Paul Eggert wrote:
> +2025-05-26 Paul Eggert <egg...@cs.ucla.edu>
> +
> + fcntl-h: support O_DIRECTORY
> + It is relatively easy to support O_DIRECTORY on platforms that
> + lack it, so let’s do that instead of having to work around bugs
> + like <https://bugs.gnu.org/78509#95>.
> + * lib/fcntl.in.h (O_DIRECTORY): Default to 0x20000000 not 0,
> + since Gnulib now supports it.
> + * lib/open.c, lib/openat.c (OPEN_TRAILING_SLASH_BUG):
> + Default to false, so that this can be used outside #if.
> + (open, openat): Add support for O_DIRECTORY on platforms that lack it.
> + If fstat fails, fail instead of assuming the file is a directory,
> + since failure can occur due to EOVERFLOW, etc.
> + Rearrange code to minimize differences between open.c and openat.c.
> + * m4/fcntl-o.m4 (gl_FCNTL_O_FLAGS): Also test O_DIRECTORY,
> + and define HAVE_WORKING_O_DIRECTORY if needed.
> + Prefer AS_CASE for Emacs’s benefit.
> + * m4/open.m4 (gl_FUNC_OPEN):
> + * m4/openat.m4 (gl_FUNC_OPENAT):
> + Require gl_FCNTL_O_FLAGS and replace the function
> + if O_DIRECTORY does not work.
> + * tests/test-open.h: Test O_DIRECTORY.
This patch, unfortunately, causes a regression: The test 'test-fts' now
fails on native Windows.
FAIL: test-fts
==============
0 needles found (should be 4)
FAIL test-fts.exe (exit status: 1)
When I single-step through the test, I see that it does not even recurse
through the directory hierarchy. It opens only "t-fts.tmp" and that's it.
The cause is that before the patch, in config.h, we have
HAVE_WORKING_O_NOATIME = 0
HAVE_WORKING_O_NOFOLLOW = 0
and after the patch
HAVE_WORKING_O_NOATIME = 1
HAVE_WORKING_O_NOFOLLOW = 1
HAVE_WORKING_O_DIRECTORY = 0
The problem is that the "checking for working fcntl.h" encounters a compilation
error (due to O_NOCTTY, O_NONBLOCK, O_SYNC that are not defined on mingw), and
the exit code 1 from the compiler gets mis-interpreted.
When I fix m4/fcntl-o.m4 to get
HAVE_WORKING_O_NOATIME = 0
HAVE_WORKING_O_NOFOLLOW = 0
HAVE_WORKING_O_DIRECTORY = 0
then test-fts still fails. This time it recurses through the subdirectories,
but it fails just before the _gl_register_fd call, in open.c.
With the two fixes from the patch below, test-fts finally works again.
2025-06-03 Bruno Haible <br...@clisp.org>
fcntl-h, open: Fix two regressions on native Windows (regr. 2025-05-26).
* m4/fcntl-o.m4 (gl_FCNTL_O_FLAGS): Reshuffle the exit code bits, so
that a compilation failure produces the "no" result.
* lib/open.c (open): Don't pass the O_DIRECTORY flag when doing
recursion with /dev/null.
diff --git a/lib/open.c b/lib/open.c
index 3da2dce072..8356c14f5b 100644
--- a/lib/open.c
+++ b/lib/open.c
@@ -202,7 +202,7 @@ open (const char *filename, int flags, ...)
&& S_ISDIR (statbuf.st_mode)))
{
/* Maximum recursion depth of 1. */
- fd = open ("/dev/null", flags, mode);
+ fd = open ("/dev/null", flags & ~O_DIRECTORY, mode);
if (0 <= fd)
fd = _gl_register_fd (fd, filename);
}
diff --git a/m4/fcntl-o.m4 b/m4/fcntl-o.m4
index 9c19b582f8..38321e5964 100644
--- a/m4/fcntl-o.m4
+++ b/m4/fcntl-o.m4
@@ -1,5 +1,5 @@
# fcntl-o.m4
-# serial 10
+# serial 11
dnl Copyright (C) 2006, 2009-2025 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
@@ -57,42 +57,41 @@ AC_DEFUN([gl_FCNTL_O_FLAGS]
]],
[[
int result = !constants;
-
- {
- int fd = open ("confdefs.h", O_SEARCH | O_DIRECTORY);
- result |= ! (fd < 0 && errno == ENOTDIR);
- if (0 <= fd)
- close (fd);
- }
-
#if HAVE_SYMLINK
{
static char const sym[] = "conftest.sym";
if (symlink ("/dev/null", sym) != 0)
- result |= 2;
+ result |= 1;
else
{
int fd = open (sym, O_WRONLY | O_NOFOLLOW | O_CREAT, 0);
if (fd >= 0)
{
close (fd);
- result |= 4;
+ result |= 2;
}
}
if (unlink (sym) != 0 || symlink (".", sym) != 0)
- result |= 2;
+ result |= 1;
else
{
int fd = open (sym, O_RDONLY | O_NOFOLLOW);
if (fd >= 0)
{
close (fd);
- result |= 4;
+ result |= 2;
}
}
unlink (sym);
}
#endif
+ {
+ int fd = open ("confdefs.h", O_SEARCH | O_DIRECTORY);
+ if (!(fd < 0 && errno == ENOTDIR))
+ result |= 4;
+ if (0 <= fd)
+ close (fd);
+ }
{
static char const file[] = "confdefs.h";
int fd = open (file, O_RDONLY | O_NOATIME);
@@ -129,13 +128,16 @@ AC_DEFUN([gl_FCNTL_O_FLAGS]
return result;]])],
[gl_cv_header_working_fcntl_h=yes],
[AS_CASE([$?],
- [ 1], [gl_cv_header_working_fcntl_h="no (bad O_DIRECTORY)"],
- [ 4], [gl_cv_header_working_fcntl_h="no (bad O_NOFOLLOW)"],
- [ 5], [gl_cv_header_working_fcntl_h="no (bad O_DIRECTORY,
O_NOFOLLOW)"],
+ dnl We cannot catch exit code 1 here, because exit code 1 can occur
+ dnl through a compilation error (e.g. when O_NOCTTY, O_NONBLOCK,
O_SYNC
+ dnl are not defined) or when result = 1.
+ [ 2], [gl_cv_header_working_fcntl_h="no (bad O_NOFOLLOW)"],
+ [ 4], [gl_cv_header_working_fcntl_h="no (bad O_DIRECTORY)"],
+ [ 6], [gl_cv_header_working_fcntl_h="no (bad O_NOFOLLOW,
O_DIRECTORY)"],
[64], [gl_cv_header_working_fcntl_h="no (bad O_NOATIME)"],
- [65], [gl_cv_header_working_fcntl_h="no (bad O_DIRECTORY,
O_NOATIME)"],
- [68], [gl_cv_header_working_fcntl_h="no (bad O_NOATIME,
O_NOFOLLOW)"],
- [69], [gl_cv_header_working_fcntl_h="no (bad O_DIRECTORY, O_NOATIME,
O_NOFOLLOW)"],
+ [66], [gl_cv_header_working_fcntl_h="no (bad O_NOFOLLOW,
O_NOATIME)"],
+ [68], [gl_cv_header_working_fcntl_h="no (bad O_DIRECTORY,
O_NOATIME)"],
+ [70], [gl_cv_header_working_fcntl_h="no (bad O_NOFOLLOW,
O_DIRECTORY, O_NOATIME)"],
[gl_cv_header_working_fcntl_h="no"])],
[AS_CASE([$host_os,$gl_cross_guess_normal],
# The O_DIRECTORY test is known to fail on Mac OS X 10.4.11 (2007)
