cpp_iterator.hpp

C++的一个好库。。。现在很流行

        new iteration_context_type(native_path.native_file_string().c_str(), 
            act_pos, ctx.get_language()));

    // call the include policy trace function
        ctx.get_trace_policy().opened_include_file(dir_path, file_path,
            ctx.get_iteration_depth(), is_system);

    // store current file position
        iter_ctx->filename = act_pos.get_file();
        iter_ctx->line = act_pos.get_line();
        iter_ctx->if_block_depth = ctx.get_if_block_depth();
        
    // push the old iteration context onto the stack and continue with the new
        ctx.push_iteration_context(act_pos, iter_ctx);
        iter_ctx = new_iter_ctx;
        seen_newline = true;        // fake a newline to trigger pp_directive
        must_emit_line_directive = true;
        
        act_pos.set_file(iter_ctx->filename);  // initialize file position
#if BOOST_WAVE_SUPPORT_PRAGMA_ONCE != 0
        ctx.set_current_filename(iter_ctx->real_filename.c_str());
#endif 

//        last_line = iter_ctx->line;
        act_pos.set_line(iter_ctx->line);
        act_pos.set_column(0);
    }
}

///////////////////////////////////////////////////////////////////////////////
//  
//  on_include(): handle #include ... directives
//
///////////////////////////////////////////////////////////////////////////////

namespace {

    // trim all whitespace from the beginning and the end of the given string
    template <typename StringT>
    inline StringT 
    trim_whitespace(StringT const &s)
    {
        typedef typename StringT::size_type size_type;
        
        size_type first = s.find_first_not_of(" \t\v\f");
        if (StringT::npos == first)
            return StringT();
        size_type last = s.find_last_not_of(" \t\v\f");
        return s.substr(first, last-first+1);
    }
}

template <typename ContextT> 
inline void  
pp_iterator_functor<ContextT>::on_include(
    typename parse_tree_type::const_iterator const &begin,
    typename parse_tree_type::const_iterator const &end, bool include_next)
{
    BOOST_ASSERT(ctx.get_if_block_status());

// preprocess the given token sequence (the body of the #include directive)
get_token_value<result_type, parse_node_type> get_value;
token_sequence_type expanded;
token_sequence_type toexpand;

    std::copy(make_ref_transform_iterator(begin, get_value), 
        make_ref_transform_iterator(end, get_value),
        std::inserter(toexpand, toexpand.end()));

    typename token_sequence_type::iterator begin2 = toexpand.begin();
    ctx.expand_whole_tokensequence(begin2, toexpand.end(), expanded, 
        false);

// now, include the file
string_type s (trim_whitespace(boost::wave::util::impl::as_string(expanded)));
bool is_system = '<' == s[0] && '>' == s[s.size()-1];

    if (!is_system && !('\"' == s[0] && '\"' == s[s.size()-1])) {
    // should resolve into something like <...> or "..."
        BOOST_WAVE_THROW(preprocess_exception, bad_include_statement, 
            s.c_str(), act_pos);
    }
    on_include(s, is_system, include_next);
}

///////////////////////////////////////////////////////////////////////////////
//  
//  on_define(): handle #define directives
//
///////////////////////////////////////////////////////////////////////////////

template <typename ContextT> 
inline void  
pp_iterator_functor<ContextT>::on_define (parse_node_type const &node) 
{
    BOOST_ASSERT(ctx.get_if_block_status());

// retrieve the macro definition from the parse tree
result_type macroname;
std::vector<result_type> macroparameters;
token_sequence_type macrodefinition;
bool has_parameters = false;

    boost::wave::util::retrieve_macroname(node, 
        cpp_grammar_type::rule_ids.plain_define_id, macroname, 
        act_token.get_position());
    has_parameters = boost::wave::util::retrieve_macrodefinition(node, 
        cpp_grammar_type::rule_ids.macro_parameters_id, macroparameters, act_token);
    boost::wave::util::retrieve_macrodefinition(node, 
        cpp_grammar_type::rule_ids.macro_definition_id, macrodefinition, act_token);

    if (has_parameters) {
#if BOOST_WAVE_SUPPORT_VARIADICS_PLACEMARKERS != 0
        if (boost::wave::need_variadics(ctx.get_language())) {
        // test whether ellipsis are given, and if yes, if these are placed as the
        // last argument
            using namespace cpplexer;
            typedef typename std::vector<result_type>::iterator 
                parameter_iterator_t;
            
            bool seen_ellipses = false;
            parameter_iterator_t end = macroparameters.end();
            for (parameter_iterator_t pit = macroparameters.begin(); 
                pit != end; ++pit) 
            {
                if (seen_ellipses) {
                // ellipses are not the last given formal argument
                    BOOST_WAVE_THROW(preprocess_exception, bad_define_statement, 
                        macroname.get_value().c_str(), (*pit).get_position());
                }
                if (T_ELLIPSIS == token_id(*pit)) 
                    seen_ellipses = true;
            }
            
        // if there wasn't an ellipsis, then there shouldn't be a __VA_ARGS__ 
        // placeholder in the definition too [C99 Standard 6.10.3.5]
            if (!seen_ellipses) {
                typedef typename token_sequence_type::iterator definition_iterator_t;

                bool seen_va_args = false;
                definition_iterator_t pend = macrodefinition.end();
                for (definition_iterator_t dit = macrodefinition.begin(); 
                     dit != pend; ++dit) 
                {
                    if (T_IDENTIFIER == token_id(*dit) && 
                        "__VA_ARGS__" == (*dit).get_value())
                    {
                        seen_va_args = true;
                    }
                }
                if (seen_va_args) {
                // must not have seen __VA_ARGS__ placeholder
                    BOOST_WAVE_THROW(preprocess_exception, bad_define_statement, 
                        macroname.get_value().c_str(), act_token.get_position());
                }
            }
        }
        else
#endif // BOOST_WAVE_SUPPORT_VARIADICS_PLACEMARKERS != 0
        {
        // test, that there is no T_ELLIPSES given
            using namespace cpplexer;
            typedef typename std::vector<result_type>::iterator 
                parameter_iterator_t;
            
            parameter_iterator_t end = macroparameters.end();
            for (parameter_iterator_t pit = macroparameters.begin(); 
                pit != end; ++pit) 
            {
                if (T_ELLIPSIS == token_id(*pit)) {
                // if variadics are disabled, no ellipses should be given
                    BOOST_WAVE_THROW(preprocess_exception, bad_define_statement, 
                        macroname.get_value().c_str(), (*pit).get_position());
                }
            }
        }
    }
    
// add the new macro to the macromap
    ctx.add_macro_definition(macroname, has_parameters, macroparameters, 
        macrodefinition);
}

///////////////////////////////////////////////////////////////////////////////
//  
//  on_undefine(): handle #undef directives
//
///////////////////////////////////////////////////////////////////////////////
template <typename ContextT> 
inline void  
pp_iterator_functor<ContextT>::on_undefine (result_type const &token) 
{
    BOOST_ASSERT(ctx.get_if_block_status());

// retrieve the macro name to undefine from the parse tree
    ctx.remove_macro_definition(token.get_value()); // throws for predefined macros
}

///////////////////////////////////////////////////////////////////////////////
//  
//  on_ifdef(): handle #ifdef directives
//
///////////////////////////////////////////////////////////////////////////////
template <typename ContextT> 
inline void  
pp_iterator_functor<ContextT>::on_ifdef(
    typename parse_tree_type::const_iterator const &begin,
    typename parse_tree_type::const_iterator const &end)
{
get_token_value<result_type, parse_node_type> get_value;
bool is_defined = ctx.is_defined_macro(
        make_ref_transform_iterator((*begin).children.begin(), get_value), 
        make_ref_transform_iterator((*begin).children.end(), get_value));

    ctx.enter_if_block(is_defined);
}

///////////////////////////////////////////////////////////////////////////////
//  
//  on_ifndef(): handle #ifndef directives
//
///////////////////////////////////////////////////////////////////////////////
template <typename ContextT> 
inline void  
pp_iterator_functor<ContextT>::on_ifndef(
    typename parse_tree_type::const_iterator const &begin,
    typename parse_tree_type::const_iterator const &end)
{
get_token_value<result_type, parse_node_type> get_value;
bool is_defined = ctx.is_defined_macro(
        make_ref_transform_iterator((*begin).children.begin(), get_value), 
        make_ref_transform_iterator((*begin).children.end(), get_value));

    ctx.enter_if_block(!is_defined);
}

///////////////////////////////////////////////////////////////////////////////
//  
//  on_else(): handle #else directives
//
///////////////////////////////////////////////////////////////////////////////
template <typename ContextT> 
inline void  
pp_iterator_functor<ContextT>::on_else()
{
    if (!ctx.enter_else_block()) {
    // #else without matching #if
        BOOST_WAVE_THROW(preprocess_exception, missing_matching_if, "#else", 
            act_pos);
    }
}

///////////////////////////////////////////////////////////////////////////////
//  
//  on_endif(): handle #endif directives
//
///////////////////////////////////////////////////////////////////////////////
template <typename ContextT> 
inline void  
pp_iterator_functor<ContextT>::on_endif()
{
    if (!ctx.exit_if_block()) {
    // #endif without matching #if
        BOOST_WAVE_THROW(preprocess_exception, missing_matching_if, "#endif", 
            act_pos);
    }
}

///////////////////////////////////////////////////////////////////////////////
//  
//  on_if(): handle #if directives
//
///////////////////////////////////////////////////////////////////////////////
template <typename ContextT> 
inline void  
pp_iterator_functor<ContextT>::on_if(
    typename parse_tree_type::const_iterator const &begin,
    typename parse_tree_type::const_iterator const &end)
{
// preprocess the given sequence into the provided list
get_token_value<result_type, parse_node_type> get_value;
token_sequence_type expanded;
token_sequence_type toexpand;

    std::copy(make_ref_transform_iterator(begin, get_value), 
        make_ref_transform_iterator(end, get_value),
        std::inserter(toexpand, toexpand.end()));

    typename token_sequence_type::iterator begin2 = toexpand.begin();
    ctx.expand_whole_tokensequence(begin2, toexpand.end(), expanded);

// replace all remaining (== undefined) identifiers with an integer literal '0'
    typename token_sequence_type::iterator exp_end = expanded.end();
    for (typename token_sequence_type::iterator exp_it = expanded.begin();
         exp_it != exp_end; ++exp_it)
    {
        using namespace boost::wave;
        
        token_id id = token_id(*exp_it);
        if (IS_CATEGORY(id, IdentifierTokenType) ||
            IS_CATEGORY(id, KeywordTokenType))
        {
            (*exp_it).set_token_id(T_INTLIT);
            (*exp_it).set_value("0");
        }
    }
    
#if BOOST_WAVE_DUMP_CONDITIONAL_EXPRESSIONS != 0
    {
        string_type outstr(boost::wave::util::impl::as_string(toexpand));
        outstr += "(" + boost::wave::util::impl::as_string(expanded) + ")";
        BOOST_WAVE_DUMP_CONDITIONAL_EXPRESSIONS_OUT << "#if " << outstr 
            << std::endl;
    }
#endif

// parse the expression and enter the #if block
    ctx.enter_if_block(grammars::expression_grammar_gen<result_type>::
            evaluate(expanded.begin(), expanded.end(), act_pos,
                ctx.get_if_block_status()));
}

///////////////////////////////////////////////////////////////////////////////
//  
//  on_elif(): handle #elif directives
//
///////////////////////////////////////////////////////////////////////////////
template <typename ContextT> 
inline void  
pp_iterator_functor<ContextT>::on_elif(
    typename parse_tree_type::const_iterator const &begin,
    typename parse_tree_type::const_iterator const &end)
{
    if (ctx.get_if_block_status()) {
        if (!ctx.enter_elif_block(false)) {
        // #else without matching #if
            BOOST_WAVE_THROW(preprocess_exception, missing_matching_if, "#elif", 
                act_pos);
        }
        return;     // #if/previous #elif was true, so don't enter this #elif 
    }
            
// preprocess the given sequence into the provided list
get_token_value<result_type, parse_node_type> get_value;
token_sequence_type expanded;
token_sequence_type toexpand;

    std::copy(make_ref_transform_iterator(begin, get_value),