libcpp.cpp

一个实时的驱动支持库

/*
    This is a C++ run-time library for Windows kernel-mode drivers.
    Copyright (C) 2004 Bo Brant閚.
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
*/

extern "C" {
#include <ntddk.h>
}

#include <libcpp.h>

typedef void (__cdecl *func_t)();

//
// Data segment with pointers to C++ initializers.
//
#pragma data_seg(".CRT$XCA")
func_t xc_a[] = { 0 };
#pragma data_seg(".CRT$XCZ")
func_t xc_z[] = { 0 };
#pragma data_seg()
#pragma comment(linker, "/merge:.CRT=.data")

//
// Simple class to keep track of functions registred to be called when
// unloading the driver. Since we only use this internaly from the load
// and unload functions it doesn't need to be thread safe.
//
class AtExitCall {
public:
    AtExitCall(func_t f) : m_func(f), m_next(m_exit_list) { m_exit_list = this; }
    ~AtExitCall() { m_func(); m_exit_list = m_next; }
    static run() { while (m_exit_list) delete m_exit_list; }
private:
    func_t              m_func;
    AtExitCall*         m_next;
    static AtExitCall*  m_exit_list;
};

AtExitCall* AtExitCall::m_exit_list = 0;

void* __cdecl operator new(size_t size)
{
    return size ? ExAllocatePool(NonPagedPool, size) : 0;
}

void* __cdecl operator new(size_t size, POOL_TYPE type)
{
    return size ? ExAllocatePool(type, size) : 0;
}

void __cdecl operator delete(void* p)
{
    if (p) { ExFreePool(p); }
}

extern "C" {

//
// Calls functions the compiler has registred to call constructors
// for global and static objects.
//
void __cdecl libcpp_init()
{
    for (func_t* f = xc_a; f < xc_z; f++) if (*f) (*f)();
}

//
// Calls functions the compiler has registred to call destructors
// for global and static objects.
//
void __cdecl libcpp_exit()
{
    AtExitCall::run();
}

//
// Registers a function to be called when unloading the driver. If memory
// couldn't be allocated the function is called immediately since it never
// will be called otherwise.
//
int __cdecl atexit(func_t f)
{
    return (new AtExitCall(f) == 0) ? (*f)(), 1 : 0;
}

} // extern "C"