lcpu: Cleanup, and begin the implementation of a new system for Lua binding

I didn't like how I did it before, and I don't like how right now everything binds a bit differently.

So let's unify it using the way I like (from the LuaDevice binding)!

lua/autorun/lcpu_load.lua

@@ -10,6 +10,22 @@ if SERVER then
 		return
 	end
 
+----[[
+	testobj = LCPUNative.CreateTest()
+	print(testobj:Test())
+	print(testobj.Variable)
+
+	testobj.MemberVariable = 32.9
+	print(testobj.MemberVariable)
+
+	testobj.Variable = 32.1 -- this should fial
+	testobj.Test = nil;
+
+	print(testobj.Variable)
+
+	print(testobj.Name)
+--]]
+
 	-- rapid iteration requires rapid solutions
 	--[[
 	device = LCPUNative.CreateDevice(0x100000f0, 0x10)

native/projects/lcpu/src/LcpuGlobals.cpp

@@ -1,10 +1,43 @@
 #include "LcpuGlobals.hpp"
 
 #include "GarrysMod/Lua/Interface.h"
+#include "GarrysMod/Lua/LuaBase.h"
 #include "LuaCpu.hpp"
 #include "LuaDevice.hpp"
 #include "LuaHelpers.hpp"
 
+/// test for the "new" lua object system
+struct TestLuaObject : public lcpu::lua::LuaObject<TestLuaObject> {
+	static const char* Name() { return "TestLuaObject"; }
+
+	static void RegisterClass(GarrysMod::Lua::ILuaBase* LUA) {
+		RegisterClassStart(LUA);
+			// Metamethods can be registered here; in this case, our test object doesn't need any
+		RegisterClassEnd(LUA);
+
+		// Register methods. Maybe later I'll do some crazy template stuff; for now this is pretty barebones.
+		RegisterMethod("Test", &Test);
+		RegisterGetter("Variable", [](GarrysMod::Lua::ILuaBase* LUA) { LUA->PushNumber(32.6); });
+		RegisterGetter("MemberVariable", [](GarrysMod::Lua::ILuaBase* LUA) {
+			auto self = TestLuaObject::FromLua(LUA, 1);
+			LUA->PushNumber(self->n);
+		});
+		RegisterSetter("MemberVariable", [](GarrysMod::Lua::ILuaBase* LUA) {
+			// 3 will be the assignment stack position
+			auto self = TestLuaObject::FromLua(LUA, 1);
+			self->n = LUA->GetNumber(3);
+		});
+	}
+
+	LUA_MEMBER_FUNCTION(Test)
+	double n;
+};
+
+LUA_MEMBER_FUNCTION_IMPLEMENT(TestLuaObject, Test) {
+	LUA->PushString("hi :)");
+	return 1;
+}
+
 LUA_FUNCTION(LCPUNative_CreateCPU) {
 	LUA->CheckType(1, GarrysMod::Lua::Type::Number);
 	auto memorySize = static_cast<u32>(LUA->GetNumber(1));
@@ -20,15 +53,23 @@ LUA_FUNCTION(LCPUNative_CreateCPU) {
 LUA_FUNCTION(LCPUNative_CreateDevice) {
 	auto base = LUA->CheckNumber(1);
 	auto size = LUA->CheckNumber(2);
-	lucore::LogInfo("Creating Lua device object mapped @ 0x{:08x} with size 0x{:08x}", static_cast<riscv::Address>(base), static_cast<riscv::Address>(size));
+	lucore::LogInfo("Creating Lua device object mapped @ 0x{:08x} with size 0x{:08x}", static_cast<riscv::Address>(base),
+					static_cast<riscv::Address>(size));
 	LuaDevice::Create(LUA, static_cast<riscv::Address>(base), static_cast<riscv::Address>(size));
 	return 1;
 }
 
+ LUA_FUNCTION(LCPUNative_CreateTest) {
+	TestLuaObject::Create(LUA);
+	return 1;
+}
+
 void GlobalsBind(GarrysMod::Lua::ILuaBase* LUA) {
 	LuaCpu::Bind(LUA);
 	LuaDevice::Bind(LUA);
 
+	TestLuaObject::RegisterClass(LUA);
+
 	// clang-format off
 	LUA->PushSpecial(GarrysMod::Lua::SPECIAL_GLOB);
 	LUA->CreateTable();
@@ -37,6 +78,8 @@ void GlobalsBind(GarrysMod::Lua::ILuaBase* LUA) {
 
 		LUA_SET_C_FUNCTION_NAME(LCPUNative_CreateCPU, "CreateCPU");
 		LUA_SET_C_FUNCTION_NAME(LCPUNative_CreateDevice, "CreateDevice");
+
+		LUA_SET_C_FUNCTION_NAME(LCPUNative_CreateTest, "CreateTest");
 	LUA->SetField(-2, "LCPUNative");
 	LUA->Pop();
 	// clang-format on

native/projects/lcpu/src/LuaDevice.cpp

@@ -9,6 +9,7 @@ bool LuaDevice::Clocked() const {
 }
 
 void LuaDevice::Clock() {
+	// clang-format off
 	LuaState->ReferencePush(tableReference);
 		LuaState->GetField(-1,"Clock");
 			if(LuaState->GetType(-1) == GarrysMod::Lua::Type::Function) { 
@@ -18,6 +19,7 @@ void LuaDevice::Clock() {
 				LuaState->Pop(); // pop the Clock function off the stack
 			}
 	LuaState->Pop(); // pop the reference
+	// clang-format off
 }
 
 riscv::Address LuaDevice::Base() const {
@@ -29,15 +31,7 @@ riscv::Address LuaDevice::Size() const {
 }
 
 u32 LuaDevice::Peek(riscv::Address address) {
-	/*if(peekHandlerReference != -1) {
+	// clang-format off
-		LuaState->ReferencePush(resetHandlerReference);
-		LuaState->PushNumber(static_cast<double>(address));
-		LuaState->Call(1, 1);
-		auto result = LuaState->GetNumber(-1);
-		LuaState->Pop();
-		return static_cast<u32>(result);
-	}*/
-
 	LuaState->ReferencePush(tableReference);
 		LuaState->GetField(-1,"Peek");
 			if(LuaState->GetType(-1) == GarrysMod::Lua::Type::Function) { 
@@ -52,17 +46,12 @@ u32 LuaDevice::Peek(riscv::Address address) {
 				LuaState->Pop(); // pop whatever Peek is off the stack
 			}
 	LuaState->Pop(); // pop the table reference
+	// clang-format on
 	return 0xffffffff;
 }
 
 void LuaDevice::Poke(riscv::Address address, u32 value) {
-	/*if(pokeHandlerReference != -1) {
+	// clang-format off
-		LuaState->ReferencePush(pokeHandlerReference);
-		LuaState->PushNumber(address);
-		LuaState->PushNumber(value);
-		LuaState->Call(2, 0);
-	}*/
-
 	LuaState->ReferencePush(tableReference);
 		LuaState->GetField(-1,"Poke");
 			if(LuaState->GetType(-1) == GarrysMod::Lua::Type::Function) { 
@@ -74,14 +63,11 @@ void LuaDevice::Poke(riscv::Address address, u32 value) {
 				LuaState->Pop(); // pop whatever Peek is
 			}
 	LuaState->Pop(); // pop the table reference
+	// clang-format on
 }
 
 void LuaDevice::Reset() {
-	/*if(resetHandlerReference != -1) {
+	// clang-format off
-		LuaState->ReferencePush(resetHandlerReference);
-		LuaState->Call(0, 0);
-	}*/
-
 	LuaState->ReferencePush(tableReference);
 		LuaState->GetField(-1,"Reset");
 		if(LuaState->GetType(-1) == GarrysMod::Lua::Type::Function) { 
@@ -91,6 +77,7 @@ void LuaDevice::Reset() {
 			LuaState->Pop(); // pop whatever reset is
 		}
 	LuaState->Pop(); // pop the reference
+	// clang-format on
 }
 
 LuaDevice::LuaDevice(riscv::Address base, riscv::Address size) : base(base), size(size) {
@@ -146,8 +133,6 @@ void LuaDevice::Bind(GarrysMod::Lua::ILuaBase* LUA) {
 		LUA_SET_C_FUNCTION(__newindex)
 	LUA_CLASS_BIND_END();
 	// clang-format on
-
-
 }
 
 void LuaDevice::Create(GarrysMod::Lua::ILuaBase* LUA, riscv::Address base, riscv::Address size) {

native/projects/lcpu/src/LuaHelpers.hpp

@@ -4,6 +4,9 @@
 #include <GarrysMod/Lua/Interface.h>
 
 #include <lucore/Logger.hpp>
+#include <unordered_map>
+
+#include "GarrysMod/Lua/LuaBase.h"
 
 // These are like the official GMOD header LUA_FUNCTION but allow forward declaration
 // and implementation inside of classes, making writing class bindings that much less
@@ -49,7 +52,6 @@
 		return 0;                                                                    \
 	}
 
-
 // Begin the Bind() method of a class. This just sets up boilerplate
 // and required things to setup a class.
 #define LUA_CLASS_BIND_BEGIN(T)                    \
@@ -75,6 +77,7 @@
 	LUA->PushCFunction(name);                  \
 	LUA->SetField(-2, altName);
 
+namespace lcpu::lua {
 
 	inline std::string GetLuaString(GarrysMod::Lua::ILuaBase* LUA, int stackPos) {
 		unsigned len {};
@@ -85,3 +88,176 @@ inline std::string GetLuaString(GarrysMod::Lua::ILuaBase* LUA, int stackPos) {
 			return {};
 		}
 	}
+
+	template <class TImpl>
+	struct LuaObject {
+		using CFunc = GarrysMod::Lua::CFunc;
+		using ILuaFunc = void (*)(GarrysMod::Lua::ILuaBase*);
+
+		/// Register a C++ method.
+		static void RegisterMethod(const std::string& name, CFunc func) { methods()[name] = func; }
+
+		/// Register a getter for a value to be read.
+		static void RegisterGetter(const std::string& name, ILuaFunc func) { getters()[name] = func; }
+
+		/// Register a setter. This can be used to make a
+		/// C++ registered value read-write.
+		static void RegisterSetter(const std::string& name, ILuaFunc func) { setters()[name] = func; }
+
+		// addl. arguments are forwarded to the C++ constructor
+		template <class... Args>
+		static void Create(GarrysMod::Lua::ILuaBase* LUA, Args&&... args) {
+			auto ptr = new TImpl(static_cast<Args&&>(args)...);
+			ptr->InitLuaStuff(LUA);
+			LUA->PushUserType(ptr, __lua_typeid);
+		}
+
+		static TImpl* FromLua(GarrysMod::Lua::ILuaBase* LUA, int stackPos) {
+			LUA->CheckType(stackPos, __lua_typeid);
+			return LUA->GetUserType<TImpl>(stackPos, __lua_typeid);
+		}
+
+	   protected:
+		/// This should be called first in your RegisterClass static method.
+		/// This doesn't pop the metatable off so you can keep adding things to it
+		static void RegisterClassStart(GarrysMod::Lua::ILuaBase* LUA) {
+			auto typeid_name = std::format("{}__typeid", TImpl::Name());
+
+			// clang-format off
+			__lua_typeid = LUA->CreateMetaTable(TImpl::Name());
+				LUA->PushSpecial(GarrysMod::Lua::SPECIAL_REG);
+					LUA->PushNumber(__lua_typeid);
+					LUA->SetField(-2, typeid_name.c_str());
+				LUA->Pop(); /* pop registry */
+				LUA_SET_C_FUNCTION(__gc)
+				LUA_SET_C_FUNCTION(__index)
+				LUA_SET_C_FUNCTION(__newindex)
+			// clang-format on
+		}
+
+		/// Call in your RegisterClass() method when done registering metamethods.
+		static void RegisterClassEnd(GarrysMod::Lua::ILuaBase* LUA) { LUA->Pop(); }
+
+		/// A detail function used to setup some stuff in the Create() method.
+		void InitLuaStuff(GarrysMod::Lua::ILuaBase* LUA) {
+			lua = LUA;
+
+			// create the table used to store user properties
+			// from Lua
+			LUA->CreateTable();
+			tableReference = LUA->ReferenceCreate();
+
+			// register some convinence things
+			RegisterGetter("Name", [](GarrysMod::Lua::ILuaBase* LUA) { LUA->PushString(TImpl::Name()); });
+		}
+
+		LuaObject() = default;
+		~LuaObject() {
+			// free the table reference
+			if(tableReference != -1)
+				lua->ReferenceFree(tableReference);
+		}
+
+	   private:
+		// base metamethods
+		LUA_MEMBER_FUNCTION(__gc)
+		LUA_MEMBER_FUNCTION(__index)
+		LUA_MEMBER_FUNCTION(__newindex)
+
+		// static stuff
+		static int __lua_typeid;
+
+		static auto& methods() {
+			static std::unordered_map<std::string, GarrysMod::Lua::CFunc> methods__;
+			return methods__;
+		}
+
+		static auto& getters() {
+			static std::unordered_map<std::string, ILuaFunc> getters__;
+			return getters__;
+		}
+
+		static auto& setters() {
+			static std::unordered_map<std::string, ILuaFunc> setters__;
+			return setters__;
+		}
+
+		// instance stuff
+		int tableReference { -1 };
+		GarrysMod::Lua::ILuaBase* lua;
+	};
+
+	template <class TImpl>
+	int LuaObject<TImpl>::__lua_typeid = 0;
+
+	template <class TImpl>
+	LUA_MEMBER_FUNCTION_IMPLEMENT(LuaObject<TImpl>, __gc) {
+		auto self = FromLua(LUA, 1);
+		if(self != nullptr) {
+			lucore::LogInfo("GCing LuaObject-based object @ {:p}", static_cast<void*>(self));
+			delete self;
+		}
+		return 0;
+	}
+
+	template <class TImpl>
+	LUA_MEMBER_FUNCTION_IMPLEMENT(LuaObject<TImpl>, __index) {
+		auto self = FromLua(LUA, 1);
+
+		if(LUA->GetType(2) == GarrysMod::Lua::Type::String) {
+			auto key = GetLuaString(LUA, 2);
+
+			if(methods().find(key) != methods().end()) {
+				LUA->PushCFunction(methods()[key]);
+				return 1;
+			}
+
+			if(getters().find(key) != getters().end()) {
+				// getters explicitly push their return onto the stack
+				getters()[key](LUA);
+				return 1;
+			}
+		}
+
+		// look up from the table
+		// clang-format off
+		LUA->ReferencePush(self->tableReference);
+			LUA->Push(2);
+		LUA->GetTable(-2);
+		// clang-format on
+		return 1;
+	}
+
+	template <class TImpl>
+	LUA_MEMBER_FUNCTION_IMPLEMENT(LuaObject<TImpl>, __newindex) {
+		auto self = FromLua(LUA, 1);
+
+		if(LUA->GetType(2) == GarrysMod::Lua::Type::String) {
+			auto key = GetLuaString(LUA, 2);
+
+			if(methods().find(key) != methods().end()) {
+				return 0;
+			}
+
+			if(getters().find(key) != getters().end() && setters().find(key) == setters().end()) {
+				return 0;
+			}
+
+			if(setters().find(key) != setters().end()) {
+				setters()[key](LUA);
+				return 0;
+			}
+		}
+
+		// push onto the table
+		// clang-format off
+		LUA->ReferencePush(self->tableReference);
+			LUA->Push(2);
+			LUA->Push(3);
+			LUA->SetTable(-3);
+		LUA->Pop();
+		// clang-format on
+		return 0;
+	}
+
+} // namespace lcpu::lua