/src/php-src/ext/pcre/pcre2lib/pcre2_find_bracket.c

Source
/*************************************************
*      Perl-Compatible Regular Expressions       *
*************************************************/

/* PCRE is a library of functions to support regular expressions whose syntax
and semantics are as close as possible to those of the Perl 5 language.

                       Written by Philip Hazel
     Original API code Copyright (c) 1997-2012 University of Cambridge
          New API code Copyright (c) 2016-2023 University of Cambridge

-----------------------------------------------------------------------------
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice,
      this list of conditions and the following disclaimer.

    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.

    * Neither the name of the University of Cambridge nor the names of its
      contributors may be used to endorse or promote products derived from
      this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
-----------------------------------------------------------------------------
*/


/* This module contains a single function that scans through a compiled pattern
until it finds a capturing bracket with the given number, or, if the number is
negative, an instance of OP_REVERSE or OP_VREVERSE for a lookbehind. The
function is called from pcre2_compile.c and also from pcre2_study.c when
finding the minimum matching length. */


#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "pcre2_internal.h"


/*************************************************
*    Scan compiled regex for specific bracket    *
*************************************************/

/*
Arguments:
  code        points to start of expression
  utf         TRUE in UTF mode
  number      the required bracket number or negative to find a lookbehind

Returns:      pointer to the opcode for the bracket, or NULL if not found
*/

PCRE2_SPTR
PRIV(find_bracket)(PCRE2_SPTR code, BOOL utf, int number)
{
for (;;)
  {
  PCRE2_UCHAR c = *code;

  if (c == OP_END) return NULL;

  /* XCLASS is used for classes that cannot be represented just by a bit map.
  This includes negated single high-valued characters. CALLOUT_STR is used for
  callouts with string arguments. In both cases the length in the table is
  zero; the actual length is stored in the compiled code. */

  if (c == OP_XCLASS) code += GET(code, 1);
    else if (c == OP_CALLOUT_STR) code += GET(code, 1 + 2*LINK_SIZE);

  /* Handle lookbehind */

  else if (c == OP_REVERSE || c == OP_VREVERSE)
    {
    if (number < 0) return (PCRE2_UCHAR *)code;
    code += PRIV(OP_lengths)[c];
    }

  /* Handle capturing bracket */

  else if (c == OP_CBRA || c == OP_SCBRA ||
           c == OP_CBRAPOS || c == OP_SCBRAPOS)
    {
    int n = (int)GET2(code, 1+LINK_SIZE);
    if (n == number) return (PCRE2_UCHAR *)code;
    code += PRIV(OP_lengths)[c];
    }

  /* Otherwise, we can get the item's length from the table, except that for
  repeated character types, we have to test for \p and \P, which have an extra
  two bytes of parameters, and for MARK/PRUNE/SKIP/THEN with an argument, we
  must add in its length. */

  else
    {
    switch(c)
      {
      case OP_TYPESTAR:
      case OP_TYPEMINSTAR:
      case OP_TYPEPLUS:
      case OP_TYPEMINPLUS:
      case OP_TYPEQUERY:
      case OP_TYPEMINQUERY:
      case OP_TYPEPOSSTAR:
      case OP_TYPEPOSPLUS:
      case OP_TYPEPOSQUERY:
      if (code[1] == OP_PROP || code[1] == OP_NOTPROP) code += 2;
      break;

      case OP_TYPEUPTO:
      case OP_TYPEMINUPTO:
      case OP_TYPEEXACT:
      case OP_TYPEPOSUPTO:
      if (code[1 + IMM2_SIZE] == OP_PROP || code[1 + IMM2_SIZE] == OP_NOTPROP)
        code += 2;
      break;

      case OP_MARK:
      case OP_COMMIT_ARG:
      case OP_PRUNE_ARG:
      case OP_SKIP_ARG:
      case OP_THEN_ARG:
      code += code[1];
      break;
      }

    /* Add in the fixed length from the table */

    code += PRIV(OP_lengths)[c];

  /* In UTF-8 and UTF-16 modes, opcodes that are followed by a character may be
  followed by a multi-byte character. The length in the table is a minimum, so
  we have to arrange to skip the extra bytes. */

#ifdef MAYBE_UTF_MULTI
    if (utf) switch(c)
      {
      case OP_CHAR:
      case OP_CHARI:
      case OP_NOT:
      case OP_NOTI:
      case OP_EXACT:
      case OP_EXACTI:
      case OP_NOTEXACT:
      case OP_NOTEXACTI:
      case OP_UPTO:
      case OP_UPTOI:
      case OP_NOTUPTO:
      case OP_NOTUPTOI:
      case OP_MINUPTO:
      case OP_MINUPTOI:
      case OP_NOTMINUPTO:
      case OP_NOTMINUPTOI:
      case OP_POSUPTO:
      case OP_POSUPTOI:
      case OP_NOTPOSUPTO:
      case OP_NOTPOSUPTOI:
      case OP_STAR:
      case OP_STARI:
      case OP_NOTSTAR:
      case OP_NOTSTARI:
      case OP_MINSTAR:
      case OP_MINSTARI:
      case OP_NOTMINSTAR:
      case OP_NOTMINSTARI:
      case OP_POSSTAR:
      case OP_POSSTARI:
      case OP_NOTPOSSTAR:
      case OP_NOTPOSSTARI:
      case OP_PLUS:
      case OP_PLUSI:
      case OP_NOTPLUS:
      case OP_NOTPLUSI:
      case OP_MINPLUS:
      case OP_MINPLUSI:
      case OP_NOTMINPLUS:
      case OP_NOTMINPLUSI:
      case OP_POSPLUS:
      case OP_POSPLUSI:
      case OP_NOTPOSPLUS:
      case OP_NOTPOSPLUSI:
      case OP_QUERY:
      case OP_QUERYI:
      case OP_NOTQUERY:
      case OP_NOTQUERYI:
      case OP_MINQUERY:
      case OP_MINQUERYI:
      case OP_NOTMINQUERY:
      case OP_NOTMINQUERYI:
      case OP_POSQUERY:
      case OP_POSQUERYI:
      case OP_NOTPOSQUERY:
      case OP_NOTPOSQUERYI:
      if (HAS_EXTRALEN(code[-1])) code += GET_EXTRALEN(code[-1]);
      break;
      }
#else
    (void)(utf);  /* Keep compiler happy by referencing function argument */
#endif  /* MAYBE_UTF_MULTI */
    }
  }
}

/* End of pcre2_find_bracket.c */

Coverage Report

Created: 2026-10-28 06:20

Line	Count	Source
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		Original API code Copyright (c) 1997-2012 University of Cambridge
10		New API code Copyright (c) 2016-2023 University of Cambridge
11
12		-----------------------------------------------------------------------------
13		Redistribution and use in source and binary forms, with or without
14		modification, are permitted provided that the following conditions are met:
15
16		* Redistributions of source code must retain the above copyright notice,
17		this list of conditions and the following disclaimer.
18
19		* Redistributions in binary form must reproduce the above copyright
20		notice, this list of conditions and the following disclaimer in the
21		documentation and/or other materials provided with the distribution.
22
23		* Neither the name of the University of Cambridge nor the names of its
24		contributors may be used to endorse or promote products derived from
25		this software without specific prior written permission.
26
27		THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
28		AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29		IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30		ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
31		LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32		CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33		SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34		INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35		CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36		ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37		POSSIBILITY OF SUCH DAMAGE.
38		-----------------------------------------------------------------------------
39		*/
40
41
42		/* This module contains a single function that scans through a compiled pattern
43		until it finds a capturing bracket with the given number, or, if the number is
44		negative, an instance of OP_REVERSE or OP_VREVERSE for a lookbehind. The
45		function is called from pcre2_compile.c and also from pcre2_study.c when
46		finding the minimum matching length. */
47
48
49		#ifdef HAVE_CONFIG_H
50		#include "config.h"
51		#endif
52
53		#include "pcre2_internal.h"
54
55
56		/*************************************************
57		* Scan compiled regex for specific bracket *
58		*************************************************/
59
60		/*
61		Arguments:
62		code points to start of expression
63		utf TRUE in UTF mode
64		number the required bracket number or negative to find a lookbehind
65
66		Returns: pointer to the opcode for the bracket, or NULL if not found
67		*/
68
69		PCRE2_SPTR
70		PRIV(find_bracket)(PCRE2_SPTR code, BOOL utf, int number)
71	1	{
72	1	for (;;)
73	53	{
74	53	PCRE2_UCHAR c = *code;
75
76	53	if (c == OP_END) return NULL;
77
78		/* XCLASS is used for classes that cannot be represented just by a bit map.
79		This includes negated single high-valued characters. CALLOUT_STR is used for
80		callouts with string arguments. In both cases the length in the table is
81		zero; the actual length is stored in the compiled code. */
82
83	53	if (c == OP_XCLASS) code += GET(code, 1);
84	53	else if (c == OP_CALLOUT_STR) code += GET(code, 1 + 2*LINK_SIZE);
85
86		/* Handle lookbehind */
87
88	53	else if (c == OP_REVERSE \|\| c == OP_VREVERSE)
89	0	{
90	0	if (number < 0) return (PCRE2_UCHAR *)code;
91	0	code += PRIV(OP_lengths)[c];
92	0	}
93
94		/* Handle capturing bracket */
95
96	53	else if (c == OP_CBRA \|\| c == OP_SCBRA \|\|
97	50	c == OP_CBRAPOS \|\| c == OP_SCBRAPOS)
98	3	{
99	3	int n = (int)GET2(code, 1+LINK_SIZE);
100	3	if (n == number) return (PCRE2_UCHAR *)code;
101	2	code += PRIV(OP_lengths)[c];
102	2	}
103
104		/* Otherwise, we can get the item's length from the table, except that for
105		repeated character types, we have to test for \p and \P, which have an extra
106		two bytes of parameters, and for MARK/PRUNE/SKIP/THEN with an argument, we
107		must add in its length. */
108
109	50	else
110	50	{
111	50	switch(c)
112	50	{
113	0	case OP_TYPESTAR:
114	0	case OP_TYPEMINSTAR:
115	0	case OP_TYPEPLUS:
116	0	case OP_TYPEMINPLUS:
117	0	case OP_TYPEQUERY:
118	0	case OP_TYPEMINQUERY:
119	0	case OP_TYPEPOSSTAR:
120	0	case OP_TYPEPOSPLUS:
121	0	case OP_TYPEPOSQUERY:
122	0	if (code[1] == OP_PROP \|\| code[1] == OP_NOTPROP) code += 2;
123	0	break;
124
125	0	case OP_TYPEUPTO:
126	0	case OP_TYPEMINUPTO:
127	0	case OP_TYPEEXACT:
128	0	case OP_TYPEPOSUPTO:
129	0	if (code[1 + IMM2_SIZE] == OP_PROP \|\| code[1 + IMM2_SIZE] == OP_NOTPROP)
130	0	code += 2;
131	0	break;
132
133	0	case OP_MARK:
134	0	case OP_COMMIT_ARG:
135	0	case OP_PRUNE_ARG:
136	0	case OP_SKIP_ARG:
137	0	case OP_THEN_ARG:
138	0	code += code[1];
139	0	break;
140	50	}
141
142		/* Add in the fixed length from the table */
143
144	50	code += PRIV(OP_lengths)[c];
145
146		/* In UTF-8 and UTF-16 modes, opcodes that are followed by a character may be
147		followed by a multi-byte character. The length in the table is a minimum, so
148		we have to arrange to skip the extra bytes. */
149
150	50	#ifdef MAYBE_UTF_MULTI
151	50	if (utf) switch(c)
152	50	{
153	0	case OP_CHAR:
154	45	case OP_CHARI:
155	45	case OP_NOT:
156	45	case OP_NOTI:
157	45	case OP_EXACT:
158	45	case OP_EXACTI:
159	45	case OP_NOTEXACT:
160	45	case OP_NOTEXACTI:
161	45	case OP_UPTO:
162	45	case OP_UPTOI:
163	45	case OP_NOTUPTO:
164	45	case OP_NOTUPTOI:
165	45	case OP_MINUPTO:
166	45	case OP_MINUPTOI:
167	45	case OP_NOTMINUPTO:
168	45	case OP_NOTMINUPTOI:
169	45	case OP_POSUPTO:
170	45	case OP_POSUPTOI:
171	45	case OP_NOTPOSUPTO:
172	45	case OP_NOTPOSUPTOI:
173	45	case OP_STAR:
174	45	case OP_STARI:
175	45	case OP_NOTSTAR:
176	45	case OP_NOTSTARI:
177	45	case OP_MINSTAR:
178	45	case OP_MINSTARI:
179	45	case OP_NOTMINSTAR:
180	45	case OP_NOTMINSTARI:
181	45	case OP_POSSTAR:
182	45	case OP_POSSTARI:
183	45	case OP_NOTPOSSTAR:
184	45	case OP_NOTPOSSTARI:
185	45	case OP_PLUS:
186	45	case OP_PLUSI:
187	45	case OP_NOTPLUS:
188	45	case OP_NOTPLUSI:
189	45	case OP_MINPLUS:
190	45	case OP_MINPLUSI:
191	45	case OP_NOTMINPLUS:
192	45	case OP_NOTMINPLUSI:
193	45	case OP_POSPLUS:
194	45	case OP_POSPLUSI:
195	45	case OP_NOTPOSPLUS:
196	45	case OP_NOTPOSPLUSI:
197	45	case OP_QUERY:
198	45	case OP_QUERYI:
199	45	case OP_NOTQUERY:
200	45	case OP_NOTQUERYI:
201	45	case OP_MINQUERY:
202	45	case OP_MINQUERYI:
203	45	case OP_NOTMINQUERY:
204	45	case OP_NOTMINQUERYI:
205	45	case OP_POSQUERY:
206	45	case OP_POSQUERYI:
207	45	case OP_NOTPOSQUERY:
208	45	case OP_NOTPOSQUERYI:
209	45	if (HAS_EXTRALEN(code[-1])) code += GET_EXTRALEN(code[-1]);
210	45	break;
211	50	}
212		#else
213		(void)(utf); /* Keep compiler happy by referencing function argument */
214		#endif /* MAYBE_UTF_MULTI */
215	50	}
216	53	}
217	1	}
218
219		/* End of pcre2_find_bracket.c */