Objective-C. When we use @selector(save:), etc. there may be more

than one method with mismatched type of same selector name. 
clang issues a warning to point this out since it may cause 
undefined behavior. There are cases though that some APIs 
don't care about user methods and such warnings are perceived as 
noise. This patch allows users to add paren delimiters around
selector name to turn off such warnings. So, @selector((save:)) will
turn off the warning. It also provides 'fixit' so user knows 
what to do. // rdar://16458579

llvm-svn: 211611

1 files changed, 10 insertions, 3 deletions

diff --git a/clang/lib/Parse/ParseObjc.cpp b/clang/lib/Parse/ParseObjc.cpp
index e3fd7adfdf2..7fe72ec0c3b 100644
--- a/clang/lib/Parse/ParseObjc.cpp
+++ b/clang/lib/Parse/ParseObjc.cpp
@@ -2839,7 +2839,7 @@ Parser::ParseObjCProtocolExpression(SourceLocation AtLoc) {
 }
 
 ///     objc-selector-expression
-///       @selector '(' objc-keyword-selector ')'
+///       @selector '(' '('[opt] objc-keyword-selector ')'[opt] ')'
 ExprResult Parser::ParseObjCSelectorExpression(SourceLocation AtLoc) {
   SourceLocation SelectorLoc = ConsumeToken();
 
@@ -2851,7 +2851,10 @@ ExprResult Parser::ParseObjCSelectorExpression(SourceLocation AtLoc) {
   
   BalancedDelimiterTracker T(*this, tok::l_paren);
   T.consumeOpen();
-
+  bool HasOptionalParen = Tok.is(tok::l_paren);
+  if (HasOptionalParen)
+    ConsumeParen();
+  
   if (Tok.is(tok::code_completion)) {
     Actions.CodeCompleteObjCSelector(getCurScope(), KeyIdents);
     cutOffParsing();
@@ -2864,6 +2867,7 @@ ExprResult Parser::ParseObjCSelectorExpression(SourceLocation AtLoc) {
     return ExprError(Diag(Tok, diag::err_expected) << tok::identifier);
 
   KeyIdents.push_back(SelIdent);
+  
   unsigned nColons = 0;
   if (Tok.isNot(tok::r_paren)) {
     while (1) {
@@ -2891,11 +2895,14 @@ ExprResult Parser::ParseObjCSelectorExpression(SourceLocation AtLoc) {
         break;
     }
   }
+  if (HasOptionalParen && Tok.is(tok::r_paren))
+    ConsumeParen(); // ')'
   T.consumeClose();
   Selector Sel = PP.getSelectorTable().getSelector(nColons, &KeyIdents[0]);
   return Actions.ParseObjCSelectorExpression(Sel, AtLoc, SelectorLoc,
                                              T.getOpenLocation(),
-                                             T.getCloseLocation());
+                                             T.getCloseLocation(),
+                                             !HasOptionalParen);
  }
 
 void Parser::ParseLexedObjCMethodDefs(LexedMethod &LM, bool parseMethod) {