r178721 - Protect the values of array and dictionary literals from the
John McCall
rjmccall at apple.com
Wed Apr 3 17:20:38 PDT 2013
Author: rjmccall
Date: Wed Apr 3 19:20:38 2013
New Revision: 178721
URL: http://llvm.org/viewvc/llvm-project?rev=178721&view=rev
Log:
Protect the values of array and dictionary literals from the
ARC optimizer while they're held in local unsafe buffers.
Based on a patch by Jesse Rusak!
rdar://13573224
Modified:
cfe/trunk/lib/CodeGen/CGObjC.cpp
cfe/trunk/test/CodeGenObjC/arc-literals.m
Modified: cfe/trunk/lib/CodeGen/CGObjC.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGObjC.cpp?rev=178721&r1=178720&r2=178721&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGObjC.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGObjC.cpp Wed Apr 3 19:20:38 2013
@@ -109,32 +109,50 @@ llvm::Value *CodeGenFunction::EmitObjCCo
if (DLE)
Keys = CreateMemTemp(ElementArrayType, "keys");
+ // In ARC, we may need to do extra work to keep all the keys and
+ // values alive until after the call.
+ SmallVector<llvm::Value *, 16> NeededObjects;
+ bool TrackNeededObjects =
+ (getLangOpts().ObjCAutoRefCount &&
+ CGM.getCodeGenOpts().OptimizationLevel != 0);
+
// Perform the actual initialialization of the array(s).
for (uint64_t i = 0; i < NumElements; i++) {
if (ALE) {
- // Emit the initializer.
+ // Emit the element and store it to the appropriate array slot.
const Expr *Rhs = ALE->getElement(i);
LValue LV = LValue::MakeAddr(Builder.CreateStructGEP(Objects, i),
ElementType,
Context.getTypeAlignInChars(Rhs->getType()),
Context);
- EmitScalarInit(Rhs, /*D=*/0, LV, /*capturedByInit=*/false);
+
+ llvm::Value *value = EmitScalarExpr(Rhs);
+ EmitStoreThroughLValue(RValue::get(value), LV, true);
+ if (TrackNeededObjects) {
+ NeededObjects.push_back(value);
+ }
} else {
- // Emit the key initializer.
+ // Emit the key and store it to the appropriate array slot.
const Expr *Key = DLE->getKeyValueElement(i).Key;
LValue KeyLV = LValue::MakeAddr(Builder.CreateStructGEP(Keys, i),
ElementType,
Context.getTypeAlignInChars(Key->getType()),
Context);
- EmitScalarInit(Key, /*D=*/0, KeyLV, /*capturedByInit=*/false);
+ llvm::Value *keyValue = EmitScalarExpr(Key);
+ EmitStoreThroughLValue(RValue::get(keyValue), KeyLV, /*isInit=*/true);
- // Emit the value initializer.
+ // Emit the value and store it to the appropriate array slot.
const Expr *Value = DLE->getKeyValueElement(i).Value;
LValue ValueLV = LValue::MakeAddr(Builder.CreateStructGEP(Objects, i),
ElementType,
Context.getTypeAlignInChars(Value->getType()),
Context);
- EmitScalarInit(Value, /*D=*/0, ValueLV, /*capturedByInit=*/false);
+ llvm::Value *valueValue = EmitScalarExpr(Value);
+ EmitStoreThroughLValue(RValue::get(valueValue), ValueLV, /*isInit=*/true);
+ if (TrackNeededObjects) {
+ NeededObjects.push_back(keyValue);
+ NeededObjects.push_back(valueValue);
+ }
}
}
@@ -172,6 +190,15 @@ llvm::Value *CodeGenFunction::EmitObjCCo
Sel,
Receiver, Args, Class,
MethodWithObjects);
+
+ // The above message send needs these objects, but in ARC they are
+ // passed in a buffer that is essentially __unsafe_unretained.
+ // Therefore we must prevent the optimizer from releasing them until
+ // after the call.
+ if (TrackNeededObjects) {
+ EmitARCIntrinsicUse(NeededObjects);
+ }
+
return Builder.CreateBitCast(result.getScalarVal(),
ConvertType(E->getType()));
}
Modified: cfe/trunk/test/CodeGenObjC/arc-literals.m
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenObjC/arc-literals.m?rev=178721&r1=178720&r2=178721&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenObjC/arc-literals.m (original)
+++ cfe/trunk/test/CodeGenObjC/arc-literals.m Wed Apr 3 19:20:38 2013
@@ -35,18 +35,28 @@ void test_numeric() {
// CHECK: define void @test_array
void test_array(id a, id b) {
+ // CHECK: [[A:%.*]] = alloca i8*,
+ // CHECK: [[B:%.*]] = alloca i8*,
+
// Retaining parameters
// CHECK: call i8* @objc_retain(i8*
// CHECK: call i8* @objc_retain(i8*
// Constructing the array
- // CHECK: getelementptr inbounds [2 x i8*]* [[OBJECTS:%[A-Za-z0-9]+]], i32 0, i32 0
- // CHECK: store i8*
- // CHECK: getelementptr inbounds [2 x i8*]* [[OBJECTS]], i32 0, i32 1
- // CHECK: store i8*
-
- // CHECK: {{call i8*.*objc_msgSend.*i64 2}}
- // CHECK: call i8* @objc_retainAutoreleasedReturnValue
+ // CHECK: [[T0:%.*]] = getelementptr inbounds [2 x i8*]* [[OBJECTS:%[A-Za-z0-9]+]], i32 0, i32 0
+ // CHECK-NEXT: [[V0:%.*]] = load i8** [[A]],
+ // CHECK-NEXT: store i8* [[V0]], i8** [[T0]]
+ // CHECK-NEXT: [[T0:%.*]] = getelementptr inbounds [2 x i8*]* [[OBJECTS]], i32 0, i32 1
+ // CHECK-NEXT: [[V1:%.*]] = load i8** [[B]],
+ // CHECK-NEXT: store i8* [[V1]], i8** [[T0]]
+
+ // CHECK-NEXT: [[T0:%.*]] = load [[CLASS_T:%.*]]** @"\01L_OBJC_CLASSLIST
+ // CHECK-NEXT: [[SEL:%.*]] = load i8** @"\01L_OBJC_SELECTOR_REFERENCES
+ // CHECK-NEXT: [[T1:%.*]] = bitcast [[CLASS_T]]* [[T0]] to i8*
+ // CHECK-NEXT: [[T2:%.*]] = bitcast [2 x i8*]* [[OBJECTS]] to i8**
+ // CHECK-NEXT: [[T3:%.*]] = call i8* bitcast ({{.*@objc_msgSend.*}})(i8* [[T1]], i8* [[SEL]], i8** [[T2]], i64 2)
+ // CHECK-NEXT: [[T4:%.*]] = call i8* @objc_retainAutoreleasedReturnValue(i8* [[T3]])
+ // CHECK: call void (...)* @clang.arc.use(i8* [[V0]], i8* [[V1]])
id arr = @[a, b];
// CHECK: call void @objc_release
@@ -57,6 +67,11 @@ void test_array(id a, id b) {
// CHECK: define void @test_dictionary
void test_dictionary(id k1, id o1, id k2, id o2) {
+ // CHECK: [[K1:%.*]] = alloca i8*,
+ // CHECK: [[O1:%.*]] = alloca i8*,
+ // CHECK: [[K2:%.*]] = alloca i8*,
+ // CHECK: [[O2:%.*]] = alloca i8*,
+
// Retaining parameters
// CHECK: call i8* @objc_retain(i8*
// CHECK: call i8* @objc_retain(i8*
@@ -64,18 +79,29 @@ void test_dictionary(id k1, id o1, id k2
// CHECK: call i8* @objc_retain(i8*
// Constructing the arrays
- // CHECK: getelementptr inbounds [2 x i8*]* [[KEYS:%[A-Za-z0-9]+]], i32 0, i32 0
- // CHECK: store i8*
- // CHECK: getelementptr inbounds [2 x i8*]* [[OBJECTS:%[A-Za-z0-9]+]], i32 0, i32 0
- // CHECK: store i8*
- // CHECK: getelementptr inbounds [2 x i8*]* [[KEYS]], i32 0, i32 1
- // CHECK: store i8*
- // CHECK: getelementptr inbounds [2 x i8*]* [[OBJECTS]], i32 0, i32 1
- // CHECK: store i8*
+ // CHECK: [[T0:%.*]] = getelementptr inbounds [2 x i8*]* [[KEYS:%[A-Za-z0-9]+]], i32 0, i32 0
+ // CHECK-NEXT: [[V0:%.*]] = load i8** [[K1]],
+ // CHECK-NEXT: store i8* [[V0]], i8** [[T0]]
+ // CHECK-NEXT: [[T0:%.*]] = getelementptr inbounds [2 x i8*]* [[OBJECTS:%[A-Za-z0-9]+]], i32 0, i32 0
+ // CHECK-NEXT: [[V1:%.*]] = load i8** [[O1]],
+ // CHECK-NEXT: store i8* [[V1]], i8** [[T0]]
+ // CHECK-NEXT: [[T0:%.*]] = getelementptr inbounds [2 x i8*]* [[KEYS]], i32 0, i32 1
+ // CHECK-NEXT: [[V2:%.*]] = load i8** [[K2]],
+ // CHECK-NEXT: store i8* [[V2]], i8** [[T0]]
+ // CHECK-NEXT: [[T0:%.*]] = getelementptr inbounds [2 x i8*]* [[OBJECTS]], i32 0, i32 1
+ // CHECK-NEXT: [[V3:%.*]] = load i8** [[O2]],
+ // CHECK-NEXT: store i8* [[V3]], i8** [[T0]]
// Constructing the dictionary
- // CHECK: {{call i8.*@objc_msgSend}}
- // CHECK: call i8* @objc_retainAutoreleasedReturnValue
+ // CHECK-NEXT: [[T0:%.*]] = load [[CLASS_T:%.*]]** @"\01L_OBJC_CLASSLIST
+ // CHECK-NEXT: [[SEL:%.*]] = load i8** @"\01L_OBJC_SELECTOR_REFERENCES
+ // CHECK-NEXT: [[T1:%.*]] = bitcast [[CLASS_T]]* [[T0]] to i8*
+ // CHECK-NEXT: [[T2:%.*]] = bitcast [2 x i8*]* [[OBJECTS]] to i8**
+ // CHECK-NEXT: [[T3:%.*]] = bitcast [2 x i8*]* [[KEYS]] to i8**
+ // CHECK-NEXT: [[T4:%.*]] = call i8* bitcast ({{.*@objc_msgSend.*}})(i8* [[T1]], i8* [[SEL]], i8** [[T2]], i8** [[T3]], i64 2)
+ // CHECK-NEXT: [[T5:%.*]] = call i8* @objc_retainAutoreleasedReturnValue(i8* [[T4]])
+ // CHECK-NEXT: call void (...)* @clang.arc.use(i8* [[V0]], i8* [[V1]], i8* [[V2]], i8* [[V3]])
+
id dict = @{ k1 : o1, k2 : o2 };
// CHECK: call void @objc_release
@@ -98,19 +124,36 @@ void test_property(B *b) {
// Retain parameter
// CHECK: call i8* @objc_retain
+ // CHECK: [[T0:%.*]] = getelementptr inbounds [1 x i8*]* [[OBJECTS:%.*]], i32 0, i32 0
+
// Invoke 'prop'
- // CHECK: load i8** @"\01L_OBJC_SELECTOR_REFERENCES
- // CHECK: {{call.*@objc_msgSend}}
- // CHECK: call i8* @objc_retainAutoreleasedReturnValue
+ // CHECK: [[SEL:%.*]] = load i8** @"\01L_OBJC_SELECTOR_REFERENCES
+ // CHECK-NEXT: [[T1:%.*]] = bitcast
+ // CHECK-NEXT: [[T2:%.*]] = call [[B:%.*]]* bitcast ({{.*}} @objc_msgSend to {{.*}})(i8* [[T1]], i8* [[SEL]])
+ // CHECK-NEXT: [[T3:%.*]] = bitcast [[B]]* [[T2]] to i8*
+ // CHECK-NEXT: [[T4:%.*]] = call i8* @objc_retainAutoreleasedReturnValue(i8* [[T3]])
+ // CHECK-NEXT: [[V0:%.*]] = bitcast i8* [[T4]] to [[B]]*
+ // CHECK-NEXT: [[V1:%.*]] = bitcast [[B]]* [[V0]] to i8*
+
+ // Store to array.
+ // CHECK-NEXT: store i8* [[V1]], i8** [[T0]]
// Invoke arrayWithObjects:count:
- // CHECK: load i8** @"\01L_OBJC_SELECTOR_REFERENCES
- // CHECK: {{call.*objc_msgSend}}
- // CHECK: call i8* @objc_retainAutoreleasedReturnValue
+ // CHECK-NEXT: [[T0:%.*]] = load [[CLASS_T]]** @"\01L_OBJC_CLASSLIST
+ // CHECK-NEXT: [[SEL:%.*]] = load i8** @"\01L_OBJC_SELECTOR_REFERENCES
+ // CHECK-NEXT: [[T1:%.*]] = bitcast [[CLASS_T]]* [[T0]] to i8*
+ // CHECK-NEXT: [[T2:%.*]] = bitcast [1 x i8*]* [[OBJECTS]] to i8**
+ // CHECK-NEXT: [[T3:%.*]] = call i8* bitcast ({{.*}} @objc_msgSend to {{.*}}(i8* [[T1]], i8* [[SEL]], i8** [[T2]], i64 1)
+ // CHECK-NEXT: call i8* @objc_retainAutoreleasedReturnValue(i8* [[T3]])
+ // CHECK-NEXT: call void (...)* @clang.arc.use(i8* [[V1]])
+ // CHECK-NEXT: bitcast
+ // CHECK-NEXT: bitcast
+ // CHECK-NEXT: store
id arr = @[ b.prop ];
// Release b.prop
- // CHECK: call void @objc_release
+ // CHECK-NEXT: [[T0:%.*]] = bitcast [[B]]* [[V0]] to i8*
+ // CHECK-NEXT: call void @objc_release(i8* [[T0]])
// Destroy arr
// CHECK: call void @objc_release
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