The result of the Microsoft __uuidof operator must be considered a global lvalue during constant expression evaluation.

Otherwise we would get this error in C++11 mode (because of a recent change):
   error: non-type template argument of type 'const _GUID *' is not a constant expression

For code like:
template <const GUID* g = &__uuidof(struct_with_uuid)>
class COM_CLASS { };

llvm-svn: 154790

1 files changed, 6 insertions, 0 deletions

diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 98fc0e5cf3c..4a06e746158 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -934,6 +934,7 @@ static bool IsGlobalLValue(APValue::LValueBase B) {
   case Expr::ObjCStringLiteralClass:
   case Expr::ObjCEncodeExprClass:
   case Expr::CXXTypeidExprClass:
+  case Expr::CXXUuidofExprClass:
     return true;
   case Expr::CallExprClass:
     return IsStringLiteralCall(cast<CallExpr>(E));
@@ -2872,6 +2873,7 @@ public:
   bool VisitStringLiteral(const StringLiteral *E) { return Success(E); }
   bool VisitObjCEncodeExpr(const ObjCEncodeExpr *E) { return Success(E); }
   bool VisitCXXTypeidExpr(const CXXTypeidExpr *E);
+  bool VisitCXXUuidofExpr(const CXXUuidofExpr *E);
   bool VisitArraySubscriptExpr(const ArraySubscriptExpr *E);
   bool VisitUnaryDeref(const UnaryOperator *E);
   bool VisitUnaryReal(const UnaryOperator *E);
@@ -2977,6 +2979,10 @@ bool LValueExprEvaluator::VisitCXXTypeidExpr(const CXXTypeidExpr *E) {
   return Success(E);
 }
 
+bool LValueExprEvaluator::VisitCXXUuidofExpr(const CXXUuidofExpr *E) {
+  return Success(E);
+} 
+
 bool LValueExprEvaluator::VisitMemberExpr(const MemberExpr *E) {
   // Handle static data members.
   if (const VarDecl *VD = dyn_cast<VarDecl>(E->getMemberDecl())) {