1BSD/eyacc/ey4.c
# include "ey.h"
output(){ /* print the output for the states */
int i, j, k, c;
settab();
arrset("yyact");
for( i=0; i<nstate; ++i ){ /* output the stuff for state i */
nolook = (tystate[i]==0);
closure(i);
/* output actions */
aryfil( temp1, nterms+1, 0 );
for( j=0; j<cwset; ++j ){ /* look at the items */
c = *( wsets[j].pitem );
if( c>0 && c<NTBASE && temp1[c]==0 ) temp1[c] = go2(i,c);
}
if( i == 1 ) temp1[1] = ACCEPTCODE;
/* now, we have the shifts; look at the reductions */
lastred = 0;
for( j=0; j<cwset; ++j ){
c = *( wsets[j].pitem );
if( c<=0 ){ /* reduction */
lastred = -c;
for( k=1; k<=nterms; ++k ){
if( ((wsets[j].ws[k>>4])&(1<<(k&017))) != 0 ) {
if( temp1[k] == 0 ) temp1[k] = c;
else if( temp1[k]<0 ){ /* reduce/reduce conflict */
settty();
printf("\n%d: reduce/reduce conflict (red'ns %d and %d ) on %s",
i, -temp1[k], lastred, symnam(k) );
if( -temp1[k] > lastred ) temp1[k] = -lastred;
++zzrrconf;
settab();
}
else { /* potential shift/reduce conflict */
switch( precftn( lastred, k ) ) {
case 0: /* precedence does not apply */
settty();
printf("\n%d: shift/reduce conflict (shift %d, red'n %d) on %s", i,
temp1[k], lastred, symnam(k) );
++zzsrconf;
settab();
break;
case 1: /* reduce */
temp1[k] = -lastred;
break;
case 2: /* error, binary operator */
temp1[k] = ERRCODE;
break;
case 3: /* shift ... leave the entry alone */
break;
}
}
}
}
}
}
wract(i);
}
settab();
arrdone();
/* now, output the pointers to the action array */
/* also output the info about reductions */
prred();
}
prred(){ /* print the information about the actions and the reductions */
int index, i;
arrset("yypact");
index = 1; /* position in the output table */
for( i=0; i<nstate; ++i ){
if( tystate[i]>0 ){ /* the state is real */
temp1[i] = index;
arrval( index );
index =+ tystate[i];
}
else {
arrval( temp1[-tystate[i]] );
}
}
arrdone();
arrset("yyr1");
for( i=1; i<nprod; ++i ) arrval( *prdptr[i] - NTBASE );
arrdone();
arrset("yyr2");
for( i=1; i<nprod; ++i ) arrval( ( prdptr[i+1]-prdptr[i]-2 ) );
arrdone();
}
go2(i,c){ /* do a goto on the closure state, not worrying about lookaheads */
if( c<NTBASE ) return( amem[ apstate[i]+c ] );
else return( amem[ apstate[i] + c - NTBASE + nterms ] );
}
int pkdebug 0;
apack(p, n ) int *p;{ /* pack state i from temp1 into amem */
_REGISTER k, l, off;
int j;
/* find the spot */
j = n;
for( off = 0; off <= j && p[off] == 0; ++off ) ;
if( off > j ){ /* no actions */
return(0);
}
j =- off;
for( k=0; k<actsiz; ++k ){
for( l=0; l<=j; ++l ){
if( p[off+l] != 0 ){
if( p[off+l] != amem[k+l] && amem[k+l] != 0 ) goto nextk;
}
}
if( pkdebug ){ settty(); printf("off = %d, k = %d\n", off, k ); }
/* we have found an acceptable k */
for( l=0; l<=j; ++l ){
if( p[off+l] ){
if( k+l >= actsiz ) error("action table overflow");
if( k+l >= memact ) memact = k+l;
amem[k+l] = p[off+l];
}
}
if( pkdebug ){
for( k=0; k<memact; k=+10){
printf("\t");
for( l=0; l<=9; ++l ) printf("%d ", amem[k+l] );
printf("\n");
}
}
return(k-off);
nextk: ;
}
error("no space in action table");
}
go2out(){ /* output the gotos for the nontermninals */
int i, j, k, best, offset, count, cbest, times;
settab();
arrset("yygo");
offset = 1;
for( i=1; i<=nnonter; ++i ) {
go2gen(i);
/* find the best one to make default */
temp2[i] = offset;
best = -1;
times = 0;
for( j=0; j<=nstate; ++j ){ /* is j the most frequent */
if( tystate[j] == 0 ) continue;
if( tystate[j] == best ) continue;
/* is tystate[j] the most frequent */
count = 0;
cbest = tystate[j];
for( k=j; k<=nstate; ++k ) if( tystate[k]==cbest ) ++count;
if( count > times ){
best = cbest;
times = count;
}
}
/* best is now the default entry */
zzgobest =+ (times-1)*2;
settab();
for( j=0; j<=nstate; ++j ){
if( tystate[j] != 0 && tystate[j]!=best ){
arrval( j );
arrval( tystate[j] );
offset =+ 2;
zzgoent =+ 2;
}
}
/* now, the default */
zzgoent =+ 2;
arrval( -1 );
arrval( best );
offset =+ 2;
}
arrdone();
arrset("yypgo");
for( i=1; i<=nnonter; ++i ) arrval( temp2[i] );
arrdone();
}
int g2debug 0;
go2gen(c){ /* output the gotos for nonterminal c */
int i, work, cc;
struct item *p, *q;
/* first, find nonterminals with gotos on c */
aryfil( temp1, nnonter+1, 0 );
temp1[c] = 1;
work = 1;
while( work ){
work = 0;
for( i=0; i<nprod; ++i ){
if( (cc=prdptr[i][1]-NTBASE) >= 0 ){ /* cc is a nonterminal */
if( temp1[cc] != 0 ){ /* cc has a goto on c */
cc = *prdptr[i]-NTBASE; /* thus, the left side of production i does too */
if( temp1[cc] == 0 ){
work = 1;
temp1[cc] = 1;
}
}
}
}
}
/* now, we have temp1[c] = 1 if a goto on c in closure of cc */
if( g2debug ){
settty();
printf("%s: gotos on ", nontrst[c].name );
for( i=0; i<=nnonter; ++i ) if( temp1[i]) printf("%s ", nontrst[i].name);
printf("\n");
}
/* now, go through and put gotos into tystate */
aryfil( tystate, nstate, 0 );
settty();
printf("\nnonterminal %s\n", nontrst[c].name );
for( i=0; i<nstate; ++i ){
q = pstate[i+1];
for( p=pstate[i]; p<q; ++p ){
if( (cc= *p->pitem) >= NTBASE ){
if( temp1[cc =- NTBASE] ){ /* goto on c is possible */
tystate[i] = amem[indgo[i]+c];
break;
}
}
}
if( tystate[i] ) printf("\t%d\t%d\n", i, tystate[i]);
}
}
precftn(r,t){ /* decide a shift/reduce conflict by precedence.
Returns 0 if action is 'do nothing',1 if action is reduce,
2 if the action is 'error,binary operator'
and 3 if the action is 'reduce'. */
int lp,lt;
lp = levprd[r];
lt = trmlev[t];
if ((lt==0)||((lp&03)==0))return(0);
if((lt>>3) == (lp>>3)){
return(lt&03);
}
if((lt>>3) > (lp>>3)) return(3);
return(1);
}
int cdebug 0; /* debug for common states */
wract(i){ /* output state i */
/* temp1 has the actions, lastred the default */
int p, p0, p1, size;
int ntimes, tred, count, j;
struct item *q0, *q1;
/* find the best choice for lastred */
lastred = 0;
ntimes = 0;
/***** UCB MOD - full state spec if shift on error *****/
if (temp1[2] <= 0)
for( j=1; j<=nterms; ++j ){
if( temp1[j] >= 0 ) continue;
if( temp1[j]+lastred == 0 ) continue;
/* count the number of appearances of temp1[j] */
count = 0;
tred = -temp1[j];
for( p=1; p<=nterms; ++p ){
if( temp1[p]+tred == 0 ) ++count;
}
if( count >ntimes ){
lastred = tred;
ntimes = count;
}
}
/* clear out entries in temp1 which equal lastred */
for( p=1; p<= nterms; ++p ) if( temp1[p]+lastred == 0 )temp1[p]=0;
/* write out the state */
/* first, check for equality with another state */
/* see if there is a nonterminal with all dots before it. */
p0 = 0;
q1 = pstate[i+1];
for( q0=pstate[i]; q0<q1; ++q0 ){
if( (p1= *(q0->pitem) ) < NTBASE ) goto standard;
if( p0 == 0 ) p0 = p1;
else if( p0 != p1 ) goto standard;
}
/* now, all items have dots before p0 */
if( cdebug ){
settty();
printf("state %d, pre-nonterminal %s\n",i,nontrst[p0-NTBASE].name);
}
for( j=0; j<i; ++j ){
if( apstate[i] != apstate[j] ) continue;
/* equal positions -- check items */
if( cdebug )printf("states %d and %d have equal positions\n",i,j);
q1 = pstate[j+1];
for( q0=pstate[j]; q0<q1; ++q0 ){
if( *(q0->pitem) != p0 ) goto nextj;
}
/* we have a match with state j ! */
tystate[i] = -j;
zzacsave =+ tystate[j];
zznsave++;
wrstate(i);
return;
nextj: ;
}
standard:
tystate[i] = 2;
wrstate(i);
size = 0;
for( p0=1; p0<=nterms; ++p0 )
if( (p1=temp1[p0])!=0 ) {
/***** UCB MOD - test actions are negative of symbol to be tested
this speeds up the parser as it is easy to check for
*****/
arrval( -trmset[p0].value );
if( p1 < 0 ) arrval( REDUCACT - p1 );
else if( p1 == ACCEPTCODE ) arrval( ACCEPTACT );
else if( p1 == ERRCODE ) arrval( ERRACT );
else arrval( SHIFTACT + p1 );
size =+ 2;
}
if( lastred ) arrval( REDUCACT + lastred );
else arrval( ERRACT );
tystate[i] = size+1; /* store entry size in tystate */
zzacent =+ (size+1);
return;
}
wrstate(i){ /* writes state i */
int j0,j1,s;
struct item *pp, *qq;
settty();
printf("\nstate %d\n",i);
qq = pstate[i+1];
for( pp=pstate[i]; pp<qq; ++pp) printf("\t%s\n", writem(pp));
/* check for state equal to another */
if( tystate[i] <= 0 ){
printf("\n\tsame as %d\n\n", -tystate[i] );
return;
}
for( j0=1; j0<=nterms; ++j0 ) if( (j1=temp1[j0]) != 0 ){
printf("\n\t%s ", symnam(j0) );
if( j1>0 ){ /* shift, error, or accept */
if( j1 == ACCEPTCODE ) printf( "accept" );
else if( j1 == ERRCODE ) printf( "error" );
else printf( "shift %d", j1 );
}
else printf("reduce %d",-j1 );
}
/* output the final production */
if( lastred ) printf("\n\t. reduce %d\n\n", lastred );
else printf("\n\t. error\n\n" );
ret:
settab();
}