// Copyright 2014 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

#include "core/fxcrt/fx_memory.h"

#include <stdlib.h>  // For abort().

#include <limits>

#include "build/build_config.h"
#include "core/fxcrt/fx_safe_types.h"
#include "third_party/base/debug/alias.h"
#include "third_party/base/numerics/safe_math.h"

#if BUILDFLAG(IS_WIN)
#include <windows.h>
#endif

void* FXMEM_DefaultAlloc(size_t byte_size) {
  return pdfium::internal::Alloc(byte_size, 1);
}

void* FXMEM_DefaultCalloc(size_t num_elems, size_t byte_size) {
  return pdfium::internal::Calloc(num_elems, byte_size);
}

void* FXMEM_DefaultRealloc(void* pointer, size_t new_size) {
  return pdfium::internal::Realloc(pointer, new_size, 1);
}

void FXMEM_DefaultFree(void* pointer) {
  FX_Free(pointer);
}

NOINLINE void FX_OutOfMemoryTerminate(size_t size) {
  // Convince the linker this should not be folded with similar functions using
  // Identical Code Folding.
  static int make_this_function_aliased = 0xbd;
  pdfium::base::debug::Alias(&make_this_function_aliased);

#if BUILDFLAG(IS_WIN)
  // The same custom Windows exception code used in Chromium and Breakpad.
  constexpr DWORD kOomExceptionCode = 0xe0000008;
  ULONG_PTR exception_args[] = {size};
  ::RaiseException(kOomExceptionCode, EXCEPTION_NONCONTINUABLE,
                   std::size(exception_args), exception_args);
#endif

  // Terminate cleanly.
  abort();
}

namespace pdfium {
namespace internal {

void* AllocOrDie(size_t num_members, size_t member_size) {
  void* result = Alloc(num_members, member_size);
  if (!result)
    FX_OutOfMemoryTerminate(0);  // Never returns.

  return result;
}

void* AllocOrDie2D(size_t w, size_t h, size_t member_size) {
  if (w >= std::numeric_limits<size_t>::max() / h)
    FX_OutOfMemoryTerminate(0);  // Never returns.

  return AllocOrDie(w * h, member_size);
}
void* CallocOrDie(size_t num_members, size_t member_size) {
  void* result = Calloc(num_members, member_size);
  if (!result)
    FX_OutOfMemoryTerminate(0);  // Never returns.

  return result;
}

void* CallocOrDie2D(size_t w, size_t h, size_t member_size) {
  if (w >= std::numeric_limits<size_t>::max() / h)
    FX_OutOfMemoryTerminate(0);  // Never returns.

  return CallocOrDie(w * h, member_size);
}

void* ReallocOrDie(void* ptr, size_t num_members, size_t member_size) {
  void* result = Realloc(ptr, num_members, member_size);
  if (!result)
    FX_OutOfMemoryTerminate(0);  // Never returns.

  return result;
}

void* StringAllocOrDie(size_t num_members, size_t member_size) {
  void* result = StringAlloc(num_members, member_size);
  if (!result)
    FX_OutOfMemoryTerminate(0);  // Never returns.

  return result;
}
}  // namespace internal
}  // namespace pdfium

size_t Fx2DSizeOrDie(size_t w, size_t h) {
  pdfium::base::CheckedNumeric<size_t> safe_size = w;
  safe_size *= h;
  return safe_size.ValueOrDie();
}