[committed] libstdc++: Add TSan annotations to std::atomic>

[Jonathan Wakely via Gcc-patches]

Tested powerpc64le-linux, pushed to trunk.

-- >8 --

This adds annotations to std::atomic<shared_ptr<T>> to enable TSan to
understand the custom locking. Without this, TSan reports data races for
accesses to the _M_ptr member, even though those are correctly
synchronized using atomic operations on the tagged pointer.

libstdc++-v3/ChangeLog:

        * include/bits/shared_ptr_atomic.h (_GLIBCXX_TSAN_MUTEX_DESTROY)
        (_GLIBCXX_TSAN_MUTEX_PRE_LOCK, _GLIBCXX_TSAN_MUTEX_POST_LOCK)
        (_GLIBCXX_TSAN_MUTEX_PRE_UNLOCK, _GLIBCXX_TSAN_MUTEX_POST_UNLOCK)
        (_GLIBCXX_TSAN_MUTEX_PRE_SIGNAL, _GLIBCXX_TSAN_MUTEX_POST_SIGNAL):
        Define macros for TSan annotation functions.
        (_Sp_atomic::_Atomic_count): Add annotations.
---
 libstdc++-v3/include/bits/shared_ptr_atomic.h | 38 +++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/libstdc++-v3/include/bits/shared_ptr_atomic.h 
b/libstdc++-v3/include/bits/shared_ptr_atomic.h
index d4bd712fc7d..4580807f42c 100644
--- a/libstdc++-v3/include/bits/shared_ptr_atomic.h
+++ b/libstdc++-v3/include/bits/shared_ptr_atomic.h
@@ -32,6 +32,30 @@
 
 #include <bits/atomic_base.h>
 
+#if defined _GLIBCXX_TSAN && __has_include(<sanitizer/tsan_interface.h>)
+#include <sanitizer/tsan_interface.h>
+#define _GLIBCXX_TSAN_MUTEX_DESTROY(X) \
+  __tsan_mutex_destroy(X, __tsan_mutex_not_static)
+#define _GLIBCXX_TSAN_MUTEX_PRE_LOCK(X) \
+  __tsan_mutex_pre_lock(X, __tsan_mutex_not_static)
+#define _GLIBCXX_TSAN_MUTEX_POST_LOCK(X) \
+  __tsan_mutex_post_lock(X, __tsan_mutex_not_static, 0)
+#define _GLIBCXX_TSAN_MUTEX_PRE_UNLOCK(X) \
+  __tsan_mutex_pre_unlock(X, __tsan_mutex_not_static)
+#define _GLIBCXX_TSAN_MUTEX_POST_UNLOCK(X) \
+  __tsan_mutex_post_unlock(X, __tsan_mutex_not_static)
+#define _GLIBCXX_TSAN_MUTEX_PRE_SIGNAL(X) __tsan_mutex_pre_signal(X, 0)
+#define _GLIBCXX_TSAN_MUTEX_POST_SIGNAL(X) __tsan_mutex_post_signal(X, 0)
+#else
+#define _GLIBCXX_TSAN_MUTEX_DESTROY(X)
+#define _GLIBCXX_TSAN_MUTEX_PRE_LOCK(X)
+#define _GLIBCXX_TSAN_MUTEX_POST_LOCK(X)
+#define _GLIBCXX_TSAN_MUTEX_PRE_UNLOCK(X)
+#define _GLIBCXX_TSAN_MUTEX_POST_UNLOCK(X)
+#define _GLIBCXX_TSAN_MUTEX_PRE_SIGNAL(X)
+#define _GLIBCXX_TSAN_MUTEX_POST_SIGNAL(X)
+#endif
+
 namespace std _GLIBCXX_VISIBILITY(default)
 {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION
@@ -377,6 +401,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
        ~_Atomic_count()
        {
          auto __val = _M_val.load(memory_order_relaxed);
+         _GLIBCXX_TSAN_MUTEX_DESTROY(&_M_val);
          __glibcxx_assert(!(__val & _S_lock_bit));
          if (auto __pi = reinterpret_cast<pointer>(__val))
            {
@@ -406,6 +431,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
              __current = _M_val.load(memory_order_relaxed);
            }
 
+         _GLIBCXX_TSAN_MUTEX_PRE_LOCK(&_M_val);
+
          while (!_M_val.compare_exchange_strong(__current,
                                                 __current | _S_lock_bit,
                                                 __o,
@@ -416,6 +443,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 #endif
              __current = __current & ~_S_lock_bit;
            }
+         _GLIBCXX_TSAN_MUTEX_POST_LOCK(&_M_val);
          return reinterpret_cast<pointer>(__current);
        }
 
@@ -423,7 +451,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
        void
        unlock(memory_order __o) const noexcept
        {
+         _GLIBCXX_TSAN_MUTEX_PRE_UNLOCK(&_M_val);
          _M_val.fetch_sub(1, __o);
+         _GLIBCXX_TSAN_MUTEX_POST_UNLOCK(&_M_val);
        }
 
        // Swaps the values of *this and __c, and unlocks *this.
@@ -434,7 +464,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
          if (__o != memory_order_seq_cst)
            __o = memory_order_release;
          auto __x = reinterpret_cast<uintptr_t>(__c._M_pi);
+         _GLIBCXX_TSAN_MUTEX_PRE_UNLOCK(&_M_val);
          __x = _M_val.exchange(__x, __o);
+         _GLIBCXX_TSAN_MUTEX_POST_UNLOCK(&_M_val);
          __c._M_pi = reinterpret_cast<pointer>(__x & ~_S_lock_bit);
        }
 
@@ -443,20 +475,26 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
        void
        _M_wait_unlock(memory_order __o) const noexcept
        {
+         _GLIBCXX_TSAN_MUTEX_PRE_UNLOCK(&_M_val);
          auto __v = _M_val.fetch_sub(1, memory_order_relaxed);
+         _GLIBCXX_TSAN_MUTEX_POST_UNLOCK(&_M_val);
          _M_val.wait(__v & ~_S_lock_bit, __o);
        }
 
        void
        notify_one() noexcept
        {
+         _GLIBCXX_TSAN_MUTEX_PRE_SIGNAL(&_M_val);
          _M_val.notify_one();
+         _GLIBCXX_TSAN_MUTEX_POST_SIGNAL(&_M_val);
        }
 
        void
        notify_all() noexcept
        {
+         _GLIBCXX_TSAN_MUTEX_PRE_SIGNAL(&_M_val);
          _M_val.notify_all();
+         _GLIBCXX_TSAN_MUTEX_POST_SIGNAL(&_M_val);
        }
 #endif
 
-- 
2.37.3