text: // Copyright 2014 PDFium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
  
  #ifndef CORE_FXCRT_FX_SYSTEM_H_
  #define CORE_FXCRT_FX_SYSTEM_H_
  
  #include <stddef.h>
  #include <stdint.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <wchar.h>
  
  #include "build/build_config.h"
  #include "core/fxcrt/fx_types.h"
  
  #if defined(_MSC_VER) && _MSC_VER < 1900
  #error Sorry, VC++ 2015 or later is required to compile PDFium.
  #endif  // defined(_MSC_VER) && _MSC_VER < 1900
  
  #if defined(__wasm__) && defined(PDF_ENABLE_V8)
  #error Cannot compile v8 with wasm.
  #endif  // PDF_ENABLE_V8
  
  #if BUILDFLAG(IS_WIN)
  #include <windows.h>
  #endif  // BUILDFLAG(IS_WIN)
  
  #ifdef __cplusplus
  extern "C" {
  #endif  // __cplusplus
  
  #define FXSYS_IsFloatZero(f) ((f) < 0.0001 && (f) > -0.0001)
  #define FXSYS_IsFloatBigger(fa, fb) \
    ((fa) > (fb) && !FXSYS_IsFloatZero((fa) - (fb)))
  #define FXSYS_IsFloatSmaller(fa, fb) \
    ((fa) < (fb) && !FXSYS_IsFloatZero((fa) - (fb)))
  #define FXSYS_IsFloatEqual(fa, fb) FXSYS_IsFloatZero((fa) - (fb))
  
  // M_PI not universally present on all platforms.
  #define FXSYS_PI 3.1415926535897932384626433832795f
  #define FXSYS_BEZIER 0.5522847498308f
  
  // NOTE: prevent use of the return value from snprintf() since some platforms
  // have different return values.
  #define FXSYS_snprintf (void)snprintf
  #define FXSYS_vsnprintf (void)vsnprintf
  #define FXSYS_sprintf DO_NOT_USE_SPRINTF_DIE_DIE_DIE
  #define FXSYS_vsprintf DO_NOT_USE_VSPRINTF_DIE_DIE_DIE
  
  #if BUILDFLAG(IS_WIN)
  #define FXSYS_itoa _itoa
  #define FXSYS_strlwr _strlwr
  #define FXSYS_strupr _strupr
  #define FXSYS_stricmp _stricmp
  #define FXSYS_wcsicmp _wcsicmp
  #define FXSYS_wcslwr _wcslwr
  #define FXSYS_wcsupr _wcsupr
  size_t FXSYS_wcsftime(wchar_t* strDest,
                        size_t maxsize,
                        const wchar_t* format,
                        const struct tm* timeptr);
  #define FXSYS_SetLastError SetLastError
  #define FXSYS_GetLastError GetLastError
  #else  // BUILDFLAG(IS_WIN)
  char* FXSYS_itoa(int value, char* str, int radix);
  char* FXSYS_strlwr(char* str);
  char* FXSYS_strupr(char* str);
  int FXSYS_stricmp(const char* str1, const char* str2);
  int FXSYS_wcsicmp(const wchar_t* str1, const wchar_t* str2);
  wchar_t* FXSYS_wcslwr(wchar_t* str);
  wchar_t* FXSYS_wcsupr(wchar_t* str);
  #define FXSYS_wcsftime wcsftime
  void FXSYS_SetLastError(uint32_t err);
  uint32_t FXSYS_GetLastError();
  #endif  // BUILDFLAG(IS_WIN)
  
  int32_t FXSYS_atoi(const char* str);
  uint32_t FXSYS_atoui(const char* str);
  int32_t FXSYS_wtoi(const wchar_t* str);
  int64_t FXSYS_atoi64(const char* str);
  const char* FXSYS_i64toa(int64_t value, char* str, int radix);
  int FXSYS_roundf(float f);
  int FXSYS_round(double d);
  float FXSYS_sqrt2(float a, float b);
  
  #ifdef __cplusplus
  }  // extern "C"
  
  // C++-only section
  
  // Overloaded functions for C++ templates
  inline size_t FXSYS_len(const char* ptr) {
    return strlen(ptr);
  }
  
  inline size_t FXSYS_len(const wchar_t* ptr) {
    return wcslen(ptr);
  }
  
  inline int FXSYS_cmp(const char* ptr1, const char* ptr2, size_t len) {
    return memcmp(ptr1, ptr2, len);
  }
  
  inline int FXSYS_cmp(const wchar_t* ptr1, const wchar_t* ptr2, size_t len) {
    return wmemcmp(ptr1, ptr2, len);
  }
  
  inline const char* FXSYS_chr(const char* ptr, char ch, size_t len) {
    return reinterpret_cast<const char*>(memchr(ptr, ch, len));
  }
  
  inline const wchar_t* FXSYS_chr(const wchar_t* ptr, wchar_t ch, size_t len) {
    return wmemchr(ptr, ch, len);
  }
  
  // Could be C, but uses C++-style casting.
  #define FXSYS_UINT16_GET_LSBFIRST(p)                               \
    (static_cast<uint16_t>(                                          \
        (static_cast<uint32_t>(static_cast<uint8_t>((p)[1])) << 8) | \
        (static_cast<uint32_t>(static_cast<uint8_t>((p)[0])))))
  #define FXSYS_UINT16_GET_MSBFIRST(p)                               \
    (static_cast<uint16_t>(                                          \
        (static_cast<uint32_t>(static_cast<uint8_t>((p)[0])) << 8) | \
        (static_cast<uint32_t>(static_cast<uint8_t>((p)[1])))))
  #define FXSYS_UINT32_GET_LSBFIRST(p)                             \
    ((static_cast<uint32_t>(static_cast<uint8_t>((p)[3])) << 24) | \
     (static_cast<uint32_t>(static_cast<uint8_t>((p)[2])) << 16) | \
     (static_cast<uint32_t>(static_cast<uint8_t>((p)[1])) << 8) |  \
     (static_cast<uint32_t>(static_cast<uint8_t>((p)[0]))))
  #define FXSYS_UINT32_GET_MSBFIRST(p)                             \
    ((static_cast<uint32_t>(static_cast<uint8_t>((p)[0])) << 24) | \
     (static_cast<uint32_t>(static_cast<uint8_t>((p)[1])) << 16) | \
     (static_cast<uint32_t>(static_cast<uint8_t>((p)[2])) << 8) |  \
     (static_cast<uint32_t>(static_cast<uint8_t>((p)[3]))))
  #endif  // __cplusplus
  
  #endif  // CORE_FXCRT_FX_SYSTEM_H_
  