set basic repo structure

src/main.cpp

@@ -0,0 +1,28 @@
+#include <argparse/argparse.hpp>
+#include <fstream>
+#include <iostream>
+#include "semantic/semantic.h"
+
+int main(int argc, char **argv) {
+  argparse::ArgumentParser program("mxcompiler");
+
+  program.add_argument("input").help("input file path").required();
+
+  program.add_argument("-o", "--output").help("output file path").nargs(1).required();
+
+  try {
+    program.parse_args(argc, argv);
+  } catch (const std::runtime_error &err) {
+    std::cerr << err.what() << std::endl;
+    std::cerr << program;
+    return 1;
+  }
+
+  auto input_file = program.get<std::string>("input");
+  auto output_file = program.get<std::string>("output");
+  std::ifstream fin(input_file);
+  int err_code = SemanticCheck(fin);
+  if (err_code != 0) return err_code;
+
+  return 0;
+}