Function backtrace_symbols_demangle_fd

src/debug.cpp:1722–1763

#ifdef HAVE_BACKTRACE

void backtrace_symbols_demangle_fd(void **trace, size_t csym, int fd)
{
    char **syms = backtrace_symbols(trace, csym);
    char symbuf[1024];
    for (size_t itrace = 0; itrace < csym; ++itrace)
    {
        int status = 0;

        // First find the symbol (preceded by a '(')
        char *pchSymStart = syms[itrace];
        while (*pchSymStart != '(' && *pchSymStart != '\0')
            ++pchSymStart;
        if (*pchSymStart != '\0')
            ++pchSymStart;  // skip the '('
        char *pchSymEnd = pchSymStart;
        while (*pchSymEnd != '+' && *pchSymEnd != '\0')
            ++pchSymEnd;

        if ((pchSymEnd - pchSymStart) < 1023)
        {
            memcpy(symbuf, pchSymStart, pchSymEnd - pchSymStart);
            symbuf[pchSymEnd - pchSymStart] = '\0';
            char *sz = abi::__cxa_demangle(symbuf, nullptr, nullptr, &status);
            if (status == 0)
            {
                safe_write(fd, syms[itrace], pchSymStart - syms[itrace]);
                safe_write(fd, sz, strlen(sz));
                safe_write(fd, pchSymEnd, (syms[itrace] + strlen(syms[itrace])-pchSymEnd));
            }
            else
            {
                safe_write(fd, syms[itrace], strlen(syms[itrace]));
            }
            free(sz);
        }
        else {
            safe_write(fd, syms[itrace], strlen(syms[itrace]));
        }
        safe_write(fd, "\n", 1);   
    }
    free(syms);
}

/* Logs the stack trace using the backtrace() call. This function is designed
 * to be called from signal handlers safely.