mirror of
https://github.com/geode-sdk/geode.git
synced 2024-12-03 04:36:55 -05:00
127 lines
4.2 KiB
C++
127 lines
4.2 KiB
C++
|
#pragma once
|
||
|
|
||
|
namespace geode::cast {
|
||
|
using uinthalf_t = uint32_t;
|
||
|
using inthalf_t = int32_t;
|
||
|
|
||
|
struct DummyClass {
|
||
|
virtual ~DummyClass() {}
|
||
|
};
|
||
|
|
||
|
struct DummySingleClass : DummyClass {};
|
||
|
|
||
|
struct DummyClass2 {};
|
||
|
|
||
|
struct DummyMultipleClass : DummySingleClass, DummyClass2 {};
|
||
|
|
||
|
struct ClassTypeinfoType {
|
||
|
void** m_typeinfoVtable;
|
||
|
char const* m_typeinfoName;
|
||
|
};
|
||
|
|
||
|
struct SingleClassTypeinfoType : ClassTypeinfoType {
|
||
|
ClassTypeinfoType* m_baseClassTypeinfo;
|
||
|
};
|
||
|
|
||
|
#pragma pack(push, 1)
|
||
|
|
||
|
struct MultipleClassSingleEntryType {
|
||
|
ClassTypeinfoType* m_baseClassTypeinfo;
|
||
|
uint8_t m_visibilityFlag;
|
||
|
inthalf_t m_offset;
|
||
|
uint8_t m_padding[sizeof(inthalf_t) - 1];
|
||
|
};
|
||
|
|
||
|
#pragma pack(pop)
|
||
|
|
||
|
struct MultipleClassTypeinfoType : ClassTypeinfoType {
|
||
|
uint32_t m_flags;
|
||
|
uint32_t m_numBaseClass;
|
||
|
MultipleClassSingleEntryType m_baseClasses[0x100];
|
||
|
};
|
||
|
|
||
|
struct VtableTypeinfoType {
|
||
|
inthalf_t m_offset;
|
||
|
ClassTypeinfoType* m_typeinfo;
|
||
|
};
|
||
|
|
||
|
struct VtableType {
|
||
|
void* m_vtable[0x100];
|
||
|
};
|
||
|
|
||
|
struct CompleteVtableType : VtableTypeinfoType, VtableType {};
|
||
|
|
||
|
inline void** typeinfoVtableOf(void* ptr) {
|
||
|
auto vftable = *reinterpret_cast<VtableType**>(ptr);
|
||
|
|
||
|
auto typeinfoPtr =
|
||
|
static_cast<VtableTypeinfoType*>(static_cast<CompleteVtableType*>(vftable));
|
||
|
|
||
|
return typeinfoPtr->m_typeinfo->m_typeinfoVtable;
|
||
|
}
|
||
|
|
||
|
inline void* traverseTypeinfoFor(
|
||
|
void* ptr, ClassTypeinfoType const* typeinfo, char const* afterIdent
|
||
|
) {
|
||
|
DummySingleClass dummySingleClass;
|
||
|
DummyMultipleClass dummyMultipleClass;
|
||
|
|
||
|
{
|
||
|
auto optionIdent = typeinfo->m_typeinfoName;
|
||
|
if (std::strcmp(optionIdent, afterIdent) == 0) {
|
||
|
return ptr;
|
||
|
}
|
||
|
}
|
||
|
if (typeinfo->m_typeinfoVtable == typeinfoVtableOf(&dummySingleClass)) {
|
||
|
auto siTypeinfo = static_cast<SingleClassTypeinfoType const*>(typeinfo);
|
||
|
return traverseTypeinfoFor(ptr, siTypeinfo->m_baseClassTypeinfo, afterIdent);
|
||
|
}
|
||
|
else if (typeinfo->m_typeinfoVtable == typeinfoVtableOf(&dummyMultipleClass)) {
|
||
|
auto vmiTypeinfo = static_cast<MultipleClassTypeinfoType const*>(typeinfo);
|
||
|
for (int i = 0; i < vmiTypeinfo->m_numBaseClass; ++i) {
|
||
|
auto& entry = vmiTypeinfo->m_baseClasses[i];
|
||
|
auto optionPtr = reinterpret_cast<std::byte*>(ptr) + entry.m_offset;
|
||
|
auto ret = traverseTypeinfoFor(optionPtr, entry.m_baseClassTypeinfo, afterIdent);
|
||
|
if (ret != nullptr) return ret;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
return nullptr;
|
||
|
}
|
||
|
|
||
|
inline void* typeinfoCastInternal(void* ptr, ClassTypeinfoType const* beforeTypeinfo, ClassTypeinfoType const* afterTypeinfo, size_t hint) {
|
||
|
// we're not using either because uhhh idk
|
||
|
// hint is for diamond inheritance iirc which is never
|
||
|
// used in gd, so should be pretty safe to ignore
|
||
|
if (!ptr) {
|
||
|
return nullptr;
|
||
|
}
|
||
|
|
||
|
(void)beforeTypeinfo;
|
||
|
(void)hint;
|
||
|
|
||
|
auto vftable = *reinterpret_cast<VtableType**>(ptr);
|
||
|
auto dataPointer = static_cast<VtableTypeinfoType*>(static_cast<CompleteVtableType*>(vftable));
|
||
|
auto typeinfo = dataPointer->m_typeinfo;
|
||
|
auto basePtr = static_cast<std::byte*>(ptr) + dataPointer->m_offset;
|
||
|
|
||
|
auto afterIdent = afterTypeinfo->m_typeinfoName;
|
||
|
|
||
|
return traverseTypeinfoFor(basePtr, typeinfo, afterIdent);
|
||
|
}
|
||
|
|
||
|
template <class After, class Before>
|
||
|
inline After typeinfo_cast(Before ptr) {
|
||
|
static_assert(
|
||
|
std::is_polymorphic_v<std::remove_pointer_t<Before>> && std::is_polymorphic_v<std::remove_pointer_t<After>>,
|
||
|
"Input is not a polymorphic type"
|
||
|
);
|
||
|
if (!ptr) {
|
||
|
return static_cast<After>(nullptr);
|
||
|
}
|
||
|
|
||
|
auto beforeTypeinfo = reinterpret_cast<ClassTypeinfoType const*>(&typeid(std::remove_pointer_t<Before>));
|
||
|
auto afterTypeinfo = reinterpret_cast<ClassTypeinfoType const*>(&typeid(std::remove_pointer_t<After>));
|
||
|
return static_cast<After>(typeinfoCastInternal(ptr, beforeTypeinfo, afterTypeinfo, 0));
|
||
|
}
|
||
|
}
|