posix detects posix_pathconf api.

alpine linux throws undefined reference at build time, thus
 not assuming it s necessarily available.

Closes GH-10350.

Author: devnexen

ext/posix/config.m4

@@ -10,7 +10,7 @@ if test "$PHP_POSIX" = "yes"; then
 
   AC_CHECK_HEADERS([sys/mkdev.h sys/sysmacros.h])
 
-  AC_CHECK_FUNCS(seteuid setegid setsid getsid getpgid ctermid mkfifo mknod setrlimit getrlimit getgroups makedev initgroups getgrgid_r)
+  AC_CHECK_FUNCS(seteuid setegid setsid getsid getpgid ctermid mkfifo mknod setrlimit getrlimit getgroups makedev initgroups getgrgid_r posix_pathconf)
 
   AC_MSG_CHECKING([for working ttyname_r() implementation])
   AC_RUN_IFELSE([AC_LANG_SOURCE([[

ext/posix/posix.c

@@ -1197,6 +1197,7 @@ PHP_FUNCTION(posix_sysconf)
 	RETURN_LONG(sysconf(conf_id));
 }
 
+#ifdef HAVE_POSIX_PATHCONF
 PHP_FUNCTION(posix_pathconf)
 {
 	zend_long name, ret;
@@ -1257,3 +1258,4 @@ PHP_FUNCTION(posix_fpathconf)
 
 	RETURN_LONG(ret);
 }
+#endif

ext/posix/posix.stub.php

@@ -428,6 +428,8 @@ function posix_initgroups(string $username, int $group_id): bool {}
 
 function posix_sysconf(int $conf_id): int {}
 
+#ifdef HAVE_POSIX_PATHCONF
 function posix_pathconf(string $path, int $name): int|false {}
 /** @param resource|int $file_descriptor */
 function posix_fpathconf($file_descriptor, int $name): int|false {}
+#endif

ext/posix/posix_arginfo.h

@@ -2,6 +2,10 @@
 Test posix_fpathconf
 --EXTENSIONS--
 posix
+--SKIPIF--
+<?php
+if (!function_exists("posix_pathconf")) die("skip only platforms with posix_pathconf");
+?>
 --FILE--
 <?php
 var_dump(posix_fpathconf(-1, POSIX_PC_PATH_MAX));

ext/posix/tests/posix_fpathconf.phpt

@@ -2,6 +2,10 @@
 Test posix_pathconf
 --EXTENSIONS--
 posix
+--SKIPIF--
+<?php
+if (!function_exists("posix_pathconf")) die("skip only platforms with posix_pathconf");
+?>
 --FILE--
 <?php
 try {