[libcxx-commits] [libcxx] [libc++] Guard include of <features.h> with __has_include (PR #127691)

[Louis Dionne via libcxx-commits]

https://github.com/ldionne created https://github.com/llvm/llvm-project/pull/127691

Some configurations define __AMDGPU__ or __NVPTX__ on platforms that don't provide <features.h>, such as CUDA on Mac.

>From 1ec64e8f73ffefa55706106e220c686463f3270f Mon Sep 17 00:00:00 2001
From: Louis Dionne <ldionne.2 at gmail.com>
Date: Tue, 18 Feb 2025 14:39:45 -0500
Subject: [PATCH] [libc++] Guard include of <features.h> with __has_include

Some configurations define __AMDGPU__ or __NVPTX__ on platforms
that don't provide <features.h>, such as CUDA on Mac.
---
 libcxx/include/__configuration/platform.h | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/libcxx/include/__configuration/platform.h b/libcxx/include/__configuration/platform.h
index cff99376ee24b..8d0f8f63f5213 100644
--- a/libcxx/include/__configuration/platform.h
+++ b/libcxx/include/__configuration/platform.h
@@ -32,12 +32,14 @@
 
 // Need to detect which libc we're using if we're on Linux.
 #if defined(__linux__) || defined(__AMDGPU__) || defined(__NVPTX__)
-#  include <features.h>
-#  if defined(__GLIBC_PREREQ)
-#    define _LIBCPP_GLIBC_PREREQ(a, b) __GLIBC_PREREQ(a, b)
-#  else
-#    define _LIBCPP_GLIBC_PREREQ(a, b) 0
-#  endif // defined(__GLIBC_PREREQ)
+#  if __has_include(<features.h>)
+#    include <features.h>
+#    if defined(__GLIBC_PREREQ)
+#      define _LIBCPP_GLIBC_PREREQ(a, b) __GLIBC_PREREQ(a, b)
+#    else
+#      define _LIBCPP_GLIBC_PREREQ(a, b) 0
+#    endif // defined(__GLIBC_PREREQ)
+#  endif
 #endif
 
 #ifndef __BYTE_ORDER__