diff options
Diffstat (limited to 'BaseTools/Source/C/VfrCompile/Pccts/antlr/fset.c')
| -rw-r--r-- | BaseTools/Source/C/VfrCompile/Pccts/antlr/fset.c | 1555 |
1 files changed, 0 insertions, 1555 deletions
diff --git a/BaseTools/Source/C/VfrCompile/Pccts/antlr/fset.c b/BaseTools/Source/C/VfrCompile/Pccts/antlr/fset.c deleted file mode 100644 index e1a76ec620..0000000000 --- a/BaseTools/Source/C/VfrCompile/Pccts/antlr/fset.c +++ /dev/null @@ -1,1555 +0,0 @@ -/*
- * fset.c
- *
- * Compute FIRST and FOLLOW sets.
- *
- * SOFTWARE RIGHTS
- *
- * We reserve no LEGAL rights to the Purdue Compiler Construction Tool
- * Set (PCCTS) -- PCCTS is in the public domain. An individual or
- * company may do whatever they wish with source code distributed with
- * PCCTS or the code generated by PCCTS, including the incorporation of
- * PCCTS, or its output, into commerical software.
- *
- * We encourage users to develop software with PCCTS. However, we do ask
- * that credit is given to us for developing PCCTS. By "credit",
- * we mean that if you incorporate our source code into one of your
- * programs (commercial product, research project, or otherwise) that you
- * acknowledge this fact somewhere in the documentation, research report,
- * etc... If you like PCCTS and have developed a nice tool with the
- * output, please mention that you developed it using PCCTS. In
- * addition, we ask that this header remain intact in our source code.
- * As long as these guidelines are kept, we expect to continue enhancing
- * this system and expect to make other tools available as they are
- * completed.
- *
- * ANTLR 1.33
- * Terence Parr
- * Parr Research Corporation
- * with Purdue University and AHPCRC, University of Minnesota
- * 1989-2001
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-
-#include "pcctscfg.h"
-
-#include "set.h"
-#include "syn.h"
-#include "hash.h"
-#include "generic.h"
-#include "dlgdef.h"
-#include "limits.h"
-
-#ifdef __USE_PROTOS
-static void ensure_predicates_cover_ambiguous_lookahead_sequences
- (Junction *, Junction *, char *, Tree *);
-#else
-static void ensure_predicates_cover_ambiguous_lookahead_sequences();
-#endif
-
-/*
- * What tokens are k tokens away from junction q?
- *
- * Follow both p1 and p2 paths (unless RuleBlk) to collect the tokens k away from this
- * node.
- * We lock the junction according to k--the lookahead. If we have been at this
- * junction before looking for the same, k, number of lookahead tokens, we will
- * do it again and again...until we blow up the stack. Locks are only used on aLoopBlk,
- * RuleBlk, aPlusBlk and EndRule junctions to remove/detect infinite recursion from
- * FIRST and FOLLOW calcs.
- *
- * If p->jtype == EndRule we are going to attempt a FOLLOW. (FOLLOWs are really defined
- * in terms of FIRST's, however). To proceed with the FOLLOW, p->halt cannot be
- * set. p->halt is set to indicate that a reference to the current rule is in progress
- * and the FOLLOW is not desirable.
- *
- * If we attempt a FOLLOW and find that there is no FOLLOW or REACHing beyond the EndRule
- * junction yields an empty set, replace the empty set with EOF. No FOLLOW means that
- * only EOF can follow the current rule. This normally occurs only on the start symbol
- * since all other rules are referenced by another rule somewhere.
- *
- * Normally, both p1 and p2 are followed. However, checking p2 on a RuleBlk node is
- * the same as checking the next rule which is clearly incorrect.
- *
- * Cycles in the FOLLOW sense are possible. e.g. Fo(c) requires Fo(b) which requires
- * Fo(c). Both Fo(b) and Fo(c) are defined to be Fo(b) union Fo(c). Let's say
- * Fo(c) is attempted first. It finds all of the FOLLOW symbols and then attempts
- * to do Fo(b) which finds of its FOLLOW symbols. So, we have:
- *
- * Fo(c)
- * / \
- * a set Fo(b)
- * / \
- * a set Fo(c) .....Hmmmm..... Infinite recursion!
- *
- * The 2nd Fo(c) is not attempted and Fo(b) is left deficient, but Fo(c) is now
- * correctly Fo(c) union Fo(b). We wish to pick up where we left off, so the fact
- * that Fo(b) terminated early means that we lack Fo(c) in the Fo(b) set already
- * laying around. SOOOOoooo, we track FOLLOW cycles. All FOLLOW computations are
- * cached in a hash table. After the sequence of FOLLOWs finish, we reconcile all
- * cycles --> correct all Fo(rule) sets in the cache.
- *
- * Confused? Good! Read my MS thesis [Purdue Technical Report TR90-30].
- * TJP 8/93 -- can now read PhD thesis from Purdue.
- *
- * Also, FIRST sets are cached in the hash table. Keys are (rulename,Fi/Fo,k).
- * Only FIRST sets, for which the FOLLOW is not included, are stored.
- *
- * SPECIAL CASE of (...)+ blocks:
- * I added an optional alt so that the alts could see what
- * was behind the (...)+ block--thus using enough lookahead
- * to branch out rather than just enough to distinguish
- * between alts in the (...)+. However, when the FIRST("(...)+") is
- * is needed, must not use this last "optional" alt. This routine
- * turns off this path by setting a new 'ignore' flag for
- * the alt and then resetting it afterwards.
- */
-
-set
-#ifdef __USE_PROTOS
-rJunc( Junction *p, int k, set *rk )
-#else
-rJunc( p, k, rk )
-Junction *p;
-int k;
-set *rk;
-#endif
-{
- set a, b;
-
- require(p!=NULL, "rJunc: NULL node");
- require(p->ntype==nJunction, "rJunc: not junction");
-
-#ifdef DBG_LL1
- if ( p->jtype == RuleBlk ) fprintf(stderr, "FIRST(%s,%d) \n",((Junction *)p)->rname,k);
- else fprintf(stderr, "rJunc: %s in rule %s\n",
- decodeJType[p->jtype], ((Junction *)p)->rname);
-#endif
- /* if this is one of the added optional alts for (...)+ then return */
-
- /* no need to pop backtrace - hasn't been pushed */
-
- if ( p->ignore ) return empty;
-
- if (MR_MaintainBackTrace) MR_pointerStackPush(&MR_BackTraceStack,p);
-
-/* MR14 */ if (AlphaBetaTrace && p->alpha_beta_guess_end) {
-/* MR14 */ warnFL(
-/* MR14 */ "not possible to compute follow set for alpha in an \"(alpha)? beta\" block. ",
-/* MR14 */ FileStr[p->file],p->line);
-/* MR14 */ MR_alphaBetaTraceReport();
-/* MR14 */ };
-
-/* MR14 */ if (p->alpha_beta_guess_end) {
-/* MR14 */ if (MR_MaintainBackTrace) MR_pointerStackPop(&MR_BackTraceStack);
-/* MR14 */ return empty;
-/* MR14 */ }
-
- /* locks are valid for aLoopBlk,aPlusBlk,RuleBlk,EndRule junctions only */
- if ( p->jtype==aLoopBlk || p->jtype==RuleBlk ||
- p->jtype==aPlusBlk || p->jtype==EndRule )
- {
- require(p->lock!=NULL, "rJunc: lock array is NULL");
- if ( p->lock[k] )
- {
- if ( p->jtype == EndRule ) /* FOLLOW cycle? */
- {
-#ifdef DBG_LL1
- fprintf(stderr, "FOLLOW cycle to %s: panic!\n", p->rname);
-#endif
- if (! MR_AmbSourceSearch) RegisterCycle(p->rname, k);
- }
- if (MR_MaintainBackTrace) MR_pointerStackPop(&MR_BackTraceStack);
- return empty;
- }
- if ( p->jtype == RuleBlk &&
- p->end->halt &&
- ! MR_AmbSourceSearch) /* check for FIRST cache */
- {
- CacheEntry *q = (CacheEntry *) hash_get(Fcache, Fkey(p->rname,'i',k));
- if ( q != NULL )
- {
- set_orin(rk, q->rk);
- if (MR_MaintainBackTrace) MR_pointerStackPop(&MR_BackTraceStack);
- return set_dup( q->fset );
- }
- }
- if ( p->jtype == EndRule &&
- !p->halt && /* MR11 was using cache even when halt set */
- ! MR_AmbSourceSearch) /* FOLLOW set cached already? */
- {
- CacheEntry *q = (CacheEntry *) hash_get(Fcache, Fkey(p->rname,'o',k));
- if ( q != NULL )
- {
-#ifdef DBG_LL1
- fprintf(stderr, "cache for FOLLOW(%s,%d):", p->rname,k);
- s_fprT(stderr, q->fset);
- if ( q->incomplete ) fprintf(stderr, " (incomplete)");
- fprintf(stderr, "\n");
-#endif
- if ( !q->incomplete )
- {
- if (MR_MaintainBackTrace) MR_pointerStackPop(&MR_BackTraceStack);
- return set_dup( q->fset );
- }
- }
- }
- p->lock[k] = TRUE; /* This rule is busy */
- }
-
- a = b = empty;
-
- if ( p->jtype == EndRule )
- {
- if (p->halt ) /* don't want FOLLOW here? */ /* unless MR10 hoisting */
- {
- p->lock[k] = FALSE;
- set_orel(k, rk); /* indicate this k value needed */
- if (MR_MaintainBackTrace) MR_pointerStackPop(&MR_BackTraceStack);
- return empty;
- }
- if (! MR_AmbSourceSearch) FoPush(p->rname, k); /* Attempting FOLLOW */
- if ( p->p1 == NULL ) set_orel((TokenInd!=NULL?TokenInd[EofToken]:EofToken), &a);/* if no FOLLOW assume EOF */
-#ifdef DBG_LL1
- fprintf(stderr, "-->FOLLOW(%s,%d)\n", p->rname,k);
-#endif
- }
-
- if ( p->p1 != NULL ) {
-/* MR14 */ if (p->guess) {
-/* MR14 */ if (p->guess_analysis_point == NULL) {
-/* MR14 */ Node * guess_point;
-/* MR14 */ guess_point=(Node *)analysis_point(p);
-/* MR14 */ if (guess_point == (Node *)p) {
-/* MR14 */ guess_point=p->p1;
-/* MR14 */ }
-/* MR14 */ p->guess_analysis_point=guess_point;
-/* MR14 */ }
-/* MR14 */ REACH(p->guess_analysis_point, k, rk, a);
- } else {
- REACH(p->p1, k, rk, a);
- }
- }
-
- /* C a c h e R e s u l t s */
-
- if ( p->jtype == RuleBlk && p->end->halt && ! MR_AmbSourceSearch) /* can save FIRST set? */
- {
- CacheEntry *q = newCacheEntry( Fkey(p->rname,'i',k) );
- /*fprintf(stderr, "Caching %s FIRST %d\n", p->rname, k);*/
- hash_add(Fcache, Fkey(p->rname,'i',k), (Entry *)q);
- q->fset = set_dup( a );
- q->rk = set_dup( *rk );
- }
-
- if ( p->jtype == EndRule &&
- !p->halt && /* MR11 was using cache even with halt set */
- ! MR_AmbSourceSearch) /* just completed FOLLOW? */
- {
- /* Cache Follow set */
- CacheEntry *q = (CacheEntry *) hash_get(Fcache, Fkey(p->rname,'o',k));
- if ( q==NULL )
- {
- q = newCacheEntry( Fkey(p->rname,'o',k) );
- hash_add(Fcache, Fkey(p->rname,'o',k), (Entry *)q);
- }
- /*fprintf(stderr, "Caching %s FOLLOW %d\n", p->rname, k);*/
- if ( set_nil(a) && !q->incomplete )
- {
- /* Don't ever save a nil set as complete.
- * Turn it into an eof set.
- */
- set_orel(EofToken, &a);
- }
- set_orin(&(q->fset), a);
- FoPop( k );
- if ( FoTOS[k] == NULL && Cycles[k] != NULL ) ResolveFoCycles(k);
-#ifdef DBG_LL1
- fprintf(stderr, "saving FOLLOW(%s,%d):", p->rname, k);
- s_fprT(stderr, q->fset);
- if ( q->incomplete ) fprintf(stderr, " (incomplete)");
- fprintf(stderr, "\n");
-#endif
- }
-
- if (p->jtype != RuleBlk && p->p2 != NULL && /* MR14 */ ! p->guess) {
- REACH(p->p2, k, rk, b);
- }
-
- if ( p->jtype==aLoopBlk || p->jtype==RuleBlk ||
- p->jtype==aPlusBlk || p->jtype==EndRule )
- p->lock[k] = FALSE; /* unlock node */
-
- set_orin(&a, b);
- set_free(b);
- if (MR_MaintainBackTrace) MR_pointerStackPop(&MR_BackTraceStack);
- return a;
-}
-
-set
-#ifdef __USE_PROTOS
-rRuleRef( RuleRefNode *p, int k, set *rk_out )
-#else
-rRuleRef( p, k, rk_out )
-RuleRefNode *p;
-int k;
-set *rk_out;
-#endif
-{
- set rk;
- Junction *r;
- int k2;
- set a, rk2, b;
- int save_halt;
- RuleEntry *q = (RuleEntry *) hash_get(Rname, p->text);
- require(p!=NULL, "rRuleRef: NULL node");
- require(p->ntype==nRuleRef, "rRuleRef: not rule ref");
-
-#ifdef DBG_LL1
- fprintf(stderr, "rRuleRef: %s\n", p->text);
-#endif
-
- if (MR_MaintainBackTrace) MR_pointerStackPush(&MR_BackTraceStack,p);
-
- if ( q == NULL )
- {
- warnFL( eMsg1("rule %s not defined",p->text), FileStr[p->file], p->line );
- REACH(p->next, k, rk_out, a);
- if (MR_MaintainBackTrace) MR_pointerStackPop(&MR_BackTraceStack);
- return a;
- }
- rk2 = empty;
-
-/* MR9 Problems with rule references in guarded predicates */
-/* MR9 Perhaps can use hash table to find rule ? */
-
-/* MR9 */ if (RulePtr == NULL) {
-/* MR9 */ fatalFL(eMsg2("Rule %s uses rule %s via RulePtr before it has been initialized",
-/* MR9 */ p->rname,q->str),FileStr[p->file],p->line);
-/* MR9 */ };
-
- r = RulePtr[q->rulenum];
- if ( r->lock[k] )
- {
- errNoFL( eMsg2("infinite left-recursion to rule %s from rule %s",
- r->rname, p->rname) );
-
- if (MR_MaintainBackTrace) MR_pointerStackPop(&MR_BackTraceStack);
-
- return empty;
- }
-
- save_halt = r->end->halt;
- r->end->halt = TRUE; /* don't let reach fall off end of rule here */
- rk = empty;
- REACH(r, k, &rk, a);
- r->end->halt = save_halt;
- while ( !set_nil(rk) ) {
- k2 = set_int(rk); /* MR11 this messes up the ambiguity search routine */
- set_rm(k2, rk);
- REACH(p->next, k2, &rk2, b); /* MR11 by changing the value of k */
- set_orin(&a, b);
- set_free(b);
- }
- set_free(rk); /* this has no members, but free it's memory */
- set_orin(rk_out, rk2); /* remember what we couldn't do */
- set_free(rk2);
- if (MR_MaintainBackTrace) MR_pointerStackPop(&MR_BackTraceStack);
- return a;
-}
-
-/*
- * Return FIRST sub k ( token_node )
- *
- * TJP 10/11/93 modified this so that token nodes that are actually
- * ranges (T1..T2) work.
- */
-set
-#ifdef __USE_PROTOS
-rToken( TokNode *p, int k, set *rk )
-#else
-rToken( p, k, rk )
-TokNode *p;
-int k;
-set *rk;
-#endif
-{
- set a;
-
- require(p!=NULL, "rToken: NULL node");
- require(p->ntype==nToken, "rToken: not token node");
-
-#ifdef DBG_LL1
- fprintf(stderr, "rToken: %s\n", (TokenString(p->token)!=NULL)?TokenString(p->token):
- ExprString(p->token));
-#endif
-
-
- if (MR_MaintainBackTrace) MR_pointerStackPush(&MR_BackTraceStack,p);
-
- if (MR_AmbSourceSearch && (k-1) == 0) {
-
- set localConstrain;
- set intersection;
-
- localConstrain=fset[maxk-k+1];
-
- if (! set_nil(p->tset)) {
- intersection=set_and(localConstrain,p->tset);
- if (! set_nil(intersection)) {
- MR_backTraceReport();
- };
- set_free(intersection);
- } else {
- if (set_el( (unsigned) p->token,localConstrain)) {
- MR_backTraceReport();
- }
- };
- };
-
- if ( k-1 == 0 ) {
-
- if (MR_MaintainBackTrace) MR_pointerStackPop(&MR_BackTraceStack);
-
- if ( !set_nil(p->tset) ) {
- return set_dup(p->tset);
- } else {
- return set_of(p->token);
- };
- }
-
- REACH(p->next, k-1, rk, a);
-
- if (MR_MaintainBackTrace) MR_pointerStackPop(&MR_BackTraceStack);
-
- return a;
-}
-
-set
-#ifdef __USE_PROTOS
-rAction( ActionNode *p, int k, set *rk )
-#else
-rAction( p, k, rk )
-ActionNode *p;
-int k;
-set *rk;
-#endif
-{
- set a;
-
- require(p!=NULL, "rJunc: NULL node");
- require(p->ntype==nAction, "rJunc: not action");
-
-/* MR11 */ if (p->is_predicate && p->ampersandPred != NULL) {
-/* MR11 */ Predicate *pred=p->ampersandPred;
-/* MR11 */ if (k <= pred->k) {
-/* MR11 */ REACH(p->guardNodes,k,rk,a);
-/* MR11 */ return a;
-/* MR11 */ };
-/* MR11 */ };
-
- /* it might be a good idea when doing an MR_AmbSourceSearch
- to *not* look behind predicates under some circumstances
- we'll look into that later
- */
-
- REACH(p->next, k, rk, a); /* ignore actions */
- return a;
-}
-
- /* A m b i g u i t y R e s o l u t i o n */
-
-
-void
-#ifdef __USE_PROTOS
-dumpAmbigMsg( set *fset, FILE *f, int want_nls )
-#else
-dumpAmbigMsg( fset, f, want_nls )
-set *fset;
-FILE *f;
-int want_nls;
-#endif
-{
- int i;
-
- set copy; /* MR11 */
-
- if ( want_nls ) fprintf(f, "\n\t");
- else fprintf(f, " ");
-
- for (i=1; i<=CLL_k; i++)
- {
- copy=set_dup(fset[i]); /* MR11 */
-
- if ( i>1 )
- {
- if ( !want_nls ) fprintf(f, ", ");
- }
- if ( set_deg(copy) > 3 && elevel == 1 )
- {
- int e,m;
- fprintf(f, "{");
- for (m=1; m<=3; m++)
- {
- e=set_int(copy);
- fprintf(f, " %s", TerminalString(e));
- set_rm(e, copy);
- }
- fprintf(f, " ... }");
- }
- else s_fprT(f, copy);
- if ( want_nls ) fprintf(f, "\n\t");
- set_free(copy);
- }
- fprintf(f, "\n");
-
-}
-
-static void
-#ifdef __USE_PROTOS
-verify_context(Predicate *predicate)
-#else
-verify_context(predicate)
-Predicate *predicate;
-#endif
-{
- if ( predicate == NULL ) return;
-
- if ( predicate->expr == PRED_OR_LIST ||
- predicate->expr == PRED_AND_LIST )
- {
- verify_context(predicate->down);
- verify_context(predicate->right); /* MR10 */
- return;
- }
-
- if ( !predicate->source->ctxwarned && predicate->source->guardpred==NULL &&
- ((predicate->k > 1 &&
- !is_single_tuple(predicate->tcontext)) ||
- ( predicate->k == 1 &&
- set_deg(predicate->scontext[1])>1 )) )
- {
-
-/* MR9 Suppress annoying messages caused by our own clever(?) fix */
-
- fprintf(stderr, ErrHdr, FileStr[predicate->source->file],
- predicate->source->line);
- fprintf(stderr, " warning: predicate applied for >1 lookahead %d-sequences\n", predicate->k);
- fprintf(stderr, ErrHdr, FileStr[predicate->source->file],
- predicate->source->line);
- fprintf(stderr, " predicate text: \"%s\"\n",
- (predicate->expr == NULL ? "(null)" : predicate->expr) );
- fprintf(stderr, ErrHdr, FileStr[predicate->source->file],
- predicate->source->line);
- fprintf(stderr, " You may only want one lookahead %d-sequence to apply\n", predicate->k);
- fprintf(stderr, ErrHdr, FileStr[predicate->source->file],
- predicate->source->line);
- fprintf(stderr, " Try using a context guard '(...)? =>'\n");
- predicate->source->ctxwarned = 1;
- }
- verify_context(predicate->right); /* MR10 */
-}
-
-/*
- * If delta is the set of ambiguous lookahead sequences, then make sure that
- * the predicate(s) for productions alt1,alt2 cover the sequences in delta.
- *
- * For example,
- * a : <<PRED1>>? (A B|A C)
- * | b
- * ;
- * b : <<PRED2>>? A B
- * | A C
- * ;
- *
- * This should give a warning that (A C) predicts both productions and alt2
- * does not have a predicate in the production that generates (A C).
- *
- * The warning detection is simple. Let delta = LOOK(alt1) intersection LOOK(alt2).
- * Now, if ( delta set-difference context(predicates-for-alt1) != empty then
- * alt1 does not "cover" all ambiguous sequences.
- *
- * If ambig is nonempty, then ambig in LL(k) sense -> use tree info; else use fset
- * info. Actually, sets are used only if k=1 for this grammar.
- */
-static void
-#ifdef __USE_PROTOS
-ensure_predicates_cover_ambiguous_lookahead_sequences
- ( Junction *alt1, Junction *alt2, char *sub, Tree *ambig )
-#else
-ensure_predicates_cover_ambiguous_lookahead_sequences( alt1, alt2, sub, ambig )
-Junction *alt1;
-Junction *alt2;
-char *sub;
-Tree *ambig;
-#endif
-{
- if ( !ParseWithPredicates ) return;
-
- if ( ambig!=NULL )
- {
- Tree *non_covered = NULL;
- if ( alt1->predicate!=NULL )
- non_covered = tdif(ambig, alt1->predicate, alt1->fset, alt2->fset);
- if ( (non_covered!=NULL || alt1->predicate==NULL) && WarningLevel>1 )
- {
- fprintf(stderr, ErrHdr, FileStr[alt1->file], alt1->line);
- fprintf(stderr, " warning: alt %d %shas no predicate to resolve ambiguity",
- alt1->altnum, sub);
- if ( alt1->predicate!=NULL && non_covered!=NULL )
- {
- fprintf(stderr, " upon");
- preorder(non_covered);
- }
- else if ( alt1->predicate==NULL )
- {
- fprintf(stderr, " upon");
- preorder(ambig->down);
- }
- fprintf(stderr, "\n");
- }
- Tfree(non_covered);
- non_covered = NULL;
- if ( alt2->predicate!=NULL )
- non_covered = tdif(ambig, alt2->predicate, alt1->fset, alt2->fset);
- if ( (non_covered!=NULL || alt2->predicate==NULL) && WarningLevel>1 )
- {
- fprintf(stderr, ErrHdr, FileStr[alt2->file], alt2->line);
- fprintf(stderr, " warning: alt %d %shas no predicate to resolve ambiguity",
- alt2->altnum, sub);
- if ( alt2->predicate!=NULL && non_covered!=NULL )
- {
- fprintf(stderr, " upon");
- preorder(non_covered);
- }
- else if ( alt2->predicate==NULL )
- {
- fprintf(stderr, " upon");
- preorder(ambig->down);
- }
- fprintf(stderr, "\n");
- }
- Tfree(non_covered);
- }
- else if ( !set_nil(alt1->fset[1]) )
- {
- set delta, non_covered;
- delta = set_and(alt1->fset[1], alt2->fset[1]);
- non_covered = set_dif(delta, covered_set(alt1->predicate));
- if ( set_deg(non_covered)>0 && WarningLevel>1 )
- {
- fprintf(stderr, ErrHdr, FileStr[alt1->file], alt1->line);
- fprintf(stderr, " warning: alt %d %shas no predicate to resolve ambiguity",
- alt1->altnum, sub);
- if ( alt1->predicate!=NULL )
- {
- fprintf(stderr, " upon ");
- s_fprT(stderr, non_covered);
- }
- fprintf(stderr, "\n");
- }
- set_free( non_covered );
- non_covered = set_dif(delta, covered_set(alt2->predicate));
- if ( set_deg(non_covered)>0 && WarningLevel>1 )
- {
- fprintf(stderr, ErrHdr, FileStr[alt2->file], alt2->line);
- fprintf(stderr, " warning: alt %d %shas no predicate to resolve ambiguity",
- alt2->altnum, sub);
- if ( alt2->predicate!=NULL )
- {
- fprintf(stderr, " upon ");
- s_fprT(stderr, non_covered);
- }
- fprintf(stderr, "\n");
- }
- set_free( non_covered );
- set_free( delta );
- }
- else fatal_internal("productions have no lookahead in predicate checking routine");
-}
-
-#ifdef __USE_PROTOS
-void MR_doPredicatesHelp(int inGuessBlock,Junction *alt1,Junction *alt2,int jtype,char *sub)
-#else
-void MR_doPredicatesHelp(inGuessBlock,alt1,alt2,jtype,sub)
- int inGuessBlock;
- Junction *alt1;
- Junction *alt2;
- int jtype;
- char *sub;
-#endif
-{
- Predicate *p1;
- Predicate *p2;
-
- Junction *parentRule=MR_nameToRuleBlk(alt1->rname);
-
- if (inGuessBlock && WarningLevel <= 1) return;
-
- /* let antlr give the usual error message */
-
- if (alt1->predicate == NULL && alt2->predicate == NULL) return;
-
- if ( (jtype == RuleBlk || jtype == aSubBlk)
- && (alt1->predicate == NULL && alt2->predicate != NULL)) {
- fprintf(stderr, ErrHdr, FileStr[parentRule->file],parentRule->line);
- fprintf(stderr," warning: alt %d line %d and alt %d line %d of %s\n%s%s%s",
- alt1->altnum,
- alt1->line,
- alt2->altnum,
- alt2->line,
- sub,
- " These alts have ambig lookahead sequences resolved by a predicate for\n",
- " the second choice. The second choice may not be reachable.\n",
- " You may want to use a complementary predicate or rearrange the alts\n"
- );
- return;
- };
-
- /* first do the easy comparison. then do the hard one */
-
- if (MR_comparePredicates(alt1->predicate,alt2->predicate)) {
-
- if (jtype == aLoopBegin || jtype == aPlusBlk ) {
-
- /* I'm not sure this code is reachable.
- Predicates following a (...)+ or (...)* block are probably
- considered validation predicates and therefore not
- participate in the predication expression
- */
-
- fprintf(stderr, ErrHdr,FileStr[parentRule->file],parentRule->line);
- fprintf(stderr," warning: %s of %s in rule %s\n (file %s alt %d line %d and alt %d line %d)\n%s",
- "the predicates used to disambiguate optional/exit paths of ",
- sub,
- CurRule,
- FileStr[alt1->file],
- alt1->altnum,
- alt1->line,
- alt2->altnum,
- alt2->line,
- " are identical and have no resolving power\n");
- } else {
- fprintf(stderr, ErrHdr, FileStr[parentRule->file], parentRule->line);
- fprintf(stderr," warning: %s rule %s\n (file %s alt %d line %d and alt %d line %d)\n%s",
- "the predicates used to disambiguate",
- CurRule,
- FileStr[alt1->file],
- alt1->altnum,
- alt1->line,
- alt2->altnum,
- alt2->line,
- " are identical and have no resolving power\n");
- };
- } else {
- p1=predicate_dup_without_context(alt1->predicate);
- p1=MR_unfold(p1);
- MR_clearPredEntry(p1);
- MR_simplifyInverted(p1,0);
- p1=MR_predSimplifyALL(p1);
- p2=predicate_dup_without_context(alt2->predicate);
- p2=MR_unfold(p2);
- MR_clearPredEntry(p2);
- MR_simplifyInverted(p2,0);
- p2=MR_predSimplifyALL(p2);
- if (MR_comparePredicates(p1,p2)) {
- if (jtype == aLoopBegin || jtype == aPlusBlk ) {
- fprintf(stderr, ErrHdr, FileStr[parentRule->file], parentRule->line);
- fprintf(stderr," warning: %s of %s in rule %s\n (file %s alt %d line %d and alt %d line %d)\n%s%s",
- "the predicates used to disambiguate optional/exit paths of ",
- sub,
- CurRule,
- FileStr[alt1->file],
- alt1->altnum,
- alt1->line,
- alt2->altnum,
- alt2->line,
- " are identical when compared without context and may have no\n",
- " resolving power for some lookahead sequences.\n");
- } else {
- fprintf(stderr, ErrHdr, FileStr[parentRule->file], parentRule->line);
- fprintf(stderr," warning: %s rule %s\n (file %s alt %d line %d and alt %d line %d)\n%s%s",
- "the predicates used to disambiguate",
- CurRule,
- FileStr[alt1->file],
- alt1->altnum,
- alt1->line,
- alt2->altnum,
- alt2->line,
- " are identical when compared without context and may have no\n",
- " resolving power for some lookahead sequences.\n");
- };
- if (InfoP) {
- fprintf(output,"\n#if 0\n\n");
- fprintf(output,"The following predicates are identical when compared without\n");
- fprintf(output," lookahead context information. For some ambiguous lookahead\n");
- fprintf(output," sequences they may not have any power to resolve the ambiguity.\n");
- fprintf(output,"\n");
-
- fprintf(output,"Choice 1: %s alt %d line %d file %s\n\n",
- MR_ruleNamePlusOffset( (Node *) alt1),
- alt1->altnum,
- alt1->line,
- FileStr[alt1->file]);
- fprintf(output," The original predicate for choice 1 with available context information:\n\n");
- MR_dumpPred1(2,alt1->predicate,1);
- fprintf(output," The predicate for choice 1 after expansion (but without context information):\n\n");
- MR_dumpPred1(2,p1,0);
- if (p1 == NULL) {
- Predicate *phelp;
- fprintf(output," The predicate for choice 1 after expansion (but before simplification)\n\n");
- phelp=predicate_dup_without_context(alt1->predicate);
- phelp=MR_unfold(phelp);
- MR_clearPredEntry(phelp);
- MR_simplifyInverted(phelp,0);
- phelp=MR_predSimplifyALLX(phelp,1);
- MR_dumpPred1(2,phelp,0);
- predicate_free(phelp);
- };
- fprintf(output,"\n");
-
- fprintf(output,"Choice 2: %s alt %d line %d file %s\n\n",
- MR_ruleNamePlusOffset( (Node *) alt2),
- alt2->altnum,
- alt2->line,
- FileStr[alt2->file]);
- fprintf(output," The original predicate for choice 2 with available context information:\n\n");
- MR_dumpPred1(1,alt2->predicate,1);
- fprintf(output," The predicate for choice 2 after expansion (but without context information):\n\n");
- MR_dumpPred1(1,p2,0);
- if (p2 == NULL) {
- Predicate *phelp;
- fprintf(output," The predicate for choice 2 after expansion (but before simplification)\n\n");
- phelp=predicate_dup_without_context(alt2->predicate);
- phelp=MR_unfold(phelp);
- MR_clearPredEntry(phelp);
- MR_simplifyInverted(phelp,0);
- phelp=MR_predSimplifyALLX(phelp,1);
- MR_dumpPred1(2,phelp,0);
- predicate_free(phelp);
- };
- fprintf(output,"\n#endif\n");
- };
- } else if (MR_secondPredicateUnreachable(p1,p2)) {
- if (jtype == aLoopBegin || jtype == aPlusBlk ) {
- fprintf(stderr, ErrHdr, FileStr[parentRule->file], parentRule->line);
- fprintf(stderr," warning: %s of %s in rule %s\n (file %s alt %d line %d and alt %d line %d)\n%s%s",
- "the predicate used to disambiguate the first choice of the optional/exit paths of ",
- sub,
- CurRule,
- FileStr[alt1->file],
- alt1->altnum,
- alt1->line,
- alt2->altnum,
- alt2->line,
- " appears to \"cover\" the second predicate when compared without context.\n",
- " The second predicate may have no resolving power for some lookahead sequences.\n");
- } else {
- fprintf(stderr, ErrHdr, FileStr[parentRule->file], parentRule->line);
- fprintf(stderr," warning: %s rule %s\n (file %s alt %d line %d and alt %d line %d)\n%s%s",
- "the predicate used to disambiguate the first choice of",
- CurRule,
- FileStr[alt1->file],
- alt1->altnum,
- alt1->line,
- alt2->altnum,
- alt2->line,
- " appears to \"cover\" the second predicate when compared without context.\n",
- " The second predicate may have no resolving power for some lookahead sequences.\n");
- };
- if (InfoP) {
- fprintf(output,"\n#if 0\n\n");
- fprintf(output,"The first predicate appears to \"cover\" the second predicate when they\n");
- fprintf(output," are compared without lookahead context information. For some ambiguous\n");
- fprintf(output," lookahead sequences the second predicate may not have any power to\n");
- fprintf(output," resolve the ambiguity.\n");
- fprintf(output,"\n");
- fprintf(output,"Choice 1: %s alt %d line %d file %s\n\n",
- MR_ruleNamePlusOffset( (Node *) alt1),
- alt1->altnum,
- alt1->line,
- FileStr[alt1->file]);
- fprintf(output," The original predicate for choice 1 with available context information:\n\n");
- MR_dumpPred1(2,alt1->predicate,1);
- fprintf(output," The predicate for choice 1 after expansion (but without context information):\n\n");
- MR_dumpPred1(2,p1,0);
- if (p1 == NULL) {
- Predicate *phelp;
- fprintf(output," The predicate for choice 1 after expansion (but before simplification)\n\n");
- phelp=predicate_dup_without_context(alt1->predicate);
- phelp=MR_unfold(phelp);
- MR_clearPredEntry(phelp);
- MR_simplifyInverted(phelp,0);
- phelp=MR_predSimplifyALLX(phelp,1);
- MR_dumpPred1(2,phelp,0);
- predicate_free(phelp);
- };
- fprintf(output,"\n");
-
- fprintf(output,"Choice 2: %s alt %d line %d file %s\n\n",
- MR_ruleNamePlusOffset( (Node *) alt2),
- alt2->altnum,
- alt2->line,
- FileStr[alt2->file]);
- fprintf(output," The original predicate for choice 2 with available context information:\n\n");
- MR_dumpPred1(1,alt2->predicate,1);
- fprintf(output," The predicate for choice 2 after expansion (but without context information):\n\n");
- MR_dumpPred1(1,p2,0);
- if (p2 == NULL) {
- Predicate *phelp;
- fprintf(output," The predicate for choice 2 after expansion (but before simplification)\n\n");
- phelp=predicate_dup_without_context(alt2->predicate);
- phelp=MR_unfold(phelp);
- MR_clearPredEntry(phelp);
- MR_simplifyInverted(phelp,0);
- phelp=MR_predSimplifyALLX(phelp,1);
- MR_dumpPred1(2,phelp,0);
- predicate_free(phelp);
- };
- fprintf(output,"\n#endif\n");
- };
- };
- predicate_free(p1);
- predicate_free(p2);
- };
-}
-
-static int totalOverflow=0; /* MR9 */
-
-void
-#ifdef __USE_PROTOS
-HandleAmbiguity( Junction *block, Junction *alt1, Junction *alt2, int jtype )
-#else
-HandleAmbiguity( block, alt1, alt2, jtype )
-Junction *block;
-Junction *alt1;
-Junction *alt2;
-int jtype;
-#endif
-{
- unsigned **ftbl;
- set *fset, b;
- int i, numAmbig,n2;
- Tree *ambig=NULL, *t, *u;
- char *sub = "";
- long n;
- int thisOverflow=0; /* MR9 */
- long set_deg_value; /* MR10 */
- long threshhold; /* MR10 */
-
- require(block!=NULL, "NULL block");
- require(block->ntype==nJunction, "invalid block");
-
- /* These sets are used to constrain LL_k set, but are made CLL_k long anyway */
- fset = (set *) calloc(CLL_k+1, sizeof(set));
- require(fset!=NULL, "cannot allocate fset");
- ftbl = (unsigned **) calloc(CLL_k+1, sizeof(unsigned *));
- require(ftbl!=NULL, "cannot allocate ftbl");
-
- /* create constraint table and count number of possible ambiguities (use<=LL_k) */
- for (n=1,i=1; i<=CLL_k; i++)
- {
- b = set_and(alt1->fset[i], alt2->fset[i]);
-/* MR9 */ set_deg_value = set_deg(b);
-/* MR10 */ if (n > 0) {
-/* MR10 */ threshhold = LONG_MAX / n;
-/* MR10 */ if (set_deg_value <= threshhold) {
-/* MR10 */ n *= set_deg_value;
-/* MR10 */ } else {
-/* MR10 */ n=LONG_MAX;
-/* MR9 */ if (totalOverflow == 0) {
-#if 0
- /* MR10 comment this out because it just makes users worry */
-
-/* MR9 */ warnNoFL("Overflow in computing number of possible ambiguities in HandleAmbiguity\n");
-#endif
-/* MR9 */ };
-/* MR9 */ thisOverflow++;
-/* MR9 */ totalOverflow++;
-/* MR9 */ };
-/* MR10 */ } else {
-/* MR10 */ n *= set_deg_value;
-/* MR9 */ };
- fset[i] = set_dup(b);
- ftbl[i] = set_pdq(b);
- set_free(b);
- }
-
- switch ( jtype )
- {
- case aSubBlk: sub = "of (..) "; break;
- case aOptBlk: sub = "of {..} "; break;
- case aLoopBegin: sub = "of (..)* "; break;
- case aLoopBlk: sub = "of (..)* "; break;
- case aPlusBlk: sub = "of (..)+ "; break;
- case RuleBlk: sub = "of the rule itself "; break;
- default : sub = ""; break;
- }
-
- /* If the block is marked as a compressed lookahead only block, then
- * simply return; ambiguity warning is given only at warning level 2.
- */
- if ( block->approx>0 )
- {
- if ( ParseWithPredicates )
- {
- if (alt1->predicate != NULL) predicate_free(alt1->predicate); /* MR12 */
- if (alt2->predicate != NULL) predicate_free(alt2->predicate); /* MR12 */
-
- require(MR_PredRuleRefStack.count == 0,"PredRuleRef stack not empty");
- alt1->predicate = MR_find_predicates_and_supp((Node *)alt1->p1);
- require(MR_PredRuleRefStack.count == 0,"PredRuleRef stack not empty");
- require (MR_predicate_context_completed(alt1->predicate),"predicate alt 1 not completed");
- alt1->predicate=MR_predSimplifyALL(alt1->predicate);
-
- require(MR_PredRuleRefStack.count == 0,"PredRuleRef stack not empty");
- alt2->predicate = MR_find_predicates_and_supp((Node *)alt2->p1);
- require(MR_PredRuleRefStack.count == 0,"PredRuleRef stack not empty");
- require (MR_predicate_context_completed(alt2->predicate),"predicate alt 2 not completed");
- alt2->predicate=MR_predSimplifyALL(alt2->predicate);
-
- MR_doPredicatesHelp(0,alt1,alt2,jtype,sub);
-
- if ( HoistPredicateContext
- && (alt1->predicate!=NULL||alt2->predicate!=NULL) )
- {
- verify_context(alt1->predicate);
- verify_context(alt2->predicate);
- }
-
- if ( HoistPredicateContext
- && (alt1->predicate!=NULL||alt2->predicate!=NULL)
- && WarningLevel>1 )
- ensure_predicates_cover_ambiguous_lookahead_sequences(alt1, alt2, sub, ambig);
- }
-
- if ( WarningLevel>1 )
- {
- fprintf(stderr, ErrHdr, FileStr[alt1->file], alt1->line);
- if ( jtype == aLoopBegin || jtype == aPlusBlk )
- fprintf(stderr, " warning: optional/exit path and alt(s) %sambiguous upon", sub);
- else
- fprintf(stderr, " warning(approx): alts %d and %d %sambiguous upon",
- alt1->altnum, alt2->altnum, sub);
- dumpAmbigMsg(fset, stderr, 0);
- MR_traceAmbSource(fset,alt1,alt2);
- }
- for (i=1; i<=CLL_k; i++) set_free( fset[i] );
- free((char *)fset);
- for (i=1; i<=CLL_k; i++) free( (char *)ftbl[i] );
- free((char *)ftbl);
- return;
- }
-
- /* if all sets have degree 1 for k<LL_k, then must be ambig upon >=1 permutation;
- * don't bother doing full LL(k) analysis.
- * (This "if" block handles the LL(1) case)
- */
-
- n2 = 0;
- for (i=1; i<LL_k; i++) n2 += set_deg(alt1->fset[i])+set_deg(alt2->fset[i]);
-
- /* here STARTS the special case in which the lookahead sets for alt1 and alt2
- all have degree 1 for k<LL_k (including LL_k=1)
- */
-
- if ( n2==2*(LL_k-1) )
- {
-
- /* TJP: added to fix the case where LL(1) and syntactic predicates didn't
- * work. It now recognizes syntactic predicates, but does not like combo:
- * LL(1)/syn/sem predicates. (10/24/93)
- */
-
- if ( first_item_is_guess_block_extra((Junction *)alt1->p1)!=NULL )
- {
- if ( WarningLevel==1 )
- {
- for (i=1; i<=CLL_k; i++) set_free( fset[i] );
- free((char *)fset);
- for (i=1; i<=CLL_k; i++) free( (char *)ftbl[i] );
- free((char *)ftbl);
- return;
- }
-
- fprintf(stderr, ErrHdr, FileStr[alt1->file], alt1->line);
- if ( jtype == aLoopBegin || jtype == aPlusBlk )
- fprintf(stderr, " warning: optional/exit path and alt(s) %sambiguous upon", sub);
- else
- fprintf(stderr, " warning: alts %d and %d %sambiguous upon",
- alt1->altnum, alt2->altnum, sub);
- dumpAmbigMsg(fset, stderr, 0);
- MR_traceAmbSource(fset,alt1,alt2);
- }
-
- ambig = NULL;
- if ( LL_k>1 ) ambig = make_tree_from_sets(alt1->fset, alt2->fset);
- if ( ParseWithPredicates )
- {
- if (alt1->predicate != NULL) predicate_free(alt1->predicate); /* MR12 */
- if (alt2->predicate != NULL) predicate_free(alt2->predicate); /* MR12 */
-
- require(MR_PredRuleRefStack.count == 0,"PredRuleRef stack not empty");
- alt1->predicate = MR_find_predicates_and_supp((Node *)alt1->p1);
- require(MR_PredRuleRefStack.count == 0,"PredRuleRef stack not empty");
- require (MR_predicate_context_completed(alt1->predicate),"predicate alt 1 not completed");
- alt1->predicate=MR_predSimplifyALL(alt1->predicate);
-
- require(MR_PredRuleRefStack.count == 0,"PredRuleRef stack not empty");
- alt2->predicate = MR_find_predicates_and_supp((Node *)alt2->p1);
- require(MR_PredRuleRefStack.count == 0,"PredRuleRef stack not empty");
- require (MR_predicate_context_completed(alt2->predicate),"predicate alt 2 not completed");
- alt2->predicate=MR_predSimplifyALL(alt2->predicate);
-
- MR_doPredicatesHelp(0,alt1,alt2,jtype,sub);
-
- if ( HoistPredicateContext && (alt1->predicate!=NULL||alt2->predicate!=NULL) )
- {
- verify_context(alt1->predicate);
- verify_context(alt2->predicate);
- }
- if (HoistPredicateContext&&(alt1->predicate!=NULL||alt2->predicate!=NULL) && WarningLevel>1)
- ensure_predicates_cover_ambiguous_lookahead_sequences(alt1, alt2, sub, ambig);
- if ( WarningLevel == 1 &&
- (alt1->predicate!=NULL||alt2->predicate!=NULL))
- {
- for (i=1; i<=CLL_k; i++) set_free( fset[i] );
- free((char *)fset);
- for (i=1; i<=CLL_k; i++) free( (char *)ftbl[i] );
- free((char *)ftbl);
- Tfree(ambig);
- return;
- }
- }
-/* end TJP (10/24/93) */
-
- fprintf(stderr, ErrHdr, FileStr[alt1->file], alt1->line);
- if ( jtype == aLoopBegin || jtype == aPlusBlk )
- fprintf(stderr, " warning: optional/exit path and alt(s) %sambiguous upon", sub);
- else
- fprintf(stderr, " warning: alts %d and %d %sambiguous upon",
- alt1->altnum, alt2->altnum, sub);
- if ( elevel == 3 && LL_k>1 )
- {
- preorder(ambig);
- fprintf(stderr, "\n");
- for (i=1; i<=CLL_k; i++) set_free( fset[i] );
- free((char *)fset);
- for (i=1; i<=CLL_k; i++) free( (char *)ftbl[i] );
- free((char *)ftbl);
- Tfree(ambig);
- return;
- };
-
- Tfree(ambig);
- dumpAmbigMsg(fset, stderr, 0);
-
- /* because this is a special case in which both alt1 and alt2 have
- lookahead sets of degree 1 for k<LL_k (including k=1) the linear
- lookahead style search is adequate
- */
-
- MR_traceAmbSource(fset,alt1,alt2);
-
- for (i=1; i<=CLL_k; i++) set_free( fset[i] );
- free((char *)fset);
- for (i=1; i<=CLL_k; i++) free( (char *)ftbl[i] );
- free((char *)ftbl);
- return;
- }
-
- /* here ENDS the special case in which the lookahead sets for alt1 and alt2
- all have degree 1 for k<LL_k (including LL_k=1)
- */
-
- /* in case tree construction runs out of memory, set info to make good err msg */
-
- CurAmbigAlt1 = alt1->altnum;
- CurAmbigAlt2 = alt2->altnum;
- CurAmbigbtype = sub;
- CurAmbigfile = alt1->file;
- CurAmbigline = alt1->line;
-
- /* Don't do full LL(n) analysis if (...)? block because the block,
- by definition, defies LL(n) analysis.
- If guess (...)? block and ambiguous then don't remove anything from
- 2nd alt to resolve ambig.
- Want to predict with LL sup 1 ( n ) decision not LL(n) if guess block
- since it is much cheaper than LL(n). LL sup 1 ( n ) "covers" the LL(n)
- lookahead information.
-
- Note: LL(n) context cannot be computed for semantic predicates when
- followed by (..)?.
-
- If (..)? then we scream "AAAHHHH! No LL(n) analysis will help"
-
- Is 'ambig' always defined if we enter this if? I hope so
- because the 'ensure...()' func references it. TJP Nov 1993.
- */
-
- /* THM MR30: Instead of using first_item_is_guss_block we use
- first_item_is_guess_block_extra which will look inside a
- loop block for a guess block. In other words ( (...)? )*.
- It there is an ambiguity in this circumstance then we suppress
- the normal methods of resolving ambiguities.
- */
-
- if ( first_item_is_guess_block_extra((Junction *)alt1->p1)!=NULL )
- {
- if ( ParseWithPredicates )
- {
- if (alt1->predicate != NULL) predicate_free(alt1->predicate); /* MR12 */
- if (alt2->predicate != NULL) predicate_free(alt2->predicate); /* MR12 */
- require(MR_PredRuleRefStack.count == 0,"PredRuleRef stack not empty");
- alt1->predicate = MR_find_predicates_and_supp((Node *)alt1->p1);
- require(MR_PredRuleRefStack.count == 0,"PredRuleRef stack not empty");
- require (MR_predicate_context_completed(alt1->predicate),"predicate alt 1 not completed");
- alt1->predicate=MR_predSimplifyALL(alt1->predicate);
-
- require(MR_PredRuleRefStack.count == 0,"PredRuleRef stack not empty");
- alt2->predicate = MR_find_predicates_and_supp((Node *)alt2->p1);
- require(MR_PredRuleRefStack.count == 0,"PredRuleRef stack not empty");
- require (MR_predicate_context_completed(alt2->predicate),"predicate alt 2 not completed");
- alt2->predicate=MR_predSimplifyALL(alt2->predicate);
-
- MR_doPredicatesHelp(1,alt1,alt2,jtype,sub);
-
- if ( HoistPredicateContext && (alt1->predicate!=NULL||alt2->predicate!=NULL) )
- {
- verify_context(alt1->predicate);
- verify_context(alt2->predicate);
- }
- if ( HoistPredicateContext && (alt1->predicate!=NULL||alt2->predicate!=NULL) && WarningLevel>1 )
- ensure_predicates_cover_ambiguous_lookahead_sequences(alt1, alt2, sub, ambig);
- if ( WarningLevel==1 &&
- (alt1->predicate!=NULL||alt2->predicate!=NULL))
- {
- for (i=1; i<=CLL_k; i++) set_free( fset[i] );
- free((char *)fset);
- for (i=1; i<=CLL_k; i++) free( (char *)ftbl[i] );
- free((char *)ftbl);
- return;
- }
- }
-
- if ( WarningLevel>1 )
- {
- fprintf(stderr, ErrHdr, FileStr[alt1->file], alt1->line);
- if ( jtype == aLoopBegin || jtype == aPlusBlk )
- fprintf(stderr, " warning: optional/exit path and alt(s) %sambiguous upon", sub);
- else
- fprintf(stderr, " warning: alts %d and %d %sambiguous upon",
- alt1->altnum, alt2->altnum, sub);
- dumpAmbigMsg(fset, stderr, 0);
- MR_traceAmbSource(fset,alt1,alt2);
- }
-
- for (i=1; i<=CLL_k; i++) set_free( fset[i] );
- free((char *)fset);
- for (i=1; i<=CLL_k; i++) free( (char *)ftbl[i] );
- free((char *)ftbl);
- return;
- }
-
- /* Not resolved with (..)? block. Do full LL(n) analysis */
-
- /* ambig is the set of k-tuples truly in common between alt 1 and alt 2 */
- /* MR11 VerifyAmbig once used fset destructively */
-
- ambig = VerifyAmbig(alt1, alt2, ftbl, fset, &t, &u, &numAmbig);
-
- /* are all things in intersection really ambigs? */
-
- if (thisOverflow || numAmbig < n ) /* MR9 */
- {
- Tree *v;
-
- /* remove ambig permutation from 2nd alternative to resolve ambig;
- * We want to compute the set of artificial tuples, arising from
- * LL sup 1 (n) compression, that collide with real tuples from the
- * 2nd alternative. This is the set of "special case" tuples that
- * the LL sup 1 (n) decision template maps incorrectly.
- */
-
- /* when generating code in genExpr() it does
- *
- * if ( genExprSets(j->fset) && !genExprTree(j->ftree)) {...
- *
- * Sooooo the j->ftree is the tree of alt2
- * after removal of conflicts, not alt1 !
- */
-
- if ( ambig!=NULL )
- {
- /* at the top of ambig is an ALT node */
-
- for (v=ambig->down; v!=NULL; v=v->right)
- {
- u = trm_perm(u, v); /* remove v FROM u */
- }
-/* fprintf(stderr, "after rm alt2:"); preorder(u); fprintf(stderr, "\n");*/
- }
- Tfree( t );
- alt1->ftree = tappend(alt1->ftree, u);
- alt1->ftree = tleft_factor(alt1->ftree);
- }
-
- if ( ambig==NULL )
- {
- for (i=1; i<=CLL_k; i++) set_free( fset[i] );
- free((char *)fset);
- for (i=1; i<=CLL_k; i++) free( (char *)ftbl[i] );
- free((char *)ftbl);
- return;
- }
-
- ambig = tleft_factor(ambig);
-
-/* TJP:
- * At this point, we surely have an LL(k) ambiguity. Check for predicates
- */
- if ( ParseWithPredicates )
- {
- if (alt1->predicate != NULL) predicate_free(alt1->predicate); /* MR12 */
- if (alt2->predicate != NULL) predicate_free(alt2->predicate); /* MR12 */
- require(MR_PredRuleRefStack.count == 0,"PredRuleRef stack not empty");
- alt1->predicate = MR_find_predicates_and_supp((Node *)alt1->p1);
- require(MR_PredRuleRefStack.count == 0,"PredRuleRef stack not empty");
- require (MR_predicate_context_completed(alt1->predicate),"predicate alt 1 not completed");
- alt1->predicate=MR_predSimplifyALL(alt1->predicate);
-
- require(MR_PredRuleRefStack.count == 0,"PredRuleRef stack not empty");
- alt2->predicate = MR_find_predicates_and_supp((Node *)alt2->p1);
- require(MR_PredRuleRefStack.count == 0,"PredRuleRef stack not empty");
- require (MR_predicate_context_completed(alt2->predicate),"predicate alt 2 not completed");
- alt2->predicate=MR_predSimplifyALL(alt2->predicate);
-
- MR_doPredicatesHelp(0,alt1,alt2,jtype,sub);
-
- if ( HoistPredicateContext && (alt1->predicate!=NULL||alt2->predicate!=NULL) )
- {
- verify_context(alt1->predicate);
- verify_context(alt2->predicate);
- }
- if ( HoistPredicateContext && (alt1->predicate!=NULL||alt2->predicate!=NULL) && WarningLevel>1 )
- ensure_predicates_cover_ambiguous_lookahead_sequences(alt1, alt2, sub, ambig);
- if ( WarningLevel==1 &&
- (alt1->predicate!=NULL||alt2->predicate!=NULL))
- {
-
- /* We found at least one pred for at least one of the alts;
- * If warnings are low, just return.
- */
-
- Tfree(ambig);
- for (i=1; i<=CLL_k; i++) set_free( fset[i] );
- free((char *)fset);
- for (i=1; i<=CLL_k; i++) free( (char *)ftbl[i] );
- free((char *)ftbl);
- return;
- }
- /* else we're gonna give a warning */
- }
-/* end TJP addition */
-
- fprintf(stderr, ErrHdr, FileStr[alt1->file], alt1->line);
- if ( jtype == aLoopBegin || jtype == aPlusBlk )
- fprintf(stderr, " warning: optional/exit path and alt(s) %sambiguous upon", sub);
- else
- fprintf(stderr, " warning: alts %d and %d %sambiguous upon",
- alt1->altnum, alt2->altnum, sub);
- if ( elevel == 3 )
- {
- preorder(ambig->down); /* <===== k>1 ambiguity message data */
- fprintf(stderr, "\n");
- } else {
- MR_skipped_e3_report=1;
- dumpAmbigMsg(fset, stderr, 0);
- };
-
- MR_traceAmbSourceK(ambig,alt1,alt2); /* <====== k>1 ambiguity aid */
-
- Tfree(ambig);
-
- for (i=1; i<=CLL_k; i++) set_free( fset[i] );
- free((char *)fset);
- for (i=1; i<=CLL_k; i++) free( (char *)ftbl[i] );
- free((char *)ftbl);
-}
-
-/* Don't analyze alpha block of (alpha)?beta; if (alpha)? then analyze
- * Return the 1st node of the beta block if present else return j.
- */
-Junction *
-#ifdef __USE_PROTOS
-analysis_point( Junction *j )
-#else
-analysis_point( j )
-Junction *j;
-#endif
-{
- Junction *gblock;
-
- /* MR13b When there was an action/predicate preceding a guess block
- the guess block became invisible at the analysis_point.
-
- first_item_is_guess_block accepts any kind of node,
- despite the fact that the formal is a junction. But
- I don't want to have to change it all over the place
- until I know it works.
- */
-
- if ( j->ntype != nJunction && j->ntype != nAction) return j;
-
- gblock = first_item_is_guess_block((Junction *)j);
-
- if ( gblock!=NULL )
- {
- Junction *past = gblock->end;
- Junction *p;
- require(past!=NULL, "analysis_point: no end block on (...)? block");
-
- for (p=(Junction *)past->p1; p!=NULL; )
- {
- if ( p->ntype==nAction )
- {
- p=(Junction *)((ActionNode *)p)->next;
- continue;
- }
- if ( p->ntype!=nJunction )
- {
- past->alpha_beta_guess_end=1; /* MR14 */
- return (Junction *)past->p1;
- }
- if ( p->jtype==EndBlk || p->jtype==EndRule )
- {
- return j;
- }
-/* MR6 */
-/* MR6 A guess block is of the form "(alpha)? beta" or "(alpha)?". */
-/* MR6 When beta is omitted (second form) this means "(alpha)? alpha". */
-/* MR6 The program does not store another copy of alpha in this case. */
-/* MR6 During analysis when the program needs to know what follows the */
-/* MR6 guess clause. It calls this routine. */
-/* MR6 */
-/* MR6 If it is of the form "(alpha)? beta" it returns a pointer to beta.*/
-/* MR6 */
-/* MR6 If it is of the form "(alpha)?" it returns a pointer to the guess */
-/* MR6 block itself thereby reusing the junction tree. */
-/* MR6 */
-/* MR6 It works by searching the "next in sequence" chain (skipping actions) */
-/* MR6 searching for a RuleRef or Token node. (Those are the only 4 kinds */
-/* MR6 of nodes: Junctions, RuleRef, Token, and Action.) */
-/* MR6 */
-/* MR6 This won't work for the special case "(alpha)? ()" because it has no */
-/* MR6 rule references or token nodes. It eventually encounters a */
-/* MR6 junction of type EndBlk or EndRule and says to its caller: nothing */
-/* MR6 more here to analyze - must be of the form "(alpha)?". */
-/* MR6 */
-/* MR6 In the case of "(alpha)? ()" it should return a pointer to "()" */
-/* MR6 */
-/* MR6 I think. */
-/* MR6 */
- if ( p->jtype!=Generic) { /* MR6 */
- past->alpha_beta_guess_end=1; /* MR14 */
- return (Junction *)past->p1; /* MR6 */
- }; /* MR6 */
- p=(Junction *)p->p1;
- }
- }
- return j;
-}
-
-set
-#ifdef __USE_PROTOS
-First( Junction *j, int k, int jtype, int *max_k )
-#else
-First( j, k, jtype, max_k )
-Junction *j;
-int k;
-int jtype;
-int *max_k;
-#endif
-{
- Junction *alt1, *alt2;
- set a, rk, fCurBlk;
- int savek;
- int p1, p2;
-
- int save_maintainBackTrace;
-
- require(j->ntype==nJunction, "First: non junction passed");
-
- /* C o m p u t e F I R S T s e t w i t h k l o o k a h e a d */
- fCurBlk = rk = empty;
- for (alt1=j; alt1!=NULL; alt1 = (Junction *)alt1->p2 )
- {
- Junction * p = NULL;
- Junction * p1junction = NULL;
- p = analysis_point((Junction *)alt1->p1);
- p1junction = (Junction *) (alt1->p1);
-#if 0
- if (p != p1junction) {
- fprintf(stdout,"Analysis point for #%d is #%d", p1junction->seq, p->seq); /* debug */
- }
-#endif
- REACH(p, k, &rk, alt1->fset[k]);
- require(set_nil(rk), "rk != nil");
- set_free(rk);
- set_orin(&fCurBlk, alt1->fset[k]);
- }
-
- /* D e t e c t A m b i g u i t i e s */
- *max_k = 1;
- for (p1=1,alt1=j; alt1!=NULL; alt1 = (Junction *)alt1->p2, p1++)
- {
- for (p2=1,alt2=(Junction *)alt1->p2; alt2!=NULL; alt2 = (Junction *)alt2->p2, p2++)
- {
- savek = k;
- a = set_and(alt1->fset[k], alt2->fset[k]);
- while ( !set_nil(a) )
- {
- /* if we have hit the max k requested, just give warning */
- if ( j->approx==k ) {
- }
-
- if ( k==CLL_k )
- {
-#ifdef NOT_USED
-*** int save_LL_k = LL_k;
-*** int save_CLL_k = CLL_k;
-*** /* Get new LL_k from interactive feature if enabled */
-*** if ( AImode )
-*** AmbiguityDialog(j, jtype, alt1, alt2, &CLL_k, &LL_k);
-#endif
- *max_k = CLL_k;
- save_maintainBackTrace=MR_MaintainBackTrace;
- if (AlphaBetaTrace) MR_MaintainBackTrace=0;
- HandleAmbiguity(j, alt1, alt2, jtype);
- MR_MaintainBackTrace=save_maintainBackTrace;
- break;
- }
- else
- {
- Junction *p = analysis_point((Junction *)alt1->p1);
- Junction *q = analysis_point((Junction *)alt2->p1);
- k++; /* attempt ambig alts again with more lookahead */
-
- REACH(p, k, &rk, alt1->fset[k]);
- require(set_nil(rk), "rk != nil");
- REACH(q, k, &rk, alt2->fset[k]);
- require(set_nil(rk), "rk != nil");
- set_free(a);
- a = set_and(alt1->fset[k], alt2->fset[k]);
- if ( k > *max_k ) *max_k = k;
- }
- }
- set_free(a);
- k = savek;
- }
- }
-
- return fCurBlk;
-}
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