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Diffstat (limited to 'gnulib/import/m4/dirfd.m4')
-rw-r--r-- | gnulib/import/m4/dirfd.m4 | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/gnulib/import/m4/dirfd.m4 b/gnulib/import/m4/dirfd.m4 new file mode 100644 index 0000000..1d7cb08 --- /dev/null +++ b/gnulib/import/m4/dirfd.m4 @@ -0,0 +1,85 @@ +# serial 24 -*- Autoconf -*- + +dnl Find out how to get the file descriptor associated with an open DIR*. + +# Copyright (C) 2001-2006, 2008-2016 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]) + + 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 +]) +]) |