X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Ffchdir.m4;h=a387dbb4f9fa80860cd3221c8128ad130436667b;hb=9c5e07d317077af2cfc3f0816bcc8cab03dd4260;hp=6998eae435a7e1fa8525252a2a564b478b5f255b;hpb=8e2cdb066af972ddb93eb27bb1f7cdb51193c5e5;p=gnulib.git

diff --git a/m4/fchdir.m4 b/m4/fchdir.m4
index 6998eae43..a387dbb4f 100644
--- a/m4/fchdir.m4
+++ b/m4/fchdir.m4
@@ -1,27 +1,55 @@
-# fchdir.m4 serial 2
-dnl Copyright (C) 2006-2007 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.
 
 AC_DEFUN([gl_FUNC_FCHDIR],
 [
-  AC_REQUIRE([gl_HEADER_UNISTD_DEFAULTS])
-  AC_CHECK_FUNCS_ONCE([fchdir])
-  if test $ac_cv_func_fchdir = no; then
+  AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+  AC_REQUIRE([gl_DIRENT_H_DEFAULTS])
+  AC_REQUIRE([gl_SYS_STAT_H_DEFAULTS])
+
+  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 $HAVE_FCHDIR = 0; then
     AC_LIBOBJ([fchdir])
     gl_PREREQ_FCHDIR
-    AC_DEFINE([FCHDIR_REPLACEMENT], 1,
-      [Define if gnulib's fchdir() replacement is used.])
-    gl_ABSOLUTE_HEADER([dirent.h])
-    ABSOLUTE_DIRENT_H=\"$gl_cv_absolute_dirent_h\"
-    DIRENT_H='dirent.h'
-    UNISTD_H='unistd.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
+    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
+])
+
+# 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
-  AC_SUBST([ABSOLUTE_DIRENT_H])
-  AC_SUBST([DIRENT_H])
 ])
 
 # Prerequisites of lib/fchdir.c.