Adds tools/symbolize_crash.cpp, built alongside the game as a console exe:
it reads a crash_report_*.txt written by writeExceptionBacktrace and prints
the backtrace with function names, source lines and inlined frames, in call
order, coloured when standard output is a console.
Symbols come from DbgHelp against the build's PDB rather than an external
symbolizer. SymLoadModuleEx takes the runtime base out of the report's
module table, so the relocation arithmetic /DYNAMICBASE forces on us is
DbgHelp's problem now; a report predating the module table loads at the
image's preferred base, which is where it ran. Verified under Wine: PDB
line info and inline traces both resolve.
The tool wants C++23 (std::print, std::format) where the game is C++17, so
the standard is set on the target alone. Both MSVC 19.51 and clang-cl build
it clean in all three configurations.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Report crashes for every player, not only those running under Wine's WINEDEBUG.
A last-chance UnhandledExceptionFilter is no good: faults on the message-pump /
WindowProcedure path have no game __except on their stack, and under Wine the
WndProc dispatch swallows them before they ever reach "unhandled". Install a
vectored handler instead -- it runs first-chance, ahead of every frame handler,
records the fault and returns EXCEPTION_CONTINUE_SEARCH, so normal SEH is
unaffected.
The dump is deliberately heap-free. The crash most worth reporting is often heap
corruption, so anything that allocates (the game Logger, std::vector, DbgHelp's
Sym* family) would fault again and take the report down with it. Using only stack
buffers and raw Win32, writeExceptionBacktrace writes the registers, the faulting
address, a UTC timestamp, the build id, the loaded-module table and a
bounds-checked manual EBP walk into a fresh numbered crash_report_NNN.txt.
The module table is what makes the addresses mean anything. Our executables are
linked /DYNAMICBASE and keep their .reloc section, so the loader is free to move
the image: Wine leaves it at the preferred base, Windows ASLR does not. A report
listing only runtime addresses is symbolizable by luck, and silently wrong once
the luck runs out. Recording where each image actually landed turns the offset
into arithmetic:
llvm-symbolizer --obj=JA2.exe --adjust-vma=$((<JA2.exe base> - 0x400000))
It is walked off the PEB loader list because both alternatives -- EnumProcessModules
and DbgHelp's module APIs -- allocate, and this path must not. Having the table
also frees the backtrace from restricting itself to our own module's return
addresses: a fault inside ddraw/fmod/bink is exactly the case worth seeing, and
an address belonging to no module is recognizable as the frame-pointer debris it
is.
Two things go into the report beside the machine state. czVersionString stamps
the build, so a report matches the exact PDB it has to be symbolized against, and
the optional HANDLE from Ja2 Settings names the player, so a report can be tied
to whoever raises it with us. The handle is sanitized where it is set rather than
where it is used: it is player input that lands in a line-oriented text report,
so anything that could forge a line (CR/LF, control and non-ASCII characters) is
dropped and the length is capped.
Finally the player is told. The message is composed in the handler, while the
fault details and the report's filename are still in hand, but shown from
SGPExit: first-chance means the exception may yet be handled downstream, and a
message box pumps messages, which on the heap that just faulted is a second
crash. It replaces the generic "Unhandled exception. Unable to recover." box
rather than adding to it -- it says more, and it names the file we need attached
to the bug report.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Each of these takes the address of an object that has no name:
bool b = client->Startup(1,30,&SocketDescriptor(), 1);
OutputToStream(msg, &(SGP_LOG(s_log.id)));
MSVC allows it as an extension. The temporary lives to the end of the full
expression, which is past the call, so all three happen to work; clang rejects
the address-of outright.
Naming the object changes nothing about when it is built or what is passed,
only that the pointer now refers to something that outlives the statement.
MemMan.cpp already does this with the same logger call:
sgp::Logger::LogInstance memLeak = SGP_LOG(log_id);
Verification:
ninja -C build parse # address-of-temporary class gone: 24 -> 21 sites
ninja -C build -k 0 # Release, four applications, green
ninja -C build-debug -k 0 # Debug, four applications, green
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
