Fix crash when checking a dependently-typed reference that is

initialized from a non-value-dependent initializer.

llvm-svn: 363622

Author: zygoloid

clang/lib/AST/Decl.cpp

@@ -2282,7 +2282,7 @@ bool VarDecl::isUsableInConstantExpressions(ASTContext &Context) const {
   //   declaration is encountered...
   const VarDecl *DefVD = nullptr;
   const Expr *Init = getAnyInitializer(DefVD);
-  if (!Init || Init->isValueDependent())
+  if (!Init || Init->isValueDependent() || getType()->isDependentType())
     return false;
   //   ... if it is a constexpr variable, or it is of reference type or of
   //   const-qualified integral or enumeration type, ...

clang/test/SemaTemplate/dependent-expr.cpp

@@ -63,6 +63,14 @@ namespace test5 {
   };
 }
 
+namespace test6 {
+  template<typename T> T f() {
+    const T &v(0);
+    return v;
+  }
+  int use = f<int>();
+}
+
 namespace PR8795 {
   template <class _CharT> int test(_CharT t)
   {