Changeset: 49 Convert codegen output to use template specialization

6 files changed, 157 insertions, 60 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 19518bf..0e8dc26 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -15,10 +15,10 @@ add_subdirectory(3rdparty/tracy)
 
 # ==============================================================================
 
-file(GLOB_RECURSE commonthings_SOURCES source-common/*.c source-common/*.cpp)
-add_library(commonthings OBJECT ${commonthings_SOURCES})
+file(GLOB_RECURSE things_common_SOURCES source-common/*.c source-common/*.cpp)
+add_library(things_common OBJECT ${things_common_SOURCES})
 
-set_target_properties(commonthings PROPERTIES
+set_target_properties(things_common PROPERTIES
 	CXX_STANDARD 20
 	CXX_STANDARD_REQUIRED ON
 	CXX_EXTENSIONS OFF
@@ -27,8 +27,8 @@ set_target_properties(commonthings PROPERTIES
 	UNITY_BUILD OFF
 )
 
-target_include_directories(commonthings PUBLIC source-common)
-target_link_libraries(commonthings PUBLIC
+target_include_directories(things_common PUBLIC source-common)
+target_link_libraries(things_common PUBLIC
 	# External dependencies
 	${CONAN_LIBS}
 	glm::glm
@@ -37,25 +37,45 @@ target_link_libraries(commonthings PUBLIC
 # ==============================================================================
 
 # NOTE: delibrately not recursive, see README.md in the folder for details
-file(GLOB meta_codegen_SOURCES buildtools/codegen/*.c buildtools/codegen/*.cpp)
-add_executable(meta_codegen ${meta_codegen_SOURCES})
+file(GLOB codegen_SOURCES buildtools/codegen/*.c buildtools/codegen/*.cpp)
+add_executable(codegen ${codegen_SOURCES})
 
-set_target_properties(meta_codegen PROPERTIES	
+set_target_properties(codegen PROPERTIES	
 	CXX_STANDARD 20
 	CXX_STANDARD_REQUIRED ON
 	CXX_EXTENSIONS OFF
 	UNITY_BUILD OFF
 )
 
-target_link_libraries(meta_codegen PRIVATE
+target_link_libraries(codegen PRIVATE
 	# External dependencies
 	${CONAN_LIBS}
 
 	# Project internal components
-	commonthings
+	things_common
 )
 
-target_flag_rtti(meta_codegen OFF)
+target_flag_rtti(codegen OFF)
+
+# ==============================================================================
+
+file(GLOB_RECURSE things_codegen_base_SOURCES source-common/*.c source-common/*.cpp)
+add_library(things_codegen_base OBJECT ${things_codegen_base_SOURCES})
+
+set_target_properties(things_common PROPERTIES
+	CXX_STANDARD 20
+	CXX_STANDARD_REQUIRED ON
+	CXX_EXTENSIONS OFF
+)
+
+target_include_directories(things_codegen_base PUBLIC source-codegen-base)
+target_link_libraries(things_codegen_base PUBLIC
+	# External dependencies
+	${CONAN_LIBS}
+
+	# Project internal components
+	things_common
+)
 
 # ==============================================================================
 
@@ -95,7 +115,8 @@ target_link_libraries(${PROJECT_NAME} PRIVATE
 	tracy
 
 	# Project internal components
-	commonthings
+	things_common
+	things_metadata
 )
 
 option(BRUSSEL_ENABLE_PROFILING "Whether profiling support is enabled or not." OFF)
diff --git a/README.md b/README.md
index dc0b4c1..5caf9f7 100644
--- a/README.md
+++ b/README.md
@@ -5,3 +5,12 @@
 + [Urho3D](https://urho3d.io/)
 + [godot](https://godotengine.org/)
 + Everything else in `3rdparty/`
+
+## Project Structure
+- `buildtools`
+    - `cmake`: CMake scripts consumed by the root `CMakeLists.txt`.
+    - `codegen`: Code generator similar to Qt MOC.
+    Currently runs on: `source`.
+- `source-common`: Code that's compiled as a part of all targets. Check each target's build script for details.
+- `source-codegen-base`: Code that's consumed along with output of `buildtools/codegen`.
+- `source`: The main game.
diff --git a/buildtools/codegen/CodegenOutput.inl b/buildtools/codegen/CodegenOutput.inl
index d1f2e50..edd9abc 100644
--- a/buildtools/codegen/CodegenOutput.inl
+++ b/buildtools/codegen/CodegenOutput.inl
@@ -38,9 +38,8 @@ public:
 		std::move(other.mOutFunctions.begin(), other.mOutFunctions.end(), std::back_inserter(this->mOutFunctions));
 	}
 
-	void Write(FILE* file) {
+	void Write(FILE* file) const {
 		for (auto& thing : mOutThings) {
-			WRITE_LIT(file, "// Output thing\n");
 			fwrite(thing.text.c_str(), sizeof(char), thing.text.size(), file);
 			WRITE_LIT(file, "\n");
 		}
diff --git a/buildtools/codegen/main.cpp b/buildtools/codegen/main.cpp
index df52b66..e759c31 100644
--- a/buildtools/codegen/main.cpp
+++ b/buildtools/codegen/main.cpp
@@ -273,7 +273,7 @@ std::string GenerateEnumStringMap(CodegenOutput& out, const DeclEnum& decl, bool
 	return mapName;
 }
 
-void GenerateForEnum(CodegenOutput& out, const DeclEnum& decl, EnumFlags<EnumMetaGenOptions> options) {
+void GenerateForEnum(CodegenOutput& headerOut, CodegenOutput& sourceOut, const DeclEnum& decl, EnumFlags<EnumMetaGenOptions> options) {
 	bool useExcludeHeuristics = options.IsSet(EMGO_ExcludeUseHeuristics);
 
 	if (options.IsSet(EMGO_ToString)) {
@@ -281,7 +281,7 @@ void GenerateForEnum(CodegenOutput& out, const DeclEnum& decl, EnumFlags<EnumMet
 
 		switch (decl.GetPattern()) {
 			case EVP_Continuous: {
-				auto arrayName = GenerateEnumStringArray(out, decl, useExcludeHeuristics);
+				auto arrayName = GenerateEnumStringArray(sourceOut, decl, useExcludeHeuristics);
 				int minVal = decl.elements.front().value;
 				int maxVal = decl.elements.back().value;
 				if (useExcludeHeuristics &&
@@ -292,23 +292,30 @@ void GenerateForEnum(CodegenOutput& out, const DeclEnum& decl, EnumFlags<EnumMet
 					maxVal = decl.elements[decl.elements.size() - 2].value;
 				}
 
-				CodegenOutputThing lookupFunction;
-				auto& o = lookupFunction.text;
-				APPEND_FMT_LN(o, "std::string_view EnumToString_%s(%s value) {", decl.name.c_str(), decl.name.c_str());
-				APPEND_FMT_LN(o, "    if (value < 0 || value >= %d) return {};", maxVal);
-				APPEND_FMT_LN(o, "    return %s[value - %d];", arrayName.c_str(), minVal);
-				APPEND_LIT_LN(o, "}");
+				CodegenOutputThing lookupFunctionDecl;
+				auto& o1 = lookupFunctionDecl.text;
+				APPEND_LIT_LN(o1, "template <>");
+				APPEND_FMT_LN(o1, "std::string_view Metadata::EnumToString<%s>(%s);", decl.name.c_str(), decl.name.c_str());
 
-				out.AddOutputThing(std::move(lookupFunction));
+				CodegenOutputThing lookupFunctionDef;
+				auto& o2 = lookupFunctionDef.text;
+				APPEND_LIT_LN(o2, "template <>");
+				APPEND_FMT_LN(o2, "std::string_view Metadata::EnumToString<%s>(%s value) {", decl.name.c_str(), decl.name.c_str());
+				APPEND_FMT_LN(o2, "    if (value < 0 || value >= %d) return {};", maxVal);
+				APPEND_FMT_LN(o2, "    return %s[value - %d];", arrayName.c_str(), minVal);
+				APPEND_LIT_LN(o2, "}");
+
+				headerOut.AddOutputThing(std::move(lookupFunctionDecl));
+				sourceOut.AddOutputThing(std::move(lookupFunctionDef));
 			} break;
 
 			case EVP_Bits: {
-				auto arrayName = GenerateEnumStringArray(out, decl, useExcludeHeuristics);
+				auto arrayName = GenerateEnumStringArray(sourceOut, decl, useExcludeHeuristics);
 				// TODO
 			} break;
 
 			case EVP_Random: {
-				auto mapName = GenerateEnumStringMap(out, decl, useExcludeHeuristics);
+				auto mapName = GenerateEnumStringMap(sourceOut, decl, useExcludeHeuristics);
 				// TODO
 			} break;
 
@@ -330,19 +337,26 @@ void GenerateForEnum(CodegenOutput& out, const DeclEnum& decl, EnumFlags<EnumMet
 		APPEND_LIT_LN(o1, "};");
 
 		// Generate lookup function
-		CodegenOutputThing lookupFunction;
-		auto& o2 = lookupFunction.text;
-		APPEND_FMT_LN(o2, "std::optional<%s> EnumFromString_%s(std::string_view value) {", decl.name.c_str(), decl.name.c_str());
-		APPEND_FMT_LN(o2, "    auto iter = %s.find(value);", mapName);
-		APPEND_FMT_LN(o2, "    if (iter != %s.end()) {", mapName);
-		APPEND_LIT_LN(o2, "        return iter->second;");
-		APPEND_LIT_LN(o2, "    } else {");
-		APPEND_LIT_LN(o2, "        return {};");
-		APPEND_LIT_LN(o2, "    }");
-		APPEND_LIT_LN(o2, "}");
+		CodegenOutputThing lookupFunctionDecl;
+		auto& o2 = lookupFunctionDecl.text;
+		APPEND_LIT_LN(o2, "template <>");
+		APPEND_FMT_LN(o2, "std::optional<%s> Metadata::EnumFromString<%s>(std::string_view);", decl.name.c_str(), decl.name.c_str());
+
+		CodegenOutputThing lookupFunctionDef;
+		auto& o3 = lookupFunctionDef.text;
+		APPEND_LIT_LN(o3, "template <>");
+		APPEND_FMT_LN(o3, "std::optional<%s> Metadata::EnumFromString<%s>(std::string_view value) {", decl.name.c_str(), decl.name.c_str());
+		APPEND_FMT_LN(o3, "    auto iter = %s.find(value);", mapName);
+		APPEND_FMT_LN(o3, "    if (iter != %s.end()) {", mapName);
+		APPEND_LIT_LN(o3, "        return iter->second;");
+		APPEND_LIT_LN(o3, "    } else {");
+		APPEND_LIT_LN(o3, "        return {};");
+		APPEND_LIT_LN(o3, "    }");
+		APPEND_LIT_LN(o3, "}");
 
-		out.AddOutputThing(std::move(lookupTable));
-		out.AddOutputThing(std::move(lookupFunction));
+		sourceOut.AddOutputThing(std::move(lookupTable));
+		headerOut.AddOutputThing(std::move(lookupFunctionDecl));
+		sourceOut.AddOutputThing(std::move(lookupFunctionDef));
 	}
 }
 
@@ -358,8 +372,9 @@ void HandleInputFile(AppState& state, std::string_view source) {
 	printf("END tokens\n");
 #endif
 
-	CodegenInput fileInput;
-	CodegenOutput fileOutput;
+	CodegenInput cgInput;
+	auto& cgHeaderOutput = state.headerOutput;
+	auto& cgSourceOutput = state.sourceOutput;
 
 	int bracePairDepth = 0;
 	while (idx < tokens.size()) {
@@ -444,7 +459,7 @@ void HandleInputFile(AppState& state, std::string_view source) {
 							++idx;
 						}
 
-						fileInput.AddEnum(std::move(enumDecl));
+						cgInput.AddEnum(std::move(enumDecl));
 						goto endIdenCase;
 					}
 
@@ -480,7 +495,7 @@ void HandleInputFile(AppState& state, std::string_view source) {
 						}
 
 						auto& enumName = argList[0][0]->text;
-						auto enumDecl = fileInput.FindEnumByName(enumName);
+						auto enumDecl = cgInput.FindEnumByName(enumName);
 						if (!enumDecl) {
 							printf("[ERROR] BRUSSEL_ENUM: referring to non-existent enum '%s'\n", enumName.c_str());
 							break;
@@ -497,7 +512,7 @@ void HandleInputFile(AppState& state, std::string_view source) {
 							}
 						}
 
-						GenerateForEnum(fileOutput, *enumDecl, options);
+						GenerateForEnum(cgHeaderOutput, cgSourceOutput, *enumDecl, options);
 
 						idx = newIdx;
 						incrementTokenIdx = false;
@@ -530,8 +545,6 @@ void HandleInputFile(AppState& state, std::string_view source) {
 	if (bracePairDepth != 0) {
 		printf("[WARNING] unbalanced brace at end of file.");
 	}
-
-	state.sourceOutput.MergeContents(std::move(fileOutput));
 }
 
 std::string ReadFileAtOnce(const fs::path& path) {
@@ -596,6 +609,23 @@ InputOpcode ParseInputOpcode(std::string_view text) {
 	return IOP_COUNT;
 }
 
+bool WriteOutputFile(const CodegenOutput& output, const char* dirPath, const char* fileName) {
+	char path[2048];
+	snprintf(path, sizeof(path), "%s/%s", dirPath, fileName);
+
+	auto outputFile = Utils::OpenCstdioFile(path, Utils::WriteTruncate);
+	if (!outputFile) {
+		printf("[ERROR] unable to open output file %s", path);
+		return false;
+	}
+	DEFER { fclose(outputFile); };
+
+	DEBUG_PRINTF("Writing output %s", path);
+	output.Write(outputFile);
+
+	return true;
+}
+
 int main(int argc, char* argv[]) {
 	STR_LUT_INIT(ClexNames);
 	BSTR_LUT_INIT(CppKeyword);
@@ -609,14 +639,22 @@ int main(int argc, char* argv[]) {
 
 	AppState state;
 
+	state.headerOutput.AddOutputThing(CodegenOutputThing{
+		.text = &R"""(
+// This file is generated. Any changes will be overidden when building.
+#pragma once
+
+#include <MetadataBase.hpp>
+)"""[1],
+	});
+
 	state.sourceOutput.AddOutputThing(CodegenOutputThing{
 		.text = &R"""(
 // This file is generated. Any changes will be overidden when building.
+#include "MetadataImpl.hpp"
 
 #include <frozen/string.h>
 #include <frozen/unordered_map.h>
-#include <optional>
-#include <string_view>
 using namespace std::literals;
 		)"""[1],
 	});
@@ -627,7 +665,7 @@ using namespace std::literals;
 		// NOTE: keep in sync with various enum options and parser code
 		printf(&R"""(
 USAGE: codegen.exe <output path> [<opcode>:<input path>]...
-where   <output path>: the _file_ to write generated contents to
+where   <output path>: the directory to write generated contents to. This will NOT automatically create the directory.
         <opcode> is one of:
             "single" process this <input path> file only
             "rec" starting at the given directory <input path>, recursively process all .h .c .hpp .cpp files
@@ -635,8 +673,33 @@ where   <output path>: the _file_ to write generated contents to
 		return -1;
 	}
 
-	const char* outputFilePath = argv[1];
-	DEBUG_PRINTF("Outputting to file %s.\n", outputFilePath);
+	const char* outputDir = argv[1];
+	DEBUG_PRINTF("Outputting to directory %s.\n", outputDirPath);
+
+	{
+		char path[2048];
+		snprintf(path, sizeof(path), "%s/%s", outputDir, "Metadata.hpp");
+
+		auto fileContent = R"""(
+// This file is generated. Any changes will be overidden when building.
+// This file is an umbrella header for all generated metadata. End users simply include this file to get access to everything.
+#pragma once
+
+#include <MetadataBase.hpp>
+
+#include <generated/MetadataImpl.hpp>
+)"""sv.substr(1); // Get rid of the \n at the beginning
+
+		auto file = Utils::OpenCstdioFile(path, Utils::WriteTruncate);
+		if (!file) {
+			printf("[ERROR] unable to open output file %s", path);
+			return -1;
+		}
+		DEFER { fclose(file); };
+
+		DEBUG_PRINTF("Writing output file %s", path);
+		fwrite(fileContent.data(), sizeof(decltype(fileContent)::value_type), fileContent.size(), file);
+	}
 
 	for (int i = 2; i < argc; ++i) {
 		std::string_view arg(argv[i]);
@@ -652,15 +715,8 @@ where   <output path>: the _file_ to write generated contents to
 		}
 	}
 
-	{
-		auto outputFile = Utils::OpenCstdioFile(outputFilePath, Utils::WriteTruncate);
-		if (!outputFile) {
-			printf("[ERROR] unable to open output file %s", outputFilePath);
-			return -1;
-		}
-		DEFER { fclose(outputFile); };
-		state.sourceOutput.Write(outputFile);
-	}
+	WriteOutputFile(state.headerOutput, outputDir, "MetadataImpl.hpp");
+	WriteOutputFile(state.sourceOutput, outputDir, "MetadataImpl.cpp");
 
 	return 0;
 }
diff --git a/buildtools/codegen/tests/examples/TestEnum.hpp b/buildtools/codegen/tests/examples/TestEnum.hpp.txt
index 6b4ab33..e596c5e 100644
--- a/buildtools/codegen/tests/examples/TestEnum.hpp
+++ b/buildtools/codegen/tests/examples/TestEnum.hpp.txt
@@ -1,5 +1,3 @@
-#include "MacrosCodegen.hpp"
-
 enum MyEnum {
 	EnumElement1,
 	EnumElement2,
diff --git a/source-codegen-base/MetadataBase.hpp b/source-codegen-base/MetadataBase.hpp
new file mode 100644
index 0000000..59c61da
--- /dev/null
+++ b/source-codegen-base/MetadataBase.hpp
@@ -0,0 +1,14 @@
+#pragma once
+
+#include <optional>
+#include <string_view>
+
+namespace Metadata {
+
+template <class TEnum>
+std::string_view EnumToString(TEnum value) = delete;
+
+template <class TEnum>
+std::optional<TEnum> EnumFromString(std::string_view str) = delete;
+
+} // namespace Metadata