libcruft-util/debug/system.cpp

84 lines
2.5 KiB
C++

/*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* Copyright 2010-2019 Danny Robson <danny@nerdcruft.net>
*/
#include "./system.hpp"
#include "debugger.hpp"
#include "except.hpp"
#include "crash.hpp"
#include "../backtrace.hpp"
#include "../log.hpp"
#include <cstdlib>
////////////////////////////////////////////////////////////////////////////////
static std::terminate_handler old_handler = nullptr;
//-----------------------------------------------------------------------------
static void abort_with_trace (void)
{
// We used to trigger a breakpoint so that our debugger didn't just let the
// child terminate (ie, the behaviour of CLion/Win32/GDB).
//
// But this might silently terminate the program instead of allowing us the
// chance to dump a backtrace depending on the precise mechanism for
// `breakpoint`; in particular SIGTRAP and SIGINT trigger this.
#if 0
breakpoint ();
#endif
// If we're here because of an exception we may as well rethrow and hope
// that the system will print exception data during the abort process.
//
// But we can at least try to print anything derived from std::exception
// (which is a likely guess) before we self-destruct.
if (auto ptr = std::current_exception (); ptr) {
try {
std::rethrow_exception (ptr);
} catch (std::exception const &x) {
LOG_EMERGENCY ("unhandled exception: %!\n%!", x.what (), ::cruft::backtrace {});
} catch (cruft::error const &x) {
LOG_EMERGENCY ("unhandled exception: %!\n%!", x, ::cruft::backtrace {});
} catch (...) {
LOG_EMERGENCY ("unhandled exception\n%!", ::cruft::backtrace {});
}
} else {
LOG_EMERGENCY ("aborting: %!", ::cruft::backtrace {});
}
old_handler ();
}
///////////////////////////////////////////////////////////////////////////////
void
cruft::debug::init (void)
{
init_crash_handler ();
old_handler = std::set_terminate (abort_with_trace);
CHECK_NEQ (
reinterpret_cast<void*> (old_handler),
reinterpret_cast<void*> (abort_with_trace)
);
if (!debug_enabled && !getenv ("DEBUG"))
return;
LOG_DEBUG ("setting debug environment");
//enable_fpe ();
force_console ();
prepare_debugger ();
if (getenv ("DEBUG_WAIT"))
await_debugger ();
}