Fix macOS posix_spawn_file_actions_addchdir availability handling

[arshidkv12]

#21720

[NattyNarwhal]

I think this might be able to be simplified by checking __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__/__ENVIRONMENT_OS_VERSION_MIN_REQUIRED__ instead, since we don't need any real runtime differences, it's just a symbol name, and the old one is unlikely to go away right now even if it's deprecated. It should respect -mmacosx-version-min as well.

[arshidkv12]

Thank you

[NattyNarwhal]

Still triggers the deprecation on 26;

/Users/calvin/src/php-src/ext/standard/proc_open.c:1409:7: error: 'posix_spawn_file_actions_addchdir_np' is deprecated: first deprecated in macOS
      26.0 - posix_spawn_file_actions_addchdir(3) has replaced posix_spawn_file_actions_addchdir_np(3) [-Werror,-Wdeprecated-declarations]
 1409 |                 r = POSIX_SPAWN_FILE_ACTIONS_ADDCHDIR(&factions, cwd);
      |                     ^
/Users/calvin/src/php-src/ext/standard/proc_open.c:53:44: note: expanded from macro 'POSIX_SPAWN_FILE_ACTIONS_ADDCHDIR'
   53 |         #define POSIX_SPAWN_FILE_ACTIONS_ADDCHDIR posix_spawn_file_actions_addchdir_np
      |                                                   ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/spawn.h:182:9: note: 
      'posix_spawn_file_actions_addchdir_np' has been explicitly marked deprecated here
  182 | int     posix_spawn_file_actions_addchdir_np(posix_spawn_file_actions_t *,
      |         ^

I think you need the AvailabilityMacros.h header to use the unembellished macro names:

calvin@anika-5 php-src % echo | cc -dM -E -mmacosx-version-min=10.15 - | grep MAC_OS_X_VERSION_MIN_REQUIRED
#define __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ 101500
calvin@anika-5 php-src % echo "#include <AvailabilityMacros.h>" | cc -dM -E -mmacosx-version-min=10.15 - | grep MAC_OS_X_VERSION_MIN_REQUIRED
#define MAC_OS_X_VERSION_MIN_REQUIRED __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__
#define __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ 101500
#define __MAC_OS_X_VERSION_MIN_REQUIRED __ENVIRONMENT_OS_VERSION_MIN_REQUIRED__

[NattyNarwhal]

Builds with -enable-werror for me on 26 (well, and -Wno-unterminated-string-initialization, but that's a lexbor thing).

[arshidkv12]

Please check it

[NickSdot]

I can reproduce this, and tested this PR's patch locally: it fixes the crash for me.

Environment:

• macOS 15.7.3 (24G419)
• arm64
• Xcode 26.3 (Build version 17C529)

➜ printf '#include <AvailabilityMacros.h>\nMAC_OS_X_VERSION_MIN_REQUIRED\n' | cc -E - | tail -n 1
150000

➜ nm -gU /usr/lib/system/libsystem_kernel.dylib | rg posix_spawn_file_actions_addchdir
0000000000015318 T _posix_spawn_file_actions_addchdir_np

➜ nm -m sapi/cli/php | grep posix_spawn_file_actions_addchdir
(undefined) external _posix_spawn_file_actions_addchdir_np (from libSystem)

Agent Feedback

I first hit this through the PHPT runner, which segfaulted immediately, but I was also able to reduce it to a minimal proc_open() repro:

<?php
echo "before\n";
$spec = [
    0 => ["pipe", "r"],
    1 => ["pipe", "w"],
    2 => ["pipe", "w"],
];
proc_open(["/bin/echo", "ok"], $spec, $pipes, getcwd(), []);
echo "after\n";

With current upstream proc_open.c, this prints:

before

and then segfaults.

From what I can tell, this started after commit c3a1214 (ext/standard: Use posix_spawn_file_actions_addchdir when available), which prefers posix_spawn_file_actions_addchdir() when the SDK advertises it.

With this PR's fix applied and rebuilt it works. On my setup that selects posix_spawn_file_actions_addchdir_np for MAC_OS_X_VERSION_MIN_REQUIRED == 150000, and the crash goes away:

• the minimal proc_open() repro prints before / after
• the PHPT runner works again