#if !defined(lint) && defined(DOSCCS) static char sccsid[] = "@(#)y3.c 4.1.1 (2.11BSD) 1995/05/11"; #endif # include "dextern" /* important local variables */ int lastred; /* the number of the last reduction of a state */ int defact[NSTATES]; /* the default actions of states */ output(){ /* print the output for the states */ int i, k; register int c; register struct wset *u, *v; fprintf( ftable, "short yyexca[] ={\n" ); SLOOP(i) { /* output the stuff for state i */ nolook = !(tystate[i]==MUSTLOOKAHEAD); closure(i); /* output actions */ nolook = 1; aryfil( temp1, ntokens+nnonter+1, 0 ); WSLOOP(wsets,u){ c = *( u->pitem ); if( c>1 && cpitem) ) putitem( v->pitem+1, (struct looksets *)0 ); } temp1[c] = state(c); } else if( c > NTBASE && temp1[ (c -= NTBASE) + ntokens ] == 0 ){ temp1[ c+ntokens ] = amem[indgo[i]+c]; } } if( i == 1 ) temp1[1] = ACCEPTCODE; /* now, we have the shifts; look at the reductions */ lastred = 0; WSLOOP(wsets,u){ c = *( u->pitem ); if( c<=0 ){ /* reduction */ lastred = -c; TLOOP(k){ if( BIT(u->ws.lset,k) ){ if( temp1[k] == 0 ) temp1[k] = c; else if( temp1[k]<0 ){ /* reduce/reduce conflict */ if( foutput!=NULL ) fprintf( foutput, "\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; } else { /* potential shift/reduce conflict */ precftn( lastred, k, i ); } } } } } wract(i); } fprintf( ftable, "\t};\n" ); wdef( "YYNPROD", nprod ); } int pkdebug = 0; apack(p, n ) int *p;{ /* pack state i from temp1 into amem */ int off; register *pp, *qq, *rr; int *q, *r; /* we don't need to worry about checking because we we will only look entries known to be there... */ /* eliminate leading and trailing 0's */ q = p+n; for( pp=p,off=0 ; *pp==0 && pp<=q; ++pp,--off ) /* VOID */ ; if( pp > q ) return(0); /* no actions */ p = pp; /* now, find a place for the elements from p to q, inclusive */ r = &amem[ACTSIZE-1]; for( rr=amem; rr<=r; ++rr,++off ){ /* try rr */ for( qq=rr,pp=p ; pp<=q ; ++pp,++qq){ if( *pp != 0 ){ if( *pp != *qq && *qq != 0 ) goto nextk; } } /* we have found an acceptable k */ if( pkdebug && foutput!=NULL ) fprintf( foutput, "off = %d, k = %d\n", off, rr-amem ); for( qq=rr,pp=p; pp<=q; ++pp,++qq ){ if( *pp ){ if( qq > r ) error( "action table overflow" ); if( qq>memp ) memp = qq; *qq = *pp; } } if( pkdebug && foutput!=NULL ){ for( pp=amem; pp<= memp; pp+=10 ){ fprintf( foutput, "\t"); for( qq=pp; qq<=pp+9; ++qq ) fprintf( foutput, "%d ", *qq ); fprintf( foutput, "\n"); } } return( off ); nextk: ; } error("no space in action table" ); /* NOTREACHED */ } go2out(){ /* output the gotos for the nontermninals */ register int i, j, k; int best, count, cbest, times; fprintf( ftemp, "$\n" ); /* mark begining of gotos */ for( i=1; i<=nnonter; ++i ) { go2gen(i); /* find the best one to make default */ 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); for( j=0; j<=nstate; ++j ){ if( tystate[j] != 0 && tystate[j]!=best ){ fprintf( ftemp, "%d,%d,", j, tystate[j] ); zzgoent += 1; } } /* now, the default */ zzgoent += 1; fprintf( ftemp, "%d\n", best ); } } int g2debug = 0; go2gen(c){ /* output the gotos for nonterminal c */ register int i, cc; int work; 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; PLOOP(0,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 && foutput!=NULL ){ fprintf( foutput, "%s: gotos on ", nontrst[c].name ); NTLOOP(i) if( temp1[i] ) fprintf( foutput, "%s ", nontrst[i].name); fprintf( foutput, "\n"); } /* now, go through and put gotos into tystate */ aryfil( tystate, nstate, 0 ); SLOOP(i){ ITMLOOP(i,p,q){ if( (cc= *p->pitem) >= NTBASE ){ if( temp1[cc -= NTBASE] ){ /* goto on c is possible */ tystate[i] = amem[indgo[i]+c]; break; } } } } } precftn(r,t,s) register int t; { /* decide a shift/reduce conflict by precedence. /* r is a rule number, t a token number */ /* the conflict is in state s */ /* temp1[t] is changed to reflect the action */ int lp,lt, action; lp = levprd[r]; lt = toklev[t]; if( PLEVEL(lt) == 0 || PLEVEL(lp) == 0 ) { /* conflict */ if( foutput != NULL ) fprintf( foutput, "\n%d: shift/reduce conflict (shift %d, red'n %d) on %s", s, temp1[t], r, symnam(t) ); ++zzsrconf; return; } if( PLEVEL(lt) == PLEVEL(lp) ) action = ASSOC(lt); else if( PLEVEL(lt) > PLEVEL(lp) ) action = RASC; /* shift */ else action = LASC; /* reduce */ switch( action ){ case BASC: /* error action */ temp1[t] = ERRCODE; return; case LASC: /* reduce */ temp1[t] = -r; return; } } wract(i) register int i; { /* output state i */ /* temp1 has the actions, lastred the default */ int p, p0, p1; int ntimes, tred, count; register int j; int flag; /* find the best choice for lastred */ lastred = 0; ntimes = 0; TLOOP(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]; levprd[tred] |= REDFLAG; TLOOP(p){ if( temp1[p]+tred == 0 ) ++count; } if( count >ntimes ){ lastred = tred; ntimes = count; } } /* for error recovery, arrange that, if there is a shift on the /* error recovery token, `error', that the default be the error action */ if( temp1[1] > 0 ) lastred = 0; /* clear out entries in temp1 which equal lastred */ TLOOP(p) if( temp1[p]+lastred == 0 )temp1[p]=0; wrstate(i); defact[i] = lastred; flag = 0; TLOOP(p0){ if( (p1=temp1[p0])!=0 ) { if( p1 < 0 ){ p1 = -p1; goto exc; } else if( p1 == ACCEPTCODE ) { p1 = -1; goto exc; } else if( p1 == ERRCODE ) { p1 = 0; goto exc; exc: if( flag++ == 0 ) fprintf( ftable, "-1, %d,\n", i ); fprintf( ftable, "\t%d, %d,\n", tokset[p0].value, p1 ); ++zzexcp; } else { fprintf( ftemp, "%d,%d,", tokset[p0].value, p1 ); ++zzacent; } } } if( flag ) { defact[i] = -2; fprintf( ftable, "\t-2, %d,\n", lastred ); } fprintf( ftemp, "\n" ); return; } wrstate(i){ /* writes state i */ register j0,j1; register struct item *pp, *qq; register struct wset *u; if( foutput == NULL ) return; fprintf( foutput, "\nstate %d\n",i); ITMLOOP(i,pp,qq) fprintf( foutput, "\t%s\n", writem(pp->pitem)); if( tystate[i] == MUSTLOOKAHEAD ){ /* print out empty productions in closure */ WSLOOP( wsets+(pstate[i+1]-pstate[i]), u ){ if( *(u->pitem) < 0 ) fprintf( foutput, "\t%s\n", writem(u->pitem) ); } } /* check for state equal to another */ TLOOP(j0) if( (j1=temp1[j0]) != 0 ){ fprintf( foutput, "\n\t%s ", symnam(j0) ); if( j1>0 ){ /* shift, error, or accept */ if( j1 == ACCEPTCODE ) fprintf( foutput, "accept" ); else if( j1 == ERRCODE ) fprintf( foutput, "error" ); else fprintf( foutput, "shift %d", j1 ); } else fprintf( foutput, "reduce %d",-j1 ); } /* output the final production */ if( lastred ) fprintf( foutput, "\n\t. reduce %d\n\n", lastred ); else fprintf( foutput, "\n\t. error\n\n" ); /* now, output nonterminal actions */ j1 = ntokens; for( j0 = 1; j0 <= nnonter; ++j0 ){ if( temp1[++j1] ) fprintf( foutput, "\t%s goto %d\n", symnam( j0+NTBASE), temp1[j1] ); } } wdef( s, n ) char *s; { /* output a definition of s to the value n */ fprintf( ftable, "# define %s %d\n", s, n ); } warray( s, v, n ) char *s; int *v, n; { register i; fprintf( ftable, "short %s[]={\n", s ); for( i=0; i