022439931f5be77efaf80b44d587666b0c9b13b5 added code that is only enabled
when COMPILER_RT_DEBUG is enabled. This code doesn't build on targets
that don't support thread local storage because the code added uses the
THREADLOCAL macro. Consequently the COMPILER_RT_DEBUG build broke for
some Apple targets (e.g. 32-bit iOS simulators).
```
/Volumes/user_data/dev/llvm/llvm.org/main/src/llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_mutex.cpp:216:8: error: thread-local storage is not supported for the current target
static THREADLOCAL InternalDeadlockDetector deadlock_detector;
^
/Volumes/user_data/dev/llvm/llvm.org/main/src/llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_internal_defs.h:227:24: note: expanded from macro 'THREADLOCAL'
# define THREADLOCAL __thread
^
1 error generated.
```
To fix this, this patch introduces a `SANITIZER_SUPPORTS_THREADLOCAL`
macro that is `1` iff thread local storage is supported by the current
target. That condition is then added to `SANITIZER_CHECK_DEADLOCKS` to
ensure the code is only enabled when thread local storage is available.
The implementation of `SANITIZER_SUPPORTS_THREADLOCAL` currently assumes
Clang. See `llvm-project/clang/include/clang/Basic/Features.def` for the
definition of the `tls` feature.
rdar://
81543007
Differential Revision: https://reviews.llvm.org/D107524
// Go linker does not support THREADLOCAL variables,
// so we can't use per-thread state.
-#define SANITIZER_CHECK_DEADLOCKS (SANITIZER_DEBUG && !SANITIZER_GO)
+#define SANITIZER_CHECK_DEADLOCKS \
+ (SANITIZER_DEBUG && !SANITIZER_GO && SANITIZER_SUPPORTS_THREADLOCAL)
#if SANITIZER_CHECK_DEADLOCKS
struct MutexMeta {
#define SANITIZER_SUPPORTS_INIT_FOR_DLOPEN 0
#endif
+// SANITIZER_SUPPORTS_THREADLOCAL
+// 1 - THREADLOCAL macro is supported by target
+// 0 - THREADLOCAL macro is not supported by target
+#ifndef __has_feature
+// TODO: Support other compilers here
+# define SANITIZER_SUPPORTS_THREADLOCAL 1
+#else
+# if __has_feature(tls)
+# define SANITIZER_SUPPORTS_THREADLOCAL 1
+# else
+# define SANITIZER_SUPPORTS_THREADLOCAL 0
+# endif
+#endif
+
#endif // SANITIZER_PLATFORM_H