tests/conflicts.at

   1 # Exercising Bison on conflicts.                         -*- Autotest -*-
   2
   3 # Copyright (C) 2002, 2003, 2004, 2005, 2007 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
 620
 621
 622 ## ---------------------------------------------- ##
 623 ## Unreachable States After Conflict Resolution.  ##
 624 ## ---------------------------------------------- ##
 625
 626 AT_SETUP([[Unreachable States After Conflict Resolution]])
 627
 628 # If conflict resolution makes states unreachable, remove those states, report
 629 # rules that are then unused, and don't report conflicts in those states.  Test
 630 # what happens when a nonterminal becomes useless as a result of state removal
 631 # since that causes lalr.o's goto map to be rewritten.
 632
 633 AT_DATA([[input.y]],
 634 [[%output "input.c"
 635 %left 'a'
 636
 637 %%
 638
 639 start: resolved_conflict 'a' reported_conflicts 'a' ;
 640
 641 /* S/R conflict resolved as shift, so the state with item
 642  * (resolved_conflict: 'a' . unreachable1) and all it transition successors are
 643  * unreachable, and the associated production is useless.  */
 644 resolved_conflict:
 645     'a' unreachable1
 646   | %prec 'a'
 647   ;
 648
 649 /* S/R conflict that need not be reported since it is unreachable because of
 650  * the previous conflict resolution.  Nonterminal unreachable1 and all its
 651  * productions are useless.  */
 652 unreachable1:
 653     'a' unreachable2
 654   |
 655   ;
 656
 657 /* Likewise for a R/R conflict and nonterminal unreachable2.  */
 658 unreachable2: | ;
 659
 660 /* Make sure remaining S/R and R/R conflicts are still reported correctly even
 661  * when their states are renumbered due to state removal.  */
 662 reported_conflicts:
 663     'a'
 664   | 'a'
 665   |
 666   ;
 667
 668 ]])
 669
 670 AT_CHECK([[bison --report=all input.y]], 0, [],
 671 [[input.y: conflicts: 1 shift/reduce, 1 reduce/reduce
 672 input.y:12.5-20: warning: rule never reduced because of conflicts: resolved_conflict: 'a' unreachable1
 673 input.y:20.5-20: warning: rule never reduced because of conflicts: unreachable1: 'a' unreachable2
 674 input.y:21.4: warning: rule never reduced because of conflicts: unreachable1: /* empty */
 675 input.y:25.13: warning: rule never reduced because of conflicts: unreachable2: /* empty */
 676 input.y:25.16: warning: rule never reduced because of conflicts: unreachable2: /* empty */
 677 input.y:31.5-7: warning: rule never reduced because of conflicts: reported_conflicts: 'a'
 678 input.y:32.4: warning: rule never reduced because of conflicts: reported_conflicts: /* empty */
 679 ]])
 680
 681 AT_CHECK([[cat input.output]], 0,
 682 [[Rules never reduced
 683
 684     2 resolved_conflict: 'a' unreachable1
 685
 686     4 unreachable1: 'a' unreachable2
 687     5             | /* empty */
 688
 689     6 unreachable2: /* empty */
 690     7             | /* empty */
 691
 692     9 reported_conflicts: 'a'
 693    10                   | /* empty */
 694
 695
 696 State 4 conflicts: 1 shift/reduce
 697 State 5 conflicts: 1 reduce/reduce
 698
 699
 700 Grammar
 701
 702     0 $accept: start $end
 703
 704     1 start: resolved_conflict 'a' reported_conflicts 'a'
 705
 706     2 resolved_conflict: 'a' unreachable1
 707     3                  | /* empty */
 708
 709     4 unreachable1: 'a' unreachable2
 710     5             | /* empty */
 711
 712     6 unreachable2: /* empty */
 713     7             | /* empty */
 714
 715     8 reported_conflicts: 'a'
 716     9                   | 'a'
 717    10                   | /* empty */
 718
 719
 720 Terminals, with rules where they appear
 721
 722 $end (0) 0
 723 'a' (97) 1 2 4 8 9
 724 error (256)
 725
 726
 727 Nonterminals, with rules where they appear
 728
 729 $accept (4)
 730     on left: 0
 731 start (5)
 732     on left: 1, on right: 0
 733 resolved_conflict (6)
 734     on left: 2 3, on right: 1
 735 unreachable1 (7)
 736     on left: 4 5, on right: 2
 737 unreachable2 (8)
 738     on left: 6 7, on right: 4
 739 reported_conflicts (9)
 740     on left: 8 9 10, on right: 1
 741
 742
 743 state 0
 744
 745     0 $accept: . start $end
 746     1 start: . resolved_conflict 'a' reported_conflicts 'a'
 747     2 resolved_conflict: . 'a' unreachable1
 748     3                  | .  ['a']
 749
 750     $default  reduce using rule 3 (resolved_conflict)
 751
 752     start              go to state 1
 753     resolved_conflict  go to state 2
 754
 755     Conflict between rule 3 and token 'a' resolved as reduce (%left 'a').
 756
 757
 758 state 1
 759
 760     0 $accept: start . $end
 761
 762     $end  shift, and go to state 3
 763
 764
 765 state 2
 766
 767     1 start: resolved_conflict . 'a' reported_conflicts 'a'
 768
 769     'a'  shift, and go to state 4
 770
 771
 772 state 3
 773
 774     0 $accept: start $end .
 775
 776     $default  accept
 777
 778
 779 state 4
 780
 781     1 start: resolved_conflict 'a' . reported_conflicts 'a'
 782     8 reported_conflicts: . 'a'
 783     9                   | . 'a'
 784    10                   | .  ['a']
 785
 786     'a'  shift, and go to state 5
 787
 788     'a'  [reduce using rule 10 (reported_conflicts)]
 789
 790     reported_conflicts  go to state 6
 791
 792
 793 state 5
 794
 795     8 reported_conflicts: 'a' .  ['a']
 796     9                   | 'a' .  ['a']
 797
 798     'a'       reduce using rule 8 (reported_conflicts)
 799     'a'       [reduce using rule 9 (reported_conflicts)]
 800     $default  reduce using rule 8 (reported_conflicts)
 801
 802
 803 state 6
 804
 805     1 start: resolved_conflict 'a' reported_conflicts . 'a'
 806
 807     'a'  shift, and go to state 7
 808
 809
 810 state 7
 811
 812     1 start: resolved_conflict 'a' reported_conflicts 'a' .
 813
 814     $default  reduce using rule 1 (start)
 815 ]])
 816
 817 AT_CLEANUP
 818
 819
 820 ## ------------------------------------------------------------ ##
 821 ## Solved conflicts report for multiple reductions in a state.  ##
 822 ## ------------------------------------------------------------ ##
 823
 824 AT_SETUP([[Solved conflicts report for multiple reductions in a state]])
 825
 826 # Used to lose earlier solved conflict messages even within a single S/R/R.
 827
 828 AT_DATA([[input.y]],
 829 [[%left 'a'
 830 %right 'b'
 831 %right 'c'
 832 %right 'd'
 833 %%
 834 start:
 835     'a'
 836   | empty_a 'a'
 837   | 'b'
 838   | empty_b 'b'
 839   | 'c'
 840   | empty_c1 'c'
 841   | empty_c2 'c'
 842   | empty_c3 'c'
 843   ;
 844 empty_a: %prec 'a' ;
 845 empty_b: %prec 'b' ;
 846 empty_c1: %prec 'c' ;
 847 empty_c2: %prec 'c' ;
 848 empty_c3: %prec 'd' ;
 849 ]])
 850 AT_CHECK([[bison --report=all -o input.c input.y]], 0, [], [ignore])
 851 AT_CHECK([[cat input.output | sed -n '/^state 0$/,/^state 1$/p']], 0,
 852 [[state 0
 853
 854     0 $accept: . start $end
 855     1 start: . 'a'
 856     2      | . empty_a 'a'
 857     3      | . 'b'
 858     4      | . empty_b 'b'
 859     5      | . 'c'
 860     6      | . empty_c1 'c'
 861     7      | . empty_c2 'c'
 862     8      | . empty_c3 'c'
 863     9 empty_a: .  ['a']
 864    10 empty_b: .  []
 865    11 empty_c1: .  []
 866    12 empty_c2: .  []
 867    13 empty_c3: .  ['c']
 868
 869     'b'  shift, and go to state 1
 870
 871     'c'       reduce using rule 13 (empty_c3)
 872     $default  reduce using rule 9 (empty_a)
 873
 874     start     go to state 2
 875     empty_a   go to state 3
 876     empty_b   go to state 4
 877     empty_c1  go to state 5
 878     empty_c2  go to state 6
 879     empty_c3  go to state 7
 880
 881     Conflict between rule 9 and token 'a' resolved as reduce (%left 'a').
 882     Conflict between rule 10 and token 'b' resolved as shift (%right 'b').
 883     Conflict between rule 11 and token 'c' resolved as shift (%right 'c').
 884     Conflict between rule 12 and token 'c' resolved as shift (%right 'c').
 885     Conflict between rule 13 and token 'c' resolved as reduce ('c' < 'd').
 886
 887
 888 state 1
 889 ]])
 890
 891 AT_CLEANUP
 892
 893
 894 ## ------------------------------------------------------------ ##
 895 ## %nonassoc error actions for multiple reductions in a state.  ##
 896 ## ------------------------------------------------------------ ##
 897
 898 # Used to abort when trying to resolve conflicts as %nonassoc error actions for
 899 # multiple reductions in a state.
 900
 901 # For a %nonassoc error action token, used to print the first remaining
 902 # reduction on that token without brackets.
 903
 904 AT_SETUP([[%nonassoc error actions for multiple reductions in a state]])
 905
 906 AT_DATA([[input.y]],
 907 [[%nonassoc 'a' 'b' 'c'
 908 %%
 909 start:
 910     'a'
 911   | empty_a 'a'
 912   | 'b'
 913   | empty_b 'b'
 914   | 'c'
 915   | empty_c1 'c'
 916   | empty_c2 'c'
 917   | empty_c3 'c'
 918   ;
 919 empty_a: %prec 'a' ;
 920 empty_b: %prec 'b' ;
 921 empty_c1: %prec 'c' ;
 922 empty_c2: %prec 'c' ;
 923 empty_c3: %prec 'c' ;
 924 ]])
 925
 926 AT_CHECK([[bison --report=all -o input.c input.y]], 0, [], [ignore])
 927 AT_CHECK([[cat input.output | sed -n '/^state 0$/,/^state 1$/p']], 0,
 928 [[state 0
 929
 930     0 $accept: . start $end
 931     1 start: . 'a'
 932     2      | . empty_a 'a'
 933     3      | . 'b'
 934     4      | . empty_b 'b'
 935     5      | . 'c'
 936     6      | . empty_c1 'c'
 937     7      | . empty_c2 'c'
 938     8      | . empty_c3 'c'
 939     9 empty_a: .  []
 940    10 empty_b: .  []
 941    11 empty_c1: .  []
 942    12 empty_c2: .  ['c']
 943    13 empty_c3: .  ['c']
 944
 945     'a'  error (nonassociative)
 946     'b'  error (nonassociative)
 947     'c'  error (nonassociative)
 948
 949     'c'  [reduce using rule 12 (empty_c2)]
 950     'c'  [reduce using rule 13 (empty_c3)]
 951
 952     start     go to state 1
 953     empty_a   go to state 2
 954     empty_b   go to state 3
 955     empty_c1  go to state 4
 956     empty_c2  go to state 5
 957     empty_c3  go to state 6
 958
 959     Conflict between rule 9 and token 'a' resolved as an error (%nonassoc 'a').
 960     Conflict between rule 10 and token 'b' resolved as an error (%nonassoc 'b').
 961     Conflict between rule 11 and token 'c' resolved as an error (%nonassoc 'c').
 962
 963
 964 state 1
 965 ]])
 966 AT_CLEANUP