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Diffstat (limited to 'regex/regcomp.c')
| -rw-r--r-- | regex/regcomp.c | 1621 |
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diff --git a/regex/regcomp.c b/regex/regcomp.c new file mode 100644 index 00000000..0747190a --- /dev/null +++ b/regex/regcomp.c @@ -0,0 +1,1621 @@ +/*- + * Copyright (c) 1992, 1993, 1994 Henry Spencer. + * Copyright (c) 1992, 1993, 1994 + * The Regents of the University of California. All rights reserved. + * + * 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. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 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/types.h> +#include <stdio.h> +#include <string.h> +#include <ctype.h> +#include <limits.h> +#include <stdlib.h> +#include "regex.h" + +#include "utils.h" +#include "regex2.h" + +#include "cclass.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 __P((struct parse *p, int stop)); +static void p_ere_exp __P((struct parse *p)); +static void p_str __P((struct parse *p)); +static void p_bre __P((struct parse *p, int end1, int end2)); +static int p_simp_re __P((struct parse *p, int starordinary)); +static int p_count __P((struct parse *p)); +static void p_bracket __P((struct parse *p)); +static void p_b_term __P((struct parse *p, cset *cs)); +static void p_b_cclass __P((struct parse *p, cset *cs)); +static void p_b_eclass __P((struct parse *p, cset *cs)); +static char p_b_symbol __P((struct parse *p)); +static char p_b_coll_elem __P((struct parse *p, int endc)); +static char othercase __P((int ch)); +static void bothcases __P((struct parse *p, int ch)); +static void ordinary __P((struct parse *p, int ch)); +static void nonnewline __P((struct parse *p)); +static void repeat __P((struct parse *p, sopno start, int from, int to)); +static int seterr __P((struct parse *p, int e)); +static cset *allocset __P((struct parse *p)); +static void freeset __P((struct parse *p, cset *cs)); +static int freezeset __P((struct parse *p, cset *cs)); +static int firstch __P((struct parse *p, cset *cs)); +static int nch __P((struct parse *p, cset *cs)); +static void mcadd __P((struct parse *p, cset *cs, char *cp)); +static void mcsub __P((cset *cs, char *cp)); +static int mcin __P((cset *cs, char *cp)); +static char *mcfind __P((cset *cs, char *cp)); +static void mcinvert __P((struct parse *p, cset *cs)); +static void mccase __P((struct parse *p, cset *cs)); +static int isinsets __P((struct re_guts *g, int c)); +static int samesets __P((struct re_guts *g, int c1, int c2)); +static void categorize __P((struct parse *p, struct re_guts *g)); +static sopno dupl __P((struct parse *p, sopno start, sopno finish)); +static void doemit __P((struct parse *p, sop op, size_t opnd)); +static void doinsert __P((struct parse *p, sop op, size_t opnd, sopno pos)); +static void dofwd __P((struct parse *p, sopno pos, sop value)); +static void enlarge __P((struct parse *p, sopno size)); +static void stripsnug __P((struct parse *p, struct re_guts *g)); +static void findmust __P((struct parse *p, struct re_guts *g)); +static sopno pluscount __P((struct parse *p, struct re_guts *g)); + +#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 SETERROR(e) seterr(p, (e)) +#define REQUIRE(co, e) ((void) ((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 + +/* + - 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 __stdcall /* 0 success, otherwise REG_something */ +regcomp(regex_t *preg, const char *pattern, int cflags) +{ + struct parse pa; + register struct re_guts *g; + register struct parse *p = &pa; + register int i; + register 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) + + (NC-1)*sizeof(cat_t)); + 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->csetsize = NC; + g->sets = NULL; + g->setbits = NULL; + g->ncsets = 0; + g->cflags = cflags; + g->iflags = 0; + g->nbol = 0; + g->neol = 0; + g->must = NULL; + g->mlen = 0; + g->nsub = 0; + g->ncategories = 1; /* category 0 is "everything else" */ + g->categories = &g->catspace[-(CHAR_MIN)]; + (void) memset((char *)g->catspace, 0, NC*sizeof(cat_t)); + 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 */ + categorize(p, g); + stripsnug(p, g); + findmust(p, g); + 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(register struct parse *p, int stop); + */ +static void +p_ere(struct parse *p, + int stop) /* character this ERE should end at */ +{ + register char c; + register sopno prevback; + register sopno prevfwd; + register sopno conc; + register 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); + 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(register struct parse *p); + */ +static void +p_ere_exp(struct parse *p) +{ + register char c; + register sopno pos; + register int count; + register int count2; + register sopno subno; + int wascaret = 0; + + assert(MORE()); /* caller should have ensured this */ + c = GETNEXT(); + + pos = HERE(); + switch (c) { + case '(': + 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); + 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 '\\': + REQUIRE(MORE(), REG_EESCAPE); + c = GETNEXT(); + ordinary(p, c); + break; + case '{': /* okay as ordinary except if digit follows */ + REQUIRE(!MORE() || !isdigit(PEEK()), REG_BADRPT); + /* FALLTHROUGH */ + default: + ordinary(p, c); + break; + } + + if (!MORE()) + return; + c = PEEK(); + /* we call { a repetition if followed by a digit */ + if (!( c == '*' || c == '+' || c == '?' || + (c == '{' && MORE2() && isdigit(PEEK2())) )) + return; /* no repetition, we're done */ + NEXT(); + + 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(PEEK())) { + count2 = p_count(p); + 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(); + REQUIRE(MORE(), REG_EBRACE); + SETERROR(REG_BADBR); + } + break; + } + + if (!MORE()) + return; + c = PEEK(); + if (!( c == '*' || c == '+' || c == '?' || + (c == '{' && MORE2() && isdigit(PEEK2())) ) ) + return; + SETERROR(REG_BADRPT); +} + +/* + - p_str - string (no metacharacters) "parser" + == static void p_str(register struct parse *p); + */ +static void +p_str(struct parse *p) +{ + REQUIRE(MORE(), REG_EMPTY); + while (MORE()) + ordinary(p, GETNEXT()); +} + +/* + - p_bre - BRE parser top level, anchoring and concatenation + == static void p_bre(register struct parse *p, register int end1, \ + == register 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 + * only undesirable side effect is that '$' gets included as a character + * category in such cases. This is fairly harmless; not worth fixing. + * 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 */ +{ + register sopno start = HERE(); + register int first = 1; /* first subexpression? */ + register 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++; + } + + 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(register 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? */ +{ + register int c; + register int count; + register int count2; + register sopno pos; + register int i; + register 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 == '\\') { + REQUIRE(MORE(), REG_EESCAPE); + c = BACKSL | (unsigned char)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); + 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 '*': + REQUIRE(starordinary, REG_BADRPT); + /* FALLTHROUGH */ + default: + ordinary(p, c &~ BACKSL); + 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(PEEK())) { + count2 = p_count(p); + 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(); + REQUIRE(MORE(), REG_EBRACE); + SETERROR(REG_BADBR); + } + } else if (c == (unsigned char)'$') /* $ (but not \$) ends it */ + return(1); + + return(0); +} + +/* + - p_count - parse a repetition count + == static int p_count(register struct parse *p); + */ +static int /* the value */ +p_count(struct parse *p) +{ + register int count = 0; + register int ndigits = 0; + + while (MORE() && isdigit(PEEK()) && count <= DUPMAX) { + count = count*10 + (GETNEXT() - '0'); + ndigits++; + } + + REQUIRE(ndigits > 0 && count <= DUPMAX, REG_BADBR); + return(count); +} + +/* + - p_bracket - parse a bracketed character list + == static void p_bracket(register struct parse *p); + * + * Note a significant property of this code: if the allocset() did SETERROR, + * no set operations are done. + */ +static void +p_bracket(struct parse *p) +{ + register cset *cs = allocset(p); + register int invert = 0; + + /* 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 (EAT('^')) + invert++; /* make note to invert set at end */ + if (EAT(']')) + CHadd(cs, ']'); + else if (EAT('-')) + CHadd(cs, '-'); + while (MORE() && PEEK() != ']' && !SEETWO('-', ']')) + p_b_term(p, cs); + if (EAT('-')) + CHadd(cs, '-'); + MUSTEAT(']', REG_EBRACK); + + if (p->error != 0) /* don't mess things up further */ + return; + + if (p->g->cflags®_ICASE) { + register int i; + register int ci; + + for (i = p->g->csetsize - 1; i >= 0; i--) + if (CHIN(cs, i) && isalpha(i)) { + ci = othercase(i); + if (ci != i) + CHadd(cs, ci); + } + if (cs->multis != NULL) + mccase(p, cs); + } + if (invert) { + register int i; + + for (i = p->g->csetsize - 1; i >= 0; i--) + if (CHIN(cs, i)) + CHsub(cs, i); + else + CHadd(cs, i); + if (p->g->cflags®_NEWLINE) + CHsub(cs, '\n'); + if (cs->multis != NULL) + mcinvert(p, cs); + } + + assert(cs->multis == NULL); /* xxx */ + + if (nch(p, cs) == 1) { /* optimize singleton sets */ + ordinary(p, firstch(p, cs)); + freeset(p, cs); + } else + EMIT(OANYOF, freezeset(p, cs)); +} + +/* + - p_b_term - parse one term of a bracketed character list + == static void p_b_term(register struct parse *p, register cset *cs); + */ +static void +p_b_term(struct parse *p, cset *cs) +{ + register char c; + register char start, finish; + register int i; + + /* 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(); + REQUIRE(MORE(), REG_EBRACK); + c = PEEK(); + REQUIRE(c != '-' && c != ']', REG_ECTYPE); + p_b_cclass(p, cs); + REQUIRE(MORE(), REG_EBRACK); + REQUIRE(EATTWO(':', ']'), REG_ECTYPE); + break; + case '=': /* equivalence class */ + NEXT2(); + REQUIRE(MORE(), REG_EBRACK); + c = PEEK(); + REQUIRE(c != '-' && c != ']', REG_ECOLLATE); + p_b_eclass(p, cs); + REQUIRE(MORE(), REG_EBRACK); + REQUIRE(EATTWO('=', ']'), REG_ECOLLATE); + break; + default: /* symbol, ordinary character, or range */ +/* xxx revision needed for multichar stuff */ + start = p_b_symbol(p); + if (SEE('-') && MORE2() && PEEK2() != ']') { + /* range */ + NEXT(); + if (EAT('-')) + finish = '-'; + else + finish = p_b_symbol(p); + } else + finish = start; +/* xxx what about signed chars here... */ + REQUIRE(start <= finish, REG_ERANGE); + for (i = start; i <= finish; i++) + CHadd(cs, i); + break; + } +} + +/* + - p_b_cclass - parse a character-class name and deal with it + == static void p_b_cclass(register struct parse *p, register cset *cs); + */ +static void +p_b_cclass(struct parse *p, cset *cs) +{ + register char *sp = p->next; + register struct cclass *cp; + register size_t len; + register char *u; + register char c; + + while (MORE() && isalpha(PEEK())) + NEXT(); + len = p->next - sp; + for (cp = cclasses; cp->name != NULL; cp++) + if (strncmp(cp->name, sp, len) == 0 && cp->name[len] == '\0') + break; + if (cp->name == NULL) { + /* oops, didn't find it */ + SETERROR(REG_ECTYPE); + return; + } + + u = cp->chars; + while ((c = *u++) != '\0') + CHadd(cs, c); + for (u = cp->multis; *u != '\0'; u += strlen(u) + 1) + MCadd(p, cs, u); +} + +/* + - p_b_eclass - parse an equivalence-class name and deal with it + == static void p_b_eclass(register struct parse *p, register cset *cs); + * + * This implementation is incomplete. xxx + */ +static void +p_b_eclass(struct parse *p, cset *cs) +{ + register char c; + + c = p_b_coll_elem(p, '='); + CHadd(cs, c); +} + +/* + - p_b_symbol - parse a character or [..]ed multicharacter collating symbol + == static char p_b_symbol(register struct parse *p); + */ +static char /* value of symbol */ +p_b_symbol(struct parse *p) +{ + register char value; + + REQUIRE(MORE(), REG_EBRACK); + if (!EATTWO('[', '.')) + return(GETNEXT()); + + /* collating symbol */ + value = p_b_coll_elem(p, '.'); + REQUIRE(EATTWO('.', ']'), REG_ECOLLATE); + return(value); +} + +/* + - p_b_coll_elem - parse a collating-element name and look it up + == static char p_b_coll_elem(register struct parse *p, int endc); + */ +static char /* value of collating element */ +p_b_coll_elem(struct parse *p, + int endc) /* name ended by endc,']' */ +{ + register char *sp = p->next; + register struct cname *cp; + register int 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 && cp->name[len] == '\0') + return(cp->code); /* known name */ + if (len == 1) + return(*sp); /* single character */ + SETERROR(REG_ECOLLATE); /* neither */ + return(0); +} + +/* + - othercase - return the case counterpart of an alphabetic + == static char othercase(int ch); + */ +static char /* if no counterpart, return ch */ +othercase(int ch) +{ + assert(isalpha(ch)); + if (isupper(ch)) + return(tolower(ch)); + else if (islower(ch)) + return(toupper(ch)); + else /* peculiar, but could happen */ + return(ch); +} + +/* + - bothcases - emit a dualcase version of a two-case character + == static void bothcases(register struct parse *p, int ch); + * + * Boy, is this implementation ever a kludge... + */ +static void +bothcases(struct parse *p, int ch) +{ + register char *oldnext = p->next; + register char *oldend = p->end; + char bracket[3]; + + assert(othercase(ch) != ch); /* p_bracket() would recurse */ + p->next = bracket; + p->end = bracket+2; + bracket[0] = ch; + bracket[1] = ']'; + bracket[2] = '\0'; + p_bracket(p); + assert(p->next == bracket+2); + p->next = oldnext; + p->end = oldend; +} + +/* + - ordinary - emit an ordinary character + == static void ordinary(register struct parse *p, register int ch); + */ +static void +ordinary(struct parse *p, int ch) +{ + register cat_t *cap = p->g->categories; + + if ((p->g->cflags®_ICASE) && isalpha(ch) && othercase(ch) != ch) + bothcases(p, ch); + else { + EMIT(OCHAR, (unsigned char)ch); + if (cap[ch] == 0) + cap[ch] = p->g->ncategories++; + } +} + +/* + - nonnewline - emit REG_NEWLINE version of OANY + == static void nonnewline(register struct parse *p); + * + * Boy, is this implementation ever a kludge... + */ +static void +nonnewline(struct parse *p) +{ + register char *oldnext = p->next; + register 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(register 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) */ +{ + register 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) + register 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; + } +} + +/* + - seterr - set an error condition + == static int seterr(register 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(register struct parse *p); + */ +static cset * +allocset(struct parse *p) +{ + register int no = p->g->ncsets++; + register size_t nc; + register size_t nbytes; + register cset *cs; + register size_t css = (size_t)p->g->csetsize; + register int i; + + if (no >= p->ncsalloc) { /* need another column of space */ + p->ncsalloc += CHAR_BIT; + nc = p->ncsalloc; + assert(nc % CHAR_BIT == 0); + nbytes = nc / CHAR_BIT * css; + if (p->g->sets == NULL) + p->g->sets = (cset *)malloc(nc * sizeof(cset)); + else + p->g->sets = (cset *)realloc((char *)p->g->sets, + nc * sizeof(cset)); + if (p->g->setbits == NULL) + p->g->setbits = (uch *)malloc(nbytes); + else { + p->g->setbits = (uch *)realloc((char *)p->g->setbits, + nbytes); + /* xxx this isn't right if setbits is now NULL */ + for (i = 0; i < no; i++) + p->g->sets[i].ptr = p->g->setbits + css*(i/CHAR_BIT); + } + if (p->g->sets != NULL && p->g->setbits != NULL) + (void) memset((char *)p->g->setbits + (nbytes - css), + 0, css); + else { + no = 0; + SETERROR(REG_ESPACE); + /* caller's responsibility not to do set ops */ + } + } + + assert(p->g->sets != NULL); /* xxx */ + cs = &p->g->sets[no]; + cs->ptr = p->g->setbits + css*((no)/CHAR_BIT); + cs->mask = 1 << ((no) % CHAR_BIT); + cs->hash = 0; + cs->smultis = 0; + cs->multis = NULL; + + return(cs); +} + +/* + - freeset - free a now-unused set + == static void freeset(register struct parse *p, register cset *cs); + */ +static void +freeset(struct parse *p, cset *cs) +{ + register int i; + register cset *top = &p->g->sets[p->g->ncsets]; + register size_t css = (size_t)p->g->csetsize; + + for (i = 0; i < css; i++) + CHsub(cs, i); + if (cs == top-1) /* recover only the easy case */ + p->g->ncsets--; +} + +/* + - freezeset - final processing on a set of characters + == static int freezeset(register struct parse *p, register cset *cs); + * + * The main task here is merging identical sets. This is usually a waste + * of time (although the hash code minimizes the overhead), but can win + * big if REG_ICASE is being used. REG_ICASE, by the way, is why the hash + * is done using addition rather than xor -- all ASCII [aA] sets xor to + * the same value! + */ +static int /* set number */ +freezeset(struct parse *p, cset *cs) +{ + register uch h = cs->hash; + register int i; + register cset *top = &p->g->sets[p->g->ncsets]; + register cset *cs2; + register size_t css = (size_t)p->g->csetsize; + + /* look for an earlier one which is the same */ + for (cs2 = &p->g->sets[0]; cs2 < top; cs2++) + if (cs2->hash == h && cs2 != cs) { + /* maybe */ + for (i = 0; i < css; i++) + if (!!CHIN(cs2, i) != !!CHIN(cs, i)) + break; /* no */ + if (i == css) + break; /* yes */ + } + + if (cs2 < top) { /* found one */ + freeset(p, cs); + cs = cs2; + } + + return((int)(cs - p->g->sets)); +} + +/* + - firstch - return first character in a set (which must have at least one) + == static int firstch(register struct parse *p, register cset *cs); + */ +static int /* character; there is no "none" value */ +firstch(struct parse *p, cset *cs) +{ + register int i; + register size_t css = (size_t)p->g->csetsize; + + for (i = 0; i < css; i++) + if (CHIN(cs, i)) + return((char)i); + assert(never); + return(0); /* arbitrary */ +} + +/* + - nch - number of characters in a set + == static int nch(register struct parse *p, register cset *cs); + */ +static int +nch(struct parse *p, cset *cs) +{ + register int i; + register size_t css = (size_t)p->g->csetsize; + register int n = 0; + + for (i = 0; i < css; i++) + if (CHIN(cs, i)) + n++; + return(n); +} + +/* + - mcadd - add a collating element to a cset + == static void mcadd(register struct parse *p, register cset *cs, \ + == register char *cp); + */ +static void +mcadd(struct parse *p, cset *cs, char *cp) +{ + register size_t oldend = cs->smultis; + + cs->smultis += strlen(cp) + 1; + if (cs->multis == NULL) + cs->multis = malloc(cs->smultis); + else + cs->multis = realloc(cs->multis, cs->smultis); + if (cs->multis == NULL) { + SETERROR(REG_ESPACE); + return; + } + + (void) strcpy(cs->multis + oldend - 1, cp); + cs->multis[cs->smultis - 1] = '\0'; +} + +/* + - mcsub - subtract a collating element from a cset + == static void mcsub(register cset *cs, register char *cp); + */ +static void +mcsub(cset *cs, char *cp) +{ + register char *fp = mcfind(cs, cp); + register size_t len = strlen(fp); + + assert(fp != NULL); + (void) memmove(fp, fp + len + 1, + cs->smultis - (fp + len + 1 - cs->multis)); + cs->smultis -= len; + + if (cs->smultis == 0) { + free(cs->multis); + cs->multis = NULL; + return; + } + + cs->multis = realloc(cs->multis, cs->smultis); + assert(cs->multis != NULL); +} + +/* + - mcin - is a collating element in a cset? + == static int mcin(register cset *cs, register char *cp); + */ +static int +mcin(cset *cs, char *cp) +{ + return(mcfind(cs, cp) != NULL); +} + +/* + - mcfind - find a collating element in a cset + == static char *mcfind(register cset *cs, register char *cp); + */ +static char * +mcfind(cset *cs, char *cp) +{ + register char *p; + + if (cs->multis == NULL) + return(NULL); + for (p = cs->multis; *p != '\0'; p += strlen(p) + 1) + if (strcmp(cp, p) == 0) + return(p); + return(NULL); +} + +/* + - mcinvert - invert the list of collating elements in a cset + == static void mcinvert(register struct parse *p, register cset *cs); + * + * This would have to know the set of possibilities. Implementation + * is deferred. + */ +static void +mcinvert(struct parse *p, cset *cs) +{ + assert(cs->multis == NULL); /* xxx */ +} + +/* + - mccase - add case counterparts of the list of collating elements in a cset + == static void mccase(register struct parse *p, register cset *cs); + * + * This would have to know the set of possibilities. Implementation + * is deferred. + */ +static void +mccase(struct parse *p, cset *cs) +{ + assert(cs->multis == NULL); /* xxx */ +} + +/* + - isinsets - is this character in any sets? + == static int isinsets(register struct re_guts *g, int c); + */ +static int /* predicate */ +isinsets(struct re_guts *g, int c) +{ + register uch *col; + register int i; + register int ncols = (g->ncsets+(CHAR_BIT-1)) / CHAR_BIT; + register unsigned uc = (unsigned char)c; + + for (i = 0, col = g->setbits; i < ncols; i++, col += g->csetsize) + if (col[uc] != 0) + return(1); + return(0); +} + +/* + - samesets - are these two characters in exactly the same sets? + == static int samesets(register struct re_guts *g, int c1, int c2); + */ +static int /* predicate */ +samesets(struct re_guts *g, int c1, int c2) +{ + register uch *col; + register int i; + register int ncols = (g->ncsets+(CHAR_BIT-1)) / CHAR_BIT; + register unsigned uc1 = (unsigned char)c1; + register unsigned uc2 = (unsigned char)c2; + + for (i = 0, col = g->setbits; i < ncols; i++, col += g->csetsize) + if (col[uc1] != col[uc2]) + return(0); + return(1); +} + +/* + - categorize - sort out character categories + == static void categorize(struct parse *p, register struct re_guts *g); + */ +static void +categorize(struct parse *p, struct re_guts *g) +{ + register cat_t *cats = g->categories; + register int c; + register int c2; + register cat_t cat; + + /* avoid making error situations worse */ + if (p->error != 0) + return; + + for (c = CHAR_MIN; c <= CHAR_MAX; c++) + if (cats[c] == 0 && isinsets(g, c)) { + cat = g->ncategories++; + cats[c] = cat; + for (c2 = c+1; c2 <= CHAR_MAX; c2++) + if (cats[c2] == 0 && samesets(g, c, c2)) + cats[c2] = cat; + } +} + +/* + - dupl - emit a duplicate of a bunch of sops + == static sopno dupl(register 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 */ +{ + register sopno ret = HERE(); + register sopno len = finish - start; + + assert(finish >= start); + if (len == 0) + return(ret); + enlarge(p, p->ssize + len); /* this many unexpected additions */ + assert(p->ssize >= p->slen + len); + (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(register 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) + enlarge(p, (p->ssize+1) / 2 * 3); /* +50% */ + assert(p->slen < p->ssize); + + /* 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(register struct parse *p, sop op, size_t opnd, sopno pos); + */ +static void +doinsert(struct parse *p, sop op, size_t opnd, sopno pos) +{ + register sopno sn; + register sop s; + register 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(register 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 void enlarge(register struct parse *p, sopno size); + */ +static void +enlarge(struct parse *p, sopno size) +{ + register sop *sp; + + if (p->ssize >= size) + return; + + sp = (sop *)realloc(p->strip, size*sizeof(sop)); + if (sp == NULL) { + SETERROR(REG_ESPACE); + return; + } + p->strip = sp; + p->ssize = size; +} + +/* + - stripsnug - compact the strip + == static void stripsnug(register struct parse *p, register 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(register struct parse *p, register 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) +{ + register sop *scan; + sop *start; + register sop *newstart; + register sopno newlen; + register sop s; + register char *cp; + register sopno i; + + /* avoid making error situations worse */ + if (p->error != 0) + return; + + /* find the longest OCHAR sequence in strip */ + newlen = 0; + scan = g->strip + 1; + do { + s = *scan++; + switch (OP(s)) { + case OCHAR: /* sequence member */ + if (newlen == 0) /* new sequence */ + newstart = scan - 1; + newlen++; + break; + case OPLUS_: /* things that don't break one */ + case OLPAREN: + case ORPAREN: + break; + case OQUEST_: /* things that must be skipped */ + case OCH_: + 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 */ + default: /* things that break a sequence */ + if (newlen > g->mlen) { /* ends one */ + start = newstart; + g->mlen = newlen; + } + newlen = 0; + break; + } + } while (OP(s) != OEND); + + if (g->mlen == 0) /* there isn't one */ + 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; + return; + } + cp = g->must; + scan = start; + for (i = g->mlen; i > 0; i--) { + while (OP(s = *scan++) != OCHAR) + continue; + assert(cp < g->must + g->mlen); + *cp++ = (char)OPND(s); + } + assert(cp == g->must + g->mlen); + *cp++ = '\0'; /* just on general principles */ +} + +/* + - pluscount - count + nesting + == static sopno pluscount(register struct parse *p, register struct re_guts *g); + */ +static sopno /* nesting depth */ +pluscount(struct parse *p, struct re_guts *g) +{ + register sop *scan; + register sop s; + register sopno plusnest = 0; + register 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); +} |