gzdoom-gles/src/scripting/vm/vm.h

/*
** vm.h
** VM <-> native interface
**
**---------------------------------------------------------------------------
** Copyright -2016 Randy Heit
** Copyright 2016 Christoph Oelckers
** 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 VM_H
#define VM_H

#include "autosegs.h"
#include "zstring.h"
#include "vectors.h"
#include "cmdlib.h"
#include "doomerrors.h"
#include "memarena.h"
#include "scripting/backend/scopebarrier.h"

class DObject;
union VMOP;
class VMScriptFunction;

extern FMemArena ClassDataAllocator;

#define MAX_RETURNS		8	// Maximum number of results a function called by script code can return
#define MAX_TRY_DEPTH	8	// Maximum number of nested TRYs in a single function

void JitRelease();


typedef unsigned char		VM_UBYTE;
typedef signed char			VM_SBYTE;
typedef unsigned short		VM_UHALF;
typedef signed short		VM_SHALF;
typedef unsigned int		VM_UWORD;
typedef signed int			VM_SWORD;

#define VM_EPSILON			(1/65536.0)

// Register types for VMParam
enum
{
	REGT_INT		= 0,
	REGT_FLOAT		= 1,
	REGT_STRING		= 2,
	REGT_POINTER	= 3,
	REGT_TYPE		= 3,

	REGT_KONST		= 4,
	REGT_MULTIREG2	= 8,
	REGT_MULTIREG3	= 16,	// (e.g. a vector)
	REGT_MULTIREG	= 24,
	REGT_ADDROF		= 32,	// used with PARAM: pass address of this register

	REGT_NIL		= 128	// parameter was omitted
};

#define RET_FINAL	(0x80)	// Used with RET and RETI in the destination slot: this is the final return value


enum EVMAbortException
{
	X_OTHER,
	X_READ_NIL,
	X_WRITE_NIL,
	X_TOO_MANY_TRIES,
	X_ARRAY_OUT_OF_BOUNDS,
	X_DIVISION_BY_ZERO,
	X_BAD_SELF,
	X_FORMAT_ERROR
};

class CVMAbortException : public CDoomError
{
public:
	static FString stacktrace;
	CVMAbortException(EVMAbortException reason, const char *moreinfo, va_list ap);
	void MaybePrintMessage();
};

// This must be a separate function because the VC compiler would otherwise allocate memory on the stack for every separate instance of the exception object that may get thrown.
void ThrowAbortException(EVMAbortException reason, const char *moreinfo, ...);
void ThrowAbortException(VMScriptFunction *sfunc, VMOP *line, EVMAbortException reason, const char *moreinfo, ...);

struct VMReturn
{
	void *Location;
	VM_UBYTE RegType;	// Same as VMParam RegType, except REGT_KONST is invalid; only used by asserts

	void SetInt(int val)
	{
		assert(RegType == REGT_INT);
		*(int *)Location = val;
	}
	void SetFloat(double val)
	{
		assert(RegType == REGT_FLOAT);
		*(double *)Location = val;
	}
	void SetVector(const double val[3])
	{	
		assert(RegType == (REGT_FLOAT|REGT_MULTIREG3));
		((double *)Location)[0] = val[0];
		((double *)Location)[1] = val[1];
		((double *)Location)[2] = val[2];
	}
	void SetVector(const DVector3 &val)
	{
		assert(RegType == (REGT_FLOAT | REGT_MULTIREG3));
		((double *)Location)[0] = val[0];
		((double *)Location)[1] = val[1];
		((double *)Location)[2] = val[2];
	}
	void SetVector2(const double val[2])
	{
		assert(RegType == (REGT_FLOAT|REGT_MULTIREG2));
		((double *)Location)[0] = val[0];
		((double *)Location)[1] = val[1];
	}
	void SetVector2(const DVector2 &val)
	{
		assert(RegType == (REGT_FLOAT | REGT_MULTIREG2));
		((double *)Location)[0] = val[0];
		((double *)Location)[1] = val[1];
	}
	void SetString(const FString &val)
	{
		assert(RegType == REGT_STRING);
		*(FString *)Location = val;
	}

	void SetPointer(void *val)
	{
		assert(RegType == REGT_POINTER);
		*(void **)Location = val;
	}

	void SetObject(DObject *val)
	{
		assert(RegType == REGT_POINTER);
		*(void **)Location = val;
	}

	void IntAt(int *loc)
	{
		Location = loc;
		RegType = REGT_INT;
	}
	void FloatAt(double *loc)
	{
		Location = loc;
		RegType = REGT_FLOAT;
	}
	void Vec2At(DVector2 *loc)
	{
		Location = loc;
		RegType = REGT_FLOAT | REGT_MULTIREG2;
	}
	void StringAt(FString *loc)
	{
		Location = loc;
		RegType = REGT_STRING;
	}
	void PointerAt(void **loc)
	{
		Location = loc;
		RegType = REGT_POINTER;
	}
	VMReturn() { }
	VMReturn(int *loc) { IntAt(loc); }
	VMReturn(double *loc) { FloatAt(loc); }
	VMReturn(DVector2 *loc) { Vec2At(loc); }
	VMReturn(FString *loc) { StringAt(loc); }
	VMReturn(void **loc) { PointerAt(loc); }
};

struct VMRegisters;

struct TypedVMValue
{
	union
	{
		int i;
		void *a;
		double f;
		struct { int pad[3]; VM_UBYTE Type; };
		struct { int foo[4]; } biggest;
		const FString *sp;
	};

	const FString &s() const { return *sp; }

	TypedVMValue()
	{
		a = NULL;
		Type = REGT_NIL;
	}
	TypedVMValue(const TypedVMValue &o)
	{
		biggest = o.biggest;
	}
	TypedVMValue(int v)
	{
		i = v;
		Type = REGT_INT;
	}
	TypedVMValue(double v)
	{
		f = v;
		Type = REGT_FLOAT;
	}

	TypedVMValue(const FString *s)
	{
		sp = s;
		Type = REGT_STRING;
	}
	TypedVMValue(DObject *v)
	{
		a = v;
		Type = REGT_POINTER;
	}
	TypedVMValue(void *v)
	{
		a = v;
		Type = REGT_POINTER;
	}
	TypedVMValue &operator=(const TypedVMValue &o)
	{
		biggest = o.biggest;
		return *this;
	}
	TypedVMValue &operator=(int v)
	{
		i = v;
		Type = REGT_INT;
		return *this;
	}
	TypedVMValue &operator=(double v)
	{
		f = v;
		Type = REGT_FLOAT;
		return *this;
	}
	TypedVMValue &operator=(const FString *v)
	{
		sp = v;
		Type = REGT_STRING;
		return *this;
	}
	TypedVMValue &operator=(DObject *v)
	{
		a = v;
		Type = REGT_POINTER;
		return *this;
	}
};


struct VMValue
{
	union
	{
		int i;
		void *a;
		double f;
		struct { int foo[2]; } biggest;
		const FString *sp;
	};

	const FString &s() const { return *sp; }

	VMValue()
	{
		a = NULL;
	}
	VMValue(const VMValue &o)
	{
		biggest = o.biggest;
	}
	VMValue(int v)
	{
		i = v;
	}
	VMValue(double v)
	{
		f = v;
	}
	VMValue(const char *s) = delete;
	VMValue(const FString &s) = delete;

	VMValue(const FString *s)
	{
		sp = s;
	}
	VMValue(DObject *v)
	{
		a = v;
	}
	VMValue(void *v)
	{
		a = v;
	}
	VMValue &operator=(const VMValue &o)
	{
		biggest = o.biggest;
		return *this;
	}
	VMValue &operator=(const TypedVMValue &o)
	{
		memcpy(&biggest, &o.biggest, sizeof(biggest));
		return *this;
	}
	VMValue &operator=(int v)
	{
		i = v;
		return *this;
	}
	VMValue &operator=(double v)
	{
		f = v;
		return *this;
	}
	VMValue &operator=(const FString *v)
	{
		sp = v;
		return *this;
	}
	VMValue &operator=(const FString &v) = delete;
	VMValue &operator=(const char *v) = delete;
	VMValue &operator=(DObject *v)
	{
		a = v;
		return *this;
	}
	int ToInt(int Type)
	{
		if (Type == REGT_INT)
		{
			return i;
		}
		if (Type == REGT_FLOAT)
		{
			return int(f);
		}
		if (Type == REGT_STRING)
		{
			return s().ToLong();
		}
		// FIXME
		return 0;
	}
	double ToDouble(int Type)
	{
		if (Type == REGT_FLOAT)
		{
			return f;
		}
		if (Type == REGT_INT)
		{
			return i;
		}
		if (Type == REGT_STRING)
		{
			return s().ToDouble();
		}
		// FIXME
		return 0;
	}
};

class VMFunction
{
public:
	bool Unsafe = false;
	uint8_t ImplicitArgs = 0;	// either 0 for static, 1 for method or 3 for action
	int VarFlags = 0; // [ZZ] this replaces 5+ bool fields
	unsigned VirtualIndex = ~0u;
	FName Name;
	const uint8_t *RegTypes = nullptr;
	TArray<TypedVMValue> DefaultArgs;
	FString PrintableName;	// so that the VM can print meaningful info if something in this function goes wrong.

	class PPrototype *Proto;
	TArray<uint32_t> ArgFlags;		// Should be the same length as Proto->ArgumentTypes

	int(*ScriptCall)(VMFunction *func, VMValue *params, int numparams, VMReturn *ret, int numret) = nullptr;

	VMFunction(FName name = NAME_None) : ImplicitArgs(0), Name(name), Proto(NULL)
	{
		AllFunctions.Push(this);
	}
	virtual ~VMFunction() {}

	void *operator new(size_t size)
	{
		return ClassDataAllocator.Alloc(size);
	}

	void operator delete(void *block) {}
	void operator delete[](void *block) {}
	static void DeleteAll()
	{
		for (auto f : AllFunctions)
		{
			f->~VMFunction();
		}
		AllFunctions.Clear();
		// also release any JIT data
		JitRelease();
	}
	static void CreateRegUseInfo()
	{
		for (auto f : AllFunctions)
		{
			f->CreateRegUse();
		}
	}
	static TArray<VMFunction *> AllFunctions;
protected:
	void CreateRegUse();
};

// Use this in the prototype for a native function.

#ifdef NDEBUG
#define VM_ARGS			VMValue *param, int numparam, VMReturn *ret, int numret
#define VM_ARGS_NAMES	param, numparam, ret, numret
#define VM_INVOKE(param, numparam, ret, numret, reginfo) (param), (numparam), (ret), (numret)
#else
#define VM_ARGS			VMValue *param, int numparam, VMReturn *ret, int numret, const uint8_t *reginfo
#define VM_ARGS_NAMES	param, numparam, ret, numret, reginfo
#define VM_INVOKE(param, numparam, ret, numret, reginfo) (param), (numparam), (ret), (numret), (reginfo)
#endif

class VMNativeFunction : public VMFunction
{
public:
	typedef int (*NativeCallType)(VM_ARGS);

	// 8 is VARF_Native. I can't write VARF_Native because of circular references between this and dobject/dobjtype.
	VMNativeFunction() : NativeCall(NULL) { VarFlags = 8; ScriptCall = &VMNativeFunction::NativeScriptCall; }
	VMNativeFunction(NativeCallType call) : NativeCall(call) { VarFlags = 8; ScriptCall = &VMNativeFunction::NativeScriptCall; }
	VMNativeFunction(NativeCallType call, FName name) : VMFunction(name), NativeCall(call) { VarFlags = 8; ScriptCall = &VMNativeFunction::NativeScriptCall; }

	// Return value is the number of results.
	NativeCallType NativeCall;

	// Function pointer to a native function to be called directly by the JIT using the platform calling convention
	void *DirectNativeCall = nullptr;

private:
	static int NativeScriptCall(VMFunction *func, VMValue *params, int numparams, VMReturn *ret, int numret);
};

int VMCall(VMFunction *func, VMValue *params, int numparams, VMReturn *results, int numresults/*, VMException **trap = NULL*/);
int VMCallWithDefaults(VMFunction *func, TArray<VMValue> &params, VMReturn *results, int numresults/*, VMException **trap = NULL*/);

inline int VMCallAction(VMFunction *func, VMValue *params, int numparams, VMReturn *results, int numresults/*, VMException **trap = NULL*/)
{
	return VMCall(func, params, numparams, results, numresults);
}

// Use these to collect the parameters in a native function.
// variable name <x> at position <p>
void NullParam(const char *varname);

#ifndef NDEBUG
bool AssertObject(void * ob);
#endif

#define PARAM_NULLCHECK(ptr, var) (ptr == nullptr? NullParam(#var), ptr : ptr)

// This cannot assert because there is no info for varargs
#define PARAM_VA_POINTER(x)			const uint8_t *x = (const uint8_t *)param[numparam-1].a;

// For required parameters.
#define PARAM_INT_AT(p,x)			assert((p) < numparam); assert(reginfo[p] == REGT_INT); int x = param[p].i;
#define PARAM_UINT_AT(p,x)			assert((p) < numparam); assert(reginfo[p] == REGT_INT); unsigned x = param[p].i;
#define PARAM_BOOL_AT(p,x)			assert((p) < numparam); assert(reginfo[p] == REGT_INT); bool x = !!param[p].i;
#define PARAM_NAME_AT(p,x)			assert((p) < numparam); assert(reginfo[p] == REGT_INT); FName x = ENamedName(param[p].i);
#define PARAM_SOUND_AT(p,x)			assert((p) < numparam); assert(reginfo[p] == REGT_INT); FSoundID x = param[p].i;
#define PARAM_COLOR_AT(p,x)			assert((p) < numparam); assert(reginfo[p] == REGT_INT); PalEntry x; x.d = param[p].i;
#define PARAM_FLOAT_AT(p,x)			assert((p) < numparam); assert(reginfo[p] == REGT_FLOAT); double x = param[p].f;
#define PARAM_ANGLE_AT(p,x)			assert((p) < numparam); assert(reginfo[p] == REGT_FLOAT); DAngle x = param[p].f;
#define PARAM_STRING_VAL_AT(p,x)	assert((p) < numparam); assert(reginfo[p] == REGT_STRING); FString x = param[p].s();
#define PARAM_STRING_AT(p,x)		assert((p) < numparam); assert(reginfo[p] == REGT_STRING); const FString &x = param[p].s();
#define PARAM_STATE_AT(p,x)			assert((p) < numparam); assert(reginfo[p] == REGT_INT); FState *x = (FState *)StateLabels.GetState(param[p].i, self->GetClass());
#define PARAM_STATE_ACTION_AT(p,x)	assert((p) < numparam); assert(reginfo[p] == REGT_INT); FState *x = (FState *)StateLabels.GetState(param[p].i, stateowner->GetClass());
#define PARAM_POINTER_AT(p,x,type)	assert((p) < numparam); assert(reginfo[p] == REGT_POINTER); type *x = (type *)param[p].a;
#define PARAM_OUTPOINTER_AT(p,x,type)	assert((p) < numparam); type *x = (type *)param[p].a;
#define PARAM_POINTERTYPE_AT(p,x,type)	assert((p) < numparam); assert(reginfo[p] == REGT_POINTER); type x = (type )param[p].a;
#define PARAM_OBJECT_AT(p,x,type)	assert((p) < numparam); assert(reginfo[p] == REGT_POINTER && AssertObject(param[p].a)); type *x = (type *)param[p].a; assert(x == NULL || x->IsKindOf(RUNTIME_CLASS(type)));
#define PARAM_CLASS_AT(p,x,base)	assert((p) < numparam); assert(reginfo[p] == REGT_POINTER); base::MetaClass *x = (base::MetaClass *)param[p].a; assert(x == NULL || x->IsDescendantOf(RUNTIME_CLASS(base)));
#define PARAM_POINTER_NOT_NULL_AT(p,x,type)	assert((p) < numparam); assert(reginfo[p] == REGT_POINTER); type *x = (type *)PARAM_NULLCHECK(param[p].a, #x);
#define PARAM_OBJECT_NOT_NULL_AT(p,x,type)	assert((p) < numparam); assert(reginfo[p] == REGT_POINTER && (AssertObject(param[p].a))); type *x = (type *)PARAM_NULLCHECK(param[p].a, #x); assert(x == NULL || x->IsKindOf(RUNTIME_CLASS(type)));
#define PARAM_CLASS_NOT_NULL_AT(p,x,base)	assert((p) < numparam); assert(reginfo[p] == REGT_POINTER); base::MetaClass *x = (base::MetaClass *)PARAM_NULLCHECK(param[p].a, #x); assert(x == NULL || x->IsDescendantOf(RUNTIME_CLASS(base)));


// The above, but with an automatically increasing position index.
#define PARAM_PROLOGUE				int paramnum = -1;

#define PARAM_INT(x)				++paramnum; PARAM_INT_AT(paramnum,x)
#define PARAM_UINT(x)				++paramnum; PARAM_UINT_AT(paramnum,x)
#define PARAM_BOOL(x)				++paramnum; PARAM_BOOL_AT(paramnum,x)
#define PARAM_NAME(x)				++paramnum; PARAM_NAME_AT(paramnum,x)
#define PARAM_SOUND(x)				++paramnum; PARAM_SOUND_AT(paramnum,x)
#define PARAM_COLOR(x)				++paramnum; PARAM_COLOR_AT(paramnum,x)
#define PARAM_FLOAT(x)				++paramnum; PARAM_FLOAT_AT(paramnum,x)
#define PARAM_ANGLE(x)				++paramnum; PARAM_ANGLE_AT(paramnum,x)
#define PARAM_STRING(x)				++paramnum; PARAM_STRING_AT(paramnum,x)
#define PARAM_STRING_VAL(x)				++paramnum; PARAM_STRING_VAL_AT(paramnum,x)
#define PARAM_STATE(x)				++paramnum; PARAM_STATE_AT(paramnum,x)
#define PARAM_STATE_ACTION(x)		++paramnum; PARAM_STATE_ACTION_AT(paramnum,x)
#define PARAM_POINTER(x,type)		++paramnum; PARAM_POINTER_AT(paramnum,x,type)
#define PARAM_OUTPOINTER(x,type)		++paramnum; PARAM_OUTPOINTER_AT(paramnum,x,type)
#define PARAM_POINTERTYPE(x,type)	++paramnum; PARAM_POINTERTYPE_AT(paramnum,x,type)
#define PARAM_OBJECT(x,type)		++paramnum; PARAM_OBJECT_AT(paramnum,x,type)
#define PARAM_CLASS(x,base)			++paramnum; PARAM_CLASS_AT(paramnum,x,base)
#define PARAM_CLASS(x,base)			++paramnum; PARAM_CLASS_AT(paramnum,x,base)
#define PARAM_POINTER_NOT_NULL(x,type)		++paramnum; PARAM_POINTER_NOT_NULL_AT(paramnum,x,type)
#define PARAM_OBJECT_NOT_NULL(x,type)		++paramnum; PARAM_OBJECT_NOT_NULL_AT(paramnum,x,type)
#define PARAM_CLASS_NOT_NULL(x,base)		++paramnum; PARAM_CLASS_NOT_NULL_AT(paramnum,x,base)

typedef int(*actionf_p)(VM_ARGS);

struct FieldDesc
{
	const char *ClassName;
	const char *FieldName;
	size_t FieldOffset;
	unsigned FieldSize;
	int BitValue;
};

// Compile time validation of direct native functions
struct DirectNativeDesc
{
	DirectNativeDesc() = default;

	#define TP(n) typename P##n
	#define VP(n) ValidateType<P##n>()
	template<typename Ret> DirectNativeDesc(Ret(*func)()) : Ptr(reinterpret_cast<void*>(func)) { ValidateType<Ret>(); }
	template<typename Ret, TP(1)> DirectNativeDesc(Ret(*func)(P1)) : Ptr(reinterpret_cast<void*>(func)) { ValidateType<Ret>(); VP(1); }
	template<typename Ret, TP(1), TP(2)> DirectNativeDesc(Ret(*func)(P1,P2)) : Ptr(reinterpret_cast<void*>(func)) { ValidateType<Ret>(); VP(1); VP(2); }
	template<typename Ret, TP(1), TP(2), TP(3)> DirectNativeDesc(Ret(*func)(P1,P2,P3)) : Ptr(reinterpret_cast<void*>(func)) { ValidateType<Ret>(); VP(1); VP(2); VP(3); }
	template<typename Ret, TP(1), TP(2), TP(3), TP(4)> DirectNativeDesc(Ret(*func)(P1, P2, P3, P4)) : Ptr(reinterpret_cast<void*>(func)) { ValidateType<Ret>(); VP(1); VP(2); VP(3); VP(4); }
	template<typename Ret, TP(1), TP(2), TP(3), TP(4), TP(5)> DirectNativeDesc(Ret(*func)(P1, P2, P3, P4, P5)) : Ptr(reinterpret_cast<void*>(func)) { ValidateType<Ret>(); VP(1); VP(2); VP(3); VP(4); VP(5); }
	template<typename Ret, TP(1), TP(2), TP(3), TP(4), TP(5), TP(6)> DirectNativeDesc(Ret(*func)(P1, P2, P3, P4, P5, P6)) : Ptr(reinterpret_cast<void*>(func)) { ValidateType<Ret>(); VP(1); VP(2); VP(3); VP(4); VP(5); VP(6); }
	template<typename Ret, TP(1), TP(2), TP(3), TP(4), TP(5), TP(6), TP(7)> DirectNativeDesc(Ret(*func)(P1, P2, P3, P4, P5, P6, P7)) : Ptr(reinterpret_cast<void*>(func)) { ValidateType<Ret>(); VP(1); VP(2); VP(3); VP(4); VP(5); VP(6); VP(7); }
	template<typename Ret, TP(1), TP(2), TP(3), TP(4), TP(5), TP(6), TP(7), TP(8)> DirectNativeDesc(Ret(*func)(P1, P2, P3, P4, P5, P6, P7, P8)) : Ptr(reinterpret_cast<void*>(func)) { ValidateType<Ret>(); VP(1); VP(2); VP(3); VP(4); VP(5); VP(6); VP(7); VP(8); }
	template<typename Ret, TP(1), TP(2), TP(3), TP(4), TP(5), TP(6), TP(7), TP(8), TP(9)> DirectNativeDesc(Ret(*func)(P1, P2, P3, P4, P5, P6, P7, P8, P9)) : Ptr(reinterpret_cast<void*>(func)) { ValidateType<Ret>(); VP(1); VP(2); VP(3); VP(4); VP(5); VP(6); VP(7); VP(8); VP(9); }
	template<typename Ret, TP(1), TP(2), TP(3), TP(4), TP(5), TP(6), TP(7), TP(8), TP(9), TP(10)> DirectNativeDesc(Ret(*func)(P1, P2, P3, P4, P5, P6, P7, P8, P9, P10)) : Ptr(reinterpret_cast<void*>(func)) { ValidateType<Ret>(); VP(1); VP(2); VP(3); VP(4); VP(5); VP(6); VP(7); VP(8); VP(9); VP(10); }
	#undef TP
	#undef VP

	template<typename T> void ValidateType() { static_assert(is_valid<T>::value, "Argument type is not valid as a direct native parameter or return type"); }

	// Traits for the types we are interested in
	template<typename T> struct is_valid { static const bool value = false; };
	template<typename T> struct is_valid<T*> { static const bool value = true; };
	template<typename T> struct is_valid<T&> { static const bool value = true; };
	template<> struct is_valid<void> { static const bool value = true; };
	template<> struct is_valid<int> { static const bool value = true; };
	template<> struct is_valid<double> { static const bool value = true; };

	operator void *() const { return Ptr; }

	void *Ptr = nullptr;
};

struct AFuncDesc
{
	const char *ClassName;
	const char *FuncName;
	actionf_p Function;
	VMNativeFunction **VMPointer;
	DirectNativeDesc DirectNative;
};

#if defined(_MSC_VER)
#pragma section(".areg$u",read)
#pragma section(".freg$u",read)

#define MSVC_ASEG __declspec(allocate(".areg$u"))
#define MSVC_FSEG __declspec(allocate(".freg$u"))
#define GCC_ASEG
#define GCC_FSEG
#else
#define MSVC_ASEG
#define MSVC_FSEG
#define GCC_ASEG __attribute__((section(SECTION_AREG))) __attribute__((used))
#define GCC_FSEG __attribute__((section(SECTION_FREG))) __attribute__((used))
#endif

// Macros to handle action functions. These are here so that I don't have to
// change every single use in case the parameters change.

#define DEFINE_ACTION_FUNCTION_NATIVE(cls, name, native) \
	static int AF_##cls##_##name(VM_ARGS); \
	VMNativeFunction *cls##_##name##_VMPtr; \
	static const AFuncDesc cls##_##name##_Hook = { #cls, #name, AF_##cls##_##name, &cls##_##name##_VMPtr, native }; \
	extern AFuncDesc const *const cls##_##name##_HookPtr; \
	MSVC_ASEG AFuncDesc const *const cls##_##name##_HookPtr GCC_ASEG = &cls##_##name##_Hook; \
	static int AF_##cls##_##name(VM_ARGS)

#define DEFINE_ACTION_FUNCTION(cls, name) \
	static int AF_##cls##_##name(VM_ARGS); \
	VMNativeFunction *cls##_##name##_VMPtr; \
	static const AFuncDesc cls##_##name##_Hook = { #cls, #name, AF_##cls##_##name, &cls##_##name##_VMPtr, {} }; \
	extern AFuncDesc const *const cls##_##name##_HookPtr; \
	MSVC_ASEG AFuncDesc const *const cls##_##name##_HookPtr GCC_ASEG = &cls##_##name##_Hook; \
	static int AF_##cls##_##name(VM_ARGS)

// cls is the scripted class name, icls the internal one (e.g. player_t vs. Player)
#define DEFINE_FIELD_X(cls, icls, name) \
	static const FieldDesc VMField_##icls##_##name = { "A" #cls, #name, (unsigned)myoffsetof(icls, name), (unsigned)sizeof(icls::name), 0 }; \
	extern FieldDesc const *const VMField_##icls##_##name##_HookPtr; \
	MSVC_FSEG FieldDesc const *const VMField_##icls##_##name##_HookPtr GCC_FSEG = &VMField_##icls##_##name;

// This is for cases where the internal size does not match the part that gets exported.
#define DEFINE_FIELD_UNSIZED(cls, icls, name) \
	static const FieldDesc VMField_##icls##_##name = { "A" #cls, #name, (unsigned)myoffsetof(icls, name), ~0u, 0 }; \
	extern FieldDesc const *const VMField_##icls##_##name##_HookPtr; \
	MSVC_FSEG FieldDesc const *const VMField_##icls##_##name##_HookPtr GCC_FSEG = &VMField_##icls##_##name;

#define DEFINE_FIELD_NAMED_X(cls, icls, name, scriptname) \
	static const FieldDesc VMField_##cls##_##scriptname = { "A" #cls, #scriptname, (unsigned)myoffsetof(icls, name), (unsigned)sizeof(icls::name), 0 }; \
	extern FieldDesc const *const VMField_##cls##_##scriptname##_HookPtr; \
	MSVC_FSEG FieldDesc const *const VMField_##cls##_##scriptname##_HookPtr GCC_FSEG = &VMField_##cls##_##scriptname;

#define DEFINE_FIELD_X_BIT(cls, icls, name, bitval) \
	static const FieldDesc VMField_##icls##_##name = { "A" #cls, #name, (unsigned)myoffsetof(icls, name), (unsigned)sizeof(icls::name), bitval }; \
	extern FieldDesc const *const VMField_##icls##_##name##_HookPtr; \
	MSVC_FSEG FieldDesc const *const VMField_##icls##_##name##_HookPtr GCC_FSEG = &VMField_##cls##_##name;

#define DEFINE_FIELD(cls, name) \
	static const FieldDesc VMField_##cls##_##name = { #cls, #name, (unsigned)myoffsetof(cls, name), (unsigned)sizeof(cls::name), 0 }; \
	extern FieldDesc const *const VMField_##cls##_##name##_HookPtr; \
	MSVC_FSEG FieldDesc const *const VMField_##cls##_##name##_HookPtr GCC_FSEG = &VMField_##cls##_##name;

#define DEFINE_FIELD_NAMED(cls, name, scriptname) \
		static const FieldDesc VMField_##cls##_##scriptname = { #cls, #scriptname, (unsigned)myoffsetof(cls, name), (unsigned)sizeof(cls::name), 0 }; \
	extern FieldDesc const *const VMField_##cls##_##scriptname##_HookPtr; \
	MSVC_FSEG FieldDesc const *const VMField_##cls##_##scriptname##_HookPtr GCC_FSEG = &VMField_##cls##_##scriptname;

#define DEFINE_FIELD_BIT(cls, name, scriptname, bitval) \
		static const FieldDesc VMField_##cls##_##scriptname = { #cls, #scriptname, (unsigned)myoffsetof(cls, name), (unsigned)sizeof(cls::name), bitval }; \
	extern FieldDesc const *const VMField_##cls##_##scriptname##_HookPtr; \
	MSVC_FSEG FieldDesc const *const VMField_##cls##_##scriptname##_HookPtr GCC_FSEG = &VMField_##cls##_##scriptname;

#define DEFINE_GLOBAL(name) \
	static const FieldDesc VMGlobal_##name = { "", #name, (size_t)&name, (unsigned)sizeof(name), 0 }; \
	extern FieldDesc const *const VMGlobal_##name##_HookPtr; \
	MSVC_FSEG FieldDesc const *const VMGlobal_##name##_HookPtr GCC_FSEG = &VMGlobal_##name;

#define DEFINE_GLOBAL_NAMED(iname, name) \
	static const FieldDesc VMGlobal_##name = { "", #name, (size_t)&iname, (unsigned)sizeof(iname), 0 }; \
	extern FieldDesc const *const VMGlobal_##name##_HookPtr; \
	MSVC_FSEG FieldDesc const *const VMGlobal_##name##_HookPtr GCC_FSEG = &VMGlobal_##name;


class AActor;

#define ACTION_RETURN_STATE(v) do { FState *state = v; if (numret > 0) { assert(ret != NULL); ret->SetPointer(state); return 1; } return 0; } while(0)
#define ACTION_RETURN_POINTER(v) do { void *state = v; if (numret > 0) { assert(ret != NULL); ret->SetPointer(state); return 1; } return 0; } while(0)
#define ACTION_RETURN_OBJECT(v) do { auto state = v; if (numret > 0) { assert(ret != NULL); ret->SetObject(state); return 1; } return 0; } while(0)
#define ACTION_RETURN_FLOAT(v) do { double u = v; if (numret > 0) { assert(ret != nullptr); ret->SetFloat(u); return 1; } return 0; } while(0)
#define ACTION_RETURN_VEC2(v) do { DVector2 u = v; if (numret > 0) { assert(ret != nullptr); ret[0].SetVector2(u); return 1; } return 0; } while(0)
#define ACTION_RETURN_VEC3(v) do { DVector3 u = v; if (numret > 0) { assert(ret != nullptr); ret[0].SetVector(u); return 1; } return 0; } while(0)
#define ACTION_RETURN_INT(v) do { int u = v; if (numret > 0) { assert(ret != NULL); ret->SetInt(u); return 1; } return 0; } while(0)
#define ACTION_RETURN_BOOL(v) ACTION_RETURN_INT(v)
#define ACTION_RETURN_STRING(v) do { FString u = v; if (numret > 0) { assert(ret != NULL); ret->SetString(u); return 1; } return 0; } while(0)

// Checks to see what called the current action function
#define ACTION_CALL_FROM_ACTOR() (stateinfo == nullptr || stateinfo->mStateType == STATE_Actor)
#define ACTION_CALL_FROM_PSPRITE() (self->player && stateinfo != nullptr && stateinfo->mStateType == STATE_Psprite)
#define ACTION_CALL_FROM_INVENTORY() (stateinfo != nullptr && stateinfo->mStateType == STATE_StateChain)

// Standard parameters for all action functions
//   self         - Actor this action is to operate on (player if a weapon)
//   stateowner   - Actor this action really belongs to (may be an item)
//   callingstate - State this action was called from
#define PARAM_ACTION_PROLOGUE(type) \
	PARAM_PROLOGUE; \
	PARAM_OBJECT_NOT_NULL (self, AActor); \
	PARAM_OBJECT (stateowner, type) \
	PARAM_POINTER  (stateinfo, FStateParamInfo) \

// Number of action paramaters
#define NAP 3

#define PARAM_SELF_PROLOGUE(type) \
	PARAM_PROLOGUE; \
	PARAM_OBJECT_NOT_NULL(self, type);

// for structs we cannot do a class validation
#define PARAM_SELF_STRUCT_PROLOGUE(type) \
	PARAM_PROLOGUE; \
	PARAM_POINTER_NOT_NULL(self, type);

class PFunction;

VMFunction *FindVMFunction(PClass *cls, const char *name);
#define DECLARE_VMFUNC(cls, name) static VMFunction *name; if (name == nullptr) name = FindVMFunction(RUNTIME_CLASS(cls), #name);

FString FStringFormat(VM_ARGS, int offset = 0);

#define IFVM(cls, funcname) \
	static VMFunction * func = nullptr; \
	if (func == nullptr) { \
		PClass::FindFunction(&func, #cls, #funcname); \
		assert(func); \
	} \
	if (func != nullptr)



unsigned GetVirtualIndex(PClass *cls, const char *funcname);

#define IFVIRTUALPTR(self, cls, funcname) \
	static unsigned VIndex = ~0u; \
	if (VIndex == ~0u) { \
		VIndex = GetVirtualIndex(RUNTIME_CLASS(cls), #funcname); \
		assert(VIndex != ~0u); \
	} \
	auto clss = self->GetClass(); \
	VMFunction *func = clss->Virtuals.Size() > VIndex? clss->Virtuals[VIndex] : nullptr;  \
	if (func != nullptr)

#define IFVIRTUAL(cls, funcname) IFVIRTUALPTR(this, cls, funcname)

#define IFVIRTUALPTRNAME(self, cls, funcname) \
	static unsigned VIndex = ~0u; \
	if (VIndex == ~0u) { \
		VIndex = GetVirtualIndex(PClass::FindClass(cls), #funcname); \
		assert(VIndex != ~0u); \
	} \
	auto clss = self->GetClass(); \
	VMFunction *func = clss->Virtuals.Size() > VIndex? clss->Virtuals[VIndex] : nullptr;  \
	if (func != nullptr)

#endif