- implemented pass-by-reference arguments - so far only for memory based variables.

- changed Dehacked weapon function lookup to check the symbol table instead of directly referencing the VM functions. Once scriptified these pointers will no longer be available.
- removed all special ATAGs from the VM. While well intentioned any pointer tagged with them is basically unusable because it'd trigger asserts all over the place.
- scriptified A_Punch for testing pass-by-reference parameters and stack variables.

src/d_dehacked.cpp

@@ -166,36 +166,27 @@ static TArray<CodePointerAlias> MBFCodePointers;
 
 struct AmmoPerAttack
 {
-	VMNativeFunction **func;
+	ENamedName func;
 	int ammocount;
+	VMFunction *ptr;
 };
 
 DECLARE_ACTION(A_Punch)
-DECLARE_ACTION(A_FirePistol)
-DECLARE_ACTION(A_FireShotgun)
-DECLARE_ACTION(A_FireShotgun2)
-DECLARE_ACTION(A_FireCGun)
-DECLARE_ACTION(A_FireMissile)
-DECLARE_ACTION(A_Saw)
-DECLARE_ACTION(A_FirePlasma)
-DECLARE_ACTION(A_FireBFG)
-DECLARE_ACTION(A_FireOldBFG)
-DECLARE_ACTION(A_FireRailgun)
 
 // Default ammo use of the various weapon attacks
 static AmmoPerAttack AmmoPerAttacks[] = {
-	{ &AActor_A_Punch_VMPtr, 0},
-	{ &AActor_A_FirePistol_VMPtr, 1},
-	{ &AActor_A_FireShotgun_VMPtr, 1},
-	{ &AActor_A_FireShotgun2_VMPtr, 2},
-	{ &AActor_A_FireCGun_VMPtr, 1},
-	{ &AActor_A_FireMissile_VMPtr, 1},
-	{ &AActor_A_Saw_VMPtr, 0},
-	{ &AActor_A_FirePlasma_VMPtr, 1},
-	{ &AActor_A_FireBFG_VMPtr, -1},	// uses deh.BFGCells
-	{ &AActor_A_FireOldBFG_VMPtr, 1},
-	{ &AActor_A_FireRailgun_VMPtr, 1},
-	{ NULL, 0}
+	{ NAME_A_Punch, 0},
+	{ NAME_A_FirePistol, 1},
+	{ NAME_A_FireShotgun, 1},
+	{ NAME_A_FireShotgun2, 2},
+	{ NAME_A_FireCGun, 1},
+	{ NAME_A_FireMissile, 1},
+	{ NAME_A_Saw, 0},
+	{ NAME_A_FirePlasma, 1},
+	{ NAME_A_FireBFG, -1},	// uses deh.BFGCells
+	{ NAME_A_FireOldBFG, 1},
+	{ NAME_A_FireRailgun, 1},
+	{ NAME_None, 0}
 };
 
 
@@ -3095,7 +3086,12 @@ void FinishDehPatch ()
 				StateVisited[state] = true;
 				for(unsigned j = 0; AmmoPerAttacks[j].func != NULL; j++)
 				{
-					if (state->ActionFunc == *AmmoPerAttacks[j].func)
+					if (AmmoPerAttacks[i].ptr == nullptr)
+					{
+						auto p = dyn_cast<PFunction>(RUNTIME_CLASS(AStateProvider)->Symbols.FindSymbol(AmmoPerAttacks[i].func, true));
+						if (p != nullptr) AmmoPerAttacks[i].ptr = p->Variants[0].Implementation;
+					}
+					if (state->ActionFunc == AmmoPerAttacks[j].ptr)
 					{
 						found = true;
 						int use = AmmoPerAttacks[j].ammocount;

src/d_player.h

@@ -253,11 +253,10 @@ enum
 	WF_USER4OK			= 1 << 11,
 };
 
-#define WPIECE1		1
-#define WPIECE2		2
-#define WPIECE3		4
-
-#define WP_NOCHANGE ((AWeapon*)~0)
+// The VM cannot deal with this as an invalid pointer because it performs a read barrier on every object pointer read.
+// This doesn't have to point to a valid weapon, though, because WP_NOCHANGE is never dereferenced, but it must point to a valid object
+// and the class descriptor just works fine for that.
+#define WP_NOCHANGE ((AWeapon*)RUNTIME_CLASS_CASTLESS(AWeapon))
 
 
 #define MAXPLAYERNAME	15

src/dobjtype.h

@@ -32,6 +32,7 @@ enum
 	VARF_Static			= (1<<13),	// static class data (by necessity read only.)
 	VARF_InternalAccess	= (1<<14),	// overrides VARF_ReadOnly for internal script code.
 	VARF_Override		= (1<<15),	// overrides a virtual function from the parent class.
+	VARF_Ref			= (1<<16),	// argument is passed by reference.
 };
 
 // Symbol information -------------------------------------------------------

src/g_doom/a_doomweaps.cpp

@@ -15,7 +15,6 @@
 #include "doomstat.h"
 */
 
-static FRandom pr_punch ("Punch");
 static FRandom pr_saw ("Saw");
 static FRandom pr_fireshotgun2 ("FireSG2");
 static FRandom pr_fireplasma ("FirePlasma");
@@ -23,47 +22,6 @@ static FRandom pr_firerail ("FireRail");
 static FRandom pr_bfgspray ("BFGSpray");
 static FRandom pr_oldbfg ("OldBFG");
 
-//
-// A_Punch
-//
-DEFINE_ACTION_FUNCTION(AActor, A_Punch)
-{
-	PARAM_ACTION_PROLOGUE(AActor);
-
-	DAngle 	angle;
-	int 		damage;
-	DAngle 		pitch;
-	FTranslatedLineTarget t;
-
-	if (self->player != NULL)
-	{
-		AWeapon *weapon = self->player->ReadyWeapon;
-		if (weapon != NULL && !(weapon->WeaponFlags & WIF_DEHAMMO) && ACTION_CALL_FROM_PSPRITE())
-		{
-			if (!weapon->DepleteAmmo (weapon->bAltFire))
-				return 0;
-		}
-	}
-
-	damage = (pr_punch()%10+1)<<1;
-
-	if (self->FindInventory<APowerStrength>())	
-		damage *= 10;
-
-	angle = self->Angles.Yaw + pr_punch.Random2() * (5.625 / 256);
-	pitch = P_AimLineAttack (self, angle, MELEERANGE);
-
-	P_LineAttack (self, angle, MELEERANGE, pitch, damage, NAME_Melee, NAME_BulletPuff, LAF_ISMELEEATTACK, &t);
-
-	// turn to face target
-	if (t.linetarget)
-	{
-		S_Sound (self, CHAN_WEAPON, "*fist", 1, ATTN_NORM);
-		self->Angles.Yaw = t.angleFromSource;
-	}
-	return 0;
-}
-
 //
 // A_FirePistol
 //

src/g_shared/a_pickups.h

@@ -289,6 +289,7 @@ public:
 class AWeapon : public AStateProvider
 {
 	DECLARE_CLASS_WITH_META(AWeapon, AStateProvider, PClassWeapon)
+	HAS_FIELDS
 	HAS_OBJECT_POINTERS
 public:
 	DWORD WeaponFlags;

src/g_shared/a_weapons.cpp

@@ -17,10 +17,13 @@
 #include "g_level.h"
 #include "d_net.h"
 #include "serializer.h"
+#include "thingdef.h"
 
 #define BONUSADD 6
 
-IMPLEMENT_CLASS(AWeapon, false, true, false, false)
+extern FFlagDef WeaponFlagDefs[];
+
+IMPLEMENT_CLASS(AWeapon, false, true, true, false)
 
 IMPLEMENT_POINTERS_START(AWeapon)
 	IMPLEMENT_POINTER(Ammo1)
@@ -28,6 +31,26 @@ IMPLEMENT_POINTERS_START(AWeapon)
 	IMPLEMENT_POINTER(SisterWeapon)
 IMPLEMENT_POINTERS_END
 
+void AWeapon::InitNativeFields()
+{
+	auto meta = RUNTIME_CLASS(AWeapon);
+
+	meta->AddNativeField("bAltFire", TypeBool, myoffsetof(AWeapon, bAltFire));
+
+
+	// synthesize a symbol for each flag from the flag name tables to avoid redundant declaration of them.
+	for (size_t i = 0; WeaponFlagDefs[i].flagbit != 0xffffffff; i++)
+	{
+		if (WeaponFlagDefs[i].structoffset > 0)
+		{
+			meta->AddNativeField(FStringf("b%s", WeaponFlagDefs[i].name), (WeaponFlagDefs[i].fieldsize == 4 ? TypeSInt32 : TypeSInt16), WeaponFlagDefs[i].structoffset, WeaponFlagDefs[i].varflags, WeaponFlagDefs[i].flagbit);
+		}
+	}
+	// This flag is not accessible through actor definitions.
+	meta->AddNativeField("bDehAmmo", TypeSInt32, myoffsetof(AWeapon, WeaponFlags), VARF_ReadOnly, WIF_DEHAMMO);
+
+}
+
 FString WeaponSection;
 TArray<FString> KeyConfWeapons;
 FWeaponSlots *PlayingKeyConf;
@@ -651,6 +674,15 @@ bool AWeapon::DepleteAmmo (bool altFire, bool checkEnough, int ammouse)
 	return true;
 }
 
+DEFINE_ACTION_FUNCTION(AWeapon, DepleteAmmo)
+{
+	PARAM_SELF_PROLOGUE(AWeapon);
+	PARAM_BOOL(altfire);
+	PARAM_BOOL_DEF(checkenough);
+	PARAM_INT_DEF(ammouse);
+	ACTION_RETURN_BOOL(self->DepleteAmmo(altfire, checkenough, ammouse));
+}
+
 
 //===========================================================================
 //

src/namedef.h

@@ -738,3 +738,15 @@ xx(Length)
 xx(Unit)
 xx(StateLabel)
 xx(Overlay)
+
+xx(A_Punch)
+xx(A_FirePistol)
+xx(A_FireShotgun)
+xx(A_FireShotgun2)
+xx(A_FireCGun)
+xx(A_FireMissile)
+xx(A_Saw)
+xx(A_FirePlasma)
+xx(A_FireBFG)
+xx(A_FireOldBFG)
+xx(A_FireRailgun)

src/p_mobj.cpp

@@ -1035,6 +1035,14 @@ AInventory *AActor::FindInventory (FName type)
 	return FindInventory(PClass::FindActor(type));
 }
 
+DEFINE_ACTION_FUNCTION(AActor, FindInventory)
+{
+	PARAM_SELF_PROLOGUE(AActor);
+	PARAM_CLASS(type, AInventory);
+	PARAM_BOOL_DEF(subclass);
+	ACTION_RETURN_OBJECT(self->FindInventory(type, subclass));
+}
+
 //============================================================================
 //
 // AActor :: GiveInventoryType

src/scripting/codegeneration/codegen.cpp

@@ -3547,7 +3547,7 @@ ExpEmit FxShift::Emit(VMFunctionBuilder *build)
 	if (!op1.Konst)
 	{
 		op1.Free(build);
-		instr = InstrMap[index][op2.Konst? 0:2];
+		instr = InstrMap[index][op2.Konst? 2:0];
 	}
 	else
 	{
@@ -7067,7 +7067,8 @@ FxExpression *FxVMFunctionCall::Resolve(FCompileContext& ctx)
 	SAFE_RESOLVE_OPT(Self, ctx);
 	bool failed = false;
 	auto proto = Function->Variants[0].Proto;
-	auto argtypes = proto->ArgumentTypes;
+	auto &argtypes = proto->ArgumentTypes;
+	auto &argflags = Function->Variants[0].ArgFlags;
 
 	int implicit = Function->GetImplicitArgs();
 
@@ -7100,8 +7101,29 @@ FxExpression *FxVMFunctionCall::Resolve(FCompileContext& ctx)
 			}
 			assert(type != nullptr);
 
-			FxExpression *x = new FxTypeCast(ArgList[i], type, false);
+			FxExpression *x;
+			if (!(argflags[i + implicit] & VARF_Ref))
+			{
+				x = new FxTypeCast(ArgList[i], type, false);
 				x = x->Resolve(ctx);
+			}
+			else
+			{
+				bool writable;
+				ArgList[i] = ArgList[i]->Resolve(ctx);	// nust be resolved before the address is requested.
+				ArgList[i]->RequestAddress(ctx, &writable);
+				ArgList[i]->ValueType = NewPointer(ArgList[i]->ValueType);
+				// For a reference argument the types must match 100%.
+				if (type != ArgList[i]->ValueType)
+				{
+					ScriptPosition.Message(MSG_ERROR, "Type mismatch in reference argument", Function->SymbolName.GetChars());
+					x = nullptr;
+				}
+				else
+				{
+					x = ArgList[i];
+				}
+			}
 			failed |= (x == nullptr);
 			ArgList[i] = x;
 		}

src/scripting/thingdef.cpp

@@ -131,7 +131,7 @@ void SetImplicitArgs(TArray<PType *> *args, TArray<DWORD> *argflags, TArray<FNam
 			{
 				args->Push(NewPointer(cls));
 			}
-			args->Push(TypeState/*Info*/);	// fixme: TypeState is not the correct type here!!!
+			args->Push(NewPointer(NewStruct("FStateParamInfo", nullptr)));
 		}
 		if (argflags != nullptr)
 		{

src/scripting/thingdef_data.cpp

@@ -388,7 +388,7 @@ static FFlagDef InventoryFlagDefs[] =
 	DEFINE_DEPRECATED_FLAG(INTERHUBSTRIP),
 };
 
-static FFlagDef WeaponFlagDefs[] =
+FFlagDef WeaponFlagDefs[] =
 {
 	// Weapon flags
 	DEFINE_FLAG(WIF, NOAUTOFIRE, AWeapon, WeaponFlags),
@@ -411,12 +411,14 @@ static FFlagDef WeaponFlagDefs[] =
 	DEFINE_FLAG(WIF, NOAUTOAIM, AWeapon, WeaponFlags),
 	DEFINE_FLAG(WIF, NODEATHDESELECT, AWeapon, WeaponFlags),
 	DEFINE_FLAG(WIF, NODEATHINPUT, AWeapon, WeaponFlags),
+	DEFINE_FLAG(WIF, ALT_USES_BOTH, AWeapon, WeaponFlags),
 
 	DEFINE_DUMMY_FLAG(NOLMS, false),
-	DEFINE_FLAG(WIF, ALT_USES_BOTH, AWeapon, WeaponFlags),
 	DEFINE_DUMMY_FLAG(ALLOW_WITH_RESPAWN_INVUL, false),
 };
 
+
+
 static FFlagDef PlayerPawnFlagDefs[] =
 {
 	// PlayerPawn flags

src/scripting/vm/vm.h

@@ -157,13 +157,15 @@ enum
 	ATAG_OBJECT,			// pointer to an object; will be followed by GC
 
 	// The following are all for documentation during debugging and are
-	// functionally no different than ATAG_GENERIC.
+	// functionally no different than ATAG_GENERIC (meaning they are useless because they trigger asserts all over the place.)
 
+	/*
 	ATAG_FRAMEPOINTER,		// pointer to extra stack frame space for this function
 	ATAG_DREGISTER,			// pointer to a data register
 	ATAG_FREGISTER,			// pointer to a float register
 	ATAG_SREGISTER,			// pointer to a string register
 	ATAG_AREGISTER,			// pointer to an address register
+	*/
 
 	ATAG_RNG,				// pointer to FRandom
 	ATAG_STATE  = ATAG_GENERIC,			// pointer to FState (cannot have its own type because there's no means to track inside the VM.)

src/scripting/vm/vmexec.h

@@ -87,7 +87,7 @@ begin:
 	OP(LFP):
 		ASSERTA(a); assert(sfunc != NULL); assert(sfunc->ExtraSpace > 0);
 		reg.a[a] = f->GetExtra();
-		reg.atag[a] = ATAG_FRAMEPOINTER;
+		reg.atag[a] = ATAG_GENERIC;	// using ATAG_FRAMEPOINTER will cause endless asserts.
 		NEXTOP;
 
 	OP(LB):
@@ -461,7 +461,7 @@ begin:
 					break;
 				case REGT_INT | REGT_ADDROF:
 					assert(C < f->NumRegD);
-					::new(param) VMValue(&reg.d[C], ATAG_DREGISTER);
+					::new(param) VMValue(&reg.d[C], ATAG_GENERIC);
 					break;
 				case REGT_INT | REGT_KONST:
 					assert(C < sfunc->NumKonstD);
@@ -473,7 +473,7 @@ begin:
 					break;
 				case REGT_STRING | REGT_ADDROF:
 					assert(C < f->NumRegS);
-					::new(param) VMValue(&reg.s[C], ATAG_SREGISTER);
+					::new(param) VMValue(&reg.s[C], ATAG_GENERIC);
 					break;
 				case REGT_STRING | REGT_KONST:
 					assert(C < sfunc->NumKonstS);
@@ -485,7 +485,7 @@ begin:
 					break;
 				case REGT_POINTER | REGT_ADDROF:
 					assert(C < f->NumRegA);
-					::new(param) VMValue(&reg.a[C], ATAG_AREGISTER);
+					::new(param) VMValue(&reg.a[C], ATAG_GENERIC);
 					break;
 				case REGT_POINTER | REGT_KONST:
 					assert(C < sfunc->NumKonstA);
@@ -512,7 +512,7 @@ begin:
 					break;
 				case REGT_FLOAT | REGT_ADDROF:
 					assert(C < f->NumRegF);
-					::new(param) VMValue(&reg.f[C], ATAG_FREGISTER);
+					::new(param) VMValue(&reg.f[C], ATAG_GENERIC);
 					break;
 				case REGT_FLOAT | REGT_KONST:
 					assert(C < sfunc->NumKonstF);

src/scripting/zscript/zcc_compile.cpp

@@ -2160,6 +2160,7 @@ void ZCCCompiler::InitFunctions()
 								if ((flags & VARF_Out) || (type != TypeVector2 && type != TypeVector3))
 								{
 									type = NewPointer(type);
+									flags |= VARF_Ref;
 								}
 								else if (type == TypeVector2)
 								{

wadsrc/static/zscript.txt

@@ -48,6 +48,7 @@ zscript/doom/cyberdemon.txt
 zscript/doom/spidermaster.txt
 zscript/doom/keen.txt
 zscript/doom/bossbrain.txt
+zscript/doom/weaponfist.txt
 
 zscript/doom/deadthings.txt
 zscript/doom/doomammo.txt

wadsrc/static/zscript/actor.txt

@@ -133,6 +133,7 @@ class Actor : Thinker native
 
 	// DECORATE compatible functions
 	native bool CheckClass(class<Actor> checkclass, int ptr_select = AAPTR_DEFAULT, bool match_superclass = false);
+	native Inventory FindInventory(class<Inventory> itemtype, bool subclass = false);
 	native int	CountInv(class<Inventory> itemtype, int ptr_select = AAPTR_DEFAULT);
 	native float GetDistance(bool checkz, int ptr = AAPTR_TARGET);
 	native float GetAngle(int flags, int ptr = AAPTR_DEFAULT);
@@ -471,7 +472,6 @@ class Actor : Thinker native
 	native void A_DeQueueCorpse();
 	native void A_ClearLastHeard();
 	native bool A_SelectWeapon(class<Weapon> whichweapon, int flags = 0);
-	action native void A_Punch();
 	native void A_Feathers();
 	native void A_ClassBossHealth();
 	native void A_ShootGun();

wadsrc/static/zscript/constants.txt

@@ -829,7 +829,7 @@ enum EStateType
 struct FStateParamInfo
 {
 	state mCallingState;
-	EStateType mStateType;
+	/*EStateType*/int mStateType;
 	int mPSPIndex;
 }
 

wadsrc/static/zscript/doom/doomweapons.txt

@@ -12,44 +12,6 @@ class DoomWeapon : Weapon
 	}
 }
 
-// --------------------------------------------------------------------------
-//
-// Fist 
-//
-// --------------------------------------------------------------------------
-
-class Fist : Weapon
-{
-	Default
-	{
-		Weapon.SelectionOrder 3700;
-		Weapon.Kickback 100;
-		Obituary "$OB_MPFIST";
-		Tag "$TAG_FIST";
-		+WEAPON.WIMPY_WEAPON
-		+WEAPON.MELEEWEAPON
-	}
-	States
-	{
-	Ready:
-		PUNG A 1 A_WeaponReady;
-		Loop;
-	Deselect:
-		PUNG A 1 A_Lower;
-		Loop;
-	Select:
-		PUNG A 1 A_Raise;
-		Loop;
-	Fire:
-		PUNG B 4;
-		PUNG C 4 A_Punch;
-		PUNG D 5;
-		PUNG C 4;
-		PUNG B 5 A_ReFire;
-		Goto Ready;
-	}
-}
-	
 
 // --------------------------------------------------------------------------
 //

wadsrc/static/zscript/doom/weaponfist.txt

@@ -0,0 +1,80 @@
+// --------------------------------------------------------------------------
+//
+// Fist 
+//
+// --------------------------------------------------------------------------
+
+class Fist : Weapon
+{
+	Default
+	{
+		Weapon.SelectionOrder 3700;
+		Weapon.Kickback 100;
+		Obituary "$OB_MPFIST";
+		Tag "$TAG_FIST";
+		+WEAPON.WIMPY_WEAPON
+		+WEAPON.MELEEWEAPON
+	}
+	States
+	{
+	Ready:
+		PUNG A 1 A_WeaponReady;
+		Loop;
+	Deselect:
+		PUNG A 1 A_Lower;
+		Loop;
+	Select:
+		PUNG A 1 A_Raise;
+		Loop;
+	Fire:
+		PUNG B 4;
+		PUNG C 4 A_Punch;
+		PUNG D 5;
+		PUNG C 4;
+		PUNG B 5 A_ReFire;
+		Goto Ready;
+	}
+}
+
+
+//===========================================================================
+//
+// Code (must be attached to Actor)
+//
+//===========================================================================
+
+extend class Actor
+{	
+	action void A_Punch()
+	{
+		FTranslatedLineTarget t;
+
+		if (player != null)
+		{
+			Weapon weap = player.ReadyWeapon;
+			if (weap != null && !weap.bDehAmmo && invoker == weap && stateinfo != null && stateinfo.mStateType == STATE_Psprite)
+			{
+				if (!weap.DepleteAmmo (weap.bAltFire))
+					return;
+			}
+		}
+
+		int damage = random[Punch](1, 10) << 1;
+
+		if (FindInventory("PowerStrength"))
+			damage *= 10;
+
+		double ang = angle + Random2[Punch]() * (5.625 / 256);
+		double pitch = AimLineAttack (ang, MELEERANGE);
+
+		LineAttack (ang, MELEERANGE, pitch, damage, 'Melee', "BulletPuff", LAF_ISMELEEATTACK, t);
+
+		// turn to face target
+		if (t.linetarget)
+		{
+			A_PlaySound ("*fist", CHAN_WEAPON);
+			angle = t.angleFromSource;
+		}
+	}
+
+}

wadsrc/static/zscript/shared/inventory.txt

@@ -473,6 +473,8 @@ class Weapon : StateProvider native
 		Stop;
 	}
 	
+	native bool DepleteAmmo(bool altFire, bool checkEnough = true, int ammouse = -1);
+	
 	native action void A_ZoomFactor(float scale = 1, int flags = 0);
 	native action void A_SetCrosshair(int xhair);
 	const ZOOM_INSTANT = 1;