/* * mrhoist.c * * 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 1.33MR10 * */ #include #include "pcctscfg.h" #include "set.h" #include "syn.h" #include "hash.h" #include "generic.h" #include "dlgdef.h" #include #ifdef __USE_PROTOS void dumppred(Predicate *); #else void dumppred(); #endif /* Try to determine whether predicate "first" is true for all cases where "second" is true. Comparison takes place without regard to context. Assumes that predicate symbols have been expanded. Assumes that there are no NAND or NOR nodes */ #ifdef __USE_PROTOS int MR_secondPredicateUnreachable(Predicate *first,Predicate *second) #else int MR_secondPredicateUnreachable(first,second) Predicate *first; Predicate *second; #endif { Predicate *f; Predicate *s; if (first == NULL) { return 1; } else if (second == NULL) { return 0; } else if (first->down == NULL && second->down == NULL) { if (first->source == second->source && first->inverted == second->inverted) { return 1; /* look identical - will never reach alt2 */ } else { return 0; /* look different */ }; } else if (first->down == NULL && second->down != NULL) { if (second->expr == PRED_AND_LIST) { /* unreachable if first covers any child of second */ for (s=second->down; s != NULL; s=s->right) { if (MR_secondPredicateUnreachable(first,s)) { return 1; }; }; return 0; } else if (second->expr == PRED_OR_LIST) { /* unreachable if first covers every child of second */ for (s=second->down; s != NULL; s=s->right) { if (!MR_secondPredicateUnreachable(first,s)) { return 0; }; }; return 1; } else { require (0,"Illegal pred->expr"); return 0; /* MR20 Make compiler happy */ }; } else if (first->down != NULL && second->down == NULL) { if (first->expr == PRED_AND_LIST) { /* unreachable if every child of first covers second */ for (f=first->down; f != NULL; f=f->right) { if (!MR_secondPredicateUnreachable(f,second)) { return 0; }; }; return 1; } else if (first->expr == PRED_OR_LIST) { /* unreachable if any child of first covers second */ for (f=first->down; f != NULL; f=f->right) { if (MR_secondPredicateUnreachable(f,second)) { return 1; }; }; return 0; } else { require (0,"Illegal predicate->expr"); return 0; /* MR20 Make compiler happy */ }; } else { if (first->expr == PRED_AND_LIST && second->expr == PRED_AND_LIST) { /* unreachable if each child of first covers at least one child of second */ for (f=first->down; f != NULL ; f=f->right) { for (s=second->down; s != NULL ; s=s->right) { if (MR_secondPredicateUnreachable(f,s)) goto A_next_f; }; return 0; A_next_f: continue; }; return 1; } else if (first->expr == PRED_AND_LIST && second->expr == PRED_OR_LIST) { /* unreachable if each child of first covers ALL of second's children */ for (f=first->down; f != NULL ; f=f->right) { for (s=second->down; s != NULL ; s=s->right) { if (!MR_secondPredicateUnreachable(f,s)) return 0; }; }; return 1; } else if (first->expr == PRED_OR_LIST && second->expr == PRED_AND_LIST) { /* unreachable if any child of second is covered by any child of first */ for (f=first->down; f != NULL ; f=f->right) { for (s=second->down; s != NULL ; s=s->right) { if (MR_secondPredicateUnreachable(f,s)) return 1; }; }; return 0; } else if (first->expr == PRED_OR_LIST && second->expr == PRED_OR_LIST) { /* unreachable if every child of second is covered by some child of first */ for (f=first->down; f != NULL ; f=f->right) { for (s=second->down; s != NULL ; s=s->right) { if (MR_secondPredicateUnreachable(f,s)) goto B_next_f; }; return 0; B_next_f: continue; }; return 1; } else { require (0,"Illegal predicate->expr"); return 0; /* MR20 Make compiler happy */ }; }; return 0; /* MR20 MSVC 5.0 complains about missing return statement */ } #ifdef __USE_PROTOS void MR_xxxIndent(FILE *f,int depth) #else void MR_xxxIndent(f,depth) FILE *f; int depth; #endif { int i; for (i=0; irname,rrn->line,FileStr[rrn->file],rrn->text); }; lastOne=MR_ruleReferenced(rrn); if (lastOne != NULL) { for (j=0; jrname,lastOne->line,FileStr[lastOne->file]); }; } #ifdef __USE_PROTOS void MR_dumpTreeF(FILE *f,int depth,Tree *tree,int across) #else void MR_dumpTreeF(f,depth,tree,across) FILE *f; Tree *tree; int depth; int across; #endif { int newAcross=across; if (tree == NULL ) return; if (tree->down != NULL ) { fprintf(output,"\n"); MR_outputIndent(depth); fprintf(output, "(root ="); }; if (tree->token == ALT ) { fprintf(output," %-16s","Alt"); } else if (tree->token==EpToken ) { fprintf(output,"(%d)%13s",tree->v.rk," "); } else { fprintf(output," %-16s",TerminalString(tree->token)); }; if (tree->down != NULL) { fprintf(output,"\n"); MR_outputIndent(depth+1); MR_dumpTreeF(f,depth+1,tree->down,1); newAcross=0; fprintf(output,"\n"); MR_outputIndent(depth); fprintf(output,")"); }; if (newAcross > 3) { fprintf(output,"\n"); MR_outputIndent(depth); newAcross=0; }; MR_dumpTreeF(f,depth,tree->right,newAcross+1); } #ifdef __USE_PROTOS void MR_dumpTreeX(int depth,Tree *tree,int across) #else void MR_dumpTreeX(depth,tree,across) Tree *tree; int depth; int across; #endif { MR_dumpTreeF(output,depth,tree,across); } #ifdef __USE_PROTOS void MR_dumpTokenSet(FILE *f,int depth,set s) #else void MR_dumpTokenSet(f,depth,s) FILE *f; int depth; set s; #endif { int i; int j; unsigned *pdq; if (set_nil(s)) { fprintf(f,"\n"); MR_xxxIndent(f,depth+1); fprintf(f,"nil\n"); return; }; pdq=set_pdq(s); require(pdq != NULL,"set_pdq failed"); i=0; for (i=0 ; ; i=i+4) { fprintf(f,"\n"); MR_xxxIndent(f,depth+1); for (j=0; j < 4 ; j++) { if (pdq[i+j] == nil) break; fprintf(f," %-16s",TerminalString(pdq[i+j])); }; if (pdq[i+j] == nil) break; }; fprintf(f,"\n"); free( (char *) pdq); } #ifdef __USE_PROTOS void MR_dumpPred1(int depth,Predicate *p,int withContext) #else void MR_dumpPred1(depth,p,withContext) int depth; Predicate *p; int withContext; #endif { unsigned k; if (p == NULL) { MR_outputIndent(depth); fprintf(output,"The predicate is empty (or always true)\n\n"); return; }; if (p->down != NULL) { MR_outputIndent(depth); if (p->inverted) { /* MR14a Left out print expression in fprintf Reported by Manuel Kessler (mlkessle@cip.physik.uni-wuerzburg.de) */ if (p->expr == PRED_AND_LIST) fprintf(output,"%s NAND (not AND) expr\n\n",p->expr); if (p->expr == PRED_OR_LIST) fprintf(output,"%s NOR (not OR) expr\n\n",p->expr); } else { fprintf(output,"%s expr\n\n",p->expr); }; } else { MR_outputIndent(depth); fprintf(output,"pred %s <<%s>>?\n", (p->inverted ? " *not*" : ""), (p->expr == NULL ? "null expr" : p->expr)); MR_outputIndent(depth+1); fprintf(output," "); fprintf(output," depth=k=%d",p->k); if (p->source != NULL && p->source->guardpred) { fprintf(output," (\"=>\" guard)"); } if (p->source != NULL && p->source->ampersandPred != NULL) { fprintf(output," (\"&&\" guard)"); }; k=set_int(p->completionSet); if (k != nil) { fprintf(output," Incomplete Set at k=%d !",k); }; k=set_int(p->completionTree); if (k != nil) { fprintf(output," Incomplete Tree at k=%d !",k); }; if (p->source != NULL) { fprintf(output," rule %s line %d %s", p->source->rname,p->source->line,FileStr[p->source->file]); }; fprintf(output,"\n"); if (withContext && (HoistPredicateContext || ! set_nil(p->scontext[1]) || p->tcontext != NULL)) { if (p->k == 1) { MR_outputIndent(depth+1); fprintf(output,"set context: "); MR_dumpTokenSet(output,depth+1,p->scontext[1]); } if (p->k != 1) { MR_outputIndent(depth+1); fprintf(output,"tree context:"); if (p->tcontext == NULL) { fprintf(output," null"); } else { MR_dumpTreeX(depth+2,p->tcontext,0); }; fprintf(output,"\n"); }; }; fprintf(output,"\n"); }; if (p->down != NULL) { MR_dumpPred1(depth+1,p->down,withContext); }; if (p->right != NULL) { MR_dumpPred1(depth,p->right,withContext); }; } #ifdef __USE_PROTOS void MR_dumpPred(Predicate *p,int withContext) #else void MR_dumpPred(p,withContext) Predicate *p; int withContext; #endif { MR_dumpPred1(0,p,withContext); } #ifdef __USE_PROTOS Tree * MR_make_tree_from_set(set s) #else Tree * MR_make_tree_from_set(s) set s; #endif { Tree *t=NULL; Tree *node; Tree **tp=&t; int i; unsigned *pdq=set_pdq(s); if (pdq != NULL) { for (i=0 ; pdq[i] != nil ; i++) { node=tnode( (int) pdq[i]); *tp=node; tp=&(node->right); }; *tp=NULL; free ( (char *) pdq); }; return t; } #ifdef __USE_PROTOS void MR_check_pred_too_long(Predicate *p,set completion) #else void MR_check_pred_too_long(p,completion) Predicate *p; set completion; #endif { if (p != NULL && p->source != NULL && ! p->source->predTooLong) { if ( !set_nil(completion)) { p->source->predTooLong=1; warnFL("It is unusual (but ok) for a semantic predicate to test context past the end of its own rule", FileStr[p->source->file],p->source->line); }; }; } #ifdef __USE_PROTOS int MR_predicate_context_completed(Predicate *p) #else int MR_predicate_context_completed(p) Predicate *p; #endif { if (p == NULL) return 1; if (p->expr != PRED_AND_LIST && p->expr != PRED_OR_LIST) { if ( ! set_nil(p->completionSet)) return 0; if ( ! set_nil(p->completionTree)) return 0; }; return MR_predicate_context_completed(p->down) & MR_predicate_context_completed(p->right); } #ifdef __USE_PROTOS Node * MR_advance(Node *n) #else Node * MR_advance(n) Node *n; #endif { if (n == NULL) return NULL; switch (n->ntype) { case nJunction: return ((Junction *)n)->p1; case nToken: return ((TokNode *)n)->next; case nRuleRef: return ((RuleRefNode *)n)->next; case nAction: return ((ActionNode *)n)->next; default: return NULL; }; return NULL; /* MSVC 5.0 complains about missing return statement */ } #ifdef __USE_PROTOS Junction * MR_find_endRule(Node *n) #else Junction * MR_find_endRule(n) Node *n; #endif { Node *next; if (n == NULL) return NULL; for (next=n; next != NULL; next=MR_advance(next)) { if (next->ntype == nJunction && ( (Junction *) next)->jtype == EndRule) { break; }; }; return (Junction *)next; } /* Intersection: a branch which is shorter is chosen over one which is longer: (A B C) intersect (A B) yields (A B). AND: a branch which is longer is chosen over the one which is shorter: (A B C) AND (A B) yields (A B C) */ #ifdef __USE_PROTOS Tree *MR_computeTreeIntersection(Tree *l,Tree *r) #else Tree *MR_computeTreeIntersection(l,r) Tree *l; Tree *r; #endif { Tree *result=NULL; Tree **tail; Tree *p; Tree *q; Tree *match; if (l == NULL || r == NULL) return NULL; for (p=l; p != NULL; p=p->right) { require(p->token != EpToken,"MR_computeTreeIntersection: p->EpToken unexpected\n"); require (p->token != ALT,"MR_computeTreeIntersection: p->ALT unexpected\n"); }; for (q=r; q != NULL; q=q->right) { require(q->token != EpToken,"MR_computeTreeIntersection: q->EpToken unexpected\n"); require(q->token != ALT,"MR_computeTreeIntersection: q->ALT unexpected\n"); }; result=tnode(ALT); tail=&(result->down); for (p=l; p != NULL ; p=p->right) { for (q=r; q != NULL ; q=q->right) { if (p->token == q->token) { match=tnode(p->token); match->down=MR_computeTreeIntersection(p->down,q->down); *tail=match; tail=&(match->right); }; }; }; *tail=NULL; result=tshrink(result); result=tflatten( result ); result=tleft_factor( result ); return result; } /* the predicates which are ANDed together have a common context: they must all have common roots. Thus the AND operation is more like an OR operation because branches which are longer are grafted onto shorter branches of the AND tree. For instance combining (A B C) with (A B C D) gives (A B C D). There should never be a case of (A B C) and (A B D) because they have the same context. Actually, this may not be true once one throws in guard predicates which are defined by the user, not the context. */ /* requires input trees to be in "canonical" format */ #ifdef __USE_PROTOS Tree *MR_computeTreeAND(Tree *l,Tree *r) #else Tree *MR_computeTreeAND(l,r) Tree *l; Tree *r; #endif { Tree *result=NULL; Tree **tail; Tree *p; Tree *q; Tree *match; if (l == NULL) return tdup(r); if (r == NULL) return tdup(l); for (p=l; p != NULL; p=p->right) { /**** require(p->token != EpToken,"MR_computeTreeAND: p->EpToken unexpected\n"); ****/ require (p->token != ALT,"MR_computeTreeAND: p->ALT unexpected\n"); }; for (q=r; q != NULL; q=q->right) { /**** require(q->token != EpToken,"MR_computeTreeAND: q->EpToken unexpected\n"); ****/ require(q->token != ALT,"MR_computeTreeAND: q->ALT unexpected\n"); }; result=tnode(ALT); tail=&(result->down); for (p=l; p != NULL ; p=p->right) { for (q=r; q != NULL ; q=q->right) { if (p->token == q->token) { match=tnode(p->token); match->down=MR_computeTreeAND(p->down,q->down); *tail=match; tail=&(match->right); }; }; }; *tail=NULL; result=tshrink(result); result=tflatten( result ); result=tleft_factor( result ); return result; } #ifdef __USE_PROTOS void MR_union_plain_sets1(Predicate *p,set *theUnion) #else void MR_union_plain_sets1(p,theUnion) Predicate *p; set *theUnion; #endif { if (p == NULL) return; MR_union_plain_sets1(p->down,theUnion); MR_union_plain_sets1(p->right,theUnion); set_orin(theUnion,p->plainSet); return; } #ifdef __USE_PROTOS set MR_union_plain_sets(Predicate *p) #else set MR_union_plain_sets(p) Predicate *p; #endif { set theUnion; theUnion=empty; MR_union_plain_sets1(p,&theUnion); return theUnion; } /* does NOT left factor: do not want to merge (A B) with (A) to get (A B) in fact the opposite: (A B) with (A) gives (A) */ #ifdef __USE_PROTOS Tree *MR_compute_pred_tree_ctxXX(Predicate *p) #else Tree *MR_compute_pred_tree_ctxXX(p) Predicate *p; #endif { Tree *result=NULL; Predicate *q; Tree *t; if (p == NULL) return NULL; /* this appears strange: why do we OR the context of and AND predicate ? It is because of the way that predicates are evaluated: if the context is wrong then it's the same as if the predicate was true. That means that even when one leg of an AND has unmatched context, if the other leg has matched context and is true then the predicate succeeds. It's only when all the legs have unmatched context that this one can skip evaluation of the predicates. */ if (p->expr == PRED_OR_LIST || p->expr == PRED_AND_LIST) { for (q=p->down; q != NULL ; q=q->right) { t=MR_compute_pred_tree_ctxXX(q); result=tappend(result,t); t=NULL; }; result=tshrink(result); result=tflatten( result ); /* does NOT left factor: do not want to merge (A B) with (A) to get (A B) in fact the opposite: (A B) with (A) gives (A) */ /**** result=tleft_factor( result ); ****/ return result; }; #if 0 ** if (p->expr == PRED_AND_LIST) { ** ** Predicate *l; ** Predicate *r; ** Tree *l1; ** Tree *r1; ** Tree *prevl1; ** ** l=p->down; ** require (l->right != NULL,"MR_compute_pred_tree - AND has only one child"); ** **/* l1 and r1 should already be in "canonical" format */ ** ** l1=MR_compute_pred_tree(l); ** for (r=l->right; r != NULL; r=r->right) { ** r1=MR_compute_pred_tree(r); ** prevl1=l1; ** l1=MR_computeTreeAND(l1,r1); ** Tfree(r1); ** Tfree(prevl1); ** }; ** **/* result from computeTreeAND should be in "canonical" format */ ** ** result=l1; ** **/* result of MR_computeTreeAND should be in "canonical" format */ ** ** return result; ** }; #endif if (p->k == 1) { result=MR_make_tree_from_set(p->scontext[1]); } else { result=tdup(p->tcontext); result=MR_remove_epsilon_from_tree(result); result=tshrink(result); result=tflatten(result); result=tleft_factor(result); }; return result; } #ifdef __USE_PROTOS void MR_pred_depth(Predicate *p,int *maxDepth) #else void MR_pred_depth(p,maxDepth) Predicate *p; int *maxDepth; #endif { if (p == NULL) return; if (p->expr != PRED_OR_LIST && p->expr != PRED_AND_LIST) { if (p->k > *maxDepth) *maxDepth=p->k; }; MR_pred_depth(p->down,maxDepth); MR_pred_depth(p->right,maxDepth); } /* this computes the OR of all the contexts */ #ifdef __USE_PROTOS set MR_compute_pred_set(Predicate *p) #else set MR_compute_pred_set(p) Predicate *p; #endif { set result; Predicate *q; result=empty; if (p == NULL) return empty; if (p->expr == PRED_OR_LIST || p->expr == PRED_AND_LIST) { /* yes, I do mean PRED_AND_LIST ! */ /* remember: r1: (A)? => <

>? r2; */ /* r2: (B)? => <>? r3; */ set t; t=empty; result=empty; for (q=p->down; q != NULL; q=q->right) { t=MR_compute_pred_set(q); set_orin(&result,t); set_free(t); }; return result; } else if (p->k > 1) { return empty; } else { return set_dup(p->scontext[1]); }; } #ifdef __USE_PROTOS set MR_First(int ck,Junction *j,set *incomplete) #else set MR_First(ck,j,incomplete) int ck; Junction *j; set *incomplete; #endif { Junction *p; set tokensUsed; tokensUsed=empty; require(j->ntype==nJunction, "MR_First: non junction passed"); p = analysis_point((Junction *)j->p1); REACH(p,ck,incomplete,tokensUsed); return tokensUsed; } #ifdef __USE_PROTOS void MR_cleanup_pred_trees(Predicate *p) #else void MR_cleanup_pred_trees(p) Predicate *p; #endif { Tree *t; if (p == NULL) return; if (p->expr != PRED_OR_LIST && p->expr != PRED_AND_LIST) { t=p->tcontext; t=tshrink(t); t=tflatten(t); t=tleft_factor(t); p->tcontext=t; }; MR_cleanup_pred_trees(p->down); MR_cleanup_pred_trees(p->right); } /* does NOT return canonical tree */ #ifdef __USE_PROTOS Tree * MR_remove_epsilon_from_tree(Tree *t) #else Tree * MR_remove_epsilon_from_tree(t) Tree *t; #endif { if (t == NULL) return NULL; /* I think ALT can be ignored as a special case */ if (t->token != EpToken) { t->down=MR_remove_epsilon_from_tree(t->down); t->right=MR_remove_epsilon_from_tree(t->right); return t; } else { Tree *u; u=MR_remove_epsilon_from_tree(t->right); t->right=NULL; Tfree(t); return u; }; } #ifdef __USE_PROTOS void MR_complete_set(int predDepth,set *tokensUsed,set *incomplete) #else void MR_complete_set(predDepth,tokensUsed,incomplete) int predDepth; set *tokensUsed; set *incomplete; #endif { int i; RuleRefNode *ruleRef; set rk2; set b; int k2; Junction *save_MR_RuleBlkWithHalt; if (set_int(*incomplete) > (unsigned) predDepth) { return; }; require(MR_PredRuleRefStack.count == MR_RuleBlkWithHaltStack.count, "RuleRefStack and RuleBlkWithHaltStack not same size"); require(MR_RuleBlkWithHalt == NULL || (MR_RuleBlkWithHalt->jtype == RuleBlk && MR_RuleBlkWithHalt->end->halt == TRUE), "RuleBlkWithHalt has no halt set"); save_MR_RuleBlkWithHalt=MR_RuleBlkWithHalt; if (MR_RuleBlkWithHalt != NULL) { MR_RuleBlkWithHalt->end->halt=FALSE; }; for (i=MR_PredRuleRefStack.count-1; i >= 0 ; i--) { ruleRef=(RuleRefNode *)MR_PredRuleRefStack.data[i]; if (ruleRef == NULL) continue; MR_RuleBlkWithHalt=(Junction *)MR_RuleBlkWithHaltStack.data[i]; if (MR_RuleBlkWithHalt != NULL) MR_RuleBlkWithHalt->end->halt=TRUE; rk2=empty; b=empty; while ( !set_nil(*incomplete) ) { k2=set_int(*incomplete); if (k2 > predDepth) break; /* <=== another exit from loop */ set_rm(k2,*incomplete); REACH(ruleRef->next,k2,&rk2,b); set_orin(tokensUsed,b); set_free(b); }; if (MR_RuleBlkWithHalt != NULL) MR_RuleBlkWithHalt->end->halt=FALSE; set_orin(incomplete,rk2); /* remember what we couldn't do */ set_free(rk2); if (set_int(*incomplete) > (unsigned) predDepth) break; /* <=== another exit from loop */ }; MR_RuleBlkWithHalt=save_MR_RuleBlkWithHalt; if (MR_RuleBlkWithHalt != NULL) { MR_RuleBlkWithHalt->end->halt=TRUE; }; } #ifdef __USE_PROTOS void MR_complete_tree(int predDepth,Tree **t,set *incomplete) #else void MR_complete_tree(predDepth,t,incomplete) int predDepth; Tree **t; set *incomplete; #endif { int i; RuleRefNode *ruleRef; set rk2; Tree *u; unsigned k2; Junction *save_MR_RuleBlkWithHalt; int saveConstrainSearch; if (set_int(*incomplete) > (unsigned) predDepth) { return; }; require(MR_PredRuleRefStack.count == MR_RuleBlkWithHaltStack.count, "RuleRefStack and RuleBlkWithHaltStack not same size"); require(MR_RuleBlkWithHalt == NULL || (MR_RuleBlkWithHalt->jtype == RuleBlk && MR_RuleBlkWithHalt->end->halt == TRUE), "RuleBlkWithHalt has no halt set"); save_MR_RuleBlkWithHalt=MR_RuleBlkWithHalt; saveConstrainSearch=ConstrainSearch; ConstrainSearch=0; if (MR_RuleBlkWithHalt != NULL) { MR_RuleBlkWithHalt->end->halt=FALSE; }; for (i=MR_PredRuleRefStack.count-1; i >= 0 ; i--) { ruleRef=(RuleRefNode *)MR_PredRuleRefStack.data[i]; if (ruleRef == NULL) continue; MR_RuleBlkWithHalt=(Junction *)MR_RuleBlkWithHaltStack.data[i]; if (MR_RuleBlkWithHalt != NULL) MR_RuleBlkWithHalt->end->halt=TRUE; rk2=empty; while ( !set_nil(*incomplete) ) { k2 = set_int(*incomplete); if (k2 > (unsigned) predDepth) break; /* <=== another exit from loop */ set_rm(k2,*incomplete); u = NULL; TRAV(ruleRef->next,k2,&rk2,u); /* any subtrees missing k2 tokens, add u onto end */ *t=tlink(*t,u,k2); Tfree(u); } set_orin(incomplete,rk2); /* remember what we couldn't do */ set_free(rk2); if (MR_RuleBlkWithHalt != NULL) MR_RuleBlkWithHalt->end->halt=FALSE; if (set_int(*incomplete) > (unsigned) predDepth) break; /* <=== another exit from loop */ }; MR_RuleBlkWithHalt=save_MR_RuleBlkWithHalt; if (MR_RuleBlkWithHalt != NULL) { MR_RuleBlkWithHalt->end->halt=TRUE; }; ConstrainSearch=saveConstrainSearch; } #ifdef __USE_PROTOS void MR_complete_predicates(int predDepth,Predicate *pred) #else void MR_complete_predicates(predDepth,pred) int predDepth; Predicate *pred; #endif { if (pred == NULL) return; if (pred->expr != PRED_AND_LIST && pred->expr != PRED_OR_LIST) { MR_complete_set(predDepth,&(pred->scontext[1]),&(pred->completionSet)); MR_complete_tree(predDepth,&(pred->tcontext),&(pred->completionTree)); }; MR_complete_predicates(predDepth,pred->down); MR_complete_predicates(predDepth,pred->right); } #ifdef __USE_PROTOS Junction * MR_junctionWithoutP2(Junction *j) #else Junction * MR_junctionWithoutP2(j) Junction *j; #endif { Junction *thisAlt; /* don't want to follow p2 to the next alternative of this rule */ /* insert a generic node with null p2 if necessary */ /* however FIRST requires a junction */ thisAlt=j; if (thisAlt->p2 != NULL) { if (thisAlt->p1->ntype == nJunction) { thisAlt=(Junction *) thisAlt->p1; } else { thisAlt=newJunction(); thisAlt->p1=j->p1; thisAlt->rname=j->rname; thisAlt->file=j->file; thisAlt->line=j->line; j->p1=(Node *)thisAlt; }; }; return thisAlt; } #ifdef __USE_PROTOS int MR_tree_equ(Tree *big, Tree *small) { #else int MR_tree_equ(big,small) Tree *big; Tree *small; { #endif Tree *b; Tree *s; int bcount=0; int scount=0; if (small == NULL && big == NULL) return 1; if (small == NULL) return 0; if (big == NULL) return 0; if (small->token == ALT) { require(small->right == NULL, "MR_tree_equ: small: ALT node has siblings"); return MR_tree_equ(big,small->down); }; if (big->token == ALT) { require(big->right == NULL, "MR_tree_equ: big: ALT node has siblings"); return MR_tree_equ(big->down,small); }; for (s=small; s != NULL; s=s->right) { scount++; require(s->token != EpToken,"MR_tree_equ: s->EpToken unexpected\n"); }; for (b=big; b != NULL; b=b->right) { bcount++; require(b->token != EpToken,"MR_tree_equ: b->EpToken unexpected\n"); }; if (bcount != scount) return 0; for (s=small; s != NULL; s=s->right) { for (b=big; b!= NULL; b=b->right) { if (s->token == b->token) { if (MR_tree_equ(b->down,s->down)) goto next_s; }; }; return 0; next_s: continue; }; return 1; } /* this does not compare sources - only contexts ! */ #ifdef __USE_PROTOS int MR_identicalContext(Predicate *p,Predicate *q) #else int MR_identicalContext(p,q) Predicate *p; Predicate *q; #endif { if (p->k != q->k) return 0; require ( (p->tcontext == NULL) == (q->tcontext == NULL), "tcontext inconsistent"); if (p->k == 1) { return set_equ(p->scontext[1],q->scontext[1]); } else { return MR_tree_equ(p->tcontext,q->tcontext); }; } #ifdef __USE_PROTOS void MR_reportSetSuppression(int predDepth, set predSet,set plainSet,Junction *jPred,Junction *jPlain,Predicate *p) #else void MR_reportSetSuppression(predDepth,predSet,plainSet,jPred,jPlain,p) int predDepth; set predSet; set plainSet; Junction *jPred; Junction *jPlain; Predicate *p; #endif { if (InfoP) { fprintf(output,"\n#if 0\n\n"); fprintf(output,"Hoisting of predicate suppressed by alternative without predicate.\n"); fprintf(output,"The alt without the predicate includes all cases where the predicate is false.\n\n"); fprintf(output," WITH predicate: line %d %s\n",jPred->line,FileStr[jPred->file]); if (jPlain != NULL) { fprintf(output," WITHOUT predicate: line %d %s\n",jPlain->line,FileStr[jPlain->file]); } else { fprintf(output," WITHOUT predicate: all alternatives without predicates (combined)\n"); }; if (predDepth == 1) { fprintf(output,"\nThe context set for the predicate:\n"); MR_dumpTokenSet(output,1,predSet); }; fprintf(output,"\nThe lookahead set for the alt WITHOUT the semantic predicate:\n"); MR_dumpTokenSet(output,1,plainSet); fprintf(output,"\nThe predicate:\n\n"); MR_dumpPred1(1,p,1); fprintf(output,"Chain of referenced rules:\n\n"); MR_dumpPredRuleRefStack(output,4); fprintf(output,"\n#endif\n"); }; } #ifdef __USE_PROTOS void MR_reportSetRestriction(int predDepth,set predSet,set plainSet, Junction *jPred,Junction *jPlain,Predicate *origPred,Predicate *newPred) #else void MR_reportSetRestriction(predDepth,predSet,plainSet,jPred,jPlain,origPred,newPred) int predDepth; set predSet; set plainSet; Junction *jPred; Junction *jPlain; Predicate *origPred; Predicate *newPred; #endif { set intersect; intersect=empty; if (! InfoP) return; fprintf(output,"\n#if 0\n\n"); fprintf(output,"Restricting the context of a predicate because of overlap in the lookahead set\n"); fprintf(output," between the alternative with the semantic predicate and one without\n"); fprintf(output,"Without this restriction the alternative without the predicate could not\n"); fprintf(output," be reached when input matched the context of the predicate and the predicate\n"); fprintf(output," was false.\n\n"); fprintf(output," WITH predicate: line %d %s\n",jPred->line,FileStr[jPred->file]); if (jPlain != NULL) { fprintf(output," WITHOUT predicate: line %d %s\n",jPlain->line,FileStr[jPlain->file]); } else { fprintf(output," WITHOUT predicate: all alternatives without predicates (combined)\n"); }; if (predDepth == 1) { fprintf(output,"\nThe original context set for the predicate:\n"); MR_dumpTokenSet(output,1,predSet); }; fprintf(output,"\nThe lookahead set for the alt WITHOUT the semantic predicate:\n"); MR_dumpTokenSet(output,1,plainSet); if (predDepth == 1) { fprintf(output,"\nThe intersection of the two sets\n"); intersect=set_and(predSet,plainSet); MR_dumpTokenSet(output,1,intersect); set_free(intersect); }; fprintf(output,"\nThe original predicate:\n\n"); MR_dumpPred1(1,origPred,1); fprintf(output,"The new (modified) form of the predicate:\n\n"); MR_dumpPred1(1,newPred,1); fprintf(output,"#endif\n"); } /* don't use Pass3 by itself unless you know that inverted is not important */ #ifdef __USE_PROTOS Predicate * MR_removeRedundantPredPass3(Predicate *p) #else Predicate * MR_removeRedundantPredPass3(p) Predicate *p; #endif { Predicate *q; if (p == NULL) return NULL; p->right=MR_removeRedundantPredPass3(p->right); p->down=MR_removeRedundantPredPass3(p->down); if (p->redundant) { q=p->right; p->right=NULL; predicate_free(p); return q; }; if (p->expr == PRED_AND_LIST || p->expr == PRED_OR_LIST) { if (p->down == NULL) { q=p->right; p->right=NULL; predicate_free(p); return q; }; if (p->down != NULL && p->down->right == NULL) { q=p->down; q->right=p->right; p->right=NULL; p->down=NULL; return q; }; }; return p; } #ifdef __USE_PROTOS void MR_removeRedundantPredPass2(Predicate *p) #else void MR_removeRedundantPredPass2(p) Predicate *p; #endif { Predicate *q; if (p == NULL) return; if (p->expr == PRED_AND_LIST) { for (q=p->down ; q != NULL ; q=q->right) { MR_removeRedundantPredPass2(q); if (q->isConst) { if (q->constValue == 0) { p->isConst=1; p->constValue=0; return; } else { q->redundant=1; }; }; }; }; if (p->expr == PRED_OR_LIST) { for (q=p->down ; q != NULL ; q=q->right) { MR_removeRedundantPredPass2(q); if (q->isConst) { if (q->constValue == 0) { q->redundant=1; } else { p->isConst=1; p->constValue=1; return; }; }; }; }; return; } #if 0 this totally ignores the implications of guarded predicates in which the part after the guard could possibly cover a predicate. that would be much harder: rule : (A)? => <

>? sub1; /* 1 */ | (B)? => <>? sub2 /* 2 */ sub1 : (A)? => <>? A B /* 3 */ | B /* 4 - suppresses line 2 */ ; #endif #ifdef __USE_PROTOS void MR_apply_restriction1(Predicate *pred,set *plainSet,int *changed) #else void MR_apply_restriction1(pred,plainSet,changed) Predicate *pred; set *plainSet; int *changed; #endif { if (pred == NULL) return; MR_apply_restriction1(pred->right,plainSet,changed); if (pred->down != NULL) { MR_apply_restriction1(pred->down,plainSet,changed); } else { set t; if (pred->k == 1) { t=set_dif(pred->scontext[1],*plainSet); if (*changed == 0 && !set_equ(t,pred->scontext[1])) { *changed=1; }; if (set_nil(t)) { pred->redundant=1; }; set_free(pred->scontext[1]); pred->scontext[1]=t; }; }; } #ifdef __USE_PROTOS void MR_orin_plainSet(Predicate *p,set plainSet) #else void MR_orin_plainSet(p,plainSet) Predicate *p; set plainSet; #endif { if (p == NULL) return; MR_orin_plainSet(p->down,plainSet); MR_orin_plainSet(p->right,plainSet); set_orin(&p->plainSet,plainSet); } Predicate *PRED_SUPPRESS; #ifdef __USE_PROTOS Predicate * MR_find_in_aSubBlk(Junction *alt) #else Predicate * MR_find_in_aSubBlk(alt) Junction *alt; #endif { Predicate *root=NULL; Predicate **tail=NULL; Junction *p; int nAlts=0; Junction **jList; Predicate **predList; int *matchList; set predSet; int i; int j; int m; int predDepth; set incomplete; set union_plainSet; set setChange; int changed; Predicate *newPred; set setDif; Predicate *origPred; int depth1=1; /* const int */ set *plainContext; set plainSet; predSet=empty; incomplete=empty; union_plainSet=empty; setChange=empty; setDif=empty; plainSet=empty; if (PRED_SUPPRESS == NULL) { PRED_SUPPRESS=new_pred(); PRED_SUPPRESS->expr="Predicate Suppressed"; }; /* this section just counts the number of "interesting" alternatives */ /* in order to allocate arrays */ for (p=alt; p!=NULL; p=(Junction *)p->p2) { /* ignore empty alts */ if ( p->p1->ntype != nJunction || ((Junction *)p->p1)->jtype != EndBlk ) { nAlts++; }; }; /* if this is a (...)+ block then don't count the last alt because it can't be taken until at least one time through the block. In other words it isn't a real choice until the (...)+ is entered at which point the hoisting issue is moot. Maybe look at "ignore" instead ? */ if (alt->jtype == aPlusBlk) { nAlts--; }; jList=(Junction **)calloc(nAlts,sizeof(Junction *)); require(jList!=NULL,"cannot allocate MR_find_in_aSubBlk jList"); plainContext=(set *)calloc(nAlts,sizeof(set)); require(plainContext!=NULL,"cannot allocate MR_find_in_aSubBlk plainContext"); for (m=0; m < nAlts; m++) plainContext[m]=empty; predList=(Predicate **)calloc(nAlts,sizeof(Predicate *)); require(predList!=NULL,"cannot allocate MR_find_in_aSubBlk predList"); matchList=(int *)calloc(nAlts,sizeof(int)); require(matchList!=NULL,"cannot allocate MR_find_in_aSubBlk matchList"); /* this section just fills in the arrays previously allocated */ /* the most interesting one is matchList[] */ /* */ /* bit 0 => this alt has a semantic pred which is "covered" */ /* by an alt without a semantic pred. Don't hoist. */ for (i=0,p=alt; p!=NULL && ip2) { /* ignore empty alts */ if ( p->p1->ntype != nJunction || ((Junction *)p->p1)->jtype != EndBlk ) { jList[i]=MR_junctionWithoutP2(p); predList[i]=find_predicates(p->p1); /* should be jList ????? */ if (predList[i] != NULL) { MR_cleanup_pred_trees(predList[i]); /* flatten & left factor */ plainContext[i]=MR_union_plain_sets(predList[i]); } else { MR_set_reuse(&plainSet); MR_set_reuse(&incomplete); plainSet=MR_First(depth1,jList[i],&incomplete); MR_complete_set(depth1,&plainSet,&incomplete); require(set_nil(incomplete),"couldn't complete k=1"); plainContext[i]=plainSet; plainSet=empty; }; set_orin(&union_plainSet,plainContext[i]); }; }; if (nAlts == 1) { goto EXIT_SIMPLE; }; /* * Looking for cases where alt i has a semantic pred and alt j does not. * Don't care about cases where lookahead for semantic predicates overlap * because normal predicate hoisting does the correct thing automatically. * Don't care about cases where lookahead for alts without semantic predicates * overlap because normal prediction does the correct thing automatically. * * When we find such a case check for one of three subcases: * * 1. if lookahead for alt i is contained in the lookahead for any * alt j then ignore semantic predicate of alt i * 2. if lookahead for alt i is not contained in the lookahead for * any alt j then add add predicate i to the OR list to be hoisted * 3. if lookahead for alt i overlaps the lookahead for some alt j then * add a dummy semantic predicate for alt j * * There is an implicit assumption that the context of all alternatives following * the rule being processed here are identical (but may vary from hoist to * hoist depending on the place where the rule was invoked that led to hoisting * these predicates. In othere words in the fragment: * * ( <>? a1 a2 a3 | <>? b1 b2 b3 ) * * both a3 and b3 have the same follow sets because they are both at the end of * alternatives in the same block. */ for (i=0; i < nAlts; i++) { if (jList[i] == NULL) continue; if (predList[i] == NULL) continue; /* if the predicate depth turns out to be one token only */ /* then it is can be easily represented as a set and */ /* compared to the junction set create by MR_First() */ predDepth=0; MR_pred_depth(predList[i],&predDepth); require (predDepth >= 1,"MR_find_in_aSubBlk: pred depth < 1"); require (predDepth <= CLL_k,"MR_find_in_aSubBlk: predDepth > CLL_k"); /* complete predicates to predDepth If completed to depth=1 then the context would be incomplete. The context would be truncated and the predicate simplify routine would have incomplete information. It would lead to either false matches of failure to find true matches. */ MR_complete_predicates(predDepth,predList[i]); if (predList[i] != NULL) { MR_cleanup_pred_trees(predList[i]); /* flatten & left factor */ }; /* If the predicate depth is 1 then it is possible to suppress a predicate completely using a single plain alt. Check for suppression by a single plain alt first because it gives better messages. If that fails try the union of all the plain alts. */ if (predDepth == 1) { MR_set_reuse(&predSet); predSet=MR_compute_pred_set(predList[i]); /* ignores k>1 predicates */ for (j=0; j < nAlts; j++) { if (jList[j] == NULL) continue; if (j == i) continue; MR_set_reuse(&setDif); setDif=set_dif(predSet,plainContext[j]); if (set_nil(setDif)) { matchList[i] |= 1; MR_reportSetSuppression(predDepth,predSet,plainContext[j],jList[i],jList[j],predList[i]); predicate_free(predList[i]); predList[i]=PRED_SUPPRESS; goto next_i; }; }; /* end loop on j */ changed=0; /* predicate_dup is only to give good error messages */ /* remember to do a predicate_free() */ origPred=predicate_dup(predList[i]); MR_apply_restriction1(predList[i],&union_plainSet,&changed); if (changed) { /* don't use Pass3 by itself unless you know that inverted is not important */ newPred=MR_removeRedundantPredPass3(predList[i]); newPred=MR_predSimplifyALL(newPred); if (newPred == NULL) { matchList[i] |= 1; MR_reportSetSuppression(predDepth,predSet,union_plainSet,jList[i], NULL,origPred); predList[i]=PRED_SUPPRESS; } else { MR_reportSetRestriction(predDepth,predSet,union_plainSet,jList[i], NULL,origPred,newPred); predList[i]=newPred; }; }; predicate_free(origPred); origPred=NULL; }; /* If the predicate depth is > 1 then it can't be suppressed completely because the code doesn't support inspection of such things. They're much messier than k=1 sets. */ if (predDepth > 1 ) { changed=0; /* predicate_dup is only to give good error messages */ /* remember to do a predicate_free() */ origPred=predicate_dup(predList[i]); MR_apply_restriction1(predList[i],&union_plainSet,&changed); if (changed) { newPred=MR_removeRedundantPredPass3(predList[i]); newPred=MR_predSimplifyALL(newPred); if (newPred == NULL) { matchList[i] |= 1; MR_reportSetSuppression(predDepth,predSet,union_plainSet,jList[i], NULL,origPred); predList[i]=PRED_SUPPRESS; } else { MR_reportSetRestriction(predDepth,predSet,union_plainSet,jList[i], NULL,origPred,newPred); predList[i]=newPred; }; }; predicate_free(origPred); origPred=NULL; }; next_i: continue; }; EXIT_SIMPLE: root = new_pred(); root->expr=PRED_OR_LIST; tail = &(root->down); for (i=0 ; i< nAlts ; i++) { if (jList[i] == NULL) continue; if (predList[i] == NULL) { continue; } else if ( (matchList[i] & 1) != 0) { if (predList[i] != PRED_SUPPRESS) { predicate_free(predList[i]); }; continue; }; /* make an OR list of predicates */ *tail=predList[i]; tail=&(predList[i]->right); }; /* if just one pred, remove OR root */ if (root->down == NULL) { predicate_free(root); root=NULL; } else if (root->down->right == NULL) { Predicate *p=root->down; root->down=NULL; predicate_free(root); root=p; } root=MR_predSimplifyALL(root); MR_orin_plainSet(root,union_plainSet); set_free(predSet); set_free(union_plainSet); set_free(incomplete); set_free(setChange); set_free(setDif); for (m=0; m < nAlts; m++) set_free(plainContext[m]); free ( (char *) jList); free ( (char *) predList); free ( (char *) matchList); free ( (char *) plainContext); return root; } #ifdef __USE_PROTOS void MR_predContextPresent(Predicate *p,int *allHaveContext,int *noneHaveContext) #else void MR_predContextPresent(p,allHaveContext,noneHaveContext) Predicate *p; int *allHaveContext; int *noneHaveContext; #endif { if (p == NULL) return; MR_predContextPresent(p->right,allHaveContext,noneHaveContext); if (p->expr != PRED_AND_LIST && p->expr != PRED_OR_LIST) { if (set_nil(p->scontext[1]) == 0 || (p->tcontext != NULL)) { *noneHaveContext=0; } else { *allHaveContext=0; }; }; MR_predContextPresent(p->down,allHaveContext,noneHaveContext); } #ifdef __USE_PROTOS int MR_pointerStackPush(PointerStack *ps,void *dataPointer) #else int MR_pointerStackPush(ps,dataPointer) PointerStack *ps; void *dataPointer; #endif { void **newStack; int newSize; int i; if (ps->count == ps->size) { newSize=20+ps->size*2; newStack=(void **)calloc(newSize,sizeof(void *)); require (newStack != NULL,"cannot allocate PointerStack"); for (i=0; i < ps->size; i++) { newStack[i]=ps->data[i]; }; if (ps->data != NULL) free( (char *) ps->data); ps->data=newStack; ps->size=newSize; }; ps->data[ps->count]=dataPointer; ps->count++; return ps->count-1; } #ifdef __USE_PROTOS void * MR_pointerStackPop(PointerStack *ps) #else void * MR_pointerStackPop(ps) PointerStack *ps; #endif { void *dataPointer; require(ps->count > 0,"MR_pointerStackPop underflow"); dataPointer=ps->data[ps->count-1]; ps->data[ps->count-1]=NULL; (ps->count)--; return dataPointer; } #ifdef __USE_PROTOS void * MR_pointerStackTop(PointerStack *ps) #else void * MR_pointerStackTop(ps) PointerStack *ps; #endif { require(ps->count > 0,"MR_pointerStackTop underflow"); return ps->data[ps->count-1]; } #ifdef __USE_PROTOS void MR_pointerStackReset(PointerStack *ps) #else void MR_pointerStackReset(ps) PointerStack *ps; #endif { int i; if (ps->data != NULL) { for (i=0; i < ps->count ; i++) { ps->data[i]=NULL; }; }; ps->count=0; } #ifdef __USE_PROTOS Junction *MR_nameToRuleBlk(char *name) #else Junction *MR_nameToRuleBlk(name) char *name; #endif { RuleEntry *q; require (RulePtr != NULL,"MR_nameToRule: RulePtr not initialized"); if (name == NULL) return NULL; q = (RuleEntry *) hash_get(Rname,name); if ( q == NULL ) { return NULL; } else { return RulePtr[q->rulenum]; }; } #ifdef __USE_PROTOS Junction * MR_ruleReferenced(RuleRefNode *rrn) #else Junction * MR_ruleReferenced(rrn) RuleRefNode *rrn; #endif { return MR_nameToRuleBlk(rrn->text); } #ifdef __USE_PROTOS void MR_comparePredLeaves(Predicate *me,Predicate *myParent,Predicate *him,Predicate *hisParent) #else void MR_comparePredLeaves(me,myParent,him,hisParent) Predicate *me; Predicate *myParent; Predicate *him; Predicate *hisParent; #endif { if (me == NULL) return; if (me == him) { MR_comparePredLeaves(me->right,myParent,him,hisParent); return; } else if (me->expr == PRED_AND_LIST || me->expr == PRED_OR_LIST) { MR_comparePredLeaves(me->down,me,him,hisParent); MR_comparePredLeaves(me->right,myParent,him,hisParent); return; } else { if (me->source != NULL) { /* predicate->invert can be set only in the predEntry predicates */ /* thus they are only visible after the predEntry predicates have been "unfolded" */ int sameSource=(me->source == him->source); int sameInvert=1 & (1 + me->inverted + him->inverted + me->source->inverted + him->source->inverted); int samePredEntry=(me->source->predEntry != NULL && him->source->predEntry != NULL && me->source->predEntry == him->source->predEntry); if (sameInvert && (sameSource || samePredEntry)) { if (MR_identicalContext(me,him)) { /* identical predicates */ if (hisParent->expr == PRED_OR_LIST && myParent->expr == PRED_OR_LIST) { me->redundant=1; } else if (hisParent->expr == PRED_AND_LIST && myParent->expr == PRED_AND_LIST) { me->redundant=1; } else if ( (hisParent->expr == PRED_OR_LIST && myParent->expr == PRED_AND_LIST) || (hisParent->expr == PRED_AND_LIST && myParent->expr == PRED_OR_LIST) ) { myParent->redundant=1; } else { require (0,"MR_comparePredLeaves: not both PRED_LIST"); }; }; }; /* end same source or same predEntrr with same invert sense */ /* same predEntry but opposite invert sense */ if (!sameInvert && (sameSource || samePredEntry)) { if (MR_identicalContext(me,him)) { if (hisParent->expr == PRED_OR_LIST && myParent->expr == PRED_OR_LIST) { myParent->isConst=1; myParent->constValue=1; } else if (hisParent->expr == PRED_AND_LIST && myParent->expr == PRED_AND_LIST) { myParent->isConst=1; myParent->constValue=0; } else if ( (hisParent->expr == PRED_OR_LIST && myParent->expr == PRED_AND_LIST) || (hisParent->expr == PRED_AND_LIST && myParent->expr == PRED_OR_LIST) ) { me->redundant=1; } else { require (0,"MR_comparePredLeaves: not both PRED_LIST"); }; }; }; /* end same predEntry with opposite invert sense */ }; MR_comparePredLeaves(me->right,myParent,him,hisParent); return; }; } #ifdef __USE_PROTOS void MR_removeRedundantPredPass1(Predicate *me,Predicate *myParent) #else void MR_removeRedundantPredPass1(me,myParent) Predicate *me; Predicate *myParent; #endif { if (me == NULL) return; if (me->redundant) { MR_removeRedundantPredPass1(me->right,myParent); return; }; if (me->expr == PRED_AND_LIST || me->expr == PRED_OR_LIST) { MR_removeRedundantPredPass1(me->down,me); MR_removeRedundantPredPass1(me->right,myParent); } else { require (me->source != NULL,"me->source == NULL"); if (myParent != NULL) { MR_comparePredLeaves(myParent->down,myParent,me,myParent); }; MR_removeRedundantPredPass1(me->right,myParent); }; } /* pretty much ignores things with the inverted bit set */ #ifdef __USE_PROTOS Predicate *MR_predFlatten(Predicate *p) #else Predicate *MR_predFlatten(p) Predicate *p; #endif { if (p == NULL) return NULL; if (p->expr == PRED_OR_LIST || p->expr == PRED_AND_LIST) { Predicate *child; Predicate *gchild; Predicate **tail; Predicate *next; char *PRED_XXX_LIST=p->expr; require (p->down != NULL,"MR_predFlatten AND/OR no child"); p->down=MR_predFlatten(p->down); p->right=MR_predFlatten(p->right); child=p->down; if (child->right == NULL) { child->right=p->right; p->right=NULL; p->down=NULL; if (p->inverted) child->inverted=!child->inverted; predicate_free(p); return child; }; /* make a single list of all children and grandchildren */ tail=&(p->down); for (child=p->down; child != NULL; child=next) { if (child->expr != PRED_XXX_LIST || child->inverted || child->predEntry != NULL) { *tail=child; tail=&(child->right); next=child->right; } else { for (gchild=child->down; gchild != NULL; gchild=gchild->right) { *tail=gchild; tail=&(gchild->right); }; next=child->right; child->right=NULL; child->down=NULL; predicate_free(child); }; }; *tail=NULL; return p; } else { p->right=MR_predFlatten(p->right); return p; }; } static char *alwaysFalseWarning=NULL; #ifdef __USE_PROTOS Predicate *checkPredicateConflict(Predicate *p) #else Predicate *checkPredicateConflict(p) Predicate *p; #endif { if (p->isConst) { if (p->constValue == 1) { predicate_free(p); return NULL; } else { if (InfoP && !p->conflictReported) { p->conflictReported=1; fprintf(output,"\n#if 0\n\n"); fprintf(output,"The following predicate expression will always be false:\n\n"); MR_dumpPred1(1,p,1); fprintf(output,"\n#endif\n"); }; if (alwaysFalseWarning != CurRule) { alwaysFalseWarning=CurRule; if (InfoP) { warnNoFL(eMsg1("one (or more) predicate expression hoisted into rule \"%s\" are always false \ - see output file for more information",CurRule)); } else { warnNoFL(eMsg1("one (or more) predicate expressions hoisted into rule \"%s\" are always false \ - use \"-info p\" for more information",CurRule)); }; }; }; }; return p; } #ifdef __USE_PROTOS int MR_countPredNodes(Predicate *p) #else int MR_countPredNodes(p) Predicate *p; #endif { if (p == NULL) return 0; return 1 + MR_countPredNodes(p->down) + MR_countPredNodes(p->right); } #ifdef __USE_PROTOS Predicate *MR_predSimplifyALLX(Predicate *p,int skipPass3) #else Predicate *MR_predSimplifyALLX(p,skipPass3) Predicate *p; int skipPass3; #endif { int countBefore; int countAfter; countAfter=MR_countPredNodes(p); do { if (p == NULL) return NULL; if (p->right == NULL && p->down == NULL) return p; countBefore=countAfter; MR_simplifyInverted(p,0); p=MR_predFlatten(p); MR_removeRedundantPredPass1(p,NULL); MR_removeRedundantPredPass2(p); if (! skipPass3) { p=checkPredicateConflict(p); p=MR_removeRedundantPredPass3(p); }; countAfter=MR_countPredNodes(p); } while (countBefore != countAfter); return p; } #ifdef __USE_PROTOS Predicate *MR_predSimplifyALL(Predicate *p) #else Predicate *MR_predSimplifyALL(p) Predicate *p; #endif { return MR_predSimplifyALLX(p,0); } #ifdef __USE_PROTOS void MR_releaseResourcesUsedInRule(Node *n) #else void MR_releaseResourcesUsedInRule(n) Node *n; #endif { Node *next; Junction *j; int i; if (n == NULL) return; if (n->ntype == nJunction) { j=(Junction *) n; if (j->predicate != NULL) { predicate_free(j->predicate); j->predicate=NULL; }; for (i=0; i< CLL_k; i++) { set_free(j->fset[i]); j->fset[i]=empty; }; if (j->ftree != NULL) { Tfree(j->ftree); j->ftree=NULL; }; if (j->jtype == EndRule) return; if (j->jtype != RuleBlk && j->jtype != EndBlk) { if (j->p2 != NULL && !j->ignore) { /* MR11 */ MR_releaseResourcesUsedInRule(j->p2); }; }; }; next=MR_advance(n); MR_releaseResourcesUsedInRule(next); } #ifdef __USE_PROTOS int MR_allPredLeaves(Predicate *p) #else int MR_allPredLeaves(p) Predicate *p; #endif { Predicate *q; if (p == NULL) return 1; for (q=p; q != NULL; q=q->right) { if (q->down != NULL) return 0; }; return 1; } /* make sure it works for the last rule in a file */ #ifdef __USE_PROTOS int MR_offsetFromRule(Node *n) #else int MR_offsetFromRule(n) Node *n; #endif { Junction *j; int offset=(-1); for (j=SynDiag; j != NULL; j=(Junction *)j->p2) { require (j->ntype == nJunction && j->jtype == RuleBlk,"Not a rule block"); if (n->file < j->file) { return offset; }; if (n->file == j->file) { if (n->line < j->line) { return (offset < 0) ? 0 : offset; } else { offset=n->line - j->line; if (offset == 0) return 0; }; }; }; return offset; } #define ruleNameMax 50 static char ruleNameStatic1[ruleNameMax]; static char ruleNameStatic2[ruleNameMax+10]; #ifdef __USE_PROTOS char * MR_ruleNamePlusOffset(Node *n) #else char * MR_ruleNamePlusOffset(n) Node *n; #endif { int offset=MR_offsetFromRule(n); strncpy(ruleNameStatic1,n->rname,ruleNameMax); if (offset < 0) { sprintf(ruleNameStatic2,"%s/?",ruleNameStatic1); } else { sprintf(ruleNameStatic2,"%s/%d",ruleNameStatic1,offset+1); }; return ruleNameStatic2; } #ifdef __USE_PROTOS int MR_max_height_of_tree(Tree *t) #else int MR_max_height_of_tree(t) Tree *t; #endif { int h; int height=0; Tree *u; if (t == NULL) return 0; require (t->token != ALT && t->token != EpToken,"MR_max_height_of_tree ALT or EpToken"); for (u=t; u != NULL; u=u->right) { h=MR_max_height_of_tree(u->down)+1; if (h > height) height=h; }; return height; } #ifdef __USE_PROTOS int MR_all_leaves_same_height(Tree *t,int depth) #else int MR_all_leaves_same_height(t,depth) Tree *t; int depth; #endif { if (t == NULL) { return (depth==0); }; require (t->token != ALT && t->token != EpToken,"MR_all_leaves_same_height ALT or EpToken"); if (depth == 0) { return 0; } else { if ( ! MR_all_leaves_same_height(t->down,depth-1)) { return 0; }; if (t->right == NULL) { return 1; } else { return MR_all_leaves_same_height(t->right,depth); }; }; } #ifdef __USE_PROTOS void MR_projectTreeOntoSet(Tree *tree,int ck,set *ckset) #else void MR_projectTreeOntoSet(tree,ck,ckset) Tree *tree; int ck; set *ckset; #endif { if (tree == NULL) return; require(tree->token != EpToken,"MR_projectTreeOntoSet: EpToken unexpected\n"); MR_projectTreeOntoSet(tree->right,ck,ckset); if (tree->token == ALT) { MR_projectTreeOntoSet(tree->down,ck,ckset); } else { if (ck > 1) { MR_projectTreeOntoSet(tree->down,ck-1,ckset); } else { set_orel(tree->token,ckset); }; }; } #ifdef __USE_PROTOS int MR_comparePredicates(Predicate *a,Predicate *b) #else int MR_comparePredicates(a,b) Predicate *a; Predicate *b; #endif { Predicate *p; Predicate *q; if (a == b) return 1; if (a == NULL || b == NULL ) return 0; if (a->down == NULL && b->down == NULL) { /* predicate->invert can be set only in the predEntry predicates */ /* thus they are only visible after the predEntry predicates have been "unfolded" */ int sameSource=(a->source == b->source); int sameInvert= 1 & (1 +a->inverted + b->inverted + a->source->inverted + b->source->inverted); int samePredEntry=(a->source->predEntry != NULL && b->source->predEntry != NULL && a->source->predEntry == b->source->predEntry); if (sameInvert && (sameSource || samePredEntry)) { if (MR_identicalContext(a,b)) { return 1; }; }; return 0; }; if (a->down == NULL || b->down == NULL) return 0; if (a->expr != b->expr) return 0; for (p=a->down; p != NULL; p=p->right) { for (q=b->down; q != NULL; q=q->right) { if (MR_comparePredicates(p,q)) goto NEXT_P; }; return 0; NEXT_P: continue; }; return 1; } /* * action->inverted can be set only when a predicate symbol appears in * a rule: "rule : <>? X". It cannot be set under any * other circumstances. In particular it cannot be set by * "#pred NotA !A" or by "#pred Nota <>?". The first case * creates a predEntry and the predicate expression of that predEntry * has inverted set. In the second case, the code for handling "!" * is only present in buildAction, which is not called by the #pred * semantic routines, only when a <<...>>? is recognized as part of * a rule definition. * * predicate->inverted can only be set by a predicate created by a #pred * expression, such as "#pred NotA !A" or "#pred NotXY ! (X && Y) or * "#pred XbarY !(X && Y)". In particular, it cannot be set by any * predicate expression occurring under any other circumstances. * The #pred predicate expresssions are stored with in predEntry->pred * and do not normally appear anywhere else until the predicates are * "unfolded" in order to recognize redundancies, conflicts, and * tautologies. * * The unfold routine expands all references to #pred expressions. * * The simplifyInvert goes through and propagates the invert bit so that * all OR and AND nodes are un-inverted. * * Note that !(A and B) => (!A or !B) * !(A or B) => (!A and !B) * * MR_unfold() is called to expand predicate symbols by replacing predicates * that reference predicate entries with the copies of the predicate entries. * Each reference receives a duplicate of the original. This is necessary * because the next phase involves simplification and removal of redundant * predicate nodes. Anyway, the point I'm making is that predicate->invert * should not be set in any predicate until it has been expanded. * * This is a recursive structure, but there is no need for "recursive expansion" * by which I mean a predicate symbol refers to other predicate symbols which * must also be expanded. * * Recursive expansion is *not* performed by this routine because it is not * necessary. Expansion of references is performed by predPrimary when * a new predicate symbol is created by referring to others in the pred expr. */ #ifdef __USE_PROTOS Predicate *MR_unfold(Predicate *pred) #else Predicate *MR_unfold(pred) Predicate *pred; #endif { Predicate *result; if (pred == NULL) return NULL; pred->right=MR_unfold(pred->right); if (pred->down == NULL) { if (pred->source->predEntry != NULL) { if (pred->source->predEntry->pred == NULL) { ; /* do nothing */ /* a reference to a literal #pred (perhaps with "!" */ } else { result=predicate_dup_without_context(pred->source->predEntry->pred); if (pred->inverted) { result->inverted=!result->inverted; }; if (pred->source->inverted) { result->inverted=!result->inverted; }; result->right=pred->right; pred->right=NULL; predicate_free(pred); /*** result=MR_unfold(result); *** not necessary */ /* recursive expansion */ return result; }; } else { ; /* do nothing */ /* an inline literal predicate */ }; } else { pred->down=MR_unfold(pred->down); }; return pred; } /* this should be called immediately after MR_unfold() and at no other times */ #ifdef __USE_PROTOS void MR_simplifyInverted(Predicate *pred,int inverted) #else void MR_simplifyInverted(pred,inverted) Predicate *pred; int inverted; #endif { int newInverted; if (pred == NULL) return; MR_simplifyInverted(pred->right,inverted); newInverted= 1 & (inverted + pred->inverted); if (pred->down == NULL) { pred->inverted=newInverted; } else { if (newInverted != 0) { if (pred->expr == PRED_AND_LIST) { pred->expr=PRED_OR_LIST; } else { pred->expr=PRED_AND_LIST; }; }; pred->inverted=0; MR_simplifyInverted(pred->down,newInverted); }; } /* only remove it from AND and OR nodes, not leaves */ #ifdef __USE_PROTOS void MR_clearPredEntry(Predicate *p) #else void MR_clearPredEntry(p) Predicate *p; #endif { if (p == NULL) return; MR_clearPredEntry(p->down); MR_clearPredEntry(p->right); if (p->down != NULL) p->predEntry=NULL; } #ifdef __USE_PROTOS void MR_orphanRules(FILE *f) #else void MR_orphanRules(f) FILE *f; #endif { set a; Junction *p; unsigned e; RuleEntry *re; a=empty; if (! InfoO) return; for (p=SynDiag; p!=NULL; p = (Junction *)p->p2) { if ( (Junction *) (p->end)->p1 == NULL) { re=(RuleEntry *) hash_get(Rname,p->rname); require (re != NULL,"RuleEntry == NULL"); set_orel(re->rulenum, &a); } } if (set_deg(a) > 1) { fprintf(f,"note: Start rules: {"); for (; !set_nil(a); set_rm(e,a)) { e=set_int(a); fprintf(f," %s",RulePtr[e]->rname); }; fprintf(f," }\n"); }; set_free( a ); } /* merge (X Y) and (X) to create (X) */ static int *mergeChain; static Tree *mergeTree; #ifdef __USE_PROTOS Tree *MR_merge_tree_contexts_client(Tree *t,int chain[]) #else Tree *MR_merge_tree_contexts_client(t,chain) Tree *t; int chain[]; #endif { if (t == NULL) return NULL; if (chain[0] == 0) { Tree *u=t->right; t->right=NULL; Tfree(t); return MR_merge_tree_contexts_client(u,&chain[0]); } if (chain[0] == t->token) { t->down=MR_merge_tree_contexts_client(t->down,&chain[1]); }; t->right=MR_merge_tree_contexts_client(t->right,&chain[0]); return t; } #ifdef __USE_PROTOS void MR_iterateOverTreeContexts(Tree *t,int chain[]) #else void MR_iterateOverTreeContexts(t,chain) Tree *t; int chain[]; #endif { if (t == NULL) return; chain[0]=t->token; if (t->down != NULL) { MR_iterateOverTreeContexts(t->down,&chain[1]); } else { MR_merge_tree_contexts_client(mergeTree,mergeChain); }; MR_iterateOverTreeContexts(t->right,&chain[0]); chain[0]=0; } #ifdef __USE_PROTOS Tree *MR_merge_tree_contexts(Tree *t) #else Tree *MR_merge_tree_contexts(t) Tree *t; #endif { int h=MR_max_height_of_tree(t); mergeTree=t; mergeChain=(int *) calloc(h+1,sizeof(int)); require (mergeChain != NULL,"MR_merge_tree_contexts: can't alloc chain"); MR_iterateOverTreeContexts(t,mergeChain); t=tshrink(t); t=tflatten(t); t=tleft_factor(t); free ( (char *) mergeChain); mergeChain=NULL; return t; } #ifdef __USE_PROTOS Tree *MR_compute_pred_tree_context(Predicate *p) #else Tree *MR_compute_pred_tree_context(p) Predicate *p; #endif { Tree *t; t=MR_compute_pred_tree_ctxXX(p); MR_merge_tree_contexts(t); return t; } #ifdef __USE_PROTOS void MR_guardPred_plainSet(ActionNode *anode,Predicate *pred) #else void MR_guardPred_plainSet(anode,pred) ActionNode *anode; Predicate *pred; #endif { Junction *j; Predicate *workPred; set maskSet; maskSet=empty; if (!MRhoisting) return; /* it doesn't really matter whether the predicate has depth k=1 or k>1 because we're not really looking at the predicate itself, just the stuff "behind" the predicate. */ /* shouldn't have to worry about REACHing off the end of the rule containing the predicate because the Rule->end->halt should have been set already by the the code which handles RuleRef nodes. We don't want to REACH off the end of the rule because this would give the "global" follow context rather than the "local" context. r1a : (A)? => <

>? r2 (A|B) r1b : (A)? => <

>? r2 (A|C) r2 : (); For r1a we want follow of predicate = {A B} we want plainSet = {B} For r1b we want follow of predicate = {A C} we want plainSet = {C} */ require (anode->next->ntype == nJunction,"MR_guardpred_plainSet not Junction"); j=(Junction *)(anode->next); workPred=predicate_dup_without_context(pred); workPred->k=1; workPred->scontext[1]=MR_First(1,j, &(workPred->completionSet) ); MR_complete_predicates(1,workPred); if (pred->k == 1) { maskSet=pred->scontext[1]; } else { MR_projectTreeOntoSet(pred->tcontext,1,&maskSet); } pred->plainSet=set_dif(workPred->scontext[1],maskSet); predicate_free(workPred); } /*******************************************************************************/ static Tree * suppressTree; static int * suppressChain; /* element 0 not used */ static set * suppressSets; static Node * suppressNode; static int suppressChainLength; int MR_SuppressSearch=0; static int suppressSucceeded; static Predicate * suppressPredicate; #ifdef __USE_PROTOS int MR_isChain(Tree *t) #else int MR_isChain(t) Tree *t; #endif { Tree *u; for (u=t; u != NULL; u=u->down) { if (u->right != NULL) return 0; } return 1; } #ifdef __USE_PROTOS int MR_suppressK_client(Tree *tree,int tokensInChain[]) #else int MR_suppressK_client(tree,tokensInChain) Tree *tree; int tokensInChain[]; #endif { int i; set *save_fset; int save_ConstrainSearch; set incomplete; Tree *t; suppressSucceeded=0; /* volatile */ if (suppressSets == NULL) { suppressSets=(set *) calloc (CLL_k+1,sizeof(set)); require (suppressSets != NULL,"MR_suppressK_client: suppressSets alloc"); }; for (suppressChainLength=1; tokensInChain[suppressChainLength+1] != 0; suppressChainLength++) {}; require (suppressChainLength != 0,"MR_suppressK_client: chain empty"); for (i=1 ; i <= suppressChainLength ; i++) { set_clr(suppressSets[i]); set_orel( (unsigned) tokensInChain[i], &suppressSets[i]); }; save_fset=fset; save_ConstrainSearch=ConstrainSearch; fset=suppressSets; MR_SuppressSearch=1; MR_AmbSourceSearch=1; MR_MaintainBackTrace=1; ConstrainSearch=1; maxk = suppressChainLength; incomplete=empty; t=NULL; /*** constrain = &(fset[1]); ***/ MR_setConstrainPointer(&(fset[1])); /* MR18 */ MR_pointerStackReset(&MR_BackTraceStack); TRAV(suppressNode,maxk,&incomplete,t); Tfree(t); require (set_nil(incomplete),"MR_suppressK_client TRAV incomplete"); require (MR_BackTraceStack.count == 0, "MR_suppressK_client: MR_BackTraceStack.count != 0"); set_free(incomplete); ConstrainSearch=save_ConstrainSearch; fset=save_fset; MR_AmbSourceSearch=0; MR_MaintainBackTrace=0; MR_SuppressSearch=0; return suppressSucceeded; } #ifdef __USE_PROTOS Tree * MR_iterateOverTreeSuppressK(Tree *t,int chain[]) #else Tree * MR_iterateOverTreeSuppressK(t,chain) Tree *t; int chain[]; #endif { if (t == NULL) return NULL; t->right=MR_iterateOverTreeSuppressK(t->right,&chain[0]); chain[0]=t->token; if (t->down != NULL) { t->down=MR_iterateOverTreeSuppressK(t->down,&chain[1]); if (t->down == NULL) { Tree *u=t->right; t->right=NULL; Tfree(t); chain[0]=0; return u; }; } else { MR_suppressK_client(suppressTree,suppressChain); if (suppressSucceeded) { Tree *u=t->right; t->right=NULL; Tfree(t); chain[0]=0; return u; }; }; chain[0]=0; return t; } /* @@@ */ #ifdef __USE_PROTOS Predicate * MR_suppressK(Node *j,Predicate *p) #else Predicate * MR_suppressK(j,p) Node *j; Predicate *p; #endif { Predicate *result; int guardPred=0; int ampersandPred=0; Node *nodePrime; if (! MRhoistingk) { return p; } if (! MRhoisting) return p; if (CLL_k == 1) return p; if (suppressChain == NULL) { suppressChain=(int *) calloc(CLL_k+2,sizeof(int)); require (suppressChain != NULL,"MR_suppressK: can't allocate chain"); } if (p == NULL) return NULL; if (j->ntype == nJunction) { nodePrime=(Node *) MR_junctionWithoutP2( (Junction *) j); } else { nodePrime=j; }; p->down=MR_suppressK(j,p->down); p->right=MR_suppressK(j,p->right); if (p->down != NULL) { result=p; goto EXIT; }; if (p->k == 1) { result=p; goto EXIT; }; if (p->source != NULL) { if (p->source->guardpred != NULL) guardPred=1; if (p->source->ampersandPred != NULL) ampersandPred=1; } suppressPredicate=p; suppressNode=nodePrime; /* was j*/ suppressTree=p->tcontext; if (guardPred || ampersandPred) { p->tcontext=MR_iterateOverTreeSuppressK(suppressTree,&suppressChain[1]); if (p->tcontext == NULL) { predicate_free(p); result=NULL; goto EXIT; }; } else { if (MR_isChain(p->tcontext)) { p->tcontext=MR_iterateOverTreeSuppressK(suppressTree,&suppressChain[1]); if (p->tcontext == NULL) { predicate_free(p); result=NULL; goto EXIT; }; } } result=p; EXIT: return result; } #ifdef __USE_PROTOS void MR_suppressSearchReport(void) #else void MR_suppressSearchReport() #endif { int i; Node *p; TokNode *tn; int depth; set setAnd; /* number of tokens in back trace stack matches length of chain */ depth=0; for (i=0; i < MR_BackTraceStack.count ; i++) { p=(Node *) MR_BackTraceStack.data[i]; if (p->ntype == nToken) depth++; }; require (depth == suppressChainLength,"depth > suppressChainLength"); /* token codes match chain */ depth=0; for (i=0; i < MR_BackTraceStack.count ; i++) { p=(Node *) MR_BackTraceStack.data[i]; if (p->ntype != nToken) continue; tn=(TokNode *) p; depth++; if (set_nil(tn->tset)) { require(set_el( (unsigned) tn->token,fset[depth]), "MR_suppressSearchReport: no match to #token in chain"); } else { setAnd=set_and(fset[depth],tn->tset); require(!set_nil(setAnd), "MR_suppressSearchReport: no match to #token set in chain"); set_free(setAnd); }; }; /* have a match - now remove it from the predicate */ suppressSucceeded=1; if (suppressSucceeded) { fprintf(output,"\n"); fprintf(output,"#if 0\n"); fprintf(output,"\n"); fprintf(output,"Part (or all) of predicate with depth > 1 suppressed by "); fprintf(output,"alternative without predicate\n\n"); MR_dumpPred(suppressPredicate,1); fprintf(output,"The token sequence which is suppressed:"); fprintf(output," ("); for (i=1; i <= suppressChainLength; i++) { fprintf(output," %s",TerminalString(suppressChain[i])); }; fprintf(output," )\n"); fprintf(output,"The sequence of references which generate that sequence of tokens:\n\n"); MR_backTraceDumpItemReset(); for (i=0; i < MR_BackTraceStack.count ; i++) { MR_backTraceDumpItem(output,0,(Node *) MR_BackTraceStack.data[i]); }; fprintf(output,"\n"); fprintf(output,"#endif\n"); } } #ifdef __USE_PROTOS void MR_markCompromisedRule(Node *n) #else void MR_markCompromisedRule(n) Node *n; #endif { RuleEntry *q; Node *mark=NULL; Junction *j; if (n->ntype == nRuleRef) { mark=(Node *) MR_ruleReferenced( (RuleRefNode *) n); } else if (n->ntype == nToken) { mark=n; } else if (n->ntype == nJunction) { j=(Junction *)n; switch (j->jtype) { case aOptBlk: case aLoopBlk: case RuleBlk: case EndRule: case aPlusBlk: case aLoopBegin: mark=n; break; default: break; }; } if (mark == NULL) return; require (RulePtr != NULL,"RulePtr not initialized"); q = (RuleEntry *) hash_get(Rname,mark->rname); require (q != NULL,"RuleEntry not found"); set_orel(q->rulenum,&MR_CompromisedRules); } #ifdef __USE_PROTOS void MR_alphaBetaTraceReport(void) #else void MR_alphaBetaTraceReport() #endif { int i; if (! AlphaBetaTrace) return; MR_AlphaBetaMessageCount++; fprintf(output,"\n"); fprintf(output,"#if 0\n"); fprintf(output,"\n"); fprintf(output,"Trace of references leading to attempt to compute the follow set of\n"); fprintf(output,"alpha in an \"(alpha)? beta\" block. It is not possible for antlr to\n"); fprintf(output,"compute this follow set because it is not known what part of beta has\n"); fprintf(output,"already been matched by alpha and what part remains to be matched.\n"); fprintf(output,"\n"); fprintf(output,"Rules which make use of the incorrect follow set will also be incorrect\n"); fprintf(output,"\n"); MR_backTraceDumpItemReset(); for (i=0; i < MR_BackTraceStack.count ; i++) { MR_backTraceDumpItem(output,0,(Node *) MR_BackTraceStack.data[i]); if (i < MR_BackTraceStack.count-1) { MR_markCompromisedRule( (Node *) MR_BackTraceStack.data[i]); }; }; fprintf(output,"\n"); fprintf(output,"#endif\n"); } #ifdef __USE_PROTOS void MR_dumpRuleSet(set s) #else void MR_dumpRuleSet(s) set s; #endif { unsigned *cursor; unsigned *origin=set_pdq(s); require(origin != NULL,"set_pdq failed"); if (RulePtr == NULL) { fprintf(stderr,"RulePtr[] not yet initialized"); } else { for (cursor=origin; *cursor != nil ; cursor++) { /**** if (cursor != origin) fprintf(stderr,","); ****/ fprintf(stderr," %s",RulePtr[*cursor]->rname); fprintf(stderr,"\n"); }; free( (char *) origin); }; }