text: // 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.
  //
  // See www.openfst.org for extensive documentation on this weighted
  // finite-state transducer library.
  //
  // Google-style logging declarations and inline definitions.
  
  #ifndef FST_LIB_LOG_H_
  #define FST_LIB_LOG_H_
  
  #include <cassert>
  #include <iostream>
  #include <string>
  
  #include <fst/types.h>
  #include <fst/flags.h>
  
  DECLARE_int32(v);
  
  class LogMessage {
   public:
    LogMessage(const std::string &type) : fatal_(type == "FATAL") {
      std::cerr << type << ": ";
    }
    ~LogMessage() {
      std::cerr << std::endl;
      if(fatal_)
        exit(1);
    }
    std::ostream &stream() { return std::cerr; }
  
   private:
    bool fatal_;
  };
  
  #define LOG(type) LogMessage(#type).stream()
  #define VLOG(level) if ((level) <= FLAGS_v) LOG(INFO)
  
  // Checks
  inline void FstCheck(bool x, const char* expr,
                  const char *file, int line) {
    if (!x) {
      LOG(FATAL) << "Check failed: \"" << expr
                 << "\" file: " << file
                 << " line: " << line;
    }
  }
  
  #define CHECK(x) FstCheck(static_cast<bool>(x), #x, __FILE__, __LINE__)
  #define CHECK_EQ(x, y) CHECK((x) == (y))
  #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_NE(x, y) CHECK((x) != (y))
  
  // Debug checks
  #define DCHECK(x) assert(x)
  #define DCHECK_EQ(x, y) DCHECK((x) == (y))
  #define DCHECK_LT(x, y) DCHECK((x) < (y))
  #define DCHECK_GT(x, y) DCHECK((x) > (y))
  #define DCHECK_LE(x, y) DCHECK((x) <= (y))
  #define DCHECK_GE(x, y) DCHECK((x) >= (y))
  #define DCHECK_NE(x, y) DCHECK((x) != (y))
  
  
  // Ports
  #define ATTRIBUTE_DEPRECATED __attribute__((deprecated))
  
  #endif  // FST_LIB_LOG_H_
  