implement a basic logger as a part of lucore

I could have implemented a spdlog sink, however spdlog isn't setup for standard format header being a thing yet.

This also introduces a temporary executable target for my own testing of lucore utilities.

native/CMakeLists.txt

@@ -4,6 +4,7 @@ project(lcpu-native
 )
 
 add_subdirectory(projects/lucore)
+add_subdirectory(projects/lucore_test)
 
 # RISC-V emulation library
 add_subdirectory(projects/riscv)

native/projects/lucore/CMakeLists.txt

@@ -7,6 +7,7 @@ project(lucore
 
 add_library(lucore
 	src/Assert.cpp
+	src/Logger.cpp
 )
 
 target_compile_features(lucore PUBLIC cxx_std_20)

native/projects/lucore/include/lucore/Assert.hpp

@@ -2,34 +2,30 @@
 
 #pragma once
 
-#include <cstdio>
+#include <format>
 
 namespace lucore {
 
 	// TODO: wrapper which uses source_location (we don't need no macros anymore!)
 	[[noreturn]] void ExitMsg(const char* fileName, int fileLine, const char* message);
 
-}
+} // namespace lucore
 
 #ifndef NDEBUG
-	#define LUCORE_ASSERT(expr, format, ...)                                                    \
+	#define LUCORE_ASSERT(expr, fmt, ...)                                             \
 		if(!(expr)) [[unlikely]] {                                                    \
-			char buffer[256];                                                                   \
-			std::snprintf(&buffer[0], sizeof(buffer),                                           \
-						  "[Lucore] Assertion \"%s\" failed with message: " format "\n", #expr, \
-						  ##__VA_ARGS__);                                                       \
-			::lucore::ExitMsg(__FILE__, __LINE__, &buffer[0]);                                  \
+			auto msg = std::format("Assertion \"{}\" failed with message: {}", #expr, \
+								   std::format(fmt, ##__VA_ARGS__));                  \
+			::lucore::ExitMsg(__FILE__, __LINE__, msg.c_str());                       \
 		}
 #else
 	#define LUCORE_ASSERT(expr, format, ...)
 #endif
 
 // CHECK() is always active, even in release builds
-#define LUCORE_CHECK(expr, format, ...)                                                 \
+#define LUCORE_CHECK(expr, fmt, ...)                                          \
 	if(!(expr)) [[unlikely]] {                                                \
-		char buffer[256];                                                               \
-		std::snprintf(&buffer[0], sizeof(buffer),                                       \
-					  "[Lucore] Check \"%s\" failed with message: " format "\n", #expr, \
-					  ##__VA_ARGS__);                                                   \
-		::lucore::ExitMsg(__FILE__, __LINE__, &buffer[0]);                              \
+		auto msg = std::format("Check \"{}\" failed with message: {}", #expr, \
+							   std::format(fmt, ##__VA_ARGS__));              \
+		::lucore::ExitMsg(__FILE__, __LINE__, msg.c_str());                   \
 	}

native/projects/lucore/include/lucore/Logger.hpp

@@ -0,0 +1,96 @@
+//! Logging utilities for Lucore
+//! Using Standard C++ <format>
+
+#include <format>
+#include <cstdint>
+
+namespace lucore {
+
+	/// The Lucore logger.
+	struct Logger {
+		enum class MessageSeverity {
+			Debug,
+			Info,
+			Warning,
+			Error,
+			Fatal
+		};
+
+		static constexpr std::string_view SeverityToString(MessageSeverity sev) {
+			const char* table[] = {
+				"Deb",
+				"Inf",
+				"Wrn",
+				"Err",
+				"Ftl"
+			};
+			return table[static_cast<std::size_t>(sev)];
+		}
+
+		/// A sink.
+		struct Sink {
+			virtual void OutputMessage(MessageSeverity severity, std::string_view format, std::format_args args) = 0;
+		};
+
+
+		static Logger& The();
+
+		Logger() = default;
+		Logger(const Logger&) = delete;
+		Logger(Logger&&) = delete;
+
+		void AttachSink(Sink& sink);
+
+		MessageSeverity GetLogLevel() const {
+			return logLevel;
+		}
+
+		void SetLogLevel(MessageSeverity newLogLevel) {
+			logLevel = newLogLevel;
+		}
+
+		template<class... Args>
+		inline void Debug(std::string_view fmt, Args... args) {
+			VOut(MessageSeverity::Debug, fmt, std::make_format_args(std::forward<Args>(args)...));
+		}
+
+		template<class... Args>
+		inline void Info(std::string_view fmt, Args... args) {
+			VOut(MessageSeverity::Info, fmt, std::make_format_args(std::forward<Args>(args)...));
+		}
+		
+		template<class... Args>
+		inline void Warning(std::string_view fmt, Args... args) {
+			VOut(MessageSeverity::Warning, fmt, std::make_format_args(std::forward<Args>(args)...));
+		}
+
+		template<class... Args>
+		inline void Error(std::string_view fmt, Args... args) {
+			VOut(MessageSeverity::Error, fmt, std::make_format_args(std::forward<Args>(args)...));
+		}
+
+		template<class... Args>
+		inline void Fatal(std::string_view fmt, Args... args) {
+			VOut(MessageSeverity::Fatal, fmt, std::make_format_args(std::forward<Args>(args)...));
+		}
+
+	private:
+		void VOut(MessageSeverity severity, std::string_view format, std::format_args args);
+
+		MessageSeverity logLevel{MessageSeverity::Info};
+
+		Sink* sinks[4];
+		std::uint8_t sinkCount;
+	};
+
+	/// A logger sink implementation that prints to standard output.
+	struct StdoutSink : public Logger::Sink {
+		static StdoutSink& The();
+
+		virtual void OutputMessage(Logger::MessageSeverity severity, std::string_view format, std::format_args args) override;
+	};
+
+	/// Attach stdout to the logger.
+	void LoggerAttachStdout();
+
+}

native/projects/lucore/include/lucore/OptionalRef.hpp

@@ -9,9 +9,6 @@ namespace lucore::detail {
 	/// Sentinel value to explicitly not populate an OptionalRef.
 	inline static Nullref_t NullRef {};
 
-	template <class T>
-	struct OptionalRef; // sfinae on non-reference types
-
 	/// Like std::optional<T>, but optimized specifically for references to objects.
 	///
 	/// Additionally, as a bonus, since the repressentation is so simple, this is
@@ -21,7 +18,7 @@ namespace lucore::detail {
 	/// Treat this class like [std::reference_wrapper].
 	/// Do *not* give this class invalid references.
 	template <class T>
-	struct OptionalRef<T&> {
+	struct OptionalRef {
 		constexpr OptionalRef() : ptr(nullptr) {
 		}
 
@@ -34,7 +31,7 @@ namespace lucore::detail {
 
 		// polymorphic downconstruction from another OptionalRef<U>
 		template <class U>
-		constexpr OptionalRef(const OptionalRef<U&>& other) : ptr(&other.ptr) {
+		constexpr OptionalRef(const OptionalRef<U>& other) : ptr(&other.ptr) {
 		}
 
 		constexpr T& Value() const {

native/projects/lucore/src/Assert.cpp

@@ -2,13 +2,12 @@
 
 #include <cstdio>
 #include <cstdlib>
+#include <lucore/Logger.hpp>
 
 namespace lucore {
 
 	[[noreturn]] void ExitMsg(const char* fileName, int fileLine, const char* message) {
-		// TODO: move this to logger functionality of lucore (the native module will end up
-		// containing a Sink implementation that funnels to either gmod or tier libs..)
-		std::puts(message);
+		Logger::The().Fatal("{}", message);
 		std::quick_exit(0xAF);
 	}
 

native/projects/lucore/src/Logger.cpp

@@ -0,0 +1,38 @@
+#include <format>
+#include <lucore/Logger.hpp>
+
+
+namespace lucore {
+
+	Logger& Logger::The() {
+		static Logger logger;
+		return logger;
+	}
+
+	void Logger::AttachSink(Sink& sink) {
+		sinks[sinkCount++] = &sink;
+	}
+
+	void Logger::VOut(MessageSeverity severity, std::string_view format, std::format_args args) {
+		if(severity < logLevel)
+			return;
+
+		for(int i = 0; i < sinkCount; ++i)
+			sinks[i]->OutputMessage(severity, format, args);
+	}
+
+	StdoutSink& StdoutSink::The() {
+		static StdoutSink sink;
+		return sink;
+	}
+
+	void StdoutSink::OutputMessage(Logger::MessageSeverity severity, std::string_view format, std::format_args args) {
+		auto message = std::vformat(format, args);
+		std::printf("[Lucore Stdout/%s] %s\n", Logger::SeverityToString(severity).data(), message.c_str());
+	}
+
+	void LoggerAttachStdout() {
+		Logger::The().AttachSink(StdoutSink::The());
+	}
+
+}

native/projects/lucore_test/CMakeLists.txt

@@ -0,0 +1,8 @@
+# this is a temporary project to test lucore functionality while it's in development
+
+add_executable(lucore_test
+	main.cpp
+)
+
+target_link_libraries(lucore_test PUBLIC
+	lucore::lucore)

native/projects/lucore_test/main.cpp

@@ -0,0 +1,28 @@
+#include <format>
+#include <lucore/Assert.hpp>
+#include <lucore/Logger.hpp>
+
+/// Sample implementation of lucore logger sink.
+struct MySink : public lucore::Logger::Sink {
+	void OutputMessage(lucore::Logger::MessageSeverity sev, std::string_view fmt, std::format_args args) override {
+		std::printf("[My Sink] [%s] %s\n", lucore::Logger::SeverityToString(sev).data(), std::vformat(fmt, args).c_str());
+	}
+
+	static MySink& The() {
+		static MySink sink;
+		return sink;
+	}
+};
+
+int main() {
+	lucore::LoggerAttachStdout();
+	auto& logger = lucore::Logger::The();
+
+	logger.AttachSink(MySink::The()); // attach our sink
+
+	logger.Info("Hello World {}", 123.456);
+	logger.Warning("sample warning");
+	logger.Error("Smaple Error");
+
+	LUCORE_CHECK(false, "should appear");
+}

native/projects/riscv/include/riscv/Bus.hpp

@@ -21,8 +21,6 @@ namespace riscv {
 			// Used to allow bus devices to know when they are attached to a memory bus,
 			// and ultimately, an instance of a System
 			virtual void Attached(Bus* memoryBus, AddressT baseAddress) = 0;
-			virtual AddressT BaseAddress() const = 0; // TODO(cleanup): Make this non-virtual?
-
 
 			/// Is this device clocked?
 			virtual bool Clocked() const { return false; }
@@ -35,6 +33,9 @@ namespace riscv {
 			// from devices. This needs to be implemented to facilitate the
 			// implementation of the timer device as an actual Device implmentation
 			// instead of poorly hard-coding it into the CPU core logic.
+			//
+			// Also, default implementations of Peek* and Poke* should trap.
+
 
 			// Peek() -> reads a value from this device.
 			virtual u8 PeekByte(AddressT offset) = 0;
@@ -75,11 +76,11 @@ namespace riscv {
 		void PokeWord(AddressT address, u32 value);
 	private:
 
-		lucore::OptionalRef<Device&> FindDeviceForAddress(AddressT address) const;
+		lucore::OptionalRef<Device> FindDeviceForAddress(AddressT address) const;
 
 		CPU* attachedCpu{};
 
-		// TODO: if this ends up being a hotpath replace with robinhood unordered map
+		// TODO: if this ends up being a hotpath replace with ankerl::unordered_dense
 		std::unordered_map<AddressT, Device*> mapped_devices;
 	};
 

native/projects/riscv/src/Bus.cpp

@@ -33,41 +33,41 @@ namespace riscv {
 
 	u8 Bus::PeekByte(AddressT address) {
 		if(auto opt = FindDeviceForAddress(address); opt)
-			return opt->PeekByte(address - opt->BaseAddress());
+			return opt->PeekByte(address);
 		return -1;
 	}
 
 	u16 Bus::PeekShort(AddressT address) {
 		if(auto opt = FindDeviceForAddress(address); opt)
-			return opt->PeekShort(address - opt->BaseAddress());
+			return opt->PeekShort(address);
 		return -1;
 	}
 
 	u32 Bus::PeekWord(AddressT address) {
 		if(auto opt = FindDeviceForAddress(address); opt)
-			return opt->PeekWord(address - opt->BaseAddress());
+			return opt->PeekWord(address);
 		return -1;
 	}
 
 	void Bus::PokeByte(AddressT address, u8 value) {
 		if(auto opt = FindDeviceForAddress(address); opt)
-			return opt->PokeByte(address - opt->BaseAddress(), value);
+			return opt->PokeByte(address, value);
 	}
 
 	void Bus::PokeShort(AddressT address, u16 value) {
 		if(auto opt = FindDeviceForAddress(address); opt)
-			return opt->PokeShort(address - opt->BaseAddress(), value);
+			return opt->PokeShort(address, value);
 	}
 
 	void Bus::PokeWord(AddressT address, u32 value) {
 		if(auto opt = FindDeviceForAddress(address); opt)
-			return opt->PokeWord(address - opt->BaseAddress(), value);
+			return opt->PokeWord(address, value);
 	}
 
-	lucore::OptionalRef<Bus::Device&> Bus::FindDeviceForAddress(AddressT address) const {
+	lucore::OptionalRef<Bus::Device> Bus::FindDeviceForAddress(AddressT address) const {
 		auto it = std::find_if(mapped_devices.begin(), mapped_devices.end(), [&](const auto& pair) {
 			return
-			// We can shorcut the region checking if the requested addess matches base address.
+			// We can shorcut region checking if the requested addess matches base address.
 			pair.first == address ||
 			// If it doesn't we really can't, though.
 			(address >= pair.first && address < pair.first + pair.second->Size());

native/projects/riscv/src/MemoryDevice.cpp

@@ -1,7 +1,4 @@
 #include <riscv/Bus.hpp>
-#include <span>
-
-#include "riscv/Types.hpp"
 
 namespace riscv {
 
@@ -9,7 +6,7 @@ namespace riscv {
 
 		template <bool Rom>
 		struct BasicMemoryDevice : public Bus::Device {
-			BasicMemoryDevice(usize size) : memorySize(size) {
+			BasicMemoryDevice(usize size) : Bus::Device(), memorySize(size) {
 				memory = new u8[size];
 				LUCORE_CHECK(memory, "Could not allocate buffer for memory device.");
 			}
@@ -19,6 +16,10 @@ namespace riscv {
 					delete[] memory;
 			}
 
+			AddressT Size() const override {
+				return memorySize;
+			}
+
 			// Implementation of Device interface
 
 			void Attached(Bus* bus, AddressT base) override {
@@ -26,51 +27,41 @@ namespace riscv {
 				baseAddress = base;
 			}
 
-			AddressT BaseAddress() const override {
-				return baseAddress;
+			u8 PeekByte(AddressT address) override {
+				return memory[AddressToIndex<u8>(address)];
 			}
 
-			u8 PeekByte(AddressT offset) override {
-				return memory[offset % memorySize];
+			u16 PeekShort(AddressT address) override {
+				return std::bit_cast<u16*>(memory)[AddressToIndex<u16>(address)];
 			}
 
-			u16 PeekShort(AddressT offset) override {
-				return std::bit_cast<u16*>(memory)[OffsetToIndex<u16>(offset)];
+			u32 PeekWord(AddressT address) override {
+				return std::bit_cast<u32*>(memory)[AddressToIndex<u32>(address)];
 			}
 
-			u32 PeekWord(AddressT offset) override {
-				return std::bit_cast<u32*>(memory)[OffsetToIndex<u32>(offset)];
-			}
-
-			void PokeByte(AddressT offset, u8 value) override {
+			void PokeByte(AddressT address, u8 value) override {
 				if constexpr(!Rom) {
-					memory[offset % memorySize] = value;
-				} else {
-					// TODO: trap here
+					memory[AddressToIndex<u8>(address)] = value;
 				}
 			}
 
-			void PokeShort(AddressT offset, u16 value) override {
+			void PokeShort(AddressT address, u16 value) override {
 				if constexpr(!Rom) {
-					std::bit_cast<u16*>(memory)[OffsetToIndex<u16>(offset)] = value;
-				} else {
-					// TODO: trap here
+					std::bit_cast<u16*>(memory)[AddressToIndex<u16>(address)] = value;
 				}
 			}
 
-			void PokeWord(AddressT offset, u32 value) override {
+			void PokeWord(AddressT address, u32 value) override {
 				if constexpr(!Rom) {
-					std::bit_cast<u32*>(memory)[OffsetToIndex<u32>(offset)] = value;
-				} else {
-					// TODO: trap here
+					std::bit_cast<u32*>(memory)[AddressToIndex<u32>(address)] = value;
 				}
 			}
 
 		   private:
 			/// helper used for implementing stuff
 			template <class T>
-			constexpr usize OffsetToIndex(AddressT offset) {
-				return (offset % memorySize) / sizeof(T);
+			constexpr usize AddressToIndex(AddressT address) {
+				return ((address - baseAddress) % memorySize) / sizeof(T);
 			}
 
 			// remember what we were attached to via "signal"
@@ -86,6 +77,8 @@ namespace riscv {
 
 	} // namespace
 
-	// Bus::Device* NewRam()
+	Bus::Device* NewRam(usize size) {
+		return new RamDevice(size);
+	}
 
 } // namespace riscv