tests/conflicts.at

   1 # Exercising Bison on conflicts.                         -*- Autotest -*-
   2 # Copyright (C) 2002 Free Software Foundation, Inc.
   3
   4 # This program is free software; you can redistribute it and/or modify
   5 # it under the terms of the GNU General Public License as published by
   6 # the Free Software Foundation; either version 2, or (at your option)
   7 # any later version.
   8
   9 # This program is distributed in the hope that it will be useful,
  10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 # GNU General Public License for more details.
  13
  14 # You should have received a copy of the GNU General Public License
  15 # along with this program; if not, write to the Free Software
  16 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  17 # 02111-1307, USA.
  18
  19 AT_BANNER([[Conflicts.]])
  20
  21
  22 ## ---------------- ##
  23 ## S/R in initial.  ##
  24 ## ---------------- ##
  25
  26 # I once hacked Bison in such a way that it lost its reductions on the
  27 # initial state (because it was confusing it with the last state).  It
  28 # took me a while to strip down my failures to this simple case.  So
  29 # make sure it finds the s/r conflict below.
  30
  31 AT_SETUP([S/R in initial])
  32
  33 AT_DATA([[input.y]],
  34 [[%expect 1
  35 %%
  36 exp: e 'e';
  37 e: 'e' | /* Nothing. */;
  38 ]])
  39
  40 AT_CHECK([bison input.y -o input.c])
  41
  42 AT_CLEANUP
  43
  44
  45 ## ------------------- ##
  46 ## %nonassoc and eof.  ##
  47 ## ------------------- ##
  48
  49 AT_SETUP([%nonassoc and eof])
  50
  51 AT_DATA([input.y],
  52 [[
  53 %{
  54 #include <config.h>
  55 /* We don't need a perfect malloc for these tests. */
  56 #undef malloc
  57 #include <stdio.h>
  58
  59 #if STDC_HEADERS
  60 # include <stdlib.h>
  61 #endif
  62
  63 #define YYERROR_VERBOSE 1
  64 static void
  65 yyerror (const char *msg)
  66 {
  67   fprintf (stderr, "%s\n", msg);
  68   exit (1);
  69 }
  70
  71 /* The current argument. */
  72 static const char *input = NULL;
  73
  74 static int
  75 yylex (void)
  76 {
  77   /* No token stands for end of file. */
  78   if (input && *input)
  79     return *input++;
  80   else
  81     return 0;
  82 }
  83
  84 %}
  85
  86 %nonassoc '<' '>'
  87
  88 %%
  89 expr: expr '<' expr
  90     | expr '>' expr
  91     | '0'
  92     ;
  93 %%
  94 int
  95 main (int argc, const char *argv[])
  96 {
  97   if (argc > 1)
  98     input = argv[1];
  99   return yyparse ();
 100 }
 101 ]])
 102
 103 # Specify the output files to avoid problems on different file systems.
 104 AT_CHECK([bison input.y -o input.c])
 105 AT_COMPILE([input])
 106
 107 AT_PARSER_CHECK([./input '0<0'])
 108 # FIXME: This is an actual bug, but a new one, in the sense that
 109 # no one has ever spotted it!  The messages are *wrong*: there should
 110 # be nothing there, it should be expected eof.
 111 AT_PARSER_CHECK([./input '0<0<0'], [1], [],
 112          [parse error, unexpected '<', expecting '<' or '>'
 113 ])
 114
 115 AT_PARSER_CHECK([./input '0>0'])
 116 AT_PARSER_CHECK([./input '0>0>0'], [1], [],
 117          [parse error, unexpected '>', expecting '<' or '>'
 118 ])
 119
 120 AT_PARSER_CHECK([./input '0<0>0'], [1], [],
 121          [parse error, unexpected '>', expecting '<' or '>'
 122 ])
 123
 124 AT_CLEANUP
 125
 126
 127
 128 ## ------------------------- ##
 129 ## Unresolved SR Conflicts.  ##
 130 ## ------------------------- ##
 131
 132 AT_SETUP([Unresolved SR Conflicts])
 133
 134 AT_KEYWORDS([report])
 135
 136 AT_DATA([input.y],
 137 [[%token NUM OP
 138 %%
 139 exp: exp OP exp | NUM;
 140 ]])
 141
 142 AT_CHECK([bison input.y -o input.c --report=all], 0, [],
 143 [input.y contains 1 shift/reduce conflict.
 144 ])
 145
 146 # Check the contents of the report.
 147 AT_CHECK([cat input.output], [],
 148 [[State 5 contains 1 shift/reduce conflict.
 149
 150
 151 Grammar
 152
 153     0 $accept: exp $end
 154
 155     1 exp: exp OP exp
 156     2    | NUM
 157
 158
 159 Terminals, with rules where they appear
 160
 161 $end (0) 0
 162 error (256)
 163 NUM (258) 2
 164 OP (259) 1
 165
 166
 167 Nonterminals, with rules where they appear
 168
 169 $accept (5)
 170     on left: 0
 171 exp (6)
 172     on left: 1 2, on right: 0 1
 173
 174
 175 state 0
 176
 177     0 $accept: . exp $end
 178     1 exp: . exp OP exp
 179     2    | . NUM
 180
 181     NUM  shift, and go to state 1
 182
 183     exp  go to state 2
 184
 185
 186 state 1
 187
 188     2 exp: NUM .
 189
 190     $default  reduce using rule 2 (exp)
 191
 192
 193 state 2
 194
 195     0 $accept: exp . $end
 196     1 exp: exp . OP exp
 197
 198     $end  shift, and go to state 3
 199     OP    shift, and go to state 4
 200
 201
 202 state 3
 203
 204     0 $accept: exp $end .
 205
 206     $default    accept
 207
 208
 209 state 4
 210
 211     1 exp: . exp OP exp
 212     1    | exp OP . exp
 213     2    | . NUM
 214
 215     NUM  shift, and go to state 1
 216
 217     exp  go to state 5
 218
 219
 220 state 5
 221
 222     1 exp: exp . OP exp  [$end, OP]
 223     1    | exp OP exp .  [$end, OP]
 224
 225     OP  shift, and go to state 4
 226
 227     OP        [reduce using rule 1 (exp)]
 228     $default  reduce using rule 1 (exp)
 229 ]])
 230
 231 AT_CLEANUP
 232
 233
 234
 235 ## ----------------------- ##
 236 ## Resolved SR Conflicts.  ##
 237 ## ----------------------- ##
 238
 239 AT_SETUP([Resolved SR Conflicts])
 240
 241 AT_KEYWORDS([report])
 242
 243 AT_DATA([input.y],
 244 [[%token NUM OP
 245 %left OP
 246 %%
 247 exp: exp OP exp | NUM;
 248 ]])
 249
 250 AT_CHECK([bison input.y -o input.c --report=all])
 251
 252 # Check the contents of the report.
 253 AT_CHECK([cat input.output], [],
 254 [[Grammar
 255
 256     0 $accept: exp $end
 257
 258     1 exp: exp OP exp
 259     2    | NUM
 260
 261
 262 Terminals, with rules where they appear
 263
 264 $end (0) 0
 265 error (256)
 266 NUM (258) 2
 267 OP (259) 1
 268
 269
 270 Nonterminals, with rules where they appear
 271
 272 $accept (5)
 273     on left: 0
 274 exp (6)
 275     on left: 1 2, on right: 0 1
 276
 277
 278 state 0
 279
 280     0 $accept: . exp $end
 281     1 exp: . exp OP exp
 282     2    | . NUM
 283
 284     NUM  shift, and go to state 1
 285
 286     exp  go to state 2
 287
 288
 289 state 1
 290
 291     2 exp: NUM .
 292
 293     $default  reduce using rule 2 (exp)
 294
 295
 296 state 2
 297
 298     0 $accept: exp . $end
 299     1 exp: exp . OP exp
 300
 301     $end  shift, and go to state 3
 302     OP    shift, and go to state 4
 303
 304
 305 state 3
 306
 307     0 $accept: exp $end .
 308
 309     $default    accept
 310
 311
 312 state 4
 313
 314     1 exp: . exp OP exp
 315     1    | exp OP . exp
 316     2    | . NUM
 317
 318     NUM  shift, and go to state 1
 319
 320     exp  go to state 5
 321
 322
 323 state 5
 324
 325     1 exp: exp . OP exp  [$end, OP]
 326     1    | exp OP exp .  [$end, OP]
 327
 328     $default  reduce using rule 1 (exp)
 329     Conflict between rule 1 and token OP resolved as reduce (%left OP).
 330 ]])
 331
 332 AT_CLEANUP
 333
 334
 335 ## -------------------------------- ##
 336 ## Defaulted Conflicted Reduction.  ##
 337 ## -------------------------------- ##
 338
 339 # When there are RR conflicts, some rules are disabled.  Usually it is
 340 # simply displayed as:
 341 #
 342 #    $end           reduce using rule 3 (num)
 343 #    $end           [reduce using rule 4 (id)]
 344 #
 345 # But when `reduce 3' is the default action, we'd produce:
 346 #
 347 #    $end           [reduce using rule 4 (id)]
 348 #    $default    reduce using rule 3 (num)
 349 #
 350 # In this precise case (a reduction is masked by the default
 351 # reduction), we make the `reduce 3' explicit:
 352 #
 353 #    $end           reduce using rule 3 (num)
 354 #    $end           [reduce using rule 4 (id)]
 355 #    $default    reduce using rule 3 (num)
 356 #
 357 # Maybe that's not the best display, but then, please propose something
 358 # else.
 359
 360 AT_SETUP([Defaulted Conflicted Reduction])
 361 AT_KEYWORDS([report])
 362
 363 AT_DATA([input.y],
 364 [[%%
 365 exp: num | id;
 366 num: '0';
 367 id : '0';
 368 %%
 369 ]])
 370
 371 AT_CHECK([bison input.y -o input.c --report=all], 0, [],
 372 [input.y contains 1 reduce/reduce conflict.
 373 ])
 374
 375 # Check the contents of the report.
 376 AT_CHECK([cat input.output], [],
 377 [[State 1 contains 1 reduce/reduce conflict.
 378
 379
 380 Grammar
 381
 382     0 $accept: exp $end
 383
 384     1 exp: num
 385     2    | id
 386
 387     3 num: '0'
 388
 389     4 id: '0'
 390
 391
 392 Terminals, with rules where they appear
 393
 394 $end (0) 0
 395 '0' (48) 3 4
 396 error (256)
 397
 398
 399 Nonterminals, with rules where they appear
 400
 401 $accept (4)
 402     on left: 0
 403 exp (5)
 404     on left: 1 2, on right: 0
 405 num (6)
 406     on left: 3, on right: 1
 407 id (7)
 408     on left: 4, on right: 2
 409
 410
 411 state 0
 412
 413     0 $accept: . exp $end
 414     1 exp: . num
 415     2    | . id
 416     3 num: . '0'
 417     4 id: . '0'
 418
 419     '0'  shift, and go to state 1
 420
 421     exp  go to state 2
 422     num  go to state 3
 423     id   go to state 4
 424
 425
 426 state 1
 427
 428     3 num: '0' .  [$end]
 429     4 id: '0' .  [$end]
 430
 431     $end      reduce using rule 3 (num)
 432     $end      [reduce using rule 4 (id)]
 433     $default  reduce using rule 3 (num)
 434
 435
 436 state 2
 437
 438     0 $accept: exp . $end
 439
 440     $end  shift, and go to state 5
 441
 442
 443 state 3
 444
 445     1 exp: num .
 446
 447     $default  reduce using rule 1 (exp)
 448
 449
 450 state 4
 451
 452     2 exp: id .
 453
 454     $default  reduce using rule 2 (exp)
 455
 456
 457 state 5
 458
 459     0 $accept: exp $end .
 460
 461     $default    accept
 462 ]])
 463
 464 AT_CLEANUP
 465
 466
 467
 468
 469 ## -------------------- ##
 470 ## %expect not enough.  ##
 471 ## -------------------- ##
 472
 473 AT_SETUP([%expect not enough])
 474
 475 AT_DATA([input.y],
 476 [[%token NUM OP
 477 %expect 0
 478 %%
 479 exp: exp OP exp | NUM;
 480 ]])
 481
 482 AT_CHECK([bison input.y -o input.c], 1, [],
 483 [input.y contains 1 shift/reduce conflict.
 484 expected 0 shift/reduce conflicts
 485 ])
 486 AT_CLEANUP
 487
 488
 489 ## --------------- ##
 490 ## %expect right.  ##
 491 ## --------------- ##
 492
 493 AT_SETUP([%expect right])
 494
 495 AT_DATA([input.y],
 496 [[%token NUM OP
 497 %expect 1
 498 %%
 499 exp: exp OP exp | NUM;
 500 ]])
 501
 502 AT_CHECK([bison input.y -o input.c])
 503 AT_CLEANUP
 504
 505
 506 ## ------------------ ##
 507 ## %expect too much.  ##
 508 ## ------------------ ##
 509
 510 AT_SETUP([%expect too much])
 511
 512 AT_DATA([input.y],
 513 [[%token NUM OP
 514 %expect 2
 515 %%
 516 exp: exp OP exp | NUM;
 517 ]])
 518
 519 AT_CHECK([bison input.y -o input.c], 1, [],
 520 [input.y contains 1 shift/reduce conflict.
 521 expected 2 shift/reduce conflicts
 522 ])
 523 AT_CLEANUP