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Reland "[Intrinsics][ObjC] Mark objc_retain and friends as thisreturn."
This reverts commit cb62f67. Fixes: #69658
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6 files changed

+54
-25
lines changed

6 files changed

+54
-25
lines changed

‎clang/lib/CodeGen/CGCall.cpp

Lines changed: 3 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -3448,9 +3448,9 @@ static llvm::Value *tryRemoveRetainOfSelf(CodeGenFunction &CGF,
34483448
const VarDecl *self = method->getSelfDecl();
34493449
if (!self->getType().isConstQualified()) return nullptr;
34503450

3451-
// Look for a retain call.
3452-
llvm::CallInst *retainCall =
3453-
dyn_cast<llvm::CallInst>(result->stripPointerCasts());
3451+
// Look for a retain call. Note: stripPointerCasts looks through returned arg
3452+
// functions, which would cause us to miss the retain.
3453+
llvm::CallInst *retainCall = dyn_cast<llvm::CallInst>(result);
34543454
if (!retainCall || retainCall->getCalledOperand() !=
34553455
CGF.CGM.getObjCEntrypoints().objc_retain)
34563456
return nullptr;

‎clang/test/CodeGenObjC/arc.m

Lines changed: 10 additions & 10 deletions
Original file line numberDiff line numberDiff line change
@@ -7,30 +7,30 @@
77
// RUN: %clang_cc1 -fobjc-runtime=macosx-10.7.0 -triple x86_64-apple-darwin11 -Wno-objc-root-class -Wno-incompatible-pointer-types -Wno-arc-unsafe-retained-assign -emit-llvm -fblocks -fobjc-arc -fobjc-runtime-has-weak -o - %s | FileCheck -check-prefix=ARC-NATIVE %s
88

99
// ARC-ALIEN: declare extern_weak void @llvm.objc.storeStrong(ptr, ptr)
10-
// ARC-ALIEN: declare extern_weak ptr @llvm.objc.retain(ptr)
11-
// ARC-ALIEN: declare extern_weak ptr @llvm.objc.autoreleaseReturnValue(ptr)
10+
// ARC-ALIEN: declare extern_weak ptr @llvm.objc.retain(ptr returned)
11+
// ARC-ALIEN: declare extern_weak ptr @llvm.objc.autoreleaseReturnValue(ptr returned)
1212
// ARC-ALIEN: declare ptr @objc_msgSend(ptr, ptr, ...) [[NLB:#[0-9]+]]
1313
// ARC-ALIEN: declare extern_weak void @llvm.objc.release(ptr)
14-
// ARC-ALIEN: declare extern_weak ptr @llvm.objc.retainAutoreleasedReturnValue(ptr)
14+
// ARC-ALIEN: declare extern_weak ptr @llvm.objc.retainAutoreleasedReturnValue(ptr returned)
1515
// ARC-ALIEN: declare extern_weak ptr @llvm.objc.initWeak(ptr, ptr)
1616
// ARC-ALIEN: declare extern_weak ptr @llvm.objc.storeWeak(ptr, ptr)
1717
// ARC-ALIEN: declare extern_weak ptr @llvm.objc.loadWeakRetained(ptr)
1818
// ARC-ALIEN: declare extern_weak void @llvm.objc.destroyWeak(ptr)
19-
// ARC-ALIEN: declare extern_weak ptr @llvm.objc.autorelease(ptr)
20-
// ARC-ALIEN: declare extern_weak ptr @llvm.objc.retainAutorelease(ptr)
19+
// ARC-ALIEN: declare extern_weak ptr @llvm.objc.autorelease(ptr returned)
20+
// ARC-ALIEN: declare extern_weak ptr @llvm.objc.retainAutorelease(ptr returned)
2121

2222
// ARC-NATIVE: declare void @llvm.objc.storeStrong(ptr, ptr)
23-
// ARC-NATIVE: declare ptr @llvm.objc.retain(ptr)
24-
// ARC-NATIVE: declare ptr @llvm.objc.autoreleaseReturnValue(ptr)
23+
// ARC-NATIVE: declare ptr @llvm.objc.retain(ptr returned)
24+
// ARC-NATIVE: declare ptr @llvm.objc.autoreleaseReturnValue(ptr returned)
2525
// ARC-NATIVE: declare ptr @objc_msgSend(ptr, ptr, ...) [[NLB:#[0-9]+]]
2626
// ARC-NATIVE: declare void @llvm.objc.release(ptr)
27-
// ARC-NATIVE: declare ptr @llvm.objc.retainAutoreleasedReturnValue(ptr)
27+
// ARC-NATIVE: declare ptr @llvm.objc.retainAutoreleasedReturnValue(ptr returned)
2828
// ARC-NATIVE: declare ptr @llvm.objc.initWeak(ptr, ptr)
2929
// ARC-NATIVE: declare ptr @llvm.objc.storeWeak(ptr, ptr)
3030
// ARC-NATIVE: declare ptr @llvm.objc.loadWeakRetained(ptr)
3131
// ARC-NATIVE: declare void @llvm.objc.destroyWeak(ptr)
32-
// ARC-NATIVE: declare ptr @llvm.objc.autorelease(ptr)
33-
// ARC-NATIVE: declare ptr @llvm.objc.retainAutorelease(ptr)
32+
// ARC-NATIVE: declare ptr @llvm.objc.autorelease(ptr returned)
33+
// ARC-NATIVE: declare ptr @llvm.objc.retainAutorelease(ptr returned)
3434

3535
// CHECK-LABEL: define{{.*}} void @test0
3636
void test0(id x) {

‎clang/test/CodeGenObjC/convert-messages-to-runtime-calls.m

Lines changed: 5 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -28,6 +28,11 @@ void test1(id x) {
2828
// MSGS: {{call.*@objc_msgSend}}
2929
// CALLS: {{call.*@objc_alloc}}
3030
// CALLS: {{call.*@objc_allocWithZone}}
31+
32+
// Note that calls to the intrinsics are not allowed for
33+
// retain/release/autorelease they're marked `thisreturn`, which isn't
34+
// guaranteed to be true for classes that define their own `-retain`, for
35+
// example. Be sure to keep these as normal function calls:
3136
// CALLS: {{call.*@objc_retain}}
3237
// CALLS: {{call.*@objc_release}}
3338
// CALLS: {{tail call.*@objc_autorelease}}

‎llvm/include/llvm/IR/Intrinsics.td

Lines changed: 12 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -720,11 +720,13 @@ def int_gcwrite : Intrinsic<[],
720720
// eliminate retain and releases where possible.
721721

722722
def int_objc_autorelease : Intrinsic<[llvm_ptr_ty],
723-
[llvm_ptr_ty]>;
723+
[llvm_ptr_ty],
724+
[Returned<ArgIndex<0>>]>;
724725
def int_objc_autoreleasePoolPop : Intrinsic<[], [llvm_ptr_ty]>;
725726
def int_objc_autoreleasePoolPush : Intrinsic<[llvm_ptr_ty], []>;
726727
def int_objc_autoreleaseReturnValue : Intrinsic<[llvm_ptr_ty],
727-
[llvm_ptr_ty]>;
728+
[llvm_ptr_ty],
729+
[Returned<ArgIndex<0>>]>;
728730
def int_objc_copyWeak : Intrinsic<[],
729731
[llvm_ptr_ty,
730732
llvm_ptr_ty]>;
@@ -741,11 +743,14 @@ def int_objc_moveWeak : Intrinsic<[],
741743
llvm_ptr_ty]>;
742744
def int_objc_release : Intrinsic<[], [llvm_ptr_ty]>;
743745
def int_objc_retain : Intrinsic<[llvm_ptr_ty],
744-
[llvm_ptr_ty]>;
746+
[llvm_ptr_ty],
747+
[Returned<ArgIndex<0>>]>;
745748
def int_objc_retainAutorelease : Intrinsic<[llvm_ptr_ty],
746-
[llvm_ptr_ty]>;
749+
[llvm_ptr_ty],
750+
[Returned<ArgIndex<0>>]>;
747751
def int_objc_retainAutoreleaseReturnValue : Intrinsic<[llvm_ptr_ty],
748-
[llvm_ptr_ty]>;
752+
[llvm_ptr_ty],
753+
[Returned<ArgIndex<0>>]>;
749754
def int_objc_retainAutoreleasedReturnValue : Intrinsic<[llvm_ptr_ty],
750755
[llvm_ptr_ty]>;
751756
def int_objc_retainBlock : Intrinsic<[llvm_ptr_ty],
@@ -770,7 +775,8 @@ def int_objc_unretainedObject : Intrinsic<[llvm_ptr_ty],
770775
def int_objc_unretainedPointer : Intrinsic<[llvm_ptr_ty],
771776
[llvm_ptr_ty]>;
772777
def int_objc_retain_autorelease : Intrinsic<[llvm_ptr_ty],
773-
[llvm_ptr_ty]>;
778+
[llvm_ptr_ty],
779+
[Returned<ArgIndex<0>>]>;
774780
def int_objc_sync_enter : Intrinsic<[llvm_i32_ty],
775781
[llvm_ptr_ty]>;
776782
def int_objc_sync_exit : Intrinsic<[llvm_i32_ty],

‎llvm/lib/CodeGen/PreISelIntrinsicLowering.cpp

Lines changed: 10 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -162,6 +162,16 @@ static bool lowerObjCCall(Function &F, const char *NewFn,
162162
CallInst::TailCallKind TCK = CI->getTailCallKind();
163163
NewCI->setTailCallKind(std::max(TCK, OverridingTCK));
164164

165+
// Transfer the 'returned' attribute from the intrinsic to the call site.
166+
// By applying this only to intrinsic call sites, we avoid applying it to
167+
// non-ARC explicit calls to things like objc_retain which have not been
168+
// auto-upgraded to use the intrinsics.
169+
unsigned Index;
170+
if (F.getAttributes().hasAttrSomewhere(Attribute::Returned, &Index) &&
171+
Index)
172+
NewCI->addParamAttr(Index - AttributeList::FirstArgIndex,
173+
Attribute::Returned);
174+
165175
if (!CI->use_empty())
166176
CI->replaceAllUsesWith(NewCI);
167177
CI->eraseFromParent();

‎llvm/test/Transforms/PreISelIntrinsicLowering/X86/objc-arc.ll

Lines changed: 14 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -9,7 +9,7 @@ declare i32 @__gxx_personality_v0(...)
99
define ptr @test_objc_autorelease(ptr %arg0) {
1010
; CHECK-LABEL: test_objc_autorelease
1111
; CHECK-NEXT: entry
12-
; CHECK-NEXT: %0 = notail call ptr @objc_autorelease(ptr %arg0)
12+
; CHECK-NEXT: %0 = notail call ptr @objc_autorelease(ptr returned %arg0)
1313
; CHECK-NEXT: ret ptr %0
1414
entry:
1515
%0 = call ptr @llvm.objc.autorelease(ptr %arg0)
@@ -39,7 +39,7 @@ entry:
3939
define ptr @test_objc_autoreleaseReturnValue(ptr %arg0) {
4040
; CHECK-LABEL: test_objc_autoreleaseReturnValue
4141
; CHECK-NEXT: entry
42-
; CHECK-NEXT: %0 = tail call ptr @objc_autoreleaseReturnValue(ptr %arg0)
42+
; CHECK-NEXT: %0 = tail call ptr @objc_autoreleaseReturnValue(ptr returned %arg0)
4343
; CHECK-NEXT: ret ptr %0
4444
entry:
4545
%0 = call ptr @llvm.objc.autoreleaseReturnValue(ptr %arg0)
@@ -119,7 +119,7 @@ entry:
119119
define ptr @test_objc_retain(ptr %arg0) {
120120
; CHECK-LABEL: test_objc_retain
121121
; CHECK-NEXT: entry
122-
; CHECK-NEXT: %0 = tail call ptr @objc_retain(ptr %arg0)
122+
; CHECK-NEXT: %0 = tail call ptr @objc_retain(ptr returned %arg0)
123123
; CHECK-NEXT: ret ptr %0
124124
entry:
125125
%0 = call ptr @llvm.objc.retain(ptr %arg0)
@@ -129,7 +129,7 @@ entry:
129129
define ptr @test_objc_retainAutorelease(ptr %arg0) {
130130
; CHECK-LABEL: test_objc_retainAutorelease
131131
; CHECK-NEXT: entry
132-
; CHECK-NEXT: %0 = call ptr @objc_retainAutorelease(ptr %arg0)
132+
; CHECK-NEXT: %0 = call ptr @objc_retainAutorelease(ptr returned %arg0)
133133
; CHECK-NEXT: ret ptr %0
134134
entry:
135135
%0 = call ptr @llvm.objc.retainAutorelease(ptr %arg0)
@@ -139,13 +139,17 @@ entry:
139139
define ptr @test_objc_retainAutoreleaseReturnValue(ptr %arg0) {
140140
; CHECK-LABEL: test_objc_retainAutoreleaseReturnValue
141141
; CHECK-NEXT: entry
142-
; CHECK-NEXT: %0 = tail call ptr @objc_retainAutoreleaseReturnValue(ptr %arg0)
142+
; CHECK-NEXT: %0 = tail call ptr @objc_retainAutoreleaseReturnValue(ptr returned %arg0)
143143
; CHECK-NEXT: ret ptr %0
144144
entry:
145145
%0 = tail call ptr @llvm.objc.retainAutoreleaseReturnValue(ptr %arg0)
146146
ret ptr %0
147147
}
148148

149+
; Note: we don't want this intrinsic to have its argument marked 'returned',
150+
; since that breaks the autorelease elision marker optimization when
151+
; save/restores of the reciever are introduced between the msg send and the
152+
; retain. See issue#69658.
149153
define ptr @test_objc_retainAutoreleasedReturnValue(ptr %arg0) {
150154
; CHECK-LABEL: test_objc_retainAutoreleasedReturnValue
151155
; CHECK-NEXT: entry
@@ -210,6 +214,10 @@ entry:
210214
ret ptr %0
211215
}
212216

217+
; Note: we don't want this intrinsic to have its argument marked 'returned',
218+
; since that breaks the autorelease elision marker optimization when
219+
; save/restores of the reciever are introduced between the msg send and the
220+
; claim. See issue#69658.
213221
define ptr @test_objc_unsafeClaimAutoreleasedReturnValue(ptr %arg0) {
214222
; CHECK-LABEL: test_objc_unsafeClaimAutoreleasedReturnValue
215223
; CHECK-NEXT: entry
@@ -260,7 +268,7 @@ entry:
260268
define ptr @test_objc_retain_autorelease(ptr %arg0) {
261269
; CHECK-LABEL: test_objc_retain_autorelease
262270
; CHECK-NEXT: entry
263-
; CHECK-NEXT: %0 = call ptr @objc_retain_autorelease(ptr %arg0)
271+
; CHECK-NEXT: %0 = call ptr @objc_retain_autorelease(ptr returned %arg0)
264272
; CHECK-NEXT: ret ptr %0
265273
entry:
266274
%0 = call ptr @llvm.objc.retain.autorelease(ptr %arg0)

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