pred.c
资源名称:pccts133.zip [点击查看]
上传用户:itx_2006
上传日期:2007-01-06
资源大小:493k
文件大小:19k
源码类别:
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开发平台:
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- /*
- * pred.c -- source for predicate detection, manipulation
- *
- * 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
- * 1989-1998
- */
- #include <stdio.h>
- #ifdef __cplusplus
- #ifndef __STDC__
- #define __STDC__
- #endif
- #endif
- #include "set.h"
- #include "syn.h"
- #include "hash.h"
- #include "generic.h"
- #include "dlgdef.h"
- #include <ctype.h>
- #ifdef __STDC__
- static void complete_context_sets(RuleRefNode *, Predicate *);
- static void complete_context_trees(RuleRefNode *, Predicate *);
- #else
- static void complete_context_sets();
- static void complete_context_trees();
- #endif
- char *PRED_AND_LIST = "AND";
- char *PRED_OR_LIST = "OR";
- /*
- * In C mode, return the largest constant integer found as the
- * sole argument to LATEXT(i).
- *
- * In C++ mode, return the largest constant integer found as the
- * sole argument to LT(i) given that the char before is nonalpha.
- */
- int
- #ifdef __STDC__
- predicateLookaheadDepth(ActionNode *a)
- #else
- predicateLookaheadDepth(a)
- ActionNode *a;
- #endif
- {
- int max_k=0;
- if (a->predEntry != NULL) {
- MR_pred_depth(a->predEntry->pred,&max_k);
- goto PREDENTRY_EXIT;
- }
- if ( GenCC )
- {
- /* scan for LT(i) */
- int k = 0;
- char *p = a->action;
- while ( p!=NULL )
- {
- p = strstr(p, "LT(");
- if ( p!=NULL )
- {
- if ( p>=a->action && !isalpha(*(p-1)) )
- {
- k = atoi(p+strlen("LT("));
- if ( k>max_k ) max_k=k;
- }
- p += strlen("LT(");
- }
- }
- }
- else {
- /* scan for LATEXT(i) */
- int k = 0;
- char *p = a->action;
- while ( p!=NULL )
- {
- p = strstr(p, "LATEXT(");
- if ( p!=NULL )
- {
- p += strlen("LATEXT(");
- k = atoi(p);
- if ( k>max_k ) max_k=k;
- }
- }
- }
- if ( max_k==0 )
- {
- if ( !a->frmwarned )
- {
- a->frmwarned = 1;
- warnFL(eMsg1("predicate: %s missing, bad, or with i=0; assuming i=1",
- GenCC?"LT(i)":"LATEXT(i)"),
- FileStr[a->file], a->line);
- }
- max_k = 1;
- }
- /* MR10 */ if ( max_k > CLL_k) {
- /* MR10 */ if ( !a->frmwarned )
- /* MR10 */ {
- /* MR10 */ a->frmwarned = 1;
- /* MR11 */ errFL(eMsgd2("predicate refers to lookahead token %d. Semantic lookahead is limited to max(k,ck)==%d",
- /* MR10 */ max_k,CLL_k),
- /* MR10 */ FileStr[a->file],a->line);
- /* MR10 */ if (max_k >= OutputLL_k) {
- /* MR10 */ if (!GenCC) {
- /* MR10 */ errFL(eMsgd(" the lookahead buffer size in C mode is %d token(s) (including the one just recognized)",
- /* MR10 */ OutputLL_k),
- /* MR10 */ FileStr[a->file],a->line);
- /* MR10 */ };
- /* MR10 */ };
- /* MR10 */ };
- /* MR10 */ max_k= CLL_k;
- /* MR10 */ };
- PREDENTRY_EXIT:
- return max_k;
- }
- /* Find all predicates in a block of alternatives. DO NOT find predicates
- * behind the block because that predicate could depend on things set in
- * one of the nonoptional blocks
- */
- Predicate *
- #ifdef __STDC__
- find_in_aSubBlk( Junction *alt )
- #else
- find_in_aSubBlk( alt )
- Junction *alt;
- #endif
- {
- Predicate *a, *head=NULL, *tail=NULL, *root=NULL;
- Junction *p = alt;
- if (MRhoisting) {
- return MR_find_in_aSubBlk(alt);
- };
- for (; p!=NULL; p=(Junction *)p->p2)
- {
- /* ignore empty alts */
- if ( p->p1->ntype != nJunction ||
- ((Junction *)p->p1)->jtype != EndBlk )
- {
- a = find_predicates(p->p1); /* get preds for this alt */
- if ( a==NULL ) continue;
- /* make an OR list of predicates */
- if ( head==NULL )
- {
- root = new_pred();
- root->expr = PRED_OR_LIST;
- head = tail = a;
- root->down = head;
- }
- else {
- tail->right = a;
- a->left = tail;
- a->up = tail->up;
- tail = a;
- }
- }
- }
- /* if just one pred, remove OR root */
- if ( root!=NULL && root->down->right == NULL )
- {
- Predicate *d = root->down;
- free( (char *) root);
- return d;
- }
- return root;
- }
- Predicate *
- #ifdef __STDC__
- find_in_aOptBlk( Junction *alt )
- #else
- find_in_aOptBlk( alt )
- Junction *alt;
- #endif
- {
- return find_in_aSubBlk( alt );
- }
- Predicate *
- #ifdef __STDC__
- find_in_aLoopBegin( Junction *alt )
- #else
- find_in_aLoopBegin( alt )
- Junction *alt;
- #endif
- {
- return find_in_aSubBlk( (Junction *) alt->p1 ); /* get preds in alts */
- }
- Predicate *
- #ifdef __STDC__
- find_in_aPlusBlk( Junction *alt )
- #else
- find_in_aPlusBlk( alt )
- Junction *alt;
- #endif
- {
- require(alt!=NULL&&alt->p2!=NULL, "invalid aPlusBlk");
- return find_in_aSubBlk( alt );
- }
- /* Look for a predicate;
- *
- * Do not pass anything but Junction nodes; no Actions, Tokens, RuleRefs.
- * This means that a "hoisting distance" of zero is the only distance
- * allowable. Init actions are ignored.
- *
- * WARNING:
- * Assumes no (..)? block after predicate for the moment.
- * Does not check to see if pred is in production that can generate
- * a sequence contained in the set of ambiguous tuples.
- *
- * Return the predicate found if any.
- */
- Predicate *
- #ifdef __STDC__
- find_predicates( Node *alt )
- #else
- find_predicates( alt )
- Node *alt;
- #endif
- {
- #ifdef DBG_PRED
- Junction *j;
- RuleRefNode *r;
- TokNode *t;
- #endif
- Predicate *pred;
- if ( alt==NULL ) return NULL;
- #ifdef DBG_PRED
- switch ( alt->ntype )
- {
- case nJunction :
- j = (Junction *) alt;
- fprintf(stderr, "Junction(in %s)", j->rname);
- switch ( j->jtype )
- {
- case aSubBlk :
- fprintf(stderr,"aSubBlkn");
- break;
- case aOptBlk :
- fprintf(stderr,"aOptBlkn");
- break;
- case aLoopBegin :
- fprintf(stderr,"aLoopBeginBlkn");
- break;
- case aLoopBlk :
- fprintf(stderr,"aLoopBlkn");
- break;
- case aPlusBlk :
- fprintf(stderr,"aPlusBlkn");
- break;
- case EndBlk :
- fprintf(stderr,"EndBlkn");
- break;
- case RuleBlk :
- fprintf(stderr,"RuleBlkn");
- break;
- case Generic :
- fprintf(stderr,"Genericn");
- break;
- case EndRule :
- fprintf(stderr,"EndRulen");
- break;
- }
- break;
- case nRuleRef :
- r = (RuleRefNode *) alt;
- fprintf(stderr, "RuleRef(in %s)n", r->rname);
- break;
- case nToken :
- t = (TokNode *) alt;
- fprintf(stderr, "TokenNode(in %s)%sn", t->rname, TokenString(t->token));
- break;
- case nAction :
- fprintf(stderr, "Actionn");
- break;
- }
- #endif
- switch ( alt->ntype )
- {
- case nJunction :
- {
- Predicate *a, *b;
- Junction *p = (Junction *) alt;
- /* lock nodes */
- if ( p->jtype==aLoopBlk || p->jtype==RuleBlk ||
- p->jtype==aPlusBlk || p->jtype==EndRule )
- {
- require(p->pred_lock!=NULL, "rJunc: lock array is NULL");
- if ( p->pred_lock[1] )
- {
- return NULL;
- }
- p->pred_lock[1] = TRUE;
- }
- switch ( p->jtype )
- {
- case aSubBlk :
- a = find_in_aSubBlk(p);
- return a; /* nothing is visible past this guy */
- case aOptBlk :
- a = find_in_aOptBlk(p);
- return a;
- case aLoopBegin :
- a = find_in_aLoopBegin(p);
- return a;
- case aLoopBlk :
- a = find_in_aSubBlk(p);
- p->pred_lock[1] = FALSE;
- return a;
- case aPlusBlk :
- a = find_in_aPlusBlk(p);
- p->pred_lock[1] = FALSE;
- return a; /* nothing is visible past this guy */
- case RuleBlk :
- a = find_predicates(p->p1);
- p->pred_lock[1] = FALSE;
- return a;
- case Generic :
- a = find_predicates(p->p1);
- b = find_predicates(p->p2);
- if ( p->pred_lock!=NULL ) p->pred_lock[1] = FALSE;
- if ( a==NULL ) return b;
- if ( b==NULL ) return a;
- /* otherwise OR the two preds together */
- {
- fatal_internal("hit unknown situation during predicate hoisting");
- }
- case EndBlk :
- case EndRule : /* Find no predicates after a rule ref */
- return NULL;
- default:
- fatal_internal("this cannot be printedn");
- break;
- }
- }
- case nAction :
- {
- ActionNode *p = (ActionNode *) alt;
- if ( p->noHoist) return NULL; /* MR12c */
- if ( p->init_action ) return find_predicates(p->next);
- if ( p->is_predicate )
- {
- Tree *t=NULL;
- #ifdef DBG_PRED
- fprintf(stderr, "predicate: <<%s>>?n", p->action);
- #endif
- if ( p->guardpred!=NULL )
- {
- pred = predicate_dup(p->guardpred);
- MR_guardPred_plainSet(p,pred); /* MR12c */
- }
- else
- {
- pred = new_pred();
- pred->k = predicateLookaheadDepth(p);
- pred->source = p;
- pred->expr = p->action;
- if ( HoistPredicateContext && pred->k > 1 )
- {
- if ( first_item_is_guess_block((Junction *)p->next) )
- {
- warnFL("cannot compute context of predicate in front of (..)? block",
- FileStr[p->file], p->line);
- }
- else
- {
- ConstrainSearch = 0;
- /* MR11 */ if (p->ampersandPred != NULL) {
- /* MR11 */ TRAV(p,
- /* MR11 */ pred->k,
- /* MR11 */ &(pred->completionTree), t);
- /* MR11 */ } else {
- TRAV(p->next,
- pred->k,
- &(pred->completionTree), t);
- };
- pred->tcontext = t;
- MR_check_pred_too_long(pred,pred->completionTree);
- #ifdef DBG_PRED
- fprintf(stderr, "LL(%d) context:", pred->k);
- preorder(t);
- fprintf(stderr, "n");
- #endif
- }
- }
- else if ( HoistPredicateContext && pred->k == 1 )
- {
- pred->scontext[1] = empty;
- if ( first_item_is_guess_block((Junction *)p->next) )
- {
- warnFL("cannot compute context of predicate in front of (..)? block",
- FileStr[p->file], p->line);
- }
- else
- {
- REACH((Junction *)p->next,
- 1,
- &(pred->completionSet),
- pred->scontext[1]);
- MR_check_pred_too_long(pred,pred->completionSet);
- #ifdef DBG_PRED
- fprintf(stderr, "LL(1) context:");
- s_fprT(stderr, pred->scontext[1]);
- fprintf(stderr, "n");
- #endif
- }
- }
- }
- {
- Predicate *d = find_predicates(p->next);
- Predicate *root;
- /* Warning: Doesn't seem like the up pointers will all be set correctly;
- * TJP: that's ok, we're not using them now.
- */
- if ( d!=NULL )
- {
- root = new_pred();
- root->expr = PRED_AND_LIST;
- root->down = pred;
- pred->right = d;
- pred->up = root;
- d->left = pred;
- d->up = pred->up;
- return root;
- }
- }
- return pred;
- }
- return NULL;
- }
- case nRuleRef :
- {
- Predicate *a;
- RuleRefNode *p = (RuleRefNode *) alt;
- Junction *r;
- Junction *save_MR_RuleBlkWithHalt;
- RuleEntry *q = (RuleEntry *) hash_get(Rname, p->text);
- if ( q == NULL )
- {
- warnFL( eMsg1("rule %s not defined",p->text), FileStr[p->file], p->line );
- return NULL;
- }
- r = RulePtr[q->rulenum];
- if ( r->pred_lock[1] )
- {
- /* infinite left-recursion; ignore 'cause LL sup 1 (k) analysis
- * must have seen it earlier.
- */
- return NULL;
- }
- /* MR10 There should only be one halt set at a time. */
- /* MR10 Life would have been easier with a global variable */
- /* MR10 (at least for this particular need) */
- /* MR10 Unset the old one and set the new one, later undo. */
- require(r->end->halt == FALSE,"should only have one halt at a time");
- /* MR10 */ require(MR_RuleBlkWithHalt == NULL ||
- /* MR10 */ (MR_RuleBlkWithHalt->jtype == RuleBlk && MR_RuleBlkWithHalt->end->halt == TRUE),
- /* MR10 */ "RuleBlkWithHalt->end not RuleBlk or does not have halt set");
- /* MR10 */ if (MR_RuleBlkWithHalt != NULL) {
- /* MR10 */ MR_RuleBlkWithHalt->end->halt=FALSE;
- /* MR10 */ };
- /*** fprintf(stderr,"nSetting halt on junction #%dn",r->end->seq); ***/
- require(r->end->halt == FALSE,"rule->end->halt already set");
- save_MR_RuleBlkWithHalt=MR_RuleBlkWithHalt;
- /* MR10 */ MR_pointerStackPush(&MR_RuleBlkWithHaltStack,MR_RuleBlkWithHalt);
- /* MR10 */ MR_pointerStackPush(&MR_PredRuleRefStack,p);
- r->end->halt = TRUE;
- /* MR10 */ MR_RuleBlkWithHalt=r;
- a = find_predicates((Node *)r);
- require(r->end->halt == TRUE,"rule->end->halt not set");
- r->end->halt = FALSE;
- /* MR10 */ MR_pointerStackPop(&MR_PredRuleRefStack);
- /* MR10 */ MR_RuleBlkWithHalt=(Junction *) MR_pointerStackPop(&MR_RuleBlkWithHaltStack);
- require (MR_RuleBlkWithHalt==save_MR_RuleBlkWithHalt,
- "RuleBlkWithHaltStack not consistent");
- /* MR10 */ require(MR_RuleBlkWithHalt == NULL ||
- /* MR10 */ (MR_RuleBlkWithHalt->jtype == RuleBlk && MR_RuleBlkWithHalt->end->halt == FALSE),
- /* MR10 */ "RuleBlkWithHalt->end not RuleBlk or has no halt set");
- /* MR10 */ if (MR_RuleBlkWithHalt != NULL) {
- /* MR10 */ MR_RuleBlkWithHalt->end->halt=TRUE;
- /* MR10 */ };
- /*** fprintf(stderr,"nRestoring halt on junction #%dn",r->end->seq); ***/
- if ( a==NULL ) return NULL;
- /* attempt to compute the "local" FOLLOW just like in normal lookahead
- * computation if needed
- */
- complete_context_sets(p,a);
- complete_context_trees(p,a);
- /* MR10 */ MR_cleanup_pred_trees(a);
- return a;
- }
- case nToken :
- break;
- }
- return NULL;
- }
- #ifdef __STDC__
- Predicate *MR_find_predicates_and_supp(Node *alt)
- #else
- Predicate *MR_find_predicates_and_supp(alt)
- Node *alt;
- #endif
- {
- Predicate *p;
- p=find_predicates(alt);
- p=MR_suppressK(alt,p);
- return p;
- }
- Predicate *
- #ifdef __STDC__
- new_pred( void )
- #else
- new_pred( )
- #endif
- {
- Predicate *p = (Predicate *) calloc(1,sizeof(Predicate)); /* MR10 */
- require(p!=NULL, "new_pred: cannot alloc predicate");
- p->scontext[0]=empty;
- p->scontext[1]=empty;
- p->completionTree=empty;
- p->completionSet=empty;
- p->plainSet=empty;
- return p;
- }
- static void
- #ifdef __STDC__
- complete_context_sets( RuleRefNode *p, Predicate *a )
- #else
- complete_context_sets( p, a )
- RuleRefNode *p;
- Predicate *a;
- #endif
- {
- set rk2, b;
- int k2;
- #ifdef DBG_PRED
- fprintf(stderr, "enter complete_context_setsn");
- #endif
- for (; a!=NULL; a=a->right)
- {
- if ( a->expr == PRED_AND_LIST || a->expr == PRED_OR_LIST )
- {
- complete_context_sets(p,a->down);
- continue;
- }
- rk2 = b = empty;
- while ( !set_nil(a->completionSet) )
- {
- k2 = set_int(a->completionSet);
- set_rm(k2, a->completionSet);
- REACH(p->next, k2, &rk2, b);
- set_orin(&(a->scontext[1]), b);
- set_free(b);
- }
- set_orin(&(a->completionSet), rk2);/* remember what we couldn't do */
- set_free(rk2);
- #ifdef DBG_PRED
- fprintf(stderr, "LL(1) context for %s(addr 0x%x) after ruleref:", a->expr, a);
- s_fprT(stderr, a->scontext[1]);
- fprintf(stderr, "n");
- #endif
- /* complete_context_sets(p, a->down);*/
- }
- #ifdef DBG_PRED
- fprintf(stderr, "exit complete_context_setsn");
- #endif
- }
- static void
- #ifdef __STDC__
- complete_context_trees( RuleRefNode *p, Predicate *a )
- #else
- complete_context_trees( p, a )
- RuleRefNode *p;
- Predicate *a;
- #endif
- {
- set rk2;
- int k2;
- Tree *u;
- #ifdef DBG_PRED
- fprintf(stderr, "enter complete_context_treesn");
- #endif
- for (; a!=NULL; a=a->right)
- {
- if ( a->expr == PRED_AND_LIST || a->expr == PRED_OR_LIST )
- {
- complete_context_trees(p, a->down);
- continue;
- }
- rk2 = empty;
- /* any k left to do? if so, link onto tree */
- while ( !set_nil(a->completionTree) )
- {
- k2 = set_int(a->completionTree);
- set_rm(k2, a->completionTree);
- u = NULL;
- TRAV(p->next, k2, &rk2, u);
- /* any subtrees missing k2 tokens, add u onto end */
- a->tcontext = tlink(a->tcontext, u, k2);
- Tfree(u); /* MR10 */
- }
- set_orin(&(a->completionTree), rk2);/* remember what we couldn't do */
- set_free(rk2);
- #ifdef DBG_PRED
- fprintf(stderr, "LL(i<%d) context after ruleref:", LL_k);
- preorder(a->tcontext);
- fprintf(stderr, "n");
- #endif
- /* complete_context_trees(p, a->down);*/
- }
- #ifdef DBG_PRED
- fprintf(stderr, "exit complete_context_treesn");
- #endif
- }
- /* Walk a list of predicates and return the set of all tokens in scontext[1]'s */
- set
- #ifdef __STDC__
- covered_set( Predicate *p )
- #else
- covered_set( p )
- Predicate *p;
- #endif
- {
- set a;
- a = empty;
- for (; p!=NULL; p=p->right)
- {
- if ( p->expr == PRED_AND_LIST || p->expr == PRED_OR_LIST )
- {
- set_orin(&a, covered_set(p->down));
- continue;
- }
- set_orin(&a, p->scontext[1]);
- set_orin(&a, covered_set(p->down));
- }
- return a;
- }
- /* MR10 predicate_free()
- MR10 Don't free the leaf nodes since they are part of the action node
- */
- #ifdef __STDC__
- void predicate_free(Predicate *p)
- #else
- void predicate_free(p)
- Predicate *p;
- #endif
- {
- if (p == NULL) return;
- predicate_free(p->right);
- predicate_free(p->down);
- if (p->cloned ||
- p->source == NULL ||
- p->source->guardpred == NULL ||
- p->expr == PRED_AND_LIST ||
- p->expr == PRED_OR_LIST) {
- set_free(p->scontext[1]);
- set_free(p->completionSet);
- set_free(p->completionTree);
- set_free(p->plainSet);
- Tfree(p->tcontext);
- free( (char *) p);
- } else {
- p->right=NULL;
- p->down=NULL; /* MR13 *** debug */
- };
- }
- /* MR10 predicate_dup() */
- #ifdef __STDC__
- Predicate * predicate_dup_xxx(Predicate *p,int contextToo)
- #else
- Predicate * predicate_dup_xxx(p,contextToo)
- Predicate *p;
- int contextToo;
- #endif
- {
- Predicate *q;
- if (p == NULL) return NULL;
- q=new_pred();
- q->down=predicate_dup(p->down);
- q->right=predicate_dup(p->right);
- /*
- don't replicate expr - it is read-only
- and address comparison is used to look
- for identical predicates.
- */
- q->expr=p->expr;
- q->k=p->k;
- q->source=p->source;
- q->cloned=1;
- q->ampersandStyle=p->ampersandStyle;
- q->inverted=p->inverted;
- q->predEntry=p->predEntry;
- q->plainSet=set_dup(p->plainSet);
- if (contextToo) {
- q->tcontext=tdup(p->tcontext);
- q->scontext[0]=set_dup(p->scontext[0]);
- q->scontext[1]=set_dup(p->scontext[1]);
- q->completionTree=set_dup(p->completionTree);
- q->completionSet=set_dup(p->completionSet);
- };
- /* don't need to dup "redundant" */
- return q;
- }
- #ifdef __STDC__
- Predicate * predicate_dup_without_context(Predicate *p)
- #else
- Predicate * predicate_dup_without_context(p)
- Predicate *p;
- #endif
- {
- return predicate_dup_xxx(p,0);
- }
- #ifdef __STDC__
- Predicate * predicate_dup(Predicate *p)
- #else
- Predicate * predicate_dup(p)
- Predicate *p;
- #endif
- {
- return predicate_dup_xxx(p,1);
- }