tests/conflicts.at

   1 # Exercising Bison on conflicts.                         -*- Autotest -*-
   2
   3 # Copyright (C) 2002-2005, 2007, 2009-2012 Free Software Foundation,
   4 # Inc.
   5
   6 # This program is free software: you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation, either version 3 of the License, or
   9 # (at your option) any later version.
  10 #
  11 # This program is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 # GNU General Public License for more details.
  15 #
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  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_BISON_CHECK([-o input.c input.y], 0, [],
  41 [[input.y:4.9: warning: rule useless in parser due to conflicts: e: /* empty */
  42 ]])
  43
  44 AT_BISON_CHECK([-fcaret -o input.c input.y], 0, [],
  45 [[input.y:4.9: warning: rule useless in parser due to conflicts
  46  e: 'e' | /* Nothing. */;
  47          ^
  48 ]])
  49
  50 AT_CLEANUP
  51
  52
  53 ## ------------------- ##
  54 ## %nonassoc and eof.  ##
  55 ## ------------------- ##
  56
  57 AT_SETUP([%nonassoc and eof])
  58
  59 AT_BISON_OPTION_PUSHDEFS
  60 AT_DATA_GRAMMAR([input.y],
  61 [[
  62 %{
  63 #include <stdio.h>
  64 #include <stdlib.h>
  65 #include <string.h>
  66 #include <assert.h>
  67
  68 #define YYERROR_VERBOSE 1
  69 ]AT_YYERROR_DEFINE[
  70 /* The current argument. */
  71 static const char *input;
  72
  73 static int
  74 yylex (void)
  75 {
  76   static size_t toknum;
  77   assert (toknum <= strlen (input));
  78   return input[toknum++];
  79 }
  80
  81 %}
  82
  83 %nonassoc '<' '>'
  84
  85 %%
  86 expr: expr '<' expr
  87     | expr '>' expr
  88     | '0'
  89     ;
  90 %%
  91 int
  92 main (int argc, const char *argv[])
  93 {
  94   input = argc <= 1 ? "" : argv[1];
  95   return yyparse ();
  96 }
  97 ]])
  98 AT_BISON_OPTION_POPDEFS
  99
 100 m4_pushdef([AT_NONASSOC_AND_EOF_CHECK],
 101 [AT_BISON_CHECK([$1[ -o input.c input.y]])
 102 AT_COMPILE([input])
 103
 104 m4_pushdef([AT_EXPECTING], [m4_if($2, [correct], [[, expecting $end]])])
 105
 106 AT_PARSER_CHECK([./input '0<0'])
 107 AT_PARSER_CHECK([./input '0<0<0'], [1], [],
 108          [syntax error, unexpected '<'AT_EXPECTING
 109 ])
 110
 111 AT_PARSER_CHECK([./input '0>0'])
 112 AT_PARSER_CHECK([./input '0>0>0'], [1], [],
 113          [syntax error, unexpected '>'AT_EXPECTING
 114 ])
 115
 116 AT_PARSER_CHECK([./input '0<0>0'], [1], [],
 117          [syntax error, unexpected '>'AT_EXPECTING
 118 ])
 119
 120 m4_popdef([AT_EXPECTING])])
 121
 122 # Expected token list is missing.
 123 AT_NONASSOC_AND_EOF_CHECK([], [[incorrect]])
 124
 125 # We must disable default reductions in inconsistent states in order to
 126 # have an explicit list of all expected tokens.
 127 AT_NONASSOC_AND_EOF_CHECK([[-Dlr.default-reductions=consistent]],
 128                           [[correct]])
 129
 130 # lr.default-reductions=consistent happens to work for this test case.
 131 # However, for other grammars, lookahead sets can be merged for
 132 # different left contexts, so it is still possible to have an incorrect
 133 # expected list.  Canonical LR is almost a general solution (that is, it
 134 # can fail only when %nonassoc is used), so make sure it gives the same
 135 # result as above.
 136 AT_NONASSOC_AND_EOF_CHECK([[-Dlr.type=canonical-lr]], [[correct]])
 137
 138 # parse.lac=full is a completely general solution that does not require
 139 # any of the above sacrifices.  Of course, it does not extend the
 140 # language-recognition power of LALR to (IE)LR, but it does ensure that
 141 # the reported list of expected tokens matches what the given parser
 142 # would have accepted in place of the unexpected token.
 143 AT_NONASSOC_AND_EOF_CHECK([[-Dparse.lac=full]], [[correct]])
 144
 145 m4_popdef([AT_NONASSOC_AND_EOF_CHECK])
 146
 147 AT_CLEANUP
 148
 149
 150
 151 ## -------------------------------------- ##
 152 ## %error-verbose and consistent errors.  ##
 153 ## -------------------------------------- ##
 154
 155 AT_SETUP([[%error-verbose and consistent errors]])
 156
 157 m4_pushdef([AT_CONSISTENT_ERRORS_CHECK], [
 158
 159 AT_BISON_OPTION_PUSHDEFS([$1])
 160
 161 m4_pushdef([AT_YYLEX_PROTOTYPE],
 162 [AT_SKEL_CC_IF([[int yylex (yy::parser::semantic_type *lvalp)]],
 163                [[int yylex (YYSTYPE *lvalp)]])])
 164
 165 AT_SKEL_JAVA_IF([AT_DATA], [AT_DATA_GRAMMAR])([input.y],
 166 [AT_SKEL_JAVA_IF([[
 167
 168 %code imports {
 169   import java.io.IOException;
 170 }]], [[
 171
 172 %code {]AT_SKEL_CC_IF([[
 173   #include <cassert>
 174   #include <string>]], [[
 175   #include <assert.h>
 176   #include <stdio.h>
 177   ]AT_YYERROR_DECLARE])[
 178   ]AT_YYLEX_PROTOTYPE[;
 179   #define USE(Var)
 180 }
 181
 182 ]AT_SKEL_CC_IF([[%defines]], [[%define api.pure]])])[
 183
 184 ]$1[
 185
 186 %error-verbose
 187
 188 %%
 189
 190 ]$2[
 191
 192 ]AT_SKEL_JAVA_IF([[%code lexer {]], [[%%]])[
 193
 194 /*--------.
 195 | yylex.  |
 196 `--------*/]AT_SKEL_JAVA_IF([[
 197
 198 public String input = "]$3[";
 199 public int index = 0;
 200 public int yylex ()
 201 {
 202   if (index < input.length ())
 203     return input.charAt (index++);
 204   else
 205     return 0;
 206 }
 207 public Object getLVal ()
 208 {
 209   return new Integer(1);
 210 }]], [[
 211
 212 ]AT_YYLEX_PROTOTYPE[
 213 {
 214   static char const *input = "]$3[";
 215   *lvalp = 1;
 216   return *input++;
 217 }]])[
 218 ]AT_YYERROR_DEFINE[
 219 ]AT_SKEL_JAVA_IF([[
 220 };
 221
 222 %%]])[
 223
 224 /*-------.
 225 | main.  |
 226 `-------*/]AT_SKEL_JAVA_IF([[
 227
 228 class input
 229 {
 230   public static void main (String args[]) throws IOException
 231   {
 232     YYParser p = new YYParser ();
 233     p.parse ();
 234   }
 235 }]], [AT_SKEL_CC_IF([[
 236
 237 int
 238 main (void)
 239 {
 240   yy::parser parser;
 241   return parser.parse ();
 242 }]], [[
 243
 244 int
 245 main (void)
 246 {
 247   return yyparse ();
 248 }]])])[
 249 ]])
 250
 251 AT_FULL_COMPILE([[input]])
 252
 253 m4_pushdef([AT_EXPECTING], [m4_if($5, [ab], [[, expecting 'a' or 'b']],
 254                                   $5, [a],  [[, expecting 'a']],
 255                                   $5, [b],  [[, expecting 'b']])])
 256
 257 AT_SKEL_JAVA_IF([AT_JAVA_PARSER_CHECK([[input]], [[0]]],
 258                 [AT_PARSER_CHECK([[./input]], [[1]]]),
 259 [[]],
 260 [[syntax error, unexpected ]$4[]AT_EXPECTING[
 261 ]])
 262
 263 m4_popdef([AT_EXPECTING])
 264 m4_popdef([AT_YYLEX_PROTOTYPE])
 265 AT_BISON_OPTION_POPDEFS
 266
 267 ])
 268
 269 m4_pushdef([AT_PREVIOUS_STATE_GRAMMAR],
 270 [[%nonassoc 'a';
 271
 272 start: consistent-error-on-a-a 'a' ;
 273
 274 consistent-error-on-a-a:
 275     'a' default-reduction
 276   | 'a' default-reduction 'a'
 277   | 'a' shift
 278   ;
 279
 280 default-reduction: /*empty*/ ;
 281 shift: 'b' ;
 282
 283 // Provide another context in which all rules are useful so that this
 284 // test case looks a little more realistic.
 285 start: 'b' consistent-error-on-a-a 'c' ;
 286 ]])
 287
 288 m4_pushdef([AT_PREVIOUS_STATE_INPUT], [[a]])
 289
 290 # Unfortunately, no expected tokens are reported even though 'b' can be
 291 # accepted.  Nevertheless, the main point of this test is to make sure
 292 # that at least the unexpected token is reported.  In a previous version
 293 # of Bison, it wasn't reported because the error is detected in a
 294 # consistent state with an error action, and that case always triggered
 295 # the simple "syntax error" message.
 296 #
 297 # The point isn't to test IELR here, but state merging happens to
 298 # complicate this example.
 299 AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr]],
 300                            [AT_PREVIOUS_STATE_GRAMMAR],
 301                            [AT_PREVIOUS_STATE_INPUT],
 302                            [[$end]], [[none]])
 303 AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr
 304                              %glr-parser]],
 305                            [AT_PREVIOUS_STATE_GRAMMAR],
 306                            [AT_PREVIOUS_STATE_INPUT],
 307                            [[$end]], [[none]])
 308 AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr
 309                              %language "c++"]],
 310                            [AT_PREVIOUS_STATE_GRAMMAR],
 311                            [AT_PREVIOUS_STATE_INPUT],
 312                            [[$end]], [[none]])
 313 AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr
 314                              %language "java"]],
 315                            [AT_PREVIOUS_STATE_GRAMMAR],
 316                            [AT_PREVIOUS_STATE_INPUT],
 317                            [[end of input]], [[none]])
 318
 319 # Even canonical LR doesn't foresee the error for 'a'!
 320 AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr
 321                              %define lr.default-reductions consistent]],
 322                            [AT_PREVIOUS_STATE_GRAMMAR],
 323                            [AT_PREVIOUS_STATE_INPUT],
 324                            [[$end]], [[ab]])
 325 AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr
 326                              %define lr.default-reductions accepting]],
 327                            [AT_PREVIOUS_STATE_GRAMMAR],
 328                            [AT_PREVIOUS_STATE_INPUT],
 329                            [[$end]], [[ab]])
 330 AT_CONSISTENT_ERRORS_CHECK([[%define lr.type canonical-lr]],
 331                            [AT_PREVIOUS_STATE_GRAMMAR],
 332                            [AT_PREVIOUS_STATE_INPUT],
 333                            [[$end]], [[ab]])
 334
 335 # Only LAC gets it right.
 336 AT_CONSISTENT_ERRORS_CHECK([[%define lr.type canonical-lr
 337                              %define parse.lac full]],
 338                            [AT_PREVIOUS_STATE_GRAMMAR],
 339                            [AT_PREVIOUS_STATE_INPUT],
 340                            [[$end]], [[b]])
 341 AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr
 342                              %define parse.lac full]],
 343                            [AT_PREVIOUS_STATE_GRAMMAR],
 344                            [AT_PREVIOUS_STATE_INPUT],
 345                            [[$end]], [[b]])
 346
 347 m4_popdef([AT_PREVIOUS_STATE_GRAMMAR])
 348 m4_popdef([AT_PREVIOUS_STATE_INPUT])
 349
 350 m4_pushdef([AT_USER_ACTION_GRAMMAR],
 351 [[%nonassoc 'a';
 352
 353 // If $$ = 0 here, then we know that the 'a' destructor is being invoked
 354 // incorrectly for the 'b' set in the semantic action below.  All 'a'
 355 // tokens are returned by yylex, which sets $$ = 1.
 356 %destructor {
 357   if (!$$)
 358     fprintf (stderr, "Wrong destructor.\n");
 359 } 'a';
 360
 361 // Rather than depend on an inconsistent state to induce reading a
 362 // lookahead as in the previous grammar, just assign the lookahead in a
 363 // semantic action.  That lookahead isn't needed before either error
 364 // action is encountered.  In a previous version of Bison, this was a
 365 // problem as it meant yychar was not translated into yytoken before
 366 // either error action.  The second error action thus invoked a
 367 // destructor that it selected according to the incorrect yytoken.  The
 368 // first error action would have reported an incorrect unexpected token
 369 // except that, due to the bug described in the previous grammar, the
 370 // unexpected token was not reported at all.
 371 start: error-reduce consistent-error 'a' { USE ($][3); } ;
 372
 373 error-reduce:
 374   'a' 'a' consistent-reduction consistent-error 'a'
 375   { USE (($][1, $][2, $][5)); }
 376 | 'a' error
 377   { USE ($][1); }
 378 ;
 379
 380 consistent-reduction: /*empty*/ {
 381   assert (yychar == ]AT_SKEL_CC_IF([[yyempty_]], [[YYEMPTY]])[);
 382   yylval = 0;
 383   yychar = 'b';
 384 } ;
 385
 386 consistent-error:
 387   'a' { USE ($][1); }
 388 | /*empty*/ %prec 'a'
 389 ;
 390
 391 // Provide another context in which all rules are useful so that this
 392 // test case looks a little more realistic.
 393 start: 'b' consistent-error 'b' ;
 394 ]])
 395 m4_pushdef([AT_USER_ACTION_INPUT], [[aa]])
 396
 397 AT_CONSISTENT_ERRORS_CHECK([[]],
 398                            [AT_USER_ACTION_GRAMMAR],
 399                            [AT_USER_ACTION_INPUT],
 400                            [['b']], [[none]])
 401 AT_CONSISTENT_ERRORS_CHECK([[%glr-parser]],
 402                            [AT_USER_ACTION_GRAMMAR],
 403                            [AT_USER_ACTION_INPUT],
 404                            [['b']], [[none]])
 405 AT_CONSISTENT_ERRORS_CHECK([[%language "c++"]],
 406                            [AT_USER_ACTION_GRAMMAR],
 407                            [AT_USER_ACTION_INPUT],
 408                            [['b']], [[none]])
 409 # No Java test because yychar cannot be manipulated by users.
 410
 411 AT_CONSISTENT_ERRORS_CHECK([[%define lr.default-reductions consistent]],
 412                            [AT_USER_ACTION_GRAMMAR],
 413                            [AT_USER_ACTION_INPUT],
 414                            [['b']], [[none]])
 415
 416 # Canonical LR doesn't foresee the error for 'a'!
 417 AT_CONSISTENT_ERRORS_CHECK([[%define lr.default-reductions accepting]],
 418                            [AT_USER_ACTION_GRAMMAR],
 419                            [AT_USER_ACTION_INPUT],
 420                            [[$end]], [[a]])
 421 AT_CONSISTENT_ERRORS_CHECK([[%define lr.type canonical-lr]],
 422                            [AT_USER_ACTION_GRAMMAR],
 423                            [AT_USER_ACTION_INPUT],
 424                            [[$end]], [[a]])
 425
 426 AT_CONSISTENT_ERRORS_CHECK([[%define parse.lac full]],
 427                            [AT_USER_ACTION_GRAMMAR],
 428                            [AT_USER_ACTION_INPUT],
 429                            [['b']], [[none]])
 430 AT_CONSISTENT_ERRORS_CHECK([[%define parse.lac full
 431                              %define lr.default-reductions accepting]],
 432                            [AT_USER_ACTION_GRAMMAR],
 433                            [AT_USER_ACTION_INPUT],
 434                            [[$end]], [[none]])
 435
 436 m4_popdef([AT_USER_ACTION_GRAMMAR])
 437 m4_popdef([AT_USER_ACTION_INPUT])
 438
 439 m4_popdef([AT_CONSISTENT_ERRORS_CHECK])
 440
 441 AT_CLEANUP
 442
 443
 444
 445 ## ------------------------------------------------------- ##
 446 ## LAC: %nonassoc requires splitting canonical LR states.  ##
 447 ## ------------------------------------------------------- ##
 448
 449 # This test case demonstrates that, when %nonassoc is used, canonical
 450 # LR(1) parser table construction followed by conflict resolution
 451 # without further state splitting is not always sufficient to produce a
 452 # parser that can detect all syntax errors as soon as possible on one
 453 # token of lookahead.  However, LAC solves the problem completely even
 454 # with minimal LR parser tables.
 455
 456 AT_SETUP([[LAC: %nonassoc requires splitting canonical LR states]])
 457 AT_BISON_OPTION_PUSHDEFS
 458 AT_DATA_GRAMMAR([[input.y]],
 459 [[%code {
 460   #include <stdio.h>
 461   ]AT_YYERROR_DECLARE[
 462   ]AT_YYLEX_DECLARE[
 463 }
 464
 465 %error-verbose
 466 %nonassoc 'a'
 467
 468 %%
 469
 470 start:
 471   'a' problem 'a' // First context.
 472 | 'b' problem 'b' // Second context.
 473 | 'c' reduce-nonassoc // Just makes reduce-nonassoc useful.
 474 ;
 475
 476 problem:
 477   look reduce-nonassoc
 478 | look 'a'
 479 | look 'b'
 480 ;
 481
 482 // For the state reached after shifting the 'a' in these productions,
 483 // lookahead sets are the same in both the first and second contexts.
 484 // Thus, canonical LR reuses the same state for both contexts.  However,
 485 // the lookahead 'a' for the reduction "look: 'a'" later becomes an
 486 // error action only in the first context.  In order to immediately
 487 // detect the syntax error on 'a' here for only the first context, this
 488 // canonical LR state would have to be split into two states, and the
 489 // 'a' lookahead would have to be removed from only one of the states.
 490 look:
 491   'a' // Reduction lookahead set is always ['a', 'b'].
 492 | 'a' 'b'
 493 | 'a' 'c' // 'c' is forgotten as an expected token.
 494 ;
 495
 496 reduce-nonassoc: %prec 'a';
 497
 498 %%
 499 ]AT_YYERROR_DEFINE[
 500 ]AT_YYLEX_DEFINE(["aaa"])[
 501
 502 int
 503 main (void)
 504 {
 505   return yyparse ();
 506 }
 507 ]])
 508 AT_BISON_OPTION_POPDEFS
 509
 510 # Show canonical LR's failure.
 511 AT_BISON_CHECK([[-Dlr.type=canonical-lr -o input.c input.y]],
 512                [[0]], [[]],
 513 [[input.y: conflicts: 2 shift/reduce
 514 ]])
 515 AT_COMPILE([[input]])
 516 AT_PARSER_CHECK([[./input]], [[1]], [[]],
 517 [[syntax error, unexpected 'a', expecting 'b'
 518 ]])
 519
 520 # It's corrected by LAC.
 521 AT_BISON_CHECK([[-Dlr.type=canonical-lr -Dparse.lac=full \
 522                  -o input.c input.y]], [[0]], [[]],
 523 [[input.y: conflicts: 2 shift/reduce
 524 ]])
 525 AT_COMPILE([[input]])
 526 AT_PARSER_CHECK([[./input]], [[1]], [[]],
 527 [[syntax error, unexpected 'a', expecting 'b' or 'c'
 528 ]])
 529
 530 # IELR is sufficient when LAC is used.
 531 AT_BISON_CHECK([[-Dlr.type=ielr -Dparse.lac=full -o input.c input.y]],
 532                [[0]], [[]],
 533 [[input.y: conflicts: 2 shift/reduce
 534 ]])
 535 AT_COMPILE([[input]])
 536 AT_PARSER_CHECK([[./input]], [[1]], [[]],
 537 [[syntax error, unexpected 'a', expecting 'b' or 'c'
 538 ]])
 539
 540 AT_CLEANUP
 541
 542 ## ------------------------- ##
 543 ## Unresolved SR Conflicts.  ##
 544 ## ------------------------- ##
 545
 546 AT_SETUP([Unresolved SR Conflicts])
 547
 548 AT_KEYWORDS([report])
 549
 550 AT_DATA([input.y],
 551 [[%token NUM OP
 552 %%
 553 exp: exp OP exp | NUM;
 554 ]])
 555
 556 AT_BISON_CHECK([-o input.c --report=all input.y], 0, [],
 557 [input.y: conflicts: 1 shift/reduce
 558 ])
 559
 560 # Check the contents of the report.
 561 AT_CHECK([cat input.output], [],
 562 [[State 5 conflicts: 1 shift/reduce
 563
 564
 565 Grammar
 566
 567     0 $accept: exp $end
 568
 569     1 exp: exp OP exp
 570     2    | NUM
 571
 572
 573 Terminals, with rules where they appear
 574
 575 $end (0) 0
 576 error (256)
 577 NUM (258) 2
 578 OP (259) 1
 579
 580
 581 Nonterminals, with rules where they appear
 582
 583 $accept (5)
 584     on left: 0
 585 exp (6)
 586     on left: 1 2, on right: 0 1
 587
 588
 589 State 0
 590
 591     0 $accept: . exp $end
 592     1 exp: . exp OP exp
 593     2    | . NUM
 594
 595     NUM  shift, and go to state 1
 596
 597     exp  go to state 2
 598
 599
 600 State 1
 601
 602     2 exp: NUM .
 603
 604     $default  reduce using rule 2 (exp)
 605
 606
 607 State 2
 608
 609     0 $accept: exp . $end
 610     1 exp: exp . OP exp
 611
 612     $end  shift, and go to state 3
 613     OP    shift, and go to state 4
 614
 615
 616 State 3
 617
 618     0 $accept: exp $end .
 619
 620     $default  accept
 621
 622
 623 State 4
 624
 625     1 exp: . exp OP exp
 626     1    | exp OP . exp
 627     2    | . NUM
 628
 629     NUM  shift, and go to state 1
 630
 631     exp  go to state 5
 632
 633
 634 State 5
 635
 636     1 exp: exp . OP exp
 637     1    | exp OP exp .  [$end, OP]
 638
 639     OP  shift, and go to state 4
 640
 641     OP        [reduce using rule 1 (exp)]
 642     $default  reduce using rule 1 (exp)
 643 ]])
 644
 645 AT_CLEANUP
 646
 647
 648
 649 ## ----------------------- ##
 650 ## Resolved SR Conflicts.  ##
 651 ## ----------------------- ##
 652
 653 AT_SETUP([Resolved SR Conflicts])
 654
 655 AT_KEYWORDS([report])
 656
 657 AT_DATA([input.y],
 658 [[%token NUM OP
 659 %left OP
 660 %%
 661 exp: exp OP exp | NUM;
 662 ]])
 663
 664 AT_BISON_CHECK([-o input.c --report=all input.y])
 665
 666 # Check the contents of the report.
 667 AT_CHECK([cat input.output], [],
 668 [[Grammar
 669
 670     0 $accept: exp $end
 671
 672     1 exp: exp OP exp
 673     2    | NUM
 674
 675
 676 Terminals, with rules where they appear
 677
 678 $end (0) 0
 679 error (256)
 680 NUM (258) 2
 681 OP (259) 1
 682
 683
 684 Nonterminals, with rules where they appear
 685
 686 $accept (5)
 687     on left: 0
 688 exp (6)
 689     on left: 1 2, on right: 0 1
 690
 691
 692 State 0
 693
 694     0 $accept: . exp $end
 695     1 exp: . exp OP exp
 696     2    | . NUM
 697
 698     NUM  shift, and go to state 1
 699
 700     exp  go to state 2
 701
 702
 703 State 1
 704
 705     2 exp: NUM .
 706
 707     $default  reduce using rule 2 (exp)
 708
 709
 710 State 2
 711
 712     0 $accept: exp . $end
 713     1 exp: exp . OP exp
 714
 715     $end  shift, and go to state 3
 716     OP    shift, and go to state 4
 717
 718
 719 State 3
 720
 721     0 $accept: exp $end .
 722
 723     $default  accept
 724
 725
 726 State 4
 727
 728     1 exp: . exp OP exp
 729     1    | exp OP . exp
 730     2    | . NUM
 731
 732     NUM  shift, and go to state 1
 733
 734     exp  go to state 5
 735
 736
 737 State 5
 738
 739     1 exp: exp . OP exp
 740     1    | exp OP exp .  [$end, OP]
 741
 742     $default  reduce using rule 1 (exp)
 743
 744     Conflict between rule 1 and token OP resolved as reduce (%left OP).
 745 ]])
 746
 747 AT_CLEANUP
 748
 749
 750 ## -------------------------------- ##
 751 ## Defaulted Conflicted Reduction.  ##
 752 ## -------------------------------- ##
 753
 754 # When there are RR conflicts, some rules are disabled.  Usually it is
 755 # simply displayed as:
 756 #
 757 #    $end           reduce using rule 3 (num)
 758 #    $end           [reduce using rule 4 (id)]
 759 #
 760 # But when `reduce 3' is the default action, we'd produce:
 761 #
 762 #    $end           [reduce using rule 4 (id)]
 763 #    $default    reduce using rule 3 (num)
 764 #
 765 # In this precise case (a reduction is masked by the default
 766 # reduction), we make the `reduce 3' explicit:
 767 #
 768 #    $end           reduce using rule 3 (num)
 769 #    $end           [reduce using rule 4 (id)]
 770 #    $default    reduce using rule 3 (num)
 771 #
 772 # Maybe that's not the best display, but then, please propose something
 773 # else.
 774
 775 AT_SETUP([Defaulted Conflicted Reduction])
 776 AT_KEYWORDS([report])
 777
 778 AT_DATA([input.y],
 779 [[%%
 780 exp: num | id;
 781 num: '0';
 782 id : '0';
 783 %%
 784 ]])
 785
 786 AT_BISON_CHECK([-o input.c --report=all input.y], 0, [],
 787 [[input.y: conflicts: 1 reduce/reduce
 788 input.y:4.6-8: warning: rule useless in parser due to conflicts: id: '0'
 789 ]])
 790
 791 # Check the contents of the report.
 792 AT_CHECK([cat input.output], [],
 793 [[Rules useless in parser due to conflicts
 794
 795     4 id: '0'
 796
 797
 798 State 1 conflicts: 1 reduce/reduce
 799
 800
 801 Grammar
 802
 803     0 $accept: exp $end
 804
 805     1 exp: num
 806     2    | id
 807
 808     3 num: '0'
 809
 810     4 id: '0'
 811
 812
 813 Terminals, with rules where they appear
 814
 815 $end (0) 0
 816 '0' (48) 3 4
 817 error (256)
 818
 819
 820 Nonterminals, with rules where they appear
 821
 822 $accept (4)
 823     on left: 0
 824 exp (5)
 825     on left: 1 2, on right: 0
 826 num (6)
 827     on left: 3, on right: 1
 828 id (7)
 829     on left: 4, on right: 2
 830
 831
 832 State 0
 833
 834     0 $accept: . exp $end
 835     1 exp: . num
 836     2    | . id
 837     3 num: . '0'
 838     4 id: . '0'
 839
 840     '0'  shift, and go to state 1
 841
 842     exp  go to state 2
 843     num  go to state 3
 844     id   go to state 4
 845
 846
 847 State 1
 848
 849     3 num: '0' .  [$end]
 850     4 id: '0' .  [$end]
 851
 852     $end      reduce using rule 3 (num)
 853     $end      [reduce using rule 4 (id)]
 854     $default  reduce using rule 3 (num)
 855
 856
 857 State 2
 858
 859     0 $accept: exp . $end
 860
 861     $end  shift, and go to state 5
 862
 863
 864 State 3
 865
 866     1 exp: num .
 867
 868     $default  reduce using rule 1 (exp)
 869
 870
 871 State 4
 872
 873     2 exp: id .
 874
 875     $default  reduce using rule 2 (exp)
 876
 877
 878 State 5
 879
 880     0 $accept: exp $end .
 881
 882     $default  accept
 883 ]])
 884
 885 AT_CLEANUP
 886
 887
 888
 889
 890 ## -------------------- ##
 891 ## %expect not enough.  ##
 892 ## -------------------- ##
 893
 894 AT_SETUP([%expect not enough])
 895
 896 AT_DATA([input.y],
 897 [[%token NUM OP
 898 %expect 0
 899 %%
 900 exp: exp OP exp | NUM;
 901 ]])
 902
 903 AT_BISON_CHECK([-o input.c input.y], 1, [],
 904 [input.y: conflicts: 1 shift/reduce
 905 input.y: error: expected 0 shift/reduce conflicts
 906 ])
 907 AT_CLEANUP
 908
 909
 910 ## --------------- ##
 911 ## %expect right.  ##
 912 ## --------------- ##
 913
 914 AT_SETUP([%expect right])
 915
 916 AT_DATA([input.y],
 917 [[%token NUM OP
 918 %expect 1
 919 %%
 920 exp: exp OP exp | NUM;
 921 ]])
 922
 923 AT_BISON_CHECK([-o input.c input.y])
 924 AT_CLEANUP
 925
 926
 927 ## ------------------ ##
 928 ## %expect too much.  ##
 929 ## ------------------ ##
 930
 931 AT_SETUP([%expect too much])
 932
 933 AT_DATA([input.y],
 934 [[%token NUM OP
 935 %expect 2
 936 %%
 937 exp: exp OP exp | NUM;
 938 ]])
 939
 940 AT_BISON_CHECK([-o input.c input.y], 1, [],
 941 [input.y: conflicts: 1 shift/reduce
 942 input.y: error: expected 2 shift/reduce conflicts
 943 ])
 944 AT_CLEANUP
 945
 946
 947 ## ------------------------------- ##
 948 ## %expect with reduce conflicts.  ##
 949 ## ------------------------------- ##
 950
 951 AT_SETUP([%expect with reduce conflicts])
 952
 953 AT_DATA([input.y],
 954 [[%expect 0
 955 %%
 956 program: a 'a' | a a;
 957 a: 'a';
 958 ]])
 959
 960 AT_BISON_CHECK([-o input.c input.y], 1, [],
 961 [input.y: conflicts: 1 reduce/reduce
 962 input.y: error: expected 0 reduce/reduce conflicts
 963 ])
 964 AT_CLEANUP
 965
 966
 967 ## ------------------------- ##
 968 ## %prec with user strings.  ##
 969 ## ------------------------- ##
 970
 971 AT_SETUP([%prec with user string])
 972
 973 AT_DATA([[input.y]],
 974 [[%%
 975 exp:
 976   "foo" %prec "foo"
 977 ;
 978 ]])
 979
 980 AT_BISON_CHECK([-o input.c input.y])
 981 AT_CLEANUP
 982
 983
 984 ## -------------------------------- ##
 985 ## %no-default-prec without %prec.  ##
 986 ## -------------------------------- ##
 987
 988 AT_SETUP([%no-default-prec without %prec])
 989
 990 AT_DATA([[input.y]],
 991 [[%left '+'
 992 %left '*'
 993
 994 %%
 995
 996 %no-default-prec;
 997
 998 e:   e '+' e
 999    | e '*' e
1000    | '0'
1001    ;
1002 ]])
1003
1004 AT_BISON_CHECK([-o input.c input.y], 0, [],
1005 [[input.y: conflicts: 4 shift/reduce
1006 ]])
1007 AT_CLEANUP
1008
1009
1010 ## ----------------------------- ##
1011 ## %no-default-prec with %prec.  ##
1012 ## ----------------------------- ##
1013
1014 AT_SETUP([%no-default-prec with %prec])
1015
1016 AT_DATA([[input.y]],
1017 [[%left '+'
1018 %left '*'
1019
1020 %%
1021
1022 %no-default-prec;
1023
1024 e:   e '+' e %prec '+'
1025    | e '*' e %prec '*'
1026    | '0'
1027    ;
1028 ]])
1029
1030 AT_BISON_CHECK([-o input.c input.y])
1031 AT_CLEANUP
1032
1033
1034 ## --------------- ##
1035 ## %default-prec.  ##
1036 ## --------------- ##
1037
1038 AT_SETUP([%default-prec])
1039
1040 AT_DATA([[input.y]],
1041 [[%left '+'
1042 %left '*'
1043
1044 %%
1045
1046 %default-prec;
1047
1048 e:   e '+' e
1049    | e '*' e
1050    | '0'
1051    ;
1052 ]])
1053
1054 AT_BISON_CHECK([-o input.c input.y])
1055 AT_CLEANUP
1056
1057
1058 ## ---------------------------------------------- ##
1059 ## Unreachable States After Conflict Resolution.  ##
1060 ## ---------------------------------------------- ##
1061
1062 AT_SETUP([[Unreachable States After Conflict Resolution]])
1063
1064 # If conflict resolution makes states unreachable, remove those states, report
1065 # rules that are then unused, and don't report conflicts in those states.  Test
1066 # what happens when a nonterminal becomes useless as a result of state removal
1067 # since that causes lalr.o's goto map to be rewritten.
1068
1069 AT_DATA([[input.y]],
1070 [[%output "input.c"
1071 %left 'a'
1072
1073 %%
1074
1075 start: resolved_conflict 'a' reported_conflicts 'a' ;
1076
1077 /* S/R conflict resolved as reduce, so the state with item
1078  * (resolved_conflict: 'a' . unreachable1) and all it transition successors are
1079  * unreachable, and the associated production is useless.  */
1080 resolved_conflict:
1081     'a' unreachable1
1082   | %prec 'a'
1083   ;
1084
1085 /* S/R conflict that need not be reported since it is unreachable because of
1086  * the previous conflict resolution.  Nonterminal unreachable1 and all its
1087  * productions are useless.  */
1088 unreachable1:
1089     'a' unreachable2
1090   |
1091   ;
1092
1093 /* Likewise for a R/R conflict and nonterminal unreachable2.  */
1094 unreachable2: | ;
1095
1096 /* Make sure remaining S/R and R/R conflicts are still reported correctly even
1097  * when their states are renumbered due to state removal.  */
1098 reported_conflicts:
1099     'a'
1100   | 'a'
1101   |
1102   ;
1103
1104 ]])
1105
1106 AT_BISON_CHECK([[--report=all input.y]], 0, [],
1107 [[input.y: conflicts: 1 shift/reduce, 1 reduce/reduce
1108 input.y:12.5-20: warning: rule useless in parser due to conflicts: resolved_conflict: 'a' unreachable1
1109 input.y:20.5-20: warning: rule useless in parser due to conflicts: unreachable1: 'a' unreachable2
1110 input.y:21.4: warning: rule useless in parser due to conflicts: unreachable1: /* empty */
1111 input.y:25.13: warning: rule useless in parser due to conflicts: unreachable2: /* empty */
1112 input.y:25.16: warning: rule useless in parser due to conflicts: unreachable2: /* empty */
1113 input.y:31.5-7: warning: rule useless in parser due to conflicts: reported_conflicts: 'a'
1114 input.y:32.4: warning: rule useless in parser due to conflicts: reported_conflicts: /* empty */
1115 ]])
1116
1117 AT_CHECK([[cat input.output]], 0,
1118 [[Rules useless in parser due to conflicts
1119
1120     2 resolved_conflict: 'a' unreachable1
1121
1122     4 unreachable1: 'a' unreachable2
1123     5             | /* empty */
1124
1125     6 unreachable2: /* empty */
1126     7             | /* empty */
1127
1128     9 reported_conflicts: 'a'
1129    10                   | /* empty */
1130
1131
1132 State 4 conflicts: 1 shift/reduce
1133 State 5 conflicts: 1 reduce/reduce
1134
1135
1136 Grammar
1137
1138     0 $accept: start $end
1139
1140     1 start: resolved_conflict 'a' reported_conflicts 'a'
1141
1142     2 resolved_conflict: 'a' unreachable1
1143     3                  | /* empty */
1144
1145     4 unreachable1: 'a' unreachable2
1146     5             | /* empty */
1147
1148     6 unreachable2: /* empty */
1149     7             | /* empty */
1150
1151     8 reported_conflicts: 'a'
1152     9                   | 'a'
1153    10                   | /* empty */
1154
1155
1156 Terminals, with rules where they appear
1157
1158 $end (0) 0
1159 'a' (97) 1 2 4 8 9
1160 error (256)
1161
1162
1163 Nonterminals, with rules where they appear
1164
1165 $accept (4)
1166     on left: 0
1167 start (5)
1168     on left: 1, on right: 0
1169 resolved_conflict (6)
1170     on left: 2 3, on right: 1
1171 unreachable1 (7)
1172     on left: 4 5, on right: 2
1173 unreachable2 (8)
1174     on left: 6 7, on right: 4
1175 reported_conflicts (9)
1176     on left: 8 9 10, on right: 1
1177
1178
1179 State 0
1180
1181     0 $accept: . start $end
1182     1 start: . resolved_conflict 'a' reported_conflicts 'a'
1183     2 resolved_conflict: . 'a' unreachable1
1184     3                  | .  ['a']
1185
1186     $default  reduce using rule 3 (resolved_conflict)
1187
1188     start              go to state 1
1189     resolved_conflict  go to state 2
1190
1191     Conflict between rule 3 and token 'a' resolved as reduce (%left 'a').
1192
1193
1194 State 1
1195
1196     0 $accept: start . $end
1197
1198     $end  shift, and go to state 3
1199
1200
1201 State 2
1202
1203     1 start: resolved_conflict . 'a' reported_conflicts 'a'
1204
1205     'a'  shift, and go to state 4
1206
1207
1208 State 3
1209
1210     0 $accept: start $end .
1211
1212     $default  accept
1213
1214
1215 State 4
1216
1217     1 start: resolved_conflict 'a' . reported_conflicts 'a'
1218     8 reported_conflicts: . 'a'
1219     9                   | . 'a'
1220    10                   | .  ['a']
1221
1222     'a'  shift, and go to state 5
1223
1224     'a'  [reduce using rule 10 (reported_conflicts)]
1225
1226     reported_conflicts  go to state 6
1227
1228
1229 State 5
1230
1231     8 reported_conflicts: 'a' .  ['a']
1232     9                   | 'a' .  ['a']
1233
1234     'a'       reduce using rule 8 (reported_conflicts)
1235     'a'       [reduce using rule 9 (reported_conflicts)]
1236     $default  reduce using rule 8 (reported_conflicts)
1237
1238
1239 State 6
1240
1241     1 start: resolved_conflict 'a' reported_conflicts . 'a'
1242
1243     'a'  shift, and go to state 7
1244
1245
1246 State 7
1247
1248     1 start: resolved_conflict 'a' reported_conflicts 'a' .
1249
1250     $default  reduce using rule 1 (start)
1251 ]])
1252
1253 AT_DATA([[input-keep.y]],
1254 [[%define lr.keep-unreachable-states
1255 ]])
1256 AT_CHECK([[cat input.y >> input-keep.y]])
1257
1258 AT_BISON_CHECK([[input-keep.y]], 0, [],
1259 [[input-keep.y: conflicts: 2 shift/reduce, 2 reduce/reduce
1260 input-keep.y:22.4: warning: rule useless in parser due to conflicts: unreachable1: /* empty */
1261 input-keep.y:26.16: warning: rule useless in parser due to conflicts: unreachable2: /* empty */
1262 input-keep.y:32.5-7: warning: rule useless in parser due to conflicts: reported_conflicts: 'a'
1263 input-keep.y:33.4: warning: rule useless in parser due to conflicts: reported_conflicts: /* empty */
1264 ]])
1265
1266 AT_CLEANUP
1267
1268
1269 ## ------------------------------------------------------------ ##
1270 ## Solved conflicts report for multiple reductions in a state.  ##
1271 ## ------------------------------------------------------------ ##
1272
1273 AT_SETUP([[Solved conflicts report for multiple reductions in a state]])
1274
1275 # Used to lose earlier solved conflict messages even within a single S/R/R.
1276
1277 AT_DATA([[input.y]],
1278 [[%left 'a'
1279 %right 'b'
1280 %right 'c'
1281 %right 'd'
1282 %%
1283 start:
1284     'a'
1285   | empty_a 'a'
1286   | 'b'
1287   | empty_b 'b'
1288   | 'c'
1289   | empty_c1 'c'
1290   | empty_c2 'c'
1291   | empty_c3 'c'
1292   ;
1293 empty_a: %prec 'a' ;
1294 empty_b: %prec 'b' ;
1295 empty_c1: %prec 'c' ;
1296 empty_c2: %prec 'c' ;
1297 empty_c3: %prec 'd' ;
1298 ]])
1299 AT_BISON_CHECK([[--report=all -o input.c input.y]], 0, [], [ignore])
1300 AT_CHECK([[cat input.output | sed -n '/^State 0$/,/^State 1$/p']], 0,
1301 [[State 0
1302
1303     0 $accept: . start $end
1304     1 start: . 'a'
1305     2      | . empty_a 'a'
1306     3      | . 'b'
1307     4      | . empty_b 'b'
1308     5      | . 'c'
1309     6      | . empty_c1 'c'
1310     7      | . empty_c2 'c'
1311     8      | . empty_c3 'c'
1312     9 empty_a: .  ['a']
1313    10 empty_b: .  []
1314    11 empty_c1: .  []
1315    12 empty_c2: .  []
1316    13 empty_c3: .  ['c']
1317
1318     'b'  shift, and go to state 1
1319
1320     'c'       reduce using rule 13 (empty_c3)
1321     $default  reduce using rule 9 (empty_a)
1322
1323     start     go to state 2
1324     empty_a   go to state 3
1325     empty_b   go to state 4
1326     empty_c1  go to state 5
1327     empty_c2  go to state 6
1328     empty_c3  go to state 7
1329
1330     Conflict between rule 9 and token 'a' resolved as reduce (%left 'a').
1331     Conflict between rule 10 and token 'b' resolved as shift (%right 'b').
1332     Conflict between rule 11 and token 'c' resolved as shift (%right 'c').
1333     Conflict between rule 12 and token 'c' resolved as shift (%right 'c').
1334     Conflict between rule 13 and token 'c' resolved as reduce ('c' < 'd').
1335
1336
1337 State 1
1338 ]])
1339
1340 AT_CLEANUP
1341
1342
1343 ## ------------------------------------------------------------ ##
1344 ## %nonassoc error actions for multiple reductions in a state.  ##
1345 ## ------------------------------------------------------------ ##
1346
1347 # Used to abort when trying to resolve conflicts as %nonassoc error actions for
1348 # multiple reductions in a state.
1349
1350 # For a %nonassoc error action token, used to print the first remaining
1351 # reduction on that token without brackets.
1352
1353 AT_SETUP([[%nonassoc error actions for multiple reductions in a state]])
1354
1355 AT_DATA([[input.y]],
1356 [[%nonassoc 'a' 'b' 'c'
1357 %%
1358 start:
1359     'a'
1360   | empty_a 'a'
1361   | 'b'
1362   | empty_b 'b'
1363   | 'c'
1364   | empty_c1 'c'
1365   | empty_c2 'c'
1366   | empty_c3 'c'
1367   ;
1368 empty_a: %prec 'a' ;
1369 empty_b: %prec 'b' ;
1370 empty_c1: %prec 'c' ;
1371 empty_c2: %prec 'c' ;
1372 empty_c3: %prec 'c' ;
1373 ]])
1374
1375 AT_BISON_CHECK([[--report=all -o input.c input.y]], 0, [], [ignore])
1376 AT_CHECK([[cat input.output | sed -n '/^State 0$/,/^State 1$/p']], 0,
1377 [[State 0
1378
1379     0 $accept: . start $end
1380     1 start: . 'a'
1381     2      | . empty_a 'a'
1382     3      | . 'b'
1383     4      | . empty_b 'b'
1384     5      | . 'c'
1385     6      | . empty_c1 'c'
1386     7      | . empty_c2 'c'
1387     8      | . empty_c3 'c'
1388     9 empty_a: .  []
1389    10 empty_b: .  []
1390    11 empty_c1: .  []
1391    12 empty_c2: .  ['c']
1392    13 empty_c3: .  ['c']
1393
1394     'a'  error (nonassociative)
1395     'b'  error (nonassociative)
1396     'c'  error (nonassociative)
1397
1398     'c'  [reduce using rule 12 (empty_c2)]
1399     'c'  [reduce using rule 13 (empty_c3)]
1400
1401     start     go to state 1
1402     empty_a   go to state 2
1403     empty_b   go to state 3
1404     empty_c1  go to state 4
1405     empty_c2  go to state 5
1406     empty_c3  go to state 6
1407
1408     Conflict between rule 9 and token 'a' resolved as an error (%nonassoc 'a').
1409     Conflict between rule 10 and token 'b' resolved as an error (%nonassoc 'b').
1410     Conflict between rule 11 and token 'c' resolved as an error (%nonassoc 'c').
1411
1412
1413 State 1
1414 ]])
1415 AT_CLEANUP
1416
1417
1418 ## --------------------------------- ##
1419 ## -W versus %expect and %expect-rr  ##
1420 ## --------------------------------- ##
1421
1422 AT_SETUP([[-W versus %expect and %expect-rr]])
1423
1424 AT_DATA([[sr-rr.y]],
1425 [[%glr-parser
1426 %%
1427 start: 'a' | A 'a' | B 'a' ;
1428 A: ;
1429 B: ;
1430 ]])
1431 AT_DATA([[sr.y]],
1432 [[%glr-parser
1433 %%
1434 start: 'a' | A 'a' ;
1435 A: ;
1436 ]])
1437 AT_DATA([[rr.y]],
1438 [[%glr-parser
1439 %%
1440 start: A | B ;
1441 A: ;
1442 B: ;
1443 ]])
1444
1445 AT_BISON_CHECK([[sr-rr.y]], [[0]], [[]],
1446 [[sr-rr.y: conflicts: 1 shift/reduce, 1 reduce/reduce
1447 ]])
1448 AT_BISON_CHECK([[-Wno-conflicts-sr sr-rr.y]], [[0]], [[]],
1449 [[sr-rr.y: conflicts: 1 reduce/reduce
1450 ]])
1451 AT_BISON_CHECK([[-Wno-conflicts-rr sr-rr.y]], [[0]], [[]],
1452 [[sr-rr.y: conflicts: 1 shift/reduce
1453 ]])
1454
1455 [for gram in sr-rr sr rr; do
1456   for sr_exp_i in '' 0 1 2; do
1457     for rr_exp_i in '' 0 1 2; do
1458       test -z "$sr_exp_i" && test -z "$rr_exp_i" && continue
1459
1460       # Build grammar file.
1461       sr_exp=0
1462       rr_exp=0
1463       file=$gram
1464       directives=
1465       if test -n "$sr_exp_i"; then
1466         sr_exp=$sr_exp_i
1467         file=$file-expect-$sr_exp
1468         directives="%expect $sr_exp"
1469       fi
1470       if test -n "$rr_exp_i"; then
1471         rr_exp=$rr_exp_i
1472         file=$file-expect-rr-$rr_exp
1473         directives="$directives %expect-rr $rr_exp"
1474       fi
1475       file=$file.y
1476       echo "$directives" > $file
1477       cat $gram.y >> $file
1478
1479       # Count actual conflicts.
1480       conflicts=
1481       sr_count=0
1482       rr_count=0
1483       if test $gram = sr || test $gram = sr-rr; then
1484         conflicts="1 shift/reduce"
1485         sr_count=1
1486       fi
1487       if test $gram = rr || test $gram = sr-rr; then
1488         if test -n "$conflicts"; then
1489           conflicts="$conflicts, "
1490         fi
1491         conflicts="${conflicts}1 reduce/reduce"
1492         rr_count=1
1493       fi
1494
1495       # Run tests.
1496       if test $sr_count -eq $sr_exp && test $rr_count -eq $rr_exp; then
1497         ]AT_BISON_CHECK([[-Wnone $file]])[
1498         ]AT_BISON_CHECK([[-Werror $file]])[
1499       else
1500         echo "$file: conflicts: $conflicts" > experr
1501         if test $sr_count -ne $sr_exp; then
1502           if test $sr_exp -ne 1; then s=s; else s= ; fi
1503           echo "$file: error: expected $sr_exp shift/reduce conflict$s" >> experr
1504         fi
1505         if test $rr_count -ne $rr_exp; then
1506           if test $rr_exp -ne 1; then s=s; else s= ; fi
1507           echo "$file: error: expected $rr_exp reduce/reduce conflict$s" >> experr
1508         fi
1509         ]AT_BISON_CHECK([[-Wnone $file]], [[1]], [[]], [[experr]])[
1510         ]AT_BISON_CHECK([[-Werror $file]], [[1]], [[]], [[experr]])[
1511       fi
1512     done
1513   done
1514 done]
1515
1516 AT_CLEANUP