expects

// -*- C++ -*-
// This file is a part of the IncludeOS unikernel - www.includeos.org
//
// Copyright 2015 Oslo and Akershus University College of Applied Sciences
// and Alfred Bratterud
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#pragma once
#ifndef INCLUDEOS_EXPECTS_HEADER
#define INCLUDEOS_EXPECTS_HEADER

// LIKELY/UNLIKELY
#include <likely>
#include <cstdlib>

#undef Expects
#undef Ensures

#ifdef INCLUDEOS_SMP_ENABLE
#include <smp>
#endif

#include <os.hpp>
#include <serial>

inline bool __expect_is_recursive() {
#ifndef UNITTESTS
  static volatile bool in_failure = false;
  if (in_failure) return true;
  in_failure = true;
  return false;
#else
  return false;
#endif
}

inline void __expect_emit_failure(std::string_view msg, std::string_view panic_text) {
#ifndef UNITTESTS

#ifdef INCLUDEOS_SMP_ENABLE
  SMP::global_lock();
#endif

  std::fprintf(stderr, "%.*s\n", int(msg.size()), msg.data());
  fflush(NULL);
#ifdef INCLUDEOS_SMP_ENABLE
  SMP::global_unlock();
#endif
  os::panic(std::string(panic_text).c_str());

#else // UNITTESTS
  (void) panic_text;
  // throw here to allow tests to capture the error
  #include <stdexcept>
  throw std::runtime_error(std::string(msg));
#endif
}

template <class... Args>
inline void __expect_failf(const char *err_prefix, const char * cond, const char *file, int line, const char *func, std::format_string<Args...> fmt, Args&&... args){
  if (__expect_is_recursive()) {
    kprint("Fatal Expects/Ensures recursion. (libc not initialized?)\n");

    kprint("Condition was '");
    kprint(cond); kprint("' @ ");
    kprint(file); kprint(":");
    kprint(func); kprint(" with fmt=");
    kprint(fmt.get().data()); kprint("\n");

    // os::shutdown();
    __arch_poweroff();
  }
  auto reason_msg = std::format(fmt, std::forward<Args>(args)...);
  auto error_msg = std::format("{}:{}:{}: {}: {}", file, line, func, err_prefix, reason_msg);
  __expect_emit_failure(error_msg, reason_msg);
}

inline void __expect_failf(const char *err_prefix, const char *cond, const char *file, int line, const char *func){
  if (__expect_is_recursive()) {
    kprint("Fatal Expects/Ensures recursion (libc not initialized?)\n");

    kprint("Condition was '");
    kprint(cond); kprint("' @ ");
    kprint(file); kprint(":");
    kprint(func); kprint("\n");

    // os::shutdown();
    __arch_poweroff();
  }
  auto reason_msg = std::format("{}: {}", err_prefix, cond);
  auto error_msg = std::format("{}:{}:{}: {}", file, line, func, err_prefix);
  __expect_emit_failure(error_msg, reason_msg);
}

#define Expects(cond) ((void)((cond) || (__expect_failf("Expects failed", #cond, __FILE__, __LINE__, __func__),0)))
#define Ensures(cond) ((void)((cond) || (__expect_failf("Ensures failed", #cond, __FILE__, __LINE__, __func__),0)))

#define Expectsf(cond, fmt, ...) ((void)((cond) || (__expect_failf("Expects failed", #cond, __FILE__, __LINE__, __func__, fmt, ##__VA_ARGS__),0)))
#define Ensuresf(cond, fmt, ...) ((void)((cond) || (__expect_failf("Ensures failed", #cond, __FILE__, __LINE__, __func__, fmt, ##__VA_ARGS__),0)))

namespace os {
// parameter for noexcept specifier when bypassing noexcept for testing
#if defined(TEST)
  constexpr bool hard_noexcept = false;
#else
  constexpr bool hard_noexcept = true;
#endif

}
#endif //< INCLUDEOS_EXPECTS_HEADER