cpp_macromap.hpp

C++的一个好库。。。现在很流行

    if (name.size() < 8 || '_' != name[0] || '_' != name[1])
        return false;       // quick check failed

    return name == "__LINE__" || name == "__FILE__" || 
        name == "__INCLUDE_LEVEL__";
}

template <typename ContextT>
template <typename IteratorT>
inline bool 
macromap<ContextT>::is_defined(IteratorT const &begin, 
    IteratorT const &end) 
{
// in normal mode the name under inspection should consist of an identifier
// only
token_id id = token_id(*begin);

    if (T_IDENTIFIER != id && 
        !IS_CATEGORY(id, KeywordTokenType) &&
        !IS_EXTCATEGORY(id, OperatorTokenType|AltExtTokenType)) 
    {
        BOOST_WAVE_THROW(preprocess_exception, invalid_macroname, 
            impl::get_full_name(begin, end).c_str(), main_pos);
    }

IteratorT it = begin;
string_type name ((*it).get_value());
typename defined_macros_type::iterator cit(current_macros -> find(name));

    if (++it != end) {
    // there should be only one token as the inspected name
        BOOST_WAVE_THROW(preprocess_exception, invalid_macroname, 
            impl::get_full_name(begin, end).c_str(), main_pos);
    }
    return cit != current_macros -> end();
}

///////////////////////////////////////////////////////////////////////////////
// 
//  remove_macro(): remove a macro from the macromap
//
///////////////////////////////////////////////////////////////////////////////
template <typename ContextT>
inline bool 
macromap<ContextT>::remove_macro(token_type const &token, 
    bool even_predefined)
{
    string_type name (token.get_value());
    typename defined_macros_type::iterator it = current_macros->find(name);
    
    if (it != current_macros->end()) {
        if ((*it).second->is_predefined) {
            if (!even_predefined || impl::is_special_macroname(name)) {
                BOOST_WAVE_THROW(preprocess_exception, bad_undefine_statement, 
                    name.c_str(), main_pos);
            }
        }
        current_macros->erase(it);
        
    // call the context supplied preprocessing hook function
        ctx.undefined_macro(token);
        return true;
    }
    else if (impl::is_special_macroname(name)) {
        BOOST_WAVE_THROW(preprocess_exception, bad_undefine_statement, 
            name.c_str(), main_pos);
    }
    return false;       // macro was not defined
}

///////////////////////////////////////////////////////////////////////////////
// 
//  expand_tokensequence
//
//      This function is a helper function which wraps the given iterator 
//      range into corresponding unput_iterator's and calls the main workhorse
//      of the macro expansion engine (the function expand_tokensequence_worker)
//
//      This is the top level macro expansion function called from the 
//      preprocessing iterator component only.
//
///////////////////////////////////////////////////////////////////////////////
template <typename ContextT>
template <typename IteratorT, typename ContainerT>
inline typename ContextT::token_type const &
macromap<ContextT>::expand_tokensequence(IteratorT &first, 
    IteratorT const &last, ContainerT &pending, ContainerT &expanded, 
    bool expand_operator_defined)
{
    typedef impl::gen_unput_queue_iterator<IteratorT, token_type, ContainerT> 
        gen_type;
    typedef typename gen_type::return_type iterator_type;

    iterator_type first_it = gen_type::generate(expanded, first);
    iterator_type last_it = gen_type::generate(last);

on_exit::assign<IteratorT, iterator_type> on_exit(first, first_it);

    return expand_tokensequence_worker(pending, first_it, last_it, 
        expand_operator_defined);
}

///////////////////////////////////////////////////////////////////////////////
//
//  expand_tokensequence_worker
//
//      This function is the main workhorse of the macro expansion engine. It
//      expands as much tokens as needed to identify the next preprocessed 
//      token to return to the caller. 
//      It returns the next preprocessed token.
//
//      The iterator 'first' is adjusted accordingly.
//
///////////////////////////////////////////////////////////////////////////////
template <typename ContextT>
template <typename IteratorT, typename ContainerT>
inline typename ContextT::token_type const &
macromap<ContextT>::expand_tokensequence_worker(
    ContainerT &pending, 
    unput_queue_iterator<IteratorT, token_type, ContainerT> &first, 
    unput_queue_iterator<IteratorT, token_type, ContainerT> const &last, 
    bool expand_operator_defined)
{
// if there exist pending tokens (tokens, which are already preprocessed), then
// return the next one from there
    if (!pending.empty()) {
    on_exit::pop_front<definition_container_type> pop_front_token(pending);
    
        return act_token = pending.front();
    }

//  analyze the next element of the given sequence, if it is an 
//  T_IDENTIFIER token, try to replace this as a macro etc.
    using namespace boost::wave;
    typedef unput_queue_iterator<IteratorT, token_type, ContainerT> iterator_type;
    
    if (first != last) {
    token_id id = token_id(*first);

    // ignore placeholder tokens
        if (T_PLACEHOLDER == id) {
        token_type placeholder = *first;
        
            ++first;
            if (first == last)
                return act_token = placeholder;
            id = token_id(*first);
        }
            
        if (T_IDENTIFIER == id || IS_CATEGORY(id, KeywordTokenType) ||
            IS_EXTCATEGORY(id, OperatorTokenType|AltExtTokenType)) 
        {
        // try to replace this identifier as a macro
            if (expand_operator_defined && (*first).get_value() == "defined") {
            // resolve operator defined()
                return resolve_defined(first, last, pending);
            }
            else if (boost::wave::need_variadics(ctx.get_language()) && 
                (*first).get_value() == "_Pragma") 
            {
            // in C99 mode only: resolve the operator _Pragma
            token_type curr_token = *first;
            
                if (!resolve_operator_pragma(first, last, pending) ||
                    pending.size() > 0) 
                {
                // unknown to us pragma or supplied replacement, return the 
                // next token
                on_exit::pop_front<definition_container_type> pop_token(pending);

                    return act_token = pending.front();
                }
                
            // the operator _Pragma() was eaten completely, continue
                return act_token = token_type(T_PLACEHOLDER, "_", 
                    curr_token.get_position());
            }

        token_type name_token (*first);
        typename defined_macros_type::iterator it;
        
            if (is_defined(name_token.get_value(), it)) {
            // the current token contains an identifier, which is currently 
            // defined as a macro
                if (expand_macro(pending, name_token, it, first, last, 
                    expand_operator_defined)) 
                {
                // the tokens returned by expand_macro should be rescanned
                // beginning at the last token of the returned replacement list
                    if (first != last) {
                    // splice the last token back into the input queue
                    typename ContainerT::reverse_iterator rit = pending.rbegin();
                    
                        first.get_unput_queue().splice(
                            first.get_unput_queue().begin(), pending,
                            (++rit).base(), pending.end());
                    }
                                            
                // fall through ...
                }
                else if (!pending.empty()) {
                // return the first token from the pending queue
                on_exit::pop_front<definition_container_type> pop_queue (pending);
                
                    return act_token = pending.front();
                }
                else {
                // macro expansion reached the eoi
                    return act_token = token_type();
                }

            // return the next preprocessed token
                return expand_tokensequence_worker(pending, first, last, 
                    expand_operator_defined);
            }
//            else if (expand_operator_defined) {
//            // in preprocessing conditionals undefined identifiers and keywords 
//            // are to be replaced with '0' (see. C++ standard 16.1.4, [cpp.cond])
//                return act_token = 
//                    token_type(T_INTLIT, "0", (*first++).get_position());
//            }
            else {
                act_token = name_token;
                ++first;
                return act_token;
            }
        }
        else if (expand_operator_defined && IS_CATEGORY(*first, BoolLiteralTokenType)) {
        // expanding a constant expression inside #if/#elif, special handling
        // of 'true' and 'false'        

        // all remaining identifiers and keywords, except for true and false, 
        // are replaced with the pp-number 0 (C++ standard 16.1.4, [cpp.cond])
            return act_token = token_type(T_INTLIT, T_TRUE != id ? "0" : "1", 
                (*first++).get_position());
        }
        else {
            act_token = *first;
            ++first;
            return act_token;
        }
    }
    return act_token = token_type();     // eoi
}

///////////////////////////////////////////////////////////////////////////////
// 
//  collect_arguments(): collect the actual arguments of a macro invocation
//
//      return the number of successfully detected non-empty arguments
//
///////////////////////////////////////////////////////////////////////////////
template <typename ContextT>
template <typename IteratorT, typename ContainerT, typename SizeT>
inline typename std::vector<ContainerT>::size_type 
macromap<ContextT>::collect_arguments (token_type const curr_token, 
    std::vector<ContainerT> &arguments, IteratorT &next, IteratorT const &end, 
    SizeT const &parameter_count)
{
    using namespace boost::wave;

    arguments.push_back(ContainerT());
    
// collect the actual arguments
typename std::vector<ContainerT>::size_type count_arguments = 0;
int nested_parenthesis_level = 1;
ContainerT *argument = &arguments[0];
bool was_whitespace = false;
token_type startof_argument_list = *next;

    while (++next != end && nested_parenthesis_level) {
    token_id id = token_id(*next);

        if (0 == parameter_count && 
            !IS_CATEGORY((*next), WhiteSpaceTokenType) && id != T_NEWLINE &&
            id != T_RIGHTPAREN && id != T_LEFTPAREN) 
        {
        // there shouldn't be any arguments
            BOOST_WAVE_THROW(preprocess_exception, too_many_macroarguments, 
                curr_token.get_value().c_str(), main_pos);
        }
        
        switch (static_cast<unsigned int>(id)) {
        case T_LEFTPAREN:
            ++nested_parenthesis_level;
            argument->push_back(*next);
            was_whitespace = false;
            break;
            
        case T_RIGHTPAREN:
            {
                if (--nested_parenthesis_level >= 1)
                    argument->push_back(*next);
                else {
                // found closing parenthesis
//                    trim_argument(argument);
                    if (parameter_count > 0) {
                        if (argument->empty() || 
                            impl::is_whitespace_only(*argument)) 
                        {
#if BOOST_WAVE_SUPPORT_VARIADICS_PLACEMARKERS != 0
                            if (boost::wave::need_variadics(ctx.get_language())) {
                            // store a placemarker as the argument
                                argument->push_back(token_type(T_PLACEMARKER, "