idl.cpp

C++的一个好库。。。现在很流行

            vector<string>::const_iterator end = syspaths.end();
            for (vector<string>::const_iterator cit = syspaths.begin(); 
                 cit != end; ++cit)
            {
                ctx.add_sysinclude_path((*cit).c_str());
            }
        }
        
    // add include directories to the include search paths
        if (vm.count("include")) {
            cmd_line_util::include_paths const &ip = 
                vm["include"].as<cmd_line_util::include_paths>();
            vector<string>::const_iterator end = ip.paths.end();

            for (vector<string>::const_iterator cit = ip.paths.begin(); 
                 cit != end; ++cit)
            {
                ctx.add_include_path((*cit).c_str());
            }

        // if on the command line was given -I- , this has to be propagated
            if (ip.seen_separator) 
                ctx.set_sysinclude_delimiter();
                 
        // add system include directories to the include path
            vector<string>::const_iterator sysend = ip.syspaths.end();
            for (vector<string>::const_iterator syscit = ip.syspaths.begin(); 
                 syscit != sysend; ++syscit)
            {
                ctx.add_sysinclude_path((*syscit).c_str());
            }
        }
    
    // add additional defined macros 
        if (vm.count("define")) {
            vector<string> const &macros = vm["define"].as<vector<string> >();
            vector<string>::const_iterator end = macros.end();
            for (vector<string>::const_iterator cit = macros.begin(); 
                 cit != end; ++cit)
            {
                ctx.add_macro_definition(*cit);
            }
        }

    // add additional predefined macros 
        if (vm.count("predefine")) {
            vector<string> const &predefmacros = 
                vm["predefine"].as<vector<string> >();
            vector<string>::const_iterator end = predefmacros.end();
            for (vector<string>::const_iterator cit = predefmacros.begin(); 
                 cit != end; ++cit)
            {
                ctx.add_macro_definition(*cit, true);
            }
        }

    // undefine specified macros
        if (vm.count("undefine")) {
            vector<string> const &undefmacros = 
                vm["undefine"].as<vector<string> >();
            vector<string>::const_iterator end = undefmacros.end();
            for (vector<string>::const_iterator cit = undefmacros.begin(); 
                 cit != end; ++cit)
            {
                ctx.remove_macro_definition((*cit).c_str(), true);
            }
        }

    // open the output file
    std::ofstream output;
    
        if (vm.count("output")) {
        // try to open the file, where to put the preprocessed output
        string out_file (vm["output"].as<string>());
        
            output.open(out_file.c_str());
            if (!output.is_open()) {
                cerr << "waveidl: could not open output file: " << out_file 
                     << endl;
                return -1;
            }
        }
        else {
        // output the preprocessed result to std::cout
            output.copyfmt(cout);
            output.clear(cout.rdstate());
            static_cast<std::basic_ios<char> &>(output).rdbuf(cout.rdbuf());
        }

    // analyze the input file
    context_type::iterator_type first = ctx.begin();
    context_type::iterator_type last = ctx.end();
    
    // loop over all generated tokens outputing the generated text 
        while (first != last) {
        // print out the string representation of this token (skip comments)
            using namespace boost::wave;

        // store the last known good token position
            current_position = (*first).get_position();

        token_id id = token_id(*first);

            if (T_CPPCOMMENT == id || T_NEWLINE == id) {
            // C++ comment tokens contain the trailing newline
                output << endl;
            }
            else if (id != T_CCOMMENT) {
            // print out the current token value
                output << (*first).get_value();
            }
            ++first;        // advance to the next token
        }
    }
    catch (boost::wave::cpp_exception &e) {
    // some preprocessing error
        cerr 
            << e.file_name() << "(" << e.line_no() << "): "
            << e.description() << endl;
        return 1;
    }
    catch (boost::wave::cpplexer::lexing_exception &e) {
    // some lexing error
        cerr 
            << e.file_name() << "(" << e.line_no() << "): "
            << e.description() << endl;
        return 2;
    }
    catch (std::exception &e) {
    // use last recognized token to retrieve the error position
        cerr 
            << current_position.get_file() 
            << "(" << current_position.get_line() << "): "
            << "exception caught: " << e.what()
            << endl;
        return 3;
    }
    catch (...) {
    // use last recognized token to retrieve the error position
        cerr 
            << current_position.get_file() 
            << "(" << current_position.get_line() << "): "
            << "unexpected exception caught." << endl;
        return 4;
    }
    return 0;
}

///////////////////////////////////////////////////////////////////////////////
//  main entry point
int
main (int argc, char *argv[])
{
    try {
    // analyze the command line options and arguments
    
    // declare the options allowed from the command line only
    po::options_description desc_cmdline ("Options allowed on the command line only");
        
        desc_cmdline.add_options()
            ("help,h", "print out program usage (this message)")
            ("version,v", "print the version number")
            ("copyright,c", "print out the copyright statement")
            ("config-file", po::value<vector<string> >(), 
                "specify a config file (alternatively: @filepath)")
        ;

    // declare the options allowed on command line and in config files
    po::options_description desc_generic ("Options allowed additionally in a config file");

        desc_generic.add_options()
            ("output,o", "specify a file to use for output instead of stdout")
            ("include,I", po::value<cmd_line_util::include_paths>()->composing(), 
                "specify an additional include directory")
            ("sysinclude,S", po::value<vector<string> >()->composing(), 
                "specify an additional system include directory")
            ("define,D", po::value<vector<string> >()->composing(), 
                "specify a macro to define (as macro[=[value]])")
            ("predefine,P", po::value<vector<string> >()->composing(), 
                "specify a macro to predefine (as macro[=[value]])")
            ("undefine,U", po::value<vector<string> >()->composing(), 
                "specify a macro to undefine")
        ;
        
    // combine the options for the different usage schemes
    po::options_description desc_overall_cmdline;
    po::options_description desc_overall_cfgfile;

        desc_overall_cmdline.add(desc_cmdline).add(desc_generic);
        desc_overall_cfgfile.add(desc_generic);
        
    // parse command line and store results
        using namespace boost::program_options::command_line_style;

    po::parsed_options opts = po::parse_command_line(argc, argv, 
        desc_overall_cmdline, unix_style, cmd_line_util::at_option_parser);
    po::variables_map vm;
    
        po::store(opts, vm);
        po::notify(vm);
        
    // Try to find a waveidl.cfg in the same directory as the executable was 
    // started from. If this exists, treat it as a wave config file
    fs::path filename(argv[0], fs::native);

        filename = filename.branch_path() / "waveidl.cfg";
        cmd_line_util::read_config_file_options(filename.string(), 
            desc_overall_cfgfile, vm, true);

    // if there is specified at least one config file, parse it and add the 
    // options to the main variables_map
        if (vm.count("config-file")) {
            vector<string> const &cfg_files = 
                vm["config-file"].as<vector<string> >();
            vector<string>::const_iterator end = cfg_files.end();
            for (vector<string>::const_iterator cit = cfg_files.begin(); 
                 cit != end; ++cit)
            {
            // parse a single config file and store the results
                cmd_line_util::read_config_file_options(*cit, 
                    desc_overall_cfgfile, vm);
            }
        }

    // ... act as required 
        if (vm.count("help")) {
        po::options_description desc_help (
            "Usage: waveidl [options] [@config-file(s)] file");

            desc_help.add(desc_cmdline).add(desc_generic);
            cout << desc_help << endl;
            return 1;
        }
        
        if (vm.count("version")) {
            return print_version();
        }

        if (vm.count("copyright")) {
            return print_copyright();
        }
        
    // extract the arguments from the parsed command line
    vector<po::option> arguments;
    
        std::remove_copy_if(opts.options.begin(), opts.options.end(), 
            inserter(arguments, arguments.end()), cmd_line_util::is_argument());
            
    // if there is no input file given, then exit
        if (0 == arguments.size() || 0 == arguments[0].value.size()) {
            cerr << "waveidl: no input file given, "
                 << "use --help to get a hint." << endl;
            return 5;
        }

    // preprocess the given input file
        return do_actual_work(arguments[0].value[0], vm);
    }
    catch (std::exception &e) {
        cout << "waveidl: exception caught: " << e.what() << endl;
        return 6;
    }
    catch (...) {
        cerr << "waveidl: unexpected exception caught." << endl;
        return 7;
    }
}