span, ident: ast::Ident) -> ast::Lifetime {
+        ast::Lifetime { id: ast::DUMMY_NODE_ID, span: span, ident: ident }
     }
 
     fn lifetime_def(&self,
                     span: Span,
-                    name: ast::Name,
+                    ident: ast::Ident,
                     attrs: Vec<ast::Attribute>,
                     bounds: Vec<ast::Lifetime>)
                     -> ast::LifetimeDef {
         ast::LifetimeDef {
             attrs: attrs.into(),
-            lifetime: self.lifetime(span, name),
+            lifetime: self.lifetime(span, ident),
             bounds: bounds
         }
     }
diff --git a/src/libsyntax/ext/derive.rs b/src/libsyntax/ext/derive.rs
index 77cc7bab031..e7c5d8278d9 100644
--- a/src/libsyntax/ext/derive.rs
+++ b/src/libsyntax/ext/derive.rs
@@ -9,73 +9,71 @@
 // except according to those terms.
 
 use attr::HasAttrs;
-use {ast, codemap};
+use ast;
+use codemap::{ExpnInfo, NameAndSpan, ExpnFormat};
 use ext::base::ExtCtxt;
 use ext::build::AstBuilder;
+use parse::parser::PathStyle;
 use symbol::Symbol;
 use syntax_pos::Span;
 
-pub fn collect_derives(cx: &mut ExtCtxt, attrs: &mut Vec<ast::Attribute>) -> Vec<(Symbol, Span)> {
+use std::collections::HashSet;
+
+pub fn collect_derives(cx: &mut ExtCtxt, attrs: &mut Vec<ast::Attribute>) -> Vec<ast::Path> {
     let mut result = Vec::new();
     attrs.retain(|attr| {
-        if attr.name() != "derive" {
+        if attr.path != "derive" {
             return true;
         }
 
-        if attr.value_str().is_some() {
-            cx.span_err(attr.span, "unexpected value in `derive`");
-            return false;
-        }
-
-        let traits = attr.meta_item_list().unwrap_or(&[]).to_owned();
-        if traits.is_empty() {
-            cx.span_warn(attr.span, "empty trait list in `derive`");
-            return false;
-        }
-
-        for titem in traits {
-            if titem.word().is_none() {
-                cx.span_err(titem.span, "malformed `derive` entry");
-                return false;
+        match attr.parse_list(cx.parse_sess,
+                              |parser| parser.parse_path_allowing_meta(PathStyle::Mod)) {
+            Ok(ref traits) if traits.is_empty() => {
+                cx.span_warn(attr.span, "empty trait list in `derive`");
+                false
+            }
+            Ok(traits) => {
+                result.extend(traits);
+                true
+            }
+            Err(mut e) => {
+                e.emit();
+                false
             }
-            result.push((titem.name().unwrap(), titem.span));
         }
-
-        true
     });
     result
 }
 
-fn allow_unstable(cx: &mut ExtCtxt, span: Span, attr_name: &str) -> Span {
-    Span {
-        expn_id: cx.codemap().record_expansion(codemap::ExpnInfo {
-            call_site: span,
-            callee: codemap::NameAndSpan {
-                format: codemap::MacroAttribute(Symbol::intern(attr_name)),
-                span: Some(span),
-                allow_internal_unstable: true,
-            },
-        }),
-        ..span
+pub fn add_derived_markers<T>(cx: &mut ExtCtxt, span: Span, traits: &[ast::Path], item: T) -> T
+    where T: HasAttrs,
+{
+    let (mut names, mut pretty_name) = (HashSet::new(), "derive(".to_owned());
+    for (i, path) in traits.iter().enumerate() {
+        if i > 0 {
+            pretty_name.push_str(", ");
+        }
+        pretty_name.push_str(&path.to_string());
+        names.insert(unwrap_or!(path.segments.get(0), continue).identifier.name);
     }
-}
+    pretty_name.push(')');
 
-pub fn add_derived_markers<T: HasAttrs>(cx: &mut ExtCtxt, traits: &[(Symbol, Span)], item: T) -> T {
-    let span = match traits.get(0) {
-        Some(&(_, span)) => span,
-        None => return item,
-    };
+    cx.current_expansion.mark.set_expn_info(ExpnInfo {
+        call_site: span,
+        callee: NameAndSpan {
+            format: ExpnFormat::MacroAttribute(Symbol::intern(&pretty_name)),
+            span: None,
+            allow_internal_unstable: true,
+        },
+    });
 
+    let span = Span { ctxt: cx.backtrace(), ..span };
     item.map_attrs(|mut attrs| {
-        if traits.iter().any(|&(name, _)| name == "PartialEq") &&
-           traits.iter().any(|&(name, _)| name == "Eq") {
-            let span = allow_unstable(cx, span, "derive(PartialEq, Eq)");
+        if names.contains(&Symbol::intern("Eq")) && names.contains(&Symbol::intern("PartialEq")) {
             let meta = cx.meta_word(span, Symbol::intern("structural_match"));
             attrs.push(cx.attribute(span, meta));
         }
-        if traits.iter().any(|&(name, _)| name == "Copy") &&
-           traits.iter().any(|&(name, _)| name == "Clone") {
-            let span = allow_unstable(cx, span, "derive(Copy, Clone)");
+        if names.contains(&Symbol::intern("Copy")) && names.contains(&Symbol::intern("Clone")) {
             let meta = cx.meta_word(span, Symbol::intern("rustc_copy_clone_marker"));
             attrs.push(cx.attribute(span, meta));
         }
diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs
index 10168f010a0..be077b48111 100644
--- a/src/libsyntax/ext/expand.rs
+++ b/src/libsyntax/ext/expand.rs
@@ -8,11 +8,12 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use ast::{self, Block, Ident, PatKind};
-use ast::{Name, MacStmtStyle, StmtKind, ItemKind};
+use ast::{self, Block, Ident, NodeId, PatKind, Path};
+use ast::{MacStmtStyle, StmtKind, ItemKind};
 use attr::{self, HasAttrs};
 use codemap::{ExpnInfo, NameAndSpan, MacroBang, MacroAttribute};
 use config::{is_test_or_bench, StripUnconfigured};
+use errors::FatalError;
 use ext::base::*;
 use ext::derive::{add_derived_markers, collect_derives};
 use ext::hygiene::Mark;
@@ -27,7 +28,7 @@ use ptr::P;
 use std_inject;
 use symbol::Symbol;
 use symbol::keywords;
-use syntax_pos::{self, Span, ExpnId};
+use syntax_pos::{Span, DUMMY_SP};
 use tokenstream::TokenStream;
 use util::small_vector::SmallVector;
 use visit::Visitor;
@@ -165,12 +166,11 @@ pub enum InvocationKind {
     },
     Attr {
         attr: Option<ast::Attribute>,
-        traits: Vec<(Symbol, Span)>,
+        traits: Vec<Path>,
         item: Annotatable,
     },
     Derive {
-        name: Symbol,
-        span: Span,
+        path: Path,
         item: Annotatable,
     },
 }
@@ -180,8 +180,8 @@ impl Invocation {
         match self.kind {
             InvocationKind::Bang { span, .. } => span,
             InvocationKind::Attr { attr: Some(ref attr), .. } => attr.span,
-            InvocationKind::Attr { attr: None, .. } => syntax_pos::DUMMY_SP,
-            InvocationKind::Derive { span, .. } => span,
+            InvocationKind::Attr { attr: None, .. } => DUMMY_SP,
+            InvocationKind::Derive { ref path, .. } => path.span,
         }
     }
 }
@@ -205,6 +205,8 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
         module.directory.pop();
         self.cx.current_expansion.module = Rc::new(module);
 
+        let orig_mod_span = krate.module.inner;
+
         let krate_item = Expansion::Items(SmallVector::one(P(ast::Item {
             attrs: krate.attrs,
             span: krate.span,
@@ -214,14 +216,22 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
             vis: ast::Visibility::Public,
         })));
 
-        match self.expand(krate_item).make_items().pop().unwrap().unwrap() {
-            ast::Item { attrs, node: ast::ItemKind::Mod(module), .. } => {
+        match self.expand(krate_item).make_items().pop().map(P::unwrap) {
+            Some(ast::Item { attrs, node: ast::ItemKind::Mod(module), .. }) => {
                 krate.attrs = attrs;
                 krate.module = module;
             },
+            None => {
+                // Resolution failed so we return an empty expansion
+                krate.attrs = vec![];
+                krate.module = ast::Mod {
+                    inner: orig_mod_span,
+                    items: vec![],
+                };
+            },
             _ => unreachable!(),
         };
-
+        self.cx.trace_macros_diag();
         krate
     }
 
@@ -272,17 +282,16 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
                     self.collect_invocations(expansion, &[])
                 } else if let InvocationKind::Attr { attr: None, traits, item } = invoc.kind {
                     let item = item
-                        .map_attrs(|mut attrs| { attrs.retain(|a| a.name() != "derive"); attrs });
+                        .map_attrs(|mut attrs| { attrs.retain(|a| a.path != "derive"); attrs });
                     let item_with_markers =
-                        add_derived_markers(&mut self.cx, &traits, item.clone());
+                        add_derived_markers(&mut self.cx, item.span(), &traits, item.clone());
                     let derives = derives.entry(invoc.expansion_data.mark).or_insert_with(Vec::new);
 
-                    for &(name, span) in &traits {
-                        let mark = Mark::fresh();
+                    for path in &traits {
+                        let mark = Mark::fresh(self.cx.current_expansion.mark);
                         derives.push(mark);
-                        let path = ast::Path::from_ident(span, Ident::with_empty_ctxt(name));
                         let item = match self.cx.resolver.resolve_macro(
-                                Mark::root(), &path, MacroKind::Derive, false) {
+                                Mark::root(), path, MacroKind::Derive, false) {
                             Ok(ext) => match *ext {
                                 SyntaxExtension::BuiltinDerive(..) => item_with_markers.clone(),
                                 _ => item.clone(),
@@ -290,7 +299,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
                             _ => item.clone(),
                         };
                         invocations.push(Invocation {
-                            kind: InvocationKind::Derive { name: name, span: span, item: item },
+                            kind: InvocationKind::Derive { path: path.clone(), item: item },
                             expansion_kind: invoc.expansion_kind,
                             expansion_data: ExpansionData {
                                 mark: mark,
@@ -323,7 +332,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
         while let Some(expansions) = expansions.pop() {
             for (mark, expansion) in expansions.into_iter().rev() {
                 let derives = derives.remove(&mark).unwrap_or_else(Vec::new);
-                placeholder_expander.add(mark.as_placeholder_id(), expansion, derives);
+                placeholder_expander.add(NodeId::placeholder_from_mark(mark), expansion, derives);
             }
         }
 
@@ -365,11 +374,26 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
     }
 
     fn expand_invoc(&mut self, invoc: Invocation, ext: Rc<SyntaxExtension>) -> Expansion {
-        match invoc.kind {
+        let result = match invoc.kind {
             InvocationKind::Bang { .. } => self.expand_bang_invoc(invoc, ext),
             InvocationKind::Attr { .. } => self.expand_attr_invoc(invoc, ext),
             InvocationKind::Derive { .. } => self.expand_derive_invoc(invoc, ext),
+        };
+
+        if self.cx.current_expansion.depth > self.cx.ecfg.recursion_limit {
+            let info = self.cx.current_expansion.mark.expn_info().unwrap();
+            let suggested_limit = self.cx.ecfg.recursion_limit * 2;
+            let mut err = self.cx.struct_span_fatal(info.call_site,
+                &format!("recursion limit reached while expanding the macro `{}`",
+                         info.callee.name()));
+            err.help(&format!(
+                "consider adding a `#![recursion_limit=\"{}\"]` attribute to your crate",
+                suggested_limit));
+            err.emit();
+            panic!(FatalError);
         }
+
+        result
     }
 
     fn expand_attr_invoc(&mut self, invoc: Invocation, ext: Rc<SyntaxExtension>) -> Expansion {
@@ -380,54 +404,42 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
         };
 
         attr::mark_used(&attr);
-        let name = attr.name();
-        self.cx.bt_push(ExpnInfo {
+        invoc.expansion_data.mark.set_expn_info(ExpnInfo {
             call_site: attr.span,
             callee: NameAndSpan {
-                format: MacroAttribute(name),
-                span: Some(attr.span),
+                format: MacroAttribute(Symbol::intern(&format!("{}", attr.path))),
+                span: None,
                 allow_internal_unstable: false,
             }
         });
 
         match *ext {
             MultiModifier(ref mac) => {
-                let item = mac.expand(self.cx, attr.span, &attr.value, item);
+                let meta = panictry!(attr.parse_meta(self.cx.parse_sess));
+                let item = mac.expand(self.cx, attr.span, &meta, item);
                 kind.expect_from_annotatables(item)
             }
             MultiDecorator(ref mac) => {
                 let mut items = Vec::new();
-                mac.expand(self.cx, attr.span, &attr.value, &item,
-                           &mut |item| items.push(item));
+                let meta = panictry!(attr.parse_meta(self.cx.parse_sess));
+                mac.expand(self.cx, attr.span, &meta, &item, &mut |item| items.push(item));
                 items.push(item);
                 kind.expect_from_annotatables(items)
             }
             SyntaxExtension::AttrProcMacro(ref mac) => {
-                let attr_toks = stream_for_attr_args(&attr, &self.cx.parse_sess);
-                let item_toks = stream_for_item(&item, &self.cx.parse_sess);
-
-                let span = Span {
-                    expn_id: self.cx.codemap().record_expansion(ExpnInfo {
-                        call_site: attr.span,
-                        callee: NameAndSpan {
-                            format: MacroAttribute(name),
-                            span: None,
-                            allow_internal_unstable: false,
-                        },
-                    }),
-                    ..attr.span
-                };
+                let item_toks = stream_for_item(&item, self.cx.parse_sess);
 
-                let tok_result = mac.expand(self.cx, attr.span, attr_toks, item_toks);
-                self.parse_expansion(tok_result, kind, name, span)
+                let span = Span { ctxt: self.cx.backtrace(), ..attr.span };
+                let tok_result = mac.expand(self.cx, attr.span, attr.tokens, item_toks);
+                self.parse_expansion(tok_result, kind, &attr.path, span)
             }
             SyntaxExtension::ProcMacroDerive(..) | SyntaxExtension::BuiltinDerive(..) => {
-                self.cx.span_err(attr.span, &format!("`{}` is a derive mode", name));
+                self.cx.span_err(attr.span, &format!("`{}` is a derive mode", attr.path));
                 kind.dummy(attr.span)
             }
             _ => {
-                let msg = &format!("macro `{}` may not be used in attributes", name);
-                self.cx.span_err(attr.span, &msg);
+                let msg = &format!("macro `{}` may not be used in attributes", attr.path);
+                self.cx.span_err(attr.span, msg);
                 kind.dummy(attr.span)
             }
         }
@@ -442,42 +454,52 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
         };
         let path = &mac.node.path;
 
-        let extname = path.segments.last().unwrap().identifier.name;
-        let ident = ident.unwrap_or(keywords::Invalid.ident());
-        let marked_tts =
-            noop_fold_tts(mac.node.stream(), &mut Marker { mark: mark, expn_id: None });
+        let ident = ident.unwrap_or_else(|| keywords::Invalid.ident());
+        let validate_and_set_expn_info = |def_site_span, allow_internal_unstable| {
+            if ident.name != keywords::Invalid.name() {
+                return Err(format!("macro {}! expects no ident argument, given '{}'", path, ident));
+            }
+            mark.set_expn_info(ExpnInfo {
+                call_site: span,
+                callee: NameAndSpan {
+                    format: MacroBang(Symbol::intern(&format!("{}", path))),
+                    span: def_site_span,
+                    allow_internal_unstable: allow_internal_unstable,
+                },
+            });
+            Ok(())
+        };
+
+        let marked_tts = noop_fold_tts(mac.node.stream(), &mut Marker(mark));
         let opt_expanded = match *ext {
-            NormalTT(ref expandfun, exp_span, allow_internal_unstable) => {
-                if ident.name != keywords::Invalid.name() {
-                    let msg =
-                        format!("macro {}! expects no ident argument, given '{}'", extname, ident);
+            SyntaxExtension::DeclMacro(ref expand, def_site_span) => {
+                if let Err(msg) = validate_and_set_expn_info(def_site_span, false) {
                     self.cx.span_err(path.span, &msg);
                     return kind.dummy(span);
                 }
+                kind.make_from(expand.expand(self.cx, span, marked_tts))
+            }
 
-                self.cx.bt_push(ExpnInfo {
-                    call_site: span,
-                    callee: NameAndSpan {
-                        format: MacroBang(extname),
-                        span: exp_span,
-                        allow_internal_unstable: allow_internal_unstable,
-                    },
-                });
-
+            NormalTT(ref expandfun, def_info, allow_internal_unstable) => {
+                if let Err(msg) = validate_and_set_expn_info(def_info.map(|(_, s)| s),
+                                                             allow_internal_unstable) {
+                    self.cx.span_err(path.span, &msg);
+                    return kind.dummy(span);
+                }
                 kind.make_from(expandfun.expand(self.cx, span, marked_tts))
             }
 
             IdentTT(ref expander, tt_span, allow_internal_unstable) => {
                 if ident.name == keywords::Invalid.name() {
                     self.cx.span_err(path.span,
-                                    &format!("macro {}! expects an ident argument", extname));
+                                    &format!("macro {}! expects an ident argument", path));
                     return kind.dummy(span);
                 };
 
-                self.cx.bt_push(ExpnInfo {
+                invoc.expansion_data.mark.set_expn_info(ExpnInfo {
                     call_site: span,
                     callee: NameAndSpan {
-                        format: MacroBang(extname),
+                        format: MacroBang(Symbol::intern(&format!("{}", path))),
                         span: tt_span,
                         allow_internal_unstable: allow_internal_unstable,
                     }
@@ -489,27 +511,27 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
 
             MultiDecorator(..) | MultiModifier(..) | SyntaxExtension::AttrProcMacro(..) => {
                 self.cx.span_err(path.span,
-                                 &format!("`{}` can only be used in attributes", extname));
+                                 &format!("`{}` can only be used in attributes", path));
                 return kind.dummy(span);
             }
 
             SyntaxExtension::ProcMacroDerive(..) | SyntaxExtension::BuiltinDerive(..) => {
-                self.cx.span_err(path.span, &format!("`{}` is a derive mode", extname));
+                self.cx.span_err(path.span, &format!("`{}` is a derive mode", path));
                 return kind.dummy(span);
             }
 
             SyntaxExtension::ProcMacro(ref expandfun) => {
                 if ident.name != keywords::Invalid.name() {
                     let msg =
-                        format!("macro {}! expects no ident argument, given '{}'", extname, ident);
+                        format!("macro {}! expects no ident argument, given '{}'", path, ident);
                     self.cx.span_err(path.span, &msg);
                     return kind.dummy(span);
                 }
 
-                self.cx.bt_push(ExpnInfo {
+                invoc.expansion_data.mark.set_expn_info(ExpnInfo {
                     call_site: span,
                     callee: NameAndSpan {
-                        format: MacroBang(extname),
+                        format: MacroBang(Symbol::intern(&format!("{}", path))),
                         // FIXME procedural macros do not have proper span info
                         // yet, when they do, we should use it here.
                         span: None,
@@ -519,7 +541,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
                 });
 
                 let tok_result = expandfun.expand(self.cx, span, marked_tts);
-                Some(self.parse_expansion(tok_result, kind, extname, span))
+                Some(self.parse_expansion(tok_result, kind, path, span))
             }
         };
 
@@ -532,74 +554,62 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
             return kind.dummy(span);
         };
 
-        expanded.fold_with(&mut Marker {
-            mark: mark,
-            expn_id: Some(self.cx.backtrace()),
-        })
+        expanded.fold_with(&mut Marker(mark))
     }
 
     /// Expand a derive invocation. Returns the result of expansion.
     fn expand_derive_invoc(&mut self, invoc: Invocation, ext: Rc<SyntaxExtension>) -> Expansion {
         let Invocation { expansion_kind: kind, .. } = invoc;
-        let (name, span, item) = match invoc.kind {
-            InvocationKind::Derive { name, span, item } => (name, span, item),
+        let (path, item) = match invoc.kind {
+            InvocationKind::Derive { path, item } => (path, item),
             _ => unreachable!(),
         };
 
-        let mitem = ast::MetaItem { name: name, span: span, node: ast::MetaItemKind::Word };
-        let pretty_name = Symbol::intern(&format!("derive({})", name));
+        let pretty_name = Symbol::intern(&format!("derive({})", path));
+        let span = path.span;
+        let attr = ast::Attribute {
+            path: path, tokens: TokenStream::empty(), span: span,
+            // irrelevant:
+            id: ast::AttrId(0), style: ast::AttrStyle::Outer, is_sugared_doc: false,
+        };
 
-        self.cx.bt_push(ExpnInfo {
+        let mut expn_info = ExpnInfo {
             call_site: span,
             callee: NameAndSpan {
                 format: MacroAttribute(pretty_name),
-                span: Some(span),
+                span: None,
                 allow_internal_unstable: false,
             }
-        });
+        };
 
         match *ext {
             SyntaxExtension::ProcMacroDerive(ref ext, _) => {
-                let span = Span {
-                    expn_id: self.cx.codemap().record_expansion(ExpnInfo {
-                        call_site: span,
-                        callee: NameAndSpan {
-                            format: MacroAttribute(pretty_name),
-                            span: None,
-                            allow_internal_unstable: false,
-                        },
-                    }),
-                    ..span
+                invoc.expansion_data.mark.set_expn_info(expn_info);
+                let span = Span { ctxt: self.cx.backtrace(), ..span };
+                let dummy = ast::MetaItem { // FIXME(jseyfried) avoid this
+                    name: keywords::Invalid.name(),
+                    span: DUMMY_SP,
+                    node: ast::MetaItemKind::Word,
                 };
-                return kind.expect_from_annotatables(ext.expand(self.cx, span, &mitem, item));
+                kind.expect_from_annotatables(ext.expand(self.cx, span, &dummy, item))
             }
             SyntaxExtension::BuiltinDerive(func) => {
-                let span = Span {
-                    expn_id: self.cx.codemap().record_expansion(ExpnInfo {
-                        call_site: span,
-                        callee: NameAndSpan {
-                            format: MacroAttribute(pretty_name),
-                            span: None,
-                            allow_internal_unstable: true,
-                        },
-                    }),
-                    ..span
-                };
+                expn_info.callee.allow_internal_unstable = true;
+                invoc.expansion_data.mark.set_expn_info(expn_info);
+                let span = Span { ctxt: self.cx.backtrace(), ..span };
                 let mut items = Vec::new();
-                func(self.cx, span, &mitem, &item, &mut |a| {
-                    items.push(a)
-                });
-                return kind.expect_from_annotatables(items);
+                func(self.cx, span, &attr.meta().unwrap(), &item, &mut |a| items.push(a));
+                kind.expect_from_annotatables(items)
             }
             _ => {
-                let msg = &format!("macro `{}` may not be used for derive attributes", name);
-                self.cx.span_err(span, &msg);
+                let msg = &format!("macro `{}` may not be used for derive attributes", attr.path);
+                self.cx.span_err(span, msg);
                 kind.dummy(span)
             }
         }
     }
 
-    fn parse_expansion(&mut self, toks: TokenStream, kind: ExpansionKind, name: Name, span: Span)
+    fn parse_expansion(&mut self, toks: TokenStream, kind: ExpansionKind, path: &Path, span: Span)
                        -> Expansion {
         let mut parser = self.cx.new_parser_from_tts(&toks.into_trees().collect::<Vec<_>>());
         let expansion = match parser.parse_expansion(kind, false) {
@@ -609,7 +619,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
                 return kind.dummy(span);
             }
         };
-        parser.ensure_complete_parse(name, kind.name(), span);
+        parser.ensure_complete_parse(path, kind.name(), span);
         // FIXME better span info
         expansion.fold_with(&mut ChangeSpan { span: span })
     }
@@ -629,14 +639,14 @@ impl<'a> Parser<'a> {
             ExpansionKind::TraitItems => {
                 let mut items = SmallVector::new();
                 while self.token != token::Eof {
-                    items.push(self.parse_trait_item()?);
+                    items.push(self.parse_trait_item(&mut false)?);
                 }
                 Expansion::TraitItems(items)
             }
             ExpansionKind::ImplItems => {
                 let mut items = SmallVector::new();
                 while self.token != token::Eof {
-                    items.push(self.parse_impl_item()?);
+                    items.push(self.parse_impl_item(&mut false)?);
                 }
                 Expansion::ImplItems(items)
             }
@@ -653,19 +663,19 @@ impl<'a> Parser<'a> {
             }
             ExpansionKind::Expr => Expansion::Expr(self.parse_expr()?),
             ExpansionKind::OptExpr => Expansion::OptExpr(Some(self.parse_expr()?)),
-            ExpansionKind::Ty => Expansion::Ty(self.parse_ty_no_plus()?),
+            ExpansionKind::Ty => Expansion::Ty(self.parse_ty()?),
             ExpansionKind::Pat => Expansion::Pat(self.parse_pat()?),
         })
     }
 
-    pub fn ensure_complete_parse(&mut self, macro_name: ast::Name, kind_name: &str, span: Span) {
+    pub fn ensure_complete_parse(&mut self, macro_path: &Path, kind_name: &str, span: Span) {
         if self.token != token::Eof {
             let msg = format!("macro expansion ignores token `{}` and any following",
                               self.this_token_to_string());
             let mut err = self.diagnostic().struct_span_err(self.span, &msg);
             let msg = format!("caused by the macro expansion here; the usage \
                                of `{}!` is likely invalid in {} context",
-                               macro_name, kind_name);
+                               macro_path, kind_name);
             err.span_note(span, &msg).emit();
         }
     }
@@ -689,7 +699,7 @@ macro_rules! fully_configure {
 
 impl<'a, 'b> InvocationCollector<'a, 'b> {
     fn collect(&mut self, expansion_kind: ExpansionKind, kind: InvocationKind) -> Expansion {
-        let mark = Mark::fresh();
+        let mark = Mark::fresh(self.cx.current_expansion.mark);
         self.invocations.push(Invocation {
             kind: kind,
             expansion_kind: expansion_kind,
@@ -699,7 +709,7 @@ impl<'a, 'b> InvocationCollector<'a, 'b> {
                 ..self.cx.current_expansion.clone()
             },
         });
-        placeholder(expansion_kind, mark.as_placeholder_id())
+        placeholder(expansion_kind, NodeId::placeholder_from_mark(mark))
     }
 
     fn collect_bang(&mut self, mac: ast::Mac, span: Span, kind: ExpansionKind) -> Expansion {
@@ -708,20 +718,20 @@ impl<'a, 'b> InvocationCollector<'a, 'b> {
 
     fn collect_attr(&mut self,
                     attr: Option<ast::Attribute>,
-                    traits: Vec<(Symbol, Span)>,
+                    traits: Vec<Path>,
                     item: Annotatable,
                     kind: ExpansionKind)
                     -> Expansion {
         if !traits.is_empty() &&
            (kind == ExpansionKind::TraitItems || kind == ExpansionKind::ImplItems) {
-            self.cx.span_err(traits[0].1, "`derive` can be only be applied to items");
+            self.cx.span_err(traits[0].span, "`derive` can be only be applied to items");
             return kind.expect_from_annotatables(::std::iter::once(item));
         }
         self.collect(kind, InvocationKind::Attr { attr: attr, traits: traits, item: item })
     }
 
     // If `item` is an attr invocation, remove and return the macro attribute.
-    fn classify_item<T>(&mut self, mut item: T) -> (Option<ast::Attribute>, Vec<(Symbol, Span)>, T)
+    fn classify_item<T>(&mut self, mut item: T) -> (Option<ast::Attribute>, Vec<Path>, T)
         where T: HasAttrs,
     {
         let (mut attr, mut traits) = (None, Vec::new());
@@ -749,22 +759,17 @@ impl<'a, 'b> InvocationCollector<'a, 'b> {
     // Detect use of feature-gated or invalid attributes on macro invocations
     // since they will not be detected after macro expansion.
     fn check_attributes(&mut self, attrs: &[ast::Attribute]) {
-        let codemap = &self.cx.parse_sess.codemap();
         let features = self.cx.ecfg.features.unwrap();
         for attr in attrs.iter() {
-            feature_gate::check_attribute(&attr, &self.cx.parse_sess, codemap, features);
+            feature_gate::check_attribute(attr, self.cx.parse_sess, features);
         }
     }
 }
 
 pub fn find_attr_invoc(attrs: &mut Vec<ast::Attribute>) -> Option<ast::Attribute> {
-    for i in 0 .. attrs.len() {
-        if !attr::is_known(&attrs[i]) && !is_builtin_attr(&attrs[i]) {
-             return Some(attrs.remove(i));
-        }
-    }
-
-    None
+    attrs.iter()
+         .position(|a| !attr::is_known(a) && !is_builtin_attr(a))
+         .map(|i| attrs.remove(i))
 }
 
 // These are pretty nasty. Ideally, we would keep the tokens around, linked from
@@ -784,35 +789,9 @@ fn stream_for_item(item: &Annotatable, parse_sess: &ParseSess) -> TokenStream {
     string_to_stream(text, parse_sess)
 }
 
-fn stream_for_attr_args(attr: &ast::Attribute, parse_sess: &ParseSess) -> TokenStream {
-    use ast::MetaItemKind::*;
-    use print::pp::Breaks;
-    use print::pprust::PrintState;
-
-    let token_string = match attr.value.node {
-        // For `#[foo]`, an empty token
-        Word => return TokenStream::empty(),
-        // For `#[foo(bar, baz)]`, returns `(bar, baz)`
-        List(ref items) => pprust::to_string(|s| {
-            s.popen()?;
-            s.commasep(Breaks::Consistent,
-                       &items[..],
-                       |s, i| s.print_meta_list_item(&i))?;
-            s.pclose()
-        }),
-        // For `#[foo = "bar"]`, returns `= "bar"`
-        NameValue(ref lit) => pprust::to_string(|s| {
-            s.word_space("=")?;
-            s.print_literal(lit)
-        }),
-    };
-
-    string_to_stream(token_string, parse_sess)
-}
-
 fn string_to_stream(text: String, parse_sess: &ParseSess) -> TokenStream {
     let filename = String::from("<macro expansion>");
-    filemap_to_stream(parse_sess, parse_sess.codemap().new_filemap(filename, None, text))
+    filemap_to_stream(parse_sess, parse_sess.codemap().new_filemap(filename, text))
 }
 
 impl<'a, 'b> Folder for InvocationCollector<'a, 'b> {
@@ -926,7 +905,7 @@ impl<'a, 'b> Folder for InvocationCollector<'a, 'b> {
                 // Detect if this is an inline module (`mod m { ... }` as opposed to `mod m;`).
                 // In the non-inline case, `inner` is never the dummy span (c.f. `parse_item_mod`).
                 // Thus, if `inner` is the dummy span, we know the module is inline.
-                let inline_module = item.span.contains(inner) || inner == syntax_pos::DUMMY_SP;
+                let inline_module = item.span.contains(inner) || inner == DUMMY_SP;
 
                 if inline_module {
                     if let Some(path) = attr::first_attr_value_str_by_name(&item.attrs, "path") {
@@ -952,7 +931,7 @@ impl<'a, 'b> Folder for InvocationCollector<'a, 'b> {
                 let result = noop_fold_item(item, self);
                 self.cx.current_expansion.module = orig_module;
                 self.cx.current_expansion.directory_ownership = orig_directory_ownership;
-                return result;
+                result
             }
             // Ensure that test functions are accessible from the test harness.
             ast::ItemKind::Fn(..) if self.cx.ecfg.should_test => {
@@ -1067,7 +1046,7 @@ impl<'feat> ExpansionConfig<'feat> {
         ExpansionConfig {
             crate_name: crate_name,
             features: None,
-            recursion_limit: 64,
+            recursion_limit: 1024,
             trace_mac: false,
             should_test: false,
             single_step: false,
@@ -1078,6 +1057,7 @@ impl<'feat> ExpansionConfig<'feat> {
     feature_tests! {
         fn enable_quotes = quote,
         fn enable_asm = asm,
+        fn enable_global_asm = global_asm,
         fn enable_log_syntax = log_syntax,
         fn enable_concat_idents = concat_idents,
         fn enable_trace_macros = trace_macros,
@@ -1087,23 +1067,21 @@ impl<'feat> ExpansionConfig<'feat> {
     }
 }
 
-// A Marker adds the given mark to the syntax context and
-// sets spans' `expn_id` to the given expn_id (unless it is `None`).
-struct Marker { mark: Mark, expn_id: Option<ExpnId> }
+// A Marker adds the given mark to the syntax context.
+struct Marker(Mark);
 
 impl Folder for Marker {
     fn fold_ident(&mut self, mut ident: Ident) -> Ident {
-        ident.ctxt = ident.ctxt.apply_mark(self.mark);
+        ident.ctxt = ident.ctxt.apply_mark(self.0);
         ident
     }
-    fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
-        noop_fold_mac(mac, self)
-    }
 
     fn new_span(&mut self, mut span: Span) -> Span {
-        if let Some(expn_id) = self.expn_id {
-            span.expn_id = expn_id;
-        }
+        span.ctxt = span.ctxt.apply_mark(self.0);
         span
     }
+
+    fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
+        noop_fold_mac(mac, self)
+    }
 }
diff --git a/src/libsyntax/ext/hygiene.rs b/src/libsyntax/ext/hygiene.rs
deleted file mode 100644
index 57f5ab73d37..00000000000
--- a/src/libsyntax/ext/hygiene.rs
+++ /dev/null
@@ -1,127 +0,0 @@
-// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-//! Machinery for hygienic macros, inspired by the MTWT[1] paper.
-//!
-//! [1] Matthew Flatt, Ryan Culpepper, David Darais, and Robert Bruce Findler.
-//! 2012. *Macros that work together: Compile-time bindings, partial expansion,
-//! and definition contexts*. J. Funct. Program. 22, 2 (March 2012), 181-216.
-//! DOI=10.1017/S0956796812000093 http://dx.doi.org/10.1017/S0956796812000093
-
-use ast::NodeId;
-use std::cell::RefCell;
-use std::collections::HashMap;
-use std::fmt;
-
-/// A SyntaxContext represents a chain of macro expansions (represented by marks).
-#[derive(Clone, Copy, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Default)]
-pub struct SyntaxContext(u32);
-
-#[derive(Copy, Clone)]
-pub struct SyntaxContextData {
-    pub outer_mark: Mark,
-    pub prev_ctxt: SyntaxContext,
-}
-
-/// A mark is a unique id associated with a macro expansion.
-#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug, Default, RustcEncodable, RustcDecodable)]
-pub struct Mark(u32);
-
-impl Mark {
-    pub fn fresh() -> Self {
-        HygieneData::with(|data| {
-            let next_mark = Mark(data.next_mark.0 + 1);
-            ::std::mem::replace(&mut data.next_mark, next_mark)
-        })
-    }
-
-    /// The mark of the theoretical expansion that generates freshly parsed, unexpanded AST.
-    pub fn root() -> Self {
-        Mark(0)
-    }
-
-    pub fn from_placeholder_id(id: NodeId) -> Self {
-        Mark(id.as_u32())
-    }
-
-    pub fn as_placeholder_id(self) -> NodeId {
-        NodeId::from_u32(self.0)
-    }
-
-    pub fn as_u32(self) -> u32 {
-        self.0
-    }
-}
-
-struct HygieneData {
-    syntax_contexts: Vec<SyntaxContextData>,
-    markings: HashMap<(SyntaxContext, Mark), SyntaxContext>,
-    next_mark: Mark,
-}
-
-impl HygieneData {
-    fn new() -> Self {
-        HygieneData {
-            syntax_contexts: vec![SyntaxContextData {
-                outer_mark: Mark::root(),
-                prev_ctxt: SyntaxContext::empty(),
-            }],
-            markings: HashMap::new(),
-            next_mark: Mark(1),
-        }
-    }
-
-    fn with<T, F: FnOnce(&mut HygieneData) -> T>(f: F) -> T {
-        thread_local! {
-            static HYGIENE_DATA: RefCell<HygieneData> = RefCell::new(HygieneData::new());
-        }
-        HYGIENE_DATA.with(|data| f(&mut *data.borrow_mut()))
-    }
-}
-
-pub fn reset_hygiene_data() {
-    HygieneData::with(|data| *data = HygieneData::new())
-}
-
-impl SyntaxContext {
-    pub const fn empty() -> Self {
-        SyntaxContext(0)
-    }
-
-    pub fn data(self) -> SyntaxContextData {
-        HygieneData::with(|data| data.syntax_contexts[self.0 as usize])
-    }
-
-    /// Extend a syntax context with a given mark
-    pub fn apply_mark(self, mark: Mark) -> SyntaxContext {
-        // Applying the same mark twice is a no-op
-        let ctxt_data = self.data();
-        if mark == ctxt_data.outer_mark {
-            return ctxt_data.prev_ctxt;
-        }
-
-        HygieneData::with(|data| {
-            let syntax_contexts = &mut data.syntax_contexts;
-            *data.markings.entry((self, mark)).or_insert_with(|| {
-                syntax_contexts.push(SyntaxContextData {
-                    outer_mark: mark,
-                    prev_ctxt: self,
-                });
-                SyntaxContext(syntax_contexts.len() as u32 - 1)
-            })
-        })
-    }
-}
-
-impl fmt::Debug for SyntaxContext {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "#{}", self.0)
-    }
-}
diff --git a/src/libsyntax/ext/placeholders.rs b/src/libsyntax/ext/placeholders.rs
index f60b1d17a5e..4fb138d506a 100644
--- a/src/libsyntax/ext/placeholders.rs
+++ b/src/libsyntax/ext/placeholders.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use ast;
+use ast::{self, NodeId};
 use codemap::{DUMMY_SP, dummy_spanned};
 use ext::base::ExtCtxt;
 use ext::expand::{Expansion, ExpansionKind};
@@ -88,7 +88,7 @@ impl<'a, 'b> PlaceholderExpander<'a, 'b> {
         let mut expansion = expansion.fold_with(self);
         if let Expansion::Items(mut items) = expansion {
             for derive in derives {
-                match self.remove(derive.as_placeholder_id()) {
+                match self.remove(NodeId::placeholder_from_mark(derive)) {
                     Expansion::Items(derived_items) => items.extend(derived_items),
                     _ => unreachable!(),
                 }
@@ -106,8 +106,8 @@ impl<'a, 'b> PlaceholderExpander<'a, 'b> {
 impl<'a, 'b> Folder for PlaceholderExpander<'a, 'b> {
     fn fold_item(&mut self, item: P<ast::Item>) -> SmallVector<P<ast::Item>> {
         match item.node {
-            ast::ItemKind::Mac(ref mac) if !mac.node.path.segments.is_empty() => {}
             ast::ItemKind::Mac(_) => return self.remove(item.id).make_items(),
+            ast::ItemKind::MacroDef(_) => return SmallVector::one(item),
             _ => {}
         }
 
@@ -178,17 +178,9 @@ impl<'a, 'b> Folder for PlaceholderExpander<'a, 'b> {
             block.stmts = block.stmts.move_flat_map(|mut stmt| {
                 remaining_stmts -= 1;
 
-                match stmt.node {
-                    // Avoid wasting a node id on a trailing expression statement,
-                    // which shares a HIR node with the expression itself.
-                    ast::StmtKind::Expr(ref expr) if remaining_stmts == 0 => stmt.id = expr.id,
-
-                    _ if self.monotonic => {
-                        assert_eq!(stmt.id, ast::DUMMY_NODE_ID);
-                        stmt.id = self.cx.resolver.next_node_id();
-                    }
-
-                    _ => {}
+                if self.monotonic {
+                    assert_eq!(stmt.id, ast::DUMMY_NODE_ID);
+                    stmt.id = self.cx.resolver.next_node_id();
                 }
 
                 Some(stmt)
diff --git a/src/libsyntax/ext/quote.rs b/src/libsyntax/ext/quote.rs
index 69ff726e719..f8fac847a05 100644
--- a/src/libsyntax/ext/quote.rs
+++ b/src/libsyntax/ext/quote.rs
@@ -23,7 +23,7 @@ use tokenstream::{TokenStream, TokenTree};
 ///
 /// This is registered as a set of expression syntax extension called quote!
 /// that lifts its argument token-tree to an AST representing the
-/// construction of the same token tree, with token::SubstNt interpreted
+/// construction of the same token tree, with `token::SubstNt` interpreted
 /// as antiquotes (splices).
 
 pub mod rt {
@@ -220,16 +220,24 @@ pub mod rt {
     }
 
     impl ToTokens for ast::Attribute {
-        fn to_tokens(&self, cx: &ExtCtxt) -> Vec<TokenTree> {
+        fn to_tokens(&self, _cx: &ExtCtxt) -> Vec<TokenTree> {
             let mut r = vec![];
             // FIXME: The spans could be better
             r.push(TokenTree::Token(self.span, token::Pound));
             if self.style == ast::AttrStyle::Inner {
                 r.push(TokenTree::Token(self.span, token::Not));
             }
+            let mut inner = Vec::new();
+            for (i, segment) in self.path.segments.iter().enumerate() {
+                if i > 0 {
+                    inner.push(TokenTree::Token(self.span, token::Colon).into());
+                }
+                inner.push(TokenTree::Token(self.span, token::Ident(segment.identifier)).into());
+            }
+            inner.push(self.tokens.clone());
+
             r.push(TokenTree::Delimited(self.span, tokenstream::Delimited {
-                delim: token::Bracket,
-                tts: self.value.to_tokens(cx).into_iter().collect::<TokenStream>().into(),
+                delim: token::Bracket, tts: TokenStream::concat(inner).into()
             }));
             r
         }
@@ -381,7 +389,7 @@ pub fn unflatten(tts: Vec<TokenTree>) -> Vec<TokenTree> {
                 result = results.pop().unwrap();
                 result.push(tree);
             }
-            tree @ _ => result.push(tree),
+            tree => result.push(tree),
         }
     }
     result
@@ -406,7 +414,7 @@ pub fn parse_arm_panic(parser: &mut Parser) -> Arm {
 }
 
 pub fn parse_ty_panic(parser: &mut Parser) -> P<Ty> {
-    panictry!(parser.parse_ty_no_plus())
+    panictry!(parser.parse_ty())
 }
 
 pub fn parse_stmt_panic(parser: &mut Parser) -> Option<Stmt> {
@@ -604,8 +612,11 @@ fn mk_delim(cx: &ExtCtxt, sp: Span, delim: token::DelimToken) -> P<ast::Expr> {
 #[allow(non_upper_case_globals)]
 fn expr_mk_token(cx: &ExtCtxt, sp: Span, tok: &token::Token) -> P<ast::Expr> {
     macro_rules! mk_lit {
-        ($name: expr, $suffix: expr, $($args: expr),*) => {{
-            let inner = cx.expr_call(sp, mk_token_path(cx, sp, $name), vec![$($args),*]);
+        ($name: expr, $suffix: expr, $content: expr $(, $count: expr)*) => {{
+            let name = mk_name(cx, sp, ast::Ident::with_empty_ctxt($content));
+            let inner = cx.expr_call(sp, mk_token_path(cx, sp, $name), vec![
+                name $(, cx.expr_usize(sp, $count))*
+            ]);
             let suffix = match $suffix {
                 Some(name) => cx.expr_some(sp, mk_name(cx, sp, ast::Ident::with_empty_ctxt(name))),
                 None => cx.expr_none(sp)
@@ -613,7 +624,8 @@ fn expr_mk_token(cx: &ExtCtxt, sp: Span, tok: &token::Token) -> P<ast::Expr> {
             cx.expr_call(sp, mk_token_path(cx, sp, "Literal"), vec![inner, suffix])
         }}
     }
-    match *tok {
+
+    let name = match *tok {
         token::BinOp(binop) => {
             return cx.expr_call(sp, mk_token_path(cx, sp, "BinOp"), vec![mk_binop(cx, sp, binop)]);
         }
@@ -631,34 +643,14 @@ fn expr_mk_token(cx: &ExtCtxt, sp: Span, tok: &token::Token) -> P<ast::Expr> {
                                 vec![mk_delim(cx, sp, delim)]);
         }
 
-        token::Literal(token::Byte(i), suf) => {
-            let e_byte = mk_name(cx, sp, ast::Ident::with_empty_ctxt(i));
-            return mk_lit!("Byte", suf, e_byte);
-        }
-
-        token::Literal(token::Char(i), suf) => {
-            let e_char = mk_name(cx, sp, ast::Ident::with_empty_ctxt(i));
-            return mk_lit!("Char", suf, e_char);
-        }
-
-        token::Literal(token::Integer(i), suf) => {
-            let e_int = mk_name(cx, sp, ast::Ident::with_empty_ctxt(i));
-            return mk_lit!("Integer", suf, e_int);
-        }
-
-        token::Literal(token::Float(fident), suf) => {
-            let e_fident = mk_name(cx, sp, ast::Ident::with_empty_ctxt(fident));
-            return mk_lit!("Float", suf, e_fident);
-        }
-
-        token::Literal(token::Str_(ident), suf) => {
-            return mk_lit!("Str_", suf, mk_name(cx, sp, ast::Ident::with_empty_ctxt(ident)))
-        }
-
-        token::Literal(token::StrRaw(ident, n), suf) => {
-            return mk_lit!("StrRaw", suf, mk_name(cx, sp, ast::Ident::with_empty_ctxt(ident)),
-                           cx.expr_usize(sp, n))
-        }
+        token::Literal(token::Byte(i), suf) => return mk_lit!("Byte", suf, i),
+        token::Literal(token::Char(i), suf) => return mk_lit!("Char", suf, i),
+        token::Literal(token::Integer(i), suf) => return mk_lit!("Integer", suf, i),
+        token::Literal(token::Float(i), suf) => return mk_lit!("Float", suf, i),
+        token::Literal(token::Str_(i), suf) => return mk_lit!("Str_", suf, i),
+        token::Literal(token::StrRaw(i, n), suf) => return mk_lit!("StrRaw", suf, i, n),
+        token::Literal(token::ByteStr(i), suf) => return mk_lit!("ByteStr", suf, i),
+        token::Literal(token::ByteStrRaw(i, n), suf) => return mk_lit!("ByteStrRaw", suf, i, n),
 
         token::Ident(ident) => {
             return cx.expr_call(sp,
@@ -680,10 +672,6 @@ fn expr_mk_token(cx: &ExtCtxt, sp: Span, tok: &token::Token) -> P<ast::Expr> {
 
         token::Interpolated(_) => panic!("quote! with interpolated token"),
 
-        _ => ()
-    }
-
-    let name = match *tok {
         token::Eq           => "Eq",
         token::Lt           => "Lt",
         token::Le           => "Le",
@@ -698,6 +686,7 @@ fn expr_mk_token(cx: &ExtCtxt, sp: Span, tok: &token::Token) -> P<ast::Expr> {
         token::At           => "At",
         token::Dot          => "Dot",
         token::DotDot       => "DotDot",
+        token::DotDotDot    => "DotDotDot",
         token::Comma        => "Comma",
         token::Semi         => "Semi",
         token::Colon        => "Colon",
@@ -710,7 +699,10 @@ fn expr_mk_token(cx: &ExtCtxt, sp: Span, tok: &token::Token) -> P<ast::Expr> {
         token::Question     => "Question",
         token::Underscore   => "Underscore",
         token::Eof          => "Eof",
-        _                   => panic!("unhandled token in quote!"),
+
+        token::Whitespace | token::SubstNt(_) | token::Comment | token::Shebang(_) => {
+            panic!("unhandled token in quote!");
+        }
     };
     mk_token_path(cx, sp, name)
 }
diff --git a/src/libsyntax/ext/source_util.rs b/src/libsyntax/ext/source_util.rs
index 39b92c7d007..3cdd3a4b2c3 100644
--- a/src/libsyntax/ext/source_util.rs
+++ b/src/libsyntax/ext/source_util.rs
@@ -35,7 +35,7 @@ pub fn expand_line(cx: &mut ExtCtxt, sp: Span, tts: &[tokenstream::TokenTree])
                    -> Box<base::MacResult+'static> {
     base::check_zero_tts(cx, sp, tts, "line!");
 
-    let topmost = cx.expansion_cause();
+    let topmost = cx.expansion_cause().unwrap_or(sp);
     let loc = cx.codemap().lookup_char_pos(topmost.lo);
 
     base::MacEager::expr(cx.expr_u32(topmost, loc.line as u32))
@@ -46,7 +46,7 @@ pub fn expand_column(cx: &mut ExtCtxt, sp: Span, tts: &[tokenstream::TokenTree])
                   -> Box<base::MacResult+'static> {
     base::check_zero_tts(cx, sp, tts, "column!");
 
-    let topmost = cx.expansion_cause();
+    let topmost = cx.expansion_cause().unwrap_or(sp);
     let loc = cx.codemap().lookup_char_pos(topmost.lo);
 
     base::MacEager::expr(cx.expr_u32(topmost, loc.col.to_usize() as u32))
@@ -59,7 +59,7 @@ pub fn expand_file(cx: &mut ExtCtxt, sp: Span, tts: &[tokenstream::TokenTree])
                    -> Box<base::MacResult+'static> {
     base::check_zero_tts(cx, sp, tts, "file!");
 
-    let topmost = cx.expansion_cause();
+    let topmost = cx.expansion_cause().unwrap_or(sp);
     let loc = cx.codemap().lookup_char_pos(topmost.lo);
     base::MacEager::expr(cx.expr_str(topmost, Symbol::intern(&loc.file.name)))
 }
@@ -142,7 +142,7 @@ pub fn expand_include_str(cx: &mut ExtCtxt, sp: Span, tts: &[tokenstream::TokenT
             // Add this input file to the code map to make it available as
             // dependency information
             let filename = format!("{}", file.display());
-            cx.codemap().new_filemap_and_lines(&filename, None, &src);
+            cx.codemap().new_filemap_and_lines(&filename, &src);
 
             base::MacEager::expr(cx.expr_str(sp, Symbol::intern(&src)))
         }
@@ -150,7 +150,7 @@ pub fn expand_include_str(cx: &mut ExtCtxt, sp: Span, tts: &[tokenstream::TokenT
             cx.span_err(sp,
                         &format!("{} wasn't a utf-8 file",
                                 file.display()));
-            return DummyResult::expr(sp);
+            DummyResult::expr(sp)
         }
     }
 }
@@ -167,13 +167,13 @@ pub fn expand_include_bytes(cx: &mut ExtCtxt, sp: Span, tts: &[tokenstream::Toke
         Err(e) => {
             cx.span_err(sp,
                         &format!("couldn't read {}: {}", file.display(), e));
-            return DummyResult::expr(sp);
+            DummyResult::expr(sp)
         }
         Ok(..) => {
             // Add this input file to the code map to make it available as
             // dependency information, but don't enter it's contents
             let filename = format!("{}", file.display());
-            cx.codemap().new_filemap_and_lines(&filename, None, "");
+            cx.codemap().new_filemap_and_lines(&filename, "");
 
             base::MacEager::expr(cx.expr_lit(sp, ast::LitKind::ByteStr(Rc::new(bytes))))
         }
@@ -185,7 +185,7 @@ pub fn expand_include_bytes(cx: &mut ExtCtxt, sp: Span, tts: &[tokenstream::Toke
 fn res_rel_file(cx: &mut ExtCtxt, sp: syntax_pos::Span, arg: &Path) -> PathBuf {
     // NB: relative paths are resolved relative to the compilation unit
     if !arg.is_absolute() {
-        let callsite = cx.codemap().source_callsite(sp);
+        let callsite = sp.source_callsite();
         let mut cu = PathBuf::from(&cx.codemap().span_to_filename(callsite));
         cu.pop();
         cu.push(arg);
diff --git a/src/libsyntax/ext/tt/macro_parser.rs b/src/libsyntax/ext/tt/macro_parser.rs
index b9cb3d82d4f..0b6a2eb536a 100644
--- a/src/libsyntax/ext/tt/macro_parser.rs
+++ b/src/libsyntax/ext/tt/macro_parser.rs
@@ -36,50 +36,54 @@
 //! repetitions indicated by Kleene stars. It only advances or calls out to the
 //! real Rust parser when no `cur_eis` items remain
 //!
-//! Example: Start parsing `a a a a b` against [· a $( a )* a b].
+//! Example:
 //!
-//! Remaining input: `a a a a b`
+//! ```text, ignore
+//! Start parsing a a a a b against [· a $( a )* a b].
+//!
+//! Remaining input: a a a a b
 //! next_eis: [· a $( a )* a b]
 //!
-//! - - - Advance over an `a`. - - -
+//! - - - Advance over an a. - - -
 //!
-//! Remaining input: `a a a b`
+//! Remaining input: a a a b
 //! cur: [a · $( a )* a b]
 //! Descend/Skip (first item).
 //! next: [a $( · a )* a b]  [a $( a )* · a b].
 //!
-//! - - - Advance over an `a`. - - -
+//! - - - Advance over an a. - - -
 //!
-//! Remaining input: `a a b`
+//! Remaining input: a a b
 //! cur: [a $( a · )* a b]  next: [a $( a )* a · b]
 //! Finish/Repeat (first item)
 //! next: [a $( a )* · a b]  [a $( · a )* a b]  [a $( a )* a · b]
 //!
-//! - - - Advance over an `a`. - - - (this looks exactly like the last step)
+//! - - - Advance over an a. - - - (this looks exactly like the last step)
 //!
-//! Remaining input: `a b`
+//! Remaining input: a b
 //! cur: [a $( a · )* a b]  next: [a $( a )* a · b]
 //! Finish/Repeat (first item)
 //! next: [a $( a )* · a b]  [a $( · a )* a b]  [a $( a )* a · b]
 //!
-//! - - - Advance over an `a`. - - - (this looks exactly like the last step)
+//! - - - Advance over an a. - - - (this looks exactly like the last step)
 //!
-//! Remaining input: `b`
+//! Remaining input: b
 //! cur: [a $( a · )* a b]  next: [a $( a )* a · b]
 //! Finish/Repeat (first item)
 //! next: [a $( a )* · a b]  [a $( · a )* a b]
 //!
-//! - - - Advance over a `b`. - - -
+//! - - - Advance over a b. - - -
 //!
-//! Remaining input: ``
+//! Remaining input: ''
 //! eof: [a $( a )* a b ·]
+//! ```
 
 pub use self::NamedMatch::*;
 pub use self::ParseResult::*;
 use self::TokenTreeOrTokenTreeVec::*;
 
 use ast::Ident;
-use syntax_pos::{self, BytePos, mk_sp, Span};
+use syntax_pos::{self, BytePos, Span};
 use codemap::Spanned;
 use errors::FatalError;
 use ext::tt::quoted::{self, TokenTree};
@@ -178,20 +182,20 @@ fn initial_matcher_pos(ms: Vec<TokenTree>, lo: BytePos) -> Box<MatcherPos> {
     })
 }
 
-/// NamedMatch is a pattern-match result for a single token::MATCH_NONTERMINAL:
+/// `NamedMatch` is a pattern-match result for a single `token::MATCH_NONTERMINAL`:
 /// so it is associated with a single ident in a parse, and all
-/// `MatchedNonterminal`s in the NamedMatch have the same nonterminal type
-/// (expr, item, etc). Each leaf in a single NamedMatch corresponds to a
-/// single token::MATCH_NONTERMINAL in the TokenTree that produced it.
+/// `MatchedNonterminal`s in the `NamedMatch` have the same nonterminal type
+/// (expr, item, etc). Each leaf in a single `NamedMatch` corresponds to a
+/// single `token::MATCH_NONTERMINAL` in the `TokenTree` that produced it.
 ///
-/// The in-memory structure of a particular NamedMatch represents the match
+/// The in-memory structure of a particular `NamedMatch` represents the match
 /// that occurred when a particular subset of a matcher was applied to a
 /// particular token tree.
 ///
-/// The width of each MatchedSeq in the NamedMatch, and the identity of the
-/// `MatchedNonterminal`s, will depend on the token tree it was applied to:
-/// each MatchedSeq corresponds to a single TTSeq in the originating
-/// token tree. The depth of the NamedMatch structure will therefore depend
+/// The width of each `MatchedSeq` in the `NamedMatch`, and the identity of
+/// the `MatchedNonterminal`s, will depend on the token tree it was applied
+/// to: each `MatchedSeq` corresponds to a single `TTSeq` in the originating
+/// token tree. The depth of the `NamedMatch` structure will therefore depend
 /// only on the nesting depth of `ast::TTSeq`s in the originating
 /// token tree it was derived from.
 
@@ -267,11 +271,12 @@ pub fn parse_failure_msg(tok: Token) -> String {
 
 /// Perform a token equality check, ignoring syntax context (that is, an unhygienic comparison)
 fn token_name_eq(t1 : &Token, t2 : &Token) -> bool {
-    match (t1,t2) {
-        (&token::Ident(id1),&token::Ident(id2))
-        | (&token::Lifetime(id1),&token::Lifetime(id2)) =>
-            id1.name == id2.name,
-        _ => *t1 == *t2
+    if let (Some(id1), Some(id2)) = (t1.ident(), t2.ident()) {
+        id1.name == id2.name
+    } else if let (&token::Lifetime(id1), &token::Lifetime(id2)) = (t1, t2) {
+        id1.name == id2.name
+    } else {
+        *t1 == *t2
     }
 }
 
@@ -285,7 +290,7 @@ fn inner_parse_loop(sess: &ParseSess,
                     eof_eis: &mut SmallVector<Box<MatcherPos>>,
                     bb_eis: &mut SmallVector<Box<MatcherPos>>,
                     token: &Token,
-                    span: &syntax_pos::Span)
+                    span: syntax_pos::Span)
                     -> ParseResult<()> {
     while let Some(mut ei) = cur_eis.pop() {
         // When unzipped trees end, remove them
@@ -323,8 +328,7 @@ fn inner_parse_loop(sess: &ParseSess,
                     for idx in ei.match_lo..ei.match_hi {
                         let sub = ei.matches[idx].clone();
                         new_pos.matches[idx]
-                            .push(Rc::new(MatchedSeq(sub, mk_sp(ei.sp_lo,
-                                                                span.hi))));
+                            .push(Rc::new(MatchedSeq(sub, Span { lo: ei.sp_lo, ..span })));
                     }
 
                     new_pos.match_cur = ei.match_hi;
@@ -335,7 +339,7 @@ fn inner_parse_loop(sess: &ParseSess,
                 // Check if we need a separator
                 if idx == len && ei.sep.is_some() {
                     // We have a separator, and it is the current token.
-                    if ei.sep.as_ref().map(|ref sep| token_name_eq(&token, sep)).unwrap_or(false) {
+                    if ei.sep.as_ref().map(|sep| token_name_eq(token, sep)).unwrap_or(false) {
                         ei.idx += 1;
                         next_eis.push(ei);
                     }
@@ -402,7 +406,7 @@ fn inner_parse_loop(sess: &ParseSess,
                     cur_eis.push(ei);
                 }
                 TokenTree::Token(_, ref t) => {
-                    if token_name_eq(t, &token) {
+                    if token_name_eq(t, token) {
                         ei.idx += 1;
                         next_eis.push(ei);
                     }
@@ -414,9 +418,13 @@ fn inner_parse_loop(sess: &ParseSess,
     Success(())
 }
 
-pub fn parse(sess: &ParseSess, tts: TokenStream, ms: &[TokenTree], directory: Option<Directory>)
+pub fn parse(sess: &ParseSess,
+             tts: TokenStream,
+             ms: &[TokenTree],
+             directory: Option<Directory>,
+             recurse_into_modules: bool)
              -> NamedParseResult {
-    let mut parser = Parser::new(sess, tts, directory, true);
+    let mut parser = Parser::new(sess, tts, directory, recurse_into_modules, true);
     let mut cur_eis = SmallVector::one(initial_matcher_pos(ms.to_owned(), parser.span.lo));
     let mut next_eis = Vec::new(); // or proceed normally
 
@@ -426,7 +434,7 @@ pub fn parse(sess: &ParseSess, tts: TokenStream, ms: &[TokenTree], directory: Op
         assert!(next_eis.is_empty());
 
         match inner_parse_loop(sess, &mut cur_eis, &mut next_eis, &mut eof_eis, &mut bb_eis,
-                               &parser.token, &parser.span) {
+                               &parser.token, parser.span) {
             Success(_) => {},
             Failure(sp, tok) => return Failure(sp, tok),
             Error(sp, msg) => return Error(sp, msg),
@@ -486,14 +494,11 @@ pub fn parse(sess: &ParseSess, tts: TokenStream, ms: &[TokenTree], directory: Op
 }
 
 fn parse_nt<'a>(p: &mut Parser<'a>, sp: Span, name: &str) -> Nonterminal {
-    match name {
-        "tt" => {
-            return token::NtTT(panictry!(p.parse_token_tree()));
-        }
-        _ => {}
+    if name == "tt" {
+        return token::NtTT(p.parse_token_tree());
     }
     // check at the beginning and the parser checks after each bump
-    p.check_unknown_macro_variable();
+    p.process_potential_macro_variable();
     match name {
         "item" => match panictry!(p.parse_item()) {
             Some(i) => token::NtItem(i),
@@ -512,7 +517,7 @@ fn parse_nt<'a>(p: &mut Parser<'a>, sp: Span, name: &str) -> Nonterminal {
         },
         "pat" => token::NtPat(panictry!(p.parse_pat())),
         "expr" => token::NtExpr(panictry!(p.parse_expr())),
-        "ty" => token::NtTy(panictry!(p.parse_ty_no_plus())),
+        "ty" => token::NtTy(panictry!(p.parse_ty())),
         // this could be handled like a token, since it is one
         "ident" => match p.token {
             token::Ident(sn) => {
@@ -530,6 +535,7 @@ fn parse_nt<'a>(p: &mut Parser<'a>, sp: Span, name: &str) -> Nonterminal {
             token::NtPath(panictry!(p.parse_path(PathStyle::Type)))
         },
         "meta" => token::NtMeta(panictry!(p.parse_meta_item())),
+        "vis" => token::NtVis(panictry!(p.parse_visibility(true))),
         // this is not supposed to happen, since it has been checked
         // when compiling the macro.
         _ => p.span_bug(sp, "invalid fragment specifier")
diff --git a/src/libsyntax/ext/tt/macro_rules.rs b/src/libsyntax/ext/tt/macro_rules.rs
index 7aa1230f9ae..a9252d0818e 100644
--- a/src/libsyntax/ext/tt/macro_rules.rs
+++ b/src/libsyntax/ext/tt/macro_rules.rs
@@ -18,6 +18,7 @@ use ext::tt::macro_parser::{MatchedSeq, MatchedNonterminal};
 use ext::tt::macro_parser::{parse, parse_failure_msg};
 use ext::tt::quoted;
 use ext::tt::transcribe::transcribe;
+use feature_gate::{self, emit_feature_err, Features, GateIssue};
 use parse::{Directory, ParseSess};
 use parse::parser::Parser;
 use parse::token::{self, NtTT};
@@ -25,8 +26,9 @@ use parse::token::Token::*;
 use symbol::Symbol;
 use tokenstream::{TokenStream, TokenTree};
 
-use std::collections::{HashMap};
-use std::collections::hash_map::{Entry};
+use std::cell::RefCell;
+use std::collections::HashMap;
+use std::collections::hash_map::Entry;
 use std::rc::Rc;
 
 pub struct ParserAnyMacro<'a> {
@@ -51,7 +53,8 @@ impl<'a> ParserAnyMacro<'a> {
         }
 
         // Make sure we don't have any tokens left to parse so we don't silently drop anything.
-        parser.ensure_complete_parse(macro_ident.name, kind.name(), site_span);
+        let path = ast::Path::from_ident(site_span, macro_ident);
+        parser.ensure_complete_parse(&path, kind.name(), site_span);
         expansion
     }
 }
@@ -82,7 +85,7 @@ impl TTMacroExpander for MacroRulesMacroExpander {
 }
 
 /// Given `lhses` and `rhses`, this is the new macro we create
-fn generic_extension<'cx>(cx: &'cx ExtCtxt,
+fn generic_extension<'cx>(cx: &'cx mut ExtCtxt,
                           sp: Span,
                           name: ast::Ident,
                           arg: TokenStream,
@@ -90,7 +93,9 @@ fn generic_extension<'cx>(cx: &'cx ExtCtxt,
                           rhses: &[quoted::TokenTree])
                           -> Box<MacResult+'cx> {
     if cx.trace_macros() {
-        println!("{}! {{ {} }}", name, arg);
+        let sp = sp.macro_backtrace().last().map(|trace| trace.call_site).unwrap_or(sp);
+        let mut values: &mut Vec<String> = cx.expansions.entry(sp).or_insert_with(Vec::new);
+        values.push(format!("expands to `{}! {{ {} }}`", name, arg));
     }
 
     // Which arm's failure should we report? (the one furthest along)
@@ -116,11 +121,11 @@ fn generic_extension<'cx>(cx: &'cx ExtCtxt,
                     path: cx.current_expansion.module.directory.clone(),
                     ownership: cx.current_expansion.directory_ownership,
                 };
-                let mut p = Parser::new(cx.parse_sess(), tts, Some(directory), false);
+                let mut p = Parser::new(cx.parse_sess(), tts, Some(directory), true, false);
                 p.root_module_name = cx.current_expansion.module.mod_path.last()
-                    .map(|id| (*id.name.as_str()).to_owned());
+                    .map(|id| id.name.as_str().to_string());
 
-                p.check_unknown_macro_variable();
+                p.process_potential_macro_variable();
                 // Let the context choose how to interpret the result.
                 // Weird, but useful for X-macros.
                 return Box::new(ParserAnyMacro {
@@ -153,10 +158,16 @@ fn generic_extension<'cx>(cx: &'cx ExtCtxt,
 // Holy self-referential!
 
 /// Converts a `macro_rules!` invocation into a syntax extension.
-pub fn compile(sess: &ParseSess, def: &ast::Item) -> SyntaxExtension {
+pub fn compile(sess: &ParseSess, features: &RefCell<Features>, def: &ast::Item) -> SyntaxExtension {
     let lhs_nm = ast::Ident::with_empty_ctxt(Symbol::gensym("lhs"));
     let rhs_nm = ast::Ident::with_empty_ctxt(Symbol::gensym("rhs"));
 
+    // Parse the macro_rules! invocation
+    let body = match def.node {
+        ast::ItemKind::MacroDef(ref body) => body,
+        _ => unreachable!(),
+    };
+
     // The pattern that macro_rules matches.
     // The grammar for macro_rules! is:
     // $( $lhs:tt => $rhs:tt );+
@@ -169,7 +180,7 @@ pub fn compile(sess: &ParseSess, def: &ast::Item) -> SyntaxExtension {
                 quoted::TokenTree::Token(DUMMY_SP, token::FatArrow),
                 quoted::TokenTree::MetaVarDecl(DUMMY_SP, rhs_nm, ast::Ident::from_str("tt")),
             ],
-            separator: Some(token::Semi),
+            separator: Some(if body.legacy { token::Semi } else { token::Comma }),
             op: quoted::KleeneOp::OneOrMore,
             num_captures: 2,
         })),
@@ -182,12 +193,7 @@ pub fn compile(sess: &ParseSess, def: &ast::Item) -> SyntaxExtension {
         })),
     ];
 
-    // Parse the macro_rules! invocation
-    let body = match def.node {
-        ast::ItemKind::MacroDef(ref body) => body.clone().into(),
-        _ => unreachable!(),
-    };
-    let argument_map = match parse(sess, body, &argument_gram, None) {
+    let argument_map = match parse(sess, body.stream(), &argument_gram, None, true) {
         Success(m) => m,
         Failure(sp, tok) => {
             let s = parse_failure_msg(tok);
@@ -201,13 +207,13 @@ pub fn compile(sess: &ParseSess, def: &ast::Item) -> SyntaxExtension {
     let mut valid = true;
 
     // Extract the arguments:
-    let lhses = match **argument_map.get(&lhs_nm).unwrap() {
+    let lhses = match *argument_map[&lhs_nm] {
         MatchedSeq(ref s, _) => {
             s.iter().map(|m| {
                 if let MatchedNonterminal(ref nt) = **m {
                     if let NtTT(ref tt) = **nt {
                         let tt = quoted::parse(tt.clone().into(), true, sess).pop().unwrap();
-                        valid &= check_lhs_nt_follows(sess, &tt);
+                        valid &= check_lhs_nt_follows(sess, features, &tt);
                         return tt;
                     }
                 }
@@ -217,7 +223,7 @@ pub fn compile(sess: &ParseSess, def: &ast::Item) -> SyntaxExtension {
         _ => sess.span_diagnostic.span_bug(def.span, "wrong-structured lhs")
     };
 
-    let rhses = match **argument_map.get(&rhs_nm).unwrap() {
+    let rhses = match *argument_map[&rhs_nm] {
         MatchedSeq(ref s, _) => {
             s.iter().map(|m| {
                 if let MatchedNonterminal(ref nt) = **m {
@@ -247,19 +253,25 @@ pub fn compile(sess: &ParseSess, def: &ast::Item) -> SyntaxExtension {
         valid: valid,
     });
 
-    NormalTT(exp, Some(def.span), attr::contains_name(&def.attrs, "allow_internal_unstable"))
+    if body.legacy {
+        let allow_internal_unstable = attr::contains_name(&def.attrs, "allow_internal_unstable");
+        NormalTT(exp, Some((def.id, def.span)), allow_internal_unstable)
+    } else {
+        SyntaxExtension::DeclMacro(exp, Some(def.span))
+    }
 }
 
-fn check_lhs_nt_follows(sess: &ParseSess, lhs: &quoted::TokenTree) -> bool {
+fn check_lhs_nt_follows(sess: &ParseSess,
+                        features: &RefCell<Features>,
+                        lhs: &quoted::TokenTree) -> bool {
     // lhs is going to be like TokenTree::Delimited(...), where the
     // entire lhs is those tts. Or, it can be a "bare sequence", not wrapped in parens.
-    match lhs {
-        &quoted::TokenTree::Delimited(_, ref tts) => check_matcher(sess, &tts.tts),
-        _ => {
-            let msg = "invalid macro matcher; matchers must be contained in balanced delimiters";
-            sess.span_diagnostic.span_err(lhs.span(), msg);
-            false
-        }
+    if let quoted::TokenTree::Delimited(_, ref tts) = *lhs {
+        check_matcher(sess, features, &tts.tts)
+    } else {
+        let msg = "invalid macro matcher; matchers must be contained in balanced delimiters";
+        sess.span_diagnostic.span_err(lhs.span(), msg);
+        false
     }
     // we don't abort on errors on rejection, the driver will do that for us
     // after parsing/expansion. we can report every error in every macro this way.
@@ -276,17 +288,15 @@ fn check_lhs_no_empty_seq(sess: &ParseSess, tts: &[quoted::TokenTree]) -> bool {
                 return false;
             },
             TokenTree::Sequence(span, ref seq) => {
-                if seq.separator.is_none() {
-                    if seq.tts.iter().all(|seq_tt| {
-                        match *seq_tt {
-                            TokenTree::Sequence(_, ref sub_seq) =>
-                                sub_seq.op == quoted::KleeneOp::ZeroOrMore,
-                            _ => false,
-                        }
-                    }) {
-                        sess.span_diagnostic.span_err(span, "repetition matches empty token tree");
-                        return false;
+                if seq.separator.is_none() && seq.tts.iter().all(|seq_tt| {
+                    match *seq_tt {
+                        TokenTree::Sequence(_, ref sub_seq) =>
+                            sub_seq.op == quoted::KleeneOp::ZeroOrMore,
+                        _ => false,
                     }
+                }) {
+                    sess.span_diagnostic.span_err(span, "repetition matches empty token tree");
+                    return false;
                 }
                 if !check_lhs_no_empty_seq(sess, &seq.tts) {
                     return false;
@@ -306,11 +316,13 @@ fn check_rhs(sess: &ParseSess, rhs: &quoted::TokenTree) -> bool {
     false
 }
 
-fn check_matcher(sess: &ParseSess, matcher: &[quoted::TokenTree]) -> bool {
+fn check_matcher(sess: &ParseSess,
+                 features: &RefCell<Features>,
+                 matcher: &[quoted::TokenTree]) -> bool {
     let first_sets = FirstSets::new(matcher);
     let empty_suffix = TokenSet::empty();
     let err = sess.span_diagnostic.err_count();
-    check_matcher_core(sess, &first_sets, matcher, &empty_suffix);
+    check_matcher_core(sess, features, &first_sets, matcher, &empty_suffix);
     err == sess.span_diagnostic.err_count()
 }
 
@@ -398,7 +410,7 @@ impl FirstSets {
                 }
             }
 
-            return first;
+            first
         }
     }
 
@@ -460,7 +472,7 @@ impl FirstSets {
         // we only exit the loop if `tts` was empty or if every
         // element of `tts` matches the empty sequence.
         assert!(first.maybe_empty);
-        return first;
+        first
     }
 }
 
@@ -552,6 +564,7 @@ impl TokenSet {
 // Requires that `first_sets` is pre-computed for `matcher`;
 // see `FirstSets::new`.
 fn check_matcher_core(sess: &ParseSess,
+                      features: &RefCell<Features>,
                       first_sets: &FirstSets,
                       matcher: &[quoted::TokenTree],
                       follow: &TokenSet) -> TokenSet {
@@ -569,7 +582,7 @@ fn check_matcher_core(sess: &ParseSess,
         let build_suffix_first = || {
             let mut s = first_sets.first(suffix);
             if s.maybe_empty { s.add_all(follow); }
-            return s;
+            s
         };
 
         // (we build `suffix_first` on demand below; you can tell
@@ -582,12 +595,11 @@ fn check_matcher_core(sess: &ParseSess,
         match *token {
             TokenTree::Token(..) | TokenTree::MetaVarDecl(..) => {
                 let can_be_followed_by_any;
-                if let Err(bad_frag) = has_legal_fragment_specifier(token) {
+                if let Err(bad_frag) = has_legal_fragment_specifier(sess, features, token) {
                     let msg = format!("invalid fragment specifier `{}`", bad_frag);
                     sess.span_diagnostic.struct_span_err(token.span(), &msg)
-                        .help("valid fragment specifiers are `ident`, `block`, \
-                               `stmt`, `expr`, `pat`, `ty`, `path`, `meta`, `tt` \
-                               and `item`")
+                        .help("valid fragment specifiers are `ident`, `block`, `stmt`, `expr`, \
+                              `pat`, `ty`, `path`, `meta`, `tt`, `item` and `vis`")
                         .emit();
                     // (This eliminates false positives and duplicates
                     // from error messages.)
@@ -609,7 +621,7 @@ fn check_matcher_core(sess: &ParseSess,
             }
             TokenTree::Delimited(span, ref d) => {
                 let my_suffix = TokenSet::singleton(d.close_tt(span));
-                check_matcher_core(sess, first_sets, &d.tts, &my_suffix);
+                check_matcher_core(sess, features, first_sets, &d.tts, &my_suffix);
                 // don't track non NT tokens
                 last.replace_with_irrelevant();
 
@@ -641,7 +653,7 @@ fn check_matcher_core(sess: &ParseSess,
                 // At this point, `suffix_first` is built, and
                 // `my_suffix` is some TokenSet that we can use
                 // for checking the interior of `seq_rep`.
-                let next = check_matcher_core(sess, first_sets, &seq_rep.tts, my_suffix);
+                let next = check_matcher_core(sess, features, first_sets, &seq_rep.tts, my_suffix);
                 if next.maybe_empty {
                     last.add_all(&next);
                 } else {
@@ -789,30 +801,61 @@ fn is_in_follow(tok: &quoted::TokenTree, frag: &str) -> Result<bool, (String, &'
                 // harmless
                 Ok(true)
             },
+            "vis" => {
+                // Explicitly disallow `priv`, on the off chance it comes back.
+                match *tok {
+                    TokenTree::Token(_, ref tok) => match *tok {
+                        Comma => Ok(true),
+                        Ident(i) if i.name != "priv" => Ok(true),
+                        ref tok => Ok(tok.can_begin_type())
+                    },
+                    TokenTree::MetaVarDecl(_, _, frag) if frag.name == "ident"
+                                                       || frag.name == "ty"
+                                                       || frag.name == "path" => Ok(true),
+                    _ => Ok(false)
+                }
+            },
             "" => Ok(true), // keywords::Invalid
             _ => Err((format!("invalid fragment specifier `{}`", frag),
                      "valid fragment specifiers are `ident`, `block`, \
-                      `stmt`, `expr`, `pat`, `ty`, `path`, `meta`, `tt` \
-                      and `item`"))
+                      `stmt`, `expr`, `pat`, `ty`, `path`, `meta`, `tt`, \
+                      `item` and `vis`"))
         }
     }
 }
 
-fn has_legal_fragment_specifier(tok: &quoted::TokenTree) -> Result<(), String> {
+fn has_legal_fragment_specifier(sess: &ParseSess,
+                                features: &RefCell<Features>,
+                                tok: &quoted::TokenTree) -> Result<(), String> {
     debug!("has_legal_fragment_specifier({:?})", tok);
-    if let quoted::TokenTree::MetaVarDecl(_, _, frag_spec) = *tok {
-        let s = &frag_spec.name.as_str();
-        if !is_legal_fragment_specifier(s) {
-            return Err(s.to_string());
+    if let quoted::TokenTree::MetaVarDecl(_, _, ref frag_spec) = *tok {
+        let frag_name = frag_spec.name.as_str();
+        let frag_span = tok.span();
+        if !is_legal_fragment_specifier(sess, features, &frag_name, frag_span) {
+            return Err(frag_name.to_string());
         }
     }
     Ok(())
 }
 
-fn is_legal_fragment_specifier(frag: &str) -> bool {
-    match frag {
+fn is_legal_fragment_specifier(sess: &ParseSess,
+                               features: &RefCell<Features>,
+                               frag_name: &str,
+                               frag_span: Span) -> bool {
+    match frag_name {
         "item" | "block" | "stmt" | "expr" | "pat" |
         "path" | "ty" | "ident" | "meta" | "tt" | "" => true,
+        "vis" => {
+            if !features.borrow().macro_vis_matcher {
+                let explain = feature_gate::EXPLAIN_VIS_MATCHER;
+                emit_feature_err(sess,
+                                 "macro_vis_matcher",
+                                 frag_span,
+                                 GateIssue::Language,
+                                 explain);
+            }
+            true
+        },
         _ => false,
     }
 }
@@ -821,6 +864,7 @@ fn quoted_tt_to_string(tt: &quoted::TokenTree) -> String {
     match *tt {
         quoted::TokenTree::Token(_, ref tok) => ::print::pprust::token_to_string(tok),
         quoted::TokenTree::MetaVarDecl(_, name, kind) => format!("${}:{}", name, kind),
-        _ => panic!("unexpected quoted::TokenTree::{Sequence or Delimited} in follow set checker"),
+        _ => panic!("unexpected quoted::TokenTree::{{Sequence or Delimited}} \
+                     in follow set checker"),
     }
 }
diff --git a/src/libsyntax/ext/tt/quoted.rs b/src/libsyntax/ext/tt/quoted.rs
index d56859d805c..fa65e9501c2 100644
--- a/src/libsyntax/ext/tt/quoted.rs
+++ b/src/libsyntax/ext/tt/quoted.rs
@@ -34,17 +34,19 @@ impl Delimited {
     }
 
     pub fn open_tt(&self, span: Span) -> TokenTree {
-        let open_span = match span {
-            DUMMY_SP => DUMMY_SP,
-            _ => Span { hi: span.lo + BytePos(self.delim.len() as u32), ..span },
+        let open_span = if span == DUMMY_SP {
+            DUMMY_SP
+        } else {
+            Span { hi: span.lo + BytePos(self.delim.len() as u32), ..span }
         };
         TokenTree::Token(open_span, self.open_token())
     }
 
     pub fn close_tt(&self, span: Span) -> TokenTree {
-        let close_span = match span {
-            DUMMY_SP => DUMMY_SP,
-            _ => Span { lo: span.hi - BytePos(self.delim.len() as u32), ..span },
+        let close_span = if span == DUMMY_SP {
+            DUMMY_SP
+        } else {
+            Span { lo: span.hi - BytePos(self.delim.len() as u32), ..span }
         };
         TokenTree::Token(close_span, self.close_token())
     }
@@ -94,6 +96,17 @@ impl TokenTree {
         }
     }
 
+    pub fn is_empty(&self) -> bool {
+        match *self {
+            TokenTree::Delimited(_, ref delimed) => match delimed.delim {
+                token::NoDelim => delimed.tts.is_empty(),
+                _ => false,
+            },
+            TokenTree::Sequence(_, ref seq) => seq.tts.is_empty(),
+            _ => true,
+        }
+    }
+
     pub fn get_tt(&self, index: usize) -> TokenTree {
         match (self, index) {
             (&TokenTree::Delimited(_, ref delimed), _) if delimed.delim == token::NoDelim => {
@@ -134,14 +147,17 @@ pub fn parse(input: tokenstream::TokenStream, expect_matchers: bool, sess: &Pars
             TokenTree::Token(start_sp, token::SubstNt(ident)) if expect_matchers => {
                 let span = match trees.next() {
                     Some(tokenstream::TokenTree::Token(span, token::Colon)) => match trees.next() {
-                        Some(tokenstream::TokenTree::Token(end_sp, token::Ident(kind))) => {
-                            let span = Span { lo: start_sp.lo, ..end_sp };
-                            result.push(TokenTree::MetaVarDecl(span, ident, kind));
-                            continue
-                        }
-                        tree @ _ => tree.as_ref().map(tokenstream::TokenTree::span).unwrap_or(span),
+                        Some(tokenstream::TokenTree::Token(end_sp, ref tok)) => match tok.ident() {
+                            Some(kind) => {
+                                let span = Span { lo: start_sp.lo, ..end_sp };
+                                result.push(TokenTree::MetaVarDecl(span, ident, kind));
+                                continue
+                            }
+                            _ => end_sp,
+                        },
+                        tree => tree.as_ref().map(tokenstream::TokenTree::span).unwrap_or(span),
                     },
-                    tree @ _ => tree.as_ref().map(tokenstream::TokenTree::span).unwrap_or(start_sp),
+                    tree => tree.as_ref().map(tokenstream::TokenTree::span).unwrap_or(start_sp),
                 };
                 sess.missing_fragment_specifiers.borrow_mut().insert(span);
                 result.push(TokenTree::MetaVarDecl(span, ident, keywords::Invalid.ident()));
@@ -223,10 +239,10 @@ fn parse_sep_and_kleene_op<I>(input: &mut I, span: Span, sess: &ParseSess)
                     Some(op) => return (Some(tok), op),
                     None => span,
                 },
-                tree @ _ => tree.as_ref().map(tokenstream::TokenTree::span).unwrap_or(span),
+                tree => tree.as_ref().map(tokenstream::TokenTree::span).unwrap_or(span),
             }
         },
-        tree @ _ => tree.as_ref().map(tokenstream::TokenTree::span).unwrap_or(span),
+        tree => tree.as_ref().map(tokenstream::TokenTree::span).unwrap_or(span),
     };
 
     sess.span_diagnostic.span_err(span, "expected `*` or `+`");
diff --git a/src/libsyntax/ext/tt/transcribe.rs b/src/libsyntax/ext/tt/transcribe.rs
index 24004492be2..2a435bdea10 100644
--- a/src/libsyntax/ext/tt/transcribe.rs
+++ b/src/libsyntax/ext/tt/transcribe.rs
@@ -12,7 +12,7 @@ use ast::Ident;
 use errors::Handler;
 use ext::tt::macro_parser::{NamedMatch, MatchedSeq, MatchedNonterminal};
 use ext::tt::quoted;
-use parse::token::{self, SubstNt, Token, NtIdent, NtTT};
+use parse::token::{self, SubstNt, Token, NtTT};
 use syntax_pos::{Span, DUMMY_SP};
 use tokenstream::{TokenStream, TokenTree, Delimited};
 use util::small_vector::SmallVector;
@@ -121,20 +121,20 @@ pub fn transcribe(sp_diag: &Handler,
                                          &repeats) {
                     LockstepIterSize::Unconstrained => {
                         panic!(sp_diag.span_fatal(
-                            sp.clone(), /* blame macro writer */
+                            sp, /* blame macro writer */
                             "attempted to repeat an expression \
                              containing no syntax \
                              variables matched as repeating at this depth"));
                     }
                     LockstepIterSize::Contradiction(ref msg) => {
                         // FIXME #2887 blame macro invoker instead
-                        panic!(sp_diag.span_fatal(sp.clone(), &msg[..]));
+                        panic!(sp_diag.span_fatal(sp, &msg[..]));
                     }
                     LockstepIterSize::Constraint(len, _) => {
                         if len == 0 {
                             if seq.op == quoted::KleeneOp::OneOrMore {
                                 // FIXME #2887 blame invoker
-                                panic!(sp_diag.span_fatal(sp.clone(),
+                                panic!(sp_diag.span_fatal(sp,
                                                           "this must repeat at least once"));
                             }
                         } else {
@@ -154,13 +154,6 @@ pub fn transcribe(sp_diag: &Handler,
                     None => result.push(TokenTree::Token(sp, SubstNt(ident)).into()),
                     Some(cur_matched) => if let MatchedNonterminal(ref nt) = *cur_matched {
                         match **nt {
-                            // sidestep the interpolation tricks for ident because
-                            // (a) idents can be in lots of places, so it'd be a pain
-                            // (b) we actually can, since it's a token.
-                            NtIdent(ref sn) => {
-                                let token = TokenTree::Token(sn.span, token::Ident(sn.node));
-                                result.push(token.into());
-                            }
                             NtTT(ref tt) => result.push(tt.clone().into()),
                             _ => {
                                 let token = TokenTree::Token(sp, token::Interpolated(nt.clone()));
diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs
index e7bf16eae9e..c119fad1b73 100644
--- a/src/libsyntax/feature_gate.rs
+++ b/src/libsyntax/feature_gate.rs
@@ -28,7 +28,7 @@ use self::AttributeGate::*;
 use abi::Abi;
 use ast::{self, NodeId, PatKind, RangeEnd};
 use attr;
-use codemap::{CodeMap, Spanned};
+use codemap::Spanned;
 use syntax_pos::Span;
 use errors::{DiagnosticBuilder, Handler, FatalError};
 use visit::{self, FnKind, Visitor};
@@ -260,9 +260,6 @@ declare_features! (
     // impl specialization (RFC 1210)
     (active, specialization, "1.7.0", Some(31844)),
 
-    // pub(restricted) visibilities (RFC 1422)
-    (active, pub_restricted, "1.9.0", Some(32409)),
-
     // Allow Drop types in statics/const functions (RFC 1440)
     (active, drop_types_in_const, "1.9.0", Some(33156)),
 
@@ -272,9 +269,6 @@ declare_features! (
     // Allows `impl Trait` in function return types.
     (active, conservative_impl_trait, "1.12.0", Some(34511)),
 
-    // Permits numeric fields in struct expressions and patterns.
-    (active, relaxed_adts, "1.12.0", Some(35626)),
-
     // The `!` type
     (active, never_type, "1.13.0", Some(35121)),
 
@@ -295,17 +289,11 @@ declare_features! (
     // Allows attributes on lifetime/type formal parameters in generics (RFC 1327)
     (active, generic_param_attrs, "1.11.0", Some(34761)),
 
-    // The #![windows_subsystem] attribute
-    (active, windows_subsystem, "1.14.0", Some(37499)),
-
     // Allows #[link(..., cfg(..))]
     (active, link_cfg, "1.14.0", Some(37406)),
 
     (active, use_extern_macros, "1.15.0", Some(35896)),
 
-    // Allows `break {expr}` with a value inside `loop`s.
-    (active, loop_break_value, "1.14.0", Some(37339)),
-
     // Allows #[target_feature(...)]
     (active, target_feature, "1.15.0", None),
 
@@ -318,9 +306,12 @@ declare_features! (
     // The `unadjusted` ABI. Perma unstable.
     (active, abi_unadjusted, "1.16.0", None),
 
-    // Macros 1.1
+    // Procedural macros 2.0.
     (active, proc_macro, "1.16.0", Some(38356)),
 
+    // Declarative macros 2.0 (`macro`).
+    (active, decl_macro, "1.17.0", Some(39412)),
+
     // Allows attributes on struct literal fields.
     (active, struct_field_attributes, "1.16.0", Some(38814)),
 
@@ -339,6 +330,31 @@ declare_features! (
 
     // `extern "x86-interrupt" fn()`
     (active, abi_x86_interrupt, "1.17.0", Some(40180)),
+
+
+    // Allows the `catch {...}` expression
+    (active, catch_expr, "1.17.0", Some(31436)),
+
+    // Allows `repr(align(u16))` struct attribute (RFC 1358)
+    (active, repr_align, "1.17.0", Some(33626)),
+
+    // See rust-lang/rfcs#1414. Allows code like `let x: &'static u32 = &42` to work.
+    (active, rvalue_static_promotion, "1.15.1", Some(38865)),
+
+    // Used to preserve symbols (see llvm.used)
+    (active, used, "1.18.0", Some(40289)),
+
+    // Allows module-level inline assembly by way of global_asm!()
+    (active, global_asm, "1.18.0", Some(35119)),
+
+    // Allows overlapping impls of marker traits
+    (active, overlapping_marker_traits, "1.18.0", Some(29864)),
+
+    // Allows use of the :vis macro fragment specifier
+    (active, macro_vis_matcher, "1.18.0", Some(41022)),
+
+    // rustc internal
+    (active, abi_thiscall, "1.19.0", None),
 );
 
 declare_features! (
@@ -394,7 +410,7 @@ declare_features! (
     (accepted, question_mark, "1.13.0", Some(31436)),
     // Allows `..` in tuple (struct) patterns
     (accepted, dotdot_in_tuple_patterns, "1.14.0", Some(33627)),
-    (accepted, item_like_imports, "1.14.0", Some(35120)),
+    (accepted, item_like_imports, "1.15.0", Some(35120)),
     // Allows using `Self` and associated types in struct expressions and patterns.
     (accepted, more_struct_aliases, "1.16.0", Some(37544)),
     // elide `'static` lifetimes in `static`s and `const`s
@@ -403,7 +419,16 @@ declare_features! (
     (accepted, field_init_shorthand, "1.17.0", Some(37340)),
     // Allows the definition recursive static items.
     (accepted, static_recursion, "1.17.0", Some(29719)),
+    // pub(restricted) visibilities (RFC 1422)
+    (accepted, pub_restricted, "1.18.0", Some(32409)),
+    // The #![windows_subsystem] attribute
+    (accepted, windows_subsystem, "1.18.0", Some(37499)),
+    // Allows `break {expr}` with a value inside `loop`s.
+    (accepted, loop_break_value, "1.19.0", Some(37339)),
+    // Permits numeric fields in struct expressions and patterns.
+    (accepted, relaxed_adts, "1.19.0", Some(35626)),
 );
+
 // If you change this, please modify src/doc/unstable-book as well. You must
 // move that documentation into the relevant place in the other docs, and
 // remove the chapter on the flag.
@@ -452,7 +477,7 @@ pub enum Stability {
 impl ::std::fmt::Debug for AttributeGate {
     fn fmt(&self, fmt: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
         match *self {
-            Gated(ref stab, ref name, ref expl, _) =>
+            Gated(ref stab, name, expl, _) =>
                 write!(fmt, "Gated({:?}, {}, {})", stab, name, expl),
             Ungated => write!(fmt, "Ungated")
         }
@@ -742,6 +767,10 @@ pub const BUILTIN_ATTRIBUTES: &'static [(&'static str, AttributeType, AttributeG
                                   "unwind_attributes",
                                   "#[unwind] is experimental",
                                   cfg_fn!(unwind_attributes))),
+    ("used", Whitelisted, Gated(
+        Stability::Unstable, "used",
+        "the `#[used]` attribute is an experimental feature",
+        cfg_fn!(used))),
 
     // used in resolve
     ("prelude_import", Whitelisted, Gated(Stability::Unstable,
@@ -762,11 +791,7 @@ pub const BUILTIN_ATTRIBUTES: &'static [(&'static str, AttributeType, AttributeG
                                         "unboxed_closures are still evolving",
                                         cfg_fn!(unboxed_closures))),
 
-    ("windows_subsystem", Whitelisted, Gated(Stability::Unstable,
-                                             "windows_subsystem",
-                                             "the windows subsystem attribute \
-                                              is currently unstable",
-                                             cfg_fn!(windows_subsystem))),
+    ("windows_subsystem", Whitelisted, Ungated),
 
     ("proc_macro_attribute", Normal, Gated(Stability::Unstable,
                                            "proc_macro",
@@ -796,7 +821,7 @@ pub const BUILTIN_ATTRIBUTES: &'static [(&'static str, AttributeType, AttributeG
 ];
 
 // cfg(...)'s that are feature gated
-const GATED_CFGS: &'static [(&'static str, &'static str, fn(&Features) -> bool)] = &[
+const GATED_CFGS: &[(&str, &str, fn(&Features) -> bool)] = &[
     // (name in cfg, feature, function to check if the feature is enabled)
     ("target_feature", "cfg_target_feature", cfg_fn!(cfg_target_feature)),
     ("target_vendor", "cfg_target_vendor", cfg_fn!(cfg_target_vendor)),
@@ -812,7 +837,7 @@ pub struct GatedCfg {
 
 impl GatedCfg {
     pub fn gate(cfg: &ast::MetaItem) -> Option<GatedCfg> {
-        let name = &*cfg.name().as_str();
+        let name = cfg.name().as_str();
         GATED_CFGS.iter()
                   .position(|info| info.0 == name)
                   .map(|idx| {
@@ -825,7 +850,7 @@ impl GatedCfg {
 
     pub fn check_and_emit(&self, sess: &ParseSess, features: &Features) {
         let (cfg, feature, has_feature) = GATED_CFGS[self.index];
-        if !has_feature(features) && !sess.codemap().span_allows_unstable(self.span) {
+        if !has_feature(features) && !self.span.allows_unstable() {
             let explain = format!("`cfg({})` is experimental and subject to change", cfg);
             emit_feature_err(sess, feature, self.span, GateIssue::Language, &explain);
         }
@@ -835,7 +860,6 @@ impl GatedCfg {
 struct Context<'a> {
     features: &'a Features,
     parse_sess: &'a ParseSess,
-    cm: &'a CodeMap,
     plugin_attributes: &'a [(String, AttributeType)],
 }
 
@@ -844,7 +868,7 @@ macro_rules! gate_feature_fn {
         let (cx, has_feature, span, name, explain) = ($cx, $has_feature, $span, $name, $explain);
         let has_feature: bool = has_feature(&$cx.features);
         debug!("gate_feature(feature = {:?}, span = {:?}); has? {}", name, span, has_feature);
-        if !has_feature && !cx.cm.span_allows_unstable(span) {
+        if !has_feature && !span.allows_unstable() {
             emit_feature_err(cx.parse_sess, name, span, GateIssue::Language, explain);
         }
     }}
@@ -859,22 +883,22 @@ macro_rules! gate_feature {
 impl<'a> Context<'a> {
     fn check_attribute(&self, attr: &ast::Attribute, is_macro: bool) {
         debug!("check_attribute(attr = {:?})", attr);
-        let name = &*attr.name().as_str();
+        let name = unwrap_or!(attr.name(), return).as_str();
         for &(n, ty, ref gateage) in BUILTIN_ATTRIBUTES {
-            if n == name {
-                if let &Gated(_, ref name, ref desc, ref has_feature) = gateage {
+            if name == n {
+                if let Gated(_, name, desc, ref has_feature) = *gateage {
                     gate_feature_fn!(self, has_feature, attr.span, name, desc);
                 }
-                debug!("check_attribute: {:?} is builtin, {:?}, {:?}", name, ty, gateage);
+                debug!("check_attribute: {:?} is builtin, {:?}, {:?}", attr.path, ty, gateage);
                 return;
             }
         }
         for &(ref n, ref ty) in self.plugin_attributes {
-            if n == name {
+            if attr.path == &**n {
                 // Plugins can't gate attributes, so we don't check for it
                 // unlike the code above; we only use this loop to
                 // short-circuit to avoid the checks below
-                debug!("check_attribute: {:?} is registered by a plugin, {:?}", name, ty);
+                debug!("check_attribute: {:?} is registered by a plugin, {:?}", attr.path, ty);
                 return;
             }
         }
@@ -885,9 +909,7 @@ impl<'a> Context<'a> {
                            are reserved for internal compiler diagnostics");
         } else if name.starts_with("derive_") {
             gate_feature!(self, custom_derive, attr.span, EXPLAIN_DERIVE_UNDERSCORE);
-        } else if attr::is_known(attr) {
-            debug!("check_attribute: {:?} is known", name);
-        } else {
+        } else if !attr::is_known(attr) {
             // Only run the custom attribute lint during regular
             // feature gate checking. Macro gating runs
             // before the plugin attributes are registered
@@ -898,18 +920,14 @@ impl<'a> Context<'a> {
                                         unknown to the compiler and \
                                         may have meaning \
                                         added to it in the future",
-                                       name));
+                                       attr.path));
             }
         }
     }
 }
 
-pub fn check_attribute(attr: &ast::Attribute, parse_sess: &ParseSess,
-                       cm: &CodeMap, features: &Features) {
-    let cx = Context {
-        features: features, parse_sess: parse_sess,
-        cm: cm, plugin_attributes: &[]
-    };
+pub fn check_attribute(attr: &ast::Attribute, parse_sess: &ParseSess, features: &Features) {
+    let cx = Context { features: features, parse_sess: parse_sess, plugin_attributes: &[] };
     cx.check_attribute(attr, true);
 }
 
@@ -978,6 +996,9 @@ pub const EXPLAIN_STMT_ATTR_SYNTAX: &'static str =
 pub const EXPLAIN_ASM: &'static str =
     "inline assembly is not stable enough for use and is subject to change";
 
+pub const EXPLAIN_GLOBAL_ASM: &'static str =
+    "`global_asm!` is not stable enough for use and is subject to change";
+
 pub const EXPLAIN_LOG_SYNTAX: &'static str =
     "`log_syntax!` is not stable enough for use and is subject to change";
 
@@ -999,6 +1020,9 @@ pub const EXPLAIN_DEPR_CUSTOM_DERIVE: &'static str =
 pub const EXPLAIN_DERIVE_UNDERSCORE: &'static str =
     "attributes of the form `#[derive_*]` are reserved for the compiler";
 
+pub const EXPLAIN_VIS_MATCHER: &'static str =
+    ":vis fragment specifier is experimental and subject to change";
+
 pub const EXPLAIN_PLACEMENT_IN: &'static str =
     "placement-in expression syntax is experimental and subject to change.";
 
@@ -1012,7 +1036,7 @@ struct PostExpansionVisitor<'a> {
 macro_rules! gate_feature_post {
     ($cx: expr, $feature: ident, $span: expr, $explain: expr) => {{
         let (cx, span) = ($cx, $span);
-        if !cx.context.cm.span_allows_unstable(span) {
+        if !span.allows_unstable() {
             gate_feature!(cx.context, $feature, span, $explain)
         }
     }}
@@ -1033,6 +1057,10 @@ impl<'a> PostExpansionVisitor<'a> {
                 gate_feature_post!(&self, abi_vectorcall, span,
                                    "vectorcall is experimental and subject to change");
             },
+            Abi::Thiscall => {
+                gate_feature_post!(&self, abi_thiscall, span,
+                                   "thiscall is experimental and subject to change");
+            },
             Abi::RustCall => {
                 gate_feature_post!(&self, unboxed_closures, span,
                                    "rust-call ABI is subject to change");
@@ -1079,25 +1107,26 @@ fn contains_novel_literal(item: &ast::MetaItem) -> bool {
         NameValue(ref lit) => !lit.node.is_str(),
         List(ref list) => list.iter().any(|li| {
             match li.node {
-                MetaItem(ref mi) => contains_novel_literal(&mi),
+                MetaItem(ref mi) => contains_novel_literal(mi),
                 Literal(_) => true,
             }
         }),
     }
 }
 
-fn starts_with_digit(s: &str) -> bool {
-    s.as_bytes().first().cloned().map_or(false, |b| b >= b'0' && b <= b'9')
-}
-
 impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
     fn visit_attribute(&mut self, attr: &ast::Attribute) {
-        if !self.context.cm.span_allows_unstable(attr.span) {
+        if !attr.span.allows_unstable() {
             // check for gated attributes
             self.context.check_attribute(attr, false);
         }
 
-        if contains_novel_literal(&attr.value) {
+        if self.context.features.proc_macro && attr::is_known(attr) {
+            return
+        }
+
+        let meta = panictry!(attr.parse_meta(self.context.parse_sess));
+        if contains_novel_literal(&meta) {
             gate_feature_post!(&self, attr_literals, attr.span,
                                "non-string literals in attributes, or string \
                                literals in top-level positions, are experimental");
@@ -1160,25 +1189,24 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
                                                                        `#[repr(simd)]` instead");
                 }
                 for attr in &i.attrs {
-                    if attr.name() == "repr" {
-                        for item in attr.meta_item_list().unwrap_or(&[]) {
+                    if attr.path == "repr" {
+                        for item in attr.meta_item_list().unwrap_or_else(Vec::new) {
                             if item.check_name("simd") {
                                 gate_feature_post!(&self, repr_simd, i.span,
                                                    "SIMD types are experimental \
                                                     and possibly buggy");
 
                             }
+                            if item.check_name("align") {
+                                gate_feature_post!(&self, repr_align, i.span,
+                                                   "the struct `#[repr(align(u16))]` attribute \
+                                                    is experimental");
+                            }
                         }
                     }
                 }
             }
 
-            ast::ItemKind::Union(..) => {
-                gate_feature_post!(&self, untagged_unions,
-                                   i.span,
-                                   "unions are unstable and possibly buggy");
-            }
-
             ast::ItemKind::DefaultImpl(..) => {
                 gate_feature_post!(&self, optin_builtin_traits,
                                    i.span,
@@ -1186,18 +1214,26 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
                                     and possibly buggy");
             }
 
-            ast::ItemKind::Impl(_, polarity, _, _, _, _) => {
-                match polarity {
-                    ast::ImplPolarity::Negative => {
-                        gate_feature_post!(&self, optin_builtin_traits,
-                                           i.span,
-                                           "negative trait bounds are not yet fully implemented; \
-                                            use marker types for now");
-                    },
-                    _ => {}
+            ast::ItemKind::Impl(_, polarity, defaultness, _, _, _, _) => {
+                if polarity == ast::ImplPolarity::Negative {
+                    gate_feature_post!(&self, optin_builtin_traits,
+                                       i.span,
+                                       "negative trait bounds are not yet fully implemented; \
+                                        use marker types for now");
+                }
+
+                if let ast::Defaultness::Default = defaultness {
+                    gate_feature_post!(&self, specialization,
+                                       i.span,
+                                       "specialization is unstable");
                 }
             }
 
+            ast::ItemKind::MacroDef(ast::MacroDef { legacy: false, .. }) => {
+                let msg = "`macro` is experimental";
+                gate_feature_post!(&self, decl_macro, i.span, msg);
+            }
+
             _ => {}
         }
 
@@ -1237,11 +1273,9 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
 
     fn visit_fn_ret_ty(&mut self, ret_ty: &'a ast::FunctionRetTy) {
         if let ast::FunctionRetTy::Ty(ref output_ty) = *ret_ty {
-            match output_ty.node {
-                ast::TyKind::Never => return,
-                _ => (),
-            };
-            self.visit_ty(output_ty)
+            if output_ty.node != ast::TyKind::Never {
+                self.visit_ty(output_ty)
+            }
         }
     }
 
@@ -1262,19 +1296,6 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
             ast::ExprKind::InPlace(..) => {
                 gate_feature_post!(&self, placement_in_syntax, e.span, EXPLAIN_PLACEMENT_IN);
             }
-            ast::ExprKind::Struct(_, ref fields, _) => {
-                for field in fields {
-                    if starts_with_digit(&field.ident.node.name.as_str()) {
-                        gate_feature_post!(&self, relaxed_adts,
-                                          field.span,
-                                          "numeric fields in struct expressions are unstable");
-                    }
-                }
-            }
-            ast::ExprKind::Break(_, Some(_)) => {
-                gate_feature_post!(&self, loop_break_value, e.span,
-                                   "`break` with a value is experimental");
-            }
             ast::ExprKind::Lit(ref lit) => {
                 if let ast::LitKind::Int(_, ref ty) = lit.node {
                     match *ty {
@@ -1287,6 +1308,9 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
                     }
                 }
             }
+            ast::ExprKind::Catch(_) => {
+                gate_feature_post!(&self, catch_expr, e.span, "`catch` expression is experimental");
+            }
             _ => {}
         }
         visit::walk_expr(self, e);
@@ -1311,15 +1335,6 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
                                   pattern.span,
                                   "box pattern syntax is experimental");
             }
-            PatKind::Struct(_, ref fields, _) => {
-                for field in fields {
-                    if starts_with_digit(&field.node.ident.name.as_str()) {
-                        gate_feature_post!(&self, relaxed_adts,
-                                          field.span,
-                                          "numeric fields in struct patterns are unstable");
-                    }
-                }
-            }
             PatKind::Range(_, _, RangeEnd::Excluded) => {
                 gate_feature_post!(&self, exclusive_range_pattern, pattern.span,
                                    "exclusive range pattern syntax is experimental");
@@ -1335,17 +1350,14 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
                 span: Span,
                 _node_id: NodeId) {
         // check for const fn declarations
-        match fn_kind {
-            FnKind::ItemFn(_, _, _, Spanned { node: ast::Constness::Const, .. }, _, _, _) => {
-                gate_feature_post!(&self, const_fn, span, "const fn is unstable");
-            }
-            _ => {
-                // stability of const fn methods are covered in
-                // visit_trait_item and visit_impl_item below; this is
-                // because default methods don't pass through this
-                // point.
-            }
+        if let FnKind::ItemFn(_, _, _, Spanned { node: ast::Constness::Const, .. }, _, _, _) =
+            fn_kind {
+            gate_feature_post!(&self, const_fn, span, "const fn is unstable");
         }
+        // stability of const fn methods are covered in
+        // visit_trait_item and visit_impl_item below; this is
+        // because default methods don't pass through this
+        // point.
 
         match fn_kind {
             FnKind::ItemFn(_, _, _, _, abi, _, _) |
@@ -1404,17 +1416,6 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
         visit::walk_impl_item(self, ii);
     }
 
-    fn visit_vis(&mut self, vis: &'a ast::Visibility) {
-        let span = match *vis {
-            ast::Visibility::Crate(span) => span,
-            ast::Visibility::Restricted { ref path, .. } => path.span,
-            _ => return,
-        };
-        gate_feature_post!(&self, pub_restricted, span, "`pub(restricted)` syntax is experimental");
-
-        visit::walk_vis(self, vis)
-    }
-
     fn visit_generics(&mut self, g: &'a ast::Generics) {
         for t in &g.ty_params {
             if !t.attrs.is_empty() {
@@ -1529,7 +1530,6 @@ pub fn check_crate(krate: &ast::Crate,
     let ctx = Context {
         features: features,
         parse_sess: sess,
-        cm: sess.codemap(),
         plugin_attributes: plugin_attributes,
     };
     visit::walk_crate(&mut PostExpansionVisitor { context: &ctx }, krate);
diff --git a/src/libsyntax/fold.rs b/src/libsyntax/fold.rs
index fb4eb19be2b..4c6cf49a8db 100644
--- a/src/libsyntax/fold.rs
+++ b/src/libsyntax/fold.rs
@@ -140,6 +140,10 @@ pub trait Folder : Sized {
         noop_fold_foreign_mod(nm, self)
     }
 
+    fn fold_global_asm(&mut self, ga: P<GlobalAsm>) -> P<GlobalAsm> {
+        noop_fold_global_asm(ga, self)
+    }
+
     fn fold_variant(&mut self, v: Variant) -> Variant {
         noop_fold_variant(v, self)
     }
@@ -185,6 +189,10 @@ pub trait Folder : Sized {
         // fold::noop_fold_mac(_mac, self)
     }
 
+    fn fold_macro_def(&mut self, def: MacroDef) -> MacroDef {
+        noop_fold_macro_def(def, self)
+    }
+
     fn fold_lifetime(&mut self, l: Lifetime) -> Lifetime {
         noop_fold_lifetime(l, self)
     }
@@ -358,7 +366,7 @@ pub fn noop_fold_ty<T: Folder>(t: P<Ty>, fld: &mut T) -> P<Ty> {
     t.map(|Ty {id, node, span}| Ty {
         id: fld.new_id(id),
         node: match node {
-            TyKind::Infer | TyKind::ImplicitSelf => node,
+            TyKind::Infer | TyKind::ImplicitSelf | TyKind::Err => node,
             TyKind::Slice(ty) => TyKind::Slice(fld.fold_ty(ty)),
             TyKind::Ptr(mt) => TyKind::Ptr(fld.fold_mt(mt)),
             TyKind::Rptr(region, mt) => {
@@ -412,10 +420,15 @@ pub fn noop_fold_foreign_mod<T: Folder>(ForeignMod {abi, items}: ForeignMod,
     }
 }
 
+pub fn noop_fold_global_asm<T: Folder>(ga: P<GlobalAsm>,
+                                       _: &mut T) -> P<GlobalAsm> {
+    ga
+}
+
 pub fn noop_fold_variant<T: Folder>(v: Variant, fld: &mut T) -> Variant {
     Spanned {
         node: Variant_ {
-            name: v.node.name,
+            name: fld.fold_ident(v.node.name),
             attrs: fold_attrs(v.node.attrs, fld),
             data: fld.fold_variant_data(v.node.data),
             disr_expr: v.node.disr_expr.map(|e| fld.fold_expr(e)),
@@ -434,8 +447,9 @@ pub fn noop_fold_usize<T: Folder>(i: usize, _: &mut T) -> usize {
 
 pub fn noop_fold_path<T: Folder>(Path { segments, span }: Path, fld: &mut T) -> Path {
     Path {
-        segments: segments.move_map(|PathSegment {identifier, parameters}| PathSegment {
+        segments: segments.move_map(|PathSegment {identifier, span, parameters}| PathSegment {
             identifier: fld.fold_ident(identifier),
+            span: fld.new_span(span),
             parameters: parameters.map(|ps| ps.map(|ps| fld.fold_path_parameters(ps))),
         }),
         span: fld.new_span(span)
@@ -488,7 +502,8 @@ pub fn noop_fold_attribute<T: Folder>(attr: Attribute, fld: &mut T) -> Option<At
     Some(Attribute {
         id: attr.id,
         style: attr.style,
-        value: fld.fold_meta_item(attr.value),
+        path: fld.fold_path(attr.path),
+        tokens: fld.fold_tts(attr.tokens),
         is_sugared_doc: attr.is_sugared_doc,
         span: fld.new_span(attr.span),
     })
@@ -504,6 +519,13 @@ pub fn noop_fold_mac<T: Folder>(Spanned {node, span}: Mac, fld: &mut T) -> Mac {
     }
 }
 
+pub fn noop_fold_macro_def<T: Folder>(def: MacroDef, fld: &mut T) -> MacroDef {
+    MacroDef {
+        tokens: fld.fold_tts(def.tokens.into()).into(),
+        legacy: def.legacy,
+    }
+}
+
 pub fn noop_fold_meta_list_item<T: Folder>(li: NestedMetaItem, fld: &mut T)
     -> NestedMetaItem {
     Spanned {
@@ -611,7 +633,7 @@ pub fn noop_fold_interpolated<T: Folder>(nt: token::Nonterminal, fld: &mut T)
         token::NtExpr(expr) => token::NtExpr(fld.fold_expr(expr)),
         token::NtTy(ty) => token::NtTy(fld.fold_ty(ty)),
         token::NtIdent(id) => token::NtIdent(Spanned::<Ident>{node: fld.fold_ident(id.node), ..id}),
-        token::NtMeta(meta_item) => token::NtMeta(fld.fold_meta_item(meta_item)),
+        token::NtMeta(meta) => token::NtMeta(fld.fold_meta_item(meta)),
         token::NtPath(path) => token::NtPath(fld.fold_path(path)),
         token::NtTT(tt) => token::NtTT(fld.fold_tt(tt)),
         token::NtArm(arm) => token::NtArm(fld.fold_arm(arm)),
@@ -625,6 +647,7 @@ pub fn noop_fold_interpolated<T: Folder>(nt: token::Nonterminal, fld: &mut T)
         token::NtWhereClause(where_clause) =>
             token::NtWhereClause(fld.fold_where_clause(where_clause)),
         token::NtArg(arg) => token::NtArg(fld.fold_arg(arg)),
+        token::NtVis(vis) => token::NtVis(fld.fold_vis(vis)),
     }
 }
 
@@ -671,7 +694,7 @@ pub fn noop_fold_ty_params<T: Folder>(tps: Vec<TyParam>, fld: &mut T) -> Vec<TyP
 pub fn noop_fold_lifetime<T: Folder>(l: Lifetime, fld: &mut T) -> Lifetime {
     Lifetime {
         id: fld.new_id(l.id),
-        name: l.name,
+        ident: fld.fold_ident(l.ident),
         span: fld.new_span(l.span)
     }
 }
@@ -865,6 +888,7 @@ pub fn noop_fold_item_kind<T: Folder>(i: ItemKind, folder: &mut T) -> ItemKind {
         }
         ItemKind::Mod(m) => ItemKind::Mod(folder.fold_mod(m)),
         ItemKind::ForeignMod(nm) => ItemKind::ForeignMod(folder.fold_foreign_mod(nm)),
+        ItemKind::GlobalAsm(ga) => ItemKind::GlobalAsm(folder.fold_global_asm(ga)),
         ItemKind::Ty(t, generics) => {
             ItemKind::Ty(folder.fold_ty(t), folder.fold_generics(generics))
         }
@@ -884,9 +908,16 @@ pub fn noop_fold_item_kind<T: Folder>(i: ItemKind, folder: &mut T) -> ItemKind {
         ItemKind::DefaultImpl(unsafety, ref trait_ref) => {
             ItemKind::DefaultImpl(unsafety, folder.fold_trait_ref((*trait_ref).clone()))
         }
-        ItemKind::Impl(unsafety, polarity, generics, ifce, ty, impl_items) => ItemKind::Impl(
+        ItemKind::Impl(unsafety,
+                       polarity,
+                       defaultness,
+                       generics,
+                       ifce,
+                       ty,
+                       impl_items) => ItemKind::Impl(
             unsafety,
             polarity,
+            defaultness,
             folder.fold_generics(generics),
             ifce.map(|trait_ref| folder.fold_trait_ref(trait_ref.clone())),
             folder.fold_ty(ty),
@@ -899,7 +930,7 @@ pub fn noop_fold_item_kind<T: Folder>(i: ItemKind, folder: &mut T) -> ItemKind {
             items.move_flat_map(|item| folder.fold_trait_item(item)),
         ),
         ItemKind::Mac(m) => ItemKind::Mac(folder.fold_mac(m)),
-        ItemKind::MacroDef(tts) => ItemKind::MacroDef(folder.fold_tts(tts.into()).into()),
+        ItemKind::MacroDef(def) => ItemKind::MacroDef(folder.fold_macro_def(def)),
     }
 }
 
@@ -1268,6 +1299,7 @@ pub fn noop_fold_expr<T: Folder>(Expr {id, node, span, attrs}: Expr, folder: &mu
                 };
             }
             ExprKind::Try(ex) => ExprKind::Try(folder.fold_expr(ex)),
+            ExprKind::Catch(body) => ExprKind::Catch(folder.fold_block(body)),
         },
         id: folder.new_id(id),
         span: folder.new_span(span),
@@ -1369,7 +1401,7 @@ mod tests {
             matches_codepattern,
             "matches_codepattern",
             pprust::to_string(|s| fake_print_crate(s, &folded_crate)),
-            "#[a]mod zz{fn zz(zz:zz,zz:zz){zz!(zz,zz,zz);zz;zz}}".to_string());
+            "#[zz]mod zz{fn zz(zz:zz,zz:zz){zz!(zz,zz,zz);zz;zz}}".to_string());
     }
 
     // even inside macro defs....
diff --git a/src/libsyntax/json.rs b/src/libsyntax/json.rs
index fd762552248..f37dcfdde89 100644
--- a/src/libsyntax/json.rs
+++ b/src/libsyntax/json.rs
@@ -19,7 +19,7 @@
 
 // FIXME spec the JSON output properly.
 
-use codemap::CodeMap;
+use codemap::{CodeMap, FilePathMapping};
 use syntax_pos::{self, MacroBacktrace, Span, SpanLabel, MultiSpan};
 use errors::registry::Registry;
 use errors::{DiagnosticBuilder, SubDiagnostic, RenderSpan, CodeSuggestion, CodeMapper};
@@ -48,7 +48,8 @@ impl JsonEmitter {
     }
 
     pub fn basic() -> JsonEmitter {
-        JsonEmitter::stderr(None, Rc::new(CodeMap::new()))
+        let file_path_mapping = FilePathMapping::empty();
+        JsonEmitter::stderr(None, Rc::new(CodeMap::new(file_path_mapping)))
     }
 
     pub fn new(dst: Box<Write + Send>,
@@ -152,6 +153,18 @@ impl Diagnostic {
     fn from_diagnostic_builder(db: &DiagnosticBuilder,
                                je: &JsonEmitter)
                                -> Diagnostic {
+        let sugg = db.suggestions.iter().flat_map(|sugg| {
+            je.render(sugg).into_iter().map(move |rendered| {
+                Diagnostic {
+                    message: sugg.msg.clone(),
+                    code: None,
+                    level: "help",
+                    spans: DiagnosticSpan::from_suggestion(sugg, je),
+                    children: vec![],
+                    rendered: Some(rendered),
+                }
+            })
+        });
         Diagnostic {
             message: db.message(),
             code: DiagnosticCode::map_opt_string(db.code.clone(), je),
@@ -159,7 +172,7 @@ impl Diagnostic {
             spans: DiagnosticSpan::from_multispan(&db.span, je),
             children: db.children.iter().map(|c| {
                 Diagnostic::from_sub_diagnostic(c, je)
-            }).collect(),
+            }).chain(sugg).collect(),
             rendered: None,
         }
     }
@@ -173,8 +186,7 @@ impl Diagnostic {
                      .map(|sp| DiagnosticSpan::from_render_span(sp, je))
                      .unwrap_or_else(|| DiagnosticSpan::from_multispan(&db.span, je)),
             children: vec![],
-            rendered: db.render_span.as_ref()
-                                    .and_then(|rsp| je.render(rsp)),
+            rendered: None,
         }
     }
 }
@@ -202,7 +214,7 @@ impl DiagnosticSpan {
         // backtrace ourselves, but the `macro_backtrace` helper makes
         // some decision, such as dropping some frames, and I don't
         // want to duplicate that logic here.
-        let backtrace = je.cm.macro_backtrace(span).into_iter();
+        let backtrace = span.macro_backtrace().into_iter();
         DiagnosticSpan::from_span_full(span,
                                        is_primary,
                                        label,
@@ -267,14 +279,19 @@ impl DiagnosticSpan {
 
     fn from_suggestion(suggestion: &CodeSuggestion, je: &JsonEmitter)
                        -> Vec<DiagnosticSpan> {
-        assert_eq!(suggestion.msp.span_labels().len(), suggestion.substitutes.len());
-        suggestion.msp.span_labels()
-                      .into_iter()
-                      .zip(&suggestion.substitutes)
-                      .map(|(span_label, suggestion)| {
-                          DiagnosticSpan::from_span_label(span_label,
-                                                          Some(suggestion),
-                                                          je)
+        suggestion.substitution_parts
+                      .iter()
+                      .flat_map(|substitution| {
+                          substitution.substitutions.iter().map(move |suggestion| {
+                              let span_label = SpanLabel {
+                                  span: substitution.span,
+                                  is_primary: true,
+                                  label: None,
+                              };
+                              DiagnosticSpan::from_span_label(span_label,
+                                                              Some(suggestion),
+                                                              je)
+                          })
                       })
                       .collect()
     }
@@ -283,8 +300,9 @@ impl DiagnosticSpan {
         match *rsp {
             RenderSpan::FullSpan(ref msp) =>
                 DiagnosticSpan::from_multispan(msp, je),
-            RenderSpan::Suggestion(ref suggestion) =>
-                DiagnosticSpan::from_suggestion(suggestion, je),
+            // regular diagnostics don't produce this anymore
+            // FIXME(oli_obk): remove it entirely
+            RenderSpan::Suggestion(_) => unreachable!(),
         }
     }
 }
@@ -319,7 +337,7 @@ impl DiagnosticSpanLine {
                       })
                      .collect()
              })
-            .unwrap_or(vec![])
+            .unwrap_or_else(|_| vec![])
     }
 }
 
@@ -340,17 +358,8 @@ impl DiagnosticCode {
 }
 
 impl JsonEmitter {
-    fn render(&self, render_span: &RenderSpan) -> Option<String> {
-        use std::borrow::Borrow;
-
-        match *render_span {
-            RenderSpan::FullSpan(_) => {
-                None
-            }
-            RenderSpan::Suggestion(ref suggestion) => {
-                Some(suggestion.splice_lines(self.cm.borrow()))
-            }
-        }
+    fn render(&self, suggestion: &CodeSuggestion) -> Vec<String> {
+        suggestion.splice_lines(&*self.cm)
     }
 }
 
diff --git a/src/libsyntax/lib.rs b/src/libsyntax/lib.rs
index 39a9aff48bf..32dafcdb582 100644
--- a/src/libsyntax/lib.rs
+++ b/src/libsyntax/lib.rs
@@ -15,7 +15,6 @@
 //! This API is completely unstable and subject to change.
 
 #![crate_name = "syntax"]
-#![unstable(feature = "rustc_private", issue = "27812")]
 #![crate_type = "dylib"]
 #![crate_type = "rlib"]
 #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
@@ -24,20 +23,17 @@
        test(attr(deny(warnings))))]
 #![deny(warnings)]
 
-#![feature(associated_consts)]
-#![feature(const_fn)]
-#![feature(optin_builtin_traits)]
-#![feature(rustc_private)]
-#![feature(staged_api)]
-#![feature(str_escape)]
 #![feature(unicode)]
 #![feature(rustc_diagnostic_macros)]
-#![feature(specialization)]
 #![feature(i128_type)]
 
+#![cfg_attr(stage0, unstable(feature = "rustc_private", issue = "27812"))]
+#![cfg_attr(stage0, feature(rustc_private))]
+#![cfg_attr(stage0, feature(staged_api))]
+
 extern crate serialize;
 #[macro_use] extern crate log;
-#[macro_use] #[no_link] extern crate rustc_bitflags;
+#[macro_use] extern crate bitflags;
 extern crate std_unicode;
 pub extern crate rustc_errors as errors;
 extern crate syntax_pos;
@@ -65,6 +61,16 @@ macro_rules! panictry {
     })
 }
 
+#[macro_export]
+macro_rules! unwrap_or {
+    ($opt:expr, $default:expr) => {
+        match $opt {
+            Some(x) => x,
+            None => $default,
+        }
+    }
+}
+
 #[macro_use]
 pub mod diagnostics {
     #[macro_use]
@@ -115,7 +121,7 @@ pub mod ptr;
 pub mod show_span;
 pub mod std_inject;
 pub mod str;
-pub mod symbol;
+pub use syntax_pos::symbol;
 pub mod test;
 pub mod tokenstream;
 pub mod visit;
@@ -126,12 +132,12 @@ pub mod print {
 }
 
 pub mod ext {
+    pub use syntax_pos::hygiene;
     pub mod base;
     pub mod build;
     pub mod derive;
     pub mod expand;
     pub mod placeholders;
-    pub mod hygiene;
     pub mod quote;
     pub mod source_util;
 
diff --git a/src/libsyntax/parse/attr.rs b/src/libsyntax/parse/attr.rs
index ded676da3c6..082930777e5 100644
--- a/src/libsyntax/parse/attr.rs
+++ b/src/libsyntax/parse/attr.rs
@@ -10,12 +10,12 @@
 
 use attr;
 use ast;
-use syntax_pos::{mk_sp, Span};
-use codemap::spanned;
+use codemap::respan;
 use parse::common::SeqSep;
 use parse::PResult;
-use parse::token;
-use parse::parser::{Parser, TokenType};
+use parse::token::{self, Nonterminal};
+use parse::parser::{Parser, TokenType, PathStyle};
+use tokenstream::TokenStream;
 
 #[derive(PartialEq, Eq, Debug)]
 enum InnerAttributeParsePolicy<'a> {
@@ -48,8 +48,7 @@ impl<'a> Parser<'a> {
                     just_parsed_doc_comment = false;
                 }
                 token::DocComment(s) => {
-                    let Span { lo, hi, .. } = self.span;
-                    let attr = attr::mk_sugared_doc_attr(attr::mk_attr_id(), s, lo, hi);
+                    let attr = attr::mk_sugared_doc_attr(attr::mk_attr_id(), s, self.span);
                     if attr.style != ast::AttrStyle::Outer {
                         let mut err = self.fatal("expected outer doc comment");
                         err.note("inner doc comments like this (starting with \
@@ -63,7 +62,7 @@ impl<'a> Parser<'a> {
                 _ => break,
             }
         }
-        return Ok(attrs);
+        Ok(attrs)
     }
 
     /// Matches `attribute = # ! [ meta_item ]`
@@ -91,9 +90,9 @@ impl<'a> Parser<'a> {
         debug!("parse_attribute_with_inner_parse_policy: inner_parse_policy={:?} self.token={:?}",
                inner_parse_policy,
                self.token);
-        let (span, value, mut style) = match self.token {
+        let (span, path, tokens, mut style) = match self.token {
             token::Pound => {
-                let lo = self.span.lo;
+                let lo = self.span;
                 self.bump();
 
                 if inner_parse_policy == InnerAttributeParsePolicy::Permitted {
@@ -119,11 +118,11 @@ impl<'a> Parser<'a> {
                 };
 
                 self.expect(&token::OpenDelim(token::Bracket))?;
-                let meta_item = self.parse_meta_item()?;
+                let (path, tokens) = self.parse_path_and_tokens()?;
                 self.expect(&token::CloseDelim(token::Bracket))?;
-                let hi = self.prev_span.hi;
+                let hi = self.prev_span;
 
-                (mk_sp(lo, hi), meta_item, style)
+                (lo.to(hi), path, tokens, style)
             }
             _ => {
                 let token_str = self.this_token_to_string();
@@ -143,12 +142,30 @@ impl<'a> Parser<'a> {
         Ok(ast::Attribute {
             id: attr::mk_attr_id(),
             style: style,
-            value: value,
+            path: path,
+            tokens: tokens,
             is_sugared_doc: false,
             span: span,
         })
     }
 
+    pub fn parse_path_and_tokens(&mut self) -> PResult<'a, (ast::Path, TokenStream)> {
+        let meta = match self.token {
+            token::Interpolated(ref nt) => match **nt {
+                Nonterminal::NtMeta(ref meta) => Some(meta.clone()),
+                _ => None,
+            },
+            _ => None,
+        };
+        Ok(if let Some(meta) = meta {
+            self.bump();
+            (ast::Path::from_ident(meta.span, ast::Ident::with_empty_ctxt(meta.name)),
+             meta.node.tokens(meta.span))
+        } else {
+            (self.parse_path(PathStyle::Mod)?, self.parse_tokens())
+        })
+    }
+
     /// Parse attributes that appear after the opening of an item. These should
     /// be preceded by an exclamation mark, but we accept and warn about one
     /// terminated by a semicolon.
@@ -165,13 +182,12 @@ impl<'a> Parser<'a> {
                     }
 
                     let attr = self.parse_attribute(true)?;
-                    assert!(attr.style == ast::AttrStyle::Inner);
+                    assert_eq!(attr.style, ast::AttrStyle::Inner);
                     attrs.push(attr);
                 }
                 token::DocComment(s) => {
                     // we need to get the position of this token before we bump.
-                    let Span { lo, hi, .. } = self.span;
-                    let attr = attr::mk_sugared_doc_attr(attr::mk_attr_id(), s, lo, hi);
+                    let attr = attr::mk_sugared_doc_attr(attr::mk_attr_id(), s, self.span);
                     if attr.style == ast::AttrStyle::Inner {
                         attrs.push(attr);
                         self.bump();
@@ -219,41 +235,44 @@ impl<'a> Parser<'a> {
             return Ok(meta);
         }
 
-        let lo = self.span.lo;
+        let lo = self.span;
         let ident = self.parse_ident()?;
-        let node = if self.eat(&token::Eq) {
+        let node = self.parse_meta_item_kind()?;
+        Ok(ast::MetaItem { name: ident.name, node: node, span: lo.to(self.prev_span) })
+    }
+
+    pub fn parse_meta_item_kind(&mut self) -> PResult<'a, ast::MetaItemKind> {
+        Ok(if self.eat(&token::Eq) {
             ast::MetaItemKind::NameValue(self.parse_unsuffixed_lit()?)
         } else if self.token == token::OpenDelim(token::Paren) {
             ast::MetaItemKind::List(self.parse_meta_seq()?)
         } else {
+            self.eat(&token::OpenDelim(token::Paren));
             ast::MetaItemKind::Word
-        };
-        let hi = self.prev_span.hi;
-        Ok(ast::MetaItem { name: ident.name, node: node, span: mk_sp(lo, hi) })
+        })
     }
 
     /// matches meta_item_inner : (meta_item | UNSUFFIXED_LIT) ;
     fn parse_meta_item_inner(&mut self) -> PResult<'a, ast::NestedMetaItem> {
-        let sp = self.span;
-        let lo = self.span.lo;
+        let lo = self.span;
 
         match self.parse_unsuffixed_lit() {
             Ok(lit) => {
-                return Ok(spanned(lo, self.prev_span.hi, ast::NestedMetaItemKind::Literal(lit)))
+                return Ok(respan(lo.to(self.prev_span), ast::NestedMetaItemKind::Literal(lit)))
             }
             Err(ref mut err) => self.diagnostic().cancel(err)
         }
 
         match self.parse_meta_item() {
             Ok(mi) => {
-                return Ok(spanned(lo, self.prev_span.hi, ast::NestedMetaItemKind::MetaItem(mi)))
+                return Ok(respan(lo.to(self.prev_span), ast::NestedMetaItemKind::MetaItem(mi)))
             }
             Err(ref mut err) => self.diagnostic().cancel(err)
         }
 
         let found = self.this_token_to_string();
         let msg = format!("expected unsuffixed literal or identifier, found {}", found);
-        Err(self.diagnostic().struct_span_err(sp, &msg))
+        Err(self.diagnostic().struct_span_err(lo, &msg))
     }
 
     /// matches meta_seq = ( COMMASEP(meta_item_inner) )
diff --git a/src/libsyntax/parse/classify.rs b/src/libsyntax/parse/classify.rs
index 4fe4ec7e4c0..0c6f09ba766 100644
--- a/src/libsyntax/parse/classify.rs
+++ b/src/libsyntax/parse/classify.rs
@@ -43,14 +43,14 @@ pub fn expr_is_simple_block(e: &ast::Expr) -> bool {
 }
 
 /// this statement requires a semicolon after it.
-/// note that in one case (stmt_semi), we've already
+/// note that in one case (`stmt_semi`), we've already
 /// seen the semicolon, and thus don't need another.
 pub fn stmt_ends_with_semi(stmt: &ast::StmtKind) -> bool {
     match *stmt {
         ast::StmtKind::Local(_) => true,
-        ast::StmtKind::Item(_) => false,
         ast::StmtKind::Expr(ref e) => expr_requires_semi_to_be_stmt(e),
-        ast::StmtKind::Semi(..) => false,
+        ast::StmtKind::Item(_) |
+        ast::StmtKind::Semi(..) |
         ast::StmtKind::Mac(..) => false,
     }
 }
diff --git a/src/libsyntax/parse/common.rs b/src/libsyntax/parse/common.rs
index b57708f9193..fe931f7cf6a 100644
--- a/src/libsyntax/parse/common.rs
+++ b/src/libsyntax/parse/common.rs
@@ -12,7 +12,7 @@
 
 use parse::token;
 
-/// SeqSep : a sequence separator (token)
+/// `SeqSep` : a sequence separator (token)
 /// and whether a trailing separator is allowed.
 pub struct SeqSep {
     pub sep: Option<token::Token>,
diff --git a/src/libsyntax/parse/lexer/comments.rs b/src/libsyntax/parse/lexer/comments.rs
index c97b8ddf919..8b545d3b909 100644
--- a/src/libsyntax/parse/lexer/comments.rs
+++ b/src/libsyntax/parse/lexer/comments.rs
@@ -77,7 +77,7 @@ pub fn strip_doc_comment_decoration(comment: &str) -> String {
         while j > i && lines[j - 1].trim().is_empty() {
             j -= 1;
         }
-        lines[i..j].iter().cloned().collect()
+        lines[i..j].to_vec()
     }
 
     /// remove a "[ \t]*\*" block from each line, if possible
@@ -348,8 +348,8 @@ pub fn gather_comments_and_literals(sess: &ParseSess, path: String, srdr: &mut R
     let mut src = Vec::new();
     srdr.read_to_end(&mut src).unwrap();
     let src = String::from_utf8(src).unwrap();
-    let cm = CodeMap::new();
-    let filemap = cm.new_filemap(path, None, src);
+    let cm = CodeMap::new(sess.codemap().path_mapping().clone());
+    let filemap = cm.new_filemap(path, src);
     let mut rdr = lexer::StringReader::new_raw(sess, filemap);
 
     let mut comments: Vec<Comment> = Vec::new();
diff --git a/src/libsyntax/parse/lexer/mod.rs b/src/libsyntax/parse/lexer/mod.rs
index de8a87e3a2b..0bcd4578518 100644
--- a/src/libsyntax/parse/lexer/mod.rs
+++ b/src/libsyntax/parse/lexer/mod.rs
@@ -9,8 +9,8 @@
 // except according to those terms.
 
 use ast::{self, Ident};
-use syntax_pos::{self, BytePos, CharPos, Pos, Span};
-use codemap::CodeMap;
+use syntax_pos::{self, BytePos, CharPos, Pos, Span, NO_EXPANSION};
+use codemap::{CodeMap, FilePathMapping};
 use errors::{FatalError, DiagnosticBuilder};
 use parse::{token, ParseSess};
 use str::char_at;
@@ -68,8 +68,12 @@ pub struct StringReader<'a> {
     open_braces: Vec<(token::DelimToken, Span)>,
 }
 
+fn mk_sp(lo: BytePos, hi: BytePos) -> Span {
+    Span { lo: lo, hi: hi, ctxt: NO_EXPANSION }
+}
+
 impl<'a> StringReader<'a> {
-    fn next_token(&mut self) -> TokenAndSpan where Self: Sized {
+    fn next_token(&mut self) -> TokenAndSpan {
         let res = self.try_next_token();
         self.unwrap_or_abort(res)
     }
@@ -140,7 +144,7 @@ impl<'a> StringReader<'a> {
 
 impl<'a> StringReader<'a> {
     /// For comments.rs, which hackily pokes into next_pos and ch
-    pub fn new_raw<'b>(sess: &'a ParseSess, filemap: Rc<syntax_pos::FileMap>) -> Self {
+    pub fn new_raw(sess: &'a ParseSess, filemap: Rc<syntax_pos::FileMap>) -> Self {
         let mut sr = StringReader::new_raw_internal(sess, filemap);
         sr.bump();
         sr
@@ -176,7 +180,7 @@ impl<'a> StringReader<'a> {
 
     pub fn new(sess: &'a ParseSess, filemap: Rc<syntax_pos::FileMap>) -> Self {
         let mut sr = StringReader::new_raw(sess, filemap);
-        if let Err(_) = sr.advance_token() {
+        if sr.advance_token().is_err() {
             sr.emit_fatal_errors();
             panic!(FatalError);
         }
@@ -201,7 +205,7 @@ impl<'a> StringReader<'a> {
 
         sr.bump();
 
-        if let Err(_) = sr.advance_token() {
+        if sr.advance_token().is_err() {
             sr.emit_fatal_errors();
             panic!(FatalError);
         }
@@ -225,12 +229,12 @@ impl<'a> StringReader<'a> {
 
     /// Report a fatal error spanning [`from_pos`, `to_pos`).
     fn fatal_span_(&self, from_pos: BytePos, to_pos: BytePos, m: &str) -> FatalError {
-        self.fatal_span(syntax_pos::mk_sp(from_pos, to_pos), m)
+        self.fatal_span(mk_sp(from_pos, to_pos), m)
     }
 
     /// Report a lexical error spanning [`from_pos`, `to_pos`).
     fn err_span_(&self, from_pos: BytePos, to_pos: BytePos, m: &str) {
-        self.err_span(syntax_pos::mk_sp(from_pos, to_pos), m)
+        self.err_span(mk_sp(from_pos, to_pos), m)
     }
 
     /// Report a lexical error spanning [`from_pos`, `to_pos`), appending an
@@ -254,7 +258,7 @@ impl<'a> StringReader<'a> {
         for c in c.escape_default() {
             m.push(c)
         }
-        self.sess.span_diagnostic.struct_span_fatal(syntax_pos::mk_sp(from_pos, to_pos), &m[..])
+        self.sess.span_diagnostic.struct_span_fatal(mk_sp(from_pos, to_pos), &m[..])
     }
 
     /// Report a lexical error spanning [`from_pos`, `to_pos`), appending an
@@ -278,7 +282,7 @@ impl<'a> StringReader<'a> {
         for c in c.escape_default() {
             m.push(c)
         }
-        self.sess.span_diagnostic.struct_span_err(syntax_pos::mk_sp(from_pos, to_pos), &m[..])
+        self.sess.span_diagnostic.struct_span_err(mk_sp(from_pos, to_pos), &m[..])
     }
 
     /// Report a lexical error spanning [`from_pos`, `to_pos`), appending the
@@ -302,11 +306,11 @@ impl<'a> StringReader<'a> {
             None => {
                 if self.is_eof() {
                     self.peek_tok = token::Eof;
-                    self.peek_span = syntax_pos::mk_sp(self.filemap.end_pos, self.filemap.end_pos);
+                    self.peek_span = mk_sp(self.filemap.end_pos, self.filemap.end_pos);
                 } else {
                     let start_bytepos = self.pos;
                     self.peek_tok = self.next_token_inner()?;
-                    self.peek_span = syntax_pos::mk_sp(start_bytepos, self.pos);
+                    self.peek_span = mk_sp(start_bytepos, self.pos);
                 };
             }
         }
@@ -489,7 +493,7 @@ impl<'a> StringReader<'a> {
         if let Some(c) = self.ch {
             if c.is_whitespace() {
                 let msg = "called consume_any_line_comment, but there was whitespace";
-                self.sess.span_diagnostic.span_err(syntax_pos::mk_sp(self.pos, self.pos), msg);
+                self.sess.span_diagnostic.span_err(mk_sp(self.pos, self.pos), msg);
             }
         }
 
@@ -500,7 +504,7 @@ impl<'a> StringReader<'a> {
                     self.bump();
 
                     // line comments starting with "///" or "//!" are doc-comments
-                    let doc_comment = self.ch_is('/') || self.ch_is('!');
+                    let doc_comment = (self.ch_is('/') && !self.nextch_is('/')) || self.ch_is('!');
                     let start_bpos = self.pos - BytePos(2);
 
                     while !self.is_eof() {
@@ -521,7 +525,7 @@ impl<'a> StringReader<'a> {
                         self.bump();
                     }
 
-                    return if doc_comment {
+                    if doc_comment {
                         self.with_str_from(start_bpos, |string| {
                             // comments with only more "/"s are not doc comments
                             let tok = if is_doc_comment(string) {
@@ -532,15 +536,15 @@ impl<'a> StringReader<'a> {
 
                             Some(TokenAndSpan {
                                 tok: tok,
-                                sp: syntax_pos::mk_sp(start_bpos, self.pos),
+                                sp: mk_sp(start_bpos, self.pos),
                             })
                         })
                     } else {
                         Some(TokenAndSpan {
                             tok: token::Comment,
-                            sp: syntax_pos::mk_sp(start_bpos, self.pos),
+                            sp: mk_sp(start_bpos, self.pos),
                         })
-                    };
+                    }
                 }
                 Some('*') => {
                     self.bump();
@@ -559,7 +563,7 @@ impl<'a> StringReader<'a> {
 
                 // I guess this is the only way to figure out if
                 // we're at the beginning of the file...
-                let cmap = CodeMap::new();
+                let cmap = CodeMap::new(FilePathMapping::empty());
                 cmap.files.borrow_mut().push(self.filemap.clone());
                 let loc = cmap.lookup_char_pos_adj(self.pos);
                 debug!("Skipping a shebang");
@@ -571,7 +575,7 @@ impl<'a> StringReader<'a> {
                     }
                     return Some(TokenAndSpan {
                         tok: token::Shebang(self.name_from(start)),
-                        sp: syntax_pos::mk_sp(start, self.pos),
+                        sp: mk_sp(start, self.pos),
                     });
                 }
             }
@@ -599,7 +603,7 @@ impl<'a> StringReader<'a> {
                 }
                 let c = Some(TokenAndSpan {
                     tok: token::Whitespace,
-                    sp: syntax_pos::mk_sp(start_bpos, self.pos),
+                    sp: mk_sp(start_bpos, self.pos),
                 });
                 debug!("scanning whitespace: {:?}", c);
                 c
@@ -661,7 +665,7 @@ impl<'a> StringReader<'a> {
 
             Some(TokenAndSpan {
                 tok: tok,
-                sp: syntax_pos::mk_sp(start_bpos, self.pos),
+                sp: mk_sp(start_bpos, self.pos),
             })
         })
     }
@@ -725,7 +729,7 @@ impl<'a> StringReader<'a> {
                     base = 16;
                     num_digits = self.scan_digits(16, 16);
                 }
-                '0'...'9' | '_' | '.' => {
+                '0'...'9' | '_' | '.' | 'e' | 'E' => {
                     num_digits = self.scan_digits(10, 10) + 1;
                 }
                 _ => {
@@ -750,9 +754,7 @@ impl<'a> StringReader<'a> {
         // integer literal followed by field/method access or a range pattern
         // (`0..2` and `12.foo()`)
         if self.ch_is('.') && !self.nextch_is('.') &&
-           !self.nextch()
-                .unwrap_or('\0')
-                .is_xid_start() {
+           !ident_start(self.nextch()) {
             // might have stuff after the ., and if it does, it needs to start
             // with a number
             self.bump();
@@ -762,7 +764,7 @@ impl<'a> StringReader<'a> {
             }
             let pos = self.pos;
             self.check_float_base(start_bpos, pos, base);
-            return token::Float(self.name_from(start_bpos));
+            token::Float(self.name_from(start_bpos))
         } else {
             // it might be a float if it has an exponent
             if self.ch_is('e') || self.ch_is('E') {
@@ -772,7 +774,7 @@ impl<'a> StringReader<'a> {
                 return token::Float(self.name_from(start_bpos));
             }
             // but we certainly have an integer!
-            return token::Integer(self.name_from(start_bpos));
+            token::Integer(self.name_from(start_bpos))
         }
     }
 
@@ -858,7 +860,7 @@ impl<'a> StringReader<'a> {
                                 let valid = if self.ch_is('{') {
                                     self.scan_unicode_escape(delim) && !ascii_only
                                 } else {
-                                    let span = syntax_pos::mk_sp(start, self.pos);
+                                    let span = mk_sp(start, self.pos);
                                     self.sess.span_diagnostic
                                         .struct_span_err(span, "incorrect unicode escape sequence")
                                         .span_help(span,
@@ -896,13 +898,13 @@ impl<'a> StringReader<'a> {
                                                                         },
                                                                         c);
                                 if e == '\r' {
-                                    err.span_help(syntax_pos::mk_sp(escaped_pos, pos),
+                                    err.span_help(mk_sp(escaped_pos, pos),
                                                   "this is an isolated carriage return; consider \
                                                    checking your editor and version control \
                                                    settings");
                                 }
                                 if (e == '{' || e == '}') && !ascii_only {
-                                    err.span_help(syntax_pos::mk_sp(escaped_pos, pos),
+                                    err.span_help(mk_sp(escaped_pos, pos),
                                                   "if used in a formatting string, curly braces \
                                                    are escaped with `{{` and `}}`");
                                 }
@@ -1049,9 +1051,9 @@ impl<'a> StringReader<'a> {
         self.bump();
         if self.ch_is('=') {
             self.bump();
-            return token::BinOpEq(op);
+            token::BinOpEq(op)
         } else {
-            return token::BinOp(op);
+            token::BinOp(op)
         }
     }
 
@@ -1098,15 +1100,15 @@ impl<'a> StringReader<'a> {
             // One-byte tokens.
             ';' => {
                 self.bump();
-                return Ok(token::Semi);
+                Ok(token::Semi)
             }
             ',' => {
                 self.bump();
-                return Ok(token::Comma);
+                Ok(token::Comma)
             }
             '.' => {
                 self.bump();
-                return if self.ch_is('.') {
+                if self.ch_is('.') {
                     self.bump();
                     if self.ch_is('.') {
                         self.bump();
@@ -1116,61 +1118,61 @@ impl<'a> StringReader<'a> {
                     }
                 } else {
                     Ok(token::Dot)
-                };
+                }
             }
             '(' => {
                 self.bump();
-                return Ok(token::OpenDelim(token::Paren));
+                Ok(token::OpenDelim(token::Paren))
             }
             ')' => {
                 self.bump();
-                return Ok(token::CloseDelim(token::Paren));
+                Ok(token::CloseDelim(token::Paren))
             }
             '{' => {
                 self.bump();
-                return Ok(token::OpenDelim(token::Brace));
+                Ok(token::OpenDelim(token::Brace))
             }
             '}' => {
                 self.bump();
-                return Ok(token::CloseDelim(token::Brace));
+                Ok(token::CloseDelim(token::Brace))
             }
             '[' => {
                 self.bump();
-                return Ok(token::OpenDelim(token::Bracket));
+                Ok(token::OpenDelim(token::Bracket))
             }
             ']' => {
                 self.bump();
-                return Ok(token::CloseDelim(token::Bracket));
+                Ok(token::CloseDelim(token::Bracket))
             }
             '@' => {
                 self.bump();
-                return Ok(token::At);
+                Ok(token::At)
             }
             '#' => {
                 self.bump();
-                return Ok(token::Pound);
+                Ok(token::Pound)
             }
             '~' => {
                 self.bump();
-                return Ok(token::Tilde);
+                Ok(token::Tilde)
             }
             '?' => {
                 self.bump();
-                return Ok(token::Question);
+                Ok(token::Question)
             }
             ':' => {
                 self.bump();
                 if self.ch_is(':') {
                     self.bump();
-                    return Ok(token::ModSep);
+                    Ok(token::ModSep)
                 } else {
-                    return Ok(token::Colon);
+                    Ok(token::Colon)
                 }
             }
 
             '$' => {
                 self.bump();
-                return Ok(token::Dollar);
+                Ok(token::Dollar)
             }
 
             // Multi-byte tokens.
@@ -1178,21 +1180,21 @@ impl<'a> StringReader<'a> {
                 self.bump();
                 if self.ch_is('=') {
                     self.bump();
-                    return Ok(token::EqEq);
+                    Ok(token::EqEq)
                 } else if self.ch_is('>') {
                     self.bump();
-                    return Ok(token::FatArrow);
+                    Ok(token::FatArrow)
                 } else {
-                    return Ok(token::Eq);
+                    Ok(token::Eq)
                 }
             }
             '!' => {
                 self.bump();
                 if self.ch_is('=') {
                     self.bump();
-                    return Ok(token::Ne);
+                    Ok(token::Ne)
                 } else {
-                    return Ok(token::Not);
+                    Ok(token::Not)
                 }
             }
             '<' => {
@@ -1200,21 +1202,21 @@ impl<'a> StringReader<'a> {
                 match self.ch.unwrap_or('\x00') {
                     '=' => {
                         self.bump();
-                        return Ok(token::Le);
+                        Ok(token::Le)
                     }
                     '<' => {
-                        return Ok(self.binop(token::Shl));
+                        Ok(self.binop(token::Shl))
                     }
                     '-' => {
                         self.bump();
                         match self.ch.unwrap_or('\x00') {
                             _ => {
-                                return Ok(token::LArrow);
+                                Ok(token::LArrow)
                             }
                         }
                     }
                     _ => {
-                        return Ok(token::Lt);
+                        Ok(token::Lt)
                     }
                 }
             }
@@ -1223,13 +1225,13 @@ impl<'a> StringReader<'a> {
                 match self.ch.unwrap_or('\x00') {
                     '=' => {
                         self.bump();
-                        return Ok(token::Ge);
+                        Ok(token::Ge)
                     }
                     '>' => {
-                        return Ok(self.binop(token::Shr));
+                        Ok(self.binop(token::Shr))
                     }
                     _ => {
-                        return Ok(token::Gt);
+                        Ok(token::Gt)
                     }
                 }
             }
@@ -1299,7 +1301,7 @@ impl<'a> StringReader<'a> {
                 };
                 self.bump(); // advance ch past token
                 let suffix = self.scan_optional_raw_name();
-                return Ok(token::Literal(token::Char(id), suffix));
+                Ok(token::Literal(token::Char(id), suffix))
             }
             'b' => {
                 self.bump();
@@ -1310,7 +1312,7 @@ impl<'a> StringReader<'a> {
                     _ => unreachable!(),  // Should have been a token::Ident above.
                 };
                 let suffix = self.scan_optional_raw_name();
-                return Ok(token::Literal(lit, suffix));
+                Ok(token::Literal(lit, suffix))
             }
             '"' => {
                 let start_bpos = self.pos;
@@ -1341,7 +1343,7 @@ impl<'a> StringReader<'a> {
                 };
                 self.bump();
                 let suffix = self.scan_optional_raw_name();
-                return Ok(token::Literal(token::Str_(id), suffix));
+                Ok(token::Literal(token::Str_(id), suffix))
             }
             'r' => {
                 let start_bpos = self.pos;
@@ -1412,24 +1414,24 @@ impl<'a> StringReader<'a> {
                     Symbol::intern("??")
                 };
                 let suffix = self.scan_optional_raw_name();
-                return Ok(token::Literal(token::StrRaw(id, hash_count), suffix));
+                Ok(token::Literal(token::StrRaw(id, hash_count), suffix))
             }
             '-' => {
                 if self.nextch_is('>') {
                     self.bump();
                     self.bump();
-                    return Ok(token::RArrow);
+                    Ok(token::RArrow)
                 } else {
-                    return Ok(self.binop(token::Minus));
+                    Ok(self.binop(token::Minus))
                 }
             }
             '&' => {
                 if self.nextch_is('&') {
                     self.bump();
                     self.bump();
-                    return Ok(token::AndAnd);
+                    Ok(token::AndAnd)
                 } else {
-                    return Ok(self.binop(token::And));
+                    Ok(self.binop(token::And))
                 }
             }
             '|' => {
@@ -1437,27 +1439,27 @@ impl<'a> StringReader<'a> {
                     Some('|') => {
                         self.bump();
                         self.bump();
-                        return Ok(token::OrOr);
+                        Ok(token::OrOr)
                     }
                     _ => {
-                        return Ok(self.binop(token::Or));
+                        Ok(self.binop(token::Or))
                     }
                 }
             }
             '+' => {
-                return Ok(self.binop(token::Plus));
+                Ok(self.binop(token::Plus))
             }
             '*' => {
-                return Ok(self.binop(token::Star));
+                Ok(self.binop(token::Star))
             }
             '/' => {
-                return Ok(self.binop(token::Slash));
+                Ok(self.binop(token::Slash))
             }
             '^' => {
-                return Ok(self.binop(token::Caret));
+                Ok(self.binop(token::Caret))
             }
             '%' => {
-                return Ok(self.binop(token::Percent));
+                Ok(self.binop(token::Percent))
             }
             c => {
                 let last_bpos = self.pos;
@@ -1466,7 +1468,7 @@ impl<'a> StringReader<'a> {
                                                           bpos,
                                                           "unknown start of token",
                                                           c);
-                unicode_chars::check_for_substitution(&self, c, &mut err);
+                unicode_chars::check_for_substitution(self, c, &mut err);
                 self.fatal_errs.push(err);
                 Err(())
             }
@@ -1488,14 +1490,14 @@ impl<'a> StringReader<'a> {
         if self.ch_is('\n') {
             self.bump();
         }
-        return val;
+        val
     }
 
     fn read_one_line_comment(&mut self) -> String {
         let val = self.read_to_eol();
         assert!((val.as_bytes()[0] == b'/' && val.as_bytes()[1] == b'/') ||
                 (val.as_bytes()[0] == b'#' && val.as_bytes()[1] == b'!'));
-        return val;
+        val
     }
 
     fn consume_non_eol_whitespace(&mut self) {
@@ -1539,7 +1541,7 @@ impl<'a> StringReader<'a> {
             Symbol::intern("?")
         };
         self.bump(); // advance ch past token
-        return token::Byte(id);
+        token::Byte(id)
     }
 
     fn scan_byte_escape(&mut self, delim: char, below_0x7f_only: bool) -> bool {
@@ -1572,7 +1574,7 @@ impl<'a> StringReader<'a> {
             Symbol::intern("??")
         };
         self.bump();
-        return token::ByteStr(id);
+        token::ByteStr(id)
     }
 
     fn scan_raw_byte_string(&mut self) -> token::Lit {
@@ -1625,8 +1627,8 @@ impl<'a> StringReader<'a> {
             self.bump();
         }
         self.bump();
-        return token::ByteStrRaw(self.name_from_to(content_start_bpos, content_end_bpos),
-                                 hash_count);
+        token::ByteStrRaw(self.name_from_to(content_start_bpos, content_end_bpos),
+                                 hash_count)
     }
 }
 
@@ -1644,7 +1646,7 @@ fn in_range(c: Option<char>, lo: char, hi: char) -> bool {
 }
 
 fn is_dec_digit(c: Option<char>) -> bool {
-    return in_range(c, '0', '9');
+    in_range(c, '0', '9')
 }
 
 pub fn is_doc_comment(s: &str) -> bool {
@@ -1714,13 +1716,13 @@ mod tests {
                  sess: &'a ParseSess,
                  teststr: String)
                  -> StringReader<'a> {
-        let fm = cm.new_filemap("zebra.rs".to_string(), None, teststr);
+        let fm = cm.new_filemap("zebra.rs".to_string(), teststr);
         StringReader::new(sess, fm)
     }
 
     #[test]
     fn t1() {
-        let cm = Rc::new(CodeMap::new());
+        let cm = Rc::new(CodeMap::new(FilePathMapping::empty()));
         let sh = mk_sess(cm.clone());
         let mut string_reader = setup(&cm,
                                       &sh,
@@ -1735,7 +1737,7 @@ mod tests {
             sp: Span {
                 lo: BytePos(21),
                 hi: BytePos(23),
-                expn_id: NO_EXPANSION,
+                ctxt: NO_EXPANSION,
             },
         };
         assert_eq!(tok1, tok2);
@@ -1749,7 +1751,7 @@ mod tests {
             sp: Span {
                 lo: BytePos(24),
                 hi: BytePos(28),
-                expn_id: NO_EXPANSION,
+                ctxt: NO_EXPANSION,
             },
         };
         assert_eq!(tok3, tok4);
@@ -1772,7 +1774,7 @@ mod tests {
 
     #[test]
     fn doublecolonparsing() {
-        let cm = Rc::new(CodeMap::new());
+        let cm = Rc::new(CodeMap::new(FilePathMapping::empty()));
         let sh = mk_sess(cm.clone());
         check_tokenization(setup(&cm, &sh, "a b".to_string()),
                            vec![mk_ident("a"), token::Whitespace, mk_ident("b")]);
@@ -1780,7 +1782,7 @@ mod tests {
 
     #[test]
     fn dcparsing_2() {
-        let cm = Rc::new(CodeMap::new());
+        let cm = Rc::new(CodeMap::new(FilePathMapping::empty()));
         let sh = mk_sess(cm.clone());
         check_tokenization(setup(&cm, &sh, "a::b".to_string()),
                            vec![mk_ident("a"), token::ModSep, mk_ident("b")]);
@@ -1788,7 +1790,7 @@ mod tests {
 
     #[test]
     fn dcparsing_3() {
-        let cm = Rc::new(CodeMap::new());
+        let cm = Rc::new(CodeMap::new(FilePathMapping::empty()));
         let sh = mk_sess(cm.clone());
         check_tokenization(setup(&cm, &sh, "a ::b".to_string()),
                            vec![mk_ident("a"), token::Whitespace, token::ModSep, mk_ident("b")]);
@@ -1796,7 +1798,7 @@ mod tests {
 
     #[test]
     fn dcparsing_4() {
-        let cm = Rc::new(CodeMap::new());
+        let cm = Rc::new(CodeMap::new(FilePathMapping::empty()));
         let sh = mk_sess(cm.clone());
         check_tokenization(setup(&cm, &sh, "a:: b".to_string()),
                            vec![mk_ident("a"), token::ModSep, token::Whitespace, mk_ident("b")]);
@@ -1804,7 +1806,7 @@ mod tests {
 
     #[test]
     fn character_a() {
-        let cm = Rc::new(CodeMap::new());
+        let cm = Rc::new(CodeMap::new(FilePathMapping::empty()));
         let sh = mk_sess(cm.clone());
         assert_eq!(setup(&cm, &sh, "'a'".to_string()).next_token().tok,
                    token::Literal(token::Char(Symbol::intern("a")), None));
@@ -1812,7 +1814,7 @@ mod tests {
 
     #[test]
     fn character_space() {
-        let cm = Rc::new(CodeMap::new());
+        let cm = Rc::new(CodeMap::new(FilePathMapping::empty()));
         let sh = mk_sess(cm.clone());
         assert_eq!(setup(&cm, &sh, "' '".to_string()).next_token().tok,
                    token::Literal(token::Char(Symbol::intern(" ")), None));
@@ -1820,7 +1822,7 @@ mod tests {
 
     #[test]
     fn character_escaped() {
-        let cm = Rc::new(CodeMap::new());
+        let cm = Rc::new(CodeMap::new(FilePathMapping::empty()));
         let sh = mk_sess(cm.clone());
         assert_eq!(setup(&cm, &sh, "'\\n'".to_string()).next_token().tok,
                    token::Literal(token::Char(Symbol::intern("\\n")), None));
@@ -1828,7 +1830,7 @@ mod tests {
 
     #[test]
     fn lifetime_name() {
-        let cm = Rc::new(CodeMap::new());
+        let cm = Rc::new(CodeMap::new(FilePathMapping::empty()));
         let sh = mk_sess(cm.clone());
         assert_eq!(setup(&cm, &sh, "'abc".to_string()).next_token().tok,
                    token::Lifetime(Ident::from_str("'abc")));
@@ -1836,7 +1838,7 @@ mod tests {
 
     #[test]
     fn raw_string() {
-        let cm = Rc::new(CodeMap::new());
+        let cm = Rc::new(CodeMap::new(FilePathMapping::empty()));
         let sh = mk_sess(cm.clone());
         assert_eq!(setup(&cm, &sh, "r###\"\"#a\\b\x00c\"\"###".to_string())
                        .next_token()
@@ -1846,7 +1848,7 @@ mod tests {
 
     #[test]
     fn literal_suffixes() {
-        let cm = Rc::new(CodeMap::new());
+        let cm = Rc::new(CodeMap::new(FilePathMapping::empty()));
         let sh = mk_sess(cm.clone());
         macro_rules! test {
             ($input: expr, $tok_type: ident, $tok_contents: expr) => {{
@@ -1890,7 +1892,7 @@ mod tests {
 
     #[test]
     fn nested_block_comments() {
-        let cm = Rc::new(CodeMap::new());
+        let cm = Rc::new(CodeMap::new(FilePathMapping::empty()));
         let sh = mk_sess(cm.clone());
         let mut lexer = setup(&cm, &sh, "/* /* */ */'a'".to_string());
         match lexer.next_token().tok {
@@ -1903,12 +1905,12 @@ mod tests {
 
     #[test]
     fn crlf_comments() {
-        let cm = Rc::new(CodeMap::new());
+        let cm = Rc::new(CodeMap::new(FilePathMapping::empty()));
         let sh = mk_sess(cm.clone());
         let mut lexer = setup(&cm, &sh, "// test\r\n/// test\r\n".to_string());
         let comment = lexer.next_token();
         assert_eq!(comment.tok, token::Comment);
-        assert_eq!(comment.sp, ::syntax_pos::mk_sp(BytePos(0), BytePos(7)));
+        assert_eq!((comment.sp.lo, comment.sp.hi), (BytePos(0), BytePos(7)));
         assert_eq!(lexer.next_token().tok, token::Whitespace);
         assert_eq!(lexer.next_token().tok,
                    token::DocComment(Symbol::intern("/// test")));
diff --git a/src/libsyntax/parse/lexer/unicode_chars.rs b/src/libsyntax/parse/lexer/unicode_chars.rs
index 6da3e5de75c..83a164bdb96 100644
--- a/src/libsyntax/parse/lexer/unicode_chars.rs
+++ b/src/libsyntax/parse/lexer/unicode_chars.rs
@@ -11,7 +11,7 @@
 // Characters and their corresponding confusables were collected from
 // http://www.unicode.org/Public/security/revision-06/confusables.txt
 
-use syntax_pos::mk_sp as make_span;
+use syntax_pos::{Span, NO_EXPANSION};
 use errors::DiagnosticBuilder;
 use super::StringReader;
 
@@ -234,11 +234,11 @@ pub fn check_for_substitution<'a>(reader: &StringReader<'a>,
     .iter()
     .find(|&&(c, _, _)| c == ch)
     .map(|&(_, u_name, ascii_char)| {
-        let span = make_span(reader.pos, reader.next_pos);
+        let span = Span { lo: reader.pos, hi: reader.next_pos, ctxt: NO_EXPANSION };
         match ASCII_ARRAY.iter().find(|&&(c, _)| c == ascii_char) {
             Some(&(ascii_char, ascii_name)) => {
                 let msg =
-                    format!("unicode character '{}' ({}) looks much like '{}' ({}), but it's not",
+                    format!("unicode character '{}' ({}) looks like '{}' ({}), but it's not",
                             ch, u_name, ascii_char, ascii_name);
                 err.span_help(span, &msg);
             },
diff --git a/src/libsyntax/parse/mod.rs b/src/libsyntax/parse/mod.rs
index c00d2952b3b..3a68a6ba764 100644
--- a/src/libsyntax/parse/mod.rs
+++ b/src/libsyntax/parse/mod.rs
@@ -11,8 +11,8 @@
 //! The main parser interface
 
 use ast::{self, CrateConfig};
-use codemap::CodeMap;
-use syntax_pos::{self, Span, FileMap};
+use codemap::{CodeMap, FilePathMapping};
+use syntax_pos::{self, Span, FileMap, NO_EXPANSION};
 use errors::{Handler, ColorConfig, DiagnosticBuilder};
 use feature_gate::UnstableFeatures;
 use parse::parser::Parser;
@@ -53,8 +53,8 @@ pub struct ParseSess {
 }
 
 impl ParseSess {
-    pub fn new() -> Self {
-        let cm = Rc::new(CodeMap::new());
+    pub fn new(file_path_mapping: FilePathMapping) -> Self {
+        let cm = Rc::new(CodeMap::new(file_path_mapping));
         let handler = Handler::with_tty_emitter(ColorConfig::Auto,
                                                 true,
                                                 false,
@@ -107,18 +107,18 @@ pub fn parse_crate_attrs_from_file<'a>(input: &Path, sess: &'a ParseSess)
     parser.parse_inner_attributes()
 }
 
-pub fn parse_crate_from_source_str<'a>(name: String, source: String, sess: &'a ParseSess)
-                                       -> PResult<'a, ast::Crate> {
+pub fn parse_crate_from_source_str(name: String, source: String, sess: &ParseSess)
+                                       -> PResult<ast::Crate> {
     new_parser_from_source_str(sess, name, source).parse_crate_mod()
 }
 
-pub fn parse_crate_attrs_from_source_str<'a>(name: String, source: String, sess: &'a ParseSess)
-                                             -> PResult<'a, Vec<ast::Attribute>> {
+pub fn parse_crate_attrs_from_source_str(name: String, source: String, sess: &ParseSess)
+                                             -> PResult<Vec<ast::Attribute>> {
     new_parser_from_source_str(sess, name, source).parse_inner_attributes()
 }
 
-pub fn parse_expr_from_source_str<'a>(name: String, source: String, sess: &'a ParseSess)
-                                      -> PResult<'a, P<ast::Expr>> {
+pub fn parse_expr_from_source_str(name: String, source: String, sess: &ParseSess)
+                                      -> PResult<P<ast::Expr>> {
     new_parser_from_source_str(sess, name, source).parse_expr()
 }
 
@@ -126,30 +126,32 @@ pub fn parse_expr_from_source_str<'a>(name: String, source: String, sess: &'a Pa
 ///
 /// Returns `Ok(Some(item))` when successful, `Ok(None)` when no item was found, and`Err`
 /// when a syntax error occurred.
-pub fn parse_item_from_source_str<'a>(name: String, source: String, sess: &'a ParseSess)
-                                      -> PResult<'a, Option<P<ast::Item>>> {
+pub fn parse_item_from_source_str(name: String, source: String, sess: &ParseSess)
+                                      -> PResult<Option<P<ast::Item>>> {
     new_parser_from_source_str(sess, name, source).parse_item()
 }
 
-pub fn parse_meta_from_source_str<'a>(name: String, source: String, sess: &'a ParseSess)
-                                      -> PResult<'a, ast::MetaItem> {
+pub fn parse_meta_from_source_str(name: String, source: String, sess: &ParseSess)
+                                      -> PResult<ast::MetaItem> {
     new_parser_from_source_str(sess, name, source).parse_meta_item()
 }
 
-pub fn parse_stmt_from_source_str<'a>(name: String, source: String, sess: &'a ParseSess)
-                                      -> PResult<'a, Option<ast::Stmt>> {
+pub fn parse_stmt_from_source_str(name: String, source: String, sess: &ParseSess)
+                                      -> PResult<Option<ast::Stmt>> {
     new_parser_from_source_str(sess, name, source).parse_stmt()
 }
 
-pub fn parse_stream_from_source_str<'a>(name: String, source: String, sess: &'a ParseSess)
+pub fn parse_stream_from_source_str(name: String, source: String, sess: &ParseSess)
                                         -> TokenStream {
-    filemap_to_stream(sess, sess.codemap().new_filemap(name, None, source))
+    filemap_to_stream(sess, sess.codemap().new_filemap(name, source))
 }
 
 // Create a new parser from a source string
-pub fn new_parser_from_source_str<'a>(sess: &'a ParseSess, name: String, source: String)
-                                      -> Parser<'a> {
-    filemap_to_parser(sess, sess.codemap().new_filemap(name, None, source))
+pub fn new_parser_from_source_str(sess: &ParseSess, name: String, source: String)
+                                      -> Parser {
+    let mut parser = filemap_to_parser(sess, sess.codemap().new_filemap(name, source));
+    parser.recurse_into_file_modules = false;
+    parser
 }
 
 /// Create a new parser, handling errors as appropriate
@@ -173,12 +175,12 @@ pub fn new_sub_parser_from_file<'a>(sess: &'a ParseSess,
 }
 
 /// Given a filemap and config, return a parser
-pub fn filemap_to_parser<'a>(sess: &'a ParseSess, filemap: Rc<FileMap>, ) -> Parser<'a> {
+pub fn filemap_to_parser(sess: & ParseSess, filemap: Rc<FileMap>, ) -> Parser {
     let end_pos = filemap.end_pos;
     let mut parser = stream_to_parser(sess, filemap_to_stream(sess, filemap));
 
     if parser.token == token::Eof && parser.span == syntax_pos::DUMMY_SP {
-        parser.span = syntax_pos::mk_sp(end_pos, end_pos);
+        parser.span = Span { lo: end_pos, hi: end_pos, ctxt: NO_EXPANSION };
     }
 
     parser
@@ -186,7 +188,7 @@ pub fn filemap_to_parser<'a>(sess: &'a ParseSess, filemap: Rc<FileMap>, ) -> Par
 
 // must preserve old name for now, because quote! from the *existing*
 // compiler expands into it
-pub fn new_parser_from_tts<'a>(sess: &'a ParseSess, tts: Vec<TokenTree>) -> Parser<'a> {
+pub fn new_parser_from_tts(sess: &ParseSess, tts: Vec<TokenTree>) -> Parser {
     stream_to_parser(sess, tts.into_iter().collect())
 }
 
@@ -216,11 +218,9 @@ pub fn filemap_to_stream(sess: &ParseSess, filemap: Rc<FileMap>) -> TokenStream
     panictry!(srdr.parse_all_token_trees())
 }
 
-/// Given stream and the ParseSess, produce a parser
-pub fn stream_to_parser<'a>(sess: &'a ParseSess, stream: TokenStream) -> Parser<'a> {
-    let mut p = Parser::new(sess, stream, None, false);
-    p.check_unknown_macro_variable();
-    p
+/// Given stream and the `ParseSess`, produce a parser
+pub fn stream_to_parser(sess: &ParseSess, stream: TokenStream) -> Parser {
+    Parser::new(sess, stream, None, true, false)
 }
 
 /// Parse a string representing a character literal into its final form.
@@ -253,7 +253,7 @@ pub fn char_lit(lit: &str) -> (char, isize) {
             (c, 4)
         }
         'u' => {
-            assert!(lit.as_bytes()[2] == b'{');
+            assert_eq!(lit.as_bytes()[2], b'{');
             let idx = lit.find('}').unwrap();
             let v = u32::from_str_radix(&lit[3..idx], 16).unwrap();
             let c = char::from_u32(v).unwrap();
@@ -263,10 +263,14 @@ pub fn char_lit(lit: &str) -> (char, isize) {
     }
 }
 
+pub fn escape_default(s: &str) -> String {
+    s.chars().map(char::escape_default).flat_map(|x| x).collect()
+}
+
 /// Parse a string representing a string literal into its final form. Does
 /// unescaping.
 pub fn str_lit(lit: &str) -> String {
-    debug!("parse_str_lit: given {}", lit.escape_default());
+    debug!("parse_str_lit: given {}", escape_default(lit));
     let mut res = String::with_capacity(lit.len());
 
     // FIXME #8372: This could be a for-loop if it didn't borrow the iterator
@@ -285,51 +289,46 @@ pub fn str_lit(lit: &str) -> String {
     }
 
     let mut chars = lit.char_indices().peekable();
-    loop {
-        match chars.next() {
-            Some((i, c)) => {
-                match c {
-                    '\\' => {
-                        let ch = chars.peek().unwrap_or_else(|| {
-                            panic!("{}", error(i))
-                        }).1;
-
-                        if ch == '\n' {
-                            eat(&mut chars);
-                        } else if ch == '\r' {
-                            chars.next();
-                            let ch = chars.peek().unwrap_or_else(|| {
-                                panic!("{}", error(i))
-                            }).1;
-
-                            if ch != '\n' {
-                                panic!("lexer accepted bare CR");
-                            }
-                            eat(&mut chars);
-                        } else {
-                            // otherwise, a normal escape
-                            let (c, n) = char_lit(&lit[i..]);
-                            for _ in 0..n - 1 { // we don't need to move past the first \
-                                chars.next();
-                            }
-                            res.push(c);
-                        }
-                    },
-                    '\r' => {
-                        let ch = chars.peek().unwrap_or_else(|| {
-                            panic!("{}", error(i))
-                        }).1;
+    while let Some((i, c)) = chars.next() {
+        match c {
+            '\\' => {
+                let ch = chars.peek().unwrap_or_else(|| {
+                    panic!("{}", error(i))
+                }).1;
+
+                if ch == '\n' {
+                    eat(&mut chars);
+                } else if ch == '\r' {
+                    chars.next();
+                    let ch = chars.peek().unwrap_or_else(|| {
+                        panic!("{}", error(i))
+                    }).1;
 
-                        if ch != '\n' {
-                            panic!("lexer accepted bare CR");
-                        }
+                    if ch != '\n' {
+                        panic!("lexer accepted bare CR");
+                    }
+                    eat(&mut chars);
+                } else {
+                    // otherwise, a normal escape
+                    let (c, n) = char_lit(&lit[i..]);
+                    for _ in 0..n - 1 { // we don't need to move past the first \
                         chars.next();
-                        res.push('\n');
                     }
-                    c => res.push(c),
+                    res.push(c);
                 }
             },
-            None => break
+            '\r' => {
+                let ch = chars.peek().unwrap_or_else(|| {
+                    panic!("{}", error(i))
+                }).1;
+
+                if ch != '\n' {
+                    panic!("lexer accepted bare CR");
+                }
+                chars.next();
+                res.push('\n');
+            }
+            c => res.push(c),
         }
     }
 
@@ -341,25 +340,19 @@ pub fn str_lit(lit: &str) -> String {
 /// Parse a string representing a raw string literal into its final form. The
 /// only operation this does is convert embedded CRLF into a single LF.
 pub fn raw_str_lit(lit: &str) -> String {
-    debug!("raw_str_lit: given {}", lit.escape_default());
+    debug!("raw_str_lit: given {}", escape_default(lit));
     let mut res = String::with_capacity(lit.len());
 
-    // FIXME #8372: This could be a for-loop if it didn't borrow the iterator
     let mut chars = lit.chars().peekable();
-    loop {
-        match chars.next() {
-            Some(c) => {
-                if c == '\r' {
-                    if *chars.peek().unwrap() != '\n' {
-                        panic!("lexer accepted bare CR");
-                    }
-                    chars.next();
-                    res.push('\n');
-                } else {
-                    res.push(c);
-                }
-            },
-            None => break
+    while let Some(c) = chars.next() {
+        if c == '\r' {
+            if *chars.peek().unwrap() != '\n' {
+                panic!("lexer accepted bare CR");
+            }
+            chars.next();
+            res.push('\n');
+        } else {
+            res.push(c);
         }
     }
 
@@ -374,38 +367,80 @@ fn looks_like_width_suffix(first_chars: &[char], s: &str) -> bool {
         s[1..].chars().all(|c| '0' <= c && c <= '9')
 }
 
-fn filtered_float_lit(data: Symbol, suffix: Option<Symbol>, sd: &Handler, sp: Span)
-                      -> ast::LitKind {
+macro_rules! err {
+    ($opt_diag:expr, |$span:ident, $diag:ident| $($body:tt)*) => {
+        match $opt_diag {
+            Some(($span, $diag)) => { $($body)* }
+            None => return None,
+        }
+    }
+}
+
+pub fn lit_token(lit: token::Lit, suf: Option<Symbol>, diag: Option<(Span, &Handler)>)
+                 -> (bool /* suffix illegal? */, Option<ast::LitKind>) {
+    use ast::LitKind;
+
+    match lit {
+       token::Byte(i) => (true, Some(LitKind::Byte(byte_lit(&i.as_str()).0))),
+       token::Char(i) => (true, Some(LitKind::Char(char_lit(&i.as_str()).0))),
+
+        // There are some valid suffixes for integer and float literals,
+        // so all the handling is done internally.
+        token::Integer(s) => (false, integer_lit(&s.as_str(), suf, diag)),
+        token::Float(s) => (false, float_lit(&s.as_str(), suf, diag)),
+
+        token::Str_(s) => {
+            let s = Symbol::intern(&str_lit(&s.as_str()));
+            (true, Some(LitKind::Str(s, ast::StrStyle::Cooked)))
+        }
+        token::StrRaw(s, n) => {
+            let s = Symbol::intern(&raw_str_lit(&s.as_str()));
+            (true, Some(LitKind::Str(s, ast::StrStyle::Raw(n))))
+        }
+        token::ByteStr(i) => {
+            (true, Some(LitKind::ByteStr(byte_str_lit(&i.as_str()))))
+        }
+        token::ByteStrRaw(i, _) => {
+            (true, Some(LitKind::ByteStr(Rc::new(i.to_string().into_bytes()))))
+        }
+    }
+}
+
+fn filtered_float_lit(data: Symbol, suffix: Option<Symbol>, diag: Option<(Span, &Handler)>)
+                      -> Option<ast::LitKind> {
     debug!("filtered_float_lit: {}, {:?}", data, suffix);
     let suffix = match suffix {
         Some(suffix) => suffix,
-        None => return ast::LitKind::FloatUnsuffixed(data),
+        None => return Some(ast::LitKind::FloatUnsuffixed(data)),
     };
 
-    match &*suffix.as_str() {
+    Some(match &*suffix.as_str() {
         "f32" => ast::LitKind::Float(data, ast::FloatTy::F32),
         "f64" => ast::LitKind::Float(data, ast::FloatTy::F64),
         suf => {
-            if suf.len() >= 2 && looks_like_width_suffix(&['f'], suf) {
-                // if it looks like a width, lets try to be helpful.
-                sd.struct_span_err(sp, &format!("invalid width `{}` for float literal", &suf[1..]))
-                 .help("valid widths are 32 and 64")
-                 .emit();
-            } else {
-                sd.struct_span_err(sp, &format!("invalid suffix `{}` for float literal", suf))
-                  .help("valid suffixes are `f32` and `f64`")
-                  .emit();
-            }
+            err!(diag, |span, diag| {
+                if suf.len() >= 2 && looks_like_width_suffix(&['f'], suf) {
+                    // if it looks like a width, lets try to be helpful.
+                    let msg = format!("invalid width `{}` for float literal", &suf[1..]);
+                    diag.struct_span_err(span, &msg).help("valid widths are 32 and 64").emit()
+                } else {
+                    let msg = format!("invalid suffix `{}` for float literal", suf);
+                    diag.struct_span_err(span, &msg)
+                        .help("valid suffixes are `f32` and `f64`")
+                        .emit();
+                }
+            });
 
             ast::LitKind::FloatUnsuffixed(data)
         }
-    }
+    })
 }
-pub fn float_lit(s: &str, suffix: Option<Symbol>, sd: &Handler, sp: Span) -> ast::LitKind {
+pub fn float_lit(s: &str, suffix: Option<Symbol>, diag: Option<(Span, &Handler)>)
+                 -> Option<ast::LitKind> {
     debug!("float_lit: {:?}, {:?}", s, suffix);
     // FIXME #2252: bounds checking float literals is deferred until trans
     let s = s.chars().filter(|&c| c != '_').collect::<String>();
-    filtered_float_lit(Symbol::intern(&s), suffix, sd, sp)
+    filtered_float_lit(Symbol::intern(&s), suffix, diag)
 }
 
 /// Parse a string representing a byte literal into its final form. Similar to `char_lit`
@@ -415,7 +450,7 @@ pub fn byte_lit(lit: &str) -> (u8, usize) {
     if lit.len() == 1 {
         (lit.as_bytes()[0], 1)
     } else {
-        assert!(lit.as_bytes()[0] == b'\\', err(0));
+        assert_eq!(lit.as_bytes()[0], b'\\', "{}", err(0));
         let b = match lit.as_bytes()[1] {
             b'"' => b'"',
             b'n' => b'\n',
@@ -436,7 +471,7 @@ pub fn byte_lit(lit: &str) -> (u8, usize) {
                 }
             }
         };
-        return (b, 2);
+        (b, 2)
     }
 }
 
@@ -447,7 +482,7 @@ pub fn byte_str_lit(lit: &str) -> Rc<Vec<u8>> {
     let error = |i| format!("lexer should have rejected {} at {}", lit, i);
 
     /// Eat everything up to a non-whitespace
-    fn eat<'a, I: Iterator<Item=(usize, u8)>>(it: &mut iter::Peekable<I>) {
+    fn eat<I: Iterator<Item=(usize, u8)>>(it: &mut iter::Peekable<I>) {
         loop {
             match it.peek().map(|x| x.1) {
                 Some(b' ') | Some(b'\n') | Some(b'\r') | Some(b'\t') => {
@@ -500,7 +535,8 @@ pub fn byte_str_lit(lit: &str) -> Rc<Vec<u8>> {
     Rc::new(res)
 }
 
-pub fn integer_lit(s: &str, suffix: Option<Symbol>, sd: &Handler, sp: Span) -> ast::LitKind {
+pub fn integer_lit(s: &str, suffix: Option<Symbol>, diag: Option<(Span, &Handler)>)
+                   -> Option<ast::LitKind> {
     // s can only be ascii, byte indexing is fine
 
     let s2 = s.chars().filter(|&c| c != '_').collect::<String>();
@@ -524,13 +560,16 @@ pub fn integer_lit(s: &str, suffix: Option<Symbol>, sd: &Handler, sp: Span) -> a
     // 1f64 and 2f32 etc. are valid float literals.
     if let Some(suf) = suffix {
         if looks_like_width_suffix(&['f'], &suf.as_str()) {
-            match base {
-                16 => sd.span_err(sp, "hexadecimal float literal is not supported"),
-                8 => sd.span_err(sp, "octal float literal is not supported"),
-                2 => sd.span_err(sp, "binary float literal is not supported"),
-                _ => ()
+            let err = match base {
+                16 => Some("hexadecimal float literal is not supported"),
+                8 => Some("octal float literal is not supported"),
+                2 => Some("binary float literal is not supported"),
+                _ => None,
+            };
+            if let Some(err) = err {
+                err!(diag, |span, diag| diag.span_err(span, err));
             }
-            return filtered_float_lit(Symbol::intern(&s), Some(suf), sd, sp)
+            return filtered_float_lit(Symbol::intern(s), Some(suf), diag)
         }
     }
 
@@ -539,7 +578,9 @@ pub fn integer_lit(s: &str, suffix: Option<Symbol>, sd: &Handler, sp: Span) -> a
     }
 
     if let Some(suf) = suffix {
-        if suf.as_str().is_empty() { sd.span_bug(sp, "found empty literal suffix in Some")}
+        if suf.as_str().is_empty() {
+            err!(diag, |span, diag| diag.span_bug(span, "found empty literal suffix in Some"));
+        }
         ty = match &*suf.as_str() {
             "isize" => ast::LitIntType::Signed(ast::IntTy::Is),
             "i8"  => ast::LitIntType::Signed(ast::IntTy::I8),
@@ -556,17 +597,20 @@ pub fn integer_lit(s: &str, suffix: Option<Symbol>, sd: &Handler, sp: Span) -> a
             suf => {
                 // i<digits> and u<digits> look like widths, so lets
                 // give an error message along those lines
-                if looks_like_width_suffix(&['i', 'u'], suf) {
-                    sd.struct_span_err(sp, &format!("invalid width `{}` for integer literal",
-                                             &suf[1..]))
-                      .help("valid widths are 8, 16, 32, 64 and 128")
-                      .emit();
-                } else {
-                    sd.struct_span_err(sp, &format!("invalid suffix `{}` for numeric literal", suf))
-                      .help("the suffix must be one of the integral types \
-                             (`u32`, `isize`, etc)")
-                      .emit();
-                }
+                err!(diag, |span, diag| {
+                    if looks_like_width_suffix(&['i', 'u'], suf) {
+                        let msg = format!("invalid width `{}` for integer literal", &suf[1..]);
+                        diag.struct_span_err(span, &msg)
+                            .help("valid widths are 8, 16, 32, 64 and 128")
+                            .emit();
+                    } else {
+                        let msg = format!("invalid suffix `{}` for numeric literal", suf);
+                        diag.struct_span_err(span, &msg)
+                            .help("the suffix must be one of the integral types \
+                                   (`u32`, `isize`, etc)")
+                            .emit();
+                    }
+                });
 
                 ty
             }
@@ -576,7 +620,7 @@ pub fn integer_lit(s: &str, suffix: Option<Symbol>, sd: &Handler, sp: Span) -> a
     debug!("integer_lit: the type is {:?}, base {:?}, the new string is {:?}, the original \
            string was {:?}, the original suffix was {:?}", ty, base, s, orig, suffix);
 
-    match u128::from_str_radix(s, base) {
+    Some(match u128::from_str_radix(s, base) {
         Ok(r) => ast::LitKind::Int(r, ty),
         Err(_) => {
             // small bases are lexed as if they were base 10, e.g, the string
@@ -588,11 +632,11 @@ pub fn integer_lit(s: &str, suffix: Option<Symbol>, sd: &Handler, sp: Span) -> a
                 s.chars().any(|c| c.to_digit(10).map_or(false, |d| d >= base));
 
             if !already_errored {
-                sd.span_err(sp, "int literal is too large");
+                err!(diag, |span, diag| diag.span_err(span, "int literal is too large"));
             }
             ast::LitKind::Int(0, ty)
         }
-    }
+    })
 }
 
 #[cfg(test)]
@@ -614,7 +658,11 @@ mod tests {
 
     // produce a syntax_pos::span
     fn sp(a: u32, b: u32) -> Span {
-        Span {lo: BytePos(a), hi: BytePos(b), expn_id: NO_EXPANSION}
+        Span {lo: BytePos(a), hi: BytePos(b), ctxt: NO_EXPANSION}
+    }
+
+    fn str2seg(s: &str, lo: u32, hi: u32) -> ast::PathSegment {
+        ast::PathSegment::from_ident(Ident::from_str(s), sp(lo, hi))
     }
 
     #[test] fn path_exprs_1() {
@@ -623,7 +671,7 @@ mod tests {
                     id: ast::DUMMY_NODE_ID,
                     node: ast::ExprKind::Path(None, ast::Path {
                         span: sp(0, 1),
-                        segments: vec![Ident::from_str("a").into()],
+                        segments: vec![str2seg("a", 0, 1)],
                     }),
                     span: sp(0, 1),
                     attrs: ThinVec::new(),
@@ -637,8 +685,8 @@ mod tests {
                     node: ast::ExprKind::Path(None, ast::Path {
                         span: sp(0, 6),
                         segments: vec![ast::PathSegment::crate_root(),
-                                       Ident::from_str("a").into(),
-                                       Ident::from_str("b").into()]
+                                       str2seg("a", 2, 3),
+                                       str2seg("b", 5, 6)]
                     }),
                     span: sp(0, 6),
                     attrs: ThinVec::new(),
@@ -744,7 +792,7 @@ mod tests {
                         id: ast::DUMMY_NODE_ID,
                         node:ast::ExprKind::Path(None, ast::Path{
                             span: sp(7, 8),
-                            segments: vec![Ident::from_str("d").into()],
+                            segments: vec![str2seg("d", 7, 8)],
                         }),
                         span:sp(7,8),
                         attrs: ThinVec::new(),
@@ -761,7 +809,7 @@ mod tests {
                            id: ast::DUMMY_NODE_ID,
                            node: ast::ExprKind::Path(None, ast::Path {
                                span:sp(0,1),
-                               segments: vec![Ident::from_str("b").into()],
+                               segments: vec![str2seg("b", 0, 1)],
                             }),
                            span: sp(0,1),
                            attrs: ThinVec::new()})),
@@ -775,7 +823,7 @@ mod tests {
     }
 
     #[test] fn parse_ident_pat () {
-        let sess = ParseSess::new();
+        let sess = ParseSess::new(FilePathMapping::empty());
         let mut parser = string_to_parser(&sess, "b".to_string());
         assert!(panictry!(parser.parse_pat())
                 == P(ast::Pat{
@@ -802,7 +850,7 @@ mod tests {
                                     ty: P(ast::Ty{id: ast::DUMMY_NODE_ID,
                                                   node: ast::TyKind::Path(None, ast::Path{
                                         span:sp(10,13),
-                                        segments: vec![Ident::from_str("i32").into()],
+                                        segments: vec![str2seg("i32", 10, 13)],
                                         }),
                                         span:sp(10,13)
                                     }),
@@ -844,7 +892,7 @@ mod tests {
                                                 node: ast::ExprKind::Path(None,
                                                       ast::Path{
                                                         span:sp(17,18),
-                                                        segments: vec![Ident::from_str("b").into()],
+                                                        segments: vec![str2seg("b", 17, 18)],
                                                       }),
                                                 span: sp(17,18),
                                                 attrs: ThinVec::new()})),
@@ -945,7 +993,7 @@ mod tests {
     }
 
     #[test] fn crlf_doc_comments() {
-        let sess = ParseSess::new();
+        let sess = ParseSess::new(FilePathMapping::empty());
 
         let name = "<source>".to_string();
         let source = "/// doc comment\r\nfn foo() {}".to_string();
@@ -957,7 +1005,7 @@ mod tests {
         let source = "/// doc comment\r\n/// line 2\r\nfn foo() {}".to_string();
         let item = parse_item_from_source_str(name.clone(), source, &sess)
             .unwrap().unwrap();
-        let docs = item.attrs.iter().filter(|a| a.name() == "doc")
+        let docs = item.attrs.iter().filter(|a| a.path == "doc")
                     .map(|a| a.value_str().unwrap().to_string()).collect::<Vec<_>>();
         let b: &[_] = &["/// doc comment".to_string(), "/// line 2".to_string()];
         assert_eq!(&docs[..], b);
@@ -970,7 +1018,7 @@ mod tests {
 
     #[test]
     fn ttdelim_span() {
-        let sess = ParseSess::new();
+        let sess = ParseSess::new(FilePathMapping::empty());
         let expr = parse::parse_expr_from_source_str("foo".to_string(),
             "foo!( fn main() { body } )".to_string(), &sess).unwrap();
 
@@ -986,4 +1034,23 @@ mod tests {
             Err(_) => panic!("could not get snippet"),
         }
     }
+
+    // This tests that when parsing a string (rather than a file) we don't try
+    // and read in a file for a module declaration and just parse a stub.
+    // See `recurse_into_file_modules` in the parser.
+    #[test]
+    fn out_of_line_mod() {
+        let sess = ParseSess::new(FilePathMapping::empty());
+        let item = parse_item_from_source_str(
+            "foo".to_owned(),
+            "mod foo { struct S; mod this_does_not_exist; }".to_owned(),
+            &sess,
+        ).unwrap().unwrap();
+
+        if let ast::ItemKind::Mod(ref m) = item.node {
+            assert!(m.items.len() == 2);
+        } else {
+            panic!();
+        }
+    }
 }
diff --git a/src/libsyntax/parse/obsolete.rs b/src/libsyntax/parse/obsolete.rs
index a46a788ca08..078e86aa294 100644
--- a/src/libsyntax/parse/obsolete.rs
+++ b/src/libsyntax/parse/obsolete.rs
@@ -36,6 +36,7 @@ pub trait ParserObsoleteMethods {
 impl<'a> ParserObsoleteMethods for parser::Parser<'a> {
     /// Reports an obsolete syntax non-fatal error.
     #[allow(unused_variables)]
+    #[allow(unreachable_code)]
     fn obsolete(&mut self, sp: Span, kind: ObsoleteSyntax) {
         let (kind_str, desc, error) = match kind {
             // Nothing here at the moment
@@ -58,7 +59,7 @@ impl<'a> ParserObsoleteMethods for parser::Parser<'a> {
 
         if !self.obsolete_set.contains(&kind) &&
             (error || self.sess.span_diagnostic.can_emit_warnings) {
-            err.note(&format!("{}", desc));
+            err.note(desc);
             self.obsolete_set.insert(kind);
         }
         err.emit();
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 6446d38e5ef..8d7c8c5248b 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -27,7 +27,7 @@ use ast::Local;
 use ast::MacStmtStyle;
 use ast::Mac_;
 use ast::{MutTy, Mutability};
-use ast::{Pat, PatKind};
+use ast::{Pat, PatKind, PathSegment};
 use ast::{PolyTraitRef, QSelf};
 use ast::{Stmt, StmtKind};
 use ast::{VariantData, StructField};
@@ -40,8 +40,8 @@ use ast::{Visibility, WhereClause};
 use ast::{BinOpKind, UnOp};
 use ast::RangeEnd;
 use {ast, attr};
-use codemap::{self, CodeMap, Spanned, spanned, respan};
-use syntax_pos::{self, Span, Pos, BytePos, mk_sp};
+use codemap::{self, CodeMap, Spanned, respan};
+use syntax_pos::{self, Span, BytePos};
 use errors::{self, DiagnosticBuilder};
 use parse::{self, classify, token};
 use parse::common::SeqSep;
@@ -57,13 +57,14 @@ use tokenstream::{self, Delimited, ThinTokenStream, TokenTree, TokenStream};
 use symbol::{Symbol, keywords};
 use util::ThinVec;
 
+use std::cmp;
 use std::collections::HashSet;
-use std::{cmp, mem, slice};
-use std::path::{Path, PathBuf};
-use std::rc::Rc;
+use std::mem;
+use std::path::{self, Path, PathBuf};
+use std::slice;
 
 bitflags! {
-    flags Restrictions: u8 {
+    pub flags Restrictions: u8 {
         const RESTRICTION_STMT_EXPR         = 1 << 0,
         const RESTRICTION_NO_STRUCT_LITERAL = 1 << 1,
     }
@@ -86,12 +87,18 @@ pub enum PathStyle {
     Expr,
 }
 
-#[derive(Clone, Copy, PartialEq)]
+#[derive(Clone, Copy, Debug, PartialEq)]
 pub enum SemiColonMode {
     Break,
     Ignore,
 }
 
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub enum BlockMode {
+    Break,
+    Ignore,
+}
+
 /// Possibly accept an `token::Interpolated` expression (a pre-parsed expression
 /// dropped into the token stream, which happens while parsing the result of
 /// macro expansion). Placement of these is not as complex as I feared it would
@@ -109,13 +116,13 @@ macro_rules! maybe_whole_expr {
                     $p.bump();
                     let span = $p.span;
                     let kind = ExprKind::Path(None, (*path).clone());
-                    return Ok($p.mk_expr(span.lo, span.hi, kind, ThinVec::new()));
+                    return Ok($p.mk_expr(span, kind, ThinVec::new()));
                 }
                 token::NtBlock(ref block) => {
                     $p.bump();
                     let span = $p.span;
                     let kind = ExprKind::Block((*block).clone());
-                    return Ok($p.mk_expr(span.lo, span.hi, kind, ThinVec::new()));
+                    return Ok($p.mk_expr(span, kind, ThinVec::new()));
                 }
                 _ => {},
             };
@@ -147,6 +154,7 @@ fn maybe_append(mut lhs: Vec<Attribute>, rhs: Option<Vec<Attribute>>)
 enum PrevTokenKind {
     DocComment,
     Comma,
+    Plus,
     Interpolated,
     Eof,
     Other,
@@ -161,6 +169,7 @@ pub struct Parser<'a> {
     /// the span of the current token:
     pub span: Span,
     /// the span of the previous token:
+    pub meta_var_span: Option<Span>,
     pub prev_span: Span,
     /// the previous token kind
     prev_token_kind: PrevTokenKind,
@@ -170,6 +179,8 @@ pub struct Parser<'a> {
     pub obsolete_set: HashSet<ObsoleteSyntax>,
     /// Used to determine the path to externally loaded source files
     pub directory: Directory,
+    /// Whether to parse sub-modules in other files.
+    pub recurse_into_file_modules: bool,
     /// Name of the root module this parser originated from. If `None`, then the
     /// name is not known. This does not change while the parser is descending
     /// into modules, and sub-parsers have new values for this name.
@@ -181,6 +192,7 @@ pub struct Parser<'a> {
     pub cfg_mods: bool,
 }
 
+
 struct TokenCursor {
     frame: TokenCursorFrame,
     stack: Vec<TokenCursorFrame>,
@@ -239,7 +251,7 @@ impl TokenCursor {
     fn next_desugared(&mut self) -> TokenAndSpan {
         let (sp, name) = match self.next() {
             TokenAndSpan { sp, tok: token::DocComment(name) } => (sp, name),
-            tok @ _ => return tok,
+            tok => return tok,
         };
 
         let stripped = strip_doc_comment_decoration(&name.as_str());
@@ -345,7 +357,7 @@ pub enum Error {
 }
 
 impl Error {
-    pub fn span_err<'a>(self, sp: Span, handler: &'a errors::Handler) -> DiagnosticBuilder<'a> {
+    pub fn span_err(self, sp: Span, handler: &errors::Handler) -> DiagnosticBuilder {
         match self {
             Error::FileNotFoundForModule { ref mod_name,
                                            ref default_path,
@@ -407,10 +419,30 @@ impl From<P<Expr>> for LhsExpr {
     }
 }
 
+/// Create a placeholder argument.
+fn dummy_arg(span: Span) -> Arg {
+    let spanned = Spanned {
+        span: span,
+        node: keywords::Invalid.ident()
+    };
+    let pat = P(Pat {
+        id: ast::DUMMY_NODE_ID,
+        node: PatKind::Ident(BindingMode::ByValue(Mutability::Immutable), spanned, None),
+        span: span
+    });
+    let ty = Ty {
+        node: TyKind::Err,
+        span: span,
+        id: ast::DUMMY_NODE_ID
+    };
+    Arg { ty: P(ty), pat: pat, id: ast::DUMMY_NODE_ID }
+}
+
 impl<'a> Parser<'a> {
     pub fn new(sess: &'a ParseSess,
                tokens: TokenStream,
                directory: Option<Directory>,
+               recurse_into_file_modules: bool,
                desugar_doc_comments: bool)
                -> Self {
         let mut parser = Parser {
@@ -418,9 +450,11 @@ impl<'a> Parser<'a> {
             token: token::Underscore,
             span: syntax_pos::DUMMY_SP,
             prev_span: syntax_pos::DUMMY_SP,
+            meta_var_span: None,
             prev_token_kind: PrevTokenKind::Other,
             restrictions: Restrictions::empty(),
             obsolete_set: HashSet::new(),
+            recurse_into_file_modules: recurse_into_file_modules,
             directory: Directory { path: PathBuf::new(), ownership: DirectoryOwnership::Owned },
             root_module_name: None,
             expected_tokens: Vec::new(),
@@ -438,19 +472,23 @@ impl<'a> Parser<'a> {
         let tok = parser.next_tok();
         parser.token = tok.tok;
         parser.span = tok.sp;
+
         if let Some(directory) = directory {
             parser.directory = directory;
         } else if parser.span != syntax_pos::DUMMY_SP {
             parser.directory.path = PathBuf::from(sess.codemap().span_to_filename(parser.span));
             parser.directory.path.pop();
         }
+
+        parser.process_potential_macro_variable();
         parser
     }
 
     fn next_tok(&mut self) -> TokenAndSpan {
-        let mut next = match self.desugar_doc_comments {
-            true => self.token_cursor.next_desugared(),
-            false => self.token_cursor.next(),
+        let mut next = if self.desugar_doc_comments {
+            self.token_cursor.next_desugared()
+        } else {
+            self.token_cursor.next()
         };
         if next.sp == syntax_pos::DUMMY_SP {
             next.sp = self.prev_span;
@@ -521,7 +559,7 @@ impl<'a> Parser<'a> {
             // This might be a sign we need a connect method on Iterator.
             let b = i.next()
                      .map_or("".to_string(), |t| t.to_string());
-            i.enumerate().fold(b, |mut b, (i, ref a)| {
+            i.enumerate().fold(b, |mut b, (i, a)| {
                 if tokens.len() > 2 && i == tokens.len() - 2 {
                     b.push_str(", or ");
                 } else if tokens.len() == 2 && i == tokens.len() - 2 {
@@ -549,20 +587,35 @@ impl<'a> Parser<'a> {
             expected.dedup();
             let expect = tokens_to_string(&expected[..]);
             let actual = self.this_token_to_string();
-            Err(self.fatal(
-                &(if expected.len() > 1 {
-                    (format!("expected one of {}, found `{}`",
-                             expect,
-                             actual))
-                } else if expected.is_empty() {
-                    (format!("unexpected token: `{}`",
-                             actual))
+            let (msg_exp, (label_sp, label_exp)) = if expected.len() > 1 {
+                let short_expect = if expected.len() > 6 {
+                    format!("{} possible tokens", expected.len())
                 } else {
-                    (format!("expected {}, found `{}`",
-                             expect,
-                             actual))
-                })[..]
-            ))
+                    expect.clone()
+                };
+                (format!("expected one of {}, found `{}`", expect, actual),
+                 (self.prev_span.next_point(), format!("expected one of {} here", short_expect)))
+            } else if expected.is_empty() {
+                (format!("unexpected token: `{}`", actual),
+                 (self.prev_span, "unexpected token after this".to_string()))
+            } else {
+                (format!("expected {}, found `{}`", expect, actual),
+                 (self.prev_span.next_point(), format!("expected {} here", expect)))
+            };
+            let mut err = self.fatal(&msg_exp);
+            let sp = if self.token == token::Token::Eof {
+                // This is EOF, don't want to point at the following char, but rather the last token
+                self.prev_span
+            } else {
+                label_sp
+            };
+            if self.span.contains(sp) {
+                err.span_label(self.span, label_exp);
+            } else {
+                err.span_label(sp, label_exp);
+                err.span_label(self.span, "unexpected token");
+            }
+            Err(err)
         }
     }
 
@@ -732,7 +785,7 @@ impl<'a> Parser<'a> {
             token::AndAnd => {
                 let span = self.span;
                 let lo = span.lo + BytePos(1);
-                Ok(self.bump_with(token::BinOp(token::And), lo, span.hi))
+                Ok(self.bump_with(token::BinOp(token::And), Span { lo: lo, ..span }))
             }
             _ => self.unexpected()
         }
@@ -766,7 +819,7 @@ impl<'a> Parser<'a> {
             token::BinOp(token::Shl) => {
                 let span = self.span;
                 let lo = span.lo + BytePos(1);
-                self.bump_with(token::Lt, lo, span.hi);
+                self.bump_with(token::Lt, Span { lo: lo, ..span });
                 true
             }
             _ => false,
@@ -794,17 +847,17 @@ impl<'a> Parser<'a> {
             token::BinOp(token::Shr) => {
                 let span = self.span;
                 let lo = span.lo + BytePos(1);
-                Ok(self.bump_with(token::Gt, lo, span.hi))
+                Ok(self.bump_with(token::Gt, Span { lo: lo, ..span }))
             }
             token::BinOpEq(token::Shr) => {
                 let span = self.span;
                 let lo = span.lo + BytePos(1);
-                Ok(self.bump_with(token::Ge, lo, span.hi))
+                Ok(self.bump_with(token::Ge, Span { lo: lo, ..span }))
             }
             token::Ge => {
                 let span = self.span;
                 let lo = span.lo + BytePos(1);
-                Ok(self.bump_with(token::Eq, lo, span.hi))
+                Ok(self.bump_with(token::Eq, Span { lo: lo, ..span }))
             }
             _ => self.unexpected()
         }
@@ -891,7 +944,7 @@ impl<'a> Parser<'a> {
 
         self.parse_seq_to_before_tokens(kets,
                                         SeqSep::none(),
-                                        |p| p.parse_token_tree(),
+                                        |p| Ok(p.parse_token_tree()),
                                         |mut e| handler.cancel(&mut e));
     }
 
@@ -940,18 +993,15 @@ impl<'a> Parser<'a> {
                 token::CloseDelim(..) | token::Eof => break,
                 _ => {}
             };
-            match sep.sep {
-                Some(ref t) => {
-                    if first {
-                        first = false;
-                    } else {
-                        if let Err(e) = self.expect(t) {
-                            fe(e);
-                            break;
-                        }
+            if let Some(ref t) = sep.sep {
+                if first {
+                    first = false;
+                } else {
+                    if let Err(e) = self.expect(t) {
+                        fe(e);
+                        break;
                     }
                 }
-                _ => ()
             }
             if sep.trailing_sep_allowed && kets.iter().any(|k| self.check(k)) {
                 break;
@@ -998,12 +1048,12 @@ impl<'a> Parser<'a> {
                            -> PResult<'a, Spanned<Vec<T>>> where
         F: FnMut(&mut Parser<'a>) -> PResult<'a,  T>,
     {
-        let lo = self.span.lo;
+        let lo = self.span;
         self.expect(bra)?;
         let result = self.parse_seq_to_before_end(ket, sep, f);
-        let hi = self.span.hi;
+        let hi = self.span;
         self.bump();
-        Ok(spanned(lo, hi, result))
+        Ok(respan(lo.to(hi), result))
     }
 
     /// Advance the parser by one token
@@ -1013,12 +1063,13 @@ impl<'a> Parser<'a> {
             self.bug("attempted to bump the parser past EOF (may be stuck in a loop)");
         }
 
-        self.prev_span = self.span;
+        self.prev_span = self.meta_var_span.take().unwrap_or(self.span);
 
         // Record last token kind for possible error recovery.
         self.prev_token_kind = match self.token {
             token::DocComment(..) => PrevTokenKind::DocComment,
             token::Comma => PrevTokenKind::Comma,
+            token::BinOp(token::Plus) => PrevTokenKind::Plus,
             token::Interpolated(..) => PrevTokenKind::Interpolated,
             token::Eof => PrevTokenKind::Eof,
             _ => PrevTokenKind::Other,
@@ -1029,21 +1080,18 @@ impl<'a> Parser<'a> {
         self.token = next.tok;
         self.expected_tokens.clear();
         // check after each token
-        self.check_unknown_macro_variable();
+        self.process_potential_macro_variable();
     }
 
     /// Advance the parser using provided token as a next one. Use this when
     /// consuming a part of a token. For example a single `<` from `<<`.
-    pub fn bump_with(&mut self,
-                     next: token::Token,
-                     lo: BytePos,
-                     hi: BytePos) {
-        self.prev_span = mk_sp(self.span.lo, lo);
+    pub fn bump_with(&mut self, next: token::Token, span: Span) {
+        self.prev_span = Span { hi: span.lo, ..self.span };
         // It would be incorrect to record the kind of the current token, but
         // fortunately for tokens currently using `bump_with`, the
         // prev_token_kind will be of no use anyway.
         self.prev_token_kind = PrevTokenKind::Other;
-        self.span = mk_sp(lo, hi);
+        self.span = span;
         self.token = next;
         self.expected_tokens.clear();
     }
@@ -1117,57 +1165,13 @@ impl<'a> Parser<'a> {
             self.check_keyword(keywords::Extern)
     }
 
-    pub fn get_lifetime(&mut self) -> ast::Ident {
+    fn get_label(&mut self) -> ast::Ident {
         match self.token {
             token::Lifetime(ref ident) => *ident,
             _ => self.bug("not a lifetime"),
         }
     }
 
-    pub fn parse_for_in_type(&mut self) -> PResult<'a, TyKind> {
-        /*
-        Parses whatever can come after a `for` keyword in a type.
-        The `for` hasn't been consumed.
-
-        - for <'lt> [unsafe] [extern "ABI"] fn (S) -> T
-        - for <'lt> path::foo(a, b) + Trait + 'a
-        */
-
-        let lo = self.span.lo;
-        let lifetime_defs = self.parse_late_bound_lifetime_defs()?;
-
-        // examine next token to decide to do
-        if self.token_is_bare_fn_keyword() {
-            self.parse_ty_bare_fn(lifetime_defs)
-        } else {
-            let hi = self.span.hi;
-            let trait_ref = self.parse_trait_ref()?;
-            let poly_trait_ref = PolyTraitRef { bound_lifetimes: lifetime_defs,
-                                                trait_ref: trait_ref,
-                                                span: mk_sp(lo, hi)};
-            let other_bounds = if self.eat(&token::BinOp(token::Plus)) {
-                self.parse_ty_param_bounds()?
-            } else {
-                Vec::new()
-            };
-            let all_bounds =
-                Some(TraitTyParamBound(poly_trait_ref, TraitBoundModifier::None)).into_iter()
-                .chain(other_bounds)
-                .collect();
-            Ok(ast::TyKind::TraitObject(all_bounds))
-        }
-    }
-
-    pub fn parse_impl_trait_type(&mut self) -> PResult<'a, TyKind> {
-        // Parses whatever can come after a `impl` keyword in a type.
-        // The `impl` has already been consumed.
-        Ok(ast::TyKind::ImplTrait(self.parse_ty_param_bounds()?))
-    }
-
-    pub fn parse_ty_path(&mut self) -> PResult<'a, TyKind> {
-        Ok(TyKind::Path(None, self.parse_path(PathStyle::Type)?))
-    }
-
     /// parse a TyKind::BareFn type:
     pub fn parse_ty_bare_fn(&mut self, lifetime_defs: Vec<LifetimeDef>)
                             -> PResult<'a, TyKind> {
@@ -1215,17 +1219,17 @@ impl<'a> Parser<'a> {
     }
 
     /// Parse the items in a trait declaration
-    pub fn parse_trait_item(&mut self) -> PResult<'a, TraitItem> {
+    pub fn parse_trait_item(&mut self, at_end: &mut bool) -> PResult<'a, TraitItem> {
         maybe_whole!(self, NtTraitItem, |x| x);
         let mut attrs = self.parse_outer_attributes()?;
-        let lo = self.span.lo;
+        let lo = self.span;
 
         let (name, node) = if self.eat_keyword(keywords::Type) {
             let TyParam {ident, bounds, default, ..} = self.parse_ty_param(vec![])?;
             self.expect(&token::Semi)?;
             (ident, TraitItemKind::Type(bounds, default))
         } else if self.is_const_item() {
-                self.expect_keyword(keywords::Const)?;
+            self.expect_keyword(keywords::Const)?;
             let ident = self.parse_ident()?;
             self.expect(&token::Colon)?;
             let ty = self.parse_ty()?;
@@ -1242,9 +1246,17 @@ impl<'a> Parser<'a> {
         } else if self.token.is_path_start() {
             // trait item macro.
             // code copied from parse_macro_use_or_failure... abstraction!
-            let lo = self.span.lo;
+            let prev_span = self.prev_span;
+            let lo = self.span;
             let pth = self.parse_path(PathStyle::Mod)?;
-            self.expect(&token::Not)?;
+
+            if pth.segments.len() == 1 {
+                if !self.eat(&token::Not) {
+                    return Err(self.missing_assoc_item_kind_err("trait", prev_span));
+                }
+            } else {
+                self.expect(&token::Not)?;
+            }
 
             // eat a matched-delimiter token tree:
             let (delim, tts) = self.expect_delimited_token_tree()?;
@@ -1252,30 +1264,12 @@ impl<'a> Parser<'a> {
                 self.expect(&token::Semi)?
             }
 
-            let mac = spanned(lo, self.prev_span.hi, Mac_ { path: pth, tts: tts });
+            let mac = respan(lo.to(self.prev_span), Mac_ { path: pth, tts: tts });
             (keywords::Invalid.ident(), ast::TraitItemKind::Macro(mac))
         } else {
             let (constness, unsafety, abi) = match self.parse_fn_front_matter() {
                 Ok(cua) => cua,
-                Err(e) => {
-                    loop {
-                        match self.token {
-                            token::Eof => break,
-                            token::CloseDelim(token::Brace) |
-                            token::Semi => {
-                                self.bump();
-                                break;
-                            }
-                            token::OpenDelim(token::Brace) => {
-                                self.parse_token_tree()?;
-                                break;
-                            }
-                            _ => self.bump(),
-                        }
-                    }
-
-                    return Err(e);
-                }
+                Err(e) => return Err(e),
             };
 
             let ident = self.parse_ident()?;
@@ -1300,11 +1294,13 @@ impl<'a> Parser<'a> {
             let body = match self.token {
                 token::Semi => {
                     self.bump();
+                    *at_end = true;
                     debug!("parse_trait_methods(): parsing required method");
                     None
                 }
                 token::OpenDelim(token::Brace) => {
                     debug!("parse_trait_methods(): parsing provided method");
+                    *at_end = true;
                     let (inner_attrs, body) = self.parse_inner_attrs_and_block()?;
                     attrs.extend(inner_attrs.iter().cloned());
                     Some(body)
@@ -1322,110 +1318,22 @@ impl<'a> Parser<'a> {
             ident: name,
             attrs: attrs,
             node: node,
-            span: mk_sp(lo, self.prev_span.hi),
+            span: lo.to(self.prev_span),
         })
     }
 
-
-    /// Parse the items in a trait declaration
-    pub fn parse_trait_items(&mut self) -> PResult<'a,  Vec<TraitItem>> {
-        self.parse_unspanned_seq(
-            &token::OpenDelim(token::Brace),
-            &token::CloseDelim(token::Brace),
-            SeqSep::none(),
-            |p| -> PResult<'a, TraitItem> {
-                p.parse_trait_item()
-            })
-    }
-
     /// Parse optional return type [ -> TY ] in function decl
     pub fn parse_ret_ty(&mut self) -> PResult<'a, FunctionRetTy> {
         if self.eat(&token::RArrow) {
             Ok(FunctionRetTy::Ty(self.parse_ty_no_plus()?))
         } else {
-            let pos = self.span.lo;
-            Ok(FunctionRetTy::Default(mk_sp(pos, pos)))
+            Ok(FunctionRetTy::Default(Span { hi: self.span.lo, ..self.span }))
         }
     }
 
-    /// Parse a type.
+    // Parse a type
     pub fn parse_ty(&mut self) -> PResult<'a, P<Ty>> {
-        let lo = self.span.lo;
-        let lhs = self.parse_ty_no_plus()?;
-
-        if !self.eat(&token::BinOp(token::Plus)) {
-            return Ok(lhs);
-        }
-
-        let mut bounds = self.parse_ty_param_bounds()?;
-
-        // In type grammar, `+` is treated like a binary operator,
-        // and hence both L and R side are required.
-        if bounds.is_empty() {
-            let prev_span = self.prev_span;
-            self.span_err(prev_span,
-                          "at least one type parameter bound \
-                          must be specified");
-        }
-
-        let mut lhs = lhs.unwrap();
-        if let TyKind::Paren(ty) = lhs.node {
-            // We have to accept the first bound in parens for backward compatibility.
-            // Example: `(Bound) + Bound + Bound`
-            lhs = ty.unwrap();
-        }
-        if let TyKind::Path(None, path) = lhs.node {
-            let poly_trait_ref = PolyTraitRef {
-                bound_lifetimes: Vec::new(),
-                trait_ref: TraitRef { path: path, ref_id: lhs.id },
-                span: lhs.span,
-            };
-            let poly_trait_ref = TraitTyParamBound(poly_trait_ref, TraitBoundModifier::None);
-            bounds.insert(0, poly_trait_ref);
-        } else {
-            let mut err = struct_span_err!(self.sess.span_diagnostic, lhs.span, E0178,
-                                            "expected a path on the left-hand side \
-                                            of `+`, not `{}`",
-                                            pprust::ty_to_string(&lhs));
-            err.span_label(lhs.span, &format!("expected a path"));
-            let hi = bounds.iter().map(|x| match *x {
-                TraitTyParamBound(ref tr, _) => tr.span.hi,
-                RegionTyParamBound(ref r) => r.span.hi,
-            }).max_by_key(|x| x.to_usize());
-            let full_span = hi.map(|hi| Span {
-                lo: lhs.span.lo,
-                hi: hi,
-                expn_id: lhs.span.expn_id,
-            });
-            match (&lhs.node, full_span) {
-                (&TyKind::Rptr(ref lifetime, ref mut_ty), Some(full_span)) => {
-                    let ty_str = pprust::to_string(|s| {
-                        use print::pp::word;
-                        use print::pprust::PrintState;
-
-                        word(&mut s.s, "&")?;
-                        s.print_opt_lifetime(lifetime)?;
-                        s.print_mutability(mut_ty.mutbl)?;
-                        s.popen()?;
-                        s.print_type(&mut_ty.ty)?;
-                        s.print_bounds(" +", &bounds)?;
-                        s.pclose()
-                    });
-                    err.span_suggestion(full_span, "try adding parentheses (per RFC 438):",
-                                        ty_str);
-                }
-
-                _ => {
-                    help!(&mut err,
-                                "perhaps you forgot parentheses? (per RFC 438)");
-                }
-            }
-            err.emit();
-        }
-
-        let sp = mk_sp(lo, self.prev_span.hi);
-        let sum = TyKind::TraitObject(bounds);
-        Ok(P(Ty {id: ast::DUMMY_NODE_ID, node: sum, span: sp}))
+        self.parse_ty_common(true)
     }
 
     /// Parse a type in restricted contexts where `+` is not permitted.
@@ -1433,15 +1341,17 @@ impl<'a> Parser<'a> {
     ///     `+` is prohibited to maintain operator priority (P(+) < P(&)).
     /// Example 2: `value1 as TYPE + value2`
     ///     `+` is prohibited to avoid interactions with expression grammar.
-    pub fn parse_ty_no_plus(&mut self) -> PResult<'a, P<Ty>> {
-        maybe_whole!(self, NtTy, |x| x);
+    fn parse_ty_no_plus(&mut self) -> PResult<'a, P<Ty>> {
+        self.parse_ty_common(false)
+    }
 
-        let lo = self.span.lo;
+    fn parse_ty_common(&mut self, allow_plus: bool) -> PResult<'a, P<Ty>> {
+        maybe_whole!(self, NtTy, |x| x);
 
-        let t = if self.eat(&token::OpenDelim(token::Paren)) {
-            // (t) is a parenthesized ty
-            // (t,) is the type of a tuple with only one field,
-            // of type t
+        let lo = self.span;
+        let node = if self.eat(&token::OpenDelim(token::Paren)) {
+            // `(TYPE)` is a parenthesized type.
+            // `(TYPE,)` is a tuple with a single field of type TYPE.
             let mut ts = vec![];
             let mut last_comma = false;
             while self.token != token::CloseDelim(token::Paren) {
@@ -1453,81 +1363,173 @@ impl<'a> Parser<'a> {
                     break;
                 }
             }
-
+            let trailing_plus = self.prev_token_kind == PrevTokenKind::Plus;
             self.expect(&token::CloseDelim(token::Paren))?;
+
             if ts.len() == 1 && !last_comma {
-                TyKind::Paren(ts.into_iter().nth(0).unwrap())
+                let ty = ts.into_iter().nth(0).unwrap().unwrap();
+                let maybe_bounds = allow_plus && self.token == token::BinOp(token::Plus);
+                match ty.node {
+                    // `(TY_BOUND_NOPAREN) + BOUND + ...`.
+                    TyKind::Path(None, ref path) if maybe_bounds => {
+                        self.parse_remaining_bounds(Vec::new(), path.clone(), lo, true)?
+                    }
+                    TyKind::TraitObject(ref bounds)
+                            if maybe_bounds && bounds.len() == 1 && !trailing_plus => {
+                        let path = match bounds[0] {
+                            TraitTyParamBound(ref pt, ..) => pt.trait_ref.path.clone(),
+                            _ => self.bug("unexpected lifetime bound"),
+                        };
+                        self.parse_remaining_bounds(Vec::new(), path, lo, true)?
+                    }
+                    // `(TYPE)`
+                    _ => TyKind::Paren(P(ty))
+                }
             } else {
                 TyKind::Tup(ts)
             }
         } else if self.eat(&token::Not) {
+            // Never type `!`
             TyKind::Never
         } else if self.eat(&token::BinOp(token::Star)) {
-            // STAR POINTER (bare pointer?)
+            // Raw pointer
             TyKind::Ptr(self.parse_ptr()?)
         } else if self.eat(&token::OpenDelim(token::Bracket)) {
-            // VECTOR
+            // Array or slice
             let t = self.parse_ty()?;
-
-            // Parse the `; e` in `[ i32; e ]`
-            // where `e` is a const expression
+            // Parse optional `; EXPR` in `[TYPE; EXPR]`
             let t = match self.maybe_parse_fixed_length_of_vec()? {
                 None => TyKind::Slice(t),
-                Some(suffix) => TyKind::Array(t, suffix)
+                Some(suffix) => TyKind::Array(t, suffix),
             };
             self.expect(&token::CloseDelim(token::Bracket))?;
             t
-        } else if self.check(&token::BinOp(token::And)) ||
-                  self.check(&token::AndAnd) {
-            // BORROWED POINTER
+        } else if self.check(&token::BinOp(token::And)) || self.check(&token::AndAnd) {
+            // Reference
             self.expect_and()?;
             self.parse_borrowed_pointee()?
-        } else if self.check_keyword(keywords::For) {
-            // FIXME `+` has incorrect priority in trait object types starting with `for` (#39317).
-            self.parse_for_in_type()?
-        } else if self.eat_keyword(keywords::Impl) {
-            // FIXME figure out priority of `+` in `impl Trait1 + Trait2` (#34511).
-            self.parse_impl_trait_type()?
-        } else if self.token_is_bare_fn_keyword() {
-            // BARE FUNCTION
-            self.parse_ty_bare_fn(Vec::new())?
         } else if self.eat_keyword_noexpect(keywords::Typeof) {
-            // TYPEOF
+            // `typeof(EXPR)`
             // In order to not be ambiguous, the type must be surrounded by parens.
             self.expect(&token::OpenDelim(token::Paren))?;
             let e = self.parse_expr()?;
             self.expect(&token::CloseDelim(token::Paren))?;
             TyKind::Typeof(e)
+        } else if self.eat(&token::Underscore) {
+            // A type to be inferred `_`
+            TyKind::Infer
         } else if self.eat_lt() {
+            // Qualified path
             let (qself, path) = self.parse_qualified_path(PathStyle::Type)?;
             TyKind::Path(Some(qself), path)
         } else if self.token.is_path_start() {
+            // Simple path
             let path = self.parse_path(PathStyle::Type)?;
             if self.eat(&token::Not) {
-                // MACRO INVOCATION
+                // Macro invocation in type position
                 let (_, tts) = self.expect_delimited_token_tree()?;
-                let hi = self.span.hi;
-                TyKind::Mac(spanned(lo, hi, Mac_ { path: path, tts: tts }))
+                TyKind::Mac(respan(lo.to(self.span), Mac_ { path: path, tts: tts }))
             } else {
-                // NAMED TYPE
-                TyKind::Path(None, path)
+                // Just a type path or bound list (trait object type) starting with a trait.
+                //   `Type`
+                //   `Trait1 + Trait2 + 'a`
+                if allow_plus && self.check(&token::BinOp(token::Plus)) {
+                    self.parse_remaining_bounds(Vec::new(), path, lo, true)?
+                } else {
+                    TyKind::Path(None, path)
+                }
             }
-        } else if self.eat(&token::Underscore) {
-            // TYPE TO BE INFERRED
-            TyKind::Infer
+        } else if self.token_is_bare_fn_keyword() {
+            // Function pointer type
+            self.parse_ty_bare_fn(Vec::new())?
+        } else if self.check_keyword(keywords::For) {
+            // Function pointer type or bound list (trait object type) starting with a poly-trait.
+            //   `for<'lt> [unsafe] [extern "ABI"] fn (&'lt S) -> T`
+            //   `for<'lt> Trait1<'lt> + Trait2 + 'a`
+            let lo = self.span;
+            let lifetime_defs = self.parse_late_bound_lifetime_defs()?;
+            if self.token_is_bare_fn_keyword() {
+                self.parse_ty_bare_fn(lifetime_defs)?
+            } else {
+                let path = self.parse_path(PathStyle::Type)?;
+                let parse_plus = allow_plus && self.check(&token::BinOp(token::Plus));
+                self.parse_remaining_bounds(lifetime_defs, path, lo, parse_plus)?
+            }
+        } else if self.eat_keyword(keywords::Impl) {
+            // FIXME: figure out priority of `+` in `impl Trait1 + Trait2` (#34511).
+            TyKind::ImplTrait(self.parse_ty_param_bounds()?)
+        } else if self.check(&token::Question) ||
+                  self.check_lifetime() && self.look_ahead(1, |t| t == &token::BinOp(token::Plus)){
+            // Bound list (trait object type)
+            TyKind::TraitObject(self.parse_ty_param_bounds_common(allow_plus)?)
         } else {
             let msg = format!("expected type, found {}", self.this_token_descr());
             return Err(self.fatal(&msg));
         };
 
-        let sp = mk_sp(lo, self.prev_span.hi);
-        Ok(P(Ty {id: ast::DUMMY_NODE_ID, node: t, span: sp}))
+        let span = lo.to(self.prev_span);
+        let ty = Ty { node: node, span: span, id: ast::DUMMY_NODE_ID };
+
+        // Try to recover from use of `+` with incorrect priority.
+        self.maybe_recover_from_bad_type_plus(allow_plus, &ty)?;
+
+        Ok(P(ty))
+    }
+
+    fn parse_remaining_bounds(&mut self, lifetime_defs: Vec<LifetimeDef>, path: ast::Path,
+                              lo: Span, parse_plus: bool) -> PResult<'a, TyKind> {
+        let poly_trait_ref = PolyTraitRef::new(lifetime_defs, path, lo.to(self.prev_span));
+        let mut bounds = vec![TraitTyParamBound(poly_trait_ref, TraitBoundModifier::None)];
+        if parse_plus {
+            self.bump(); // `+`
+            bounds.append(&mut self.parse_ty_param_bounds()?);
+        }
+        Ok(TyKind::TraitObject(bounds))
     }
 
-    pub fn parse_borrowed_pointee(&mut self) -> PResult<'a, TyKind> {
-        // look for `&'lt` or `&'foo ` and interpret `foo` as the region name:
-        let opt_lifetime = self.eat_lifetime();
-        let mutbl = self.parse_mutability()?;
+    fn maybe_recover_from_bad_type_plus(&mut self, allow_plus: bool, ty: &Ty) -> PResult<'a, ()> {
+        // Do not add `+` to expected tokens.
+        if !allow_plus || self.token != token::BinOp(token::Plus) {
+            return Ok(())
+        }
+
+        self.bump(); // `+`
+        let bounds = self.parse_ty_param_bounds()?;
+        let sum_span = ty.span.to(self.prev_span);
+
+        let mut err = struct_span_err!(self.sess.span_diagnostic, sum_span, E0178,
+            "expected a path on the left-hand side of `+`, not `{}`", pprust::ty_to_string(ty));
+
+        match ty.node {
+            TyKind::Rptr(ref lifetime, ref mut_ty) => {
+                let sum_with_parens = pprust::to_string(|s| {
+                    use print::pp::word;
+                    use print::pprust::PrintState;
+
+                    word(&mut s.s, "&")?;
+                    s.print_opt_lifetime(lifetime)?;
+                    s.print_mutability(mut_ty.mutbl)?;
+                    s.popen()?;
+                    s.print_type(&mut_ty.ty)?;
+                    s.print_bounds(" +", &bounds)?;
+                    s.pclose()
+                });
+                err.span_suggestion(sum_span, "try adding parentheses:", sum_with_parens);
+            }
+            TyKind::Ptr(..) | TyKind::BareFn(..) => {
+                err.span_label(sum_span, "perhaps you forgot parentheses?");
+            }
+            _ => {
+                err.span_label(sum_span, "expected a path");
+            },
+        }
+        err.emit();
+        Ok(())
+    }
+
+    fn parse_borrowed_pointee(&mut self) -> PResult<'a, TyKind> {
+        let opt_lifetime = if self.check_lifetime() { Some(self.expect_lifetime()) } else { None };
+        let mutbl = self.parse_mutability();
         let ty = self.parse_ty_no_plus()?;
         return Ok(TyKind::Rptr(opt_lifetime, MutTy { ty: ty, mutbl: mutbl }));
     }
@@ -1550,7 +1552,7 @@ impl<'a> Parser<'a> {
 
     pub fn is_named_argument(&mut self) -> bool {
         let offset = match self.token {
-            token::BinOp(token::And) => 1,
+            token::BinOp(token::And) |
             token::AndAnd => 1,
             _ if self.token.is_keyword(keywords::Mut) => 1,
             _ => 0
@@ -1614,7 +1616,7 @@ impl<'a> Parser<'a> {
             P(Ty {
                 id: ast::DUMMY_NODE_ID,
                 node: TyKind::Infer,
-                span: mk_sp(self.span.lo, self.span.hi),
+                span: self.span,
             })
         };
         Ok(Arg {
@@ -1643,44 +1645,15 @@ impl<'a> Parser<'a> {
                 _ => { return self.unexpected_last(&self.token); }
             },
             token::Literal(lit, suf) => {
-                let (suffix_illegal, out) = match lit {
-                    token::Byte(i) => (true, LitKind::Byte(parse::byte_lit(&i.as_str()).0)),
-                    token::Char(i) => (true, LitKind::Char(parse::char_lit(&i.as_str()).0)),
-
-                    // there are some valid suffixes for integer and
-                    // float literals, so all the handling is done
-                    // internally.
-                    token::Integer(s) => {
-                        let diag = &self.sess.span_diagnostic;
-                        (false, parse::integer_lit(&s.as_str(), suf, diag, self.span))
-                    }
-                    token::Float(s) => {
-                        let diag = &self.sess.span_diagnostic;
-                        (false, parse::float_lit(&s.as_str(), suf, diag, self.span))
-                    }
-
-                    token::Str_(s) => {
-                        let s = Symbol::intern(&parse::str_lit(&s.as_str()));
-                        (true, LitKind::Str(s, ast::StrStyle::Cooked))
-                    }
-                    token::StrRaw(s, n) => {
-                        let s = Symbol::intern(&parse::raw_str_lit(&s.as_str()));
-                        (true, LitKind::Str(s, ast::StrStyle::Raw(n)))
-                    }
-                    token::ByteStr(i) => {
-                        (true, LitKind::ByteStr(parse::byte_str_lit(&i.as_str())))
-                    }
-                    token::ByteStrRaw(i, _) => {
-                        (true, LitKind::ByteStr(Rc::new(i.to_string().into_bytes())))
-                    }
-                };
+                let diag = Some((self.span, &self.sess.span_diagnostic));
+                let (suffix_illegal, result) = parse::lit_token(lit, suf, diag);
 
                 if suffix_illegal {
                     let sp = self.span;
                     self.expect_no_suffix(sp, &format!("{} literal", lit.short_name()), suf)
                 }
 
-                out
+                result.unwrap()
             }
             _ => { return self.unexpected_last(&self.token); }
         };
@@ -1691,7 +1664,7 @@ impl<'a> Parser<'a> {
 
     /// Matches lit = true | false | token_lit
     pub fn parse_lit(&mut self) -> PResult<'a, Lit> {
-        let lo = self.span.lo;
+        let lo = self.span;
         let lit = if self.eat_keyword(keywords::True) {
             LitKind::Bool(true)
         } else if self.eat_keyword(keywords::False) {
@@ -1700,22 +1673,22 @@ impl<'a> Parser<'a> {
             let lit = self.parse_lit_token()?;
             lit
         };
-        Ok(codemap::Spanned { node: lit, span: mk_sp(lo, self.prev_span.hi) })
+        Ok(codemap::Spanned { node: lit, span: lo.to(self.prev_span) })
     }
 
     /// matches '-' lit | lit
     pub fn parse_pat_literal_maybe_minus(&mut self) -> PResult<'a, P<Expr>> {
-        let minus_lo = self.span.lo;
+        let minus_lo = self.span;
         let minus_present = self.eat(&token::BinOp(token::Minus));
-        let lo = self.span.lo;
+        let lo = self.span;
         let literal = P(self.parse_lit()?);
-        let hi = self.prev_span.hi;
-        let expr = self.mk_expr(lo, hi, ExprKind::Lit(literal), ThinVec::new());
+        let hi = self.prev_span;
+        let expr = self.mk_expr(lo.to(hi), ExprKind::Lit(literal), ThinVec::new());
 
         if minus_present {
-            let minus_hi = self.prev_span.hi;
+            let minus_hi = self.prev_span;
             let unary = self.mk_unary(UnOp::Neg, expr);
-            Ok(self.mk_expr(minus_lo, minus_hi, unary, ThinVec::new()))
+            Ok(self.mk_expr(minus_lo.to(minus_hi), unary, ThinVec::new()))
         } else {
             Ok(expr)
         }
@@ -1792,7 +1765,7 @@ impl<'a> Parser<'a> {
     pub fn parse_path(&mut self, mode: PathStyle) -> PResult<'a, ast::Path> {
         maybe_whole!(self, NtPath, |x| x);
 
-        let lo = self.span.lo;
+        let lo = self.meta_var_span.unwrap_or(self.span);
         let is_global = self.eat(&token::ModSep);
 
         // Parse any number of segments and bound sets. A segment is an
@@ -1811,28 +1784,45 @@ impl<'a> Parser<'a> {
         };
 
         if is_global {
-            segments.insert(0, ast::PathSegment::crate_root());
+            segments.insert(0, PathSegment::crate_root());
         }
 
-        // Assemble the span.
-        // FIXME(#39450) This is bogus if part of the path is macro generated.
-        let span = mk_sp(lo, self.prev_span.hi);
-
         // Assemble the result.
         Ok(ast::Path {
-            span: span,
+            span: lo.to(self.prev_span),
             segments: segments,
         })
     }
 
+    /// Like `parse_path`, but also supports parsing `Word` meta items into paths for back-compat.
+    /// This is used when parsing derive macro paths in `#[derive]` attributes.
+    pub fn parse_path_allowing_meta(&mut self, mode: PathStyle) -> PResult<'a, ast::Path> {
+        let meta_ident = match self.token {
+            token::Interpolated(ref nt) => match **nt {
+                token::NtMeta(ref meta) => match meta.node {
+                    ast::MetaItemKind::Word => Some(ast::Ident::with_empty_ctxt(meta.name)),
+                    _ => None,
+                },
+                _ => None,
+            },
+            _ => None,
+        };
+        if let Some(ident) = meta_ident {
+            self.bump();
+            return Ok(ast::Path::from_ident(self.prev_span, ident));
+        }
+        self.parse_path(mode)
+    }
+
     /// Examples:
     /// - `a::b<T,U>::c<V,W>`
     /// - `a::b<T,U>::c(V) -> W`
     /// - `a::b<T,U>::c(V)`
-    pub fn parse_path_segments_without_colons(&mut self) -> PResult<'a, Vec<ast::PathSegment>> {
+    pub fn parse_path_segments_without_colons(&mut self) -> PResult<'a, Vec<PathSegment>> {
         let mut segments = Vec::new();
         loop {
             // First, parse an identifier.
+            let ident_span = self.span;
             let identifier = self.parse_path_segment_ident()?;
 
             if self.check(&token::ModSep) && self.look_ahead(1, |t| *t == token::Lt) {
@@ -1856,7 +1846,7 @@ impl<'a> Parser<'a> {
                     bindings: bindings,
                 }.into()
             } else if self.eat(&token::OpenDelim(token::Paren)) {
-                let lo = self.prev_span.lo;
+                let lo = self.prev_span;
 
                 let inputs = self.parse_seq_to_end(
                     &token::CloseDelim(token::Paren),
@@ -1869,10 +1859,10 @@ impl<'a> Parser<'a> {
                     None
                 };
 
-                let hi = self.prev_span.hi;
+                let hi = self.prev_span;
 
                 Some(P(ast::PathParameters::Parenthesized(ast::ParenthesizedParameterData {
-                    span: mk_sp(lo, hi),
+                    span: lo.to(hi),
                     inputs: inputs,
                     output: output_ty,
                 })))
@@ -1881,7 +1871,11 @@ impl<'a> Parser<'a> {
             };
 
             // Assemble and push the result.
-            segments.push(ast::PathSegment { identifier: identifier, parameters: parameters });
+            segments.push(PathSegment {
+                identifier: identifier,
+                span: ident_span,
+                parameters: parameters
+            });
 
             // Continue only if we see a `::`
             if !self.eat(&token::ModSep) {
@@ -1892,15 +1886,16 @@ impl<'a> Parser<'a> {
 
     /// Examples:
     /// - `a::b::<T,U>::c`
-    pub fn parse_path_segments_with_colons(&mut self) -> PResult<'a, Vec<ast::PathSegment>> {
+    pub fn parse_path_segments_with_colons(&mut self) -> PResult<'a, Vec<PathSegment>> {
         let mut segments = Vec::new();
         loop {
             // First, parse an identifier.
+            let ident_span = self.span;
             let identifier = self.parse_path_segment_ident()?;
 
             // If we do not see a `::`, stop.
             if !self.eat(&token::ModSep) {
-                segments.push(identifier.into());
+                segments.push(PathSegment::from_ident(identifier, ident_span));
                 return Ok(segments);
             }
 
@@ -1909,8 +1904,9 @@ impl<'a> Parser<'a> {
                 // Consumed `a::b::<`, go look for types
                 let (lifetimes, types, bindings) = self.parse_generic_args()?;
                 self.expect_gt()?;
-                segments.push(ast::PathSegment {
+                segments.push(PathSegment {
                     identifier: identifier,
+                    span: ident_span,
                     parameters: ast::AngleBracketedParameterData {
                         lifetimes: lifetimes,
                         types: types,
@@ -1924,7 +1920,7 @@ impl<'a> Parser<'a> {
                 }
             } else {
                 // Consumed `a::`, go look for `b`
-                segments.push(identifier.into());
+                segments.push(PathSegment::from_ident(identifier, ident_span));
             }
         }
     }
@@ -1932,14 +1928,15 @@ impl<'a> Parser<'a> {
     /// Examples:
     /// - `a::b::c`
     pub fn parse_path_segments_without_types(&mut self)
-                                             -> PResult<'a, Vec<ast::PathSegment>> {
+                                             -> PResult<'a, Vec<PathSegment>> {
         let mut segments = Vec::new();
         loop {
             // First, parse an identifier.
+            let ident_span = self.span;
             let identifier = self.parse_path_segment_ident()?;
 
             // Assemble and push the result.
-            segments.push(identifier.into());
+            segments.push(PathSegment::from_ident(identifier, ident_span));
 
             // If we do not see a `::` or see `::{`/`::*`, stop.
             if !self.check(&token::ModSep) || self.is_import_coupler() {
@@ -1950,30 +1947,29 @@ impl<'a> Parser<'a> {
         }
     }
 
-    /// Parse single lifetime 'a or nothing.
-    pub fn eat_lifetime(&mut self) -> Option<Lifetime> {
+    fn check_lifetime(&mut self) -> bool {
+        self.expected_tokens.push(TokenType::Lifetime);
+        self.token.is_lifetime()
+    }
+
+    /// Parse single lifetime 'a or panic.
+    fn expect_lifetime(&mut self) -> Lifetime {
         match self.token {
             token::Lifetime(ident) => {
+                let ident_span = self.span;
                 self.bump();
-                Some(Lifetime {
-                    id: ast::DUMMY_NODE_ID,
-                    span: self.prev_span,
-                    name: ident.name
-                })
-            }
-            _ => {
-                self.expected_tokens.push(TokenType::Lifetime);
-                None
+                Lifetime { ident: ident, span: ident_span, id: ast::DUMMY_NODE_ID }
             }
+            _ => self.span_bug(self.span, "not a lifetime")
         }
     }
 
     /// Parse mutability (`mut` or nothing).
-    pub fn parse_mutability(&mut self) -> PResult<'a, Mutability> {
+    fn parse_mutability(&mut self) -> Mutability {
         if self.eat_keyword(keywords::Mut) {
-            Ok(Mutability::Mutable)
+            Mutability::Mutable
         } else {
-            Ok(Mutability::Immutable)
+            Mutability::Immutable
         }
     }
 
@@ -1989,38 +1985,37 @@ impl<'a> Parser<'a> {
     /// Parse ident (COLON expr)?
     pub fn parse_field(&mut self) -> PResult<'a, Field> {
         let attrs = self.parse_outer_attributes()?;
-        let lo = self.span.lo;
+        let lo = self.span;
         let hi;
 
         // Check if a colon exists one ahead. This means we're parsing a fieldname.
         let (fieldname, expr, is_shorthand) = if self.look_ahead(1, |t| t == &token::Colon) {
             let fieldname = self.parse_field_name()?;
             self.bump();
-            hi = self.prev_span.hi;
+            hi = self.prev_span;
             (fieldname, self.parse_expr()?, false)
         } else {
             let fieldname = self.parse_ident()?;
-            hi = self.prev_span.hi;
+            hi = self.prev_span;
 
             // Mimic `x: x` for the `x` field shorthand.
-            let path = ast::Path::from_ident(mk_sp(lo, hi), fieldname);
-            (fieldname, self.mk_expr(lo, hi, ExprKind::Path(None, path), ThinVec::new()), true)
+            let path = ast::Path::from_ident(lo.to(hi), fieldname);
+            (fieldname, self.mk_expr(lo.to(hi), ExprKind::Path(None, path), ThinVec::new()), true)
         };
         Ok(ast::Field {
-            ident: spanned(lo, hi, fieldname),
-            span: mk_sp(lo, expr.span.hi),
+            ident: respan(lo.to(hi), fieldname),
+            span: lo.to(expr.span),
             expr: expr,
             is_shorthand: is_shorthand,
             attrs: attrs.into(),
         })
     }
 
-    pub fn mk_expr(&mut self, lo: BytePos, hi: BytePos, node: ExprKind, attrs: ThinVec<Attribute>)
-                   -> P<Expr> {
+    pub fn mk_expr(&mut self, span: Span, node: ExprKind, attrs: ThinVec<Attribute>) -> P<Expr> {
         P(Expr {
             id: ast::DUMMY_NODE_ID,
             node: node,
-            span: mk_sp(lo, hi),
+            span: span,
             attrs: attrs.into(),
         })
     }
@@ -2074,12 +2069,11 @@ impl<'a> Parser<'a> {
         ExprKind::AssignOp(binop, lhs, rhs)
     }
 
-    pub fn mk_mac_expr(&mut self, lo: BytePos, hi: BytePos,
-                       m: Mac_, attrs: ThinVec<Attribute>) -> P<Expr> {
+    pub fn mk_mac_expr(&mut self, span: Span, m: Mac_, attrs: ThinVec<Attribute>) -> P<Expr> {
         P(Expr {
             id: ast::DUMMY_NODE_ID,
-            node: ExprKind::Mac(codemap::Spanned {node: m, span: mk_sp(lo, hi)}),
-            span: mk_sp(lo, hi),
+            node: ExprKind::Mac(codemap::Spanned {node: m, span: span}),
+            span: span,
             attrs: attrs,
         })
     }
@@ -2101,10 +2095,10 @@ impl<'a> Parser<'a> {
 
     fn expect_delimited_token_tree(&mut self) -> PResult<'a, (token::DelimToken, ThinTokenStream)> {
         match self.token {
-            token::OpenDelim(delim) => self.parse_token_tree().map(|tree| match tree {
-                TokenTree::Delimited(_, delimited) => (delim, delimited.stream().into()),
+            token::OpenDelim(delim) => match self.parse_token_tree() {
+                TokenTree::Delimited(_, delimited) => Ok((delim, delimited.stream().into())),
                 _ => unreachable!(),
-            }),
+            },
             _ => Err(self.fatal("expected open delimiter")),
         }
     }
@@ -2126,8 +2120,8 @@ impl<'a> Parser<'a> {
         // attributes by giving them a empty "already parsed" list.
         let mut attrs = ThinVec::new();
 
-        let lo = self.span.lo;
-        let mut hi = self.span.hi;
+        let lo = self.span;
+        let mut hi = self.span;
 
         let ex: ExprKind;
 
@@ -2156,18 +2150,19 @@ impl<'a> Parser<'a> {
                 }
                 self.bump();
 
-                hi = self.prev_span.hi;
+                hi = self.prev_span;
+                let span = lo.to(hi);
                 return if es.len() == 1 && !trailing_comma {
-                    Ok(self.mk_expr(lo, hi, ExprKind::Paren(es.into_iter().nth(0).unwrap()), attrs))
+                    Ok(self.mk_expr(span, ExprKind::Paren(es.into_iter().nth(0).unwrap()), attrs))
                 } else {
-                    Ok(self.mk_expr(lo, hi, ExprKind::Tup(es), attrs))
+                    Ok(self.mk_expr(span, ExprKind::Tup(es), attrs))
                 }
             },
             token::OpenDelim(token::Brace) => {
                 return self.parse_block_expr(lo, BlockCheckMode::Default, attrs);
             },
             token::BinOp(token::Or) |  token::OrOr => {
-                let lo = self.span.lo;
+                let lo = self.span;
                 return self.parse_lambda_expr(lo, CaptureBy::Ref, attrs);
             },
             token::OpenDelim(token::Bracket) => {
@@ -2205,34 +2200,34 @@ impl<'a> Parser<'a> {
                         ex = ExprKind::Array(vec![first_expr]);
                     }
                 }
-                hi = self.prev_span.hi;
+                hi = self.prev_span;
             }
             _ => {
                 if self.eat_lt() {
                     let (qself, path) =
                         self.parse_qualified_path(PathStyle::Expr)?;
-                    hi = path.span.hi;
-                    return Ok(self.mk_expr(lo, hi, ExprKind::Path(Some(qself), path), attrs));
+                    hi = path.span;
+                    return Ok(self.mk_expr(lo.to(hi), ExprKind::Path(Some(qself), path), attrs));
                 }
                 if self.eat_keyword(keywords::Move) {
-                    let lo = self.prev_span.lo;
+                    let lo = self.prev_span;
                     return self.parse_lambda_expr(lo, CaptureBy::Value, attrs);
                 }
                 if self.eat_keyword(keywords::If) {
                     return self.parse_if_expr(attrs);
                 }
                 if self.eat_keyword(keywords::For) {
-                    let lo = self.prev_span.lo;
+                    let lo = self.prev_span;
                     return self.parse_for_expr(None, lo, attrs);
                 }
                 if self.eat_keyword(keywords::While) {
-                    let lo = self.prev_span.lo;
+                    let lo = self.prev_span;
                     return self.parse_while_expr(None, lo, attrs);
                 }
                 if self.token.is_lifetime() {
-                    let label = Spanned { node: self.get_lifetime(),
+                    let label = Spanned { node: self.get_label(),
                                           span: self.span };
-                    let lo = self.span.lo;
+                    let lo = self.span;
                     self.bump();
                     self.expect(&token::Colon)?;
                     if self.eat_keyword(keywords::While) {
@@ -2247,13 +2242,13 @@ impl<'a> Parser<'a> {
                     return Err(self.fatal("expected `while`, `for`, or `loop` after a label"))
                 }
                 if self.eat_keyword(keywords::Loop) {
-                    let lo = self.prev_span.lo;
+                    let lo = self.prev_span;
                     return self.parse_loop_expr(None, lo, attrs);
                 }
                 if self.eat_keyword(keywords::Continue) {
                     let ex = if self.token.is_lifetime() {
                         let ex = ExprKind::Continue(Some(Spanned{
-                            node: self.get_lifetime(),
+                            node: self.get_label(),
                             span: self.span
                         }));
                         self.bump();
@@ -2261,8 +2256,8 @@ impl<'a> Parser<'a> {
                     } else {
                         ExprKind::Continue(None)
                     };
-                    let hi = self.prev_span.hi;
-                    return Ok(self.mk_expr(lo, hi, ex, attrs));
+                    let hi = self.prev_span;
+                    return Ok(self.mk_expr(lo.to(hi), ex, attrs));
                 }
                 if self.eat_keyword(keywords::Match) {
                     return self.parse_match_expr(attrs);
@@ -2273,10 +2268,16 @@ impl<'a> Parser<'a> {
                         BlockCheckMode::Unsafe(ast::UserProvided),
                         attrs);
                 }
+                if self.is_catch_expr() {
+                    assert!(self.eat_keyword(keywords::Do));
+                    assert!(self.eat_keyword(keywords::Catch));
+                    let lo = self.prev_span;
+                    return self.parse_catch_expr(lo, attrs);
+                }
                 if self.eat_keyword(keywords::Return) {
                     if self.token.can_begin_expr() {
                         let e = self.parse_expr()?;
-                        hi = e.span.hi;
+                        hi = e.span;
                         ex = ExprKind::Ret(Some(e));
                     } else {
                         ex = ExprKind::Ret(None);
@@ -2284,7 +2285,7 @@ impl<'a> Parser<'a> {
                 } else if self.eat_keyword(keywords::Break) {
                     let lt = if self.token.is_lifetime() {
                         let spanned_lt = Spanned {
-                            node: self.get_lifetime(),
+                            node: self.get_label(),
                             span: self.span
                         };
                         self.bump();
@@ -2295,13 +2296,13 @@ impl<'a> Parser<'a> {
                     let e = if self.token.can_begin_expr()
                                && !(self.token == token::OpenDelim(token::Brace)
                                     && self.restrictions.contains(
-                                           Restrictions::RESTRICTION_NO_STRUCT_LITERAL)) {
+                                           RESTRICTION_NO_STRUCT_LITERAL)) {
                         Some(self.parse_expr()?)
                     } else {
                         None
                     };
                     ex = ExprKind::Break(lt, e);
-                    hi = self.prev_span.hi;
+                    hi = self.prev_span;
                 } else if self.token.is_keyword(keywords::Let) {
                     // Catch this syntax error here, instead of in `check_strict_keywords`, so
                     // that we can explicitly mention that let is not to be used as an expression
@@ -2315,26 +2316,26 @@ impl<'a> Parser<'a> {
                     if self.eat(&token::Not) {
                         // MACRO INVOCATION expression
                         let (_, tts) = self.expect_delimited_token_tree()?;
-                        let hi = self.prev_span.hi;
-                        return Ok(self.mk_mac_expr(lo, hi, Mac_ { path: pth, tts: tts }, attrs));
+                        let hi = self.prev_span;
+                        return Ok(self.mk_mac_expr(lo.to(hi), Mac_ { path: pth, tts: tts }, attrs));
                     }
                     if self.check(&token::OpenDelim(token::Brace)) {
                         // This is a struct literal, unless we're prohibited
                         // from parsing struct literals here.
                         let prohibited = self.restrictions.contains(
-                            Restrictions::RESTRICTION_NO_STRUCT_LITERAL
+                            RESTRICTION_NO_STRUCT_LITERAL
                         );
                         if !prohibited {
                             return self.parse_struct_expr(lo, pth, attrs);
                         }
                     }
 
-                    hi = pth.span.hi;
+                    hi = pth.span;
                     ex = ExprKind::Path(None, pth);
                 } else {
                     match self.parse_lit() {
                         Ok(lit) => {
-                            hi = lit.span.hi;
+                            hi = lit.span;
                             ex = ExprKind::Lit(P(lit));
                         }
                         Err(mut err) => {
@@ -2348,10 +2349,10 @@ impl<'a> Parser<'a> {
             }
         }
 
-        return Ok(self.mk_expr(lo, hi, ex, attrs));
+        return Ok(self.mk_expr(lo.to(hi), ex, attrs));
     }
 
-    fn parse_struct_expr(&mut self, lo: BytePos, pth: ast::Path, mut attrs: ThinVec<Attribute>)
+    fn parse_struct_expr(&mut self, lo: Span, pth: ast::Path, mut attrs: ThinVec<Attribute>)
                          -> PResult<'a, P<Expr>> {
         self.bump();
         let mut fields = Vec::new();
@@ -2393,9 +2394,9 @@ impl<'a> Parser<'a> {
             }
         }
 
-        let hi = self.span.hi;
+        let span = lo.to(self.span);
         self.expect(&token::CloseDelim(token::Brace))?;
-        return Ok(self.mk_expr(lo, hi, ExprKind::Struct(pth, fields, base), attrs));
+        return Ok(self.mk_expr(span, ExprKind::Struct(pth, fields, base), attrs));
     }
 
     fn parse_or_use_outer_attributes(&mut self,
@@ -2409,7 +2410,7 @@ impl<'a> Parser<'a> {
     }
 
     /// Parse a block or unsafe block
-    pub fn parse_block_expr(&mut self, lo: BytePos, blk_mode: BlockCheckMode,
+    pub fn parse_block_expr(&mut self, lo: Span, blk_mode: BlockCheckMode,
                             outer_attrs: ThinVec<Attribute>)
                             -> PResult<'a, P<Expr>> {
 
@@ -2419,7 +2420,7 @@ impl<'a> Parser<'a> {
         attrs.extend(self.parse_inner_attributes()?);
 
         let blk = self.parse_block_tail(lo, blk_mode)?;
-        return Ok(self.mk_expr(blk.span.lo, blk.span.hi, ExprKind::Block(blk), attrs));
+        return Ok(self.mk_expr(blk.span, ExprKind::Block(blk), attrs));
     }
 
     /// parse a.b or a(13) or a[4] or just a
@@ -2430,12 +2431,12 @@ impl<'a> Parser<'a> {
 
         let b = self.parse_bottom_expr();
         let (span, b) = self.interpolated_or_expr_span(b)?;
-        self.parse_dot_or_call_expr_with(b, span.lo, attrs)
+        self.parse_dot_or_call_expr_with(b, span, attrs)
     }
 
     pub fn parse_dot_or_call_expr_with(&mut self,
                                        e0: P<Expr>,
-                                       lo: BytePos,
+                                       lo: Span,
                                        mut attrs: ThinVec<Attribute>)
                                        -> PResult<'a, P<Expr>> {
         // Stitch the list of outer attributes onto the return value.
@@ -2466,11 +2467,7 @@ impl<'a> Parser<'a> {
 
     // Assuming we have just parsed `.foo` (i.e., a dot and an ident), continue
     // parsing into an expression.
-    fn parse_dot_suffix(&mut self,
-                        ident: Ident,
-                        ident_span: Span,
-                        self_value: P<Expr>,
-                        lo: BytePos)
+    fn parse_dot_suffix(&mut self, ident: Ident, ident_span: Span, self_value: P<Expr>, lo: Span)
                         -> PResult<'a, P<Expr>> {
         let (_, tys, bindings) = if self.eat(&token::ModSep) {
             self.expect_lt()?;
@@ -2495,12 +2492,12 @@ impl<'a> Parser<'a> {
                     SeqSep::trailing_allowed(token::Comma),
                     |p| Ok(p.parse_expr()?)
                 )?;
-                let hi = self.prev_span.hi;
+                let hi = self.prev_span;
 
                 es.insert(0, self_value);
-                let id = spanned(ident_span.lo, ident_span.hi, ident);
+                let id = respan(ident_span.to(ident_span), ident);
                 let nd = self.mk_method_call(id, tys, es);
-                self.mk_expr(lo, hi, nd, ThinVec::new())
+                self.mk_expr(lo.to(hi), nd, ThinVec::new())
             }
             // Field access.
             _ => {
@@ -2511,32 +2508,30 @@ impl<'a> Parser<'a> {
                                    have type parameters");
                 }
 
-                let id = spanned(ident_span.lo, ident_span.hi, ident);
+                let id = respan(ident_span.to(ident_span), ident);
                 let field = self.mk_field(self_value, id);
-                self.mk_expr(lo, ident_span.hi, field, ThinVec::new())
+                self.mk_expr(lo.to(ident_span), field, ThinVec::new())
             }
         })
     }
 
-    fn parse_dot_or_call_expr_with_(&mut self, e0: P<Expr>, lo: BytePos) -> PResult<'a, P<Expr>> {
+    fn parse_dot_or_call_expr_with_(&mut self, e0: P<Expr>, lo: Span) -> PResult<'a, P<Expr>> {
         let mut e = e0;
         let mut hi;
         loop {
             // expr?
             while self.eat(&token::Question) {
-                let hi = self.prev_span.hi;
-                e = self.mk_expr(lo, hi, ExprKind::Try(e), ThinVec::new());
+                let hi = self.prev_span;
+                e = self.mk_expr(lo.to(hi), ExprKind::Try(e), ThinVec::new());
             }
 
             // expr.f
             if self.eat(&token::Dot) {
                 match self.token {
                   token::Ident(i) => {
-                    let dot_pos = self.prev_span.hi;
-                    hi = self.span.hi;
+                    let ident_span = self.span;
                     self.bump();
-
-                    e = self.parse_dot_suffix(i, mk_sp(dot_pos, hi), e, lo)?;
+                    e = self.parse_dot_suffix(i, ident_span, e, lo)?;
                   }
                   token::Literal(token::Integer(n), suf) => {
                     let sp = self.span;
@@ -2544,16 +2539,16 @@ impl<'a> Parser<'a> {
                     // A tuple index may not have a suffix
                     self.expect_no_suffix(sp, "tuple index", suf);
 
-                    let dot = self.prev_span.hi;
-                    hi = self.span.hi;
+                    let dot_span = self.prev_span;
+                    hi = self.span;
                     self.bump();
 
                     let index = n.as_str().parse::<usize>().ok();
                     match index {
                         Some(n) => {
-                            let id = spanned(dot, hi, n);
+                            let id = respan(dot_span.to(hi), n);
                             let field = self.mk_tup_field(e, id);
-                            e = self.mk_expr(lo, hi, field, ThinVec::new());
+                            e = self.mk_expr(lo.to(hi), field, ThinVec::new());
                         }
                         None => {
                             let prev_span = self.prev_span;
@@ -2563,10 +2558,10 @@ impl<'a> Parser<'a> {
                   }
                   token::Literal(token::Float(n), _suf) => {
                     self.bump();
-                    let prev_span = self.prev_span;
                     let fstr = n.as_str();
-                    let mut err = self.diagnostic().struct_span_err(prev_span,
+                    let mut err = self.diagnostic().struct_span_err(self.prev_span,
                         &format!("unexpected token: `{}`", n));
+                    err.span_label(self.prev_span, "unexpected token");
                     if fstr.chars().all(|x| "0123456789.".contains(x)) {
                         let float = match fstr.parse::<f64>().ok() {
                             Some(f) => f,
@@ -2584,7 +2579,7 @@ impl<'a> Parser<'a> {
                             word(&mut s.s, fstr.splitn(2, ".").last().unwrap())
                         });
                         err.span_suggestion(
-                            prev_span,
+                            lo.to(self.prev_span),
                             "try parenthesizing the first index",
                             sugg);
                     }
@@ -2596,10 +2591,8 @@ impl<'a> Parser<'a> {
                     let actual = self.this_token_to_string();
                     self.span_err(self.span, &format!("unexpected token: `{}`", actual));
 
-                    let dot_pos = self.prev_span.hi;
-                    e = self.parse_dot_suffix(keywords::Invalid.ident(),
-                                              mk_sp(dot_pos, dot_pos),
-                                              e, lo)?;
+                    let dot_span = self.prev_span;
+                    e = self.parse_dot_suffix(keywords::Invalid.ident(), dot_span, e, lo)?;
                   }
                 }
                 continue;
@@ -2614,10 +2607,10 @@ impl<'a> Parser<'a> {
                     SeqSep::trailing_allowed(token::Comma),
                     |p| Ok(p.parse_expr()?)
                 )?;
-                hi = self.prev_span.hi;
+                hi = self.prev_span;
 
                 let nd = self.mk_call(e, es);
-                e = self.mk_expr(lo, hi, nd, ThinVec::new());
+                e = self.mk_expr(lo.to(hi), nd, ThinVec::new());
               }
 
               // expr[...]
@@ -2625,10 +2618,10 @@ impl<'a> Parser<'a> {
               token::OpenDelim(token::Bracket) => {
                 self.bump();
                 let ix = self.parse_expr()?;
-                hi = self.span.hi;
+                hi = self.span;
                 self.expect(&token::CloseDelim(token::Bracket))?;
                 let index = self.mk_index(e, ix);
-                e = self.mk_expr(lo, hi, index, ThinVec::new())
+                e = self.mk_expr(lo.to(hi), index, ThinVec::new())
               }
               _ => return Ok(e)
             }
@@ -2636,31 +2629,43 @@ impl<'a> Parser<'a> {
         return Ok(e);
     }
 
-    pub fn check_unknown_macro_variable(&mut self) {
-        if let token::SubstNt(name) = self.token {
-            self.fatal(&format!("unknown macro variable `{}`", name)).emit()
-        }
+    pub fn process_potential_macro_variable(&mut self) {
+        let ident = match self.token {
+            token::SubstNt(name) => {
+                self.fatal(&format!("unknown macro variable `{}`", name)).emit();
+                return
+            }
+            token::Interpolated(ref nt) => {
+                self.meta_var_span = Some(self.span);
+                match **nt {
+                    token::NtIdent(ident) => ident,
+                    _ => return,
+                }
+            }
+            _ => return,
+        };
+        self.token = token::Ident(ident.node);
+        self.span = ident.span;
     }
 
     /// parse a single token tree from the input.
-    pub fn parse_token_tree(&mut self) -> PResult<'a, TokenTree> {
+    pub fn parse_token_tree(&mut self) -> TokenTree {
         match self.token {
             token::OpenDelim(..) => {
                 let frame = mem::replace(&mut self.token_cursor.frame,
                                          self.token_cursor.stack.pop().unwrap());
                 self.span = frame.span;
                 self.bump();
-                return Ok(TokenTree::Delimited(frame.span, Delimited {
+                TokenTree::Delimited(frame.span, Delimited {
                     delim: frame.delim,
                     tts: frame.tree_cursor.original_stream().into(),
-                }));
+                })
             },
             token::CloseDelim(_) | token::Eof => unreachable!(),
             _ => {
-                let token = mem::replace(&mut self.token, token::Underscore);
-                let res = Ok(TokenTree::Token(self.span, token));
+                let (token, span) = (mem::replace(&mut self.token, token::Underscore), self.span);
                 self.bump();
-                res
+                TokenTree::Token(span, token)
             }
         }
     }
@@ -2670,71 +2675,88 @@ impl<'a> Parser<'a> {
     pub fn parse_all_token_trees(&mut self) -> PResult<'a, Vec<TokenTree>> {
         let mut tts = Vec::new();
         while self.token != token::Eof {
-            tts.push(self.parse_token_tree()?);
+            tts.push(self.parse_token_tree());
         }
         Ok(tts)
     }
 
+    pub fn parse_tokens(&mut self) -> TokenStream {
+        let mut result = Vec::new();
+        loop {
+            match self.token {
+                token::Eof | token::CloseDelim(..) => break,
+                _ => result.push(self.parse_token_tree().into()),
+            }
+        }
+        TokenStream::concat(result)
+    }
+
     /// Parse a prefix-unary-operator expr
     pub fn parse_prefix_expr(&mut self,
                              already_parsed_attrs: Option<ThinVec<Attribute>>)
                              -> PResult<'a, P<Expr>> {
         let attrs = self.parse_or_use_outer_attributes(already_parsed_attrs)?;
-        let lo = self.span.lo;
-        let hi;
+        let lo = self.span;
         // Note: when adding new unary operators, don't forget to adjust Token::can_begin_expr()
-        let ex = match self.token {
+        let (hi, ex) = match self.token {
             token::Not => {
                 self.bump();
                 let e = self.parse_prefix_expr(None);
                 let (span, e) = self.interpolated_or_expr_span(e)?;
-                hi = span.hi;
-                self.mk_unary(UnOp::Not, e)
+                (span, self.mk_unary(UnOp::Not, e))
+            }
+            // Suggest `!` for bitwise negation when encountering a `~`
+            token::Tilde => {
+                self.bump();
+                let e = self.parse_prefix_expr(None);
+                let (span, e) = self.interpolated_or_expr_span(e)?;
+                let span_of_tilde = lo;
+                let mut err = self.diagnostic().struct_span_err(span_of_tilde,
+                        "`~` can not be used as a unary operator");
+                err.span_label(span_of_tilde, "did you mean `!`?");
+                err.help("use `!` instead of `~` if you meant to perform bitwise negation");
+                err.emit();
+                (span, self.mk_unary(UnOp::Not, e))
             }
             token::BinOp(token::Minus) => {
                 self.bump();
                 let e = self.parse_prefix_expr(None);
                 let (span, e) = self.interpolated_or_expr_span(e)?;
-                hi = span.hi;
-                self.mk_unary(UnOp::Neg, e)
+                (span, self.mk_unary(UnOp::Neg, e))
             }
             token::BinOp(token::Star) => {
                 self.bump();
                 let e = self.parse_prefix_expr(None);
                 let (span, e) = self.interpolated_or_expr_span(e)?;
-                hi = span.hi;
-                self.mk_unary(UnOp::Deref, e)
+                (span, self.mk_unary(UnOp::Deref, e))
             }
             token::BinOp(token::And) | token::AndAnd => {
                 self.expect_and()?;
-                let m = self.parse_mutability()?;
+                let m = self.parse_mutability();
                 let e = self.parse_prefix_expr(None);
                 let (span, e) = self.interpolated_or_expr_span(e)?;
-                hi = span.hi;
-                ExprKind::AddrOf(m, e)
+                (span, ExprKind::AddrOf(m, e))
             }
             token::Ident(..) if self.token.is_keyword(keywords::In) => {
                 self.bump();
                 let place = self.parse_expr_res(
-                    Restrictions::RESTRICTION_NO_STRUCT_LITERAL,
+                    RESTRICTION_NO_STRUCT_LITERAL,
                     None,
                 )?;
                 let blk = self.parse_block()?;
                 let span = blk.span;
-                hi = span.hi;
-                let blk_expr = self.mk_expr(span.lo, hi, ExprKind::Block(blk), ThinVec::new());
-                ExprKind::InPlace(place, blk_expr)
+                let blk_expr = self.mk_expr(span, ExprKind::Block(blk), ThinVec::new());
+                (span, ExprKind::InPlace(place, blk_expr))
             }
             token::Ident(..) if self.token.is_keyword(keywords::Box) => {
                 self.bump();
                 let e = self.parse_prefix_expr(None);
                 let (span, e) = self.interpolated_or_expr_span(e)?;
-                hi = span.hi;
-                ExprKind::Box(e)
+                (span, ExprKind::Box(e))
             }
             _ => return self.parse_dot_or_call_expr(Some(attrs))
         };
-        return Ok(self.mk_expr(lo, hi, ex, attrs));
+        return Ok(self.mk_expr(lo.to(hi), ex, attrs));
     }
 
     /// Parse an associative expression
@@ -2781,7 +2803,7 @@ impl<'a> Parser<'a> {
 
             let cur_op_span = self.span;
             let restrictions = if op.is_assign_like() {
-                self.restrictions & Restrictions::RESTRICTION_NO_STRUCT_LITERAL
+                self.restrictions & RESTRICTION_NO_STRUCT_LITERAL
             } else {
                 self.restrictions
             };
@@ -2795,13 +2817,11 @@ impl<'a> Parser<'a> {
             // Special cases:
             if op == AssocOp::As {
                 let rhs = self.parse_ty_no_plus()?;
-                let (lo, hi) = (lhs_span.lo, rhs.span.hi);
-                lhs = self.mk_expr(lo, hi, ExprKind::Cast(lhs, rhs), ThinVec::new());
+                lhs = self.mk_expr(lhs_span.to(rhs.span), ExprKind::Cast(lhs, rhs), ThinVec::new());
                 continue
             } else if op == AssocOp::Colon {
                 let rhs = self.parse_ty_no_plus()?;
-                let (lo, hi) = (lhs_span.lo, rhs.span.hi);
-                lhs = self.mk_expr(lo, hi, ExprKind::Type(lhs, rhs), ThinVec::new());
+                lhs = self.mk_expr(lhs_span.to(rhs.span), ExprKind::Type(lhs, rhs), ThinVec::new());
                 continue
             } else if op == AssocOp::DotDot || op == AssocOp::DotDotDot {
                 // If we didn’t have to handle `x..`/`x...`, it would be pretty easy to
@@ -2827,19 +2847,19 @@ impl<'a> Parser<'a> {
                 };
 
                 let r = try!(self.mk_range(Some(lhs), rhs, limits));
-                lhs = self.mk_expr(lhs_span.lo, rhs_span.hi, r, ThinVec::new());
+                lhs = self.mk_expr(lhs_span.to(rhs_span), r, ThinVec::new());
                 break
             }
 
             let rhs = match op.fixity() {
                 Fixity::Right => self.with_res(
-                    restrictions - Restrictions::RESTRICTION_STMT_EXPR,
+                    restrictions - RESTRICTION_STMT_EXPR,
                     |this| {
                         this.parse_assoc_expr_with(op.precedence(),
                             LhsExpr::NotYetParsed)
                 }),
                 Fixity::Left => self.with_res(
-                    restrictions - Restrictions::RESTRICTION_STMT_EXPR,
+                    restrictions - RESTRICTION_STMT_EXPR,
                     |this| {
                         this.parse_assoc_expr_with(op.precedence() + 1,
                             LhsExpr::NotYetParsed)
@@ -2847,14 +2867,14 @@ impl<'a> Parser<'a> {
                 // We currently have no non-associative operators that are not handled above by
                 // the special cases. The code is here only for future convenience.
                 Fixity::None => self.with_res(
-                    restrictions - Restrictions::RESTRICTION_STMT_EXPR,
+                    restrictions - RESTRICTION_STMT_EXPR,
                     |this| {
                         this.parse_assoc_expr_with(op.precedence() + 1,
                             LhsExpr::NotYetParsed)
                 }),
             }?;
 
-            let (lo, hi) = (lhs_span.lo, rhs.span.hi);
+            let span = lhs_span.to(rhs.span);
             lhs = match op {
                 AssocOp::Add | AssocOp::Subtract | AssocOp::Multiply | AssocOp::Divide |
                 AssocOp::Modulus | AssocOp::LAnd | AssocOp::LOr | AssocOp::BitXor |
@@ -2863,12 +2883,12 @@ impl<'a> Parser<'a> {
                 AssocOp::Greater | AssocOp::GreaterEqual => {
                     let ast_op = op.to_ast_binop().unwrap();
                     let binary = self.mk_binary(codemap::respan(cur_op_span, ast_op), lhs, rhs);
-                    self.mk_expr(lo, hi, binary, ThinVec::new())
+                    self.mk_expr(span, binary, ThinVec::new())
                 }
                 AssocOp::Assign =>
-                    self.mk_expr(lo, hi, ExprKind::Assign(lhs, rhs), ThinVec::new()),
+                    self.mk_expr(span, ExprKind::Assign(lhs, rhs), ThinVec::new()),
                 AssocOp::Inplace =>
-                    self.mk_expr(lo, hi, ExprKind::InPlace(lhs, rhs), ThinVec::new()),
+                    self.mk_expr(span, ExprKind::InPlace(lhs, rhs), ThinVec::new()),
                 AssocOp::AssignOp(k) => {
                     let aop = match k {
                         token::Plus =>    BinOpKind::Add,
@@ -2883,7 +2903,7 @@ impl<'a> Parser<'a> {
                         token::Shr =>     BinOpKind::Shr,
                     };
                     let aopexpr = self.mk_assign_op(codemap::respan(cur_op_span, aop), lhs, rhs);
-                    self.mk_expr(lo, hi, aopexpr, ThinVec::new())
+                    self.mk_expr(span, aopexpr, ThinVec::new())
                 }
                 AssocOp::As | AssocOp::Colon | AssocOp::DotDot | AssocOp::DotDotDot => {
                     self.bug("As, Colon, DotDot or DotDotDot branch reached")
@@ -2903,10 +2923,13 @@ impl<'a> Parser<'a> {
         match lhs.node {
             ExprKind::Binary(op, _, _) if op.node.is_comparison() => {
                 // respan to include both operators
-                let op_span = mk_sp(op.span.lo, self.span.hi);
+                let op_span = op.span.to(self.span);
                 let mut err = self.diagnostic().struct_span_err(op_span,
                     "chained comparison operators require parentheses");
-                if op.node == BinOpKind::Lt && *outer_op == AssocOp::Greater {
+                if op.node == BinOpKind::Lt &&
+                    *outer_op == AssocOp::Less ||  // Include `<` to provide this recommendation
+                    *outer_op == AssocOp::Greater  // even in a case like the following:
+                {                                  //     Foo<Bar<Baz<Qux, ()>>>
                     err.help(
                         "use `::<...>` instead of `<...>` if you meant to specify type arguments");
                 }
@@ -2923,8 +2946,8 @@ impl<'a> Parser<'a> {
         debug_assert!(self.token == token::DotDot || self.token == token::DotDotDot);
         let tok = self.token.clone();
         let attrs = self.parse_or_use_outer_attributes(already_parsed_attrs)?;
-        let lo = self.span.lo;
-        let mut hi = self.span.hi;
+        let lo = self.span;
+        let mut hi = self.span;
         self.bump();
         let opt_end = if self.is_at_start_of_range_notation_rhs() {
             // RHS must be parsed with more associativity than the dots.
@@ -2932,7 +2955,7 @@ impl<'a> Parser<'a> {
             Some(self.parse_assoc_expr_with(next_prec,
                                             LhsExpr::NotYetParsed)
                 .map(|x|{
-                    hi = x.span.hi;
+                    hi = x.span;
                     x
                 })?)
          } else {
@@ -2947,14 +2970,14 @@ impl<'a> Parser<'a> {
         let r = try!(self.mk_range(None,
                                    opt_end,
                                    limits));
-        Ok(self.mk_expr(lo, hi, r, attrs))
+        Ok(self.mk_expr(lo.to(hi), r, attrs))
     }
 
     fn is_at_start_of_range_notation_rhs(&self) -> bool {
         if self.token.can_begin_expr() {
             // parse `for i in 1.. { }` as infinite loop, not as `for i in (1..{})`.
             if self.token == token::OpenDelim(token::Brace) {
-                return !self.restrictions.contains(Restrictions::RESTRICTION_NO_STRUCT_LITERAL);
+                return !self.restrictions.contains(RESTRICTION_NO_STRUCT_LITERAL);
             }
             true
         } else {
@@ -2967,60 +2990,59 @@ impl<'a> Parser<'a> {
         if self.check_keyword(keywords::Let) {
             return self.parse_if_let_expr(attrs);
         }
-        let lo = self.prev_span.lo;
-        let cond = self.parse_expr_res(Restrictions::RESTRICTION_NO_STRUCT_LITERAL, None)?;
+        let lo = self.prev_span;
+        let cond = self.parse_expr_res(RESTRICTION_NO_STRUCT_LITERAL, None)?;
         let thn = self.parse_block()?;
         let mut els: Option<P<Expr>> = None;
-        let mut hi = thn.span.hi;
+        let mut hi = thn.span;
         if self.eat_keyword(keywords::Else) {
             let elexpr = self.parse_else_expr()?;
-            hi = elexpr.span.hi;
+            hi = elexpr.span;
             els = Some(elexpr);
         }
-        Ok(self.mk_expr(lo, hi, ExprKind::If(cond, thn, els), attrs))
+        Ok(self.mk_expr(lo.to(hi), ExprKind::If(cond, thn, els), attrs))
     }
 
     /// Parse an 'if let' expression ('if' token already eaten)
     pub fn parse_if_let_expr(&mut self, attrs: ThinVec<Attribute>)
                              -> PResult<'a, P<Expr>> {
-        let lo = self.prev_span.lo;
+        let lo = self.prev_span;
         self.expect_keyword(keywords::Let)?;
         let pat = self.parse_pat()?;
         self.expect(&token::Eq)?;
-        let expr = self.parse_expr_res(Restrictions::RESTRICTION_NO_STRUCT_LITERAL, None)?;
+        let expr = self.parse_expr_res(RESTRICTION_NO_STRUCT_LITERAL, None)?;
         let thn = self.parse_block()?;
         let (hi, els) = if self.eat_keyword(keywords::Else) {
             let expr = self.parse_else_expr()?;
-            (expr.span.hi, Some(expr))
+            (expr.span, Some(expr))
         } else {
-            (thn.span.hi, None)
+            (thn.span, None)
         };
-        Ok(self.mk_expr(lo, hi, ExprKind::IfLet(pat, expr, thn, els), attrs))
+        Ok(self.mk_expr(lo.to(hi), ExprKind::IfLet(pat, expr, thn, els), attrs))
     }
 
     // `move |args| expr`
     pub fn parse_lambda_expr(&mut self,
-                             lo: BytePos,
+                             lo: Span,
                              capture_clause: CaptureBy,
                              attrs: ThinVec<Attribute>)
                              -> PResult<'a, P<Expr>>
     {
         let decl = self.parse_fn_block_decl()?;
-        let decl_hi = self.prev_span.hi;
+        let decl_hi = self.prev_span;
         let body = match decl.output {
             FunctionRetTy::Default(_) => self.parse_expr()?,
             _ => {
                 // If an explicit return type is given, require a
                 // block to appear (RFC 968).
-                let body_lo = self.span.lo;
+                let body_lo = self.span;
                 self.parse_block_expr(body_lo, BlockCheckMode::Default, ThinVec::new())?
             }
         };
 
         Ok(self.mk_expr(
-            lo,
-            body.span.hi,
-            ExprKind::Closure(capture_clause, decl, body, mk_sp(lo, decl_hi)),
+            lo.to(body.span),
+            ExprKind::Closure(capture_clause, decl, body, lo.to(decl_hi)),
             attrs))
     }
 
@@ -3030,73 +3052,78 @@ impl<'a> Parser<'a> {
             return self.parse_if_expr(ThinVec::new());
         } else {
             let blk = self.parse_block()?;
-            return Ok(self.mk_expr(blk.span.lo, blk.span.hi, ExprKind::Block(blk), ThinVec::new()));
+            return Ok(self.mk_expr(blk.span, ExprKind::Block(blk), ThinVec::new()));
         }
     }
 
     /// Parse a 'for' .. 'in' expression ('for' token already eaten)
     pub fn parse_for_expr(&mut self, opt_ident: Option<ast::SpannedIdent>,
-                          span_lo: BytePos,
+                          span_lo: Span,
                           mut attrs: ThinVec<Attribute>) -> PResult<'a, P<Expr>> {
         // Parse: `for <src_pat> in <src_expr> <src_loop_block>`
 
         let pat = self.parse_pat()?;
         self.expect_keyword(keywords::In)?;
-        let expr = self.parse_expr_res(Restrictions::RESTRICTION_NO_STRUCT_LITERAL, None)?;
+        let expr = self.parse_expr_res(RESTRICTION_NO_STRUCT_LITERAL, None)?;
         let (iattrs, loop_block) = self.parse_inner_attrs_and_block()?;
         attrs.extend(iattrs);
 
-        let hi = self.prev_span.hi;
-
-        Ok(self.mk_expr(span_lo, hi,
-                        ExprKind::ForLoop(pat, expr, loop_block, opt_ident),
-                        attrs))
+        let hi = self.prev_span;
+        Ok(self.mk_expr(span_lo.to(hi), ExprKind::ForLoop(pat, expr, loop_block, opt_ident), attrs))
     }
 
     /// Parse a 'while' or 'while let' expression ('while' token already eaten)
     pub fn parse_while_expr(&mut self, opt_ident: Option<ast::SpannedIdent>,
-                            span_lo: BytePos,
+                            span_lo: Span,
                             mut attrs: ThinVec<Attribute>) -> PResult<'a, P<Expr>> {
         if self.token.is_keyword(keywords::Let) {
             return self.parse_while_let_expr(opt_ident, span_lo, attrs);
         }
-        let cond = self.parse_expr_res(Restrictions::RESTRICTION_NO_STRUCT_LITERAL, None)?;
+        let cond = self.parse_expr_res(RESTRICTION_NO_STRUCT_LITERAL, None)?;
         let (iattrs, body) = self.parse_inner_attrs_and_block()?;
         attrs.extend(iattrs);
-        let hi = body.span.hi;
-        return Ok(self.mk_expr(span_lo, hi, ExprKind::While(cond, body, opt_ident),
-                               attrs));
+        let span = span_lo.to(body.span);
+        return Ok(self.mk_expr(span, ExprKind::While(cond, body, opt_ident), attrs));
     }
 
     /// Parse a 'while let' expression ('while' token already eaten)
     pub fn parse_while_let_expr(&mut self, opt_ident: Option<ast::SpannedIdent>,
-                                span_lo: BytePos,
+                                span_lo: Span,
                                 mut attrs: ThinVec<Attribute>) -> PResult<'a, P<Expr>> {
         self.expect_keyword(keywords::Let)?;
         let pat = self.parse_pat()?;
         self.expect(&token::Eq)?;
-        let expr = self.parse_expr_res(Restrictions::RESTRICTION_NO_STRUCT_LITERAL, None)?;
+        let expr = self.parse_expr_res(RESTRICTION_NO_STRUCT_LITERAL, None)?;
         let (iattrs, body) = self.parse_inner_attrs_and_block()?;
         attrs.extend(iattrs);
-        let hi = body.span.hi;
-        return Ok(self.mk_expr(span_lo, hi, ExprKind::WhileLet(pat, expr, body, opt_ident), attrs));
+        let span = span_lo.to(body.span);
+        return Ok(self.mk_expr(span, ExprKind::WhileLet(pat, expr, body, opt_ident), attrs));
     }
 
     // parse `loop {...}`, `loop` token already eaten
     pub fn parse_loop_expr(&mut self, opt_ident: Option<ast::SpannedIdent>,
-                           span_lo: BytePos,
+                           span_lo: Span,
                            mut attrs: ThinVec<Attribute>) -> PResult<'a, P<Expr>> {
         let (iattrs, body) = self.parse_inner_attrs_and_block()?;
         attrs.extend(iattrs);
-        let hi = body.span.hi;
-        Ok(self.mk_expr(span_lo, hi, ExprKind::Loop(body, opt_ident), attrs))
+        let span = span_lo.to(body.span);
+        Ok(self.mk_expr(span, ExprKind::Loop(body, opt_ident), attrs))
+    }
+
+    /// Parse a `do catch {...}` expression (`do catch` token already eaten)
+    pub fn parse_catch_expr(&mut self, span_lo: Span, mut attrs: ThinVec<Attribute>)
+        -> PResult<'a, P<Expr>>
+    {
+        let (iattrs, body) = self.parse_inner_attrs_and_block()?;
+        attrs.extend(iattrs);
+        Ok(self.mk_expr(span_lo.to(body.span), ExprKind::Catch(body), attrs))
     }
 
     // `match` token already eaten
     fn parse_match_expr(&mut self, mut attrs: ThinVec<Attribute>) -> PResult<'a, P<Expr>> {
         let match_span = self.prev_span;
-        let lo = self.prev_span.lo;
-        let discriminant = self.parse_expr_res(Restrictions::RESTRICTION_NO_STRUCT_LITERAL,
+        let lo = self.prev_span;
+        let discriminant = self.parse_expr_res(RESTRICTION_NO_STRUCT_LITERAL,
                                                None)?;
         if let Err(mut e) = self.expect(&token::OpenDelim(token::Brace)) {
             if self.token == token::Token::Semi {
@@ -3114,17 +3141,17 @@ impl<'a> Parser<'a> {
                     // Recover by skipping to the end of the block.
                     e.emit();
                     self.recover_stmt();
-                    let hi = self.span.hi;
+                    let span = lo.to(self.span);
                     if self.token == token::CloseDelim(token::Brace) {
                         self.bump();
                     }
-                    return Ok(self.mk_expr(lo, hi, ExprKind::Match(discriminant, arms), attrs));
+                    return Ok(self.mk_expr(span, ExprKind::Match(discriminant, arms), attrs));
                 }
             }
         }
-        let hi = self.span.hi;
+        let hi = self.span;
         self.bump();
-        return Ok(self.mk_expr(lo, hi, ExprKind::Match(discriminant, arms), attrs));
+        return Ok(self.mk_expr(lo.to(hi), ExprKind::Match(discriminant, arms), attrs));
     }
 
     pub fn parse_arm(&mut self) -> PResult<'a, Arm> {
@@ -3132,12 +3159,13 @@ impl<'a> Parser<'a> {
 
         let attrs = self.parse_outer_attributes()?;
         let pats = self.parse_pats()?;
-        let mut guard = None;
-        if self.eat_keyword(keywords::If) {
-            guard = Some(self.parse_expr()?);
-        }
+        let guard = if self.eat_keyword(keywords::If) {
+            Some(self.parse_expr()?)
+        } else {
+            None
+        };
         self.expect(&token::FatArrow)?;
-        let expr = self.parse_expr_res(Restrictions::RESTRICTION_STMT_EXPR, None)?;
+        let expr = self.parse_expr_res(RESTRICTION_STMT_EXPR, None)?;
 
         let require_comma =
             !classify::expr_is_simple_block(&expr)
@@ -3298,7 +3326,7 @@ impl<'a> Parser<'a> {
             }
 
             let attrs = self.parse_outer_attributes()?;
-            let lo = self.span.lo;
+            let lo = self.span;
             let hi;
 
             if self.check(&token::DotDot) {
@@ -3318,16 +3346,16 @@ impl<'a> Parser<'a> {
                 let fieldname = self.parse_field_name()?;
                 self.bump();
                 let pat = self.parse_pat()?;
-                hi = pat.span.hi;
+                hi = pat.span;
                 (pat, fieldname, false)
             } else {
                 // Parsing a pattern of the form "(box) (ref) (mut) fieldname"
                 let is_box = self.eat_keyword(keywords::Box);
-                let boxed_span_lo = self.span.lo;
+                let boxed_span = self.span;
                 let is_ref = self.eat_keyword(keywords::Ref);
                 let is_mut = self.eat_keyword(keywords::Mut);
                 let fieldname = self.parse_ident()?;
-                hi = self.prev_span.hi;
+                hi = self.prev_span;
 
                 let bind_type = match (is_ref, is_mut) {
                     (true, true) => BindingMode::ByRef(Mutability::Mutable),
@@ -3339,14 +3367,14 @@ impl<'a> Parser<'a> {
                 let fieldpat = P(ast::Pat{
                     id: ast::DUMMY_NODE_ID,
                     node: PatKind::Ident(bind_type, fieldpath, None),
-                    span: mk_sp(boxed_span_lo, hi),
+                    span: boxed_span.to(hi),
                 });
 
                 let subpat = if is_box {
                     P(ast::Pat{
                         id: ast::DUMMY_NODE_ID,
                         node: PatKind::Box(fieldpat),
-                        span: mk_sp(lo, hi),
+                        span: lo.to(hi),
                     })
                 } else {
                     fieldpat
@@ -3354,7 +3382,7 @@ impl<'a> Parser<'a> {
                 (subpat, fieldname, true)
             };
 
-            fields.push(codemap::Spanned { span: mk_sp(lo, hi),
+            fields.push(codemap::Spanned { span: lo.to(hi),
                                            node: ast::FieldPat {
                                                ident: fieldname,
                                                pat: subpat,
@@ -3368,7 +3396,7 @@ impl<'a> Parser<'a> {
 
     fn parse_pat_range_end(&mut self) -> PResult<'a, P<Expr>> {
         if self.token.is_path_start() {
-            let lo = self.span.lo;
+            let lo = self.span;
             let (qself, path) = if self.eat_lt() {
                 // Parse a qualified path
                 let (qself, path) =
@@ -3378,8 +3406,8 @@ impl<'a> Parser<'a> {
                 // Parse an unqualified path
                 (None, self.parse_path(PathStyle::Expr)?)
             };
-            let hi = self.prev_span.hi;
-            Ok(self.mk_expr(lo, hi, ExprKind::Path(qself, path), ThinVec::new()))
+            let hi = self.prev_span;
+            Ok(self.mk_expr(lo.to(hi), ExprKind::Path(qself, path), ThinVec::new()))
         } else {
             self.parse_pat_literal_maybe_minus()
         }
@@ -3405,7 +3433,7 @@ impl<'a> Parser<'a> {
     pub fn parse_pat(&mut self) -> PResult<'a, P<Pat>> {
         maybe_whole!(self, NtPat, |x| x);
 
-        let lo = self.span.lo;
+        let lo = self.span;
         let pat;
         match self.token {
             token::Underscore => {
@@ -3416,7 +3444,7 @@ impl<'a> Parser<'a> {
             token::BinOp(token::And) | token::AndAnd => {
                 // Parse &pat / &mut pat
                 self.expect_and()?;
-                let mutbl = self.parse_mutability()?;
+                let mutbl = self.parse_mutability();
                 if let token::Lifetime(ident) = self.token {
                     return Err(self.fatal(&format!("unexpected lifetime `{}` in pattern", ident)));
                 }
@@ -3443,7 +3471,7 @@ impl<'a> Parser<'a> {
                 pat = self.parse_pat_ident(BindingMode::ByValue(Mutability::Mutable))?;
             } else if self.eat_keyword(keywords::Ref) {
                 // Parse ref ident @ pat / ref mut ident @ pat
-                let mutbl = self.parse_mutability()?;
+                let mutbl = self.parse_mutability();
                 pat = self.parse_pat_ident(BindingMode::ByRef(mutbl))?;
             } else if self.eat_keyword(keywords::Box) {
                 // Parse box pat
@@ -3471,7 +3499,7 @@ impl<'a> Parser<'a> {
                         // Parse macro invocation
                         self.bump();
                         let (_, tts) = self.expect_delimited_token_tree()?;
-                        let mac = spanned(lo, self.prev_span.hi, Mac_ { path: path, tts: tts });
+                        let mac = respan(lo.to(self.prev_span), Mac_ { path: path, tts: tts });
                         pat = PatKind::Mac(mac);
                     }
                     token::DotDotDot | token::DotDot => {
@@ -3481,9 +3509,8 @@ impl<'a> Parser<'a> {
                             _ => panic!("can only parse `..` or `...` for ranges (checked above)"),
                         };
                         // Parse range
-                        let hi = self.prev_span.hi;
-                        let begin =
-                              self.mk_expr(lo, hi, ExprKind::Path(qself, path), ThinVec::new());
+                        let span = lo.to(self.prev_span);
+                        let begin = self.mk_expr(span, ExprKind::Path(qself, path), ThinVec::new());
                         self.bump();
                         let end = self.parse_pat_range_end()?;
                         pat = PatKind::Range(begin, end, end_kind);
@@ -3537,11 +3564,10 @@ impl<'a> Parser<'a> {
             }
         }
 
-        let hi = self.prev_span.hi;
         Ok(P(ast::Pat {
             id: ast::DUMMY_NODE_ID,
             node: pat,
-            span: mk_sp(lo, hi),
+            span: lo.to(self.prev_span),
         }))
     }
 
@@ -3551,9 +3577,9 @@ impl<'a> Parser<'a> {
     fn parse_pat_ident(&mut self,
                        binding_mode: ast::BindingMode)
                        -> PResult<'a, PatKind> {
+        let ident_span = self.span;
         let ident = self.parse_ident()?;
-        let prev_span = self.prev_span;
-        let name = codemap::Spanned{span: prev_span, node: ident};
+        let name = codemap::Spanned{span: ident_span, node: ident};
         let sub = if self.eat(&token::At) {
             Some(self.parse_pat()?)
         } else {
@@ -3577,27 +3603,28 @@ impl<'a> Parser<'a> {
 
     /// Parse a local variable declaration
     fn parse_local(&mut self, attrs: ThinVec<Attribute>) -> PResult<'a, P<Local>> {
-        let lo = self.span.lo;
+        let lo = self.span;
         let pat = self.parse_pat()?;
 
-        let mut ty = None;
-        if self.eat(&token::Colon) {
-            ty = Some(self.parse_ty()?);
-        }
+        let ty = if self.eat(&token::Colon) {
+            Some(self.parse_ty()?)
+        } else {
+            None
+        };
         let init = self.parse_initializer()?;
         Ok(P(ast::Local {
             ty: ty,
             pat: pat,
             init: init,
             id: ast::DUMMY_NODE_ID,
-            span: mk_sp(lo, self.prev_span.hi),
+            span: lo.to(self.prev_span),
             attrs: attrs,
         }))
     }
 
     /// Parse a structure field
     fn parse_name_and_ty(&mut self,
-                         lo: BytePos,
+                         lo: Span,
                          vis: Visibility,
                          attrs: Vec<Attribute>)
                          -> PResult<'a, StructField> {
@@ -3605,7 +3632,7 @@ impl<'a> Parser<'a> {
         self.expect(&token::Colon)?;
         let ty = self.parse_ty()?;
         Ok(StructField {
-            span: mk_sp(lo, self.prev_span.hi),
+            span: lo.to(self.prev_span),
             ident: Some(name),
             vis: vis,
             id: ast::DUMMY_NODE_ID,
@@ -3635,22 +3662,33 @@ impl<'a> Parser<'a> {
     //
     // We terminate when we find an unmatched `}` (without consuming it).
     fn recover_stmt(&mut self) {
-        self.recover_stmt_(SemiColonMode::Ignore)
+        self.recover_stmt_(SemiColonMode::Ignore, BlockMode::Ignore)
     }
+
     // If `break_on_semi` is `Break`, then we will stop consuming tokens after
     // finding (and consuming) a `;` outside of `{}` or `[]` (note that this is
     // approximate - it can mean we break too early due to macros, but that
     // shoud only lead to sub-optimal recovery, not inaccurate parsing).
-    fn recover_stmt_(&mut self, break_on_semi: SemiColonMode) {
+    //
+    // If `break_on_block` is `Break`, then we will stop consuming tokens
+    // after finding (and consuming) a brace-delimited block.
+    fn recover_stmt_(&mut self, break_on_semi: SemiColonMode, break_on_block: BlockMode) {
         let mut brace_depth = 0;
         let mut bracket_depth = 0;
-        debug!("recover_stmt_ enter loop");
+        let mut in_block = false;
+        debug!("recover_stmt_ enter loop (semi={:?}, block={:?})",
+               break_on_semi, break_on_block);
         loop {
             debug!("recover_stmt_ loop {:?}", self.token);
             match self.token {
                 token::OpenDelim(token::DelimToken::Brace) => {
                     brace_depth += 1;
                     self.bump();
+                    if break_on_block == BlockMode::Break &&
+                       brace_depth == 1 &&
+                       bracket_depth == 0 {
+                        in_block = true;
+                    }
                 }
                 token::OpenDelim(token::DelimToken::Bracket) => {
                     bracket_depth += 1;
@@ -3663,6 +3701,10 @@ impl<'a> Parser<'a> {
                     }
                     brace_depth -= 1;
                     self.bump();
+                    if in_block && bracket_depth == 0 && brace_depth == 0 {
+                        debug!("recover_stmt_ return - block end {:?}", self.token);
+                        return;
+                    }
                 }
                 token::CloseDelim(token::DelimToken::Bracket) => {
                     bracket_depth -= 1;
@@ -3694,11 +3736,20 @@ impl<'a> Parser<'a> {
     fn parse_stmt_(&mut self, macro_legacy_warnings: bool) -> Option<Stmt> {
         self.parse_stmt_without_recovery(macro_legacy_warnings).unwrap_or_else(|mut e| {
             e.emit();
-            self.recover_stmt_(SemiColonMode::Break);
+            self.recover_stmt_(SemiColonMode::Break, BlockMode::Ignore);
             None
         })
     }
 
+    fn is_catch_expr(&mut self) -> bool {
+        self.token.is_keyword(keywords::Do) &&
+        self.look_ahead(1, |t| t.is_keyword(keywords::Catch)) &&
+        self.look_ahead(2, |t| *t == token::OpenDelim(token::Brace)) &&
+
+        // prevent `while catch {} {}`, `if catch {} {} else {}`, etc.
+        !self.restrictions.contains(RESTRICTION_NO_STRUCT_LITERAL)
+    }
+
     fn is_union_item(&self) -> bool {
         self.token.is_keyword(keywords::Union) &&
         self.look_ahead(1, |t| t.is_ident() && !t.is_any_keyword())
@@ -3706,32 +3757,60 @@ impl<'a> Parser<'a> {
 
     fn eat_macro_def(&mut self, attrs: &[Attribute], vis: &Visibility)
                      -> PResult<'a, Option<P<Item>>> {
-        let lo = self.span.lo;
-        match self.token {
-            token::Ident(ident) if ident.name == "macro_rules" => {
-                if self.look_ahead(1, |t| *t == token::Not) {
-                    let prev_span = self.prev_span;
-                    self.complain_if_pub_macro(vis, prev_span);
-                    self.bump();
-                    self.bump();
+        let lo = self.span;
+        let (ident, def) = match self.token {
+            token::Ident(ident) if ident.name == keywords::Macro.name() => {
+                self.bump();
+                let ident = self.parse_ident()?;
+                let tokens = if self.check(&token::OpenDelim(token::Brace)) {
+                    match self.parse_token_tree() {
+                        TokenTree::Delimited(_, ref delimited) => delimited.stream(),
+                        _ => unreachable!(),
+                    }
+                } else if self.check(&token::OpenDelim(token::Paren)) {
+                    let args = self.parse_token_tree();
+                    let body = if self.check(&token::OpenDelim(token::Brace)) {
+                        self.parse_token_tree()
+                    } else {
+                        self.unexpected()?;
+                        unreachable!()
+                    };
+                    TokenStream::concat(vec![
+                        args.into(),
+                        TokenTree::Token(lo.to(self.prev_span), token::FatArrow).into(),
+                        body.into(),
+                    ])
+                } else {
+                    self.unexpected()?;
+                    unreachable!()
+                };
+
+                (ident, ast::MacroDef { tokens: tokens.into(), legacy: false })
+            }
+            token::Ident(ident) if ident.name == "macro_rules" &&
+                                   self.look_ahead(1, |t| *t == token::Not) => {
+                let prev_span = self.prev_span;
+                self.complain_if_pub_macro(vis, prev_span);
+                self.bump();
+                self.bump();
+
+                let ident = self.parse_ident()?;
+                let (delim, tokens) = self.expect_delimited_token_tree()?;
+                if delim != token::Brace {
+                    if !self.eat(&token::Semi) {
+                        let msg = "macros that expand to items must either \
+                                   be surrounded with braces or followed by a semicolon";
+                        self.span_err(self.prev_span, msg);
+                    }
                 }
+
+                (ident, ast::MacroDef { tokens: tokens, legacy: true })
             }
             _ => return Ok(None),
         };
 
-        let id = self.parse_ident()?;
-        let (delim, tts) = self.expect_delimited_token_tree()?;
-        if delim != token::Brace {
-            if !self.eat(&token::Semi) {
-                let msg = "macros that expand to items must either be surrounded with braces \
-                           or followed by a semicolon";
-                self.span_err(self.prev_span, msg);
-            }
-        }
-
-        let hi = self.prev_span.hi;
-        let kind = ItemKind::MacroDef(tts);
-        Ok(Some(self.mk_item(lo, hi, id, kind, Visibility::Inherited, attrs.to_owned())))
+        let span = lo.to(self.prev_span);
+        Ok(Some(self.mk_item(span, ident, ItemKind::MacroDef(def), vis.clone(), attrs.to_vec())))
     }
 
     fn parse_stmt_without_recovery(&mut self,
@@ -3740,19 +3819,19 @@ impl<'a> Parser<'a> {
         maybe_whole!(self, NtStmt, |x| Some(x));
 
         let attrs = self.parse_outer_attributes()?;
-        let lo = self.span.lo;
+        let lo = self.span;
 
         Ok(Some(if self.eat_keyword(keywords::Let) {
             Stmt {
                 id: ast::DUMMY_NODE_ID,
                 node: StmtKind::Local(self.parse_local(attrs.into())?),
-                span: mk_sp(lo, self.prev_span.hi),
+                span: lo.to(self.prev_span),
             }
         } else if let Some(macro_def) = self.eat_macro_def(&attrs, &Visibility::Inherited)? {
             Stmt {
                 id: ast::DUMMY_NODE_ID,
                 node: StmtKind::Item(macro_def),
-                span: mk_sp(lo, self.prev_span.hi),
+                span: lo.to(self.prev_span),
             }
         // Starts like a simple path, but not a union item.
         } else if self.token.is_path_start() &&
@@ -3764,11 +3843,11 @@ impl<'a> Parser<'a> {
                 let expr = if self.check(&token::OpenDelim(token::Brace)) {
                     self.parse_struct_expr(lo, pth, ThinVec::new())?
                 } else {
-                    let hi = self.prev_span.hi;
-                    self.mk_expr(lo, hi, ExprKind::Path(None, pth), ThinVec::new())
+                    let hi = self.prev_span;
+                    self.mk_expr(lo.to(hi), ExprKind::Path(None, pth), ThinVec::new())
                 };
 
-                let expr = self.with_res(Restrictions::RESTRICTION_STMT_EXPR, |this| {
+                let expr = self.with_res(RESTRICTION_STMT_EXPR, |this| {
                     let expr = this.parse_dot_or_call_expr_with(expr, lo, attrs.into())?;
                     this.parse_assoc_expr_with(0, LhsExpr::AlreadyParsed(expr))
                 })?;
@@ -3776,7 +3855,7 @@ impl<'a> Parser<'a> {
                 return Ok(Some(Stmt {
                     id: ast::DUMMY_NODE_ID,
                     node: StmtKind::Expr(expr),
-                    span: mk_sp(lo, self.prev_span.hi),
+                    span: lo.to(self.prev_span),
                 }));
             }
 
@@ -3807,7 +3886,7 @@ impl<'a> Parser<'a> {
             };
 
             let (_, tts) = self.expect_delimited_token_tree()?;
-            let hi = self.prev_span.hi;
+            let hi = self.prev_span;
 
             let style = if delim == token::Brace {
                 MacStmtStyle::Braces
@@ -3816,7 +3895,7 @@ impl<'a> Parser<'a> {
             };
 
             if id.name == keywords::Invalid.name() {
-                let mac = spanned(lo, hi, Mac_ { path: pth, tts: tts });
+                let mac = respan(lo.to(hi), Mac_ { path: pth, tts: tts });
                 let node = if delim == token::Brace ||
                               self.token == token::Semi || self.token == token::Eof {
                     StmtKind::Mac(P((mac, style, attrs.into())))
@@ -3836,14 +3915,14 @@ impl<'a> Parser<'a> {
                     self.warn_missing_semicolon();
                     StmtKind::Mac(P((mac, style, attrs.into())))
                 } else {
-                    let e = self.mk_mac_expr(lo, hi, mac.node, ThinVec::new());
+                    let e = self.mk_mac_expr(lo.to(hi), mac.node, ThinVec::new());
                     let e = self.parse_dot_or_call_expr_with(e, lo, attrs.into())?;
                     let e = self.parse_assoc_expr_with(0, LhsExpr::AlreadyParsed(e))?;
                     StmtKind::Expr(e)
                 };
                 Stmt {
                     id: ast::DUMMY_NODE_ID,
-                    span: mk_sp(lo, hi),
+                    span: lo.to(hi),
                     node: node,
                 }
             } else {
@@ -3858,13 +3937,14 @@ impl<'a> Parser<'a> {
                                        followed by a semicolon");
                     }
                 }
+                let span = lo.to(hi);
                 Stmt {
                     id: ast::DUMMY_NODE_ID,
-                    span: mk_sp(lo, hi),
+                    span: span,
                     node: StmtKind::Item({
                         self.mk_item(
-                            lo, hi, id /*id is good here*/,
-                            ItemKind::Mac(spanned(lo, hi, Mac_ { path: pth, tts: tts })),
+                            span, id /*id is good here*/,
+                            ItemKind::Mac(respan(span, Mac_ { path: pth, tts: tts })),
                             Visibility::Inherited,
                             attrs)
                     }),
@@ -3876,15 +3956,16 @@ impl<'a> Parser<'a> {
                 mem::replace(&mut self.directory.ownership, DirectoryOwnership::UnownedViaBlock);
             let item = self.parse_item_(attrs.clone(), false, true)?;
             self.directory.ownership = old_directory_ownership;
+
             match item {
                 Some(i) => Stmt {
                     id: ast::DUMMY_NODE_ID,
-                    span: mk_sp(lo, i.span.hi),
+                    span: lo.to(i.span),
                     node: StmtKind::Item(i),
                 },
                 None => {
                     let unused_attrs = |attrs: &[_], s: &mut Self| {
-                        if attrs.len() > 0 {
+                        if !attrs.is_empty() {
                             if s.prev_token_kind == PrevTokenKind::DocComment {
                                 s.span_fatal_err(s.prev_span, Error::UselessDocComment).emit();
                             } else {
@@ -3907,10 +3988,10 @@ impl<'a> Parser<'a> {
 
                     // Remainder are line-expr stmts.
                     let e = self.parse_expr_res(
-                        Restrictions::RESTRICTION_STMT_EXPR, Some(attrs.into()))?;
+                        RESTRICTION_STMT_EXPR, Some(attrs.into()))?;
                     Stmt {
                         id: ast::DUMMY_NODE_ID,
-                        span: mk_sp(lo, e.span.hi),
+                        span: lo.to(e.span),
                         node: StmtKind::Expr(e),
                     }
                 }
@@ -3920,7 +4001,7 @@ impl<'a> Parser<'a> {
 
     /// Is this expression a successfully-parsed statement?
     fn expr_is_complete(&mut self, e: &Expr) -> bool {
-        self.restrictions.contains(Restrictions::RESTRICTION_STMT_EXPR) &&
+        self.restrictions.contains(RESTRICTION_STMT_EXPR) &&
             !classify::expr_requires_semi_to_be_stmt(e)
     }
 
@@ -3928,7 +4009,7 @@ impl<'a> Parser<'a> {
     pub fn parse_block(&mut self) -> PResult<'a, P<Block>> {
         maybe_whole!(self, NtBlock, |x| x);
 
-        let lo = self.span.lo;
+        let lo = self.span;
 
         if !self.eat(&token::OpenDelim(token::Brace)) {
             let sp = self.span;
@@ -3958,7 +4039,7 @@ impl<'a> Parser<'a> {
                     e.span_suggestion(stmt_span, "try placing this code inside a block", sugg);
                 }
                 Err(mut e) => {
-                    self.recover_stmt_(SemiColonMode::Break);
+                    self.recover_stmt_(SemiColonMode::Break, BlockMode::Ignore);
                     self.cancel(&mut e);
                 }
                 _ => ()
@@ -3973,7 +4054,7 @@ impl<'a> Parser<'a> {
     fn parse_inner_attrs_and_block(&mut self) -> PResult<'a, (Vec<Attribute>, P<Block>)> {
         maybe_whole!(self, NtBlock, |x| (Vec::new(), x));
 
-        let lo = self.span.lo;
+        let lo = self.span;
         self.expect(&token::OpenDelim(token::Brace))?;
         Ok((self.parse_inner_attributes()?,
             self.parse_block_tail(lo, BlockCheckMode::Default)?))
@@ -3981,7 +4062,7 @@ impl<'a> Parser<'a> {
 
     /// Parse the rest of a block expression or function body
     /// Precondition: already parsed the '{'.
-    fn parse_block_tail(&mut self, lo: BytePos, s: BlockCheckMode) -> PResult<'a, P<Block>> {
+    fn parse_block_tail(&mut self, lo: Span, s: BlockCheckMode) -> PResult<'a, P<Block>> {
         let mut stmts = vec![];
 
         while !self.eat(&token::CloseDelim(token::Brace)) {
@@ -3999,7 +4080,7 @@ impl<'a> Parser<'a> {
             stmts: stmts,
             id: ast::DUMMY_NODE_ID,
             rules: s,
-            span: mk_sp(lo, self.prev_span.hi),
+            span: lo.to(self.prev_span),
         }))
     }
 
@@ -4050,34 +4131,51 @@ impl<'a> Parser<'a> {
         }).emit();
     }
 
-    // Parse bounds of a type parameter `BOUND + BOUND + BOUND` without trailing `+`.
+    // Parse bounds of a type parameter `BOUND + BOUND + BOUND`, possibly with trailing `+`.
     // BOUND = TY_BOUND | LT_BOUND
     // LT_BOUND = LIFETIME (e.g. `'a`)
-    // TY_BOUND = [?] [for<LT_PARAM_DEFS>] SIMPLE_PATH (e.g. `?for<'a: 'b> m::Trait<'a>`)
-    fn parse_ty_param_bounds(&mut self) -> PResult<'a, TyParamBounds>
-    {
+    // TY_BOUND = TY_BOUND_NOPAREN | (TY_BOUND_NOPAREN)
+    // TY_BOUND_NOPAREN = [?] [for<LT_PARAM_DEFS>] SIMPLE_PATH (e.g. `?for<'a: 'b> m::Trait<'a>`)
+    fn parse_ty_param_bounds_common(&mut self, allow_plus: bool) -> PResult<'a, TyParamBounds> {
         let mut bounds = Vec::new();
         loop {
-            let question = if self.eat(&token::Question) { Some(self.prev_span) } else { None };
-            if let Some(lifetime) = self.eat_lifetime() {
-                if let Some(question_span) = question {
-                    self.span_err(question_span,
-                                  "`?` may only modify trait bounds, not lifetime bounds");
-                }
-                bounds.push(RegionTyParamBound(lifetime));
-            } else {if self.check_keyword(keywords::For) || self.check_path() {
-                let poly_trait_ref = self.parse_poly_trait_ref()?;
-                let modifier = if question.is_some() {
-                    TraitBoundModifier::Maybe
+            let is_bound_start = self.check_path() || self.check_lifetime() ||
+                                 self.check(&token::Question) ||
+                                 self.check_keyword(keywords::For) ||
+                                 self.check(&token::OpenDelim(token::Paren));
+            if is_bound_start {
+                let has_parens = self.eat(&token::OpenDelim(token::Paren));
+                let question = if self.eat(&token::Question) { Some(self.prev_span) } else { None };
+                if self.token.is_lifetime() {
+                    if let Some(question_span) = question {
+                        self.span_err(question_span,
+                                      "`?` may only modify trait bounds, not lifetime bounds");
+                    }
+                    bounds.push(RegionTyParamBound(self.expect_lifetime()));
                 } else {
-                    TraitBoundModifier::None
-                };
-                bounds.push(TraitTyParamBound(poly_trait_ref, modifier));
+                    let lo = self.span;
+                    let lifetime_defs = self.parse_late_bound_lifetime_defs()?;
+                    let path = self.parse_path(PathStyle::Type)?;
+                    let poly_trait = PolyTraitRef::new(lifetime_defs, path, lo.to(self.prev_span));
+                    let modifier = if question.is_some() {
+                        TraitBoundModifier::Maybe
+                    } else {
+                        TraitBoundModifier::None
+                    };
+                    bounds.push(TraitTyParamBound(poly_trait, modifier));
+                }
+                if has_parens {
+                    self.expect(&token::CloseDelim(token::Paren))?;
+                    if let Some(&RegionTyParamBound(..)) = bounds.last() {
+                        self.span_err(self.prev_span,
+                                      "parenthesized lifetime bounds are not supported");
+                    }
+                }
             } else {
                 break
-            }}
+            }
 
-            if !self.eat(&token::BinOp(token::Plus)) {
+            if !allow_plus || !self.eat(&token::BinOp(token::Plus)) {
                 break
             }
         }
@@ -4085,12 +4183,16 @@ impl<'a> Parser<'a> {
         return Ok(bounds);
     }
 
-    // Parse bounds of a type parameter `BOUND + BOUND + BOUND` without trailing `+`.
+    fn parse_ty_param_bounds(&mut self) -> PResult<'a, TyParamBounds> {
+        self.parse_ty_param_bounds_common(true)
+    }
+
+    // Parse bounds of a lifetime parameter `BOUND + BOUND + BOUND`, possibly with trailing `+`.
     // BOUND = LT_BOUND (e.g. `'a`)
     fn parse_lt_param_bounds(&mut self) -> Vec<Lifetime> {
         let mut lifetimes = Vec::new();
-        while let Some(lifetime) = self.eat_lifetime() {
-            lifetimes.push(lifetime);
+        while self.check_lifetime() {
+            lifetimes.push(self.expect_lifetime());
 
             if !self.eat(&token::BinOp(token::Plus)) {
                 break
@@ -4135,7 +4237,8 @@ impl<'a> Parser<'a> {
         let mut seen_ty_param = false;
         loop {
             let attrs = self.parse_outer_attributes()?;
-            if let Some(lifetime) = self.eat_lifetime() {
+            if self.check_lifetime() {
+                let lifetime = self.expect_lifetime();
                 // Parse lifetime parameter.
                 let bounds = if self.eat(&token::Colon) {
                     self.parse_lt_param_bounds()
@@ -4151,7 +4254,7 @@ impl<'a> Parser<'a> {
                     self.span_err(self.prev_span,
                         "lifetime parameters must be declared prior to type parameters");
                 }
-            } else {if self.check_ident() {
+            } else if self.check_ident() {
                 // Parse type parameter.
                 ty_params.push(self.parse_ty_param(attrs)?);
                 seen_ty_param = true;
@@ -4163,7 +4266,7 @@ impl<'a> Parser<'a> {
                         &format!("trailing attribute after {} parameters", param_kind));
                 }
                 break
-            }}
+            }
 
             if !self.eat(&token::Comma) {
                 break
@@ -4182,7 +4285,7 @@ impl<'a> Parser<'a> {
     pub fn parse_generics(&mut self) -> PResult<'a, ast::Generics> {
         maybe_whole!(self, NtGenerics, |x| x);
 
-        let span_lo = self.span.lo;
+        let span_lo = self.span;
         if self.eat_lt() {
             let (lifetime_defs, ty_params) = self.parse_generic_params()?;
             self.expect_gt()?;
@@ -4193,7 +4296,7 @@ impl<'a> Parser<'a> {
                     id: ast::DUMMY_NODE_ID,
                     predicates: Vec::new(),
                 },
-                span: mk_sp(span_lo, self.prev_span.hi),
+                span: span_lo.to(self.prev_span),
             })
         } else {
             Ok(ast::Generics::default())
@@ -4209,16 +4312,16 @@ impl<'a> Parser<'a> {
         let mut seen_type = false;
         let mut seen_binding = false;
         loop {
-            if let Some(lifetime) = self.eat_lifetime() {
+            if self.check_lifetime() && self.look_ahead(1, |t| t != &token::BinOp(token::Plus)) {
                 // Parse lifetime argument.
-                lifetimes.push(lifetime);
+                lifetimes.push(self.expect_lifetime());
                 if seen_type || seen_binding {
                     self.span_err(self.prev_span,
                         "lifetime parameters must be declared prior to type parameters");
                 }
-            } else {if self.check_ident() && self.look_ahead(1, |t| t == &token::Eq) {
+            } else if self.check_ident() && self.look_ahead(1, |t| t == &token::Eq) {
                 // Parse associated type binding.
-                let lo = self.span.lo;
+                let lo = self.span;
                 let ident = self.parse_ident()?;
                 self.bump();
                 let ty = self.parse_ty()?;
@@ -4226,7 +4329,7 @@ impl<'a> Parser<'a> {
                     id: ast::DUMMY_NODE_ID,
                     ident: ident,
                     ty: ty,
-                    span: mk_sp(lo, self.prev_span.hi),
+                    span: lo.to(self.prev_span),
                 });
                 seen_binding = true;
             } else if self.check_type() {
@@ -4239,7 +4342,7 @@ impl<'a> Parser<'a> {
                 seen_type = true;
             } else {
                 break
-            }}
+            }
 
             if !self.eat(&token::Comma) {
                 break
@@ -4283,19 +4386,20 @@ impl<'a> Parser<'a> {
         }
 
         loop {
-            let lo = self.span.lo;
-            if let Some(lifetime) = self.eat_lifetime() {
+            let lo = self.span;
+            if self.check_lifetime() && self.look_ahead(1, |t| t != &token::BinOp(token::Plus)) {
+                let lifetime = self.expect_lifetime();
                 // Bounds starting with a colon are mandatory, but possibly empty.
                 self.expect(&token::Colon)?;
                 let bounds = self.parse_lt_param_bounds();
                 where_clause.predicates.push(ast::WherePredicate::RegionPredicate(
                     ast::WhereRegionPredicate {
-                        span: mk_sp(lo, self.prev_span.hi),
+                        span: lo.to(self.prev_span),
                         lifetime: lifetime,
                         bounds: bounds,
                     }
                 ));
-            } else {if self.check_type() {
+            } else if self.check_type() {
                 // Parse optional `for<'a, 'b>`.
                 // This `for` is parsed greedily and applies to the whole predicate,
                 // the bounded type can have its own `for` applying only to it.
@@ -4311,7 +4415,7 @@ impl<'a> Parser<'a> {
                     let bounds = self.parse_ty_param_bounds()?;
                     where_clause.predicates.push(ast::WherePredicate::BoundPredicate(
                         ast::WhereBoundPredicate {
-                            span: mk_sp(lo, self.prev_span.hi),
+                            span: lo.to(self.prev_span),
                             bound_lifetimes: lifetime_defs,
                             bounded_ty: ty,
                             bounds: bounds,
@@ -4322,7 +4426,7 @@ impl<'a> Parser<'a> {
                     let rhs_ty = self.parse_ty()?;
                     where_clause.predicates.push(ast::WherePredicate::EqPredicate(
                         ast::WhereEqPredicate {
-                            span: mk_sp(lo, self.prev_span.hi),
+                            span: lo.to(self.prev_span),
                             lhs_ty: ty,
                             rhs_ty: rhs_ty,
                             id: ast::DUMMY_NODE_ID,
@@ -4333,7 +4437,7 @@ impl<'a> Parser<'a> {
                 }
             } else {
                 break
-            }}
+            }
 
             if !self.eat(&token::Comma) {
                 break
@@ -4373,8 +4477,12 @@ impl<'a> Parser<'a> {
                             Ok(arg) => Ok(Some(arg)),
                             Err(mut e) => {
                                 e.emit();
+                                let lo = p.prev_span;
+                                // Skip every token until next possible arg or end.
                                 p.eat_to_tokens(&[&token::Comma, &token::CloseDelim(token::Paren)]);
-                                Ok(None)
+                                // Create a placeholder argument for proper arg count (#34264).
+                                let span = lo.to(p.prev_span);
+                                Ok(Some(dummy_arg(span)))
                             }
                         }
                     }
@@ -4408,7 +4516,7 @@ impl<'a> Parser<'a> {
     fn parse_self_arg(&mut self) -> PResult<'a, Option<Arg>> {
         let expect_ident = |this: &mut Self| match this.token {
             // Preserve hygienic context.
-            token::Ident(ident) => { this.bump(); codemap::respan(this.prev_span, ident) }
+            token::Ident(ident) => { let sp = this.span; this.bump(); codemap::respan(sp, ident) }
             _ => unreachable!()
         };
         let isolated_self = |this: &mut Self, n| {
@@ -4419,7 +4527,7 @@ impl<'a> Parser<'a> {
         // Parse optional self parameter of a method.
         // Only a limited set of initial token sequences is considered self parameters, anything
         // else is parsed as a normal function parameter list, so some lookahead is required.
-        let eself_lo = self.span.lo;
+        let eself_lo = self.span;
         let (eself, eself_ident) = match self.token {
             token::BinOp(token::And) => {
                 // &self
@@ -4438,13 +4546,13 @@ impl<'a> Parser<'a> {
                 } else if self.look_ahead(1, |t| t.is_lifetime()) &&
                           isolated_self(self, 2) {
                     self.bump();
-                    let lt = self.eat_lifetime().expect("not a lifetime");
+                    let lt = self.expect_lifetime();
                     (SelfKind::Region(Some(lt), Mutability::Immutable), expect_ident(self))
                 } else if self.look_ahead(1, |t| t.is_lifetime()) &&
                           self.look_ahead(2, |t| t.is_keyword(keywords::Mut)) &&
                           isolated_self(self, 3) {
                     self.bump();
-                    let lt = self.eat_lifetime().expect("not a lifetime");
+                    let lt = self.expect_lifetime();
                     self.bump();
                     (SelfKind::Region(Some(lt), Mutability::Mutable), expect_ident(self))
                 } else {
@@ -4501,7 +4609,7 @@ impl<'a> Parser<'a> {
             _ => return Ok(None),
         };
 
-        let eself = codemap::respan(mk_sp(eself_lo, self.prev_span.hi), eself);
+        let eself = codemap::respan(eself_lo.to(self.prev_span), eself);
         Ok(Some(Arg::from_self(eself, eself_ident)))
     }
 
@@ -4573,8 +4681,7 @@ impl<'a> Parser<'a> {
         Ok((id, generics))
     }
 
-    fn mk_item(&mut self, lo: BytePos, hi: BytePos, ident: Ident,
-               node: ItemKind, vis: Visibility,
+    fn mk_item(&mut self, span: Span, ident: Ident, node: ItemKind, vis: Visibility,
                attrs: Vec<Attribute>) -> P<Item> {
         P(Item {
             ident: ident,
@@ -4582,7 +4689,7 @@ impl<'a> Parser<'a> {
             id: ast::DUMMY_NODE_ID,
             node: node,
             vis: vis,
-            span: mk_sp(lo, hi)
+            span: span,
         })
     }
 
@@ -4636,12 +4743,12 @@ impl<'a> Parser<'a> {
     }
 
     /// Parse an impl item.
-    pub fn parse_impl_item(&mut self) -> PResult<'a, ImplItem> {
+    pub fn parse_impl_item(&mut self, at_end: &mut bool) -> PResult<'a, ImplItem> {
         maybe_whole!(self, NtImplItem, |x| x);
 
         let mut attrs = self.parse_outer_attributes()?;
-        let lo = self.span.lo;
-        let vis = self.parse_visibility(true)?;
+        let lo = self.span;
+        let vis = self.parse_visibility(false)?;
         let defaultness = self.parse_defaultness()?;
         let (name, node) = if self.eat_keyword(keywords::Type) {
             let name = self.parse_ident()?;
@@ -4659,14 +4766,14 @@ impl<'a> Parser<'a> {
             self.expect(&token::Semi)?;
             (name, ast::ImplItemKind::Const(typ, expr))
         } else {
-            let (name, inner_attrs, node) = self.parse_impl_method(&vis)?;
+            let (name, inner_attrs, node) = self.parse_impl_method(&vis, at_end)?;
             attrs.extend(inner_attrs);
             (name, node)
         };
 
         Ok(ImplItem {
             id: ast::DUMMY_NODE_ID,
-            span: mk_sp(lo, self.prev_span.hi),
+            span: lo.to(self.prev_span),
             ident: name,
             vis: vis,
             defaultness: defaultness,
@@ -4675,51 +4782,85 @@ impl<'a> Parser<'a> {
         })
     }
 
-    fn complain_if_pub_macro(&mut self, visa: &Visibility, span: Span) {
-        match *visa {
-            Visibility::Inherited => (),
+    fn complain_if_pub_macro(&mut self, vis: &Visibility, sp: Span) {
+        if let Err(mut err) = self.complain_if_pub_macro_diag(vis, sp) {
+            err.emit();
+        }
+    }
+
+    fn complain_if_pub_macro_diag(&mut self, vis: &Visibility, sp: Span) -> PResult<'a, ()> {
+        match *vis {
+            Visibility::Inherited => Ok(()),
             _ => {
                 let is_macro_rules: bool = match self.token {
                     token::Ident(sid) => sid.name == Symbol::intern("macro_rules"),
                     _ => false,
                 };
                 if is_macro_rules {
-                    self.diagnostic().struct_span_err(span, "can't qualify macro_rules \
-                                                             invocation with `pub`")
-                                     .help("did you mean #[macro_export]?")
-                                     .emit();
+                    let mut err = self.diagnostic()
+                        .struct_span_err(sp, "can't qualify macro_rules invocation with `pub`");
+                    err.help("did you mean #[macro_export]?");
+                    Err(err)
                 } else {
-                    self.diagnostic().struct_span_err(span, "can't qualify macro \
-                                                             invocation with `pub`")
-                                     .help("try adjusting the macro to put `pub` \
-                                            inside the invocation")
-                                     .emit();
+                    let mut err = self.diagnostic()
+                        .struct_span_err(sp, "can't qualify macro invocation with `pub`");
+                    err.help("try adjusting the macro to put `pub` inside the invocation");
+                    Err(err)
                 }
             }
         }
     }
 
+    fn missing_assoc_item_kind_err(&mut self, item_type: &str, prev_span: Span)
+                                   -> DiagnosticBuilder<'a>
+    {
+        // Given this code `path(`, it seems like this is not
+        // setting the visibility of a macro invocation, but rather
+        // a mistyped method declaration.
+        // Create a diagnostic pointing out that `fn` is missing.
+        //
+        // x |     pub path(&self) {
+        //   |        ^ missing `fn`, `type`, or `const`
+        //     pub  path(
+        //        ^^ `sp` below will point to this
+        let sp = prev_span.between(self.prev_span);
+        let mut err = self.diagnostic().struct_span_err(
+            sp,
+            &format!("missing `fn`, `type`, or `const` for {}-item declaration",
+                     item_type));
+        err.span_label(sp, "missing `fn`, `type`, or `const`");
+        err
+    }
+
     /// Parse a method or a macro invocation in a trait impl.
-    fn parse_impl_method(&mut self, vis: &Visibility)
+    fn parse_impl_method(&mut self, vis: &Visibility, at_end: &mut bool)
                          -> PResult<'a, (Ident, Vec<ast::Attribute>, ast::ImplItemKind)> {
         // code copied from parse_macro_use_or_failure... abstraction!
         if self.token.is_path_start() {
-            // method macro.
+            // Method macro.
 
             let prev_span = self.prev_span;
-            self.complain_if_pub_macro(&vis, prev_span);
 
-            let lo = self.span.lo;
+            let lo = self.span;
             let pth = self.parse_path(PathStyle::Mod)?;
-            self.expect(&token::Not)?;
+            if pth.segments.len() == 1 {
+                if !self.eat(&token::Not) {
+                    return Err(self.missing_assoc_item_kind_err("impl", prev_span));
+                }
+            } else {
+                self.expect(&token::Not)?;
+            }
+
+            self.complain_if_pub_macro(vis, prev_span);
 
             // eat a matched-delimiter token tree:
+            *at_end = true;
             let (delim, tts) = self.expect_delimited_token_tree()?;
             if delim != token::Brace {
                 self.expect(&token::Semi)?
             }
 
-            let mac = spanned(lo, self.prev_span.hi, Mac_ { path: pth, tts: tts });
+            let mac = respan(lo.to(self.prev_span), Mac_ { path: pth, tts: tts });
             Ok((keywords::Invalid.ident(), vec![], ast::ImplItemKind::Macro(mac)))
         } else {
             let (constness, unsafety, abi) = self.parse_fn_front_matter()?;
@@ -4727,6 +4868,7 @@ impl<'a> Parser<'a> {
             let mut generics = self.parse_generics()?;
             let decl = self.parse_fn_decl_with_self(|p| p.parse_arg())?;
             generics.where_clause = self.parse_where_clause()?;
+            *at_end = true;
             let (inner_attrs, body) = self.parse_inner_attrs_and_block()?;
             Ok((ident, inner_attrs, ast::ImplItemKind::Method(ast::MethodSig {
                 generics: generics,
@@ -4752,15 +4894,30 @@ impl<'a> Parser<'a> {
 
         tps.where_clause = self.parse_where_clause()?;
 
-        let meths = self.parse_trait_items()?;
-        Ok((ident, ItemKind::Trait(unsafety, tps, bounds, meths), None))
+        self.expect(&token::OpenDelim(token::Brace))?;
+        let mut trait_items = vec![];
+        while !self.eat(&token::CloseDelim(token::Brace)) {
+            let mut at_end = false;
+            match self.parse_trait_item(&mut at_end) {
+                Ok(item) => trait_items.push(item),
+                Err(mut e) => {
+                    e.emit();
+                    if !at_end {
+                        self.recover_stmt_(SemiColonMode::Break, BlockMode::Break);
+                    }
+                }
+            }
+        }
+        Ok((ident, ItemKind::Trait(unsafety, tps, bounds, trait_items), None))
     }
 
     /// Parses items implementations variants
     ///    impl<T> Foo { ... }
     ///    impl<T> ToString for &'static T { ... }
     ///    impl Send for .. {}
-    fn parse_item_impl(&mut self, unsafety: ast::Unsafety) -> PResult<'a, ItemInfo> {
+    fn parse_item_impl(&mut self,
+                       unsafety: ast::Unsafety,
+                       defaultness: Defaultness) -> PResult<'a, ItemInfo> {
         let impl_span = self.span;
 
         // First, parse type parameters if necessary.
@@ -4796,13 +4953,10 @@ impl<'a> Parser<'a> {
                 }
             }
         } else {
-            match polarity {
-                ast::ImplPolarity::Negative => {
-                    // This is a negated type implementation
-                    // `impl !MyType {}`, which is not allowed.
-                    self.span_err(neg_span, "inherent implementation can't be negated");
-                },
-                _ => {}
+            if polarity == ast::ImplPolarity::Negative {
+                // This is a negated type implementation
+                // `impl !MyType {}`, which is not allowed.
+                self.span_err(neg_span, "inherent implementation can't be negated");
             }
             None
         };
@@ -4813,6 +4967,11 @@ impl<'a> Parser<'a> {
                                           allowed to have generics");
             }
 
+            if let ast::Defaultness::Default = defaultness {
+                self.span_err(impl_span, "`default impl` is not allowed for \
+                                         default trait implementations");
+            }
+
             self.expect(&token::OpenDelim(token::Brace))?;
             self.expect(&token::CloseDelim(token::Brace))?;
             Ok((keywords::Invalid.ident(),
@@ -4828,23 +4987,24 @@ impl<'a> Parser<'a> {
 
             let mut impl_items = vec![];
             while !self.eat(&token::CloseDelim(token::Brace)) {
-                impl_items.push(self.parse_impl_item()?);
+                let mut at_end = false;
+                match self.parse_impl_item(&mut at_end) {
+                    Ok(item) => impl_items.push(item),
+                    Err(mut e) => {
+                        e.emit();
+                        if !at_end {
+                            self.recover_stmt_(SemiColonMode::Break, BlockMode::Break);
+                        }
+                    }
+                }
             }
 
             Ok((keywords::Invalid.ident(),
-             ItemKind::Impl(unsafety, polarity, generics, opt_trait, ty, impl_items),
+             ItemKind::Impl(unsafety, polarity, defaultness, generics, opt_trait, ty, impl_items),
              Some(attrs)))
         }
     }
 
-    /// Parse a::B<String,i32>
-    fn parse_trait_ref(&mut self) -> PResult<'a, TraitRef> {
-        Ok(TraitRef {
-            path: self.parse_path(PathStyle::Type)?,
-            ref_id: ast::DUMMY_NODE_ID,
-        })
-    }
-
     fn parse_late_bound_lifetime_defs(&mut self) -> PResult<'a, Vec<LifetimeDef>> {
         if self.eat_keyword(keywords::For) {
             self.expect_lt()?;
@@ -4860,21 +5020,10 @@ impl<'a> Parser<'a> {
         }
     }
 
-    /// Parse for<'l> a::B<String,i32>
-    fn parse_poly_trait_ref(&mut self) -> PResult<'a, PolyTraitRef> {
-        let lo = self.span.lo;
-        let lifetime_defs = self.parse_late_bound_lifetime_defs()?;
-
-        Ok(PolyTraitRef {
-            bound_lifetimes: lifetime_defs,
-            trait_ref: self.parse_trait_ref()?,
-            span: mk_sp(lo, self.prev_span.hi),
-        })
-    }
-
     /// Parse struct Foo { ... }
     fn parse_item_struct(&mut self) -> PResult<'a, ItemInfo> {
         let class_name = self.parse_ident()?;
+
         let mut generics = self.parse_generics()?;
 
         // There is a special case worth noting here, as reported in issue #17904.
@@ -4924,6 +5073,7 @@ impl<'a> Parser<'a> {
     /// Parse union Foo { ... }
     fn parse_item_union(&mut self) -> PResult<'a, ItemInfo> {
         let class_name = self.parse_ident()?;
+
         let mut generics = self.parse_generics()?;
 
         let vdata = if self.token.is_keyword(keywords::Where) {
@@ -4971,28 +5121,11 @@ impl<'a> Parser<'a> {
             SeqSep::trailing_allowed(token::Comma),
             |p| {
                 let attrs = p.parse_outer_attributes()?;
-                let lo = p.span.lo;
-                let mut vis = p.parse_visibility(false)?;
-                let ty_is_interpolated =
-                    p.token.is_interpolated() || p.look_ahead(1, |t| t.is_interpolated());
-                let mut ty = p.parse_ty()?;
-
-                // Handle `pub(path) type`, in which `vis` will be `pub` and `ty` will be `(path)`.
-                if vis == Visibility::Public && !ty_is_interpolated &&
-                   p.token != token::Comma && p.token != token::CloseDelim(token::Paren) {
-                    ty = if let TyKind::Paren(ref path_ty) = ty.node {
-                        if let TyKind::Path(None, ref path) = path_ty.node {
-                            vis = Visibility::Restricted { path: P(path.clone()), id: path_ty.id };
-                            Some(p.parse_ty()?)
-                        } else {
-                            None
-                        }
-                    } else {
-                        None
-                    }.unwrap_or(ty);
-                }
+                let lo = p.span;
+                let vis = p.parse_visibility(true)?;
+                let ty = p.parse_ty()?;
                 Ok(StructField {
-                    span: mk_sp(lo, p.span.hi),
+                    span: lo.to(p.span),
                     vis: vis,
                     ident: None,
                     id: ast::DUMMY_NODE_ID,
@@ -5006,7 +5139,7 @@ impl<'a> Parser<'a> {
 
     /// Parse a structure field declaration
     pub fn parse_single_struct_field(&mut self,
-                                     lo: BytePos,
+                                     lo: Span,
                                      vis: Visibility,
                                      attrs: Vec<Attribute> )
                                      -> PResult<'a, StructField> {
@@ -5028,39 +5161,70 @@ impl<'a> Parser<'a> {
     /// Parse an element of a struct definition
     fn parse_struct_decl_field(&mut self) -> PResult<'a, StructField> {
         let attrs = self.parse_outer_attributes()?;
-        let lo = self.span.lo;
-        let vis = self.parse_visibility(true)?;
+        let lo = self.span;
+        let vis = self.parse_visibility(false)?;
         self.parse_single_struct_field(lo, vis, attrs)
     }
 
-    // If `allow_path` is false, just parse the `pub` in `pub(path)` (but still parse `pub(crate)`)
-    fn parse_visibility(&mut self, allow_path: bool) -> PResult<'a, Visibility> {
-        let pub_crate = |this: &mut Self| {
-            let span = this.prev_span;
-            this.expect(&token::CloseDelim(token::Paren))?;
-            Ok(Visibility::Crate(span))
-        };
+    /// Parse `pub`, `pub(crate)` and `pub(in path)` plus shortcuts `pub(self)` for `pub(in self)`
+    /// and `pub(super)` for `pub(in super)`.  If the following element can't be a tuple (i.e. it's
+    /// a function definition, it's not a tuple struct field) and the contents within the parens
+    /// isn't valid, emit a proper diagnostic.
+    pub fn parse_visibility(&mut self, can_take_tuple: bool) -> PResult<'a, Visibility> {
+        maybe_whole!(self, NtVis, |x| x);
 
         if !self.eat_keyword(keywords::Pub) {
-            Ok(Visibility::Inherited)
-        } else if !allow_path {
-            // Look ahead to avoid eating the `(` in `pub(path)` while still parsing `pub(crate)`
-            if self.token == token::OpenDelim(token::Paren) &&
-               self.look_ahead(1, |t| t.is_keyword(keywords::Crate)) {
-                self.bump(); self.bump();
-                pub_crate(self)
-            } else {
-                Ok(Visibility::Public)
-            }
-        } else if !self.eat(&token::OpenDelim(token::Paren)) {
-            Ok(Visibility::Public)
-        } else if self.eat_keyword(keywords::Crate) {
-            pub_crate(self)
-        } else {
-            let path = self.parse_path(PathStyle::Mod)?.default_to_global();
-            self.expect(&token::CloseDelim(token::Paren))?;
-            Ok(Visibility::Restricted { path: P(path), id: ast::DUMMY_NODE_ID })
-        }
+            return Ok(Visibility::Inherited)
+        }
+
+        if self.check(&token::OpenDelim(token::Paren)) {
+            // We don't `self.bump()` the `(` yet because this might be a struct definition where
+            // `()` or a tuple might be allowed. For example, `struct Struct(pub (), pub (usize));`.
+            // Because of this, we only `bump` the `(` if we're assured it is appropriate to do so
+            // by the following tokens.
+            if self.look_ahead(1, |t| t.is_keyword(keywords::Crate)) {
+                // `pub(crate)`
+                self.bump(); // `(`
+                self.bump(); // `crate`
+                let vis = Visibility::Crate(self.prev_span);
+                self.expect(&token::CloseDelim(token::Paren))?; // `)`
+                return Ok(vis)
+            } else if self.look_ahead(1, |t| t.is_keyword(keywords::In)) {
+                // `pub(in path)`
+                self.bump(); // `(`
+                self.bump(); // `in`
+                let path = self.parse_path(PathStyle::Mod)?.default_to_global(); // `path`
+                let vis = Visibility::Restricted { path: P(path), id: ast::DUMMY_NODE_ID };
+                self.expect(&token::CloseDelim(token::Paren))?; // `)`
+                return Ok(vis)
+            } else if self.look_ahead(2, |t| t == &token::CloseDelim(token::Paren)) &&
+                      self.look_ahead(1, |t| t.is_keyword(keywords::Super) ||
+                                             t.is_keyword(keywords::SelfValue)) {
+                // `pub(self)` or `pub(super)`
+                self.bump(); // `(`
+                let path = self.parse_path(PathStyle::Mod)?.default_to_global(); // `super`/`self`
+                let vis = Visibility::Restricted { path: P(path), id: ast::DUMMY_NODE_ID };
+                self.expect(&token::CloseDelim(token::Paren))?; // `)`
+                return Ok(vis)
+            } else if !can_take_tuple {  // Provide this diagnostic if this is not a tuple struct
+                // `pub(something) fn ...` or `struct X { pub(something) y: Z }`
+                self.bump(); // `(`
+                let msg = "incorrect visibility restriction";
+                let suggestion = r##"some possible visibility restrictions are:
+`pub(crate)`: visible only on the current crate
+`pub(super)`: visible only in the current module's parent
+`pub(in path::to::module)`: visible only on the specified path"##;
+                let path = self.parse_path(PathStyle::Mod)?;
+                let path_span = self.prev_span;
+                let help_msg = format!("make this visible only to module `{}` with `in`:", path);
+                self.expect(&token::CloseDelim(token::Paren))?;  // `)`
+                let mut err = self.span_fatal_help(path_span, msg, suggestion);
+                err.span_suggestion(path_span, &help_msg, format!("in {}", path));
+                err.emit();  // emit diagnostic, but continue with public visibility
+            }
+        }
+
+        Ok(Visibility::Public)
     }
 
     /// Parse defaultness: DEFAULT or nothing
@@ -5073,7 +5237,7 @@ impl<'a> Parser<'a> {
     }
 
     /// Given a termination token, parse all of the items in a module
-    fn parse_mod_items(&mut self, term: &token::Token, inner_lo: BytePos) -> PResult<'a, Mod> {
+    fn parse_mod_items(&mut self, term: &token::Token, inner_lo: Span) -> PResult<'a, Mod> {
         let mut items = vec![];
         while let Some(item) = self.parse_item()? {
             items.push(item);
@@ -5087,11 +5251,11 @@ impl<'a> Parser<'a> {
         let hi = if self.span == syntax_pos::DUMMY_SP {
             inner_lo
         } else {
-            self.prev_span.hi
+            self.prev_span
         };
 
         Ok(ast::Mod {
-            inner: mk_sp(inner_lo, hi),
+            inner: inner_lo.to(hi),
             items: items
         })
     }
@@ -5126,7 +5290,7 @@ impl<'a> Parser<'a> {
         let id = self.parse_ident()?;
         if self.check(&token::Semi) {
             self.bump();
-            if in_cfg {
+            if in_cfg && self.recurse_into_file_modules {
                 // This mod is in an external file. Let's go get it!
                 let ModulePathSuccess { path, directory_ownership, warn } =
                     self.submod_path(id, &outer_attrs, id_span)?;
@@ -5136,11 +5300,9 @@ impl<'a> Parser<'a> {
                     let attr = ast::Attribute {
                         id: attr::mk_attr_id(),
                         style: ast::AttrStyle::Outer,
-                        value: ast::MetaItem {
-                            name: Symbol::intern("warn_directory_ownership"),
-                            node: ast::MetaItemKind::Word,
-                            span: syntax_pos::DUMMY_SP,
-                        },
+                        path: ast::Path::from_ident(syntax_pos::DUMMY_SP,
+                                                    Ident::from_str("warn_directory_ownership")),
+                        tokens: TokenStream::empty(),
                         is_sugared_doc: false,
                         span: syntax_pos::DUMMY_SP,
                     };
@@ -5155,10 +5317,12 @@ impl<'a> Parser<'a> {
         } else {
             let old_directory = self.directory.clone();
             self.push_directory(id, &outer_attrs);
+
             self.expect(&token::OpenDelim(token::Brace))?;
-            let mod_inner_lo = self.span.lo;
+            let mod_inner_lo = self.span;
             let attrs = self.parse_inner_attributes()?;
             let module = self.parse_mod_items(&token::CloseDelim(token::Brace), mod_inner_lo)?;
+
             self.directory = old_directory;
             Ok((id, ItemKind::Mod(module), Some(attrs)))
         }
@@ -5166,22 +5330,22 @@ impl<'a> Parser<'a> {
 
     fn push_directory(&mut self, id: Ident, attrs: &[Attribute]) {
         if let Some(path) = attr::first_attr_value_str_by_name(attrs, "path") {
-            self.directory.path.push(&*path.as_str());
+            self.directory.path.push(&path.as_str());
             self.directory.ownership = DirectoryOwnership::Owned;
         } else {
-            self.directory.path.push(&*id.name.as_str());
+            self.directory.path.push(&id.name.as_str());
         }
     }
 
     pub fn submod_path_from_attr(attrs: &[ast::Attribute], dir_path: &Path) -> Option<PathBuf> {
-        attr::first_attr_value_str_by_name(attrs, "path").map(|d| dir_path.join(&*d.as_str()))
+        attr::first_attr_value_str_by_name(attrs, "path").map(|d| dir_path.join(&d.as_str()))
     }
 
     /// Returns either a path to a module, or .
     pub fn default_submod_path(id: ast::Ident, dir_path: &Path, codemap: &CodeMap) -> ModulePath {
         let mod_name = id.to_string();
         let default_path_str = format!("{}.rs", mod_name);
-        let secondary_path_str = format!("{}/mod.rs", mod_name);
+        let secondary_path_str = format!("{}{}mod.rs", mod_name, path::MAIN_SEPARATOR);
         let default_path = dir_path.join(&default_path_str);
         let secondary_path = dir_path.join(&secondary_path_str);
         let default_exists = codemap.file_exists(&default_path);
@@ -5221,7 +5385,8 @@ impl<'a> Parser<'a> {
     fn submod_path(&mut self,
                    id: ast::Ident,
                    outer_attrs: &[ast::Attribute],
-                   id_sp: Span) -> PResult<'a, ModulePathSuccess> {
+                   id_sp: Span)
+                   -> PResult<'a, ModulePathSuccess> {
         if let Some(path) = Parser::submod_path_from_attr(outer_attrs, &self.directory.path) {
             return Ok(ModulePathSuccess {
                 directory_ownership: match path.file_name().and_then(|s| s.to_str()) {
@@ -5253,23 +5418,25 @@ impl<'a> Parser<'a> {
             }
             let mut err = self.diagnostic().struct_span_err(id_sp,
                 "cannot declare a new module at this location");
-            let this_module = match self.directory.path.file_name() {
-                Some(file_name) => file_name.to_str().unwrap().to_owned(),
-                None => self.root_module_name.as_ref().unwrap().clone(),
-            };
-            err.span_note(id_sp,
-                          &format!("maybe move this module `{0}` to its own directory \
-                                     via `{0}/mod.rs`",
-                                    this_module));
+            if id_sp != syntax_pos::DUMMY_SP {
+                let src_path = PathBuf::from(self.sess.codemap().span_to_filename(id_sp));
+                if let Some(stem) = src_path.file_stem() {
+                    let mut dest_path = src_path.clone();
+                    dest_path.set_file_name(stem);
+                    dest_path.push("mod.rs");
+                    err.span_note(id_sp,
+                                  &format!("maybe move this module `{}` to its own \
+                                            directory via `{}`", src_path.to_string_lossy(),
+                                           dest_path.to_string_lossy()));
+                }
+            }
             if paths.path_exists {
                 err.span_note(id_sp,
                               &format!("... or maybe `use` the module `{}` instead \
                                         of possibly redeclaring it",
                                        paths.name));
-                Err(err)
-            } else {
-                Err(err)
             }
+            Err(err)
         } else {
             paths.result.map_err(|err| self.span_fatal_err(id_sp, err))
         }
@@ -5299,7 +5466,7 @@ impl<'a> Parser<'a> {
         let mut p0 =
             new_sub_parser_from_file(self.sess, &path, directory_ownership, Some(name), id_sp);
         p0.cfg_mods = self.cfg_mods;
-        let mod_inner_lo = p0.span.lo;
+        let mod_inner_lo = p0.span;
         let mod_attrs = p0.parse_inner_attributes()?;
         let m0 = p0.parse_mod_items(&token::Eof, mod_inner_lo)?;
         self.sess.included_mod_stack.borrow_mut().pop();
@@ -5307,42 +5474,42 @@ impl<'a> Parser<'a> {
     }
 
     /// Parse a function declaration from a foreign module
-    fn parse_item_foreign_fn(&mut self, vis: ast::Visibility, lo: BytePos,
-                             attrs: Vec<Attribute>) -> PResult<'a, ForeignItem> {
+    fn parse_item_foreign_fn(&mut self, vis: ast::Visibility, lo: Span, attrs: Vec<Attribute>)
+                             -> PResult<'a, ForeignItem> {
         self.expect_keyword(keywords::Fn)?;
 
         let (ident, mut generics) = self.parse_fn_header()?;
         let decl = self.parse_fn_decl(true)?;
         generics.where_clause = self.parse_where_clause()?;
-        let hi = self.span.hi;
+        let hi = self.span;
         self.expect(&token::Semi)?;
         Ok(ast::ForeignItem {
             ident: ident,
             attrs: attrs,
             node: ForeignItemKind::Fn(decl, generics),
             id: ast::DUMMY_NODE_ID,
-            span: mk_sp(lo, hi),
+            span: lo.to(hi),
             vis: vis
         })
     }
 
     /// Parse a static item from a foreign module
-    fn parse_item_foreign_static(&mut self, vis: ast::Visibility, lo: BytePos,
-                                 attrs: Vec<Attribute>) -> PResult<'a, ForeignItem> {
+    fn parse_item_foreign_static(&mut self, vis: ast::Visibility, lo: Span, attrs: Vec<Attribute>)
+                                 -> PResult<'a, ForeignItem> {
         self.expect_keyword(keywords::Static)?;
         let mutbl = self.eat_keyword(keywords::Mut);
 
         let ident = self.parse_ident()?;
         self.expect(&token::Colon)?;
         let ty = self.parse_ty()?;
-        let hi = self.span.hi;
+        let hi = self.span;
         self.expect(&token::Semi)?;
         Ok(ForeignItem {
             ident: ident,
             attrs: attrs,
             node: ForeignItemKind::Static(ty, mutbl),
             id: ast::DUMMY_NODE_ID,
-            span: mk_sp(lo, hi),
+            span: lo.to(hi),
             vis: vis
         })
     }
@@ -5354,7 +5521,7 @@ impl<'a> Parser<'a> {
     /// extern crate foo;
     /// extern crate bar as foo;
     fn parse_item_extern_crate(&mut self,
-                               lo: BytePos,
+                               lo: Span,
                                visibility: Visibility,
                                attrs: Vec<Attribute>)
                                 -> PResult<'a, P<Item>> {
@@ -5368,8 +5535,7 @@ impl<'a> Parser<'a> {
         self.expect(&token::Semi)?;
 
         let prev_span = self.prev_span;
-        Ok(self.mk_item(lo,
-                        prev_span.hi,
+        Ok(self.mk_item(lo.to(prev_span),
                         ident,
                         ItemKind::ExternCrate(maybe_path),
                         visibility,
@@ -5387,7 +5553,7 @@ impl<'a> Parser<'a> {
     /// extern "C" {}
     /// extern {}
     fn parse_item_foreign_mod(&mut self,
-                              lo: BytePos,
+                              lo: Span,
                               opt_abi: Option<abi::Abi>,
                               visibility: Visibility,
                               mut attrs: Vec<Attribute>)
@@ -5409,12 +5575,8 @@ impl<'a> Parser<'a> {
             abi: abi,
             items: foreign_items
         };
-        Ok(self.mk_item(lo,
-                     prev_span.hi,
-                     keywords::Invalid.ident(),
-                     ItemKind::ForeignMod(m),
-                     visibility,
-                     attrs))
+        let invalid = keywords::Invalid.ident();
+        Ok(self.mk_item(lo.to(prev_span), invalid, ItemKind::ForeignMod(m), visibility, attrs))
     }
 
     /// Parse type Foo = Bar;
@@ -5435,7 +5597,7 @@ impl<'a> Parser<'a> {
         let mut any_disr = None;
         while self.token != token::CloseDelim(token::Brace) {
             let variant_attrs = self.parse_outer_attributes()?;
-            let vlo = self.span.lo;
+            let vlo = self.span;
 
             let struct_def;
             let mut disr_expr = None;
@@ -5463,7 +5625,7 @@ impl<'a> Parser<'a> {
                 data: struct_def,
                 disr_expr: disr_expr,
             };
-            variants.push(spanned(vlo, self.prev_span.hi, vr));
+            variants.push(respan(vlo.to(self.prev_span), vr));
 
             if !self.eat(&token::Comma) { break; }
         }
@@ -5533,9 +5695,9 @@ impl<'a> Parser<'a> {
             Some(P(item))
         });
 
-        let lo = self.span.lo;
+        let lo = self.span;
 
-        let visibility = self.parse_visibility(true)?;
+        let visibility = self.parse_visibility(false)?;
 
         if self.eat_keyword(keywords::Use) {
             // USE ITEM
@@ -5543,12 +5705,8 @@ impl<'a> Parser<'a> {
             self.expect(&token::Semi)?;
 
             let prev_span = self.prev_span;
-            let item = self.mk_item(lo,
-                                    prev_span.hi,
-                                    keywords::Invalid.ident(),
-                                    item_,
-                                    visibility,
-                                    attrs);
+            let invalid = keywords::Invalid.ident();
+            let item = self.mk_item(lo.to(prev_span), invalid, item_, visibility, attrs);
             return Ok(Some(item));
         }
 
@@ -5568,8 +5726,7 @@ impl<'a> Parser<'a> {
                                        respan(fn_span, Constness::NotConst),
                                        abi)?;
                 let prev_span = self.prev_span;
-                let item = self.mk_item(lo,
-                                        prev_span.hi,
+                let item = self.mk_item(lo.to(prev_span),
                                         ident,
                                         item_,
                                         visibility,
@@ -5591,8 +5748,7 @@ impl<'a> Parser<'a> {
             };
             let (ident, item_, extra_attrs) = self.parse_item_const(Some(m))?;
             let prev_span = self.prev_span;
-            let item = self.mk_item(lo,
-                                    prev_span.hi,
+            let item = self.mk_item(lo.to(prev_span),
                                     ident,
                                     item_,
                                     visibility,
@@ -5616,8 +5772,7 @@ impl<'a> Parser<'a> {
                                        respan(const_span, Constness::Const),
                                        Abi::Rust)?;
                 let prev_span = self.prev_span;
-                let item = self.mk_item(lo,
-                                        prev_span.hi,
+                let item = self.mk_item(lo.to(prev_span),
                                         ident,
                                         item_,
                                         visibility,
@@ -5634,8 +5789,7 @@ impl<'a> Parser<'a> {
             }
             let (ident, item_, extra_attrs) = self.parse_item_const(None)?;
             let prev_span = self.prev_span;
-            let item = self.mk_item(lo,
-                                    prev_span.hi,
+            let item = self.mk_item(lo.to(prev_span),
                                     ident,
                                     item_,
                                     visibility,
@@ -5651,24 +5805,28 @@ impl<'a> Parser<'a> {
             let (ident, item_, extra_attrs) =
                 self.parse_item_trait(ast::Unsafety::Unsafe)?;
             let prev_span = self.prev_span;
-            let item = self.mk_item(lo,
-                                    prev_span.hi,
+            let item = self.mk_item(lo.to(prev_span),
                                     ident,
                                     item_,
                                     visibility,
                                     maybe_append(attrs, extra_attrs));
             return Ok(Some(item));
         }
-        if self.check_keyword(keywords::Unsafe) &&
-            self.look_ahead(1, |t| t.is_keyword(keywords::Impl))
+        if (self.check_keyword(keywords::Unsafe) &&
+            self.look_ahead(1, |t| t.is_keyword(keywords::Impl))) ||
+           (self.check_keyword(keywords::Default) &&
+            self.look_ahead(1, |t| t.is_keyword(keywords::Unsafe)) &&
+            self.look_ahead(2, |t| t.is_keyword(keywords::Impl)))
         {
             // IMPL ITEM
+            let defaultness = self.parse_defaultness()?;
             self.expect_keyword(keywords::Unsafe)?;
             self.expect_keyword(keywords::Impl)?;
-            let (ident, item_, extra_attrs) = self.parse_item_impl(ast::Unsafety::Unsafe)?;
+            let (ident,
+                 item_,
+                 extra_attrs) = self.parse_item_impl(ast::Unsafety::Unsafe, defaultness)?;
             let prev_span = self.prev_span;
-            let item = self.mk_item(lo,
-                                    prev_span.hi,
+            let item = self.mk_item(lo.to(prev_span),
                                     ident,
                                     item_,
                                     visibility,
@@ -5684,8 +5842,7 @@ impl<'a> Parser<'a> {
                                    respan(fn_span, Constness::NotConst),
                                    Abi::Rust)?;
             let prev_span = self.prev_span;
-            let item = self.mk_item(lo,
-                                    prev_span.hi,
+            let item = self.mk_item(lo.to(prev_span),
                                     ident,
                                     item_,
                                     visibility,
@@ -5708,8 +5865,7 @@ impl<'a> Parser<'a> {
                                    respan(fn_span, Constness::NotConst),
                                    abi)?;
             let prev_span = self.prev_span;
-            let item = self.mk_item(lo,
-                                    prev_span.hi,
+            let item = self.mk_item(lo.to(prev_span),
                                     ident,
                                     item_,
                                     visibility,
@@ -5721,8 +5877,7 @@ impl<'a> Parser<'a> {
             let (ident, item_, extra_attrs) =
                 self.parse_item_mod(&attrs[..])?;
             let prev_span = self.prev_span;
-            let item = self.mk_item(lo,
-                                    prev_span.hi,
+            let item = self.mk_item(lo.to(prev_span),
                                     ident,
                                     item_,
                                     visibility,
@@ -5733,8 +5888,7 @@ impl<'a> Parser<'a> {
             // TYPE ITEM
             let (ident, item_, extra_attrs) = self.parse_item_type()?;
             let prev_span = self.prev_span;
-            let item = self.mk_item(lo,
-                                    prev_span.hi,
+            let item = self.mk_item(lo.to(prev_span),
                                     ident,
                                     item_,
                                     visibility,
@@ -5745,8 +5899,7 @@ impl<'a> Parser<'a> {
             // ENUM ITEM
             let (ident, item_, extra_attrs) = self.parse_item_enum()?;
             let prev_span = self.prev_span;
-            let item = self.mk_item(lo,
-                                    prev_span.hi,
+            let item = self.mk_item(lo.to(prev_span),
                                     ident,
                                     item_,
                                     visibility,
@@ -5758,20 +5911,25 @@ impl<'a> Parser<'a> {
             let (ident, item_, extra_attrs) =
                 self.parse_item_trait(ast::Unsafety::Normal)?;
             let prev_span = self.prev_span;
-            let item = self.mk_item(lo,
-                                    prev_span.hi,
+            let item = self.mk_item(lo.to(prev_span),
                                     ident,
                                     item_,
                                     visibility,
                                     maybe_append(attrs, extra_attrs));
             return Ok(Some(item));
         }
-        if self.eat_keyword(keywords::Impl) {
+        if (self.check_keyword(keywords::Impl)) ||
+           (self.check_keyword(keywords::Default) &&
+            self.look_ahead(1, |t| t.is_keyword(keywords::Impl)))
+        {
             // IMPL ITEM
-            let (ident, item_, extra_attrs) = self.parse_item_impl(ast::Unsafety::Normal)?;
+            let defaultness = self.parse_defaultness()?;
+            self.expect_keyword(keywords::Impl)?;
+            let (ident,
+                 item_,
+                 extra_attrs) = self.parse_item_impl(ast::Unsafety::Normal, defaultness)?;
             let prev_span = self.prev_span;
-            let item = self.mk_item(lo,
-                                    prev_span.hi,
+            let item = self.mk_item(lo.to(prev_span),
                                     ident,
                                     item_,
                                     visibility,
@@ -5782,8 +5940,7 @@ impl<'a> Parser<'a> {
             // STRUCT ITEM
             let (ident, item_, extra_attrs) = self.parse_item_struct()?;
             let prev_span = self.prev_span;
-            let item = self.mk_item(lo,
-                                    prev_span.hi,
+            let item = self.mk_item(lo.to(prev_span),
                                     ident,
                                     item_,
                                     visibility,
@@ -5795,8 +5952,7 @@ impl<'a> Parser<'a> {
             self.bump();
             let (ident, item_, extra_attrs) = self.parse_item_union()?;
             let prev_span = self.prev_span;
-            let item = self.mk_item(lo,
-                                    prev_span.hi,
+            let item = self.mk_item(lo.to(prev_span),
                                     ident,
                                     item_,
                                     visibility,
@@ -5813,8 +5969,8 @@ impl<'a> Parser<'a> {
     /// Parse a foreign item.
     fn parse_foreign_item(&mut self) -> PResult<'a, Option<ForeignItem>> {
         let attrs = self.parse_outer_attributes()?;
-        let lo = self.span.lo;
-        let visibility = self.parse_visibility(true)?;
+        let lo = self.span;
+        let visibility = self.parse_visibility(false)?;
 
         if self.check_keyword(keywords::Static) {
             // FOREIGN STATIC ITEM
@@ -5840,7 +5996,7 @@ impl<'a> Parser<'a> {
         attrs: Vec<Attribute> ,
         macros_allowed: bool,
         attributes_allowed: bool,
-        lo: BytePos,
+        lo: Span,
         visibility: Visibility
     ) -> PResult<'a, Option<P<Item>>> {
         if macros_allowed && self.token.is_path_start() {
@@ -5849,7 +6005,7 @@ impl<'a> Parser<'a> {
             let prev_span = self.prev_span;
             self.complain_if_pub_macro(&visibility, prev_span);
 
-            let mac_lo = self.span.lo;
+            let mac_lo = self.span;
 
             // item macro.
             let pth = self.parse_path(PathStyle::Mod)?;
@@ -5875,9 +6031,9 @@ impl<'a> Parser<'a> {
                 }
             }
 
-            let hi = self.prev_span.hi;
-            let mac = spanned(mac_lo, hi, Mac_ { path: pth, tts: tts });
-            let item = self.mk_item(lo, hi, id, ItemKind::Mac(mac), visibility, attrs);
+            let hi = self.prev_span;
+            let mac = respan(mac_lo.to(hi), Mac_ { path: pth, tts: tts });
+            let item = self.mk_item(lo.to(hi), id, ItemKind::Mac(mac), visibility, attrs);
             return Ok(Some(item));
         }
 
@@ -5905,7 +6061,7 @@ impl<'a> Parser<'a> {
         self.parse_unspanned_seq(&token::OpenDelim(token::Brace),
                                  &token::CloseDelim(token::Brace),
                                  SeqSep::trailing_allowed(token::Comma), |this| {
-            let lo = this.span.lo;
+            let lo = this.span;
             let ident = if this.eat_keyword(keywords::SelfValue) {
                 keywords::SelfValue.ident()
             } else {
@@ -5917,8 +6073,7 @@ impl<'a> Parser<'a> {
                 rename: rename,
                 id: ast::DUMMY_NODE_ID
             };
-            let hi = this.prev_span.hi;
-            Ok(spanned(lo, hi, node))
+            Ok(respan(lo.to(this.prev_span), node))
         })
     }
 
@@ -5936,21 +6091,21 @@ impl<'a> Parser<'a> {
     /// MOD_SEP? non_global_path MOD_SEP LBRACE item_seq RBRACE
     /// MOD_SEP? LBRACE item_seq RBRACE
     fn parse_view_path(&mut self) -> PResult<'a, P<ViewPath>> {
-        let lo = self.span.lo;
+        let lo = self.span;
         if self.check(&token::OpenDelim(token::Brace)) || self.check(&token::BinOp(token::Star)) ||
            self.is_import_coupler() {
             // `{foo, bar}`, `::{foo, bar}`, `*`, or `::*`.
             self.eat(&token::ModSep);
             let prefix = ast::Path {
-                segments: vec![ast::PathSegment::crate_root()],
-                span: mk_sp(lo, self.span.hi),
+                segments: vec![PathSegment::crate_root()],
+                span: lo.to(self.span),
             };
             let view_path_kind = if self.eat(&token::BinOp(token::Star)) {
                 ViewPathGlob(prefix)
             } else {
                 ViewPathList(prefix, self.parse_path_list_items()?)
             };
-            Ok(P(spanned(lo, self.span.hi, view_path_kind)))
+            Ok(P(respan(lo.to(self.span), view_path_kind)))
         } else {
             let prefix = self.parse_path(PathStyle::Mod)?.default_to_global();
             if self.is_import_coupler() {
@@ -5958,16 +6113,16 @@ impl<'a> Parser<'a> {
                 self.bump();
                 if self.check(&token::BinOp(token::Star)) {
                     self.bump();
-                    Ok(P(spanned(lo, self.span.hi, ViewPathGlob(prefix))))
+                    Ok(P(respan(lo.to(self.span), ViewPathGlob(prefix))))
                 } else {
                     let items = self.parse_path_list_items()?;
-                    Ok(P(spanned(lo, self.span.hi, ViewPathList(prefix, items))))
+                    Ok(P(respan(lo.to(self.span), ViewPathList(prefix, items))))
                 }
             } else {
                 // `foo::bar` or `foo::bar as baz`
                 let rename = self.parse_rename()?.
                                   unwrap_or(prefix.segments.last().unwrap().identifier);
-                Ok(P(spanned(lo, self.prev_span.hi, ViewPathSimple(rename, prefix))))
+                Ok(P(respan(lo.to(self.prev_span), ViewPathSimple(rename, prefix))))
             }
         }
     }
@@ -5983,11 +6138,11 @@ impl<'a> Parser<'a> {
     /// Parses a source module as a crate. This is the main
     /// entry point for the parser.
     pub fn parse_crate_mod(&mut self) -> PResult<'a, Crate> {
-        let lo = self.span.lo;
+        let lo = self.span;
         Ok(ast::Crate {
             attrs: self.parse_inner_attributes()?,
             module: self.parse_mod_items(&token::Eof, lo)?,
-            span: mk_sp(lo, self.span.lo),
+            span: lo.to(self.span),
         })
     }
 
diff --git a/src/libsyntax/parse/token.rs b/src/libsyntax/parse/token.rs
index 5b65aac92b8..77db604c56e 100644
--- a/src/libsyntax/parse/token.rs
+++ b/src/libsyntax/parse/token.rs
@@ -17,7 +17,7 @@ pub use self::Token::*;
 use ast::{self};
 use ptr::P;
 use symbol::keywords;
-use tokenstream;
+use tokenstream::TokenTree;
 
 use std::fmt;
 use std::rc::Rc;
@@ -53,6 +53,10 @@ impl DelimToken {
     pub fn len(self) -> usize {
         if self == NoDelim { 0 } else { 1 }
     }
+
+    pub fn is_empty(self) -> bool {
+        self == NoDelim
+    }
 }
 
 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Hash, Debug, Copy)]
@@ -86,6 +90,7 @@ fn ident_can_begin_expr(ident: ast::Ident) -> bool {
     !ident_token.is_any_keyword() ||
     ident_token.is_path_segment_keyword() ||
     [
+        keywords::Do.name(),
         keywords::Box.name(),
         keywords::Break.name(),
         keywords::Continue.name(),
@@ -102,6 +107,21 @@ fn ident_can_begin_expr(ident: ast::Ident) -> bool {
     ].contains(&ident.name)
 }
 
+fn ident_can_begin_type(ident: ast::Ident) -> bool {
+    let ident_token: Token = Ident(ident);
+
+    !ident_token.is_any_keyword() ||
+    ident_token.is_path_segment_keyword() ||
+    [
+        keywords::For.name(),
+        keywords::Impl.name(),
+        keywords::Fn.name(),
+        keywords::Unsafe.name(),
+        keywords::Extern.name(),
+        keywords::Typeof.name(),
+    ].contains(&ident.name)
+}
+
 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Hash, Debug)]
 pub enum Token {
     /* Expression-operator symbols. */
@@ -181,25 +201,21 @@ impl Token {
     /// Returns `true` if the token can appear at the start of an expression.
     pub fn can_begin_expr(&self) -> bool {
         match *self {
-            OpenDelim(..)               => true,
-            Ident(ident)                => ident_can_begin_expr(ident),
-            Literal(..)                 => true,
-            Not                         => true,
-            BinOp(Minus)                => true,
-            BinOp(Star)                 => true,
-            BinOp(And)                  => true,
-            BinOp(Or)                   => true, // in lambda syntax
-            OrOr                        => true, // in lambda syntax
-            AndAnd                      => true, // double borrow
-            DotDot | DotDotDot          => true, // range notation
-            Lt | BinOp(Shl)             => true, // associated path
-            ModSep                      => true,
-            Pound                       => true, // for expression attributes
+            Ident(ident)                => ident_can_begin_expr(ident), // value name or keyword
+            OpenDelim(..)               | // tuple, array or block
+            Literal(..)                 | // literal
+            Not                         | // operator not
+            BinOp(Minus)                | // unary minus
+            BinOp(Star)                 | // dereference
+            BinOp(Or) | OrOr            | // closure
+            BinOp(And)                  | // reference
+            AndAnd                      | // double reference
+            DotDot | DotDotDot          | // range notation
+            Lt | BinOp(Shl)             | // associated path
+            ModSep                      | // global path
+            Pound                       => true, // expression attributes
             Interpolated(ref nt) => match **nt {
-                NtExpr(..) => true,
-                NtIdent(..) => true,
-                NtBlock(..) => true,
-                NtPath(..) => true,
+                NtIdent(..) | NtExpr(..) | NtBlock(..) | NtPath(..) => true,
                 _ => false,
             },
             _ => false,
@@ -209,20 +225,20 @@ impl Token {
     /// Returns `true` if the token can appear at the start of a type.
     pub fn can_begin_type(&self) -> bool {
         match *self {
-            OpenDelim(Paren)            => true, // tuple
-            OpenDelim(Bracket)          => true, // array
-            Ident(..)                   => true, // type name or keyword
-            Underscore                  => true, // placeholder
-            Not                         => true, // never
-            BinOp(Star)                 => true, // raw pointer
-            BinOp(And)                  => true, // reference
-            AndAnd                      => true, // double reference
-            Lt | BinOp(Shl)             => true, // associated path
+            Ident(ident)                => ident_can_begin_type(ident), // type name or keyword
+            OpenDelim(Paren)            | // tuple
+            OpenDelim(Bracket)          | // array
+            Underscore                  | // placeholder
+            Not                         | // never
+            BinOp(Star)                 | // raw pointer
+            BinOp(And)                  | // reference
+            AndAnd                      | // double reference
+            Question                    | // maybe bound in trait object
+            Lifetime(..)                | // lifetime bound in trait object
+            Lt | BinOp(Shl)             | // associated path
             ModSep                      => true, // global path
             Interpolated(ref nt) => match **nt {
-                NtTy(..) => true,
-                NtIdent(..) => true,
-                NtPath(..) => true,
+                NtIdent(..) | NtTy(..) | NtPath(..) => true,
                 _ => false,
             },
             _ => false,
@@ -237,14 +253,22 @@ impl Token {
         }
     }
 
-    /// Returns `true` if the token is an identifier.
-    pub fn is_ident(&self) -> bool {
+    pub fn ident(&self) -> Option<ast::Ident> {
         match *self {
-            Ident(..)   => true,
-            _           => false,
+            Ident(ident) => Some(ident),
+            Interpolated(ref nt) => match **nt {
+                NtIdent(ident) => Some(ident.node),
+                _ => None,
+            },
+            _ => None,
         }
     }
 
+    /// Returns `true` if the token is an identifier.
+    pub fn is_ident(&self) -> bool {
+        self.ident().is_some()
+    }
+
     /// Returns `true` if the token is a documentation comment.
     pub fn is_doc_comment(&self) -> bool {
         match *self {
@@ -296,18 +320,15 @@ impl Token {
 
     /// Returns `true` if the token is a given keyword, `kw`.
     pub fn is_keyword(&self, kw: keywords::Keyword) -> bool {
-        match *self {
-            Ident(id) => id.name == kw.name(),
-            _ => false,
-        }
+        self.ident().map(|ident| ident.name == kw.name()).unwrap_or(false)
     }
 
     pub fn is_path_segment_keyword(&self) -> bool {
-        match *self {
-            Ident(id) => id.name == keywords::Super.name() ||
-                         id.name == keywords::SelfValue.name() ||
-                         id.name == keywords::SelfType.name(),
-            _ => false,
+        match self.ident() {
+            Some(id) => id.name == keywords::Super.name() ||
+                        id.name == keywords::SelfValue.name() ||
+                        id.name == keywords::SelfType.name(),
+            None => false,
         }
     }
 
@@ -318,18 +339,16 @@ impl Token {
 
     /// Returns `true` if the token is a strict keyword.
     pub fn is_strict_keyword(&self) -> bool {
-        match *self {
-            Ident(id) => id.name >= keywords::As.name() &&
-                         id.name <= keywords::While.name(),
+        match self.ident() {
+            Some(id) => id.name >= keywords::As.name() && id.name <= keywords::While.name(),
             _ => false,
         }
     }
 
     /// Returns `true` if the token is a keyword reserved for possible future use.
     pub fn is_reserved_keyword(&self) -> bool {
-        match *self {
-            Ident(id) => id.name >= keywords::Abstract.name() &&
-                         id.name <= keywords::Yield.name(),
+        match self.ident() {
+            Some(id) => id.name >= keywords::Abstract.name() && id.name <= keywords::Yield.name(),
             _ => false,
         }
     }
@@ -348,7 +367,8 @@ pub enum Nonterminal {
     /// Stuff inside brackets for attributes
     NtMeta(ast::MetaItem),
     NtPath(ast::Path),
-    NtTT(tokenstream::TokenTree),
+    NtVis(ast::Visibility),
+    NtTT(TokenTree),
     // These are not exposed to macros, but are used by quasiquote.
     NtArm(ast::Arm),
     NtImplItem(ast::ImplItem),
@@ -377,6 +397,7 @@ impl fmt::Debug for Nonterminal {
             NtGenerics(..) => f.pad("NtGenerics(..)"),
             NtWhereClause(..) => f.pad("NtWhereClause(..)"),
             NtArg(..) => f.pad("NtArg(..)"),
+            NtVis(..) => f.pad("NtVis(..)"),
         }
     }
 }
diff --git a/src/libsyntax/print/pp.rs b/src/libsyntax/print/pp.rs
index 1d67c2a2c2b..e893c859247 100644
--- a/src/libsyntax/print/pp.rs
+++ b/src/libsyntax/print/pp.rs
@@ -113,22 +113,22 @@
 //! between using 'left' and 'right' terms to denote the wrapped-to-ring-buffer
 //! and point-in-infinite-stream senses freely.
 //!
-//! There is a parallel ring buffer, 'size', that holds the calculated size of
+//! There is a parallel ring buffer, `size`, that holds the calculated size of
 //! each token. Why calculated? Because for Begin/End pairs, the "size"
 //! includes everything between the pair. That is, the "size" of Begin is
 //! actually the sum of the sizes of everything between Begin and the paired
-//! End that follows. Since that is arbitrarily far in the future, 'size' is
+//! End that follows. Since that is arbitrarily far in the future, `size` is
 //! being rewritten regularly while the printer runs; in fact most of the
-//! machinery is here to work out 'size' entries on the fly (and give up when
+//! machinery is here to work out `size` entries on the fly (and give up when
 //! they're so obviously over-long that "infinity" is a good enough
 //! approximation for purposes of line breaking).
 //!
 //! The "input side" of the printer is managed as an abstract process called
-//! SCAN, which uses 'scan_stack', to manage calculating 'size'. SCAN is, in
+//! SCAN, which uses `scan_stack`, to manage calculating `size`. SCAN is, in
 //! other words, the process of calculating 'size' entries.
 //!
 //! The "output side" of the printer is managed by an abstract process called
-//! PRINT, which uses 'print_stack', 'margin' and 'space' to figure out what to
+//! PRINT, which uses `print_stack`, `margin` and `space` to figure out what to
 //! do with each token/size pair it consumes as it goes. It's trying to consume
 //! the entire buffered window, but can't output anything until the size is >=
 //! 0 (sizes are set to negative while they're pending calculation).
@@ -409,7 +409,7 @@ impl<'a> Printer<'a> {
     pub fn advance_right(&mut self) {
         self.right += 1;
         self.right %= self.buf_len;
-        assert!(self.right != self.left);
+        assert_ne!(self.right, self.left);
     }
     pub fn advance_left(&mut self) -> io::Result<()> {
         debug!("advance_left Vec<{},{}>, sizeof({})={}", self.left, self.right,
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index 3efadbd00d1..073ededcb0c 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -28,7 +28,7 @@ use ptr::P;
 use std_inject;
 use symbol::{Symbol, keywords};
 use syntax_pos::DUMMY_SP;
-use tokenstream::{self, TokenTree};
+use tokenstream::{self, TokenStream, TokenTree};
 
 use std::ascii;
 use std::io::{self, Write, Read};
@@ -233,7 +233,7 @@ pub fn token_to_string(tok: &Token) -> String {
         token::CloseDelim(token::Bracket) => "]".to_string(),
         token::OpenDelim(token::Brace) => "{".to_string(),
         token::CloseDelim(token::Brace) => "}".to_string(),
-        token::OpenDelim(token::NoDelim) => " ".to_string(),
+        token::OpenDelim(token::NoDelim) |
         token::CloseDelim(token::NoDelim) => " ".to_string(),
         token::Pound                => "#".to_string(),
         token::Dollar               => "$".to_string(),
@@ -244,7 +244,7 @@ pub fn token_to_string(tok: &Token) -> String {
             let mut out = match lit {
                 token::Byte(b)           => format!("b'{}'", b),
                 token::Char(c)           => format!("'{}'", c),
-                token::Float(c)          => c.to_string(),
+                token::Float(c)          |
                 token::Integer(c)        => c.to_string(),
                 token::Str_(s)           => format!("\"{}\"", s),
                 token::StrRaw(s, n)      => format!("r{delim}\"{string}\"{delim}",
@@ -277,22 +277,23 @@ pub fn token_to_string(tok: &Token) -> String {
         token::Shebang(s)           => format!("/* shebang: {}*/", s),
 
         token::Interpolated(ref nt) => match **nt {
-            token::NtExpr(ref e)        => expr_to_string(&e),
-            token::NtMeta(ref e)        => meta_item_to_string(&e),
-            token::NtTy(ref e)          => ty_to_string(&e),
-            token::NtPath(ref e)        => path_to_string(&e),
-            token::NtItem(ref e)        => item_to_string(&e),
-            token::NtBlock(ref e)       => block_to_string(&e),
-            token::NtStmt(ref e)        => stmt_to_string(&e),
-            token::NtPat(ref e)         => pat_to_string(&e),
+            token::NtExpr(ref e)        => expr_to_string(e),
+            token::NtMeta(ref e)        => meta_item_to_string(e),
+            token::NtTy(ref e)          => ty_to_string(e),
+            token::NtPath(ref e)        => path_to_string(e),
+            token::NtItem(ref e)        => item_to_string(e),
+            token::NtBlock(ref e)       => block_to_string(e),
+            token::NtStmt(ref e)        => stmt_to_string(e),
+            token::NtPat(ref e)         => pat_to_string(e),
             token::NtIdent(ref e)       => ident_to_string(e.node),
             token::NtTT(ref tree)       => tt_to_string(tree.clone()),
-            token::NtArm(ref e)         => arm_to_string(&e),
-            token::NtImplItem(ref e)    => impl_item_to_string(&e),
-            token::NtTraitItem(ref e)   => trait_item_to_string(&e),
-            token::NtGenerics(ref e)    => generics_to_string(&e),
-            token::NtWhereClause(ref e) => where_clause_to_string(&e),
-            token::NtArg(ref e)         => arg_to_string(&e),
+            token::NtArm(ref e)         => arm_to_string(e),
+            token::NtImplItem(ref e)    => impl_item_to_string(e),
+            token::NtTraitItem(ref e)   => trait_item_to_string(e),
+            token::NtGenerics(ref e)    => generics_to_string(e),
+            token::NtWhereClause(ref e) => where_clause_to_string(e),
+            token::NtArg(ref e)         => arg_to_string(e),
+            token::NtVis(ref e)         => vis_to_string(e),
         }
     }
 }
@@ -329,6 +330,10 @@ pub fn tts_to_string(tts: &[tokenstream::TokenTree]) -> String {
     to_string(|s| s.print_tts(tts.iter().cloned().collect()))
 }
 
+pub fn tokens_to_string(tokens: TokenStream) -> String {
+    to_string(|s| s.print_tts(tokens))
+}
+
 pub fn stmt_to_string(stmt: &ast::Stmt) -> String {
     to_string(|s| s.print_stmt(stmt))
 }
@@ -369,6 +374,10 @@ pub fn ident_to_string(id: ast::Ident) -> String {
     to_string(|s| s.print_ident(id))
 }
 
+pub fn vis_to_string(v: &ast::Visibility) -> String {
+    to_string(|s| s.print_visibility(v))
+}
+
 pub fn fun_to_string(decl: &ast::FnDecl,
                      unsafety: ast::Unsafety,
                      constness: ast::Constness,
@@ -423,13 +432,7 @@ pub fn mac_to_string(arg: &ast::Mac) -> String {
 }
 
 pub fn visibility_qualified(vis: &ast::Visibility, s: &str) -> String {
-    match *vis {
-        ast::Visibility::Public => format!("pub {}", s),
-        ast::Visibility::Crate(_) => format!("pub(crate) {}", s),
-        ast::Visibility::Restricted { ref path, .. } =>
-            format!("pub({}) {}", to_string(|s| s.print_path(path, false, 0, true)), s),
-        ast::Visibility::Inherited => s.to_string()
-    }
+    format!("{}{}", to_string(|s| s.print_visibility(vis)), s)
 }
 
 fn needs_parentheses(expr: &ast::Expr) -> bool {
@@ -517,8 +520,7 @@ pub trait PrintState<'a> {
 
         let mut result = None;
 
-        if let &Some(ref lits) = self.literals()
-        {
+        if let Some(ref lits) = *self.literals() {
             while cur_lit < lits.len() {
                 let ltrl = (*lits)[cur_lit].clone();
                 if ltrl.pos > pos { break; }
@@ -615,11 +617,8 @@ pub trait PrintState<'a> {
 
     fn print_literal(&mut self, lit: &ast::Lit) -> io::Result<()> {
         self.maybe_print_comment(lit.span.lo)?;
-        match self.next_lit(lit.span.lo) {
-            Some(ref ltrl) => {
-                return word(self.writer(), &(*ltrl).lit);
-            }
-            _ => ()
+        if let Some(ref ltrl) = self.next_lit(lit.span.lo) {
+            return word(self.writer(), &(*ltrl).lit);
         }
         match lit.node {
             ast::LitKind::Str(st, style) => self.print_string(&st.as_str(), style),
@@ -674,7 +673,7 @@ pub trait PrintState<'a> {
                     style: ast::StrStyle) -> io::Result<()> {
         let st = match style {
             ast::StrStyle::Cooked => {
-                (format!("\"{}\"", st.escape_default()))
+                (format!("\"{}\"", parse::escape_default(st)))
             }
             ast::StrStyle::Raw(n) => {
                 (format!("r{delim}\"{string}\"{delim}",
@@ -750,7 +749,21 @@ pub trait PrintState<'a> {
                 ast::AttrStyle::Inner => word(self.writer(), "#![")?,
                 ast::AttrStyle::Outer => word(self.writer(), "#[")?,
             }
-            self.print_meta_item(&attr.meta())?;
+            if let Some(mi) = attr.meta() {
+                self.print_meta_item(&mi)?
+            } else {
+                for (i, segment) in attr.path.segments.iter().enumerate() {
+                    if i > 0 {
+                        word(self.writer(), "::")?
+                    }
+                    if segment.identifier.name != keywords::CrateRoot.name() &&
+                       segment.identifier.name != "$crate" {
+                        word(self.writer(), &segment.identifier.name.as_str())?;
+                    }
+                }
+                space(self.writer())?;
+                self.print_tts(attr.tokens.clone())?;
+            }
             word(self.writer(), "]")
         }
     }
@@ -782,13 +795,52 @@ pub trait PrintState<'a> {
                 self.popen()?;
                 self.commasep(Consistent,
                               &items[..],
-                              |s, i| s.print_meta_list_item(&i))?;
+                              |s, i| s.print_meta_list_item(i))?;
                 self.pclose()?;
             }
         }
         self.end()
     }
 
+    /// This doesn't deserve to be called "pretty" printing, but it should be
+    /// meaning-preserving. A quick hack that might help would be to look at the
+    /// spans embedded in the TTs to decide where to put spaces and newlines.
+    /// But it'd be better to parse these according to the grammar of the
+    /// appropriate macro, transcribe back into the grammar we just parsed from,
+    /// and then pretty-print the resulting AST nodes (so, e.g., we print
+    /// expression arguments as expressions). It can be done! I think.
+    fn print_tt(&mut self, tt: tokenstream::TokenTree) -> io::Result<()> {
+        match tt {
+            TokenTree::Token(_, ref tk) => {
+                word(self.writer(), &token_to_string(tk))?;
+                match *tk {
+                    parse::token::DocComment(..) => {
+                        hardbreak(self.writer())
+                    }
+                    _ => Ok(())
+                }
+            }
+            TokenTree::Delimited(_, ref delimed) => {
+                word(self.writer(), &token_to_string(&delimed.open_token()))?;
+                space(self.writer())?;
+                self.print_tts(delimed.stream())?;
+                space(self.writer())?;
+                word(self.writer(), &token_to_string(&delimed.close_token()))
+            },
+        }
+    }
+
+    fn print_tts(&mut self, tts: tokenstream::TokenStream) -> io::Result<()> {
+        self.ibox(0)?;
+        for (i, tt) in tts.into_trees().enumerate() {
+            if i != 0 {
+                space(self.writer())?;
+            }
+            self.print_tt(tt)?;
+        }
+        self.end()
+    }
+
     fn space_if_not_bol(&mut self) -> io::Result<()> {
         if !self.is_bol() { space(self.writer())?; }
         Ok(())
@@ -926,14 +978,14 @@ impl<'a> State<'a> {
 
     pub fn commasep_exprs(&mut self, b: Breaks,
                           exprs: &[P<ast::Expr>]) -> io::Result<()> {
-        self.commasep_cmnt(b, exprs, |s, e| s.print_expr(&e), |e| e.span)
+        self.commasep_cmnt(b, exprs, |s, e| s.print_expr(e), |e| e.span)
     }
 
     pub fn print_mod(&mut self, _mod: &ast::Mod,
                      attrs: &[ast::Attribute]) -> io::Result<()> {
         self.print_inner_attributes(attrs)?;
         for item in &_mod.items {
-            self.print_item(&item)?;
+            self.print_item(item)?;
         }
         Ok(())
     }
@@ -962,7 +1014,7 @@ impl<'a> State<'a> {
         match ty.node {
             ast::TyKind::Slice(ref ty) => {
                 word(&mut self.s, "[")?;
-                self.print_type(&ty)?;
+                self.print_type(ty)?;
                 word(&mut self.s, "]")?;
             }
             ast::TyKind::Ptr(ref mt) => {
@@ -984,7 +1036,7 @@ impl<'a> State<'a> {
             ast::TyKind::Tup(ref elts) => {
                 self.popen()?;
                 self.commasep(Inconsistent, &elts[..],
-                              |s, ty| s.print_type(&ty))?;
+                              |s, ty| s.print_type(ty))?;
                 if elts.len() == 1 {
                     word(&mut self.s, ",")?;
                 }
@@ -992,7 +1044,7 @@ impl<'a> State<'a> {
             }
             ast::TyKind::Paren(ref typ) => {
                 self.popen()?;
-                self.print_type(&typ)?;
+                self.print_type(typ)?;
                 self.pclose()?;
             }
             ast::TyKind::BareFn(ref f) => {
@@ -1025,19 +1077,22 @@ impl<'a> State<'a> {
             }
             ast::TyKind::Array(ref ty, ref v) => {
                 word(&mut self.s, "[")?;
-                self.print_type(&ty)?;
+                self.print_type(ty)?;
                 word(&mut self.s, "; ")?;
-                self.print_expr(&v)?;
+                self.print_expr(v)?;
                 word(&mut self.s, "]")?;
             }
             ast::TyKind::Typeof(ref e) => {
                 word(&mut self.s, "typeof(")?;
-                self.print_expr(&e)?;
+                self.print_expr(e)?;
                 word(&mut self.s, ")")?;
             }
             ast::TyKind::Infer => {
                 word(&mut self.s, "_")?;
             }
+            ast::TyKind::Err => {
+                word(&mut self.s, "?")?;
+            }
             ast::TyKind::ImplicitSelf => {
                 word(&mut self.s, "Self")?;
             }
@@ -1071,7 +1126,7 @@ impl<'a> State<'a> {
                 }
                 self.print_ident(item.ident)?;
                 self.word_space(":")?;
-                self.print_type(&t)?;
+                self.print_type(t)?;
                 word(&mut self.s, ";")?;
                 self.end()?; // end the head-ibox
                 self.end() // end the outer cbox
@@ -1128,7 +1183,7 @@ impl<'a> State<'a> {
                 self.head(&visibility_qualified(&item.vis, "extern crate"))?;
                 if let Some(p) = *optional_path {
                     let val = p.as_str();
-                    if val.contains("-") {
+                    if val.contains('-') {
                         self.print_string(&val, ast::StrStyle::Cooked)?;
                     } else {
                         self.print_name(p)?;
@@ -1144,7 +1199,7 @@ impl<'a> State<'a> {
             }
             ast::ItemKind::Use(ref vp) => {
                 self.head(&visibility_qualified(&item.vis, "use"))?;
-                self.print_view_path(&vp)?;
+                self.print_view_path(vp)?;
                 word(&mut self.s, ";")?;
                 self.end()?; // end inner head-block
                 self.end()?; // end outer head-block
@@ -1156,12 +1211,12 @@ impl<'a> State<'a> {
                 }
                 self.print_ident(item.ident)?;
                 self.word_space(":")?;
-                self.print_type(&ty)?;
+                self.print_type(ty)?;
                 space(&mut self.s)?;
                 self.end()?; // end the head-ibox
 
                 self.word_space("=")?;
-                self.print_expr(&expr)?;
+                self.print_expr(expr)?;
                 word(&mut self.s, ";")?;
                 self.end()?; // end the outer cbox
             }
@@ -1169,12 +1224,12 @@ impl<'a> State<'a> {
                 self.head(&visibility_qualified(&item.vis, "const"))?;
                 self.print_ident(item.ident)?;
                 self.word_space(":")?;
-                self.print_type(&ty)?;
+                self.print_type(ty)?;
                 space(&mut self.s)?;
                 self.end()?; // end the head-ibox
 
                 self.word_space("=")?;
-                self.print_expr(&expr)?;
+                self.print_expr(expr)?;
                 word(&mut self.s, ";")?;
                 self.end()?; // end the outer cbox
             }
@@ -1190,7 +1245,7 @@ impl<'a> State<'a> {
                     &item.vis
                 )?;
                 word(&mut self.s, " ")?;
-                self.print_block_with_attrs(&body, &item.attrs)?;
+                self.print_block_with_attrs(body, &item.attrs)?;
             }
             ast::ItemKind::Mod(ref _mod) => {
                 self.head(&visibility_qualified(&item.vis, "mod"))?;
@@ -1207,6 +1262,11 @@ impl<'a> State<'a> {
                 self.print_foreign_mod(nmod, &item.attrs)?;
                 self.bclose(item.span)?;
             }
+            ast::ItemKind::GlobalAsm(ref ga) => {
+                self.head(&visibility_qualified(&item.vis, "global_asm!"))?;
+                word(&mut self.s, &ga.asm.as_str())?;
+                self.end()?;
+            }
             ast::ItemKind::Ty(ref ty, ref params) => {
                 self.ibox(INDENT_UNIT)?;
                 self.ibox(0)?;
@@ -1218,7 +1278,7 @@ impl<'a> State<'a> {
                 self.print_where_clause(&params.where_clause)?;
                 space(&mut self.s)?;
                 self.word_space("=")?;
-                self.print_type(&ty)?;
+                self.print_type(ty)?;
                 word(&mut self.s, ";")?;
                 self.end()?; // end the outer ibox
             }
@@ -1233,11 +1293,11 @@ impl<'a> State<'a> {
             }
             ast::ItemKind::Struct(ref struct_def, ref generics) => {
                 self.head(&visibility_qualified(&item.vis, "struct"))?;
-                self.print_struct(&struct_def, generics, item.ident, item.span, true)?;
+                self.print_struct(struct_def, generics, item.ident, item.span, true)?;
             }
             ast::ItemKind::Union(ref struct_def, ref generics) => {
                 self.head(&visibility_qualified(&item.vis, "union"))?;
-                self.print_struct(&struct_def, generics, item.ident, item.span, true)?;
+                self.print_struct(struct_def, generics, item.ident, item.span, true)?;
             }
             ast::ItemKind::DefaultImpl(unsafety, ref trait_ref) => {
                 self.head("")?;
@@ -1253,12 +1313,14 @@ impl<'a> State<'a> {
             }
             ast::ItemKind::Impl(unsafety,
                           polarity,
+                          defaultness,
                           ref generics,
                           ref opt_trait,
                           ref ty,
                           ref impl_items) => {
                 self.head("")?;
                 self.print_visibility(&item.vis)?;
+                self.print_defaultness(defaultness)?;
                 self.print_unsafety(unsafety)?;
                 self.word_nbsp("impl")?;
 
@@ -1267,11 +1329,8 @@ impl<'a> State<'a> {
                     space(&mut self.s)?;
                 }
 
-                match polarity {
-                    ast::ImplPolarity::Negative => {
-                        word(&mut self.s, "!")?;
-                    },
-                    _ => {}
+                if polarity == ast::ImplPolarity::Negative {
+                    word(&mut self.s, "!")?;
                 }
 
                 if let Some(ref t) = *opt_trait {
@@ -1280,7 +1339,7 @@ impl<'a> State<'a> {
                     self.word_space("for")?;
                 }
 
-                self.print_type(&ty)?;
+                self.print_type(ty)?;
                 self.print_where_clause(&generics.where_clause)?;
 
                 space(&mut self.s)?;
@@ -1333,7 +1392,7 @@ impl<'a> State<'a> {
                 self.print_ident(item.ident)?;
                 self.cbox(INDENT_UNIT)?;
                 self.popen()?;
-                self.print_tts(tts.clone().into())?;
+                self.print_tts(tts.stream())?;
                 self.pclose()?;
                 word(&mut self.s, ";")?;
                 self.end()?;
@@ -1403,12 +1462,23 @@ impl<'a> State<'a> {
             ast::Visibility::Crate(_) => self.word_nbsp("pub(crate)"),
             ast::Visibility::Restricted { ref path, .. } => {
                 let path = to_string(|s| s.print_path(path, false, 0, true));
-                self.word_nbsp(&format!("pub({})", path))
+                if path == "self" || path == "super" {
+                    self.word_nbsp(&format!("pub({})", path))
+                } else {
+                    self.word_nbsp(&format!("pub(in {})", path))
+                }
             }
             ast::Visibility::Inherited => Ok(())
         }
     }
 
+    pub fn print_defaultness(&mut self, defatulness: ast::Defaultness) -> io::Result<()> {
+        if let ast::Defaultness::Default = defatulness {
+            try!(self.word_nbsp("default"));
+        }
+        Ok(())
+    }
+
     pub fn print_struct(&mut self,
                         struct_def: &ast::VariantData,
                         generics: &ast::Generics,
@@ -1458,45 +1528,6 @@ impl<'a> State<'a> {
         }
     }
 
-    /// This doesn't deserve to be called "pretty" printing, but it should be
-    /// meaning-preserving. A quick hack that might help would be to look at the
-    /// spans embedded in the TTs to decide where to put spaces and newlines.
-    /// But it'd be better to parse these according to the grammar of the
-    /// appropriate macro, transcribe back into the grammar we just parsed from,
-    /// and then pretty-print the resulting AST nodes (so, e.g., we print
-    /// expression arguments as expressions). It can be done! I think.
-    pub fn print_tt(&mut self, tt: tokenstream::TokenTree) -> io::Result<()> {
-        match tt {
-            TokenTree::Token(_, ref tk) => {
-                word(&mut self.s, &token_to_string(tk))?;
-                match *tk {
-                    parse::token::DocComment(..) => {
-                        hardbreak(&mut self.s)
-                    }
-                    _ => Ok(())
-                }
-            }
-            TokenTree::Delimited(_, ref delimed) => {
-                word(&mut self.s, &token_to_string(&delimed.open_token()))?;
-                space(&mut self.s)?;
-                self.print_tts(delimed.stream())?;
-                space(&mut self.s)?;
-                word(&mut self.s, &token_to_string(&delimed.close_token()))
-            },
-        }
-    }
-
-    pub fn print_tts(&mut self, tts: tokenstream::TokenStream) -> io::Result<()> {
-        self.ibox(0)?;
-        for (i, tt) in tts.into_trees().enumerate() {
-            if i != 0 {
-                space(&mut self.s)?;
-            }
-            self.print_tt(tt)?;
-        }
-        self.end()
-    }
-
     pub fn print_variant(&mut self, v: &ast::Variant) -> io::Result<()> {
         self.head("")?;
         let generics = ast::Generics::default();
@@ -1505,7 +1536,7 @@ impl<'a> State<'a> {
             Some(ref d) => {
                 space(&mut self.s)?;
                 self.word_space("=")?;
-                self.print_expr(&d)
+                self.print_expr(d)
             }
             _ => Ok(())
         }
@@ -1533,7 +1564,7 @@ impl<'a> State<'a> {
         self.print_outer_attributes(&ti.attrs)?;
         match ti.node {
             ast::TraitItemKind::Const(ref ty, ref default) => {
-                self.print_associated_const(ti.ident, &ty,
+                self.print_associated_const(ti.ident, ty,
                                             default.as_ref().map(|expr| &**expr),
                                             &ast::Visibility::Inherited)?;
             }
@@ -1573,12 +1604,10 @@ impl<'a> State<'a> {
         self.hardbreak_if_not_bol()?;
         self.maybe_print_comment(ii.span.lo)?;
         self.print_outer_attributes(&ii.attrs)?;
-        if let ast::Defaultness::Default = ii.defaultness {
-            self.word_nbsp("default")?;
-        }
+        self.print_defaultness(ii.defaultness)?;
         match ii.node {
             ast::ImplItemKind::Const(ref ty, ref expr) => {
-                self.print_associated_const(ii.ident, &ty, Some(&expr), &ii.vis)?;
+                self.print_associated_const(ii.ident, ty, Some(expr), &ii.vis)?;
             }
             ast::ImplItemKind::Method(ref sig, ref body) => {
                 self.head("")?;
@@ -1614,38 +1643,38 @@ impl<'a> State<'a> {
                 self.word_nbsp("let")?;
 
                 self.ibox(INDENT_UNIT)?;
-                self.print_local_decl(&loc)?;
+                self.print_local_decl(loc)?;
                 self.end()?;
                 if let Some(ref init) = loc.init {
                     self.nbsp()?;
                     self.word_space("=")?;
-                    self.print_expr(&init)?;
+                    self.print_expr(init)?;
                 }
                 word(&mut self.s, ";")?;
                 self.end()?;
             }
-            ast::StmtKind::Item(ref item) => self.print_item(&item)?,
+            ast::StmtKind::Item(ref item) => self.print_item(item)?,
             ast::StmtKind::Expr(ref expr) => {
                 self.space_if_not_bol()?;
-                self.print_expr_outer_attr_style(&expr, false)?;
+                self.print_expr_outer_attr_style(expr, false)?;
                 if parse::classify::expr_requires_semi_to_be_stmt(expr) {
                     word(&mut self.s, ";")?;
                 }
             }
             ast::StmtKind::Semi(ref expr) => {
                 self.space_if_not_bol()?;
-                self.print_expr_outer_attr_style(&expr, false)?;
+                self.print_expr_outer_attr_style(expr, false)?;
                 word(&mut self.s, ";")?;
             }
             ast::StmtKind::Mac(ref mac) => {
                 let (ref mac, style, ref attrs) = **mac;
                 self.space_if_not_bol()?;
-                self.print_outer_attributes(&attrs)?;
+                self.print_outer_attributes(attrs)?;
                 let delim = match style {
                     ast::MacStmtStyle::Braces => token::Brace,
                     _ => token::Paren
                 };
-                self.print_mac(&mac, delim)?;
+                self.print_mac(mac, delim)?;
                 if style == ast::MacStmtStyle::Semicolon {
                     word(&mut self.s, ";")?;
                 }
@@ -1699,7 +1728,7 @@ impl<'a> State<'a> {
                 ast::StmtKind::Expr(ref expr) if i == blk.stmts.len() - 1 => {
                     self.maybe_print_comment(st.span.lo)?;
                     self.space_if_not_bol()?;
-                    self.print_expr_outer_attr_style(&expr, false)?;
+                    self.print_expr_outer_attr_style(expr, false)?;
                     self.maybe_print_trailing_comment(expr.span, Some(blk.span.hi))?;
                 }
                 _ => self.print_stmt(st)?,
@@ -1719,9 +1748,9 @@ impl<'a> State<'a> {
                         self.cbox(INDENT_UNIT - 1)?;
                         self.ibox(0)?;
                         word(&mut self.s, " else if ")?;
-                        self.print_expr(&i)?;
+                        self.print_expr(i)?;
                         space(&mut self.s)?;
-                        self.print_block(&then)?;
+                        self.print_block(then)?;
                         self.print_else(e.as_ref().map(|e| &**e))
                     }
                     // "another else-if-let"
@@ -1729,12 +1758,12 @@ impl<'a> State<'a> {
                         self.cbox(INDENT_UNIT - 1)?;
                         self.ibox(0)?;
                         word(&mut self.s, " else if let ")?;
-                        self.print_pat(&pat)?;
+                        self.print_pat(pat)?;
                         space(&mut self.s)?;
                         self.word_space("=")?;
-                        self.print_expr(&expr)?;
+                        self.print_expr(expr)?;
                         space(&mut self.s)?;
-                        self.print_block(&then)?;
+                        self.print_block(then)?;
                         self.print_else(e.as_ref().map(|e| &**e))
                     }
                     // "final else"
@@ -1742,7 +1771,7 @@ impl<'a> State<'a> {
                         self.cbox(INDENT_UNIT - 1)?;
                         self.ibox(0)?;
                         word(&mut self.s, " else ")?;
-                        self.print_block(&b)
+                        self.print_block(b)
                     }
                     // BLEAH, constraints would be great here
                     _ => {
@@ -1808,12 +1837,8 @@ impl<'a> State<'a> {
                                       binop: ast::BinOp) -> bool {
         match sub_expr.node {
             ast::ExprKind::Binary(ref sub_op, _, _) => {
-                if AssocOp::from_ast_binop(sub_op.node).precedence() <
-                    AssocOp::from_ast_binop(binop.node).precedence() {
-                    true
-                } else {
-                    false
-                }
+                AssocOp::from_ast_binop(sub_op.node).precedence() <
+                    AssocOp::from_ast_binop(binop.node).precedence()
             }
             _ => true
         }
@@ -1893,7 +1918,7 @@ impl<'a> State<'a> {
                     space(&mut self.s)?;
                 }
                 word(&mut self.s, "..")?;
-                self.print_expr(&expr)?;
+                self.print_expr(expr)?;
                 self.end()?;
             }
             _ => if !fields.is_empty() {
@@ -1933,7 +1958,7 @@ impl<'a> State<'a> {
         if !tys.is_empty() {
             word(&mut self.s, "::<")?;
             self.commasep(Inconsistent, tys,
-                          |s, ty| s.print_type(&ty))?;
+                          |s, ty| s.print_type(ty))?;
             word(&mut self.s, ">")?;
         }
         self.print_call_post(base_args)
@@ -2002,7 +2027,7 @@ impl<'a> State<'a> {
                 self.print_expr_vec(&exprs[..], attrs)?;
             }
             ast::ExprKind::Repeat(ref element, ref count) => {
-                self.print_expr_repeat(&element, &count, attrs)?;
+                self.print_expr_repeat(element, count, attrs)?;
             }
             ast::ExprKind::Struct(ref path, ref fields, ref wth) => {
                 self.print_expr_struct(path, &fields[..], wth, attrs)?;
@@ -2011,43 +2036,43 @@ impl<'a> State<'a> {
                 self.print_expr_tup(&exprs[..], attrs)?;
             }
             ast::ExprKind::Call(ref func, ref args) => {
-                self.print_expr_call(&func, &args[..])?;
+                self.print_expr_call(func, &args[..])?;
             }
             ast::ExprKind::MethodCall(ident, ref tys, ref args) => {
                 self.print_expr_method_call(ident, &tys[..], &args[..])?;
             }
             ast::ExprKind::Binary(op, ref lhs, ref rhs) => {
-                self.print_expr_binary(op, &lhs, &rhs)?;
+                self.print_expr_binary(op, lhs, rhs)?;
             }
             ast::ExprKind::Unary(op, ref expr) => {
-                self.print_expr_unary(op, &expr)?;
+                self.print_expr_unary(op, expr)?;
             }
             ast::ExprKind::AddrOf(m, ref expr) => {
-                self.print_expr_addr_of(m, &expr)?;
+                self.print_expr_addr_of(m, expr)?;
             }
             ast::ExprKind::Lit(ref lit) => {
-                self.print_literal(&lit)?;
+                self.print_literal(lit)?;
             }
             ast::ExprKind::Cast(ref expr, ref ty) => {
                 if let ast::ExprKind::Cast(..) = expr.node {
-                    self.print_expr(&expr)?;
+                    self.print_expr(expr)?;
                 } else {
-                    self.print_expr_maybe_paren(&expr)?;
+                    self.print_expr_maybe_paren(expr)?;
                 }
                 space(&mut self.s)?;
                 self.word_space("as")?;
-                self.print_type(&ty)?;
+                self.print_type(ty)?;
             }
             ast::ExprKind::Type(ref expr, ref ty) => {
-                self.print_expr(&expr)?;
+                self.print_expr(expr)?;
                 self.word_space(":")?;
-                self.print_type(&ty)?;
+                self.print_type(ty)?;
             }
             ast::ExprKind::If(ref test, ref blk, ref elseopt) => {
-                self.print_if(&test, &blk, elseopt.as_ref().map(|e| &**e))?;
+                self.print_if(test, blk, elseopt.as_ref().map(|e| &**e))?;
             }
             ast::ExprKind::IfLet(ref pat, ref expr, ref blk, ref elseopt) => {
-                self.print_if_let(&pat, &expr, &blk, elseopt.as_ref().map(|e| &**e))?;
+                self.print_if_let(pat, expr, blk, elseopt.as_ref().map(|e| &**e))?;
             }
             ast::ExprKind::While(ref test, ref blk, opt_ident) => {
                 if let Some(ident) = opt_ident {
@@ -2055,9 +2080,9 @@ impl<'a> State<'a> {
                     self.word_space(":")?;
                 }
                 self.head("while")?;
-                self.print_expr(&test)?;
+                self.print_expr(test)?;
                 space(&mut self.s)?;
-                self.print_block_with_attrs(&blk, attrs)?;
+                self.print_block_with_attrs(blk, attrs)?;
             }
             ast::ExprKind::WhileLet(ref pat, ref expr, ref blk, opt_ident) => {
                 if let Some(ident) = opt_ident {
@@ -2065,12 +2090,12 @@ impl<'a> State<'a> {
                     self.word_space(":")?;
                 }
                 self.head("while let")?;
-                self.print_pat(&pat)?;
+                self.print_pat(pat)?;
                 space(&mut self.s)?;
                 self.word_space("=")?;
-                self.print_expr(&expr)?;
+                self.print_expr(expr)?;
                 space(&mut self.s)?;
-                self.print_block_with_attrs(&blk, attrs)?;
+                self.print_block_with_attrs(blk, attrs)?;
             }
             ast::ExprKind::ForLoop(ref pat, ref iter, ref blk, opt_ident) => {
                 if let Some(ident) = opt_ident {
@@ -2078,12 +2103,12 @@ impl<'a> State<'a> {
                     self.word_space(":")?;
                 }
                 self.head("for")?;
-                self.print_pat(&pat)?;
+                self.print_pat(pat)?;
                 space(&mut self.s)?;
                 self.word_space("in")?;
-                self.print_expr(&iter)?;
+                self.print_expr(iter)?;
                 space(&mut self.s)?;
-                self.print_block_with_attrs(&blk, attrs)?;
+                self.print_block_with_attrs(blk, attrs)?;
             }
             ast::ExprKind::Loop(ref blk, opt_ident) => {
                 if let Some(ident) = opt_ident {
@@ -2092,13 +2117,13 @@ impl<'a> State<'a> {
                 }
                 self.head("loop")?;
                 space(&mut self.s)?;
-                self.print_block_with_attrs(&blk, attrs)?;
+                self.print_block_with_attrs(blk, attrs)?;
             }
             ast::ExprKind::Match(ref expr, ref arms) => {
                 self.cbox(INDENT_UNIT)?;
                 self.ibox(4)?;
                 self.word_nbsp("match")?;
-                self.print_expr(&expr)?;
+                self.print_expr(expr)?;
                 space(&mut self.s)?;
                 self.bopen()?;
                 self.print_inner_attributes_no_trailing_hardbreak(attrs)?;
@@ -2110,7 +2135,7 @@ impl<'a> State<'a> {
             ast::ExprKind::Closure(capture_clause, ref decl, ref body, _) => {
                 self.print_capture_clause(capture_clause)?;
 
-                self.print_fn_block_args(&decl)?;
+                self.print_fn_block_args(decl)?;
                 space(&mut self.s)?;
                 self.print_expr(body)?;
                 self.end()?; // need to close a box
@@ -2125,48 +2150,48 @@ impl<'a> State<'a> {
                 self.cbox(INDENT_UNIT)?;
                 // head-box, will be closed by print-block after {
                 self.ibox(0)?;
-                self.print_block_with_attrs(&blk, attrs)?;
+                self.print_block_with_attrs(blk, attrs)?;
             }
             ast::ExprKind::Assign(ref lhs, ref rhs) => {
-                self.print_expr(&lhs)?;
+                self.print_expr(lhs)?;
                 space(&mut self.s)?;
                 self.word_space("=")?;
-                self.print_expr(&rhs)?;
+                self.print_expr(rhs)?;
             }
             ast::ExprKind::AssignOp(op, ref lhs, ref rhs) => {
-                self.print_expr(&lhs)?;
+                self.print_expr(lhs)?;
                 space(&mut self.s)?;
                 word(&mut self.s, op.node.to_string())?;
                 self.word_space("=")?;
-                self.print_expr(&rhs)?;
+                self.print_expr(rhs)?;
             }
             ast::ExprKind::Field(ref expr, id) => {
-                self.print_expr(&expr)?;
+                self.print_expr(expr)?;
                 word(&mut self.s, ".")?;
                 self.print_ident(id.node)?;
             }
             ast::ExprKind::TupField(ref expr, id) => {
-                self.print_expr(&expr)?;
+                self.print_expr(expr)?;
                 word(&mut self.s, ".")?;
                 self.print_usize(id.node)?;
             }
             ast::ExprKind::Index(ref expr, ref index) => {
-                self.print_expr(&expr)?;
+                self.print_expr(expr)?;
                 word(&mut self.s, "[")?;
-                self.print_expr(&index)?;
+                self.print_expr(index)?;
                 word(&mut self.s, "]")?;
             }
             ast::ExprKind::Range(ref start, ref end, limits) => {
-                if let &Some(ref e) = start {
-                    self.print_expr(&e)?;
+                if let Some(ref e) = *start {
+                    self.print_expr(e)?;
                 }
                 if limits == ast::RangeLimits::HalfOpen {
                     word(&mut self.s, "..")?;
                 } else {
                     word(&mut self.s, "...")?;
                 }
-                if let &Some(ref e) = end {
-                    self.print_expr(&e)?;
+                if let Some(ref e) = *end {
+                    self.print_expr(e)?;
                 }
             }
             ast::ExprKind::Path(None, ref path) => {
@@ -2197,12 +2222,9 @@ impl<'a> State<'a> {
             }
             ast::ExprKind::Ret(ref result) => {
                 word(&mut self.s, "return")?;
-                match *result {
-                    Some(ref expr) => {
-                        word(&mut self.s, " ")?;
-                        self.print_expr(&expr)?;
-                    }
-                    _ => ()
+                if let Some(ref expr) = *result {
+                    word(&mut self.s, " ")?;
+                    self.print_expr(expr)?;
                 }
             }
             ast::ExprKind::InlineAsm(ref a) => {
@@ -2232,7 +2254,7 @@ impl<'a> State<'a> {
                 self.commasep(Inconsistent, &a.inputs, |s, &(co, ref o)| {
                     s.print_string(&co.as_str(), ast::StrStyle::Cooked)?;
                     s.popen()?;
-                    s.print_expr(&o)?;
+                    s.print_expr(o)?;
                     s.pclose()?;
                     Ok(())
                 })?;
@@ -2272,13 +2294,18 @@ impl<'a> State<'a> {
             ast::ExprKind::Paren(ref e) => {
                 self.popen()?;
                 self.print_inner_attributes_inline(attrs)?;
-                self.print_expr(&e)?;
+                self.print_expr(e)?;
                 self.pclose()?;
             },
             ast::ExprKind::Try(ref e) => {
                 self.print_expr(e)?;
                 word(&mut self.s, "?")?
             }
+            ast::ExprKind::Catch(ref blk) => {
+                self.head("do catch")?;
+                space(&mut self.s)?;
+                self.print_block_with_attrs(blk, attrs)?
+            }
         }
         self.ann.post(self, NodeExpr(expr))?;
         self.end()
@@ -2288,7 +2315,7 @@ impl<'a> State<'a> {
         self.print_pat(&loc.pat)?;
         if let Some(ref ty) = loc.ty {
             self.word_space(":")?;
-            self.print_type(&ty)?;
+            self.print_type(ty)?;
         }
         Ok(())
     }
@@ -2356,7 +2383,7 @@ impl<'a> State<'a> {
             space(&mut self.s)?;
             self.word_space("as")?;
             let depth = path.segments.len() - qself.position;
-            self.print_path(&path, false, depth, false)?;
+            self.print_path(path, false, depth, false)?;
         }
         word(&mut self.s, ">")?;
         word(&mut self.s, "::")?;
@@ -2397,7 +2424,7 @@ impl<'a> State<'a> {
                     self.commasep(
                         Inconsistent,
                         &data.types,
-                        |s, ty| s.print_type(&ty))?;
+                        |s, ty| s.print_type(ty))?;
                         comma = true;
                 }
 
@@ -2420,13 +2447,13 @@ impl<'a> State<'a> {
                 self.commasep(
                     Inconsistent,
                     &data.inputs,
-                    |s, ty| s.print_type(&ty))?;
+                    |s, ty| s.print_type(ty))?;
                 word(&mut self.s, ")")?;
 
                 if let Some(ref ty) = data.output {
                     self.space_if_not_bol()?;
                     self.word_space("->")?;
-                    self.print_type(&ty)?;
+                    self.print_type(ty)?;
                 }
             }
         }
@@ -2455,24 +2482,24 @@ impl<'a> State<'a> {
                 self.print_ident(path1.node)?;
                 if let Some(ref p) = *sub {
                     word(&mut self.s, "@")?;
-                    self.print_pat(&p)?;
+                    self.print_pat(p)?;
                 }
             }
             PatKind::TupleStruct(ref path, ref elts, ddpos) => {
                 self.print_path(path, true, 0, false)?;
                 self.popen()?;
                 if let Some(ddpos) = ddpos {
-                    self.commasep(Inconsistent, &elts[..ddpos], |s, p| s.print_pat(&p))?;
+                    self.commasep(Inconsistent, &elts[..ddpos], |s, p| s.print_pat(p))?;
                     if ddpos != 0 {
                         self.word_space(",")?;
                     }
                     word(&mut self.s, "..")?;
                     if ddpos != elts.len() {
                         word(&mut self.s, ",")?;
-                        self.commasep(Inconsistent, &elts[ddpos..], |s, p| s.print_pat(&p))?;
+                        self.commasep(Inconsistent, &elts[ddpos..], |s, p| s.print_pat(p))?;
                     }
                 } else {
-                    self.commasep(Inconsistent, &elts[..], |s, p| s.print_pat(&p))?;
+                    self.commasep(Inconsistent, &elts[..], |s, p| s.print_pat(p))?;
                 }
                 self.pclose()?;
             }
@@ -2508,17 +2535,17 @@ impl<'a> State<'a> {
             PatKind::Tuple(ref elts, ddpos) => {
                 self.popen()?;
                 if let Some(ddpos) = ddpos {
-                    self.commasep(Inconsistent, &elts[..ddpos], |s, p| s.print_pat(&p))?;
+                    self.commasep(Inconsistent, &elts[..ddpos], |s, p| s.print_pat(p))?;
                     if ddpos != 0 {
                         self.word_space(",")?;
                     }
                     word(&mut self.s, "..")?;
                     if ddpos != elts.len() {
                         word(&mut self.s, ",")?;
-                        self.commasep(Inconsistent, &elts[ddpos..], |s, p| s.print_pat(&p))?;
+                        self.commasep(Inconsistent, &elts[ddpos..], |s, p| s.print_pat(p))?;
                     }
                 } else {
-                    self.commasep(Inconsistent, &elts[..], |s, p| s.print_pat(&p))?;
+                    self.commasep(Inconsistent, &elts[..], |s, p| s.print_pat(p))?;
                     if elts.len() == 1 {
                         word(&mut self.s, ",")?;
                     }
@@ -2527,41 +2554,41 @@ impl<'a> State<'a> {
             }
             PatKind::Box(ref inner) => {
                 word(&mut self.s, "box ")?;
-                self.print_pat(&inner)?;
+                self.print_pat(inner)?;
             }
             PatKind::Ref(ref inner, mutbl) => {
                 word(&mut self.s, "&")?;
                 if mutbl == ast::Mutability::Mutable {
                     word(&mut self.s, "mut ")?;
                 }
-                self.print_pat(&inner)?;
+                self.print_pat(inner)?;
             }
             PatKind::Lit(ref e) => self.print_expr(&**e)?,
             PatKind::Range(ref begin, ref end, ref end_kind) => {
-                self.print_expr(&begin)?;
+                self.print_expr(begin)?;
                 space(&mut self.s)?;
                 match *end_kind {
                     RangeEnd::Included => word(&mut self.s, "...")?,
                     RangeEnd::Excluded => word(&mut self.s, "..")?,
                 }
-                self.print_expr(&end)?;
+                self.print_expr(end)?;
             }
             PatKind::Slice(ref before, ref slice, ref after) => {
                 word(&mut self.s, "[")?;
                 self.commasep(Inconsistent,
                                    &before[..],
-                                   |s, p| s.print_pat(&p))?;
+                                   |s, p| s.print_pat(p))?;
                 if let Some(ref p) = *slice {
                     if !before.is_empty() { self.word_space(",")?; }
                     if p.node != PatKind::Wild {
-                        self.print_pat(&p)?;
+                        self.print_pat(p)?;
                     }
                     word(&mut self.s, "..")?;
                     if !after.is_empty() { self.word_space(",")?; }
                 }
                 self.commasep(Inconsistent,
                                    &after[..],
-                                   |s, p| s.print_pat(&p))?;
+                                   |s, p| s.print_pat(p))?;
                 word(&mut self.s, "]")?;
             }
             PatKind::Mac(ref m) => self.print_mac(m, token::Paren)?,
@@ -2587,12 +2614,12 @@ impl<'a> State<'a> {
                 space(&mut self.s)?;
                 self.word_space("|")?;
             }
-            self.print_pat(&p)?;
+            self.print_pat(p)?;
         }
         space(&mut self.s)?;
         if let Some(ref e) = arm.guard {
             self.word_space("if")?;
-            self.print_expr(&e)?;
+            self.print_expr(e)?;
             space(&mut self.s)?;
         }
         self.word_space("=>")?;
@@ -2600,7 +2627,7 @@ impl<'a> State<'a> {
         match arm.body.node {
             ast::ExprKind::Block(ref blk) => {
                 // the block will close the pattern's ibox
-                self.print_block_unclosed_indent(&blk, INDENT_UNIT)?;
+                self.print_block_unclosed_indent(blk, INDENT_UNIT)?;
 
                 // If it is a user-provided unsafe block, print a comma after it
                 if let BlockCheckMode::Unsafe(ast::UserProvided) = blk.rules {
@@ -2632,7 +2659,7 @@ impl<'a> State<'a> {
                 self.print_mutability(m)?;
                 word(&mut self.s, "self")?;
                 self.word_space(":")?;
-                self.print_type(&typ)
+                self.print_type(typ)
             }
         }
     }
@@ -2684,7 +2711,7 @@ impl<'a> State<'a> {
         self.word_space("->")?;
         match decl.output {
             ast::FunctionRetTy::Ty(ref ty) => {
-                self.print_type(&ty)?;
+                self.print_type(ty)?;
                 self.maybe_print_comment(ty.span.lo)
             }
             ast::FunctionRetTy::Default(..) => unreachable!(),
@@ -2737,7 +2764,7 @@ impl<'a> State<'a> {
                           lifetime: &ast::Lifetime)
                           -> io::Result<()>
     {
-        self.print_name(lifetime.name)
+        self.print_name(lifetime.ident.name)
     }
 
     pub fn print_lifetime_bounds(&mut self,
@@ -2798,7 +2825,7 @@ impl<'a> State<'a> {
             Some(ref default) => {
                 space(&mut self.s)?;
                 self.word_space("=")?;
-                self.print_type(&default)
+                self.print_type(default)
             }
             _ => Ok(())
         }
@@ -2824,7 +2851,7 @@ impl<'a> State<'a> {
                                                                              ref bounds,
                                                                              ..}) => {
                     self.print_formal_lifetime_list(bound_lifetimes)?;
-                    self.print_type(&bounded_ty)?;
+                    self.print_type(bounded_ty)?;
                     self.print_bounds(":", bounds)?;
                 }
                 ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate{ref lifetime,
@@ -2936,7 +2963,7 @@ impl<'a> State<'a> {
         match decl.output {
             ast::FunctionRetTy::Default(..) => unreachable!(),
             ast::FunctionRetTy::Ty(ref ty) =>
-                self.print_type(&ty)?
+                self.print_type(ty)?
         }
         self.end()?;
 
@@ -3003,14 +3030,9 @@ impl<'a> State<'a> {
         if self.next_comment().is_none() {
             hardbreak(&mut self.s)?;
         }
-        loop {
-            match self.next_comment() {
-                Some(ref cmnt) => {
-                    self.print_comment(cmnt)?;
-                    self.cur_cmnt_and_lit.cur_cmnt += 1;
-                }
-                _ => break
-            }
+        while let Some(ref cmnt) = self.next_comment() {
+            self.print_comment(cmnt)?;
+            self.cur_cmnt_and_lit.cur_cmnt += 1;
         }
         Ok(())
     }
diff --git a/src/libsyntax/ptr.rs b/src/libsyntax/ptr.rs
index 58750158931..15111bbba0a 100644
--- a/src/libsyntax/ptr.rs
+++ b/src/libsyntax/ptr.rs
@@ -43,6 +43,8 @@ use std::{mem, ptr, slice, vec};
 
 use serialize::{Encodable, Decodable, Encoder, Decoder};
 
+use rustc_data_structures::stable_hasher::{StableHasher, StableHasherResult,
+                                           HashStable};
 /// An owned smart pointer.
 #[derive(Hash, PartialEq, Eq, PartialOrd, Ord)]
 pub struct P<T: ?Sized> {
@@ -215,3 +217,13 @@ impl<T: Decodable> Decodable for P<[T]> {
         }))
     }
 }
+
+impl<CTX, T> HashStable<CTX> for P<T>
+    where T: ?Sized + HashStable<CTX>
+{
+    fn hash_stable<W: StableHasherResult>(&self,
+                                          hcx: &mut CTX,
+                                          hasher: &mut StableHasher<W>) {
+        (**self).hash_stable(hcx, hasher);
+    }
+}
diff --git a/src/libsyntax/std_inject.rs b/src/libsyntax/std_inject.rs
index 4a2dfaf6124..a8a9ae556f1 100644
--- a/src/libsyntax/std_inject.rs
+++ b/src/libsyntax/std_inject.rs
@@ -10,28 +10,27 @@
 
 use ast;
 use attr;
+use ext::hygiene::{Mark, SyntaxContext};
 use symbol::{Symbol, keywords};
 use syntax_pos::{DUMMY_SP, Span};
 use codemap::{self, ExpnInfo, NameAndSpan, MacroAttribute};
-use parse::ParseSess;
 use ptr::P;
+use tokenstream::TokenStream;
 
 /// Craft a span that will be ignored by the stability lint's
-/// call to codemap's is_internal check.
+/// call to codemap's `is_internal` check.
 /// The expanded code uses the unstable `#[prelude_import]` attribute.
-fn ignored_span(sess: &ParseSess, sp: Span) -> Span {
-    let info = ExpnInfo {
+fn ignored_span(sp: Span) -> Span {
+    let mark = Mark::fresh(Mark::root());
+    mark.set_expn_info(ExpnInfo {
         call_site: DUMMY_SP,
         callee: NameAndSpan {
             format: MacroAttribute(Symbol::intern("std_inject")),
             span: None,
             allow_internal_unstable: true,
         }
-    };
-    let expn_id = sess.codemap().record_expansion(info);
-    let mut sp = sp;
-    sp.expn_id = expn_id;
-    return sp;
+    });
+    Span { ctxt: SyntaxContext::empty().apply_mark(mark), ..sp }
 }
 
 pub fn injected_crate_name(krate: &ast::Crate) -> Option<&'static str> {
@@ -44,16 +43,13 @@ pub fn injected_crate_name(krate: &ast::Crate) -> Option<&'static str> {
     }
 }
 
-pub fn maybe_inject_crates_ref(sess: &ParseSess,
-                               mut krate: ast::Crate,
-                               alt_std_name: Option<String>)
-                               -> ast::Crate {
+pub fn maybe_inject_crates_ref(mut krate: ast::Crate, alt_std_name: Option<String>) -> ast::Crate {
     let name = match injected_crate_name(&krate) {
         Some(name) => name,
         None => return krate,
     };
 
-    let crate_name = Symbol::intern(&alt_std_name.unwrap_or(name.to_string()));
+    let crate_name = Symbol::intern(&alt_std_name.unwrap_or_else(|| name.to_string()));
 
     krate.module.items.insert(0, P(ast::Item {
         attrs: vec![attr::mk_attr_outer(DUMMY_SP,
@@ -66,15 +62,12 @@ pub fn maybe_inject_crates_ref(sess: &ParseSess,
         span: DUMMY_SP,
     }));
 
-    let span = ignored_span(sess, DUMMY_SP);
+    let span = ignored_span(DUMMY_SP);
     krate.module.items.insert(0, P(ast::Item {
         attrs: vec![ast::Attribute {
             style: ast::AttrStyle::Outer,
-            value: ast::MetaItem {
-                name: Symbol::intern("prelude_import"),
-                node: ast::MetaItemKind::Word,
-                span: span,
-            },
+            path: ast::Path::from_ident(span, ast::Ident::from_str("prelude_import")),
+            tokens: TokenStream::empty(),
             id: attr::mk_attr_id(),
             is_sugared_doc: false,
             span: span,
@@ -82,7 +75,7 @@ pub fn maybe_inject_crates_ref(sess: &ParseSess,
         vis: ast::Visibility::Inherited,
         node: ast::ItemKind::Use(P(codemap::dummy_spanned(ast::ViewPathGlob(ast::Path {
             segments: ["{{root}}", name, "prelude", "v1"].into_iter().map(|name| {
-                ast::Ident::from_str(name).into()
+                ast::PathSegment::from_ident(ast::Ident::from_str(name), DUMMY_SP)
             }).collect(),
             span: span,
         })))),
diff --git a/src/libsyntax/symbol.rs b/src/libsyntax/symbol.rs
deleted file mode 100644
index c278171aa10..00000000000
--- a/src/libsyntax/symbol.rs
+++ /dev/null
@@ -1,305 +0,0 @@
-// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-//! An "interner" is a data structure that associates values with usize tags and
-//! allows bidirectional lookup; i.e. given a value, one can easily find the
-//! type, and vice versa.
-
-use serialize::{Decodable, Decoder, Encodable, Encoder};
-use std::cell::RefCell;
-use std::collections::HashMap;
-use std::fmt;
-
-/// A symbol is an interned or gensymed string.
-#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct Symbol(u32);
-
-// The interner in thread-local, so `Symbol` shouldn't move between threads.
-impl !Send for Symbol { }
-
-impl Symbol {
-    /// Maps a string to its interned representation.
-    pub fn intern(string: &str) -> Self {
-        with_interner(|interner| interner.intern(string))
-    }
-
-    /// gensym's a new usize, using the current interner.
-    pub fn gensym(string: &str) -> Self {
-        with_interner(|interner| interner.gensym(string))
-    }
-
-    pub fn as_str(self) -> InternedString {
-        with_interner(|interner| unsafe {
-            InternedString {
-                string: ::std::mem::transmute::<&str, &str>(interner.get(self))
-            }
-        })
-    }
-
-    pub fn as_u32(self) -> u32 {
-        self.0
-    }
-}
-
-impl fmt::Debug for Symbol {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "{}({})", self, self.0)
-    }
-}
-
-impl fmt::Display for Symbol {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        fmt::Display::fmt(&self.as_str(), f)
-    }
-}
-
-impl Encodable for Symbol {
-    fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
-        s.emit_str(&self.as_str())
-    }
-}
-
-impl Decodable for Symbol {
-    fn decode<D: Decoder>(d: &mut D) -> Result<Symbol, D::Error> {
-        Ok(Symbol::intern(&d.read_str()?))
-    }
-}
-
-impl<'a> PartialEq<&'a str> for Symbol {
-    fn eq(&self, other: &&str) -> bool {
-        *self.as_str() == **other
-    }
-}
-
-#[derive(Default)]
-pub struct Interner {
-    names: HashMap<Box<str>, Symbol>,
-    strings: Vec<Box<str>>,
-}
-
-impl Interner {
-    pub fn new() -> Self {
-        Interner::default()
-    }
-
-    fn prefill(init: &[&str]) -> Self {
-        let mut this = Interner::new();
-        for &string in init {
-            this.intern(string);
-        }
-        this
-    }
-
-    pub fn intern(&mut self, string: &str) -> Symbol {
-        if let Some(&name) = self.names.get(string) {
-            return name;
-        }
-
-        let name = Symbol(self.strings.len() as u32);
-        let string = string.to_string().into_boxed_str();
-        self.strings.push(string.clone());
-        self.names.insert(string, name);
-        name
-    }
-
-    fn gensym(&mut self, string: &str) -> Symbol {
-        let gensym = Symbol(self.strings.len() as u32);
-        // leave out of `names` to avoid colliding
-        self.strings.push(string.to_string().into_boxed_str());
-        gensym
-    }
-
-    pub fn get(&self, name: Symbol) -> &str {
-        &self.strings[name.0 as usize]
-    }
-}
-
-// In this macro, there is the requirement that the name (the number) must be monotonically
-// increasing by one in the special identifiers, starting at 0; the same holds for the keywords,
-// except starting from the next number instead of zero.
-macro_rules! declare_keywords {(
-    $( ($index: expr, $konst: ident, $string: expr) )*
-) => {
-    pub mod keywords {
-        use ast;
-        #[derive(Clone, Copy, PartialEq, Eq)]
-        pub struct Keyword {
-            ident: ast::Ident,
-        }
-        impl Keyword {
-            #[inline] pub fn ident(self) -> ast::Ident { self.ident }
-            #[inline] pub fn name(self) -> ast::Name { self.ident.name }
-        }
-        $(
-            #[allow(non_upper_case_globals)]
-            pub const $konst: Keyword = Keyword {
-                ident: ast::Ident::with_empty_ctxt(super::Symbol($index))
-            };
-        )*
-    }
-
-    impl Interner {
-        fn fresh() -> Self {
-            Interner::prefill(&[$($string,)*])
-        }
-    }
-}}
-
-// NB: leaving holes in the ident table is bad! a different ident will get
-// interned with the id from the hole, but it will be between the min and max
-// of the reserved words, and thus tagged as "reserved".
-// After modifying this list adjust `is_strict_keyword`/`is_reserved_keyword`,
-// this should be rarely necessary though if the keywords are kept in alphabetic order.
-declare_keywords! {
-    // Invalid identifier
-    (0,  Invalid,        "")
-
-    // Strict keywords used in the language.
-    (1,  As,             "as")
-    (2,  Box,            "box")
-    (3,  Break,          "break")
-    (4,  Const,          "const")
-    (5,  Continue,       "continue")
-    (6,  Crate,          "crate")
-    (7,  Else,           "else")
-    (8,  Enum,           "enum")
-    (9,  Extern,         "extern")
-    (10, False,          "false")
-    (11, Fn,             "fn")
-    (12, For,            "for")
-    (13, If,             "if")
-    (14, Impl,           "impl")
-    (15, In,             "in")
-    (16, Let,            "let")
-    (17, Loop,           "loop")
-    (18, Match,          "match")
-    (19, Mod,            "mod")
-    (20, Move,           "move")
-    (21, Mut,            "mut")
-    (22, Pub,            "pub")
-    (23, Ref,            "ref")
-    (24, Return,         "return")
-    (25, SelfValue,      "self")
-    (26, SelfType,       "Self")
-    (27, Static,         "static")
-    (28, Struct,         "struct")
-    (29, Super,          "super")
-    (30, Trait,          "trait")
-    (31, True,           "true")
-    (32, Type,           "type")
-    (33, Unsafe,         "unsafe")
-    (34, Use,            "use")
-    (35, Where,          "where")
-    (36, While,          "while")
-
-    // Keywords reserved for future use.
-    (37, Abstract,       "abstract")
-    (38, Alignof,        "alignof")
-    (39, Become,         "become")
-    (40, Do,             "do")
-    (41, Final,          "final")
-    (42, Macro,          "macro")
-    (43, Offsetof,       "offsetof")
-    (44, Override,       "override")
-    (45, Priv,           "priv")
-    (46, Proc,           "proc")
-    (47, Pure,           "pure")
-    (48, Sizeof,         "sizeof")
-    (49, Typeof,         "typeof")
-    (50, Unsized,        "unsized")
-    (51, Virtual,        "virtual")
-    (52, Yield,          "yield")
-
-    // Weak keywords, have special meaning only in specific contexts.
-    (53, Default,        "default")
-    (54, StaticLifetime, "'static")
-    (55, Union,          "union")
-
-    // A virtual keyword that resolves to the crate root when used in a lexical scope.
-    (56, CrateRoot, "{{root}}")
-}
-
-// If an interner exists in TLS, return it. Otherwise, prepare a fresh one.
-fn with_interner<T, F: FnOnce(&mut Interner) -> T>(f: F) -> T {
-    thread_local!(static INTERNER: RefCell<Interner> = {
-        RefCell::new(Interner::fresh())
-    });
-    INTERNER.with(|interner| f(&mut *interner.borrow_mut()))
-}
-
-/// Represents a string stored in the thread-local interner. Because the
-/// interner lives for the life of the thread, this can be safely treated as an
-/// immortal string, as long as it never crosses between threads.
-///
-/// FIXME(pcwalton): You must be careful about what you do in the destructors
-/// of objects stored in TLS, because they may run after the interner is
-/// destroyed. In particular, they must not access string contents. This can
-/// be fixed in the future by just leaking all strings until thread death
-/// somehow.
-#[derive(Clone, PartialEq, Hash, PartialOrd, Eq, Ord)]
-pub struct InternedString {
-    string: &'static str,
-}
-
-impl !Send for InternedString { }
-
-impl ::std::ops::Deref for InternedString {
-    type Target = str;
-    fn deref(&self) -> &str { self.string }
-}
-
-impl fmt::Debug for InternedString {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        fmt::Debug::fmt(self.string, f)
-    }
-}
-
-impl fmt::Display for InternedString {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        fmt::Display::fmt(self.string, f)
-    }
-}
-
-impl Decodable for InternedString {
-    fn decode<D: Decoder>(d: &mut D) -> Result<InternedString, D::Error> {
-        Ok(Symbol::intern(&d.read_str()?).as_str())
-    }
-}
-
-impl Encodable for InternedString {
-    fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
-        s.emit_str(self.string)
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn interner_tests() {
-        let mut i: Interner = Interner::new();
-        // first one is zero:
-        assert_eq!(i.intern("dog"), Symbol(0));
-        // re-use gets the same entry:
-        assert_eq!(i.intern ("dog"), Symbol(0));
-        // different string gets a different #:
-        assert_eq!(i.intern("cat"), Symbol(1));
-        assert_eq!(i.intern("cat"), Symbol(1));
-        // dog is still at zero
-        assert_eq!(i.intern("dog"), Symbol(0));
-        // gensym gets 3
-        assert_eq!(i.gensym("zebra"), Symbol(2));
-        // gensym of same string gets new number :
-        assert_eq!(i.gensym("zebra"), Symbol(3));
-        // gensym of *existing* string gets new number:
-        assert_eq!(i.gensym("dog"), Symbol(4));
-    }
-}
diff --git a/src/libsyntax/test.rs b/src/libsyntax/test.rs
index dd2756cd2b2..837c3eb0100 100644
--- a/src/libsyntax/test.rs
+++ b/src/libsyntax/test.rs
@@ -31,6 +31,7 @@ use entry::{self, EntryPointType};
 use ext::base::{ExtCtxt, Resolver};
 use ext::build::AstBuilder;
 use ext::expand::ExpansionConfig;
+use ext::hygiene::{Mark, SyntaxContext};
 use fold::Folder;
 use util::move_map::MoveMap;
 use fold;
@@ -62,6 +63,7 @@ struct TestCtxt<'a> {
     testfns: Vec<Test>,
     reexport_test_harness_main: Option<Symbol>,
     is_test_crate: bool,
+    ctxt: SyntaxContext,
 
     // top-level re-export submodule, filled out after folding is finished
     toplevel_reexport: Option<Ident>,
@@ -104,9 +106,8 @@ impl<'a> fold::Folder for TestHarnessGenerator<'a> {
         // Add a special __test module to the crate that will contain code
         // generated for the test harness
         let (mod_, reexport) = mk_test_module(&mut self.cx);
-        match reexport {
-            Some(re) => folded.module.items.push(re),
-            None => {}
+        if let Some(re) = reexport {
+            folded.module.items.push(re)
         }
         folded.module.items.push(mod_);
         folded
@@ -255,7 +256,7 @@ fn mk_reexport_mod(cx: &mut TestCtxt,
     let parent = if parent == ast::DUMMY_NODE_ID { ast::CRATE_NODE_ID } else { parent };
     cx.ext_cx.current_expansion.mark = cx.ext_cx.resolver.get_module_scope(parent);
     let it = cx.ext_cx.monotonic_expander().fold_item(P(ast::Item {
-        ident: sym.clone(),
+        ident: sym,
         attrs: Vec::new(),
         id: ast::DUMMY_NODE_ID,
         node: ast::ItemKind::Mod(reexport_mod),
@@ -275,6 +276,7 @@ fn generate_test_harness(sess: &ParseSess,
     let mut cleaner = EntryPointCleaner { depth: 0 };
     let krate = cleaner.fold_crate(krate);
 
+    let mark = Mark::fresh(Mark::root());
     let mut cx: TestCtxt = TestCtxt {
         sess: sess,
         span_diagnostic: sd,
@@ -284,15 +286,16 @@ fn generate_test_harness(sess: &ParseSess,
         reexport_test_harness_main: reexport_test_harness_main,
         is_test_crate: is_test_crate(&krate),
         toplevel_reexport: None,
+        ctxt: SyntaxContext::empty().apply_mark(mark),
     };
     cx.ext_cx.crate_root = Some("std");
 
-    cx.ext_cx.bt_push(ExpnInfo {
+    mark.set_expn_info(ExpnInfo {
         call_site: DUMMY_SP,
         callee: NameAndSpan {
             format: MacroAttribute(Symbol::intern("test")),
             span: None,
-            allow_internal_unstable: false,
+            allow_internal_unstable: true,
         }
     });
 
@@ -304,21 +307,10 @@ fn generate_test_harness(sess: &ParseSess,
 }
 
 /// Craft a span that will be ignored by the stability lint's
-/// call to codemap's is_internal check.
+/// call to codemap's `is_internal` check.
 /// The expanded code calls some unstable functions in the test crate.
 fn ignored_span(cx: &TestCtxt, sp: Span) -> Span {
-    let info = ExpnInfo {
-        call_site: sp,
-        callee: NameAndSpan {
-            format: MacroAttribute(Symbol::intern("test")),
-            span: None,
-            allow_internal_unstable: true,
-        }
-    };
-    let expn_id = cx.sess.codemap().record_expansion(info);
-    let mut sp = sp;
-    sp.expn_id = expn_id;
-    return sp;
+    Span { ctxt: cx.ctxt, ..sp }
 }
 
 #[derive(PartialEq)]
@@ -361,7 +353,7 @@ fn is_test_fn(cx: &TestCtxt, i: &ast::Item) -> bool {
         }
     }
 
-    return has_test_attr && has_test_signature(i) == Yes;
+    has_test_attr && has_test_signature(i) == Yes
 }
 
 fn is_bench_fn(cx: &TestCtxt, i: &ast::Item) -> bool {
@@ -392,7 +384,7 @@ fn is_bench_fn(cx: &TestCtxt, i: &ast::Item) -> bool {
                       `fn(&mut Bencher) -> ()`");
     }
 
-    return has_bench_attr && has_test_signature(i);
+    has_bench_attr && has_test_signature(i)
 }
 
 fn is_ignored(i: &ast::Item) -> bool {
@@ -449,7 +441,7 @@ We're going to be building a module that looks more or less like:
 mod __test {
   extern crate test (name = "test", vers = "...");
   fn main() {
-    test::test_main_static(&::os::args()[], tests)
+    test::test_main_static(&::os::args()[], tests, test::Options::new())
   }
 
   static tests : &'static [test::TestDescAndFn] = &[
@@ -485,7 +477,7 @@ fn mk_main(cx: &mut TestCtxt) -> P<ast::Item> {
     //        pub fn main() {
     //            #![main]
     //            use std::slice::AsSlice;
-    //            test::test_main_static(::std::os::args().as_slice(), TESTS);
+    //            test::test_main_static(::std::os::args().as_slice(), TESTS, test::Options::new());
     //        }
 
     let sp = ignored_span(cx, DUMMY_SP);
@@ -511,16 +503,14 @@ fn mk_main(cx: &mut TestCtxt) -> P<ast::Item> {
                            ast::Unsafety::Normal,
                            dummy_spanned(ast::Constness::NotConst),
                            ::abi::Abi::Rust, ast::Generics::default(), main_body);
-    let main = P(ast::Item {
+    P(ast::Item {
         ident: Ident::from_str("main"),
         attrs: vec![main_attr],
         id: ast::DUMMY_NODE_ID,
         node: main,
         vis: ast::Visibility::Public,
         span: sp
-    });
-
-    return main;
+    })
 }
 
 fn mk_test_module(cx: &mut TestCtxt) -> (P<ast::Item>, Option<P<ast::Item>>) {
@@ -580,7 +570,7 @@ fn nospan<T>(t: T) -> codemap::Spanned<T> {
 fn path_node(ids: Vec<Ident>) -> ast::Path {
     ast::Path {
         span: DUMMY_SP,
-        segments: ids.into_iter().map(Into::into).collect(),
+        segments: ids.into_iter().map(|id| ast::PathSegment::from_ident(id, DUMMY_SP)).collect(),
     }
 }
 
@@ -601,7 +591,7 @@ fn mk_tests(cx: &TestCtxt) -> P<ast::Item> {
     let struct_type = ecx.ty_path(ecx.path(sp, vec![ecx.ident_of("self"),
                                                     ecx.ident_of("test"),
                                                     ecx.ident_of("TestDescAndFn")]));
-    let static_lt = ecx.lifetime(sp, keywords::StaticLifetime.name());
+    let static_lt = ecx.lifetime(sp, keywords::StaticLifetime.ident());
     // &'static [self::test::TestDescAndFn]
     let static_type = ecx.ty_rptr(sp,
                                   ecx.ty(sp, ast::TyKind::Slice(struct_type)),
@@ -616,7 +606,7 @@ fn mk_tests(cx: &TestCtxt) -> P<ast::Item> {
 
 fn is_test_crate(krate: &ast::Crate) -> bool {
     match attr::find_crate_name(&krate.attrs) {
-        Some(s) if "test" == &*s.as_str() => true,
+        Some(s) if "test" == s.as_str() => true,
         _ => false
     }
 }
diff --git a/src/libsyntax/test_snippet.rs b/src/libsyntax/test_snippet.rs
index c6d6e6237f2..b3fa1e97376 100644
--- a/src/libsyntax/test_snippet.rs
+++ b/src/libsyntax/test_snippet.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use codemap::CodeMap;
+use codemap::{CodeMap, FilePathMapping};
 use errors::Handler;
 use errors::emitter::EmitterWriter;
 use std::io;
@@ -47,8 +47,8 @@ impl<T: Write> Write for Shared<T> {
 fn test_harness(file_text: &str, span_labels: Vec<SpanLabel>, expected_output: &str) {
     let output = Arc::new(Mutex::new(Vec::new()));
 
-    let code_map = Rc::new(CodeMap::new());
-    code_map.new_filemap_and_lines("test.rs", None, &file_text);
+    let code_map = Rc::new(CodeMap::new(FilePathMapping::empty()));
+    code_map.new_filemap_and_lines("test.rs", &file_text);
 
     let primary_span = make_span(&file_text, &span_labels[0].start, &span_labels[0].end);
     let mut msp = MultiSpan::from_span(primary_span);
@@ -83,7 +83,7 @@ fn make_span(file_text: &str, start: &Position, end: &Position) -> Span {
     Span {
         lo: BytePos(start as u32),
         hi: BytePos(end as u32),
-        expn_id: NO_EXPANSION,
+        ctxt: NO_EXPANSION,
     }
 }
 
@@ -128,9 +128,9 @@ error: foo
  --> test.rs:2:10
   |
 2 |   fn foo() {
-  |  __________^ starting here...
+  |  __________^
 3 | | }
-  | |_^ ...ending here: test
+  | |_^ test
 
 "#);
 }
@@ -161,11 +161,11 @@ error: foo
  --> test.rs:2:10
   |
 2 |   fn foo() {
-  |  __________^ starting here...
+  |  __________^
 3 | |
 4 | |
 5 | |   }
-  | |___^ ...ending here: test
+  | |___^ test
 
 "#);
 }
@@ -207,14 +207,14 @@ error: foo
  --> test.rs:3:3
   |
 3 |      X0 Y0
-  |  ____^__- starting here...
+  |  ____^__-
   | | ___|
-  | ||   starting here...
+  | ||
 4 | ||   X1 Y1
 5 | ||   X2 Y2
-  | ||____^__- ...ending here: `Y` is a good letter too
+  | ||____^__- `Y` is a good letter too
   |  |____|
-  |       ...ending here: `X` is a good letter
+  |       `X` is a good letter
 
 "#);
 }
@@ -256,13 +256,13 @@ error: foo
  --> test.rs:3:3
   |
 3 |      X0 Y0
-  |  ____^__- starting here...
+  |  ____^__-
   | | ___|
-  | ||   starting here...
+  | ||
 4 | ||   Y1 X1
-  | ||____-__^ ...ending here: `X` is a good letter
+  | ||____-__^ `X` is a good letter
   | |_____|
-  |       ...ending here: `Y` is a good letter too
+  |       `Y` is a good letter too
 
 "#);
 }
@@ -306,13 +306,13 @@ error: foo
  --> test.rs:3:6
   |
 3 |      X0 Y0 Z0
-  |   ______^ starting here...
+  |   ______^
 4 |  |   X1 Y1 Z1
-  |  |_________- starting here...
+  |  |_________-
 5 | ||   X2 Y2 Z2
-  | ||____^ ...ending here: `X` is a good letter
+  | ||____^ `X` is a good letter
 6 | |    X3 Y3 Z3
-  | |_____- ...ending here: `Y` is a good letter too
+  | |_____- `Y` is a good letter too
 
 "#);
 }
@@ -366,16 +366,16 @@ error: foo
  --> test.rs:3:3
   |
 3 |       X0 Y0 Z0
-  |  _____^__-__- starting here...
+  |  _____^__-__-
   | | ____|__|
-  | || ___|  starting here...
-  | |||   starting here...
+  | || ___|
+  | |||
 4 | |||   X1 Y1 Z1
 5 | |||   X2 Y2 Z2
-  | |||____^__-__- ...ending here: `Z` label
+  | |||____^__-__- `Z` label
   |  ||____|__|
-  |   |____|  ...ending here: `Y` is a good letter too
-  |        ...ending here: `X` is a good letter
+  |   |____|  `Y` is a good letter too
+  |        `X` is a good letter
 
 "#);
 }
@@ -430,17 +430,17 @@ error: foo
  --> test.rs:3:6
   |
 3 |      X0 Y0 Z0
-  |   ______^ starting here...
+  |   ______^
 4 |  |   X1 Y1 Z1
-  |  |____^_- starting here...
+  |  |____^_-
   | ||____|
-  | |     ...ending here: `X` is a good letter
+  | |     `X` is a good letter
 5 | |    X2 Y2 Z2
-  | |____-______- ...ending here: `Y` is a good letter too
+  | |____-______- `Y` is a good letter too
   |  ____|
-  | |    starting here...
+  | |
 6 | |    X3 Y3 Z3
-  | |________- ...ending here: `Z`
+  | |________- `Z`
 
 "#);
 }
@@ -458,7 +458,7 @@ fn foo() {
     vec![
         SpanLabel {
             start: Position {
-                string: "Y0",
+                string: "X0",
                 count: 1,
             },
             end: Position {
@@ -481,16 +481,15 @@ fn foo() {
     ],
     r#"
 error: foo
- --> test.rs:3:6
+ --> test.rs:3:3
   |
-3 |     X0 Y0 Z0
-  |  ______^ starting here...
+3 | /   X0 Y0 Z0
 4 | |   X1 Y1 Z1
-  | |____^ ...ending here: `X` is a good letter
+  | |____^ `X` is a good letter
 5 |     X2 Y2 Z2
-  |  ______- starting here...
+  |  ______-
 6 | |   X3 Y3 Z3
-  | |__________- ...ending here: `Y` is a good letter too
+  | |__________- `Y` is a good letter too
 
 "#);
 }
@@ -534,14 +533,14 @@ error: foo
  --> test.rs:3:6
   |
 3 |      X0 Y0 Z0
-  |   ______^ starting here...
+  |   ______^
 4 |  |   X1 Y1 Z1
-  |  |____^____- starting here...
+  |  |____^____-
   | ||____|
-  | |     ...ending here: `X` is a good letter
+  | |     `X` is a good letter
 5 | |    X2 Y2 Z2
 6 | |    X3 Y3 Z3
-  | |___________- ...ending here: `Y` is a good letter too
+  | |___________- `Y` is a good letter too
 
 "#);
 }
@@ -932,3 +931,137 @@ error: foo
 
 "#);
 }
+
+#[test]
+fn long_snippet() {
+    test_harness(r#"
+fn foo() {
+  X0 Y0 Z0
+  X1 Y1 Z1
+1
+2
+3
+4
+5
+6
+7
+8
+9
+10
+  X2 Y2 Z2
+  X3 Y3 Z3
+}
+"#,
+    vec![
+        SpanLabel {
+            start: Position {
+                string: "Y0",
+                count: 1,
+            },
+            end: Position {
+                string: "X1",
+                count: 1,
+            },
+            label: "`X` is a good letter",
+        },
+        SpanLabel {
+            start: Position {
+                string: "Z1",
+                count: 1,
+            },
+            end: Position {
+                string: "Z3",
+                count: 1,
+            },
+            label: "`Y` is a good letter too",
+        },
+    ],
+    r#"
+error: foo
+  --> test.rs:3:6
+   |
+3  |      X0 Y0 Z0
+   |   ______^
+4  |  |   X1 Y1 Z1
+   |  |____^____-
+   | ||____|
+   | |     `X` is a good letter
+5  | |  1
+6  | |  2
+7  | |  3
+...  |
+15 | |    X2 Y2 Z2
+16 | |    X3 Y3 Z3
+   | |___________- `Y` is a good letter too
+
+"#);
+}
+
+#[test]
+fn long_snippet_multiple_spans() {
+    test_harness(r#"
+fn foo() {
+  X0 Y0 Z0
+1
+2
+3
+  X1 Y1 Z1
+4
+5
+6
+  X2 Y2 Z2
+7
+8
+9
+10
+  X3 Y3 Z3
+}
+"#,
+    vec![
+        SpanLabel {
+            start: Position {
+                string: "Y0",
+                count: 1,
+            },
+            end: Position {
+                string: "Y3",
+                count: 1,
+            },
+            label: "`Y` is a good letter",
+        },
+        SpanLabel {
+            start: Position {
+                string: "Z1",
+                count: 1,
+            },
+            end: Position {
+                string: "Z2",
+                count: 1,
+            },
+            label: "`Z` is a good letter too",
+        },
+    ],
+    r#"
+error: foo
+  --> test.rs:3:6
+   |
+3  |      X0 Y0 Z0
+   |   ______^
+4  |  | 1
+5  |  | 2
+6  |  | 3
+7  |  |   X1 Y1 Z1
+   |  |_________-
+8  | || 4
+9  | || 5
+10 | || 6
+11 | ||   X2 Y2 Z2
+   | ||__________- `Z` is a good letter too
+...   |
+15 |  | 10
+16 |  |   X3 Y3 Z3
+   |  |_______^ `Y` is a good letter
+
+"#);
+}
+
diff --git a/src/libsyntax/tokenstream.rs b/src/libsyntax/tokenstream.rs
index 2da442a1a53..339e7c0b628 100644
--- a/src/libsyntax/tokenstream.rs
+++ b/src/libsyntax/tokenstream.rs
@@ -10,16 +10,16 @@
 
 //! # Token Streams
 //!
-//! TokenStreams represent syntactic objects before they are converted into ASTs.
+//! `TokenStream`s represent syntactic objects before they are converted into ASTs.
 //! A `TokenStream` is, roughly speaking, a sequence (eg stream) of `TokenTree`s,
 //! which are themselves a single `Token` or a `Delimited` subsequence of tokens.
 //!
 //! ## Ownership
-//! TokenStreams are persistent data structures constructed as ropes with reference
-//! counted-children. In general, this means that calling an operation on a TokenStream
-//! (such as `slice`) produces an entirely new TokenStream from the borrowed reference to
-//! the original. This essentially coerces TokenStreams into 'views' of their subparts,
-//! and a borrowed TokenStream is sufficient to build an owned TokenStream without taking
+//! `TokenStreams` are persistent data structures constructed as ropes with reference
+//! counted-children. In general, this means that calling an operation on a `TokenStream`
+//! (such as `slice`) produces an entirely new `TokenStream` from the borrowed reference to
+//! the original. This essentially coerces `TokenStream`s into 'views' of their subparts,
+//! and a borrowed `TokenStream` is sufficient to build an owned `TokenStream` without taking
 //! ownership of the original.
 
 use syntax_pos::{BytePos, Span, DUMMY_SP};
@@ -56,18 +56,20 @@ impl Delimited {
 
     /// Returns the opening delimiter as a token tree.
     pub fn open_tt(&self, span: Span) -> TokenTree {
-        let open_span = match span {
-            DUMMY_SP => DUMMY_SP,
-            _ => Span { hi: span.lo + BytePos(self.delim.len() as u32), ..span },
+        let open_span = if span == DUMMY_SP {
+            DUMMY_SP
+        } else {
+            Span { hi: span.lo + BytePos(self.delim.len() as u32), ..span }
         };
         TokenTree::Token(open_span, self.open_token())
     }
 
     /// Returns the closing delimiter as a token tree.
     pub fn close_tt(&self, span: Span) -> TokenTree {
-        let close_span = match span {
-            DUMMY_SP => DUMMY_SP,
-            _ => Span { lo: span.hi - BytePos(self.delim.len() as u32), ..span },
+        let close_span = if span == DUMMY_SP {
+            DUMMY_SP
+        } else {
+            Span { lo: span.hi - BytePos(self.delim.len() as u32), ..span }
         };
         TokenTree::Token(close_span, self.close_token())
     }
@@ -86,7 +88,7 @@ impl Delimited {
 /// If the syntax extension is an MBE macro, it will attempt to match its
 /// LHS token tree against the provided token tree, and if it finds a
 /// match, will transcribe the RHS token tree, splicing in any captured
-/// macro_parser::matched_nonterminals into the `SubstNt`s it finds.
+/// `macro_parser::matched_nonterminals` into the `SubstNt`s it finds.
 ///
 /// The RHS of an MBE macro is the only place `SubstNt`s are substituted.
 /// Nothing special happens to misnamed or misplaced `SubstNt`s.
@@ -107,7 +109,7 @@ impl TokenTree {
             path: cx.current_expansion.module.directory.clone(),
             ownership: cx.current_expansion.directory_ownership,
         };
-        macro_parser::parse(cx.parse_sess(), tts, mtch, Some(directory))
+        macro_parser::parse(cx.parse_sess(), tts, mtch, Some(directory), true)
     }
 
     /// Check if this TokenTree is equal to the other, regardless of span information.
@@ -162,6 +164,12 @@ impl From<TokenTree> for TokenStream {
     }
 }
 
+impl From<Token> for TokenStream {
+    fn from(token: Token) -> TokenStream {
+        TokenTree::Token(DUMMY_SP, token).into()
+    }
+}
+
 impl<T: Into<TokenStream>> iter::FromIterator<T> for TokenStream {
     fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> Self {
         TokenStream::concat(iter.into_iter().map(Into::into).collect::<Vec<_>>())
@@ -360,7 +368,7 @@ impl PartialEq<ThinTokenStream> for ThinTokenStream {
 
 impl fmt::Display for TokenStream {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        f.write_str(&pprust::tts_to_string(&self.trees().collect::<Vec<_>>()))
+        f.write_str(&pprust::tokens_to_string(self.clone()))
     }
 }
 
@@ -419,7 +427,7 @@ mod tests {
         Span {
             lo: BytePos(a),
             hi: BytePos(b),
-            expn_id: NO_EXPANSION,
+            ctxt: NO_EXPANSION,
         }
     }
 
diff --git a/src/libsyntax/util/lev_distance.rs b/src/libsyntax/util/lev_distance.rs
index a6fff2d7074..9307f3c58d4 100644
--- a/src/libsyntax/util/lev_distance.rs
+++ b/src/libsyntax/util/lev_distance.rs
@@ -53,9 +53,10 @@ pub fn find_best_match_for_name<'a, T>(iter_names: T,
     iter_names
     .filter_map(|&name| {
         let dist = lev_distance(lookup, &name.as_str());
-        match dist <= max_dist {    // filter the unwanted cases
-            true => Some((name, dist)),
-            false => None,
+        if dist <= max_dist {    // filter the unwanted cases
+            Some((name, dist))
+        } else {
+            None
         }
     })
     .min_by_key(|&(_, val)| val)    // extract the tuple containing the minimum edit distance
diff --git a/src/libsyntax/util/move_map.rs b/src/libsyntax/util/move_map.rs
index fe05e2958b3..8cc37afa354 100644
--- a/src/libsyntax/util/move_map.rs
+++ b/src/libsyntax/util/move_map.rs
@@ -37,10 +37,10 @@ impl<T> MoveMap<T> for Vec<T> {
                 // move the read_i'th item out of the vector and map it
                 // to an iterator
                 let e = ptr::read(self.get_unchecked(read_i));
-                let mut iter = f(e).into_iter();
+                let iter = f(e).into_iter();
                 read_i += 1;
 
-                while let Some(e) = iter.next() {
+                for e in iter {
                     if write_i < read_i {
                         ptr::write(self.get_unchecked_mut(write_i), e);
                         write_i += 1;
@@ -93,10 +93,10 @@ impl<T> MoveMap<T> for SmallVector<T> {
                 // move the read_i'th item out of the vector and map it
                 // to an iterator
                 let e = ptr::read(self.get_unchecked(read_i));
-                let mut iter = f(e).into_iter();
+                let iter = f(e).into_iter();
                 read_i += 1;
 
-                while let Some(e) = iter.next() {
+                for e in iter {
                     if write_i < read_i {
                         ptr::write(self.get_unchecked_mut(write_i), e);
                         write_i += 1;
diff --git a/src/libsyntax/util/node_count.rs b/src/libsyntax/util/node_count.rs
index 9d9957a0f45..0a5d0c2e7fe 100644
--- a/src/libsyntax/util/node_count.rs
+++ b/src/libsyntax/util/node_count.rs
@@ -31,7 +31,7 @@ impl<'ast> Visitor<'ast> for NodeCounter {
         self.count += 1;
         walk_ident(self, span, ident);
     }
-    fn visit_mod(&mut self, m: &Mod, _s: Span, _n: NodeId) {
+    fn visit_mod(&mut self, m: &Mod, _s: Span, _a: &[Attribute], _n: NodeId) {
         self.count += 1;
         walk_mod(self, m)
     }
diff --git a/src/libsyntax/util/parser_testing.rs b/src/libsyntax/util/parser_testing.rs
index 51eb295b502..2727ab79ebf 100644
--- a/src/libsyntax/util/parser_testing.rs
+++ b/src/libsyntax/util/parser_testing.rs
@@ -9,6 +9,7 @@
 // except according to those terms.
 
 use ast::{self, Ident};
+use codemap::FilePathMapping;
 use parse::{ParseSess, PResult, filemap_to_stream};
 use parse::{lexer, new_parser_from_source_str};
 use parse::parser::Parser;
@@ -18,8 +19,8 @@ use std::iter::Peekable;
 
 /// Map a string to tts, using a made-up filename:
 pub fn string_to_stream(source_str: String) -> TokenStream {
-    let ps = ParseSess::new();
-    filemap_to_stream(&ps, ps.codemap().new_filemap("bogofile".to_string(), None, source_str))
+    let ps = ParseSess::new(FilePathMapping::empty());
+    filemap_to_stream(&ps, ps.codemap().new_filemap("bogofile".to_string(), source_str))
 }
 
 /// Map string to parser (via tts)
@@ -38,7 +39,7 @@ fn with_error_checking_parse<'a, T, F>(s: String, ps: &'a ParseSess, f: F) -> T
 
 /// Parse a string, return a crate.
 pub fn string_to_crate (source_str : String) -> ast::Crate {
-    let ps = ParseSess::new();
+    let ps = ParseSess::new(FilePathMapping::empty());
     with_error_checking_parse(source_str, &ps, |p| {
         p.parse_crate_mod()
     })
@@ -46,7 +47,7 @@ pub fn string_to_crate (source_str : String) -> ast::Crate {
 
 /// Parse a string, return an expr
 pub fn string_to_expr (source_str : String) -> P<ast::Expr> {
-    let ps = ParseSess::new();
+    let ps = ParseSess::new(FilePathMapping::empty());
     with_error_checking_parse(source_str, &ps, |p| {
         p.parse_expr()
     })
@@ -54,7 +55,7 @@ pub fn string_to_expr (source_str : String) -> P<ast::Expr> {
 
 /// Parse a string, return an item
 pub fn string_to_item (source_str : String) -> Option<P<ast::Item>> {
-    let ps = ParseSess::new();
+    let ps = ParseSess::new(FilePathMapping::empty());
     with_error_checking_parse(source_str, &ps, |p| {
         p.parse_item()
     })
@@ -62,7 +63,7 @@ pub fn string_to_item (source_str : String) -> Option<P<ast::Item>> {
 
 /// Parse a string, return a stmt
 pub fn string_to_stmt(source_str : String) -> Option<ast::Stmt> {
-    let ps = ParseSess::new();
+    let ps = ParseSess::new(FilePathMapping::empty());
     with_error_checking_parse(source_str, &ps, |p| {
         p.parse_stmt()
     })
@@ -71,7 +72,7 @@ pub fn string_to_stmt(source_str : String) -> Option<ast::Stmt> {
 /// Parse a string, return a pat. Uses "irrefutable"... which doesn't
 /// (currently) affect parsing.
 pub fn string_to_pat(source_str: String) -> P<ast::Pat> {
-    let ps = ParseSess::new();
+    let ps = ParseSess::new(FilePathMapping::empty());
     with_error_checking_parse(source_str, &ps, |p| {
         p.parse_pat()
     })
diff --git a/src/libsyntax/util/rc_slice.rs b/src/libsyntax/util/rc_slice.rs
index 195fb23f9d8..2d9fd7aa875 100644
--- a/src/libsyntax/util/rc_slice.rs
+++ b/src/libsyntax/util/rc_slice.rs
@@ -12,6 +12,9 @@ use std::fmt;
 use std::ops::Deref;
 use std::rc::Rc;
 
+use rustc_data_structures::stable_hasher::{StableHasher, StableHasherResult,
+                                           HashStable};
+
 #[derive(Clone)]
 pub struct RcSlice<T> {
     data: Rc<Box<[T]>>,
@@ -41,3 +44,13 @@ impl<T: fmt::Debug> fmt::Debug for RcSlice<T> {
         fmt::Debug::fmt(self.deref(), f)
     }
 }
+
+impl<CTX, T> HashStable<CTX> for RcSlice<T>
+    where T: HashStable<CTX>
+{
+    fn hash_stable<W: StableHasherResult>(&self,
+                                          hcx: &mut CTX,
+                                          hasher: &mut StableHasher<W>) {
+        (**self).hash_stable(hcx, hasher);
+    }
+}
diff --git a/src/libsyntax/visit.rs b/src/libsyntax/visit.rs
index ee7dd18247b..18a0949af0e 100644
--- a/src/libsyntax/visit.rs
+++ b/src/libsyntax/visit.rs
@@ -56,8 +56,11 @@ pub trait Visitor<'ast>: Sized {
     fn visit_ident(&mut self, span: Span, ident: Ident) {
         walk_ident(self, span, ident);
     }
-    fn visit_mod(&mut self, m: &'ast Mod, _s: Span, _n: NodeId) { walk_mod(self, m) }
+    fn visit_mod(&mut self, m: &'ast Mod, _s: Span, _attrs: &[Attribute], _n: NodeId) {
+        walk_mod(self, m);
+    }
     fn visit_foreign_item(&mut self, i: &'ast ForeignItem) { walk_foreign_item(self, i) }
+    fn visit_global_asm(&mut self, ga: &'ast GlobalAsm) { walk_global_asm(self, ga) }
     fn visit_item(&mut self, i: &'ast Item) { walk_item(self, i) }
     fn visit_local(&mut self, l: &'ast Local) { walk_local(self, l) }
     fn visit_block(&mut self, b: &'ast Block) { walk_block(self, b) }
@@ -109,6 +112,9 @@ pub trait Visitor<'ast>: Sized {
         // definition in your trait impl:
         // visit::walk_mac(self, _mac)
     }
+    fn visit_mac_def(&mut self, _mac: &'ast MacroDef, _id: NodeId) {
+        // Nothing to do
+    }
     fn visit_path(&mut self, path: &'ast Path, _id: NodeId) {
         walk_path(self, path)
     }
@@ -171,7 +177,7 @@ pub fn walk_ident<'a, V: Visitor<'a>>(visitor: &mut V, span: Span, ident: Ident)
 }
 
 pub fn walk_crate<'a, V: Visitor<'a>>(visitor: &mut V, krate: &'a Crate) {
-    visitor.visit_mod(&krate.module, krate.span, CRATE_NODE_ID);
+    visitor.visit_mod(&krate.module, krate.span, &krate.attrs, CRATE_NODE_ID);
     walk_list!(visitor, visit_attribute, &krate.attrs);
 }
 
@@ -189,7 +195,7 @@ pub fn walk_local<'a, V: Visitor<'a>>(visitor: &mut V, local: &'a Local) {
 }
 
 pub fn walk_lifetime<'a, V: Visitor<'a>>(visitor: &mut V, lifetime: &'a Lifetime) {
-    visitor.visit_name(lifetime.span, lifetime.name);
+    visitor.visit_ident(lifetime.span, lifetime.ident);
 }
 
 pub fn walk_lifetime_def<'a, V: Visitor<'a>>(visitor: &mut V, lifetime_def: &'a LifetimeDef) {
@@ -248,11 +254,12 @@ pub fn walk_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a Item) {
                              item.id)
         }
         ItemKind::Mod(ref module) => {
-            visitor.visit_mod(module, item.span, item.id)
+            visitor.visit_mod(module, item.span, &item.attrs, item.id)
         }
         ItemKind::ForeignMod(ref foreign_module) => {
             walk_list!(visitor, visit_foreign_item, &foreign_module.items);
         }
+        ItemKind::GlobalAsm(ref ga) => visitor.visit_global_asm(ga),
         ItemKind::Ty(ref typ, ref type_parameters) => {
             visitor.visit_ty(typ);
             visitor.visit_generics(type_parameters)
@@ -264,7 +271,7 @@ pub fn walk_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a Item) {
         ItemKind::DefaultImpl(_, ref trait_ref) => {
             visitor.visit_trait_ref(trait_ref)
         }
-        ItemKind::Impl(_, _,
+        ItemKind::Impl(_, _, _,
                  ref type_parameters,
                  ref opt_trait_reference,
                  ref typ,
@@ -286,7 +293,7 @@ pub fn walk_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a Item) {
             walk_list!(visitor, visit_trait_item, methods);
         }
         ItemKind::Mac(ref mac) => visitor.visit_mac(mac),
-        ItemKind::MacroDef(..) => {},
+        ItemKind::MacroDef(ref ts) => visitor.visit_mac_def(ts, item.id),
     }
     walk_list!(visitor, visit_attribute, &item.attrs);
 }
@@ -341,16 +348,14 @@ pub fn walk_ty<'a, V: Visitor<'a>>(visitor: &mut V, typ: &'a Ty) {
             visitor.visit_ty(ty);
             visitor.visit_expr(expression)
         }
-        TyKind::TraitObject(ref bounds) => {
-            walk_list!(visitor, visit_ty_param_bound, bounds);
-        }
+        TyKind::TraitObject(ref bounds) |
         TyKind::ImplTrait(ref bounds) => {
             walk_list!(visitor, visit_ty_param_bound, bounds);
         }
         TyKind::Typeof(ref expression) => {
             visitor.visit_expr(expression)
         }
-        TyKind::Infer | TyKind::ImplicitSelf => {}
+        TyKind::Infer | TyKind::ImplicitSelf | TyKind::Err => {}
         TyKind::Mac(ref mac) => {
             visitor.visit_mac(mac)
         }
@@ -464,6 +469,10 @@ pub fn walk_foreign_item<'a, V: Visitor<'a>>(visitor: &mut V, foreign_item: &'a
     walk_list!(visitor, visit_attribute, &foreign_item.attrs);
 }
 
+pub fn walk_global_asm<'a, V: Visitor<'a>>(_: &mut V, _: &'a GlobalAsm) {
+    // Empty!
+}
+
 pub fn walk_ty_param_bound<'a, V: Visitor<'a>>(visitor: &mut V, bound: &'a TyParamBound) {
     match *bound {
         TraitTyParamBound(ref typ, ref modifier) => {
@@ -534,7 +543,7 @@ pub fn walk_fn<'a, V>(visitor: &mut V, kind: FnKind<'a>, declaration: &'a FnDecl
             walk_fn_decl(visitor, declaration);
             visitor.visit_block(body);
         }
-        FnKind::Method(_, ref sig, _, body) => {
+        FnKind::Method(_, sig, _, body) => {
             visitor.visit_generics(&sig.generics);
             walk_fn_decl(visitor, declaration);
             visitor.visit_block(body);
@@ -770,7 +779,7 @@ pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) {
         }
         ExprKind::InlineAsm(ref ia) => {
             for &(_, ref input) in &ia.inputs {
-                visitor.visit_expr(&input)
+                visitor.visit_expr(input)
             }
             for output in &ia.outputs {
                 visitor.visit_expr(&output.expr)
@@ -779,6 +788,9 @@ pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) {
         ExprKind::Try(ref subexpression) => {
             visitor.visit_expr(subexpression)
         }
+        ExprKind::Catch(ref body) => {
+            visitor.visit_block(body)
+        }
     }
 
     visitor.visit_expr_post(expression)