cosmopolitan/libc/runtime/ftraceinit.greg.c
Justine Tunney e522aa3a07
Make more threading improvements
- ASAN memory morgue is now lockless
- Make C11 atomics header more portable
- Rewrote pthread keys support to be lockless
- Simplify Python's unicode table unpacking code
- Make crash report write(2) closer to being atomic
- Make it possible to strace/ftrace a single thread
- ASAN now checks nul-terminated strings fast and properly
- Windows fork() now restores TLS memory of calling thread
2022-11-01 23:28:26 -07:00

42 lines
2.6 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 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/runtime/internal.h"
#include "libc/runtime/runtime.h"
#include "libc/str/str.h"
#include "libc/thread/tls.h"
/**
* Enables plaintext function tracing if `--ftrace` flag is passed.
*
* The `--ftrace` CLI arg is removed before main() is called. This code
* is intended for diagnostic purposes and assumes binaries are
* trustworthy and stack isn't corrupted. Logging plain text allows
* program structure to easily be visualized and hotspots identified w/
* `sed | sort | uniq -c | sort`. A compressed trace can be made by
* appending `--ftrace 2>&1 | gzip -4 >trace.gz` to the CLI arguments.
*
* @see libc/runtime/_init.S for documentation
*/
textstartup int ftrace_init(void) {
if (__intercept_flag(&__argc, __argv, "--ftrace")) {
ftrace_install();
ftrace_enabled(+1);
}
return __argc;
}