dynarmic/src/backend_x64/devirtualize.h
2020-04-22 20:46:22 +01:00

79 lines
2.7 KiB
C++

/* This file is part of the dynarmic project.
* Copyright (c) 2018 MerryMage
* This software may be used and distributed according to the terms of the GNU
* General Public License version 2 or any later version.
*/
#pragma once
#include <cstring>
#include <memory>
#include "backend_x64/callback.h"
#include "common/assert.h"
#include "common/cast_util.h"
#include "common/common_types.h"
#include "common/mp/function_info.h"
namespace Dynarmic {
namespace BackendX64 {
namespace impl {
template <typename FunctionType, FunctionType mfp>
struct ThunkBuilder;
template <typename C, typename R, typename... Args, R(C::*mfp)(Args...)>
struct ThunkBuilder<R(C::*)(Args...), mfp> {
static R Thunk(C* this_, Args... args) {
return (this_->*mfp)(std::forward<Args>(args)...);
}
};
} // namespace impl
template <typename FunctionType, FunctionType mfp>
ArgCallback DevirtualizeGeneric(Common::mp::class_type_t<FunctionType>* this_) {
return ArgCallback{&impl::ThunkBuilder<FunctionType, mfp>::Thunk, reinterpret_cast<u64>(this_)};
}
template <typename FunctionType, FunctionType mfp>
ArgCallback DevirtualizeWindows(Common::mp::class_type_t<FunctionType>* this_) {
static_assert(sizeof(mfp) == 8);
return ArgCallback{Common::BitCast<u64>(mfp), reinterpret_cast<u64>(this_)};
}
template <typename FunctionType, FunctionType mfp>
ArgCallback DevirtualizeItanium(Common::mp::class_type_t<FunctionType>* this_) {
struct MemberFunctionPointer {
/// For a non-virtual function, this is a simple function pointer.
/// For a virtual function, it is (1 + virtual table offset in bytes).
u64 ptr;
/// The required adjustment to `this`, prior to the call.
u64 adj;
} mfp_struct = Common::BitCast<MemberFunctionPointer>(mfp);
static_assert(sizeof(MemberFunctionPointer) == 16);
static_assert(sizeof(MemberFunctionPointer) == sizeof(mfp));
u64 fn_ptr = mfp_struct.ptr;
u64 this_ptr = reinterpret_cast<u64>(this_) + mfp_struct.adj;
if (mfp_struct.ptr & 1) {
u64 vtable = Common::BitCastPointee<u64>(this_ptr);
fn_ptr = Common::BitCastPointee<u64>(vtable + fn_ptr - 1);
}
return ArgCallback{fn_ptr, this_ptr};
}
#if defined(__APPLE__) || defined(linux) || defined(__linux) || defined(__linux__)
#define DEVIRT(this_, mfp) Dynarmic::BackendX64::DevirtualizeItanium<decltype(mfp), mfp>(this_)
#elif defined(__MINGW64__)
#define DEVIRT(this_, mfp) Dynarmic::BackendX64::DevirtualizeItanium<decltype(mfp), mfp>(this_)
#elif defined(_WIN32)
#define DEVIRT(this_, mfp) Dynarmic::BackendX64::DevirtualizeWindows<decltype(mfp), mfp>(this_)
#else
#define DEVIRT(this_, mfp) Dynarmic::BackendX64::DevirtualizeGeneric<decltype(mfp), mfp>(this_)
#endif
} // namespace BackendX64
} // namespace Dynarmic