Changeset: 38 Branch comment: [] Add infrastructure for codegen

2 files changed, 107 insertions, 0 deletions

diff --git a/buildtools/codegen/README.md b/buildtools/codegen/README.md
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index 0000000..7164132
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+++ b/buildtools/codegen/README.md
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+# Code Generator
+The main code generator.
+
+## Folder structure
+The main program's source files are all located in this folder directly. Text tempaltes are located in `templates/` and none of the files are compiled (even if they end with .c or .cpp).
diff --git a/buildtools/codegen/main.cpp b/buildtools/codegen/main.cpp
new file mode 100644
index 0000000..4a1d486
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+++ b/buildtools/codegen/main.cpp
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+#include "ScopeGuard.hpp"
+#include "Utils.hpp"
+
+#include <stb_c_lexer.h>
+#include <filesystem>
+#include <string>
+#include <string_view>
+
+using namespace std::literals;
+namespace fs = std::filesystem;
+
+enum InputOpcode {
+	IOP_ProcessSingleFile,
+	IOP_ProcessRecursively,
+	IOP_COUNT,
+};
+
+InputOpcode ParseInputOpcode(std::string_view text) {
+	if (text == "single"sv) {
+		return IOP_ProcessSingleFile;
+	} else if (text == "rec"sv) {
+		return IOP_ProcessRecursively;
+	}
+	return IOP_COUNT;
+}
+
+void HandleInputFile(std::string_view source) {
+	stb_lexer lexer;
+	char stringStorage[65536];
+	const char* srcBegin = source.data();
+	const char* srcEnd = srcBegin + source.length();
+	stb_c_lexer_init(&lexer, srcBegin, srcEnd, stringStorage, sizeof(stringStorage));
+
+	// TODO
+}
+
+std::string ReadFileAtOnce(const fs::path& path) {
+	auto file = Utils::OpenCstdioFile(path, Utils::Read);
+	if (!file) throw std::runtime_error("Failed to open source file.");
+	DEFER { fclose(file); };
+
+	fseek(file, 0, SEEK_END);
+	auto fileSize = ftell(file);
+	rewind(file);
+
+	std::string result(fileSize, '\0');
+	fread(result.data(), fileSize, 1, file);
+
+	return result;
+}
+
+void HandleArgument(InputOpcode opcode, std::string_view operand) {
+	switch (opcode) {
+		case IOP_ProcessSingleFile: {
+			fs::path filePath(operand);
+			auto source = ReadFileAtOnce(filePath);
+			HandleInputFile(source);
+		} break;
+
+		case IOP_ProcessRecursively: {
+			fs::path startPath(operand);
+			for (auto& item : fs::directory_iterator(startPath)) {
+				if (!item.is_regular_file()) {
+					continue;
+				}
+
+				auto& path = item.path();
+				auto filename = path.filename().string();
+				if (filename != ".c" ||
+					filename != ".cpp")
+				{
+					continue;
+				}
+
+				auto source = ReadFileAtOnce(path);
+				HandleInputFile(source);
+			}
+		} break;
+
+		case IOP_COUNT: break;
+	}
+}
+
+int main(int argc, char* argv[]) {
+	// TODO better arg parser
+	//      option 1: use cxxopts and positional arguments
+	//      option 1: take one argument only, being a json objecet
+
+	// If no cli is provided (argv[0]), this loop will do nothing
+	// Otherwise, start with the 2nd element which is the 1st argument
+	for (int i = 1; i < argc; ++i) {
+		std::string_view arg(argv[i]);
+		auto separatorLoc = arg.find(':');
+		if (separatorLoc != std::string_view::npos) {
+			auto opcode = ParseInputOpcode(arg.substr(0, separatorLoc));
+			auto operand = arg.substr(separatorLoc);
+			HandleArgument(opcode, operand);
+		}
+	}
+
+	return 0;
+}