/* $OpenBSD: regcomp.c,v 1.43 2021/01/03 17:07:57 tb Exp $ */ /*- * 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. 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 */ #include #include #include #include #include #include #include #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 { const char *next; /* next character in RE */ const char *end; /* end of string (-> NUL normally) */ int error; /* has an error been seen? */ sop *strip; /* malloced strip */ sopno ssize; /* malloced strip size (allocated) */ sopno slen; /* malloced strip length (used) */ int ncsalloc; /* number of csets allocated */ struct re_guts *g; # define NPAREN 10 /* we need to remember () 1-9 for back refs */ sopno pbegin[NPAREN]; /* -> ( ([0] unused) */ sopno pend[NPAREN]; /* -> ) ([0] unused) */ }; static void p_ere(struct parse *, int); static void p_ere_exp(struct parse *); static void p_str(struct parse *); static void p_bre(struct parse *, int, int); static int p_simp_re(struct parse *, int); static int p_count(struct parse *); static void p_bracket(struct parse *); static void p_b_term(struct parse *, cset *); static void p_b_cclass(struct parse *, cset *); static void p_b_eclass(struct parse *, cset *); static char p_b_symbol(struct parse *); static char p_b_coll_elem(struct parse *, int); static char othercase(int); static void bothcases(struct parse *, int); static void ordinary(struct parse *, int); static void backslash(struct parse *, int); static void nonnewline(struct parse *); static void repeat(struct parse *, sopno, int, int); static void seterr(struct parse *, int); static cset *allocset(struct parse *); static void freeset(struct parse *, cset *); static int freezeset(struct parse *, cset *); static int firstch(struct parse *, cset *); static int nch(struct parse *, cset *); static sopno dupl(struct parse *, sopno, sopno); static void doemit(struct parse *, sop, size_t); static void doinsert(struct parse *, sop, size_t, sopno); static void dofwd(struct parse *, sopno, sop); static int enlarge(struct parse *, sopno); static void stripsnug(struct parse *, struct re_guts *); static void findmust(struct parse *, struct re_guts *); static sopno pluscount(struct parse *, struct re_guts *); 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 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) do { if (!(co)) SETERROR(e); } while (0) #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 s have bugs too */ #endif /* - regcomp - interface for parser and compilation */ int /* 0 success, otherwise REG_something */ regcomp(regex_t *preg, const char *pattern, int cflags) { struct parse pa; struct re_guts *g; struct parse *p = &pa; int i; size_t len; #ifdef REDEBUG # define GOODFLAGS(f) (f) #else # define GOODFLAGS(f) ((f)&~REG_DUMP) #endif cflags = GOODFLAGS(cflags); if ((cflags®_EXTENDED) && (cflags®_NOSPEC)) return(REG_INVARG); if (cflags®_PEND) { if (preg->re_endp < pattern) return(REG_INVARG); len = preg->re_endp - pattern; } else len = strlen((char *)pattern); /* do the mallocs early so failure handling is easy */ g = malloc(sizeof(struct re_guts)); if (g == NULL) return(REG_ESPACE); p->ssize = len/(size_t)2*(size_t)3 + (size_t)1; /* ugh */ p->strip = reallocarray(NULL, p->ssize, sizeof(sop)); p->slen = 0; if (p->strip == NULL) { free(g); return(REG_ESPACE); } /* set things up */ p->g = g; p->next = pattern; 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->backrefs = 0; /* do it */ EMIT(OEND, 0); g->firststate = THERE(); if (cflags®_EXTENDED) p_ere(p, OUT); else if (cflags®_NOSPEC) p_str(p); else p_bre(p, OUT, OUT); EMIT(OEND, 0); g->laststate = THERE(); /* tidy up loose ends and fill things in */ stripsnug(p, g); findmust(p, g); g->nplus = pluscount(p, g); g->magic = MAGIC2; preg->re_nsub = g->nsub; preg->re_g = g; preg->re_magic = MAGIC1; #ifndef REDEBUG /* not debugging, so can't rely on the assert() in regexec() */ if (g->iflags&BAD) SETERROR(REG_ASSERT); #endif /* win or lose, we're done */ if (p->error != 0) /* lose */ regfree(preg); return(p->error); } /* - p_ere - ERE parser top level, concatenation and alternation */ static void p_ere(struct parse *p, int stop) /* character this ERE should end at */ { char c; sopno prevback; sopno prevfwd; sopno conc; int first = 1; /* is this the first alternative? */ for (;;) { /* do a bunch of concatenated expressions */ conc = HERE(); while (MORE() && (c = PEEK()) != '|' && c != stop) p_ere_exp(p); REQUIRE(HERE() != conc, REG_EMPTY); /* require nonempty */ if (!EAT('|')) break; /* NOTE BREAK OUT */ if (first) { INSERT(OCH_, conc); /* offset is wrong */ prevfwd = conc; prevback = conc; first = 0; } ASTERN(OOR1, prevback); prevback = THERE(); AHEAD(prevfwd); /* fix previous offset */ prevfwd = HERE(); EMIT(OOR2, 0); /* offset is very wrong */ } if (!first) { /* tail-end fixups */ AHEAD(prevfwd); ASTERN(O_CH, prevback); } assert(!MORE() || SEE(stop)); } /* - p_ere_exp - parse one subERE, an atom possibly followed by a repetition op */ static void p_ere_exp(struct parse *p) { char c; sopno pos; int count; int count2; sopno subno; int wascaret = 0; assert(MORE()); /* caller should have ensured this */ c = GETNEXT(); pos = HERE(); switch (c) { case '(': 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); REQUIRE(MORE() && GETNEXT() == ')', REG_EPAREN); break; 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(); backslash(p, c); break; case '{': /* okay as ordinary except if digit follows */ REQUIRE(!MORE() || !isdigit((uch)PEEK()), REG_BADRPT); /* FALLTHROUGH */ default: if (p->error != 0) return; 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((uch)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((uch)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((uch)PEEK2())) ) ) return; SETERROR(REG_BADRPT); } /* - p_str - string (no metacharacters) "parser" */ 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 * 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 */ { sopno start = HERE(); int first = 1; /* first subexpression? */ int wasdollar = 0; if (EAT('^')) { EMIT(OBOL, 0); p->g->iflags |= USEBOL; p->g->nbol++; } while (MORE() && !SEETWO(end1, end2)) { wasdollar = p_simp_re(p, first); first = 0; } if (wasdollar) { /* oops, that was a trailing anchor */ DROP(1); EMIT(OEOL, 0); p->g->iflags |= USEEOL; p->g->neol++; } REQUIRE(HERE() != start, REG_EMPTY); /* require nonempty */ } /* - p_simp_re - parse a simple RE, an atom possibly followed by a repetition */ static int /* was the simple RE an unbackslashed $? */ p_simp_re(struct parse *p, int starordinary) /* is a leading * an ordinary character? */ { int c; int count; int count2; sopno pos; int i; sopno subno; # define BACKSL (1<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_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: if (p->error != 0) return(0); /* Definitely not $... */ ordinary(p, (char)c); break; } if (EAT('*')) { /* implemented as +? */ /* this case does not require the (y|) trick, noKLUDGE */ INSERT(OPLUS_, pos); ASTERN(O_PLUS, pos); INSERT(OQUEST_, pos); ASTERN(O_QUEST, pos); } else if (EATTWO('\\', '{')) { count = p_count(p); if (EAT(',')) { if (MORE() && isdigit((uch)PEEK())) { count2 = p_count(p); REQUIRE(count <= count2, REG_BADBR); } else /* single number with comma */ count2 = INFINITY; } else /* just a single number */ count2 = count; repeat(p, pos, count, count2); if (!EATTWO('\\', '}')) { /* error heuristics */ while (MORE() && !SEETWO('\\', '}')) NEXT(); REQUIRE(MORE(), REG_EBRACE); SETERROR(REG_BADBR); } } else if (c == '$') /* $ (but not \$) ends it */ return(1); return(0); } /* - p_count - parse a repetition count */ 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++; } REQUIRE(ndigits > 0 && count <= DUPMAX, REG_BADBR); return(count); } /* - p_bracket - parse a bracketed character list * * Note a significant property of this code: if the allocset() did SETERROR, * no set operations are done. */ static void p_bracket(struct parse *p) { cset *cs; int invert = 0; /* 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) { /* allocset did set error status in p */ 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, '-'); REQUIRE(MORE() && GETNEXT() == ']', REG_EBRACK); if (p->error != 0) { /* don't mess things up further */ freeset(p, cs); return; } if (p->g->cflags®_ICASE) { int i; 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 (invert) { 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 (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(struct parse *p, cset *cs) { char c; char start, finish; 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(struct parse *p, cset *cs) { const char *sp = p->next; const struct cclass *cp; size_t len; const char *u; char c; while (MORE() && isalpha((uch)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); } /* - p_b_eclass - parse an equivalence-class name and deal with it * * This implementation is incomplete. xxx */ static void p_b_eclass(struct parse *p, cset *cs) { char c; c = p_b_coll_elem(p, '='); CHadd(cs, c); } /* - p_b_symbol - parse a character or [..]ed multicharacter collating symbol */ static char /* value of symbol */ p_b_symbol(struct parse *p) { 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 /* value of collating element */ p_b_coll_elem(struct parse *p, int endc) /* name ended by endc,']' */ { const char *sp = p->next; const struct cname *cp; size_t 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 */ if (len == 1) return(*sp); /* single character */ SETERROR(REG_ECOLLATE); /* neither */ return(0); } /* - othercase - return the case counterpart of an alphabetic */ static char /* if no counterpart, return ch */ othercase(int ch) { ch = (uch)ch; assert(isalpha(ch)); if (isupper(ch)) return ((uch)tolower(ch)); else if (islower(ch)) return ((uch)toupper(ch)); else /* peculiar, but could happen */ return(ch); } /* - bothcases - emit a dualcase version of a two-case character * * Boy, is this implementation ever a kludge... */ static void bothcases(struct parse *p, int ch) { const char *oldnext = p->next; const char *oldend = p->end; char bracket[3]; ch = (uch)ch; 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(struct parse *p, int ch) { if ((p->g->cflags®_ICASE) && isalpha((uch)ch) && othercase(ch) != ch) bothcases(p, ch); else EMIT(OCHAR, (uch)ch); } /* * do something magic with this character, but only if it's extra magic */ static void backslash(struct parse *p, int ch) { switch (ch) { case '<': EMIT(OBOW, 0); break; case '>': EMIT(OEOW, 0); break; default: ordinary(p, ch); break; } } /* - nonnewline - emit REG_NEWLINE version of OANY * * Boy, is this implementation ever a kludge... */ static void nonnewline(struct parse *p) { const char *oldnext = p->next; const char *oldend = p->end; static const char bracket[4] = { '^', '\n', ']', '\0' }; p->next = bracket; p->end = bracket+3; 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, /* 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; } } /* - seterr - set an error condition */ static void 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; } /* - allocset - allocate a set of characters for [] */ static cset * allocset(struct parse *p) { int no = p->g->ncsets++; size_t nc; size_t nbytes; cset *cs; size_t css = (size_t)p->g->csetsize; int i; if (no >= p->ncsalloc) { /* need another column of space */ void *ptr; p->ncsalloc += CHAR_BIT; nc = p->ncsalloc; assert(nc % CHAR_BIT == 0); ptr = reallocarray(p->g->sets, nc, sizeof(cset)); if (ptr == NULL) goto nomem; p->g->sets = ptr; ptr = reallocarray(p->g->setbits, nc / CHAR_BIT, css); if (ptr == NULL) goto nomem; nbytes = (nc / CHAR_BIT) * css; p->g->setbits = ptr; for (i = 0; i < no; i++) p->g->sets[i].ptr = p->g->setbits + css*(i/CHAR_BIT); (void) memset((char *)p->g->setbits + (nbytes - css), 0, css); } /* XXX should not happen */ if (p->g->sets == NULL || p->g->setbits == NULL) goto nomem; cs = &p->g->sets[no]; cs->ptr = p->g->setbits + css*((no)/CHAR_BIT); cs->mask = 1 << ((no) % CHAR_BIT); cs->hash = 0; return(cs); nomem: free(p->g->sets); p->g->sets = NULL; free(p->g->setbits); p->g->setbits = NULL; SETERROR(REG_ESPACE); /* caller's responsibility not to do set ops */ return(NULL); } /* - freeset - free a now-unused set */ static void freeset(struct parse *p, cset *cs) { int i; cset *top = &p->g->sets[p->g->ncsets]; 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 * * 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) { uch h = cs->hash; int i; cset *top = &p->g->sets[p->g->ncsets]; cset *cs2; 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 /* character; there is no "none" value */ firstch(struct parse *p, cset *cs) { int i; 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(struct parse *p, cset *cs) { int i; size_t css = (size_t)p->g->csetsize; int n = 0; for (i = 0; i < css; i++) if (CHIN(cs, i)) n++; return(n); } /* - dupl - emit a duplicate of a bunch of sops */ 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(p->strip + p->slen, p->strip + start, len * sizeof(sop)); p->slen += len; return(ret); } /* - doemit - emit a strip operator * * 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<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) { 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) { /* avoid making error situations worse */ if (p->error != 0) return; assert(value < 1<strip[pos] = OP(p->strip[pos]) | value; } /* - enlarge - enlarge the strip */ 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) { g->nstates = p->slen; g->strip = reallocarray(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 * * 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; /* start initialized in the default case, after that */ sop *newstart; /* newstart was initialized in the OCHAR case */ sopno newlen; sop s; char *cp; 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 /* 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); }