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#serial 2
# Check whether getcwd has the bug that it succeeds for a working directory
# longer than PATH_MAX, yet returns a truncated directory name.
# If so, arrange to compile the wrapper function.
# This is necessary for at least GNU libc on linux-2.4.19 and 2.4.20.
# I've heard that this is due to a Linux kernel bug, and that it has
# been fixed between 2.4.21-pre3 and 2.4.21-pre4. */
# From Jim Meyering
AC_DEFUN([GL_FUNC_GETCWD_PATH_MAX],
[
AC_CACHE_CHECK([whether getcwd properly handles paths longer than PATH_MAX],
gl_cv_func_getcwd_vs_path_max,
[
AC_CHECK_DECLS([getcwd])
# Arrange for deletion of the temporary directory this test creates.
ac_clean_files="$ac_clean_files confdir3"
AC_RUN_IFELSE([AC_LANG_SOURCE([[
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <limits.h>
#include <sys/stat.h>
#include <sys/types.h>
/* Don't get link errors because mkdir is redefined to rpl_mkdir. */
#undef mkdir
#ifndef CHAR_BIT
# define CHAR_BIT 8
#endif
/* The extra casts work around common compiler bugs. */
#define TYPE_SIGNED(t) (! ((t) 0 < (t) -1))
/* The outer cast is needed to work around a bug in Cray C 5.0.3.0.
It is necessary at least when t == time_t. */
#define TYPE_MINIMUM(t) ((t) (TYPE_SIGNED (t) \
? ~ (t) 0 << (sizeof (t) * CHAR_BIT - 1) : (t) 0))
#define TYPE_MAXIMUM(t) ((t) (~ (t) 0 - TYPE_MINIMUM (t)))
#ifndef INT_MAX
# define INT_MAX TYPE_MAXIMUM (int)
#endif
#ifndef PATH_MAX
/* There might be a better way to handle this case, but note:
- the value shouldn't be anywhere near INT_MAX, and
- the value shouldn't be so big that the local declaration, below,
blows the stack. */
# define PATH_MAX 40000
#endif
/* The length of this name must be 8. */
#define DIR_NAME "confdir3"
int
main ()
{
/* The '9' comes from strlen (DIR_NAME) + 1. */
#if INT_MAX - 9 <= PATH_MAX
/* FIXME: Assuming there's a system for which this is true -- Hurd?,
this should be done in a compile test. */
exit (0);
#else
char buf[PATH_MAX + 20];
char *cwd = getcwd (buf, PATH_MAX);
size_t cwd_len;
int fail = 0;
size_t n_chdirs = 0;
if (cwd == NULL)
exit (1);
cwd_len = strlen (cwd);
while (1)
{
char *c;
size_t len;
cwd_len += 1 + strlen (DIR_NAME);
/* If mkdir or chdir fails, be pessimistic and consider that
as a failure, too. */
if (mkdir (DIR_NAME, 0700) < 0 || chdir (DIR_NAME) < 0)
{
fail = 1;
break;
}
if ((c = getcwd (buf, PATH_MAX)) == NULL)
{
/* This allows any failure to indicate there is no bug.
FIXME: check errno? */
break;
}
if ((len = strlen (c)) != cwd_len)
{
fail = 1;
break;
}
++n_chdirs;
if (PATH_MAX < len)
break;
}
/* Leaving behind such a deep directory is not polite.
So clean up here, right away, even though the driving
shell script would also clean up. */
{
size_t i;
/* Unlink first, in case the chdir failed. */
unlink (DIR_NAME);
for (i = 0; i <= n_chdirs; i++)
{
if (chdir ("..") < 0)
break;
rmdir (DIR_NAME);
}
}
exit (fail);
#endif
}
]])],
[gl_cv_func_getcwd_vs_path_max=yes],
[gl_cv_func_getcwd_vs_path_max=no],
[gl_cv_func_getcwd_vs_path_max=no])])
if test $gl_cv_func_getcwd_vs_path_max = yes; then
AC_LIBOBJ(getcwd)
AC_DEFINE(getcwd, rpl_getcwd,
[Define to rpl_getcwd if the wrapper function should be used.])
fi
])
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