Add the thread sanitizer support for X86_64 WatchOS simulators

[yfyang]

Summary

Allow TSan in clang driver for X86_64 WatchOS simulator.

It was already functional, and Apple's downstream fork of clang allows it, but that change had not made it upstream yet.

[jyknight]

Thanks for the change.

The description is a bit misleading, this would be better:

Allow TSan in clang driver for X86_64 WatchOS simulator.

It was already functional, and Apple's downstream fork of clang allows it, but that change had not made it upstream yet.

cc+=yln FYI, though this change seems obvious enough I'm comfortable to approve it directly.

[yln]

Thank you! LGTM, with one nit.

@rsundahl: can you keep an eye on this and resolve any potential Apple-internal conflicts? Thanks!

clang/lib/Driver/ToolChains/Darwin.cpp

3280–3286

Yes, for watchOS simulator. I think we can also drop the constraint on x86_64 and then merge the if. TSan should be supported for simulators on Apple Silicon. Can you add additional tests for these 3 cases? Thanks!

[rsundahl]

In D139652#3983079, @yln wrote:

@rsundahl: can you keep an eye on this and resolve any potential Apple-internal conflicts? Thanks!

Will do @yln.

[yfyang]

Addressing comments.

[yfyang]

Formatting

[yfyang]

• Add TSAN support for Apple arm64 simulators
• Formatting

clang/lib/Driver/ToolChains/Darwin.cpp

 //===--- Darwin.cpp - Darwin Tool and ToolChain Implementations -*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
SanitizerMask Darwin::getSupportedSanitizers() const {
 
   // Prior to 10.9, macOS shipped a version of the C++ standard library without
   // C++11 support. The same is true of iOS prior to version 5. These OS'es are
   // incompatible with -fsanitize=vptr.
   if (!(isTargetMacOSBased() && isMacosxVersionLT(10, 9)) &&
       !(isTargetIPhoneOS() && isIPhoneOSVersionLT(5, 0)))
     Res |= SanitizerKind::Vptr;
 
   if ((IsX86_64 || IsAArch64) && isTargetMacOSBased()) {
     Res |= SanitizerKind::Thread;
-  } else if (isTargetIOSSimulator() || isTargetTvOSSimulator()) {
+  } else if (isTargetIOSSimulator() || isTargetTvOSSimulator() ||
+             isTargetWatchOSSimulator()) {
     if (IsX86_64)
       Res |= SanitizerKind::Thread;
   }
   return Res;
 }
 
 void Darwin::printVerboseInfo(raw_ostream &OS) const {
   CudaInstallation.print(OS);
   RocmInstallation.print(OS);
 }

clang/test/Driver/fsanitize.c

 // RUN: %clang --target=x86_64-apple-macos -fsanitize=thread %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-TSAN-X86-64-MACOS
 // CHECK-TSAN-X86-64-MACOS-NOT: unsupported option
 // RUN: %clang --target=arm64-apple-macos -fsanitize=thread %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-TSAN-ARM64-MACOS
 // CHECK-TSAN-ARM64-MACOS-NOT: unsupported option
 
 // RUN: %clang --target=x86_64-apple-ios-simulator -fsanitize=thread %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-TSAN-X86-64-IOSSIMULATOR
 // CHECK-TSAN-X86-64-IOSSIMULATOR-NOT: unsupported option
 
+// RUN: %clang --target=x86_64-apple-watchos-simulator -fsanitize=thread %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-TSAN-X86-64-WATCHOSSIMULATOR
+// CHECK-TSAN-X86-64-WATCHOSSIMULATOR-NOT: unsupported option
+
 // RUN: %clang --target=x86_64-apple-tvos-simulator -fsanitize=thread %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-TSAN-X86-64-TVOSSIMULATOR
 // CHECK-TSAN-X86-64-TVOSSIMULATOR-NOT: unsupported option
 
 // RUN: %clang --target=i386-apple-darwin -fsanitize=thread %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-TSAN-I386-DARWIN
 // CHECK-TSAN-I386-DARWIN: unsupported option '-fsanitize=thread' for target 'i386-apple-darwin'
 
 // RUN: %clang --target=arm-apple-ios -fsanitize=thread %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-TSAN-ARM-IOS
 // CHECK-TSAN-ARM-IOS: unsupported option '-fsanitize=thread' for target 'arm-apple-ios'