- more preparations to compile functions:

* Allow PFunction to work without a VMFunction being attached.
 * The Variant for a function must store the prototype itself instead of relying on the VMFunction it points to. Otherwise it would not be possible to reference a prototype during compilation of the function because it does not exist yet.
 * Give the variant a list of the function's argument's names, because these are also needed to compile the function.
 * create an anonymous function symbol when the function gets registered to the builder. At this point we have all the needed information to set it up correctly, but later this is no longer the case. This is the most convenient info to have here because it contains everything that's needed to compile the function in the proper context, so it has to be present when starting compilation.
 * added some preparations to implement special handling for weapons and custom inventory items, which can run action functions in another actor's context. This part is not active yet but the basics are present in SetImplicitArgs.

src/dobjtype.cpp

@@ -2490,14 +2490,14 @@ size_t PFunction::PropagateMark()
 //
 //==========================================================================
 
-unsigned PFunction::AddVariant(PPrototype *proto, TArray<DWORD> &argflags, VMFunction *impl)
+unsigned PFunction::AddVariant(PPrototype *proto, TArray<DWORD> &argflags, TArray<FName> &argnames, VMFunction *impl)
 {
 	Variant variant;
 
-	//variant.Proto = proto;
+	variant.Proto = proto;
 	variant.ArgFlags = argflags;
 	variant.Implementation = impl;
-	impl->Proto = proto;
+	if (impl != nullptr) impl->Proto = proto;
 	return Variants.Push(variant);
 }
 

src/dobjtype.h

@@ -692,14 +692,15 @@ class PFunction : public PSymbol
 public:
 	struct Variant
 	{
-		//PPrototype *Proto;
+		PPrototype *Proto;
 		VMFunction *Implementation;
 		TArray<DWORD> ArgFlags;		// Should be the same length as Proto->ArgumentTypes
+		TArray<FName> ArgNames;		// we need the names to access them later when the function gets compiled.
 	};
 	TArray<Variant> Variants;
 	DWORD Flags;
 
-	unsigned AddVariant(PPrototype *proto, TArray<DWORD> &argflags, VMFunction *impl);
+	unsigned AddVariant(PPrototype *proto, TArray<DWORD> &argflags, TArray<FName> &argnames, VMFunction *impl);
 
 	size_t PropagateMark();
 

src/namedef.h

@@ -717,7 +717,7 @@ xx(Max_10_Exp)
 
 // implicit function parameters
 xx(self)
-xx(caller)
+xx(invoker)
 xx(stateinfo)
 
 xx(__decorate_internal_int__)

src/scripting/codegeneration/codegen.cpp

@@ -3883,7 +3883,7 @@ FxVMFunctionCall::~FxVMFunctionCall()
 PPrototype *FxVMFunctionCall::ReturnProto()
 {
 	EmitTail = true;
-	return Function->Variants[0].Implementation->Proto;
+	return Function->Variants[0].Proto;
 }
 
 //==========================================================================
@@ -3916,7 +3916,7 @@ FxExpression *FxVMFunctionCall::Resolve(FCompileContext& ctx)
 {
 	CHECKRESOLVED();
 	bool failed = false;
-	auto proto = Function->Variants[0].Implementation->Proto;
+	auto proto = Function->Variants[0].Proto;
 	auto argtypes = proto->ArgumentTypes;
 
 	int implicit;

src/scripting/decorate/thingdef_parse.cpp

@@ -458,6 +458,7 @@ void ParseFunctionDef(FScanner &sc, PClassActor *cls, FName funcname,
 	const AFuncDesc *afd;
 	TArray<PType *> args;
 	TArray<DWORD> argflags;
+	TArray<FName> argnames;
 
 	afd = FindFunction(funcname);
 	if (afd == NULL)
@@ -467,13 +468,14 @@ void ParseFunctionDef(FScanner &sc, PClassActor *cls, FName funcname,
 	}
 	sc.MustGetToken('(');
 
-	SetImplicitArgs(&args, &argflags, cls, funcflags);
+	SetImplicitArgs(&args, &argflags, &argnames, cls, funcflags);
+	// This function will be removed once all internal classes have been ported so don't bother filling in the function's argument names, because for anything going through here they'll never be used.
 	ParseArgListDef(sc, cls, args, argflags);
 
 	if (afd != NULL)
 	{
 		PFunction *sym = new PFunction(funcname);
-		sym->AddVariant(NewPrototype(rets, args), argflags, *(afd->VMPointer));
+		sym->AddVariant(NewPrototype(rets, args), argflags, argnames, *(afd->VMPointer));
 		sym->Flags = funcflags;
 		if (cls->Symbols.AddSymbol(sym) == NULL)
 		{

src/scripting/decorate/thingdef_states.cpp

@@ -322,7 +322,8 @@ do_stop:
 endofstate:
 			if (ScriptCode != nullptr)
 			{
-				state.ActionFunc = FunctionBuildList.AddFunction(actor, ScriptCode, FStringf("%s.StateFunction.%d", actor->TypeName.GetChars(), bag.statedef.GetStateCount()), true);
+				auto funcsym = CreateAnonymousFunction(actor, nullptr, VARF_Method | VARF_Action);
+				state.ActionFunc = FunctionBuildList.AddFunction(funcsym, ScriptCode, FStringf("%s.StateFunction.%d", actor->TypeName.GetChars(), bag.statedef.GetStateCount()), true);
 			}
 			int count = bag.statedef.AddStates(&state, statestring);
 			if (count < 0)
@@ -595,7 +596,7 @@ FxVMFunctionCall *ParseAction(FScanner &sc, FState state, FString statestring, B
 void ParseFunctionParameters(FScanner &sc, PClassActor *cls, TArray<FxExpression *> &out_params,
 	PFunction *afd, FString statestring, FStateDefinitions *statedef)
 {
-	const TArray<PType *> &params = afd->Variants[0].Implementation->Proto->ArgumentTypes;
+	const TArray<PType *> &params = afd->Variants[0].Proto->ArgumentTypes;
 	const TArray<DWORD> &paramflags = afd->Variants[0].ArgFlags;
 	int numparams = (int)params.Size();
 	int pnum = 0;

src/scripting/thingdef.cpp

@@ -80,34 +80,74 @@ PClassActor *QuestItemClasses[31];
 //
 //==========================================================================
 
-void SetImplicitArgs(TArray<PType *> *args, TArray<DWORD> *argflags, PClass *cls, DWORD funcflags)
+void SetImplicitArgs(TArray<PType *> *args, TArray<DWORD> *argflags, TArray<FName> *argnames, PClass *cls, DWORD funcflags)
 {
 	// Must be called before adding any other arguments.
-	assert(args == NULL || args->Size() == 0);
-	assert(argflags == NULL || argflags->Size() == 0);
+	assert(args == nullptr || args->Size() == 0);
+	assert(argflags == nullptr || argflags->Size() == 0);
 
 	if (funcflags & VARF_Method)
 	{
 		// implied self pointer
-		if (args != NULL)		args->Push(NewClassPointer(cls)); 
-		if (argflags != NULL)	argflags->Push(VARF_Implicit);
+		if (args != nullptr)		args->Push(cls); 
+		if (argflags != nullptr)	argflags->Push(VARF_Implicit);
+		if (argnames != nullptr)	argnames->Push(NAME_self);
 	}
 	if (funcflags & VARF_Action)
 	{
 		// implied caller and callingstate pointers
-		if (args != NULL)
+		if (args != nullptr)
 		{
-			args->Insert(0, NewClassPointer(RUNTIME_CLASS(AActor)));	// the caller must go before self due to an old design mistake.
-			args->Push(TypeState);
+			// Special treatment for weapons and CustomInventorys: 'self' is not the defining class but the actual user of the item, so this pointer must be of type 'Actor'
+			/* if (cls->IsDescendantOf(RUNTIME_CLASS(AStateProvider)))
+			{
+				args->Insert(0, RUNTIME_CLASS(AActor));	// this must go in before the real pointer to the containing class.
+			}
+			else*/
+			{
+				args->Push(cls);
+			}
+			args->Push(TypeState/*Info*/);	// fixme: TypeState is not the correct type here!!!
 		}
-		if (argflags != NULL)
+		if (argflags != nullptr)
 		{
 			argflags->Push(VARF_Implicit);
 			argflags->Push(VARF_Implicit);
 		}
+		if (argnames != nullptr)
+		{
+			argnames->Push(NAME_invoker);
+			argnames->Push(NAME_stateinfo);
+		}
 	}
 }
 
+//==========================================================================
+//
+// CreateAnonymousFunction
+//
+// Creates a function symbol for an anonymous function
+// This contains actual info about the implied variables which is needed
+// during code generation.
+//
+//==========================================================================
+
+PFunction *CreateAnonymousFunction(PClass *containingclass, PType *returntype, int flags)
+{
+	TArray<PType *> rets(1);
+	TArray<PType *> args;
+	TArray<uint32_t> argflags;
+	TArray<FName> argnames;
+
+	rets[0] = returntype != nullptr? returntype : TypeError;	// Use TypeError as placeholder if we do not know the return type yet.
+	SetImplicitArgs(&args, &argflags, &argnames, containingclass, flags);
+
+	PFunction *sym = new PFunction(NAME_None);	// anonymous functions do not have names.
+	sym->AddVariant(NewPrototype(rets, args), argflags, argnames, nullptr);
+	sym->Flags = VARF_Action;
+	return sym;
+}
+
 //==========================================================================
 //
 // LoadActors

src/scripting/thingdef.h

@@ -150,7 +150,8 @@ void ParseFunctionParameters(FScanner &sc, PClassActor *cls, TArray<FxExpression
 FxExpression *ParseActions(FScanner &sc, FState state, FString statestring, Baggage &bag, bool &endswithret);
 class FxVMFunctionCall *ParseAction(FScanner &sc, FState state, FString statestring, Baggage &bag);
 FName CheckCastKludges(FName in);
-void SetImplicitArgs(TArray<PType *> *args, TArray<DWORD> *argflags, PClass *cls, DWORD funcflags);
+void SetImplicitArgs(TArray<PType *> *args, TArray<DWORD> *argflags, TArray<FName> *argnames, PClass *cls, DWORD funcflags);
+PFunction *CreateAnonymousFunction(PClass *containingclass, PType *returntype, int flags);
 
 //==========================================================================
 //

src/scripting/thingdef_properties.cpp

@@ -657,7 +657,8 @@ DEFINE_PROPERTY(damage, X, Actor)
 	}
 	else
 	{
-		defaults->DamageFunc = FunctionBuildList.AddFunction(bag.Info, id, FStringf("%s.DamageFunction", bag.Info->TypeName.GetChars()), false);
+		auto funcsym = CreateAnonymousFunction(bag.Info, TypeSInt32, VARF_Method);
+		defaults->DamageFunc = FunctionBuildList.AddFunction(funcsym, id, FStringf("%s.DamageFunction", bag.Info->TypeName.GetChars()), false);
 	}
 }
 

src/scripting/vm/vmbuilder.cpp

@@ -649,7 +649,7 @@ void VMFunctionBuilder::BackpatchToHere(size_t loc)
 //==========================================================================
 FFunctionBuildList FunctionBuildList;
 
-VMFunction *FFunctionBuildList::AddFunction(PClass *cls, FxExpression *code, const FString &name, bool statecall)
+VMFunction *FFunctionBuildList::AddFunction(PFunction *functype, FxExpression *code, const FString &name, bool statecall)
 {
 	auto func = code->GetDirectFunction();
 	if (func != nullptr)
@@ -661,7 +661,7 @@ VMFunction *FFunctionBuildList::AddFunction(PClass *cls, FxExpression *code, con
 	//Printf("Adding %s\n", name.GetChars());
 
 	Item it;
-	it.Class = cls;
+	it.Func = functype;
 	it.Code = code;
 	it.DumpName = name;
 	it.Function = new VMScriptFunction;
@@ -684,8 +684,11 @@ void FFunctionBuildList::Build()
 	{
 		assert(item.Code != NULL);
 
+		// This needs to be fixed, so that the compile context receives the entire function symbol, including the containing class, the prototype and argument names, which will be needed to run the code generator
+		// As a first step this just needs to get working so fetch the class type from the prototype's argument list.
+		auto cls = static_cast<PClass*>(item.Func->Variants[0].Proto->ArgumentTypes[!!(item.Func->Flags & VARF_Action)]);
 		// We don't know the return type in advance for anonymous functions.
-		FCompileContext ctx(item.Class, nullptr);
+		FCompileContext ctx(cls, nullptr);
 		item.Code = item.Code->Resolve(ctx);
 		item.Proto = ctx.ReturnProto;
 
@@ -695,32 +698,15 @@ void FFunctionBuildList::Build()
 			VMFunctionBuilder buildit(true);
 
 			assert(item.Proto != nullptr);
-
-			int numargs;
-			int flags;
-
-			// Kludge alert. This needs to be done in a more universal fashion.
-			// Right now there's only action and damage functions, so for the time being
-			// this will do to get the whole thing started first.
-
-			if (item.type == 1)	// anonymous action function
-			{
-				numargs = NAP;
-				flags = VARF_Method | VARF_Action;
-			}
-			else
-			{
-				numargs = 1;
-				flags = VARF_Method;
-			}
+			auto numargs = item.Func->Variants[0].Proto->ArgumentTypes.Size();
 
 			// Generate prototype for this anonymous function
+			// Fixme: This later needs to do proper allocation for the function's entire argument list, once non-anonymous functions can be done.
 			buildit.Registers[REGT_POINTER].Get(numargs);
-			TArray<PType *> args(numargs);
-			SetImplicitArgs(&args, nullptr, item.Class, flags);
 
 			VMScriptFunction *sfunc = item.Function;
-			item.Function->Proto = NewPrototype(item.Proto->ReturnTypes, args);
+			// create a new prototype from the now known return type and the argument list of the function's template prototype.
+			item.Function->Proto = NewPrototype(item.Proto->ReturnTypes, item.Func->Variants[0].Proto->ArgumentTypes);
 
 			// Emit code
 			item.Code->Emit(&buildit);
@@ -731,7 +717,7 @@ void FFunctionBuildList::Build()
 			{
 				char label[64];
 				int labellen = mysnprintf(label, countof(label), item.DumpName,
-				item.Class->TypeName.GetChars());
+				cls->TypeName.GetChars());
 				DumpFunction(dump, sfunc, label, labellen);
 				codesize += sfunc->CodeSize;
 			}

src/scripting/vm/vmbuilder.h

@@ -101,7 +101,7 @@ class FFunctionBuildList
 {
 	struct Item
 	{
-		PClass *Class = nullptr;
+		PFunction *Func = nullptr;
 		FxExpression *Code = nullptr;
 		PPrototype *Proto = nullptr;
 		VMScriptFunction *Function = nullptr;
@@ -112,7 +112,7 @@ class FFunctionBuildList
 	TArray<Item> mItems;
 
 public:
-	VMFunction *AddFunction(PClass *cls, FxExpression *code, const FString &name, bool statecall = false);
+	VMFunction *AddFunction(PFunction *func, FxExpression *code, const FString &name, bool statecall = false);
 	void Build();
 };
 

src/scripting/zscript/zcc_compile.cpp

@@ -1870,7 +1870,7 @@ void ZCCCompiler::InitFunctions()
 	TArray<PType *> rets(1);
 	TArray<PType *> args;
 	TArray<uint32_t> argflags;
-	TArray<ENamedName> argnames;
+	TArray<FName> argnames;
 
 	for (auto c : Classes)
 	{
@@ -1925,20 +1925,7 @@ void ZCCCompiler::InitFunctions()
 						Error(f, "The function '%s' has not been exported from the executable.", FName(f->Name).GetChars());
 					}
 				}
-				SetImplicitArgs(&args, &argflags, c->Type(), varflags);
-				// Give names to the implicit parameters.
-				// Note that 'self' is the second argument on action functions, because this is the one referring to the owning class.
-				if (varflags & VARF_Action)
-				{
-					argnames.Push(NAME_caller);
-					argnames.Push(NAME_self);
-					argnames.Push(NAME_stateinfo);
-				}
-				else if (varflags & VARF_Method)
-				{
-					argnames.Push(NAME_self);
-				}
-
+				SetImplicitArgs(&args, &argflags, &argnames, c->Type(), varflags);
 				auto p = f->Params;
 				if (p != nullptr)
 				{
@@ -1974,7 +1961,7 @@ void ZCCCompiler::InitFunctions()
 				}
 
 				PFunction *sym = new PFunction(f->Name);
-				sym->AddVariant(NewPrototype(rets, args), argflags, afd == nullptr? nullptr : *(afd->VMPointer));
+				sym->AddVariant(NewPrototype(rets, args), argflags, argnames, afd == nullptr? nullptr : *(afd->VMPointer));
 				sym->Flags = varflags;
 				c->Type()->Symbols.ReplaceSymbol(sym);
 
@@ -2025,7 +2012,7 @@ FxExpression *ZCCCompiler::SetupActionFunction(PClassActor *cls, ZCC_TreeNode *a
 		{
 			if (fc->Parameters == nullptr && (afd->Flags & VARF_Action))
 			{
-				// This is the simple case which doesn't require work on the tree.
+				// We can use this function directly without wrapping it in a caller.
 				return new FxVMFunctionCall(afd, nullptr, *af, true);
 			}
 		}
@@ -2040,6 +2027,7 @@ FxExpression *ZCCCompiler::SetupActionFunction(PClassActor *cls, ZCC_TreeNode *a
 			// Action specials fall through to the code generator.
 		}
 	}
+	ConvertClass = cls;
 	return ConvertAST(af);
 
 	//Error(af, "Complex action functions not supported yet.");
@@ -2173,7 +2161,8 @@ void ZCCCompiler::CompileStates()
 						auto code = SetupActionFunction(static_cast<PClassActor *>(c->Type()), sl->Action);
 						if (code != nullptr)
 						{
-							state.ActionFunc = FunctionBuildList.AddFunction(c->Type(), code, FStringf("%s.StateFunction.%d", c->Type()->TypeName.GetChars(), statedef.GetStateCount()), true);
+							auto funcsym = CreateAnonymousFunction(c->Type(), nullptr, VARF_Method | VARF_Action);
+							state.ActionFunc = FunctionBuildList.AddFunction(funcsym, code, FStringf("%s.StateFunction.%d", c->Type()->TypeName.GetChars(), statedef.GetStateCount()), true);
 						}
 					}
 
@@ -2289,10 +2278,10 @@ FxExpression *ZCCCompiler::ConvertNode(ZCC_TreeNode *ast)
 	case AST_ExprFuncCall:
 	{
 		auto fcall = static_cast<ZCC_ExprFuncCall *>(ast);
-		//return ConvertFunctionCall(fcall);
 		assert(fcall->Function->NodeType == AST_ExprID);	// of course this cannot remain. Right now nothing more complex can come along but later this will have to be decomposed into 'self' and the actual function name.
 		auto fname = static_cast<ZCC_ExprID *>(fcall->Function)->Identifier;
 		return new FxFunctionCall(nullptr, fname, ConvertNodeList(fcall->Parameters), *ast);
+		//return ConvertFunctionCall(fcall->Function, ConvertNodeList(fcall->Parameters), ConvertClass, *ast);
 	}
 
 	case AST_FuncParm:

src/scripting/zscript/zcc_compile.h

@@ -143,6 +143,7 @@ private:
 	FArgumentList *ConvertNodeList(ZCC_TreeNode *head);
 
 	DObject *Outer;
+	PClass *ConvertClass;	// class type to be used when resoving symbold while converting an AST
 	PSymbolTable *GlobalTreeNodes;
 	PSymbolTable *OutputSymbols;
 	ZCC_AST *