Disable thread safety analysis for some functions in __thread_support

Many thread-related libc++ test cases fail on FreeBSD, due to the
following -Werror warnings:

    In file included from test/std/thread/thread.threads/thread.thread.this/sleep_until.pass.cpp:17:
    In file included from include/thread:97:
    In file included from include/__mutex_base:17:
    include/__threading_support:222:1: error: mutex '__m' is still held at the end of function [-Werror,-Wthread-safety-analysis]
    }
    ^
    include/__threading_support:221:10: note: mutex acquired here
      return pthread_mutex_lock(__m);
             ^
    include/__threading_support:231:10: error: releasing mutex '__m' that was not held [-Werror,-Wthread-safety-analysis]
      return pthread_mutex_unlock(__m);
             ^
    include/__threading_support:242:1: error: mutex '__m' is still held at the end of function [-Werror,-Wthread-safety-analysis]
    }
    ^
    include/__threading_support:241:10: note: mutex acquired here
      return pthread_mutex_lock(__m);
             ^
    include/__threading_support:251:10: error: releasing mutex '__m' that was not held [-Werror,-Wthread-safety-analysis]
      return pthread_mutex_unlock(__m);
             ^
    include/__threading_support:272:10: error: calling function 'pthread_cond_wait' requires holding mutex '__m' exclusively [-Werror,-Wthread-safety-analysis]
      return pthread_cond_wait(__cv, __m);
             ^
    include/__threading_support:278:10: error: calling function 'pthread_cond_timedwait' requires holding mutex '__m' exclusively [-Werror,-Wthread-safety-analysis]
      return pthread_cond_timedwait(__cv, __m, __ts);
             ^
    6 errors generated.

This is because on FreeBSD, the pthread functions have lock annotations.
Since the functions in __thread_support are internal to libc++ only, add
no_thread_safety_analysis attributes to suppress these warnings.

Reviewers: mclow.lists, EricWF, delesley, aaron.ballman
Reviewed By: aaron.ballman
Subscribers: ed, aaron.ballman, joerg, emaste, cfe-commits
Differential Revision: https://reviews.llvm.org/D28520

llvm-svn: 293197

1 files changed, 14 insertions, 8 deletions

diff --git a/libcxx/include/__threading_support b/libcxx/include/__threading_support
index dfe7fe111e6..d049c9193d9 100644
--- a/libcxx/include/__threading_support
+++ b/libcxx/include/__threading_support
@@ -40,6 +40,12 @@
 #define _LIBCPP_THREAD_ABI_VISIBILITY inline _LIBCPP_INLINE_VISIBILITY
 #endif
 
+#if defined(__FreeBSD__) && defined(__clang__) && __has_attribute(no_thread_safety_analysis)
+#define _LIBCPP_NO_THREAD_SAFETY_ANALYSIS __attribute__((no_thread_safety_analysis))
+#else
+#define _LIBCPP_NO_THREAD_SAFETY_ANALYSIS
+#endif
+
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 #if defined(_LIBCPP_HAS_THREAD_API_PTHREAD)
@@ -102,25 +108,25 @@ typedef DWORD __libcpp_tls_key;
 _LIBCPP_THREAD_ABI_VISIBILITY
 int __libcpp_recursive_mutex_init(__libcpp_recursive_mutex_t *__m);
 
-_LIBCPP_THREAD_ABI_VISIBILITY
+_LIBCPP_THREAD_ABI_VISIBILITY _LIBCPP_NO_THREAD_SAFETY_ANALYSIS
 int __libcpp_recursive_mutex_lock(__libcpp_recursive_mutex_t *__m);
 
-_LIBCPP_THREAD_ABI_VISIBILITY
+_LIBCPP_THREAD_ABI_VISIBILITY _LIBCPP_NO_THREAD_SAFETY_ANALYSIS
 bool __libcpp_recursive_mutex_trylock(__libcpp_recursive_mutex_t *__m);
 
-_LIBCPP_THREAD_ABI_VISIBILITY
+_LIBCPP_THREAD_ABI_VISIBILITY _LIBCPP_NO_THREAD_SAFETY_ANALYSIS
 int __libcpp_recursive_mutex_unlock(__libcpp_recursive_mutex_t *__m);
 
 _LIBCPP_THREAD_ABI_VISIBILITY
 int __libcpp_recursive_mutex_destroy(__libcpp_recursive_mutex_t *__m);
 
-_LIBCPP_THREAD_ABI_VISIBILITY
+_LIBCPP_THREAD_ABI_VISIBILITY _LIBCPP_NO_THREAD_SAFETY_ANALYSIS
 int __libcpp_mutex_lock(__libcpp_mutex_t *__m);
 
-_LIBCPP_THREAD_ABI_VISIBILITY
+_LIBCPP_THREAD_ABI_VISIBILITY _LIBCPP_NO_THREAD_SAFETY_ANALYSIS
 bool __libcpp_mutex_trylock(__libcpp_mutex_t *__m);
 
-_LIBCPP_THREAD_ABI_VISIBILITY
+_LIBCPP_THREAD_ABI_VISIBILITY _LIBCPP_NO_THREAD_SAFETY_ANALYSIS
 int __libcpp_mutex_unlock(__libcpp_mutex_t *__m);
 
 _LIBCPP_THREAD_ABI_VISIBILITY
@@ -133,10 +139,10 @@ int __libcpp_condvar_signal(__libcpp_condvar_t* __cv);
 _LIBCPP_THREAD_ABI_VISIBILITY
 int __libcpp_condvar_broadcast(__libcpp_condvar_t* __cv);
 
-_LIBCPP_THREAD_ABI_VISIBILITY
+_LIBCPP_THREAD_ABI_VISIBILITY _LIBCPP_NO_THREAD_SAFETY_ANALYSIS
 int __libcpp_condvar_wait(__libcpp_condvar_t* __cv, __libcpp_mutex_t* __m);
 
-_LIBCPP_THREAD_ABI_VISIBILITY
+_LIBCPP_THREAD_ABI_VISIBILITY _LIBCPP_NO_THREAD_SAFETY_ANALYSIS
 int __libcpp_condvar_timedwait(__libcpp_condvar_t *__cv, __libcpp_mutex_t *__m,
                                timespec *__ts);