1 #serial 12 -*- Autoconf -*-
3 dnl Find out how to get the file descriptor associated with an open DIR*.
5 # Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006 Free Software
7 # This file is free software; the Free Software Foundation
8 # gives unlimited permission to copy and/or distribute it,
9 # with or without modifications, as long as this notice is preserved.
13 AC_DEFUN([gl_FUNC_DIRFD],
15 AC_LIBSOURCES([dirfd.c, dirfd.h])
17 dnl Work around a bug of AC_EGREP_CPP in autoconf-2.57.
18 AC_REQUIRE([AC_PROG_CPP])
19 AC_REQUIRE([AC_PROG_EGREP])
20 AC_CHECK_HEADERS_ONCE([dirent.h])dnl
26 # define dirent direct
31 AC_CHECK_DECLS([dirfd], , , $dirfd_headers)
33 AC_CACHE_CHECK([whether dirfd is a macro],
34 gl_cv_func_dirfd_macro,
35 [AC_EGREP_CPP([dirent_header_defines_dirfd], [$dirfd_headers
37 dirent_header_defines_dirfd
39 gl_cv_func_dirfd_macro=yes,
40 gl_cv_func_dirfd_macro=no)])
42 # Use the replacement only if we have no function, macro,
43 # or declaration with that name.
44 if test $ac_cv_func_dirfd,$ac_cv_have_decl_dirfd,$gl_cv_func_dirfd_macro \
46 AC_REPLACE_FUNCS([dirfd])
48 [how to get the file descriptor associated with an open DIR*],
49 gl_cv_sys_dir_fd_member_name,
51 dirfd_save_CFLAGS=$CFLAGS
52 for ac_expr in d_fd dd_fd; do
54 CFLAGS="$CFLAGS -DDIR_FD_MEMBER_NAME=$ac_expr"
58 [DIR *dir_p = opendir("."); (void) dir_p->DIR_FD_MEMBER_NAME;],
61 CFLAGS=$dirfd_save_CFLAGS
62 test "$dir_fd_found" = yes && break
64 test "$dir_fd_found" = yes || ac_expr=no_such_member
66 gl_cv_sys_dir_fd_member_name=$ac_expr
69 if test $gl_cv_sys_dir_fd_member_name != no_such_member; then
70 AC_DEFINE_UNQUOTED(DIR_FD_MEMBER_NAME,
71 $gl_cv_sys_dir_fd_member_name,
72 [the name of the file descriptor member of DIR])
74 AH_VERBATIM(DIR_TO_FD,
75 [#ifdef DIR_FD_MEMBER_NAME
76 # define DIR_TO_FD(Dir_p) ((Dir_p)->DIR_FD_MEMBER_NAME)
78 # define DIR_TO_FD(Dir_p) -1