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Editing: regcomp.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? */ int gnuext; 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? */ int pflags; /* other parsing flags -- legacy escapes? */ bool (*parse_expr)(struct parse *, struct branchc *); void (*pre_parse)(struct parse *, struct branchc *); void (*post_parse)(struct parse *, struct branchc *); }; #define PFLAG_LEGACY_ESC 0x00000001 /* ========= 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 int p_b_pseudoclass(struct parse *p, char c); static void p_b_cclass(struct parse *p, cset *cs); static void p_b_cclass_named(struct parse *p, cset *cs, const char[]); 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 bool may_escape(struct parse *p, const wint_t ch); 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->end - p->next > 0) #define MORE2() (p->end - p->next > 1) #define SEE(c) (MORE() && PEEK() == (c)) #define SEETWO(a, b) (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 EATSPEC(a) (p->bre ? EATTWO('\\', a) : EAT(a)) #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)) static int /* 0 success, otherwise REG_something */ regcomp_internal(regex_t * __restrict preg, const char * __restrict pattern, int cflags, int pflags) { 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®_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(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; p->pflags = pflags; for (i = 0; i < NPAREN; i++) { p->pbegin[i] = 0; p->pend[i] = 0; } #ifdef LIBREGEX if (cflags®_POSIX) { p->gnuext = false; p->allowbranch = (cflags & REG_EXTENDED) != 0; } else p->gnuext = p->allowbranch = true; #else p->gnuext = false; p->allowbranch = (cflags & REG_EXTENDED) != 0; #endif if (cflags & REG_EXTENDED) { p->bre = false; p->parse_expr = p_ere_exp; p->pre_parse = NULL; p->post_parse = NULL; } else { 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); } /* - 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) { return (regcomp_internal(preg, pattern, cflags, 0)); } #ifndef LIBREGEX /* * Legacy interface that requires more lax escaping behavior. */ int freebsd12_regcomp(regex_t * __restrict preg, const char * __restrict pattern, int cflags, int pflags) { return (regcomp_internal(preg, pattern, cflags, PFLAG_LEGACY_ESC)); } __sym_compat(regcomp, freebsd12_regcomp, FBSD_1.0); #endif /* !LIBREGEX */ /* - 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; #ifdef LIBREGEX int i; int handled; #endif sopno subno; int wascaret = 0; (void)bc; assert(MORE()); /* caller should have ensured this */ c = GETNEXT(); #ifdef LIBREGEX handled = 0; #endif 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®_NEWLINE) nonnewline(p); else EMIT(OANY, 0); break; case '[': p_bracket(p); break; case '\\': (void)REQUIRE(MORE(), REG_EESCAPE); wc = WGETNEXT(); #ifdef LIBREGEX if (p->gnuext) { handled = 1; switch (wc) { case '`': EMIT(OBOS, 0); break; case '\'': EMIT(OEOS, 0); break; case 'B': EMIT(ONWBND, 0); break; case 'b': EMIT(OWBND, 0); break; case 'W': case 'w': case 'S': case 's': p_b_pseudoclass(p, wc); break; case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': i = wc - '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; default: handled = 0; } /* Don't proceed to the POSIX bits if we've already handled it */ if (handled) break; } #endif switch (wc) { case '<': EMIT(OBOW, 0); break; case '>': EMIT(OEOW, 0); break; default: if (may_escape(p, wc)) ordinary(p, wc); else SETERROR(REG_EESCAPE); 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 (EATSPEC('|')) ++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(p->gnuext || HERE() != bc.start, REG_EMPTY); #ifdef LIBREGEX if (HERE() == bc.start && !p_branch_empty(p, &bc)) break; #endif 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 cc; /* convenient/control character */ int count; int count2; sopno pos; bool handled; int i; wint_t wc; sopno subno; # define BACKSL (1<<CHAR_BIT) pos = HERE(); /* repetition op, if any, covers from here */ handled = false; assert(MORE()); /* caller should have ensured this */ c = GETNEXT(); if (c == '\\') { (void)REQUIRE(MORE(), REG_EESCAPE); cc = GETNEXT(); c = BACKSL | cc; #ifdef LIBREGEX if (p->gnuext) { handled = true; switch (c) { case BACKSL|'`': EMIT(OBOS, 0); break; case BACKSL|'\'': EMIT(OEOS, 0); break; case BACKSL|'B': EMIT(ONWBND, 0); break; case BACKSL|'b': EMIT(OWBND, 0); break; case BACKSL|'W': case BACKSL|'w': case BACKSL|'S': case BACKSL|'s': p_b_pseudoclass(p, cc); break; default: handled = false; } } #endif } if (!handled) { switch (c) { case '.': if (p->g->cflags®_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 $... */ p->next--; wc = WGETNEXT(); if ((c & BACKSL) == 0 || may_escape(p, wc)) ordinary(p, wc); else SETERROR(REG_EESCAPE); break; } } if (EAT('*')) { /* implemented as +? */ /* this case does not require the (y|) trick, noKLUDGE */ INSERT(OPLUS_, pos); ASTERN(O_PLUS, pos); INSERT(OQUEST_, pos); ASTERN(O_QUEST, pos); #ifdef LIBREGEX } else if (p->gnuext && EATTWO('\\', '?')) { INSERT(OQUEST_, pos); ASTERN(O_QUEST, pos); } else if (p->gnuext && EATTWO('\\', '+')) { INSERT(OPLUS_, pos); ASTERN(O_PLUS, pos); #endif } else if (EATTWO('\\', '{')) { count = p_count(p); if (EAT(',')) { if (MORE() && isdigit((uch)PEEK())) { count2 = p_count(p); (void)REQUIRE(count <= count2, REG_BADBR); } else /* single number with comma */ count2 = INFINITY; } else /* just a single number */ count2 = count; repeat(p, pos, count, count2); if (!EATTWO('\\', '}')) { /* error heuristics */ while (MORE() && !SEETWO('\\', '}')) NEXT(); (void)REQUIRE(MORE(), REG_EBRACE); SETERROR(REG_BADBR); } } else if (c == '$') /* $ (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->end - p->next > 5) { if (strncmp(p->next, "[:<:]]", 6) == 0) { EMIT(OBOW, 0); NEXTn(6); return; } if (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)); } 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_pseudoclass - parse a pseudo-class (\w, \W, \s, \S) == static int p_b_pseudoclass(struct parse *p, char c) */ static int p_b_pseudoclass(struct parse *p, char c) { cset *cs; if ((cs = allocset(p)) == NULL) return(0); if (p->g->cflags®_ICASE) cs->icase = 1; switch (c) { case 'W': cs->invert = 1; /* PASSTHROUGH */ case 'w': p_b_cclass_named(p, cs, "alnum"); break; case 'S': cs->invert = 1; /* PASSTHROUGH */ case 's': p_b_cclass_named(p, cs, "space"); break; default: return(0); } EMIT(OANYOF, (int)(cs - p->g->sets)); return(1); } /* - 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; 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'; p_b_cclass_named(p, cs, clname); } /* - p_b_cclass_named - deal with a named character class == static void p_b_cclass_named(struct parse *p, cset *cs, const char []); */ static void p_b_cclass_named(struct parse *p, cset *cs, const char clname[]) { wctype_t wct; 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); } /* - may_escape - determine whether 'ch' is escape-able in the current context == static int may_escape(struct parse *p, const wint_t ch) */ static bool may_escape(struct parse *p, const wint_t ch) { if ((p->pflags & PFLAG_LEGACY_ESC) != 0) return (true); if (isalpha(ch) || ch == '\'' || ch == '`') return (false); return (true); #ifdef NOTYET /* * Build a whitelist of characters that may be escaped to produce an * ordinary in the current context. This assumes that these have not * been otherwise interpreted as a special character. Escaping an * ordinary character yields undefined results according to * IEEE 1003.1-2008. Some extensions (notably, some GNU extensions) take * advantage of this and use escaped ordinary characters to provide * special meaning, e.g. \b, \B, \w, \W, \s, \S. */ switch(ch) { case '|': case '+': case '?': /* The above characters may not be escaped in BREs */ if (!(p->g->cflags®_EXTENDED)) return (false); /* Fallthrough */ case '(': case ')': case '{': case '}': case '.': case '[': case ']': case '\\': case '*': case '^': case '$': return (true); default: return (false); } #endif } /* - 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®_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 OBOS: case OEOS: case OWBND: case ONWBND: 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 OWBND: case ONWBND: 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); }
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