Function DumpStack

core/debug.cc:304–369

}

[[gnu::noinline]] std::string DumpStack() {
  const size_t max_stack_depth = 64;
  void *addrs[max_stack_depth] = {};

  std::ostringstream stack;

  char **symbols;
  int skips = 0;

  // the linker requires -rdynamic for non-exported symbols
  int cnt = backtrace(addrs, max_stack_depth);

  // in some cases the bottom of the stack is NULL - not useful at all, remove.
  while (cnt > 0 && !addrs[cnt - 1]) {
    cnt--;
  }

  // The return addresses point to the next instruction after its call,
  // so adjust them by -1
  for (int i = 0; i < cnt; i++) {
    if (addrs[i] != trap_ip) {
      addrs[i] =
          reinterpret_cast<void *>(reinterpret_cast<uintptr_t>(addrs[i]) - 1);
    }
  }

  symbols = backtrace_symbols(addrs, cnt);
  if (!symbols) {
    return "ERROR: backtrace_symbols() failed\n";
  }

  // Triggered by a signal? (trap_ip is set)
  if (trap_ip) {
    // addrs[0]: DumpStack() <- this function calling backtrace()
    // addrs[1]: TrapHandler()
    // addrs[2]: sigaction in glibc, or pthread signal handler
    // addrs[3]: the trigerring instruction pointer *or* its caller
    //           (depending on the kernel behavior?)
    if (addrs[3] == trap_ip) {
      skips = 3;
    } else {
      skips = 2;
      addrs[2] = trap_ip;
    }
  } else {
    // LOG(FATAL) or CHECK() failed
    // addrs[0]: DumpStack() <- this function calling backtrace()
    // addrs[1]: GoPanic()
    // addrs[2]: caller of GoPanic()
    skips = 2;
    while (skips < cnt && SkipSymbol(symbols[skips])) {
      skips++;
    }
  }

  stack << "Backtrace (recent calls first) ---" << std::endl;

  for (int i = skips; i < cnt; i++) {