ref: 12e226ac6798412271020d42645f69138715c519
dir: /utils/libregexp/rregexec.c/
#include <lib9.h> #include "regexp.h" #include "regcomp.h" /* * return 0 if no match * >0 if a match * <0 if we ran out of _relist space */ static int rregexec1(Reprog *progp, /* program to run */ Rune *bol, /* string to run machine on */ Resub *mp, /* subexpression elements */ int ms, /* number of elements at mp */ Reljunk *j) { int flag=0; Reinst *inst; Relist *tlp; Rune *s; int i, checkstart; Rune r, *rp, *ep; Relist* tl; /* This list, next list */ Relist* nl; Relist* tle; /* ends of this and next list */ Relist* nle; int match; match = 0; checkstart = j->startchar; if(mp) for(i=0; i<ms; i++) { mp[i].s.rsp = 0; mp[i].e.rep = 0; } j->relist[0][0].inst = 0; j->relist[1][0].inst = 0; /* Execute machine once for each character, including terminal NUL */ s = j->rstarts; do{ /* fast check for first char */ if(checkstart) { switch(j->starttype) { case RUNE: while(*s != j->startchar) { if(*s == 0 || s == j->reol) return match; s++; } break; case BOL: if(s == bol) break; while(*s != '\n') { if(*s == 0 || s == j->reol) return match; s++; } break; } } r = *s; /* switch run lists */ tl = j->relist[flag]; tle = j->reliste[flag]; nl = j->relist[flag^=1]; nle = j->reliste[flag]; nl->inst = 0; /* Add first instruction to current list */ _rrenewemptythread(tl, progp->startinst, s); /* Execute machine until current list is empty */ for(tlp=tl; tlp->inst; tlp++){ for(inst=tlp->inst; ; inst = inst->u2.next){ switch(inst->type){ case RUNE: /* regular character */ if(inst->u1.r == r) if(_renewthread(nl, inst->u2.next, &tlp->se)==nle) return -1; break; case LBRA: tlp->se.m[inst->u1.subid].s.rsp = s; continue; case RBRA: tlp->se.m[inst->u1.subid].e.rep = s; continue; case ANY: if(r != '\n') if(_renewthread(nl, inst->u2.next, &tlp->se)==nle) return -1; break; case ANYNL: if(_renewthread(nl, inst->u2.next, &tlp->se)==nle) return -1; break; case BOL: if(s == bol || *(s-1) == '\n') continue; break; case EOL: if(s == j->reol || r == 0 || r == '\n') continue; break; case CCLASS: ep = inst->u1.cp->end; for(rp = inst->u1.cp->spans; rp < ep; rp += 2) if(r >= rp[0] && r <= rp[1]){ if(_renewthread(nl, inst->u2.next, &tlp->se)==nle) return -1; break; } break; case NCCLASS: ep = inst->u1.cp->end; for(rp = inst->u1.cp->spans; rp < ep; rp += 2) if(r >= rp[0] && r <= rp[1]) break; if(rp == ep) if(_renewthread(nl, inst->u2.next, &tlp->se)==nle) return -1; break; case OR: /* evaluate right choice later */ if(_renewthread(tlp, inst->u1.right, &tlp->se) == tle) return -1; /* efficiency: advance and re-evaluate */ continue; case END: /* Match! */ match = 1; tlp->se.m[0].e.rep = s; if(mp != 0) _renewmatch(mp, ms, &tlp->se); break; } break; } } if(s == j->reol) break; checkstart = j->startchar && nl->inst==0; s++; }while(r); return match; } static int rregexec2(Reprog *progp, /* program to run */ Rune *bol, /* string to run machine on */ Resub *mp, /* subexpression elements */ int ms, /* number of elements at mp */ Reljunk *j ) { Relist relist0[5*LISTSIZE], relist1[5*LISTSIZE]; /* mark space */ j->relist[0] = relist0; j->relist[1] = relist1; j->reliste[0] = relist0 + nelem(relist0) - 2; j->reliste[1] = relist1 + nelem(relist1) - 2; return rregexec1(progp, bol, mp, ms, j); } extern int rregexec(Reprog *progp, /* program to run */ Rune *bol, /* string to run machine on */ Resub *mp, /* subexpression elements */ int ms) /* number of elements at mp */ { Reljunk j; Relist relist0[LISTSIZE], relist1[LISTSIZE]; int rv; /* * use user-specified starting/ending location if specified */ j.rstarts = bol; j.reol = 0; if(mp && ms>0){ if(mp->s.sp) j.rstarts = mp->s.rsp; if(mp->e.ep) j.reol = mp->e.rep; } j.starttype = 0; j.startchar = 0; if(progp->startinst->type == RUNE && progp->startinst->u1.r < (Rune)Runeself) { j.starttype = RUNE; j.startchar = progp->startinst->u1.r; } if(progp->startinst->type == BOL) j.starttype = BOL; /* mark space */ j.relist[0] = relist0; j.relist[1] = relist1; j.reliste[0] = relist0 + nelem(relist0) - 2; j.reliste[1] = relist1 + nelem(relist1) - 2; rv = rregexec1(progp, bol, mp, ms, &j); if(rv >= 0) return rv; rv = rregexec2(progp, bol, mp, ms, &j); if(rv >= 0) return rv; return -1; }