core/fxcrt/fx_memcpy_wrappers.h

// Copyright 2023 The PDFium Authors
// 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_MEMCPY_WRAPPERS_H_
#define CORE_FXCRT_FX_MEMCPY_WRAPPERS_H_

#include <stddef.h>
#include <stdint.h>
#include <string.h>
#include <wchar.h>

#include "core/fxcrt/compiler_specific.h"

// Wrappers to avoid the zero-length w/NULL arg gotchas in C spec. Use these
// if there is a possibility of a NULL arg (or a bad arg) that is to be ignored
// when the length is zero, otherwise just call the C Run Time Library function
// itself.
UNSAFE_BUFFER_USAGE inline int FXSYS_memcmp(const void* ptr1,
                                            const void* ptr2,
                                            size_t len) {
  // SAFETY: required from caller, enforced by UNSAFE_BUFFER_USAGE.
  return len ? UNSAFE_BUFFERS(memcmp(ptr1, ptr2, len)) : 0;
}

UNSAFE_BUFFER_USAGE inline int FXSYS_wmemcmp(const wchar_t* ptr1,
                                             const wchar_t* ptr2,
                                             size_t len) {
  // SAFETY: required from caller, enforced by UNSAFE_BUFFER_USAGE.
  return len ? UNSAFE_BUFFERS(wmemcmp(ptr1, ptr2, len)) : 0;
}

UNSAFE_BUFFER_USAGE inline void* FXSYS_memcpy(void* ptr1,
                                              const void* ptr2,
                                              size_t len) {
  // SAFETY: required from caller, enforced by UNSAFE_BUFFER_USAGE.
  return len ? UNSAFE_BUFFERS(memcpy(ptr1, ptr2, len)) : ptr1;
}

UNSAFE_BUFFER_USAGE inline wchar_t* FXSYS_wmemcpy(wchar_t* ptr1,
                                                  const wchar_t* ptr2,
                                                  size_t len) {
  // SAFETY: required from caller, enforced by UNSAFE_BUFFER_USAGE.
  return len ? UNSAFE_BUFFERS(wmemcpy(ptr1, ptr2, len)) : ptr1;
}

UNSAFE_BUFFER_USAGE inline void* FXSYS_memmove(void* ptr1,
                                               const void* ptr2,
                                               size_t len) {
  // SAFETY: required from caller, enforced by UNSAFE_BUFFER_USAGE.
  return len ? UNSAFE_BUFFERS(memmove(ptr1, ptr2, len)) : ptr1;
}

UNSAFE_BUFFER_USAGE inline wchar_t* FXSYS_wmemmove(wchar_t* ptr1,
                                                   const wchar_t* ptr2,
                                                   size_t len) {
  // SAFETY: required from caller, enforced by UNSAFE_BUFFER_USAGE.
  return len ? UNSAFE_BUFFERS(wmemmove(ptr1, ptr2, len)) : ptr1;
}

UNSAFE_BUFFER_USAGE inline void* FXSYS_memset(void* ptr1, int val, size_t len) {
  // SAFETY: required from caller, enforced by UNSAFE_BUFFER_USAGE.
  return len ? UNSAFE_BUFFERS(memset(ptr1, val, len)) : ptr1;
}

UNSAFE_BUFFER_USAGE inline wchar_t* FXSYS_wmemset(wchar_t* ptr1,
                                                  int val,
                                                  size_t len) {
  // SAFETY: required from caller, enforced by UNSAFE_BUFFER_USAGE.
  return len ? UNSAFE_BUFFERS(wmemset(ptr1, val, len)) : ptr1;
}

UNSAFE_BUFFER_USAGE inline const void* FXSYS_memchr(const void* ptr1,
                                                    int val,
                                                    size_t len) {
  // SAFETY: required from caller, enforced by UNSAFE_BUFFER_USAGE.
  return len ? UNSAFE_BUFFERS(memchr(ptr1, val, len)) : nullptr;
}

UNSAFE_BUFFER_USAGE inline const wchar_t* FXSYS_wmemchr(const wchar_t* ptr1,
                                                        wchar_t val,
                                                        size_t len) {
  // SAFETY: required from caller, enforced by UNSAFE_BUFFER_USAGE.
  return len ? UNSAFE_BUFFERS(wmemchr(ptr1, val, len)) : nullptr;
}

#endif  // CORE_FXCRT_FX_MEMCPY_WRAPPERS_H_