property reference expression used on lhs of assignment

follows objective's semantics and is not overload'able
with an assignment operator. Fixes a crash and a missing
diagnostics. Radar 8379892.

llvm-svn: 113555

clang/lib/AST/ExprClassification.cpp

@@ -420,7 +420,8 @@ static Cl::ModifiableType IsModifiable(ASTContext &Ctx, const Expr *E,
 
   // Records with any const fields (recursively) are not modifiable.
   if (const RecordType *R = CT->getAs<RecordType>()) {
-    assert(!Ctx.getLangOptions().CPlusPlus &&
+    assert((isa<ObjCImplicitSetterGetterRefExpr>(E) || 
+            !Ctx.getLangOptions().CPlusPlus) &&
            "C++ struct assignment should be resolved by the "
            "copy assignment operator.");
     if (R->hasConstFields())

clang/lib/Sema/SemaExpr.cpp

@@ -6685,6 +6685,8 @@ ExprResult Sema::BuildBinOp(Scope *S, SourceLocation OpLoc,
                             BinaryOperatorKind Opc,
                             Expr *lhs, Expr *rhs) {
   if (getLangOptions().CPlusPlus &&
+      (!isa<ObjCImplicitSetterGetterRefExpr>(lhs) ||
+       rhs->isTypeDependent()) &&
       (lhs->getType()->isOverloadableType() ||
        rhs->getType()->isOverloadableType())) {
     // Find all of the overloaded operators visible from this

clang/test/CodeGenObjCXX/property-objects.mm

@@ -57,3 +57,22 @@ int main() {
   return 0;
 }
 
+// rdar://8379892
+// CHECK: define void @_Z1fP1A
+// CHECK: @objc_msgSend to void
+struct X {
+  X();
+  X(const X&);
+  ~X();
+};
+
+@interface A {
+  X xval;
+}
+- (X)x;
+- (void)setX:(X)x;
+@end
+
+void f(A* a) {
+  a.x = X();
+}

clang/test/SemaObjCXX/propert-dot-error.mm

@@ -0,0 +1,21 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+// rdar: // 8379892
+
+struct X {
+  X();
+  X(const X&);
+  ~X();
+};
+
+@interface A {
+  X xval;
+}
+
+- (X)x;
+- (void)setx:(X)x;
+@end
+
+void f(A* a) {
+  a.x = X(); // expected-error {{setter method is needed to assign to object using property assignment syntax}}
+}
+