objective-c: provide a useful 'fixit' suggestion when
errornously using commas to separate ObjC message arguments.
// rdar://11376372


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@157216 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Parse/ParseObjc.cpp b/lib/Parse/ParseObjc.cpp
index 164c2f4..f7efad5 100644
--- a/lib/Parse/ParseObjc.cpp
+++ b/lib/Parse/ParseObjc.cpp
@@ -2452,10 +2452,14 @@
     }
     // Parse the, optional, argument list, comma separated.
     while (Tok.is(tok::comma)) {
-      ConsumeToken(); // Eat the ','.
+      SourceLocation commaLoc = ConsumeToken(); // Eat the ','.
       ///  Parse the expression after ','
       ExprResult Res(ParseAssignmentExpression());
       if (Res.isInvalid()) {
+        if (Tok.is(tok::colon)) {
+          Diag(commaLoc, diag::note_extra_comma_message_arg) <<
+            FixItHint::CreateRemoval(commaLoc);
+        }
         // We must manually skip to a ']', otherwise the expression skipper will
         // stop at the ']' when it skips to the ';'.  We want it to skip beyond
         // the enclosing expression.