cosmopolitan/libc/calls/fstat.c
Justine Tunney 2db2f40a98
Rewrite special file handling on Windows
This change gets GNU grep working. What caused it to not work, is it
wouldn't write to an output file descriptor when its dev/ino equaled
/dev/null's. So now we invent special dev/ino values for these files
2023-10-14 02:53:34 -07:00

63 lines
3.2 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/calls.h"
#include "libc/calls/internal.h"
#include "libc/calls/struct/stat.internal.h"
#include "libc/dce.h"
#include "libc/intrin/asan.internal.h"
#include "libc/intrin/describeflags.internal.h"
#include "libc/intrin/strace.internal.h"
#include "libc/intrin/weaken.h"
#include "libc/runtime/zipos.internal.h"
#include "libc/sysv/errfuns.h"
/**
* Returns information about file, via open()'d descriptor.
*
* On Windows, this implementation always sets `st_uid` and `st_gid` to
* `getuid()` and `getgid()`. The `st_mode` field is generated based on
* the current umask().
*
* @return 0 on success or -1 w/ errno
* @raise EBADF if `fd` isn't a valid file descriptor
* @raise EIO if an i/o error happens while reading from file system
* @raise EOVERFLOW shouldn't be possible on 64-bit systems
* @asyncsignalsafe
*/
int fstat(int fd, struct stat *st) {
int rc;
if (IsAsan() && !__asan_is_valid(st, sizeof(*st))) {
rc = efault();
} else if (__isfdkind(fd, kFdZip)) {
rc = _weaken(__zipos_fstat)(
(struct ZiposHandle *)(intptr_t)g_fds.p[fd].handle, st);
} else if (IsLinux() || IsXnu() || IsFreebsd() || IsOpenbsd() || IsNetbsd()) {
rc = sys_fstat(fd, st);
} else if (IsMetal()) {
rc = sys_fstat_metal(fd, st);
} else if (IsWindows()) {
rc = sys_fstat_nt(fd, st);
} else {
rc = enosys();
}
STRACE("fstat(%d, [%s]) → %d% m", fd, DescribeStat(rc, st), rc);
return rc;
}
__strong_reference(fstat, fstat64);