-#serial 4
+# unlink.m4 serial 5
+dnl Copyright (C) 2009, 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.
-dnl From J. David Anglin.
-
-dnl HPUX and other systems can't unlink shared text that is being executed.
-
-AC_DEFUN(jm_FUNC_UNLINK_BUSY_TEXT,
-[dnl
- AC_CACHE_CHECK([whether a program can unlink itself],
- jm_cv_func_unlink_busy_text,
- [
- AC_TRY_RUN([
- main (argc, argv)
- int argc;
- char **argv;
- {
- if (!argc)
- exit (-1);
- exit (unlink (argv[0]));
- }
- ],
- jm_cv_func_unlink_busy_text=yes,
- jm_cv_func_unlink_busy_text=no,
- jm_cv_func_unlink_busy_text=no
- )
- ]
- )
-
- if test $jm_cv_func_unlink_busy_text = no; then
- INSTALL=$ac_install_sh
+AC_DEFUN([gl_FUNC_UNLINK],
+[
+ AC_REQUIRE([gl_AC_DOS])
+ AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+ AC_REQUIRE([AC_CANONICAL_HOST])
+ dnl Detect FreeBSD 7.2, AIX 7.1, Solaris 9 bug.
+ AC_CACHE_CHECK([whether unlink honors trailing slashes],
+ [gl_cv_func_unlink_honors_slashes],
+ [touch conftest.file
+ # Assume that if we have lstat, we can also check symlinks.
+ if test $ac_cv_func_lstat = yes; then
+ ln -s conftest.file conftest.lnk
+ fi
+ AC_RUN_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <unistd.h>
+ #include <errno.h>
+]], [[if (!unlink ("conftest.file/") || errno != ENOTDIR) return 1;
+#if HAVE_LSTAT
+ if (!unlink ("conftest.lnk/") || errno != ENOTDIR) return 2;
+#endif
+ ]])],
+ [gl_cv_func_unlink_honors_slashes=yes],
+ [gl_cv_func_unlink_honors_slashes=no],
+ [gl_cv_func_unlink_honors_slashes="guessing no"])
+ rm -f conftest.file conftest.lnk])
+ dnl Detect MacOS X 10.5.6 bug: On read-write HFS mounts, unlink("..") or
+ dnl unlink("../..") succeeds without doing anything.
+ AC_CACHE_CHECK([whether unlink of a parent directory fails is it should],
+ [gl_cv_func_unlink_parent_fails],
+ [case "$host_os" in
+ darwin*)
+ dnl Try to unlink a subdirectory of /tmp, because /tmp is usually on a
+ dnl HFS mount on MacOS X. Use a subdirectory, owned by the current
+ dnl user, because otherwise unlink() may fail due to permissions
+ dnl reasons, and because when running as root we don't want to risk
+ dnl destroying the entire /tmp.
+ if {
+ # Use the mktemp program if available. If not available, hide the error
+ # message.
+ tmp=`(umask 077 && mktemp -d /tmp/gtXXXXXX) 2>/dev/null` &&
+ test -n "$tmp" && test -d "$tmp"
+ } ||
+ {
+ # Use a simple mkdir command. It is guaranteed to fail if the directory
+ # already exists. $RANDOM is bash specific and expands to empty in shells
+ # other than bash, ksh and zsh. Its use does not increase security;
+ # rather, it minimizes the probability of failure in a very cluttered /tmp
+ # directory.
+ tmp=/tmp/gt$$-$RANDOM
+ (umask 077 && mkdir "$tmp")
+ }; then
+ mkdir "$tmp/subdir"
+ GL_SUBDIR_FOR_UNLINK="$tmp/subdir"
+ export GL_SUBDIR_FOR_UNLINK
+ AC_RUN_IFELSE(
+ [AC_LANG_SOURCE([[
+ #include <stdlib.h>
+ #include <unistd.h>
+ int main ()
+ {
+ if (chdir (getenv ("GL_SUBDIR_FOR_UNLINK")) != 0)
+ return 1;
+ return unlink ("..") == 0;
+ }
+ ]])],
+ [gl_cv_func_unlink_parent_fails=yes],
+ [gl_cv_func_unlink_parent_fails=no],
+ [gl_cv_func_unlink_parent_fails="guessing no"])
+ unset GL_SUBDIR_FOR_UNLINK
+ rm -rf "$tmp"
+ else
+ gl_cv_func_unlink_parent_fails="guessing no"
+ fi
+ ;;
+ *)
+ gl_cv_func_unlink_parent_fails="guessing yes"
+ ;;
+ esac
+ ])
+ case "$gl_cv_func_unlink_parent_fails" in
+ *no)
+ AC_DEFINE([UNLINK_PARENT_BUG], [1],
+ [Define to 1 if unlink() on a parent directory may succeed])
+ ;;
+ esac
+ if test "$gl_cv_func_unlink_honors_slashes" != yes \
+ || { case "$gl_cv_func_unlink_parent_fails" in
+ *yes) false;;
+ *no) true;;
+ esac
+ }; then
+ REPLACE_UNLINK=1
+ AC_LIBOBJ([unlink])
fi
])
projects / gnulib.git / blobdiff