Fix PR20334: invalid assertion while diagnosing list initialization failure

https://llvm.org/bugs/show_bug.cgi?id=20334

Unfortunately, clang currently checks for a certain brokenness of implementations of std::initializer_list in CodeGen (void 
AggExprEmitter::VisitCXXStdInitializerListExpr), not in SemaInit.  Until that is fixed, make sure we don't let broken attempts that are aggregates leak through into sema, which allows maintenance of expected invariants, and avoids triggering an assertion.



 

llvm-svn: 254889

clang/lib/Sema/SemaInit.cpp

@@ -3732,7 +3732,9 @@ static void TryListInitialization(Sema &S,
 
   // C++11 [dcl.init.list]p3:
   //   - If T is an aggregate, aggregate initialization is performed.
-  if (DestType->isRecordType() && !DestType->isAggregateType()) {
+  if ((DestType->isRecordType() && !DestType->isAggregateType()) ||
+      (S.getLangOpts().CPlusPlus11 &&
+       S.isStdInitializerList(DestType, nullptr))) {
     if (S.getLangOpts().CPlusPlus11) {
       //   - Otherwise, if the initializer list has no elements and T is a
       //     class type with a default constructor, the object is

clang/test/SemaCXX/PR20334-std_initializer_list_diagnosis_assertion.cpp

@@ -0,0 +1,20 @@
+// RUN: %clang_cc1 -std=c++11 -verify -emit-llvm-only %s
+// RUN: %clang_cc1 -std=c++98 -fsyntax-only -verify %s -DCPP98
+
+namespace std {
+  template <class _E>
+  class initializer_list
+  {};
+}
+
+template<class E> int f(std::initializer_list<E> il);
+	
+
+int F = f({1, 2, 3});
+#ifdef CPP98
+//expected-error@-2{{expected expression}}
+#else
+//expected-error@-4{{cannot compile}}
+#endif
+
+