mirror of
https://sourceware.org/git/binutils-gdb.git
synced 2024-12-27 04:52:05 +08:00
dc6c21dabf
This updates gnulib to a relatively recent commit. Most of this was done by the gnulib import script; the only change I made was to update-gnulib.sh. Tested on x86-64 Fedora 34. I also did a mingw cross build.
105 lines
3.1 KiB
C
105 lines
3.1 KiB
C
/* Read the contents of a symbolic link.
|
|
Copyright (C) 2003-2007, 2009-2022 Free Software Foundation, Inc.
|
|
|
|
This file is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU Lesser General Public License as
|
|
published by the Free Software Foundation; either version 2.1 of the
|
|
License, or (at your option) any later version.
|
|
|
|
This file is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public License
|
|
along with this program. If not, see <https://www.gnu.org/licenses/>. */
|
|
|
|
#include <config.h>
|
|
|
|
/* Specification. */
|
|
#include <unistd.h>
|
|
|
|
#include <errno.h>
|
|
#include <string.h>
|
|
#include <sys/stat.h>
|
|
|
|
#if !HAVE_READLINK
|
|
|
|
/* readlink() substitute for systems that don't have a readlink() function,
|
|
such as DJGPP 2.03 and mingw32. */
|
|
|
|
ssize_t
|
|
readlink (char const *file, _GL_UNUSED char *buf,
|
|
_GL_UNUSED size_t bufsize)
|
|
{
|
|
struct stat statbuf;
|
|
|
|
/* In general we should use lstat() here, not stat(). But on platforms
|
|
without symbolic links, lstat() - if it exists - would be equivalent to
|
|
stat(), therefore we can use stat(). This saves us a configure check. */
|
|
if (stat (file, &statbuf) >= 0)
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
#else /* HAVE_READLINK */
|
|
|
|
# undef readlink
|
|
|
|
/* readlink() wrapper that uses correct types, for systems like cygwin
|
|
1.5.x where readlink returns int, and which rejects trailing slash,
|
|
for Solaris 9. */
|
|
|
|
ssize_t
|
|
rpl_readlink (char const *file, char *buf, size_t bufsize)
|
|
{
|
|
# if READLINK_TRAILING_SLASH_BUG
|
|
size_t file_len = strlen (file);
|
|
if (file_len && file[file_len - 1] == '/')
|
|
{
|
|
/* Even if FILE without the slash is a symlink to a directory,
|
|
both lstat() and stat() must resolve the trailing slash to
|
|
the directory rather than the symlink. We can therefore
|
|
safely use stat() to distinguish between EINVAL and
|
|
ENOTDIR/ENOENT, avoiding extra overhead of rpl_lstat(). */
|
|
struct stat st;
|
|
if (stat (file, &st) == 0 || errno == EOVERFLOW)
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
# endif /* READLINK_TRAILING_SLASH_BUG */
|
|
|
|
ssize_t r = readlink (file, buf, bufsize);
|
|
|
|
# if READLINK_TRUNCATE_BUG
|
|
if (r < 0 && errno == ERANGE)
|
|
{
|
|
/* Try again with a bigger buffer. This is just for test cases;
|
|
real code invariably discards short reads. */
|
|
char stackbuf[4032];
|
|
r = readlink (file, stackbuf, sizeof stackbuf);
|
|
if (r < 0)
|
|
{
|
|
if (errno == ERANGE)
|
|
{
|
|
/* Clear the buffer, which is good enough for real code.
|
|
Thankfully, no test cases try short reads of enormous
|
|
symlinks and what would be the point anyway? */
|
|
r = bufsize;
|
|
memset (buf, 0, r);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (bufsize < r)
|
|
r = bufsize;
|
|
memcpy (buf, stackbuf, r);
|
|
}
|
|
}
|
|
# endif
|
|
|
|
return r;
|
|
}
|
|
|
|
#endif /* HAVE_READLINK */
|