Fix a slight oversight in computing whether a copy constructor is elidable.

Fixes PR5695.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@90702 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Sema/SemaDeclCXX.cpp

@@ -3369,8 +3369,10 @@ Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
     if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E))
       if (ICE->getCastKind() == CastExpr::CK_NoOp)
         E = ICE->getSubExpr();
-    
-    if (isa<CallExpr>(E) || isa<CXXTemporaryObjectExpr>(E))
+
+    if (CallExpr *CE = dyn_cast<CallExpr>(E))
+      Elidable = !CE->getCallReturnType()->isReferenceType();
+    else if (isa<CXXTemporaryObjectExpr>(E))
       Elidable = true;
   }
 

test/CodeGenCXX/elide-call-reference.cpp

@@ -0,0 +1,11 @@
+// RUN: clang-cc %s -emit-llvm -o - | FileCheck %s
+// PR5695
+
+struct A { A(const A&); ~A(); };
+A& a();
+void b() {
+  A x = a();
+}
+
+// CHECK: call void @_ZN1AC1ERKS_
+// CHECK: call void @_ZN1AD1Ev