1# serial 6 2# See if we need to provide readlinkat replacement. 3 4dnl Copyright (C) 2009-2021 Free Software Foundation, Inc. 5dnl This file is free software; the Free Software Foundation 6dnl gives unlimited permission to copy and/or distribute it, 7dnl with or without modifications, as long as this notice is preserved. 8 9# Written by Eric Blake. 10 11AC_DEFUN([gl_FUNC_READLINKAT], 12[ 13 AC_REQUIRE([gl_UNISTD_H_DEFAULTS]) 14 AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) 15 AC_CHECK_FUNCS_ONCE([readlinkat]) 16 AC_REQUIRE([gl_FUNC_READLINK]) 17 if test $ac_cv_func_readlinkat = no; then 18 HAVE_READLINKAT=0 19 else 20 AC_CACHE_CHECK([whether readlinkat signature is correct], 21 [gl_cv_decl_readlinkat_works], 22 [AC_COMPILE_IFELSE( 23 [AC_LANG_PROGRAM( 24 [[#include <unistd.h> 25 /* Check whether original declaration has correct type. */ 26 ssize_t readlinkat (int, char const *, char *, size_t);]])], 27 [gl_cv_decl_readlinkat_works=yes], 28 [gl_cv_decl_readlinkat_works=no])]) 29 # Assume readlinkat has the same bugs as readlink, 30 # as is the case on OS X 10.10 with trailing slashes. 31 case $gl_cv_decl_readlinkat_works,$gl_cv_func_readlink_trailing_slash,$gl_cv_func_readlink_truncate in 32 *yes,*yes,*yes) 33 ;; 34 *) 35 REPLACE_READLINKAT=1 36 ;; 37 esac 38 fi 39]) 40