cosmopolitan/examples/auto-launch-gdb-on-crash.c
Justine Tunney 5e8ae2d5bc Restart CI for New Technology and UBSAN hunting
Continuous Integration (via runit and runitd) is now re-enabled on win7
and win10. The `make test` command, which runs the tests on all systems
is now the fastest and most stable it's been since the project started.

UBSAN is now enabled in MODE=dbg in addition to ASAN. Many instances of
undefined behavior have been removed. Mostly things like passing a NULL
argument to memcpy(), which works fine with Cosmopolitan Libc, but that
doesn't prevents the compiler from being unhappy. There was an issue w/
GNU make where static analysis claims a sprintf() call can overflow. We
also now have nicer looking crash reports on Windows since uname should
now be supported and msys64 addr2line works reliably.
2022-03-21 04:32:57 -07:00

46 lines
2.1 KiB
C

#if 0
/*─────────────────────────────────────────────────────────────────╗
│ To the extent possible under law, Justine Tunney has waived │
│ all copyright and related or neighboring rights to this file, │
│ as it is written in the following disclaimers: │
│ • http://unlicense.org/ │
│ • http://creativecommons.org/publicdomain/zero/1.0/ │
╚─────────────────────────────────────────────────────────────────*/
#endif
#include "libc/log/log.h"
/**
* Automatically launchs GDB Debugger TUI during crash.
*
* Run the following inside a terminal:
*
* sudo apt install gdb
* make -j12 o//examples/auto-launch-gdb-on-crash.com
* o//examples/auto-launch-gdb-on-crash.com
*
* Backtrace is logged instead if run outside interactive terminal. We
* also don't auto-launch GDB on non-Linux since the development tools
* on other platforms generally can't be relied upon to correctly debug
* binaries built with a Linux toolchain. Environmental factors such as
* GDB, MAKEFLAGS, ADDR2LINE, TERM, and isatty(STDERR_FILENO) should
* also be taken into consideration:
*
* $ export GDB=eoatuhshtuone
* $ o//examples/auto-launch-gdb-on-crash.com
* error: Uncaught SIGTRAP
* etc. etc.
*
* @see https://www.felixcloutier.com/x86/intn:into:int3:int1
* @see https://en.wikipedia.org/wiki/INT_(x86_instruction)#INT3
* @see examples and reference material on using the asm() keyword
* - libc/nexgen32e/bsf.h
* - libc/nexgen32e/tzcnt.h
* - libc/nexgen32e/cpuid4.internal.h
* - https://gist.github.com/jart/fe8d104ef93149b5ba9b72912820282c
*/
int main(int argc, char *argv[]) {
ShowCrashReports();
asm("int3"); /* cf. __die(), perror("msg"), abort(), exit(1), _Exit(1) */
return 0;
}