mirror of
https://git.savannah.gnu.org/git/emacs.git
synced 2024-12-15 09:47:20 +00:00
846657afaf
This incorporates: 2020-08-16 time_rz: remove unused functions 2020-08-16 time_rz: fix issues with mktime_z failures 2020-08-16 nstrftime: Guide inlining also on clang 2020-08-16 intprops: Avoid bogus warning on clang 2020-08-16 libc-config: Enable __REDIRECT macro also on clang 2020-08-16 regex: Use initializer shorthand syntax also with clang 2020-08-16 regex: Use space optimization also with clang 2020-08-16 Use _Static_assert and static_assert when present on clang 2020-08-16 Use 'throw ()' for optimization in C++ mode also on clang 2020-08-16 stdio: Don't break attribute 'scanf' on clang 2020-08-16 Fix "warning: 'format' attribute ...: rpl_printf" 2020-08-16 Fix "warning: attribute declaration must precede definition" 2020-08-16 Fix undesired warnings 2020-08-16 Don't use Autoconf quadrigraphsxo 2020-08-16 Fix quoting of AC_LANG_PROGRAM arguments 2020-08-16 Assume autoconf >= 2.64 2020-08-15 nstrftime: be more predictable about errno 2020-08-15 canonicalize: Fix autoconf test on MSVC/clang 2020-08-15 Support compiling without -loldnames on native Windows 2020-08-14 mktime, mktime-internal: Remove obsolete code 2020-08-14 Assume tzset exists * lib/c++defs.h, lib/canonicalize-lgpl.c, lib/cdefs.h, lib/dup2.c: * lib/fcntl.in.h, lib/getopt-cdefs.in.h, lib/intprops.h, lib/md5.h: * lib/mktime.c, lib/nstrftime.c, lib/open.c, lib/regcomp.c: * lib/regex_internal.h, lib/stdio.in.h, lib/stdlib.in.h: * lib/strftime.h, lib/string.in.h, lib/sys_select.in.h: * lib/sys_stat.in.h, lib/sys_time.in.h, lib/time.in.h, lib/time_rz.c: * lib/unistd.in.h, lib/verify.h, m4/00gnulib.m4: * m4/absolute-header.m4, m4/alloca.m4, m4/canonicalize.m4, m4/dup2.m4: * m4/fchmodat.m4, m4/fcntl.m4, m4/fdopendir.m4, m4/fpending.m4: * m4/futimens.m4, m4/getdtablesize.m4, m4/getloadavg.m4: * m4/gnulib-common.m4, m4/include_next.m4, m4/largefile.m4: * m4/manywarnings.m4, m4/mktime.m4, m4/nstrftime.m4, m4/open-slash.m4: * m4/pselect.m4, m4/pthread_sigmask.m4, m4/time_h.m4, m4/utimens.m4: * m4/utimensat.m4, m4/utimes.m4, m4/warnings.m4: Copy from Gnulib. * lib/gnulib.mk.in: Regenerate.
210 lines
6.7 KiB
C
210 lines
6.7 KiB
C
/* Open a descriptor to a file.
|
|
Copyright (C) 2007-2020 Free Software Foundation, Inc.
|
|
|
|
This program is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program 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 General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <https://www.gnu.org/licenses/>. */
|
|
|
|
/* Written by Bruno Haible <bruno@clisp.org>, 2007. */
|
|
|
|
/* If the user's config.h happens to include <fcntl.h>, let it include only
|
|
the system's <fcntl.h> here, so that orig_open doesn't recurse to
|
|
rpl_open. */
|
|
#define __need_system_fcntl_h
|
|
#include <config.h>
|
|
|
|
/* Get the original definition of open. It might be defined as a macro. */
|
|
#include <fcntl.h>
|
|
#include <sys/types.h>
|
|
#undef __need_system_fcntl_h
|
|
|
|
static int
|
|
orig_open (const char *filename, int flags, mode_t mode)
|
|
{
|
|
#if defined _WIN32 && !defined __CYGWIN__
|
|
return _open (filename, flags, mode);
|
|
#else
|
|
return open (filename, flags, mode);
|
|
#endif
|
|
}
|
|
|
|
/* Specification. */
|
|
/* Write "fcntl.h" here, not <fcntl.h>, otherwise OSF/1 5.1 DTK cc eliminates
|
|
this include because of the preliminary #include <fcntl.h> above. */
|
|
#include "fcntl.h"
|
|
|
|
#include "cloexec.h"
|
|
|
|
#include <errno.h>
|
|
#include <stdarg.h>
|
|
#include <string.h>
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
#include <unistd.h>
|
|
|
|
#ifndef REPLACE_OPEN_DIRECTORY
|
|
# define REPLACE_OPEN_DIRECTORY 0
|
|
#endif
|
|
|
|
int
|
|
open (const char *filename, int flags, ...)
|
|
{
|
|
/* 0 = unknown, 1 = yes, -1 = no. */
|
|
#if GNULIB_defined_O_CLOEXEC
|
|
int have_cloexec = -1;
|
|
#else
|
|
static int have_cloexec;
|
|
#endif
|
|
|
|
mode_t mode;
|
|
int fd;
|
|
|
|
mode = 0;
|
|
if (flags & O_CREAT)
|
|
{
|
|
va_list arg;
|
|
va_start (arg, flags);
|
|
|
|
/* We have to use PROMOTED_MODE_T instead of mode_t, otherwise GCC 4
|
|
creates crashing code when 'mode_t' is smaller than 'int'. */
|
|
mode = va_arg (arg, PROMOTED_MODE_T);
|
|
|
|
va_end (arg);
|
|
}
|
|
|
|
#if GNULIB_defined_O_NONBLOCK
|
|
/* The only known platform that lacks O_NONBLOCK is mingw, but it
|
|
also lacks named pipes and Unix sockets, which are the only two
|
|
file types that require non-blocking handling in open().
|
|
Therefore, it is safe to ignore O_NONBLOCK here. It is handy
|
|
that mingw also lacks openat(), so that is also covered here. */
|
|
flags &= ~O_NONBLOCK;
|
|
#endif
|
|
|
|
#if defined _WIN32 && ! defined __CYGWIN__
|
|
if (strcmp (filename, "/dev/null") == 0)
|
|
filename = "NUL";
|
|
#endif
|
|
|
|
#if OPEN_TRAILING_SLASH_BUG
|
|
/* Fail if one of O_CREAT, O_WRONLY, O_RDWR is specified and the filename
|
|
ends in a slash, as POSIX says such a filename must name a directory
|
|
<https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_13>:
|
|
"A pathname that contains at least one non-<slash> character and that
|
|
ends with one or more trailing <slash> characters shall not be resolved
|
|
successfully unless the last pathname component before the trailing
|
|
<slash> characters names an existing directory"
|
|
If the named file already exists as a directory, then
|
|
- if O_CREAT is specified, open() must fail because of the semantics
|
|
of O_CREAT,
|
|
- if O_WRONLY or O_RDWR is specified, open() must fail because POSIX
|
|
<https://pubs.opengroup.org/onlinepubs/9699919799/functions/open.html>
|
|
says that it fails with errno = EISDIR in this case.
|
|
If the named file does not exist or does not name a directory, then
|
|
- if O_CREAT is specified, open() must fail since open() cannot create
|
|
directories,
|
|
- if O_WRONLY or O_RDWR is specified, open() must fail because the
|
|
file does not contain a '.' directory. */
|
|
if ((flags & O_CREAT)
|
|
|| (flags & O_ACCMODE) == O_RDWR
|
|
|| (flags & O_ACCMODE) == O_WRONLY)
|
|
{
|
|
size_t len = strlen (filename);
|
|
if (len > 0 && filename[len - 1] == '/')
|
|
{
|
|
errno = EISDIR;
|
|
return -1;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
fd = orig_open (filename,
|
|
flags & ~(have_cloexec < 0 ? O_CLOEXEC : 0), mode);
|
|
|
|
if (flags & O_CLOEXEC)
|
|
{
|
|
if (! have_cloexec)
|
|
{
|
|
if (0 <= fd)
|
|
have_cloexec = 1;
|
|
else if (errno == EINVAL)
|
|
{
|
|
fd = orig_open (filename, flags & ~O_CLOEXEC, mode);
|
|
have_cloexec = -1;
|
|
}
|
|
}
|
|
if (have_cloexec < 0 && 0 <= fd)
|
|
set_cloexec_flag (fd, true);
|
|
}
|
|
|
|
|
|
#if REPLACE_FCHDIR
|
|
/* Implementing fchdir and fdopendir requires the ability to open a
|
|
directory file descriptor. If open doesn't support that (as on
|
|
mingw), we use a dummy file that behaves the same as directories
|
|
on Linux (ie. always reports EOF on attempts to read()), and
|
|
override fstat() in fchdir.c to hide the fact that we have a
|
|
dummy. */
|
|
if (REPLACE_OPEN_DIRECTORY && fd < 0 && errno == EACCES
|
|
&& ((flags & O_ACCMODE) == O_RDONLY
|
|
|| (O_SEARCH != O_RDONLY && (flags & O_ACCMODE) == O_SEARCH)))
|
|
{
|
|
struct stat statbuf;
|
|
if (stat (filename, &statbuf) == 0 && S_ISDIR (statbuf.st_mode))
|
|
{
|
|
/* Maximum recursion depth of 1. */
|
|
fd = open ("/dev/null", flags, mode);
|
|
if (0 <= fd)
|
|
fd = _gl_register_fd (fd, filename);
|
|
}
|
|
else
|
|
errno = EACCES;
|
|
}
|
|
#endif
|
|
|
|
#if OPEN_TRAILING_SLASH_BUG
|
|
/* If the filename ends in a slash and fd does not refer to a directory,
|
|
then fail.
|
|
Rationale: POSIX says such a filename must name a directory
|
|
<https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_13>:
|
|
"A pathname that contains at least one non-<slash> character and that
|
|
ends with one or more trailing <slash> characters shall not be resolved
|
|
successfully unless the last pathname component before the trailing
|
|
<slash> characters names an existing directory"
|
|
If the named file without the slash is not a directory, open() must fail
|
|
with ENOTDIR. */
|
|
if (fd >= 0)
|
|
{
|
|
/* We know len is positive, since open did not fail with ENOENT. */
|
|
size_t len = strlen (filename);
|
|
if (filename[len - 1] == '/')
|
|
{
|
|
struct stat statbuf;
|
|
|
|
if (fstat (fd, &statbuf) >= 0 && !S_ISDIR (statbuf.st_mode))
|
|
{
|
|
close (fd);
|
|
errno = ENOTDIR;
|
|
return -1;
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if REPLACE_FCHDIR
|
|
if (!REPLACE_OPEN_DIRECTORY && 0 <= fd)
|
|
fd = _gl_register_fd (fd, filename);
|
|
#endif
|
|
|
|
return fd;
|
|
}
|