1 /*
2 * Copyright (c) 2001-2009 Ville Laurikari <vl@iki.fi>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 /*
30 tre_regexec.c - TRE POSIX compatible matching functions (and more).
31 */
32
33 #include <assert.h>
34 #include <limits.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <wchar.h>
38 #include <wctype.h>
39
40 #include "tre-internal.h"
41 #include "tre-match-utils.h"
42 #include "tre.h"
43
44 /* For each tre_last_matched_t in the lm array, find the last matched branch by
45 comparing the touch value of the cmp_tag's. For all other branches, reset
46 the corresponding tags. If reset_all is non-zero, reset all tags in all
47 branches. Recurse into the nested last matched structures, clearing tags as
48 apprpriate. */
49 static void
50 tre_reset_last_matched_branches(tre_tag_t *tags, const tre_last_matched_t *lm,
51 int n, int start_tag, int reset_all)
52 {
53 int max, i, reset;
54 tre_last_matched_branch_t *b;
55
56 DPRINT(("tre_reset_last_matched_branches: n=%d start_tag=%d reset_all=%d\n",
57 n, start_tag, reset_all));
58 for (; n-- > 0; lm++)
59 {
60 if (lm->n_branches == 1)
61 {
62 b = lm->branches;
63 if (start_tag > 0)
64 {
65 DPRINT((" b->cmp_tag=%d %d <? %d\n", b->cmp_tag,
66 tre_tag_touch_get(tags, b->cmp_tag),
67 tre_tag_touch_get(tags, start_tag)));
68 reset = (reset_all || tre_tag_touch_get(tags, b->cmp_tag) <
69 tre_tag_touch_get(tags, start_tag));
70 }
71 else
72 reset = 0;
73
74 if (reset)
75 {
76 int *t;
77
78 for (i = b->n_tags, t = b->tags; i > 0; i--, t++)
79 {
80 DPRINT((" Resetting t%d\n", *t));
81 tre_tag_reset(tags, *t);
82 }
83 }
84 if (b->n_last_matched > 0)
85 tre_reset_last_matched_branches(tags, b->last_matched,
86 b->n_last_matched,
87 lm->start_tag, reset);
88 }
89 else
90 {
91 if (!reset_all)
92 {
93 #ifdef TRE_DEBUG
94 int last;
95 #endif /* TRE_DEBUG */
96 max = 0;
97 for (i = lm->n_branches, b = lm->branches; i > 0; i--, b++)
98 {
99 int t = b->cmp_tag;
100 int touch = tre_tag_touch_get(tags, t);
101 if (touch > max)
102 {
103 max = touch;
104 #ifdef TRE_DEBUG
105 last = t;
106 #endif /* TRE_DEBUG */
107 }
108 }
109 DPRINT((" Last touched end tag t%d=%d\n", last, max));
110 }
111
112 for (i = lm->n_branches, b = lm->branches; i > 0; i--, b++)
113 {
114 reset = (reset_all || tre_tag_touch_get(tags, b->cmp_tag) < max);
115 if (reset)
116 {
117 int j;
118 int *t;
119
120 for (j = b->n_tags, t = b->tags; j > 0; j--, t++)
121 {
122 DPRINT((" Resetting t%d\n", *t));
123 tre_tag_reset(tags, *t);
124 }
125 }
126 if (b->n_last_matched > 0)
127 tre_reset_last_matched_branches(tags, b->last_matched,
128 b->n_last_matched,
129 lm->start_tag, reset);
130 }
131 }
132 }
133 }
134
135 /* Fills the POSIX.2 regmatch_t array according to the TNFA tag and match
136 endpoint values. */
137 reg_errcode_t
138 tre_fill_pmatch(size_t nmatch, regmatch_t pmatch[], int cflags,
139 const tre_tnfa_t *tnfa, const tre_tag_t *intags, int match_eo)
140 {
141 unsigned int i;
142
143 if (cflags & REG_NOSUB) return REG_OK;
144
145 i = 0;
146 if (match_eo >= 0 && intags)
147 {
148 const tre_tag_t *tags = intags;
149 tre_submatch_data_t *submatch_data;
150
151 if (tnfa->last_matched_branch &&
152 tnfa->last_matched_branch->n_last_matched > 0)
153 {
154 tre_tag_t *t;
155 t = malloc(sizeof(*t) * tnfa->num_tags);
156 if (!t) return REG_ESPACE;
157 memcpy(t, intags, tnfa->num_tags * sizeof(tre_tag_t));
158 tre_reset_last_matched_branches(t,
159 tnfa->last_matched_branch->last_matched,
160 tnfa->last_matched_branch->n_last_matched,
161 0, 0);
162 tags = t;
163 }
164 /* Construct submatch offsets from the tags. */
165 DPRINT(("end tag = t%d = %d\n", tnfa->end_tag, match_eo));
166 submatch_data = tnfa->submatch_data;
167 while (i < tnfa->num_submatches && i < nmatch)
168 {
169 if (submatch_data[i].so_tag == tnfa->end_tag)
170 pmatch[i].rm_so = match_eo;
171 else
172 pmatch[i].rm_so = tre_tag_get(tags, submatch_data[i].so_tag);
173
174 if (submatch_data[i].eo_tag == tnfa->end_tag)
175 pmatch[i].rm_eo = match_eo;
176 else
177 pmatch[i].rm_eo = tre_tag_get(tags, submatch_data[i].eo_tag);
178
179 /* If either of the endpoints were not used, this submatch
180 was not part of the match. */
181 if (pmatch[i].rm_so == -1 || pmatch[i].rm_eo == -1)
182 pmatch[i].rm_so = pmatch[i].rm_eo = -1;
183
184 DPRINT(("pmatch[%d] = {t%d = %qd, t%d = %qd}\n", i,
185 submatch_data[i].so_tag, pmatch[i].rm_so,
186 submatch_data[i].eo_tag, pmatch[i].rm_eo));
187 i++;
188 }
189 if (tags != intags) free(__DECONST(tre_tag_t *,tags));
190 }
191
192 while (i < nmatch)
193 {
194 pmatch[i].rm_so = -1;
195 pmatch[i].rm_eo = -1;
196 i++;
197 }
198
199 return REG_OK;
200 }
201
202 /*
203 Wrapper functions for POSIX compatible regexp matching.
204 */
205
206 int
207 tre_have_backrefs(const regex_t *preg)
208 {
209 tre_tnfa_t *tnfa = (void *)preg->TRE_REGEX_T_FIELD;
210 return tnfa->have_backrefs;
211 }
212
213 static int
214 tre_match(const tre_tnfa_t *tnfa, const void *string, size_t len,
215 tre_str_type_t type, size_t nmatch, regmatch_t pmatch[],
216 int eflags)
217 {
218 reg_errcode_t status;
219 tre_tag_t *tags = NULL;
220 int eo;
221 size_t offset = 0, count = 0;
222 if (tnfa->num_tags > 0 && nmatch > 0)
223 {
224 tags = malloc(sizeof(*tags) * tnfa->num_tags);
225 if (tags == NULL)
226 return REG_ESPACE;
227 }
228
229 if (
230 (eflags & REG_STARTEND) && pmatch)
231 {
232 if (pmatch->rm_so < 0)
233 return REG_INVARG;
234 if (len == (size_t)-1)
235 {
236 if (pmatch->rm_eo < 0 || pmatch->rm_so > pmatch->rm_eo)
237 return REG_INVARG;
238 len = pmatch->rm_eo - pmatch->rm_so;
239 }
240 count = offset = pmatch->rm_so;
241 if (type == STR_WIDE) offset *= sizeof(wchar_t);
242 }
243
244 /* Dispatch to the appropriate matcher. */
245 #ifdef REG_BACKTRACKING_MATCHER
246 if (tnfa->have_backrefs || eflags & REG_BACKTRACKING_MATCHER)
247 #else
248 if (tnfa->have_backrefs)
249 #endif
250 {
251 /* The regex has back references, use the backtracking matcher. */
252 status = tre_tnfa_run_backtrack(tnfa, string + offset, (int)len, type,
253 tags, eflags, &eo);
254 }
255 else
256 {
257 /* Exact matching, no back references, use the parallel matcher. */
258 status = tre_tnfa_run_parallel(tnfa, string + offset, (int)len, type,
259 tags, eflags, &eo);
260 }
261
262 if (status == REG_OK)
263 {
264 /* A match was found, so fill the submatch registers. */
265 status = tre_fill_pmatch(nmatch, pmatch, tnfa->cflags, tnfa, tags, eo);
266 /* If doing REG_STARTEND, adjust the pmatch array (we can't build
267 this into tre_fill_pmatch, because tre_tnfa_run_backtrack calls
268 tre_fill_pmatch itself). */
269 if (status == REG_OK && !(tnfa->cflags & REG_NOSUB) &&
270 (eflags & REG_STARTEND) && pmatch && nmatch > 0)
271 {
272 size_t i;
273 regmatch_t *p;
274 for (i = nmatch, p = pmatch; i > 0; p++, i--)
275 {
276 if (p->rm_so >= 0) p->rm_so += count;
277 if (p->rm_eo >= 0) p->rm_eo += count;
278 }
279 }
280 }
281 if (tags)
282 free(tags);
283 return status;
284 }
285
286 int
287 tre_regnexec(const regex_t *preg, const char *str, size_t len,
288 size_t nmatch, regmatch_t pmatch[], int eflags)
289 {
290 tre_tnfa_t *tnfa = (void *)preg->TRE_REGEX_T_FIELD;
291 tre_str_type_t type = (TRE_MB_CUR_MAX_L(tnfa->loc) == 1) ? STR_BYTE : STR_MBS;
292
293 if (preg->re_magic != RE_MAGIC) return REG_BADPAT;
294
295 return tre_match(tnfa, str, len, type, nmatch, pmatch, eflags);
296 }
297
298 int
299 regexec(const regex_t *_RESTRICT_KYWD preg, const char *_RESTRICT_KYWD str,
300 size_t nmatch, regmatch_t pmatch[_RESTRICT_KYWD], int eflags)
301 {
302 return tre_regnexec(preg, str, (size_t)-1, nmatch, pmatch, eflags);
303 }