1 // class template regex -*- C++ -*-
2
3 // Copyright (C) 2013-2016 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_scanner.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 struct _ScannerBase
43 {
44 public:
45 /// Token types returned from the scanner.
46 enum _TokenT
47 {
48 _S_token_anychar,
49 _S_token_ord_char,
50 _S_token_oct_num,
51 _S_token_hex_num,
52 _S_token_backref,
53 _S_token_subexpr_begin,
54 _S_token_subexpr_no_group_begin,
55 _S_token_subexpr_lookahead_begin, // neg if _M_value[0] == 'n'
56 _S_token_subexpr_end,
57 _S_token_bracket_begin,
58 _S_token_bracket_neg_begin,
59 _S_token_bracket_end,
60 _S_token_interval_begin,
61 _S_token_interval_end,
62 _S_token_quoted_class,
63 _S_token_char_class_name,
64 _S_token_collsymbol,
65 _S_token_equiv_class_name,
66 _S_token_opt,
67 _S_token_or,
68 _S_token_closure0,
69 _S_token_closure1,
70 _S_token_line_begin,
71 _S_token_line_end,
72 _S_token_word_bound, // neg if _M_value[0] == 'n'
73 _S_token_comma,
74 _S_token_dup_count,
75 _S_token_eof,
76 _S_token_unknown
77 };
78
79 protected:
80 typedef regex_constants::syntax_option_type _FlagT;
81
82 enum _StateT
83 {
84 _S_state_normal,
85 _S_state_in_brace,
86 _S_state_in_bracket,
87 };
88
89 protected:
90 _ScannerBase(_FlagT __flags)
91 : _M_state(_S_state_normal),
92 _M_flags(__flags),
93 _M_escape_tbl(_M_is_ecma()
94 ? _M_ecma_escape_tbl
95 : _M_awk_escape_tbl),
96 _M_spec_char(_M_is_ecma()
97 ? _M_ecma_spec_char
98 : _M_flags & regex_constants::basic
99 ? _M_basic_spec_char
100 : _M_flags & regex_constants::extended
101 ? _M_extended_spec_char
102 : _M_flags & regex_constants::grep
103 ? ".[\\*^$\n"
104 : _M_flags & regex_constants::egrep
105 ? ".[\\()*+?{|^$\n"
106 : _M_flags & regex_constants::awk
107 ? _M_extended_spec_char
108 : nullptr),
109 _M_at_bracket_start(false)
110 { __glibcxx_assert(_M_spec_char); }
111
112 protected:
113 const char*
114 _M_find_escape(char __c)
115 {
116 auto __it = _M_escape_tbl;
117 for (; __it->first != '\0'; ++__it)
118 if (__it->first == __c)
119 return &__it->second;
120 return nullptr;
121 }
122
123 bool
124 _M_is_ecma() const
125 { return _M_flags & regex_constants::ECMAScript; }
126
127 bool
128 _M_is_basic() const
129 { return _M_flags & (regex_constants::basic | regex_constants::grep); }
130
131 bool
132 _M_is_extended() const
133 {
134 return _M_flags & (regex_constants::extended
135 | regex_constants::egrep
136 | regex_constants::awk);
137 }
138
139 bool
140 _M_is_grep() const
141 { return _M_flags & (regex_constants::grep | regex_constants::egrep); }
142
143 bool
144 _M_is_awk() const
145 { return _M_flags & regex_constants::awk; }
146
147 protected:
148 // TODO: Make them static in the next abi change.
149 const std::pair<char, _TokenT> _M_token_tbl[9] =
150 {
151 {'^', _S_token_line_begin},
152 {'$', _S_token_line_end},
153 {'.', _S_token_anychar},
154 {'*', _S_token_closure0},
155 {'+', _S_token_closure1},
156 {'?', _S_token_opt},
157 {'|', _S_token_or},
158 {'\n', _S_token_or}, // grep and egrep
159 {'\0', _S_token_or},
160 };
161 const std::pair<char, char> _M_ecma_escape_tbl[8] =
162 {
163 {'0', '\0'},
164 {'b', '\b'},
165 {'f', '\f'},
166 {'n', '\n'},
167 {'r', '\r'},
168 {'t', '\t'},
169 {'v', '\v'},
170 {'\0', '\0'},
171 };
172 const std::pair<char, char> _M_awk_escape_tbl[11] =
173 {
174 {'"', '"'},
175 {'/', '/'},
176 {'\\', '\\'},
177 {'a', '\a'},
178 {'b', '\b'},
179 {'f', '\f'},
180 {'n', '\n'},
181 {'r', '\r'},
182 {'t', '\t'},
183 {'v', '\v'},
184 {'\0', '\0'},
185 };
186 const char* _M_ecma_spec_char = "^$\\.*+?()[]{}|";
187 const char* _M_basic_spec_char = ".[\\*^$";
188 const char* _M_extended_spec_char = ".[\\()*+?{|^$";
189
190 _StateT _M_state;
191 _FlagT _M_flags;
192 _TokenT _M_token;
193 const std::pair<char, char>* _M_escape_tbl;
194 const char* _M_spec_char;
195 bool _M_at_bracket_start;
196 };
197
198 /**
199 * @brief Scans an input range for regex tokens.
200 *
201 * The %_Scanner class interprets the regular expression pattern in
202 * the input range passed to its constructor as a sequence of parse
203 * tokens passed to the regular expression compiler. The sequence
204 * of tokens provided depends on the flag settings passed to the
205 * constructor: different regular expression grammars will interpret
206 * the same input pattern in syntactically different ways.
207 */
208 template<typename _CharT>
209 class _Scanner
210 : public _ScannerBase
211 {
212 public:
213 typedef const _CharT* _IterT;
214 typedef std::basic_string<_CharT> _StringT;
215 typedef regex_constants::syntax_option_type _FlagT;
216 typedef const std::ctype<_CharT> _CtypeT;
217
218 _Scanner(_IterT __begin, _IterT __end,
219 _FlagT __flags, std::locale __loc);
220
221 void
222 _M_advance();
223
224 _TokenT
225 _M_get_token() const
226 { return _M_token; }
227
228 const _StringT&
229 _M_get_value() const
230 { return _M_value; }
231
232 #ifdef _GLIBCXX_DEBUG
233 std::ostream&
234 _M_print(std::ostream&);
235 #endif
236
237 private:
238 void
239 _M_scan_normal();
240
241 void
242 _M_scan_in_bracket();
243
244 void
245 _M_scan_in_brace();
246
247 void
248 _M_eat_escape_ecma();
249
250 void
251 _M_eat_escape_posix();
252
253 void
254 _M_eat_escape_awk();
255
256 void
257 _M_eat_class(char);
258
259 _IterT _M_current;
260 _IterT _M_end;
261 _CtypeT& _M_ctype;
262 _StringT _M_value;
263 void (_Scanner::* _M_eat_escape)();
264 };
265
266 //@} regex-detail
267 _GLIBCXX_END_NAMESPACE_VERSION
268 } // namespace __detail
269 } // namespace std
270
271 #include <bits/regex_scanner.tcc>
272