ceph/src/boost/libs/wave/samples/preprocess_pragma_output/preprocess_pragma_output.cpp

   1 /*=============================================================================
   2     Boost.Wave: A Standard compliant C++ preprocessor library
   3     Example demonstrating how to preprocess the token stream generated by a
   4     #pragma directive
   5
   6     http://www.boost.org/
   7
   8     Copyright (c) 2001-2010 Hartmut Kaiser. Distributed under the Boost
   9     Software License, Version 1.0. (See accompanying file
  10     LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  11 =============================================================================*/
  12
  13 #include <iostream>
  14 #include <fstream>
  15 #include <string>
  16 #include <vector>
  17
  18 ///////////////////////////////////////////////////////////////////////////////
  19 //  Include Wave itself
  20 #include <boost/wave.hpp>
  21
  22 ///////////////////////////////////////////////////////////////////////////////
  23 // Include the lexer stuff
  24 #include <boost/wave/cpplexer/cpp_lex_token.hpp>    // token class
  25 #include <boost/wave/cpplexer/cpp_lex_iterator.hpp> // lexer class
  26
  27 ///////////////////////////////////////////////////////////////////////////////
  28 // Include special preprocessing hooks
  29 #include "preprocess_pragma_output.hpp"
  30
  31 ///////////////////////////////////////////////////////////////////////////////
  32 // main entry point
  33 int main(int argc, char *argv[])
  34 {
  35     if (2 != argc) {
  36         std::cerr << "Usage: preprocess_pragma_output infile" << std::endl;
  37         return -1;
  38     }
  39
  40 // current file position is saved for exception handling
  41 boost::wave::util::file_position_type current_position;
  42
  43     try {
  44     //  Open and read in the specified input file.
  45     std::ifstream instream(argv[1]);
  46     std::string instring;
  47
  48         if (!instream.is_open()) {
  49             std::cerr << "Could not open input file: " << argv[1] << std::endl;
  50             return -2;
  51         }
  52         instream.unsetf(std::ios::skipws);
  53         instring = std::string(std::istreambuf_iterator<char>(instream.rdbuf()),
  54                                 std::istreambuf_iterator<char>());
  55
  56     //  The template boost::wave::cpplexer::lex_token<> is the token type to be
  57     //  used by the Wave library.
  58         typedef boost::wave::cpplexer::lex_token<> token_type;
  59
  60     //  The template boost::wave::cpplexer::lex_iterator<> is the lexer type to
  61     //  be used by the Wave library.
  62         typedef boost::wave::cpplexer::lex_iterator<token_type> lex_iterator_type;
  63
  64     //  This is the resulting context type to use.
  65         typedef boost::wave::context<
  66             std::string::iterator, lex_iterator_type,
  67             boost::wave::iteration_context_policies::load_file_to_string,
  68             preprocess_pragma_output_hooks>
  69         context_type;
  70
  71     // The preprocessor iterator shouldn't be constructed directly. It is
  72     // to be generated through a wave::context<> object. This wave:context<>
  73     // object is to be used additionally to initialize and define different
  74     // parameters of the actual preprocessing (not done here).
  75     //
  76     // The preprocessing of the input stream is done on the fly behind the
  77     // scenes during iteration over the context_type::iterator_type stream.
  78     context_type ctx (instring.begin(), instring.end(), argv[1]);
  79
  80     // analyze the input file
  81     context_type::iterator_type first = ctx.begin();
  82     context_type::iterator_type last = ctx.end();
  83
  84         while (first != last) {
  85             current_position = (*first).get_position();
  86             std::cout << (*first).get_value();
  87             ++first;
  88         }
  89     }
  90     catch (boost::wave::cpp_exception const& e) {
  91     // some preprocessing error
  92         std::cerr
  93             << e.file_name() << "(" << e.line_no() << "): "
  94             << e.description() << std::endl;
  95         return 2;
  96     }
  97     catch (std::exception const& e) {
  98     // use last recognized token to retrieve the error position
  99         std::cerr
 100             << current_position.get_file()
 101             << "(" << current_position.get_line() << "): "
 102             << "exception caught: " << e.what()
 103             << std::endl;
 104         return 3;
 105     }
 106     catch (...) {
 107     // use last recognized token to retrieve the error position
 108         std::cerr
 109             << current_position.get_file()
 110             << "(" << current_position.get_line() << "): "
 111             << "unexpected exception caught." << std::endl;
 112         return 4;
 113     }
 114     return 0;
 115 }