1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1992, 1993, 1994 Henry Spencer.
5 * Copyright (c) 1992, 1993, 1994
6 *	The Regents of the University of California.  All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * Henry Spencer.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36/*
37 * First, the stuff that ends up in the outside-world include file
38 = typedef off_t regoff_t;
39 = typedef struct {
40 = 	int re_magic;
41 = 	size_t re_nsub;		// number of parenthesized subexpressions
42 = 	const char *re_endp;	// end pointer for REG_PEND
43 = 	struct re_guts *re_g;	// none of your business :-)
44 = } regex_t;
45 = typedef struct {
46 = 	regoff_t rm_so;		// start of match
47 = 	regoff_t rm_eo;		// end of match
48 = } regmatch_t;
49 */
50/*
51 * internals of regex_t
52 */
53#define	MAGIC1	((('r'^0200)<<8) | 'e')
54
55/*
56 * The internal representation is a *strip*, a sequence of
57 * operators ending with an endmarker.  (Some terminology etc. is a
58 * historical relic of earlier versions which used multiple strips.)
59 * Certain oddities in the representation are there to permit running
60 * the machinery backwards; in particular, any deviation from sequential
61 * flow must be marked at both its source and its destination.  Some
62 * fine points:
63 *
64 * - OPLUS_ and O_PLUS are *inside* the loop they create.
65 * - OQUEST_ and O_QUEST are *outside* the bypass they create.
66 * - OCH_ and O_CH are *outside* the multi-way branch they create, while
67 *   OOR1 and OOR2 are respectively the end and the beginning of one of
68 *   the branches.  Note that there is an implicit OOR2 following OCH_
69 *   and an implicit OOR1 preceding O_CH.
70 *
71 * In state representations, an operator's bit is on to signify a state
72 * immediately *preceding* "execution" of that operator.
73 */
74typedef unsigned long sop;	/* strip operator */
75typedef unsigned long sopno;
76#define	OPRMASK	0xf8000000L
77#define	OPDMASK	0x07ffffffL
78#define	OPSHIFT	((unsigned)27)
79#define	OP(n)	((n)&OPRMASK)
80#define	OPND(n)	((n)&OPDMASK)
81#define	SOP(op, opnd)	((op)|(opnd))
82/* operators			   meaning	operand			*/
83/*						(back, fwd are offsets)	*/
84#define	OEND	(1L<<OPSHIFT)	/* endmarker	-			*/
85#define	OCHAR	(2L<<OPSHIFT)	/* character	wide character		*/
86#define	OBOL	(3L<<OPSHIFT)	/* left anchor	-			*/
87#define	OEOL	(4L<<OPSHIFT)	/* right anchor	-			*/
88#define	OANY	(5L<<OPSHIFT)	/* .		-			*/
89#define	OANYOF	(6L<<OPSHIFT)	/* [...]	set number		*/
90#define	OBACK_	(7L<<OPSHIFT)	/* begin \d	paren number		*/
91#define	O_BACK	(8L<<OPSHIFT)	/* end \d	paren number		*/
92#define	OPLUS_	(9L<<OPSHIFT)	/* + prefix	fwd to suffix		*/
93#define	O_PLUS	(10L<<OPSHIFT)	/* + suffix	back to prefix		*/
94#define	OQUEST_	(11L<<OPSHIFT)	/* ? prefix	fwd to suffix		*/
95#define	O_QUEST	(12L<<OPSHIFT)	/* ? suffix	back to prefix		*/
96#define	OLPAREN	(13L<<OPSHIFT)	/* (		fwd to )		*/
97#define	ORPAREN	(14L<<OPSHIFT)	/* )		back to (		*/
98#define	OCH_	(15L<<OPSHIFT)	/* begin choice	fwd to OOR2		*/
99#define	OOR1	(16L<<OPSHIFT)	/* | pt. 1	back to OOR1 or OCH_	*/
100#define	OOR2	(17L<<OPSHIFT)	/* | pt. 2	fwd to OOR2 or O_CH	*/
101#define	O_CH	(18L<<OPSHIFT)	/* end choice	back to OOR1		*/
102#define	OBOW	(19L<<OPSHIFT)	/* begin word	-			*/
103#define	OEOW	(20L<<OPSHIFT)	/* end word	-			*/
104#define	OBOS	(21L<<OPSHIFT)	/* begin subj.  -			*/
105#define	OEOS	(22L<<OPSHIFT)	/* end subj.	-			*/
106#define	OWBND	(23L<<OPSHIFT)	/* word bound	-			*/
107#define	ONWBND	(24L<<OPSHIFT)	/* not bound	-			*/
108
109/*
110 * Structures for [] character-set representation.
111 */
112typedef struct {
113	wint_t		min;
114	wint_t		max;
115} crange;
116typedef struct {
117	unsigned char	bmp[NC_MAX / 8];
118	wctype_t	*types;
119	unsigned int	ntypes;
120	wint_t		*wides;
121	unsigned int	nwides;
122	crange		*ranges;
123	unsigned int	nranges;
124	int		invert;
125	int		icase;
126} cset;
127
128static int
129CHIN1(cset *cs, wint_t ch)
130{
131	unsigned int i;
132
133	assert(ch >= 0);
134	if (ch < NC)
135		return (((cs->bmp[ch >> 3] & (1 << (ch & 7))) != 0) ^
136		    cs->invert);
137	for (i = 0; i < cs->nwides; i++) {
138		if (cs->icase) {
139			if (ch == towlower(cs->wides[i]) ||
140			    ch == towupper(cs->wides[i]))
141				return (!cs->invert);
142		} else if (ch == cs->wides[i])
143			return (!cs->invert);
144	}
145	for (i = 0; i < cs->nranges; i++)
146		if (cs->ranges[i].min <= ch && ch <= cs->ranges[i].max)
147			return (!cs->invert);
148	for (i = 0; i < cs->ntypes; i++)
149		if (iswctype(ch, cs->types[i]))
150			return (!cs->invert);
151	return (cs->invert);
152}
153
154static __inline int
155CHIN(cset *cs, wint_t ch)
156{
157
158	assert(ch >= 0);
159	if (ch < NC)
160		return (((cs->bmp[ch >> 3] & (1 << (ch & 7))) != 0) ^
161		    cs->invert);
162	else if (cs->icase)
163		return (CHIN1(cs, ch) || CHIN1(cs, towlower(ch)) ||
164		    CHIN1(cs, towupper(ch)));
165	else
166		return (CHIN1(cs, ch));
167}
168
169/*
170 * main compiled-expression structure
171 */
172struct re_guts {
173	int magic;
174#		define	MAGIC2	((('R'^0200)<<8)|'E')
175	sop *strip;		/* malloced area for strip */
176	unsigned int ncsets;	/* number of csets in use */
177	cset *sets;		/* -> cset [ncsets] */
178	int cflags;		/* copy of regcomp() cflags argument */
179	sopno nstates;		/* = number of sops */
180	sopno firststate;	/* the initial OEND (normally 0) */
181	sopno laststate;	/* the final OEND */
182	int iflags;		/* internal flags */
183#		define	USEBOL	01	/* used ^ */
184#		define	USEEOL	02	/* used $ */
185#		define	BAD	04	/* something wrong */
186	int nbol;		/* number of ^ used */
187	int neol;		/* number of $ used */
188	char *must;		/* match must contain this string */
189	int moffset;		/* latest point at which must may be located */
190	int *charjump;		/* Boyer-Moore char jump table */
191	int *matchjump;		/* Boyer-Moore match jump table */
192	int mlen;		/* length of must */
193	size_t nsub;		/* copy of re_nsub */
194	int backrefs;		/* does it use back references? */
195	sopno nplus;		/* how deep does it nest +s? */
196};
197
198/* misc utilities */
199#define	OUT	(CHAR_MIN - 1)	/* a non-character value */
200#define	IGN	(CHAR_MIN - 2)
201#define ISWORD(c)       (iswalnum((uch)(c)) || (c) == '_')
202