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1 /*=============================================================================
2     Boost.Wave: A Standard compliant C++ preprocessor library
3 
4     Definition of the lexer iterator for the xpressive lexer
5 
6     http://www.boost.org/
7 
8     Copyright (c) 2001-2010 Hartmut Kaiser. Distributed under the Boost
9     Software License, Version 1.0. (See accompanying file
10     LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
11 =============================================================================*/
12 
13 #if !defined(XLEX_ITERATOR_HPP)
14 #define XLEX_ITERATOR_HPP
15 
16 #include <string>
17 #include <iosfwd>
18 
19 #include <boost/assert.hpp>
20 #include <boost/shared_ptr.hpp>
21 #include <boost/spirit/include/support_multi_pass.hpp>
22 
23 #include <boost/wave/language_support.hpp>
24 #include <boost/wave/util/file_position.hpp>
25 #include <boost/wave/util/functor_input.hpp>
26 
27 #include "xlex_interface.hpp"
28 
29 #if 0 != __COMO_VERSION__ || !BOOST_WORKAROUND(BOOST_MSVC, <= 1310)
30 #define BOOST_WAVE_EOF_PREFIX static
31 #else
32 #define BOOST_WAVE_EOF_PREFIX
33 #endif
34 
35 ///////////////////////////////////////////////////////////////////////////////
36 namespace boost {
37 namespace wave {
38 namespace cpplexer {
39 namespace xlex {
40 namespace impl {
41 
42 ///////////////////////////////////////////////////////////////////////////////
43 //
44 //  lex_iterator_functor_shim
45 //
46 ///////////////////////////////////////////////////////////////////////////////
47 
48 template <typename TokenT>
49 class xlex_iterator_functor_shim
50 {
51     typedef typename TokenT::position_type  position_type;
52 
53 public:
xlex_iterator_functor_shim()54     xlex_iterator_functor_shim()
55 #if /*0 != __DECCXX_VER || */defined(__PGI)
56       : eof()
57 #endif // 0 != __DECCXX_VER
58     {}
59 
60 // interface to the boost::spirit::classic::iterator_policies::functor_input
61 // policy
62     typedef TokenT result_type;
63 
64     BOOST_WAVE_EOF_PREFIX result_type const eof;
65     typedef xlex_iterator_functor_shim unique;
66     typedef lex_input_interface<TokenT>* shared;
67 
68     template <typename MultiPass>
get_next(MultiPass & mp,result_type & result)69     static result_type& get_next(MultiPass& mp, result_type& result)
70     {
71         return mp.shared()->ftor->get(result);
72     }
73 
74     // this will be called whenever the last reference to a multi_pass will
75     // be released
76     template <typename MultiPass>
destroy(MultiPass & mp)77     static void destroy(MultiPass& mp)
78     {
79         delete mp.shared()->ftor;
80     }
81 
82     template <typename MultiPass>
set_position(MultiPass & mp,position_type const & pos)83     static void set_position(MultiPass& mp, position_type const &pos)
84     {
85         mp.shared()->ftor->set_position(pos);
86     }
87 
88 #if BOOST_WAVE_SUPPORT_PRAGMA_ONCE != 0
89     template <typename MultiPass>
has_include_guards(MultiPass & mp,std::string & guard_name)90     static bool has_include_guards(MultiPass& mp, std::string& guard_name)
91     {
92         return mp.shared()->ftor->has_include_guards(guard_name);
93     }
94 #endif
95 
96 private:
97     boost::shared_ptr<lex_input_interface<TokenT> > functor_ptr;
98 };
99 
100 #if 0 != __COMO_VERSION__ || !BOOST_WORKAROUND(BOOST_MSVC, <= 1310)
101 ///////////////////////////////////////////////////////////////////////////////
102 //  eof token
103 template <typename TokenT>
104 typename xlex_iterator_functor_shim<TokenT>::result_type const
105    xlex_iterator_functor_shim<TokenT>::eof =
106        typename xlex_iterator_functor_shim<TokenT>::result_type();
107 #endif // 0 != __COMO_VERSION__
108 
109 ///////////////////////////////////////////////////////////////////////////////
110 }   // namespace impl
111 
112 ///////////////////////////////////////////////////////////////////////////////
113 //
114 //  xlex_iterator
115 //
116 //      A generic C++ lexer interface class, which allows to plug in different
117 //      lexer implementations (template parameter LexT). The following
118 //      requirement apply:
119 //
120 //          - the lexer type should have a function implemented, which returns
121 //            the next lexed token from the input stream:
122 //                typename LexT::token_type get();
123 //          - at the end of the input stream this function should return the
124 //            eof token equivalent
125 //          - the lexer should implement a constructor taking two iterators
126 //            pointing to the beginning and the end of the input stream and
127 //            a third parameter containing the name of the parsed input file,
128 //            the 4th parameter contains the information about the mode the
129 //            preprocessor is used in (C99/C++ mode etc.)
130 //
131 ///////////////////////////////////////////////////////////////////////////////
132 
133 ///////////////////////////////////////////////////////////////////////////////
134 //  Divide the given functor type into its components (unique and shared)
135 //  and build a std::pair from these parts
136 template <typename FunctorData>
137 struct make_multi_pass
138 {
139     typedef
140         std::pair<typename FunctorData::unique, typename FunctorData::shared>
141     functor_data_type;
142     typedef typename FunctorData::result_type result_type;
143 
144     typedef boost::spirit::iterator_policies::split_functor_input input_policy;
145     typedef boost::spirit::iterator_policies::ref_counted ownership_policy;
146 #if defined(BOOST_WAVE_DEBUG)
147     typedef boost::spirit::iterator_policies::buf_id_check check_policy;
148 #else
149     typedef boost::spirit::iterator_policies::no_check check_policy;
150 #endif
151     typedef boost::spirit::iterator_policies::split_std_deque storage_policy;
152 
153     typedef boost::spirit::iterator_policies::default_policy<
154             ownership_policy, check_policy, input_policy, storage_policy>
155         policy_type;
156     typedef boost::spirit::multi_pass<functor_data_type, policy_type> type;
157 };
158 
159 ///////////////////////////////////////////////////////////////////////////////
160 template <typename TokenT>
161 class xlex_iterator
162 :   public make_multi_pass<impl::xlex_iterator_functor_shim<TokenT> >::type
163 {
164     typedef impl::xlex_iterator_functor_shim<TokenT> input_policy_type;
165 
166     typedef typename make_multi_pass<input_policy_type>::type base_type;
167     typedef typename make_multi_pass<input_policy_type>::functor_data_type
168         functor_data_type;
169 
170     typedef typename input_policy_type::unique unique_functor_type;
171     typedef typename input_policy_type::shared shared_functor_type;
172 
173 public:
174     typedef TokenT token_type;
175 
xlex_iterator()176     xlex_iterator()
177     {}
178 
179     template <typename IteratorT>
xlex_iterator(IteratorT const & first,IteratorT const & last,typename TokenT::position_type const & pos,boost::wave::language_support language)180     xlex_iterator(IteratorT const &first, IteratorT const &last,
181             typename TokenT::position_type const &pos,
182             boost::wave::language_support language)
183     :   base_type(
184             functor_data_type(
185                 unique_functor_type(),
186                 xlex_input_interface<TokenT>
187                     ::new_lexer(first, last, pos, language)
188             )
189         )
190     {}
191 
set_position(typename TokenT::position_type const & pos)192     void set_position(typename TokenT::position_type const &pos)
193     {
194         typedef typename token_type::position_type position_type;
195 
196     // set the new position in the current token
197     token_type const& currtoken = this->base_type::dereference(*this);
198     position_type currpos = currtoken.get_position();
199 
200         currpos.set_file(pos.get_file());
201         currpos.set_line(pos.get_line());
202         const_cast<token_type&>(currtoken).set_position(currpos);
203 
204     // set the new position for future tokens as well
205         if (token_type::string_type::npos !=
206             currtoken.get_value().find_first_of('\n'))
207         {
208             currpos.set_line(pos.get_line() + 1);
209         }
210         unique_functor_type::set_position(*this, currpos);
211     }
212 
213 #if BOOST_WAVE_SUPPORT_PRAGMA_ONCE != 0
214     // return, whether the current file has include guards
215     // this function returns meaningful results only if the file was scanned
216     // completely
has_include_guards(std::string & guard_name) const217     bool has_include_guards(std::string& guard_name) const
218     {
219         return unique_functor_type::has_include_guards(*this, guard_name);
220     }
221 #endif
222 };
223 
224 ///////////////////////////////////////////////////////////////////////////////
225 }   // namespace xlex
226 }   // namespace cpplexer
227 }   // namespace wave
228 }   // namespace boost
229 
230 #undef BOOST_WAVE_EOF_PREFIX
231 
232 #endif // !defined(XLEX_ITERATOR_HPP)
233