fix PR5740: a colon is sacred when parsing case statement expressions!

llvm-svn: 91016

2 files changed, 14 insertions, 1 deletions

diff --git a/clang/lib/Parse/ParseStmt.cpp b/clang/lib/Parse/ParseStmt.cpp
index f0de3f53456..5267ef0eccc 100644
--- a/clang/lib/Parse/ParseStmt.cpp
+++ b/clang/lib/Parse/ParseStmt.cpp
@@ -279,6 +279,11 @@ Parser::OwningStmtResult Parser::ParseCaseStatement(AttributeList *Attr) {
       ConsumeToken();
     }
     
+    /// We don't want to treat 'case x : y' as a potential typo for 'case x::y'.
+    /// Disable this form of error recovery while we're parsing the case
+    /// expression.
+    ColonProtectionRAIIObject ColonProtection(*this);
+    
     OwningExprResult LHS(ParseConstantExpression());
     if (LHS.isInvalid()) {
       SkipUntil(tok::colon);
@@ -298,6 +303,8 @@ Parser::OwningStmtResult Parser::ParseCaseStatement(AttributeList *Attr) {
         return StmtError();
       }
     }
+    
+    ColonProtection.restore();
 
     if (Tok.isNot(tok::colon)) {
       Diag(Tok, diag::err_expected_colon_after) << "'case'";
diff --git a/clang/lib/Parse/RAIIObjectsForParser.h b/clang/lib/Parse/RAIIObjectsForParser.h
index d18d2f80263..bacdf29c8ae 100644
--- a/clang/lib/Parse/RAIIObjectsForParser.h
+++ b/clang/lib/Parse/RAIIObjectsForParser.h
@@ -50,9 +50,15 @@ namespace clang {
       P.ColonIsSacred = true;
     }
     
-    ~ColonProtectionRAIIObject() {
+    /// restore - This can be used to restore the state early, before the dtor
+    /// is run.
+    void restore() {
       P.ColonIsSacred = OldVal;
     }
+    
+    ~ColonProtectionRAIIObject() {
+      restore();
+    }
   };
   
 } // end namespace clang