diff options
Diffstat (limited to 'lib/libc/regex/regcomp.c')
| -rw-r--r-- | lib/libc/regex/regcomp.c | 1789 |
1 files changed, 1789 insertions, 0 deletions
diff --git a/lib/libc/regex/regcomp.c b/lib/libc/regex/regcomp.c new file mode 100644 index 0000000..c24b382 --- /dev/null +++ b/lib/libc/regex/regcomp.c @@ -0,0 +1,1789 @@ +/*- + * 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. + * + * Copyright (c) 2011 The FreeBSD Foundation + * All rights reserved. + * Portions of this software were developed by David Chisnall + * under sponsorship from the FreeBSD Foundation. + * + * 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. + * 4. 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 <runetype.h> +#include <wchar.h> +#include <wctype.h> + +#include "collate.h" + +#include "utils.h" +#include "regex2.h" + +#include "cname.h" + +/* + * parse structure, passed up and down to avoid global variables and + * other clumsinesses + */ +struct parse { + char *next; /* next character in RE */ + 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) */ +}; + +/* ========= begin header generated by ./mkh ========= */ +#ifdef __cplusplus +extern "C" { +#endif + +/* === regcomp.c === */ +static void p_ere(struct parse *p, int stop); +static void p_ere_exp(struct parse *p); +static void p_str(struct parse *p); +static void p_bre(struct parse *p, int end1, int end2); +static int p_simp_re(struct parse *p, int starordinary); +static int p_count(struct parse *p); +static void p_bracket(struct parse *p); +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 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)) + +#ifndef NDEBUG +static int never = 0; /* for use in asserts; shuts lint up */ +#else +#define never 0 /* some <assert.h>s have bugs too */ +#endif + +/* 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; +#ifdef REDEBUG +# define GOODFLAGS(f) (f) +#else +# define GOODFLAGS(f) ((f)&~REG_DUMP) +#endif + + cflags = GOODFLAGS(cflags); + if ((cflags®_EXTENDED) && (cflags®_NOSPEC)) + return(REG_INVARG); + + if (cflags®_PEND) { + if (preg->re_endp < pattern) + return(REG_INVARG); + len = preg->re_endp - pattern; + } else + len = strlen((char *)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); + p->ssize = len/(size_t)2*(size_t)3 + (size_t)1; /* ugh */ + 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 = (char *)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; + } + 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®_EXTENDED) + p_ere(p, OUT); + else if (cflags®_NOSPEC) + p_str(p); + else + p_bre(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 - ERE parser top level, concatenation and alternation + == static void p_ere(struct parse *p, int_t stop); + */ +static void +p_ere(struct parse *p, + int stop) /* character this ERE should end at */ +{ + char c; + sopno prevback; + sopno prevfwd; + sopno conc; + int first = 1; /* is this the first alternative? */ + + for (;;) { + /* do a bunch of concatenated expressions */ + conc = HERE(); + while (MORE() && (c = PEEK()) != '|' && c != stop) + p_ere_exp(p); + (void)REQUIRE(HERE() != conc, REG_EMPTY); /* require nonempty */ + + if (!EAT('|')) + break; /* NOTE BREAK OUT */ + + if (first) { + INSERT(OCH_, conc); /* offset is wrong */ + prevfwd = conc; + prevback = conc; + first = 0; + } + ASTERN(OOR1, prevback); + prevback = THERE(); + AHEAD(prevfwd); /* fix previous offset */ + prevfwd = HERE(); + EMIT(OOR2, 0); /* offset is very wrong */ + } + + if (!first) { /* tail-end fixups */ + AHEAD(prevfwd); + ASTERN(O_CH, prevback); + } + + assert(!MORE() || SEE(stop)); +} + +/* + - p_ere_exp - parse one subERE, an atom possibly followed by a repetition op + == static void p_ere_exp(struct parse *p); + */ +static void +p_ere_exp(struct parse *p) +{ + char c; + wint_t wc; + sopno pos; + int count; + int count2; + sopno subno; + int wascaret = 0; + + 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_ere(p, ')'); + 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 '?': + SETERROR(REG_BADRPT); + break; + case '.': + if (p->g->cflags®_NEWLINE) + nonnewline(p); + else + EMIT(OANY, 0); + break; + case '[': + p_bracket(p); + break; + case '\\': + (void)REQUIRE(MORE(), REG_EESCAPE); + wc = WGETNEXT(); + ordinary(p, wc); + break; + case '{': /* okay as ordinary except if digit follows */ + (void)REQUIRE(!MORE() || !isdigit((uch)PEEK()), REG_BADRPT); + /* FALLTHROUGH */ + default: + p->next--; + wc = WGETNEXT(); + ordinary(p, wc); + break; + } + + if (!MORE()) + return; + c = PEEK(); + /* we call { a repetition if followed by a digit */ + if (!( c == '*' || c == '+' || c == '?' || + (c == '{' && MORE2() && isdigit((uch)PEEK2())) )) + return; /* no repetition, we're done */ + 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; + c = PEEK(); + if (!( c == '*' || c == '+' || c == '?' || + (c == '{' && MORE2() && isdigit((uch)PEEK2())) ) ) + return; + SETERROR(REG_BADRPT); +} + +/* + - 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()); +} + +/* + - p_bre - BRE parser top level, anchoring and concatenation + == static void p_bre(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_bre(struct parse *p, + int end1, /* first terminating character */ + int end2) /* second terminating character */ +{ + sopno start = HERE(); + int first = 1; /* first subexpression? */ + int wasdollar = 0; + + if (EAT('^')) { + EMIT(OBOL, 0); + p->g->iflags |= USEBOL; + p->g->nbol++; + } + while (MORE() && !SEETWO(end1, end2)) { + wasdollar = p_simp_re(p, first); + first = 0; + } + if (wasdollar) { /* oops, that was a trailing anchor */ + DROP(1); + EMIT(OEOL, 0); + p->g->iflags |= USEEOL; + p->g->neol++; + } + + (void)REQUIRE(HERE() != start, REG_EMPTY); /* require nonempty */ +} + +/* + - p_simp_re - parse a simple RE, an atom possibly followed by a repetition + == static int p_simp_re(struct parse *p, int starordinary); + */ +static int /* was the simple RE an unbackslashed $? */ +p_simp_re(struct parse *p, + int starordinary) /* is a leading * an ordinary character? */ +{ + int c; + int count; + int count2; + sopno pos; + int i; + wint_t wc; + sopno subno; +# define BACKSL (1<<CHAR_BIT) + + pos = HERE(); /* repetion 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®_NEWLINE) + nonnewline(p); + else + EMIT(OANY, 0); + break; + case '[': + p_bracket(p); + 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_bre(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 */ + case BACKSL|'}': + 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 '*': + (void)REQUIRE(starordinary, REG_BADRPT); + /* FALLTHROUGH */ + default: + 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(1); + + return(0); +} + +/* + - 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®_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®_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)); +} + +/* + - 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; + struct xlocale_collate *table = + (struct xlocale_collate*)__get_locale()->components[XLC_COLLATE]; + + /* classify what we've got */ + switch ((MORE()) ? PEEK() : '\0') { + case '[': + c = (MORE2()) ? PEEK2() : '\0'; + break; + case '-': + SETERROR(REG_ERANGE); + return; /* NOTE RETURN */ + break; + 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 { + if (table->__collate_load_error) { + (void)REQUIRE((uch)start <= (uch)finish, REG_ERANGE); + CHaddrange(p, cs, start, finish); + } else { + (void)REQUIRE(__collate_range_cmp(table, start, finish) <= 0, REG_ERANGE); + for (i = 0; i <= UCHAR_MAX; i++) { + if ( __collate_range_cmp(table, start, i) <= 0 + && __collate_range_cmp(table, 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) +{ + 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,']' */ +{ + char *sp = p->next; + struct cname *cp; + int len; + mbstate_t mbs; + wchar_t wc; + size_t clen; + + 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 && cp->name[len] == '\0') + 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) +{ + char *oldnext = p->next; + 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®_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) +{ + char *oldnext = p->next; + 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 = realloc(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 = realloc(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 = realloc(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].min = 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 = realloc(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 = (sop *)realloc(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 = (sop *)realloc((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; + sop *newstart; + 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) != O_QUEST && OP(s) != O_CH && + OP(s) != OOR2) { + g->iflags |= BAD; + return; + } + } while (OP(s) != O_QUEST && OP(s) != 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 > 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 > 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 > 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 > 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) != O_QUEST && OP(s) != 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) != O_QUEST && OP(s) != O_CH && + OP(s) != OOR2) + return -1; + } while (OP(s) != O_QUEST && OP(s) != 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 + 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(unsigned int)); + if (pmatches == NULL) { + g->matchjump = NULL; + return; + } + + g->matchjump = (int*) malloc(g->mlen * sizeof(unsigned int)); + if (g->matchjump == NULL) /* Not a fatal error */ + 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); +} |
