cosmopolitan/dsp/tty/ttyraw.c

162 lines
5.7 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 │
│ │
│ 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; version 2 of the License. │
│ │
│ 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, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "dsp/tty/tty.h"
#include "libc/assert.h"
#include "libc/calls/calls.h"
#include "libc/calls/sigbits.h"
#include "libc/calls/struct/sigaction.h"
#include "libc/calls/struct/siginfo.h"
#include "libc/calls/termios.h"
#include "libc/calls/typedef/sigaction_f.h"
#include "libc/calls/ucontext.h"
#include "libc/log/log.h"
#include "libc/macros.h"
#include "libc/runtime/gc.h"
#include "libc/runtime/runtime.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/fileno.h"
#include "libc/sysv/consts/sa.h"
#include "libc/sysv/consts/sig.h"
#include "libc/sysv/errfuns.h"
#include "libc/x/x.h"
/* TODO(jart): DELETE */
#define FD STDOUT_FILENO
static struct TtyRaw {
bool setup;
bool hasold;
bool noreentry;
bool initialized;
enum TtyRawFlags flags;
sigaction_f next[10];
unsigned char sigs[10];
struct termios old;
} g_ttyraw;
static textstartup int ttyraw_setup(void) {
struct termios *old;
if (isatty(FD)) {
old = !g_ttyraw.hasold ? &g_ttyraw.old : NULL;
if (ttyconfig(FD, ttysetrawmode, g_ttyraw.flags, old) != -1) {
g_ttyraw.hasold = true;
return 0;
}
}
return -1;
}
static textstartup int ttyraw_enable(void) {
int rc;
g_ttyraw.setup = (rc = ttyraw_setup()) != -1 || g_ttyraw.setup;
return rc;
}
static textstartup void ttyraw_hidecursor(void) {
if (!g_ttyraw.setup) return;
if (g_ttyraw.flags & kTtyCursor) return;
ttyhidecursor(FD);
}
static textexit int ttyraw_disable(void) {
if (!g_ttyraw.setup) return 0;
ttyshowcursor(FD);
return ttyrestore(FD, &g_ttyraw.old);
}
static textexit void ttyraw_onexit(void) {
ttyraw_disable();
}
static relegated void ttyraw_onsig(int sig, struct siginfo *info,
struct ucontext *ctx) {
size_t i;
if (g_ttyraw.noreentry) _Exit(128 + sig);
g_ttyraw.noreentry = true;
if (g_ttyraw.flags != -1) {
if (sig == SIGCONT) {
ttyraw_enable();
} else {
ttyraw_disable();
}
}
for (i = 0; i < ARRAYLEN(g_ttyraw.sigs); ++i) {
if (g_ttyraw.sigs[i] == sig) {
if (g_ttyraw.next[i] != SIG_IGN) {
if (g_ttyraw.next[i] != SIG_DFL) {
if (g_ttyraw.next[i]) {
g_ttyraw.next[i](sig, info, ctx);
}
} else if (sig != SIGCONT) {
_Exit(128 + sig);
}
}
break;
}
}
g_ttyraw.noreentry = false;
}
static textstartup void ttyraw_initsig(int sig, unsigned flags, unsigned mask) {
static unsigned i;
struct sigaction old;
g_ttyraw.next[i] = xsigaction(sig, ttyraw_onsig, flags, mask, &old) != -1
? old.sa_sigaction
: SIG_DFL;
g_ttyraw.sigs[i++] = sig;
}
static textstartup void ttyraw_init(void) {
unsigned crashmask = ~(SIGILL | SIGBUS | SIGSEGV | SIGABRT);
ttyraw_initsig(SIGILL, SA_SIGINFO | SA_NODEFER | SA_ONSTACK, crashmask);
ttyraw_initsig(SIGSEGV, SA_SIGINFO | SA_NODEFER | SA_ONSTACK, crashmask);
ttyraw_initsig(SIGBUS, SA_SIGINFO | SA_NODEFER | SA_ONSTACK, crashmask);
ttyraw_initsig(SIGABRT, SA_SIGINFO | SA_NODEFER, crashmask);
ttyraw_initsig(SIGFPE, SA_SIGINFO | SA_RESTART, crashmask);
ttyraw_initsig(SIGTRAP, SA_SIGINFO | SA_RESTART, crashmask);
ttyraw_initsig(SIGHUP, SA_SIGINFO | SA_RESTART, crashmask);
ttyraw_initsig(SIGINT, SA_SIGINFO | SA_RESTART, crashmask);
ttyraw_initsig(SIGQUIT, SA_SIGINFO | SA_RESTART, crashmask);
ttyraw_initsig(SIGCONT, SA_SIGINFO | SA_RESTART, crashmask);
atexit(ttyraw_onexit);
}
/**
* Sets raw mode, safely, the easy way.
*
* This should be called after your signal handlers have been installed.
*/
textstartup int ttyraw(enum TtyRawFlags flags) {
int rc;
if ((g_ttyraw.flags = flags) != -1) {
if (!g_ttyraw.initialized) {
g_ttyraw.initialized = true;
ttyraw_init();
}
if ((rc = ttyraw_enable()) != -1) {
ttyraw_hidecursor();
}
} else {
rc = ttyraw_disable();
}
return rc;
}