Merge pull request #12 from rust-lang/master

sync with rust-lang/rust branch master

7 files changed, 253 insertions, 200 deletions

diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs
index b0a4a6af983..5d68983d7cb 100644
--- a/src/libsyntax/ext/base.rs
+++ b/src/libsyntax/ext/base.rs
@@ -1,16 +1,17 @@
 use crate::ast::{self, NodeId, Attribute, Name, PatKind};
-use crate::attr::{HasAttrs, Stability, Deprecation};
+use crate::attr::{self, HasAttrs, Stability, Deprecation};
 use crate::source_map::SourceMap;
 use crate::edition::Edition;
 use crate::ext::expand::{self, AstFragment, Invocation};
-use crate::ext::hygiene::{ExpnId, SyntaxContext, Transparency};
+use crate::ext::hygiene::{ExpnId, Transparency};
 use crate::mut_visit::{self, MutVisitor};
-use crate::parse::{self, parser, DirectoryOwnership};
+use crate::parse::{self, parser, ParseSess, DirectoryOwnership};
 use crate::parse::token;
 use crate::ptr::P;
 use crate::symbol::{kw, sym, Ident, Symbol};
 use crate::{ThinVec, MACRO_ARGUMENTS};
 use crate::tokenstream::{self, TokenStream, TokenTree};
+use crate::visit::Visitor;
 
 use errors::{DiagnosticBuilder, DiagnosticId};
 use smallvec::{smallvec, SmallVec};
@@ -72,6 +73,17 @@ impl Annotatable {
         }
     }
 
+    pub fn visit_with<'a, V: Visitor<'a>>(&'a self, visitor: &mut V) {
+        match self {
+            Annotatable::Item(item) => visitor.visit_item(item),
+            Annotatable::TraitItem(trait_item) => visitor.visit_trait_item(trait_item),
+            Annotatable::ImplItem(impl_item) => visitor.visit_impl_item(impl_item),
+            Annotatable::ForeignItem(foreign_item) => visitor.visit_foreign_item(foreign_item),
+            Annotatable::Stmt(stmt) => visitor.visit_stmt(stmt),
+            Annotatable::Expr(expr) => visitor.visit_expr(expr),
+        }
+    }
+
     pub fn expect_item(self) -> P<ast::Item> {
         match self {
             Annotatable::Item(i) => i,
@@ -549,8 +561,6 @@ pub struct SyntaxExtension {
     pub kind: SyntaxExtensionKind,
     /// Span of the macro definition.
     pub span: Span,
-    /// Hygienic properties of spans produced by this macro by default.
-    pub default_transparency: Transparency,
     /// Whitelist of unstable features that are treated as stable inside this macro.
     pub allow_internal_unstable: Option<Lrc<[Symbol]>>,
     /// Suppresses the `unsafe_code` lint for code produced by this macro.
@@ -572,22 +582,6 @@ pub struct SyntaxExtension {
     pub is_derive_copy: bool,
 }
 
-impl SyntaxExtensionKind {
-    /// When a syntax extension is constructed,
-    /// its transparency can often be inferred from its kind.
-    fn default_transparency(&self) -> Transparency {
-        match self {
-            SyntaxExtensionKind::Bang(..) |
-            SyntaxExtensionKind::Attr(..) |
-            SyntaxExtensionKind::Derive(..) |
-            SyntaxExtensionKind::NonMacroAttr { .. } => Transparency::Opaque,
-            SyntaxExtensionKind::LegacyBang(..) |
-            SyntaxExtensionKind::LegacyAttr(..) |
-            SyntaxExtensionKind::LegacyDerive(..) => Transparency::SemiTransparent,
-        }
-    }
-}
-
 impl SyntaxExtension {
     /// Returns which kind of macro calls this syntax extension.
     pub fn macro_kind(&self) -> MacroKind {
@@ -606,7 +600,6 @@ impl SyntaxExtension {
     pub fn default(kind: SyntaxExtensionKind, edition: Edition) -> SyntaxExtension {
         SyntaxExtension {
             span: DUMMY_SP,
-            default_transparency: kind.default_transparency(),
             allow_internal_unstable: None,
             allow_internal_unsafe: false,
             local_inner_macros: false,
@@ -620,6 +613,69 @@ impl SyntaxExtension {
         }
     }
 
+    /// Constructs a syntax extension with the given properties
+    /// and other properties converted from attributes.
+    pub fn new(
+        sess: &ParseSess,
+        kind: SyntaxExtensionKind,
+        span: Span,
+        helper_attrs: Vec<Symbol>,
+        edition: Edition,
+        name: Name,
+        attrs: &[ast::Attribute],
+    ) -> SyntaxExtension {
+        let allow_internal_unstable =
+            attr::find_by_name(attrs, sym::allow_internal_unstable).map(|attr| {
+                attr.meta_item_list()
+                    .map(|list| {
+                        list.iter()
+                            .filter_map(|it| {
+                                let name = it.ident().map(|ident| ident.name);
+                                if name.is_none() {
+                                    sess.span_diagnostic.span_err(
+                                        it.span(), "allow internal unstable expects feature names"
+                                    )
+                                }
+                                name
+                            })
+                            .collect::<Vec<Symbol>>()
+                            .into()
+                    })
+                    .unwrap_or_else(|| {
+                        sess.span_diagnostic.span_warn(
+                            attr.span,
+                            "allow_internal_unstable expects list of feature names. In the future \
+                             this will become a hard error. Please use `allow_internal_unstable(\
+                             foo, bar)` to only allow the `foo` and `bar` features",
+                        );
+                        vec![sym::allow_internal_unstable_backcompat_hack].into()
+                    })
+            });
+
+        let mut local_inner_macros = false;
+        if let Some(macro_export) = attr::find_by_name(attrs, sym::macro_export) {
+            if let Some(l) = macro_export.meta_item_list() {
+                local_inner_macros = attr::list_contains_name(&l, sym::local_inner_macros);
+            }
+        }
+
+        let is_builtin = attr::contains_name(attrs, sym::rustc_builtin_macro);
+
+        SyntaxExtension {
+            kind,
+            span,
+            allow_internal_unstable,
+            allow_internal_unsafe: attr::contains_name(attrs, sym::allow_internal_unsafe),
+            local_inner_macros,
+            stability: attr::find_stability(&sess, attrs, span),
+            deprecation: attr::find_deprecation(&sess, attrs, span),
+            helper_attrs,
+            edition,
+            is_builtin,
+            is_derive_copy: is_builtin && name == sym::Copy,
+        }
+    }
+
     pub fn dummy_bang(edition: Edition) -> SyntaxExtension {
         fn expander<'cx>(_: &'cx mut ExtCtxt<'_>, span: Span, _: &[TokenTree])
                          -> Box<dyn MacResult + 'cx> {
@@ -646,7 +702,6 @@ impl SyntaxExtension {
             parent,
             call_site,
             def_site: self.span,
-            default_transparency: self.default_transparency,
             allow_internal_unstable: self.allow_internal_unstable.clone(),
             allow_internal_unsafe: self.allow_internal_unsafe,
             local_inner_macros: self.local_inner_macros,
@@ -657,6 +712,12 @@ impl SyntaxExtension {
 
 pub type NamedSyntaxExtension = (Name, SyntaxExtension);
 
+/// Result of resolving a macro invocation.
+pub enum InvocationRes {
+    Single(Lrc<SyntaxExtension>),
+    DeriveContainer(Vec<Lrc<SyntaxExtension>>),
+}
+
 /// Error type that denotes indeterminacy.
 pub struct Indeterminate;
 
@@ -682,8 +743,9 @@ pub trait Resolver {
 
     fn resolve_imports(&mut self);
 
-    fn resolve_macro_invocation(&mut self, invoc: &Invocation, invoc_id: ExpnId, force: bool)
-                                -> Result<Option<Lrc<SyntaxExtension>>, Indeterminate>;
+    fn resolve_macro_invocation(
+        &mut self, invoc: &Invocation, eager_expansion_root: ExpnId, force: bool
+    ) -> Result<InvocationRes, Indeterminate>;
 
     fn check_unused_macros(&self);
 
@@ -759,23 +821,39 @@ impl<'a> ExtCtxt<'a> {
     pub fn call_site(&self) -> Span {
         self.current_expansion.id.expn_data().call_site
     }
-    pub fn backtrace(&self) -> SyntaxContext {
-        SyntaxContext::root().apply_mark(self.current_expansion.id)
+
+    /// Equivalent of `Span::def_site` from the proc macro API,
+    /// except that the location is taken from the span passed as an argument.
+    pub fn with_def_site_ctxt(&self, span: Span) -> Span {
+        span.with_ctxt_from_mark(self.current_expansion.id, Transparency::Opaque)
+    }
+
+    /// Equivalent of `Span::call_site` from the proc macro API,
+    /// except that the location is taken from the span passed as an argument.
+    pub fn with_call_site_ctxt(&self, span: Span) -> Span {
+        span.with_ctxt_from_mark(self.current_expansion.id, Transparency::Transparent)
+    }
+
+    /// Span with a context reproducing `macro_rules` hygiene (hygienic locals, unhygienic items).
+    /// FIXME: This should be eventually replaced either with `with_def_site_ctxt` (preferably),
+    /// or with `with_call_site_ctxt` (where necessary).
+    pub fn with_legacy_ctxt(&self, span: Span) -> Span {
+        span.with_ctxt_from_mark(self.current_expansion.id, Transparency::SemiTransparent)
     }
 
     /// Returns span for the macro which originally caused the current expansion to happen.
     ///
     /// Stops backtracing at include! boundary.
     pub fn expansion_cause(&self) -> Option<Span> {
-        let mut ctxt = self.backtrace();
+        let mut expn_id = self.current_expansion.id;
         let mut last_macro = None;
         loop {
-            let expn_data = ctxt.outer_expn_data();
+            let expn_data = expn_id.expn_data();
             // Stop going up the backtrace once include! is encountered
             if expn_data.is_root() || expn_data.kind.descr() == sym::include {
                 break;
             }
-            ctxt = expn_data.call_site.ctxt();
+            expn_id = expn_data.call_site.ctxt().outer_expn();
             last_macro = Some(expn_data.call_site);
         }
         last_macro
@@ -864,7 +942,7 @@ impl<'a> ExtCtxt<'a> {
         ast::Ident::from_str(st)
     }
     pub fn std_path(&self, components: &[Symbol]) -> Vec<ast::Ident> {
-        let def_site = DUMMY_SP.apply_mark(self.current_expansion.id);
+        let def_site = self.with_def_site_ctxt(DUMMY_SP);
         iter::once(Ident::new(kw::DollarCrate, def_site))
             .chain(components.iter().map(|&s| Ident::with_dummy_span(s)))
             .collect()
@@ -908,12 +986,9 @@ impl<'a> ExtCtxt<'a> {
 /// compilation on error, merely emits a non-fatal error and returns `None`.
 pub fn expr_to_spanned_string<'a>(
     cx: &'a mut ExtCtxt<'_>,
-    mut expr: P<ast::Expr>,
+    expr: P<ast::Expr>,
     err_msg: &str,
 ) -> Result<(Symbol, ast::StrStyle, Span), Option<DiagnosticBuilder<'a>>> {
-    // Update `expr.span`'s ctxt now in case expr is an `include!` macro invocation.
-    expr.span = expr.span.apply_mark(cx.current_expansion.id);
-
     // Perform eager expansion on the expression.
     // We want to be able to handle e.g., `concat!("foo", "bar")`.
     let expr = cx.expander().fully_expand_fragment(AstFragment::Expr(expr)).make_expr();
diff --git a/src/libsyntax/ext/build.rs b/src/libsyntax/ext/build.rs
index e2ac4d573a1..e894fd17ff5 100644
--- a/src/libsyntax/ext/build.rs
+++ b/src/libsyntax/ext/build.rs
@@ -655,7 +655,7 @@ impl<'a> ExtCtxt<'a> {
               body: P<ast::Expr>)
               -> P<ast::Expr> {
         let fn_decl = self.fn_decl(
-            ids.iter().map(|id| self.arg(span, *id, self.ty_infer(span))).collect(),
+            ids.iter().map(|id| self.param(span, *id, self.ty_infer(span))).collect(),
             ast::FunctionRetTy::Default(span));
 
         // FIXME -- We are using `span` as the span of the `|...|`
@@ -693,9 +693,9 @@ impl<'a> ExtCtxt<'a> {
         self.lambda1(span, self.expr_block(self.block(span, stmts)), ident)
     }
 
-    pub fn arg(&self, span: Span, ident: ast::Ident, ty: P<ast::Ty>) -> ast::Arg {
+    pub fn param(&self, span: Span, ident: ast::Ident, ty: P<ast::Ty>) -> ast::Param {
         let arg_pat = self.pat_ident(span, ident);
-        ast::Arg {
+        ast::Param {
             attrs: ThinVec::default(),
             id: ast::DUMMY_NODE_ID,
             pat: arg_pat,
@@ -705,7 +705,7 @@ impl<'a> ExtCtxt<'a> {
     }
 
     // FIXME: unused `self`
-    pub fn fn_decl(&self, inputs: Vec<ast::Arg>, output: ast::FunctionRetTy) -> P<ast::FnDecl> {
+    pub fn fn_decl(&self, inputs: Vec<ast::Param>, output: ast::FunctionRetTy) -> P<ast::FnDecl> {
         P(ast::FnDecl {
             inputs,
             output,
@@ -731,7 +731,7 @@ impl<'a> ExtCtxt<'a> {
     pub fn item_fn_poly(&self,
                     span: Span,
                     name: Ident,
-                    inputs: Vec<ast::Arg> ,
+                    inputs: Vec<ast::Param> ,
                     output: P<ast::Ty>,
                     generics: Generics,
                     body: P<ast::Block>) -> P<ast::Item> {
@@ -752,7 +752,7 @@ impl<'a> ExtCtxt<'a> {
     pub fn item_fn(&self,
                span: Span,
                name: Ident,
-               inputs: Vec<ast::Arg> ,
+               inputs: Vec<ast::Param> ,
                output: P<ast::Ty>,
                body: P<ast::Block>
               ) -> P<ast::Item> {
diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs
index c1d52c97455..7b4a5167446 100644
--- a/src/libsyntax/ext/expand.rs
+++ b/src/libsyntax/ext/expand.rs
@@ -4,7 +4,7 @@ use crate::attr::{self, HasAttrs};
 use crate::source_map::respan;
 use crate::config::StripUnconfigured;
 use crate::ext::base::*;
-use crate::ext::proc_macro::collect_derives;
+use crate::ext::proc_macro::{collect_derives, MarkAttrs};
 use crate::ext::hygiene::{ExpnId, SyntaxContext, ExpnData, ExpnKind};
 use crate::ext::tt::macro_rules::annotate_err_with_kind;
 use crate::ext::placeholders::{placeholder, PlaceholderExpander};
@@ -305,10 +305,12 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
                 continue
             };
 
-            let scope =
+            let eager_expansion_root =
                 if self.monotonic { invoc.expansion_data.id } else { orig_expansion_data.id };
-            let ext = match self.cx.resolver.resolve_macro_invocation(&invoc, scope, force) {
-                Ok(ext) => ext,
+            let res = match self.cx.resolver.resolve_macro_invocation(
+                &invoc, eager_expansion_root, force
+            ) {
+                Ok(res) => res,
                 Err(Indeterminate) => {
                     undetermined_invocations.push(invoc);
                     continue
@@ -318,57 +320,74 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
             progress = true;
             let ExpansionData { depth, id: expn_id, .. } = invoc.expansion_data;
             self.cx.current_expansion = invoc.expansion_data.clone();
-            self.cx.current_expansion.id = scope;
 
             // FIXME(jseyfried): Refactor out the following logic
-            let (expanded_fragment, new_invocations) = if let Some(ext) = ext {
-                let fragment = self.expand_invoc(invoc, &ext.kind);
-                self.collect_invocations(fragment, &[])
-            } else if let InvocationKind::DeriveContainer { derives: traits, item } = invoc.kind {
-                if !item.derive_allowed() {
-                    let attr = attr::find_by_name(item.attrs(), sym::derive)
-                        .expect("`derive` attribute should exist");
-                    let span = attr.span;
-                    let mut err = self.cx.mut_span_err(span,
-                                                        "`derive` may only be applied to \
-                                                        structs, enums and unions");
-                    if let ast::AttrStyle::Inner = attr.style {
-                        let trait_list = traits.iter()
-                            .map(|t| t.to_string()).collect::<Vec<_>>();
-                        let suggestion = format!("#[derive({})]", trait_list.join(", "));
-                        err.span_suggestion(
-                            span, "try an outer attribute", suggestion,
-                            // We don't 𝑘𝑛𝑜𝑤 that the following item is an ADT
-                            Applicability::MaybeIncorrect
-                        );
-                    }
-                    err.emit();
+            let (expanded_fragment, new_invocations) = match res {
+                InvocationRes::Single(ext) => {
+                    let fragment = self.expand_invoc(invoc, &ext.kind);
+                    self.collect_invocations(fragment, &[])
                 }
+                InvocationRes::DeriveContainer(exts) => {
+                    let (derives, item) = match invoc.kind {
+                        InvocationKind::DeriveContainer { derives, item } => (derives, item),
+                        _ => unreachable!(),
+                    };
+                    if !item.derive_allowed() {
+                        let attr = attr::find_by_name(item.attrs(), sym::derive)
+                            .expect("`derive` attribute should exist");
+                        let span = attr.span;
+                        let mut err = self.cx.mut_span_err(span,
+                            "`derive` may only be applied to structs, enums and unions");
+                        if let ast::AttrStyle::Inner = attr.style {
+                            let trait_list = derives.iter()
+                                .map(|t| t.to_string()).collect::<Vec<_>>();
+                            let suggestion = format!("#[derive({})]", trait_list.join(", "));
+                            err.span_suggestion(
+                                span, "try an outer attribute", suggestion,
+                                // We don't 𝑘𝑛𝑜𝑤 that the following item is an ADT
+                                Applicability::MaybeIncorrect
+                            );
+                        }
+                        err.emit();
+                    }
 
-                let mut item = self.fully_configure(item);
-                item.visit_attrs(|attrs| attrs.retain(|a| a.path != sym::derive));
-                let derive_placeholders =
-                    all_derive_placeholders.entry(invoc.expansion_data.id).or_default();
-
-                derive_placeholders.reserve(traits.len());
-                invocations.reserve(traits.len());
-                for path in traits {
-                    let expn_id = ExpnId::fresh(None);
-                    derive_placeholders.push(NodeId::placeholder_from_expn_id(expn_id));
-                    invocations.push(Invocation {
-                        kind: InvocationKind::Derive { path, item: item.clone() },
-                        fragment_kind: invoc.fragment_kind,
-                        expansion_data: ExpansionData {
-                            id: expn_id,
-                            ..invoc.expansion_data.clone()
-                        },
-                    });
+                    let mut item = self.fully_configure(item);
+                    item.visit_attrs(|attrs| attrs.retain(|a| a.path != sym::derive));
+                    let mut helper_attrs = Vec::new();
+                    let mut has_copy = false;
+                    for ext in exts {
+                        helper_attrs.extend(&ext.helper_attrs);
+                        has_copy |= ext.is_derive_copy;
+                    }
+                    // Mark derive helpers inside this item as known and used.
+                    // FIXME: This is a hack, derive helpers should be integrated with regular name
+                    // resolution instead. For example, helpers introduced by a derive container
+                    // can be in scope for all code produced by that container's expansion.
+                    item.visit_with(&mut MarkAttrs(&helper_attrs));
+                    if has_copy {
+                        self.cx.resolver.add_derives(invoc.expansion_data.id, SpecialDerives::COPY);
+                    }
+
+                    let derive_placeholders =
+                        all_derive_placeholders.entry(invoc.expansion_data.id).or_default();
+                    derive_placeholders.reserve(derives.len());
+                    invocations.reserve(derives.len());
+                    for path in derives {
+                        let expn_id = ExpnId::fresh(None);
+                        derive_placeholders.push(NodeId::placeholder_from_expn_id(expn_id));
+                        invocations.push(Invocation {
+                            kind: InvocationKind::Derive { path, item: item.clone() },
+                            fragment_kind: invoc.fragment_kind,
+                            expansion_data: ExpansionData {
+                                id: expn_id,
+                                ..invoc.expansion_data.clone()
+                            },
+                        });
+                    }
+                    let fragment = invoc.fragment_kind
+                        .expect_from_annotatables(::std::iter::once(item));
+                    self.collect_invocations(fragment, derive_placeholders)
                 }
-                let fragment = invoc.fragment_kind
-                    .expect_from_annotatables(::std::iter::once(item));
-                self.collect_invocations(fragment, derive_placeholders)
-            } else {
-                unreachable!()
             };
 
             if expanded_fragments.len() < depth {
@@ -564,7 +583,6 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
                         return fragment_kind.dummy(span);
                     }
                     let meta = ast::MetaItem { node: ast::MetaItemKind::Word, span, path };
-                    let span = span.with_ctxt(self.cx.backtrace());
                     let items = expander.expand(self.cx, span, &meta, item);
                     fragment_kind.expect_from_annotatables(items)
                 }
@@ -1209,9 +1227,13 @@ impl<'a, 'b> MutVisitor for InvocationCollector<'a, 'b> {
         }
     }
 
-    fn visit_generic_params(&mut self, params: &mut Vec<ast::GenericParam>) {
-        self.cfg.configure_generic_params(params);
-        noop_visit_generic_params(params, self);
+   fn flat_map_generic_param(
+       &mut self,
+       param: ast::GenericParam
+    ) -> SmallVec<[ast::GenericParam; 1]>
+    {
+        let param = configure!(self, param);
+        noop_flat_map_generic_param(param, self)
     }
 
     fn visit_attribute(&mut self, at: &mut ast::Attribute) {
@@ -1388,17 +1410,3 @@ impl<'feat> ExpansionConfig<'feat> {
         self.features.map_or(false, |features| features.custom_inner_attributes)
     }
 }
-
-// A Marker adds the given mark to the syntax context.
-#[derive(Debug)]
-pub struct Marker(pub ExpnId);
-
-impl MutVisitor for Marker {
-    fn visit_span(&mut self, span: &mut Span) {
-        *span = span.apply_mark(self.0)
-    }
-
-    fn visit_mac(&mut self, mac: &mut ast::Mac) {
-        noop_visit_mac(mac, self)
-    }
-}
diff --git a/src/libsyntax/ext/proc_macro.rs b/src/libsyntax/ext/proc_macro.rs
index c17b6f6b424..4a44c9a9f1f 100644
--- a/src/libsyntax/ext/proc_macro.rs
+++ b/src/libsyntax/ext/proc_macro.rs
@@ -78,7 +78,6 @@ pub struct ProcMacroDerive {
     pub client: proc_macro::bridge::client::Client<
         fn(proc_macro::TokenStream) -> proc_macro::TokenStream,
     >,
-    pub attrs: Vec<ast::Name>,
 }
 
 impl MultiItemModifier for ProcMacroDerive {
@@ -111,9 +110,6 @@ impl MultiItemModifier for ProcMacroDerive {
             }
         }
 
-        // Mark attributes as known, and used.
-        MarkAttrs(&self.attrs).visit_item(&item);
-
         let token = token::Interpolated(Lrc::new(token::NtItem(item)));
         let input = tokenstream::TokenTree::token(token, DUMMY_SP).into();
 
@@ -164,7 +160,7 @@ impl MultiItemModifier for ProcMacroDerive {
     }
 }
 
-struct MarkAttrs<'a>(&'a [ast::Name]);
+crate struct MarkAttrs<'a>(crate &'a [ast::Name]);
 
 impl<'a> Visitor<'a> for MarkAttrs<'a> {
     fn visit_attribute(&mut self, attr: &Attribute) {
diff --git a/src/libsyntax/ext/proc_macro_server.rs b/src/libsyntax/ext/proc_macro_server.rs
index 1619fa69941..1a26b17dac7 100644
--- a/src/libsyntax/ext/proc_macro_server.rs
+++ b/src/libsyntax/ext/proc_macro_server.rs
@@ -7,7 +7,6 @@ use crate::tokenstream::{self, DelimSpan, IsJoint::*, TokenStream, TreeAndJoint}
 use errors::{Diagnostic, DiagnosticBuilder};
 use rustc_data_structures::sync::Lrc;
 use syntax_pos::{BytePos, FileName, MultiSpan, Pos, SourceFile, Span};
-use syntax_pos::hygiene::{SyntaxContext, Transparency};
 use syntax_pos::symbol::{kw, sym, Symbol};
 
 use proc_macro::{Delimiter, Level, LineColumn, Spacing};
@@ -361,18 +360,11 @@ pub(crate) struct Rustc<'a> {
 
 impl<'a> Rustc<'a> {
     pub fn new(cx: &'a ExtCtxt<'_>) -> Self {
-        // No way to determine def location for a proc macro right now, so use call location.
-        let location = cx.current_expansion.id.expn_data().call_site;
-        let to_span = |transparency| {
-            location.with_ctxt(
-                SyntaxContext::root()
-                    .apply_mark_with_transparency(cx.current_expansion.id, transparency),
-            )
-        };
+        let expn_data = cx.current_expansion.id.expn_data();
         Rustc {
             sess: cx.parse_sess,
-            def_site: to_span(Transparency::Opaque),
-            call_site: to_span(Transparency::Transparent),
+            def_site: cx.with_def_site_ctxt(expn_data.def_site),
+            call_site: cx.with_call_site_ctxt(expn_data.call_site),
         }
     }
 
diff --git a/src/libsyntax/ext/tt/macro_rules.rs b/src/libsyntax/ext/tt/macro_rules.rs
index b057a9ad44d..46ffa52f7f5 100644
--- a/src/libsyntax/ext/tt/macro_rules.rs
+++ b/src/libsyntax/ext/tt/macro_rules.rs
@@ -1,3 +1,5 @@
+use crate::ast;
+use crate::attr::{self, TransparencyError};
 use crate::edition::Edition;
 use crate::ext::base::{DummyResult, ExtCtxt, MacResult, TTMacroExpander};
 use crate::ext::base::{SyntaxExtension, SyntaxExtensionKind};
@@ -15,10 +17,10 @@ use crate::parse::token::{self, NtTT, Token};
 use crate::parse::{Directory, ParseSess};
 use crate::symbol::{kw, sym, Symbol};
 use crate::tokenstream::{DelimSpan, TokenStream, TokenTree};
-use crate::{ast, attr, attr::TransparencyError};
 
 use errors::{DiagnosticBuilder, FatalError};
 use log::debug;
+use syntax_pos::hygiene::Transparency;
 use syntax_pos::Span;
 
 use rustc_data_structures::fx::FxHashMap;
@@ -128,6 +130,7 @@ impl<'a> ParserAnyMacro<'a> {
 struct MacroRulesMacroExpander {
     name: ast::Ident,
     span: Span,
+    transparency: Transparency,
     lhses: Vec<quoted::TokenTree>,
     rhses: Vec<quoted::TokenTree>,
     valid: bool,
@@ -143,7 +146,9 @@ impl TTMacroExpander for MacroRulesMacroExpander {
         if !self.valid {
             return DummyResult::any(sp);
         }
-        generic_extension(cx, sp, self.span, self.name, input, &self.lhses, &self.rhses)
+        generic_extension(
+            cx, sp, self.span, self.name, self.transparency, input, &self.lhses, &self.rhses
+        )
     }
 }
 
@@ -158,6 +163,7 @@ fn generic_extension<'cx>(
     sp: Span,
     def_span: Span,
     name: ast::Ident,
+    transparency: Transparency,
     arg: TokenStream,
     lhses: &[quoted::TokenTree],
     rhses: &[quoted::TokenTree],
@@ -187,7 +193,7 @@ fn generic_extension<'cx>(
 
                 let rhs_spans = rhs.iter().map(|t| t.span()).collect::<Vec<_>>();
                 // rhs has holes ( `$id` and `$(...)` that need filled)
-                let mut tts = transcribe(cx, &named_matches, rhs);
+                let mut tts = transcribe(cx, &named_matches, rhs, transparency);
 
                 // Replace all the tokens for the corresponding positions in the macro, to maintain
                 // proper positions in error reporting, while maintaining the macro_backtrace.
@@ -285,6 +291,7 @@ pub fn compile(
     def: &ast::Item,
     edition: Edition,
 ) -> SyntaxExtension {
+    let diag = &sess.span_diagnostic;
     let lhs_nm = ast::Ident::new(sym::lhs, def.span);
     let rhs_nm = ast::Ident::new(sym::rhs, def.span);
     let tt_spec = ast::Ident::new(sym::tt, def.span);
@@ -415,75 +422,28 @@ pub fn compile(
     // that is not lint-checked and trigger the "failed to process buffered lint here" bug.
     valid &= macro_check::check_meta_variables(sess, ast::CRATE_NODE_ID, def.span, &lhses, &rhses);
 
-    let expander: Box<_> =
-        Box::new(MacroRulesMacroExpander { name: def.ident, span: def.span, lhses, rhses, valid });
-
-    let (default_transparency, transparency_error) =
-        attr::find_transparency(&def.attrs, body.legacy);
+    let (transparency, transparency_error) = attr::find_transparency(&def.attrs, body.legacy);
     match transparency_error {
         Some(TransparencyError::UnknownTransparency(value, span)) =>
-            sess.span_diagnostic.span_err(
-                span, &format!("unknown macro transparency: `{}`", value)
-            ),
+            diag.span_err(span, &format!("unknown macro transparency: `{}`", value)),
         Some(TransparencyError::MultipleTransparencyAttrs(old_span, new_span)) =>
-            sess.span_diagnostic.span_err(
-                vec![old_span, new_span], "multiple macro transparency attributes"
-            ),
+            diag.span_err(vec![old_span, new_span], "multiple macro transparency attributes"),
         None => {}
     }
 
-    let allow_internal_unstable =
-        attr::find_by_name(&def.attrs, sym::allow_internal_unstable).map(|attr| {
-            attr.meta_item_list()
-                .map(|list| {
-                    list.iter()
-                        .filter_map(|it| {
-                            let name = it.ident().map(|ident| ident.name);
-                            if name.is_none() {
-                                sess.span_diagnostic.span_err(
-                                    it.span(),
-                                    "allow internal unstable expects feature names",
-                                )
-                            }
-                            name
-                        })
-                        .collect::<Vec<Symbol>>()
-                        .into()
-                })
-                .unwrap_or_else(|| {
-                    sess.span_diagnostic.span_warn(
-                        attr.span,
-                        "allow_internal_unstable expects list of feature names. In the \
-                         future this will become a hard error. Please use `allow_internal_unstable(\
-                         foo, bar)` to only allow the `foo` and `bar` features",
-                    );
-                    vec![sym::allow_internal_unstable_backcompat_hack].into()
-                })
-        });
-
-    let mut local_inner_macros = false;
-    if let Some(macro_export) = attr::find_by_name(&def.attrs, sym::macro_export) {
-        if let Some(l) = macro_export.meta_item_list() {
-            local_inner_macros = attr::list_contains_name(&l, sym::local_inner_macros);
-        }
-    }
+    let expander: Box<_> = Box::new(MacroRulesMacroExpander {
+        name: def.ident, span: def.span, transparency, lhses, rhses, valid
+    });
 
-    let is_builtin = attr::contains_name(&def.attrs, sym::rustc_builtin_macro);
-
-    SyntaxExtension {
-        kind: SyntaxExtensionKind::LegacyBang(expander),
-        span: def.span,
-        default_transparency,
-        allow_internal_unstable,
-        allow_internal_unsafe: attr::contains_name(&def.attrs, sym::allow_internal_unsafe),
-        local_inner_macros,
-        stability: attr::find_stability(&sess, &def.attrs, def.span),
-        deprecation: attr::find_deprecation(&sess, &def.attrs, def.span),
-        helper_attrs: Vec::new(),
+    SyntaxExtension::new(
+        sess,
+        SyntaxExtensionKind::LegacyBang(expander),
+        def.span,
+        Vec::new(),
         edition,
-        is_builtin,
-        is_derive_copy: is_builtin && def.ident.name == sym::Copy,
-    }
+        def.ident.name,
+        &def.attrs,
+    )
 }
 
 fn check_lhs_nt_follows(
diff --git a/src/libsyntax/ext/tt/transcribe.rs b/src/libsyntax/ext/tt/transcribe.rs
index 214e721fd15..30d5df13dce 100644
--- a/src/libsyntax/ext/tt/transcribe.rs
+++ b/src/libsyntax/ext/tt/transcribe.rs
@@ -1,9 +1,8 @@
-use crate::ast::Ident;
+use crate::ast::{Ident, Mac};
 use crate::ext::base::ExtCtxt;
-use crate::ext::expand::Marker;
 use crate::ext::tt::macro_parser::{MatchedNonterminal, MatchedSeq, NamedMatch};
 use crate::ext::tt::quoted;
-use crate::mut_visit::noop_visit_tt;
+use crate::mut_visit::{self, MutVisitor};
 use crate::parse::token::{self, NtTT, Token};
 use crate::tokenstream::{DelimSpan, TokenStream, TokenTree, TreeAndJoint};
 
@@ -11,8 +10,31 @@ use smallvec::{smallvec, SmallVec};
 
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::sync::Lrc;
+use syntax_pos::hygiene::{ExpnId, Transparency};
+use syntax_pos::Span;
+
 use std::mem;
 
+// A Marker adds the given mark to the syntax context.
+struct Marker(ExpnId, Transparency);
+
+impl MutVisitor for Marker {
+    fn visit_span(&mut self, span: &mut Span) {
+        *span = span.apply_mark(self.0, self.1)
+    }
+
+    fn visit_mac(&mut self, mac: &mut Mac) {
+        mut_visit::noop_visit_mac(mac, self)
+    }
+}
+
+impl Marker {
+    fn visit_delim_span(&mut self, dspan: &mut DelimSpan) {
+        self.visit_span(&mut dspan.open);
+        self.visit_span(&mut dspan.close);
+    }
+}
+
 /// An iterator over the token trees in a delimited token tree (`{ ... }`) or a sequence (`$(...)`).
 enum Frame {
     Delimited { forest: Lrc<quoted::Delimited>, idx: usize, span: DelimSpan },
@@ -68,6 +90,7 @@ pub(super) fn transcribe(
     cx: &ExtCtxt<'_>,
     interp: &FxHashMap<Ident, NamedMatch>,
     src: Vec<quoted::TokenTree>,
+    transparency: Transparency,
 ) -> TokenStream {
     // Nothing for us to transcribe...
     if src.is_empty() {
@@ -96,6 +119,7 @@ pub(super) fn transcribe(
     // again, and we are done transcribing.
     let mut result: Vec<TreeAndJoint> = Vec::new();
     let mut result_stack = Vec::new();
+    let mut marker = Marker(cx.current_expansion.id, transparency);
 
     loop {
         // Look at the last frame on the stack.
@@ -207,7 +231,7 @@ pub(super) fn transcribe(
             }
 
             // Replace the meta-var with the matched token tree from the invocation.
-            quoted::TokenTree::MetaVar(mut sp, ident) => {
+            quoted::TokenTree::MetaVar(mut sp, mut ident) => {
                 // Find the matched nonterminal from the macro invocation, and use it to replace
                 // the meta-var.
                 if let Some(cur_matched) = lookup_cur_matched(ident, interp, &repeats) {
@@ -218,7 +242,7 @@ pub(super) fn transcribe(
                         if let NtTT(ref tt) = **nt {
                             result.push(tt.clone().into());
                         } else {
-                            sp = sp.apply_mark(cx.current_expansion.id);
+                            marker.visit_span(&mut sp);
                             let token = TokenTree::token(token::Interpolated(nt.clone()), sp);
                             result.push(token.into());
                         }
@@ -232,9 +256,8 @@ pub(super) fn transcribe(
                 } else {
                     // If we aren't able to match the meta-var, we push it back into the result but
                     // with modified syntax context. (I believe this supports nested macros).
-                    let ident =
-                        Ident::new(ident.name, ident.span.apply_mark(cx.current_expansion.id));
-                    sp = sp.apply_mark(cx.current_expansion.id);
+                    marker.visit_span(&mut sp);
+                    marker.visit_ident(&mut ident);
                     result.push(TokenTree::token(token::Dollar, sp).into());
                     result.push(TokenTree::Token(Token::from_ast_ident(ident)).into());
                 }
@@ -246,7 +269,7 @@ pub(super) fn transcribe(
             // jump back out of the Delimited, pop the result_stack and add the new results back to
             // the previous results (from outside the Delimited).
             quoted::TokenTree::Delimited(mut span, delimited) => {
-                span = span.apply_mark(cx.current_expansion.id);
+                marker.visit_delim_span(&mut span);
                 stack.push(Frame::Delimited { forest: delimited, idx: 0, span });
                 result_stack.push(mem::take(&mut result));
             }
@@ -254,9 +277,8 @@ pub(super) fn transcribe(
             // Nothing much to do here. Just push the token to the result, being careful to
             // preserve syntax context.
             quoted::TokenTree::Token(token) => {
-                let mut marker = Marker(cx.current_expansion.id);
                 let mut tt = TokenTree::Token(token);
-                noop_visit_tt(&mut tt, &mut marker);
+                marker.visit_tt(&mut tt);
                 result.push(tt.into());
             }