/** 定义框架中与配置相关的宏 */
/*!
 *  Copyright (c) 2015 by Contributors
 * \file base.h
 * \brief defines configuration macros
 */
#ifndef DMLC_BASE_H_
#define DMLC_BASE_H_

/** 此宏定义是否使用GLog库 */
/*! \brief whether use glog for logging */
#ifndef DMLC_USE_GLOG
#define DMLC_USE_GLOG 0
#endif

/**
* 此宏定义当FATAL错误出现时是否抛出框架定义的Error而不是调用abort
* 注意：这可能不是完善的；不要在析构器中使用FATAL和CHECK 
**/
/*!
 * \brief whether throw dmlc::Error instead of
 *  directly calling abort when FATAL error occured
 *  NOTE: this may still not be perfect.
 *  do not use FATAL and CHECK in destructors
 */
#ifndef DMLC_LOG_FATAL_THROW
#define DMLC_LOG_FATAL_THROW 1
#endif

/** 
* 此宏定义，对于fatal error是否打印栈追踪信息，追踪深度为10；当在linux上使用
* gcc时启用； __GNUC__表示gcc编译器主版本号，它是由所有使用C预处理器
*（C, C++, Objective-C and Fortran）的GNU编译器所定义；__MINGW32__表示
* 使用mingw编译器；__sun和__SVR4、__ANDROID__分别表示相应系统；
* */
/*!
 * \brief Whether to print stack trace for fatal error,
 * enabled on linux when using gcc.
 */
#if (defined(__GNUC__) && !defined(__MINGW32__) && !defined(__sun) && !defined(__SVR4) && \
     !(defined __MINGW64__) && !(defined __ANDROID__))
#if (!defined(DMLC_LOG_STACK_TRACE))
#define DMLC_LOG_STACK_TRACE 1
#endif
#if (!defined(DMLC_LOG_STACK_TRACE_SIZE))
#define DMLC_LOG_STACK_TRACE_SIZE 10
#endif
#endif

/** 编译器选项，是否启用hdfs支持 */
/*! \brief whether compile with hdfs support */
#ifndef DMLC_USE_HDFS
#define DMLC_USE_HDFS 0
#endif

/** 编译器选项，编译是否启用s3支持 */
/*! \brief whether compile with s3 support */
#ifndef DMLC_USE_S3
#define DMLC_USE_S3 0
#endif

/** 编译器选项，是否使用PS服务器 */
/*! \brief whether or not use parameter server */
#ifndef DMLC_USE_PS
#define DMLC_USE_PS 0
#endif

/** 
* 编译器选项，使用GCC C++11支持，否则使用C++ 0X；
* 或者C++版本在201103L之后或者使用微软C编译器 
**/
/*! \brief whether or not use c++11 support */
#ifndef DMLC_USE_CXX11
#define DMLC_USE_CXX11 (defined(__GXX_EXPERIMENTAL_CXX0X__) ||\
                        __cplusplus >= 201103L || defined(_MSC_VER))
#endif

/** 检测g++编译器位于4.6之前版本，排除clang++编译器 */
/// check if g++ is before 4.6
#if DMLC_USE_CXX11 && defined(__GNUC__) && !defined(__clang_version__)
#if __GNUC__ == 4 && __GNUC_MINOR__ < 6
#pragma message("Will need g++-4.6 or higher to compile all"           \
                "the features in dmlc-core, "                           \
                "compile without c++11, some features may be disabled")
#undef DMLC_USE_CXX11
#define DMLC_USE_CXX11 0
#endif
#endif

/*!
 * \brief Disable copy constructor and assignment operator.
 *
 * If C++11 is supported, both copy and move constructors and
 * assignment operators are deleted explicitly. Otherwise, they are
 * only declared but not implemented. Place this macro in private
 * section if C++11 is not available.
 */
#ifndef DISALLOW_COPY_AND_ASSIGN
#  if DMLC_USE_CXX11
#    define DISALLOW_COPY_AND_ASSIGN(T) \
       T(T const&) = delete; \
       T(T&&) = delete; \
       T& operator=(T const&) = delete; \
       T& operator=(T&&) = delete
#  else
#    define DISALLOW_COPY_AND_ASSIGN(T) \
       T(T const&); \
       T& operator=(T const&)
#  endif
#endif

///
/// code block to handle optionally loading
///
#if !defined(__GNUC__)
#define fopen64 std::fopen
#endif
#ifdef _MSC_VER
#if _MSC_VER < 1900
// NOTE: sprintf_s is not equivalent to snprintf,
// they are equivalent when success, which is sufficient for our case
#define snprintf sprintf_s
#define vsnprintf vsprintf_s
#endif
#else
#ifdef _FILE_OFFSET_BITS
#if _FILE_OFFSET_BITS == 32
#pragma message("Warning: FILE OFFSET BITS defined to be 32 bit")
#endif
#endif

#ifdef __APPLE__
#define off64_t off_t
#define fopen64 std::fopen
#endif

extern "C" {
#include <sys/types.h>
}
#endif

#ifdef _MSC_VER
//! \cond Doxygen_Suppress
typedef signed char int8_t;
typedef __int16 int16_t;
typedef __int32 int32_t;
typedef __int64 int64_t;
typedef unsigned char uint8_t;
typedef unsigned __int16 uint16_t;
typedef unsigned __int32 uint32_t;
typedef unsigned __int64 uint64_t;
//! \endcond
#else
#include <inttypes.h>
#endif
#include <string>
#include <vector>

/*! \brief namespace for dmlc */
namespace dmlc {
/*!
 * \brief safely get the beginning address of a vector
 * \param vec input vector
 * \return beginning address of a vector
 */
template <typename T>
inline T *BeginPtr(std::vector<T> &vec) {  // NOLINT(*)
  if (vec.size() == 0) {
    return NULL;
  } else {
    return &vec[0];
  }
}
/*!
 * \brief get the beginning address of a vector
 * \param vec input vector
 * \return beginning address of a vector
 */
template <typename T>
inline const T *BeginPtr(const std::vector<T> &vec) {
  if (vec.size() == 0) {
    return NULL;
  } else {
    return &vec[0];
  }
}
/*!
 * \brief get the beginning address of a vector
 * \param str input string
 * \return beginning address of a string
 */
inline char* BeginPtr(std::string &str) {  // NOLINT(*)
  if (str.length() == 0) return NULL;
  return &str[0];
}
/*!
 * \brief get the beginning address of a vector
 * \param str input string
 * \return beginning address of a string
 */
inline const char* BeginPtr(const std::string &str) {
  if (str.length() == 0) return NULL;
  return &str[0];
}
}  // namespace dmlc

#if defined(_MSC_VER) && _MSC_VER < 1900
#define constexpr const
#define alignof __alignof
#endif

#endif  // DMLC_BASE_H_