[llvm-branch-commits] [libcxx] dfca2d4 - [libc++] Make once_flag pointer-sized on MinGW (#219895)

[via llvm-branch-commits]

Author: Nikolas Klauser
Date: 2026-08-31T21:23:06+02:00
New Revision: dfca2d49b080c0f2d01b79de2ae94043cb2dca6e

URL: https://github.com/llvm/llvm-project/commit/dfca2d49b080c0f2d01b79de2ae94043cb2dca6e
DIFF: https://github.com/llvm/llvm-project/commit/dfca2d49b080c0f2d01b79de2ae94043cb2dca6e.diff

LOG: [libc++] Make once_flag pointer-sized on MinGW (#219895)

This is ABI breaking on MinGW. However, the impact is deemed small
enough that it's acceptable.

Added: 
    

Modified: 
    libcxx/include/__mutex/once_flag.h

Removed: 
    


################################################################################
diff  --git a/libcxx/include/__mutex/once_flag.h b/libcxx/include/__mutex/once_flag.h
index 9999852b8b78a..63c97a2921412 100644
--- a/libcxx/include/__mutex/once_flag.h
+++ b/libcxx/include/__mutex/once_flag.h
@@ -52,7 +52,7 @@ struct once_flag {
   once_flag(const once_flag&)            = delete;
   once_flag& operator=(const once_flag&) = delete;
 
-#if defined(_LIBCPP_ABI_MICROSOFT)
+#ifdef _WIN32
   typedef uintptr_t _State_type;
 #else
   typedef unsigned long _State_type;