cosmopolitan/libc/calls/linkat-nt.c
Justine Tunney 79516bf08e
Improve handling of weird reparse points
On Windows file system tools like `ls` would print errors when they find
things like WSL symlinks, which can't be read by WIN32. I don't know how
they got on my hard drive but this change ensures Cosmo will handle them
more gracefully. If a reparse point can't be followed, then fstatat will
return information about the link itself. If readlink encounters reparse
points that are WIN32 symlinks, then it'll log more helpful details when
using MODE=dbg (a.k.a. cosmocc -mdbg). Speaking of which, this change is
also going to help you troubleshoot locks; when you build your app using
the cosmocc -mdbg flag your --strace logs will now show lock acquisition
2024-09-02 19:05:48 -07:00

51 lines
2.9 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set et 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/syscall_support-nt.internal.h"
#include "libc/intrin/strace.h"
#include "libc/limits.h"
#include "libc/nt/files.h"
#include "libc/nt/runtime.h"
#include "libc/runtime/stack.h"
#include "libc/str/str.h"
textwindows int sys_linkat_nt(int olddirfd, const char *oldpath, //
int newdirfd, const char *newpath) {
#pragma GCC push_options
#pragma GCC diagnostic ignored "-Wframe-larger-than="
struct {
char16_t newpath16[PATH_MAX];
char16_t oldpath16[PATH_MAX];
} M;
CheckLargeStackAllocation(&M, sizeof(M));
#pragma GCC pop_options
if (__mkntpathat(olddirfd, oldpath, 0, M.oldpath16) != -1 &&
__mkntpathat(newdirfd, newpath, 0, M.newpath16) != -1) {
bool32 ok = CreateHardLink(M.newpath16, M.oldpath16, NULL);
NTTRACE("CreateHardLink(%#hs, %#hs, NULL) → {%hhhd, %d}", M.newpath16,
M.oldpath16, ok, GetLastError());
if (ok) {
return 0;
} else {
return __fix_enotdir3(__winerr(), M.newpath16, M.oldpath16);
}
} else {
return -1;
}
}