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pcreposix.c
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1 /*************************************************
2 * Perl-Compatible Regular Expressions *
3 *************************************************/
4 
5 /* PCRE is a library of functions to support regular expressions whose syntax
6 and semantics are as close as possible to those of the Perl 5 language.
7 
8  Written by Philip Hazel
9  Copyright (c) 1997-2006 University of Cambridge
10 
11 -----------------------------------------------------------------------------
12 Redistribution and use in source and binary forms, with or without
13 modification, are permitted provided that the following conditions are met:
14 
15  * Redistributions of source code must retain the above copyright notice,
16  this list of conditions and the following disclaimer.
17 
18  * Redistributions in binary form must reproduce the above copyright
19  notice, this list of conditions and the following disclaimer in the
20  documentation and/or other materials provided with the distribution.
21 
22  * Neither the name of the University of Cambridge nor the names of its
23  contributors may be used to endorse or promote products derived from
24  this software without specific prior written permission.
25 
26 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
27 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
30 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 POSSIBILITY OF SUCH DAMAGE.
37 -----------------------------------------------------------------------------
38 */
39 
40 
41 /* This module is a wrapper that provides a POSIX API to the underlying PCRE
42 functions. */
43 
44 
45 #include "pcre_internal.h"
46 #include "pcreposix.h"
47 #include "stdlib.h"
48 
49 
50 
51 /* Table to translate PCRE compile time error codes into POSIX error codes. */
52 
53 static const int eint[] = {
54  0, /* no error */
55  REG_EESCAPE, /* \ at end of pattern */
56  REG_EESCAPE, /* \c at end of pattern */
57  REG_EESCAPE, /* unrecognized character follows \ */
58  REG_BADBR, /* numbers out of order in {} quantifier */
59  REG_BADBR, /* number too big in {} quantifier */
60  REG_EBRACK, /* missing terminating ] for character class */
61  REG_ECTYPE, /* invalid escape sequence in character class */
62  REG_ERANGE, /* range out of order in character class */
63  REG_BADRPT, /* nothing to repeat */
64  REG_BADRPT, /* operand of unlimited repeat could match the empty string */
65  REG_ASSERT, /* internal error: unexpected repeat */
66  REG_BADPAT, /* unrecognized character after (? */
67  REG_BADPAT, /* POSIX named classes are supported only within a class */
68  REG_EPAREN, /* missing ) */
69  REG_ESUBREG, /* reference to non-existent subpattern */
70  REG_INVARG, /* erroffset passed as NULL */
71  REG_INVARG, /* unknown option bit(s) set */
72  REG_EPAREN, /* missing ) after comment */
73  REG_ESIZE, /* parentheses nested too deeply */
74  REG_ESIZE, /* regular expression too large */
75  REG_ESPACE, /* failed to get memory */
76  REG_EPAREN, /* unmatched brackets */
77  REG_ASSERT, /* internal error: code overflow */
78  REG_BADPAT, /* unrecognized character after (?< */
79  REG_BADPAT, /* lookbehind assertion is not fixed length */
80  REG_BADPAT, /* malformed number or name after (?( */
81  REG_BADPAT, /* conditional group contains more than two branches */
82  REG_BADPAT, /* assertion expected after (?( */
83  REG_BADPAT, /* (?R or (?digits must be followed by ) */
84  REG_ECTYPE, /* unknown POSIX class name */
85  REG_BADPAT, /* POSIX collating elements are not supported */
86  REG_INVARG, /* this version of PCRE is not compiled with PCRE_UTF8 support */
87  REG_BADPAT, /* spare error */
88  REG_BADPAT, /* character value in \x{...} sequence is too large */
89  REG_BADPAT, /* invalid condition (?(0) */
90  REG_BADPAT, /* \C not allowed in lookbehind assertion */
91  REG_EESCAPE, /* PCRE does not support \L, \l, \N, \U, or \u */
92  REG_BADPAT, /* number after (?C is > 255 */
93  REG_BADPAT, /* closing ) for (?C expected */
94  REG_BADPAT, /* recursive call could loop indefinitely */
95  REG_BADPAT, /* unrecognized character after (?P */
96  REG_BADPAT, /* syntax error in subpattern name (missing terminator) */
97  REG_BADPAT, /* two named subpatterns have the same name */
98  REG_BADPAT, /* invalid UTF-8 string */
99  REG_BADPAT, /* support for \P, \p, and \X has not been compiled */
100  REG_BADPAT, /* malformed \P or \p sequence */
101  REG_BADPAT, /* unknown property name after \P or \p */
102  REG_BADPAT, /* subpattern name is too long (maximum 32 characters) */
103  REG_BADPAT, /* too many named subpatterns (maximum 10,000) */
104  REG_BADPAT, /* repeated subpattern is too long */
105  REG_BADPAT, /* octal value is greater than \377 (not in UTF-8 mode) */
106  REG_BADPAT, /* internal error: overran compiling workspace */
107  REG_BADPAT, /* internal error: previously-checked referenced subpattern not found */
108  REG_BADPAT, /* DEFINE group contains more than one branch */
109  REG_BADPAT, /* repeating a DEFINE group is not allowed */
110  REG_INVARG, /* inconsistent NEWLINE options */
111  REG_BADPAT /* \g is not followed followed by an (optionally braced) non-zero number */
112 };
113 
114 /* Table of texts corresponding to POSIX error codes */
115 
116 static const char *const pstring[] = {
117  "", /* Dummy for value 0 */
118  "internal error", /* REG_ASSERT */
119  "invalid repeat counts in {}", /* BADBR */
120  "pattern error", /* BADPAT */
121  "? * + invalid", /* BADRPT */
122  "unbalanced {}", /* EBRACE */
123  "unbalanced []", /* EBRACK */
124  "collation error - not relevant", /* ECOLLATE */
125  "bad class", /* ECTYPE */
126  "bad escape sequence", /* EESCAPE */
127  "empty expression", /* EMPTY */
128  "unbalanced ()", /* EPAREN */
129  "bad range inside []", /* ERANGE */
130  "expression too big", /* ESIZE */
131  "failed to get memory", /* ESPACE */
132  "bad back reference", /* ESUBREG */
133  "bad argument", /* INVARG */
134  "match failed" /* NOMATCH */
135 };
136 
137 
138 
139 
140 /*************************************************
141 * Translate error code to string *
142 *************************************************/
143 
144 PCRE_DATA_SCOPE size_t
145 regerror(int errcode, const regex_t *preg, char *errbuf, size_t errbuf_size)
146 {
147 const char *message, *addmessage;
148 size_t length, addlength;
149 
150 message = (errcode >= (int)(sizeof(pstring)/sizeof(char *)))?
151  "unknown error code" : pstring[errcode];
152 length = strlen(message) + 1;
153 
154 addmessage = " at offset ";
155 addlength = (preg != NULL && (int)preg->re_erroffset != -1)?
156  strlen(addmessage) + 6 : 0;
157 
158 if (errbuf_size > 0)
159  {
160  if (addlength > 0 && errbuf_size >= length + addlength)
161  sprintf(errbuf, "%s%s%-6d", message, addmessage, (int)preg->re_erroffset);
162  else
163  {
164  strncpy(errbuf, message, errbuf_size - 1);
165  errbuf[errbuf_size-1] = 0;
166  }
167  }
168 
169 return length + addlength;
170 }
171 
172 
173 
174 
175 /*************************************************
176 * Free store held by a regex *
177 *************************************************/
178 
179 PCRE_DATA_SCOPE void
181 {
182 (pcre_free)(preg->re_pcre);
183 }
184 
185 
186 
187 
188 /*************************************************
189 * Compile a regular expression *
190 *************************************************/
191 
192 /*
193 Arguments:
194  preg points to a structure for recording the compiled expression
195  pattern the pattern to compile
196  cflags compilation flags
197 
198 Returns: 0 on success
199  various non-zero codes on failure
200 */
201 
202 PCRE_DATA_SCOPE int
203 regcomp(regex_t *preg, const char *pattern, int cflags)
204 {
205 const char *errorptr;
206 int erroffset;
207 int errorcode;
208 int options = 0;
209 
210 if ((cflags & REG_ICASE) != 0) options |= PCRE_CASELESS;
211 if ((cflags & REG_NEWLINE) != 0) options |= PCRE_MULTILINE;
212 if ((cflags & REG_DOTALL) != 0) options |= PCRE_DOTALL;
213 if ((cflags & REG_NOSUB) != 0) options |= PCRE_NO_AUTO_CAPTURE;
214 if ((cflags & REG_UTF8) != 0) options |= PCRE_UTF8;
215 
216 preg->re_pcre = pcre_compile2(pattern, options, &errorcode, &errorptr,
217  &erroffset, NULL);
218 preg->re_erroffset = erroffset;
219 
220 if (preg->re_pcre == NULL) return eint[errorcode];
221 
222 preg->re_nsub = pcre_info((const pcre *)preg->re_pcre, NULL, NULL);
223 return 0;
224 }
225 
226 
227 
228 
229 /*************************************************
230 * Match a regular expression *
231 *************************************************/
232 
233 /* Unfortunately, PCRE requires 3 ints of working space for each captured
234 substring, so we have to get and release working store instead of just using
235 the POSIX structures as was done in earlier releases when PCRE needed only 2
236 ints. However, if the number of possible capturing brackets is small, use a
237 block of store on the stack, to reduce the use of malloc/free. The threshold is
238 in a macro that can be changed at configure time.
239 
240 If REG_NOSUB was specified at compile time, the PCRE_NO_AUTO_CAPTURE flag will
241 be set. When this is the case, the nmatch and pmatch arguments are ignored, and
242 the only result is yes/no/error. */
243 
244 PCRE_DATA_SCOPE int
245 regexec(const regex_t *preg, const char *string, size_t nmatch,
246  regmatch_t pmatch[], int eflags)
247 {
248 int rc;
249 int options = 0;
250 int *ovector = NULL;
251 int small_ovector[POSIX_MALLOC_THRESHOLD * 3];
252 BOOL allocated_ovector = FALSE;
253 BOOL nosub =
254  (((const pcre *)preg->re_pcre)->options & PCRE_NO_AUTO_CAPTURE) != 0;
255 
256 if ((eflags & REG_NOTBOL) != 0) options |= PCRE_NOTBOL;
257 if ((eflags & REG_NOTEOL) != 0) options |= PCRE_NOTEOL;
258 
259 ((regex_t *)preg)->re_erroffset = (size_t)(-1); /* Only has meaning after compile */
260 
261 /* When no string data is being returned, ensure that nmatch is zero.
262 Otherwise, ensure the vector for holding the return data is large enough. */
263 
264 if (nosub) nmatch = 0;
265 
266 else if (nmatch > 0)
267  {
268  if (nmatch <= POSIX_MALLOC_THRESHOLD)
269  {
270  ovector = &(small_ovector[0]);
271  }
272  else
273  {
274  if (nmatch > INT_MAX/(sizeof(int) * 3)) return REG_ESPACE;
275  ovector = (int *)malloc(sizeof(int) * nmatch * 3);
276  if (ovector == NULL) return REG_ESPACE;
277  allocated_ovector = TRUE;
278  }
279  }
280 
281 rc = pcre_exec((const pcre *)preg->re_pcre, NULL, string, (int)strlen(string),
282  0, options, ovector, nmatch * 3);
283 
284 if (rc == 0) rc = nmatch; /* All captured slots were filled in */
285 
286 if (rc >= 0)
287  {
288  size_t i;
289  if (!nosub)
290  {
291  for (i = 0; i < (size_t)rc; i++)
292  {
293  pmatch[i].rm_so = ovector[i*2];
294  pmatch[i].rm_eo = ovector[i*2+1];
295  }
296  if (allocated_ovector) free(ovector);
297  for (; i < nmatch; i++) pmatch[i].rm_so = pmatch[i].rm_eo = -1;
298  }
299  return 0;
300  }
301 
302 else
303  {
304  if (allocated_ovector) free(ovector);
305  switch(rc)
306  {
307  case PCRE_ERROR_NOMATCH: return REG_NOMATCH;
308  case PCRE_ERROR_NULL: return REG_INVARG;
309  case PCRE_ERROR_BADOPTION: return REG_INVARG;
310  case PCRE_ERROR_BADMAGIC: return REG_INVARG;
311  case PCRE_ERROR_UNKNOWN_NODE: return REG_ASSERT;
312  case PCRE_ERROR_NOMEMORY: return REG_ESPACE;
313  case PCRE_ERROR_MATCHLIMIT: return REG_ESPACE;
314  case PCRE_ERROR_BADUTF8: return REG_INVARG;
316  default: return REG_ASSERT;
317  }
318  }
319 }
320 
321 /* End of pcreposix.c */
#define TRUE
Definition: bool.h:74
#define FALSE
Definition: bool.h:70
#define POSIX_MALLOC_THRESHOLD
Definition: config.h:6
#define PCRE_ERROR_BADUTF8_OFFSET
Definition: pcre.h:136
#define PCRE_NOTBOL
Definition: pcre.h:105
#define PCRE_UTF8
Definition: pcre.h:109
#define PCRE_ERROR_BADOPTION
Definition: pcre.h:127
#define PCRE_CASELESS
Definition: pcre.h:98
int pcre_info(const pcre *, int *, int *)
Definition: pcre_info.c:72
#define PCRE_DATA_SCOPE
Definition: pcre.h:81
#define PCRE_NOTEOL
Definition: pcre.h:106
#define PCRE_ERROR_BADMAGIC
Definition: pcre.h:128
#define PCRE_MULTILINE
Definition: pcre.h:99
void(* pcre_free)(void *)
Definition: pcre_globals.c:76
#define PCRE_NO_AUTO_CAPTURE
Definition: pcre.h:110
pcre * pcre_compile2(const char *, int, int *, const char **, int *, const unsigned char *)
#define PCRE_ERROR_UNKNOWN_NODE
Definition: pcre.h:130
#define PCRE_DOTALL
Definition: pcre.h:100
#define PCRE_ERROR_NULL
Definition: pcre.h:126
#define PCRE_ERROR_MATCHLIMIT
Definition: pcre.h:133
#define PCRE_ERROR_NOMEMORY
Definition: pcre.h:131
#define PCRE_ERROR_NOMATCH
Definition: pcre.h:125
int pcre_exec(const pcre *, const pcre_extra *, const char *, int, int, int, int *, int)
Definition: pcre_exec.c:3690
#define PCRE_ERROR_BADUTF8
Definition: pcre.h:135
int BOOL
size_t regerror(int errcode, const regex_t *preg, char *errbuf, size_t errbuf_size)
Definition: pcreposix.c:145
int regcomp(regex_t *preg, const char *pattern, int cflags)
Definition: pcreposix.c:203
static const int eint[]
Definition: pcreposix.c:53
int regexec(const regex_t *preg, const char *string, size_t nmatch, regmatch_t pmatch[], int eflags)
Definition: pcreposix.c:245
static const char *const pstring[]
Definition: pcreposix.c:116
void regfree(regex_t *preg)
Definition: pcreposix.c:180
#define REG_ICASE
Definition: pcreposix.h:55
#define REG_UTF8
Definition: pcreposix.h:61
#define REG_NOTEOL
Definition: pcreposix.h:58
#define REG_NOTBOL
Definition: pcreposix.h:57
@ REG_INVARG
Definition: pcreposix.h:86
@ REG_ERANGE
Definition: pcreposix.h:82
@ REG_ESIZE
Definition: pcreposix.h:83
@ REG_ASSERT
Definition: pcreposix.h:71
@ REG_NOMATCH
Definition: pcreposix.h:87
@ REG_BADPAT
Definition: pcreposix.h:73
@ REG_EBRACK
Definition: pcreposix.h:76
@ REG_ECTYPE
Definition: pcreposix.h:78
@ REG_ESPACE
Definition: pcreposix.h:84
@ REG_EESCAPE
Definition: pcreposix.h:79
@ REG_EPAREN
Definition: pcreposix.h:81
@ REG_ESUBREG
Definition: pcreposix.h:85
@ REG_BADBR
Definition: pcreposix.h:72
@ REG_BADRPT
Definition: pcreposix.h:74
#define REG_NEWLINE
Definition: pcreposix.h:56
#define REG_NOSUB
Definition: pcreposix.h:60
#define REG_DOTALL
Definition: pcreposix.h:59
size_t re_erroffset
Definition: pcreposix.h:96
size_t re_nsub
Definition: pcreposix.h:95
void * re_pcre
Definition: pcreposix.h:94
regoff_t rm_eo
Definition: pcreposix.h:105
regoff_t rm_so
Definition: pcreposix.h:104