// Copyright (c) Facebook, Inc. and its affiliates. (http://www.facebook.com)
#pragma once

#include <stdint.h>

// Branch prediction hints for the compiler.  Use in performance critial code
// which almost always branches one way.
#define LIKELY(x) __builtin_expect(!!(x), 1)
#define UNLIKELY(x) __builtin_expect(!!(x), 0)

#if defined(NDEBUG) && !defined(DCHECK_ALWAYS_ON)
#define DCHECK_IS_ON() 0
#else
#define DCHECK_IS_ON() 1
#endif

#define CHECK(expr, ...)                                                       \
  do {                                                                         \
    if (UNLIKELY(!(expr))) {                                                   \
      checkFailed(__FILE__, __LINE__, __func__, "check '" #expr "' failed",    \
                  __VA_ARGS__);                                                \
    }                                                                          \
  } while (0)

#define CHECK_BOUND(val, high) CHECK_RANGE(val, 0, high)

#define CHECK_INDEX(index, high)                                               \
  do {                                                                         \
    if (UNLIKELY(!((index >= 0) && (index < high)))) {                         \
      checkIndexFailed(__FILE__, __LINE__, __func__, (intptr_t)(index),        \
                       (intptr_t)(high));                                      \
    }                                                                          \
  } while (0)

#define CHECK_RANGE(val, low, high)                                            \
  do {                                                                         \
    if (UNLIKELY(!((val >= low) && (val <= high)))) {                          \
      checkBoundFailed(__FILE__, __LINE__, __func__, (intptr_t)(val),          \
                       (intptr_t)(low), (intptr_t)(high));                     \
    }                                                                          \
  } while (0)

#if DCHECK_IS_ON()
#define DCHECK(...) CHECK(__VA_ARGS__)
#define DCHECK_BOUND(val, high) CHECK_BOUND(val, high)
#define DCHECK_INDEX(index, high) CHECK_INDEX(index, high)
#define DCHECK_RANGE(val, low, high) CHECK_RANGE(val, low, high)
#else
#define DCHECK(...)                                                            \
  if (false) {                                                                 \
    CHECK(__VA_ARGS__);                                                        \
  }
#define DCHECK_BOUND(val, high) DCHECK_RANGE(val, 0, high)
#define DCHECK_INDEX(index, high)                                              \
  if (false) {                                                                 \
    CHECK_INDEX(index, high);                                                  \
  }
#define DCHECK_RANGE(val, low, high)                                           \
  if (false) {                                                                 \
    CHECK_RANGE(val, low, high);                                               \
  }
#endif

#define UNIMPLEMENTED(...)                                                     \
  checkFailed(__FILE__, __LINE__, __func__, "unimplemented", __VA_ARGS__)

#define UNREACHABLE(...)                                                       \
  checkFailed(__FILE__, __LINE__, __func__, "unreachable", __VA_ARGS__)

// From https://github.com/Moonstroke/PUCA
#if defined(__cplusplus) && __cplusplus >= 201103L /* ISO C++11 */
#define NORETURN [[noreturn]]
#else /* C++11 */
#ifdef __GNUC__
#define NORETURN __attribute__((__noreturn__))
#else /* __GNUC__ */
#ifdef _MSC_VER
#define NORETURN __declspec(noreturn)
#else                                                        /* _MSC_VER */
#if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L /* ISO C11 */
#define NORETURN _Noreturn
#else /* C11 */
#define NORETURN
#endif /* C11 */
#endif /* _MSC_VER */
#endif /* __GNUC__ */
#endif /* C++11 */

#ifdef __cplusplus
extern "C" {
#endif

NORETURN void checkFailed(const char *file, int line, const char *func,
                          const char *expr, ...);
NORETURN void checkIndexFailed(const char *file, int line, const char *func,
                               intptr_t index, intptr_t high);
NORETURN void checkBoundFailed(const char *file, int line, const char *func,
                               intptr_t value, intptr_t low, intptr_t high);

#ifdef __cplusplus
}
#endif