freebsd-dev/lib/libc/regex/regcomp.c
2019-09-24 12:21:01 +00:00

1982 lines
48 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1992, 1993, 1994 Henry Spencer.
* Copyright (c) 1992, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* Copyright (c) 2011 The FreeBSD Foundation
* All rights reserved.
* Portions of this software were developed by David Chisnall
* under sponsorship from the FreeBSD Foundation.
*
* This code is derived from software contributed to Berkeley by
* Henry Spencer.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name of the University 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 REGENTS 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 REGENTS 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.
*
* @(#)regcomp.c 8.5 (Berkeley) 3/20/94
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)regcomp.c 8.5 (Berkeley) 3/20/94";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <limits.h>
#include <stdlib.h>
#include <regex.h>
#include <stdbool.h>
#include <wchar.h>
#include <wctype.h>
#ifndef LIBREGEX
#include "collate.h"
#endif
#include "utils.h"
#include "regex2.h"
#include "cname.h"
/*
* Branching context, used to keep track of branch state for all of the branch-
* aware functions. In addition to keeping track of branch positions for the
* p_branch_* functions, we use this to simplify some clumsiness in BREs for
* detection of whether ^ is acting as an anchor or being used erroneously and
* also for whether we're in a sub-expression or not.
*/
struct branchc {
sopno start;
sopno back;
sopno fwd;
int nbranch;
int nchain;
bool outer;
bool terminate;
};
/*
* parse structure, passed up and down to avoid global variables and
* other clumsinesses
*/
struct parse {
const char *next; /* next character in RE */
const char *end; /* end of string (-> NUL normally) */
int error; /* has an error been seen? */
sop *strip; /* malloced strip */
sopno ssize; /* malloced strip size (allocated) */
sopno slen; /* malloced strip length (used) */
int ncsalloc; /* number of csets allocated */
struct re_guts *g;
# define NPAREN 10 /* we need to remember () 1-9 for back refs */
sopno pbegin[NPAREN]; /* -> ( ([0] unused) */
sopno pend[NPAREN]; /* -> ) ([0] unused) */
bool allowbranch; /* can this expression branch? */
bool bre; /* convenience; is this a BRE? */
bool (*parse_expr)(struct parse *, struct branchc *);
void (*pre_parse)(struct parse *, struct branchc *);
void (*post_parse)(struct parse *, struct branchc *);
};
/* ========= begin header generated by ./mkh ========= */
#ifdef __cplusplus
extern "C" {
#endif
/* === regcomp.c === */
static bool p_ere_exp(struct parse *p, struct branchc *bc);
static void p_str(struct parse *p);
static int p_branch_eat_delim(struct parse *p, struct branchc *bc);
static void p_branch_ins_offset(struct parse *p, struct branchc *bc);
static void p_branch_fix_tail(struct parse *p, struct branchc *bc);
static bool p_branch_empty(struct parse *p, struct branchc *bc);
static bool p_branch_do(struct parse *p, struct branchc *bc);
static void p_bre_pre_parse(struct parse *p, struct branchc *bc);
static void p_bre_post_parse(struct parse *p, struct branchc *bc);
static void p_re(struct parse *p, int end1, int end2);
static bool p_simp_re(struct parse *p, struct branchc *bc);
static int p_count(struct parse *p);
static void p_bracket(struct parse *p);
static int p_range_cmp(wchar_t c1, wchar_t c2);
static void p_b_term(struct parse *p, cset *cs);
static void p_b_cclass(struct parse *p, cset *cs);
static void p_b_eclass(struct parse *p, cset *cs);
static wint_t p_b_symbol(struct parse *p);
static wint_t p_b_coll_elem(struct parse *p, wint_t endc);
static wint_t othercase(wint_t ch);
static void bothcases(struct parse *p, wint_t ch);
static void ordinary(struct parse *p, wint_t ch);
static void nonnewline(struct parse *p);
static void repeat(struct parse *p, sopno start, int from, int to);
static int seterr(struct parse *p, int e);
static cset *allocset(struct parse *p);
static void freeset(struct parse *p, cset *cs);
static void CHadd(struct parse *p, cset *cs, wint_t ch);
static void CHaddrange(struct parse *p, cset *cs, wint_t min, wint_t max);
static void CHaddtype(struct parse *p, cset *cs, wctype_t wct);
static wint_t singleton(cset *cs);
static sopno dupl(struct parse *p, sopno start, sopno finish);
static void doemit(struct parse *p, sop op, size_t opnd);
static void doinsert(struct parse *p, sop op, size_t opnd, sopno pos);
static void dofwd(struct parse *p, sopno pos, sop value);
static int enlarge(struct parse *p, sopno size);
static void stripsnug(struct parse *p, struct re_guts *g);
static void findmust(struct parse *p, struct re_guts *g);
static int altoffset(sop *scan, int offset);
static void computejumps(struct parse *p, struct re_guts *g);
static void computematchjumps(struct parse *p, struct re_guts *g);
static sopno pluscount(struct parse *p, struct re_guts *g);
static wint_t wgetnext(struct parse *p);
#ifdef __cplusplus
}
#endif
/* ========= end header generated by ./mkh ========= */
static char nuls[10]; /* place to point scanner in event of error */
/*
* macros for use with parse structure
* BEWARE: these know that the parse structure is named `p' !!!
*/
#define PEEK() (*p->next)
#define PEEK2() (*(p->next+1))
#define MORE() (p->next < p->end)
#define MORE2() (p->next+1 < p->end)
#define SEE(c) (MORE() && PEEK() == (c))
#define SEETWO(a, b) (MORE() && MORE2() && PEEK() == (a) && PEEK2() == (b))
#define SEESPEC(a) (p->bre ? SEETWO('\\', a) : SEE(a))
#define EAT(c) ((SEE(c)) ? (NEXT(), 1) : 0)
#define EATTWO(a, b) ((SEETWO(a, b)) ? (NEXT2(), 1) : 0)
#define NEXT() (p->next++)
#define NEXT2() (p->next += 2)
#define NEXTn(n) (p->next += (n))
#define GETNEXT() (*p->next++)
#define WGETNEXT() wgetnext(p)
#define SETERROR(e) seterr(p, (e))
#define REQUIRE(co, e) ((co) || SETERROR(e))
#define MUSTSEE(c, e) (REQUIRE(MORE() && PEEK() == (c), e))
#define MUSTEAT(c, e) (REQUIRE(MORE() && GETNEXT() == (c), e))
#define MUSTNOTSEE(c, e) (REQUIRE(!MORE() || PEEK() != (c), e))
#define EMIT(op, sopnd) doemit(p, (sop)(op), (size_t)(sopnd))
#define INSERT(op, pos) doinsert(p, (sop)(op), HERE()-(pos)+1, pos)
#define AHEAD(pos) dofwd(p, pos, HERE()-(pos))
#define ASTERN(sop, pos) EMIT(sop, HERE()-pos)
#define HERE() (p->slen)
#define THERE() (p->slen - 1)
#define THERETHERE() (p->slen - 2)
#define DROP(n) (p->slen -= (n))
/* Macro used by computejump()/computematchjump() */
#define MIN(a,b) ((a)<(b)?(a):(b))
/*
- regcomp - interface for parser and compilation
= extern int regcomp(regex_t *, const char *, int);
= #define REG_BASIC 0000
= #define REG_EXTENDED 0001
= #define REG_ICASE 0002
= #define REG_NOSUB 0004
= #define REG_NEWLINE 0010
= #define REG_NOSPEC 0020
= #define REG_PEND 0040
= #define REG_DUMP 0200
*/
int /* 0 success, otherwise REG_something */
regcomp(regex_t * __restrict preg,
const char * __restrict pattern,
int cflags)
{
struct parse pa;
struct re_guts *g;
struct parse *p = &pa;
int i;
size_t len;
size_t maxlen;
#ifdef REDEBUG
# define GOODFLAGS(f) (f)
#else
# define GOODFLAGS(f) ((f)&~REG_DUMP)
#endif
cflags = GOODFLAGS(cflags);
if ((cflags&REG_EXTENDED) && (cflags&REG_NOSPEC))
return(REG_INVARG);
if (cflags&REG_PEND) {
if (preg->re_endp < pattern)
return(REG_INVARG);
len = preg->re_endp - pattern;
} else
len = strlen(pattern);
/* do the mallocs early so failure handling is easy */
g = (struct re_guts *)malloc(sizeof(struct re_guts));
if (g == NULL)
return(REG_ESPACE);
/*
* Limit the pattern space to avoid a 32-bit overflow on buffer
* extension. Also avoid any signed overflow in case of conversion
* so make the real limit based on a 31-bit overflow.
*
* Likely not applicable on 64-bit systems but handle the case
* generically (who are we to stop people from using ~715MB+
* patterns?).
*/
maxlen = ((size_t)-1 >> 1) / sizeof(sop) * 2 / 3;
if (len >= maxlen) {
free((char *)g);
return(REG_ESPACE);
}
p->ssize = len/(size_t)2*(size_t)3 + (size_t)1; /* ugh */
assert(p->ssize >= len);
p->strip = (sop *)malloc(p->ssize * sizeof(sop));
p->slen = 0;
if (p->strip == NULL) {
free((char *)g);
return(REG_ESPACE);
}
/* set things up */
p->g = g;
p->next = pattern; /* convenience; we do not modify it */
p->end = p->next + len;
p->error = 0;
p->ncsalloc = 0;
for (i = 0; i < NPAREN; i++) {
p->pbegin[i] = 0;
p->pend[i] = 0;
}
if (cflags & REG_EXTENDED) {
p->allowbranch = true;
p->bre = false;
p->parse_expr = p_ere_exp;
p->pre_parse = NULL;
p->post_parse = NULL;
} else {
p->allowbranch = false;
p->bre = true;
p->parse_expr = p_simp_re;
p->pre_parse = p_bre_pre_parse;
p->post_parse = p_bre_post_parse;
}
g->sets = NULL;
g->ncsets = 0;
g->cflags = cflags;
g->iflags = 0;
g->nbol = 0;
g->neol = 0;
g->must = NULL;
g->moffset = -1;
g->charjump = NULL;
g->matchjump = NULL;
g->mlen = 0;
g->nsub = 0;
g->backrefs = 0;
/* do it */
EMIT(OEND, 0);
g->firststate = THERE();
if (cflags & REG_NOSPEC)
p_str(p);
else
p_re(p, OUT, OUT);
EMIT(OEND, 0);
g->laststate = THERE();
/* tidy up loose ends and fill things in */
stripsnug(p, g);
findmust(p, g);
/* only use Boyer-Moore algorithm if the pattern is bigger
* than three characters
*/
if(g->mlen > 3) {
computejumps(p, g);
computematchjumps(p, g);
if(g->matchjump == NULL && g->charjump != NULL) {
free(g->charjump);
g->charjump = NULL;
}
}
g->nplus = pluscount(p, g);
g->magic = MAGIC2;
preg->re_nsub = g->nsub;
preg->re_g = g;
preg->re_magic = MAGIC1;
#ifndef REDEBUG
/* not debugging, so can't rely on the assert() in regexec() */
if (g->iflags&BAD)
SETERROR(REG_ASSERT);
#endif
/* win or lose, we're done */
if (p->error != 0) /* lose */
regfree(preg);
return(p->error);
}
/*
- p_ere_exp - parse one subERE, an atom possibly followed by a repetition op,
- return whether we should terminate or not
== static bool p_ere_exp(struct parse *p);
*/
static bool
p_ere_exp(struct parse *p, struct branchc *bc)
{
char c;
wint_t wc;
sopno pos;
int count;
int count2;
sopno subno;
int wascaret = 0;
(void)bc;
assert(MORE()); /* caller should have ensured this */
c = GETNEXT();
pos = HERE();
switch (c) {
case '(':
(void)REQUIRE(MORE(), REG_EPAREN);
p->g->nsub++;
subno = p->g->nsub;
if (subno < NPAREN)
p->pbegin[subno] = HERE();
EMIT(OLPAREN, subno);
if (!SEE(')'))
p_re(p, ')', IGN);
if (subno < NPAREN) {
p->pend[subno] = HERE();
assert(p->pend[subno] != 0);
}
EMIT(ORPAREN, subno);
(void)MUSTEAT(')', REG_EPAREN);
break;
#ifndef POSIX_MISTAKE
case ')': /* happens only if no current unmatched ( */
/*
* You may ask, why the ifndef? Because I didn't notice
* this until slightly too late for 1003.2, and none of the
* other 1003.2 regular-expression reviewers noticed it at
* all. So an unmatched ) is legal POSIX, at least until
* we can get it fixed.
*/
SETERROR(REG_EPAREN);
break;
#endif
case '^':
EMIT(OBOL, 0);
p->g->iflags |= USEBOL;
p->g->nbol++;
wascaret = 1;
break;
case '$':
EMIT(OEOL, 0);
p->g->iflags |= USEEOL;
p->g->neol++;
break;
case '|':
SETERROR(REG_EMPTY);
break;
case '*':
case '+':
case '?':
case '{':
SETERROR(REG_BADRPT);
break;
case '.':
if (p->g->cflags&REG_NEWLINE)
nonnewline(p);
else
EMIT(OANY, 0);
break;
case '[':
p_bracket(p);
break;
case '\\':
(void)REQUIRE(MORE(), REG_EESCAPE);
wc = WGETNEXT();
switch (wc) {
case '<':
EMIT(OBOW, 0);
break;
case '>':
EMIT(OEOW, 0);
break;
default:
ordinary(p, wc);
break;
}
break;
default:
if (p->error != 0)
return (false);
p->next--;
wc = WGETNEXT();
ordinary(p, wc);
break;
}
if (!MORE())
return (false);
c = PEEK();
/* we call { a repetition if followed by a digit */
if (!( c == '*' || c == '+' || c == '?' || c == '{'))
return (false); /* no repetition, we're done */
else if (c == '{')
(void)REQUIRE(MORE2() && \
(isdigit((uch)PEEK2()) || PEEK2() == ','), REG_BADRPT);
NEXT();
(void)REQUIRE(!wascaret, REG_BADRPT);
switch (c) {
case '*': /* implemented as +? */
/* this case does not require the (y|) trick, noKLUDGE */
INSERT(OPLUS_, pos);
ASTERN(O_PLUS, pos);
INSERT(OQUEST_, pos);
ASTERN(O_QUEST, pos);
break;
case '+':
INSERT(OPLUS_, pos);
ASTERN(O_PLUS, pos);
break;
case '?':
/* KLUDGE: emit y? as (y|) until subtle bug gets fixed */
INSERT(OCH_, pos); /* offset slightly wrong */
ASTERN(OOR1, pos); /* this one's right */
AHEAD(pos); /* fix the OCH_ */
EMIT(OOR2, 0); /* offset very wrong... */
AHEAD(THERE()); /* ...so fix it */
ASTERN(O_CH, THERETHERE());
break;
case '{':
count = p_count(p);
if (EAT(',')) {
if (isdigit((uch)PEEK())) {
count2 = p_count(p);
(void)REQUIRE(count <= count2, REG_BADBR);
} else /* single number with comma */
count2 = INFINITY;
} else /* just a single number */
count2 = count;
repeat(p, pos, count, count2);
if (!EAT('}')) { /* error heuristics */
while (MORE() && PEEK() != '}')
NEXT();
(void)REQUIRE(MORE(), REG_EBRACE);
SETERROR(REG_BADBR);
}
break;
}
if (!MORE())
return (false);
c = PEEK();
if (!( c == '*' || c == '+' || c == '?' ||
(c == '{' && MORE2() && isdigit((uch)PEEK2())) ) )
return (false);
SETERROR(REG_BADRPT);
return (false);
}
/*
- p_str - string (no metacharacters) "parser"
== static void p_str(struct parse *p);
*/
static void
p_str(struct parse *p)
{
(void)REQUIRE(MORE(), REG_EMPTY);
while (MORE())
ordinary(p, WGETNEXT());
}
/*
* Eat consecutive branch delimiters for the kind of expression that we are
* parsing, return the number of delimiters that we ate.
*/
static int
p_branch_eat_delim(struct parse *p, struct branchc *bc)
{
int nskip;
(void)bc;
nskip = 0;
while (EAT('|'))
++nskip;
return (nskip);
}
/*
* Insert necessary branch book-keeping operations. This emits a
* bogus 'next' offset, since we still have more to parse
*/
static void
p_branch_ins_offset(struct parse *p, struct branchc *bc)
{
if (bc->nbranch == 0) {
INSERT(OCH_, bc->start); /* offset is wrong */
bc->fwd = bc->start;
bc->back = bc->start;
}
ASTERN(OOR1, bc->back);
bc->back = THERE();
AHEAD(bc->fwd); /* fix previous offset */
bc->fwd = HERE();
EMIT(OOR2, 0); /* offset is very wrong */
++bc->nbranch;
}
/*
* Fix the offset of the tail branch, if we actually had any branches.
* This is to correct the bogus placeholder offset that we use.
*/
static void
p_branch_fix_tail(struct parse *p, struct branchc *bc)
{
/* Fix bogus offset at the tail if we actually have branches */
if (bc->nbranch > 0) {
AHEAD(bc->fwd);
ASTERN(O_CH, bc->back);
}
}
/*
* Signal to the parser that an empty branch has been encountered; this will,
* in the future, be used to allow for more permissive behavior with empty
* branches. The return value should indicate whether parsing may continue
* or not.
*/
static bool
p_branch_empty(struct parse *p, struct branchc *bc)
{
(void)bc;
SETERROR(REG_EMPTY);
return (false);
}
/*
* Take care of any branching requirements. This includes inserting the
* appropriate branching instructions as well as eating all of the branch
* delimiters until we either run out of pattern or need to parse more pattern.
*/
static bool
p_branch_do(struct parse *p, struct branchc *bc)
{
int ate = 0;
ate = p_branch_eat_delim(p, bc);
if (ate == 0)
return (false);
else if ((ate > 1 || (bc->outer && !MORE())) && !p_branch_empty(p, bc))
/*
* Halt parsing only if we have an empty branch and p_branch_empty
* indicates that we must not continue. In the future, this will not
* necessarily be an error.
*/
return (false);
p_branch_ins_offset(p, bc);
return (true);
}
static void
p_bre_pre_parse(struct parse *p, struct branchc *bc)
{
(void) bc;
/*
* Does not move cleanly into expression parser because of
* ordinary interpration of * at the beginning position of
* an expression.
*/
if (EAT('^')) {
EMIT(OBOL, 0);
p->g->iflags |= USEBOL;
p->g->nbol++;
}
}
static void
p_bre_post_parse(struct parse *p, struct branchc *bc)
{
/* Expression is terminating due to EOL token */
if (bc->terminate) {
DROP(1);
EMIT(OEOL, 0);
p->g->iflags |= USEEOL;
p->g->neol++;
}
}
/*
- p_re - Top level parser, concatenation and BRE anchoring
== static void p_re(struct parse *p, int end1, int end2);
* Giving end1 as OUT essentially eliminates the end1/end2 check.
*
* This implementation is a bit of a kludge, in that a trailing $ is first
* taken as an ordinary character and then revised to be an anchor.
* The amount of lookahead needed to avoid this kludge is excessive.
*/
static void
p_re(struct parse *p,
int end1, /* first terminating character */
int end2) /* second terminating character; ignored for EREs */
{
struct branchc bc;
bc.nbranch = 0;
if (end1 == OUT && end2 == OUT)
bc.outer = true;
else
bc.outer = false;
#define SEEEND() (!p->bre ? SEE(end1) : SEETWO(end1, end2))
for (;;) {
bc.start = HERE();
bc.nchain = 0;
bc.terminate = false;
if (p->pre_parse != NULL)
p->pre_parse(p, &bc);
while (MORE() && (!p->allowbranch || !SEESPEC('|')) && !SEEEND()) {
bc.terminate = p->parse_expr(p, &bc);
++bc.nchain;
}
if (p->post_parse != NULL)
p->post_parse(p, &bc);
(void) REQUIRE(HERE() != bc.start, REG_EMPTY);
if (!p->allowbranch)
break;
/*
* p_branch_do's return value indicates whether we should
* continue parsing or not. This is both for correctness and
* a slight optimization, because it will check if we've
* encountered an empty branch or the end of the string
* immediately following a branch delimiter.
*/
if (!p_branch_do(p, &bc))
break;
}
#undef SEE_END
if (p->allowbranch)
p_branch_fix_tail(p, &bc);
assert(!MORE() || SEE(end1));
}
/*
- p_simp_re - parse a simple RE, an atom possibly followed by a repetition
== static bool p_simp_re(struct parse *p, struct branchc *bc);
*/
static bool /* was the simple RE an unbackslashed $? */
p_simp_re(struct parse *p, struct branchc *bc)
{
int c;
int count;
int count2;
sopno pos;
int i;
wint_t wc;
sopno subno;
# define BACKSL (1<<CHAR_BIT)
pos = HERE(); /* repetition op, if any, covers from here */
assert(MORE()); /* caller should have ensured this */
c = GETNEXT();
if (c == '\\') {
(void)REQUIRE(MORE(), REG_EESCAPE);
c = BACKSL | GETNEXT();
}
switch (c) {
case '.':
if (p->g->cflags&REG_NEWLINE)
nonnewline(p);
else
EMIT(OANY, 0);
break;
case '[':
p_bracket(p);
break;
case BACKSL|'<':
EMIT(OBOW, 0);
break;
case BACKSL|'>':
EMIT(OEOW, 0);
break;
case BACKSL|'{':
SETERROR(REG_BADRPT);
break;
case BACKSL|'(':
p->g->nsub++;
subno = p->g->nsub;
if (subno < NPAREN)
p->pbegin[subno] = HERE();
EMIT(OLPAREN, subno);
/* the MORE here is an error heuristic */
if (MORE() && !SEETWO('\\', ')'))
p_re(p, '\\', ')');
if (subno < NPAREN) {
p->pend[subno] = HERE();
assert(p->pend[subno] != 0);
}
EMIT(ORPAREN, subno);
(void)REQUIRE(EATTWO('\\', ')'), REG_EPAREN);
break;
case BACKSL|')': /* should not get here -- must be user */
SETERROR(REG_EPAREN);
break;
case BACKSL|'1':
case BACKSL|'2':
case BACKSL|'3':
case BACKSL|'4':
case BACKSL|'5':
case BACKSL|'6':
case BACKSL|'7':
case BACKSL|'8':
case BACKSL|'9':
i = (c&~BACKSL) - '0';
assert(i < NPAREN);
if (p->pend[i] != 0) {
assert(i <= p->g->nsub);
EMIT(OBACK_, i);
assert(p->pbegin[i] != 0);
assert(OP(p->strip[p->pbegin[i]]) == OLPAREN);
assert(OP(p->strip[p->pend[i]]) == ORPAREN);
(void) dupl(p, p->pbegin[i]+1, p->pend[i]);
EMIT(O_BACK, i);
} else
SETERROR(REG_ESUBREG);
p->g->backrefs = 1;
break;
case '*':
/*
* Ordinary if used as the first character beyond BOL anchor of
* a (sub-)expression, counts as a bad repetition operator if it
* appears otherwise.
*/
(void)REQUIRE(bc->nchain == 0, REG_BADRPT);
/* FALLTHROUGH */
default:
if (p->error != 0)
return (false); /* Definitely not $... */
p->next--;
wc = WGETNEXT();
ordinary(p, wc);
break;
}
if (EAT('*')) { /* implemented as +? */
/* this case does not require the (y|) trick, noKLUDGE */
INSERT(OPLUS_, pos);
ASTERN(O_PLUS, pos);
INSERT(OQUEST_, pos);
ASTERN(O_QUEST, pos);
} else if (EATTWO('\\', '{')) {
count = p_count(p);
if (EAT(',')) {
if (MORE() && isdigit((uch)PEEK())) {
count2 = p_count(p);
(void)REQUIRE(count <= count2, REG_BADBR);
} else /* single number with comma */
count2 = INFINITY;
} else /* just a single number */
count2 = count;
repeat(p, pos, count, count2);
if (!EATTWO('\\', '}')) { /* error heuristics */
while (MORE() && !SEETWO('\\', '}'))
NEXT();
(void)REQUIRE(MORE(), REG_EBRACE);
SETERROR(REG_BADBR);
}
} else if (c == '$') /* $ (but not \$) ends it */
return (true);
return (false);
}
/*
- p_count - parse a repetition count
== static int p_count(struct parse *p);
*/
static int /* the value */
p_count(struct parse *p)
{
int count = 0;
int ndigits = 0;
while (MORE() && isdigit((uch)PEEK()) && count <= DUPMAX) {
count = count*10 + (GETNEXT() - '0');
ndigits++;
}
(void)REQUIRE(ndigits > 0 && count <= DUPMAX, REG_BADBR);
return(count);
}
/*
- p_bracket - parse a bracketed character list
== static void p_bracket(struct parse *p);
*/
static void
p_bracket(struct parse *p)
{
cset *cs;
wint_t ch;
/* Dept of Truly Sickening Special-Case Kludges */
if (p->next + 5 < p->end && strncmp(p->next, "[:<:]]", 6) == 0) {
EMIT(OBOW, 0);
NEXTn(6);
return;
}
if (p->next + 5 < p->end && strncmp(p->next, "[:>:]]", 6) == 0) {
EMIT(OEOW, 0);
NEXTn(6);
return;
}
if ((cs = allocset(p)) == NULL)
return;
if (p->g->cflags&REG_ICASE)
cs->icase = 1;
if (EAT('^'))
cs->invert = 1;
if (EAT(']'))
CHadd(p, cs, ']');
else if (EAT('-'))
CHadd(p, cs, '-');
while (MORE() && PEEK() != ']' && !SEETWO('-', ']'))
p_b_term(p, cs);
if (EAT('-'))
CHadd(p, cs, '-');
(void)MUSTEAT(']', REG_EBRACK);
if (p->error != 0) /* don't mess things up further */
return;
if (cs->invert && p->g->cflags&REG_NEWLINE)
cs->bmp['\n' >> 3] |= 1 << ('\n' & 7);
if ((ch = singleton(cs)) != OUT) { /* optimize singleton sets */
ordinary(p, ch);
freeset(p, cs);
} else
EMIT(OANYOF, (int)(cs - p->g->sets));
}
static int
p_range_cmp(wchar_t c1, wchar_t c2)
{
#ifndef LIBREGEX
return __wcollate_range_cmp(c1, c2);
#else
/* Copied from libc/collate __wcollate_range_cmp */
wchar_t s1[2], s2[2];
s1[0] = c1;
s1[1] = L'\0';
s2[0] = c2;
s2[1] = L'\0';
return (wcscoll(s1, s2));
#endif
}
/*
- p_b_term - parse one term of a bracketed character list
== static void p_b_term(struct parse *p, cset *cs);
*/
static void
p_b_term(struct parse *p, cset *cs)
{
char c;
wint_t start, finish;
wint_t i;
#ifndef LIBREGEX
struct xlocale_collate *table =
(struct xlocale_collate*)__get_locale()->components[XLC_COLLATE];
#endif
/* classify what we've got */
switch ((MORE()) ? PEEK() : '\0') {
case '[':
c = (MORE2()) ? PEEK2() : '\0';
break;
case '-':
SETERROR(REG_ERANGE);
return; /* NOTE RETURN */
default:
c = '\0';
break;
}
switch (c) {
case ':': /* character class */
NEXT2();
(void)REQUIRE(MORE(), REG_EBRACK);
c = PEEK();
(void)REQUIRE(c != '-' && c != ']', REG_ECTYPE);
p_b_cclass(p, cs);
(void)REQUIRE(MORE(), REG_EBRACK);
(void)REQUIRE(EATTWO(':', ']'), REG_ECTYPE);
break;
case '=': /* equivalence class */
NEXT2();
(void)REQUIRE(MORE(), REG_EBRACK);
c = PEEK();
(void)REQUIRE(c != '-' && c != ']', REG_ECOLLATE);
p_b_eclass(p, cs);
(void)REQUIRE(MORE(), REG_EBRACK);
(void)REQUIRE(EATTWO('=', ']'), REG_ECOLLATE);
break;
default: /* symbol, ordinary character, or range */
start = p_b_symbol(p);
if (SEE('-') && MORE2() && PEEK2() != ']') {
/* range */
NEXT();
if (EAT('-'))
finish = '-';
else
finish = p_b_symbol(p);
} else
finish = start;
if (start == finish)
CHadd(p, cs, start);
else {
#ifndef LIBREGEX
if (table->__collate_load_error || MB_CUR_MAX > 1) {
#else
if (MB_CUR_MAX > 1) {
#endif
(void)REQUIRE(start <= finish, REG_ERANGE);
CHaddrange(p, cs, start, finish);
} else {
(void)REQUIRE(p_range_cmp(start, finish) <= 0, REG_ERANGE);
for (i = 0; i <= UCHAR_MAX; i++) {
if (p_range_cmp(start, i) <= 0 &&
p_range_cmp(i, finish) <= 0 )
CHadd(p, cs, i);
}
}
}
break;
}
}
/*
- p_b_cclass - parse a character-class name and deal with it
== static void p_b_cclass(struct parse *p, cset *cs);
*/
static void
p_b_cclass(struct parse *p, cset *cs)
{
const char *sp = p->next;
size_t len;
wctype_t wct;
char clname[16];
while (MORE() && isalpha((uch)PEEK()))
NEXT();
len = p->next - sp;
if (len >= sizeof(clname) - 1) {
SETERROR(REG_ECTYPE);
return;
}
memcpy(clname, sp, len);
clname[len] = '\0';
if ((wct = wctype(clname)) == 0) {
SETERROR(REG_ECTYPE);
return;
}
CHaddtype(p, cs, wct);
}
/*
- p_b_eclass - parse an equivalence-class name and deal with it
== static void p_b_eclass(struct parse *p, cset *cs);
*
* This implementation is incomplete. xxx
*/
static void
p_b_eclass(struct parse *p, cset *cs)
{
wint_t c;
c = p_b_coll_elem(p, '=');
CHadd(p, cs, c);
}
/*
- p_b_symbol - parse a character or [..]ed multicharacter collating symbol
== static wint_t p_b_symbol(struct parse *p);
*/
static wint_t /* value of symbol */
p_b_symbol(struct parse *p)
{
wint_t value;
(void)REQUIRE(MORE(), REG_EBRACK);
if (!EATTWO('[', '.'))
return(WGETNEXT());
/* collating symbol */
value = p_b_coll_elem(p, '.');
(void)REQUIRE(EATTWO('.', ']'), REG_ECOLLATE);
return(value);
}
/*
- p_b_coll_elem - parse a collating-element name and look it up
== static wint_t p_b_coll_elem(struct parse *p, wint_t endc);
*/
static wint_t /* value of collating element */
p_b_coll_elem(struct parse *p,
wint_t endc) /* name ended by endc,']' */
{
const char *sp = p->next;
struct cname *cp;
mbstate_t mbs;
wchar_t wc;
size_t clen, len;
while (MORE() && !SEETWO(endc, ']'))
NEXT();
if (!MORE()) {
SETERROR(REG_EBRACK);
return(0);
}
len = p->next - sp;
for (cp = cnames; cp->name != NULL; cp++)
if (strncmp(cp->name, sp, len) == 0 && strlen(cp->name) == len)
return(cp->code); /* known name */
memset(&mbs, 0, sizeof(mbs));
if ((clen = mbrtowc(&wc, sp, len, &mbs)) == len)
return (wc); /* single character */
else if (clen == (size_t)-1 || clen == (size_t)-2)
SETERROR(REG_ILLSEQ);
else
SETERROR(REG_ECOLLATE); /* neither */
return(0);
}
/*
- othercase - return the case counterpart of an alphabetic
== static wint_t othercase(wint_t ch);
*/
static wint_t /* if no counterpart, return ch */
othercase(wint_t ch)
{
assert(iswalpha(ch));
if (iswupper(ch))
return(towlower(ch));
else if (iswlower(ch))
return(towupper(ch));
else /* peculiar, but could happen */
return(ch);
}
/*
- bothcases - emit a dualcase version of a two-case character
== static void bothcases(struct parse *p, wint_t ch);
*
* Boy, is this implementation ever a kludge...
*/
static void
bothcases(struct parse *p, wint_t ch)
{
const char *oldnext = p->next;
const char *oldend = p->end;
char bracket[3 + MB_LEN_MAX];
size_t n;
mbstate_t mbs;
assert(othercase(ch) != ch); /* p_bracket() would recurse */
p->next = bracket;
memset(&mbs, 0, sizeof(mbs));
n = wcrtomb(bracket, ch, &mbs);
assert(n != (size_t)-1);
bracket[n] = ']';
bracket[n + 1] = '\0';
p->end = bracket+n+1;
p_bracket(p);
assert(p->next == p->end);
p->next = oldnext;
p->end = oldend;
}
/*
- ordinary - emit an ordinary character
== static void ordinary(struct parse *p, wint_t ch);
*/
static void
ordinary(struct parse *p, wint_t ch)
{
cset *cs;
if ((p->g->cflags&REG_ICASE) && iswalpha(ch) && othercase(ch) != ch)
bothcases(p, ch);
else if ((ch & OPDMASK) == ch)
EMIT(OCHAR, ch);
else {
/*
* Kludge: character is too big to fit into an OCHAR operand.
* Emit a singleton set.
*/
if ((cs = allocset(p)) == NULL)
return;
CHadd(p, cs, ch);
EMIT(OANYOF, (int)(cs - p->g->sets));
}
}
/*
- nonnewline - emit REG_NEWLINE version of OANY
== static void nonnewline(struct parse *p);
*
* Boy, is this implementation ever a kludge...
*/
static void
nonnewline(struct parse *p)
{
const char *oldnext = p->next;
const char *oldend = p->end;
char bracket[4];
p->next = bracket;
p->end = bracket+3;
bracket[0] = '^';
bracket[1] = '\n';
bracket[2] = ']';
bracket[3] = '\0';
p_bracket(p);
assert(p->next == bracket+3);
p->next = oldnext;
p->end = oldend;
}
/*
- repeat - generate code for a bounded repetition, recursively if needed
== static void repeat(struct parse *p, sopno start, int from, int to);
*/
static void
repeat(struct parse *p,
sopno start, /* operand from here to end of strip */
int from, /* repeated from this number */
int to) /* to this number of times (maybe INFINITY) */
{
sopno finish = HERE();
# define N 2
# define INF 3
# define REP(f, t) ((f)*8 + (t))
# define MAP(n) (((n) <= 1) ? (n) : ((n) == INFINITY) ? INF : N)
sopno copy;
if (p->error != 0) /* head off possible runaway recursion */
return;
assert(from <= to);
switch (REP(MAP(from), MAP(to))) {
case REP(0, 0): /* must be user doing this */
DROP(finish-start); /* drop the operand */
break;
case REP(0, 1): /* as x{1,1}? */
case REP(0, N): /* as x{1,n}? */
case REP(0, INF): /* as x{1,}? */
/* KLUDGE: emit y? as (y|) until subtle bug gets fixed */
INSERT(OCH_, start); /* offset is wrong... */
repeat(p, start+1, 1, to);
ASTERN(OOR1, start);
AHEAD(start); /* ... fix it */
EMIT(OOR2, 0);
AHEAD(THERE());
ASTERN(O_CH, THERETHERE());
break;
case REP(1, 1): /* trivial case */
/* done */
break;
case REP(1, N): /* as x?x{1,n-1} */
/* KLUDGE: emit y? as (y|) until subtle bug gets fixed */
INSERT(OCH_, start);
ASTERN(OOR1, start);
AHEAD(start);
EMIT(OOR2, 0); /* offset very wrong... */
AHEAD(THERE()); /* ...so fix it */
ASTERN(O_CH, THERETHERE());
copy = dupl(p, start+1, finish+1);
assert(copy == finish+4);
repeat(p, copy, 1, to-1);
break;
case REP(1, INF): /* as x+ */
INSERT(OPLUS_, start);
ASTERN(O_PLUS, start);
break;
case REP(N, N): /* as xx{m-1,n-1} */
copy = dupl(p, start, finish);
repeat(p, copy, from-1, to-1);
break;
case REP(N, INF): /* as xx{n-1,INF} */
copy = dupl(p, start, finish);
repeat(p, copy, from-1, to);
break;
default: /* "can't happen" */
SETERROR(REG_ASSERT); /* just in case */
break;
}
}
/*
- wgetnext - helper function for WGETNEXT() macro. Gets the next wide
- character from the parse struct, signals a REG_ILLSEQ error if the
- character can't be converted. Returns the number of bytes consumed.
*/
static wint_t
wgetnext(struct parse *p)
{
mbstate_t mbs;
wchar_t wc;
size_t n;
memset(&mbs, 0, sizeof(mbs));
n = mbrtowc(&wc, p->next, p->end - p->next, &mbs);
if (n == (size_t)-1 || n == (size_t)-2) {
SETERROR(REG_ILLSEQ);
return (0);
}
if (n == 0)
n = 1;
p->next += n;
return (wc);
}
/*
- seterr - set an error condition
== static int seterr(struct parse *p, int e);
*/
static int /* useless but makes type checking happy */
seterr(struct parse *p, int e)
{
if (p->error == 0) /* keep earliest error condition */
p->error = e;
p->next = nuls; /* try to bring things to a halt */
p->end = nuls;
return(0); /* make the return value well-defined */
}
/*
- allocset - allocate a set of characters for []
== static cset *allocset(struct parse *p);
*/
static cset *
allocset(struct parse *p)
{
cset *cs, *ncs;
ncs = reallocarray(p->g->sets, p->g->ncsets + 1, sizeof(*ncs));
if (ncs == NULL) {
SETERROR(REG_ESPACE);
return (NULL);
}
p->g->sets = ncs;
cs = &p->g->sets[p->g->ncsets++];
memset(cs, 0, sizeof(*cs));
return(cs);
}
/*
- freeset - free a now-unused set
== static void freeset(struct parse *p, cset *cs);
*/
static void
freeset(struct parse *p, cset *cs)
{
cset *top = &p->g->sets[p->g->ncsets];
free(cs->wides);
free(cs->ranges);
free(cs->types);
memset(cs, 0, sizeof(*cs));
if (cs == top-1) /* recover only the easy case */
p->g->ncsets--;
}
/*
- singleton - Determine whether a set contains only one character,
- returning it if so, otherwise returning OUT.
*/
static wint_t
singleton(cset *cs)
{
wint_t i, s, n;
for (i = n = 0; i < NC; i++)
if (CHIN(cs, i)) {
n++;
s = i;
}
if (n == 1)
return (s);
if (cs->nwides == 1 && cs->nranges == 0 && cs->ntypes == 0 &&
cs->icase == 0)
return (cs->wides[0]);
/* Don't bother handling the other cases. */
return (OUT);
}
/*
- CHadd - add character to character set.
*/
static void
CHadd(struct parse *p, cset *cs, wint_t ch)
{
wint_t nch, *newwides;
assert(ch >= 0);
if (ch < NC)
cs->bmp[ch >> 3] |= 1 << (ch & 7);
else {
newwides = reallocarray(cs->wides, cs->nwides + 1,
sizeof(*cs->wides));
if (newwides == NULL) {
SETERROR(REG_ESPACE);
return;
}
cs->wides = newwides;
cs->wides[cs->nwides++] = ch;
}
if (cs->icase) {
if ((nch = towlower(ch)) < NC)
cs->bmp[nch >> 3] |= 1 << (nch & 7);
if ((nch = towupper(ch)) < NC)
cs->bmp[nch >> 3] |= 1 << (nch & 7);
}
}
/*
- CHaddrange - add all characters in the range [min,max] to a character set.
*/
static void
CHaddrange(struct parse *p, cset *cs, wint_t min, wint_t max)
{
crange *newranges;
for (; min < NC && min <= max; min++)
CHadd(p, cs, min);
if (min >= max)
return;
newranges = reallocarray(cs->ranges, cs->nranges + 1,
sizeof(*cs->ranges));
if (newranges == NULL) {
SETERROR(REG_ESPACE);
return;
}
cs->ranges = newranges;
cs->ranges[cs->nranges].min = min;
cs->ranges[cs->nranges].max = max;
cs->nranges++;
}
/*
- CHaddtype - add all characters of a certain type to a character set.
*/
static void
CHaddtype(struct parse *p, cset *cs, wctype_t wct)
{
wint_t i;
wctype_t *newtypes;
for (i = 0; i < NC; i++)
if (iswctype(i, wct))
CHadd(p, cs, i);
newtypes = reallocarray(cs->types, cs->ntypes + 1,
sizeof(*cs->types));
if (newtypes == NULL) {
SETERROR(REG_ESPACE);
return;
}
cs->types = newtypes;
cs->types[cs->ntypes++] = wct;
}
/*
- dupl - emit a duplicate of a bunch of sops
== static sopno dupl(struct parse *p, sopno start, sopno finish);
*/
static sopno /* start of duplicate */
dupl(struct parse *p,
sopno start, /* from here */
sopno finish) /* to this less one */
{
sopno ret = HERE();
sopno len = finish - start;
assert(finish >= start);
if (len == 0)
return(ret);
if (!enlarge(p, p->ssize + len)) /* this many unexpected additions */
return(ret);
(void) memcpy((char *)(p->strip + p->slen),
(char *)(p->strip + start), (size_t)len*sizeof(sop));
p->slen += len;
return(ret);
}
/*
- doemit - emit a strip operator
== static void doemit(struct parse *p, sop op, size_t opnd);
*
* It might seem better to implement this as a macro with a function as
* hard-case backup, but it's just too big and messy unless there are
* some changes to the data structures. Maybe later.
*/
static void
doemit(struct parse *p, sop op, size_t opnd)
{
/* avoid making error situations worse */
if (p->error != 0)
return;
/* deal with oversize operands ("can't happen", more or less) */
assert(opnd < 1<<OPSHIFT);
/* deal with undersized strip */
if (p->slen >= p->ssize)
if (!enlarge(p, (p->ssize+1) / 2 * 3)) /* +50% */
return;
/* finally, it's all reduced to the easy case */
p->strip[p->slen++] = SOP(op, opnd);
}
/*
- doinsert - insert a sop into the strip
== static void doinsert(struct parse *p, sop op, size_t opnd, sopno pos);
*/
static void
doinsert(struct parse *p, sop op, size_t opnd, sopno pos)
{
sopno sn;
sop s;
int i;
/* avoid making error situations worse */
if (p->error != 0)
return;
sn = HERE();
EMIT(op, opnd); /* do checks, ensure space */
assert(HERE() == sn+1);
s = p->strip[sn];
/* adjust paren pointers */
assert(pos > 0);
for (i = 1; i < NPAREN; i++) {
if (p->pbegin[i] >= pos) {
p->pbegin[i]++;
}
if (p->pend[i] >= pos) {
p->pend[i]++;
}
}
memmove((char *)&p->strip[pos+1], (char *)&p->strip[pos],
(HERE()-pos-1)*sizeof(sop));
p->strip[pos] = s;
}
/*
- dofwd - complete a forward reference
== static void dofwd(struct parse *p, sopno pos, sop value);
*/
static void
dofwd(struct parse *p, sopno pos, sop value)
{
/* avoid making error situations worse */
if (p->error != 0)
return;
assert(value < 1<<OPSHIFT);
p->strip[pos] = OP(p->strip[pos]) | value;
}
/*
- enlarge - enlarge the strip
== static int enlarge(struct parse *p, sopno size);
*/
static int
enlarge(struct parse *p, sopno size)
{
sop *sp;
if (p->ssize >= size)
return 1;
sp = reallocarray(p->strip, size, sizeof(sop));
if (sp == NULL) {
SETERROR(REG_ESPACE);
return 0;
}
p->strip = sp;
p->ssize = size;
return 1;
}
/*
- stripsnug - compact the strip
== static void stripsnug(struct parse *p, struct re_guts *g);
*/
static void
stripsnug(struct parse *p, struct re_guts *g)
{
g->nstates = p->slen;
g->strip = reallocarray((char *)p->strip, p->slen, sizeof(sop));
if (g->strip == NULL) {
SETERROR(REG_ESPACE);
g->strip = p->strip;
}
}
/*
- findmust - fill in must and mlen with longest mandatory literal string
== static void findmust(struct parse *p, struct re_guts *g);
*
* This algorithm could do fancy things like analyzing the operands of |
* for common subsequences. Someday. This code is simple and finds most
* of the interesting cases.
*
* Note that must and mlen got initialized during setup.
*/
static void
findmust(struct parse *p, struct re_guts *g)
{
sop *scan;
sop *start = NULL;
sop *newstart = NULL;
sopno newlen;
sop s;
char *cp;
int offset;
char buf[MB_LEN_MAX];
size_t clen;
mbstate_t mbs;
/* avoid making error situations worse */
if (p->error != 0)
return;
/*
* It's not generally safe to do a ``char'' substring search on
* multibyte character strings, but it's safe for at least
* UTF-8 (see RFC 3629).
*/
if (MB_CUR_MAX > 1 &&
strcmp(_CurrentRuneLocale->__encoding, "UTF-8") != 0)
return;
/* find the longest OCHAR sequence in strip */
newlen = 0;
offset = 0;
g->moffset = 0;
scan = g->strip + 1;
do {
s = *scan++;
switch (OP(s)) {
case OCHAR: /* sequence member */
if (newlen == 0) { /* new sequence */
memset(&mbs, 0, sizeof(mbs));
newstart = scan - 1;
}
clen = wcrtomb(buf, OPND(s), &mbs);
if (clen == (size_t)-1)
goto toohard;
newlen += clen;
break;
case OPLUS_: /* things that don't break one */
case OLPAREN:
case ORPAREN:
break;
case OQUEST_: /* things that must be skipped */
case OCH_:
offset = altoffset(scan, offset);
scan--;
do {
scan += OPND(s);
s = *scan;
/* assert() interferes w debug printouts */
if (OP(s) != (sop)O_QUEST &&
OP(s) != (sop)O_CH && OP(s) != (sop)OOR2) {
g->iflags |= BAD;
return;
}
} while (OP(s) != (sop)O_QUEST && OP(s) != (sop)O_CH);
/* FALLTHROUGH */
case OBOW: /* things that break a sequence */
case OEOW:
case OBOL:
case OEOL:
case O_QUEST:
case O_CH:
case OEND:
if (newlen > (sopno)g->mlen) { /* ends one */
start = newstart;
g->mlen = newlen;
if (offset > -1) {
g->moffset += offset;
offset = newlen;
} else
g->moffset = offset;
} else {
if (offset > -1)
offset += newlen;
}
newlen = 0;
break;
case OANY:
if (newlen > (sopno)g->mlen) { /* ends one */
start = newstart;
g->mlen = newlen;
if (offset > -1) {
g->moffset += offset;
offset = newlen;
} else
g->moffset = offset;
} else {
if (offset > -1)
offset += newlen;
}
if (offset > -1)
offset++;
newlen = 0;
break;
case OANYOF: /* may or may not invalidate offset */
/* First, everything as OANY */
if (newlen > (sopno)g->mlen) { /* ends one */
start = newstart;
g->mlen = newlen;
if (offset > -1) {
g->moffset += offset;
offset = newlen;
} else
g->moffset = offset;
} else {
if (offset > -1)
offset += newlen;
}
if (offset > -1)
offset++;
newlen = 0;
break;
toohard:
default:
/* Anything here makes it impossible or too hard
* to calculate the offset -- so we give up;
* save the last known good offset, in case the
* must sequence doesn't occur later.
*/
if (newlen > (sopno)g->mlen) { /* ends one */
start = newstart;
g->mlen = newlen;
if (offset > -1)
g->moffset += offset;
else
g->moffset = offset;
}
offset = -1;
newlen = 0;
break;
}
} while (OP(s) != OEND);
if (g->mlen == 0) { /* there isn't one */
g->moffset = -1;
return;
}
/* turn it into a character string */
g->must = malloc((size_t)g->mlen + 1);
if (g->must == NULL) { /* argh; just forget it */
g->mlen = 0;
g->moffset = -1;
return;
}
cp = g->must;
scan = start;
memset(&mbs, 0, sizeof(mbs));
while (cp < g->must + g->mlen) {
while (OP(s = *scan++) != OCHAR)
continue;
clen = wcrtomb(cp, OPND(s), &mbs);
assert(clen != (size_t)-1);
cp += clen;
}
assert(cp == g->must + g->mlen);
*cp++ = '\0'; /* just on general principles */
}
/*
- altoffset - choose biggest offset among multiple choices
== static int altoffset(sop *scan, int offset);
*
* Compute, recursively if necessary, the largest offset among multiple
* re paths.
*/
static int
altoffset(sop *scan, int offset)
{
int largest;
int try;
sop s;
/* If we gave up already on offsets, return */
if (offset == -1)
return -1;
largest = 0;
try = 0;
s = *scan++;
while (OP(s) != (sop)O_QUEST && OP(s) != (sop)O_CH) {
switch (OP(s)) {
case OOR1:
if (try > largest)
largest = try;
try = 0;
break;
case OQUEST_:
case OCH_:
try = altoffset(scan, try);
if (try == -1)
return -1;
scan--;
do {
scan += OPND(s);
s = *scan;
if (OP(s) != (sop)O_QUEST &&
OP(s) != (sop)O_CH && OP(s) != (sop)OOR2)
return -1;
} while (OP(s) != (sop)O_QUEST && OP(s) != (sop)O_CH);
/* We must skip to the next position, or we'll
* leave altoffset() too early.
*/
scan++;
break;
case OANYOF:
case OCHAR:
case OANY:
try++;
case OBOW:
case OEOW:
case OLPAREN:
case ORPAREN:
case OOR2:
break;
default:
try = -1;
break;
}
if (try == -1)
return -1;
s = *scan++;
}
if (try > largest)
largest = try;
return largest+offset;
}
/*
- computejumps - compute char jumps for BM scan
== static void computejumps(struct parse *p, struct re_guts *g);
*
* This algorithm assumes g->must exists and is has size greater than
* zero. It's based on the algorithm found on Computer Algorithms by
* Sara Baase.
*
* A char jump is the number of characters one needs to jump based on
* the value of the character from the text that was mismatched.
*/
static void
computejumps(struct parse *p, struct re_guts *g)
{
int ch;
int mindex;
/* Avoid making errors worse */
if (p->error != 0)
return;
g->charjump = (int *)malloc((NC_MAX + 1) * sizeof(int));
if (g->charjump == NULL) /* Not a fatal error */
return;
/* Adjust for signed chars, if necessary */
g->charjump = &g->charjump[-(CHAR_MIN)];
/* If the character does not exist in the pattern, the jump
* is equal to the number of characters in the pattern.
*/
for (ch = CHAR_MIN; ch < (CHAR_MAX + 1); ch++)
g->charjump[ch] = g->mlen;
/* If the character does exist, compute the jump that would
* take us to the last character in the pattern equal to it
* (notice that we match right to left, so that last character
* is the first one that would be matched).
*/
for (mindex = 0; mindex < g->mlen; mindex++)
g->charjump[(int)g->must[mindex]] = g->mlen - mindex - 1;
}
/*
- computematchjumps - compute match jumps for BM scan
== static void computematchjumps(struct parse *p, struct re_guts *g);
*
* This algorithm assumes g->must exists and is has size greater than
* zero. It's based on the algorithm found on Computer Algorithms by
* Sara Baase.
*
* A match jump is the number of characters one needs to advance based
* on the already-matched suffix.
* Notice that all values here are minus (g->mlen-1), because of the way
* the search algorithm works.
*/
static void
computematchjumps(struct parse *p, struct re_guts *g)
{
int mindex; /* General "must" iterator */
int suffix; /* Keeps track of matching suffix */
int ssuffix; /* Keeps track of suffixes' suffix */
int* pmatches; /* pmatches[k] points to the next i
* such that i+1...mlen is a substring
* of k+1...k+mlen-i-1
*/
/* Avoid making errors worse */
if (p->error != 0)
return;
pmatches = (int*) malloc(g->mlen * sizeof(int));
if (pmatches == NULL) {
g->matchjump = NULL;
return;
}
g->matchjump = (int*) malloc(g->mlen * sizeof(int));
if (g->matchjump == NULL) { /* Not a fatal error */
free(pmatches);
return;
}
/* Set maximum possible jump for each character in the pattern */
for (mindex = 0; mindex < g->mlen; mindex++)
g->matchjump[mindex] = 2*g->mlen - mindex - 1;
/* Compute pmatches[] */
for (mindex = g->mlen - 1, suffix = g->mlen; mindex >= 0;
mindex--, suffix--) {
pmatches[mindex] = suffix;
/* If a mismatch is found, interrupting the substring,
* compute the matchjump for that position. If no
* mismatch is found, then a text substring mismatched
* against the suffix will also mismatch against the
* substring.
*/
while (suffix < g->mlen
&& g->must[mindex] != g->must[suffix]) {
g->matchjump[suffix] = MIN(g->matchjump[suffix],
g->mlen - mindex - 1);
suffix = pmatches[suffix];
}
}
/* Compute the matchjump up to the last substring found to jump
* to the beginning of the largest must pattern prefix matching
* it's own suffix.
*/
for (mindex = 0; mindex <= suffix; mindex++)
g->matchjump[mindex] = MIN(g->matchjump[mindex],
g->mlen + suffix - mindex);
ssuffix = pmatches[suffix];
while (suffix < g->mlen) {
while (suffix <= ssuffix && suffix < g->mlen) {
g->matchjump[suffix] = MIN(g->matchjump[suffix],
g->mlen + ssuffix - suffix);
suffix++;
}
if (suffix < g->mlen)
ssuffix = pmatches[ssuffix];
}
free(pmatches);
}
/*
- pluscount - count + nesting
== static sopno pluscount(struct parse *p, struct re_guts *g);
*/
static sopno /* nesting depth */
pluscount(struct parse *p, struct re_guts *g)
{
sop *scan;
sop s;
sopno plusnest = 0;
sopno maxnest = 0;
if (p->error != 0)
return(0); /* there may not be an OEND */
scan = g->strip + 1;
do {
s = *scan++;
switch (OP(s)) {
case OPLUS_:
plusnest++;
break;
case O_PLUS:
if (plusnest > maxnest)
maxnest = plusnest;
plusnest--;
break;
}
} while (OP(s) != OEND);
if (plusnest != 0)
g->iflags |= BAD;
return(maxnest);
}