Chris@16: /*=============================================================================
Chris@16:     Boost.Wave: A Standard compliant C++ preprocessor library
Chris@16:     Whitespace eater
Chris@16:     
Chris@16:     http://www.boost.org/
Chris@16: 
Chris@16:     Copyright (c) 2003 Paul Mensonides
Chris@16:     Copyright (c) 2001-2012 Hartmut Kaiser. 
Chris@16:     Distributed under the Boost Software License, Version 1.0. (See accompanying 
Chris@16:     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: =============================================================================*/
Chris@16: 
Chris@16: #if !defined(WHITESPACE_HANDLING_HPP_INCLUDED)
Chris@16: #define WHITESPACE_HANDLING_HPP_INCLUDED
Chris@16: 
Chris@16: #include <boost/wave/wave_config.hpp>   
Chris@16: #include <boost/wave/token_ids.hpp>   
Chris@16: #include <boost/wave/preprocessing_hooks.hpp>
Chris@16: #include <boost/wave/language_support.hpp>
Chris@16: 
Chris@16: // this must occur after all of the includes and before any code appears
Chris@16: #ifdef BOOST_HAS_ABI_HEADERS
Chris@16: #include BOOST_ABI_PREFIX
Chris@16: #endif
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: namespace boost {
Chris@16: namespace wave {
Chris@16: namespace context_policies {
Chris@16: 
Chris@16: namespace util {
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     //  This function returns true if the given C style comment contains at 
Chris@16:     //  least one newline
Chris@16:     template <typename TokenT>
Chris@16:     bool ccomment_has_newline(TokenT const& token)
Chris@16:     {
Chris@16:         using namespace boost::wave;
Chris@16: 
Chris@16:         if (T_CCOMMENT == token_id(token) &&
Chris@16:             TokenT::string_type::npos != token.get_value().find_first_of("\n"))
Chris@16:         {
Chris@16:             return true;
Chris@16:         }
Chris@16:         return false;
Chris@16:     }
Chris@16: 
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     //  This function returns the number of newlines in the given C style 
Chris@16:     //  comment 
Chris@16:     template <typename TokenT>
Chris@16:     int ccomment_count_newlines(TokenT const& token)
Chris@16:     {
Chris@16:         using namespace boost::wave;
Chris@16:         int newlines = 0;
Chris@16:         if (T_CCOMMENT == token_id(token)) {
Chris@16:         typename TokenT::string_type const& value = token.get_value();
Chris@16:         typename TokenT::string_type::size_type p = value.find_first_of("\n");
Chris@16: 
Chris@16:             while (TokenT::string_type::npos != p) {
Chris@16:                 ++newlines;
Chris@16:                 p = value.find_first_of("\n", p+1);
Chris@16:             } 
Chris@16:         }
Chris@16:         return newlines;
Chris@16:     }
Chris@16: 
Chris@16: #if BOOST_WAVE_SUPPORT_CPP0X != 0
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     //  This function returns the number of newlines in the given C++11 style 
Chris@16:     //  raw string
Chris@16:     template <typename TokenT>
Chris@16:     int rawstring_count_newlines(TokenT const& token)
Chris@16:     {
Chris@16:         using namespace boost::wave;
Chris@16:         int newlines = 0;
Chris@16:         if (T_RAWSTRINGLIT == token_id(token)) {
Chris@16:         typename TokenT::string_type const& value = token.get_value();
Chris@16:         typename TokenT::string_type::size_type p = value.find_first_of("\n");
Chris@16: 
Chris@16:             while (TokenT::string_type::npos != p) {
Chris@16:                 ++newlines;
Chris@16:                 p = value.find_first_of("\n", p+1);
Chris@16:             } 
Chris@16:         }
Chris@16:         return newlines;
Chris@16:     }
Chris@16: #endif
Chris@16: }
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: template <typename TokenT>
Chris@16: class eat_whitespace 
Chris@16: :   public default_preprocessing_hooks
Chris@16: {
Chris@16: public:
Chris@16:     eat_whitespace();
Chris@16: 
Chris@16:     template <typename ContextT>
Chris@16:     bool may_skip_whitespace(ContextT const& ctx, TokenT &token, 
Chris@16:         bool &skipped_newline);
Chris@16:     template <typename ContextT>
Chris@16:     bool may_skip_whitespace(ContextT const& ctx, TokenT &token, 
Chris@16:         bool preserve_comments_, bool preserve_bol_whitespace_,
Chris@16:         bool &skipped_newline);
Chris@16: 
Chris@16: protected:
Chris@16:     bool skip_cppcomment(boost::wave::token_id id)
Chris@16:     {
Chris@16:         return !preserve_comments && T_CPPCOMMENT == id;
Chris@16:     }
Chris@16: 
Chris@16: private:
Chris@16:     typedef bool state_t(TokenT &token, bool &skipped_newline);
Chris@16:     state_t eat_whitespace::* state;
Chris@16:     state_t general, newline, newline_2nd, whitespace, bol_whitespace;
Chris@16:     bool preserve_comments;
Chris@16:     bool preserve_bol_whitespace;
Chris@16: };
Chris@16: 
Chris@16: template <typename TokenT>
Chris@16: inline 
Chris@16: eat_whitespace<TokenT>::eat_whitespace()
Chris@16: :   state(&eat_whitespace::newline), preserve_comments(false),
Chris@16:     preserve_bol_whitespace(false)
Chris@16: {
Chris@16: }
Chris@16: 
Chris@16: template <typename TokenT>
Chris@16: template <typename ContextT>
Chris@16: inline bool 
Chris@16: eat_whitespace<TokenT>::may_skip_whitespace(ContextT const& ctx, TokenT &token, 
Chris@16:     bool &skipped_newline) 
Chris@16: {
Chris@16:     // re-initialize the preserve comments state
Chris@16:     preserve_comments = boost::wave::need_preserve_comments(ctx.get_language());
Chris@16:     return (this->*state)(token, skipped_newline);
Chris@16: }
Chris@16: 
Chris@16: template <typename TokenT>
Chris@16: template <typename ContextT>
Chris@16: inline bool 
Chris@16: eat_whitespace<TokenT>::may_skip_whitespace(ContextT const& ctx, TokenT &token, 
Chris@16:     bool preserve_comments_, bool preserve_bol_whitespace_,
Chris@16:     bool &skipped_newline) 
Chris@16: {
Chris@16:     // re-initialize the preserve comments state
Chris@16:     preserve_comments = preserve_comments_;
Chris@16:     preserve_bol_whitespace = preserve_bol_whitespace_;
Chris@16:     return (this->*state)(token, skipped_newline);
Chris@16: }
Chris@16: 
Chris@16: template <typename TokenT>
Chris@16: inline bool 
Chris@16: eat_whitespace<TokenT>::general(TokenT &token, bool &skipped_newline) 
Chris@16: {
Chris@16:     using namespace boost::wave;
Chris@16: 
Chris@16:     token_id id = token_id(token);
Chris@16:     if (T_NEWLINE == id || T_CPPCOMMENT == id) {
Chris@16:         state = &eat_whitespace::newline;
Chris@16:     }
Chris@16:     else if (T_SPACE == id || T_SPACE2 == id || T_CCOMMENT == id) {
Chris@16:         state = &eat_whitespace::whitespace;
Chris@16: 
Chris@16:         if (util::ccomment_has_newline(token)) 
Chris@16:             skipped_newline = true;
Chris@16: 
Chris@16:         if ((!preserve_comments || T_CCOMMENT != id) && 
Chris@16:             token.get_value().size() > 1)
Chris@16:         {
Chris@16:             token.set_value(" ");   // replace with a single space
Chris@16:         }
Chris@16:     }
Chris@16:     else {
Chris@16:         state = &eat_whitespace::general;
Chris@16:     }
Chris@16:     return false;
Chris@16: }
Chris@16: 
Chris@16: template <typename TokenT>
Chris@16: inline bool 
Chris@16: eat_whitespace<TokenT>::newline(TokenT &token, bool &skipped_newline) 
Chris@16: {
Chris@16:     using namespace boost::wave;
Chris@16: 
Chris@16:     token_id id = token_id(token);
Chris@16:     if (T_NEWLINE == id || T_CPPCOMMENT == id) {
Chris@16:         skipped_newline = true;
Chris@16:         state = &eat_whitespace::newline_2nd;
Chris@16:         return T_NEWLINE == id || skip_cppcomment(id);
Chris@16:     }
Chris@16: 
Chris@16:     if (T_SPACE != id && T_SPACE2 != id && T_CCOMMENT != id) 
Chris@16:         return general(token, skipped_newline);
Chris@16: 
Chris@16:     if (T_CCOMMENT == id) {
Chris@16:         if (util::ccomment_has_newline(token)) {
Chris@16:             skipped_newline = true;
Chris@16:             state = &eat_whitespace::newline_2nd;
Chris@16:         }
Chris@16:         if (preserve_comments) {
Chris@16:             state = &eat_whitespace::general;
Chris@16:             return false;
Chris@16:         }
Chris@16:         return true;
Chris@16:     }
Chris@16: 
Chris@16:     if (preserve_bol_whitespace) {
Chris@16:         state = &eat_whitespace::bol_whitespace;
Chris@16:         return false;
Chris@16:     }
Chris@16: 
Chris@16:     return true;
Chris@16: }
Chris@16: 
Chris@16: template <typename TokenT>
Chris@16: inline bool 
Chris@16: eat_whitespace<TokenT>::newline_2nd(TokenT &token, bool &skipped_newline) 
Chris@16: {
Chris@16:     using namespace boost::wave;
Chris@16: 
Chris@16:     token_id id = token_id(token);
Chris@16:     if (T_SPACE == id || T_SPACE2 == id) {
Chris@16:         if (preserve_bol_whitespace) {
Chris@16:             state = &eat_whitespace::bol_whitespace;
Chris@16:             return false;
Chris@16:         }
Chris@16:         return true;
Chris@16:     }
Chris@16: 
Chris@16:     if (T_CCOMMENT == id) {
Chris@16:         if (util::ccomment_has_newline(token))
Chris@16:             skipped_newline = true;
Chris@16: 
Chris@16:         if (preserve_comments) {
Chris@16:             state = &eat_whitespace::general;
Chris@16:             return false;
Chris@16:         }
Chris@16:         return  true;
Chris@16:     }
Chris@16: 
Chris@16:     if (T_NEWLINE != id && T_CPPCOMMENT != id) 
Chris@16:         return general(token, skipped_newline);
Chris@16: 
Chris@16:     skipped_newline = true;
Chris@16:     return T_NEWLINE == id || skip_cppcomment(id);
Chris@16: }
Chris@16: 
Chris@16: template <typename TokenT>
Chris@16: inline bool 
Chris@16: eat_whitespace<TokenT>::bol_whitespace(TokenT &token, bool &skipped_newline) 
Chris@16: {
Chris@16:     using namespace boost::wave;
Chris@16: 
Chris@16:     token_id id = token_id(token);
Chris@16:     if (T_SPACE == id || T_SPACE2 == id) 
Chris@16:         return !preserve_bol_whitespace;
Chris@16: 
Chris@16:     return general(token, skipped_newline);
Chris@16: }
Chris@16: 
Chris@16: template <typename TokenT>
Chris@16: inline bool 
Chris@16: eat_whitespace<TokenT>::whitespace(TokenT &token, bool &skipped_newline) 
Chris@16: {
Chris@16:     using namespace boost::wave;
Chris@16: 
Chris@16:     token_id id = token_id(token);
Chris@16:     if (T_SPACE != id && T_SPACE2 != id && 
Chris@16:         T_CCOMMENT != id && T_CPPCOMMENT != id) 
Chris@16:     {
Chris@16:         return general(token, skipped_newline);
Chris@16:     }
Chris@16: 
Chris@16:     if (T_CCOMMENT == id) {
Chris@16:         if (util::ccomment_has_newline(token))
Chris@16:             skipped_newline = true;
Chris@16:         return !preserve_comments;
Chris@16:     }
Chris@16: 
Chris@16:     return T_SPACE == id || T_SPACE2 == id || skip_cppcomment(id);
Chris@16: }
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: }   // namespace context_policies
Chris@16: }   // namespace wave
Chris@16: }   // namespace boost
Chris@16: 
Chris@16: // the suffix header occurs after all of the code
Chris@16: #ifdef BOOST_HAS_ABI_HEADERS
Chris@16: #include BOOST_ABI_SUFFIX
Chris@16: #endif
Chris@16: 
Chris@16: #endif // !defined(WHITESPACE_HANDLING_HPP_INCLUDED)
Chris@16: