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// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// This header defines symbols to override the same functions in the Visual C++
// CRT implementation.
#ifdef BASE_ALLOCATOR_ALLOCATOR_SHIM_OVERRIDE_UCRT_SYMBOLS_WIN_H_
#error This header is meant to be included only once by allocator_shim.cc
#endif
#define BASE_ALLOCATOR_ALLOCATOR_SHIM_OVERRIDE_UCRT_SYMBOLS_WIN_H_
#include <malloc.h>
extern "C" {
void* (*malloc_unchecked)(size_t) = &base::allocator::UncheckedAlloc;
namespace {
int win_new_mode = 0;
} // namespace
// This function behaves similarly to MSVC's _set_new_mode.
// If flag is 0 (default), calls to malloc will behave normally.
// If flag is 1, calls to malloc will behave like calls to new,
// and the std_new_handler will be invoked on failure.
// Returns the previous mode.
//
// Replaces _set_new_mode in ucrt\heap\new_mode.cpp
int _set_new_mode(int flag) {
// The MS CRT calls this function early on in startup, so this serves as a low
// overhead proof that the allocator shim is in place for this process.
base::allocator::g_is_win_shim_layer_initialized = true;
int old_mode = win_new_mode;
win_new_mode = flag;
base::allocator::SetCallNewHandlerOnMallocFailure(win_new_mode != 0);
return old_mode;
}
// Replaces _query_new_mode in ucrt\heap\new_mode.cpp
int _query_new_mode() {
return win_new_mode;
}
// These symbols override the CRT's implementation of the same functions.
__declspec(restrict) void* malloc(size_t size) {
return ShimMalloc(size);
}
void free(void* ptr) {
ShimFree(ptr);
}
__declspec(restrict) void* realloc(void* ptr, size_t size) {
return ShimRealloc(ptr, size);
}
__declspec(restrict) void* calloc(size_t n, size_t size) {
return ShimCalloc(n, size);
}
// The symbols
// * __acrt_heap
// * __acrt_initialize_heap
// * __acrt_uninitialize_heap
// * _get_heap_handle
// must be overridden all or none, as they are otherwise supplied
// by heap_handle.obj in the ucrt.lib file.
HANDLE __acrt_heap = nullptr;
bool __acrt_initialize_heap() {
__acrt_heap = ::HeapCreate(0, 0, 0);
return true;
}
bool __acrt_uninitialize_heap() {
::HeapDestroy(__acrt_heap);
__acrt_heap = nullptr;
return true;
}
intptr_t _get_heap_handle(void) {
return reinterpret_cast<intptr_t>(__acrt_heap);
}
// The default dispatch translation unit has to define also the following
// symbols (unless they are ultimately routed to the system symbols):
// void malloc_stats(void);
// int mallopt(int, int);
// struct mallinfo mallinfo(void);
// size_t malloc_size(void*);
// size_t malloc_usable_size(const void*);
} // extern "C"
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