[libcxx-commits] [libcxx] c53789f - [libc++][NFC] Clean up atomic_support.h (#212464)

[via libcxx-commits]

Author: Nikolas Klauser
Date: 2026-07-29T14:09:16+02:00
New Revision: c53789fcf54979f7986d2e396920b725ce88f3e4

URL: https://github.com/llvm/llvm-project/commit/c53789fcf54979f7986d2e396920b725ce88f3e4
DIFF: https://github.com/llvm/llvm-project/commit/c53789fcf54979f7986d2e396920b725ce88f3e4.diff

LOG: [libc++][NFC] Clean up atomic_support.h (#212464)

We don't support any compilers which don't have the atomic builtins, so
we don't need to check whether they exist. There is also no need for an
anonymous namespace, since all the functions are inline.

Added: 
    

Modified: 
    libcxx/src/include/atomic_support.h

Removed: 
    


################################################################################
diff  --git a/libcxx/src/include/atomic_support.h b/libcxx/src/include/atomic_support.h
index 410f64b267111..305a53e2ee2e0 100644
--- a/libcxx/src/include/atomic_support.h
+++ b/libcxx/src/include/atomic_support.h
@@ -10,30 +10,10 @@
 #define ATOMIC_SUPPORT_H
 
 #include <__config>
-#include <memory> // for __libcpp_relaxed_load
-
-#if defined(__clang__) && __has_builtin(__atomic_load_n) && __has_builtin(__atomic_store_n) &&                         \
-    __has_builtin(__atomic_add_fetch) && __has_builtin(__atomic_exchange_n) &&                                         \
-    __has_builtin(__atomic_compare_exchange_n) && defined(__ATOMIC_RELAXED) && defined(__ATOMIC_CONSUME) &&            \
-    defined(__ATOMIC_ACQUIRE) && defined(__ATOMIC_RELEASE) && defined(__ATOMIC_ACQ_REL) && defined(__ATOMIC_SEQ_CST)
-#  define _LIBCPP_HAS_ATOMIC_BUILTINS
-#elif defined(_LIBCPP_COMPILER_GCC)
-#  define _LIBCPP_HAS_ATOMIC_BUILTINS
-#endif
-
-#if !defined(_LIBCPP_HAS_ATOMIC_BUILTINS) && _LIBCPP_HAS_THREADS
-#  if defined(_LIBCPP_WARNING)
-_LIBCPP_WARNING("Building libc++ without __atomic builtins is unsupported")
-#  else
-#    warning Building libc++ without __atomic builtins is unsupported
-#  endif
-#endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-namespace {
-
-#if defined(_LIBCPP_HAS_ATOMIC_BUILTINS) && _LIBCPP_HAS_THREADS
+#if _LIBCPP_HAS_THREADS
 
 enum __libcpp_atomic_order {
   _AO_Relaxed = __ATOMIC_RELAXED,
@@ -125,8 +105,6 @@ __libcpp_atomic_compare_exchange(_ValueType* __val, _ValueType* __expected, _Val
 
 #endif // _LIBCPP_HAS_THREADS
 
-} // namespace
-
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // ATOMIC_SUPPORT_H