Auto merge of #47748 - alexcrichton:rollup, r=alexcrichton

Rollup of 19 pull requests

- Successful merges: #47415, #47437, #47439, #47453, #47460, #47502, #47529, #47600, #47607, #47618, #47626, #47656, #47668, #47696, #47701, #47705, #47710, #47711, #47719
- Failed merges: #47455, #47521

16 files changed, 158 insertions, 167 deletions

diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index d6e26057ea8..73810b3fe81 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -34,6 +34,18 @@ use std::rc::Rc;
 use std::u32;
 
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Copy)]
+pub struct Label {
+    pub ident: Ident,
+    pub span: Span,
+}
+
+impl fmt::Debug for Label {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "label({:?})", self.ident)
+    }
+}
+
+#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Copy)]
 pub struct Lifetime {
     pub id: NodeId,
     pub span: Span,
@@ -1078,23 +1090,23 @@ pub enum ExprKind {
     /// A while loop, with an optional label
     ///
     /// `'label: while expr { block }`
-    While(P<Expr>, P<Block>, Option<SpannedIdent>),
+    While(P<Expr>, P<Block>, Option<Label>),
     /// A while-let loop, with an optional label
     ///
     /// `'label: while let pat = expr { block }`
     ///
     /// This is desugared to a combination of `loop` and `match` expressions.
-    WhileLet(P<Pat>, P<Expr>, P<Block>, Option<SpannedIdent>),
+    WhileLet(P<Pat>, P<Expr>, P<Block>, Option<Label>),
     /// A for loop, with an optional label
     ///
     /// `'label: for pat in expr { block }`
     ///
     /// This is desugared to a combination of `loop` and `match` expressions.
-    ForLoop(P<Pat>, P<Expr>, P<Block>, Option<SpannedIdent>),
+    ForLoop(P<Pat>, P<Expr>, P<Block>, Option<Label>),
     /// Conditionless loop (can be exited with break, continue, or return)
     ///
     /// `'label: loop { block }`
-    Loop(P<Block>, Option<SpannedIdent>),
+    Loop(P<Block>, Option<Label>),
     /// A `match` block.
     Match(P<Expr>, Vec<Arm>),
     /// A closure (for example, `move |a, b, c| a + b + c`)
@@ -1133,9 +1145,9 @@ pub enum ExprKind {
     /// A referencing operation (`&a` or `&mut a`)
     AddrOf(Mutability, P<Expr>),
     /// A `break`, with an optional label to break, and an optional expression
-    Break(Option<SpannedIdent>, Option<P<Expr>>),
+    Break(Option<Label>, Option<P<Expr>>),
     /// A `continue`, with an optional label
-    Continue(Option<SpannedIdent>),
+    Continue(Option<Label>),
     /// A `return`, with an optional value to be returned
     Ret(Option<P<Expr>>),
 
diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs
index 612d8501fb2..025aa94ce06 100644
--- a/src/libsyntax/ext/base.rs
+++ b/src/libsyntax/ext/base.rs
@@ -786,7 +786,7 @@ impl<'a> ExtCtxt<'a> {
     ///   substitute; we never hit resolve/type-checking so the dummy
     ///   value doesn't have to match anything)
     pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
-        panic!(self.parse_sess.span_diagnostic.span_fatal(sp, msg));
+        self.parse_sess.span_diagnostic.span_fatal(sp, msg).raise();
     }
 
     /// Emit `msg` attached to `sp`, without immediately stopping
diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs
index 11988a8f89d..44a073545a7 100644
--- a/src/libsyntax/ext/expand.rs
+++ b/src/libsyntax/ext/expand.rs
@@ -455,7 +455,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
                 suggested_limit));
             err.emit();
             self.cx.trace_macros_diag();
-            panic!(FatalError);
+            FatalError.raise();
         }
 
         Some(result)
diff --git a/src/libsyntax/ext/source_util.rs b/src/libsyntax/ext/source_util.rs
index 6b08448107a..ec4e6ced1b2 100644
--- a/src/libsyntax/ext/source_util.rs
+++ b/src/libsyntax/ext/source_util.rs
@@ -116,9 +116,10 @@ pub fn expand_include<'cx>(cx: &'cx mut ExtCtxt, sp: Span, tts: &[tokenstream::T
             while self.p.token != token::Eof {
                 match panictry!(self.p.parse_item()) {
                     Some(item) => ret.push(item),
-                    None => panic!(self.p.diagnostic().span_fatal(self.p.span,
+                    None => self.p.diagnostic().span_fatal(self.p.span,
                                                            &format!("expected item, found `{}`",
-                                                                    self.p.this_token_to_string())))
+                                                                    self.p.this_token_to_string()))
+                                               .raise()
                 }
             }
             Some(ret)
diff --git a/src/libsyntax/ext/tt/macro_parser.rs b/src/libsyntax/ext/tt/macro_parser.rs
index 124477620c2..3e3c1618fff 100644
--- a/src/libsyntax/ext/tt/macro_parser.rs
+++ b/src/libsyntax/ext/tt/macro_parser.rs
@@ -573,7 +573,7 @@ fn parse_nt<'a>(p: &mut Parser<'a>, sp: Span, name: &str) -> Nonterminal {
             Some(i) => token::NtItem(i),
             None => {
                 p.fatal("expected an item keyword").emit();
-                panic!(FatalError);
+                FatalError.raise();
             }
         },
         "block" => token::NtBlock(panictry!(p.parse_block())),
@@ -581,7 +581,7 @@ fn parse_nt<'a>(p: &mut Parser<'a>, sp: Span, name: &str) -> Nonterminal {
             Some(s) => token::NtStmt(s),
             None => {
                 p.fatal("expected a statement").emit();
-                panic!(FatalError);
+                FatalError.raise();
             }
         },
         "pat" => token::NtPat(panictry!(p.parse_pat())),
@@ -597,7 +597,7 @@ fn parse_nt<'a>(p: &mut Parser<'a>, sp: Span, name: &str) -> Nonterminal {
                 let token_str = pprust::token_to_string(&p.token);
                 p.fatal(&format!("expected ident, found {}",
                                  &token_str[..])).emit();
-                panic!(FatalError)
+                FatalError.raise()
             }
         },
         "path" => token::NtPath(panictry!(p.parse_path_common(PathStyle::Type, false))),
diff --git a/src/libsyntax/ext/tt/macro_rules.rs b/src/libsyntax/ext/tt/macro_rules.rs
index d86603e94e9..9efb4faa635 100644
--- a/src/libsyntax/ext/tt/macro_rules.rs
+++ b/src/libsyntax/ext/tt/macro_rules.rs
@@ -222,10 +222,10 @@ pub fn compile(sess: &ParseSess, features: &RefCell<Features>, def: &ast::Item)
         Success(m) => m,
         Failure(sp, tok) => {
             let s = parse_failure_msg(tok);
-            panic!(sess.span_diagnostic.span_fatal(sp.substitute_dummy(def.span), &s));
+            sess.span_diagnostic.span_fatal(sp.substitute_dummy(def.span), &s).raise();
         }
         Error(sp, s) => {
-            panic!(sess.span_diagnostic.span_fatal(sp.substitute_dummy(def.span), &s));
+            sess.span_diagnostic.span_fatal(sp.substitute_dummy(def.span), &s).raise();
         }
     };
 
diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs
index 5a7b53153fd..8512e215ca7 100644
--- a/src/libsyntax/feature_gate.rs
+++ b/src/libsyntax/feature_gate.rs
@@ -1954,7 +1954,7 @@ impl FeatureChecker {
                 .span_note(ca_span, "`#![feature(custom_attribute)]` declared here")
                 .emit();
 
-            panic!(FatalError);
+            FatalError.raise();
         }
 
         if let (Some(span), None) = (self.copy_closures, self.clone_closures) {
@@ -1963,7 +1963,7 @@ impl FeatureChecker {
                   .span_note(span, "`#![feature(copy_closures)]` declared here")
                   .emit();
 
-            panic!(FatalError);
+            FatalError.raise();
         }
     }
 }
diff --git a/src/libsyntax/fold.rs b/src/libsyntax/fold.rs
index 1e605ba3ecd..0f8fe57e380 100644
--- a/src/libsyntax/fold.rs
+++ b/src/libsyntax/fold.rs
@@ -193,6 +193,10 @@ pub trait Folder : Sized {
         noop_fold_macro_def(def, self)
     }
 
+    fn fold_label(&mut self, label: Label) -> Label {
+        noop_fold_label(label, self)
+    }
+
     fn fold_lifetime(&mut self, l: Lifetime) -> Lifetime {
         noop_fold_lifetime(l, self)
     }
@@ -696,6 +700,13 @@ pub fn noop_fold_generic_params<T: Folder>(
     params.move_map(|p| fld.fold_generic_param(p))
 }
 
+pub fn noop_fold_label<T: Folder>(label: Label, fld: &mut T) -> Label {
+    Label {
+        ident: fld.fold_ident(label.ident),
+        span: fld.new_span(label.span),
+    }
+}
+
 pub fn noop_fold_lifetime<T: Folder>(l: Lifetime, fld: &mut T) -> Lifetime {
     Lifetime {
         id: fld.new_id(l.id),
@@ -1206,30 +1217,26 @@ pub fn noop_fold_expr<T: Folder>(Expr {id, node, span, attrs}: Expr, folder: &mu
                           folder.fold_block(tr),
                           fl.map(|x| folder.fold_expr(x)))
             }
-            ExprKind::While(cond, body, opt_ident) => {
+            ExprKind::While(cond, body, opt_label) => {
                 ExprKind::While(folder.fold_expr(cond),
                           folder.fold_block(body),
-                          opt_ident.map(|label| respan(folder.new_span(label.span),
-                                                       folder.fold_ident(label.node))))
+                          opt_label.map(|label| folder.fold_label(label)))
             }
-            ExprKind::WhileLet(pat, expr, body, opt_ident) => {
+            ExprKind::WhileLet(pat, expr, body, opt_label) => {
                 ExprKind::WhileLet(folder.fold_pat(pat),
                              folder.fold_expr(expr),
                              folder.fold_block(body),
-                             opt_ident.map(|label| respan(folder.new_span(label.span),
-                                                          folder.fold_ident(label.node))))
+                             opt_label.map(|label| folder.fold_label(label)))
             }
-            ExprKind::ForLoop(pat, iter, body, opt_ident) => {
+            ExprKind::ForLoop(pat, iter, body, opt_label) => {
                 ExprKind::ForLoop(folder.fold_pat(pat),
                             folder.fold_expr(iter),
                             folder.fold_block(body),
-                            opt_ident.map(|label| respan(folder.new_span(label.span),
-                                                         folder.fold_ident(label.node))))
+                            opt_label.map(|label| folder.fold_label(label)))
             }
-            ExprKind::Loop(body, opt_ident) => {
+            ExprKind::Loop(body, opt_label) => {
                 ExprKind::Loop(folder.fold_block(body),
-                               opt_ident.map(|label| respan(folder.new_span(label.span),
-                                                            folder.fold_ident(label.node))))
+                               opt_label.map(|label| folder.fold_label(label)))
             }
             ExprKind::Match(expr, arms) => {
                 ExprKind::Match(folder.fold_expr(expr),
@@ -1278,15 +1285,13 @@ pub fn noop_fold_expr<T: Folder>(Expr {id, node, span, attrs}: Expr, folder: &mu
                 });
                 ExprKind::Path(qself, folder.fold_path(path))
             }
-            ExprKind::Break(opt_ident, opt_expr) => {
-                ExprKind::Break(opt_ident.map(|label| respan(folder.new_span(label.span),
-                                                             folder.fold_ident(label.node))),
+            ExprKind::Break(opt_label, opt_expr) => {
+                ExprKind::Break(opt_label.map(|label| folder.fold_label(label)),
                                 opt_expr.map(|e| folder.fold_expr(e)))
             }
-            ExprKind::Continue(opt_ident) => ExprKind::Continue(opt_ident.map(|label|
-                respan(folder.new_span(label.span),
-                       folder.fold_ident(label.node)))
-            ),
+            ExprKind::Continue(opt_label) => {
+                ExprKind::Continue(opt_label.map(|label| folder.fold_label(label)))
+            }
             ExprKind::Ret(e) => ExprKind::Ret(e.map(|x| folder.fold_expr(x))),
             ExprKind::InlineAsm(asm) => ExprKind::InlineAsm(asm.map(|asm| {
                 InlineAsm {
diff --git a/src/libsyntax/lib.rs b/src/libsyntax/lib.rs
index d7f7ff554db..3b4c5da10f2 100644
--- a/src/libsyntax/lib.rs
+++ b/src/libsyntax/lib.rs
@@ -54,7 +54,7 @@ macro_rules! panictry {
             Ok(e) => e,
             Err(mut e) => {
                 e.emit();
-                panic!(FatalError);
+                FatalError.raise()
             }
         }
     })
diff --git a/src/libsyntax/parse/lexer/comments.rs b/src/libsyntax/parse/lexer/comments.rs
index 49362f07799..63aa5d28ce8 100644
--- a/src/libsyntax/parse/lexer/comments.rs
+++ b/src/libsyntax/parse/lexer/comments.rs
@@ -265,7 +265,7 @@ fn read_block_comment(rdr: &mut StringReader,
         while level > 0 {
             debug!("=== block comment level {}", level);
             if rdr.is_eof() {
-                panic!(rdr.fatal("unterminated block comment"));
+                rdr.fatal("unterminated block comment").raise();
             }
             if rdr.ch_is('\n') {
                 trim_whitespace_prefix_and_push_line(&mut lines, curr_line, col);
diff --git a/src/libsyntax/parse/lexer/mod.rs b/src/libsyntax/parse/lexer/mod.rs
index 9828995362a..b95c91548d0 100644
--- a/src/libsyntax/parse/lexer/mod.rs
+++ b/src/libsyntax/parse/lexer/mod.rs
@@ -90,7 +90,7 @@ impl<'a> StringReader<'a> {
             Ok(tok) => tok,
             Err(_) => {
                 self.emit_fatal_errors();
-                panic!(FatalError);
+                FatalError.raise();
             }
         }
     }
@@ -191,7 +191,7 @@ impl<'a> StringReader<'a> {
         let mut sr = StringReader::new_raw(sess, filemap);
         if sr.advance_token().is_err() {
             sr.emit_fatal_errors();
-            panic!(FatalError);
+            FatalError.raise();
         }
         sr
     }
@@ -216,7 +216,7 @@ impl<'a> StringReader<'a> {
 
         if sr.advance_token().is_err() {
             sr.emit_fatal_errors();
-            panic!(FatalError);
+            FatalError.raise();
         }
         sr
     }
@@ -647,7 +647,7 @@ impl<'a> StringReader<'a> {
                     "unterminated block comment"
                 };
                 let last_bpos = self.pos;
-                panic!(self.fatal_span_(start_bpos, last_bpos, msg));
+                self.fatal_span_(start_bpos, last_bpos, msg).raise();
             }
             let n = self.ch.unwrap();
             match n {
@@ -808,9 +808,9 @@ impl<'a> StringReader<'a> {
         for _ in 0..n_digits {
             if self.is_eof() {
                 let last_bpos = self.pos;
-                panic!(self.fatal_span_(start_bpos,
-                                        last_bpos,
-                                        "unterminated numeric character escape"));
+                self.fatal_span_(start_bpos,
+                                 last_bpos,
+                                 "unterminated numeric character escape").raise();
             }
             if self.ch_is(delim) {
                 let last_bpos = self.pos;
@@ -1025,9 +1025,9 @@ impl<'a> StringReader<'a> {
                     }
                 },
                 None => {
-                    panic!(self.fatal_span_(start_bpos,
-                                            self.pos,
-                                            "unterminated unicode escape (found EOF)"));
+                    self.fatal_span_(start_bpos,
+                                     self.pos,
+                                     "unterminated unicode escape (found EOF)").raise();
                 }
             }
             self.bump();
@@ -1283,9 +1283,9 @@ impl<'a> StringReader<'a> {
                     // lifetimes shouldn't end with a single quote
                     // if we find one, then this is an invalid character literal
                     if self.ch_is('\'') {
-                        panic!(self.fatal_span_verbose(
-                               start_with_quote, self.next_pos,
-                               String::from("character literal may only contain one codepoint")));
+                        self.fatal_span_verbose(start_with_quote, self.next_pos,
+                                String::from("character literal may only contain one codepoint"))
+                            .raise();
 
                     }
 
@@ -1332,9 +1332,8 @@ impl<'a> StringReader<'a> {
                             break;
                         }
                     }
-                    panic!(self.fatal_span_verbose(
-                           start_with_quote, pos,
-                           String::from("character literal may only contain one codepoint")));
+                    self.fatal_span_verbose(start_with_quote, pos,
+                        String::from("character literal may only contain one codepoint")).raise();
                 }
 
                 let id = if valid {
@@ -1364,9 +1363,9 @@ impl<'a> StringReader<'a> {
                 while !self.ch_is('"') {
                     if self.is_eof() {
                         let last_bpos = self.pos;
-                        panic!(self.fatal_span_(start_bpos,
-                                                last_bpos,
-                                                "unterminated double quote string"));
+                        self.fatal_span_(start_bpos,
+                                         last_bpos,
+                                         "unterminated double quote string").raise();
                     }
 
                     let ch_start = self.pos;
@@ -1399,15 +1398,15 @@ impl<'a> StringReader<'a> {
 
                 if self.is_eof() {
                     let last_bpos = self.pos;
-                    panic!(self.fatal_span_(start_bpos, last_bpos, "unterminated raw string"));
+                    self.fatal_span_(start_bpos, last_bpos, "unterminated raw string").raise();
                 } else if !self.ch_is('"') {
                     let last_bpos = self.pos;
                     let curr_char = self.ch.unwrap();
-                    panic!(self.fatal_span_char(start_bpos,
-                                                last_bpos,
-                                                "found invalid character; only `#` is allowed \
-                                                 in raw string delimitation",
-                                                curr_char));
+                    self.fatal_span_char(start_bpos,
+                                         last_bpos,
+                                         "found invalid character; only `#` is allowed \
+                                         in raw string delimitation",
+                                         curr_char).raise();
                 }
                 self.bump();
                 let content_start_bpos = self.pos;
@@ -1416,7 +1415,7 @@ impl<'a> StringReader<'a> {
                 'outer: loop {
                     if self.is_eof() {
                         let last_bpos = self.pos;
-                        panic!(self.fatal_span_(start_bpos, last_bpos, "unterminated raw string"));
+                        self.fatal_span_(start_bpos, last_bpos, "unterminated raw string").raise();
                     }
                     // if self.ch_is('"') {
                     // content_end_bpos = self.pos;
@@ -1573,9 +1572,9 @@ impl<'a> StringReader<'a> {
             // character before position `start` are an
             // ascii single quote and ascii 'b'.
             let pos = self.pos;
-            panic!(self.fatal_span_verbose(start - BytePos(2),
-                                           pos,
-                                           "unterminated byte constant".to_string()));
+            self.fatal_span_verbose(start - BytePos(2),
+                                    pos,
+                                    "unterminated byte constant".to_string()).raise();
         }
 
         let id = if valid {
@@ -1599,7 +1598,7 @@ impl<'a> StringReader<'a> {
         while !self.ch_is('"') {
             if self.is_eof() {
                 let pos = self.pos;
-                panic!(self.fatal_span_(start, pos, "unterminated double quote byte string"));
+                self.fatal_span_(start, pos, "unterminated double quote byte string").raise();
             }
 
             let ch_start = self.pos;
@@ -1631,15 +1630,15 @@ impl<'a> StringReader<'a> {
 
         if self.is_eof() {
             let pos = self.pos;
-            panic!(self.fatal_span_(start_bpos, pos, "unterminated raw string"));
+            self.fatal_span_(start_bpos, pos, "unterminated raw string").raise();
         } else if !self.ch_is('"') {
             let pos = self.pos;
             let ch = self.ch.unwrap();
-            panic!(self.fatal_span_char(start_bpos,
+            self.fatal_span_char(start_bpos,
                                         pos,
                                         "found invalid character; only `#` is allowed in raw \
                                          string delimitation",
-                                        ch));
+                                        ch).raise();
         }
         self.bump();
         let content_start_bpos = self.pos;
@@ -1648,7 +1647,7 @@ impl<'a> StringReader<'a> {
             match self.ch {
                 None => {
                     let pos = self.pos;
-                    panic!(self.fatal_span_(start_bpos, pos, "unterminated raw string"))
+                    self.fatal_span_(start_bpos, pos, "unterminated raw string").raise()
                 }
                 Some('"') => {
                     content_end_bpos = self.pos;
diff --git a/src/libsyntax/parse/mod.rs b/src/libsyntax/parse/mod.rs
index a9b1e4aaa60..b671f81c2a8 100644
--- a/src/libsyntax/parse/mod.rs
+++ b/src/libsyntax/parse/mod.rs
@@ -212,8 +212,8 @@ fn file_to_filemap(sess: &ParseSess, path: &Path, spanopt: Option<Span>)
         Err(e) => {
             let msg = format!("couldn't read {:?}: {}", path.display(), e);
             match spanopt {
-                Some(sp) => panic!(sess.span_diagnostic.span_fatal(sp, &msg)),
-                None => panic!(sess.span_diagnostic.fatal(&msg))
+                Some(sp) => sess.span_diagnostic.span_fatal(sp, &msg).raise(),
+                None => sess.span_diagnostic.fatal(&msg).raise()
             }
         }
     }
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 8213d604b91..d393cab4718 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -23,7 +23,7 @@ use ast::{Field, FnDecl};
 use ast::{ForeignItem, ForeignItemKind, FunctionRetTy};
 use ast::GenericParam;
 use ast::{Ident, ImplItem, IsAuto, Item, ItemKind};
-use ast::{Lifetime, LifetimeDef, Lit, LitKind, UintTy};
+use ast::{Label, Lifetime, LifetimeDef, Lit, LitKind, UintTy};
 use ast::Local;
 use ast::MacStmtStyle;
 use ast::Mac_;
@@ -1325,15 +1325,17 @@ impl<'a> Parser<'a> {
             self.check_keyword(keywords::Extern)
     }
 
-    fn get_label(&mut self) -> ast::Ident {
-        match self.token {
+    fn eat_label(&mut self) -> Option<Label> {
+        let ident = match self.token {
             token::Lifetime(ref ident) => *ident,
             token::Interpolated(ref nt) => match nt.0 {
                 token::NtLifetime(lifetime) => lifetime.ident,
-                _ => self.bug("not a lifetime"),
+                _ => return None,
             },
-            _ => self.bug("not a lifetime"),
-        }
+            _ => return None,
+        };
+        self.bump();
+        Some(Label { ident, span: self.prev_span })
     }
 
     /// parse a TyKind::BareFn type:
@@ -2317,11 +2319,8 @@ impl<'a> Parser<'a> {
                     let lo = self.prev_span;
                     return self.parse_while_expr(None, lo, attrs);
                 }
-                if self.token.is_lifetime() {
-                    let label = Spanned { node: self.get_label(),
-                                          span: self.span };
-                    let lo = self.span;
-                    self.bump();
+                if let Some(label) = self.eat_label() {
+                    let lo = label.span;
                     self.expect(&token::Colon)?;
                     if self.eat_keyword(keywords::While) {
                         return self.parse_while_expr(Some(label), lo, attrs)
@@ -2339,16 +2338,8 @@ impl<'a> Parser<'a> {
                     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_label(),
-                            span: self.span
-                        }));
-                        self.bump();
-                        ex
-                    } else {
-                        ExprKind::Continue(None)
-                    };
+                    let label = self.eat_label();
+                    let ex = ExprKind::Continue(label);
                     let hi = self.prev_span;
                     return Ok(self.mk_expr(lo.to(hi), ex, attrs));
                 }
@@ -2376,16 +2367,7 @@ impl<'a> Parser<'a> {
                         ex = ExprKind::Ret(None);
                     }
                 } else if self.eat_keyword(keywords::Break) {
-                    let lt = if self.token.is_lifetime() {
-                        let spanned_lt = Spanned {
-                            node: self.get_label(),
-                            span: self.span
-                        };
-                        self.bump();
-                        Some(spanned_lt)
-                    } else {
-                        None
-                    };
+                    let label = self.eat_label();
                     let e = if self.token.can_begin_expr()
                                && !(self.token == token::OpenDelim(token::Brace)
                                     && self.restrictions.contains(
@@ -2394,7 +2376,7 @@ impl<'a> Parser<'a> {
                     } else {
                         None
                     };
-                    ex = ExprKind::Break(lt, e);
+                    ex = ExprKind::Break(label, e);
                     hi = self.prev_span;
                 } else if self.eat_keyword(keywords::Yield) {
                     if self.token.can_begin_expr() {
@@ -3291,7 +3273,7 @@ impl<'a> Parser<'a> {
     }
 
     /// Parse a 'for' .. 'in' expression ('for' token already eaten)
-    pub fn parse_for_expr(&mut self, opt_ident: Option<ast::SpannedIdent>,
+    pub fn parse_for_expr(&mut self, opt_label: Option<Label>,
                           span_lo: Span,
                           mut attrs: ThinVec<Attribute>) -> PResult<'a, P<Expr>> {
         // Parse: `for <src_pat> in <src_expr> <src_loop_block>`
@@ -3309,25 +3291,25 @@ impl<'a> Parser<'a> {
         attrs.extend(iattrs);
 
         let hi = self.prev_span;
-        Ok(self.mk_expr(span_lo.to(hi), ExprKind::ForLoop(pat, expr, loop_block, opt_ident), attrs))
+        Ok(self.mk_expr(span_lo.to(hi), ExprKind::ForLoop(pat, expr, loop_block, opt_label), attrs))
     }
 
     /// Parse a 'while' or 'while let' expression ('while' token already eaten)
-    pub fn parse_while_expr(&mut self, opt_ident: Option<ast::SpannedIdent>,
+    pub fn parse_while_expr(&mut self, opt_label: Option<Label>,
                             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);
+            return self.parse_while_let_expr(opt_label, span_lo, attrs);
         }
         let cond = self.parse_expr_res(Restrictions::NO_STRUCT_LITERAL, None)?;
         let (iattrs, body) = self.parse_inner_attrs_and_block()?;
         attrs.extend(iattrs);
         let span = span_lo.to(body.span);
-        return Ok(self.mk_expr(span, ExprKind::While(cond, body, opt_ident), attrs));
+        return Ok(self.mk_expr(span, ExprKind::While(cond, body, opt_label), attrs));
     }
 
     /// Parse a 'while let' expression ('while' token already eaten)
-    pub fn parse_while_let_expr(&mut self, opt_ident: Option<ast::SpannedIdent>,
+    pub fn parse_while_let_expr(&mut self, opt_label: Option<Label>,
                                 span_lo: Span,
                                 mut attrs: ThinVec<Attribute>) -> PResult<'a, P<Expr>> {
         self.expect_keyword(keywords::Let)?;
@@ -3337,17 +3319,17 @@ impl<'a> Parser<'a> {
         let (iattrs, body) = self.parse_inner_attrs_and_block()?;
         attrs.extend(iattrs);
         let span = span_lo.to(body.span);
-        return Ok(self.mk_expr(span, ExprKind::WhileLet(pat, expr, body, opt_ident), attrs));
+        return Ok(self.mk_expr(span, ExprKind::WhileLet(pat, expr, body, opt_label), attrs));
     }
 
     // parse `loop {...}`, `loop` token already eaten
-    pub fn parse_loop_expr(&mut self, opt_ident: Option<ast::SpannedIdent>,
+    pub fn parse_loop_expr(&mut self, opt_label: Option<Label>,
                            span_lo: Span,
                            mut attrs: ThinVec<Attribute>) -> PResult<'a, P<Expr>> {
         let (iattrs, body) = self.parse_inner_attrs_and_block()?;
         attrs.extend(iattrs);
         let span = span_lo.to(body.span);
-        Ok(self.mk_expr(span, ExprKind::Loop(body, opt_ident), attrs))
+        Ok(self.mk_expr(span, ExprKind::Loop(body, opt_label), attrs))
     }
 
     /// Parse a `do catch {...}` expression (`do catch` token already eaten)
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index 345c592a011..ae459c668aa 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -2104,9 +2104,9 @@ impl<'a> State<'a> {
             ast::ExprKind::IfLet(ref pat, ref expr, ref blk, ref elseopt) => {
                 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 {
-                    self.print_ident(ident.node)?;
+            ast::ExprKind::While(ref test, ref blk, opt_label) => {
+                if let Some(label) = opt_label {
+                    self.print_ident(label.ident)?;
                     self.word_space(":")?;
                 }
                 self.head("while")?;
@@ -2114,9 +2114,9 @@ impl<'a> State<'a> {
                 self.s.space()?;
                 self.print_block_with_attrs(blk, attrs)?;
             }
-            ast::ExprKind::WhileLet(ref pat, ref expr, ref blk, opt_ident) => {
-                if let Some(ident) = opt_ident {
-                    self.print_ident(ident.node)?;
+            ast::ExprKind::WhileLet(ref pat, ref expr, ref blk, opt_label) => {
+                if let Some(label) = opt_label {
+                    self.print_ident(label.ident)?;
                     self.word_space(":")?;
                 }
                 self.head("while let")?;
@@ -2127,9 +2127,9 @@ impl<'a> State<'a> {
                 self.s.space()?;
                 self.print_block_with_attrs(blk, attrs)?;
             }
-            ast::ExprKind::ForLoop(ref pat, ref iter, ref blk, opt_ident) => {
-                if let Some(ident) = opt_ident {
-                    self.print_ident(ident.node)?;
+            ast::ExprKind::ForLoop(ref pat, ref iter, ref blk, opt_label) => {
+                if let Some(label) = opt_label {
+                    self.print_ident(label.ident)?;
                     self.word_space(":")?;
                 }
                 self.head("for")?;
@@ -2140,9 +2140,9 @@ impl<'a> State<'a> {
                 self.s.space()?;
                 self.print_block_with_attrs(blk, attrs)?;
             }
-            ast::ExprKind::Loop(ref blk, opt_ident) => {
-                if let Some(ident) = opt_ident {
-                    self.print_ident(ident.node)?;
+            ast::ExprKind::Loop(ref blk, opt_label) => {
+                if let Some(label) = opt_label {
+                    self.print_ident(label.ident)?;
                     self.word_space(":")?;
                 }
                 self.head("loop")?;
@@ -2238,11 +2238,11 @@ impl<'a> State<'a> {
             ast::ExprKind::Path(Some(ref qself), ref path) => {
                 self.print_qpath(path, qself, true)?
             }
-            ast::ExprKind::Break(opt_ident, ref opt_expr) => {
+            ast::ExprKind::Break(opt_label, ref opt_expr) => {
                 self.s.word("break")?;
                 self.s.space()?;
-                if let Some(ident) = opt_ident {
-                    self.print_ident(ident.node)?;
+                if let Some(label) = opt_label {
+                    self.print_ident(label.ident)?;
                     self.s.space()?;
                 }
                 if let Some(ref expr) = *opt_expr {
@@ -2250,11 +2250,11 @@ impl<'a> State<'a> {
                     self.s.space()?;
                 }
             }
-            ast::ExprKind::Continue(opt_ident) => {
+            ast::ExprKind::Continue(opt_label) => {
                 self.s.word("continue")?;
                 self.s.space()?;
-                if let Some(ident) = opt_ident {
-                    self.print_ident(ident.node)?;
+                if let Some(label) = opt_label {
+                    self.print_ident(label.ident)?;
                     self.s.space()?
                 }
             }
diff --git a/src/libsyntax/test.rs b/src/libsyntax/test.rs
index eff7dd57f08..e73550d0719 100644
--- a/src/libsyntax/test.rs
+++ b/src/libsyntax/test.rs
@@ -123,7 +123,7 @@ impl<'a> fold::Folder for TestHarnessGenerator<'a> {
             match i.node {
                 ast::ItemKind::Fn(_, ast::Unsafety::Unsafe, _, _, _, _) => {
                     let diag = self.cx.span_diagnostic;
-                    panic!(diag.span_fatal(i.span, "unsafe functions cannot be used for tests"));
+                    diag.span_fatal(i.span, "unsafe functions cannot be used for tests").raise();
                 }
                 _ => {
                     debug!("this is a test function");
diff --git a/src/libsyntax/visit.rs b/src/libsyntax/visit.rs
index 8aeacf79cee..bbb123dab28 100644
--- a/src/libsyntax/visit.rs
+++ b/src/libsyntax/visit.rs
@@ -101,6 +101,9 @@ pub trait Visitor<'ast>: Sized {
     fn visit_variant(&mut self, v: &'ast Variant, g: &'ast Generics, item_id: NodeId) {
         walk_variant(self, v, g, item_id)
     }
+    fn visit_label(&mut self, label: &'ast Label) {
+        walk_label(self, label)
+    }
     fn visit_lifetime(&mut self, lifetime: &'ast Lifetime) {
         walk_lifetime(self, lifetime)
     }
@@ -163,25 +166,6 @@ macro_rules! walk_list {
     }
 }
 
-pub fn walk_opt_name<'a, V: Visitor<'a>>(visitor: &mut V, span: Span, opt_name: Option<Name>) {
-    if let Some(name) = opt_name {
-        visitor.visit_name(span, name);
-    }
-}
-
-pub fn walk_opt_ident<'a, V: Visitor<'a>>(visitor: &mut V, span: Span, opt_ident: Option<Ident>) {
-    if let Some(ident) = opt_ident {
-        visitor.visit_ident(span, ident);
-    }
-}
-
-pub fn walk_opt_sp_ident<'a, V: Visitor<'a>>(visitor: &mut V,
-                                             opt_sp_ident: &Option<Spanned<Ident>>) {
-    if let Some(ref sp_ident) = *opt_sp_ident {
-        visitor.visit_ident(sp_ident.span, sp_ident.node);
-    }
-}
-
 pub fn walk_ident<'a, V: Visitor<'a>>(visitor: &mut V, span: Span, ident: Ident) {
     visitor.visit_name(span, ident.name);
 }
@@ -204,6 +188,10 @@ pub fn walk_local<'a, V: Visitor<'a>>(visitor: &mut V, local: &'a Local) {
     walk_list!(visitor, visit_expr, &local.init);
 }
 
+pub fn walk_label<'a, V: Visitor<'a>>(visitor: &mut V, label: &'a Label) {
+    visitor.visit_ident(label.span, label.ident);
+}
+
 pub fn walk_lifetime<'a, V: Visitor<'a>>(visitor: &mut V, lifetime: &'a Lifetime) {
     visitor.visit_ident(lifetime.span, lifetime.ident);
 }
@@ -226,7 +214,9 @@ pub fn walk_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a Item) {
     visitor.visit_ident(item.span, item.ident);
     match item.node {
         ItemKind::ExternCrate(opt_name) => {
-            walk_opt_name(visitor, item.span, opt_name)
+            if let Some(name) = opt_name {
+                visitor.visit_name(item.span, name);
+            }
         }
         ItemKind::Use(ref use_tree) => {
             visitor.visit_use_tree(use_tree, item.id, false)
@@ -622,7 +612,9 @@ pub fn walk_struct_def<'a, V: Visitor<'a>>(visitor: &mut V, struct_definition: &
 
 pub fn walk_struct_field<'a, V: Visitor<'a>>(visitor: &mut V, struct_field: &'a StructField) {
     visitor.visit_vis(&struct_field.vis);
-    walk_opt_ident(visitor, struct_field.span, struct_field.ident);
+    if let Some(ident) = struct_field.ident {
+        visitor.visit_ident(struct_field.span, ident);
+    }
     visitor.visit_ty(&struct_field.ty);
     walk_list!(visitor, visit_attribute, &struct_field.attrs);
 }
@@ -708,10 +700,10 @@ pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) {
             visitor.visit_block(if_block);
             walk_list!(visitor, visit_expr, optional_else);
         }
-        ExprKind::While(ref subexpression, ref block, ref opt_sp_ident) => {
+        ExprKind::While(ref subexpression, ref block, ref opt_label) => {
+            walk_list!(visitor, visit_label, opt_label);
             visitor.visit_expr(subexpression);
             visitor.visit_block(block);
-            walk_opt_sp_ident(visitor, opt_sp_ident);
         }
         ExprKind::IfLet(ref pattern, ref subexpression, ref if_block, ref optional_else) => {
             visitor.visit_pat(pattern);
@@ -719,21 +711,21 @@ pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) {
             visitor.visit_block(if_block);
             walk_list!(visitor, visit_expr, optional_else);
         }
-        ExprKind::WhileLet(ref pattern, ref subexpression, ref block, ref opt_sp_ident) => {
+        ExprKind::WhileLet(ref pattern, ref subexpression, ref block, ref opt_label) => {
+            walk_list!(visitor, visit_label, opt_label);
             visitor.visit_pat(pattern);
             visitor.visit_expr(subexpression);
             visitor.visit_block(block);
-            walk_opt_sp_ident(visitor, opt_sp_ident);
         }
-        ExprKind::ForLoop(ref pattern, ref subexpression, ref block, ref opt_sp_ident) => {
+        ExprKind::ForLoop(ref pattern, ref subexpression, ref block, ref opt_label) => {
+            walk_list!(visitor, visit_label, opt_label);
             visitor.visit_pat(pattern);
             visitor.visit_expr(subexpression);
             visitor.visit_block(block);
-            walk_opt_sp_ident(visitor, opt_sp_ident);
         }
-        ExprKind::Loop(ref block, ref opt_sp_ident) => {
+        ExprKind::Loop(ref block, ref opt_label) => {
+            walk_list!(visitor, visit_label, opt_label);
             visitor.visit_block(block);
-            walk_opt_sp_ident(visitor, opt_sp_ident);
         }
         ExprKind::Match(ref subexpression, ref arms) => {
             visitor.visit_expr(subexpression);
@@ -775,12 +767,12 @@ pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) {
             }
             visitor.visit_path(path, expression.id)
         }
-        ExprKind::Break(ref opt_sp_ident, ref opt_expr) => {
-            walk_opt_sp_ident(visitor, opt_sp_ident);
+        ExprKind::Break(ref opt_label, ref opt_expr) => {
+            walk_list!(visitor, visit_label, opt_label);
             walk_list!(visitor, visit_expr, opt_expr);
         }
-        ExprKind::Continue(ref opt_sp_ident) => {
-            walk_opt_sp_ident(visitor, opt_sp_ident);
+        ExprKind::Continue(ref opt_label) => {
+            walk_list!(visitor, visit_label, opt_label);
         }
         ExprKind::Ret(ref optional_expression) => {
             walk_list!(visitor, visit_expr, optional_expression);