Don't use panicking helpers in Parser.

src/libsyntax/ext/asm.rs

@@ -79,7 +79,7 @@ pub fn expand_asm<'cx>(cx: &'cx mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
                     cx.span_err(sp, "malformed inline assembly");
                     return DummyResult::expr(sp);
                 }
-                let (s, style) = match expr_to_string(cx, p.parse_expr(),
+                let (s, style) = match expr_to_string(cx, panictry!(p.parse_expr_nopanic()),
                                                    "inline assembly must be a string literal") {
                     Some((s, st)) => (s, st),
                     // let compilation continue
@@ -102,7 +102,7 @@ pub fn expand_asm<'cx>(cx: &'cx mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
                     let span = p.last_span;
 
                     panictry!(p.expect(&token::OpenDelim(token::Paren)));
-                    let out = p.parse_expr();
+                    let out = panictry!(p.parse_expr_nopanic());
                     panictry!(p.expect(&token::CloseDelim(token::Paren)));
 
                     // Expands a read+write operand into two operands.
@@ -146,7 +146,7 @@ pub fn expand_asm<'cx>(cx: &'cx mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
                     }
 
                     panictry!(p.expect(&token::OpenDelim(token::Paren)));
-                    let input = p.parse_expr();
+                    let input = panictry!(p.parse_expr_nopanic());
                     panictry!(p.expect(&token::CloseDelim(token::Paren)));
 
                     inputs.push((constraint, input));

src/libsyntax/ext/base.rs

@@ -809,7 +809,7 @@ pub fn get_single_str_from_tts(cx: &mut ExtCtxt,
         cx.span_err(sp, &format!("{} takes 1 argument", name));
         return None
     }
-    let ret = cx.expander().fold_expr(p.parse_expr());
+    let ret = cx.expander().fold_expr(panictry!(p.parse_expr_nopanic()));
     if p.token != token::Eof {
         cx.span_err(sp, &format!("{} takes 1 argument", name));
     }
@@ -826,7 +826,7 @@ pub fn get_exprs_from_tts(cx: &mut ExtCtxt,
     let mut p = cx.new_parser_from_tts(tts);
     let mut es = Vec::new();
     while p.token != token::Eof {
-        es.push(cx.expander().fold_expr(p.parse_expr()));
+        es.push(cx.expander().fold_expr(panictry!(p.parse_expr_nopanic())));
         if panictry!(p.eat(&token::Comma)){
             continue;
         }

src/libsyntax/ext/format.rs

@@ -93,7 +93,7 @@ fn parse_args(ecx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
         ecx.span_err(sp, "requires at least a format string argument");
         return None;
     }
-    let fmtstr = p.parse_expr();
+    let fmtstr = panictry!(p.parse_expr_nopanic());
     let mut named = false;
     while p.token != token::Eof {
         if !panictry!(p.eat(&token::Comma)) {
@@ -124,7 +124,7 @@ fn parse_args(ecx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
             let name: &str = &ident.name.as_str();
 
             panictry!(p.expect(&token::Eq));
-            let e = p.parse_expr();
+            let e = panictry!(p.parse_expr_nopanic());
             match names.get(name) {
                 None => {}
                 Some(prev) => {
@@ -138,7 +138,7 @@ fn parse_args(ecx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
             order.push(name.to_string());
             names.insert(name.to_string(), e);
         } else {
-            args.push(p.parse_expr());
+            args.push(panictry!(p.parse_expr_nopanic()));
         }
     }
     Some((fmtstr, args, order, names))

src/libsyntax/ext/quote.rs

@@ -694,7 +694,7 @@ fn parse_arguments_to_quote(cx: &ExtCtxt, tts: &[ast::TokenTree])
     let mut p = cx.new_parser_from_tts(tts);
     p.quote_depth += 1;
 
-    let cx_expr = p.parse_expr();
+    let cx_expr = panictry!(p.parse_expr_nopanic());
     if !panictry!(p.eat(&token::Comma)) {
         panic!(p.fatal("expected token `,`"));
     }

src/libsyntax/ext/source_util.rs

@@ -109,13 +109,13 @@ pub fn expand_include<'cx>(cx: &'cx mut ExtCtxt, sp: Span, tts: &[ast::TokenTree
     }
     impl<'a> base::MacResult for ExpandResult<'a> {
         fn make_expr(mut self: Box<ExpandResult<'a>>) -> Option<P<ast::Expr>> {
-            Some(self.p.parse_expr())
+            Some(panictry!(self.p.parse_expr_nopanic()))
         }
         fn make_items(mut self: Box<ExpandResult<'a>>)
                       -> Option<SmallVector<P<ast::Item>>> {
             let mut ret = SmallVector::zero();
             while self.p.token != token::Eof {
-                match self.p.parse_item() {
+                match panictry!(self.p.parse_item_nopanic()) {
                     Some(item) => ret.push(item),
                     None => panic!(self.p.span_fatal(
                         self.p.span,

src/libsyntax/ext/tt/macro_parser.rs

@@ -503,18 +503,18 @@ pub fn parse_nt(p: &mut Parser, sp: Span, name: &str) -> Nonterminal {
     // check at the beginning and the parser checks after each bump
     panictry!(p.check_unknown_macro_variable());
     match name {
-        "item" => match p.parse_item() {
+        "item" => match panictry!(p.parse_item_nopanic()) {
             Some(i) => token::NtItem(i),
             None => panic!(p.fatal("expected an item keyword"))
         },
         "block" => token::NtBlock(panictry!(p.parse_block())),
-        "stmt" => match p.parse_stmt() {
+        "stmt" => match panictry!(p.parse_stmt_nopanic()) {
             Some(s) => token::NtStmt(s),
             None => panic!(p.fatal("expected a statement"))
         },
-        "pat" => token::NtPat(p.parse_pat()),
+        "pat" => token::NtPat(panictry!(p.parse_pat_nopanic())),
-        "expr" => token::NtExpr(p.parse_expr()),
+        "expr" => token::NtExpr(panictry!(p.parse_expr_nopanic())),
-        "ty" => token::NtTy(p.parse_ty()),
+        "ty" => token::NtTy(panictry!(p.parse_ty_nopanic())),
         // this could be handled like a token, since it is one
         "ident" => match p.token {
             token::Ident(sn,b) => { panictry!(p.bump()); token::NtIdent(Box::new(sn),b) }

src/libsyntax/ext/tt/macro_rules.rs

@@ -66,18 +66,18 @@ impl<'a> ParserAnyMacro<'a> {
 
 impl<'a> MacResult for ParserAnyMacro<'a> {
     fn make_expr(self: Box<ParserAnyMacro<'a>>) -> Option<P<ast::Expr>> {
-        let ret = self.parser.borrow_mut().parse_expr();
+        let ret = panictry!(self.parser.borrow_mut().parse_expr_nopanic());
         self.ensure_complete_parse(true);
         Some(ret)
     }
     fn make_pat(self: Box<ParserAnyMacro<'a>>) -> Option<P<ast::Pat>> {
-        let ret = self.parser.borrow_mut().parse_pat();
+        let ret = panictry!(self.parser.borrow_mut().parse_pat_nopanic());
         self.ensure_complete_parse(false);
         Some(ret)
     }
     fn make_items(self: Box<ParserAnyMacro<'a>>) -> Option<SmallVector<P<ast::Item>>> {
         let mut ret = SmallVector::zero();
-        while let Some(item) = self.parser.borrow_mut().parse_item() {
+        while let Some(item) = panictry!(self.parser.borrow_mut().parse_item_nopanic()) {
             ret.push(item);
         }
         self.ensure_complete_parse(false);
@@ -119,7 +119,7 @@ impl<'a> MacResult for ParserAnyMacro<'a> {
     }
 
     fn make_ty(self: Box<ParserAnyMacro<'a>>) -> Option<P<ast::Ty>> {
-        let ret = self.parser.borrow_mut().parse_ty();
+        let ret = panictry!(self.parser.borrow_mut().parse_ty_nopanic());
         self.ensure_complete_parse(true);
         Some(ret)
     }

src/libsyntax/parse/mod.rs

@@ -116,7 +116,7 @@ pub fn parse_expr_from_source_str(name: String,
                                   sess: &ParseSess)
                                   -> P<ast::Expr> {
     let mut p = new_parser_from_source_str(sess, cfg, name, source);
-    maybe_aborted(p.parse_expr(), p)
+    maybe_aborted(panictry!(p.parse_expr_nopanic()), p)
 }
 
 pub fn parse_item_from_source_str(name: String,
@@ -125,7 +125,7 @@ pub fn parse_item_from_source_str(name: String,
                                   sess: &ParseSess)
                                   -> Option<P<ast::Item>> {
     let mut p = new_parser_from_source_str(sess, cfg, name, source);
-    maybe_aborted(p.parse_item(),p)
+    maybe_aborted(panictry!(p.parse_item_nopanic()), p)
 }
 
 pub fn parse_meta_from_source_str(name: String,
@@ -134,7 +134,7 @@ pub fn parse_meta_from_source_str(name: String,
                                   sess: &ParseSess)
                                   -> P<ast::MetaItem> {
     let mut p = new_parser_from_source_str(sess, cfg, name, source);
-    maybe_aborted(p.parse_meta_item(),p)
+    maybe_aborted(p.parse_meta_item(), p)
 }
 
 pub fn parse_stmt_from_source_str(name: String,
@@ -148,7 +148,7 @@ pub fn parse_stmt_from_source_str(name: String,
         name,
         source
     );
-    maybe_aborted(p.parse_stmt(), p)
+    maybe_aborted(panictry!(p.parse_stmt_nopanic()), p)
 }
 
 // Warning: This parses with quote_depth > 0, which is not the default.

src/libsyntax/parse/parser.rs

@@ -359,7 +359,8 @@ impl<'a> Parser<'a> {
     }
 
     // Panicing fns (for now!)
-    // This is so that the quote_*!() syntax extensions
+    // These functions are used by the quote_*!() syntax extensions, but shouldn't
+    // be used otherwise.
     pub fn parse_expr(&mut self) -> P<Expr> {
         panictry!(self.parse_expr_nopanic())
     }