| 1 | #ifndef lint |
| 2 | static char sccsid[] = "@(#)y3.c 4.1 (Berkeley) %G%"; |
| 3 | #endif not lint |
| 4 | |
| 5 | # include "dextern" |
| 6 | |
| 7 | /* important local variables */ |
| 8 | int lastred; /* the number of the last reduction of a state */ |
| 9 | int defact[NSTATES]; /* the default actions of states */ |
| 10 | |
| 11 | output(){ /* print the output for the states */ |
| 12 | |
| 13 | int i, k, c; |
| 14 | register struct wset *u, *v; |
| 15 | |
| 16 | fprintf( ftable, "short yyexca[] ={\n" ); |
| 17 | |
| 18 | SLOOP(i) { /* output the stuff for state i */ |
| 19 | nolook = !(tystate[i]==MUSTLOOKAHEAD); |
| 20 | closure(i); |
| 21 | /* output actions */ |
| 22 | nolook = 1; |
| 23 | aryfil( temp1, ntokens+nnonter+1, 0 ); |
| 24 | WSLOOP(wsets,u){ |
| 25 | c = *( u->pitem ); |
| 26 | if( c>1 && c<NTBASE && temp1[c]==0 ) { |
| 27 | WSLOOP(u,v){ |
| 28 | if( c == *(v->pitem) ) putitem( v->pitem+1, (struct looksets *)0 ); |
| 29 | } |
| 30 | temp1[c] = state(c); |
| 31 | } |
| 32 | else if( c > NTBASE && temp1[ (c -= NTBASE) + ntokens ] == 0 ){ |
| 33 | temp1[ c+ntokens ] = amem[indgo[i]+c]; |
| 34 | } |
| 35 | } |
| 36 | |
| 37 | if( i == 1 ) temp1[1] = ACCEPTCODE; |
| 38 | |
| 39 | /* now, we have the shifts; look at the reductions */ |
| 40 | |
| 41 | lastred = 0; |
| 42 | WSLOOP(wsets,u){ |
| 43 | c = *( u->pitem ); |
| 44 | if( c<=0 ){ /* reduction */ |
| 45 | lastred = -c; |
| 46 | TLOOP(k){ |
| 47 | if( BIT(u->ws.lset,k) ){ |
| 48 | if( temp1[k] == 0 ) temp1[k] = c; |
| 49 | else if( temp1[k]<0 ){ /* reduce/reduce conflict */ |
| 50 | if( foutput!=NULL ) |
| 51 | fprintf( foutput, |
| 52 | "\n%d: reduce/reduce conflict (red'ns %d and %d ) on %s", |
| 53 | i, -temp1[k], lastred, symnam(k) ); |
| 54 | if( -temp1[k] > lastred ) temp1[k] = -lastred; |
| 55 | ++zzrrconf; |
| 56 | } |
| 57 | else { /* potential shift/reduce conflict */ |
| 58 | precftn( lastred, k, i ); |
| 59 | } |
| 60 | } |
| 61 | } |
| 62 | } |
| 63 | } |
| 64 | wract(i); |
| 65 | } |
| 66 | |
| 67 | fprintf( ftable, "\t};\n" ); |
| 68 | |
| 69 | wdef( "YYNPROD", nprod ); |
| 70 | |
| 71 | } |
| 72 | |
| 73 | int pkdebug = 0; |
| 74 | apack(p, n ) int *p;{ /* pack state i from temp1 into amem */ |
| 75 | int off; |
| 76 | register *pp, *qq, *rr; |
| 77 | int *q, *r; |
| 78 | |
| 79 | /* we don't need to worry about checking because we |
| 80 | we will only look entries known to be there... */ |
| 81 | |
| 82 | /* eliminate leading and trailing 0's */ |
| 83 | |
| 84 | q = p+n; |
| 85 | for( pp=p,off=0 ; *pp==0 && pp<=q; ++pp,--off ) /* VOID */ ; |
| 86 | if( pp > q ) return(0); /* no actions */ |
| 87 | p = pp; |
| 88 | |
| 89 | /* now, find a place for the elements from p to q, inclusive */ |
| 90 | |
| 91 | r = &amem[ACTSIZE-1]; |
| 92 | for( rr=amem; rr<=r; ++rr,++off ){ /* try rr */ |
| 93 | for( qq=rr,pp=p ; pp<=q ; ++pp,++qq){ |
| 94 | if( *pp != 0 ){ |
| 95 | if( *pp != *qq && *qq != 0 ) goto nextk; |
| 96 | } |
| 97 | } |
| 98 | |
| 99 | /* we have found an acceptable k */ |
| 100 | |
| 101 | if( pkdebug && foutput!=NULL ) fprintf( foutput, "off = %d, k = %d\n", off, rr-amem ); |
| 102 | |
| 103 | for( qq=rr,pp=p; pp<=q; ++pp,++qq ){ |
| 104 | if( *pp ){ |
| 105 | if( qq > r ) error( "action table overflow" ); |
| 106 | if( qq>memp ) memp = qq; |
| 107 | *qq = *pp; |
| 108 | } |
| 109 | } |
| 110 | if( pkdebug && foutput!=NULL ){ |
| 111 | for( pp=amem; pp<= memp; pp+=10 ){ |
| 112 | fprintf( foutput, "\t"); |
| 113 | for( qq=pp; qq<=pp+9; ++qq ) fprintf( foutput, "%d ", *qq ); |
| 114 | fprintf( foutput, "\n"); |
| 115 | } |
| 116 | } |
| 117 | return( off ); |
| 118 | |
| 119 | nextk: ; |
| 120 | } |
| 121 | error("no space in action table" ); |
| 122 | /* NOTREACHED */ |
| 123 | } |
| 124 | |
| 125 | go2out(){ /* output the gotos for the nontermninals */ |
| 126 | int i, j, k, best, count, cbest, times; |
| 127 | |
| 128 | fprintf( ftemp, "$\n" ); /* mark begining of gotos */ |
| 129 | |
| 130 | for( i=1; i<=nnonter; ++i ) { |
| 131 | go2gen(i); |
| 132 | |
| 133 | /* find the best one to make default */ |
| 134 | |
| 135 | best = -1; |
| 136 | times = 0; |
| 137 | |
| 138 | for( j=0; j<=nstate; ++j ){ /* is j the most frequent */ |
| 139 | if( tystate[j] == 0 ) continue; |
| 140 | if( tystate[j] == best ) continue; |
| 141 | |
| 142 | /* is tystate[j] the most frequent */ |
| 143 | |
| 144 | count = 0; |
| 145 | cbest = tystate[j]; |
| 146 | |
| 147 | for( k=j; k<=nstate; ++k ) if( tystate[k]==cbest ) ++count; |
| 148 | |
| 149 | if( count > times ){ |
| 150 | best = cbest; |
| 151 | times = count; |
| 152 | } |
| 153 | } |
| 154 | |
| 155 | /* best is now the default entry */ |
| 156 | |
| 157 | zzgobest += (times-1); |
| 158 | for( j=0; j<=nstate; ++j ){ |
| 159 | if( tystate[j] != 0 && tystate[j]!=best ){ |
| 160 | fprintf( ftemp, "%d,%d,", j, tystate[j] ); |
| 161 | zzgoent += 1; |
| 162 | } |
| 163 | } |
| 164 | |
| 165 | /* now, the default */ |
| 166 | |
| 167 | zzgoent += 1; |
| 168 | fprintf( ftemp, "%d\n", best ); |
| 169 | |
| 170 | } |
| 171 | |
| 172 | |
| 173 | |
| 174 | } |
| 175 | |
| 176 | int g2debug = 0; |
| 177 | go2gen(c){ /* output the gotos for nonterminal c */ |
| 178 | |
| 179 | int i, work, cc; |
| 180 | struct item *p, *q; |
| 181 | |
| 182 | |
| 183 | /* first, find nonterminals with gotos on c */ |
| 184 | |
| 185 | aryfil( temp1, nnonter+1, 0 ); |
| 186 | temp1[c] = 1; |
| 187 | |
| 188 | work = 1; |
| 189 | while( work ){ |
| 190 | work = 0; |
| 191 | PLOOP(0,i){ |
| 192 | if( (cc=prdptr[i][1]-NTBASE) >= 0 ){ /* cc is a nonterminal */ |
| 193 | if( temp1[cc] != 0 ){ /* cc has a goto on c */ |
| 194 | cc = *prdptr[i]-NTBASE; /* thus, the left side of production i does too */ |
| 195 | if( temp1[cc] == 0 ){ |
| 196 | work = 1; |
| 197 | temp1[cc] = 1; |
| 198 | } |
| 199 | } |
| 200 | } |
| 201 | } |
| 202 | } |
| 203 | |
| 204 | /* now, we have temp1[c] = 1 if a goto on c in closure of cc */ |
| 205 | |
| 206 | if( g2debug && foutput!=NULL ){ |
| 207 | fprintf( foutput, "%s: gotos on ", nontrst[c].name ); |
| 208 | NTLOOP(i) if( temp1[i] ) fprintf( foutput, "%s ", nontrst[i].name); |
| 209 | fprintf( foutput, "\n"); |
| 210 | } |
| 211 | |
| 212 | /* now, go through and put gotos into tystate */ |
| 213 | |
| 214 | aryfil( tystate, nstate, 0 ); |
| 215 | SLOOP(i){ |
| 216 | ITMLOOP(i,p,q){ |
| 217 | if( (cc= *p->pitem) >= NTBASE ){ |
| 218 | if( temp1[cc -= NTBASE] ){ /* goto on c is possible */ |
| 219 | tystate[i] = amem[indgo[i]+c]; |
| 220 | break; |
| 221 | } |
| 222 | } |
| 223 | } |
| 224 | } |
| 225 | } |
| 226 | |
| 227 | precftn(r,t,s){ /* decide a shift/reduce conflict by precedence. |
| 228 | /* r is a rule number, t a token number */ |
| 229 | /* the conflict is in state s */ |
| 230 | /* temp1[t] is changed to reflect the action */ |
| 231 | |
| 232 | int lp,lt, action; |
| 233 | |
| 234 | lp = levprd[r]; |
| 235 | lt = toklev[t]; |
| 236 | if( PLEVEL(lt) == 0 || PLEVEL(lp) == 0 ) { |
| 237 | /* conflict */ |
| 238 | if( foutput != NULL ) fprintf( foutput, "\n%d: shift/reduce conflict (shift %d, red'n %d) on %s", |
| 239 | s, temp1[t], r, symnam(t) ); |
| 240 | ++zzsrconf; |
| 241 | return; |
| 242 | } |
| 243 | if( PLEVEL(lt) == PLEVEL(lp) ) action = ASSOC(lt); |
| 244 | else if( PLEVEL(lt) > PLEVEL(lp) ) action = RASC; /* shift */ |
| 245 | else action = LASC; /* reduce */ |
| 246 | |
| 247 | switch( action ){ |
| 248 | |
| 249 | case BASC: /* error action */ |
| 250 | temp1[t] = ERRCODE; |
| 251 | return; |
| 252 | |
| 253 | case LASC: /* reduce */ |
| 254 | temp1[t] = -r; |
| 255 | return; |
| 256 | |
| 257 | } |
| 258 | } |
| 259 | |
| 260 | wract(i){ /* output state i */ |
| 261 | /* temp1 has the actions, lastred the default */ |
| 262 | int p, p0, p1; |
| 263 | int ntimes, tred, count, j; |
| 264 | int flag; |
| 265 | |
| 266 | /* find the best choice for lastred */ |
| 267 | |
| 268 | lastred = 0; |
| 269 | ntimes = 0; |
| 270 | TLOOP(j){ |
| 271 | if( temp1[j] >= 0 ) continue; |
| 272 | if( temp1[j]+lastred == 0 ) continue; |
| 273 | /* count the number of appearances of temp1[j] */ |
| 274 | count = 0; |
| 275 | tred = -temp1[j]; |
| 276 | levprd[tred] |= REDFLAG; |
| 277 | TLOOP(p){ |
| 278 | if( temp1[p]+tred == 0 ) ++count; |
| 279 | } |
| 280 | if( count >ntimes ){ |
| 281 | lastred = tred; |
| 282 | ntimes = count; |
| 283 | } |
| 284 | } |
| 285 | |
| 286 | /* for error recovery, arrange that, if there is a shift on the |
| 287 | /* error recovery token, `error', that the default be the error action */ |
| 288 | if( temp1[1] > 0 ) lastred = 0; |
| 289 | |
| 290 | /* clear out entries in temp1 which equal lastred */ |
| 291 | TLOOP(p) if( temp1[p]+lastred == 0 )temp1[p]=0; |
| 292 | |
| 293 | wrstate(i); |
| 294 | defact[i] = lastred; |
| 295 | |
| 296 | flag = 0; |
| 297 | TLOOP(p0){ |
| 298 | if( (p1=temp1[p0])!=0 ) { |
| 299 | if( p1 < 0 ){ |
| 300 | p1 = -p1; |
| 301 | goto exc; |
| 302 | } |
| 303 | else if( p1 == ACCEPTCODE ) { |
| 304 | p1 = -1; |
| 305 | goto exc; |
| 306 | } |
| 307 | else if( p1 == ERRCODE ) { |
| 308 | p1 = 0; |
| 309 | goto exc; |
| 310 | exc: |
| 311 | if( flag++ == 0 ) fprintf( ftable, "-1, %d,\n", i ); |
| 312 | fprintf( ftable, "\t%d, %d,\n", tokset[p0].value, p1 ); |
| 313 | ++zzexcp; |
| 314 | } |
| 315 | else { |
| 316 | fprintf( ftemp, "%d,%d,", tokset[p0].value, p1 ); |
| 317 | ++zzacent; |
| 318 | } |
| 319 | } |
| 320 | } |
| 321 | if( flag ) { |
| 322 | defact[i] = -2; |
| 323 | fprintf( ftable, "\t-2, %d,\n", lastred ); |
| 324 | } |
| 325 | fprintf( ftemp, "\n" ); |
| 326 | return; |
| 327 | } |
| 328 | |
| 329 | wrstate(i){ /* writes state i */ |
| 330 | register j0,j1; |
| 331 | register struct item *pp, *qq; |
| 332 | register struct wset *u; |
| 333 | |
| 334 | if( foutput == NULL ) return; |
| 335 | fprintf( foutput, "\nstate %d\n",i); |
| 336 | ITMLOOP(i,pp,qq) fprintf( foutput, "\t%s\n", writem(pp->pitem)); |
| 337 | if( tystate[i] == MUSTLOOKAHEAD ){ |
| 338 | /* print out empty productions in closure */ |
| 339 | WSLOOP( wsets+(pstate[i+1]-pstate[i]), u ){ |
| 340 | if( *(u->pitem) < 0 ) fprintf( foutput, "\t%s\n", writem(u->pitem) ); |
| 341 | } |
| 342 | } |
| 343 | |
| 344 | /* check for state equal to another */ |
| 345 | |
| 346 | TLOOP(j0) if( (j1=temp1[j0]) != 0 ){ |
| 347 | fprintf( foutput, "\n\t%s ", symnam(j0) ); |
| 348 | if( j1>0 ){ /* shift, error, or accept */ |
| 349 | if( j1 == ACCEPTCODE ) fprintf( foutput, "accept" ); |
| 350 | else if( j1 == ERRCODE ) fprintf( foutput, "error" ); |
| 351 | else fprintf( foutput, "shift %d", j1 ); |
| 352 | } |
| 353 | else fprintf( foutput, "reduce %d",-j1 ); |
| 354 | } |
| 355 | |
| 356 | /* output the final production */ |
| 357 | |
| 358 | if( lastred ) fprintf( foutput, "\n\t. reduce %d\n\n", lastred ); |
| 359 | else fprintf( foutput, "\n\t. error\n\n" ); |
| 360 | |
| 361 | /* now, output nonterminal actions */ |
| 362 | |
| 363 | j1 = ntokens; |
| 364 | for( j0 = 1; j0 <= nnonter; ++j0 ){ |
| 365 | if( temp1[++j1] ) fprintf( foutput, "\t%s goto %d\n", symnam( j0+NTBASE), temp1[j1] ); |
| 366 | } |
| 367 | |
| 368 | } |
| 369 | |
| 370 | wdef( s, n ) char *s; { /* output a definition of s to the value n */ |
| 371 | fprintf( ftable, "# define %s %d\n", s, n ); |
| 372 | } |
| 373 | |
| 374 | warray( s, v, n ) char *s; int *v, n; { |
| 375 | |
| 376 | register i; |
| 377 | |
| 378 | fprintf( ftable, "short %s[]={\n", s ); |
| 379 | for( i=0; i<n; ){ |
| 380 | if( i%10 == 0 ) fprintf( ftable, "\n" ); |
| 381 | fprintf( ftable, "%4d", v[i] ); |
| 382 | if( ++i == n ) fprintf( ftable, " };\n" ); |
| 383 | else fprintf( ftable, "," ); |
| 384 | } |
| 385 | } |
| 386 | |
| 387 | hideprod(){ |
| 388 | /* in order to free up the mem and amem arrays for the optimizer, |
| 389 | /* and still be able to output yyr1, etc., after the sizes of |
| 390 | /* the action array is known, we hide the nonterminals |
| 391 | /* derived by productions in levprd. |
| 392 | */ |
| 393 | |
| 394 | register i, j; |
| 395 | |
| 396 | j = 0; |
| 397 | levprd[0] = 0; |
| 398 | PLOOP(1,i){ |
| 399 | if( !(levprd[i] & REDFLAG) ){ |
| 400 | ++j; |
| 401 | if( foutput != NULL ){ |
| 402 | fprintf( foutput, "Rule not reduced: %s\n", writem( prdptr[i] ) ); |
| 403 | } |
| 404 | } |
| 405 | levprd[i] = *prdptr[i] - NTBASE; |
| 406 | } |
| 407 | if( j ) fprintf( stdout, "%d rules never reduced\n", j ); |
| 408 | } |