1 /*
2 * fset2.c
3 *
4 * Compute FIRST sets for full LL(k)
5 *
6 * SOFTWARE RIGHTS
7 *
8 * We reserve no LEGAL rights to the Purdue Compiler Construction Tool
9 * Set (PCCTS) -- PCCTS is in the public domain. An individual or
10 * company may do whatever they wish with source code distributed with
11 * PCCTS or the code generated by PCCTS, including the incorporation of
12 * PCCTS, or its output, into commerical software.
13 *
14 * We encourage users to develop software with PCCTS. However, we do ask
15 * that credit is given to us for developing PCCTS. By "credit",
16 * we mean that if you incorporate our source code into one of your
17 * programs (commercial product, research project, or otherwise) that you
18 * acknowledge this fact somewhere in the documentation, research report,
19 * etc... If you like PCCTS and have developed a nice tool with the
20 * output, please mention that you developed it using PCCTS. In
21 * addition, we ask that this header remain intact in our source code.
22 * As long as these guidelines are kept, we expect to continue enhancing
23 * this system and expect to make other tools available as they are
24 * completed.
25 *
26 * ANTLR 1.33
27 * Terence Parr
28 * Parr Research Corporation
29 * with Purdue University and AHPCRC, University of Minnesota
30 * 1989-2001
31 */
32
33 #include <stdio.h>
34 #include "pcctscfg.h"
35 #include <stdlib.h>
36
37 #ifdef PCCTS_USE_STDARG
38 #include <stdarg.h>
39 #else
40 #include <varargs.h>
41 #endif
42
43 #include "set.h"
44 #include "syn.h"
45 #include "hash.h"
46 #include "generic.h"
47 #include "dlgdef.h"
48
49 /* ick! globals. Used by permute() to track which elements of a set have been used */
50
51 static int *findex;
52 set *fset; /* MR11 make global */
53 static unsigned **ftbl;
54 static set *constrain; /* pts into fset. constrains tToken() to 'constrain' */
55 int ConstrainSearch;
56 int maxk; /* set to initial k upon tree construction request */
57 /* MR11 make global */
58 static Tree *FreeList = NULL;
59
60 #ifdef __USE_PROTOS
61 static int tmember_of_context(Tree *, Predicate *);
62 #else
63 static int tmember_of_context();
64 #endif
65
66 #if TREE_DEBUG
67 set set_of_tnodes_in_use;
68 int stop_on_tnode_seq_number=(-1); /* (-1) to disable */
69 #endif
70
71 /* Do root
72 * Then each sibling
73 */
74
75 void
76 #ifdef __USE_PROTOS
preorder(Tree * tree)77 preorder( Tree *tree )
78 #else
79 preorder( tree )
80 Tree *tree;
81 #endif
82 {
83 if ( tree == NULL ) return;
84 if ( tree->down != NULL ) fprintf(stderr, " (");
85 if ( tree->token == ALT ) fprintf(stderr, " ALT");
86 else fprintf(stderr, " %s", TerminalString(tree->token));
87 if ( tree->token==EpToken ) fprintf(stderr, "(%d)", tree->v.rk);
88 preorder(tree->down);
89 if ( tree->down != NULL ) fprintf(stderr, " )");
90 preorder(tree->right);
91 }
92
93 #ifdef __USE_PROTOS
MR_tree_matches_constraints(int k,set * constrain,Tree * t)94 int MR_tree_matches_constraints(int k,set * constrain,Tree *t)
95 #else
96 int MR_tree_matches_constraints(k,constrain,t)
97 int k;
98 set * constrain;
99 Tree * t;
100 #endif
101 {
102 int i;
103 Tree *u;
104
105 if (k == 0) return 1;
106
107 /* for testing guard predicates: if the guard tree is shorter
108 than the constraint then it is a match. The reason is that
109 a guard of (A B) should be equivalent to a guard of (A B . . .)
110 where "." matches every token. Thus a match which runs out
111 of tree before constraint is a match.
112 */
113
114 if (t == NULL) return 1;
115 require (set_deg(constrain[0]) == 1,
116 "MR_tree_matches_constraints: set_deg != 1");
117 i=set_int(constrain[0]);
118 if (t->token != i) return 0;
119 if (k-1 == 0) return 1;
120 for (u=t->down; u != NULL; u=u->right) {
121 if (MR_tree_matches_constraints(k-1,&constrain[1],u)) {
122 return 1;
123 };
124 };
125 return 0;
126 }
127
128 /* check the depth of each primary sibling to see that it is exactly
129 * k deep. e.g.;
130 *
131 * ALT
132 * |
133 * A ------- B
134 * | |
135 * C -- D E
136 *
137 * Remove all branches <= k deep.
138 *
139 * Added by TJP 9-23-92 to make the LL(k) constraint mechanism to work.
140 */
141
142 static int pruneCount=0;
143 static int prunePeak=200;
144
145 Tree *
146 #ifdef __USE_PROTOS
prune(Tree * t,int k)147 prune( Tree *t, int k )
148 #else
149 prune( t, k )
150 Tree *t;
151 int k;
152 #endif
153 {
154 pruneCount++;
155 if (pruneCount > prunePeak+100) {
156 prunePeak=pruneCount;
157 #if 0
158 *** fprintf(stderr,"pruneCount=%d\n",pruneCount);
159 /*** preorder(t); ***/
160 *** fprintf(stderr,"\n",pruneCount);
161 #endif
162 };
163 if ( t == NULL ) {
164 pruneCount--;
165 return NULL;
166 };
167 if ( t->token == ALT ) fatal_internal("prune: ALT node in FIRST tree");
168 if ( t->right!=NULL ) t->right = prune(t->right, k);
169 if ( k>1 )
170 {
171 if ( t->down!=NULL ) t->down = prune(t->down, k-1);
172 if ( t->down == NULL )
173 {
174 Tree *r = t->right;
175 t->right = NULL;
176 Tfree(t);
177 pruneCount--;
178 return r;
179 }
180 }
181 pruneCount--;
182 return t;
183 }
184
185 /* build a tree (root child1 child2 ... NULL) */
186 #ifdef PCCTS_USE_STDARG
tmake(Tree * root,...)187 Tree *tmake(Tree *root, ...)
188 #else
189 Tree *tmake(va_alist)
190 va_dcl
191 #endif
192 {
193 Tree *w;
194 va_list ap;
195 Tree *child, *sibling=NULL, *tail=NULL;
196 #ifndef PCCTS_USE_STDARG
197 Tree *root;
198 #endif
199
200 #ifdef PCCTS_USE_STDARG
201 va_start(ap, root);
202 #else
203 va_start(ap);
204 root = va_arg(ap, Tree *);
205 #endif
206 child = va_arg(ap, Tree *);
207 while ( child != NULL )
208 {
209 #ifdef DUM
210 /* added "find end of child" thing TJP March 1994 */
211 for (w=child; w->right!=NULL; w=w->right) {;} /* find end of child */
212 #else
213 w = child;
214 #endif
215
216 if ( sibling == NULL ) {sibling = child; tail = w;}
217 else {tail->right = child; tail = w;}
218 child = va_arg(ap, Tree *);
219 }
220
221 /* was "root->down = sibling;" */
222 if ( root==NULL ) root = sibling;
223 else root->down = sibling;
224
225 va_end(ap);
226 return root;
227 }
228
229 Tree *
230 #ifdef __USE_PROTOS
tnode(int tok)231 tnode( int tok )
232 #else
233 tnode( tok )
234 int tok;
235 #endif
236 {
237 Tree *p, *newblk;
238 static int n=0;
239
240 if ( FreeList == NULL )
241 {
242 /*fprintf(stderr, "tnode: %d more nodes\n", TreeBlockAllocSize);*/
243 if ( TreeResourceLimit > 0 )
244 {
245 if ( (n+TreeBlockAllocSize) >= TreeResourceLimit )
246 {
247 fprintf(stderr, ErrHdr, FileStr[CurAmbigfile], CurAmbigline);
248 fprintf(stderr, " hit analysis resource limit while analyzing alts %d and %d %s\n",
249 CurAmbigAlt1,
250 CurAmbigAlt2,
251 CurAmbigbtype);
252 exit(PCCTS_EXIT_FAILURE);
253 }
254 }
255 newblk = (Tree *)calloc(TreeBlockAllocSize, sizeof(Tree));
256 if ( newblk == NULL )
257 {
258 fprintf(stderr, ErrHdr, FileStr[CurAmbigfile], CurAmbigline);
259 fprintf(stderr, " out of memory while analyzing alts %d and %d %s\n",
260 CurAmbigAlt1,
261 CurAmbigAlt2,
262 CurAmbigbtype);
263 exit(PCCTS_EXIT_FAILURE);
264 }
265 n += TreeBlockAllocSize;
266 for (p=newblk; p<&(newblk[TreeBlockAllocSize]); p++)
267 {
268 p->right = FreeList; /* add all new Tree nodes to Free List */
269 FreeList = p;
270 }
271 }
272 p = FreeList;
273 FreeList = FreeList->right; /* remove a tree node */
274 p->right = NULL; /* zero out ptrs */
275 p->down = NULL;
276 p->token = tok;
277
278 TnodesAllocated++; /* MR10 */
279 TnodesInUse++; /* MR10 */
280 if (TnodesInUse > TnodesPeak) TnodesPeak=TnodesInUse; /* MR10 */
281
282 #ifdef TREE_DEBUG
283 require(!p->in_use, "tnode: node in use!");
284 p->in_use = 1;
285 p->seq=TnodesAllocated;
286 set_orel( (unsigned) TnodesAllocated,&set_of_tnodes_in_use);
287 if (stop_on_tnode_seq_number == p->seq) {
288 fprintf(stderr,"\n*** just allocated tnode #%d ***\n",
289 stop_on_tnode_seq_number);
290 };
291 #endif
292 return p;
293 }
294
295 static Tree *
296 #ifdef __USE_PROTOS
eofnode(int k)297 eofnode( int k )
298 #else
299 eofnode( k )
300 int k;
301 #endif
302 {
303 Tree *t=NULL;
304 int i;
305
306 for (i=1; i<=k; i++)
307 {
308 t = tmake(tnode((TokenInd!=NULL?TokenInd[EofToken]:EofToken)), t, NULL);
309 }
310 return t;
311 }
312
313
314
315 void
316 #ifdef __USE_PROTOS
_Tfree(Tree * t)317 _Tfree( Tree *t )
318 #else
319 _Tfree( t )
320 Tree *t;
321 #endif
322 {
323 if ( t!=NULL )
324 {
325 #ifdef TREE_DEBUG
326 if (t->seq == stop_on_tnode_seq_number) {
327 fprintf(stderr,"\n*** just freed tnode #%d ***\n",t->seq);
328 };
329 require(t->in_use, "_Tfree: node not in use!");
330 t->in_use = 0;
331 set_rm( (unsigned) t->seq,set_of_tnodes_in_use);
332 #endif
333 t->right = FreeList;
334 FreeList = t;
335 TnodesInUse--; /* MR10 */
336 }
337 }
338
339 /* tree duplicate */
340 Tree *
341 #ifdef __USE_PROTOS
tdup(Tree * t)342 tdup( Tree *t )
343 #else
344 tdup( t )
345 Tree *t;
346 #endif
347 {
348 Tree *u;
349
350 if ( t == NULL ) return NULL;
351 u = tnode(t->token);
352 u->v.rk = t->v.rk;
353 u->right = tdup(t->right);
354 u->down = tdup(t->down);
355 return u;
356 }
357
358 /* tree duplicate (assume tree is a chain downwards) */
359 Tree *
360 #ifdef __USE_PROTOS
tdup_chain(Tree * t)361 tdup_chain( Tree *t )
362 #else
363 tdup_chain( t )
364 Tree *t;
365 #endif
366 {
367 Tree *u;
368
369 if ( t == NULL ) return NULL;
370 u = tnode(t->token);
371 u->v.rk = t->v.rk;
372 u->down = tdup(t->down);
373 return u;
374 }
375
376 Tree *
377 #ifdef __USE_PROTOS
tappend(Tree * t,Tree * u)378 tappend( Tree *t, Tree *u )
379 #else
380 tappend( t, u )
381 Tree *t;
382 Tree *u;
383 #endif
384 {
385 Tree *w;
386
387 /*** fprintf(stderr, "tappend(");
388 *** preorder(t); fprintf(stderr, ",");
389 *** preorder(u); fprintf(stderr, " )\n");
390 */
391 if ( t == NULL ) return u;
392 if ( t->token == ALT && t->right == NULL ) return tappend(t->down, u);
393 for (w=t; w->right!=NULL; w=w->right) {;}
394 w->right = u;
395 return t;
396 }
397
398 /* dealloc all nodes in a tree */
399 void
400 #ifdef __USE_PROTOS
Tfree(Tree * t)401 Tfree( Tree *t )
402 #else
403 Tfree( t )
404 Tree *t;
405 #endif
406 {
407 if ( t == NULL ) return;
408 Tfree( t->down );
409 Tfree( t->right );
410 _Tfree( t );
411 }
412
413 /* find all children (alts) of t that require remaining_k nodes to be LL_k
414 * tokens long.
415 *
416 * t-->o
417 * |
418 * a1--a2--...--an <-- LL(1) tokens
419 * | | |
420 * b1 b2 ... bn <-- LL(2) tokens
421 * | | |
422 * . . .
423 * . . .
424 * z1 z2 ... zn <-- LL(LL_k) tokens
425 *
426 * We look for all [Ep] needing remaining_k nodes and replace with u.
427 * u is not destroyed or actually used by the tree (a copy is made).
428 */
429 Tree *
430 #ifdef __USE_PROTOS
tlink(Tree * t,Tree * u,int remaining_k)431 tlink( Tree *t, Tree *u, int remaining_k )
432 #else
433 tlink( t, u, remaining_k )
434 Tree *t;
435 Tree *u;
436 int remaining_k;
437 #endif
438 {
439 Tree *p;
440 require(remaining_k!=0, "tlink: bad tree");
441
442 if ( t==NULL ) return NULL;
443 /*fprintf(stderr, "tlink: u is:"); preorder(u); fprintf(stderr, "\n");*/
444 if ( t->token == EpToken && t->v.rk == remaining_k )
445 {
446 require(t->down==NULL, "tlink: invalid tree");
447 if ( u == NULL ) {
448 /* MR10 */ Tree *tt=t->right;
449 /* MR10 */ _Tfree(t);
450 /* MR10 */ return tt;
451 };
452 p = tdup( u );
453 p->right = t->right;
454 _Tfree( t );
455 return p;
456 }
457 t->down = tlink(t->down, u, remaining_k);
458 t->right = tlink(t->right, u, remaining_k);
459 return t;
460 }
461
462 /* remove as many ALT nodes as possible while still maintaining semantics */
463 Tree *
464 #ifdef __USE_PROTOS
tshrink(Tree * t)465 tshrink( Tree *t )
466 #else
467 tshrink( t )
468 Tree *t;
469 #endif
470 {
471 if ( t == NULL ) return NULL;
472 t->down = tshrink( t->down );
473 t->right = tshrink( t->right );
474 if ( t->down == NULL )
475 {
476 if ( t->token == ALT )
477 {
478 Tree *u = t->right;
479 _Tfree(t);
480 return u; /* remove useless alts */
481 }
482 return t;
483 }
484
485 /* (? (ALT (? ...)) s) ==> (? (? ...) s) where s = sibling, ? = match any */
486 if ( t->token == ALT && t->down->right == NULL)
487 {
488 Tree *u = t->down;
489 u->right = t->right;
490 _Tfree( t );
491 return u;
492 }
493 /* (? (A (ALT t)) s) ==> (? (A t) s) where A is a token; s,t siblings */
494 if ( t->token != ALT && t->down->token == ALT && t->down->right == NULL )
495 {
496 Tree *u = t->down->down;
497 _Tfree( t->down );
498 t->down = u;
499 return t;
500 }
501 return t;
502 }
503
504 Tree *
505 #ifdef __USE_PROTOS
tflatten(Tree * t)506 tflatten( Tree *t )
507 #else
508 tflatten( t )
509 Tree *t;
510 #endif
511 {
512 if ( t == NULL ) return NULL;
513 t->down = tflatten( t->down );
514 t->right = tflatten( t->right );
515 if ( t->down == NULL ) return t;
516
517 if ( t->token == ALT )
518 {
519 Tree *u;
520 /* find tail of children */
521 for (u=t->down; u->right!=NULL; u=u->right) {;}
522 u->right = t->right;
523 u = t->down;
524 _Tfree( t );
525 return u;
526 }
527 return t;
528 }
529
530 Tree *
531 #ifdef __USE_PROTOS
tJunc(Junction * p,int k,set * rk)532 tJunc( Junction *p, int k, set *rk )
533 #else
534 tJunc( p, k, rk )
535 Junction *p;
536 int k;
537 set *rk;
538 #endif
539 {
540 Tree *t=NULL, *u=NULL;
541 Junction *alt;
542 Tree *tail=NULL, *r;
543
544 #ifdef DBG_TRAV
545 fprintf(stderr, "tJunc(%d): %s in rule %s\n", k,
546 decodeJType[p->jtype], ((Junction *)p)->rname);
547 #endif
548
549 /* MR14 */ if (AlphaBetaTrace && p->alpha_beta_guess_end) {
550 /* MR14 */ warnFL(
551 /* MR14 */ "not possible to compute follow set for alpha in an \"(alpha)? beta\" block. ",
552 /* MR14 */ FileStr[p->file],p->line);
553 /* MR14 */ MR_alphaBetaTraceReport();
554 /* MR14 */ };
555
556 /* MR14 */ if (p->alpha_beta_guess_end) {
557 /* MR14 */ return NULL;
558 /* MR14 */ }
559
560 if ( p->jtype==aLoopBlk || p->jtype==RuleBlk ||
561 p->jtype==aPlusBlk || p->jtype==aSubBlk || p->jtype==aOptBlk )
562 {
563 if ( p->jtype!=aSubBlk && p->jtype!=aOptBlk ) {
564 require(p->lock!=NULL, "rJunc: lock array is NULL");
565 if ( p->lock[k] ) return NULL;
566 p->lock[k] = TRUE;
567 }
568
569 /* MR10 */ if (MR_MaintainBackTrace) {
570 /* MR10 */ if (p->jtype != Generic) MR_pointerStackPush(&MR_BackTraceStack,p);
571 /* MR10 */ };
572
573 TRAV(p->p1, k, rk, tail);
574
575 /* MR10 */ if (MR_MaintainBackTrace) {
576 /* MR10 */ if (p->jtype != Generic) MR_pointerStackPop(&MR_BackTraceStack);
577 /* MR10 */ };
578
579 if ( p->jtype==RuleBlk ) {p->lock[k] = FALSE; return tail;}
580 r = tmake(tnode(ALT), tail, NULL);
581 for (alt=(Junction *)p->p2; alt!=NULL; alt = (Junction *)alt->p2)
582 {
583 /* if this is one of the added optional alts for (...)+ then break */
584 if ( alt->ignore ) break;
585
586 if ( tail==NULL ) {TRAV(alt->p1, k, rk, tail); r->down = tail;}
587 else
588 {
589 /* MR10 */ if (MR_MaintainBackTrace) {
590 /* MR10 */ if (p->jtype != Generic) MR_pointerStackPush(&MR_BackTraceStack,p);
591 /* MR10 */ };
592
593 TRAV(alt->p1, k, rk, tail->right);
594
595 /* MR10 */ if (MR_MaintainBackTrace) {
596 /* MR10 */ if (p->jtype != Generic) MR_pointerStackPop(&MR_BackTraceStack);
597 /* MR10 */ };
598 if ( tail->right != NULL ) tail = tail->right;
599 }
600 }
601 if ( p->jtype!=aSubBlk && p->jtype!=aOptBlk ) p->lock[k] = FALSE;
602 #ifdef DBG_TREES
603 fprintf(stderr, "blk(%s) returns:",((Junction *)p)->rname); preorder(r); fprintf(stderr, "\n");
604 #endif
605 if ( r->down == NULL ) {_Tfree(r); return NULL;}
606 return r;
607 }
608
609 if ( p->jtype==EndRule )
610 {
611 if ( p->halt ) /* don't want FOLLOW here? */
612 {
613 /**** if ( ContextGuardTRAV ) return NULL; ****/
614 set_orel( (unsigned) k, rk); /* indicate this k value needed */ /* MR10 cast */
615 t = tnode(EpToken);
616 t->v.rk = k;
617 return t;
618 }
619 require(p->lock!=NULL, "rJunc: lock array is NULL");
620 if ( p->lock[k] ) return NULL;
621 /* if no FOLLOW assume k EOF's */
622 if ( p->p1 == NULL ) return eofnode(k);
623 p->lock[k] = TRUE;
624 }
625
626 /* MR14 */ if (p->p1 != NULL && p->guess && p->guess_analysis_point == NULL) {
627 /* MR14 */ Node * guess_point;
628 /* MR14 */ guess_point=(Node *)analysis_point(p);
629 /* MR14 */ if (guess_point == (Node *)p) {
630 /* MR14 */ guess_point=p->p1;
631 /* MR14 */ }
632 /* MR14 */ p->guess_analysis_point=guess_point;
633 /* MR14 */ }
634
635 if ( p->p2 == NULL )
636 {
637
638 /* MR10 */ if (MR_MaintainBackTrace) {
639 /* MR10 */ if (p->jtype != Generic) MR_pointerStackPush(&MR_BackTraceStack,p);
640 /* MR10 */ };
641
642 /* M14 */ if (p->guess_analysis_point != NULL) {
643 /* M14 */ TRAV(p->guess_analysis_point, k, rk,t);
644 /* M14 */ } else {
645 TRAV(p->p1, k, rk,t);
646 /* M14 */ }
647
648 /* MR10 */ if (MR_MaintainBackTrace) {
649 /* MR10 */ if (p->jtype != Generic) MR_pointerStackPop(&MR_BackTraceStack);
650 /* MR10 */ };
651
652 if ( p->jtype==EndRule ) p->lock[k]=FALSE;
653 return t;
654 }
655
656 /* MR10 */ if (MR_MaintainBackTrace) {
657 /* MR10 */ if (p->jtype != Generic) MR_pointerStackPush(&MR_BackTraceStack,p);
658 /* MR10 */ };
659
660 /* M14 */ if (p->guess_analysis_point != NULL) {
661 /* M14 */ TRAV(p->guess_analysis_point, k, rk,t);
662 /* M14 */ } else {
663 TRAV(p->p1, k, rk,t);
664 /* M14 */ }
665
666 /* MR10 */ if (MR_MaintainBackTrace) {
667 /* MR10 */ if (p->jtype != Generic) MR_pointerStackPop(&MR_BackTraceStack);
668 /* MR10 */ };
669
670 if ( p->jtype!=RuleBlk && /* MR14 */ !p->guess) TRAV(p->p2, k, rk, u);
671
672 if ( p->jtype==EndRule ) p->lock[k] = FALSE;/* unlock node */
673
674 if ( t==NULL ) return tmake(tnode(ALT), u, NULL);
675 return tmake(tnode(ALT), t, u, NULL);
676 }
677
678 Tree *
679 #ifdef __USE_PROTOS
tRuleRef(RuleRefNode * p,int k,set * rk_out)680 tRuleRef( RuleRefNode *p, int k, set *rk_out )
681 #else
682 tRuleRef( p, k, rk_out )
683 RuleRefNode *p;
684 int k;
685 set *rk_out;
686 #endif
687 {
688 int k2;
689 Tree *t=NULL, *u=NULL;
690 Junction *r;
691 set rk, rk2;
692 int save_halt;
693 RuleEntry *q = (RuleEntry *) hash_get(Rname, p->text);
694
695 #ifdef DBG_TRAV
696 fprintf(stderr, "tRuleRef: %s\n", p->text);
697 #endif
698 if ( q == NULL )
699 {
700 TRAV(p->next, k, rk_out, t);/* ignore undefined rules */
701 return t;
702 }
703 rk = rk2 = empty;
704 if (RulePtr == NULL) fatal("RulePtr==NULL");
705 r = RulePtr[q->rulenum];
706 if ( r->lock[k] ) return NULL;
707 save_halt = r->end->halt;
708 r->end->halt = TRUE; /* don't let reach fall off end of rule here */
709
710 /* MR10 */ if (MR_MaintainBackTrace) {
711 /* MR10 */ MR_pointerStackPush(&MR_BackTraceStack,p);
712 /* MR10 */ };
713
714 TRAV(r, k, &rk, t);
715
716 /* MR10 */ if (MR_MaintainBackTrace) {
717 /* MR10 */ MR_pointerStackPop(&MR_BackTraceStack);
718 /* MR10 */ };
719
720 r->end->halt = save_halt;
721 #ifdef DBG_TREES
722 fprintf(stderr, "after ruleref, t is:"); preorder(t); fprintf(stderr, "\n");
723 #endif
724 t = tshrink( t );
725 while ( !set_nil(rk) ) { /* any k left to do? if so, link onto tree */
726 k2 = set_int(rk);
727 set_rm(k2, rk);
728
729 /* MR10 */ if (MR_MaintainBackTrace) {
730 /* MR10 */ MR_pointerStackPush(&MR_BackTraceStack,p);
731 /* MR10 */ };
732
733 TRAV(p->next, k2, &rk2, u);
734
735 /* MR10 */ if (MR_MaintainBackTrace) {
736 /* MR10 */ MR_pointerStackPop(&MR_BackTraceStack);
737 /* MR10 */ };
738
739 t = tlink(t, u, k2); /* any alts missing k2 toks, add u onto end */
740 Tfree(u); /* MR10 */
741 }
742 set_free(rk); /* rk is empty, but free its memory */
743 set_orin(rk_out, rk2); /* remember what we couldn't do */
744 set_free(rk2);
745 return t;
746 }
747
748 Tree *
749 #ifdef __USE_PROTOS
tToken(TokNode * p,int k,set * rk)750 tToken( TokNode *p, int k, set *rk )
751 #else
752 tToken( p, k, rk )
753 TokNode *p;
754 int k;
755 set *rk;
756 #endif
757 {
758 Tree *t=NULL, *tset=NULL, *u;
759
760 if (ConstrainSearch) {
761 if (MR_AmbSourceSearch) {
762 require(constrain>=fset&&constrain<=&(fset[CLL_k]),"tToken: constrain is not a valid set");
763 } else {
764 require(constrain>=fset&&constrain<=&(fset[LL_k]),"tToken: constrain is not a valid set");
765 };
766 constrain = &fset[maxk-k+1];
767 }
768
769 #ifdef DBG_TRAV
770 fprintf(stderr, "tToken(%d): %s\n", k, TerminalString(p->token));
771 if ( ConstrainSearch ) {
772 fprintf(stderr, "constrain is:"); s_fprT(stderr, *constrain); fprintf(stderr, "\n");
773 }
774 #endif
775
776 /* is it a meta token (set of tokens)? */
777
778 if ( !set_nil(p->tset) )
779 {
780 unsigned e=0;
781 set a;
782 Tree *n, *tail = NULL;
783
784 if ( ConstrainSearch ) {
785 a = set_and(p->tset, *constrain);
786 if (set_nil(a)) { /* MR10 */
787 set_free(a); /* MR11 */
788 return NULL; /* MR10 */
789 }; /* MR10 */
790 } else {
791 a = set_dup(p->tset);
792 };
793
794 for (; !set_nil(a); set_rm(e, a))
795 {
796 e = set_int(a);
797 n = tnode(e);
798 if ( tset==NULL ) { tset = n; tail = n; }
799 else { tail->right = n; tail = n; }
800 }
801 set_free( a );
802 }
803 else if ( ConstrainSearch && !set_el(p->token, *constrain) )
804 {
805 /* fprintf(stderr, "ignoring token %s(%d)\n", TerminalString(p->token),
806 k);*/
807 return NULL;
808 }
809 else {
810 tset = tnode( p->token );
811 };
812
813 /* MR10 */ if (MR_MaintainBackTrace) {
814 /* MR10 */ if (k == 1) {
815 /* MR10 */ MR_pointerStackPush(&MR_BackTraceStack,p);
816 /* MR13 */ if (MR_SuppressSearch) {
817 /* MR13 */ MR_suppressSearchReport();
818 /* MR13 */ } else {
819 /* MR10 */ MR_backTraceReport();
820 /* MR13 */ };
821 /* MR10 */ MR_pointerStackPop(&MR_BackTraceStack);
822 /* MR11 */ Tfree(tset);
823 /* MR11 */ return NULL;
824 /* MR10 */ };
825 /* MR10 */ };
826
827 if ( k == 1 ) return tset;
828
829 if (MR_MaintainBackTrace) {
830 MR_pointerStackPush(&MR_BackTraceStack,p);
831 };
832
833 TRAV(p->next, k-1, rk, t);
834
835 if (MR_MaintainBackTrace) {
836 Tfree(t);
837 Tfree(tset);
838 MR_pointerStackPop(&MR_BackTraceStack);
839 return NULL;
840 };
841
842 /* here, we are positive that, at least, this tree will not contribute
843 * to the LL(2) tree since it will be too shallow, IF t==NULL.
844 * If doing a context guard walk, then don't prune.
845 */
846 if ( t == NULL && !ContextGuardTRAV ) /* tree will be too shallow */
847 {
848 if ( tset!=NULL ) Tfree( tset );
849 return NULL;
850 }
851 #ifdef DBG_TREES
852 fprintf(stderr, "tToken(%d)->next:",k); preorder(t); fprintf(stderr, "\n");
853 #endif
854
855 /* if single token root, then just make new tree and return */
856 /* MR10 - set_nil(p->tset) isn't a good test because of ConstraintSearch */
857
858 if (tset->right == NULL) return tmake(tset, t, NULL); /* MR10 */
859
860 /* here we must make a copy of t as a child of each element of the tset;
861 * e.g., "T1..T3 A" would yield ( nil ( T1 A ) ( T2 A ) ( T3 A ) )
862 */
863 for (u=tset; u!=NULL; u=u->right)
864 {
865 /* make a copy of t and hook it onto bottom of u */
866 u->down = tdup(t);
867 }
868 Tfree( t );
869 #ifdef DBG_TREES
870 fprintf(stderr, "range is:"); preorder(tset); fprintf(stderr, "\n");
871 #endif
872 return tset;
873 }
874
875 Tree *
876 #ifdef __USE_PROTOS
tAction(ActionNode * p,int k,set * rk)877 tAction( ActionNode *p, int k, set *rk )
878 #else
879 tAction( p, k, rk )
880 ActionNode *p;
881 int k;
882 set *rk;
883 #endif
884 {
885 Tree *t=NULL;
886 set *save_fset=NULL;
887 int i;
888
889 /* fprintf(stderr, "tAction\n"); */
890
891 /* An MR_SuppressSearch is looking for things that can be
892 reached even when the predicate is false.
893
894 There are three kinds of predicates:
895 plain: r1: <<p>>? r2
896 guarded: r1: (A)? => <<p>>? r2
897 ampersand style: r1: (A)? && <<p>>? r2
898
899 Of the three kinds of predicates, only a guard predicate
900 has things which are reachable even when the predicate
901 is false. To be reachable the constraint must *not*
902 match the guard.
903
904 */
905
906 if (p->is_predicate && MR_SuppressSearch) {
907
908 Predicate *pred=p->guardpred;
909
910 if (pred == NULL) {
911 t=NULL;
912 goto EXIT;
913 };
914 constrain = &fset[maxk-k+1];
915 if (pred->k == 1) {
916 set dif;
917 dif=set_dif(*constrain,pred->scontext[1]);
918 if (set_nil(dif)) {
919 set_free(dif);
920 t=NULL;
921 goto EXIT;
922 };
923 set_free(dif);
924 } else {
925 if (MR_tree_matches_constraints(k,constrain,pred->tcontext)) {
926 t=NULL;
927 goto EXIT;
928 };
929 }
930 };
931
932 /* The ampersand predicate differs from the
933 other predicates because its first set
934 is a subset of the first set behind the predicate
935
936 r1: (A)? && <<p>>? r2 ;
937 r2: A | B;
938
939 In this case first[1] of r1 is A, even
940 though first[1] of r2 is {A B}.
941 */
942
943 if (p->is_predicate && p->ampersandPred != NULL) {
944
945 Predicate *pred=p->ampersandPred;
946 Tree *tAND;
947 Tree *tset;
948
949 if (k <= pred->k) {
950 if (MR_MaintainBackTrace) MR_pointerStackPush(&MR_BackTraceStack,p);
951 TRAV(p->guardNodes,k,rk,t);
952 if (MR_MaintainBackTrace) MR_pointerStackPop(&MR_BackTraceStack);
953 return t;
954 } else {
955 require (k>1,"tAction for ampersandpred: k <= 1");
956 if (ConstrainSearch) {
957 if (MR_AmbSourceSearch) {
958 require(constrain>=fset&&constrain<=&(fset[CLL_k]),
959 "tToken: constrain is not a valid set");
960 } else {
961 require(constrain>=fset&&constrain<=&(fset[LL_k]),
962 "tToken: constrain is not a valid set");
963 };
964 save_fset=(set *) calloc (CLL_k+1,sizeof(set));
965 require (save_fset != NULL,"tAction save_fset alloc");
966 for (i=1; i <= CLL_k ; i++) {
967 save_fset[i]=set_dup(fset[i]);
968 };
969 if (pred->k == 1) {
970 constrain = &fset[maxk-k+1];
971 set_andin(constrain,pred->scontext[1]);
972 if (set_nil(*constrain)) {
973 t=NULL;
974 goto EXIT;
975 };
976 } else {
977 constrain = &fset[maxk-k+1];
978 if (! MR_tree_matches_constraints(pred->k,constrain,pred->tcontext)) {
979 t=NULL;
980 goto EXIT;
981 }; /* end loop on i */
982 }; /* end loop on pred scontext/tcontext */
983 }; /* end if on k > pred->k */
984 }; /* end if on constrain search */
985
986 TRAV(p->next,k,rk,t);
987
988 if (t != NULL) {
989 t=tshrink(t);
990 t=tflatten(t);
991 t=tleft_factor(t);
992 if (pred->tcontext != NULL) {
993 tAND=MR_computeTreeAND(t,pred->tcontext);
994 } else {
995 tset=MR_make_tree_from_set(pred->scontext[1]);
996 tAND=MR_computeTreeAND(t,tset);
997 Tfree(tset);
998 };
999 Tfree(t);
1000 t=tAND;
1001 };
1002 goto EXIT;
1003
1004 }; /* end if on ampersand predicate */
1005
1006 TRAV(p->next,k,rk,t);
1007
1008 EXIT:
1009 if (save_fset != NULL) {
1010 for (i=1 ; i <= CLL_k ; i++) {
1011 set_free(fset[i]);
1012 fset[i]=save_fset[i];
1013 };
1014 free ( (char *) save_fset);
1015 };
1016 return t;
1017 }
1018
1019 /* see if e exists in s as a possible input permutation (e is always a chain) */
1020
1021 int
1022 #ifdef __USE_PROTOS
tmember(Tree * e,Tree * s)1023 tmember( Tree *e, Tree *s )
1024 #else
1025 tmember( e, s )
1026 Tree *e;
1027 Tree *s;
1028 #endif
1029 {
1030 if ( e==NULL||s==NULL ) return 0;
1031 /** fprintf(stderr, "tmember(");
1032 *** preorder(e); fprintf(stderr, ",");
1033 *** preorder(s); fprintf(stderr, " )\n");
1034 */
1035 if ( s->token == ALT && s->right == NULL ) return tmember(e, s->down);
1036 if ( e->token!=s->token )
1037 {
1038 if ( s->right==NULL ) return 0;
1039 return tmember(e, s->right);
1040 }
1041 if ( e->down==NULL && s->down == NULL ) return 1;
1042 if ( tmember(e->down, s->down) ) return 1;
1043 if ( s->right==NULL ) return 0;
1044 return tmember(e, s->right);
1045 }
1046
1047 /* see if e exists in s as a possible input permutation (e is always a chain);
1048 * Only check s to the depth of e. In other words, 'e' can be a shorter
1049 * sequence than s.
1050 */
1051 int
1052 #ifdef __USE_PROTOS
tmember_constrained(Tree * e,Tree * s)1053 tmember_constrained( Tree *e, Tree *s)
1054 #else
1055 tmember_constrained( e, s )
1056 Tree *e;
1057 Tree *s;
1058 #endif
1059 {
1060 if ( e==NULL||s==NULL ) return 0;
1061 /** fprintf(stderr, "tmember_constrained(");
1062 *** preorder(e); fprintf(stderr, ",");
1063 *** preorder(s); fprintf(stderr, " )\n");
1064 **/
1065 if ( s->token == ALT && s->right == NULL )
1066 return tmember_constrained(e, s->down);
1067 if ( e->token!=s->token )
1068 {
1069 if ( s->right==NULL ) return 0;
1070 return tmember_constrained(e, s->right);
1071 }
1072 if ( e->down == NULL ) return 1; /* if s is matched to depth of e return */
1073 if ( tmember_constrained(e->down, s->down) ) return 1;
1074 if ( s->right==NULL ) return 0;
1075 return tmember_constrained(e, s->right);
1076 }
1077
1078 /* combine (? (A t) ... (A u) ...) into (? (A t u)) */
1079 Tree *
1080 #ifdef __USE_PROTOS
tleft_factor(Tree * t)1081 tleft_factor( Tree *t )
1082 #else
1083 tleft_factor( t )
1084 Tree *t;
1085 #endif
1086 {
1087 Tree *u, *v, *trail, *w;
1088
1089 /* left-factor what is at this level */
1090 if ( t == NULL ) return NULL;
1091 for (u=t; u!=NULL; u=u->right)
1092 {
1093 trail = u;
1094 v=u->right;
1095 while ( v!=NULL )
1096 {
1097 if ( u->token == v->token )
1098 {
1099 if ( u->down!=NULL )
1100 {
1101 for (w=u->down; w->right!=NULL; w=w->right) {;}
1102 w->right = v->down; /* link children together */
1103 }
1104 else u->down = v->down;
1105 trail->right = v->right; /* unlink factored node */
1106 _Tfree( v );
1107 v = trail->right;
1108 }
1109 else {trail = v; v=v->right;}
1110 }
1111 }
1112 /* left-factor what is below */
1113 for (u=t; u!=NULL; u=u->right) u->down = tleft_factor( u->down );
1114 return t;
1115 }
1116
1117 /* remove the permutation p from t if present */
1118 Tree *
1119 #ifdef __USE_PROTOS
trm_perm(Tree * t,Tree * p)1120 trm_perm( Tree *t, Tree *p )
1121 #else
1122 trm_perm( t, p )
1123 Tree *t;
1124 Tree *p;
1125 #endif
1126 {
1127 /*
1128 fprintf(stderr, "trm_perm(");
1129 preorder(t); fprintf(stderr, ",");
1130 preorder(p); fprintf(stderr, " )\n");
1131 */
1132 if ( t == NULL || p == NULL ) return NULL;
1133 if ( t->token == ALT )
1134 {
1135 t->down = trm_perm(t->down, p);
1136 if ( t->down == NULL ) /* nothing left below, rm cur node */
1137 {
1138 Tree *u = t->right;
1139 _Tfree( t );
1140 return trm_perm(u, p);
1141 }
1142 t->right = trm_perm(t->right, p); /* look for more instances of p */
1143 return t;
1144 }
1145 if ( p->token != t->token ) /* not found, try a sibling */
1146 {
1147 t->right = trm_perm(t->right, p);
1148 return t;
1149 }
1150 t->down = trm_perm(t->down, p->down);
1151 if ( t->down == NULL ) /* nothing left below, rm cur node */
1152 {
1153 Tree *u = t->right;
1154 _Tfree( t );
1155 return trm_perm(u, p);
1156 }
1157 t->right = trm_perm(t->right, p); /* look for more instances of p */
1158 return t;
1159 }
1160
1161 /* add the permutation 'perm' to the LL_k sets in 'fset' */
1162 void
1163 #ifdef __USE_PROTOS
tcvt(set * fset,Tree * perm)1164 tcvt( set *fset, Tree *perm )
1165 #else
1166 tcvt( fset, perm )
1167 set *fset;
1168 Tree *perm;
1169 #endif
1170 {
1171 if ( perm==NULL ) return;
1172 set_orel(perm->token, fset);
1173 tcvt(fset+1, perm->down);
1174 }
1175
1176 /* for each element of ftbl[k], make it the root of a tree with permute(ftbl[k+1])
1177 * as a child.
1178 */
1179 Tree *
1180 #ifdef __USE_PROTOS
permute(int k,int max_k)1181 permute( int k, int max_k )
1182 #else
1183 permute( k, max_k )
1184 int k, max_k;
1185 #endif
1186 {
1187 Tree *t, *u;
1188
1189 if ( k>max_k ) return NULL;
1190 if ( ftbl[k][findex[k]] == nil ) return NULL;
1191 t = permute(k+1, max_k);
1192 if ( t==NULL&&k<max_k ) /* no permutation left below for k+1 tokens? */
1193 {
1194 findex[k+1] = 0;
1195 (findex[k])++; /* try next token at this k */
1196 return permute(k, max_k);
1197 }
1198
1199 u = tmake(tnode(ftbl[k][findex[k]]), t, NULL);
1200 if ( k == max_k ) (findex[k])++;
1201 return u;
1202 }
1203
1204 /* Compute LL(k) trees for alts alt1 and alt2 of p.
1205 * function result is tree of ambiguous input permutations
1206 *
1207 * ALGORITHM may change to look for something other than LL_k size
1208 * trees ==> maxk will have to change.
1209 */
1210 Tree *
1211 #ifdef __USE_PROTOS
VerifyAmbig(Junction * alt1,Junction * alt2,unsigned ** ft,set * fs,Tree ** t,Tree ** u,int * numAmbig)1212 VerifyAmbig( Junction *alt1, Junction *alt2, unsigned **ft, set *fs, Tree **t, Tree **u, int *numAmbig )
1213 #else
1214 VerifyAmbig( alt1, alt2, ft, fs, t, u, numAmbig )
1215 Junction *alt1;
1216 Junction *alt2;
1217 unsigned **ft;
1218 set *fs;
1219 Tree **t;
1220 Tree **u;
1221 int *numAmbig;
1222 #endif
1223 {
1224 set rk;
1225 Tree *perm, *ambig=NULL;
1226 Junction *p;
1227 int k;
1228 int tnodes_at_start=TnodesAllocated;
1229 int tnodes_at_end;
1230 int tnodes_used;
1231 set *save_fs;
1232 int j;
1233
1234 save_fs=(set *) calloc(CLL_k+1,sizeof(set));
1235 require(save_fs != NULL,"save_fs calloc");
1236
1237 for (j=0; j <= CLL_k ; j++) save_fs[j]=set_dup(fs[j]);
1238
1239 maxk = LL_k; /* NOTE: for now, we look for LL_k */
1240 ftbl = ft;
1241 fset = fs;
1242 constrain = &(fset[1]);
1243 findex = (int *) calloc(LL_k+1, sizeof(int));
1244 if ( findex == NULL )
1245 {
1246 fprintf(stderr, ErrHdr, FileStr[CurAmbigfile], CurAmbigline);
1247 fprintf(stderr, " out of memory while analyzing alts %d and %d of %s\n",
1248 CurAmbigAlt1,
1249 CurAmbigAlt2,
1250 CurAmbigbtype);
1251 exit(PCCTS_EXIT_FAILURE);
1252 }
1253 for (k=1; k<=LL_k; k++) findex[k] = 0;
1254
1255 rk = empty;
1256 ConstrainSearch = 1; /* consider only tokens in ambig sets */
1257
1258 p = analysis_point((Junction *)alt1->p1);
1259 TRAV(p, LL_k, &rk, *t);
1260 *t = tshrink( *t );
1261 *t = tflatten( *t );
1262 *t = tleft_factor( *t ); /* MR10 */
1263 *t = prune(*t, LL_k);
1264 *t = tleft_factor( *t );
1265
1266 /*** fprintf(stderr, "after shrink&flatten&prune&left_factor:"); preorder(*t); fprintf(stderr, "\n");*/
1267 if ( *t == NULL )
1268 {
1269 /*** fprintf(stderr, "TreeIncomplete --> no LL(%d) ambiguity\n", LL_k);*/
1270 Tfree( *t ); /* kill if impossible to have ambig */
1271 *t = NULL;
1272 }
1273
1274 p = analysis_point((Junction *)alt2->p1);
1275
1276 TRAV(p, LL_k, &rk, *u);
1277 *u = tshrink( *u );
1278 *u = tflatten( *u );
1279 *t = tleft_factor( *t ); /* MR10 */
1280 *u = prune(*u, LL_k);
1281 *u = tleft_factor( *u );
1282 /* fprintf(stderr, "after shrink&flatten&prune&lfactor:"); preorder(*u); fprintf(stderr, "\n");*/
1283 if ( *u == NULL )
1284 {
1285 /* fprintf(stderr, "TreeIncomplete --> no LL(%d) ambiguity\n", LL_k);*/
1286 Tfree( *u );
1287 *u = NULL;
1288 }
1289
1290 for (k=1; k<=LL_k; k++) set_clr( fs[k] );
1291
1292 ambig = tnode(ALT);
1293 k = 0;
1294 if ( *t!=NULL && *u!=NULL )
1295 {
1296 while ( (perm=permute(1,LL_k))!=NULL )
1297 {
1298 /* fprintf(stderr, "chk perm:"); preorder(perm); fprintf(stderr, "\n");*/
1299 if ( tmember(perm, *t) && tmember(perm, *u) )
1300 {
1301 /* fprintf(stderr, "ambig upon"); preorder(perm); fprintf(stderr, "\n");*/
1302
1303 k++;
1304 perm->right = ambig->down;
1305 ambig->down = perm;
1306 tcvt(&(fs[1]), perm);
1307 }
1308 else Tfree( perm );
1309 }
1310 }
1311
1312 for (j=0; j <= CLL_k ; j++) fs[j]=save_fs[j];
1313 free( (char *) save_fs);
1314
1315 tnodes_at_end=TnodesAllocated;
1316 tnodes_used=tnodes_at_end - tnodes_at_start;
1317
1318 if (TnodesReportThreshold > 0 && tnodes_used > TnodesReportThreshold) {
1319 fprintf(stdout,"There were %d tuples whose ambiguity could not be resolved by full lookahead\n",k);
1320 fprintf(stdout,"There were %d tnodes created to resolve ambiguity between:\n\n",tnodes_used);
1321 fprintf(stdout," Choice 1: %s line %d file %s\n",
1322 MR_ruleNamePlusOffset( (Node *) alt1),alt1->line,FileStr[alt1->file]);
1323 fprintf(stdout," Choice 2: %s line %d file %s\n",
1324 MR_ruleNamePlusOffset( (Node *) alt2),alt2->line,FileStr[alt2->file]);
1325 for (j=1; j <= CLL_k ; j++) {
1326 fprintf(stdout,"\n Intersection of lookahead[%d] sets:\n",j);
1327 MR_dumpTokenSet(stdout,2,fs[j]);
1328 };
1329 fprintf(stdout,"\n");
1330 };
1331
1332 *numAmbig = k;
1333 if ( ambig->down == NULL ) {_Tfree(ambig); ambig = NULL;}
1334 free( (char *)findex );
1335 /* fprintf(stderr, "final ambig:"); preorder(ambig); fprintf(stderr, "\n");*/
1336 return ambig;
1337 }
1338
1339 static Tree *
1340 #ifdef __USE_PROTOS
bottom_of_chain(Tree * t)1341 bottom_of_chain( Tree *t )
1342 #else
1343 bottom_of_chain( t )
1344 Tree *t;
1345 #endif
1346 {
1347 if ( t==NULL ) return NULL;
1348 for (; t->down != NULL; t=t->down) {;}
1349 return t;
1350 }
1351
1352 /*
1353 * Make a tree from k sets where the degree of the first k-1 sets is 1.
1354 */
1355 Tree *
1356 #ifdef __USE_PROTOS
make_tree_from_sets(set * fset1,set * fset2)1357 make_tree_from_sets( set *fset1, set *fset2 )
1358 #else
1359 make_tree_from_sets( fset1, fset2 )
1360 set *fset1;
1361 set *fset2;
1362 #endif
1363 {
1364 set inter;
1365 int i;
1366 Tree *t=NULL, *n, *u;
1367 unsigned *p,*q;
1368 require(LL_k>1, "make_tree_from_sets: LL_k must be > 1");
1369
1370 /* do the degree 1 sets first */
1371 for (i=1; i<=LL_k-1; i++)
1372 {
1373 inter = set_and(fset1[i], fset2[i]);
1374 require(set_deg(inter)==1, "invalid set to tree conversion");
1375 n = tnode(set_int(inter));
1376 if (t==NULL) t=n; else tmake(t, n, NULL);
1377 set_free(inter);
1378 }
1379
1380 /* now add the chain of tokens at depth k */
1381 u = bottom_of_chain(t);
1382 inter = set_and(fset1[LL_k], fset2[LL_k]);
1383 if ( (q=p=set_pdq(inter)) == NULL ) fatal_internal("Can't alloc space for set_pdq");
1384 /* first one is linked to bottom, then others are sibling linked */
1385 n = tnode(*p++);
1386 u->down = n;
1387 u = u->down;
1388 while ( *p != nil )
1389 {
1390 n = tnode(*p);
1391 u->right = n;
1392 u = u->right;
1393 p++;
1394 }
1395 free((char *)q);
1396
1397 return t;
1398 }
1399
1400 /* create and return the tree of lookahead k-sequences that are in t, but not
1401 * in the context of predicates in predicate list p.
1402 */
1403 Tree *
1404 #ifdef __USE_PROTOS
tdif(Tree * ambig_tuples,Predicate * p,set * fset1,set * fset2)1405 tdif( Tree *ambig_tuples, Predicate *p, set *fset1, set *fset2 )
1406 #else
1407 tdif( ambig_tuples, p, fset1, fset2 )
1408 Tree *ambig_tuples;
1409 Predicate *p;
1410 set *fset1;
1411 set *fset2;
1412 #endif
1413 {
1414 unsigned **ft;
1415 Tree *dif=NULL;
1416 Tree *perm;
1417 set b;
1418 int i,k;
1419
1420 if ( p == NULL ) return tdup(ambig_tuples);
1421
1422 ft = (unsigned **) calloc(CLL_k+1, sizeof(unsigned *));
1423 require(ft!=NULL, "cannot allocate ft");
1424 for (i=1; i<=CLL_k; i++)
1425 {
1426 b = set_and(fset1[i], fset2[i]);
1427 ft[i] = set_pdq(b);
1428 set_free(b);
1429 }
1430 findex = (int *) calloc(LL_k+1, sizeof(int));
1431 if ( findex == NULL )
1432 {
1433 fatal_internal("out of memory in tdif while checking predicates");
1434 }
1435 for (k=1; k<=LL_k; k++) findex[k] = 0;
1436
1437 #ifdef DBG_TRAV
1438 fprintf(stderr, "tdif_%d[", p->k);
1439 preorder(ambig_tuples);
1440 fprintf(stderr, ",");
1441 preorder(p->tcontext);
1442 fprintf(stderr, "] =");
1443 #endif
1444
1445 ftbl = ft;
1446 while ( (perm=permute(1,p->k))!=NULL )
1447 {
1448 #ifdef DBG_TRAV
1449 fprintf(stderr, "test perm:"); preorder(perm); fprintf(stderr, "\n");
1450 #endif
1451 if ( tmember_constrained(perm, ambig_tuples) &&
1452 !tmember_of_context(perm, p) )
1453 {
1454 #ifdef DBG_TRAV
1455 fprintf(stderr, "satisfied upon"); preorder(perm); fprintf(stderr, "\n");
1456 #endif
1457 k++;
1458 if ( dif==NULL ) dif = perm;
1459 else
1460 {
1461 perm->right = dif;
1462 dif = perm;
1463 }
1464 }
1465 else Tfree( perm );
1466 }
1467
1468 #ifdef DBG_TRAV
1469 preorder(dif);
1470 fprintf(stderr, "\n");
1471 #endif
1472
1473 for (i=1; i<=CLL_k; i++) free( (char *)ft[i] );
1474 free((char *)ft);
1475 free((char *)findex);
1476
1477 return dif;
1478 }
1479
1480 /* is lookahead sequence t a member of any context tree for any
1481 * predicate in p?
1482 */
1483 static int
1484 #ifdef __USE_PROTOS
tmember_of_context(Tree * t,Predicate * p)1485 tmember_of_context( Tree *t, Predicate *p )
1486 #else
1487 tmember_of_context( t, p )
1488 Tree *t;
1489 Predicate *p;
1490 #endif
1491 {
1492 for (; p!=NULL; p=p->right)
1493 {
1494 if ( p->expr==PRED_AND_LIST || p->expr==PRED_OR_LIST )
1495 return tmember_of_context(t, p->down);
1496 if ( tmember_constrained(t, p->tcontext) ) return 1;
1497 if ( tmember_of_context(t, p->down) ) return 1;
1498 }
1499 return 0;
1500 }
1501
1502 int
1503 #ifdef __USE_PROTOS
is_single_tuple(Tree * t)1504 is_single_tuple( Tree *t )
1505 #else
1506 is_single_tuple( t )
1507 Tree *t;
1508 #endif
1509 {
1510 if ( t == NULL ) return 0;
1511 if ( t->right != NULL ) return 0;
1512 if ( t->down == NULL ) return 1;
1513 return is_single_tuple(t->down);
1514 }
1515
1516
1517 /* MR10 Check that a context guard contains only allowed things */
1518 /* MR10 (mainly token references). */
1519
1520 #ifdef __USE_PROTOS
contextGuardOK(Node * p,int h,int * hmax)1521 int contextGuardOK(Node *p,int h,int *hmax)
1522 #else
1523 int contextGuardOK(p,h,hmax)
1524 Node *p;
1525 int h;
1526 int *hmax;
1527 #endif
1528 {
1529 Junction *j;
1530 TokNode *tn;
1531
1532 if (p == NULL) return 1;
1533 if (p->ntype == nToken) {
1534 h++;
1535 if (h > *hmax) *hmax=h;
1536 tn=(TokNode *)p;
1537 if (tn->el_label != NULL) {
1538 warnFL(eMsg1("a label (\"%s\") for a context guard element is meaningless",tn->el_label),
1539 FileStr[p->file],p->line);
1540 };
1541 return contextGuardOK( ( (TokNode *) p)->next,h,hmax);
1542 } else if (p->ntype == nAction) {
1543 goto Fail;
1544 } else if (p->ntype == nRuleRef) {
1545 goto Fail;
1546 } else {
1547 require (p->ntype == nJunction,"Unexpected ntype");
1548 j=(Junction *) p;
1549 if (j->jtype != Generic &&
1550 j->jtype != aSubBlk && /* pretty sure this one is allowed */
1551 /**** j->jtype != aOptBlk && ****/ /* pretty sure this one is allowed */ /* MR11 not any more ! */
1552 j->jtype != EndBlk) {
1553 errFL("A context guard may not contain an option block: {...} or looping block: (...)* or (...)+",
1554 FileStr[p->file],p->line);
1555 contextGuardOK(j->p1,h,hmax);
1556 return 0;
1557 };
1558 /* do both p1 and p2 so use | rather than || */
1559 return contextGuardOK(j->p2,h,hmax) | contextGuardOK(j->p1,h,hmax);
1560 };
1561 Fail:
1562 errFL("A context guard may contain only Token references - guard will be ignored",
1563 FileStr[p->file],p->line);
1564 contextGuardOK( ( (ActionNode *) p)->next,h,hmax);
1565 return 0;
1566 }
1567
1568 /*
1569 * Look at a (...)? generalized-predicate context-guard and compute
1570 * either a lookahead set (k==1) or a lookahead tree for k>1. The
1571 * k level is determined by the guard itself rather than the LL_k
1572 * variable. For example, ( A B )? is an LL(2) guard and ( ID )?
1573 * is an LL(1) guard. For the moment, you can only have a single
1574 * tuple in the guard. Physically, the block must look like this
1575 * --o-->TOKEN-->o-->o-->TOKEN-->o-- ... -->o-->TOKEN-->o--
1576 * An error is printed for any other type.
1577 */
1578 Predicate *
1579 #ifdef __USE_PROTOS
computePredFromContextGuard(Graph blk,int * msgDone)1580 computePredFromContextGuard(Graph blk,int *msgDone) /* MR10 */
1581 #else
1582 computePredFromContextGuard(blk,msgDone) /* MR10 */
1583 Graph blk;
1584 int *msgDone; /* MR10 */
1585 #endif
1586 {
1587 Junction *junc = (Junction *)blk.left, *p;
1588 Tree *t=NULL;
1589 Predicate *pred = NULL;
1590 set scontext, rk;
1591 int ok;
1592 int hmax=0;
1593
1594 require(junc!=NULL && junc->ntype == nJunction, "bad context guard");
1595
1596 /* MR10 Check for anything other than Tokens and generic junctions */
1597
1598 *msgDone=0; /* MR10 */
1599 ok=contextGuardOK( (Node *)junc,0,&hmax); /* MR10 */
1600 if (! ok) { /* MR10 */
1601 *msgDone=1; /* MR10 */
1602 return NULL; /* MR10 */
1603 }; /* MR10 */
1604 if (hmax == 0) {
1605 errFL("guard is 0 tokens long",FileStr[junc->file],junc->line); /* MR11 */
1606 *msgDone=1;
1607 return NULL;
1608 };
1609 if (hmax > CLL_k) { /* MR10 */
1610 errFL(eMsgd2("guard is %d tokens long - lookahead is limited to max(k,ck)==%d", /* MR10 */
1611 hmax,CLL_k), /* MR10 */
1612 FileStr[junc->file],junc->line); /* MR10 */
1613 *msgDone=1; /* MR10 */
1614 return NULL; /* MR10 */
1615 }; /* MR10 */
1616
1617 rk = empty;
1618 p = junc;
1619 pred = new_pred();
1620 pred->k = hmax; /* MR10 should be CLL_k, not LLK ? */
1621 if (hmax > 1 ) /* MR10 was LL_k */
1622 {
1623 ConstrainSearch = 0;
1624 ContextGuardTRAV = 1;
1625 TRAV(p, hmax, &rk, t); /* MR10 was LL_k */
1626 ContextGuardTRAV = 0;
1627 set_free(rk);
1628 t = tshrink( t );
1629 t = tflatten( t );
1630 t = tleft_factor( t );
1631 /*
1632 fprintf(stderr, "ctx guard:");
1633 preorder(t);
1634 fprintf(stderr, "\n");
1635 */
1636 pred->tcontext = t;
1637 }
1638 else
1639 {
1640 REACH(p, 1, &rk, scontext);
1641 require(set_nil(rk), "rk != nil");
1642 set_free(rk);
1643 /*
1644 fprintf(stderr, "LL(1) ctx guard is:");
1645 s_fprT(stderr, scontext);
1646 fprintf(stderr, "\n");
1647 */
1648 pred->scontext[1] = scontext;
1649 }
1650
1651 list_add(&ContextGuardPredicateList,pred); /* MR13 */
1652
1653 return pred;
1654 }
1655
1656 /* MR13
1657 When the context guard is originally computed the
1658 meta-tokens are not known.
1659 */
1660
1661 #ifdef __USE_PROTOS
recomputeContextGuard(Predicate * pred)1662 void recomputeContextGuard(Predicate *pred)
1663 #else
1664 void recomputeContextGuard(pred)
1665 Predicate *pred;
1666 #endif
1667 {
1668 Tree * t=NULL;
1669 set scontext;
1670 set rk;
1671 ActionNode * actionNode;
1672 Junction * p;
1673
1674 actionNode=pred->source;
1675 require (actionNode != NULL,"context predicate's source == NULL");
1676
1677 p=actionNode->guardNodes;
1678 require (p != NULL,"context predicate's guardNodes == NULL");
1679
1680 rk = empty;
1681 if (pred->k > 1 )
1682 {
1683 ConstrainSearch = 0;
1684 ContextGuardTRAV = 1;
1685 TRAV(p, pred->k, &rk, t);
1686 ContextGuardTRAV = 0;
1687 set_free(rk);
1688 t = tshrink( t );
1689 t = tflatten( t );
1690 t = tleft_factor( t );
1691 Tfree(pred->tcontext);
1692 pred->tcontext = t;
1693 }
1694 else
1695 {
1696 REACH(p, 1, &rk, scontext);
1697 require(set_nil(rk), "rk != nil");
1698 set_free(rk);
1699 set_free(pred->scontext[1]);
1700 pred->scontext[1] = scontext;
1701 }
1702 }
1703
1704 /* MR11 - had enough of flags yet ? */
1705
1706 int MR_AmbSourceSearch=0;
1707 int MR_AmbSourceSearchGroup=0;
1708 int MR_AmbSourceSearchChoice=0;
1709 int MR_AmbSourceSearchLimit=0;
1710 int MR_matched_AmbAidRule=0;
1711
1712 static set *matchSets[2]={NULL,NULL};
1713 static int *tokensInChain=NULL;
1714 static Junction *MR_AmbSourceSearchJ[2];
1715
MR_traceAmbSourceKclient()1716 void MR_traceAmbSourceKclient()
1717 {
1718 int i;
1719 set *save_fset;
1720 int save_ConstrainSearch;
1721 set incomplete;
1722 Tree *t;
1723
1724 if (matchSets[0] == NULL) {
1725 matchSets[0]=(set *) calloc (CLL_k+1,sizeof(set));
1726 require (matchSets[0] != NULL,"matchSets[0] alloc");
1727 matchSets[1]=(set *) calloc (CLL_k+1,sizeof(set));
1728 require (matchSets[1] != NULL,"matchSets[1] alloc");
1729 };
1730
1731 for (i=1 ; i <= MR_AmbSourceSearchLimit ; i++) {
1732 set_clr(matchSets[0][i]);
1733 set_orel( (unsigned) tokensInChain[i],
1734 &matchSets[0][i]);
1735 set_clr(matchSets[1][i]);
1736 set_orel( (unsigned) tokensInChain[i],
1737 &matchSets[1][i]);
1738 };
1739
1740 save_fset=fset;
1741 save_ConstrainSearch=ConstrainSearch;
1742
1743
1744
1745 for (i=0 ; i < 2 ; i++) {
1746
1747 #if 0
1748 ** fprintf(stdout," Choice:%d Depth:%d ",i+1,MR_AmbSourceSearchLimit);
1749 ** fprintf(stdout,"(");
1750 ** for (j=1 ; j <= MR_AmbSourceSearchLimit ; j++) {
1751 ** if (j != 1) fprintf(stdout," ");
1752 ** fprintf(stdout,"%s",TerminalString(tokensInChain[j]));
1753 ** };
1754 ** fprintf(stdout,")\n\n");
1755 #endif
1756
1757 fset=matchSets[i];
1758
1759 MR_AmbSourceSearch=1;
1760 MR_MaintainBackTrace=1;
1761 MR_AmbSourceSearchChoice=i;
1762 ConstrainSearch=1;
1763
1764 maxk = MR_AmbSourceSearchLimit;
1765
1766 incomplete=empty;
1767 t=NULL;
1768
1769 constrain = &(fset[1]);
1770 MR_pointerStackReset(&MR_BackTraceStack);
1771
1772 TRAV(MR_AmbSourceSearchJ[i],maxk,&incomplete,t);
1773
1774 Tfree(t);
1775
1776 require (set_nil(incomplete),"MR_traceAmbSourceK TRAV incomplete");
1777 require (MR_BackTraceStack.count == 0,"K: MR_BackTraceStack.count != 0");
1778
1779 set_free(incomplete);
1780 };
1781
1782 ConstrainSearch=save_ConstrainSearch;
1783 fset=save_fset;
1784 MR_AmbSourceSearch=0;
1785 MR_MaintainBackTrace=0;
1786 MR_AmbSourceSearchChoice=0;
1787 }
1788
1789 #ifdef __USE_PROTOS
tTrunc(Tree * t,int depth)1790 Tree *tTrunc(Tree *t,int depth)
1791 #else
1792 Tree *tTrunc(t,depth)
1793 Tree *t;
1794 #endif
1795 {
1796 Tree *u;
1797
1798 require ( ! (t == NULL && depth > 0),"tree too short");
1799
1800 if (depth == 0) return NULL;
1801
1802 if (t->token == ALT) {
1803 u=tTrunc(t->down,depth);
1804 } else {
1805 u=tnode(t->token);
1806 u->down=tTrunc(t->down,depth-1);
1807 };
1808 if (t->right != NULL) u->right=tTrunc(t->right,depth);
1809 return u;
1810 }
1811
1812 #ifdef __USE_PROTOS
MR_iterateOverTree(Tree * t,int chain[])1813 void MR_iterateOverTree(Tree *t,int chain[])
1814 #else
1815 void MR_iterateOverTree(t,chain)
1816 Tree *t;
1817 int chain[];
1818 #endif
1819 {
1820 if (t == NULL) return;
1821 chain[0]=t->token;
1822 if (t->down != NULL) {
1823 MR_iterateOverTree(t->down,&chain[1]);
1824 } else {
1825 MR_traceAmbSourceKclient();
1826 };
1827 MR_iterateOverTree(t->right,&chain[0]);
1828 chain[0]=0;
1829 }
1830
1831 #ifdef __USE_PROTOS
MR_traceAmbSourceK(Tree * t,Junction * alt1,Junction * alt2)1832 void MR_traceAmbSourceK(Tree *t,Junction *alt1,Junction *alt2)
1833 #else
1834 void MR_traceAmbSourceK(t,alt1,alt2)
1835 Tree *t;
1836 Junction *alt1;
1837 Junction *alt2;
1838 #endif
1839 {
1840 int i;
1841 int depth;
1842 int maxDepth;
1843 Tree *truncatedTree;
1844
1845 if (MR_AmbAidRule == NULL) return;
1846
1847 if ( ! (
1848 strcmp(MR_AmbAidRule,alt1->rname) == 0 ||
1849 strcmp(MR_AmbAidRule,alt2->rname) == 0 ||
1850 MR_AmbAidLine==alt1->line ||
1851 MR_AmbAidLine==alt2->line
1852 )
1853 ) return;
1854
1855 MR_matched_AmbAidRule++;
1856
1857 /* there are no token sets in trees, only in TokNodes */
1858
1859 MR_AmbSourceSearchJ[0]=analysis_point( (Junction *) alt1->p1);
1860 MR_AmbSourceSearchJ[1]=analysis_point( (Junction *) alt2->p1);
1861
1862 if (tokensInChain == NULL) {
1863 tokensInChain=(int *) calloc (CLL_k+1,sizeof(int));
1864 require (tokensInChain != NULL,"tokensInChain alloc");
1865 };
1866
1867 MR_AmbSourceSearchGroup=0;
1868
1869 fprintf(stdout,"\n");
1870 fprintf(stdout," Ambiguity Aid ");
1871 fprintf(stdout,
1872 (MR_AmbAidDepth <= LL_k ?
1873 "(-k %d -aa %s %s -aad %d)\n\n" :
1874 "(-k %d -aa %s %s [-k value limits -aad %d])\n\n"),
1875 LL_k,
1876 MR_AmbAidRule,
1877 (MR_AmbAidMultiple ? "-aam" : ""),
1878 MR_AmbAidDepth);
1879
1880 for (i=0 ; i < 2 ; i++) {
1881 fprintf(stdout," Choice %d: %-25s line %d file %s\n",
1882 (i+1),
1883 MR_ruleNamePlusOffset( (Node *) MR_AmbSourceSearchJ[i]),
1884 MR_AmbSourceSearchJ[i]->line,
1885 FileStr[MR_AmbSourceSearchJ[i]->file]);
1886 };
1887
1888 fprintf(stdout,"\n");
1889
1890 if (MR_AmbAidDepth < LL_k) {
1891 maxDepth=MR_AmbAidDepth;
1892 } else {
1893 maxDepth=LL_k;
1894 };
1895
1896 for (depth=1 ; depth <= maxDepth; depth++) {
1897 MR_AmbSourceSearchLimit=depth;
1898 if (depth < LL_k) {
1899 truncatedTree=tTrunc(t,depth);
1900 truncatedTree=tleft_factor(truncatedTree);
1901 MR_iterateOverTree(truncatedTree,&tokensInChain[1]); /* <===== */
1902 Tfree(truncatedTree);
1903 } else {
1904 MR_iterateOverTree(t,tokensInChain); /* <===== */
1905 };
1906 fflush(stdout);
1907 fflush(stderr);
1908 };
1909
1910 fprintf(stdout,"\n");
1911 MR_AmbSourceSearch=0;
1912 MR_MaintainBackTrace=0;
1913 MR_AmbSourceSearchGroup=0;
1914 MR_AmbSourceSearchChoice=0;
1915 MR_AmbSourceSearchLimit=0;
1916
1917 }
1918
1919
1920 /* this if for k=1 grammars only
1921
1922 this is approximate only because of the limitations of linear
1923 approximation lookahead. Don't want to do a k=3 search when
1924 the user only specified a ck=3 grammar
1925 */
1926
1927 #ifdef __USE_PROTOS
MR_traceAmbSource(set * matchSets,Junction * alt1,Junction * alt2)1928 void MR_traceAmbSource(set *matchSets,Junction *alt1, Junction *alt2)
1929 #else
1930 void MR_traceAmbSource(matchSets,alt1,alt2)
1931 set *matchSets;
1932 Junction *alt1;
1933 Junction *alt2;
1934 #endif
1935 {
1936 set *save_fset;
1937 Junction *p[2];
1938 int i;
1939 int j;
1940 set *dup_matchSets;
1941 set intersection;
1942 set incomplete;
1943 set tokensUsed;
1944 int depth;
1945
1946 if (MR_AmbAidRule == NULL) return;
1947 if ( ! (
1948 strcmp(MR_AmbAidRule,alt1->rname) == 0 ||
1949 strcmp(MR_AmbAidRule,alt2->rname) == 0 ||
1950 MR_AmbAidLine==alt1->line ||
1951 MR_AmbAidLine==alt2->line
1952 )
1953 ) return;
1954
1955 MR_matched_AmbAidRule++;
1956
1957 save_fset=fset;
1958
1959 dup_matchSets=(set *) calloc(CLL_k+1,sizeof(set));
1960 require (dup_matchSets != NULL,"Can't allocate dup_matchSets");
1961
1962 p[0]=analysis_point( (Junction *) alt1->p1);
1963 p[1]=analysis_point( (Junction *) alt2->p1);
1964
1965 fprintf(stdout,"\n");
1966
1967 fprintf(stdout," Ambiguity Aid ");
1968 fprintf(stdout,
1969 (MR_AmbAidDepth <= CLL_k ?
1970 "(-ck %d -aa %s %s -aad %d)\n\n" :
1971 "(-ck %d -aa %s %s [-ck value limits -aad %d])\n\n"),
1972 CLL_k,
1973 MR_AmbAidRule,
1974 (MR_AmbAidMultiple ? "-aam" : ""),
1975 MR_AmbAidDepth);
1976
1977 for (i=0 ; i < 2 ; i++) {
1978 fprintf(stdout," Choice %d: %-25s line %d file %s\n",
1979 (i+1),
1980 MR_ruleNamePlusOffset( (Node *) p[i]),
1981 p[i]->line,FileStr[p[i]->file]);
1982 };
1983
1984 for (j=1; j <= CLL_k ; j++) {
1985 fprintf(stdout,"\n Intersection of lookahead[%d] sets:\n",j);
1986 intersection=set_and(alt1->fset[j],alt2->fset[j]);
1987 MR_dumpTokenSet(stdout,2,intersection);
1988 set_free(intersection);
1989 };
1990
1991 fprintf(stdout,"\n");
1992
1993 require (1 <= MR_AmbAidDepth && MR_AmbAidDepth <= CLL_k,
1994 "illegal MR_AmbAidDepth");
1995
1996 MR_AmbSourceSearchGroup=0;
1997 for (depth=1; depth <= MR_AmbAidDepth; depth++) {
1998 MR_AmbSourceSearchLimit=depth;
1999 for (i=0 ; i < 2 ; i++) {
2000
2001 /*** fprintf(stdout," Choice:%d Depth:%d\n\n",i+1,depth); ***/
2002
2003 for (j=0 ; j <= CLL_k ; j++) { dup_matchSets[j]=set_dup(matchSets[j]); };
2004 fset=dup_matchSets;
2005
2006 fflush(output);
2007 fflush(stdout);
2008
2009 MR_AmbSourceSearch=1;
2010 MR_MaintainBackTrace=1;
2011 MR_AmbSourceSearchChoice=i;
2012
2013 maxk = depth;
2014 tokensUsed=empty;
2015 incomplete=empty;
2016
2017 constrain = &(fset[1]);
2018 MR_pointerStackReset(&MR_BackTraceStack);
2019
2020 REACH(p[i],depth,&incomplete,tokensUsed);
2021
2022 fflush(output);
2023 fflush(stdout);
2024
2025 require (set_nil(incomplete),"MR_traceAmbSource REACH incomplete");
2026 require (MR_BackTraceStack.count == 0,"1: MR_BackTraceStack.count != 0");
2027
2028 set_free(incomplete);
2029 set_free(tokensUsed);
2030
2031 for (j=0 ; j <= CLL_k ; j++) { set_free(dup_matchSets[j]); };
2032 };
2033 };
2034
2035 fprintf(stdout,"\n");
2036
2037 MR_AmbSourceSearch=0;
2038 MR_MaintainBackTrace=0;
2039 MR_AmbSourceSearchGroup=0;
2040 MR_AmbSourceSearchChoice=0;
2041 MR_AmbSourceSearchLimit=0;
2042
2043 fset=save_fset;
2044 free ( (char *) dup_matchSets);
2045 }
2046
2047 static int itemCount;
2048
MR_backTraceDumpItemReset()2049 void MR_backTraceDumpItemReset() {
2050 itemCount=0;
2051 }
2052
2053 #ifdef __USE_PROTOS
MR_backTraceDumpItem(FILE * f,int skip,Node * n)2054 void MR_backTraceDumpItem(FILE *f,int skip,Node *n)
2055 #else
2056 void MR_backTraceDumpItem(f,skip,n)
2057 FILE *f;
2058 int skip;
2059 Node *n;
2060 #endif
2061 {
2062 TokNode *tn;
2063 RuleRefNode *rrn;
2064 Junction *j;
2065 ActionNode *a;
2066
2067 switch (n->ntype) {
2068 case nToken:
2069 itemCount++; if (skip) goto EXIT;
2070 tn=(TokNode *)n;
2071 if (set_nil(tn->tset)) {
2072 fprintf(f," %2d #token %-23s",itemCount,TerminalString(tn->token));
2073 } else {
2074 fprintf(f," %2d #tokclass %-20s",itemCount,TerminalString(tn->token));
2075 };
2076 break;
2077 case nRuleRef:
2078 itemCount++; if (skip) goto EXIT;
2079 rrn=(RuleRefNode *)n;
2080 fprintf(f," %2d to %-27s",itemCount,rrn->text);
2081 break;
2082 case nAction:
2083 a=(ActionNode *)n;
2084 goto EXIT;
2085 case nJunction:
2086
2087 j=(Junction *)n;
2088
2089 switch (j->jtype) {
2090 case aSubBlk:
2091 if (j->guess) {
2092 itemCount++; if (skip) goto EXIT;
2093 fprintf(f," %2d %-30s",itemCount,"in (...)? block at");
2094 break;
2095 };
2096 /****** fprintf(f," %2d %-32s",itemCount,"in (...) block at"); *******/
2097 /****** break; *******/
2098 goto EXIT;
2099 case aOptBlk:
2100 itemCount++; if (skip) goto EXIT;
2101 fprintf(f," %2d %-30s",itemCount,"in {...} block");
2102 break;
2103 case aLoopBlk:
2104 itemCount++; if (skip) goto EXIT;
2105 fprintf(f," %2d %-30s",itemCount,"in (...)* block");
2106 break;
2107 case EndBlk:
2108 if (j->alpha_beta_guess_end) {
2109 itemCount++; if (skip) goto EXIT;
2110 fprintf(f," %2d %-30s",itemCount,"end (...)? block at");
2111 break;
2112 };
2113 goto EXIT;
2114 /****** fprintf(f," %2d %-32s",itemCount,"end of a block at"); *****/
2115 /****** break; *****/
2116 case RuleBlk:
2117 itemCount++; if (skip) goto EXIT;
2118 fprintf(f," %2d %-30s",itemCount,j->rname);
2119 break;
2120 case Generic:
2121 goto EXIT;
2122 case EndRule:
2123 itemCount++; if (skip) goto EXIT;
2124 fprintf (f," %2d end %-26s",itemCount,j->rname);
2125 break;
2126 case aPlusBlk:
2127 itemCount++; if (skip) goto EXIT;
2128 fprintf(f," %2d %-30s",itemCount,"in (...)+ block");
2129 break;
2130 case aLoopBegin:
2131 goto EXIT;
2132 };
2133 break;
2134 };
2135 fprintf(f," %-23s line %-4d %s\n",MR_ruleNamePlusOffset(n),n->line,FileStr[n->file]);
2136 EXIT:
2137 return;
2138 }
2139
2140
2141 static PointerStack previousBackTrace={0,0,NULL};
2142
2143 #ifdef __USE_PROTOS
MR_backTraceReport(void)2144 void MR_backTraceReport(void)
2145 #else
2146 void MR_backTraceReport()
2147 #endif
2148 {
2149 int i;
2150 int match = 0;
2151 int limitMatch;
2152
2153 Node *p;
2154 TokNode *tn;
2155 set remainder;
2156 int depth;
2157
2158 /* Even when doing a k=2 search this routine can get
2159 called when there is only 1 token on the stack.
2160 This is because something like rRuleRef can change
2161 the search value of k from 2 to 1 temporarily.
2162 It does this because the it wants to know the k=1
2163 first set before it does a k=2 search
2164 */
2165
2166 depth=0;
2167 for (i=0; i < MR_BackTraceStack.count ; i++) {
2168 p=(Node *) MR_BackTraceStack.data[i];
2169 if (p->ntype == nToken) depth++;
2170 };
2171
2172 /* MR14 */ if (MR_AmbSourceSearch) {
2173 /* MR14 */ require (depth <= MR_AmbSourceSearchLimit,"depth > MR_AmbSourceSearchLimit");
2174 /* MR14 */ }
2175
2176 /* MR23 THM - Traceback report was being called at the wrong time for -alpha reports */
2177 /* Reported by Arpad Beszedes (beszedes@inf.u-szeged.hu) */
2178
2179 if (MR_AmbSourceSearchLimit == 0 || depth < MR_AmbSourceSearchLimit) {
2180 return;
2181 };
2182
2183 MR_backTraceDumpItemReset();
2184
2185 limitMatch=MR_BackTraceStack.count;
2186 if (limitMatch > previousBackTrace.count) {
2187 limitMatch=previousBackTrace.count;
2188 };
2189
2190 for (match=0; match < limitMatch; match++) {
2191 if (MR_BackTraceStack.data[match] !=
2192 previousBackTrace.data[match]) {
2193 break;
2194 };
2195 };
2196
2197 /* not sure at the moment why there would be duplicates */
2198
2199 if (match != MR_BackTraceStack.count) {
2200
2201 fprintf(stdout," Choice:%d Depth:%d Group:%d",
2202 (MR_AmbSourceSearchChoice+1),
2203 MR_AmbSourceSearchLimit,
2204 ++MR_AmbSourceSearchGroup);
2205
2206 depth=0;
2207 fprintf(stdout," (");
2208 for (i=0; i < MR_BackTraceStack.count ; i++) {
2209 p=(Node *) MR_BackTraceStack.data[i];
2210 if (p->ntype != nToken) continue;
2211 tn=(TokNode *)p;
2212 if (depth != 0) fprintf(stdout," ");
2213 fprintf(stdout, "%s", TerminalString(tn->token));
2214 depth++;
2215 if (! MR_AmbAidMultiple) {
2216 if (set_nil(tn->tset)) {
2217 set_rm( (unsigned) tn->token,fset[depth]);
2218 } else {
2219 remainder=set_dif(fset[depth],tn->tset);
2220 set_free(fset[depth]);
2221 fset[depth]=remainder;
2222 };
2223 };
2224 };
2225 fprintf(stdout,")\n");
2226
2227 for (i=0; i < MR_BackTraceStack.count ; i++) {
2228 MR_backTraceDumpItem(stdout, (i<match) ,(Node *) MR_BackTraceStack.data[i]);
2229 };
2230 fprintf(stdout,"\n");
2231 fflush(stdout);
2232
2233 MR_pointerStackReset(&previousBackTrace);
2234
2235 for (i=0; i < MR_BackTraceStack.count ; i++) {
2236 MR_pointerStackPush(&previousBackTrace,MR_BackTraceStack.data[i]);
2237 };
2238
2239 };
2240 }
2241
2242 #ifdef __USE_PROTOS
MR_setConstrainPointer(set * newConstrainValue)2243 void MR_setConstrainPointer(set * newConstrainValue)
2244 #else
2245 void MR_setConstrainPointer(newConstrainValue)
2246 set * newConstrainValue;
2247 #endif
2248 {
2249 constrain=newConstrainValue;
2250 }
2251