tests/conflicts.at

   1 # Exercising Bison on conflicts.                         -*- Autotest -*-
   2
   3 # Copyright (C) 2002-2005, 2007-2013 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 3 of the License, or
   8 # (at your option) 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, see <http://www.gnu.org/licenses/>.
  17
  18 AT_BANNER([[Conflicts.]])
  19
  20 ## ------------------------- ##
  21 ## Token declaration order.  ##
  22 ## ------------------------- ##
  23
  24 # This test checks that token are declared left to right when in a precedence
  25 # statement.
  26
  27 AT_SETUP([Token declaration order])
  28
  29 AT_BISON_OPTION_PUSHDEFS
  30
  31 AT_DATA_GRAMMAR([[input.y]],
  32 [[%code {
  33   #include <stdio.h>
  34   ]AT_YYERROR_DECLARE[
  35   ]AT_YYLEX_DECLARE[
  36 }
  37 %token A B C
  38 %token D
  39 %right E F G
  40 %right H I
  41 %right J
  42 %left  K
  43 %left  L M N
  44 %nonassoc O P Q
  45 %precedence R S T U
  46 %precedence V W
  47 %%
  48 exp: A
  49 %%
  50 ]AT_YYERROR_DEFINE[
  51 ]AT_YYLEX_DEFINE[
  52 int main (void)
  53 {
  54   assert (A < B);
  55   assert (B < C);
  56   assert (C < D);
  57   assert (D < E);
  58   assert (E < F);
  59   assert (F < G);
  60   assert (G < H);
  61   assert (H < I);
  62   assert (I < J);
  63   assert (J < K);
  64   assert (K < L);
  65   assert (L < M);
  66   assert (M < N);
  67   assert (N < O);
  68   assert (O < P);
  69   assert (P < Q);
  70   assert (Q < R);
  71   assert (R < S);
  72   assert (S < T);
  73   assert (T < U);
  74   assert (U < V);
  75   assert (V < W);
  76   return 0;
  77 }
  78 ]])
  79
  80 AT_BISON_CHECK([-o input.c input.y])
  81 AT_COMPILE([input])
  82
  83 AT_PARSER_CHECK([./input])
  84
  85 AT_BISON_OPTION_POPDEFS
  86
  87 AT_CLEANUP
  88
  89
  90 ## ------------------------------- ##
  91 ## Useless associativity warning.  ##
  92 ## ------------------------------- ##
  93
  94 AT_SETUP([Useless associativity warning])
  95
  96 AT_DATA([[input.y]],
  97 [[%nonassoc "="
  98 %left "+"
  99 %left "*"
 100 %precedence "("
 101 %%
 102 stmt:
 103   exp
 104 | "var" "=" exp
 105 ;
 106
 107 exp:
 108   exp "+" exp
 109 | exp "*" "num"
 110 | "(" exp ")"
 111 | "num"
 112 ;
 113 ]])
 114
 115 AT_BISON_CHECK([-Wprecedence input.y], 0, [],
 116 [[input.y:1.11-13: warning: useless precedence and associativity for "=" [-Wprecedence]
 117 input.y:3.7-9: warning: useless associativity for "*", use %precedence [-Wprecedence]
 118 input.y:4.13-15: warning: useless precedence for "(" [-Wprecedence]
 119 ]])
 120
 121 AT_CLEANUP
 122
 123
 124 ## ---------------------------- ##
 125 ## Useless precedence warning.  ##
 126 ## ---------------------------- ##
 127
 128 AT_SETUP([Useless precedence warning])
 129
 130 AT_DATA([[input.y]],
 131 [[%token A B
 132 %precedence Z
 133 %left X
 134 %precedence Y
 135 %left W
 136 %right V
 137 %nonassoc U
 138 %%
 139 a: b
 140  | a U b
 141  | f
 142 ;
 143 b: c
 144  | b V c
 145 ;
 146 c: d
 147  | c W d
 148 ;
 149 d: A
 150  | d X d
 151  | d Y A
 152 ;
 153 f: B
 154  | f Z B
 155 ;
 156 ]])
 157
 158 AT_BISON_CHECK([-Wprecedence -fcaret -o input.c input.y], 0, [],
 159 [[input.y:2.13: warning: useless precedence for Z [-Wprecedence]
 160  %precedence Z
 161              ^
 162 input.y:5.7: warning: useless precedence and associativity for W [-Wprecedence]
 163  %left W
 164        ^
 165 input.y:6.8: warning: useless precedence and associativity for V [-Wprecedence]
 166  %right V
 167         ^
 168 input.y:7.11: warning: useless precedence and associativity for U [-Wprecedence]
 169  %nonassoc U
 170            ^
 171 ]])
 172
 173 AT_CLEANUP
 174
 175
 176 ## ---------------- ##
 177 ## S/R in initial.  ##
 178 ## ---------------- ##
 179
 180 # I once hacked Bison in such a way that it lost its reductions on the
 181 # initial state (because it was confusing it with the last state).  It
 182 # took me a while to strip down my failures to this simple case.  So
 183 # make sure it finds the s/r conflict below.
 184
 185 AT_SETUP([S/R in initial])
 186
 187 AT_DATA([[input.y]],
 188 [[%expect 1
 189 %%
 190 exp: e 'e';
 191 e: 'e' | /* Nothing. */;
 192 ]])
 193
 194 AT_BISON_CHECK([-o input.c input.y], 0, [],
 195 [[input.y:4.9: warning: rule useless in parser due to conflicts: e: /* empty */ [-Wother]
 196 ]])
 197
 198 AT_BISON_CHECK([-fcaret -o input.c input.y], 0, [],
 199 [[input.y:4.9: warning: rule useless in parser due to conflicts [-Wother]
 200  e: 'e' | /* Nothing. */;
 201          ^
 202 ]])
 203
 204 AT_CLEANUP
 205
 206
 207 ## ------------------- ##
 208 ## %nonassoc and eof.  ##
 209 ## ------------------- ##
 210
 211 AT_SETUP([%nonassoc and eof])
 212
 213 AT_BISON_OPTION_PUSHDEFS
 214 AT_DATA_GRAMMAR([input.y],
 215 [[
 216 %{
 217 #include <stdio.h>
 218 #include <stdlib.h>
 219 #include <string.h>
 220 #include <assert.h>
 221
 222 #define YYERROR_VERBOSE 1
 223 ]AT_YYERROR_DEFINE[
 224 /* The current argument. */
 225 static const char *input;
 226
 227 static int
 228 yylex (void)
 229 {
 230   static size_t toknum;
 231   assert (toknum <= strlen (input));
 232   return input[toknum++];
 233 }
 234
 235 %}
 236
 237 %nonassoc '<' '>'
 238
 239 %%
 240 expr: expr '<' expr
 241     | expr '>' expr
 242     | '0'
 243     ;
 244 %%
 245 int
 246 main (int argc, const char *argv[])
 247 {
 248   input = argc <= 1 ? "" : argv[1];
 249   return yyparse ();
 250 }
 251 ]])
 252 AT_BISON_OPTION_POPDEFS
 253
 254 m4_pushdef([AT_NONASSOC_AND_EOF_CHECK],
 255 [AT_BISON_CHECK([$1[ -o input.c input.y]])
 256 AT_COMPILE([input])
 257
 258 m4_pushdef([AT_EXPECTING], [m4_if($2, [correct], [[, expecting $end]])])
 259
 260 AT_PARSER_CHECK([./input '0<0'])
 261 AT_PARSER_CHECK([./input '0<0<0'], [1], [],
 262          [syntax error, unexpected '<'AT_EXPECTING
 263 ])
 264
 265 AT_PARSER_CHECK([./input '0>0'])
 266 AT_PARSER_CHECK([./input '0>0>0'], [1], [],
 267          [syntax error, unexpected '>'AT_EXPECTING
 268 ])
 269
 270 AT_PARSER_CHECK([./input '0<0>0'], [1], [],
 271          [syntax error, unexpected '>'AT_EXPECTING
 272 ])
 273
 274 m4_popdef([AT_EXPECTING])])
 275
 276 # Expected token list is missing.
 277 AT_NONASSOC_AND_EOF_CHECK([], [[incorrect]])
 278
 279 # We must disable default reductions in inconsistent states in order to
 280 # have an explicit list of all expected tokens.
 281 AT_NONASSOC_AND_EOF_CHECK([[-Dlr.default-reduction=consistent]],
 282                           [[correct]])
 283
 284 # lr.default-reduction=consistent happens to work for this test case.
 285 # However, for other grammars, lookahead sets can be merged for
 286 # different left contexts, so it is still possible to have an incorrect
 287 # expected list.  Canonical LR is almost a general solution (that is, it
 288 # can fail only when %nonassoc is used), so make sure it gives the same
 289 # result as above.
 290 AT_NONASSOC_AND_EOF_CHECK([[-Dlr.type=canonical-lr]], [[correct]])
 291
 292 # parse.lac=full is a completely general solution that does not require
 293 # any of the above sacrifices.  Of course, it does not extend the
 294 # language-recognition power of LALR to (IE)LR, but it does ensure that
 295 # the reported list of expected tokens matches what the given parser
 296 # would have accepted in place of the unexpected token.
 297 AT_NONASSOC_AND_EOF_CHECK([[-Dparse.lac=full]], [[correct]])
 298
 299 m4_popdef([AT_NONASSOC_AND_EOF_CHECK])
 300
 301 AT_CLEANUP
 302
 303
 304
 305 ## ------------------------------------------- ##
 306 ## parse.error=verbose and consistent errors.  ##
 307 ## ------------------------------------------- ##
 308
 309 AT_SETUP([[parse.error=verbose and consistent errors]])
 310
 311 m4_pushdef([AT_CONSISTENT_ERRORS_CHECK], [
 312
 313 AT_BISON_OPTION_PUSHDEFS([$1])
 314
 315 m4_pushdef([AT_YYLEX_PROTOTYPE],
 316 [AT_SKEL_CC_IF([[int yylex (yy::parser::semantic_type *lvalp)]],
 317                [[int yylex (YYSTYPE *lvalp)]])])
 318
 319 AT_SKEL_JAVA_IF([AT_DATA], [AT_DATA_GRAMMAR])([input.y],
 320 [AT_SKEL_JAVA_IF([[
 321
 322 %code imports {
 323   import java.io.IOException;
 324 }]], [[
 325
 326 %code {]AT_SKEL_CC_IF([[
 327   #include <string>]], [[
 328   #include <assert.h>
 329   #include <stdio.h>
 330   ]AT_YYERROR_DECLARE])[
 331   ]AT_YYLEX_PROTOTYPE[;
 332   #define USE(Var)
 333 }
 334
 335 ]AT_SKEL_CC_IF([[%defines]], [[%define api.pure]])])[
 336
 337 ]$1[
 338
 339 %define parse.error verbose
 340
 341 %%
 342
 343 ]$2[
 344
 345 ]AT_SKEL_JAVA_IF([[%code lexer {]], [[%%]])[
 346
 347 /*--------.
 348 | yylex.  |
 349 `--------*/]AT_SKEL_JAVA_IF([[
 350
 351 public String input = "]$3[";
 352 public int index = 0;
 353 public int yylex ()
 354 {
 355   if (index < input.length ())
 356     return input.charAt (index++);
 357   else
 358     return 0;
 359 }
 360 public Object getLVal ()
 361 {
 362   return new Integer(1);
 363 }]], [[
 364
 365 ]AT_YYLEX_PROTOTYPE[
 366 {
 367   static char const *input = "]$3[";
 368   *lvalp = 1;
 369   return *input++;
 370 }]])[
 371 ]AT_YYERROR_DEFINE[
 372 ]AT_SKEL_JAVA_IF([[
 373 };
 374
 375 %%]])[
 376
 377 /*-------.
 378 | main.  |
 379 `-------*/
 380 ]AT_MAIN_DEFINE
 381 ])
 382
 383 AT_FULL_COMPILE([[input]])
 384
 385 m4_pushdef([AT_EXPECTING], [m4_if($5, [ab], [[, expecting 'a' or 'b']],
 386                                   $5, [a],  [[, expecting 'a']],
 387                                   $5, [b],  [[, expecting 'b']])])
 388
 389 AT_SKEL_JAVA_IF([AT_JAVA_PARSER_CHECK([[input]], [[0]]],
 390                 [AT_PARSER_CHECK([[./input]], [[1]]]),
 391 [[]],
 392 [[syntax error, unexpected ]$4[]AT_EXPECTING[
 393 ]])
 394
 395 m4_popdef([AT_EXPECTING])
 396 m4_popdef([AT_YYLEX_PROTOTYPE])
 397 AT_BISON_OPTION_POPDEFS
 398
 399 ])
 400
 401 m4_pushdef([AT_PREVIOUS_STATE_GRAMMAR],
 402 [[%nonassoc 'a';
 403
 404 start: consistent-error-on-a-a 'a' ;
 405
 406 consistent-error-on-a-a:
 407     'a' default-reduction
 408   | 'a' default-reduction 'a'
 409   | 'a' shift
 410   ;
 411
 412 default-reduction: /*empty*/ ;
 413 shift: 'b' ;
 414
 415 // Provide another context in which all rules are useful so that this
 416 // test case looks a little more realistic.
 417 start: 'b' consistent-error-on-a-a 'c' ;
 418 ]])
 419
 420 m4_pushdef([AT_PREVIOUS_STATE_INPUT], [[a]])
 421
 422 # Unfortunately, no expected tokens are reported even though 'b' can be
 423 # accepted.  Nevertheless, the main point of this test is to make sure
 424 # that at least the unexpected token is reported.  In a previous version
 425 # of Bison, it wasn't reported because the error is detected in a
 426 # consistent state with an error action, and that case always triggered
 427 # the simple "syntax error" message.
 428 #
 429 # The point isn't to test IELR here, but state merging happens to
 430 # complicate this example.
 431 AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr]],
 432                            [AT_PREVIOUS_STATE_GRAMMAR],
 433                            [AT_PREVIOUS_STATE_INPUT],
 434                            [[$end]], [[none]])
 435 AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr
 436                              %glr-parser]],
 437                            [AT_PREVIOUS_STATE_GRAMMAR],
 438                            [AT_PREVIOUS_STATE_INPUT],
 439                            [[$end]], [[none]])
 440 AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr
 441                              %language "c++"]],
 442                            [AT_PREVIOUS_STATE_GRAMMAR],
 443                            [AT_PREVIOUS_STATE_INPUT],
 444                            [[$end]], [[none]])
 445 AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr
 446                              %language "java"]],
 447                            [AT_PREVIOUS_STATE_GRAMMAR],
 448                            [AT_PREVIOUS_STATE_INPUT],
 449                            [[end of input]], [[none]])
 450
 451 # Even canonical LR doesn't foresee the error for 'a'!
 452 AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr
 453                              %define lr.default-reduction consistent]],
 454                            [AT_PREVIOUS_STATE_GRAMMAR],
 455                            [AT_PREVIOUS_STATE_INPUT],
 456                            [[$end]], [[ab]])
 457 AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr
 458                              %define lr.default-reduction accepting]],
 459                            [AT_PREVIOUS_STATE_GRAMMAR],
 460                            [AT_PREVIOUS_STATE_INPUT],
 461                            [[$end]], [[ab]])
 462 AT_CONSISTENT_ERRORS_CHECK([[%define lr.type canonical-lr]],
 463                            [AT_PREVIOUS_STATE_GRAMMAR],
 464                            [AT_PREVIOUS_STATE_INPUT],
 465                            [[$end]], [[ab]])
 466
 467 # Only LAC gets it right.
 468 AT_CONSISTENT_ERRORS_CHECK([[%define lr.type canonical-lr
 469                              %define parse.lac full]],
 470                            [AT_PREVIOUS_STATE_GRAMMAR],
 471                            [AT_PREVIOUS_STATE_INPUT],
 472                            [[$end]], [[b]])
 473 AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr
 474                              %define parse.lac full]],
 475                            [AT_PREVIOUS_STATE_GRAMMAR],
 476                            [AT_PREVIOUS_STATE_INPUT],
 477                            [[$end]], [[b]])
 478
 479 m4_popdef([AT_PREVIOUS_STATE_GRAMMAR])
 480 m4_popdef([AT_PREVIOUS_STATE_INPUT])
 481
 482 m4_pushdef([AT_USER_ACTION_GRAMMAR],
 483 [[%nonassoc 'a';
 484
 485 // If $$ = 0 here, then we know that the 'a' destructor is being invoked
 486 // incorrectly for the 'b' set in the semantic action below.  All 'a'
 487 // tokens are returned by yylex, which sets $$ = 1.
 488 %destructor {
 489   if (!$$)
 490     fprintf (stderr, "Wrong destructor.\n");
 491 } 'a';
 492
 493 // Rather than depend on an inconsistent state to induce reading a
 494 // lookahead as in the previous grammar, just assign the lookahead in a
 495 // semantic action.  That lookahead isn't needed before either error
 496 // action is encountered.  In a previous version of Bison, this was a
 497 // problem as it meant yychar was not translated into yytoken before
 498 // either error action.  The second error action thus invoked a
 499 // destructor that it selected according to the incorrect yytoken.  The
 500 // first error action would have reported an incorrect unexpected token
 501 // except that, due to the bug described in the previous grammar, the
 502 // unexpected token was not reported at all.
 503 start: error-reduce consistent-error 'a' { USE ($][3); } ;
 504
 505 error-reduce:
 506   'a' 'a' consistent-reduction consistent-error 'a'
 507   { USE (($][1, $][2, $][5)); }
 508 | 'a' error
 509   { USE ($][1); }
 510 ;
 511
 512 consistent-reduction: /*empty*/ {
 513   assert (yychar == YYEMPTY);
 514   yylval = 0;
 515   yychar = 'b';
 516 } ;
 517
 518 consistent-error:
 519   'a' { USE ($][1); }
 520 | /*empty*/ %prec 'a'
 521 ;
 522
 523 // Provide another context in which all rules are useful so that this
 524 // test case looks a little more realistic.
 525 start: 'b' consistent-error 'b' ;
 526 ]])
 527 m4_pushdef([AT_USER_ACTION_INPUT], [[aa]])
 528
 529 AT_CONSISTENT_ERRORS_CHECK([[]],
 530                            [AT_USER_ACTION_GRAMMAR],
 531                            [AT_USER_ACTION_INPUT],
 532                            [['b']], [[none]])
 533 AT_CONSISTENT_ERRORS_CHECK([[%glr-parser]],
 534                            [AT_USER_ACTION_GRAMMAR],
 535                            [AT_USER_ACTION_INPUT],
 536                            [['b']], [[none]])
 537 # No C++ or Java test because yychar cannot be manipulated by users.
 538
 539 AT_CONSISTENT_ERRORS_CHECK([[%define lr.default-reduction consistent]],
 540                            [AT_USER_ACTION_GRAMMAR],
 541                            [AT_USER_ACTION_INPUT],
 542                            [['b']], [[none]])
 543
 544 # Canonical LR doesn't foresee the error for 'a'!
 545 AT_CONSISTENT_ERRORS_CHECK([[%define lr.default-reduction accepting]],
 546                            [AT_USER_ACTION_GRAMMAR],
 547                            [AT_USER_ACTION_INPUT],
 548                            [[$end]], [[a]])
 549 AT_CONSISTENT_ERRORS_CHECK([[%define lr.type canonical-lr]],
 550                            [AT_USER_ACTION_GRAMMAR],
 551                            [AT_USER_ACTION_INPUT],
 552                            [[$end]], [[a]])
 553
 554 AT_CONSISTENT_ERRORS_CHECK([[%define parse.lac full]],
 555                            [AT_USER_ACTION_GRAMMAR],
 556                            [AT_USER_ACTION_INPUT],
 557                            [['b']], [[none]])
 558 AT_CONSISTENT_ERRORS_CHECK([[%define parse.lac full
 559                              %define lr.default-reduction accepting]],
 560                            [AT_USER_ACTION_GRAMMAR],
 561                            [AT_USER_ACTION_INPUT],
 562                            [[$end]], [[none]])
 563
 564 m4_popdef([AT_USER_ACTION_GRAMMAR])
 565 m4_popdef([AT_USER_ACTION_INPUT])
 566
 567 m4_popdef([AT_CONSISTENT_ERRORS_CHECK])
 568
 569 AT_CLEANUP
 570
 571
 572
 573 ## ------------------------------------------------------- ##
 574 ## LAC: %nonassoc requires splitting canonical LR states.  ##
 575 ## ------------------------------------------------------- ##
 576
 577 # This test case demonstrates that, when %nonassoc is used, canonical
 578 # LR(1) parser table construction followed by conflict resolution
 579 # without further state splitting is not always sufficient to produce a
 580 # parser that can detect all syntax errors as soon as possible on one
 581 # token of lookahead.  However, LAC solves the problem completely even
 582 # with minimal LR parser tables.
 583
 584 AT_SETUP([[LAC: %nonassoc requires splitting canonical LR states]])
 585 AT_BISON_OPTION_PUSHDEFS
 586 AT_DATA_GRAMMAR([[input.y]],
 587 [[%code {
 588   #include <stdio.h>
 589   ]AT_YYERROR_DECLARE[
 590   ]AT_YYLEX_DECLARE[
 591 }
 592
 593 %error-verbose
 594 %nonassoc 'a'
 595
 596 %%
 597
 598 start:
 599   'a' problem 'a' // First context.
 600 | 'b' problem 'b' // Second context.
 601 | 'c' reduce-nonassoc // Just makes reduce-nonassoc useful.
 602 ;
 603
 604 problem:
 605   look reduce-nonassoc
 606 | look 'a'
 607 | look 'b'
 608 ;
 609
 610 // For the state reached after shifting the 'a' in these productions,
 611 // lookahead sets are the same in both the first and second contexts.
 612 // Thus, canonical LR reuses the same state for both contexts.  However,
 613 // the lookahead 'a' for the reduction "look: 'a'" later becomes an
 614 // error action only in the first context.  In order to immediately
 615 // detect the syntax error on 'a' here for only the first context, this
 616 // canonical LR state would have to be split into two states, and the
 617 // 'a' lookahead would have to be removed from only one of the states.
 618 look:
 619   'a' // Reduction lookahead set is always ['a', 'b'].
 620 | 'a' 'b'
 621 | 'a' 'c' // 'c' is forgotten as an expected token.
 622 ;
 623
 624 reduce-nonassoc: %prec 'a';
 625
 626 %%
 627 ]AT_YYERROR_DEFINE[
 628 ]AT_YYLEX_DEFINE(["aaa"])[
 629 ]AT_MAIN_DEFINE
 630 ])
 631 AT_BISON_OPTION_POPDEFS
 632
 633 # Show canonical LR's failure.
 634 AT_BISON_CHECK([[-Dlr.type=canonical-lr -o input.c input.y]],
 635                [[0]], [[]],
 636 [[input.y: warning: 2 shift/reduce conflicts [-Wconflicts-sr]
 637 ]])
 638 AT_COMPILE([[input]])
 639 AT_PARSER_CHECK([[./input]], [[1]], [[]],
 640 [[syntax error, unexpected 'a', expecting 'b'
 641 ]])
 642
 643 # It's corrected by LAC.
 644 AT_BISON_CHECK([[-Dlr.type=canonical-lr -Dparse.lac=full \
 645                  -o input.c input.y]], [[0]], [[]],
 646 [[input.y: warning: 2 shift/reduce conflicts [-Wconflicts-sr]
 647 ]])
 648 AT_COMPILE([[input]])
 649 AT_PARSER_CHECK([[./input]], [[1]], [[]],
 650 [[syntax error, unexpected 'a', expecting 'b' or 'c'
 651 ]])
 652
 653 # IELR is sufficient when LAC is used.
 654 AT_BISON_CHECK([[-Dlr.type=ielr -Dparse.lac=full -o input.c input.y]],
 655                [[0]], [[]],
 656 [[input.y: warning: 2 shift/reduce conflicts [-Wconflicts-sr]
 657 ]])
 658 AT_COMPILE([[input]])
 659 AT_PARSER_CHECK([[./input]], [[1]], [[]],
 660 [[syntax error, unexpected 'a', expecting 'b' or 'c'
 661 ]])
 662
 663 AT_CLEANUP
 664
 665 ## ------------------------- ##
 666 ## Unresolved SR Conflicts.  ##
 667 ## ------------------------- ##
 668
 669 AT_SETUP([Unresolved SR Conflicts])
 670
 671 AT_KEYWORDS([report])
 672
 673 AT_DATA([input.y],
 674 [[%token NUM OP
 675 %%
 676 exp: exp OP exp | NUM;
 677 ]])
 678
 679 AT_BISON_CHECK([-o input.c --report=all input.y], 0, [],
 680 [[input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
 681 ]])
 682
 683 # Check the contents of the report.
 684 AT_CHECK([cat input.output], [],
 685 [[State 5 conflicts: 1 shift/reduce
 686
 687
 688 Grammar
 689
 690     0 $accept: exp $end
 691
 692     1 exp: exp OP exp
 693     2    | NUM
 694
 695
 696 Terminals, with rules where they appear
 697
 698 $end (0) 0
 699 error (256)
 700 NUM (258) 2
 701 OP (259) 1
 702
 703
 704 Nonterminals, with rules where they appear
 705
 706 $accept (5)
 707     on left: 0
 708 exp (6)
 709     on left: 1 2, on right: 0 1
 710
 711
 712 State 0
 713
 714     0 $accept: . exp $end
 715     1 exp: . exp OP exp
 716     2    | . NUM
 717
 718     NUM  shift, and go to state 1
 719
 720     exp  go to state 2
 721
 722
 723 State 1
 724
 725     2 exp: NUM .
 726
 727     $default  reduce using rule 2 (exp)
 728
 729
 730 State 2
 731
 732     0 $accept: exp . $end
 733     1 exp: exp . OP exp
 734
 735     $end  shift, and go to state 3
 736     OP    shift, and go to state 4
 737
 738
 739 State 3
 740
 741     0 $accept: exp $end .
 742
 743     $default  accept
 744
 745
 746 State 4
 747
 748     1 exp: . exp OP exp
 749     1    | exp OP . exp
 750     2    | . NUM
 751
 752     NUM  shift, and go to state 1
 753
 754     exp  go to state 5
 755
 756
 757 State 5
 758
 759     1 exp: exp . OP exp
 760     1    | exp OP exp .  [$end, OP]
 761
 762     OP  shift, and go to state 4
 763
 764     OP        [reduce using rule 1 (exp)]
 765     $default  reduce using rule 1 (exp)
 766 ]])
 767
 768 AT_CLEANUP
 769
 770
 771
 772 ## ----------------------- ##
 773 ## Resolved SR Conflicts.  ##
 774 ## ----------------------- ##
 775
 776 AT_SETUP([Resolved SR Conflicts])
 777
 778 AT_KEYWORDS([report])
 779
 780 AT_DATA([input.y],
 781 [[%token NUM OP
 782 %left OP
 783 %%
 784 exp: exp OP exp | NUM;
 785 ]])
 786
 787 AT_BISON_CHECK([-o input.c --report=all input.y])
 788
 789 # Check the contents of the report.
 790 AT_CHECK([cat input.output], [],
 791 [[Grammar
 792
 793     0 $accept: exp $end
 794
 795     1 exp: exp OP exp
 796     2    | NUM
 797
 798
 799 Terminals, with rules where they appear
 800
 801 $end (0) 0
 802 error (256)
 803 NUM (258) 2
 804 OP (259) 1
 805
 806
 807 Nonterminals, with rules where they appear
 808
 809 $accept (5)
 810     on left: 0
 811 exp (6)
 812     on left: 1 2, on right: 0 1
 813
 814
 815 State 0
 816
 817     0 $accept: . exp $end
 818     1 exp: . exp OP exp
 819     2    | . NUM
 820
 821     NUM  shift, and go to state 1
 822
 823     exp  go to state 2
 824
 825
 826 State 1
 827
 828     2 exp: NUM .
 829
 830     $default  reduce using rule 2 (exp)
 831
 832
 833 State 2
 834
 835     0 $accept: exp . $end
 836     1 exp: exp . OP exp
 837
 838     $end  shift, and go to state 3
 839     OP    shift, and go to state 4
 840
 841
 842 State 3
 843
 844     0 $accept: exp $end .
 845
 846     $default  accept
 847
 848
 849 State 4
 850
 851     1 exp: . exp OP exp
 852     1    | exp OP . exp
 853     2    | . NUM
 854
 855     NUM  shift, and go to state 1
 856
 857     exp  go to state 5
 858
 859
 860 State 5
 861
 862     1 exp: exp . OP exp
 863     1    | exp OP exp .  [$end, OP]
 864
 865     $default  reduce using rule 1 (exp)
 866
 867     Conflict between rule 1 and token OP resolved as reduce (%left OP).
 868 ]])
 869
 870 AT_CLEANUP
 871
 872
 873 ## ---------------------- ##
 874 ## %precedence suffices.  ##
 875 ## ---------------------- ##
 876
 877 AT_SETUP([%precedence suffices])
 878
 879 AT_DATA([input.y],
 880 [[%precedence "then"
 881 %precedence "else"
 882 %%
 883 stmt:
 884   "if" cond "then" stmt
 885 | "if" cond "then" stmt "else" stmt
 886 | "stmt"
 887 ;
 888
 889 cond:
 890   "exp"
 891 ;
 892 ]])
 893
 894 AT_BISON_CHECK([-o input.c input.y])
 895
 896 AT_CLEANUP
 897
 898
 899 ## ------------------------------ ##
 900 ## %precedence does not suffice.  ##
 901 ## ------------------------------ ##
 902
 903 AT_SETUP([%precedence does not suffice])
 904
 905 AT_DATA([input.y],
 906 [[%precedence "then"
 907 %precedence "else"
 908 %%
 909 stmt:
 910   "if" cond "then" stmt
 911 | "if" cond "then" stmt "else" stmt
 912 | "stmt"
 913 ;
 914
 915 cond:
 916   "exp"
 917 | cond "then" cond
 918 ;
 919 ]])
 920
 921 AT_BISON_CHECK([-o input.c input.y], 0, [],
 922 [[input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
 923 input.y:12.3-18: warning: rule useless in parser due to conflicts: cond: cond "then" cond [-Wother]
 924 ]])
 925
 926 AT_CLEANUP
 927
 928
 929 ## -------------------------------- ##
 930 ## Defaulted Conflicted Reduction.  ##
 931 ## -------------------------------- ##
 932
 933 # When there are RR conflicts, some rules are disabled.  Usually it is
 934 # simply displayed as:
 935 #
 936 #    $end           reduce using rule 3 (num)
 937 #    $end           [reduce using rule 4 (id)]
 938 #
 939 # But when `reduce 3' is the default action, we'd produce:
 940 #
 941 #    $end           [reduce using rule 4 (id)]
 942 #    $default    reduce using rule 3 (num)
 943 #
 944 # In this precise case (a reduction is masked by the default
 945 # reduction), we make the `reduce 3' explicit:
 946 #
 947 #    $end           reduce using rule 3 (num)
 948 #    $end           [reduce using rule 4 (id)]
 949 #    $default    reduce using rule 3 (num)
 950 #
 951 # Maybe that's not the best display, but then, please propose something
 952 # else.
 953
 954 AT_SETUP([Defaulted Conflicted Reduction])
 955 AT_KEYWORDS([report])
 956
 957 AT_DATA([input.y],
 958 [[%%
 959 exp: num | id;
 960 num: '0';
 961 id : '0';
 962 %%
 963 ]])
 964
 965 AT_BISON_CHECK([-o input.c --report=all input.y], 0, [],
 966 [[input.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
 967 input.y:4.6-8: warning: rule useless in parser due to conflicts: id: '0' [-Wother]
 968 ]])
 969
 970 # Check the contents of the report.
 971 AT_CHECK([cat input.output], [],
 972 [[Rules useless in parser due to conflicts
 973
 974     4 id: '0'
 975
 976
 977 State 1 conflicts: 1 reduce/reduce
 978
 979
 980 Grammar
 981
 982     0 $accept: exp $end
 983
 984     1 exp: num
 985     2    | id
 986
 987     3 num: '0'
 988
 989     4 id: '0'
 990
 991
 992 Terminals, with rules where they appear
 993
 994 $end (0) 0
 995 '0' (48) 3 4
 996 error (256)
 997
 998
 999 Nonterminals, with rules where they appear
1000
1001 $accept (4)
1002     on left: 0
1003 exp (5)
1004     on left: 1 2, on right: 0
1005 num (6)
1006     on left: 3, on right: 1
1007 id (7)
1008     on left: 4, on right: 2
1009
1010
1011 State 0
1012
1013     0 $accept: . exp $end
1014     1 exp: . num
1015     2    | . id
1016     3 num: . '0'
1017     4 id: . '0'
1018
1019     '0'  shift, and go to state 1
1020
1021     exp  go to state 2
1022     num  go to state 3
1023     id   go to state 4
1024
1025
1026 State 1
1027
1028     3 num: '0' .  [$end]
1029     4 id: '0' .  [$end]
1030
1031     $end      reduce using rule 3 (num)
1032     $end      [reduce using rule 4 (id)]
1033     $default  reduce using rule 3 (num)
1034
1035
1036 State 2
1037
1038     0 $accept: exp . $end
1039
1040     $end  shift, and go to state 5
1041
1042
1043 State 3
1044
1045     1 exp: num .
1046
1047     $default  reduce using rule 1 (exp)
1048
1049
1050 State 4
1051
1052     2 exp: id .
1053
1054     $default  reduce using rule 2 (exp)
1055
1056
1057 State 5
1058
1059     0 $accept: exp $end .
1060
1061     $default  accept
1062 ]])
1063
1064 AT_CLEANUP
1065
1066
1067
1068
1069 ## -------------------- ##
1070 ## %expect not enough.  ##
1071 ## -------------------- ##
1072
1073 AT_SETUP([%expect not enough])
1074
1075 AT_DATA([input.y],
1076 [[%token NUM OP
1077 %expect 0
1078 %%
1079 exp: exp OP exp | NUM;
1080 ]])
1081
1082 AT_BISON_CHECK([-o input.c input.y], 1, [],
1083 [[input.y: error: shift/reduce conflicts: 1 found, 0 expected
1084 ]])
1085 AT_CLEANUP
1086
1087
1088 ## --------------- ##
1089 ## %expect right.  ##
1090 ## --------------- ##
1091
1092 AT_SETUP([%expect right])
1093
1094 AT_DATA([input.y],
1095 [[%token NUM OP
1096 %expect 1
1097 %%
1098 exp: exp OP exp | NUM;
1099 ]])
1100
1101 AT_BISON_CHECK([-o input.c input.y])
1102 AT_CLEANUP
1103
1104
1105 ## ------------------ ##
1106 ## %expect too much.  ##
1107 ## ------------------ ##
1108
1109 AT_SETUP([%expect too much])
1110
1111 AT_DATA([input.y],
1112 [[%token NUM OP
1113 %expect 2
1114 %%
1115 exp: exp OP exp | NUM;
1116 ]])
1117
1118 AT_BISON_CHECK([-o input.c input.y], 1, [],
1119 [[input.y: error: shift/reduce conflicts: 1 found, 2 expected
1120 ]])
1121 AT_CLEANUP
1122
1123
1124 ## ------------------------------- ##
1125 ## %expect with reduce conflicts.  ##
1126 ## ------------------------------- ##
1127
1128 AT_SETUP([%expect with reduce conflicts])
1129
1130 AT_DATA([input.y],
1131 [[%expect 0
1132 %%
1133 program: a 'a' | a a;
1134 a: 'a';
1135 ]])
1136
1137 AT_BISON_CHECK([-o input.c input.y], 1, [],
1138 [[input.y: error: reduce/reduce conflicts: 1 found, 0 expected
1139 ]])
1140 AT_CLEANUP
1141
1142
1143 ## ------------------------- ##
1144 ## %prec with user strings.  ##
1145 ## ------------------------- ##
1146
1147 AT_SETUP([%prec with user string])
1148
1149 AT_DATA([[input.y]],
1150 [[%%
1151 exp:
1152   "foo" %prec "foo"
1153 ;
1154 ]])
1155
1156 AT_BISON_CHECK([-o input.c input.y])
1157 AT_CLEANUP
1158
1159
1160 ## -------------------------------- ##
1161 ## %no-default-prec without %prec.  ##
1162 ## -------------------------------- ##
1163
1164 AT_SETUP([%no-default-prec without %prec])
1165
1166 AT_DATA([[input.y]],
1167 [[%left '+'
1168 %left '*'
1169
1170 %%
1171
1172 %no-default-prec;
1173
1174 e:   e '+' e
1175    | e '*' e
1176    | '0'
1177    ;
1178 ]])
1179
1180 AT_BISON_CHECK([-Wall -o input.c input.y], 0, [],
1181 [[input.y: warning: 4 shift/reduce conflicts [-Wconflicts-sr]
1182 input.y:1.7-9: warning: useless precedence and associativity for '+' [-Wprecedence]
1183 input.y:2.7-9: warning: useless precedence and associativity for '*' [-Wprecedence]
1184 ]])
1185 AT_CLEANUP
1186
1187
1188 ## ----------------------------- ##
1189 ## %no-default-prec with %prec.  ##
1190 ## ----------------------------- ##
1191
1192 AT_SETUP([%no-default-prec with %prec])
1193
1194 AT_DATA([[input.y]],
1195 [[%left '+'
1196 %left '*'
1197
1198 %%
1199
1200 %no-default-prec;
1201
1202 e:   e '+' e %prec '+'
1203    | e '*' e %prec '*'
1204    | '0'
1205    ;
1206 ]])
1207
1208 AT_BISON_CHECK([-o input.c input.y])
1209 AT_CLEANUP
1210
1211
1212 ## --------------- ##
1213 ## %default-prec.  ##
1214 ## --------------- ##
1215
1216 AT_SETUP([%default-prec])
1217
1218 AT_DATA([[input.y]],
1219 [[%left '+'
1220 %left '*'
1221
1222 %%
1223
1224 %default-prec;
1225
1226 e:   e '+' e
1227    | e '*' e
1228    | '0'
1229    ;
1230 ]])
1231
1232 AT_BISON_CHECK([-o input.c input.y])
1233 AT_CLEANUP
1234
1235
1236 ## ---------------------------------------------- ##
1237 ## Unreachable States After Conflict Resolution.  ##
1238 ## ---------------------------------------------- ##
1239
1240 AT_SETUP([[Unreachable States After Conflict Resolution]])
1241
1242 # If conflict resolution makes states unreachable, remove those states, report
1243 # rules that are then unused, and don't report conflicts in those states.  Test
1244 # what happens when a nonterminal becomes useless as a result of state removal
1245 # since that causes lalr.o's goto map to be rewritten.
1246
1247 AT_DATA([[input.y]],
1248 [[%output "input.c"
1249 %left 'a'
1250
1251 %%
1252
1253 start: resolved_conflict 'a' reported_conflicts 'a' ;
1254
1255 /* S/R conflict resolved as reduce, so the state with item
1256  * (resolved_conflict: 'a' . unreachable1) and all it transition successors are
1257  * unreachable, and the associated production is useless.  */
1258 resolved_conflict:
1259     'a' unreachable1
1260   | %prec 'a'
1261   ;
1262
1263 /* S/R conflict that need not be reported since it is unreachable because of
1264  * the previous conflict resolution.  Nonterminal unreachable1 and all its
1265  * productions are useless.  */
1266 unreachable1:
1267     'a' unreachable2
1268   |
1269   ;
1270
1271 /* Likewise for a R/R conflict and nonterminal unreachable2.  */
1272 unreachable2: | ;
1273
1274 /* Make sure remaining S/R and R/R conflicts are still reported correctly even
1275  * when their states are renumbered due to state removal.  */
1276 reported_conflicts:
1277     'a'
1278   | 'a'
1279   |
1280   ;
1281
1282 ]])
1283
1284 AT_BISON_CHECK([[--report=all input.y]], 0, [],
1285 [[input.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
1286 input.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
1287 input.y:12.5-20: warning: rule useless in parser due to conflicts: resolved_conflict: 'a' unreachable1 [-Wother]
1288 input.y:20.5-20: warning: rule useless in parser due to conflicts: unreachable1: 'a' unreachable2 [-Wother]
1289 input.y:21.4: warning: rule useless in parser due to conflicts: unreachable1: /* empty */ [-Wother]
1290 input.y:25.13: warning: rule useless in parser due to conflicts: unreachable2: /* empty */ [-Wother]
1291 input.y:25.16: warning: rule useless in parser due to conflicts: unreachable2: /* empty */ [-Wother]
1292 input.y:31.5-7: warning: rule useless in parser due to conflicts: reported_conflicts: 'a' [-Wother]
1293 input.y:32.4: warning: rule useless in parser due to conflicts: reported_conflicts: /* empty */ [-Wother]
1294 ]])
1295
1296 AT_CHECK([[cat input.output]], 0,
1297 [[Rules useless in parser due to conflicts
1298
1299     2 resolved_conflict: 'a' unreachable1
1300
1301     4 unreachable1: 'a' unreachable2
1302     5             | /* empty */
1303
1304     6 unreachable2: /* empty */
1305     7             | /* empty */
1306
1307     9 reported_conflicts: 'a'
1308    10                   | /* empty */
1309
1310
1311 State 4 conflicts: 1 shift/reduce
1312 State 5 conflicts: 1 reduce/reduce
1313
1314
1315 Grammar
1316
1317     0 $accept: start $end
1318
1319     1 start: resolved_conflict 'a' reported_conflicts 'a'
1320
1321     2 resolved_conflict: 'a' unreachable1
1322     3                  | /* empty */
1323
1324     4 unreachable1: 'a' unreachable2
1325     5             | /* empty */
1326
1327     6 unreachable2: /* empty */
1328     7             | /* empty */
1329
1330     8 reported_conflicts: 'a'
1331     9                   | 'a'
1332    10                   | /* empty */
1333
1334
1335 Terminals, with rules where they appear
1336
1337 $end (0) 0
1338 'a' (97) 1 2 4 8 9
1339 error (256)
1340
1341
1342 Nonterminals, with rules where they appear
1343
1344 $accept (4)
1345     on left: 0
1346 start (5)
1347     on left: 1, on right: 0
1348 resolved_conflict (6)
1349     on left: 2 3, on right: 1
1350 unreachable1 (7)
1351     on left: 4 5, on right: 2
1352 unreachable2 (8)
1353     on left: 6 7, on right: 4
1354 reported_conflicts (9)
1355     on left: 8 9 10, on right: 1
1356
1357
1358 State 0
1359
1360     0 $accept: . start $end
1361     1 start: . resolved_conflict 'a' reported_conflicts 'a'
1362     2 resolved_conflict: . 'a' unreachable1
1363     3                  | .  ['a']
1364
1365     $default  reduce using rule 3 (resolved_conflict)
1366
1367     start              go to state 1
1368     resolved_conflict  go to state 2
1369
1370     Conflict between rule 3 and token 'a' resolved as reduce (%left 'a').
1371
1372
1373 State 1
1374
1375     0 $accept: start . $end
1376
1377     $end  shift, and go to state 3
1378
1379
1380 State 2
1381
1382     1 start: resolved_conflict . 'a' reported_conflicts 'a'
1383
1384     'a'  shift, and go to state 4
1385
1386
1387 State 3
1388
1389     0 $accept: start $end .
1390
1391     $default  accept
1392
1393
1394 State 4
1395
1396     1 start: resolved_conflict 'a' . reported_conflicts 'a'
1397     8 reported_conflicts: . 'a'
1398     9                   | . 'a'
1399    10                   | .  ['a']
1400
1401     'a'  shift, and go to state 5
1402
1403     'a'  [reduce using rule 10 (reported_conflicts)]
1404
1405     reported_conflicts  go to state 6
1406
1407
1408 State 5
1409
1410     8 reported_conflicts: 'a' .  ['a']
1411     9                   | 'a' .  ['a']
1412
1413     'a'       reduce using rule 8 (reported_conflicts)
1414     'a'       [reduce using rule 9 (reported_conflicts)]
1415     $default  reduce using rule 8 (reported_conflicts)
1416
1417
1418 State 6
1419
1420     1 start: resolved_conflict 'a' reported_conflicts . 'a'
1421
1422     'a'  shift, and go to state 7
1423
1424
1425 State 7
1426
1427     1 start: resolved_conflict 'a' reported_conflicts 'a' .
1428
1429     $default  reduce using rule 1 (start)
1430 ]])
1431
1432 AT_DATA([[input-keep.y]],
1433 [[%define lr.keep-unreachable-state
1434 ]])
1435 AT_CHECK([[cat input.y >> input-keep.y]])
1436
1437 AT_BISON_CHECK([[input-keep.y]], 0, [],
1438 [[input-keep.y: warning: 2 shift/reduce conflicts [-Wconflicts-sr]
1439 input-keep.y: warning: 2 reduce/reduce conflicts [-Wconflicts-rr]
1440 input-keep.y:22.4: warning: rule useless in parser due to conflicts: unreachable1: /* empty */ [-Wother]
1441 input-keep.y:26.16: warning: rule useless in parser due to conflicts: unreachable2: /* empty */ [-Wother]
1442 input-keep.y:32.5-7: warning: rule useless in parser due to conflicts: reported_conflicts: 'a' [-Wother]
1443 input-keep.y:33.4: warning: rule useless in parser due to conflicts: reported_conflicts: /* empty */ [-Wother]
1444 ]])
1445
1446 AT_CLEANUP
1447
1448
1449 ## ------------------------------------------------------------ ##
1450 ## Solved conflicts report for multiple reductions in a state.  ##
1451 ## ------------------------------------------------------------ ##
1452
1453 AT_SETUP([[Solved conflicts report for multiple reductions in a state]])
1454
1455 # Used to lose earlier solved conflict messages even within a single S/R/R.
1456
1457 AT_DATA([[input.y]],
1458 [[%left 'a'
1459 %right 'b'
1460 %right 'c'
1461 %right 'd'
1462 %%
1463 start:
1464     'a'
1465   | empty_a 'a'
1466   | 'b'
1467   | empty_b 'b'
1468   | 'c'
1469   | empty_c1 'c'
1470   | empty_c2 'c'
1471   | empty_c3 'c'
1472   ;
1473 empty_a: %prec 'a' ;
1474 empty_b: %prec 'b' ;
1475 empty_c1: %prec 'c' ;
1476 empty_c2: %prec 'c' ;
1477 empty_c3: %prec 'd' ;
1478 ]])
1479 AT_BISON_CHECK([[--report=all -o input.c input.y]], 0, [], [ignore])
1480 AT_CHECK([[cat input.output | sed -n '/^State 0$/,/^State 1$/p']], 0,
1481 [[State 0
1482
1483     0 $accept: . start $end
1484     1 start: . 'a'
1485     2      | . empty_a 'a'
1486     3      | . 'b'
1487     4      | . empty_b 'b'
1488     5      | . 'c'
1489     6      | . empty_c1 'c'
1490     7      | . empty_c2 'c'
1491     8      | . empty_c3 'c'
1492     9 empty_a: .  ['a']
1493    10 empty_b: .  []
1494    11 empty_c1: .  []
1495    12 empty_c2: .  []
1496    13 empty_c3: .  ['c']
1497
1498     'b'  shift, and go to state 1
1499
1500     'c'       reduce using rule 13 (empty_c3)
1501     $default  reduce using rule 9 (empty_a)
1502
1503     start     go to state 2
1504     empty_a   go to state 3
1505     empty_b   go to state 4
1506     empty_c1  go to state 5
1507     empty_c2  go to state 6
1508     empty_c3  go to state 7
1509
1510     Conflict between rule 9 and token 'a' resolved as reduce (%left 'a').
1511     Conflict between rule 10 and token 'b' resolved as shift (%right 'b').
1512     Conflict between rule 11 and token 'c' resolved as shift (%right 'c').
1513     Conflict between rule 12 and token 'c' resolved as shift (%right 'c').
1514     Conflict between rule 13 and token 'c' resolved as reduce ('c' < 'd').
1515
1516
1517 State 1
1518 ]])
1519
1520 AT_CLEANUP
1521
1522
1523 ## ------------------------------------------------------------ ##
1524 ## %nonassoc error actions for multiple reductions in a state.  ##
1525 ## ------------------------------------------------------------ ##
1526
1527 # Used to abort when trying to resolve conflicts as %nonassoc error actions for
1528 # multiple reductions in a state.
1529
1530 # For a %nonassoc error action token, used to print the first remaining
1531 # reduction on that token without brackets.
1532
1533 AT_SETUP([[%nonassoc error actions for multiple reductions in a state]])
1534
1535 AT_DATA([[input.y]],
1536 [[%nonassoc 'a' 'b' 'c'
1537 %%
1538 start:
1539     'a'
1540   | empty_a 'a'
1541   | 'b'
1542   | empty_b 'b'
1543   | 'c'
1544   | empty_c1 'c'
1545   | empty_c2 'c'
1546   | empty_c3 'c'
1547   ;
1548 empty_a: %prec 'a' ;
1549 empty_b: %prec 'b' ;
1550 empty_c1: %prec 'c' ;
1551 empty_c2: %prec 'c' ;
1552 empty_c3: %prec 'c' ;
1553 ]])
1554
1555 AT_BISON_CHECK([[--report=all -o input.c input.y]], 0, [], [ignore])
1556 AT_CHECK([[cat input.output | sed -n '/^State 0$/,/^State 1$/p']], 0,
1557 [[State 0
1558
1559     0 $accept: . start $end
1560     1 start: . 'a'
1561     2      | . empty_a 'a'
1562     3      | . 'b'
1563     4      | . empty_b 'b'
1564     5      | . 'c'
1565     6      | . empty_c1 'c'
1566     7      | . empty_c2 'c'
1567     8      | . empty_c3 'c'
1568     9 empty_a: .  []
1569    10 empty_b: .  []
1570    11 empty_c1: .  []
1571    12 empty_c2: .  ['c']
1572    13 empty_c3: .  ['c']
1573
1574     'a'  error (nonassociative)
1575     'b'  error (nonassociative)
1576     'c'  error (nonassociative)
1577
1578     'c'  [reduce using rule 12 (empty_c2)]
1579     'c'  [reduce using rule 13 (empty_c3)]
1580
1581     start     go to state 1
1582     empty_a   go to state 2
1583     empty_b   go to state 3
1584     empty_c1  go to state 4
1585     empty_c2  go to state 5
1586     empty_c3  go to state 6
1587
1588     Conflict between rule 9 and token 'a' resolved as an error (%nonassoc 'a').
1589     Conflict between rule 10 and token 'b' resolved as an error (%nonassoc 'b').
1590     Conflict between rule 11 and token 'c' resolved as an error (%nonassoc 'c').
1591
1592
1593 State 1
1594 ]])
1595 AT_CLEANUP
1596
1597
1598 ## -------------------- ##
1599 ## %expect-rr non GLR.  ##
1600 ## -------------------- ##
1601
1602 AT_SETUP([[%expect-rr non GLR]])
1603
1604 AT_DATA([[1.y]],
1605 [[%expect-rr 0
1606 %%
1607 exp: 'a'
1608 ]])
1609
1610 AT_BISON_CHECK([[1.y]], [[0]], [],
1611 [[1.y: warning: %expect-rr applies only to GLR parsers [-Wother]
1612 ]])
1613
1614 AT_DATA([[2.y]],
1615 [[%expect-rr 1
1616 %%
1617 exp: 'a' | 'a';
1618 ]])
1619
1620 AT_BISON_CHECK([[2.y]], [[0]], [],
1621 [[2.y: warning: %expect-rr applies only to GLR parsers [-Wother]
1622 2.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
1623 2.y:3.12-14: warning: rule useless in parser due to conflicts: exp: 'a' [-Wother]
1624 ]])
1625
1626 AT_CLEANUP
1627
1628
1629 ## ---------------------------------- ##
1630 ## -W versus %expect and %expect-rr.  ##
1631 ## ---------------------------------- ##
1632
1633 AT_SETUP([[-W versus %expect and %expect-rr]])
1634
1635 AT_DATA([[sr-rr.y]],
1636 [[%glr-parser
1637 %%
1638 start: 'a' | A 'a' | B 'a' ;
1639 A: ;
1640 B: ;
1641 ]])
1642 AT_DATA([[sr.y]],
1643 [[%glr-parser
1644 %%
1645 start: 'a' | A 'a' ;
1646 A: ;
1647 ]])
1648 AT_DATA([[rr.y]],
1649 [[%glr-parser
1650 %%
1651 start: A | B ;
1652 A: ;
1653 B: ;
1654 ]])
1655
1656 AT_BISON_CHECK([[sr-rr.y]], [[0]], [[]],
1657 [[sr-rr.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
1658 sr-rr.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
1659 ]])
1660 AT_BISON_CHECK([[-Wno-conflicts-sr sr-rr.y]], [[0]], [[]],
1661 [[sr-rr.y: warning: 1 reduce/reduce conflict [-Wconflicts-rr]
1662 ]])
1663 AT_BISON_CHECK([[-Wno-conflicts-rr sr-rr.y]], [[0]], [[]],
1664 [[sr-rr.y: warning: 1 shift/reduce conflict [-Wconflicts-sr]
1665 ]])
1666
1667 [
1668 # This is piece of code is rather complex for a simple task: try every
1669 # combinaison of (0 or 1 real SR) x (0 or 1 real RR) x (don't %expect
1670 # or %expect 0, 1, or 2 SR) x (don't %expect-rr or %expect-rr 0, 1, or 2
1671 # RR).
1672
1673 # Number and types of genuine conflicts in the grammar.
1674 for gram in sr-rr sr rr; do
1675   # Number of expected s/r conflicts.
1676   for sr_exp_i in '' 0 1 2; do
1677     # Number of expected r/r conflicts.
1678     for rr_exp_i in '' 0 1 2; do
1679       test -z "$sr_exp_i" && test -z "$rr_exp_i" && continue
1680
1681       # Build grammar file.
1682       sr_exp=0
1683       rr_exp=0
1684       file=$gram
1685       directives=
1686       if test -n "$sr_exp_i"; then
1687         sr_exp=$sr_exp_i
1688         file=$file-expect-$sr_exp
1689         directives="%expect $sr_exp"
1690       fi
1691       if test -n "$rr_exp_i"; then
1692         rr_exp=$rr_exp_i
1693         file=$file-expect-rr-$rr_exp
1694         directives="$directives %expect-rr $rr_exp"
1695       fi
1696       file=$file.y
1697       echo "$directives" > $file
1698       cat $gram.y >> $file
1699
1700       # Number of found conflicts.
1701       case $gram in
1702         (sr)    sr_count=1; rr_count=0;;
1703         (rr)    sr_count=0; rr_count=1;;
1704         (sr-rr) sr_count=1; rr_count=1;;
1705       esac
1706
1707       # Update number of expected conflicts: if %expect is given then
1708       # %expect-rr defaults to 0, and vice-versa.  Leave empty if
1709       # nothing expected.
1710       case $sr_exp_i:$rr_exp_i in
1711         ?:) rr_exp_i=0;;
1712         :?) sr_exp_i=0;;
1713       esac
1714
1715       # Run tests.
1716       if test $sr_count -eq $sr_exp && test $rr_count -eq $rr_exp; then
1717         ]AT_BISON_CHECK([[-Wnone $file]])[
1718         ]AT_BISON_CHECK([[-Werror $file]])[
1719       else
1720         {
1721           if test -z "$sr_exp_i" && test "$sr_count" -ne 0; then
1722             echo "warning: $sr_count shift/reduce conflicts"
1723           elif test "$sr_exp_i" -ne "$sr_count"; then
1724             echo "error: shift/reduce conflicts: $sr_count found, $sr_exp_i expected"
1725           fi
1726           if test -z "$rr_exp_i" && test "$rr_count" -ne 0; then
1727             echo "warning: $rr_count reduce/reduce conflicts"
1728           elif test "$rr_exp_i" -ne "$rr_count"; then
1729             echo "error: reduce/reduce conflicts: $rr_count found, $rr_exp_i expected"
1730           fi
1731         } | sed -e "s/^/$file: /" > experr
1732         ]AT_BISON_CHECK([[-Wnone $file]], [[1]], [[]], [[experr]])[
1733         ]AT_BISON_CHECK([[-Werror $file]], [[1]], [[]], [[experr]])[
1734       fi
1735     done
1736   done
1737 done]
1738
1739 AT_CLEANUP