cosmopolitan/libc/log/attachdebugger.c

102 lines
4.6 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 "libc/bits/safemacros.internal.h"
#include "libc/calls/calls.h"
#include "libc/calls/hefty/spawn.h"
#include "libc/fmt/fmt.h"
#include "libc/log/gdb.h"
#include "libc/log/log.h"
#include "libc/nexgen32e/stackframe.h"
#include "libc/nexgen32e/vendor.internal.h"
#include "libc/paths.h"
#include "libc/runtime/runtime.h"
#include "libc/runtime/symbols.internal.h"
#include "libc/stdio/stdio.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/fileno.h"
#include "libc/sysv/consts/o.h"
#include "libc/sysv/consts/w.h"
#define RESTORE_TTY "\e[?1000;1002;1015;1006l\e[?25h"
/**
* Launches GDB debugger GUI for current process.
*
* This function abstracts the toilsome details of configuring the best
* possible UX for debugging your app, for varying levels of available
* information, on most of the various platforms.
*
* Before calling this function, consider placing showcrashreports() in
* your main function and calling DebugBreak() wherever you want; it's
* safer. Also note the "GDB" environment variable can be set to empty
* string, as a fail-safe for disabling this behavior.
*
* @param continuetoaddr can be a code address, 0, or -1 for auto
* @return gdb pid if continuing, 0 if detached, or -1 w/ errno
* @note this is called via eponymous spinlock macro wrapper
*/
relegated int(attachdebugger)(intptr_t continuetoaddr) {
int ttyfd;
struct StackFrame *bp;
char pidstr[11], breakcmd[40];
const char *se, *elf, *gdb, *rewind, *layout;
if (IsGenuineCosmo() || !(gdb = GetGdbPath()) ||
(ttyfd = open(_PATH_TTY, O_RDWR, 0)) == -1) {
return -1;
}
write(ttyfd, RESTORE_TTY, strlen(RESTORE_TTY));
snprintf(pidstr, sizeof(pidstr), "%u", getpid());
layout = "layout asm";
if ((elf = FindDebugBinary())) {
se = "-se";
if (fileexists(__FILE__)) layout = "layout src";
} else {
se = "-q";
elf = "-q";
}
if (continuetoaddr) {
if (continuetoaddr == -1) {
bp = __builtin_frame_address(0);
continuetoaddr = bp->addr;
}
rewind = "-ex";
snprintf(breakcmd, sizeof(breakcmd), "%s *%#p", "break", continuetoaddr);
} else {
rewind = NULL;
breakcmd[0] = '\0';
}
return spawnve(0, (int[3]){ttyfd, ttyfd, STDERR_FILENO}, gdb,
(char *const[]){
"gdb", "--tui",
"-p", pidstr,
se, elf,
"-ex", "set osabi GNU/Linux",
"-ex", "set complaints 0",
"-ex", "set confirm off",
"-ex", layout,
"-ex", "layout reg",
"-ex", "set var g_gdbsync = 1",
"-q", rewind,
breakcmd, "-ex",
"c", NULL,
},
environ);
}