xref: /illumos-gate/usr/src/lib/libc/port/regex/regexec.c (revision abfaa596b786488ec4aee4fcc241f6021f04ee50)
1  /*
2   * Copyright 2010 Nexenta Systems, Inc.  All rights reserved.
3   * Copyright (c) 1992, 1993, 1994 Henry Spencer.
4   * Copyright (c) 1992, 1993, 1994
5   *	The Regents of the University of California.  All rights reserved.
6   *
7   * This code is derived from software contributed to Berkeley by
8   * Henry Spencer.
9   *
10   * Redistribution and use in source and binary forms, with or without
11   * modification, are permitted provided that the following conditions
12   * are met:
13   * 1. Redistributions of source code must retain the above copyright
14   *    notice, this list of conditions and the following disclaimer.
15   * 2. Redistributions in binary form must reproduce the above copyright
16   *    notice, this list of conditions and the following disclaimer in the
17   *    documentation and/or other materials provided with the distribution.
18   * 3. Neither the name of the University nor the names of its contributors
19   *    may be used to endorse or promote products derived from this software
20   *    without specific prior written permission.
21   *
22   * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25   * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32   * SUCH DAMAGE.
33   */
34  
35  /*
36   * the outer shell of regexec()
37   *
38   * This file includes engine.c three times, after muchos fiddling with the
39   * macros that code uses.  This lets the same code operate on two different
40   * representations for state sets and characters.
41   */
42  #include "lint.h"
43  #include "file64.h"
44  #include <sys/types.h>
45  #include <stdio.h>
46  #include <stdlib.h>
47  #include <string.h>
48  #include <limits.h>
49  #include <ctype.h>
50  #include <regex.h>
51  #include <wchar.h>
52  #include <wctype.h>
53  #include <note.h>
54  #include <assert.h>
55  
56  #include "utils.h"
57  #include "regex2.h"
58  
59  /* we want _NOTE, but not NOTE (which collides with our own use) */
60  #undef	NOTE
61  
62  static size_t
63  xmbrtowc(wint_t *wi, const char *s, size_t n, mbstate_t *mbs, wint_t dummy)
64  {
65  	size_t nr;
66  	wchar_t wc;
67  
68  	nr = mbrtowc(&wc, s, n, mbs);
69  	if (wi != NULL)
70  		*wi = wc;
71  	if (nr == 0)
72  		return (1);
73  	else if (nr == (size_t)-1 || nr == (size_t)-2) {
74  		(void) memset(mbs, 0, sizeof (*mbs));
75  		if (wi != NULL)
76  			*wi = dummy;
77  		return (1);
78  	} else
79  		return (nr);
80  }
81  
82  static size_t
83  xmbrtowc_dummy(wint_t *wi, const char *s, size_t n, mbstate_t *mbs,
84      wint_t dummy)
85  {
86  	_NOTE(ARGUNUSED(n));
87  	_NOTE(ARGUNUSED(mbs));
88  	_NOTE(ARGUNUSED(dummy));
89  
90  	if (wi != NULL)
91  		*wi = (unsigned char)*s;
92  	return (1);
93  }
94  
95  /* macros for manipulating states, small version */
96  #define	states	long
97  #define	states1	states		/* for later use in regexec() decision */
98  #define	CLEAR(v)	((v) = 0)
99  #define	SET0(v, n)	((v) &= ~((unsigned long)1 << (n)))
100  #define	SET1(v, n)	((v) |= (unsigned long)1 << (n))
101  #define	ISSET(v, n)	(((v) & ((unsigned long)1 << (n))) != 0)
102  #define	ASSIGN(d, s)	((d) = (s))
103  #define	EQ(a, b)	((a) == (b))
104  #define	STATEVARS	long dummy	/* dummy version */
105  #define	STATESETUP(m, n)	/* nothing */
106  #define	STATETEARDOWN(m)	/* nothing */
107  #define	SETUP(v)	((v) = 0)
108  #define	onestate	long
109  #define	INIT(o, n)	((o) = (unsigned long)1 << (n))
110  #define	INC(o)	((o) <<= 1)
111  #define	ISSTATEIN(v, o)	(((v) & (o)) != 0)
112  /* some abbreviations; note that some of these know variable names! */
113  /* do "if I'm here, I can also be there" etc without branches */
114  #define	FWD(dst, src, n)	((dst) |= ((unsigned long)(src)&(here)) << (n))
115  #define	BACK(dst, src, n)	((dst) |= ((unsigned long)(src)&(here)) >> (n))
116  #define	ISSETBACK(v, n)	(((v) & ((unsigned long)here >> (n))) != 0)
117  /* no multibyte support */
118  #define	XMBRTOWC	xmbrtowc_dummy
119  #define	ZAPSTATE(mbs)	((void)(mbs))
120  /* function names */
121  #define	SNAMES			/* engine.c looks after details */
122  
123  #include "engine.c"
124  
125  /* now undo things */
126  #undef	states
127  #undef	CLEAR
128  #undef	SET0
129  #undef	SET1
130  #undef	ISSET
131  #undef	ASSIGN
132  #undef	EQ
133  #undef	STATEVARS
134  #undef	STATESETUP
135  #undef	STATETEARDOWN
136  #undef	SETUP
137  #undef	onestate
138  #undef	INIT
139  #undef	INC
140  #undef	ISSTATEIN
141  #undef	FWD
142  #undef	BACK
143  #undef	ISSETBACK
144  #undef	SNAMES
145  #undef	XMBRTOWC
146  #undef	ZAPSTATE
147  
148  /* macros for manipulating states, large version */
149  #define	states	char *
150  #define	CLEAR(v)	(void) memset(v, 0, m->g->nstates)
151  #define	SET0(v, n)	((v)[n] = 0)
152  #define	SET1(v, n)	((v)[n] = 1)
153  #define	ISSET(v, n)	((v)[n])
154  #define	ASSIGN(d, s)	(void) memcpy(d, s, m->g->nstates)
155  #define	EQ(a, b)	(memcmp(a, b, m->g->nstates) == 0)
156  #define	STATEVARS	long vn; char *space
157  #define	STATESETUP(m, nv) { (m)->space = malloc((nv)*(m)->g->nstates); \
158  	if ((m)->space == NULL) \
159  		return (REG_ESPACE); \
160  	(m)->vn = 0; }
161  #define	STATETEARDOWN(m)	{ free((m)->space); }
162  #define	SETUP(v)	((v) = &m->space[m->vn++ * m->g->nstates])
163  #define	onestate	long
164  #define	INIT(o, n)	((o) = (n))
165  #define	INC(o)	((o)++)
166  #define	ISSTATEIN(v, o)	((v)[o])
167  /* some abbreviations; note that some of these know variable names! */
168  /* do "if I'm here, I can also be there" etc without branches */
169  #define	FWD(dst, src, n)	((dst)[here+(n)] |= (src)[here])
170  #define	BACK(dst, src, n)	((dst)[here-(n)] |= (src)[here])
171  #define	ISSETBACK(v, n)	((v)[here - (n)])
172  /* no multibyte support */
173  #define	XMBRTOWC	xmbrtowc_dummy
174  #define	ZAPSTATE(mbs)	((void)(mbs))
175  /* function names */
176  #define	LNAMES			/* flag */
177  
178  #include "engine.c"
179  
180  /* multibyte character & large states version */
181  #undef	LNAMES
182  #undef	XMBRTOWC
183  #undef	ZAPSTATE
184  #define	XMBRTOWC	xmbrtowc
185  #define	ZAPSTATE(mbs)	(void) memset((mbs), 0, sizeof (*(mbs)))
186  #define	MNAMES
187  
188  #include "engine.c"
189  
190  /*
191   * regexec - interface for matching
192   *
193   * We put this here so we can exploit knowledge of the state representation
194   * when choosing which matcher to call.  Also, by this point the matchers
195   * have been prototyped.
196   */
197  int				/* 0 success, REG_NOMATCH failure */
198  regexec(const regex_t *_RESTRICT_KYWD preg, const char *_RESTRICT_KYWD string,
199      size_t nmatch, regmatch_t pmatch[_RESTRICT_KYWD], int eflags)
200  {
201  	struct re_guts *g = preg->re_g;
202  #ifdef REDEBUG
203  #define	GOODFLAGS(f)	(f)
204  #else
205  #ifdef	REG_STARTEND
206  #define	GOODFLAGS(f)	((f)&(REG_NOTBOL|REG_NOTEOL|REG_STARTEND))
207  #else
208  #define	GOODFLAGS(f)	((f)&(REG_NOTBOL|REG_NOTEOL))
209  #endif
210  #endif
211  
212  	if (preg->re_magic != MAGIC1 || g->magic != MAGIC2)
213  		return (REG_BADPAT);
214  	assert(!(g->iflags&BAD));
215  	if (g->iflags&BAD)		/* backstop for no-debug case */
216  		return (REG_BADPAT);
217  	eflags = GOODFLAGS(eflags);
218  
219  	if (MB_CUR_MAX > 1)
220  		return (mmatcher(g, string, nmatch, pmatch, eflags));
221  	else if (g->nstates <= CHAR_BIT*sizeof (states1) && !(eflags&REG_LARGE))
222  		return (smatcher(g, string, nmatch, pmatch, eflags));
223  	else
224  		return (lmatcher(g, string, nmatch, pmatch, eflags));
225  }
226