cosmopolitan/libc/log/backtrace2.c

123 lines
5.0 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/alg/alg.h"
#include "libc/alg/bisectcarleft.internal.h"
#include "libc/bits/safemacros.internal.h"
#include "libc/bits/weaken.h"
#include "libc/calls/calls.h"
#include "libc/calls/hefty/spawn.h"
#include "libc/dce.h"
#include "libc/fmt/conv.h"
#include "libc/fmt/fmt.h"
#include "libc/log/backtrace.internal.h"
#include "libc/log/log.h"
#include "libc/nexgen32e/gc.internal.h"
#include "libc/runtime/runtime.h"
#include "libc/runtime/symbols.internal.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/fileno.h"
#define kBacktraceMaxFrames 128
#define kBacktraceBufSize ((kBacktraceMaxFrames - 1) * (16 + 1))
static int PrintBacktraceUsingAddr2line(int fd, const struct StackFrame *bp) {
ssize_t got;
intptr_t addr;
size_t i, j, gi;
int rc, pid, tubes[3];
struct Garbages *garbage;
const struct StackFrame *frame;
const char *debugbin, *p1, *p2, *p3, *addr2line;
char buf[kBacktraceBufSize], *argv[kBacktraceMaxFrames];
if (!(debugbin = FindDebugBinary()) || !(addr2line = GetAddr2linePath())) {
return -1;
}
i = 0;
j = 0;
argv[i++] = "addr2line";
argv[i++] = "-a"; /* filter out w/ shell script wrapper for old versions */
argv[i++] = "-pCife";
argv[i++] = debugbin;
garbage = weaken(__garbage);
gi = garbage ? garbage->i : 0;
for (frame = bp; frame && i < kBacktraceMaxFrames - 1; frame = frame->next) {
addr = frame->addr;
if (addr == weakaddr("__gc")) {
do {
--gi;
} while ((addr = garbage->p[gi].ret) == weakaddr("__gc"));
}
argv[i++] = &buf[j];
j += snprintf(&buf[j], 17, "%#x", addr - 1) + 1;
}
argv[i++] = NULL;
tubes[0] = STDIN_FILENO;
tubes[1] = -1;
tubes[2] = STDERR_FILENO;
if ((pid = spawnve(0, tubes, addr2line, argv, environ)) == -1) {
return -1;
}
while ((got = read(tubes[1], buf, kBacktraceBufSize)) > 0) {
for (p1 = buf; got;) {
/*
* remove racist output from gnu tooling, that can't be disabled
* otherwise, since it breaks other tools like emacs that aren't
* equipped to ignore it, and what's most problematic is that
* addr2line somehow manages to put the racism onto the one line
* in the backtrace we actually care about.
*/
if ((p2 = memmem(p1, got, " (discriminator ",
strlen(" (discriminator ") - 1)) &&
(p3 = memchr(p2, '\n', got - (p2 - p1)))) {
if (p3 > p2 && p3[-1] == '\r') --p3;
write(fd, p1, p2 - p1);
got -= p3 - p1;
p1 += p3 - p1;
} else {
write(fd, p1, got);
break;
}
}
}
close(tubes[1]);
if (waitpid(pid, &rc, 0) == -1) return -1;
if (WEXITSTATUS(rc) != 0) return -1;
return 0;
}
static int PrintBacktrace(int fd, const struct StackFrame *bp) {
if (!IsTiny()) {
if (PrintBacktraceUsingAddr2line(fd, bp) != -1) {
return 0;
}
}
return PrintBacktraceUsingSymbols(fd, bp, GetSymbolTable());
}
void ShowBacktrace(int fd, const struct StackFrame *bp) {
static bool noreentry;
if (!bp) bp = __builtin_frame_address(0);
if (!noreentry) {
noreentry = true;
PrintBacktrace(fd, bp);
noreentry = 0;
}
}