debug/system: make last-chance printing more reliable

This commit is contained in:
Danny Robson 2019-07-02 17:34:39 +10:00
parent 928cdb4e8b
commit af01ba0836

View File

@ -9,6 +9,7 @@
#include "./system.hpp"
#include "debugger.hpp"
#include "except.hpp"
#include "../backtrace.hpp"
#include "../log.hpp"
@ -17,15 +18,24 @@
////////////////////////////////////////////////////////////////////////////////
static std::terminate_handler old_handler = nullptr;
//-----------------------------------------------------------------------------
static void abort_with_trace (void)
{
// Manually trigger a breakpoint if possible so that the debugger won't
// silently dump us some place without further information.
// eg, CLion/GDB/Win32 silently dropping us out of the session.
// 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 this is because of an exception we may as well rethrow and hope that
// the system will print exception data during the abort process.
// 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.
@ -34,22 +44,28 @@ static void abort_with_trace (void)
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 {});
LOG_EMERGENCY ("unhandled exception\n%!", ::cruft::backtrace {});
}
} else {
LOG_EMERGENCY ("aborting: %!", ::cruft::backtrace {});
}
std::abort ();
old_handler ();
}
///////////////////////////////////////////////////////////////////////////////
void
cruft::debug::init [[gnu::constructor]] (void)
cruft::debug::init (void)
{
std::set_terminate (abort_with_trace);
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;