cosmopolitan/libc/calls/tcflow.c
Jōshin 6e6fc38935
Apply clang-format update to repo (#1154)
Commit bc6c183 introduced a bunch of discrepancies between what files
look like in the repo and what clang-format says they should look like.
However, there were already a few discrepancies prior to that. Most of
these discrepancies seemed to be unintentional, but a few of them were
load-bearing (e.g., a #include that violated header ordering needing
something to have been #defined by a 'later' #include.)

I opted to take what I hope is a relatively smooth-brained approach: I
reverted the .clang-format change, ran clang-format on the whole repo,
reapplied the .clang-format change, reran clang-format again, and then
reverted the commit that contained the first run. Thus the full effect
of this PR should only be to apply the changed formatting rules to the
repo, and from skimming the results, this seems to be the case.

My work can be checked by applying the short, manual commits, and then
rerunning the command listed in the autogenerated commits (those whose
messages I have prefixed auto:) and seeing if your results agree.

It might be that the other diffs should be fixed at some point but I'm
leaving that aside for now.

fd '\.c(c|pp)?$' --print0| xargs -0 clang-format -i
2024-04-25 10:38:00 -07:00

150 lines
5.2 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 2021 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/internal.h"
#include "libc/calls/struct/fd.internal.h"
#include "libc/calls/struct/metatermios.internal.h"
#include "libc/calls/struct/termios.h"
#include "libc/calls/syscall-sysv.internal.h"
#include "libc/calls/syscall_support-nt.internal.h"
#include "libc/calls/termios.h"
#include "libc/dce.h"
#include "libc/fmt/itoa.h"
#include "libc/intrin/strace.internal.h"
#include "libc/mem/alloca.h"
#include "libc/nt/comms.h"
#include "libc/sysv/consts/termios.h"
#include "libc/sysv/errfuns.h"
#define kNtPurgeTxabort 1
#define kNtPurgeRxabort 2
#define TCXONC 0x0000540A // linux
#define TIOCSTOP 0x2000746f // bsd
#define TIOCSTART 0x2000746e // bsd
#define TIOCIXON 0x20007481 // xnu
#define TIOCIXOFF 0x20007480 // xnu
static const char *DescribeFlow(char buf[12], int action) {
if (action == TCOOFF)
return "TCOOFF";
if (action == TCOON)
return "TCOON";
if (action == TCIOFF)
return "TCIOFF";
if (action == TCION)
return "TCION";
FormatInt32(buf, action);
return buf;
}
static int sys_tcflow_bsd_write(int fd, int cc) {
unsigned char c;
struct termios_bsd term;
if (sys_ioctl(fd, TCGETS, &term) == -1) {
return -1;
}
if ((c = term.c_cc[cc]) != _POSIX_VDISABLE &&
sys_write(fd, &c, sizeof(c)) == -1) {
return -1;
}
return 0;
}
static int sys_tcflow_bsd(int fd, int action) {
switch (action) {
case TCOOFF:
return sys_ioctl(fd, TIOCSTOP, 0);
case TCOON:
return sys_ioctl(fd, TIOCSTART, 0);
case TCION:
if (IsXnu()) {
return sys_ioctl(fd, TIOCIXON, 0);
} else {
return sys_tcflow_bsd_write(fd, VSTART);
}
case TCIOFF:
if (IsXnu()) {
return sys_ioctl(fd, TIOCIXOFF, 0);
} else {
return sys_tcflow_bsd_write(fd, VSTOP);
}
return 0;
default:
return einval();
}
}
static dontinline textwindows int sys_tcflow_nt(int fd, int action) {
bool32 ok;
int64_t h;
if (!__isfdopen(fd))
return ebadf();
h = g_fds.p[fd].handle;
switch (action) {
case TCOON:
case TCION:
ok = ClearCommBreak(h);
break;
case TCOOFF:
ok = PurgeComm(h, kNtPurgeTxabort);
break;
case TCIOFF:
ok = PurgeComm(h, kNtPurgeRxabort);
break;
default:
return einval();
}
return ok ? 0 : __winerr();
}
/**
* Changes flow of teletypewriter data.
*
* @param fd is file descriptor of tty
* @param action may be one of:
* - `TCOOFF` to suspend output
* - `TCOON` to resume output
* - `TCIOFF` to transmit a `STOP` character
* - `TCION` to transmit a `START` character
* @return 0 on success, or -1 w/ errno
* @raise EINVAL if `action` is invalid
* @raise ENOSYS on Windows and Bare Metal
* @raise EBADF if `fd` isn't an open file descriptor
* @raise ENOTTY if `fd` is open but not a teletypewriter
* @raise EIO if process group of writer is orphoned, calling thread is
* not blocking `SIGTTOU`, and process isn't ignoring `SIGTTOU`
* @asyncsignalsafe
*/
int tcflow(int fd, int action) {
int rc;
if (fd < g_fds.n && g_fds.p[fd].kind == kFdZip) {
rc = enotty();
} else if (IsLinux()) {
rc = sys_ioctl(fd, TCXONC, action);
} else if (IsBsd()) {
rc = sys_tcflow_bsd(fd, action);
} else if (IsWindows()) {
rc = sys_tcflow_nt(fd, action);
} else {
rc = enosys();
}
STRACE("tcflow(%d, %s) → %d% m", fd, DescribeFlow(alloca(12), action), rc);
return rc;
}