gzdoom/src/dobject.h

/*
** dobject.h
**
**---------------------------------------------------------------------------
** Copyright 1998-2008 Randy Heit
** All rights reserved.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions
** are met:
**
** 1. Redistributions of source code must retain the above copyright
**    notice, this list of conditions and the following disclaimer.
** 2. Redistributions in binary form must reproduce the above copyright
**    notice, this list of conditions and the following disclaimer in the
**    documentation and/or other materials provided with the distribution.
** 3. The name of the author may not be used to endorse or promote products
**    derived from this software without specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
**---------------------------------------------------------------------------
**
*/

#ifndef __DOBJECT_H__
#define __DOBJECT_H__

#include <stdlib.h>
#include <type_traits>
#include "doomtype.h"
#include "i_system.h"

class PClass;
class PType;
class FSerializer;
class FSoundID;

class   DObject;
/*
class           DConsoleCommand;
class                   DConsoleAlias;
class           DSeqNode;
class                   DSeqActorNode;
class                   DSeqPolyNode;
class                   DSeqSectorNode;
class           DThinker;
class                   AActor;
class                   DPolyAction;
class                           DMovePoly;
class                                   DPolyDoor;
class                           DRotatePoly;
class                   DPusher;
class                   DScroller;
class                   DSectorEffect;
class                           DLighting;
class                                   DFireFlicker;
class                                   DFlicker;
class                                   DGlow;
class                                   DGlow2;
class                                   DLightFlash;
class                                   DPhased;
class                                   DStrobe;
class                           DMover;
class                                   DElevator;
class                                   DMovingCeiling;
class                                           DCeiling;
class                                           DDoor;
class                                   DMovingFloor;
class                                           DFloor;
class                                           DFloorWaggle;
class                                           DPlat;
class                                   DPillar;
*/

class PClassActor;

#define RUNTIME_CLASS_CASTLESS(cls)	(cls::RegistrationInfo.MyClass)	// Passed a native class name, returns a PClass representing that class
#define RUNTIME_CLASS(cls)			((typename cls::MetaClass *)RUNTIME_CLASS_CASTLESS(cls))	// Like above, but returns the true type of the meta object
#define NATIVE_TYPE(object)			(object->StaticType())			// Passed an object, returns the type of the C++ class representing the object

// Enumerations for the meta classes created by ClassReg::RegisterClass()
enum
{
	CLASSREG_PClass,
	CLASSREG_PClassActor,
};

struct ClassReg
{
	PClass *MyClass;
	const char *Name;
	ClassReg *ParentType;
	ClassReg *_VMExport;
	const size_t *Pointers;
	void (*ConstructNative)(void *);
	void(*InitNatives)();
	unsigned int SizeOf:28;
	unsigned int MetaClassNum:4;

	PClass *RegisterClass();
	void SetupClass(PClass *cls);
};

enum EInPlace { EC_InPlace };

#define DECLARE_ABSTRACT_CLASS(cls,parent) \
public: \
	virtual PClass *StaticType() const; \
	static ClassReg RegistrationInfo, * const RegistrationInfoPtr; \
	typedef parent Super; \
private: \
	typedef cls ThisClass;

#define DECLARE_ABSTRACT_CLASS_WITH_META(cls,parent,meta) \
	DECLARE_ABSTRACT_CLASS(cls,parent) \
public: \
	typedef meta MetaClass; \
	MetaClass *GetClass() const { return static_cast<MetaClass *>(DObject::GetClass()); } \
protected: \
	enum { MetaClassNum = CLASSREG_##meta }; private: \

#define DECLARE_CLASS(cls,parent) \
	DECLARE_ABSTRACT_CLASS(cls,parent) \
		private: static void InPlaceConstructor (void *mem);

#define DECLARE_CLASS_WITH_META(cls,parent,meta) \
	DECLARE_ABSTRACT_CLASS_WITH_META(cls,parent,meta) \
		private: static void InPlaceConstructor (void *mem);

#define HAS_OBJECT_POINTERS \
	static const size_t PointerOffsets[];

#if defined(_MSC_VER)
#	pragma section(".creg$u",read)
#	define _DECLARE_TI(cls) __declspec(allocate(".creg$u")) ClassReg * const cls::RegistrationInfoPtr = &cls::RegistrationInfo;
#else
#	define _DECLARE_TI(cls) ClassReg * const cls::RegistrationInfoPtr __attribute__((section(SECTION_CREG))) = &cls::RegistrationInfo;
#endif

#define _IMP_PCLASS(cls, ptrs, create) \
	ClassReg cls::RegistrationInfo = {\
		nullptr, \
		#cls, \
		&cls::Super::RegistrationInfo, \
		nullptr, \
		ptrs, \
		create, \
		nullptr, \
		sizeof(cls), \
		cls::MetaClassNum }; \
	_DECLARE_TI(cls) \
	PClass *cls::StaticType() const { return RegistrationInfo.MyClass; }

#define IMPLEMENT_CLASS(cls, isabstract, ptrs) \
	_X_CONSTRUCTOR_##isabstract(cls) \
	_IMP_PCLASS(cls, _X_POINTERS_##ptrs(cls), _X_ABSTRACT_##isabstract(cls))

// Taking the address of a field in an object at address > 0 instead of
// address 0 keeps GCC from complaining about possible misuse of offsetof.
// Using 8 to avoid unaligned pointer use.
#define IMPLEMENT_POINTERS_START(cls)	const size_t cls::PointerOffsets[] = {
#define IMPLEMENT_POINTER(field)		((size_t)&((ThisClass*)8)->field) - 8,
#define IMPLEMENT_POINTERS_END			~(size_t)0 };

// Possible arguments for the IMPLEMENT_CLASS macro
#define _X_POINTERS_true(cls)		cls::PointerOffsets
#define _X_POINTERS_false(cls)		nullptr
#define _X_FIELDS_true(cls)			nullptr
#define _X_FIELDS_false(cls)		nullptr
#define _X_CONSTRUCTOR_true(cls)
#define _X_CONSTRUCTOR_false(cls)	void cls::InPlaceConstructor(void *mem) { new((EInPlace *)mem) cls; }
#define _X_ABSTRACT_true(cls)		nullptr
#define _X_ABSTRACT_false(cls)		cls::InPlaceConstructor
#define _X_VMEXPORT_true(cls)		nullptr
#define _X_VMEXPORT_false(cls)		nullptr

#include "dobjgc.h"

class AActor;

class DObject
{
public:
	virtual PClass *StaticType() const { return RegistrationInfo.MyClass; }
	static ClassReg RegistrationInfo, * const RegistrationInfoPtr;
	static void InPlaceConstructor (void *mem);
	typedef PClass MetaClass;
private:
	typedef DObject ThisClass;
protected:
	enum { MetaClassNum = CLASSREG_PClass };

	// Per-instance variables. There are four.
#ifndef NDEBUG
public:
	enum
	{
		MAGIC_ID = 0x1337cafe
	};
	uint32_t MagicID = MAGIC_ID;	// only used by the VM for checking native function parameter types.
#endif
private:
	PClass *Class;				// This object's type
public:
	DObject *ObjNext;			// Keep track of all allocated objects
	DObject *GCNext;			// Next object in this collection list
	uint32_t ObjectFlags;			// Flags for this object

	void *ScriptVar(FName field, PType *type);

protected:

public:
	DObject ();
	DObject (PClass *inClass);
	virtual ~DObject ();

	inline bool IsKindOf (const PClass *base) const;
	inline bool IsKindOf(FName base) const;
	inline bool IsA (const PClass *type) const;

	void SerializeUserVars(FSerializer &arc);
	virtual void Serialize(FSerializer &arc);

	// Releases the object from the GC, letting the caller care of any maintenance.
	void Release();

	// For catching Serialize functions in derived classes
	// that don't call their base class.
	void CheckIfSerialized () const;

	virtual void OnDestroy() {}
	void Destroy();

	// Add other types as needed.
	inline bool &BoolVar(FName field);
	inline int &IntVar(FName field);
	inline FTextureID &TextureIDVar(FName field);
	inline FSoundID &SoundVar(FName field);
	inline PalEntry &ColorVar(FName field);
	inline FName &NameVar(FName field);
	inline double &FloatVar(FName field);
	inline FString &StringVar(FName field);
	template<class T> T*& PointerVar(FName field);

	// This is only needed for swapping out PlayerPawns and absolutely nothing else!
	virtual size_t PointerSubstitution (DObject *old, DObject *notOld);
	static size_t StaticPointerSubstitution (AActor *old, AActor *notOld);

	PClass *GetClass() const
	{
		assert(Class != nullptr);
		return Class;
	}

	void SetClass (PClass *inClass)
	{
		Class = inClass;
	}

private:
	struct nonew
	{
	};

	void *operator new(size_t len, nonew&)
	{
		return M_Malloc(len);
	}
public:

	void operator delete (void *mem, nonew&)
	{
		M_Free(mem);
	}

	void operator delete (void *mem)
	{
		M_Free(mem);
	}

	// GC fiddling

	// An object is white if either white bit is set.
	bool IsWhite() const
	{
		return !!(ObjectFlags & OF_WhiteBits);
	}

	bool IsBlack() const
	{
		return !!(ObjectFlags & OF_Black);
	}

	// An object is gray if it isn't white or black.
	bool IsGray() const
	{
		return !(ObjectFlags & OF_MarkBits);
	}

	// An object is dead if it's the other white.
	bool IsDead() const
	{
		return !!(ObjectFlags & GC::OtherWhite() & OF_WhiteBits);
	}

	void ChangeWhite()
	{
		ObjectFlags ^= OF_WhiteBits;
	}

	void MakeWhite()
	{
		ObjectFlags = (ObjectFlags & ~OF_MarkBits) | (GC::CurrentWhite & OF_WhiteBits);
	}

	void White2Gray()
	{
		ObjectFlags &= ~OF_WhiteBits;
	}

	void Black2Gray()
	{
		ObjectFlags &= ~OF_Black;
	}

	void Gray2Black()
	{
		ObjectFlags |= OF_Black;
	}

	// Marks all objects pointed to by this one. Returns the (approximate)
	// amount of memory used by this object.
	virtual size_t PropagateMark();

protected:
	// This form of placement new and delete is for use *only* by PClass's
	// CreateNew() method. Do not use them for some other purpose.
	void *operator new(size_t, EInPlace *mem)
	{
		return (void *)mem;
	}

	void operator delete (void *mem, EInPlace *)
	{
		M_Free (mem);
	}

	template<typename T, typename... Args>
		friend T* Create(Args&&... args);

	friend class JitCompiler;
};

// This is the only method aside from calling CreateNew that should be used for creating DObjects
// to ensure that the Class pointer is always set.
template<typename T, typename... Args>
T* Create(Args&&... args)
{
	DObject::nonew nono;
	T *object = new(nono) T(std::forward<Args>(args)...);
	if (object != nullptr)
	{
		object->SetClass(RUNTIME_CLASS(T));
		assert(object->GetClass() != nullptr);	// beware of objects that get created before the type system is up.
	}
	return object;
}


// When you write to a pointer to an Object, you must call this for
// proper bookkeeping in case the Object holding this pointer has
// already been processed by the GC.
static inline void GC::WriteBarrier(DObject *pointing, DObject *pointed)
{
	if (pointed != NULL && pointed->IsWhite() && pointing->IsBlack())
	{
		Barrier(pointing, pointed);
	}
}

static inline void GC::WriteBarrier(DObject *pointed)
{
	if (pointed != NULL && State == GCS_Propagate && pointed->IsWhite())
	{
		Barrier(NULL, pointed);
	}
}

#include "memarena.h"
extern FMemArena ClassDataAllocator;
#include "symbols.h"
#include "dobjtype.h"

inline bool DObject::IsKindOf (const PClass *base) const
{
	return base->IsAncestorOf (GetClass ());
}

inline bool DObject::IsKindOf(FName base) const
{
	return GetClass()->IsDescendantOf(base);
}

inline bool DObject::IsA (const PClass *type) const
{
	return (type == GetClass());
}

template<class T> T *dyn_cast(DObject *p)
{
	if (p != NULL && p->IsKindOf(RUNTIME_CLASS_CASTLESS(T)))
	{
		return static_cast<T *>(p);
	}
	return NULL;
}



template<class T> const T *dyn_cast(const DObject *p)
{
	return dyn_cast<T>(const_cast<DObject *>(p));
}

inline bool &DObject::BoolVar(FName field)
{
	return *(bool*)ScriptVar(field, nullptr);
}

inline int &DObject::IntVar(FName field)
{
	return *(int*)ScriptVar(field, nullptr);
}

inline FTextureID &DObject::TextureIDVar(FName field)
{
	return *(FTextureID*)ScriptVar(field, nullptr);
}

inline FSoundID &DObject::SoundVar(FName field)
{
	return *(FSoundID*)ScriptVar(field, nullptr);
}

inline PalEntry &DObject::ColorVar(FName field)
{
	return *(PalEntry*)ScriptVar(field, nullptr);
}

inline FName &DObject::NameVar(FName field)
{
	return *(FName*)ScriptVar(field, nullptr);
}

inline double &DObject::FloatVar(FName field)
{
	return *(double*)ScriptVar(field, nullptr);
}

template<class T>
inline T *&DObject::PointerVar(FName field)
{
	return *(T**)ScriptVar(field, nullptr);	// pointer check is more tricky and for the handful of uses in the DECORATE parser not worth the hassle.
}

#endif //__DOBJECT_H__