[tsan] Allow TSan in the Clang driver for Apple Silicon Macs

[yln]

Simulators on Apple Silicon are not yet supported?

[yln]

clang/lib/Driver/ToolChains/Darwin.cpp

2734

This breaks the symmetry with the if below. Is this intentional?

[kubamracek]

Let's handle simulators separately.

clang/lib/Driver/ToolChains/Darwin.cpp

void Darwin::CheckObjCARC() const {
   if (isTargetIOSBased() || isTargetWatchOSBased() ||
       (isTargetMacOS() && !isMacosxVersionLT(10, 6)))
     return;
   getDriver().Diag(diag::err_arc_unsupported_on_toolchain);
 }
 
 SanitizerMask Darwin::getSupportedSanitizers() const {
   const bool IsX86_64 = getTriple().getArch() == llvm::Triple::x86_64;
+  const bool IsAArch64 = getTriple().getArch() == llvm::Triple::aarch64;
   SanitizerMask Res = ToolChain::getSupportedSanitizers();
   Res |= SanitizerKind::Address;
   Res |= SanitizerKind::PointerCompare;
   Res |= SanitizerKind::PointerSubtract;
   Res |= SanitizerKind::Leak;
   Res |= SanitizerKind::Fuzzer;
   Res |= SanitizerKind::FuzzerNoLink;
   Res |= SanitizerKind::Function;
   Res |= SanitizerKind::ObjCCast;
 
   // 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 (!(isTargetMacOS() && isMacosxVersionLT(10, 9))
       && !(isTargetIPhoneOS() && isIPhoneOSVersionLT(5, 0)))
     Res |= SanitizerKind::Vptr;
 
-  if (isTargetMacOS()) {
-    if (IsX86_64)
-      Res |= SanitizerKind::Thread;
+  if ((IsX86_64 || IsAArch64) && isTargetMacOS()) {
   } else if (isTargetIOSSimulator() || isTargetTvOSSimulator()) {
     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

 // CHECK-MSAN-TSAN-MSAN-DARWIN-NOT: unsupported option
 
 // RUN: %clang -target x86_64-apple-darwin10 -fsanitize=thread,memory -fsanitize=memory %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-TSAN-MSAN-MSAN-DARWIN
 // CHECK-TSAN-MSAN-MSAN-DARWIN: unsupported option '-fsanitize=memory' for target 'x86_64-apple-darwin10'
 // CHECK-TSAN-MSAN-MSAN-DARWIN-NOT: unsupported option
 
 // RUN: %clang -target x86_64-apple-darwin -fsanitize=thread %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-TSAN-X86-64-DARWIN
 // CHECK-TSAN-X86-64-DARWIN-NOT: unsupported option
+// 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-iossimulator -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-tvossimulator -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