feat: added codegen plugin utility functions (#134)

Author: zaucy

BUILD.bazel

@@ -30,6 +30,18 @@ cc_library(
     ],
 )
 
+cc_library(
+    name = "cpp_codegen_plugin_util",
+    hdrs = ["ecsact/cpp_codegen_plugin_util.hh"],
+    copts = copts,
+    deps = [
+        "@ecsact_runtime//:common",
+        "@ecsact_runtime//:meta",
+        "@ecsact_runtime//:codegen_plugin_cc",
+        "@ecsact_lang_cpp//:support",
+    ],
+)
+
 filegroup(
     name = "headers",
     srcs = glob(["ecsact/**/*.hh"]),

ecsact/cpp_codegen_plugin_util.hh

@@ -0,0 +1,180 @@
+#pragma once
+
+#include <cassert>
+#include <string_view>
+#include <vector>
+#include <string>
+#include <utility>
+#include "ecsact/codegen_plugin.hh"
+#include "ecsact/runtime/meta.hh"
+
+namespace ecsact::cpp_codegen_plugin_util {
+
+inline auto inc_header( //
+	ecsact::codegen_plugin_context& ctx,
+	auto&&                          header_path
+) -> void {
+	ctx.write("#include \"", header_path, "\"\n");
+}
+
+inline auto inc_package_header( //
+	ecsact::codegen_plugin_context& ctx,
+	ecsact_package_id               pkg_id,
+	std::string                     extension = ".hh"
+) -> void {
+	namespace fs = std::filesystem;
+
+	auto main_ecsact_file_path = ecsact::meta::package_file_path(ctx.package_id);
+	if(ctx.package_id == pkg_id) {
+		main_ecsact_file_path.replace_extension(
+			main_ecsact_file_path.extension().string() + extension
+		);
+
+		inc_header(ctx, main_ecsact_file_path.filename().string());
+	} else {
+		auto cpp_header_path = ecsact::meta::package_file_path(pkg_id);
+		cpp_header_path.replace_extension(
+			cpp_header_path.extension().string() + extension
+		);
+		if(main_ecsact_file_path.has_parent_path()) {
+			cpp_header_path =
+				fs::relative(cpp_header_path, main_ecsact_file_path.parent_path());
+		}
+		inc_header(ctx, cpp_header_path.filename().string());
+	}
+}
+
+class method_printer {
+	using parameters_list_t = std::vector<std::pair<std::string, std::string>>;
+
+	bool                             disposed = false;
+	std::optional<parameters_list_t> parameters;
+	ecsact::codegen_plugin_context&  ctx;
+
+	auto _parameter(std::string param_type, std::string param_name) -> void {
+		assert(!disposed);
+		if(disposed) {
+			return;
+		}
+
+		assert(
+			parameters.has_value() &&
+			"Cannot set parametrs after return type has been set"
+		);
+		parameters->push_back({param_type, param_name});
+	}
+
+	auto _return_type(std::string type) {
+		assert(!disposed);
+		if(disposed) {
+			return;
+		}
+
+		assert(parameters.has_value());
+		if(!parameters.has_value()) {
+			return;
+		}
+
+		if(!parameters->empty()) {
+			ctx.write("\n");
+		}
+
+		for(auto i = 0; parameters->size() > i; ++i) {
+			auto&& [param_type, param_name] = parameters->at(i);
+			ctx.write("\t", param_type, " ", param_name);
+			if(i + 1 < parameters->size()) {
+				ctx.write(",");
+			}
+			ctx.write("\n");
+		}
+
+		parameters = std::nullopt;
+
+		ctx.write(") -> ", type, " {");
+		ctx.indentation += 1;
+		ctx.write("\n");
+	}
+
+public:
+	method_printer( //
+		ecsact::codegen_plugin_context& ctx,
+		std::string                     method_name
+	)
+		: ctx(ctx) {
+		parameters.emplace();
+		ctx.write("auto ", method_name, "(");
+	}
+
+	method_printer(method_printer&& other) : ctx(other.ctx) {
+		disposed = other.disposed;
+
+		if(!disposed) {
+			parameters = std::move(other.parameters);
+		}
+
+		other.disposed = true;
+	}
+
+	auto parameter(
+		std::string param_type,
+		std::string param_name
+	) & -> method_printer& {
+		_parameter(param_type, param_name);
+		return *this;
+	}
+
+	auto parameter(
+		std::string param_type,
+		std::string param_name
+	) && -> method_printer {
+		_parameter(param_type, param_name);
+		return std::move(*this);
+	}
+
+	auto return_type(std::string type) & -> method_printer& {
+		_return_type(type);
+		return *this;
+	}
+
+	auto return_type(std::string type) && -> method_printer {
+		_return_type(type);
+		return std::move(*this);
+	}
+
+	~method_printer() {
+		if(disposed) {
+			return;
+		}
+		disposed = true;
+		ctx.indentation -= 1;
+		ctx.write("\n}\n\n");
+	}
+};
+
+class block_printer {
+	bool                            disposed = false;
+	ecsact::codegen_plugin_context& ctx;
+
+public:
+	block_printer(ecsact::codegen_plugin_context& ctx) : ctx(ctx) {
+		ctx.write("{");
+		ctx.indentation += 1;
+		ctx.write("\n");
+	}
+
+	block_printer(block_printer&& other) : ctx(other.ctx) {
+		disposed = other.disposed;
+		other.disposed = true;
+	}
+
+	~block_printer() {
+		if(disposed) {
+			return;
+		}
+		disposed = true;
+		ctx.indentation -= 1;
+		ctx.write("\n}\n\n");
+	}
+};
+
+} // namespace ecsact::cpp_codegen_plugin_util