Code gen for ObjCIsaExpr AST used as lvalue.

(fixes radar 7457534).



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@90995 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 30 insertions, 17 deletions

diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index 4144661f7b..e8758d814d 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -983,6 +983,7 @@ Expr::isLvalueResult Expr::isLvalue(ASTContext &Ctx) const {
 // Check whether the expression can be sanely treated like an l-value
 Expr::isLvalueResult Expr::isLvalueInternal(ASTContext &Ctx) const {
   switch (getStmtClass()) {
+  case ObjCIsaExprClass:
   case StringLiteralClass:  // C99 6.5.1p4
   case ObjCEncodeExprClass: // @encode behaves like its string in every way.
     return LV_Valid;
diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index fde944ffcd..873c28cdef 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -245,6 +245,8 @@ LValue CodeGenFunction::EmitLValue(const Expr *E) {
   switch (E->getStmtClass()) {
   default: return EmitUnsupportedLValue(E, "l-value expression");
 
+  case Expr::ObjCIsaExprClass:
+    return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
   case Expr::BinaryOperatorClass:
     return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
   case Expr::CallExprClass:
diff --git a/lib/CodeGen/CGExprScalar.cpp b/lib/CodeGen/CGExprScalar.cpp
index 9ac8b4d8b3..1ce4c5aef4 100644
--- a/lib/CodeGen/CGExprScalar.cpp
+++ b/lib/CodeGen/CGExprScalar.cpp
@@ -168,21 +168,8 @@ public:
   }
 
   Value *VisitObjCIsaExpr(ObjCIsaExpr *E) {
-    Value *V;
-    // object->isa or (*object).isa
-    // Generate code as for: *(Class*)object
-    Expr *BaseExpr = E->getBase();
-    if (E->isArrow())
-      V  = EmitLoadOfLValue(BaseExpr);
-    else
-      V  = EmitLValue(BaseExpr).getAddress();
-    
-    // build Class* type
-    const llvm::Type *ClassPtrTy = ConvertType(E->getType());
-    ClassPtrTy = ClassPtrTy->getPointerTo();
-    V = Builder.CreateBitCast(V, ClassPtrTy);
-    LValue LV = LValue::MakeAddr(V, CGF.MakeQualifiers(E->getType()));
-    V = CGF.EmitLoadOfLValue(LV, E->getType()).getScalarVal();
+    LValue LV = CGF.EmitObjCIsaExpr(E);
+    Value *V = CGF.EmitLoadOfLValue(LV, E->getType()).getScalarVal();
     return V;
   }
 
@@ -1997,3 +1984,22 @@ llvm::Value *CodeGenFunction::EmitVector(llvm::Value * const *Vals,
 
   return Vec;
 }
+
+LValue CodeGenFunction::EmitObjCIsaExpr(const ObjCIsaExpr *E) {
+  llvm::Value *V;
+  // object->isa or (*object).isa
+  // Generate code as for: *(Class*)object
+  Expr *BaseExpr = E->getBase();
+  if (E->isArrow())
+    V = ScalarExprEmitter(*this).EmitLoadOfLValue(BaseExpr);
+  else
+    V  = EmitLValue(BaseExpr).getAddress();
+  
+  // build Class* type
+  const llvm::Type *ClassPtrTy = ConvertType(E->getType());
+  ClassPtrTy = ClassPtrTy->getPointerTo();
+  V = Builder.CreateBitCast(V, ClassPtrTy);
+  LValue LV = LValue::MakeAddr(V, MakeQualifiers(E->getType()));
+  return LV;
+}
+
diff --git a/lib/CodeGen/CodeGenFunction.h b/lib/CodeGen/CodeGenFunction.h
index 70d598dc0e..30cc5d9cbf 100644
--- a/lib/CodeGen/CodeGenFunction.h
+++ b/lib/CodeGen/CodeGenFunction.h
@@ -971,6 +971,7 @@ public:
   LValue EmitArraySubscriptExpr(const ArraySubscriptExpr *E);
   LValue EmitExtVectorElementExpr(const ExtVectorElementExpr *E);
   LValue EmitMemberExpr(const MemberExpr *E);
+  LValue EmitObjCIsaExpr(const ObjCIsaExpr *E);
   LValue EmitCompoundLiteralLValue(const CompoundLiteralExpr *E);
   LValue EmitConditionalOperatorLValue(const ConditionalOperator *E);
   LValue EmitCastLValue(const CastExpr *E);
diff --git a/test/CodeGenObjC/id-isa-codegen.m b/test/CodeGenObjC/id-isa-codegen.m
index a9ab4251e2..9e8c7f6f79 100644
--- a/test/CodeGenObjC/id-isa-codegen.m
+++ b/test/CodeGenObjC/id-isa-codegen.m
@@ -8,17 +8,20 @@ typedef struct objc_object {
 
 @interface I
 + (Class) class;
-- (void)meth : (id)object;
+- (void)meth : (id)object : (id)src_object;
 + (unsigned char) isSubclassOfClass:(Class)aClass ;
 @end
 
 @implementation I
 + (Class) class {return 0;}
 + (unsigned char) isSubclassOfClass:(Class)aClass {return 0;}
-- (void)meth : (id)object {
+- (void)meth : (id)object  : (id)src_object {
     [object->isa isSubclassOfClass:[I class]];
 
     [(*object).isa isSubclassOfClass:[I class]];
+
+    object->isa = src_object->isa;
+    (*src_object).isa = (*object).isa;
 }
 @end