Remove by-mutable-ref mode from the compiler

and test cases. Closes #3513

2 files changed, 12 insertions, 6 deletions

diff --git a/src/libsyntax/parse/obsolete.rs b/src/libsyntax/parse/obsolete.rs
index 782535f5c2b..828d498ca3c 100644
--- a/src/libsyntax/parse/obsolete.rs
+++ b/src/libsyntax/parse/obsolete.rs
@@ -22,7 +22,8 @@ pub enum ObsoleteSyntax {
     ObsoleteClassMethod,
     ObsoleteClassTraits,
     ObsoletePrivSection,
-    ObsoleteModeInFnType
+    ObsoleteModeInFnType,
+    ObsoleteByMutRefMode
 }
 
 impl ObsoleteSyntax : cmp::Eq {
@@ -94,6 +95,10 @@ impl parser : ObsoleteReporter {
                 "to use a (deprecated) mode in a fn type, you should \
                  give the argument an explicit name (like `&&v: int`)"
             ),
+            ObsoleteByMutRefMode => (
+                "by-mutable-reference mode",
+                "Declare an argument of type &mut T instead"
+            ),
         };
 
         self.report(sp, kind, kind_str, desc);
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 6bee9190a83..22c25186c91 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -20,13 +20,13 @@ use obsolete::{
     ObsoleteLowerCaseKindBounds, ObsoleteLet,
     ObsoleteFieldTerminator, ObsoleteStructCtor,
     ObsoleteWith, ObsoleteClassMethod, ObsoleteClassTraits,
-    ObsoleteModeInFnType
+    ObsoleteModeInFnType, ObsoleteByMutRefMode
 };
 use ast::{_mod, add, alt_check, alt_exhaustive, arg, arm, attribute,
              bind_by_ref, bind_by_implicit_ref, bind_by_value, bind_by_move,
              bitand, bitor, bitxor, blk, blk_check_mode, bound_const,
              bound_copy, bound_send, bound_trait, bound_owned, box, by_copy,
-             by_move, by_mutbl_ref, by_ref, by_val, capture_clause,
+             by_move, by_ref, by_val, capture_clause,
              capture_item, cdir_dir_mod, cdir_src_mod, cdir_view_item,
              class_immutable, class_mutable,
              crate, crate_cfg, crate_directive, decl, decl_item, decl_local,
@@ -570,9 +570,10 @@ impl parser {
 
     fn parse_arg_mode() -> mode {
         if self.eat(token::BINOP(token::AND)) {
-            self.span_fatal(copy self.last_span,
-                            ~"Obsolete syntax has no effect");
-            expl(by_mutbl_ref)
+            self.obsolete(copy self.span,
+                          ObsoleteByMutRefMode);
+            // Bogus mode, but doesn't matter since it's an error
+            expl(by_ref)
         } else if self.eat(token::BINOP(token::MINUS)) {
             expl(by_move)
         } else if self.eat(token::ANDAND) {