1: #include "defs"
   2: 
   3: 
   4: hide(p)
   5: ptr p;
   6: {
   7: warn1("Name %s hidden by a new declaration", p->namep);
   8: hidlist = mkchain(p->varp, hidlist);
   9: p->varp = 0;
  10: ++nhid[blklevel];
  11: }
  12: 
  13: 
  14: 
  15: /*  remove all symbol table entries in terminated block,
  16:     revive old hidden names
  17: */
  18: unhide()
  19: {
  20: chainp p;
  21: register ptr q;
  22: register ptr v;
  23: register struct stentry *s;
  24: struct stentry **hp;
  25: 
  26: for(hp = hashtab ; hp<hashend ; ++hp)
  27:     if(s = *hp)
  28:         {
  29:         if( (v = s->varp) && v->blklevel == blklevel)
  30:             {
  31:             if(v->tag==TLABEL)
  32:                 if(blklevel <= 1)
  33:                     {
  34:                     if(v->labdefined==0)
  35:                         laberr("%s never defined",
  36:                             v->sthead->namep);
  37:                     s->varp = 0;
  38:                     }
  39:                 else    { /* move label out a level */
  40:                     if(v->labdefined)
  41:                         v->labinacc = 1;
  42:                     v->blklevel--;
  43:                     ++ndecl[blklevel-1];
  44:                     }
  45:             else    {
  46:                 if(v->tag == TNAME)
  47:                     {
  48:                     TEST fprintf(diagfile,"gone(%s) level %d\n",
  49:                         s->namep, blklevel);
  50:                     gonelist = mkchain(s->varp, gonelist);
  51:                     }
  52: 
  53:                 else if(v->tag!=TSTRUCT)
  54:                     {
  55:                     ++ndecl[blklevel];
  56:                     if(v->tag==TDEFINE)
  57:                         frdef(v);
  58:                     }
  59:                 s->varp = 0;
  60:                 }
  61:             --ndecl[blklevel];
  62:             }
  63:         }
  64: 
  65: for( p=hidlist  ;  p && ((v = (q=p->datap)->sthead)->varp==NULL) ; p=hidlist )
  66:     {
  67:     v->varp = q;
  68:     v->tag = q->tag;
  69:     v->subtype = q->subtype;
  70:     if(v->blklevel > q->blklevel)
  71:         v->blklevel = q->blklevel;
  72:     hidlist = p->nextp;
  73:     p->nextp = CHNULL;
  74:     frchain(&p);
  75:     --nhid[blklevel];
  76: TEST fprintf(diagfile, "unhide(%s), blklevel %d\n", v->namep, v->blklevel);
  77:     }
  78: if(ndecl[blklevel] != 0)
  79:     {
  80:     sprintf(msg, "%d declarations leftover at block level %d",
  81:         ndecl[blklevel], blklevel);
  82:     fatal(msg);
  83:     }
  84: if(nhid[blklevel] != 0)
  85:     fatal("leftover hidden variables");
  86: }
  87: 
  88: 
  89: 
  90: 
  91: ptr bgnexec()
  92: {
  93: register ptr p;
  94: 
  95: p = allexcblock();
  96: p->tag = TEXEC;
  97: p->prevexec = thisexec;
  98: if(thisexec && thisexec->copylab)
  99:     {
 100:     p->labelno = thisexec->labelno;
 101:     p->labused = thisexec->labused;
 102:     thisexec->labelno = 0;
 103:     }
 104: thisexec = p;
 105: return(p);
 106: }
 107: 
 108: 
 109: ptr addexec()
 110: {
 111: register ptr p;
 112: register ptr q;
 113: 
 114: q = thisexec;
 115: p = q->prevexec;
 116: 
 117: if(q->temps)
 118:     tempvarlist = hookup(q->temps, tempvarlist);
 119: 
 120: p->brnchend = q->brnchend;
 121: p->nftnst += q->nftnst;
 122: p->labeled |= q->labeled;
 123: p->uniffable |= q->uniffable;
 124: 
 125: if(q->labelno && !(q->labused))
 126:     {
 127:     if(q->nxtlabno)
 128:         exnull();
 129:     else q->nxtlabno = q->labelno;
 130:     }
 131: 
 132: thisexec = p;
 133: 
 134: if(q->nxtlabno)
 135:     {
 136:     if(p->labelno && !(p->labused))
 137:         exnull();
 138:     p->labelno = q->nxtlabno;
 139:     p->labused = 0;
 140:     }
 141: 
 142: frexcblock(q);
 143: return(p);
 144: }
 145: 
 146: 
 147: 
 148: pushctl(t,vp)
 149: int t;
 150: register ptr vp;
 151: {
 152: register ptr q;
 153: ptr p;
 154: int junk;
 155: 
 156: q = allexcblock();
 157: q->tag = TCONTROL;
 158: q->subtype = t;
 159: q->loopvar = vp;
 160: q->prevctl = thisctl;
 161: thisctl = q;
 162: 
 163: switch(t)
 164:     {
 165:     case STSWITCH:
 166:         q->xlab = nextlab();
 167:         q->nextlab = 0;
 168:         exgoto(q->xlab);
 169:         ncases = -1;
 170:         break;
 171: 
 172:     case STFOR:
 173:         exlab(0);
 174:         q->nextlab = nextlab();
 175:         q->xlab = nextlab();
 176:         break;
 177: 
 178:     case STWHILE:
 179:         q->nextlab = thislab();
 180:         if(vp)
 181:             exifgo( mknode(TNOTOP,OPNOT,vp,PNULL),
 182:                 q->breaklab = nextlab() );
 183:         else    thisexec->copylab = 1;
 184:         break;
 185: 
 186:     case STREPEAT:
 187:         exnull();
 188:         q->xlab = thislab();
 189:         thisexec->copylab = 1;
 190:         junk = nextindif();
 191:         indifs[junk] = 0;
 192:         q->indifn = junk;
 193:         indifs[q->indifn] = q->xlab;
 194:         break;
 195: 
 196:     case STDO:
 197:         q->nextlab = nextlab();
 198:         exlab(0);
 199:         putic(ICKEYWORD,FDO);
 200:         putic(ICLABEL, q->nextlab);
 201:         putic(ICBLANK, 1);
 202:         p = mknode(TASGNOP,OPASGN,vp->dovar,vp->dopar[0]);
 203:         prexpr(p);
 204:         frexpr(p);
 205:         putic(ICOP, OPCOMMA);
 206:         prexpr(vp->dopar[1]);
 207:         frexpr(vp->dopar[1]);
 208:         if(vp->dopar[2])
 209:             {
 210:             putic(ICOP, OPCOMMA);
 211:             prexpr(vp->dopar[2]);
 212:             frexpr(vp->dopar[2]);
 213:             }
 214:         cfree(vp);
 215:         break;
 216: 
 217:     case STIF:
 218:         exif(vp);
 219:         thisexec->nftnst = 0;
 220:         break;
 221: 
 222:     default:
 223:         fatal1("pushctl: invalid control block type %d", t);
 224:     }
 225: 
 226: ++ctllevel;
 227: }
 228: 
 229: 
 230: 
 231: popctl()
 232: {
 233: register ptr p;
 234: ptr newp;
 235: chainp q;
 236: int first, deflabno, blab, cmin, cmax, range, caseval, optcase;
 237: int labp[MAXSWITCH];
 238: 
 239: if(thisctl == 0)
 240:     fatal("empty control stack popped");
 241: 
 242: switch(thisctl->subtype)
 243:     {
 244:     case STSWITCH:
 245: /*		if(thisexec->brnchend == 0)	*/
 246:             {
 247:             if(thisctl->breaklab == 0)
 248:                 thisctl->breaklab = nextlab();
 249:             exgoto(thisctl->breaklab);
 250:             }
 251:         exlab(thisctl->xlab);
 252:         deflabno = 0;
 253:         first = YES;
 254:         optcase = (thisctl->loopvar->vtype == TYINT);
 255: 
 256:         for(p=thisctl->loopctl ; p!=0 ; p = p->nextcase)
 257:             if(p->labdefined == 0)
 258:                 {
 259:                 laberr("undefined case label", CNULL);
 260:                 optcase = NO;
 261:                 }
 262:             else if(p->casexpr == 0)
 263:                 deflabno = p->labelno;
 264:             else if( isicon(p->casexpr, &caseval))
 265:                 {
 266:                 if(first)
 267:                     {
 268:                     first = NO;
 269:                     cmin = cmax = caseval;
 270:                     }
 271:                 else    {
 272:                     if(caseval < cmin)
 273:                         cmin = caseval;
 274:                     if(caseval > cmax)
 275:                         cmax = caseval;
 276:                     }
 277:                 ++ncases;
 278:                 }
 279:             else    optcase = NO;
 280: 
 281:         range = cmax - cmin + 1;
 282:         if(optcase && ncases>2 && range<2*ncases && range<MAXSWITCH)
 283:             {
 284:             register int i;
 285:             for(i=0; i<range ; ++i)
 286:                 labp[i] = 0;
 287:             for(p=thisctl->loopctl ; p!=0 ; p = p->nextcase)
 288:                 if(p->labdefined && p->casexpr)
 289:                     {
 290:                     isicon(p->casexpr, &caseval);
 291:                     frexpr(p->casexpr);
 292:                     labp[caseval-cmin] = p->labelno;
 293:                     }
 294: 
 295:             q = CHNULL;
 296:             blab = (deflabno ? deflabno : thisctl->breaklab);
 297:             for(i=range-1 ; i>=0 ; --i)
 298:                 q = mkchain(labp[i] ? labp[i] : blab, q);
 299:             excompgoto(q, mknode(TAROP,OPPLUS, mkint(1-cmin),
 300:                      cpexpr(thisctl->loopvar) ));
 301:             }
 302:         else    {
 303:             for(p=thisctl->loopctl ; p!=0 ; p = p->nextcase)
 304:                 if(p->labdefined && p->casexpr)
 305:                     exifgo( mknode(TRELOP,OPEQ,
 306:                        cpexpr(thisctl->loopvar),p->casexpr),
 307:                        p->labelno);
 308:             }
 309:         if(deflabno)
 310:             exgoto(deflabno);
 311: 
 312:         for(p = thisctl->loopctl ; p; p = newp)
 313:             {
 314:             newp = p->nextcase;
 315:             cfree(p);
 316:             }
 317:         thisctl->loopctl = NULL;
 318:         break;
 319: 
 320:     case STFOR:
 321:         exgoto(thisctl->nextlab);
 322:         break;
 323: 
 324:     case STWHILE:
 325:         exgoto(thisctl->nextlab);
 326:         break;
 327: 
 328:     case STREPEAT:
 329:         break;
 330: 
 331:     case STDO:
 332:         exnull();
 333:         exlab(thisctl->nextlab);
 334:         putic(ICKEYWORD,FCONTINUE);
 335:         break;
 336: 
 337:     case STIF:
 338:         break;
 339: 
 340:     case STPROC:
 341:         break;
 342: 
 343:     default:
 344:         fatal1("popctl: invalid control block type %d",
 345:             thisctl->subtype);
 346:     }
 347: 
 348: if(thisctl->breaklab != 0)
 349:     thisexec->nxtlabno = thisctl->breaklab;
 350: p = thisctl->prevctl;
 351: frexcblock(thisctl);
 352: thisctl = p;
 353: --ctllevel;
 354: }

Defined functions

addexec defined in line 109; used 4 times
hide defined in line 4; used 2 times
popctl defined in line 231; used 1 times
pushctl defined in line 148; used 1 times
unhide defined in line 18; used 2 times
Last modified: 1982-06-09
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