| /*============================================================================= |
| Boost.Wave: A Standard compliant C++ preprocessor library |
| Example demonstrating how to preprocess the token stream generated by a |
| #pragma directive |
| |
| http://www.boost.org/ |
| |
| Copyright (c) 2001-2010 Hartmut Kaiser. Distributed under the Boost |
| Software License, Version 1.0. (See accompanying file |
| LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
| =============================================================================*/ |
| |
| #include <iostream> |
| #include <fstream> |
| #include <string> |
| #include <vector> |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // Include Wave itself |
| #include <boost/wave.hpp> |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // Include the lexer stuff |
| #include <boost/wave/cpplexer/cpp_lex_token.hpp> // token class |
| #include <boost/wave/cpplexer/cpp_lex_iterator.hpp> // lexer class |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // Include special preprocessing hooks |
| #include "preprocess_pragma_output.hpp" |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // main entry point |
| int main(int argc, char *argv[]) |
| { |
| if (2 != argc) { |
| std::cerr << "Usage: preprocess_pragma_output infile" << std::endl; |
| return -1; |
| } |
| |
| // current file position is saved for exception handling |
| boost::wave::util::file_position_type current_position; |
| |
| try { |
| // Open and read in the specified input file. |
| std::ifstream instream(argv[1]); |
| std::string instring; |
| |
| if (!instream.is_open()) { |
| std::cerr << "Could not open input file: " << argv[1] << std::endl; |
| return -2; |
| } |
| instream.unsetf(std::ios::skipws); |
| instring = std::string(std::istreambuf_iterator<char>(instream.rdbuf()), |
| std::istreambuf_iterator<char>()); |
| |
| // The template boost::wave::cpplexer::lex_token<> is the token type to be |
| // used by the Wave library. |
| typedef boost::wave::cpplexer::lex_token<> token_type; |
| |
| // The template boost::wave::cpplexer::lex_iterator<> is the lexer type to |
| // be used by the Wave library. |
| typedef boost::wave::cpplexer::lex_iterator<token_type> lex_iterator_type; |
| |
| // This is the resulting context type to use. |
| typedef boost::wave::context< |
| std::string::iterator, lex_iterator_type, |
| boost::wave::iteration_context_policies::load_file_to_string, |
| preprocess_pragma_output_hooks> |
| context_type; |
| |
| // The preprocessor iterator shouldn't be constructed directly. It is |
| // to be generated through a wave::context<> object. This wave:context<> |
| // object is to be used additionally to initialize and define different |
| // parameters of the actual preprocessing (not done here). |
| // |
| // The preprocessing of the input stream is done on the fly behind the |
| // scenes during iteration over the context_type::iterator_type stream. |
| context_type ctx (instring.begin(), instring.end(), argv[1]); |
| |
| // analyze the input file |
| context_type::iterator_type first = ctx.begin(); |
| context_type::iterator_type last = ctx.end(); |
| |
| while (first != last) { |
| current_position = (*first).get_position(); |
| std::cout << (*first).get_value(); |
| ++first; |
| } |
| } |
| catch (boost::wave::cpp_exception const& e) { |
| // some preprocessing error |
| std::cerr |
| << e.file_name() << "(" << e.line_no() << "): " |
| << e.description() << std::endl; |
| return 2; |
| } |
| catch (std::exception const& e) { |
| // use last recognized token to retrieve the error position |
| std::cerr |
| << current_position.get_file() |
| << "(" << current_position.get_line() << "): " |
| << "exception caught: " << e.what() |
| << std::endl; |
| return 3; |
| } |
| catch (...) { |
| // use last recognized token to retrieve the error position |
| std::cerr |
| << current_position.get_file() |
| << "(" << current_position.get_line() << "): " |
| << "unexpected exception caught." << std::endl; |
| return 4; |
| } |
| return 0; |
| } |