-#serial 1
+# serial 19 -*- Autoconf -*-
dnl Find out how to get the file descriptor associated with an open DIR*.
+
+# Copyright (C) 2001-2006, 2008-2011 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([UTILS_FUNC_DIRFD],
+AC_DEFUN([gl_FUNC_DIRFD],
[
- AC_HEADER_DIRENT
- AC_REPLACE_FUNCS([dirfd])
- dirfd_headers='
-#if HAVE_DIRENT_H
-# include <dirent.h>
-#else /* not HAVE_DIRENT_H */
-# define dirent direct
-# if HAVE_SYS_NDIR_H
-# include <sys/ndir.h>
-# endif /* HAVE_SYS_NDIR_H */
-# if HAVE_SYS_DIR_H
-# include <sys/dir.h>
-# endif /* HAVE_SYS_DIR_H */
-# if HAVE_NDIR_H
-# include <ndir.h>
-# endif /* HAVE_NDIR_H */
-#endif /* HAVE_DIRENT_H */
-'
- AC_CHECK_DECLS([dirfd], , , $dirfd_headers)
- if test $ac_cv_func_dirfd = no; then
+ AC_REQUIRE([gl_DIRENT_H_DEFAULTS])
+ gl_REPLACE_DIRENT_H
+
+ 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 only if we have no function or macro with that name.
+ if test $ac_cv_func_dirfd,$gl_cv_func_dirfd_macro = no,no; then
+ if test $ac_cv_have_decl_dirfd = yes; then
+ # If the system declares dirfd already, let's declare rpl_dirfd instead.
+ REPLACE_DIRFD=1
+ fi
+ AC_LIBOBJ([dirfd])
AC_CACHE_CHECK(
- [how to get the file descriptor associated with an open DIR*],
- ac_cv_sys_dir_to_fd,
+ [how to get the file descriptor associated with an open DIR*],
+ gl_cv_sys_dir_fd_member_name,
[
- dirfd_save_DEFS=$DEFS
- for ac_expr in \
- \
- '# Solaris' \
- 'dir_p->d_fd' \
- \
- '# Solaris' \
- 'dir_p->dd_fd' \
- \
- '# systems for which the info is not available' \
- -1 \
- ; do
+ dirfd_save_CFLAGS=$CFLAGS
+ for ac_expr in d_fd dd_fd; do
- # Skip each embedded comment.
- case "$ac_expr" in '#'*) continue;; esac
+ 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 "$dir_fd_found" = yes || ac_expr=no_such_member
- DEFS="$DEFS -DDIR_TO_FD=$ac_expr"
- AC_TRY_COMPILE(
- [$dirfd_headers
- ],
- [DIR *dir_p = opendir("."); (void) ($ac_expr);],
- dir_fd_done=yes
- )
- DEFS=$dirfd_save_DEFS
- test "$dir_fd_done" = yes && break
- done
-
- ac_cv_sys_dir_to_fd=$ac_expr
+ gl_cv_sys_dir_fd_member_name=$ac_expr
]
)
- AC_DEFINE_UNQUOTED(DIR_TO_FD,
- $ac_cv_sys_dir_to_fd,
- [the file descriptor associated with `dir_p'])
+ 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
+])
fi
])