Function logStackTrace

src/debug.cpp:1669–1716

Logs the stack trace using the libunwind call. * The eip argument is unused as libunwind only gets local context. * The uplevel argument indicates how many of the calling functions to skip. */

 * The uplevel argument indicates how many of the calling functions to skip.
 */
void logStackTrace(void * eip, int uplevel) {
    (void)eip;//UNUSED
    const char *msg;
    int fd = openDirectLogFiledes();

    if (fd == -1) return; /* If we can't log there is anything to do. */

    msg = "\n------ STACK TRACE ------\n";
    if (write(fd,msg,strlen(msg)) == -1) {/* Avoid warning. */};
    unw_cursor_t cursor;
    unw_context_t context;

    unw_getcontext(&context);
    unw_init_local(&cursor, &context);

    /* Write symbols to log file */
    msg = "\nBacktrace:\n";
    if (write(fd,msg,strlen(msg)) == -1) {/* Avoid warning. */};

    for (int i = 0; i < uplevel; i++) {
        unw_step(&cursor);
    }

    while ( unw_step(&cursor) ) {
    unw_word_t ip, sp, off;

    unw_get_reg(&cursor, UNW_REG_IP, &ip);
    unw_get_reg(&cursor, UNW_REG_SP, &sp);

    char symbol[256] = {"<unknown>"};
    char *name = symbol;

    if ( !unw_get_proc_name(&cursor, symbol, sizeof(symbol), &off) ) {
        int status;
        if ( (name = abi::__cxa_demangle(symbol, NULL, NULL, &status)) == 0 )
        name = symbol;
    }

    dprintf(fd, "%s(+0x%" PRIxPTR ") [0x%016" PRIxPTR "] sp=0x%016" PRIxPTR "\n",
        name,
        static_cast<uintptr_t>(off),
        static_cast<uintptr_t>(ip),
        static_cast<uintptr_t>(sp));

    if ( name != symbol )
        free(name);
    }
}

#endif /* UNW_LOCAL_ONLY */