www.pudn.com > pccts133.zip > fset2.c
/*
* fset2.c
*
* Compute FIRST sets for full LL(k)
*
* 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
#ifdef __cplusplus
#ifndef __STDC__
#define __STDC__
#endif
#endif
#ifdef __STDC__
#include
#else
#include
#endif
#include "set.h"
#include "syn.h"
#include "hash.h"
#include "generic.h"
#include "dlgdef.h"
extern char tokens[];
extern char *PRED_AND_LIST;
extern char *PRED_OR_LIST;
/* ick! globals. Used by permute() to track which elements of a set have been used */
static int *findex;
set *fset; /* MR11 make global */
static unsigned **ftbl;
static set *constrain; /* pts into fset. constrains tToken() to 'constrain' */
int ConstrainSearch;
int maxk; /* set to initial k upon tree construction request */
/* MR11 make global */
static Tree *FreeList = NULL;
#ifdef __STDC__
static int tmember_of_context(Tree *, Predicate *);
#else
static int tmember_of_context();
#endif
#if TREE_DEBUG
set set_of_tnodes_in_use;
int stop_on_tnode_seq_number=(-1); /* (-1) to disable */
#endif
/* Do root
* Then each sibling
*/
void
#ifdef __STDC__
preorder( Tree *tree )
#else
preorder( tree )
Tree *tree;
#endif
{
if ( tree == NULL ) return;
if ( tree->down != NULL ) fprintf(stderr, " (");
if ( tree->token == ALT ) fprintf(stderr, " ALT");
else fprintf(stderr, " %s", TerminalString(tree->token));
if ( tree->token==EpToken ) fprintf(stderr, "(%d)", tree->v.rk);
preorder(tree->down);
if ( tree->down != NULL ) fprintf(stderr, " )");
preorder(tree->right);
}
#ifdef __STDC__
int MR_tree_matches_constraints(int k,set * constrain,Tree *t)
#else
int MR_tree_matches_constraints(k,constrain,t)
int k;
set * constrain;
Tree * t;
#endif
{
int i;
Tree *u;
if (k == 0) return 1;
/* for testing guard predicates: if the guard tree is shorter
than the constraint then it is a match. The reason is that
a guard of (A B) should be equivalent to a guard of (A B . . .)
where "." matches every token. Thus a match which runs out
of tree before constraint is a match.
*/
if (t == NULL) return 1;
require (set_deg(constrain[0]) == 1,
"MR_tree_matches_constraints: set_deg != 1");
i=set_int(constrain[0]);
if (t->token != i) return 0;
if (k-1 == 0) return 1;
for (u=t->down; u != NULL; u=u->right) {
if (MR_tree_matches_constraints(k-1,&constrain[1],u)) {
return 1;
};
};
return 0;
}
/* check the depth of each primary sibling to see that it is exactly
* k deep. e.g.;
*
* ALT
* |
* A ------- B
* | |
* C -- D E
*
* Remove all branches <= k deep.
*
* Added by TJP 9-23-92 to make the LL(k) constraint mechanism to work.
*/
static int pruneCount=0;
static int prunePeak=200;
Tree *
#ifdef __STDC__
prune( Tree *t, int k )
#else
prune( t, k )
Tree *t;
int k;
#endif
{
pruneCount++;
if (pruneCount > prunePeak+100) {
prunePeak=pruneCount;
#if 0
*** fprintf(stderr,"pruneCount=%d\n",pruneCount);
/*** preorder(t); ***/
*** fprintf(stderr,"\n",pruneCount);
#endif
};
if ( t == NULL ) {
pruneCount--;
return NULL;
};
if ( t->token == ALT ) fatal_internal("prune: ALT node in FIRST tree");
if ( t->right!=NULL ) t->right = prune(t->right, k);
if ( k>1 )
{
if ( t->down!=NULL ) t->down = prune(t->down, k-1);
if ( t->down == NULL )
{
Tree *r = t->right;
t->right = NULL;
Tfree(t);
pruneCount--;
return r;
}
}
pruneCount--;
return t;
}
/* build a tree (root child1 child2 ... NULL) */
#ifdef __STDC__
Tree *tmake(Tree *root, ...)
#else
Tree *tmake(va_alist)
va_dcl
#endif
{
Tree *w;
va_list ap;
Tree *child, *sibling=NULL, *tail=NULL;
#ifndef __STDC__
Tree *root;
#endif
#ifdef __STDC__
va_start(ap, root);
#else
va_start(ap);
root = va_arg(ap, Tree *);
#endif
child = va_arg(ap, Tree *);
while ( child != NULL )
{
#ifdef DUM
/* added "find end of child" thing TJP March 1994 */
for (w=child; w->right!=NULL; w=w->right) {;} /* find end of child */
#else
w = child;
#endif
if ( sibling == NULL ) {sibling = child; tail = w;}
else {tail->right = child; tail = w;}
child = va_arg(ap, Tree *);
}
/* was "root->down = sibling;" */
if ( root==NULL ) root = sibling;
else root->down = sibling;
va_end(ap);
return root;
}
Tree *
#ifdef __STDC__
tnode( int tok )
#else
tnode( tok )
int tok;
#endif
{
Tree *p, *newblk;
static int n=0;
if ( FreeList == NULL )
{
/*fprintf(stderr, "tnode: %d more nodes\n", TreeBlockAllocSize);*/
if ( TreeResourceLimit > 0 )
{
if ( (n+TreeBlockAllocSize) >= TreeResourceLimit )
{
fprintf(stderr, ErrHdr, FileStr[CurAmbigfile], CurAmbigline);
fprintf(stderr, " hit analysis resource limit while analyzing alts %d and %d %s\n",
CurAmbigAlt1,
CurAmbigAlt2,
CurAmbigbtype);
exit(PCCTS_EXIT_FAILURE);
}
}
newblk = (Tree *)calloc(TreeBlockAllocSize, sizeof(Tree));
if ( newblk == NULL )
{
fprintf(stderr, ErrHdr, FileStr[CurAmbigfile], CurAmbigline);
fprintf(stderr, " out of memory while analyzing alts %d and %d %s\n",
CurAmbigAlt1,
CurAmbigAlt2,
CurAmbigbtype);
exit(PCCTS_EXIT_FAILURE);
}
n += TreeBlockAllocSize;
for (p=newblk; p<&(newblk[TreeBlockAllocSize]); p++)
{
p->right = FreeList; /* add all new Tree nodes to Free List */
FreeList = p;
}
}
p = FreeList;
FreeList = FreeList->right; /* remove a tree node */
p->right = NULL; /* zero out ptrs */
p->down = NULL;
p->token = tok;
TnodesAllocated++; /* MR10 */
TnodesInUse++; /* MR10 */
if (TnodesInUse > TnodesPeak) TnodesPeak=TnodesInUse; /* MR10 */
#ifdef TREE_DEBUG
require(!p->in_use, "tnode: node in use!");
p->in_use = 1;
p->seq=TnodesAllocated;
set_orel( (unsigned) TnodesAllocated,&set_of_tnodes_in_use);
if (stop_on_tnode_seq_number == p->seq) {
fprintf(stderr,"\n*** just allocated tnode #%d ***\n",
stop_on_tnode_seq_number);
};
#endif
return p;
}
static Tree *
#ifdef __STDC__
eofnode( int k )
#else
eofnode( k )
int k;
#endif
{
Tree *t=NULL;
int i;
for (i=1; i<=k; i++)
{
t = tmake(tnode((TokenInd!=NULL?TokenInd[EofToken]:EofToken)), t, NULL);
}
return t;
}
void
#ifdef __STDC__
_Tfree( Tree *t )
#else
_Tfree( t )
Tree *t;
#endif
{
if ( t!=NULL )
{
#ifdef TREE_DEBUG
if (t->seq == stop_on_tnode_seq_number) {
fprintf(stderr,"\n*** just freed tnode #%d ***\n",t->seq);
};
require(t->in_use, "_Tfree: node not in use!");
t->in_use = 0;
set_rm( (unsigned) t->seq,set_of_tnodes_in_use);
#endif
t->right = FreeList;
FreeList = t;
TnodesInUse--; /* MR10 */
}
}
/* tree duplicate */
Tree *
#ifdef __STDC__
tdup( Tree *t )
#else
tdup( t )
Tree *t;
#endif
{
Tree *u;
if ( t == NULL ) return NULL;
u = tnode(t->token);
u->v.rk = t->v.rk;
u->right = tdup(t->right);
u->down = tdup(t->down);
return u;
}
/* tree duplicate (assume tree is a chain downwards) */
Tree *
#ifdef __STDC__
tdup_chain( Tree *t )
#else
tdup_chain( t )
Tree *t;
#endif
{
Tree *u;
if ( t == NULL ) return NULL;
u = tnode(t->token);
u->v.rk = t->v.rk;
u->down = tdup(t->down);
return u;
}
Tree *
#ifdef __STDC__
tappend( Tree *t, Tree *u )
#else
tappend( t, u )
Tree *t;
Tree *u;
#endif
{
Tree *w;
/*** fprintf(stderr, "tappend(");
*** preorder(t); fprintf(stderr, ",");
*** preorder(u); fprintf(stderr, " )\n");
*/
if ( t == NULL ) return u;
if ( t->token == ALT && t->right == NULL ) return tappend(t->down, u);
for (w=t; w->right!=NULL; w=w->right) {;}
w->right = u;
return t;
}
/* dealloc all nodes in a tree */
void
#ifdef __STDC__
Tfree( Tree *t )
#else
Tfree( t )
Tree *t;
#endif
{
if ( t == NULL ) return;
Tfree( t->down );
Tfree( t->right );
_Tfree( t );
}
/* find all children (alts) of t that require remaining_k nodes to be LL_k
* tokens long.
*
* t-->o
* |
* a1--a2--...--an <-- LL(1) tokens
* | | |
* b1 b2 ... bn <-- LL(2) tokens
* | | |
* . . .
* . . .
* z1 z2 ... zn <-- LL(LL_k) tokens
*
* We look for all [Ep] needing remaining_k nodes and replace with u.
* u is not destroyed or actually used by the tree (a copy is made).
*/
Tree *
#ifdef __STDC__
tlink( Tree *t, Tree *u, int remaining_k )
#else
tlink( t, u, remaining_k )
Tree *t;
Tree *u;
int remaining_k;
#endif
{
Tree *p;
require(remaining_k!=0, "tlink: bad tree");
if ( t==NULL ) return NULL;
/*fprintf(stderr, "tlink: u is:"); preorder(u); fprintf(stderr, "\n");*/
if ( t->token == EpToken && t->v.rk == remaining_k )
{
require(t->down==NULL, "tlink: invalid tree");
if ( u == NULL ) {
/* MR10 */ Tree *tt=t->right;
/* MR10 */ _Tfree(t);
/* MR10 */ return tt;
};
p = tdup( u );
p->right = t->right;
_Tfree( t );
return p;
}
t->down = tlink(t->down, u, remaining_k);
t->right = tlink(t->right, u, remaining_k);
return t;
}
/* remove as many ALT nodes as possible while still maintaining semantics */
Tree *
#ifdef __STDC__
tshrink( Tree *t )
#else
tshrink( t )
Tree *t;
#endif
{
if ( t == NULL ) return NULL;
t->down = tshrink( t->down );
t->right = tshrink( t->right );
if ( t->down == NULL )
{
if ( t->token == ALT )
{
Tree *u = t->right;
_Tfree(t);
return u; /* remove useless alts */
}
return t;
}
/* (? (ALT (? ...)) s) ==> (? (? ...) s) where s = sibling, ? = match any */
if ( t->token == ALT && t->down->right == NULL)
{
Tree *u = t->down;
u->right = t->right;
_Tfree( t );
return u;
}
/* (? (A (ALT t)) s) ==> (? (A t) s) where A is a token; s,t siblings */
if ( t->token != ALT && t->down->token == ALT && t->down->right == NULL )
{
Tree *u = t->down->down;
_Tfree( t->down );
t->down = u;
return t;
}
return t;
}
Tree *
#ifdef __STDC__
tflatten( Tree *t )
#else
tflatten( t )
Tree *t;
#endif
{
if ( t == NULL ) return NULL;
t->down = tflatten( t->down );
t->right = tflatten( t->right );
if ( t->down == NULL ) return t;
if ( t->token == ALT )
{
Tree *u;
/* find tail of children */
for (u=t->down; u->right!=NULL; u=u->right) {;}
u->right = t->right;
u = t->down;
_Tfree( t );
return u;
}
return t;
}
Tree *
#ifdef __STDC__
tJunc( Junction *p, int k, set *rk )
#else
tJunc( p, k, rk )
Junction *p;
int k;
set *rk;
#endif
{
Tree *t=NULL, *u=NULL;
Junction *alt;
Tree *tail=NULL, *r;
#ifdef DBG_TRAV
fprintf(stderr, "tJunc(%d): %s in rule %s\n", k,
decodeJType[p->jtype], ((Junction *)p)->rname);
#endif
/* MR14 */ if (AlphaBetaTrace && p->alpha_beta_guess_end) {
/* MR14 */ warnFL(
/* MR14 */ "not possible to compute follow set for alpha in an \"(alpha)? beta\" block. ",
/* MR14 */ FileStr[p->file],p->line);
/* MR14 */ MR_alphaBetaTraceReport();
/* MR14 */ };
/* MR14 */ if (p->alpha_beta_guess_end) {
/* MR14 */ return NULL;
/* MR14 */ }
if ( p->jtype==aLoopBlk || p->jtype==RuleBlk ||
p->jtype==aPlusBlk || p->jtype==aSubBlk || p->jtype==aOptBlk )
{
if ( p->jtype!=aSubBlk && p->jtype!=aOptBlk ) {
require(p->lock!=NULL, "rJunc: lock array is NULL");
if ( p->lock[k] ) return NULL;
p->lock[k] = TRUE;
}
/* MR10 */ if (MR_MaintainBackTrace) {
/* MR10 */ if (p->jtype != Generic) MR_pointerStackPush(&MR_BackTraceStack,p);
/* MR10 */ };
TRAV(p->p1, k, rk, tail);
/* MR10 */ if (MR_MaintainBackTrace) {
/* MR10 */ if (p->jtype != Generic) MR_pointerStackPop(&MR_BackTraceStack);
/* MR10 */ };
if ( p->jtype==RuleBlk ) {p->lock[k] = FALSE; return tail;}
r = tmake(tnode(ALT), tail, NULL);
for (alt=(Junction *)p->p2; alt!=NULL; alt = (Junction *)alt->p2)
{
/* if this is one of the added optional alts for (...)+ then break */
if ( alt->ignore ) break;
if ( tail==NULL ) {TRAV(alt->p1, k, rk, tail); r->down = tail;}
else
{
/* MR10 */ if (MR_MaintainBackTrace) {
/* MR10 */ if (p->jtype != Generic) MR_pointerStackPush(&MR_BackTraceStack,p);
/* MR10 */ };
TRAV(alt->p1, k, rk, tail->right);
/* MR10 */ if (MR_MaintainBackTrace) {
/* MR10 */ if (p->jtype != Generic) MR_pointerStackPop(&MR_BackTraceStack);
/* MR10 */ };
if ( tail->right != NULL ) tail = tail->right;
}
}
if ( p->jtype!=aSubBlk && p->jtype!=aOptBlk ) p->lock[k] = FALSE;
#ifdef DBG_TREES
fprintf(stderr, "blk(%s) returns:",((Junction *)p)->rname); preorder(r); fprintf(stderr, "\n");
#endif
if ( r->down == NULL ) {_Tfree(r); return NULL;}
return r;
}
if ( p->jtype==EndRule )
{
if ( p->halt ) /* don't want FOLLOW here? */
{
/**** if ( ContextGuardTRAV ) return NULL; ****/
set_orel( (unsigned) k, rk); /* indicate this k value needed */ /* MR10 cast */
t = tnode(EpToken);
t->v.rk = k;
return t;
}
require(p->lock!=NULL, "rJunc: lock array is NULL");
if ( p->lock[k] ) return NULL;
/* if no FOLLOW assume k EOF's */
if ( p->p1 == NULL ) return eofnode(k);
p->lock[k] = TRUE;
}
/* MR14 */ if (p->p1 != NULL && p->guess && p->guess_analysis_point == NULL) {
/* MR14 */ Node * guess_point;
/* MR14 */ guess_point=(Node *)analysis_point(p);
/* MR14 */ if (guess_point == (Node *)p) {
/* MR14 */ guess_point=p->p1;
/* MR14 */ }
/* MR14 */ p->guess_analysis_point=guess_point;
/* MR14 */ }
if ( p->p2 == NULL )
{
/* MR10 */ if (MR_MaintainBackTrace) {
/* MR10 */ if (p->jtype != Generic) MR_pointerStackPush(&MR_BackTraceStack,p);
/* MR10 */ };
/* M14 */ if (p->guess_analysis_point != NULL) {
/* M14 */ TRAV(p->guess_analysis_point, k, rk,t);
/* M14 */ } else {
TRAV(p->p1, k, rk,t);
/* M14 */ }
/* MR10 */ if (MR_MaintainBackTrace) {
/* MR10 */ if (p->jtype != Generic) MR_pointerStackPop(&MR_BackTraceStack);
/* MR10 */ };
if ( p->jtype==EndRule ) p->lock[k]=FALSE;
return t;
}
/* MR10 */ if (MR_MaintainBackTrace) {
/* MR10 */ if (p->jtype != Generic) MR_pointerStackPush(&MR_BackTraceStack,p);
/* MR10 */ };
/* M14 */ if (p->guess_analysis_point != NULL) {
/* M14 */ TRAV(p->guess_analysis_point, k, rk,t);
/* M14 */ } else {
TRAV(p->p1, k, rk,t);
/* M14 */ }
/* MR10 */ if (MR_MaintainBackTrace) {
/* MR10 */ if (p->jtype != Generic) MR_pointerStackPop(&MR_BackTraceStack);
/* MR10 */ };
if ( p->jtype!=RuleBlk && /* MR14 */ !p->guess) TRAV(p->p2, k, rk, u);
if ( p->jtype==EndRule ) p->lock[k] = FALSE;/* unlock node */
if ( t==NULL ) return tmake(tnode(ALT), u, NULL);
return tmake(tnode(ALT), t, u, NULL);
}
Tree *
#ifdef __STDC__
tRuleRef( RuleRefNode *p, int k, set *rk_out )
#else
tRuleRef( p, k, rk_out )
RuleRefNode *p;
int k;
set *rk_out;
#endif
{
int k2;
Tree *t=NULL, *u=NULL;
Junction *r;
set rk, rk2;
int save_halt;
RuleEntry *q = (RuleEntry *) hash_get(Rname, p->text);
#ifdef DBG_TRAV
fprintf(stderr, "tRuleRef: %s\n", p->text);
#endif
if ( q == NULL )
{
TRAV(p->next, k, rk_out, t);/* ignore undefined rules */
return t;
}
rk = rk2 = empty;
if (RulePtr == NULL) fatal("RulePtr==NULL");
r = RulePtr[q->rulenum];
if ( r->lock[k] ) return NULL;
save_halt = r->end->halt;
r->end->halt = TRUE; /* don't let reach fall off end of rule here */
/* MR10 */ if (MR_MaintainBackTrace) {
/* MR10 */ MR_pointerStackPush(&MR_BackTraceStack,p);
/* MR10 */ };
TRAV(r, k, &rk, t);
/* MR10 */ if (MR_MaintainBackTrace) {
/* MR10 */ MR_pointerStackPop(&MR_BackTraceStack);
/* MR10 */ };
r->end->halt = save_halt;
#ifdef DBG_TREES
fprintf(stderr, "after ruleref, t is:"); preorder(t); fprintf(stderr, "\n");
#endif
t = tshrink( t );
while ( !set_nil(rk) ) { /* any k left to do? if so, link onto tree */
k2 = set_int(rk);
set_rm(k2, rk);
/* MR10 */ if (MR_MaintainBackTrace) {
/* MR10 */ MR_pointerStackPush(&MR_BackTraceStack,p);
/* MR10 */ };
TRAV(p->next, k2, &rk2, u);
/* MR10 */ if (MR_MaintainBackTrace) {
/* MR10 */ MR_pointerStackPop(&MR_BackTraceStack);
/* MR10 */ };
t = tlink(t, u, k2); /* any alts missing k2 toks, add u onto end */
Tfree(u); /* MR10 */
}
set_free(rk); /* rk is empty, but free it's memory */
set_orin(rk_out, rk2); /* remember what we couldn't do */
set_free(rk2);
return t;
}
Tree *
#ifdef __STDC__
tToken( TokNode *p, int k, set *rk )
#else
tToken( p, k, rk )
TokNode *p;
int k;
set *rk;
#endif
{
Tree *t=NULL, *tset=NULL, *u;
if (ConstrainSearch) {
if (MR_AmbSourceSearch) {
require(constrain>=fset&&constrain<=&(fset[CLL_k]),"tToken: constrain is not a valid set");
} else {
require(constrain>=fset&&constrain<=&(fset[LL_k]),"tToken: constrain is not a valid set");
};
constrain = &fset[maxk-k+1];
}
#ifdef DBG_TRAV
fprintf(stderr, "tToken(%d): %s\n", k, TerminalString(p->token));
if ( ConstrainSearch ) {
fprintf(stderr, "constrain is:"); s_fprT(stderr, *constrain); fprintf(stderr, "\n");
}
#endif
/* is it a meta token (set of tokens)? */
if ( !set_nil(p->tset) )
{
unsigned e=0;
set a;
Tree *n, *tail = NULL;
if ( ConstrainSearch ) {
a = set_and(p->tset, *constrain);
if (set_nil(a)) { /* MR10 */
set_free(a); /* MR11 */
return NULL; /* MR10 */
}; /* MR10 */
} else {
a = set_dup(p->tset);
};
for (; !set_nil(a); set_rm(e, a))
{
e = set_int(a);
n = tnode(e);
if ( tset==NULL ) { tset = n; tail = n; }
else { tail->right = n; tail = n; }
}
set_free( a );
}
else if ( ConstrainSearch && !set_el(p->token, *constrain) )
{
/* fprintf(stderr, "ignoring token %s(%d)\n", TerminalString(p->token),
k);*/
return NULL;
}
else {
tset = tnode( p->token );
};
/* MR10 */ if (MR_MaintainBackTrace) {
/* MR10 */ if (k == 1) {
/* MR10 */ MR_pointerStackPush(&MR_BackTraceStack,p);
/* MR13 */ if (MR_SuppressSearch) {
/* MR13 */ MR_suppressSearchReport();
/* MR13 */ } else {
/* MR10 */ MR_backTraceReport();
/* MR13 */ };
/* MR10 */ MR_pointerStackPop(&MR_BackTraceStack);
/* MR11 */ Tfree(tset);
/* MR11 */ return NULL;
/* MR10 */ };
/* MR10 */ };
if ( k == 1 ) return tset;
if (MR_MaintainBackTrace) {
MR_pointerStackPush(&MR_BackTraceStack,p);
};
TRAV(p->next, k-1, rk, t);
if (MR_MaintainBackTrace) {
Tfree(t);
Tfree(tset);
MR_pointerStackPop(&MR_BackTraceStack);
return NULL;
};
/* here, we are positive that, at least, this tree will not contribute
* to the LL(2) tree since it will be too shallow, IF t==NULL.
* If doing a context guard walk, then don't prune.
*/
if ( t == NULL && !ContextGuardTRAV ) /* tree will be too shallow */
{
if ( tset!=NULL ) Tfree( tset );
return NULL;
}
#ifdef DBG_TREES
fprintf(stderr, "tToken(%d)->next:",k); preorder(t); fprintf(stderr, "\n");
#endif
/* if single token root, then just make new tree and return */
/* MR10 - set_nil(p->tset) isn't a good test because of ConstraintSearch */
if (tset->right == NULL) return tmake(tset, t, NULL); /* MR10 */
/* here we must make a copy of t as a child of each element of the tset;
* e.g., "T1..T3 A" would yield ( nil ( T1 A ) ( T2 A ) ( T3 A ) )
*/
for (u=tset; u!=NULL; u=u->right)
{
/* make a copy of t and hook it onto bottom of u */
u->down = tdup(t);
}
Tfree( t );
#ifdef DBG_TREES
fprintf(stderr, "range is:"); preorder(tset); fprintf(stderr, "\n");
#endif
return tset;
}
Tree *
#ifdef __STDC__
tAction( ActionNode *p, int k, set *rk )
#else
tAction( p, k, rk )
ActionNode *p;
int k;
set *rk;
#endif
{
Tree *t=NULL;
set *save_fset=NULL;
int i;
/* fprintf(stderr, "tAction\n"); */
/* An MR_SuppressSearch is looking for things that can be
reached even when the predicate is false.
There are three kinds of predicates:
plain: r1: <>? r2
guarded: r1: (A)? => <
>? r2
ampersand style: r1: (A)? && <
>? r2
Of the three kinds of predicates, only a guard predicate
has things which are reachable even when the predicate
is false. To be reachable the constraint must *not*
match the guard.
*/
if (p->is_predicate && MR_SuppressSearch) {
Predicate *pred=p->guardpred;
if (pred == NULL) {
t=NULL;
goto EXIT;
};
constrain = &fset[maxk-k+1];
if (pred->k == 1) {
set dif;
dif=set_dif(*constrain,pred->scontext[1]);
if (set_nil(dif)) {
set_free(dif);
t=NULL;
goto EXIT;
};
set_free(dif);
} else {
if (MR_tree_matches_constraints(k,constrain,pred->tcontext)) {
t=NULL;
goto EXIT;
};
}
};
/* The ampersand predicate differs from the
other predicates because its first set
is a subset of the first set behind the predicate
r1: (A)? && <
>? r2 ;
r2: A | B;
In this case first[1] of r1 is A, even
though first[1] of r2 is {A B}.
*/
if (p->is_predicate && p->ampersandPred != NULL) {
Predicate *pred=p->ampersandPred;
Tree *tAND;
Tree *tset;
if (k <= pred->k) {
if (MR_MaintainBackTrace) MR_pointerStackPush(&MR_BackTraceStack,p);
TRAV(p->guardNodes,k,rk,t);
if (MR_MaintainBackTrace) MR_pointerStackPop(&MR_BackTraceStack);
return t;
} else {
require (k>1,"tAction for ampersandpred: k <= 1");
if (ConstrainSearch) {
if (MR_AmbSourceSearch) {
require(constrain>=fset&&constrain<=&(fset[CLL_k]),
"tToken: constrain is not a valid set");
} else {
require(constrain>=fset&&constrain<=&(fset[LL_k]),
"tToken: constrain is not a valid set");
};
save_fset=(set *) calloc (CLL_k+1,sizeof(set));
require (save_fset != NULL,"tAction save_fset alloc");
for (i=1; i <= CLL_k ; i++) {
save_fset[i]=set_dup(fset[i]);
};
if (pred->k == 1) {
constrain = &fset[maxk-k+1];
set_andin(constrain,pred->scontext[1]);
if (set_nil(*constrain)) {
t=NULL;
goto EXIT;
};
} else {
constrain = &fset[maxk-k+1];
if (! MR_tree_matches_constraints(pred->k,constrain,pred->tcontext)) {
t=NULL;
goto EXIT;
}; /* end loop on i */
}; /* end loop on pred scontext/tcontext */
}; /* end if on k > pred->k */
}; /* end if on constrain search */
TRAV(p->next,k,rk,t);
if (t != NULL) {
t=tshrink(t);
t=tflatten(t);
t=tleft_factor(t);
if (pred->tcontext != NULL) {
tAND=MR_computeTreeAND(t,pred->tcontext);
} else {
tset=MR_make_tree_from_set(pred->scontext[1]);
tAND=MR_computeTreeAND(t,tset);
Tfree(tset);
};
Tfree(t);
t=tAND;
};
goto EXIT;
}; /* end if on ampersand predicate */
TRAV(p->next,k,rk,t);
EXIT:
if (save_fset != NULL) {
for (i=1 ; i <= CLL_k ; i++) {
set_free(fset[i]);
fset[i]=save_fset[i];
};
free ( (char *) save_fset);
};
return t;
}
/* see if e exists in s as a possible input permutation (e is always a chain) */
int
#ifdef __STDC__
tmember( Tree *e, Tree *s )
#else
tmember( e, s )
Tree *e;
Tree *s;
#endif
{
if ( e==NULL||s==NULL ) return 0;
/** fprintf(stderr, "tmember(");
*** preorder(e); fprintf(stderr, ",");
*** preorder(s); fprintf(stderr, " )\n");
*/
if ( s->token == ALT && s->right == NULL ) return tmember(e, s->down);
if ( e->token!=s->token )
{
if ( s->right==NULL ) return 0;
return tmember(e, s->right);
}
if ( e->down==NULL && s->down == NULL ) return 1;
if ( tmember(e->down, s->down) ) return 1;
if ( s->right==NULL ) return 0;
return tmember(e, s->right);
}
/* see if e exists in s as a possible input permutation (e is always a chain);
* Only check s to the depth of e. In other words, 'e' can be a shorter
* sequence than s.
*/
int
#ifdef __STDC__
tmember_constrained( Tree *e, Tree *s)
#else
tmember_constrained( e, s )
Tree *e;
Tree *s;
#endif
{
if ( e==NULL||s==NULL ) return 0;
/** fprintf(stderr, "tmember_constrained(");
*** preorder(e); fprintf(stderr, ",");
*** preorder(s); fprintf(stderr, " )\n");
**/
if ( s->token == ALT && s->right == NULL )
return tmember_constrained(e, s->down);
if ( e->token!=s->token )
{
if ( s->right==NULL ) return 0;
return tmember_constrained(e, s->right);
}
if ( e->down == NULL ) return 1; /* if s is matched to depth of e return */
if ( tmember_constrained(e->down, s->down) ) return 1;
if ( s->right==NULL ) return 0;
return tmember_constrained(e, s->right);
}
/* combine (? (A t) ... (A u) ...) into (? (A t u)) */
Tree *
#ifdef __STDC__
tleft_factor( Tree *t )
#else
tleft_factor( t )
Tree *t;
#endif
{
Tree *u, *v, *trail, *w;
/* left-factor what is at this level */
if ( t == NULL ) return NULL;
for (u=t; u!=NULL; u=u->right)
{
trail = u;
v=u->right;
while ( v!=NULL )
{
if ( u->token == v->token )
{
if ( u->down!=NULL )
{
for (w=u->down; w->right!=NULL; w=w->right) {;}
w->right = v->down; /* link children together */
}
else u->down = v->down;
trail->right = v->right; /* unlink factored node */
_Tfree( v );
v = trail->right;
}
else {trail = v; v=v->right;}
}
}
/* left-factor what is below */
for (u=t; u!=NULL; u=u->right) u->down = tleft_factor( u->down );
return t;
}
/* remove the permutation p from t if present */
Tree *
#ifdef __STDC__
trm_perm( Tree *t, Tree *p )
#else
trm_perm( t, p )
Tree *t;
Tree *p;
#endif
{
/*
fprintf(stderr, "trm_perm(");
preorder(t); fprintf(stderr, ",");
preorder(p); fprintf(stderr, " )\n");
*/
if ( t == NULL || p == NULL ) return NULL;
if ( t->token == ALT )
{
t->down = trm_perm(t->down, p);
if ( t->down == NULL ) /* nothing left below, rm cur node */
{
Tree *u = t->right;
_Tfree( t );
return trm_perm(u, p);
}
t->right = trm_perm(t->right, p); /* look for more instances of p */
return t;
}
if ( p->token != t->token ) /* not found, try a sibling */
{
t->right = trm_perm(t->right, p);
return t;
}
t->down = trm_perm(t->down, p->down);
if ( t->down == NULL ) /* nothing left below, rm cur node */
{
Tree *u = t->right;
_Tfree( t );
return trm_perm(u, p);
}
t->right = trm_perm(t->right, p); /* look for more instances of p */
return t;
}
/* add the permutation 'perm' to the LL_k sets in 'fset' */
void
#ifdef __STDC__
tcvt( set *fset, Tree *perm )
#else
tcvt( fset, perm )
set *fset;
Tree *perm;
#endif
{
if ( perm==NULL ) return;
set_orel(perm->token, fset);
tcvt(fset+1, perm->down);
}
/* for each element of ftbl[k], make it the root of a tree with permute(ftbl[k+1])
* as a child.
*/
Tree *
#ifdef __STDC__
permute( int k, int max_k )
#else
permute( k, max_k )
int k, max_k;
#endif
{
Tree *t, *u;
if ( k>max_k ) return NULL;
if ( ftbl[k][findex[k]] == nil ) return NULL;
t = permute(k+1, max_k);
if ( t==NULL&&k maxk will have to change.
*/
Tree *
#ifdef __STDC__
VerifyAmbig( Junction *alt1, Junction *alt2, unsigned **ft, set *fs, Tree **t, Tree **u, int *numAmbig )
#else
VerifyAmbig( alt1, alt2, ft, fs, t, u, numAmbig )
Junction *alt1;
Junction *alt2;
unsigned **ft;
set *fs;
Tree **t;
Tree **u;
int *numAmbig;
#endif
{
set rk;
Tree *perm, *ambig=NULL;
Junction *p;
int k;
int tnodes_at_start=TnodesAllocated;
int tnodes_at_end;
int tnodes_used;
set *save_fs;
int j;
save_fs=(set *) calloc(CLL_k+1,sizeof(set));
require(save_fs != NULL,"save_fs calloc");
for (j=0; j <= CLL_k ; j++) save_fs[j]=set_dup(fs[j]);
maxk = LL_k; /* NOTE: for now, we look for LL_k */
ftbl = ft;
fset = fs;
constrain = &(fset[1]);
findex = (int *) calloc(LL_k+1, sizeof(int));
if ( findex == NULL )
{
fprintf(stderr, ErrHdr, FileStr[CurAmbigfile], CurAmbigline);
fprintf(stderr, " out of memory while analyzing alts %d and %d of %s\n",
CurAmbigAlt1,
CurAmbigAlt2,
CurAmbigbtype);
exit(PCCTS_EXIT_FAILURE);
}
for (k=1; k<=LL_k; k++) findex[k] = 0;
rk = empty;
ConstrainSearch = 1; /* consider only tokens in ambig sets */
p = analysis_point((Junction *)alt1->p1);
TRAV(p, LL_k, &rk, *t);
*t = tshrink( *t );
*t = tflatten( *t );
*t = tleft_factor( *t ); /* MR10 */
*t = prune(*t, LL_k);
*t = tleft_factor( *t );
/*** fprintf(stderr, "after shrink&flatten&prune&left_factor:"); preorder(*t); fprintf(stderr, "\n");*/
if ( *t == NULL )
{
/*** fprintf(stderr, "TreeIncomplete --> no LL(%d) ambiguity\n", LL_k);*/
Tfree( *t ); /* kill if impossible to have ambig */
*t = NULL;
}
p = analysis_point((Junction *)alt2->p1);
TRAV(p, LL_k, &rk, *u);
*u = tshrink( *u );
*u = tflatten( *u );
*t = tleft_factor( *t ); /* MR10 */
*u = prune(*u, LL_k);
*u = tleft_factor( *u );
/* fprintf(stderr, "after shrink&flatten&prune&lfactor:"); preorder(*u); fprintf(stderr, "\n");*/
if ( *u == NULL )
{
/* fprintf(stderr, "TreeIncomplete --> no LL(%d) ambiguity\n", LL_k);*/
Tfree( *u );
*u = NULL;
}
for (k=1; k<=LL_k; k++) set_clr( fs[k] );
ambig = tnode(ALT);
k = 0;
if ( *t!=NULL && *u!=NULL )
{
while ( (perm=permute(1,LL_k))!=NULL )
{
/* fprintf(stderr, "chk perm:"); preorder(perm); fprintf(stderr, "\n");*/
if ( tmember(perm, *t) && tmember(perm, *u) )
{
/* fprintf(stderr, "ambig upon"); preorder(perm); fprintf(stderr, "\n");*/
k++;
perm->right = ambig->down;
ambig->down = perm;
tcvt(&(fs[1]), perm);
}
else Tfree( perm );
}
}
for (j=0; j <= CLL_k ; j++) fs[j]=save_fs[j];
free( (char *) save_fs);
tnodes_at_end=TnodesAllocated;
tnodes_used=tnodes_at_end - tnodes_at_start;
if (TnodesReportThreshold > 0 && tnodes_used > TnodesReportThreshold) {
fprintf(stdout,"There were %d tuples whose ambiguity could not be resolved by full lookahead\n",k);
fprintf(stdout,"There were %d tnodes created to resolve ambiguity between:\n\n",tnodes_used);
fprintf(stdout," Choice 1: %s line %d file %s\n",
MR_ruleNamePlusOffset( (Node *) alt1),alt1->line,FileStr[alt1->file]);
fprintf(stdout," Choice 2: %s line %d file %s\n",
MR_ruleNamePlusOffset( (Node *) alt2),alt2->line,FileStr[alt2->file]);
for (j=1; j <= CLL_k ; j++) {
fprintf(stdout,"\n Intersection of lookahead[%d] sets:\n",j);
MR_dumpTokenSet(stdout,2,fs[j]);
};
fprintf(stdout,"\n");
};
*numAmbig = k;
if ( ambig->down == NULL ) {_Tfree(ambig); ambig = NULL;}
free( (char *)findex );
/* fprintf(stderr, "final ambig:"); preorder(ambig); fprintf(stderr, "\n");*/
return ambig;
}
static Tree *
#ifdef __STDC__
bottom_of_chain( Tree *t )
#else
bottom_of_chain( t )
Tree *t;
#endif
{
if ( t==NULL ) return NULL;
for (; t->down != NULL; t=t->down) {;}
return t;
}
/*
* Make a tree from k sets where the degree of the first k-1 sets is 1.
*/
Tree *
#ifdef __STDC__
make_tree_from_sets( set *fset1, set *fset2 )
#else
make_tree_from_sets( fset1, fset2 )
set *fset1;
set *fset2;
#endif
{
set inter;
int i;
Tree *t=NULL, *n, *u;
unsigned *p,*q;
require(LL_k>1, "make_tree_from_sets: LL_k must be > 1");
/* do the degree 1 sets first */
for (i=1; i<=LL_k-1; i++)
{
inter = set_and(fset1[i], fset2[i]);
require(set_deg(inter)==1, "invalid set to tree conversion");
n = tnode(set_int(inter));
if (t==NULL) t=n; else tmake(t, n, NULL);
set_free(inter);
}
/* now add the chain of tokens at depth k */
u = bottom_of_chain(t);
inter = set_and(fset1[LL_k], fset2[LL_k]);
if ( (q=p=set_pdq(inter)) == NULL ) fatal_internal("Can't alloc space for set_pdq");
/* first one is linked to bottom, then others are sibling linked */
n = tnode(*p++);
u->down = n;
u = u->down;
while ( *p != nil )
{
n = tnode(*p);
u->right = n;
u = u->right;
p++;
}
free((char *)q);
return t;
}
/* create and return the tree of lookahead k-sequences that are in t, but not
* in the context of predicates in predicate list p.
*/
Tree *
#ifdef __STDC__
tdif( Tree *ambig_tuples, Predicate *p, set *fset1, set *fset2 )
#else
tdif( ambig_tuples, p, fset1, fset2 )
Tree *ambig_tuples;
Predicate *p;
set *fset1;
set *fset2;
#endif
{
unsigned **ft;
Tree *dif=NULL;
Tree *perm;
set b;
int i,k;
if ( p == NULL ) return tdup(ambig_tuples);
ft = (unsigned **) calloc(CLL_k+1, sizeof(unsigned *));
require(ft!=NULL, "cannot allocate ft");
for (i=1; i<=CLL_k; i++)
{
b = set_and(fset1[i], fset2[i]);
ft[i] = set_pdq(b);
set_free(b);
}
findex = (int *) calloc(LL_k+1, sizeof(int));
if ( findex == NULL )
{
fatal_internal("out of memory in tdif while checking predicates");
}
for (k=1; k<=LL_k; k++) findex[k] = 0;
#ifdef DBG_TRAV
fprintf(stderr, "tdif_%d[", p->k);
preorder(ambig_tuples);
fprintf(stderr, ",");
preorder(p->tcontext);
fprintf(stderr, "] =");
#endif
ftbl = ft;
while ( (perm=permute(1,p->k))!=NULL )
{
#ifdef DBG_TRAV
fprintf(stderr, "test perm:"); preorder(perm); fprintf(stderr, "\n");
#endif
if ( tmember_constrained(perm, ambig_tuples) &&
!tmember_of_context(perm, p) )
{
#ifdef DBG_TRAV
fprintf(stderr, "satisfied upon"); preorder(perm); fprintf(stderr, "\n");
#endif
k++;
if ( dif==NULL ) dif = perm;
else
{
perm->right = dif;
dif = perm;
}
}
else Tfree( perm );
}
#ifdef DBG_TRAV
preorder(dif);
fprintf(stderr, "\n");
#endif
for (i=1; i<=CLL_k; i++) free( (char *)ft[i] );
free((char *)ft);
free((char *)findex);
return dif;
}
/* is lookahead sequence t a member of any context tree for any
* predicate in p?
*/
static int
#ifdef __STDC__
tmember_of_context( Tree *t, Predicate *p )
#else
tmember_of_context( t, p )
Tree *t;
Predicate *p;
#endif
{
for (; p!=NULL; p=p->right)
{
if ( p->expr==PRED_AND_LIST || p->expr==PRED_OR_LIST )
return tmember_of_context(t, p->down);
if ( tmember_constrained(t, p->tcontext) ) return 1;
if ( tmember_of_context(t, p->down) ) return 1;
}
return 0;
}
int
#ifdef __STDC__
is_single_tuple( Tree *t )
#else
is_single_tuple( t )
Tree *t;
#endif
{
if ( t == NULL ) return 0;
if ( t->right != NULL ) return 0;
if ( t->down == NULL ) return 1;
return is_single_tuple(t->down);
}
/* MR10 Check that a context guard contains only allowed things */
/* MR10 (mainly token references). */
#ifdef __STDC__
int contextGuardOK(Node *p,int h,int *hmax)
#else
int contextGuardOK(p,h,hmax)
Node *p;
int h;
int *hmax;
#endif
{
Junction *j;
TokNode *tn;
if (p == NULL) return 1;
if (p->ntype == nToken) {
h++;
if (h > *hmax) *hmax=h;
tn=(TokNode *)p;
if (tn->el_label != NULL) {
warnFL(eMsg1("a label (\"%s\") for a context guard element is meaningless",tn->el_label),
FileStr[p->file],p->line);
};
return contextGuardOK( ( (TokNode *) p)->next,h,hmax);
} else if (p->ntype == nAction) {
goto Fail;
} else if (p->ntype == nRuleRef) {
goto Fail;
} else {
require (p->ntype == nJunction,"Unexpected ntype");
j=(Junction *) p;
if (j->jtype != Generic &&
j->jtype != aSubBlk && /* pretty sure this one is allowed */
/**** j->jtype != aOptBlk && ****/ /* pretty sure this one is allowed */ /* MR11 not any more ! */
j->jtype != EndBlk) {
errFL("A context guard may not contain an option block: {...} or looping block: (...)* or (...)+",
FileStr[p->file],p->line);
contextGuardOK(j->p1,h,hmax);
return 0;
};
/* do both p1 and p2 so use | rather than || */
return contextGuardOK(j->p2,h,hmax) | contextGuardOK(j->p1,h,hmax);
};
Fail:
errFL("A context guard may contain only Token references - guard will be ignored",
FileStr[p->file],p->line);
contextGuardOK( ( (ActionNode *) p)->next,h,hmax);
return 0;
}
/*
* Look at a (...)? generalized-predicate context-guard and compute
* either a lookahead set (k==1) or a lookahead tree for k>1. The
* k level is determined by the guard itself rather than the LL_k
* variable. For example, ( A B )? is an LL(2) guard and ( ID )?
* is an LL(1) guard. For the moment, you can only have a single
* tuple in the guard. Physically, the block must look like this
* --o-->TOKEN-->o-->o-->TOKEN-->o-- ... -->o-->TOKEN-->o--
* An error is printed for any other type.
*/
Predicate *
#ifdef __STDC__
computePredicateFromContextGuard(Graph blk,int *msgDone) /* MR10 */
#else
computePredicateFromContextGuard(blk,msgDone) /* MR10 */
Graph blk;
int *msgDone; /* MR10 */
#endif
{
Junction *junc = (Junction *)blk.left, *p;
Tree *t=NULL;
Predicate *pred = NULL;
set scontext, rk;
int ok;
int hmax=0;
require(junc!=NULL && junc->ntype == nJunction, "bad context guard");
/* MR10 Check for anything other than Tokens and generic junctions */
*msgDone=0; /* MR10 */
ok=contextGuardOK( (Node *)junc,0,&hmax); /* MR10 */
if (! ok) { /* MR10 */
*msgDone=1; /* MR10 */
return NULL; /* MR10 */
}; /* MR10 */
if (hmax == 0) {
errFL("guard is 0 tokens long",FileStr[junc->file],junc->line); /* MR11 */
*msgDone=1;
return NULL;
};
if (hmax > CLL_k) { /* MR10 */
errFL(eMsgd2("guard is %d tokens long - lookahead is limited to max(k,ck)==%d", /* MR10 */
hmax,CLL_k), /* MR10 */
FileStr[junc->file],junc->line); /* MR10 */
*msgDone=1; /* MR10 */
return NULL; /* MR10 */
}; /* MR10 */
rk = empty;
p = junc;
pred = new_pred();
pred->k = hmax; /* MR10 should be CLL_k, not LLK ? */
if (hmax > 1 ) /* MR10 was LL_k */
{
ConstrainSearch = 0;
ContextGuardTRAV = 1;
TRAV(p, hmax, &rk, t); /* MR10 was LL_k */
ContextGuardTRAV = 0;
set_free(rk);
t = tshrink( t );
t = tflatten( t );
t = tleft_factor( t );
/*
fprintf(stderr, "ctx guard:");
preorder(t);
fprintf(stderr, "\n");
*/
pred->tcontext = t;
}
else
{
REACH(p, 1, &rk, scontext);
require(set_nil(rk), "rk != nil");
set_free(rk);
/*
fprintf(stderr, "LL(1) ctx guard is:");
s_fprT(stderr, scontext);
fprintf(stderr, "\n");
*/
pred->scontext[1] = scontext;
}
list_add(&ContextGuardPredicateList,pred); /* MR13 */
return pred;
}
/* MR13
When the context guard is originally computed the
meta-tokens are not known.
*/
#ifdef __STDC__
void recomputeContextGuard(Predicate *pred)
#else
void recomputeContextGuard(pred)
Predicate *pred;
#endif
{
Tree * t=NULL;
set scontext;
set rk;
ActionNode * actionNode;
Junction * p;
actionNode=pred->source;
require (actionNode != NULL,"context predicate's source == NULL");
p=actionNode->guardNodes;
require (p != NULL,"context predicate's guardNodes == NULL");
rk = empty;
if (pred->k > 1 )
{
ConstrainSearch = 0;
ContextGuardTRAV = 1;
TRAV(p, pred->k, &rk, t);
ContextGuardTRAV = 0;
set_free(rk);
t = tshrink( t );
t = tflatten( t );
t = tleft_factor( t );
Tfree(pred->tcontext);
pred->tcontext = t;
}
else
{
REACH(p, 1, &rk, scontext);
require(set_nil(rk), "rk != nil");
set_free(rk);
set_free(pred->scontext[1]);
pred->scontext[1] = scontext;
}
}
/* MR11 - had enough of flags yet ? */
int MR_AmbSourceSearch=0;
int MR_AmbSourceSearchGroup=0;
int MR_AmbSourceSearchChoice=0;
int MR_AmbSourceSearchLimit=0;
int MR_matched_AmbAidRule=0;
static set *matchSets[2]={NULL,NULL};
static int *tokensInChain=NULL;
static Junction *MR_AmbSourceSearchJ[2];
void MR_traceAmbSourceKclient()
{
int i;
set *save_fset;
int save_ConstrainSearch;
set incomplete;
Tree *t;
if (matchSets[0] == NULL) {
matchSets[0]=(set *) calloc (CLL_k+1,sizeof(set));
require (matchSets[0] != NULL,"matchSets[0] alloc");
matchSets[1]=(set *) calloc (CLL_k+1,sizeof(set));
require (matchSets[1] != NULL,"matchSets[1] alloc");
};
for (i=1 ; i <= MR_AmbSourceSearchLimit ; i++) {
set_clr(matchSets[0][i]);
set_orel( (unsigned) tokensInChain[i],
&matchSets[0][i]);
set_clr(matchSets[1][i]);
set_orel( (unsigned) tokensInChain[i],
&matchSets[1][i]);
};
save_fset=fset;
save_ConstrainSearch=ConstrainSearch;
for (i=0 ; i < 2 ; i++) {
#if 0
** fprintf(stdout," Choice:%d Depth:%d ",i+1,MR_AmbSourceSearchLimit);
** fprintf(stdout,"(");
** for (j=1 ; j <= MR_AmbSourceSearchLimit ; j++) {
** if (j != 1) fprintf(stdout," ");
** fprintf(stdout,"%s",TerminalString(tokensInChain[j]));
** };
** fprintf(stdout,")\n\n");
#endif
fset=matchSets[i];
MR_AmbSourceSearch=1;
MR_MaintainBackTrace=1;
MR_AmbSourceSearchChoice=i;
ConstrainSearch=1;
maxk = MR_AmbSourceSearchLimit;
incomplete=empty;
t=NULL;
constrain = &(fset[1]);
MR_pointerStackReset(&MR_BackTraceStack);
TRAV(MR_AmbSourceSearchJ[i],maxk,&incomplete,t);
Tfree(t);
require (set_nil(incomplete),"MR_traceAmbSourceK TRAV incomplete");
require (MR_BackTraceStack.count == 0,"K: MR_BackTraceStack.count != 0");
set_free(incomplete);
};
ConstrainSearch=save_ConstrainSearch;
fset=save_fset;
MR_AmbSourceSearch=0;
MR_MaintainBackTrace=0;
MR_AmbSourceSearchChoice=0;
}
#ifdef __STDC__
Tree *tTrunc(Tree *t,int depth)
#else
Tree *tTrunc(t,depth)
Tree *t;
#endif
{
Tree *u;
require ( ! (t == NULL && depth > 0),"tree too short");
if (depth == 0) return NULL;
if (t->token == ALT) {
u=tTrunc(t->down,depth);
} else {
u=tnode(t->token);
u->down=tTrunc(t->down,depth-1);
};
if (t->right != NULL) u->right=tTrunc(t->right,depth);
return u;
}
#ifdef __STDC__
void MR_iterateOverTree(Tree *t,int chain[])
#else
void MR_iterateOverTree(t,chain)
Tree *t;
int chain[];
#endif
{
if (t == NULL) return;
chain[0]=t->token;
if (t->down != NULL) {
MR_iterateOverTree(t->down,&chain[1]);
} else {
MR_traceAmbSourceKclient();
};
MR_iterateOverTree(t->right,&chain[0]);
chain[0]=0;
}
#ifdef __STDC__
void MR_traceAmbSourceK(Tree *t,Junction *alt1,Junction *alt2)
#else
void MR_traceAmbSourceK(t,alt1,alt2)
Tree *t;
Junction *alt1;
Junction *alt2;
#endif
{
int i;
int depth;
int maxDepth;
Tree *truncatedTree;
if (MR_AmbAidRule == NULL) return;
if ( ! (
strcmp(MR_AmbAidRule,alt1->rname) == 0 ||
strcmp(MR_AmbAidRule,alt2->rname) == 0 ||
MR_AmbAidLine==alt1->line ||
MR_AmbAidLine==alt2->line
)
) return;
MR_matched_AmbAidRule++;
/* there are no token sets in trees, only in TokNodes */
MR_AmbSourceSearchJ[0]=analysis_point( (Junction *) alt1->p1);
MR_AmbSourceSearchJ[1]=analysis_point( (Junction *) alt2->p1);
if (tokensInChain == NULL) {
tokensInChain=(int *) calloc (CLL_k+1,sizeof(int));
require (tokensInChain != NULL,"tokensInChain alloc");
};
MR_AmbSourceSearchGroup=0;
fprintf(stdout,"\n");
fprintf(stdout," Ambiguity Aid ");
fprintf(stdout,
(MR_AmbAidDepth <= LL_k ?
"(-k %d -aa %s %s -aad %d)\n\n" :
"(-k %d -aa %s %s [-k value limits -aad %d])\n\n"),
LL_k,
MR_AmbAidRule,
(MR_AmbAidMultiple ? "-aam" : ""),
MR_AmbAidDepth);
for (i=0 ; i < 2 ; i++) {
fprintf(stdout," Choice %d: %-25s line %d file %s\n",
(i+1),
MR_ruleNamePlusOffset( (Node *) MR_AmbSourceSearchJ[i]),
MR_AmbSourceSearchJ[i]->line,
FileStr[MR_AmbSourceSearchJ[i]->file]);
};
fprintf(stdout,"\n");
if (MR_AmbAidDepth < LL_k) {
maxDepth=MR_AmbAidDepth;
} else {
maxDepth=LL_k;
};
for (depth=1 ; depth <= maxDepth; depth++) {
MR_AmbSourceSearchLimit=depth;
if (depth < LL_k) {
truncatedTree=tTrunc(t,depth);
truncatedTree=tleft_factor(truncatedTree);
MR_iterateOverTree(truncatedTree,&tokensInChain[1]); /* <===== */
Tfree(truncatedTree);
} else {
MR_iterateOverTree(t,tokensInChain); /* <===== */
};
fflush(stdout);
fflush(stderr);
};
fprintf(stdout,"\n");
MR_AmbSourceSearch=0;
MR_MaintainBackTrace=0;
MR_AmbSourceSearchGroup=0;
MR_AmbSourceSearchChoice=0;
MR_AmbSourceSearchLimit=0;
}
/* this if for k=1 grammars only
this is approximate only because of the limitations of linear
approximation lookahead. Don't want to do a k=3 search when
the user only specified a ck=3 grammar
*/
#ifdef __STDC__
void MR_traceAmbSource(set *matchSets,Junction *alt1, Junction *alt2)
#else
void MR_traceAmbSource(matchSets,alt1,alt2)
set *matchSets;
Junction *alt1;
Junction *alt2;
#endif
{
set *save_fset;
Junction *p[2];
int i;
int j;
set *dup_matchSets;
set intersection;
set incomplete;
set tokensUsed;
int depth;
if (MR_AmbAidRule == NULL) return;
if ( ! (
strcmp(MR_AmbAidRule,alt1->rname) == 0 ||
strcmp(MR_AmbAidRule,alt2->rname) == 0 ||
MR_AmbAidLine==alt1->line ||
MR_AmbAidLine==alt2->line
)
) return;
MR_matched_AmbAidRule++;
save_fset=fset;
dup_matchSets=(set *) calloc(CLL_k+1,sizeof(set));
require (dup_matchSets != NULL,"Can't allocate dup_matchSets");
p[0]=analysis_point( (Junction *) alt1->p1);
p[1]=analysis_point( (Junction *) alt2->p1);
fprintf(stdout,"\n");
fprintf(stdout," Ambiguity Aid ");
fprintf(stdout,
(MR_AmbAidDepth <= CLL_k ?
"(-ck %d -aa %s %s -aad %d)\n\n" :
"(-ck %d -aa %s %s [-ck value limits -aad %d])\n\n"),
CLL_k,
MR_AmbAidRule,
(MR_AmbAidMultiple ? "-aam" : ""),
MR_AmbAidDepth);
for (i=0 ; i < 2 ; i++) {
fprintf(stdout," Choice %d: %-25s line %d file %s\n",
(i+1),
MR_ruleNamePlusOffset( (Node *) p[i]),
p[i]->line,FileStr[p[i]->file]);
};
for (j=1; j <= CLL_k ; j++) {
fprintf(stdout,"\n Intersection of lookahead[%d] sets:\n",j);
intersection=set_and(alt1->fset[j],alt2->fset[j]);
MR_dumpTokenSet(stdout,2,intersection);
set_free(intersection);
};
fprintf(stdout,"\n");
require (1 <= MR_AmbAidDepth && MR_AmbAidDepth <= CLL_k,
"illegal MR_AmbAidDepth");
MR_AmbSourceSearchGroup=0;
for (depth=1; depth <= MR_AmbAidDepth; depth++) {
MR_AmbSourceSearchLimit=depth;
for (i=0 ; i < 2 ; i++) {
/*** fprintf(stdout," Choice:%d Depth:%d\n\n",i+1,depth); ***/
for (j=0 ; j <= CLL_k ; j++) { dup_matchSets[j]=set_dup(matchSets[j]); };
fset=dup_matchSets;
fflush(output);
fflush(stdout);
MR_AmbSourceSearch=1;
MR_MaintainBackTrace=1;
MR_AmbSourceSearchChoice=i;
maxk = depth;
tokensUsed=empty;
incomplete=empty;
constrain = &(fset[1]);
MR_pointerStackReset(&MR_BackTraceStack);
REACH(p[i],depth,&incomplete,tokensUsed);
fflush(output);
fflush(stdout);
require (set_nil(incomplete),"MR_traceAmbSource REACH incomplete");
require (MR_BackTraceStack.count == 0,"1: MR_BackTraceStack.count != 0");
set_free(incomplete);
set_free(tokensUsed);
for (j=0 ; j <= CLL_k ; j++) { set_free(dup_matchSets[j]); };
};
};
fprintf(stdout,"\n");
MR_AmbSourceSearch=0;
MR_MaintainBackTrace=0;
MR_AmbSourceSearchGroup=0;
MR_AmbSourceSearchChoice=0;
MR_AmbSourceSearchLimit=0;
fset=save_fset;
free ( (char *) dup_matchSets);
}
static int itemCount;
void MR_backTraceDumpItemReset() {
itemCount=0;
}
#ifdef __STDC__
void MR_backTraceDumpItem(FILE *f,int skip,Node *n)
#else
void MR_backTraceDumpItem(f,skip,n)
FILE *f;
int skip;
Node *n;
#endif
{
TokNode *tn;
RuleRefNode *rrn;
Junction *j;
ActionNode *a;
switch (n->ntype) {
case nToken:
itemCount++; if (skip) goto EXIT;
tn=(TokNode *)n;
if (set_nil(tn->tset)) {
fprintf(f," %2d #token %-23s",itemCount,TerminalString(tn->token));
} else {
fprintf(f," %2d #tokclass %-20s",itemCount,TerminalString(tn->token));
};
break;
case nRuleRef:
itemCount++; if (skip) goto EXIT;
rrn=(RuleRefNode *)n;
fprintf(f," %2d to %-27s",itemCount,rrn->text);
break;
case nAction:
a=(ActionNode *)n;
goto EXIT;
case nJunction:
j=(Junction *)n;
switch (j->jtype) {
case aSubBlk:
if (j->guess) {
itemCount++; if (skip) goto EXIT;
fprintf(f," %2d %-30s",itemCount,"in (...)? block at");
break;
};
/****** fprintf(f," %2d %-32s",itemCount,"in (...) block at"); *******/
/****** break; *******/
goto EXIT;
case aOptBlk:
itemCount++; if (skip) goto EXIT;
fprintf(f," %2d %-30s",itemCount,"in {...} block");
break;
case aLoopBlk:
itemCount++; if (skip) goto EXIT;
fprintf(f," %2d %-30s",itemCount,"in (...)* block");
break;
case EndBlk:
if (j->alpha_beta_guess_end) {
itemCount++; if (skip) goto EXIT;
fprintf(f," %2d %-30s",itemCount,"end (...)? block at");
break;
};
goto EXIT;
/****** fprintf(f," %2d %-32s",itemCount,"end of a block at"); *****/
/****** break; *****/
case RuleBlk:
itemCount++; if (skip) goto EXIT;
fprintf(f," %2d %-30s",itemCount,j->rname);
break;
case Generic:
goto EXIT;
case EndRule:
itemCount++; if (skip) goto EXIT;
fprintf (f," %2d end %-26s",itemCount,j->rname);
break;
case aPlusBlk:
itemCount++; if (skip) goto EXIT;
fprintf(f," %2d %-30s",itemCount,"in (...)+ block");
break;
case aLoopBegin:
goto EXIT;
};
break;
};
fprintf(f," %-23s line %-4d %s\n",MR_ruleNamePlusOffset(n),n->line,FileStr[n->file]);
EXIT:
return;
}
static PointerStack previousBackTrace={0,0,NULL};
#ifdef __STDC__
void MR_backTraceReport()
#else
void MR_backTraceReport()
#endif
{
int i;
int match;
int limitMatch;
Node *p;
TokNode *tn;
set remainder;
int depth;
/* Even when doing a k=2 search this routine can get
called when there is only 1 token on the stack.
This is because something like rRuleRef can change
the search value of k from 2 to 1 temporarily.
It does this because the it wants to know the k=1
first set before it does a k=2 search
*/
depth=0;
for (i=0; i < MR_BackTraceStack.count ; i++) {
p=(Node *) MR_BackTraceStack.data[i];
if (p->ntype == nToken) depth++;
};
/* MR14 */ if (MR_AmbSourceSearch) {
/* MR14 */ require (depth <= MR_AmbSourceSearchLimit,"depth > MR_AmbSourceSearchLimit");
/* MR14 */ }
if (depth < MR_AmbSourceSearchLimit) {
return;
};
MR_backTraceDumpItemReset();
limitMatch=MR_BackTraceStack.count;
if (limitMatch > previousBackTrace.count) {
limitMatch=previousBackTrace.count;
};
for (match=0; match < limitMatch; match++) {
if (MR_BackTraceStack.data[match] !=
previousBackTrace.data[match]) {
break;
};
};
/* not sure at the moment why there would be duplicates */
if (match != MR_BackTraceStack.count) {
fprintf(stdout," Choice:%d Depth:%d Group:%d",
(MR_AmbSourceSearchChoice+1),
MR_AmbSourceSearchLimit,
++MR_AmbSourceSearchGroup);
depth=0;
fprintf(stdout," (");
for (i=0; i < MR_BackTraceStack.count ; i++) {
p=(Node *) MR_BackTraceStack.data[i];
if (p->ntype != nToken) continue;
tn=(TokNode *)p;
if (depth != 0) fprintf(stdout," ");
fprintf(stdout,TerminalString(tn->token));
depth++;
if (! MR_AmbAidMultiple) {
if (set_nil(tn->tset)) {
set_rm( (unsigned) tn->token,fset[depth]);
} else {
remainder=set_dif(fset[depth],tn->tset);
set_free(fset[depth]);
fset[depth]=remainder;
};
};
};
fprintf(stdout,")\n");
for (i=0; i < MR_BackTraceStack.count ; i++) {
MR_backTraceDumpItem(stdout, (i