Fix for PR5524: make reference binding in default argument work correctly.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@91733 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/CGExpr.cpp

@@ -97,7 +97,10 @@ RValue CodeGenFunction::EmitReferenceBindingToExpr(const Expr* E,
                                                    bool IsInitializer) {
   bool ShouldDestroyTemporaries = false;
   unsigned OldNumLiveTemporaries = 0;
-  
+
+  if (const CXXDefaultArgExpr *DAE = dyn_cast<CXXDefaultArgExpr>(E))
+    E = DAE->getExpr();
+
   if (const CXXExprWithTemporaries *TE = dyn_cast<CXXExprWithTemporaries>(E)) {
     ShouldDestroyTemporaries = true;
     

test/CodeGenCXX/reference-bind-default-argument.cpp

@@ -0,0 +1,6 @@
+// RUN: %clang_cc1 %s -emit-llvm-only -verify
+
+struct A {};
+struct B : A {};
+void a(const A& x = B());
+void b() { a(); }