// Copyright 2009 The RE2 Authors.  All Rights Reserved.

// Use of this source code is governed by a BSD-style

// license that can be found in the LICENSE file.

#ifndef UTIL_LOGGING_H_

#define UTIL_LOGGING_H_

// Simplified version of Google's logging.

#include <assert.h>

#include <stdio.h>

#include <stdlib.h>

#include <ostream>

#include <sstream>

#include "util/util.h"

// Debug-only checking.

#define DCHECK(condition) assert(condition)

#define DCHECK_EQ(val1, val2) assert((val1) == (val2))

#define DCHECK_NE(val1, val2) assert((val1) != (val2))

#define DCHECK_LE(val1, val2) assert((val1) <= (val2))

#define DCHECK_LT(val1, val2) assert((val1) < (val2))

#define DCHECK_GE(val1, val2) assert((val1) >= (val2))

#define DCHECK_GT(val1, val2) assert((val1) > (val2))

// Always-on checking

#define CHECK(x)  if(x){}else LogMessageFatal(__FILE__, __LINE__).stream() << "Check failed: " #x

#define CHECK_LT(x, y)  CHECK((x) < (y))

#define CHECK_GT(x, y)  CHECK((x) > (y))

#define CHECK_LE(x, y)  CHECK((x) <= (y))

#define CHECK_GE(x, y)  CHECK((x) >= (y))

#define CHECK_EQ(x, y)  CHECK((x) == (y))

#define CHECK_NE(x, y)  CHECK((x) != (y))

#define LOG_INFO LogMessage(__FILE__, __LINE__)

#define LOG_WARNING LogMessage(__FILE__, __LINE__)

#define LOG_ERROR LogMessage(__FILE__, __LINE__)

#define LOG_FATAL LogMessageFatal(__FILE__, __LINE__)

#define LOG_QFATAL LOG_FATAL

// It seems that one of the Windows header files defines ERROR as 0.

#ifdef _WIN32

#define LOG_0 LOG_INFO

#endif

#ifdef NDEBUG

#define LOG_DFATAL LOG_ERROR

#else

#define LOG_DFATAL LOG_FATAL

#endif

#define LOG(severity) LOG_ ## severity.stream()

#define VLOG(x) if((x)>0){}else LOG_INFO.stream()

class LogMessage {

 public:

  LogMessage(const char* file, int line)

      : flushed_(false) {

    stream() << file << ":" << line << ": ";

  }

  void Flush() {

    stream() << "\n";

    std::string s = str_.str();

    size_t n = s.size();

    if (fwrite(s.data(), 1, n, stderr) < n) {}  // shut up gcc

    flushed_ = true;

  }

  ~LogMessage() {

    if (!flushed_) {

      Flush();

    }

  }

  std::ostream& stream() { return str_; }

 private:

  bool flushed_;

  std::ostringstream str_;

  LogMessage(const LogMessage&) = delete;

  LogMessage& operator=(const LogMessage&) = delete;

};

// Silence "destructor never returns" warning for ~LogMessageFatal().

// Since this is a header file, push and then pop to limit the scope.

#ifdef _MSC_VER

#pragma warning(push)

#pragma warning(disable: 4722)

#endif

class LogMessageFatal : public LogMessage {

 public:

  LogMessageFatal(const char* file, int line)

      : LogMessage(file, line) {}

  ATTRIBUTE_NORETURN ~LogMessageFatal() {

    Flush();

    abort();

  }

 private:

  LogMessageFatal(const LogMessageFatal&) = delete;

  LogMessageFatal& operator=(const LogMessageFatal&) = delete;

};

#ifdef _MSC_VER

#pragma warning(pop)

#endif

#endif  // UTIL_LOGGING_H_