fa *mkdfa(const char *s, int anchor) /* does the real work of making a dfa */ /* anchor = 1 for anchored matches, else 0 */ { Node *p, *p1; fa *f; p = reparse(s); p1 = op2(CAT, op2(STAR, op2(ALL, NIL, NIL), NIL), p); /* put ALL STAR in front of reg. exp. */ p1 = op2(CAT, p1, op2(FINAL, NIL, NIL)); /* put FINAL after reg. exp. */ poscnt = 0; penter(p1); /* enter parent pointers and leaf indices */ if ((f = (fa *) calloc(1, sizeof(fa) + poscnt*sizeof(rrow))) == NULL) overflo("out of space for fa"); f->accept = poscnt-1; /* penter has computed number of positions in re */ cfoll(f, p1); /* set up follow sets */ freetr(p1); if ((f->posns[0] = (int *) calloc(1, *(f->re[0].lfollow)*sizeof(int))) == NULL) overflo("out of space in makedfa"); if ((f->posns[1] = (int *) calloc(1, sizeof(int))) == NULL) overflo("out of space in makedfa"); *f->posns[1] = 0; f->initstat = makeinit(f, anchor); f->anchor = anchor; f->restr = (uschar *) tostring(s); return f; }
void freetr(Node *p) /* free parse tree */ { switch (type(p)) { LEAF xfree(p); break; UNARY freetr(left(p)); xfree(p); break; case CAT: case OR: freetr(left(p)); freetr(right(p)); xfree(p); break; default: /* can't happen */ ERROR "can't happen: unknown type %d in freetr", type(p) FATAL; break; } }