[CodeGen][ObjC] Mark calls to objc_unsafeClaimAutoreleasedReturnValue as

notail on x86-64

This is needed because the epilogue code inserted before tail calls on
x86-64 breaks the handshake between the caller and callee.

Calls to objc_retainAutoreleasedReturnValue used to have the same
problem, which was fixed in https://reviews.llvm.org/D59656.

rdar://problem/66029552

Differential Revision: https://reviews.llvm.org/D84540

4 files changed, 32 insertions, 26 deletions

diff --git a/clang/lib/CodeGen/CGObjC.cpp b/clang/lib/CodeGen/CGObjC.cpp
index cd2b84f5dd20..26dfb6259a29 100644
--- a/clang/lib/CodeGen/CGObjC.cpp
+++ b/clang/lib/CodeGen/CGObjC.cpp
@@ -2250,8 +2250,7 @@ llvm::Value *
 CodeGenFunction::EmitARCRetainAutoreleasedReturnValue(llvm::Value *value) {
   emitAutoreleasedReturnValueMarker(*this);
   llvm::CallInst::TailCallKind tailKind =
-      CGM.getTargetCodeGenInfo()
-              .shouldSuppressTailCallsOfRetainAutoreleasedReturnValue()
+      CGM.getTargetCodeGenInfo().markARCOptimizedReturnCallsAsNoTail()
           ? llvm::CallInst::TCK_NoTail
           : llvm::CallInst::TCK_None;
   return emitARCValueOperation(
@@ -2270,9 +2269,14 @@ CodeGenFunction::EmitARCRetainAutoreleasedReturnValue(llvm::Value *value) {
 llvm::Value *
 CodeGenFunction::EmitARCUnsafeClaimAutoreleasedReturnValue(llvm::Value *value) {
   emitAutoreleasedReturnValueMarker(*this);
-  return emitARCValueOperation(*this, value, nullptr,
-              CGM.getObjCEntrypoints().objc_unsafeClaimAutoreleasedReturnValue,
-                     llvm::Intrinsic::objc_unsafeClaimAutoreleasedReturnValue);
+  llvm::CallInst::TailCallKind tailKind =
+      CGM.getTargetCodeGenInfo().markARCOptimizedReturnCallsAsNoTail()
+          ? llvm::CallInst::TCK_NoTail
+          : llvm::CallInst::TCK_None;
+  return emitARCValueOperation(
+      *this, value, nullptr,
+      CGM.getObjCEntrypoints().objc_unsafeClaimAutoreleasedReturnValue,
+      llvm::Intrinsic::objc_unsafeClaimAutoreleasedReturnValue, tailKind);
 }
 
 /// Release the given object.
diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp
index 9cd63ebe29ee..f31d432eb317 100644
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -2404,10 +2404,8 @@ public:
   }
 
   /// Disable tail call on x86-64. The epilogue code before the tail jump blocks
-  /// the autoreleaseRV/retainRV optimization.
-  bool shouldSuppressTailCallsOfRetainAutoreleasedReturnValue() const override {
-    return true;
-  }
+  /// autoreleaseRV/retainRV and autoreleaseRV/unsafeClaimRV optimizations.
+  bool markARCOptimizedReturnCallsAsNoTail() const override { return true; }
 
   int getDwarfEHStackPointer(CodeGen::CodeGenModule &CGM) const override {
     return 7;
diff --git a/clang/lib/CodeGen/TargetInfo.h b/clang/lib/CodeGen/TargetInfo.h
index 1152cabce4a0..0df9667e91e1 100644
--- a/clang/lib/CodeGen/TargetInfo.h
+++ b/clang/lib/CodeGen/TargetInfo.h
@@ -163,11 +163,9 @@ public:
     return "";
   }
 
-  /// Determine whether a call to objc_retainAutoreleasedReturnValue should be
-  /// marked as 'notail'.
-  virtual bool shouldSuppressTailCallsOfRetainAutoreleasedReturnValue() const {
-    return false;
-  }
+  /// Determine whether a call to objc_retainAutoreleasedReturnValue or
+  /// objc_unsafeClaimAutoreleasedReturnValue should be marked as 'notail'.
+  virtual bool markARCOptimizedReturnCallsAsNoTail() const { return false; }
 
   /// Return a constant used by UBSan as a signature to identify functions
   /// possessing type information, or 0 if the platform is unsupported.
diff --git a/clang/test/CodeGenObjC/arc-unsafeclaim.m b/clang/test/CodeGenObjC/arc-unsafeclaim.m
index a8011e024180..40f1f164455a 100644
--- a/clang/test/CodeGenObjC/arc-unsafeclaim.m
+++ b/clang/test/CodeGenObjC/arc-unsafeclaim.m
@@ -1,16 +1,16 @@
 //   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
+// 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 -check-prefix=NOTAIL-CALL
 
 //   Make sure it works on x86-32.
-// RUN: %clang_cc1 -triple i386-apple-darwin11 -fobjc-runtime=macosx-fragile-10.11 -fobjc-arc -emit-llvm -o - %s | FileCheck %s -check-prefix=CHECK -check-prefix=CHECK-UNOPTIMIZED -check-prefix=CHECK-MARKED
+// RUN: %clang_cc1 -triple i386-apple-darwin11 -fobjc-runtime=macosx-fragile-10.11 -fobjc-arc -emit-llvm -o - %s | FileCheck %s -check-prefix=CHECK -check-prefix=CHECK-UNOPTIMIZED -check-prefix=CHECK-MARKED -check-prefix=CALL
 
 //   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-passes -emit-llvm -o - %s | FileCheck %s -check-prefix=CHECK -check-prefix=CHECK-OPTIMIZED
+// 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 -check-prefix=CALL
+// RUN: %clang_cc1 -triple arm64-apple-ios9 -fobjc-runtime=ios-9.0 -fobjc-arc -O -disable-llvm-passes -emit-llvm -o - %s | FileCheck %s -check-prefix=CHECK -check-prefix=CHECK-OPTIMIZED -check-prefix=CALL
 
 //   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-passes -emit-llvm -o - %s | FileCheck %s -check-prefix=CHECK -check-prefix=CHECK-OPTIMIZED
+// 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 -check-prefix=CALL
+// RUN: %clang_cc1 -triple armv7-apple-ios9 -fobjc-runtime=ios-9.0 -fobjc-arc -O -disable-llvm-passes -emit-llvm -o - %s | FileCheck %s -check-prefix=CHECK -check-prefix=CHECK-OPTIMIZED -check-prefix=CALL
 
 //   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
@@ -29,7 +29,8 @@ void test_assign() {
 // 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* @llvm.objc.unsafeClaimAutoreleasedReturnValue(i8* [[T1]])
+// NOTAIL-CALL-NEXT:     [[T2:%.*]] = notail call i8* @llvm.objc.unsafeClaimAutoreleasedReturnValue(i8* [[T1]])
+// CALL-NEXT:            [[T2:%.*]] = call i8* @llvm.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]]
@@ -53,7 +54,8 @@ void test_assign_assign() {
 // 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* @llvm.objc.unsafeClaimAutoreleasedReturnValue(i8* [[T1]])
+// NOTAIL-CALL-NEXT:     [[T2:%.*]] = notail call i8* @llvm.objc.unsafeClaimAutoreleasedReturnValue(i8* [[T1]])
+// CALL-NEXT:            [[T2:%.*]] = call i8* @llvm.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]]
@@ -126,7 +128,8 @@ void test_init() {
 // 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* @llvm.objc.unsafeClaimAutoreleasedReturnValue(i8* [[T1]])
+// NOTAIL-CALL-NEXT:     [[T2:%.*]] = notail call i8* @llvm.objc.unsafeClaimAutoreleasedReturnValue(i8* [[T1]])
+// CALL-NEXT:            [[T2:%.*]] = call i8* @llvm.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]]
@@ -144,7 +147,8 @@ void test_init_assignment() {
 // 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* @llvm.objc.unsafeClaimAutoreleasedReturnValue(i8* [[T1]])
+// NOTAIL-CALL-NEXT:     [[T2:%.*]] = notail call i8* @llvm.objc.unsafeClaimAutoreleasedReturnValue(i8* [[T1]])
+// CALL-NEXT:            [[T2:%.*]] = call i8* @llvm.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]]
@@ -212,7 +216,8 @@ 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* @llvm.objc.unsafeClaimAutoreleasedReturnValue(i8* [[T1]])
+// NOTAIL-CALL-NEXT:  [[T2:%.*]] = notail call i8* @llvm.objc.unsafeClaimAutoreleasedReturnValue(i8* [[T1]])
+// CALL-NEXT:         [[T2:%.*]] = call i8* @llvm.objc.unsafeClaimAutoreleasedReturnValue(i8* [[T1]])
 // CHECK-NEXT:        bitcast i8* [[T2]] to [[A]]*
 // CHECK-NEXT:        ret void
 
@@ -223,7 +228,8 @@ 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* @llvm.objc.unsafeClaimAutoreleasedReturnValue(i8* [[T1]])
+// NOTAIL-CALL-NEXT:  [[T2:%.*]] = notail call i8* @llvm.objc.unsafeClaimAutoreleasedReturnValue(i8* [[T1]])
+// CALL-NEXT:         [[T2:%.*]] = call i8* @llvm.objc.unsafeClaimAutoreleasedReturnValue(i8* [[T1]])
 // CHECK-NEXT:        bitcast i8* [[T2]] to [[A]]*
 // CHECK-NEXT:        ret void