1 # Exercising Bison on conflicts. -*- Autotest -*- 2 3 # Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc. 4 5 # This program is free software; you can redistribute it and/or modify 6 # it under the terms of the GNU General Public License as published by 7 # the Free Software Foundation; either version 2, or (at your option) 8 # any later version. 9 10 # This program is distributed in the hope that it will be useful, 11 # but WITHOUT ANY WARRANTY; without even the implied warranty of 12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 # GNU General Public License for more details. 14 15 # You should have received a copy of the GNU General Public License 16 # along with this program; if not, write to the Free Software 17 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 18 # 02110-1301, USA. 19 20 AT_BANNER([[Conflicts.]]) 21 22 23 ## ---------------- ## 24 ## S/R in initial. ## 25 ## ---------------- ## 26 27 # I once hacked Bison in such a way that it lost its reductions on the 28 # initial state (because it was confusing it with the last state). It 29 # took me a while to strip down my failures to this simple case. So 30 # make sure it finds the s/r conflict below. 31 32 AT_SETUP([S/R in initial]) 33 34 AT_DATA([[input.y]], 35 [[%expect 1 36 %% 37 exp: e 'e'; 38 e: 'e' | /* Nothing. */; 39 ]]) 40 41 AT_CHECK([bison -o input.c input.y], 0, [], 42 [[input.y:4.9: warning: rule never reduced because of conflicts: e: /* empty */ 43 ]]) 44 45 AT_CLEANUP 46 47 48 ## ------------------- ## 49 ## %nonassoc and eof. ## 50 ## ------------------- ## 51 52 AT_SETUP([%nonassoc and eof]) 53 54 AT_DATA_GRAMMAR([input.y], 55 [[ 56 %{ 57 #include <stdio.h> 58 #include <stdlib.h> 59 60 #define YYERROR_VERBOSE 1 61 static void 62 yyerror (const char *msg) 63 { 64 fprintf (stderr, "%s\n", msg); 65 } 66 67 /* The current argument. */ 68 static const char *input = NULL; 69 70 static int 71 yylex (void) 72 { 73 /* No token stands for end of file. */ 74 if (input && *input) 75 return *input++; 76 else 77 return 0; 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 if (argc > 1) 94 input = argv[1]; 95 return yyparse (); 96 } 97 ]]) 98 99 # Specify the output files to avoid problems on different file systems. 100 AT_CHECK([bison -o input.c input.y]) 101 AT_COMPILE([input]) 102 103 AT_PARSER_CHECK([./input '0<0']) 104 # FIXME: This is an actual bug, but a new one, in the sense that 105 # no one has ever spotted it! The messages are *wrong*: there should 106 # be nothing there, it should be expected eof. 107 AT_PARSER_CHECK([./input '0<0<0'], [1], [], 108 [syntax error, unexpected '<', expecting '<' or '>' 109 ]) 110 111 AT_PARSER_CHECK([./input '0>0']) 112 AT_PARSER_CHECK([./input '0>0>0'], [1], [], 113 [syntax error, unexpected '>', expecting '<' or '>' 114 ]) 115 116 AT_PARSER_CHECK([./input '0<0>0'], [1], [], 117 [syntax error, unexpected '>', expecting '<' or '>' 118 ]) 119 120 AT_CLEANUP 121 122 123 124 ## ------------------------- ## 125 ## Unresolved SR Conflicts. ## 126 ## ------------------------- ## 127 128 AT_SETUP([Unresolved SR Conflicts]) 129 130 AT_KEYWORDS([report]) 131 132 AT_DATA([input.y], 133 [[%token NUM OP 134 %% 135 exp: exp OP exp | NUM; 136 ]]) 137 138 AT_CHECK([bison -o input.c --report=all input.y], 0, [], 139 [input.y: conflicts: 1 shift/reduce 140 ]) 141 142 # Check the contents of the report. 143 AT_CHECK([cat input.output], [], 144 [[State 5 conflicts: 1 shift/reduce 145 146 147 Grammar 148 149 0 $accept: exp $end 150 151 1 exp: exp OP exp 152 2 | NUM 153 154 155 Terminals, with rules where they appear 156 157 $end (0) 0 158 error (256) 159 NUM (258) 2 160 OP (259) 1 161 162 163 Nonterminals, with rules where they appear 164 165 $accept (5) 166 on left: 0 167 exp (6) 168 on left: 1 2, on right: 0 1 169 170 171 state 0 172 173 0 $accept: . exp $end 174 1 exp: . exp OP exp 175 2 | . NUM 176 177 NUM shift, and go to state 1 178 179 exp go to state 2 180 181 182 state 1 183 184 2 exp: NUM . 185 186 $default reduce using rule 2 (exp) 187 188 189 state 2 190 191 0 $accept: exp . $end 192 1 exp: exp . OP exp 193 194 $end shift, and go to state 3 195 OP shift, and go to state 4 196 197 198 state 3 199 200 0 $accept: exp $end . 201 202 $default accept 203 204 205 state 4 206 207 1 exp: . exp OP exp 208 1 | exp OP . exp 209 2 | . NUM 210 211 NUM shift, and go to state 1 212 213 exp go to state 5 214 215 216 state 5 217 218 1 exp: exp . OP exp [$end, OP] 219 1 | exp OP exp . [$end, OP] 220 221 OP shift, and go to state 4 222 223 OP [reduce using rule 1 (exp)] 224 $default reduce using rule 1 (exp) 225 ]]) 226 227 AT_CLEANUP 228 229 230 231 ## ----------------------- ## 232 ## Resolved SR Conflicts. ## 233 ## ----------------------- ## 234 235 AT_SETUP([Resolved SR Conflicts]) 236 237 AT_KEYWORDS([report]) 238 239 AT_DATA([input.y], 240 [[%token NUM OP 241 %left OP 242 %% 243 exp: exp OP exp | NUM; 244 ]]) 245 246 AT_CHECK([bison -o input.c --report=all input.y]) 247 248 # Check the contents of the report. 249 AT_CHECK([cat input.output], [], 250 [[Grammar 251 252 0 $accept: exp $end 253 254 1 exp: exp OP exp 255 2 | NUM 256 257 258 Terminals, with rules where they appear 259 260 $end (0) 0 261 error (256) 262 NUM (258) 2 263 OP (259) 1 264 265 266 Nonterminals, with rules where they appear 267 268 $accept (5) 269 on left: 0 270 exp (6) 271 on left: 1 2, on right: 0 1 272 273 274 state 0 275 276 0 $accept: . exp $end 277 1 exp: . exp OP exp 278 2 | . NUM 279 280 NUM shift, and go to state 1 281 282 exp go to state 2 283 284 285 state 1 286 287 2 exp: NUM . 288 289 $default reduce using rule 2 (exp) 290 291 292 state 2 293 294 0 $accept: exp . $end 295 1 exp: exp . OP exp 296 297 $end shift, and go to state 3 298 OP shift, and go to state 4 299 300 301 state 3 302 303 0 $accept: exp $end . 304 305 $default accept 306 307 308 state 4 309 310 1 exp: . exp OP exp 311 1 | exp OP . exp 312 2 | . NUM 313 314 NUM shift, and go to state 1 315 316 exp go to state 5 317 318 319 state 5 320 321 1 exp: exp . OP exp [$end, OP] 322 1 | exp OP exp . [$end, OP] 323 324 $default reduce using rule 1 (exp) 325 326 Conflict between rule 1 and token OP resolved as reduce (%left OP). 327 ]]) 328 329 AT_CLEANUP 330 331 332 ## -------------------------------- ## 333 ## Defaulted Conflicted Reduction. ## 334 ## -------------------------------- ## 335 336 # When there are RR conflicts, some rules are disabled. Usually it is 337 # simply displayed as: 338 # 339 # $end reduce using rule 3 (num) 340 # $end [reduce using rule 4 (id)] 341 # 342 # But when `reduce 3' is the default action, we'd produce: 343 # 344 # $end [reduce using rule 4 (id)] 345 # $default reduce using rule 3 (num) 346 # 347 # In this precise case (a reduction is masked by the default 348 # reduction), we make the `reduce 3' explicit: 349 # 350 # $end reduce using rule 3 (num) 351 # $end [reduce using rule 4 (id)] 352 # $default reduce using rule 3 (num) 353 # 354 # Maybe that's not the best display, but then, please propose something 355 # else. 356 357 AT_SETUP([Defaulted Conflicted Reduction]) 358 AT_KEYWORDS([report]) 359 360 AT_DATA([input.y], 361 [[%% 362 exp: num | id; 363 num: '0'; 364 id : '0'; 365 %% 366 ]]) 367 368 AT_CHECK([bison -o input.c --report=all input.y], 0, [], 369 [[input.y: conflicts: 1 reduce/reduce 370 input.y:4.6-8: warning: rule never reduced because of conflicts: id: '0' 371 ]]) 372 373 # Check the contents of the report. 374 AT_CHECK([cat input.output], [], 375 [[Rules never reduced 376 377 4 id: '0' 378 379 380 State 1 conflicts: 1 reduce/reduce 381 382 383 Grammar 384 385 0 $accept: exp $end 386 387 1 exp: num 388 2 | id 389 390 3 num: '0' 391 392 4 id: '0' 393 394 395 Terminals, with rules where they appear 396 397 $end (0) 0 398 '0' (48) 3 4 399 error (256) 400 401 402 Nonterminals, with rules where they appear 403 404 $accept (4) 405 on left: 0 406 exp (5) 407 on left: 1 2, on right: 0 408 num (6) 409 on left: 3, on right: 1 410 id (7) 411 on left: 4, on right: 2 412 413 414 state 0 415 416 0 $accept: . exp $end 417 1 exp: . num 418 2 | . id 419 3 num: . '0' 420 4 id: . '0' 421 422 '0' shift, and go to state 1 423 424 exp go to state 2 425 num go to state 3 426 id go to state 4 427 428 429 state 1 430 431 3 num: '0' . [$end] 432 4 id: '0' . [$end] 433 434 $end reduce using rule 3 (num) 435 $end [reduce using rule 4 (id)] 436 $default reduce using rule 3 (num) 437 438 439 state 2 440 441 0 $accept: exp . $end 442 443 $end shift, and go to state 5 444 445 446 state 3 447 448 1 exp: num . 449 450 $default reduce using rule 1 (exp) 451 452 453 state 4 454 455 2 exp: id . 456 457 $default reduce using rule 2 (exp) 458 459 460 state 5 461 462 0 $accept: exp $end . 463 464 $default accept 465 ]]) 466 467 AT_CLEANUP 468 469 470 471 472 ## -------------------- ## 473 ## %expect not enough. ## 474 ## -------------------- ## 475 476 AT_SETUP([%expect not enough]) 477 478 AT_DATA([input.y], 479 [[%token NUM OP 480 %expect 0 481 %% 482 exp: exp OP exp | NUM; 483 ]]) 484 485 AT_CHECK([bison -o input.c input.y], 1, [], 486 [input.y: conflicts: 1 shift/reduce 487 input.y: expected 0 shift/reduce conflicts 488 ]) 489 AT_CLEANUP 490 491 492 ## --------------- ## 493 ## %expect right. ## 494 ## --------------- ## 495 496 AT_SETUP([%expect right]) 497 498 AT_DATA([input.y], 499 [[%token NUM OP 500 %expect 1 501 %% 502 exp: exp OP exp | NUM; 503 ]]) 504 505 AT_CHECK([bison -o input.c input.y]) 506 AT_CLEANUP 507 508 509 ## ------------------ ## 510 ## %expect too much. ## 511 ## ------------------ ## 512 513 AT_SETUP([%expect too much]) 514 515 AT_DATA([input.y], 516 [[%token NUM OP 517 %expect 2 518 %% 519 exp: exp OP exp | NUM; 520 ]]) 521 522 AT_CHECK([bison -o input.c input.y], 1, [], 523 [input.y: conflicts: 1 shift/reduce 524 input.y: expected 2 shift/reduce conflicts 525 ]) 526 AT_CLEANUP 527 528 529 ## ------------------------------ ## 530 ## %expect with reduce conflicts ## 531 ## ------------------------------ ## 532 533 AT_SETUP([%expect with reduce conflicts]) 534 535 AT_DATA([input.y], 536 [[%expect 0 537 %% 538 program: a 'a' | a a; 539 a: 'a'; 540 ]]) 541 542 AT_CHECK([bison -o input.c input.y], 1, [], 543 [input.y: conflicts: 1 reduce/reduce 544 input.y: expected 0 reduce/reduce conflicts 545 ]) 546 AT_CLEANUP 547 548 549 ## ------------------------------- ## 550 ## %no-default-prec without %prec ## 551 ## ------------------------------- ## 552 553 AT_SETUP([%no-default-prec without %prec]) 554 555 AT_DATA([[input.y]], 556 [[%left '+' 557 %left '*' 558 559 %% 560 561 %no-default-prec; 562 563 e: e '+' e 564 | e '*' e 565 | '0' 566 ; 567 ]]) 568 569 AT_CHECK([bison -o input.c input.y], 0, [], 570 [[input.y: conflicts: 4 shift/reduce 571 ]]) 572 AT_CLEANUP 573 574 575 ## ---------------------------- ## 576 ## %no-default-prec with %prec ## 577 ## ---------------------------- ## 578 579 AT_SETUP([%no-default-prec with %prec]) 580 581 AT_DATA([[input.y]], 582 [[%left '+' 583 %left '*' 584 585 %% 586 587 %no-default-prec; 588 589 e: e '+' e %prec '+' 590 | e '*' e %prec '*' 591 | '0' 592 ; 593 ]]) 594 595 AT_CHECK([bison -o input.c input.y]) 596 AT_CLEANUP 597 598 599 ## ---------------- ## 600 ## %default-prec ## 601 ## ---------------- ## 602 603 AT_SETUP([%default-prec]) 604 605 AT_DATA([[input.y]], 606 [[%left '+' 607 %left '*' 608 609 %% 610 611 %default-prec; 612 613 e: e '+' e 614 | e '*' e 615 | '0' 616 ; 617 ]]) 618 619 AT_CHECK([bison -o input.c input.y]) 620 AT_CLEANUP 621
