Method DumpStackTraceMemory

dev/src/vm.cpp:478–552

See also imbind.cpp:DumpStackTrace and VM::DumpStackTrace()

// See also imbind.cpp:DumpStackTrace and VM::DumpStackTrace()
void VM::DumpStackTraceMemory(const string &err) {
    if (fun_id_stack.empty()) {
        // We don't have a stack trace.
        return;
    }
    // We're going to be dumping as much as possible of the memory of the program along with
    // the stack trace. To this end we're using the FlexBuffers dumper which already can deal with
    // cycles etc, so it will output max 1 copy of each data structure.
    ToFlexBufferContext fbc(*this, 1024 * 1024, flexbuffers::BUILDER_FLAG_SHARE_KEYS_AND_STRINGS);
    fbc.cycle_detect = true;
    fbc.max_depth = 64;
    fbc.ignore_unsupported_types = true;

    #ifdef USE_EXCEPTION_HANDLING
    try {
    #endif

    DumperFun dumper = [&fbc](VM &vm, string_view_nt name, const TypeInfo &ti, Value *x) {
        #if RTT_ENABLED
            auto debug_type = x->type;
        #else
            auto debug_type = ti.t;
        #endif
        if (debug_type == RTT_NIL && !ti.is_nil) {
            // Just skip, only useful in debug.
        } else if (ti.t != debug_type && !RTIsStruct(ti.t)) {
            // Just skip, only useful in debug.
        } else {
            fbc.builder.Key(name.data(), name.size());
            if (RTIsStruct(ti.t)) {
                vm.StructToFlexBuffer(fbc, ti, x, false);
            } else {
                x->ToFlexBuffer(fbc, ti.t, {}, (type_elem_t)0);
            }
        }
    };

    auto vstart = fbc.builder.StartVector();
    fbc.builder.String(err);
    auto cur_fileidx = last.fileidx;
    auto cur_line = last.line;
    for (auto &funstackelem : reverse(fun_id_stack)) {
        auto vstart2 = fbc.builder.StartVector();
        auto [name, fip] = DumpStackFrameStart(funstackelem.funstartinfo, cur_fileidx, cur_line);
        fbc.builder.String(name);
        auto mstart = fbc.builder.StartMap();
        DumpStackFrame(fip, funstackelem.locals, dumper);
        fbc.builder.EndMap(mstart);
        fbc.builder.EndVector(vstart2, false, false);
        cur_fileidx = funstackelem.fileidx;
        cur_line = funstackelem.line;
    }
    fbc.builder.EndVector(vstart, false, false);
    fbc.builder.Finish();
    auto fn = cat("crash_stack_trace_memory_dump_", GetDateTime(), ".flex");
    auto contents =
        string_view((char *)fbc.builder.GetBuffer().data(), fbc.builder.GetBuffer().size());
    if (WriteFile(fn, true, contents, false)) {