declaration requires an exit-time destructor [-Werror,-Wexit-time-destructors]

What I am trying is to compile WebRtc Library for android and I am getting this mind blowing error. Please if someone could assist me in this matter. I have these implementations:

stream_buffer.h

#ifndef AUDIO_STREAM_BUFFER_H_
#define AUDIO_STREAM_BUFFER_H_

#include <array>
#include <cstdint>
#include <iostream>
#include <list>
#include <map>
#include <utility>

// #include "api/scoped_refptr.h"
#include "rtc_base/constructor_magic.h"
#include "rtc_base/ref_count.h"
#include "rtc_base/string_encode.h"
#include "rtc_base/system/rtc_export.h"
#include "rtc_base/thread_checker.h"

namespace rtc {

class RTC_EXPORT stream_buffer {
 
 public:
  
  stream_buffer() = delete;
  ~stream_buffer();

  static std::map<unsigned char, std::list<unsigned char>> buffer;
  mutable int ref_count_ RTC_GUARDED_BY(buffer) = {};

  // typedef unsigned char uint_8;
  typedef unsigned char uint8_t;

  static void push(uint8_t ssrc, std::list<uint8_t> value);

  static void pop();

  static std::list<unsigned char> get_payload(uint8_t ssrc);

  static void get_buffer_stats();

 private:

  RTC_DISALLOW_COPY_AND_ASSIGN(stream_buffer);
};

}  // namespace rtc

#endif  // AUDIO_STREAM_BUFFER_H_

stream_buffer.cc

#include "stream_buffer.h"

namespace rtc {


 std::map<unsigned char, std::list<unsigned char>> rtc::stream_buffer::buffer = {};

void stream_buffer::push(uint8_t ssrc, std::list<uint8_t> buf) {
  std::list<unsigned char> temp = std::move(buf);

  if (buffer.find(ssrc) == buffer.end()) {
    buffer.insert(std::pair<uint8_t, std::list<uint8_t>>(ssrc, temp));
  } else {
    buffer.find(ssrc)->second.push_back(temp.front());
    std::cout << "SSRC: " << ssrc
              << " bufferSize: " << buffer.find(ssrc)->second.size() << '\n';
  }
}

void stream_buffer::pop() {
  for (auto it = buffer.begin(); it != buffer.end(); ++it) {
    if (!buffer.find(it->first)->second.empty()) {
      std::cout << "key: " << int(it->first) << " pop value: ";
      for (auto v : buffer[int(it->first)]) {
        std::cout << int(v) << ' ';
      }
      std::cout << "\n";
      buffer.find(it->first)->second.pop_front();
    } else {
      std::cout << "Empty buffer for " << it->first << '\n';
    }
  }
}

std::list<unsigned char> stream_buffer::get_payload(
    stream_buffer::uint8_t ssrc) {
  if (buffer.find(ssrc) != buffer.end()) {
    return buffer[ssrc];
  } else {
    std::cout << "\nstream_buffer.cpp -> Invalid SSRC.\n";
    return static_cast<std::list<unsigned char>>(0);
  }
}

void stream_buffer::get_buffer_stats() {
  std::cout << "\nstream_buffer.cpp -> stream_buffer stats:\n";
  for (auto it = buffer.begin(); it != buffer.end(); ++it) {
    if (buffer.find(it->first) != buffer.end()) {
      std::cout << "SSRC: " << int(it->first)
                << " bufferSize: " << buffer.find(it->first)->second.size()
                << '\n';
    }
  }
}
}

Basically I have declared a static map in one the above class with the name of stream_buffer::buffer. When I try to compile the library, I am getting the following error.

on this line in stream_buffer.cc file.

std::map<unsigned char, std::list<unsigned char>> rtc::stream_buffer::buffer = {};

I have already visited multiple stack overflow issues, but didn't find anything useful.

How to deal with “exit-time destructor” warning in clang?

I would much appreciate being pointed in the right direction on either issue.

Solution

You can create your map dynamically. Something as, simplified:

class X
{
   static std::map<int, int>* ptr_;        

public:
   static std::map<int, int>& buffer()
   {
      return *ptr_;
   }
 
   static void finalize()
   {
      delete ptr_;
   }
};

std::map<int, int>* X::ptr = new std::map<int, int>{};

Now, since the static variable is an ordinary pointer, there is no problem with constructors and destructors.

Note that you need to delete the map manually, here by calling X::finalize() somewhere at the end of your program.