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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 4973 | right-hear | 1 | /* Copyright (C) 1995 DJ Delorie, see COPYING.DJ for details */ |
| 2 | /* |
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| 3 | * The matching engine and friends. This file is #included by regexec.c |
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| 4 | * after suitable #defines of a variety of macros used herein, so that |
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| 5 | * different state representations can be used without duplicating masses |
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| 6 | * of code. |
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| 7 | */ |
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| 8 | |||
| 9 | #ifdef SNAMES |
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| 10 | #define matcher smatcher |
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| 11 | #define fast sfast |
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| 12 | #define slow sslow |
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| 13 | #define dissect sdissect |
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| 14 | #define backref sbackref |
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| 15 | #define step sstep |
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| 16 | #define print sprint |
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| 17 | #define at sat |
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| 18 | #define match smat |
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| 19 | #endif |
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| 20 | #ifdef LNAMES |
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| 21 | #define matcher lmatcher |
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| 22 | #define fast lfast |
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| 23 | #define slow lslow |
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| 24 | #define dissect ldissect |
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| 25 | #define backref lbackref |
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| 26 | #define step lstep |
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| 27 | #define print lprint |
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| 28 | #define at lat |
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| 29 | #define match lmat |
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| 30 | #endif |
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| 31 | |||
| 32 | /* another structure passed up and down to avoid zillions of parameters */ |
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| 33 | struct match { |
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| 34 | struct re_guts *g; |
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| 35 | int eflags; |
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| 36 | regmatch_t *pmatch; /* [nsub+1] (0 element unused) */ |
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| 37 | char *offp; /* offsets work from here */ |
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| 38 | char *beginp; /* start of string -- virtual NUL precedes */ |
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| 39 | char *endp; /* end of string -- virtual NUL here */ |
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| 40 | char *coldp; /* can be no match starting before here */ |
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| 41 | char **lastpos; /* [nplus+1] */ |
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| 42 | STATEVARS; |
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| 43 | states st; /* current states */ |
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| 44 | states fresh; /* states for a fresh start */ |
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| 45 | states tmp; /* temporary */ |
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| 46 | states empty; /* empty set of states */ |
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| 47 | }; |
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| 48 | |||
| 49 | #include "engine.ih" |
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| 50 | |||
| 51 | #ifdef REDEBUG |
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| 52 | #define SP(t, s, c) print(m, t, s, c, stdout) |
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| 53 | #define AT(t, p1, p2, s1, s2) at(m, t, p1, p2, s1, s2) |
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| 54 | #define NOTE(str) { if (m->eflags®_TRACE) printf("=%s\n", (str)); } |
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| 55 | #else |
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| 56 | #define SP(t, s, c) /* nothing */ |
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| 57 | #define AT(t, p1, p2, s1, s2) /* nothing */ |
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| 58 | #define NOTE(s) /* nothing */ |
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| 59 | #endif |
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| 60 | |||
| 61 | /* |
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| 62 | - matcher - the actual matching engine |
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| 63 | == static int matcher(register struct re_guts *g, char *string, \ |
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| 64 | == size_t nmatch, regmatch_t pmatch[], int eflags); |
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| 65 | */ |
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| 66 | static int /* 0 success, REG_NOMATCH failure */ |
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| 67 | matcher(g, string, nmatch, pmatch, eflags) |
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| 68 | register struct re_guts *g; |
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| 69 | char *string; |
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| 70 | size_t nmatch; |
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| 71 | regmatch_t pmatch[]; |
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| 72 | int eflags; |
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| 73 | { |
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| 74 | register char *endp; |
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| 75 | register int i; |
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| 76 | struct match mv; |
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| 77 | register struct match *m = &mv; |
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| 78 | register char *dp; |
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| 79 | const register sopno gf = g->firststate+1; /* +1 for OEND */ |
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| 80 | const register sopno gl = g->laststate; |
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| 81 | char *start; |
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| 82 | char *stop; |
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| 83 | |||
| 84 | /* simplify the situation where possible */ |
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| 85 | if (g->cflags®_NOSUB) |
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| 86 | nmatch = 0; |
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| 87 | if (eflags®_STARTEND) { |
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| 88 | start = string + pmatch[0].rm_so; |
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| 89 | stop = string + pmatch[0].rm_eo; |
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| 90 | } else { |
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| 91 | start = string; |
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| 92 | stop = start + strlen(start); |
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| 93 | } |
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| 94 | if (stop < start) |
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| 95 | return(REG_INVARG); |
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| 96 | |||
| 97 | /* prescreening; this does wonders for this rather slow code */ |
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| 98 | if (g->must != NULL) { |
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| 99 | for (dp = start; dp < stop; dp++) |
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| 100 | if (*dp == g->must[0] && stop - dp >= g->mlen && |
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| 101 | memcmp(dp, g->must, (size_t)g->mlen) == 0) |
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| 102 | break; |
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| 103 | if (dp == stop) /* we didn't find g->must */ |
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| 104 | return(REG_NOMATCH); |
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| 105 | } |
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| 106 | |||
| 107 | /* match struct setup */ |
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| 108 | m->g = g; |
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| 109 | m->eflags = eflags; |
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| 110 | m->pmatch = NULL; |
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| 111 | m->lastpos = NULL; |
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| 112 | m->offp = string; |
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| 113 | m->beginp = start; |
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| 114 | m->endp = stop; |
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| 115 | STATESETUP(m, 4); |
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| 116 | SETUP(m->st); |
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| 117 | SETUP(m->fresh); |
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| 118 | SETUP(m->tmp); |
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| 119 | SETUP(m->empty); |
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| 120 | CLEAR(m->empty); |
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| 121 | |||
| 122 | /* this loop does only one repetition except for backrefs */ |
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| 123 | for (;;) { |
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| 124 | endp = fast(m, start, stop, gf, gl); |
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| 125 | if (endp == NULL) { /* a miss */ |
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| 126 | STATETEARDOWN(m); |
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| 127 | return(REG_NOMATCH); |
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| 128 | } |
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| 129 | if (nmatch == 0 && !g->backrefs) |
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| 130 | break; /* no further info needed */ |
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| 131 | |||
| 132 | /* where? */ |
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| 133 | assert(m->coldp != NULL); |
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| 134 | for (;;) { |
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| 135 | NOTE("finding start"); |
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| 136 | endp = slow(m, m->coldp, stop, gf, gl); |
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| 137 | if (endp != NULL) |
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| 138 | break; |
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| 139 | assert(m->coldp < m->endp); |
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| 140 | m->coldp++; |
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| 141 | } |
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| 142 | if (nmatch == 1 && !g->backrefs) |
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| 143 | break; /* no further info needed */ |
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| 144 | |||
| 145 | /* oh my, he wants the subexpressions... */ |
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| 146 | if (m->pmatch == NULL) |
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| 147 | m->pmatch = (regmatch_t *)malloc((m->g->nsub + 1) * |
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| 148 | sizeof(regmatch_t)); |
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| 149 | if (m->pmatch == NULL) { |
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| 150 | STATETEARDOWN(m); |
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| 151 | return(REG_ESPACE); |
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| 152 | } |
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| 153 | for (i = 1; i <= m->g->nsub; i++) |
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| 154 | m->pmatch[i].rm_so = m->pmatch[i].rm_eo = -1; |
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| 155 | if (!g->backrefs && !(m->eflags®_BACKR)) { |
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| 156 | NOTE("dissecting"); |
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| 157 | dp = dissect(m, m->coldp, endp, gf, gl); |
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| 158 | } else { |
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| 159 | if (g->nplus > 0 && m->lastpos == NULL) |
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| 160 | m->lastpos = (char **)malloc((g->nplus+1) * |
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| 161 | sizeof(char *)); |
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| 162 | if (g->nplus > 0 && m->lastpos == NULL) { |
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| 163 | free(m->pmatch); |
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| 164 | STATETEARDOWN(m); |
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| 165 | return(REG_ESPACE); |
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| 166 | } |
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| 167 | NOTE("backref dissect"); |
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| 168 | dp = backref(m, m->coldp, endp, gf, gl, (sopno)0); |
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| 169 | } |
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| 170 | if (dp != NULL) |
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| 171 | break; |
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| 172 | |||
| 173 | /* uh-oh... we couldn't find a subexpression-level match */ |
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| 174 | assert(g->backrefs); /* must be back references doing it */ |
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| 175 | assert(g->nplus == 0 || m->lastpos != NULL); |
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| 176 | for (;;) { |
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| 177 | if (dp != NULL || endp <= m->coldp) |
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| 178 | break; /* defeat */ |
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| 179 | NOTE("backoff"); |
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| 180 | endp = slow(m, m->coldp, endp-1, gf, gl); |
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| 181 | if (endp == NULL) |
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| 182 | break; /* defeat */ |
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| 183 | /* try it on a shorter possibility */ |
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| 184 | #ifndef NDEBUG |
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| 185 | for (i = 1; i <= m->g->nsub; i++) { |
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| 186 | assert(m->pmatch[i].rm_so == -1); |
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| 187 | assert(m->pmatch[i].rm_eo == -1); |
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| 188 | } |
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| 189 | #endif |
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| 190 | NOTE("backoff dissect"); |
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| 191 | dp = backref(m, m->coldp, endp, gf, gl, (sopno)0); |
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| 192 | } |
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| 193 | assert(dp == NULL || dp == endp); |
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| 194 | if (dp != NULL) /* found a shorter one */ |
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| 195 | break; |
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| 196 | |||
| 197 | /* despite initial appearances, there is no match here */ |
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| 198 | NOTE("false alarm"); |
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| 199 | start = m->coldp + 1; /* recycle starting later */ |
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| 200 | assert(start <= stop); |
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| 201 | } |
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| 202 | |||
| 203 | /* fill in the details if requested */ |
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| 204 | if (nmatch > 0) { |
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| 205 | pmatch[0].rm_so = m->coldp - m->offp; |
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| 206 | pmatch[0].rm_eo = endp - m->offp; |
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| 207 | } |
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| 208 | if (nmatch > 1) { |
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| 209 | assert(m->pmatch != NULL); |
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| 210 | for (i = 1; i < nmatch; i++) |
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| 211 | if (i <= m->g->nsub) |
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| 212 | pmatch[i] = m->pmatch[i]; |
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| 213 | else { |
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| 214 | pmatch[i].rm_so = -1; |
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| 215 | pmatch[i].rm_eo = -1; |
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| 216 | } |
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| 217 | } |
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| 218 | |||
| 219 | if (m->pmatch != NULL) |
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| 220 | free((char *)m->pmatch); |
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| 221 | if (m->lastpos != NULL) |
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| 222 | free((char *)m->lastpos); |
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| 223 | STATETEARDOWN(m); |
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| 224 | return(0); |
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| 225 | } |
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| 226 | |||
| 227 | /* |
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| 228 | - dissect - figure out what matched what, no back references |
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| 229 | == static char *dissect(register struct match *m, char *start, \ |
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| 230 | == char *stop, sopno startst, sopno stopst); |
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| 231 | */ |
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| 232 | static char * /* == stop (success) always */ |
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| 233 | dissect(m, start, stop, startst, stopst) |
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| 234 | register struct match *m; |
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| 235 | char *start; |
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| 236 | char *stop; |
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| 237 | sopno startst; |
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| 238 | sopno stopst; |
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| 239 | { |
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| 240 | register int i; |
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| 241 | register sopno ss; /* start sop of current subRE */ |
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| 242 | register sopno es; /* end sop of current subRE */ |
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| 243 | register char *sp; /* start of string matched by it */ |
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| 244 | register char *stp; /* string matched by it cannot pass here */ |
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| 245 | register char *rest; /* start of rest of string */ |
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| 246 | register char *tail; /* string unmatched by rest of RE */ |
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| 247 | register sopno ssub; /* start sop of subsubRE */ |
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| 248 | register sopno esub; /* end sop of subsubRE */ |
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| 249 | register char *ssp; /* start of string matched by subsubRE */ |
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| 250 | register char *sep; /* end of string matched by subsubRE */ |
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| 251 | register char *oldssp; /* previous ssp */ |
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| 252 | register char *dp; |
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| 253 | |||
| 254 | AT("diss", start, stop, startst, stopst); |
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| 255 | sp = start; |
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| 256 | for (ss = startst; ss < stopst; ss = es) { |
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| 257 | /* identify end of subRE */ |
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| 258 | es = ss; |
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| 259 | switch (OP(m->g->strip[es])) { |
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| 260 | case OPLUS_: |
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| 261 | case OQUEST_: |
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| 262 | es += OPND(m->g->strip[es]); |
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| 263 | break; |
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| 264 | case OCH_: |
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| 265 | while (OP(m->g->strip[es]) != O_CH) |
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| 266 | es += OPND(m->g->strip[es]); |
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| 267 | break; |
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| 268 | } |
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| 269 | es++; |
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| 270 | |||
| 271 | /* figure out what it matched */ |
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| 272 | switch (OP(m->g->strip[ss])) { |
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| 273 | case OEND: |
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| 274 | assert(nope); |
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| 275 | break; |
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| 276 | case OCHAR: |
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| 277 | sp++; |
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| 278 | break; |
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| 279 | case OBOL: |
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| 280 | case OEOL: |
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| 281 | case OBOW: |
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| 282 | case OEOW: |
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| 283 | break; |
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| 284 | case OANY: |
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| 285 | case OANYOF: |
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| 286 | sp++; |
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| 287 | break; |
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| 288 | case OBACK_: |
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| 289 | case O_BACK: |
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| 290 | assert(nope); |
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| 291 | break; |
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| 292 | /* cases where length of match is hard to find */ |
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| 293 | case OQUEST_: |
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| 294 | stp = stop; |
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| 295 | for (;;) { |
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| 296 | /* how long could this one be? */ |
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| 297 | rest = slow(m, sp, stp, ss, es); |
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| 298 | assert(rest != NULL); /* it did match */ |
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| 299 | /* could the rest match the rest? */ |
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| 300 | tail = slow(m, rest, stop, es, stopst); |
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| 301 | if (tail == stop) |
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| 302 | break; /* yes! */ |
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| 303 | /* no -- try a shorter match for this one */ |
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| 304 | stp = rest - 1; |
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| 305 | assert(stp >= sp); /* it did work */ |
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| 306 | } |
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| 307 | ssub = ss + 1; |
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| 308 | esub = es - 1; |
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| 309 | /* did innards match? */ |
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| 310 | if (slow(m, sp, rest, ssub, esub) != NULL) { |
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| 311 | dp = dissect(m, sp, rest, ssub, esub); |
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| 312 | assert(dp == rest); |
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| 313 | } else /* no */ |
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| 314 | assert(sp == rest); |
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| 315 | sp = rest; |
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| 316 | break; |
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| 317 | case OPLUS_: |
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| 318 | stp = stop; |
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| 319 | for (;;) { |
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| 320 | /* how long could this one be? */ |
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| 321 | rest = slow(m, sp, stp, ss, es); |
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| 322 | assert(rest != NULL); /* it did match */ |
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| 323 | /* could the rest match the rest? */ |
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| 324 | tail = slow(m, rest, stop, es, stopst); |
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| 325 | if (tail == stop) |
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| 326 | break; /* yes! */ |
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| 327 | /* no -- try a shorter match for this one */ |
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| 328 | stp = rest - 1; |
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| 329 | assert(stp >= sp); /* it did work */ |
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| 330 | } |
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| 331 | ssub = ss + 1; |
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| 332 | esub = es - 1; |
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| 333 | ssp = sp; |
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| 334 | oldssp = ssp; |
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| 335 | for (;;) { /* find last match of innards */ |
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| 336 | sep = slow(m, ssp, rest, ssub, esub); |
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| 337 | if (sep == NULL || sep == ssp) |
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| 338 | break; /* failed or matched null */ |
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| 339 | oldssp = ssp; /* on to next try */ |
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| 340 | ssp = sep; |
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| 341 | } |
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| 342 | if (sep == NULL) { |
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| 343 | /* last successful match */ |
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| 344 | sep = ssp; |
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| 345 | ssp = oldssp; |
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| 346 | } |
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| 347 | assert(sep == rest); /* must exhaust substring */ |
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| 348 | assert(slow(m, ssp, sep, ssub, esub) == rest); |
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| 349 | dp = dissect(m, ssp, sep, ssub, esub); |
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| 350 | assert(dp == sep); |
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| 351 | sp = rest; |
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| 352 | break; |
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| 353 | case OCH_: |
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| 354 | stp = stop; |
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| 355 | for (;;) { |
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| 356 | /* how long could this one be? */ |
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| 357 | rest = slow(m, sp, stp, ss, es); |
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| 358 | assert(rest != NULL); /* it did match */ |
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| 359 | /* could the rest match the rest? */ |
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| 360 | tail = slow(m, rest, stop, es, stopst); |
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| 361 | if (tail == stop) |
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| 362 | break; /* yes! */ |
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| 363 | /* no -- try a shorter match for this one */ |
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| 364 | stp = rest - 1; |
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| 365 | assert(stp >= sp); /* it did work */ |
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| 366 | } |
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| 367 | ssub = ss + 1; |
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| 368 | esub = ss + OPND(m->g->strip[ss]) - 1; |
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| 369 | assert(OP(m->g->strip[esub]) == OOR1); |
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| 370 | for (;;) { /* find first matching branch */ |
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| 371 | if (slow(m, sp, rest, ssub, esub) == rest) |
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| 372 | break; /* it matched all of it */ |
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| 373 | /* that one missed, try next one */ |
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| 374 | assert(OP(m->g->strip[esub]) == OOR1); |
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| 375 | esub++; |
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| 376 | assert(OP(m->g->strip[esub]) == OOR2); |
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| 377 | ssub = esub + 1; |
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| 378 | esub += OPND(m->g->strip[esub]); |
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| 379 | if (OP(m->g->strip[esub]) == OOR2) |
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| 380 | esub--; |
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| 381 | else |
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| 382 | assert(OP(m->g->strip[esub]) == O_CH); |
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| 383 | } |
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| 384 | dp = dissect(m, sp, rest, ssub, esub); |
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| 385 | assert(dp == rest); |
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| 386 | sp = rest; |
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| 387 | break; |
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| 388 | case O_PLUS: |
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| 389 | case O_QUEST: |
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| 390 | case OOR1: |
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| 391 | case OOR2: |
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| 392 | case O_CH: |
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| 393 | assert(nope); |
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| 394 | break; |
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| 395 | case OLPAREN: |
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| 396 | i = OPND(m->g->strip[ss]); |
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| 397 | assert(0 < i && i <= m->g->nsub); |
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| 398 | m->pmatch[i].rm_so = sp - m->offp; |
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| 399 | break; |
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| 400 | case ORPAREN: |
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| 401 | i = OPND(m->g->strip[ss]); |
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| 402 | assert(0 < i && i <= m->g->nsub); |
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| 403 | m->pmatch[i].rm_eo = sp - m->offp; |
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| 404 | break; |
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| 405 | default: /* uh oh */ |
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| 406 | assert(nope); |
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| 407 | break; |
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| 408 | } |
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| 409 | } |
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| 410 | |||
| 411 | assert(sp == stop); |
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| 412 | return(sp); |
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| 413 | } |
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| 414 | |||
| 415 | /* |
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| 416 | - backref - figure out what matched what, figuring in back references |
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| 417 | == static char *backref(register struct match *m, char *start, \ |
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| 418 | == char *stop, sopno startst, sopno stopst, sopno lev); |
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| 419 | */ |
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| 420 | static char * /* == stop (success) or NULL (failure) */ |
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| 421 | backref(m, start, stop, startst, stopst, lev) |
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| 422 | register struct match *m; |
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| 423 | char *start; |
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| 424 | char *stop; |
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| 425 | sopno startst; |
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| 426 | sopno stopst; |
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| 427 | sopno lev; /* PLUS nesting level */ |
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| 428 | { |
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| 429 | register int i; |
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| 430 | register sopno ss; /* start sop of current subRE */ |
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| 431 | register char *sp; /* start of string matched by it */ |
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| 432 | register sopno ssub; /* start sop of subsubRE */ |
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| 433 | register sopno esub; /* end sop of subsubRE */ |
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| 434 | register char *ssp; /* start of string matched by subsubRE */ |
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| 435 | register char *dp; |
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| 436 | register size_t len; |
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| 437 | register int hard; |
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| 438 | register sop s; |
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| 439 | register regoff_t offsave; |
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| 440 | register cset *cs; |
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| 441 | |||
| 442 | AT("back", start, stop, startst, stopst); |
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| 443 | sp = start; |
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| 444 | |||
| 445 | /* get as far as we can with easy stuff */ |
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| 446 | hard = 0; |
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| 447 | for (ss = startst; !hard && ss < stopst; ss++) |
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| 448 | switch (OP(s = m->g->strip[ss])) { |
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| 449 | case OCHAR: |
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| 450 | if (sp == stop || *sp++ != (char)OPND(s)) |
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| 451 | return(NULL); |
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| 452 | break; |
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| 453 | case OANY: |
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| 454 | if (sp == stop) |
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| 455 | return(NULL); |
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| 456 | sp++; |
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| 457 | break; |
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| 458 | case OANYOF: |
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| 459 | cs = &m->g->sets[OPND(s)]; |
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| 460 | if (sp == stop || !CHIN(cs, *sp++)) |
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| 461 | return(NULL); |
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| 462 | break; |
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| 463 | case OBOL: |
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| 464 | if ( (sp == m->beginp && !(m->eflags®_NOTBOL)) || |
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| 465 | (sp < m->endp && *(sp-1) == '\n' && |
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| 466 | (m->g->cflags®_NEWLINE)) ) |
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| 467 | { /* yes */ } |
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| 468 | else |
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| 469 | return(NULL); |
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| 470 | break; |
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| 471 | case OEOL: |
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| 472 | if ( (sp == m->endp && !(m->eflags®_NOTEOL)) || |
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| 473 | (sp < m->endp && *sp == '\n' && |
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| 474 | (m->g->cflags®_NEWLINE)) ) |
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| 475 | { /* yes */ } |
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| 476 | else |
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| 477 | return(NULL); |
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| 478 | break; |
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| 479 | case OBOW: |
||
| 480 | if (( (sp == m->beginp && !(m->eflags®_NOTBOL)) || |
||
| 481 | (sp < m->endp && *(sp-1) == '\n' && |
||
| 482 | (m->g->cflags®_NEWLINE)) || |
||
| 483 | (sp > m->beginp && |
||
| 484 | !ISWORD(*(sp-1))) ) && |
||
| 485 | (sp < m->endp && ISWORD(*sp)) ) |
||
| 486 | { /* yes */ } |
||
| 487 | else |
||
| 488 | return(NULL); |
||
| 489 | break; |
||
| 490 | case OEOW: |
||
| 491 | if (( (sp == m->endp && !(m->eflags®_NOTEOL)) || |
||
| 492 | (sp < m->endp && *sp == '\n' && |
||
| 493 | (m->g->cflags®_NEWLINE)) || |
||
| 494 | (sp < m->endp && !ISWORD(*sp)) ) && |
||
| 495 | (sp > m->beginp && ISWORD(*(sp-1))) ) |
||
| 496 | { /* yes */ } |
||
| 497 | else |
||
| 498 | return(NULL); |
||
| 499 | break; |
||
| 500 | case O_QUEST: |
||
| 501 | break; |
||
| 502 | case OOR1: /* matches null but needs to skip */ |
||
| 503 | ss++; |
||
| 504 | s = m->g->strip[ss]; |
||
| 505 | do { |
||
| 506 | assert(OP(s) == OOR2); |
||
| 507 | ss += OPND(s); |
||
| 508 | } while (OP(s = m->g->strip[ss]) != O_CH); |
||
| 509 | /* note that the ss++ gets us past the O_CH */ |
||
| 510 | break; |
||
| 511 | default: /* have to make a choice */ |
||
| 512 | hard = 1; |
||
| 513 | break; |
||
| 514 | } |
||
| 515 | if (!hard) { /* that was it! */ |
||
| 516 | if (sp != stop) |
||
| 517 | return(NULL); |
||
| 518 | return(sp); |
||
| 519 | } |
||
| 520 | ss--; /* adjust for the for's final increment */ |
||
| 521 | |||
| 522 | /* the hard stuff */ |
||
| 523 | AT("hard", sp, stop, ss, stopst); |
||
| 524 | s = m->g->strip[ss]; |
||
| 525 | switch (OP(s)) { |
||
| 526 | case OBACK_: /* the vilest depths */ |
||
| 527 | i = OPND(s); |
||
| 528 | assert(0 < i && i <= m->g->nsub); |
||
| 529 | if (m->pmatch[i].rm_eo == -1) |
||
| 530 | return(NULL); |
||
| 531 | assert(m->pmatch[i].rm_so != -1); |
||
| 532 | len = m->pmatch[i].rm_eo - m->pmatch[i].rm_so; |
||
| 533 | assert(stop - m->beginp >= len); |
||
| 534 | if (sp > stop - len) |
||
| 535 | return(NULL); /* not enough left to match */ |
||
| 536 | ssp = m->offp + m->pmatch[i].rm_so; |
||
| 537 | if (memcmp(sp, ssp, len) != 0) |
||
| 538 | return(NULL); |
||
| 539 | while (m->g->strip[ss] != SOP(O_BACK, i)) |
||
| 540 | ss++; |
||
| 541 | return(backref(m, sp+len, stop, ss+1, stopst, lev)); |
||
| 542 | break; |
||
| 543 | case OQUEST_: /* to null or not */ |
||
| 544 | dp = backref(m, sp, stop, ss+1, stopst, lev); |
||
| 545 | if (dp != NULL) |
||
| 546 | return(dp); /* not */ |
||
| 547 | return(backref(m, sp, stop, ss+OPND(s)+1, stopst, lev)); |
||
| 548 | break; |
||
| 549 | case OPLUS_: |
||
| 550 | assert(m->lastpos != NULL); |
||
| 551 | assert(lev+1 <= m->g->nplus); |
||
| 552 | m->lastpos[lev+1] = sp; |
||
| 553 | return(backref(m, sp, stop, ss+1, stopst, lev+1)); |
||
| 554 | break; |
||
| 555 | case O_PLUS: |
||
| 556 | if (sp == m->lastpos[lev]) /* last pass matched null */ |
||
| 557 | return(backref(m, sp, stop, ss+1, stopst, lev-1)); |
||
| 558 | /* try another pass */ |
||
| 559 | m->lastpos[lev] = sp; |
||
| 560 | dp = backref(m, sp, stop, ss-OPND(s)+1, stopst, lev); |
||
| 561 | if (dp == NULL) |
||
| 562 | return(backref(m, sp, stop, ss+1, stopst, lev-1)); |
||
| 563 | else |
||
| 564 | return(dp); |
||
| 565 | break; |
||
| 566 | case OCH_: /* find the right one, if any */ |
||
| 567 | ssub = ss + 1; |
||
| 568 | esub = ss + OPND(s) - 1; |
||
| 569 | assert(OP(m->g->strip[esub]) == OOR1); |
||
| 570 | for (;;) { /* find first matching branch */ |
||
| 571 | dp = backref(m, sp, stop, ssub, esub, lev); |
||
| 572 | if (dp != NULL) |
||
| 573 | return(dp); |
||
| 574 | /* that one missed, try next one */ |
||
| 575 | if (OP(m->g->strip[esub]) == O_CH) |
||
| 576 | return(NULL); /* there is none */ |
||
| 577 | esub++; |
||
| 578 | assert(OP(m->g->strip[esub]) == OOR2); |
||
| 579 | ssub = esub + 1; |
||
| 580 | esub += OPND(m->g->strip[esub]); |
||
| 581 | if (OP(m->g->strip[esub]) == OOR2) |
||
| 582 | esub--; |
||
| 583 | else |
||
| 584 | assert(OP(m->g->strip[esub]) == O_CH); |
||
| 585 | } |
||
| 586 | break; |
||
| 587 | case OLPAREN: /* must undo assignment if rest fails */ |
||
| 588 | i = OPND(s); |
||
| 589 | assert(0 < i && i <= m->g->nsub); |
||
| 590 | offsave = m->pmatch[i].rm_so; |
||
| 591 | m->pmatch[i].rm_so = sp - m->offp; |
||
| 592 | dp = backref(m, sp, stop, ss+1, stopst, lev); |
||
| 593 | if (dp != NULL) |
||
| 594 | return(dp); |
||
| 595 | m->pmatch[i].rm_so = offsave; |
||
| 596 | return(NULL); |
||
| 597 | break; |
||
| 598 | case ORPAREN: /* must undo assignment if rest fails */ |
||
| 599 | i = OPND(s); |
||
| 600 | assert(0 < i && i <= m->g->nsub); |
||
| 601 | offsave = m->pmatch[i].rm_eo; |
||
| 602 | m->pmatch[i].rm_eo = sp - m->offp; |
||
| 603 | dp = backref(m, sp, stop, ss+1, stopst, lev); |
||
| 604 | if (dp != NULL) |
||
| 605 | return(dp); |
||
| 606 | m->pmatch[i].rm_eo = offsave; |
||
| 607 | return(NULL); |
||
| 608 | break; |
||
| 609 | default: /* uh oh */ |
||
| 610 | assert(nope); |
||
| 611 | break; |
||
| 612 | } |
||
| 613 | |||
| 614 | /* "can't happen" */ |
||
| 615 | assert(nope); |
||
| 616 | /* NOTREACHED */ |
||
| 617 | } |
||
| 618 | |||
| 619 | /* |
||
| 620 | - fast - step through the string at top speed |
||
| 621 | == static char *fast(register struct match *m, char *start, \ |
||
| 622 | == char *stop, sopno startst, sopno stopst); |
||
| 623 | */ |
||
| 624 | static char * /* where tentative match ended, or NULL */ |
||
| 625 | fast(m, start, stop, startst, stopst) |
||
| 626 | register struct match *m; |
||
| 627 | char *start; |
||
| 628 | char *stop; |
||
| 629 | sopno startst; |
||
| 630 | sopno stopst; |
||
| 631 | { |
||
| 632 | register states st = m->st; |
||
| 633 | register states fresh = m->fresh; |
||
| 634 | register states tmp = m->tmp; |
||
| 635 | register char *p = start; |
||
| 636 | register int c = (start == m->beginp) ? OUT : *(start-1); |
||
| 637 | register int lastc; /* previous c */ |
||
| 638 | register int flagch; |
||
| 639 | register int i; |
||
| 640 | register char *coldp; /* last p after which no match was underway */ |
||
| 641 | |||
| 642 | CLEAR(st); |
||
| 643 | SET1(st, startst); |
||
| 644 | st = step(m->g, startst, stopst, st, NOTHING, st); |
||
| 645 | ASSIGN(fresh, st); |
||
| 646 | SP("start", st, *p); |
||
| 647 | coldp = NULL; |
||
| 648 | for (;;) { |
||
| 649 | /* next character */ |
||
| 650 | lastc = c; |
||
| 651 | c = (p == m->endp) ? OUT : *p; |
||
| 652 | if (EQ(st, fresh)) |
||
| 653 | coldp = p; |
||
| 654 | |||
| 655 | /* is there an EOL and/or BOL between lastc and c? */ |
||
| 656 | flagch = '\0'; |
||
| 657 | i = 0; |
||
| 658 | if ( (lastc == '\n' && m->g->cflags®_NEWLINE) || |
||
| 659 | (lastc == OUT && !(m->eflags®_NOTBOL)) ) { |
||
| 660 | flagch = BOL; |
||
| 661 | i = m->g->nbol; |
||
| 662 | } |
||
| 663 | if ( (c == '\n' && m->g->cflags®_NEWLINE) || |
||
| 664 | (c == OUT && !(m->eflags®_NOTEOL)) ) { |
||
| 665 | flagch = (flagch == BOL) ? BOLEOL : EOL; |
||
| 666 | i += m->g->neol; |
||
| 667 | } |
||
| 668 | if (i != 0) { |
||
| 669 | for (; i > 0; i--) |
||
| 670 | st = step(m->g, startst, stopst, st, flagch, st); |
||
| 671 | SP("boleol", st, c); |
||
| 672 | } |
||
| 673 | |||
| 674 | /* how about a word boundary? */ |
||
| 675 | if ( (flagch == BOL || (lastc != OUT && !ISWORD(lastc))) && |
||
| 676 | (c != OUT && ISWORD(c)) ) { |
||
| 677 | flagch = BOW; |
||
| 678 | } |
||
| 679 | if ( (lastc != OUT && ISWORD(lastc)) && |
||
| 680 | (flagch == EOL || (c != OUT && !ISWORD(c))) ) { |
||
| 681 | flagch = EOW; |
||
| 682 | } |
||
| 683 | if (flagch == BOW || flagch == EOW) { |
||
| 684 | st = step(m->g, startst, stopst, st, flagch, st); |
||
| 685 | SP("boweow", st, c); |
||
| 686 | } |
||
| 687 | |||
| 688 | /* are we done? */ |
||
| 689 | if (ISSET(st, stopst) || p == stop) |
||
| 690 | break; /* NOTE BREAK OUT */ |
||
| 691 | |||
| 692 | /* no, we must deal with this character */ |
||
| 693 | ASSIGN(tmp, st); |
||
| 694 | ASSIGN(st, fresh); |
||
| 695 | assert(c != OUT); |
||
| 696 | st = step(m->g, startst, stopst, tmp, c, st); |
||
| 697 | SP("aft", st, c); |
||
| 698 | assert(EQ(step(m->g, startst, stopst, st, NOTHING, st), st)); |
||
| 699 | p++; |
||
| 700 | } |
||
| 701 | |||
| 702 | assert(coldp != NULL); |
||
| 703 | m->coldp = coldp; |
||
| 704 | if (ISSET(st, stopst)) |
||
| 705 | return(p+1); |
||
| 706 | else |
||
| 707 | return(NULL); |
||
| 708 | } |
||
| 709 | |||
| 710 | /* |
||
| 711 | - slow - step through the string more deliberately |
||
| 712 | == static char *slow(register struct match *m, char *start, \ |
||
| 713 | == char *stop, sopno startst, sopno stopst); |
||
| 714 | */ |
||
| 715 | static char * /* where it ended */ |
||
| 716 | slow(m, start, stop, startst, stopst) |
||
| 717 | register struct match *m; |
||
| 718 | char *start; |
||
| 719 | char *stop; |
||
| 720 | sopno startst; |
||
| 721 | sopno stopst; |
||
| 722 | { |
||
| 723 | register states st = m->st; |
||
| 724 | register states empty = m->empty; |
||
| 725 | register states tmp = m->tmp; |
||
| 726 | register char *p = start; |
||
| 727 | register int c = (start == m->beginp) ? OUT : *(start-1); |
||
| 728 | register int lastc; /* previous c */ |
||
| 729 | register int flagch; |
||
| 730 | register int i; |
||
| 731 | register char *matchp; /* last p at which a match ended */ |
||
| 732 | |||
| 733 | AT("slow", start, stop, startst, stopst); |
||
| 734 | CLEAR(st); |
||
| 735 | SET1(st, startst); |
||
| 736 | SP("sstart", st, *p); |
||
| 737 | st = step(m->g, startst, stopst, st, NOTHING, st); |
||
| 738 | matchp = NULL; |
||
| 739 | for (;;) { |
||
| 740 | /* next character */ |
||
| 741 | lastc = c; |
||
| 742 | c = (p == m->endp) ? OUT : *p; |
||
| 743 | |||
| 744 | /* is there an EOL and/or BOL between lastc and c? */ |
||
| 745 | flagch = '\0'; |
||
| 746 | i = 0; |
||
| 747 | if ( (lastc == '\n' && m->g->cflags®_NEWLINE) || |
||
| 748 | (lastc == OUT && !(m->eflags®_NOTBOL)) ) { |
||
| 749 | flagch = BOL; |
||
| 750 | i = m->g->nbol; |
||
| 751 | } |
||
| 752 | if ( (c == '\n' && m->g->cflags®_NEWLINE) || |
||
| 753 | (c == OUT && !(m->eflags®_NOTEOL)) ) { |
||
| 754 | flagch = (flagch == BOL) ? BOLEOL : EOL; |
||
| 755 | i += m->g->neol; |
||
| 756 | } |
||
| 757 | if (i != 0) { |
||
| 758 | for (; i > 0; i--) |
||
| 759 | st = step(m->g, startst, stopst, st, flagch, st); |
||
| 760 | SP("sboleol", st, c); |
||
| 761 | } |
||
| 762 | |||
| 763 | /* how about a word boundary? */ |
||
| 764 | if ( (flagch == BOL || (lastc != OUT && !ISWORD(lastc))) && |
||
| 765 | (c != OUT && ISWORD(c)) ) { |
||
| 766 | flagch = BOW; |
||
| 767 | } |
||
| 768 | if ( (lastc != OUT && ISWORD(lastc)) && |
||
| 769 | (flagch == EOL || (c != OUT && !ISWORD(c))) ) { |
||
| 770 | flagch = EOW; |
||
| 771 | } |
||
| 772 | if (flagch == BOW || flagch == EOW) { |
||
| 773 | st = step(m->g, startst, stopst, st, flagch, st); |
||
| 774 | SP("sboweow", st, c); |
||
| 775 | } |
||
| 776 | |||
| 777 | /* are we done? */ |
||
| 778 | if (ISSET(st, stopst)) |
||
| 779 | matchp = p; |
||
| 780 | if (EQ(st, empty) || p == stop) |
||
| 781 | break; /* NOTE BREAK OUT */ |
||
| 782 | |||
| 783 | /* no, we must deal with this character */ |
||
| 784 | ASSIGN(tmp, st); |
||
| 785 | ASSIGN(st, empty); |
||
| 786 | assert(c != OUT); |
||
| 787 | st = step(m->g, startst, stopst, tmp, c, st); |
||
| 788 | SP("saft", st, c); |
||
| 789 | assert(EQ(step(m->g, startst, stopst, st, NOTHING, st), st)); |
||
| 790 | p++; |
||
| 791 | } |
||
| 792 | |||
| 793 | return(matchp); |
||
| 794 | } |
||
| 795 | |||
| 796 | |||
| 797 | /* |
||
| 798 | - step - map set of states reachable before char to set reachable after |
||
| 799 | == static states step(register struct re_guts *g, sopno start, sopno stop, \ |
||
| 800 | == register states bef, int ch, register states aft); |
||
| 801 | == #define BOL (OUT+1) |
||
| 802 | == #define EOL (BOL+1) |
||
| 803 | == #define BOLEOL (BOL+2) |
||
| 804 | == #define NOTHING (BOL+3) |
||
| 805 | == #define BOW (BOL+4) |
||
| 806 | == #define EOW (BOL+5) |
||
| 807 | == #define CODEMAX (BOL+5) // highest code used |
||
| 808 | == #define NONCHAR(c) ((c) > CHAR_MAX) |
||
| 809 | == #define NNONCHAR (CODEMAX-CHAR_MAX) |
||
| 810 | */ |
||
| 811 | static states |
||
| 812 | step(g, start, stop, bef, ch, aft) |
||
| 813 | register struct re_guts *g; |
||
| 814 | sopno start; /* start state within strip */ |
||
| 815 | sopno stop; /* state after stop state within strip */ |
||
| 816 | register states bef; /* states reachable before */ |
||
| 817 | int ch; /* character or NONCHAR code */ |
||
| 818 | register states aft; /* states already known reachable after */ |
||
| 819 | { |
||
| 820 | register cset *cs; |
||
| 821 | register sop s; |
||
| 822 | register sopno pc; |
||
| 823 | register onestate here; /* note, macros know this name */ |
||
| 824 | register sopno look; |
||
| 825 | register int i; |
||
| 826 | |||
| 827 | for (pc = start, INIT(here, pc); pc != stop; pc++, INC(here)) { |
||
| 828 | s = g->strip[pc]; |
||
| 829 | switch (OP(s)) { |
||
| 830 | case OEND: |
||
| 831 | assert(pc == stop-1); |
||
| 832 | break; |
||
| 833 | case OCHAR: |
||
| 834 | /* only characters can match */ |
||
| 835 | assert(!NONCHAR(ch) || ch != (char)OPND(s)); |
||
| 836 | if (ch == (char)OPND(s)) |
||
| 837 | FWD(aft, bef, 1); |
||
| 838 | break; |
||
| 839 | case OBOL: |
||
| 840 | if (ch == BOL || ch == BOLEOL) |
||
| 841 | FWD(aft, bef, 1); |
||
| 842 | break; |
||
| 843 | case OEOL: |
||
| 844 | if (ch == EOL || ch == BOLEOL) |
||
| 845 | FWD(aft, bef, 1); |
||
| 846 | break; |
||
| 847 | case OBOW: |
||
| 848 | if (ch == BOW) |
||
| 849 | FWD(aft, bef, 1); |
||
| 850 | break; |
||
| 851 | case OEOW: |
||
| 852 | if (ch == EOW) |
||
| 853 | FWD(aft, bef, 1); |
||
| 854 | break; |
||
| 855 | case OANY: |
||
| 856 | if (!NONCHAR(ch)) |
||
| 857 | FWD(aft, bef, 1); |
||
| 858 | break; |
||
| 859 | case OANYOF: |
||
| 860 | cs = &g->sets[OPND(s)]; |
||
| 861 | if (!NONCHAR(ch) && CHIN(cs, ch)) |
||
| 862 | FWD(aft, bef, 1); |
||
| 863 | break; |
||
| 864 | case OBACK_: /* ignored here */ |
||
| 865 | case O_BACK: |
||
| 866 | FWD(aft, aft, 1); |
||
| 867 | break; |
||
| 868 | case OPLUS_: /* forward, this is just an empty */ |
||
| 869 | FWD(aft, aft, 1); |
||
| 870 | break; |
||
| 871 | case O_PLUS: /* both forward and back */ |
||
| 872 | FWD(aft, aft, 1); |
||
| 873 | i = ISSETBACK(aft, OPND(s)); |
||
| 874 | BACK(aft, aft, OPND(s)); |
||
| 875 | if (!i && ISSETBACK(aft, OPND(s))) { |
||
| 876 | /* oho, must reconsider loop body */ |
||
| 877 | pc -= OPND(s) + 1; |
||
| 878 | INIT(here, pc); |
||
| 879 | } |
||
| 880 | break; |
||
| 881 | case OQUEST_: /* two branches, both forward */ |
||
| 882 | FWD(aft, aft, 1); |
||
| 883 | FWD(aft, aft, OPND(s)); |
||
| 884 | break; |
||
| 885 | case O_QUEST: /* just an empty */ |
||
| 886 | FWD(aft, aft, 1); |
||
| 887 | break; |
||
| 888 | case OLPAREN: /* not significant here */ |
||
| 889 | case ORPAREN: |
||
| 890 | FWD(aft, aft, 1); |
||
| 891 | break; |
||
| 892 | case OCH_: /* mark the first two branches */ |
||
| 893 | FWD(aft, aft, 1); |
||
| 894 | assert(OP(g->strip[pc+OPND(s)]) == OOR2); |
||
| 895 | FWD(aft, aft, OPND(s)); |
||
| 896 | break; |
||
| 897 | case OOR1: /* done a branch, find the O_CH */ |
||
| 898 | if (ISSTATEIN(aft, here)) { |
||
| 899 | for (look = 1; |
||
| 900 | OP(s = g->strip[pc+look]) != O_CH; |
||
| 901 | look += OPND(s)) |
||
| 902 | assert(OP(s) == OOR2); |
||
| 903 | FWD(aft, aft, look); |
||
| 904 | } |
||
| 905 | break; |
||
| 906 | case OOR2: /* propagate OCH_'s marking */ |
||
| 907 | FWD(aft, aft, 1); |
||
| 908 | if (OP(g->strip[pc+OPND(s)]) != O_CH) { |
||
| 909 | assert(OP(g->strip[pc+OPND(s)]) == OOR2); |
||
| 910 | FWD(aft, aft, OPND(s)); |
||
| 911 | } |
||
| 912 | break; |
||
| 913 | case O_CH: /* just empty */ |
||
| 914 | FWD(aft, aft, 1); |
||
| 915 | break; |
||
| 916 | default: /* ooooops... */ |
||
| 917 | assert(nope); |
||
| 918 | break; |
||
| 919 | } |
||
| 920 | } |
||
| 921 | |||
| 922 | return(aft); |
||
| 923 | } |
||
| 924 | |||
| 925 | #ifdef REDEBUG |
||
| 926 | /* |
||
| 927 | - print - print a set of states |
||
| 928 | == #ifdef REDEBUG |
||
| 929 | == static void print(struct match *m, char *caption, states st, \ |
||
| 930 | == int ch, FILE *d); |
||
| 931 | == #endif |
||
| 932 | */ |
||
| 933 | static void |
||
| 934 | print(m, caption, st, ch, d) |
||
| 935 | struct match *m; |
||
| 936 | char *caption; |
||
| 937 | states st; |
||
| 938 | int ch; |
||
| 939 | FILE *d; |
||
| 940 | { |
||
| 941 | register struct re_guts *g = m->g; |
||
| 942 | register int i; |
||
| 943 | register int first = 1; |
||
| 944 | |||
| 945 | if (!(m->eflags®_TRACE)) |
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| 946 | return; |
||
| 947 | |||
| 948 | fprintf(d, "%s", caption); |
||
| 949 | if (ch != '\0') |
||
| 950 | fprintf(d, " %s", pchar(ch)); |
||
| 951 | for (i = 0; i < g->nstates; i++) |
||
| 952 | if (ISSET(st, i)) { |
||
| 953 | fprintf(d, "%s%d", (first) ? "\t" : ", ", i); |
||
| 954 | first = 0; |
||
| 955 | } |
||
| 956 | fprintf(d, "\n"); |
||
| 957 | } |
||
| 958 | |||
| 959 | /* |
||
| 960 | - at - print current situation |
||
| 961 | == #ifdef REDEBUG |
||
| 962 | == static void at(struct match *m, char *title, char *start, char *stop, \ |
||
| 963 | == sopno startst, sopno stopst); |
||
| 964 | == #endif |
||
| 965 | */ |
||
| 966 | static void |
||
| 967 | at(m, title, start, stop, startst, stopst) |
||
| 968 | struct match *m; |
||
| 969 | char *title; |
||
| 970 | char *start; |
||
| 971 | char *stop; |
||
| 972 | sopno startst; |
||
| 973 | sopno stopst; |
||
| 974 | { |
||
| 975 | if (!(m->eflags®_TRACE)) |
||
| 976 | return; |
||
| 977 | |||
| 978 | printf("%s %s-", title, pchar(*start)); |
||
| 979 | printf("%s ", pchar(*stop)); |
||
| 980 | printf("%ld-%ld\n", (long)startst, (long)stopst); |
||
| 981 | } |
||
| 982 | |||
| 983 | #ifndef PCHARDONE |
||
| 984 | #define PCHARDONE /* never again */ |
||
| 985 | /* |
||
| 986 | - pchar - make a character printable |
||
| 987 | == #ifdef REDEBUG |
||
| 988 | == static char *pchar(int ch); |
||
| 989 | == #endif |
||
| 990 | * |
||
| 991 | * Is this identical to regchar() over in debug.c? Well, yes. But a |
||
| 992 | * duplicate here avoids having a debugging-capable regexec.o tied to |
||
| 993 | * a matching debug.o, and this is convenient. It all disappears in |
||
| 994 | * the non-debug compilation anyway, so it doesn't matter much. |
||
| 995 | */ |
||
| 996 | static char * /* -> representation */ |
||
| 997 | pchar(ch) |
||
| 998 | int ch; |
||
| 999 | { |
||
| 1000 | static char pbuf[10]; |
||
| 1001 | |||
| 1002 | if (isprint(ch) || ch == ' ') |
||
| 1003 | sprintf(pbuf, "%c", ch); |
||
| 1004 | else |
||
| 1005 | sprintf(pbuf, "\\%o", ch); |
||
| 1006 | return(pbuf); |
||
| 1007 | } |
||
| 1008 | #endif |
||
| 1009 | #endif |
||
| 1010 | |||
| 1011 | #undef matcher |
||
| 1012 | #undef fast |
||
| 1013 | #undef slow |
||
| 1014 | #undef dissect |
||
| 1015 | #undef backref |
||
| 1016 | #undef step |
||
| 1017 | #undef print |
||
| 1018 | #undef at |
||
| 1019 | #undef match |