audk/Tools/CCode/Source/Pccts/antlr/pred.c

822 lines
20 KiB
C

/*
* 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
* 1989-2001
*/
#include <stdio.h>
#include "pcctscfg.h"
#include "set.h"
#include "syn.h"
#include "hash.h"
#include "generic.h"
#include "dlgdef.h"
#include <ctype.h>
#ifdef __USE_PROTOS
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 __USE_PROTOS
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) {
max_k = 1; /* MR33 Badly designed if didn't set max_k when CLL_k = 1 */
if (CLL_k > 1) /* MR27 Don't warn if max(k,ck) == 1 */
{
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);
}
}
}
/* 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 __USE_PROTOS
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 __USE_PROTOS
find_in_aOptBlk( Junction *alt )
#else
find_in_aOptBlk( alt )
Junction *alt;
#endif
{
return find_in_aSubBlk( alt );
}
Predicate *
#ifdef __USE_PROTOS
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 __USE_PROTOS
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 __USE_PROTOS
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,"aSubBlk\n");
break;
case aOptBlk :
fprintf(stderr,"aOptBlk\n");
break;
case aLoopBegin :
fprintf(stderr,"aLoopBeginBlk\n");
break;
case aLoopBlk :
fprintf(stderr,"aLoopBlk\n");
break;
case aPlusBlk :
fprintf(stderr,"aPlusBlk\n");
break;
case EndBlk :
fprintf(stderr,"EndBlk\n");
break;
case RuleBlk :
fprintf(stderr,"RuleBlk\n");
break;
case Generic :
fprintf(stderr,"Generic\n");
break;
case EndRule :
fprintf(stderr,"EndRule\n");
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)%s\n", t->rname, TokenString(t->token));
break;
case nAction :
fprintf(stderr, "Action\n");
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 printed\n");
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 )
{
/* MR30 No need to use first_item_is_guess_block_extra
since we know this is an action, not a (...)* or
(...)+ block.
*/
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;
/* MR30 No need to use first_item_is_guess_block_extra
since we know this is an action.
*/
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 #%d\n",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 #%d\n",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 __USE_PROTOS
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 __USE_PROTOS
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 __USE_PROTOS
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_sets\n");
#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_sets\n");
#endif
}
static void
#ifdef __USE_PROTOS
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_trees\n");
#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_trees\n");
#endif
}
/* Walk a list of predicates and return the set of all tokens in scontext[1]'s */
set
#ifdef __USE_PROTOS
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 __USE_PROTOS
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 __USE_PROTOS
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 __USE_PROTOS
Predicate * predicate_dup_without_context(Predicate *p)
#else
Predicate * predicate_dup_without_context(p)
Predicate *p;
#endif
{
return predicate_dup_xxx(p,0);
}
#ifdef __USE_PROTOS
Predicate * predicate_dup(Predicate *p)
#else
Predicate * predicate_dup(p)
Predicate *p;
#endif
{
return predicate_dup_xxx(p,1);
}