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emacs/m4/fdopendir.m4
2022-01-01 02:45:51 -05:00

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# serial 14
# See if we need to provide fdopendir.
dnl Copyright (C) 2009-2022 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.
# Written by Eric Blake.
AC_DEFUN([gl_FUNC_FDOPENDIR],
[
AC_REQUIRE([gl_DIRENT_H_DEFAULTS])
AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
dnl FreeBSD 7.3 has the function, but failed to declare it.
AC_CHECK_DECLS([fdopendir], [], [HAVE_DECL_FDOPENDIR=0], [[
#include <dirent.h>
]])
AC_CHECK_FUNCS_ONCE([fdopendir])
if test $ac_cv_func_fdopendir = no; then
HAVE_FDOPENDIR=0
else
AC_CACHE_CHECK([whether fdopendir works],
[gl_cv_func_fdopendir_works],
[AC_RUN_IFELSE(
[AC_LANG_PROGRAM([[
#include <dirent.h>
#include <fcntl.h>
#include <unistd.h>
]GL_MDA_DEFINES[
#if !HAVE_DECL_FDOPENDIR
extern
# ifdef __cplusplus
"C"
# endif
DIR *fdopendir (int);
#endif
]],
[[int result = 0;
int fd = open ("conftest.c", O_RDONLY);
if (fd < 0) result |= 1;
if (fdopendir (fd)) result |= 2;
if (close (fd)) result |= 4;
return result;
]])],
[gl_cv_func_fdopendir_works=yes],
[gl_cv_func_fdopendir_works=no],
[case "$host_os" in
# Guess yes on glibc systems.
*-gnu*) gl_cv_func_fdopendir_works="guessing yes" ;;
# Guess yes on musl systems.
*-musl*) gl_cv_func_fdopendir_works="guessing yes" ;;
# If we don't know, obey --enable-cross-guesses.
*) gl_cv_func_fdopendir_works="$gl_cross_guess_normal" ;;
esac
])])
case "$gl_cv_func_fdopendir_works" in
*yes) ;;
*)
REPLACE_FDOPENDIR=1
;;
esac
fi
])