Imported Upstream version 1.4

[debian/gzip] / m4 / fchdir.m4

diff --git a/m4/fchdir.m4 b/m4/fchdir.m4
new file mode 100644 (file)
index 0000000..c05e925
--- /dev/null
+++ b/m4/fchdir.m4
@@ -0,0 +1,47 @@
+# fchdir.m4 serial 13
+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.
+
+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 $ac_cv_func_fchdir = no; then
+    REPLACE_FCHDIR=1
+    AC_LIBOBJ([fchdir])
+    gl_PREREQ_FCHDIR
+    AC_DEFINE([REPLACE_FCHDIR], [1],
+      [Define to 1 if gnulib's fchdir() replacement is used.])
+    dnl We must also replace anything that can manipulate a directory fd,
+    dnl to keep our bookkeeping up-to-date.  We don't have to replace
+    dnl fstatat, since no platform has fstatat but lacks fchdir.
+    REPLACE_OPENDIR=1
+    REPLACE_CLOSEDIR=1
+    REPLACE_DUP=1
+    gl_REPLACE_OPEN
+    gl_REPLACE_CLOSE
+    gl_REPLACE_DUP2
+    dnl dup3 is already unconditionally replaced
+    gl_REPLACE_FCNTL
+    gl_REPLACE_DIRENT_H
+    AC_CACHE_CHECK([whether open can visit directories],
+      [gl_cv_func_open_directory_works],
+      [AC_RUN_IFELSE([AC_LANG_PROGRAM([[#include <fcntl.h>
+]], [return open(".", O_RDONLY) < 0;])],
+        [gl_cv_func_open_directory_works=yes],
+        [gl_cv_func_open_directory_works=no],
+        [gl_cv_func_open_directory_works="guessing no"])])
+    if test "$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
+])
+
+# Prerequisites of lib/fchdir.c.
+AC_DEFUN([gl_PREREQ_FCHDIR], [:])