1 // class template regex -*- C++ -*-
2 
3 // Copyright (C) 2010-2016 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library.  This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
9 // any later version.
10 
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 // GNU General Public License for more details.
15 
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19 
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23 // <http://www.gnu.org/licenses/>.
24 
25 /**
26  *  @file bits/regex_compiler.h
27  *  This is an internal header file, included by other library headers.
28  *  Do not attempt to use it directly. @headername{regex}
29  */
30 
_GLIBCXX_VISIBILITY(default)31 namespace std _GLIBCXX_VISIBILITY(default)
32 {
33 namespace __detail
34 {
35 _GLIBCXX_BEGIN_NAMESPACE_VERSION
36 
37   /**
38    * @addtogroup regex-detail
39    * @{
40    */
41 
42   template<typename, bool, bool>
43     struct _BracketMatcher;
44 
45   /**
46    * @brief Builds an NFA from an input iterator range.
47    *
48    * The %_TraitsT type should fulfill requirements [28.3].
49    */
50   template<typename _TraitsT>
51     class _Compiler
52     {
53     public:
54       typedef typename _TraitsT::char_type        _CharT;
55       typedef const _CharT*                       _IterT;
56       typedef _NFA<_TraitsT>              	  _RegexT;
57       typedef regex_constants::syntax_option_type _FlagT;
58 
59       _Compiler(_IterT __b, _IterT __e,
60 		const typename _TraitsT::locale_type& __traits, _FlagT __flags);
61 
62       shared_ptr<const _RegexT>
63       _M_get_nfa()
64       { return std::move(_M_nfa); }
65 
66     private:
67       typedef _Scanner<_CharT>               _ScannerT;
68       typedef typename _TraitsT::string_type _StringT;
69       typedef typename _ScannerT::_TokenT    _TokenT;
70       typedef _StateSeq<_TraitsT>            _StateSeqT;
71       typedef std::stack<_StateSeqT>         _StackT;
72       typedef std::ctype<_CharT>             _CtypeT;
73 
74       // accepts a specific token or returns false.
75       bool
76       _M_match_token(_TokenT __token);
77 
78       void
79       _M_disjunction();
80 
81       void
82       _M_alternative();
83 
84       bool
85       _M_term();
86 
87       bool
88       _M_assertion();
89 
90       bool
91       _M_quantifier();
92 
93       bool
94       _M_atom();
95 
96       bool
97       _M_bracket_expression();
98 
99       template<bool __icase, bool __collate>
100 	void
101 	_M_insert_any_matcher_ecma();
102 
103       template<bool __icase, bool __collate>
104 	void
105 	_M_insert_any_matcher_posix();
106 
107       template<bool __icase, bool __collate>
108 	void
109 	_M_insert_char_matcher();
110 
111       template<bool __icase, bool __collate>
112 	void
113 	_M_insert_character_class_matcher();
114 
115       template<bool __icase, bool __collate>
116 	void
117 	_M_insert_bracket_matcher(bool __neg);
118 
119       // Returns true if successfully matched one term and should continue.
120       // Returns false if the compiler should move on.
121       template<bool __icase, bool __collate>
122 	bool
123 	_M_expression_term(pair<bool, _CharT>& __last_char,
124 			   _BracketMatcher<_TraitsT, __icase, __collate>&
125 			   __matcher);
126 
127       int
128       _M_cur_int_value(int __radix);
129 
130       bool
131       _M_try_char();
132 
133       _StateSeqT
134       _M_pop()
135       {
136 	auto ret = _M_stack.top();
137 	_M_stack.pop();
138 	return ret;
139       }
140 
141       _FlagT              _M_flags;
142       _ScannerT           _M_scanner;
143       shared_ptr<_RegexT> _M_nfa;
144       _StringT            _M_value;
145       _StackT             _M_stack;
146       const _TraitsT&     _M_traits;
147       const _CtypeT&      _M_ctype;
148     };
149 
150   template<typename _Tp>
151     struct __has_contiguous_iter : std::false_type { };
152 
153   template<typename _Ch, typename _Tr, typename _Alloc>
154     struct __has_contiguous_iter<std::basic_string<_Ch, _Tr, _Alloc>>
155     : std::true_type
156     { };
157 
158   template<typename _Tp, typename _Alloc>
159     struct __has_contiguous_iter<std::vector<_Tp, _Alloc>>
160     : std::true_type
161     { };
162 
163   template<typename _Tp>
164     struct __is_contiguous_normal_iter : std::false_type { };
165 
166   template<typename _CharT>
167     struct __is_contiguous_normal_iter<_CharT*> : std::true_type { };
168 
169   template<typename _Tp, typename _Cont>
170     struct
171     __is_contiguous_normal_iter<__gnu_cxx::__normal_iterator<_Tp, _Cont>>
172     : __has_contiguous_iter<_Cont>::type
173     { };
174 
175   template<typename _Iter, typename _TraitsT>
176     using __enable_if_contiguous_normal_iter
177       = typename enable_if< __is_contiguous_normal_iter<_Iter>::value,
178                            std::shared_ptr<const _NFA<_TraitsT>> >::type;
179 
180   template<typename _Iter, typename _TraitsT>
181     using __disable_if_contiguous_normal_iter
182       = typename enable_if< !__is_contiguous_normal_iter<_Iter>::value,
183                            std::shared_ptr<const _NFA<_TraitsT>> >::type;
184 
185   template<typename _FwdIter, typename _TraitsT>
186     inline __enable_if_contiguous_normal_iter<_FwdIter, _TraitsT>
187     __compile_nfa(_FwdIter __first, _FwdIter __last,
188 		  const typename _TraitsT::locale_type& __loc,
189 		  regex_constants::syntax_option_type __flags)
190     {
191       size_t __len = __last - __first;
192       const auto* __cfirst = __len ? std::__addressof(*__first) : nullptr;
193       using _Cmplr = _Compiler<_TraitsT>;
194       return _Cmplr(__cfirst, __cfirst + __len, __loc, __flags)._M_get_nfa();
195     }
196 
197   template<typename _FwdIter, typename _TraitsT>
198     inline __disable_if_contiguous_normal_iter<_FwdIter, _TraitsT>
199     __compile_nfa(_FwdIter __first, _FwdIter __last,
200 		  const typename _TraitsT::locale_type& __loc,
201 		  regex_constants::syntax_option_type __flags)
202     {
203       using char_type = typename _TraitsT::char_type;
204       const basic_string<char_type> __str(__first, __last);
205       return __compile_nfa<const char_type*, _TraitsT>(__str.data(),
206 	  __str.data() + __str.size(), __loc, __flags);
207     }
208 
209   // [28.13.14]
210   template<typename _TraitsT, bool __icase, bool __collate>
211     class _RegexTranslator
212     {
213     public:
214       typedef typename _TraitsT::char_type	      _CharT;
215       typedef typename _TraitsT::string_type	      _StringT;
216       typedef typename std::conditional<__collate,
217 					_StringT,
218 					_CharT>::type _StrTransT;
219 
220       explicit
221       _RegexTranslator(const _TraitsT& __traits)
222       : _M_traits(__traits)
223       { }
224 
225       _CharT
226       _M_translate(_CharT __ch) const
227       {
228 	if (__icase)
229 	  return _M_traits.translate_nocase(__ch);
230 	else if (__collate)
231 	  return _M_traits.translate(__ch);
232 	else
233 	  return __ch;
234       }
235 
236       _StrTransT
237       _M_transform(_CharT __ch) const
238       {
239 	return _M_transform_impl(__ch, typename integral_constant<bool,
240 				 __collate>::type());
241       }
242 
243     private:
244       _StrTransT
245       _M_transform_impl(_CharT __ch, false_type) const
246       { return __ch; }
247 
248       _StrTransT
249       _M_transform_impl(_CharT __ch, true_type) const
250       {
251 	_StrTransT __str = _StrTransT(1, _M_translate(__ch));
252 	return _M_traits.transform(__str.begin(), __str.end());
253       }
254 
255       const _TraitsT& _M_traits;
256     };
257 
258   template<typename _TraitsT>
259     class _RegexTranslator<_TraitsT, false, false>
260     {
261     public:
262       typedef typename _TraitsT::char_type _CharT;
263       typedef _CharT                       _StrTransT;
264 
265       explicit
266       _RegexTranslator(const _TraitsT&)
267       { }
268 
269       _CharT
270       _M_translate(_CharT __ch) const
271       { return __ch; }
272 
273       _StrTransT
274       _M_transform(_CharT __ch) const
275       { return __ch; }
276     };
277 
278   template<typename _TraitsT, bool __is_ecma, bool __icase, bool __collate>
279     struct _AnyMatcher;
280 
281   template<typename _TraitsT, bool __icase, bool __collate>
282     struct _AnyMatcher<_TraitsT, false, __icase, __collate>
283     {
284       typedef _RegexTranslator<_TraitsT, __icase, __collate> _TransT;
285       typedef typename _TransT::_CharT                       _CharT;
286 
287       explicit
288       _AnyMatcher(const _TraitsT& __traits)
289       : _M_translator(__traits)
290       { }
291 
292       bool
293       operator()(_CharT __ch) const
294       {
295 	static auto __nul = _M_translator._M_translate('\0');
296 	return _M_translator._M_translate(__ch) != __nul;
297       }
298 
299       _TransT _M_translator;
300     };
301 
302   template<typename _TraitsT, bool __icase, bool __collate>
303     struct _AnyMatcher<_TraitsT, true, __icase, __collate>
304     {
305       typedef _RegexTranslator<_TraitsT, __icase, __collate> _TransT;
306       typedef typename _TransT::_CharT                       _CharT;
307 
308       explicit
309       _AnyMatcher(const _TraitsT& __traits)
310       : _M_translator(__traits)
311       { }
312 
313       bool
314       operator()(_CharT __ch) const
315       { return _M_apply(__ch, typename is_same<_CharT, char>::type()); }
316 
317       bool
318       _M_apply(_CharT __ch, true_type) const
319       {
320 	auto __c = _M_translator._M_translate(__ch);
321 	auto __n = _M_translator._M_translate('\n');
322 	auto __r = _M_translator._M_translate('\r');
323 	return __c != __n && __c != __r;
324       }
325 
326       bool
327       _M_apply(_CharT __ch, false_type) const
328       {
329 	auto __c = _M_translator._M_translate(__ch);
330 	auto __n = _M_translator._M_translate('\n');
331 	auto __r = _M_translator._M_translate('\r');
332 	auto __u2028 = _M_translator._M_translate(u'\u2028');
333 	auto __u2029 = _M_translator._M_translate(u'\u2029');
334 	return __c != __n && __c != __r && __c != __u2028 && __c != __u2029;
335       }
336 
337       _TransT _M_translator;
338     };
339 
340   template<typename _TraitsT, bool __icase, bool __collate>
341     struct _CharMatcher
342     {
343       typedef _RegexTranslator<_TraitsT, __icase, __collate> _TransT;
344       typedef typename _TransT::_CharT                       _CharT;
345 
346       _CharMatcher(_CharT __ch, const _TraitsT& __traits)
347       : _M_translator(__traits), _M_ch(_M_translator._M_translate(__ch))
348       { }
349 
350       bool
351       operator()(_CharT __ch) const
352       { return _M_ch == _M_translator._M_translate(__ch); }
353 
354       _TransT _M_translator;
355       _CharT  _M_ch;
356     };
357 
358   /// Matches a character range (bracket expression)
359   template<typename _TraitsT, bool __icase, bool __collate>
360     struct _BracketMatcher
361     {
362     public:
363       typedef _RegexTranslator<_TraitsT, __icase, __collate> _TransT;
364       typedef typename _TransT::_CharT                       _CharT;
365       typedef typename _TransT::_StrTransT                   _StrTransT;
366       typedef typename _TraitsT::string_type                 _StringT;
367       typedef typename _TraitsT::char_class_type             _CharClassT;
368 
369     public:
370       _BracketMatcher(bool __is_non_matching,
371 		      const _TraitsT& __traits)
372       : _M_class_set(0), _M_translator(__traits), _M_traits(__traits),
373       _M_is_non_matching(__is_non_matching)
374       { }
375 
376       bool
377       operator()(_CharT __ch) const
378       {
379 	_GLIBCXX_DEBUG_ASSERT(_M_is_ready);
380 	return _M_apply(__ch, _UseCache());
381       }
382 
383       void
384       _M_add_char(_CharT __c)
385       {
386 	_M_char_set.push_back(_M_translator._M_translate(__c));
387 	_GLIBCXX_DEBUG_ONLY(_M_is_ready = false);
388       }
389 
390       _StringT
391       _M_add_collate_element(const _StringT& __s)
392       {
393 	auto __st = _M_traits.lookup_collatename(__s.data(),
394 						 __s.data() + __s.size());
395 	if (__st.empty())
396 	  __throw_regex_error(regex_constants::error_collate,
397 			      "Invalid collate element.");
398 	_M_char_set.push_back(_M_translator._M_translate(__st[0]));
399 	_GLIBCXX_DEBUG_ONLY(_M_is_ready = false);
400 	return __st;
401       }
402 
403       void
404       _M_add_equivalence_class(const _StringT& __s)
405       {
406 	auto __st = _M_traits.lookup_collatename(__s.data(),
407 						 __s.data() + __s.size());
408 	if (__st.empty())
409 	  __throw_regex_error(regex_constants::error_collate,
410 			      "Invalid equivalence class.");
411 	__st = _M_traits.transform_primary(__st.data(),
412 					   __st.data() + __st.size());
413 	_M_equiv_set.push_back(__st);
414 	_GLIBCXX_DEBUG_ONLY(_M_is_ready = false);
415       }
416 
417       // __neg should be true for \D, \S and \W only.
418       void
419       _M_add_character_class(const _StringT& __s, bool __neg)
420       {
421 	auto __mask = _M_traits.lookup_classname(__s.data(),
422 						 __s.data() + __s.size(),
423 						 __icase);
424 	if (__mask == 0)
425 	  __throw_regex_error(regex_constants::error_collate,
426 			      "Invalid character class.");
427 	if (!__neg)
428 	  _M_class_set |= __mask;
429 	else
430 	  _M_neg_class_set.push_back(__mask);
431 	_GLIBCXX_DEBUG_ONLY(_M_is_ready = false);
432       }
433 
434       void
435       _M_make_range(_CharT __l, _CharT __r)
436       {
437 	if (__l > __r)
438 	  __throw_regex_error(regex_constants::error_range,
439 			      "Invalid range in bracket expression.");
440 	_M_range_set.push_back(make_pair(_M_translator._M_transform(__l),
441 					 _M_translator._M_transform(__r)));
442 	_GLIBCXX_DEBUG_ONLY(_M_is_ready = false);
443       }
444 
445       void
446       _M_ready()
447       {
448 	std::sort(_M_char_set.begin(), _M_char_set.end());
449 	auto __end = std::unique(_M_char_set.begin(), _M_char_set.end());
450 	_M_char_set.erase(__end, _M_char_set.end());
451 	_M_make_cache(_UseCache());
452 	_GLIBCXX_DEBUG_ONLY(_M_is_ready = true);
453       }
454 
455     private:
456       // Currently we only use the cache for char
457       typedef typename std::is_same<_CharT, char>::type _UseCache;
458 
459       static constexpr size_t
460       _S_cache_size()
461       {
462 	return 1ul << (sizeof(_CharT) * __CHAR_BIT__ * int(_UseCache::value));
463       }
464 
465       struct _Dummy { };
466       typedef typename std::conditional<_UseCache::value,
467 					std::bitset<_S_cache_size()>,
468 					_Dummy>::type _CacheT;
469       typedef typename std::make_unsigned<_CharT>::type _UnsignedCharT;
470 
471       bool
472       _M_apply(_CharT __ch, false_type) const;
473 
474       bool
475       _M_apply(_CharT __ch, true_type) const
476       { return _M_cache[static_cast<_UnsignedCharT>(__ch)]; }
477 
478       void
479       _M_make_cache(true_type)
480       {
481 	for (unsigned __i = 0; __i < _M_cache.size(); __i++)
482 	  _M_cache[__i] = _M_apply(static_cast<_CharT>(__i), false_type());
483       }
484 
485       void
486       _M_make_cache(false_type)
487       { }
488 
489     private:
490       std::vector<_CharT>                       _M_char_set;
491       std::vector<_StringT>                     _M_equiv_set;
492       std::vector<pair<_StrTransT, _StrTransT>> _M_range_set;
493       std::vector<_CharClassT>                  _M_neg_class_set;
494       _CharClassT                               _M_class_set;
495       _TransT                                   _M_translator;
496       const _TraitsT&                           _M_traits;
497       bool                                      _M_is_non_matching;
498       _CacheT					_M_cache;
499 #ifdef _GLIBCXX_DEBUG
500       bool                                      _M_is_ready = false;
501 #endif
502     };
503 
504  //@} regex-detail
505 _GLIBCXX_END_NAMESPACE_VERSION
506 } // namespace __detail
507 } // namespace std
508 
509 #include <bits/regex_compiler.tcc>
510