]> git.cworth.org Git - tar/blobdiff - m4/dirfd.m4
upstream: Fix extraction of device nodes.
[tar] / m4 / dirfd.m4
index baab4dddadad246ee914801d05ff2dbc8a5f9f20..48b7bae1a846d549a14a63eb5aa9cdff5d4cc0d6 100644 (file)
@@ -1,9 +1,8 @@
-#serial 15   -*- Autoconf -*-
+# serial 18   -*- Autoconf -*-
 
 dnl Find out how to get the file descriptor associated with an open DIR*.
 
-# Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2008 Free Software
-# Foundation, Inc.
+# Copyright (C) 2001-2006, 2008-2010 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.
@@ -22,7 +21,7 @@ AC_DEFUN([gl_FUNC_DIRFD],
   AC_REQUIRE([AC_PROG_CPP])
   AC_REQUIRE([AC_PROG_EGREP])
 
-  AC_CHECK_FUNCS(dirfd)
+  AC_CHECK_FUNCS([dirfd])
   AC_CHECK_DECLS([dirfd], , ,
     [#include <sys/types.h>
      #include <dirent.h>])
@@ -41,40 +40,42 @@ AC_DEFUN([gl_FUNC_DIRFD],
        gl_cv_func_dirfd_macro=yes,
        gl_cv_func_dirfd_macro=no)])
 
-  # Use the replacement only if we have no function, macro,
-  # or declaration with that name.
-  if test $ac_cv_func_dirfd,$ac_cv_have_decl_dirfd,$gl_cv_func_dirfd_macro \
-      = no,no,no; then
-    AC_REPLACE_FUNCS([dirfd])
+  # 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 $ac_cv_have_decl_dirfd = yes; then
+      # If the system declares dirfd already, let's declare rpl_dirfd instead.
+      REPLACE_DIRFD=1
+    fi
+    AC_LIBOBJ([dirfd])
     AC_CACHE_CHECK(
-             [how to get the file descriptor associated with an open DIR*],
-                  gl_cv_sys_dir_fd_member_name,
+              [how to get the file descriptor associated with an open DIR*],
+                   gl_cv_sys_dir_fd_member_name,
       [
-       dirfd_save_CFLAGS=$CFLAGS
-       for ac_expr in d_fd dd_fd; do
+        dirfd_save_CFLAGS=$CFLAGS
+        for ac_expr in d_fd dd_fd; do
 
-         CFLAGS="$CFLAGS -DDIR_FD_MEMBER_NAME=$ac_expr"
-         AC_TRY_COMPILE(
-           [#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 "$dir_fd_found" = yes || ac_expr=no_such_member
+          CFLAGS="$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=$ac_expr
+        gl_cv_sys_dir_fd_member_name=$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])
+      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
+                [#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