Emit calls to objc_unsafeClaimAutoreleasedReturnValue when

reclaiming a call result in order to ignore it or assign it
to an __unsafe_unretained variable.  This avoids adding
an unwanted retain/release pair when the return value is
not actually returned autoreleased (e.g. when it is returned
from a nonatomic getter or a typical collection accessor).

This runtime function is only available on the latest Apple
OS releases; the backwards-compatibility story is that you
don't get the optimization unless your deployment target is
recent enough.  Sorry.

rdar://20530049

llvm-svn: 258962

1 files changed, 231 insertions, 0 deletions

diff --git a/clang/test/CodeGenObjC/arc-unsafeclaim.m b/clang/test/CodeGenObjC/arc-unsafeclaim.m
new file mode 100644
index 00000000000..cda00b0a2f5
--- /dev/null
+++ b/clang/test/CodeGenObjC/arc-unsafeclaim.m
@@ -0,0 +1,231 @@
+//   Make sure it works on x86-64.
+// RUN: %clang_cc1 -triple x86_64-apple-darwin11 -fobjc-runtime=macosx-10.11 -fobjc-arc -emit-llvm -o - %s | FileCheck %s -check-prefix=CHECK -check-prefix=CHECK-UNOPTIMIZED
+
+//   Make sure it works on ARM.
+// RUN: %clang_cc1 -triple arm64-apple-ios9 -fobjc-runtime=ios-9.0 -fobjc-arc -emit-llvm -o - %s | FileCheck %s -check-prefix=CHECK -check-prefix=CHECK-UNOPTIMIZED -check-prefix=CHECK-MARKED
+// RUN: %clang_cc1 -triple arm64-apple-ios9 -fobjc-runtime=ios-9.0 -fobjc-arc -O -disable-llvm-optzns -emit-llvm -o - %s | FileCheck %s -check-prefix=CHECK -check-prefix=CHECK-OPTIMIZED
+
+//   Make sure it works on ARM64.
+// RUN: %clang_cc1 -triple armv7-apple-ios9 -fobjc-runtime=ios-9.0 -fobjc-arc -emit-llvm -o - %s | FileCheck %s -check-prefix=CHECK -check-prefix=CHECK-UNOPTIMIZED -check-prefix=CHECK-MARKED
+// RUN: %clang_cc1 -triple armv7-apple-ios9 -fobjc-runtime=ios-9.0 -fobjc-arc -O -disable-llvm-optzns -emit-llvm -o - %s | FileCheck %s -check-prefix=CHECK -check-prefix=CHECK-OPTIMIZED
+
+//   Make sure that it's implicitly disabled if the runtime version isn't high enough.
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -fobjc-runtime=macosx-10.10 -fobjc-arc -emit-llvm -o - %s | FileCheck %s -check-prefix=DISABLED
+// RUN: %clang_cc1 -triple arm64-apple-ios8 -fobjc-runtime=ios-8 -fobjc-arc -emit-llvm -o - %s | FileCheck %s -check-prefix=DISABLED -check-prefix=DISABLED-MARKED
+
+@class A;
+
+A *makeA(void);
+
+void test_assign() {
+  __unsafe_unretained id x;
+  x = makeA();
+}
+// CHECK-LABEL:        define void @test_assign()
+// CHECK:                [[X:%.*]] = alloca i8*
+// CHECK:                [[T0:%.*]] = call [[A:.*]]* @makeA()
+// CHECK-MARKED-NEXT:    call void asm sideeffect
+// CHECK-NEXT:           [[T1:%.*]] = bitcast [[A]]* [[T0]] to i8*
+// CHECK-NEXT:           [[T2:%.*]] = call i8* @objc_unsafeClaimAutoreleasedReturnValue(i8* [[T1]])
+// CHECK-NEXT:           [[T3:%.*]] = bitcast i8* [[T2]] to [[A]]*
+// CHECK-NEXT:           [[T4:%.*]] = bitcast [[A]]* [[T3]] to i8*
+// CHECK-NEXT:           store i8* [[T4]], i8** [[X]]
+// CHECK-OPTIMIZED-NEXT: bitcast
+// CHECK-OPTIMIZED-NEXT: lifetime.end
+// CHECK-NEXT:           ret void
+
+// DISABLED-LABEL:     define void @test_assign()
+// DISABLED:             [[T0:%.*]] = call [[A:.*]]* @makeA()
+// DISABLED-MARKED-NEXT: call void asm sideeffect
+// DISABLED-NEXT:        [[T1:%.*]] = bitcast [[A]]* [[T0]] to i8*
+// DISABLED-NEXT:        [[T2:%.*]] = call i8* @objc_retainAutoreleasedReturnValue(i8* [[T1]])
+
+void test_assign_assign() {
+  __unsafe_unretained id x, y;
+  x = y = makeA();
+}
+// CHECK-LABEL:        define void @test_assign_assign()
+// CHECK:                [[X:%.*]] = alloca i8*
+// CHECK:                [[Y:%.*]] = alloca i8*
+// CHECK:                [[T0:%.*]] = call [[A]]* @makeA()
+// CHECK-MARKED-NEXT:    call void asm sideeffect
+// CHECK-NEXT:           [[T1:%.*]] = bitcast [[A]]* [[T0]] to i8*
+// CHECK-NEXT:           [[T2:%.*]] = call i8* @objc_unsafeClaimAutoreleasedReturnValue(i8* [[T1]])
+// CHECK-NEXT:           [[T3:%.*]] = bitcast i8* [[T2]] to [[A]]*
+// CHECK-NEXT:           [[T4:%.*]] = bitcast [[A]]* [[T3]] to i8*
+// CHECK-NEXT:           store i8* [[T4]], i8** [[Y]]
+// CHECK-NEXT:           store i8* [[T4]], i8** [[X]]
+// CHECK-OPTIMIZED-NEXT: bitcast
+// CHECK-OPTIMIZED-NEXT: lifetime.end
+// CHECK-OPTIMIZED-NEXT: bitcast
+// CHECK-OPTIMIZED-NEXT: lifetime.end
+// CHECK-NEXT:           ret void
+
+void test_strong_assign_assign() {
+  __strong id x;
+  __unsafe_unretained id y;
+  x = y = makeA();
+}
+// CHECK-LABEL:        define void @test_strong_assign_assign()
+// CHECK:                [[X:%.*]] = alloca i8*
+// CHECK:                [[Y:%.*]] = alloca i8*
+// CHECK:                [[T0:%.*]] = call [[A]]* @makeA()
+// CHECK-MARKED-NEXT:    call void asm sideeffect
+// CHECK-NEXT:           [[T1:%.*]] = bitcast [[A]]* [[T0]] to i8*
+// CHECK-NEXT:           [[T2:%.*]] = call i8* @objc_retainAutoreleasedReturnValue(i8* [[T1]])
+// CHECK-NEXT:           [[T3:%.*]] = bitcast i8* [[T2]] to [[A]]*
+// CHECK-NEXT:           [[T4:%.*]] = bitcast [[A]]* [[T3]] to i8*
+// CHECK-NEXT:           store i8* [[T4]], i8** [[Y]]
+// CHECK-NEXT:           [[OLD:%.*]] = load i8*, i8** [[X]]
+// CHECK-NEXT:           store i8* [[T4]], i8** [[X]]
+// CHECK-NEXT:           call void @objc_release(i8* [[OLD]]
+// CHECK-OPTIMIZED-NEXT: bitcast
+// CHECK-OPTIMIZED-NEXT: lifetime.end
+// CHECK-UNOPTIMIZED-NEXT: call void @objc_storeStrong(i8** [[X]], i8* null)
+// CHECK-OPTIMIZED-NEXT: [[T0:%.*]] = load i8*, i8** [[X]]
+// CHECK-OPTIMIZED-NEXT: call void @objc_release(i8* [[T0]])
+// CHECK-OPTIMIZED-NEXT: bitcast
+// CHECK-OPTIMIZED-NEXT: lifetime.end
+// CHECK-NEXT:           ret void
+
+void test_assign_strong_assign() {
+  __unsafe_unretained id x;
+  __strong id y;
+  x = y = makeA();
+}
+// CHECK-LABEL:        define void @test_assign_strong_assign()
+// CHECK:                [[X:%.*]] = alloca i8*
+// CHECK:                [[Y:%.*]] = alloca i8*
+// CHECK:                [[T0:%.*]] = call [[A]]* @makeA()
+// CHECK-MARKED-NEXT:    call void asm sideeffect
+// CHECK-NEXT:           [[T1:%.*]] = bitcast [[A]]* [[T0]] to i8*
+// CHECK-NEXT:           [[T2:%.*]] = call i8* @objc_retainAutoreleasedReturnValue(i8* [[T1]])
+// CHECK-NEXT:           [[T3:%.*]] = bitcast i8* [[T2]] to [[A]]*
+// CHECK-NEXT:           [[T4:%.*]] = bitcast [[A]]* [[T3]] to i8*
+// CHECK-NEXT:           [[OLD:%.*]] = load i8*, i8** [[Y]]
+// CHECK-NEXT:           store i8* [[T4]], i8** [[Y]]
+// CHECK-NEXT:           call void @objc_release(i8* [[OLD]]
+// CHECK-NEXT:           store i8* [[T4]], i8** [[X]]
+// CHECK-UNOPTIMIZED-NEXT: call void @objc_storeStrong(i8** [[Y]], i8* null)
+// CHECK-OPTIMIZED-NEXT: [[T0:%.*]] = load i8*, i8** [[Y]]
+// CHECK-OPTIMIZED-NEXT: call void @objc_release(i8* [[T0]])
+// CHECK-OPTIMIZED-NEXT: bitcast
+// CHECK-OPTIMIZED-NEXT: lifetime.end
+// CHECK-OPTIMIZED-NEXT: bitcast
+// CHECK-OPTIMIZED-NEXT: lifetime.end
+// CHECK-NEXT:           ret void
+
+void test_init() {
+  __unsafe_unretained id x = makeA();
+}
+// CHECK-LABEL:        define void @test_init()
+// CHECK:                [[X:%.*]] = alloca i8*
+// CHECK:                [[T0:%.*]] = call [[A]]* @makeA()
+// CHECK-MARKED-NEXT:    call void asm sideeffect
+// CHECK-NEXT:           [[T1:%.*]] = bitcast [[A]]* [[T0]] to i8*
+// CHECK-NEXT:           [[T2:%.*]] = call i8* @objc_unsafeClaimAutoreleasedReturnValue(i8* [[T1]])
+// CHECK-NEXT:           [[T3:%.*]] = bitcast i8* [[T2]] to [[A]]*
+// CHECK-NEXT:           [[T4:%.*]] = bitcast [[A]]* [[T3]] to i8*
+// CHECK-NEXT:           store i8* [[T4]], i8** [[X]]
+// CHECK-OPTIMIZED-NEXT: bitcast
+// CHECK-OPTIMIZED-NEXT: lifetime.end
+// CHECK-NEXT:           ret void
+
+void test_init_assignment() {
+  __unsafe_unretained id x;
+  __unsafe_unretained id y = x = makeA();
+}
+// CHECK-LABEL:        define void @test_init_assignment()
+// CHECK:                [[X:%.*]] = alloca i8*
+// CHECK:                [[Y:%.*]] = alloca i8*
+// CHECK:                [[T0:%.*]] = call [[A]]* @makeA()
+// CHECK-MARKED-NEXT:    call void asm sideeffect
+// CHECK-NEXT:           [[T1:%.*]] = bitcast [[A]]* [[T0]] to i8*
+// CHECK-NEXT:           [[T2:%.*]] = call i8* @objc_unsafeClaimAutoreleasedReturnValue(i8* [[T1]])
+// CHECK-NEXT:           [[T3:%.*]] = bitcast i8* [[T2]] to [[A]]*
+// CHECK-NEXT:           [[T4:%.*]] = bitcast [[A]]* [[T3]] to i8*
+// CHECK-NEXT:           store i8* [[T4]], i8** [[X]]
+// CHECK-NEXT:           store i8* [[T4]], i8** [[Y]]
+// CHECK-OPTIMIZED-NEXT: bitcast
+// CHECK-OPTIMIZED-NEXT: lifetime.end
+// CHECK-OPTIMIZED-NEXT: bitcast
+// CHECK-OPTIMIZED-NEXT: lifetime.end
+// CHECK-NEXT: ret void
+
+void test_strong_init_assignment() {
+  __unsafe_unretained id x;
+  __strong id y = x = makeA();
+}
+// CHECK-LABEL:        define void @test_strong_init_assignment()
+// CHECK:                [[X:%.*]] = alloca i8*
+// CHECK:                [[Y:%.*]] = alloca i8*
+// CHECK:                [[T0:%.*]] = call [[A]]* @makeA()
+// CHECK-MARKED-NEXT:    call void asm sideeffect
+// CHECK-NEXT:           [[T1:%.*]] = bitcast [[A]]* [[T0]] to i8*
+// CHECK-NEXT:           [[T2:%.*]] = call i8* @objc_retainAutoreleasedReturnValue(i8* [[T1]])
+// CHECK-NEXT:           [[T3:%.*]] = bitcast i8* [[T2]] to [[A]]*
+// CHECK-NEXT:           [[T4:%.*]] = bitcast [[A]]* [[T3]] to i8*
+// CHECK-NEXT:           store i8* [[T4]], i8** [[X]]
+// CHECK-NEXT:           store i8* [[T4]], i8** [[Y]]
+// CHECK-UNOPTIMIZED-NEXT: call void @objc_storeStrong(i8** [[Y]], i8* null)
+// CHECK-OPTIMIZED-NEXT: [[T0:%.*]] = load i8*, i8** [[Y]]
+// CHECK-OPTIMIZED-NEXT: call void @objc_release(i8* [[T0]])
+// CHECK-OPTIMIZED-NEXT: bitcast
+// CHECK-OPTIMIZED-NEXT: lifetime.end
+// CHECK-OPTIMIZED-NEXT: bitcast
+// CHECK-OPTIMIZED-NEXT: lifetime.end
+// CHECK-NEXT: ret void
+
+void test_init_strong_assignment() {
+  __strong id x;
+  __unsafe_unretained id y = x = makeA();
+}
+// CHECK-LABEL:        define void @test_init_strong_assignment()
+// CHECK:                [[X:%.*]] = alloca i8*
+// CHECK:                [[Y:%.*]] = alloca i8*
+// CHECK:                [[T0:%.*]] = call [[A]]* @makeA()
+// CHECK-MARKED-NEXT:    call void asm sideeffect
+// CHECK-NEXT:           [[T1:%.*]] = bitcast [[A]]* [[T0]] to i8*
+// CHECK-NEXT:           [[T2:%.*]] = call i8* @objc_retainAutoreleasedReturnValue(i8* [[T1]])
+// CHECK-NEXT:           [[T3:%.*]] = bitcast i8* [[T2]] to [[A]]*
+// CHECK-NEXT:           [[T4:%.*]] = bitcast [[A]]* [[T3]] to i8*
+// CHECK-NEXT:           [[OLD:%.*]] = load i8*, i8** [[X]]
+// CHECK-NEXT:           store i8* [[T4]], i8** [[X]]
+// CHECK-NEXT:           call void @objc_release(i8* [[OLD]])
+// CHECK-NEXT:           store i8* [[T4]], i8** [[Y]]
+// CHECK-OPTIMIZED-NEXT: bitcast
+// CHECK-OPTIMIZED-NEXT: lifetime.end
+// CHECK-UNOPTIMIZED-NEXT: call void @objc_storeStrong(i8** [[X]], i8* null)
+// CHECK-OPTIMIZED-NEXT: [[T0:%.*]] = load i8*, i8** [[X]]
+// CHECK-OPTIMIZED-NEXT: call void @objc_release(i8* [[T0]])
+// CHECK-OPTIMIZED-NEXT: bitcast
+// CHECK-OPTIMIZED-NEXT: lifetime.end
+// CHECK-NEXT: ret void
+
+void test_ignored() {
+  makeA();
+}
+// CHECK-LABEL:     define void @test_ignored()
+// CHECK:             [[T0:%.*]] = call [[A]]* @makeA()
+// CHECK-MARKED-NEXT: call void asm sideeffect
+// CHECK-NEXT:        [[T1:%.*]] = bitcast [[A]]* [[T0]] to i8*
+// CHECK-NEXT:        [[T2:%.*]] = call i8* @objc_unsafeClaimAutoreleasedReturnValue(i8* [[T1]])
+// CHECK-NEXT:        bitcast i8* [[T2]] to [[A]]*
+// CHECK-NEXT:        ret void
+
+void test_cast_to_void() {
+  (void) makeA();
+}
+// CHECK-LABEL:     define void @test_cast_to_void()
+// CHECK:             [[T0:%.*]] = call [[A]]* @makeA()
+// CHECK-MARKED-NEXT: call void asm sideeffect
+// CHECK-NEXT:        [[T1:%.*]] = bitcast [[A]]* [[T0]] to i8*
+// CHECK-NEXT:        [[T2:%.*]] = call i8* @objc_unsafeClaimAutoreleasedReturnValue(i8* [[T1]])
+// CHECK-NEXT:        bitcast i8* [[T2]] to [[A]]*
+// CHECK-NEXT:        ret void
+
+
+
+// This is always at the end of the module.
+
+// CHECK-OPTIMIZED: !clang.arc.retainAutoreleasedReturnValueMarker = !{!0}