Disallow non-comma-delimited arguments to fmt! and bytes!

Closes #4982.

3 files changed, 7 insertions, 6 deletions

diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs
index e831e32f23d..a5c8f2a235e 100644
--- a/src/libsyntax/ext/base.rs
+++ b/src/libsyntax/ext/base.rs
@@ -357,15 +357,16 @@ pub fn get_single_str_from_tts(cx: @ExtCtxt,
     }
 }
 
-pub fn get_exprs_from_tts(cx: @ExtCtxt, tts: &[ast::token_tree])
-                       -> ~[@ast::expr] {
+pub fn get_exprs_from_tts(cx: @ExtCtxt,
+                          sp: span,
+                          tts: &[ast::token_tree]) -> ~[@ast::expr] {
     let p = parse::new_parser_from_tts(cx.parse_sess(),
                                        cx.cfg(),
                                        tts.to_owned());
     let mut es = ~[];
     while *p.token != token::EOF {
-        if es.len() != 0 {
-            p.eat(&token::COMMA);
+        if es.len() != 0 && !p.eat(&token::COMMA) {
+            cx.span_fatal(sp, "expected token: `,`");
         }
         es.push(p.parse_expr());
     }
diff --git a/src/libsyntax/ext/bytes.rs b/src/libsyntax/ext/bytes.rs
index 3f64654dd80..2092c45074e 100644
--- a/src/libsyntax/ext/bytes.rs
+++ b/src/libsyntax/ext/bytes.rs
@@ -18,7 +18,7 @@ use ext::build::AstBuilder;
 
 pub fn expand_syntax_ext(cx: @ExtCtxt, sp: span, tts: &[ast::token_tree]) -> base::MacResult {
     // Gather all argument expressions
-    let exprs = get_exprs_from_tts(cx, tts);
+    let exprs = get_exprs_from_tts(cx, sp, tts);
     let mut bytes = ~[];
 
     for exprs.iter().advance |expr| {
diff --git a/src/libsyntax/ext/fmt.rs b/src/libsyntax/ext/fmt.rs
index 333570b6c9d..737127fcae7 100644
--- a/src/libsyntax/ext/fmt.rs
+++ b/src/libsyntax/ext/fmt.rs
@@ -26,7 +26,7 @@ use parse::token::{str_to_ident};
 
 pub fn expand_syntax_ext(cx: @ExtCtxt, sp: span, tts: &[ast::token_tree])
     -> base::MacResult {
-    let args = get_exprs_from_tts(cx, tts);
+    let args = get_exprs_from_tts(cx, sp, tts);
     if args.len() == 0 {
         cx.span_fatal(sp, "fmt! takes at least 1 argument.");
     }