87 lines
2.6 KiB
Plaintext
87 lines
2.6 KiB
Plaintext
# serial 26 -*- Autoconf -*-
|
|
|
|
dnl Find out how to get the file descriptor associated with an open DIR*.
|
|
|
|
# Copyright (C) 2001-2006, 2008-2021 Free Software Foundation, Inc.
|
|
# This file is free software; the Free Software Foundation
|
|
# gives unlimited permission to copy and/or distribute it,
|
|
# with or without modifications, as long as this notice is preserved.
|
|
|
|
dnl From Jim Meyering
|
|
|
|
AC_DEFUN([gl_FUNC_DIRFD],
|
|
[
|
|
AC_REQUIRE([gl_DIRENT_H_DEFAULTS])
|
|
AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
|
|
|
|
dnl Persuade glibc <dirent.h> to declare dirfd().
|
|
AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
|
|
|
|
AC_CHECK_FUNCS([dirfd])
|
|
AC_CHECK_DECLS([dirfd], , ,
|
|
[[#include <sys/types.h>
|
|
#include <dirent.h>]])
|
|
if test $ac_cv_have_decl_dirfd = no; then
|
|
HAVE_DECL_DIRFD=0
|
|
fi
|
|
|
|
AC_CACHE_CHECK([whether dirfd is a macro],
|
|
[gl_cv_func_dirfd_macro],
|
|
[AC_EGREP_CPP([dirent_header_defines_dirfd], [
|
|
#include <sys/types.h>
|
|
#include <dirent.h>
|
|
#ifdef dirfd
|
|
dirent_header_defines_dirfd
|
|
#endif],
|
|
[gl_cv_func_dirfd_macro=yes],
|
|
[gl_cv_func_dirfd_macro=no])])
|
|
|
|
# Use the replacement if we have no function or macro with that name,
|
|
# or if OS/2 kLIBC whose dirfd() does not work.
|
|
# Replace only if the system declares dirfd already.
|
|
case $ac_cv_func_dirfd,$gl_cv_func_dirfd_macro,$host_os,$ac_cv_have_decl_dirfd in
|
|
no,no,*,yes | *,*,os2*,yes)
|
|
REPLACE_DIRFD=1
|
|
AC_DEFINE([REPLACE_DIRFD], [1],
|
|
[Define to 1 if gnulib's dirfd() replacement is used.]);;
|
|
esac
|
|
])
|
|
|
|
dnl Prerequisites of lib/dirfd.c.
|
|
AC_DEFUN([gl_PREREQ_DIRFD],
|
|
[
|
|
AC_CACHE_CHECK([how to get the file descriptor associated with an open DIR*],
|
|
[gl_cv_sys_dir_fd_member_name],
|
|
[
|
|
dirfd_save_CFLAGS=$CFLAGS
|
|
for ac_expr in d_fd dd_fd; do
|
|
|
|
CFLAGS="$CFLAGS -DDIR_FD_MEMBER_NAME=$ac_expr"
|
|
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
|
|
#include <sys/types.h>
|
|
#include <dirent.h>]],
|
|
[[DIR *dir_p = opendir("."); (void) dir_p->DIR_FD_MEMBER_NAME;]])],
|
|
[dir_fd_found=yes]
|
|
)
|
|
CFLAGS=$dirfd_save_CFLAGS
|
|
test "$dir_fd_found" = yes && break
|
|
done
|
|
test "$dir_fd_found" = yes || ac_expr=no_such_member
|
|
|
|
gl_cv_sys_dir_fd_member_name=$ac_expr
|
|
]
|
|
)
|
|
if test $gl_cv_sys_dir_fd_member_name != no_such_member; then
|
|
AC_DEFINE_UNQUOTED([DIR_FD_MEMBER_NAME],
|
|
[$gl_cv_sys_dir_fd_member_name],
|
|
[the name of the file descriptor member of DIR])
|
|
fi
|
|
AH_VERBATIM([DIR_TO_FD],
|
|
[#ifdef DIR_FD_MEMBER_NAME
|
|
# define DIR_TO_FD(Dir_p) ((Dir_p)->DIR_FD_MEMBER_NAME)
|
|
#else
|
|
# define DIR_TO_FD(Dir_p) -1
|
|
#endif
|
|
])
|
|
])
|