objective-C++ IRGen: property reference as an

lvalue when performing a derived-to-base conversion.
Fixes radar 7501812. Added an executable test to
llvm-test suite.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@106247 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index aab54099fde9131d5492f1a6601d5fbf14b0f76b..8655a66bd95390d5ceb3d594e31d1548cedfb5b5 100644 (file)
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -1818,10 +1818,18 @@ LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
       cast<CXXRecordDecl>(DerivedClassTy->getDecl());
     
     LValue LV = EmitLValue(E->getSubExpr());
+    llvm::Value *This;
+    if (LV.isPropertyRef()) {
+      RValue RV = EmitLoadOfPropertyRefLValue(LV, E->getSubExpr()->getType());
+      assert (!RV.isScalar() && "EmitCastLValue");
+      This = RV.getAggregateAddr();
+    }
+    else
+      This = LV.getAddress();
     
     // Perform the derived-to-base conversion
     llvm::Value *Base = 
-      GetAddressOfBaseClass(LV.getAddress(), DerivedClassDecl, 
+      GetAddressOfBaseClass(This, DerivedClassDecl, 
                             E->getBasePath(), /*NullCheckValue=*/false);
     
     return LValue::MakeAddr(Base, MakeQualifiers(E->getType()));

diff --git a/test/CodeGenObjCXX/property-derived-to-base-conv.mm b/test/CodeGenObjCXX/property-derived-to-base-conv.mm
new file mode 100644 (file)
index 0000000..ada1202
--- /dev/null
+++ b/test/CodeGenObjCXX/property-derived-to-base-conv.mm
@@ -0,0 +1,19 @@
+// RUN: %clang_cc1 -fobjc-gc -triple x86_64-apple-darwin10 -emit-llvm -o - %s
+// rdar: // 7501812
+
+struct A { int member; };
+struct B : A { };
+
+@interface BInt {
+@private
+  B *b;
+}
+- (B)value;
+- (void)setValue : (B) arg;
+@property B value;
+@end
+
+void g(BInt *bint) {
+  bint.value.member = 17;
+}
+