wave/samples/quick_start/quick_start.cpp
Hartmut Kaiser 15c01a454c Wave: merging from trunk for V1.50
[SVN r78634]
2012-05-26 14:47:03 +00:00

120 lines
4.6 KiB
C++

/*=============================================================================
Boost.Wave: A Standard compliant C++ preprocessor library
http://www.boost.org/
Copyright (c) 2001-2012 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
///////////////////////////////////////////////////////////////////////////////
// main entry point
int main(int argc, char *argv[])
{
if (2 != argc) {
std::cerr << "Usage: quick_start infile" << std::endl;
return -1;
}
// current file position is saved for exception handling
boost::wave::util::file_position_type current_position;
try {
//[quick_start_main
// The following preprocesses the input file given by argv[1].
// 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>());
// This token type is one of the central types used throughout the library.
// It is a template parameter to some of the public classes and instances
// of this type are returned from the iterators.
typedef boost::wave::cpplexer::lex_token<> token_type;
// The template boost::wave::cpplexer::lex_iterator<> is the lexer type to
// to use as the token source for the preprocessing engine. It is
// parametrized with the token type.
typedef boost::wave::cpplexer::lex_iterator<token_type> lex_iterator_type;
// This is the resulting context type. The first template parameter should
// match the iterator type used during construction of the context
// instance (see below). It is the type of the underlying input stream.
typedef boost::wave::context<std::string::iterator, lex_iterator_type>
context_type;
// The preprocessor iterator shouldn't be constructed directly. It is
// generated through a wave::context<> object. This wave:context<> object
// is additionally used 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 range of context_type::iterator_type
// instances.
context_type ctx (instring.begin(), instring.end(), argv[1]);
// Get the preprocessor iterators and use them to generate the token
// sequence.
context_type::iterator_type first = ctx.begin();
context_type::iterator_type last = ctx.end();
// The input stream is preprocessed for you while iterating over the range
// [first, last). The dereferenced iterator returns tokens holding
// information about the preprocessed input stream, such as token type,
// token value, and position.
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;
}