[libcxx-commits] [libcxx] [libc++] Fix missing availability check for visionOS in apple_availability.h (PR #187015)

[Louis Dionne via libcxx-commits]

https://github.com/ldionne created https://github.com/llvm/llvm-project/pull/187015

Without this, we were assuming that __ulock was unavailable on visionOS and falling back to the manual implementation, when in reality we can always rely on the existence of ulock.

Fixes #186467

>From 6eccd927e336962e2cdc31a9b0a0d5c625176eb8 Mon Sep 17 00:00:00 2001
From: Louis Dionne <ldionne.2 at gmail.com>
Date: Mon, 16 Mar 2026 18:09:18 -0400
Subject: [PATCH] [libc++] Fix missing availability check for visionOS in
 apple_availability.h

Without this, we were assuming that __ulock was unavailable on visionOS
and falling back to the manual implementation, when in reality we can
always rely on the existence of ulock.

Fixes #186467
---
 libcxx/src/include/apple_availability.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libcxx/src/include/apple_availability.h b/libcxx/src/include/apple_availability.h
index fc2ad15065416..715e187546923 100644
--- a/libcxx/src/include/apple_availability.h
+++ b/libcxx/src/include/apple_availability.h
@@ -27,6 +27,10 @@
 #    if __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ >= 60000
 #      define _LIBCPP_USE_ULOCK
 #    endif
+#  elif defined(__ENVIRONMENT_OS_VERSION_MIN_REQUIRED__) && __is_target_os(visionos)
+#    if __ENVIRONMENT_OS_VERSION_MIN_REQUIRED__ >= 10000
+#      define _LIBCPP_USE_ULOCK
+#    endif
 #  endif // __ENVIRONMENT_.*_VERSION_MIN_REQUIRED__
 
 #endif // __APPLE__