Parse: Diagnose malformed 'message' arguments for 'availability' attr

The parsing code for 'availability' wasn't prepared for string literals
like "a" L"b" showing up.  Error if this occurs.

llvm-svn: 213350

1 files changed, 12 insertions, 1 deletions

diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp
index 71b37527fd2..74df162b0b3 100644
--- a/clang/lib/Parse/ParseDecl.cpp
+++ b/clang/lib/Parse/ParseDecl.cpp
@@ -825,13 +825,24 @@ void Parser::ParseAvailabilityAttribute(IdentifierInfo &Availability,
     }
     ConsumeToken();
     if (Keyword == Ident_message) {
-      if (Tok.isNot(tok::string_literal)) { // Also reject wide string literals.
+      if (Tok.isNot(tok::string_literal)) {
         Diag(Tok, diag::err_expected_string_literal)
           << /*Source='availability attribute'*/2;
         SkipUntil(tok::r_paren, StopAtSemi);
         return;
       }
       MessageExpr = ParseStringLiteralExpression();
+      // Also reject wide string literals.
+      if (StringLiteral *MessageStringLiteral =
+              cast_or_null<StringLiteral>(MessageExpr.get())) {
+        if (MessageStringLiteral->getCharByteWidth() != 1) {
+          Diag(MessageStringLiteral->getSourceRange().getBegin(),
+               diag::err_expected_string_literal)
+            << /*Source='availability attribute'*/ 2;
+          SkipUntil(tok::r_paren, StopAtSemi);
+          return;
+        }
+      }
       break;
     }