X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Ffchdir.m4;h=a387dbb4f9fa80860cd3221c8128ad130436667b;hb=fb733077fcd97a36e1ffdb292387943df8e1b9b4;hp=6597be06c8ce002552434dccd9b64128a063b8b0;hpb=dd66a62cc2d76ab463e1167824ea4ca5fd4ef2ae;p=gnulib.git

diff --git a/m4/fchdir.m4 b/m4/fchdir.m4
index 6597be06c..a387dbb4f 100644
--- a/m4/fchdir.m4
+++ b/m4/fchdir.m4
@@ -1,5 +1,5 @@
-# fchdir.m4 serial 9
-dnl Copyright (C) 2006-2009 Free Software Foundation, Inc.
+# fchdir.m4 serial 17
+dnl Copyright (C) 2006-2011 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.
@@ -9,32 +9,48 @@ 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
+
+  AC_CHECK_DECLS_ONCE([fchdir])
+  if test $ac_cv_have_decl_fchdir = no; then
+    HAVE_DECL_FCHDIR=0
+  fi
+
+  AC_REQUIRE([gl_TEST_FCHDIR])
+  if test $HAVE_FCHDIR = 0; then
     AC_LIBOBJ([fchdir])
     gl_PREREQ_FCHDIR
     AC_DEFINE([REPLACE_FCHDIR], [1],
       [Define to 1 if gnulib's fchdir() replacement is used.])
-    REPLACE_FSTAT=1
-    gl_REPLACE_OPEN
-    gl_REPLACE_CLOSE
-    gl_REPLACE_DUP2
-    dnl dup3 is already unconditionally replaced
-    gl_REPLACE_DIRENT_H
+    dnl We must also replace anything that can manipulate a directory fd,
+    dnl to keep our bookkeeping up-to-date.  We don't have to replace
+    dnl fstatat, since no platform has fstatat but lacks fchdir.
+    REPLACE_OPENDIR=1
+    REPLACE_CLOSEDIR=1
+    REPLACE_DUP=1
     AC_CACHE_CHECK([whether open can visit directories],
       [gl_cv_func_open_directory_works],
       [AC_RUN_IFELSE([AC_LANG_PROGRAM([[#include <fcntl.h>
-]], [return open(".", O_RDONLY);])],
+]], [return open(".", O_RDONLY) < 0;])],
         [gl_cv_func_open_directory_works=yes],
         [gl_cv_func_open_directory_works=no],
         [gl_cv_func_open_directory_works="guessing no"])])
     if test "$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
 ])
 
+# Determine whether to use the overrides in lib/fchdir.c.
+AC_DEFUN([gl_TEST_FCHDIR],
+[
+  AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+  AC_CHECK_FUNCS_ONCE([fchdir])
+  if test $ac_cv_func_fchdir = no; then
+    HAVE_FCHDIR=0
+  fi
+])
+
 # Prerequisites of lib/fchdir.c.
 AC_DEFUN([gl_PREREQ_FCHDIR], [:])