int main(int argc, char** argv)
{
//argc == 2 --> only the source file is given
//argc == 4 --> source file and target C file is given
if (argc != 2 && argc != 4) { //only 2 and 4 is accepted
print_usage(argv[0]);
return -1;
//if the output file is given, flag must be -o
} else if (argc == 4 && std::string(argv[2]) != "-o") {
std::cout << "Error: Output file must be given after -o flag"
<< std::endl;
return -2;
}
//argc == 2 or argc == 4
const std::string Source_name = argv[1];
const std::string Default_output_name = strip_extensions(Source_name) +".c";
// if we have only one cmd argument, produce a result with a default name.
const std::string Output_name = (argc == 2) ? Default_output_name : argv[3];
//preprocessor strips comments from the file without deleting any line
//this way, line numbers are preserved
Preprocessor pp;
const std::string Preprocessed_name = pp.remove_comments(Source_name);
//we work on the preprocessed file
std::ifstream source_file(Preprocessed_name.c_str());
if (!source_file) {
std::cout << Preprocessed_name << " couldn't be opened" << std::endl;
return -3;
}
SymbolTable sym_table;
Lexer lexer; //lexer tokenizes the source file
Parser parser(&sym_table); //parser does the syntax check
SemanticAnalyzer sem_analyze(&sym_table); //semantic checks
//generates the code. Does semantic checks on expressions
CodeGenerator code_gen(&sym_table);
std::string line; //holds the current line
int line_count = 0;
//stores the whole file as lines. Each line is a vector of tokens and a
//statement type and the line number. See definitions.hpp for more info
std::vector<stmt_with_info> source_as_tokens;
Regex empty_line_rgx(R"(^[[:space:]]*$)");
while (std::getline(source_file, line)) {
++line_count;
//whenever we see an empty line, we go to the next line
if (!empty_line_rgx.search(line)) {
try {
//tokenize the current line
auto token_vec = lexer.tokenize(line);
if (token_vec.empty()) {
continue;
}
//parser does syntax check on the token vector and returns
//what kind of statement this particular token vector is
auto stmt_category = parser.parse(token_vec);
source_as_tokens.emplace_back(token_vec, stmt_category, line_count);
} catch (std::runtime_error e) {
//embed line info to the error and quit the program
//no file is generated up to this point. Thus, no extra cleanup
std::cout << "Error (Line " << line_count << "): " <<
e.what() << std::endl;
return -4;
}
