tests/conflicts.at

   1 # Exercising Bison on conflicts.                         -*- Autotest -*-
   2
   3 # Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
   4
   5 # This program is free software; you can redistribute it and/or modify
   6 # it under the terms of the GNU General Public License as published by
   7 # the Free Software Foundation; either version 2, or (at your option)
   8 # any later version.
   9
  10 # This program is distributed in the hope that it will be useful,
  11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 # GNU General Public License for more details.
  14
  15 # You should have received a copy of the GNU General Public License
  16 # along with this program; if not, write to the Free Software
  17 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  18 # 02110-1301, USA.
  19
  20 AT_BANNER([[Conflicts.]])
  21
  22
  23 ## ---------------- ##
  24 ## S/R in initial.  ##
  25 ## ---------------- ##
  26
  27 # I once hacked Bison in such a way that it lost its reductions on the
  28 # initial state (because it was confusing it with the last state).  It
  29 # took me a while to strip down my failures to this simple case.  So
  30 # make sure it finds the s/r conflict below.
  31
  32 AT_SETUP([S/R in initial])
  33
  34 AT_DATA([[input.y]],
  35 [[%expect 1
  36 %%
  37 exp: e 'e';
  38 e: 'e' | /* Nothing. */;
  39 ]])
  40
  41 AT_CHECK([bison -o input.c input.y], 0, [],
  42 [[input.y:4.9: warning: rule never reduced because of conflicts: e: /* empty */
  43 ]])
  44
  45 AT_CLEANUP
  46
  47
  48 ## ------------------- ##
  49 ## %nonassoc and eof.  ##
  50 ## ------------------- ##
  51
  52 AT_SETUP([%nonassoc and eof])
  53
  54 AT_DATA_GRAMMAR([input.y],
  55 [[
  56 %{
  57 #include <stdio.h>
  58 #include <stdlib.h>
  59 #include <string.h>
  60
  61 #define YYERROR_VERBOSE 1
  62 static void
  63 yyerror (const char *msg)
  64 {
  65   fprintf (stderr, "%s\n", msg);
  66 }
  67
  68 /* The current argument. */
  69 static const char *input;
  70
  71 static int
  72 yylex (void)
  73 {
  74   static size_t toknum;
  75   if (! (toknum <= strlen (input)))
  76     abort ();
  77   return input[toknum++];
  78 }
  79
  80 %}
  81
  82 %nonassoc '<' '>'
  83
  84 %%
  85 expr: expr '<' expr
  86     | expr '>' expr
  87     | '0'
  88     ;
  89 %%
  90 int
  91 main (int argc, const char *argv[])
  92 {
  93   input = argc <= 1 ? "" : argv[1];
  94   return yyparse ();
  95 }
  96 ]])
  97
  98 # Specify the output files to avoid problems on different file systems.
  99 AT_CHECK([bison -o input.c input.y])
 100 AT_COMPILE([input])
 101
 102 AT_PARSER_CHECK([./input '0<0'])
 103 # FIXME: This is an actual bug, but a new one, in the sense that
 104 # no one has ever spotted it!  The messages are *wrong*: there should
 105 # be nothing there, it should be expected eof.
 106 AT_PARSER_CHECK([./input '0<0<0'], [1], [],
 107          [syntax error, unexpected '<', expecting '<' or '>'
 108 ])
 109
 110 AT_PARSER_CHECK([./input '0>0'])
 111 AT_PARSER_CHECK([./input '0>0>0'], [1], [],
 112          [syntax error, unexpected '>', expecting '<' or '>'
 113 ])
 114
 115 AT_PARSER_CHECK([./input '0<0>0'], [1], [],
 116          [syntax error, unexpected '>', expecting '<' or '>'
 117 ])
 118
 119 AT_CLEANUP
 120
 121
 122
 123 ## ------------------------- ##
 124 ## Unresolved SR Conflicts.  ##
 125 ## ------------------------- ##
 126
 127 AT_SETUP([Unresolved SR Conflicts])
 128
 129 AT_KEYWORDS([report])
 130
 131 AT_DATA([input.y],
 132 [[%token NUM OP
 133 %%
 134 exp: exp OP exp | NUM;
 135 ]])
 136
 137 AT_CHECK([bison -o input.c --report=all input.y], 0, [],
 138 [input.y: conflicts: 1 shift/reduce
 139 ])
 140
 141 # Check the contents of the report.
 142 AT_CHECK([cat input.output], [],
 143 [[State 5 conflicts: 1 shift/reduce
 144
 145
 146 Grammar
 147
 148     0 $accept: exp $end
 149
 150     1 exp: exp OP exp
 151     2    | NUM
 152
 153
 154 Terminals, with rules where they appear
 155
 156 $end (0) 0
 157 error (256)
 158 NUM (258) 2
 159 OP (259) 1
 160
 161
 162 Nonterminals, with rules where they appear
 163
 164 $accept (5)
 165     on left: 0
 166 exp (6)
 167     on left: 1 2, on right: 0 1
 168
 169
 170 state 0
 171
 172     0 $accept: . exp $end
 173     1 exp: . exp OP exp
 174     2    | . NUM
 175
 176     NUM  shift, and go to state 1
 177
 178     exp  go to state 2
 179
 180
 181 state 1
 182
 183     2 exp: NUM .
 184
 185     $default  reduce using rule 2 (exp)
 186
 187
 188 state 2
 189
 190     0 $accept: exp . $end
 191     1 exp: exp . OP exp
 192
 193     $end  shift, and go to state 3
 194     OP    shift, and go to state 4
 195
 196
 197 state 3
 198
 199     0 $accept: exp $end .
 200
 201     $default  accept
 202
 203
 204 state 4
 205
 206     1 exp: . exp OP exp
 207     1    | exp OP . exp
 208     2    | . NUM
 209
 210     NUM  shift, and go to state 1
 211
 212     exp  go to state 5
 213
 214
 215 state 5
 216
 217     1 exp: exp . OP exp  [$end, OP]
 218     1    | exp OP exp .  [$end, OP]
 219
 220     OP  shift, and go to state 4
 221
 222     OP        [reduce using rule 1 (exp)]
 223     $default  reduce using rule 1 (exp)
 224 ]])
 225
 226 AT_CLEANUP
 227
 228
 229
 230 ## ----------------------- ##
 231 ## Resolved SR Conflicts.  ##
 232 ## ----------------------- ##
 233
 234 AT_SETUP([Resolved SR Conflicts])
 235
 236 AT_KEYWORDS([report])
 237
 238 AT_DATA([input.y],
 239 [[%token NUM OP
 240 %left OP
 241 %%
 242 exp: exp OP exp | NUM;
 243 ]])
 244
 245 AT_CHECK([bison -o input.c --report=all input.y])
 246
 247 # Check the contents of the report.
 248 AT_CHECK([cat input.output], [],
 249 [[Grammar
 250
 251     0 $accept: exp $end
 252
 253     1 exp: exp OP exp
 254     2    | NUM
 255
 256
 257 Terminals, with rules where they appear
 258
 259 $end (0) 0
 260 error (256)
 261 NUM (258) 2
 262 OP (259) 1
 263
 264
 265 Nonterminals, with rules where they appear
 266
 267 $accept (5)
 268     on left: 0
 269 exp (6)
 270     on left: 1 2, on right: 0 1
 271
 272
 273 state 0
 274
 275     0 $accept: . exp $end
 276     1 exp: . exp OP exp
 277     2    | . NUM
 278
 279     NUM  shift, and go to state 1
 280
 281     exp  go to state 2
 282
 283
 284 state 1
 285
 286     2 exp: NUM .
 287
 288     $default  reduce using rule 2 (exp)
 289
 290
 291 state 2
 292
 293     0 $accept: exp . $end
 294     1 exp: exp . OP exp
 295
 296     $end  shift, and go to state 3
 297     OP    shift, and go to state 4
 298
 299
 300 state 3
 301
 302     0 $accept: exp $end .
 303
 304     $default  accept
 305
 306
 307 state 4
 308
 309     1 exp: . exp OP exp
 310     1    | exp OP . exp
 311     2    | . NUM
 312
 313     NUM  shift, and go to state 1
 314
 315     exp  go to state 5
 316
 317
 318 state 5
 319
 320     1 exp: exp . OP exp  [$end, OP]
 321     1    | exp OP exp .  [$end, OP]
 322
 323     $default  reduce using rule 1 (exp)
 324
 325     Conflict between rule 1 and token OP resolved as reduce (%left OP).
 326 ]])
 327
 328 AT_CLEANUP
 329
 330
 331 ## -------------------------------- ##
 332 ## Defaulted Conflicted Reduction.  ##
 333 ## -------------------------------- ##
 334
 335 # When there are RR conflicts, some rules are disabled.  Usually it is
 336 # simply displayed as:
 337 #
 338 #    $end           reduce using rule 3 (num)
 339 #    $end           [reduce using rule 4 (id)]
 340 #
 341 # But when `reduce 3' is the default action, we'd produce:
 342 #
 343 #    $end           [reduce using rule 4 (id)]
 344 #    $default    reduce using rule 3 (num)
 345 #
 346 # In this precise case (a reduction is masked by the default
 347 # reduction), we make the `reduce 3' explicit:
 348 #
 349 #    $end           reduce using rule 3 (num)
 350 #    $end           [reduce using rule 4 (id)]
 351 #    $default    reduce using rule 3 (num)
 352 #
 353 # Maybe that's not the best display, but then, please propose something
 354 # else.
 355
 356 AT_SETUP([Defaulted Conflicted Reduction])
 357 AT_KEYWORDS([report])
 358
 359 AT_DATA([input.y],
 360 [[%%
 361 exp: num | id;
 362 num: '0';
 363 id : '0';
 364 %%
 365 ]])
 366
 367 AT_CHECK([bison -o input.c --report=all input.y], 0, [],
 368 [[input.y: conflicts: 1 reduce/reduce
 369 input.y:4.6-8: warning: rule never reduced because of conflicts: id: '0'
 370 ]])
 371
 372 # Check the contents of the report.
 373 AT_CHECK([cat input.output], [],
 374 [[Rules never reduced
 375
 376     4 id: '0'
 377
 378
 379 State 1 conflicts: 1 reduce/reduce
 380
 381
 382 Grammar
 383
 384     0 $accept: exp $end
 385
 386     1 exp: num
 387     2    | id
 388
 389     3 num: '0'
 390
 391     4 id: '0'
 392
 393
 394 Terminals, with rules where they appear
 395
 396 $end (0) 0
 397 '0' (48) 3 4
 398 error (256)
 399
 400
 401 Nonterminals, with rules where they appear
 402
 403 $accept (4)
 404     on left: 0
 405 exp (5)
 406     on left: 1 2, on right: 0
 407 num (6)
 408     on left: 3, on right: 1
 409 id (7)
 410     on left: 4, on right: 2
 411
 412
 413 state 0
 414
 415     0 $accept: . exp $end
 416     1 exp: . num
 417     2    | . id
 418     3 num: . '0'
 419     4 id: . '0'
 420
 421     '0'  shift, and go to state 1
 422
 423     exp  go to state 2
 424     num  go to state 3
 425     id   go to state 4
 426
 427
 428 state 1
 429
 430     3 num: '0' .  [$end]
 431     4 id: '0' .  [$end]
 432
 433     $end      reduce using rule 3 (num)
 434     $end      [reduce using rule 4 (id)]
 435     $default  reduce using rule 3 (num)
 436
 437
 438 state 2
 439
 440     0 $accept: exp . $end
 441
 442     $end  shift, and go to state 5
 443
 444
 445 state 3
 446
 447     1 exp: num .
 448
 449     $default  reduce using rule 1 (exp)
 450
 451
 452 state 4
 453
 454     2 exp: id .
 455
 456     $default  reduce using rule 2 (exp)
 457
 458
 459 state 5
 460
 461     0 $accept: exp $end .
 462
 463     $default  accept
 464 ]])
 465
 466 AT_CLEANUP
 467
 468
 469
 470
 471 ## -------------------- ##
 472 ## %expect not enough.  ##
 473 ## -------------------- ##
 474
 475 AT_SETUP([%expect not enough])
 476
 477 AT_DATA([input.y],
 478 [[%token NUM OP
 479 %expect 0
 480 %%
 481 exp: exp OP exp | NUM;
 482 ]])
 483
 484 AT_CHECK([bison -o input.c input.y], 1, [],
 485 [input.y: conflicts: 1 shift/reduce
 486 input.y: expected 0 shift/reduce conflicts
 487 ])
 488 AT_CLEANUP
 489
 490
 491 ## --------------- ##
 492 ## %expect right.  ##
 493 ## --------------- ##
 494
 495 AT_SETUP([%expect right])
 496
 497 AT_DATA([input.y],
 498 [[%token NUM OP
 499 %expect 1
 500 %%
 501 exp: exp OP exp | NUM;
 502 ]])
 503
 504 AT_CHECK([bison -o input.c input.y])
 505 AT_CLEANUP
 506
 507
 508 ## ------------------ ##
 509 ## %expect too much.  ##
 510 ## ------------------ ##
 511
 512 AT_SETUP([%expect too much])
 513
 514 AT_DATA([input.y],
 515 [[%token NUM OP
 516 %expect 2
 517 %%
 518 exp: exp OP exp | NUM;
 519 ]])
 520
 521 AT_CHECK([bison -o input.c input.y], 1, [],
 522 [input.y: conflicts: 1 shift/reduce
 523 input.y: expected 2 shift/reduce conflicts
 524 ])
 525 AT_CLEANUP
 526
 527
 528 ## ------------------------------ ##
 529 ## %expect with reduce conflicts  ##
 530 ## ------------------------------ ##
 531
 532 AT_SETUP([%expect with reduce conflicts])
 533
 534 AT_DATA([input.y],
 535 [[%expect 0
 536 %%
 537 program: a 'a' | a a;
 538 a: 'a';
 539 ]])
 540
 541 AT_CHECK([bison -o input.c input.y], 1, [],
 542 [input.y: conflicts: 1 reduce/reduce
 543 input.y: expected 0 reduce/reduce conflicts
 544 ])
 545 AT_CLEANUP
 546
 547
 548 ## ------------------------------- ##
 549 ## %no-default-prec without %prec  ##
 550 ## ------------------------------- ##
 551
 552 AT_SETUP([%no-default-prec without %prec])
 553
 554 AT_DATA([[input.y]],
 555 [[%left '+'
 556 %left '*'
 557
 558 %%
 559
 560 %no-default-prec;
 561
 562 e:   e '+' e
 563    | e '*' e
 564    | '0'
 565    ;
 566 ]])
 567
 568 AT_CHECK([bison -o input.c input.y], 0, [],
 569 [[input.y: conflicts: 4 shift/reduce
 570 ]])
 571 AT_CLEANUP
 572
 573
 574 ## ---------------------------- ##
 575 ## %no-default-prec with %prec  ##
 576 ## ---------------------------- ##
 577
 578 AT_SETUP([%no-default-prec with %prec])
 579
 580 AT_DATA([[input.y]],
 581 [[%left '+'
 582 %left '*'
 583
 584 %%
 585
 586 %no-default-prec;
 587
 588 e:   e '+' e %prec '+'
 589    | e '*' e %prec '*'
 590    | '0'
 591    ;
 592 ]])
 593
 594 AT_CHECK([bison -o input.c input.y])
 595 AT_CLEANUP
 596
 597
 598 ## ---------------- ##
 599 ## %default-prec    ##
 600 ## ---------------- ##
 601
 602 AT_SETUP([%default-prec])
 603
 604 AT_DATA([[input.y]],
 605 [[%left '+'
 606 %left '*'
 607
 608 %%
 609
 610 %default-prec;
 611
 612 e:   e '+' e
 613    | e '*' e
 614    | '0'
 615    ;
 616 ]])
 617
 618 AT_CHECK([bison -o input.c input.y])
 619 AT_CLEANUP