Imported Upstream version 1.24

[tar] / m4 / fchdir.m4

diff --git a/m4/fchdir.m4 b/m4/fchdir.m4
index fd170d294470c0ae919b02c7c27d092b2a946d4f..7bc691def2755cd00e7b92ee26cd8b6aaea0ff55 100644 (file)
--- a/m4/fchdir.m4
+++ b/m4/fchdir.m4
@@ -1,5 +1,5 @@
-# fchdir.m4 serial 4
-dnl Copyright (C) 2006-2007 Free Software Foundation, Inc.
+# fchdir.m4 serial 14
+dnl Copyright (C) 2006-2010 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.
@@ -7,19 +7,40 @@ dnl with or without modifications, as long as this notice is preserved.
 AC_DEFUN([gl_FUNC_FCHDIR],
 [
   AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+  AC_REQUIRE([gl_DIRENT_H_DEFAULTS])
+  AC_REQUIRE([gl_SYS_STAT_H_DEFAULTS])
   AC_CHECK_FUNCS_ONCE([fchdir])
   if test $ac_cv_func_fchdir = no; then
-    REPLACE_FCHDIR=1
+    HAVE_FCHDIR=0
     AC_LIBOBJ([fchdir])
     gl_PREREQ_FCHDIR
-    AC_DEFINE([FCHDIR_REPLACEMENT], 1,
-      [Define if gnulib's fchdir() replacement is used.])
-    gl_CHECK_NEXT_HEADERS([dirent.h])
-    DIRENT_H='dirent.h'
-  else
-    DIRENT_H=
+    AC_DEFINE([REPLACE_FCHDIR], [1],
+      [Define to 1 if gnulib's fchdir() replacement is used.])
+    dnl We must also replace anything that can manipulate a directory fd,
+    dnl to keep our bookkeeping up-to-date.  We don't have to replace
+    dnl fstatat, since no platform has fstatat but lacks fchdir.
+    REPLACE_OPENDIR=1
+    REPLACE_CLOSEDIR=1
+    REPLACE_DUP=1
+    gl_REPLACE_OPEN
+    gl_REPLACE_CLOSE
+    gl_REPLACE_DUP2
+    dnl dup3 is already unconditionally replaced
+    gl_REPLACE_FCNTL
+    gl_REPLACE_DIRENT_H
+    AC_CACHE_CHECK([whether open can visit directories],
+      [gl_cv_func_open_directory_works],
+      [AC_RUN_IFELSE([AC_LANG_PROGRAM([[#include <fcntl.h>
+]], [return open(".", O_RDONLY) < 0;])],
+        [gl_cv_func_open_directory_works=yes],
+        [gl_cv_func_open_directory_works=no],
+        [gl_cv_func_open_directory_works="guessing no"])])
+    if test "$gl_cv_func_open_directory_works" != yes; then
+      AC_DEFINE([REPLACE_OPEN_DIRECTORY], [1], [Define to 1 if open() should
+work around the inability to open a directory.])
+      REPLACE_FSTAT=1
+    fi
   fi
-  AC_SUBST([DIRENT_H])
 ])
 
 # Prerequisites of lib/fchdir.c.