Click here to Skip to main content
15,860,844 members
Articles / Programming Languages / C++

Wave: a Standard conformant C++ preprocessor library

Rate me:
Please Sign up or sign in to vote.
4.96/5 (58 votes)
10 Jan 200413 min read 392.1K   4.4K   81  
Describes a free and fully Standard conformant C++ preprocessor library
/*=============================================================================
    Wave: A Standard compliant C++ preprocessor

    Sample: List include dependencies of a given source file
    
    Copyright (c) 2001-2003 Hartmut Kaiser
    http://spirit.sourceforge.net/

    Permission to copy, use, modify, sell and distribute this software
    is granted provided this copyright notice appears in all copies.
    This software is provided "as is" without express or implied
    warranty, and with no claim as to its suitability for any purpose.

    See Copyright.txt for full copyright notices and acknowledgements.
=============================================================================*/

#include <iostream>
#include <fstream>
#include <string>
#include <vector>

///////////////////////////////////////////////////////////////////////////////
//  include required boost libraries
#include <boost/assert.hpp>

///////////////////////////////////////////////////////////////////////////////
//  This sample requires the program_options library written by Vladimir Prus,
//  which is currently under Boost review. 
//  It is available here: http://boost-sandbox.sourceforge.net/program_options
//
#include <boost/program_options.hpp>

#include "list_includes.hpp"            // config data
#include "list_includes_version.hpp"

#include "wave/util/time_conversion_helper.hpp"
#include "wave/util/file_position.hpp"
#include "wave/cpplexer/cpp_token_ids.hpp"
#include "wave/cpplexer/cpp_lex_iterator.hpp"
#include "wave/cpplexer/cpp_lex_token.hpp"

#include "wave/cpp_context.hpp"

///////////////////////////////////////////////////////////////////////////////
//  include lexer specifics, import lexer names
#if defined(WAVE_USE_SLEX_CPP_LEXER)
// use the slex based C++ lexer

#if !defined(WAVE_SEPARATE_LEXER_INSTANTIATION)
#include "wave/cpplexer/slex/cpp_slex_lexer.hpp"
#endif // !defined(WAVE_SEPARATE_LEXER_INSTANTIATION)

#elif defined(WAVE_USE_RE2C_CPP_LEXER)
// use the re2c based C++ lexer

#if !defined(WAVE_SEPARATE_LEXER_INSTANTIATION)
#include "wave/cpplexer/re2clex/cpp_re2c_lexer.hpp"
#endif // !defined(WAVE_SEPARATE_LEXER_INSTANTIATION)

#endif

///////////////////////////////////////////////////////////////////////////////
//  import required names
using namespace boost::spirit;

using std::string;
using std::vector;
using std::cout;
using std::cerr;
using std::endl;
using std::ifstream;
using std::ostream;
using std::istreambuf_iterator;

namespace po = boost::program_options;

///////////////////////////////////////////////////////////////////////////////
// print the current version

int print_version()
{
// get time of last compilation of this file
wave::util::time_conversion_helper compilation_time(__DATE__ " " __TIME__);

// calculate the number of days since Jan 29 2003 
// (the day the list_includes project was started)
std::tm first_day;

    std::memset (&first_day, 0, sizeof(std::tm));
    first_day.tm_mon = 0;           // Jan
    first_day.tm_mday = 29;         // 29
    first_day.tm_year = 103;        // 2003

long seconds = long(std::difftime(compilation_time.get_time(), 
    std::mktime(&first_day)));

    cout 
        << LIST_INCLUDES_VERSION_MAJOR << '.' 
        << LIST_INCLUDES_VERSION_MINOR << '.'
        << LIST_INCLUDES_VERSION_SUBMINOR << '.'
        << seconds/(3600*24);       // get number of days from seconds
    return 1;                       // exit app
}

///////////////////////////////////////////////////////////////////////////////
//  
int do_actual_work (
    po::options_and_arguments const opts, po::variables_map const &vm, 
    vector<string> const &pathes, vector<string> const &syspathes)
{
// current file position is saved for exception handling
wave::util::file_position_t current_position;

    try {
    vector<string> const &arguments = opts.arguments();
    vector<string>::const_iterator lastfile = arguments.end();

        for (vector<string>::const_iterator file_it = arguments.begin(); 
             file_it != lastfile; ++file_it)
        {
        ifstream instream((*file_it).c_str());
        string instring;

            if (!instream.is_open()) {
                cerr << "Could not open input file: " << *file_it << endl;
                continue;
            }
            instream.unsetf(ios::skipws);
            instring = string(istreambuf_iterator<char>(instream.rdbuf()),
                              istreambuf_iterator<char>());
            
        //  The template wave::cpplexer::lex_token<> is the token type to be 
        //  used by the Wave library.
            typedef wave::context<std::string::iterator, 
                wave::cpplexer::lex_token<> > context_t;

        // The C preprocessor iterator shouldn't be constructed directly. It is 
        // to be generated through a wave::context<> object. This cpp:context<> 
        // object is additionally to be used to initialize and define different 
        // parameters of the actual preprocessing.
        // The preprocessing of the input stream is done on the fly behind the 
        // scenes during iteration over the context_t::iterator_t stream.
        context_t ctx (instring.begin(), instring.end(), (*file_it).c_str());

        // add include directories to the include path
            if (vm.count("path")) {
                vector<string>::const_iterator end = pathes.end();
                for (vector<string>::const_iterator cit = pathes.begin(); 
                     cit != end; ++cit)
                {
                    ctx.add_include_path((*cit).c_str());
                }
            }
            
        // add system include directories to the include path
            if (vm.count("syspath")) {
                vector<string>::const_iterator end = syspathes.end();
                for (vector<string>::const_iterator cit = syspathes.begin(); 
                     cit != end; ++cit)
                {
                    ctx.add_sysinclude_path((*cit).c_str());
                }
            }
            
        // analyze the actual file
        context_t::iterator_t first = ctx.begin();
        context_t::iterator_t last = ctx.end();
        unsigned int iter_depth = 0;
        
            cout << "Printing dependency information for: " 
                 << *file_it << endl;
                
            while (first != last) {
            // retrieve position of the next token 
                current_position = (*first).get_position();
                
                if (iter_depth != ctx.get_iteration_depth()) {
                    if (iter_depth < ctx.get_iteration_depth()) {
                    // the get_iteration_depth() reflects the include level of
                    // the _next_ token to be returned 
                        if (++first == last)
                            break;

                        current_position = (*first).get_position();
                        
                    // extract the filename of the current token and print out 
                    // the required dependency information
                        for (unsigned int i = 0; i <= iter_depth; ++i) 
                            cout << "  ";       // indent
                        cout << current_position.file() << endl;
                    }
                    else {
                        ++first;    // advance token stream  
                    }
                    
                // save new iteration depth for later comparision
                    iter_depth = ctx.get_iteration_depth();
                }
                else {
                    ++first;            // advance token stream  
                }
            }
        
        // prepend endl before next file
            cout << endl;
        }
    }
    catch (wave::cpp_exception &e) {
    // some preprocessing 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.file() 
            << "(" << current_position.line() << "): "
            << "exception caught: " << e.what()
            << endl;
        return 3;
    }
    catch (...) {
    // use last recognized token to retrieve the error position
        cerr 
            << current_position.file() 
            << "(" << current_position.line() << "): "
            << "unexpected exception caught." << endl;
        return 4;
    }
    return 0;
}

///////////////////////////////////////////////////////////////////////////////
//  here we go!
int
main (int argc, char const *argv[])
{
    try {
    // analyze the command line options and arguments
    vector<string> pathes;
    vector<string> syspathes;
    po::options_description desc("Usage: list_includes [options] file ...");
        
        desc.add_options()
            ("help,h", "", "print out program usage")
            ("version,v", "", "print the version number")
            ("path,I", po::parameter<vector<string> >("dir", &pathes), 
                "specify additional include directory")
            ("syspath,S", po::parameter<vector<string> >("dir", &syspathes), 
                "specify additional system include directory")
        ;

    po::options_and_arguments opts = po::parse_command_line(argc, argv, desc);
    po::variables_map vm;
    
        po::store(opts, vm, desc);
        if (vm.count("help")) {
            cout << desc << endl;
            return 1;
        }
        
        if (vm.count("version")) {
            return print_version();
        }

    // if there is no input file given, then exit
        if (0 == opts.arguments().size()) {
            cerr << "list_includes: No input file given. "
                 << "Use --help to get a hint." << endl;
            return 5;
        }

    // iterate over all given input files
        return do_actual_work(opts, vm, pathes, syspathes);
    }
    catch (std::exception &e) {
        cout << "list_includes: exception caught: " << e.what() << endl;
        return 6;
    }
    catch (...) {
        cerr << "list_includes: unexpected exception caught." << endl;
        return 7;
    }
}

By viewing downloads associated with this article you agree to the Terms of Service and the article's licence.

If a file you wish to view isn't highlighted, and is a text file (not binary), please let us know and we'll add colourisation support for it.

License

This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

A list of licenses authors might use can be found here


Written By
United States United States
Actively involved in Boost and the development of the Spirit parser construction framework.

Comments and Discussions