gdb/ch-exp.y

   1 /* YACC grammar for Chill expressions, for GDB.
   2    Copyright (C) 1992 Free Software Foundation, Inc.
   3
   4 This file is part of GDB.
   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 2 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, write to the Free Software
  18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20 /* Parse a Chill expression from text in a string,
  21    and return the result as a  struct expression  pointer.
  22    That structure contains arithmetic operations in reverse polish,
  23    with constants represented by operations that are followed by special data.
  24    See expression.h for the details of the format.
  25    What is important here is that it can be built up sequentially
  26    during the process of parsing; the lower levels of the tree always
  27    come first in the result.
  28
  29    Note that malloc's and realloc's in this file are transformed to
  30    xmalloc and xrealloc respectively by the same sed command in the
  31    makefile that remaps any other malloc/realloc inserted by the parser
  32    generator.  Doing this with #defines and trying to control the interaction
  33    with include files (<malloc.h> and <stdlib.h> for example) just became
  34    too messy, particularly when such includes can be inserted at random
  35    times by the parser generator.
  36
  37    Also note that the language accepted by this parser is more liberal
  38    than the one accepted by an actual Chill compiler.  For example, the
  39    language rule that a simple name string can not be one of the reserved
  40    simple name strings is not enforced (e.g "case" is not treated as a
  41    reserved name).  Another example is that Chill is a strongly typed
  42    language, and certain expressions that violate the type constraints
  43    may still be evaluated if gdb can do so in a meaningful manner, while
  44    such expressions would be rejected by the compiler.  The reason for
  45    this more liberal behavior is the philosophy that the debugger
  46    is intended to be a tool that is used by the programmer when things
  47    go wrong, and as such, it should provide as few artificial barriers
  48    to it's use as possible.  If it can do something meaningful, even
  49    something that violates language contraints that are enforced by the
  50    compiler, it should do so without complaint.
  51
  52  */
  53
  54 %{
  55
  56 #include "defs.h"
  57 #include "expression.h"
  58 #include "language.h"
  59 #include "value.h"
  60 #include "parser-defs.h"
  61 #include "ch-lang.h"
  62
  63 /* These MUST be included in any grammar file!!!! Please choose unique names!
  64    Note that this are a combined list of variables that can be produced
  65    by any one of bison, byacc, or yacc. */
  66 #define yymaxdepth chill_maxdepth
  67 #define yyparse chill_parse
  68 #define yylex   chill_lex
  69 #define yyerror chill_error
  70 #define yylval  chill_lval
  71 #define yychar  chill_char
  72 #define yydebug chill_debug
  73 #define yypact  chill_pact
  74 #define yyr1    chill_r1
  75 #define yyr2    chill_r2
  76 #define yydef   chill_def
  77 #define yychk   chill_chk
  78 #define yypgo   chill_pgo
  79 #define yyact   chill_act
  80 #define yyexca  chill_exca
  81 #define yyerrflag chill_errflag
  82 #define yynerrs chill_nerrs
  83 #define yyps    chill_ps
  84 #define yypv    chill_pv
  85 #define yys     chill_s
  86 #define yy_yys  chill_yys
  87 #define yystate chill_state
  88 #define yytmp   chill_tmp
  89 #define yyv     chill_v
  90 #define yy_yyv  chill_yyv
  91 #define yyval   chill_val
  92 #define yylloc  chill_lloc
  93 #define yyss    chill_yyss              /* byacc */
  94 #define yyssp   chill_yysp              /* byacc */
  95 #define yyvs    chill_yyvs              /* byacc */
  96 #define yyvsp   chill_yyvsp     /* byacc */
  97
  98 static int
  99 yylex PARAMS ((void));
 100
 101 void
 102 yyerror PARAMS ((char *));
 103
 104 int
 105 yyparse PARAMS ((void));
 106
 107 /* #define      YYDEBUG 1 */
 108
 109 %}
 110
 111 /* Although the yacc "value" of an expression is not used,
 112    since the result is stored in the structure being created,
 113    other node types do have values.  */
 114
 115 %union
 116   {
 117     LONGEST lval;
 118     unsigned LONGEST ulval;
 119     struct {
 120       LONGEST val;
 121       struct type *type;
 122     } typed_val;
 123     double dval;
 124     struct symbol *sym;
 125     struct type *tval;
 126     struct stoken sval;
 127     struct ttype tsym;
 128     struct symtoken ssym;
 129     int voidval;
 130     struct block *bval;
 131     enum exp_opcode opcode;
 132     struct internalvar *ivar;
 133
 134     struct type **tvec;
 135     int *ivec;
 136   }
 137
 138 %{
 139 static int parse_number PARAMS ((void));
 140 %}
 141
 142 %token <voidval> FIXME
 143
 144 %token <typed_val>      INTEGER_LITERAL
 145 %token <ulval>          BOOLEAN_LITERAL
 146 %token <typed_val>      CHARACTER_LITERAL
 147 %token <ssym>           GENERAL_PROCEDURE_NAME
 148 %token <ssym>           LOCATION_NAME
 149 %token <voidval>        SET_LITERAL
 150 %token <voidval>        EMPTINESS_LITERAL
 151 %token <voidval>        CHARACTER_STRING_LITERAL
 152 %token <voidval>        BIT_STRING_LITERAL
 153
 154 %token <voidval>        STRING
 155 %token <voidval>        CONSTANT
 156 %token <voidval>        '.'
 157 %token <voidval>        ';'
 158 %token <voidval>        ':'
 159 %token <voidval>        CASE
 160 %token <voidval>        OF
 161 %token <voidval>        ESAC
 162 %token <voidval>        LOGIOR
 163 %token <voidval>        ORIF
 164 %token <voidval>        LOGXOR
 165 %token <voidval>        LOGAND
 166 %token <voidval>        ANDIF
 167 %token <voidval>        '='
 168 %token <voidval>        NOTEQUAL
 169 %token <voidval>        '>'
 170 %token <voidval>        GTR
 171 %token <voidval>        '<'
 172 %token <voidval>        LEQ
 173 %token <voidval>        IN
 174 %token <voidval>        '+'
 175 %token <voidval>        '-'
 176 %token <voidval>        '*'
 177 %token <voidval>        '/'
 178 %token <voidval>        SLASH_SLASH
 179 %token <voidval>        MOD
 180 %token <voidval>        REM
 181 %token <voidval>        NOT
 182 %token <voidval>        POINTER
 183 %token <voidval>        RECEIVE
 184 %token <voidval>        SC
 185 %token <voidval>        '['
 186 %token <voidval>        ']'
 187 %token <voidval>        '('
 188 %token <voidval>        ')'
 189 %token <voidval>        UP
 190 %token <voidval>        IF
 191 %token <voidval>        THEN
 192 %token <voidval>        ELSE
 193 %token <voidval>        FI
 194 %token <voidval>        ELSIF
 195 %token <voidval>        ILLEGAL_TOKEN
 196
 197 %type <voidval>         location
 198 %type <voidval>         access_name
 199 %type <voidval>         primitive_value
 200 %type <voidval>         location_contents
 201 %type <voidval>         value_name
 202 %type <voidval>         literal
 203 %type <voidval>         tuple
 204 %type <voidval>         value_string_element
 205 %type <voidval>         value_string_slice
 206 %type <voidval>         value_array_element
 207 %type <voidval>         value_array_slice
 208 %type <voidval>         value_structure_field
 209 %type <voidval>         expression_conversion
 210 %type <voidval>         value_procedure_call
 211 %type <voidval>         value_built_in_routine_call
 212 %type <voidval>         start_expression
 213 %type <voidval>         zero_adic_operator
 214 %type <voidval>         parenthesised_expression
 215 %type <voidval>         value
 216 %type <voidval>         undefined_value
 217 %type <voidval>         expression
 218 %type <voidval>         conditional_expression
 219 %type <voidval>         then_alternative
 220 %type <voidval>         else_alternative
 221 %type <voidval>         sub_expression
 222 %type <voidval>         value_case_alternative
 223 %type <voidval>         operand_0
 224 %type <voidval>         operand_1
 225 %type <voidval>         operand_2
 226 %type <voidval>         operand_3
 227 %type <voidval>         operand_4
 228 %type <voidval>         operand_5
 229 %type <voidval>         operand_6
 230 %type <voidval>         integer_literal_expression
 231 %type <voidval>         synonym_name
 232 %type <voidval>         value_enumeration_name
 233 %type <voidval>         value_do_with_name
 234 %type <voidval>         value_receive_name
 235 %type <voidval>         string_primitive_value
 236 %type <voidval>         start_element
 237 %type <voidval>         left_element
 238 %type <voidval>         right_element
 239 %type <voidval>         slice_size
 240 %type <voidval>         array_primitive_value
 241 %type <voidval>         expression_list
 242 %type <voidval>         lower_element
 243 %type <voidval>         upper_element
 244 %type <voidval>         first_element
 245 %type <voidval>         structure_primitive_value
 246 %type <voidval>         field_name
 247 %type <voidval>         mode_name
 248 %type <voidval>         boolean_expression
 249 %type <voidval>         case_selector_list
 250 %type <voidval>         subexpression
 251 %type <voidval>         case_label_specification
 252 %type <voidval>         buffer_location
 253
 254 %%
 255
 256 /* Z.200, 5.3.1 */
 257
 258 value           :       expression
 259                         {
 260                           $$ = 0;       /* FIXME */
 261                         }
 262                 |       undefined_value
 263                         {
 264                           $$ = 0;       /* FIXME */
 265                         }
 266                 ;
 267
 268 undefined_value :       FIXME
 269                         {
 270                           $$ = 0;       /* FIXME */
 271                         }
 272                 ;
 273
 274 /* Z.200, 4.2.1 */
 275
 276 location        :       access_name
 277                         {
 278                           $$ = 0;       /* FIXME */
 279                         }
 280                 |       FIXME
 281                         {
 282                           $$ = 0;       /* FIXME */
 283                         }
 284                 ;
 285
 286 /* Z.200, 4.2.2 */
 287
 288 access_name     :       LOCATION_NAME
 289                         {
 290                           write_exp_elt_opcode (OP_VAR_VALUE);
 291                           write_exp_elt_sym ($1.sym);
 292                           write_exp_elt_opcode (OP_VAR_VALUE);
 293                         }
 294                 |       FIXME
 295                         {
 296                           $$ = 0;       /* FIXME */
 297                         }
 298                 ;
 299
 300 /* Z.200, 5.2.1 */
 301
 302 primitive_value :       location_contents
 303                         {
 304                           $$ = 0;       /* FIXME */
 305                         }
 306                 |       value_name
 307                         {
 308                           $$ = 0;       /* FIXME */
 309                         }
 310                 |       literal
 311                         {
 312                           $$ = 0;       /* FIXME */
 313                         }
 314                 |       tuple
 315                         {
 316                           $$ = 0;       /* FIXME */
 317                         }
 318                 |       value_string_element
 319                         {
 320                           $$ = 0;       /* FIXME */
 321                         }
 322                 |       value_string_slice
 323                         {
 324                           $$ = 0;       /* FIXME */
 325                         }
 326                 |       value_array_element
 327                         {
 328                           $$ = 0;       /* FIXME */
 329                         }
 330                 |       value_array_slice
 331                         {
 332                           $$ = 0;       /* FIXME */
 333                         }
 334                 |       value_structure_field
 335                         {
 336                           $$ = 0;       /* FIXME */
 337                         }
 338                 |       expression_conversion
 339                         {
 340                           $$ = 0;       /* FIXME */
 341                         }
 342                 |       value_procedure_call
 343                         {
 344                           $$ = 0;       /* FIXME */
 345                         }
 346                 |       value_built_in_routine_call
 347                         {
 348                           $$ = 0;       /* FIXME */
 349                         }
 350                 |       start_expression
 351                         {
 352                           $$ = 0;       /* FIXME */
 353                         }
 354                 |       zero_adic_operator
 355                         {
 356                           $$ = 0;       /* FIXME */
 357                         }
 358                 |       parenthesised_expression
 359                         {
 360                           $$ = 0;       /* FIXME */
 361                         }
 362                 ;
 363
 364 /* Z.200, 5.2.2 */
 365
 366 location_contents:      location
 367                         {
 368                           $$ = 0;       /* FIXME */
 369                         }
 370                 ;
 371
 372 /* Z.200, 5.2.3 */
 373
 374 value_name      :       synonym_name
 375                         {
 376                           $$ = 0;       /* FIXME */
 377                         }
 378                 |       value_enumeration_name
 379                         {
 380                           $$ = 0;       /* FIXME */
 381                         }
 382                 |       value_do_with_name
 383                         {
 384                           $$ = 0;       /* FIXME */
 385                         }
 386                 |       value_receive_name
 387                         {
 388                           $$ = 0;       /* FIXME */
 389                         }
 390                 |       GENERAL_PROCEDURE_NAME
 391                         {
 392                           write_exp_elt_opcode (OP_VAR_VALUE);
 393                           write_exp_elt_sym ($1.sym);
 394                           write_exp_elt_opcode (OP_VAR_VALUE);
 395                         }
 396                 ;
 397
 398 /* Z.200, 5.2.4.1 */
 399
 400 literal         :       INTEGER_LITERAL
 401                         {
 402                           write_exp_elt_opcode (OP_LONG);
 403                           write_exp_elt_type ($1.type);
 404                           write_exp_elt_longcst ((LONGEST) ($1.val));
 405                           write_exp_elt_opcode (OP_LONG);
 406                         }
 407                 |       BOOLEAN_LITERAL
 408                         {
 409                           write_exp_elt_opcode (OP_BOOL);
 410                           write_exp_elt_longcst ((LONGEST) $1);
 411                           write_exp_elt_opcode (OP_BOOL);
 412                         }
 413                 |       CHARACTER_LITERAL
 414                         {
 415                           write_exp_elt_opcode (OP_LONG);
 416                           write_exp_elt_type ($1.type);
 417                           write_exp_elt_longcst ((LONGEST) ($1.val));
 418                           write_exp_elt_opcode (OP_LONG);
 419                         }
 420                 |       SET_LITERAL
 421                         {
 422                           $$ = 0;       /* FIXME */
 423                         }
 424                 |       EMPTINESS_LITERAL
 425                         {
 426                           $$ = 0;       /* FIXME */
 427                         }
 428                 |       CHARACTER_STRING_LITERAL
 429                         {
 430                           $$ = 0;       /* FIXME */
 431                         }
 432                 |       BIT_STRING_LITERAL
 433                         {
 434                           $$ = 0;       /* FIXME */
 435                         }
 436                 ;
 437
 438 /* Z.200, 5.2.5 */
 439
 440 tuple           :       FIXME
 441                         {
 442                           $$ = 0;       /* FIXME */
 443                         }
 444                 ;
 445
 446
 447 /* Z.200, 5.2.6 */
 448
 449 value_string_element:   string_primitive_value '(' start_element ')'
 450                         {
 451                           $$ = 0;       /* FIXME */
 452                         }
 453                 ;
 454
 455 /* Z.200, 5.2.7 */
 456
 457 value_string_slice:     string_primitive_value '(' left_element ':' right_element ')'
 458                         {
 459                           $$ = 0;       /* FIXME */
 460                         }
 461                 |       string_primitive_value '(' start_element UP slice_size ')'
 462                         {
 463                           $$ = 0;       /* FIXME */
 464                         }
 465                 ;
 466
 467 /* Z.200, 5.2.8 */
 468
 469 value_array_element:    array_primitive_value '(' expression_list ')'
 470                         {
 471                           $$ = 0;       /* FIXME */
 472                         }
 473                 ;
 474
 475 /* Z.200, 5.2.9 */
 476
 477 value_array_slice:      array_primitive_value '(' lower_element ':' upper_element ')'
 478                         {
 479                           $$ = 0;       /* FIXME */
 480                         }
 481                 |       array_primitive_value '(' first_element UP slice_size '('
 482                         {
 483                           $$ = 0;       /* FIXME */
 484                         }
 485                 ;
 486
 487 /* Z.200, 5.2.10 */
 488
 489 value_structure_field:  structure_primitive_value '.' field_name
 490                         {
 491                           $$ = 0;       /* FIXME */
 492                         }
 493                 ;
 494
 495 /* Z.200, 5.2.11 */
 496
 497 expression_conversion:  mode_name '(' expression ')'
 498                         {
 499                           $$ = 0;       /* FIXME */
 500                         }
 501                 ;
 502
 503 /* Z.200, 5.2.12 */
 504
 505 value_procedure_call:   FIXME
 506                         {
 507                           $$ = 0;       /* FIXME */
 508                         }
 509                 ;
 510
 511 /* Z.200, 5.2.13 */
 512
 513 value_built_in_routine_call:    FIXME
 514                         {
 515                           $$ = 0;       /* FIXME */
 516                         }
 517                 ;
 518
 519 /* Z.200, 5.2.14 */
 520
 521 start_expression:       FIXME
 522                         {
 523                           $$ = 0;       /* FIXME */
 524                         }       /* Not in GNU-Chill */
 525                 ;
 526
 527 /* Z.200, 5.2.15 */
 528
 529 zero_adic_operator:     FIXME
 530                         {
 531                           $$ = 0;       /* FIXME */
 532                         }
 533                 ;
 534
 535 /* Z.200, 5.2.16 */
 536
 537 parenthesised_expression:       '(' expression ')'
 538                         {
 539                           $$ = 0;       /* FIXME */
 540                         }
 541                 ;
 542
 543 /* Z.200, 5.3.2 */
 544
 545 expression      :       operand_0
 546                         {
 547                           $$ = 0;       /* FIXME */
 548                         }
 549                 |       conditional_expression
 550                         {
 551                           $$ = 0;       /* FIXME */
 552                         }
 553                 ;
 554
 555 conditional_expression : IF boolean_expression then_alternative else_alternative FI
 556                         {
 557                           $$ = 0;       /* FIXME */
 558                         }
 559                 |       CASE case_selector_list OF value_case_alternative '[' ELSE sub_expression ']' ESAC
 560                         {
 561                           $$ = 0;       /* FIXME */
 562                         }
 563                 ;
 564
 565 then_alternative:       THEN subexpression
 566                         {
 567                           $$ = 0;       /* FIXME */
 568                         }
 569                 ;
 570
 571 else_alternative:       ELSE subexpression
 572                         {
 573                           $$ = 0;       /* FIXME */
 574                         }
 575                 |       ELSIF boolean_expression then_alternative else_alternative
 576                         {
 577                           $$ = 0;       /* FIXME */
 578                         }
 579                 ;
 580
 581 sub_expression  :       expression
 582                         {
 583                           $$ = 0;       /* FIXME */
 584                         }
 585                 ;
 586
 587 value_case_alternative: case_label_specification ':' sub_expression ';'
 588                         {
 589                           $$ = 0;       /* FIXME */
 590                         }
 591                 ;
 592
 593 /* Z.200, 5.3.3 */
 594
 595 operand_0       :       operand_1
 596                         {
 597                           $$ = 0;       /* FIXME */
 598                         }
 599                 |       operand_0 LOGIOR operand_1
 600                         {
 601                           write_exp_elt_opcode (BINOP_BITWISE_IOR);
 602                         }
 603                 |       operand_0 ORIF operand_1
 604                         {
 605                           $$ = 0;       /* FIXME */
 606                         }
 607                 |       operand_0 LOGXOR operand_1
 608                         {
 609                           write_exp_elt_opcode (BINOP_BITWISE_XOR);
 610                         }
 611                 ;
 612
 613 /* Z.200, 5.3.4 */
 614
 615 operand_1       :       operand_2
 616                         {
 617                           $$ = 0;       /* FIXME */
 618                         }
 619                 |       operand_1 LOGAND operand_2
 620                         {
 621                           write_exp_elt_opcode (BINOP_BITWISE_AND);
 622                         }
 623                 |       operand_1 ANDIF operand_2
 624                         {
 625                           $$ = 0;       /* FIXME */
 626                         }
 627                 ;
 628
 629 /* Z.200, 5.3.5 */
 630
 631 operand_2       :       operand_3
 632                         {
 633                           $$ = 0;       /* FIXME */
 634                         }
 635                 |       operand_2 '=' operand_3
 636                         {
 637                           write_exp_elt_opcode (BINOP_EQUAL);
 638                         }
 639                 |       operand_2 NOTEQUAL operand_3
 640                         {
 641                           write_exp_elt_opcode (BINOP_NOTEQUAL);
 642                         }
 643                 |       operand_2 '>' operand_3
 644                         {
 645                           write_exp_elt_opcode (BINOP_GTR);
 646                         }
 647                 |       operand_2 GTR operand_3
 648                         {
 649                           write_exp_elt_opcode (BINOP_GEQ);
 650                         }
 651                 |       operand_2 '<' operand_3
 652                         {
 653                           write_exp_elt_opcode (BINOP_LESS);
 654                         }
 655                 |       operand_2 LEQ operand_3
 656                         {
 657                           write_exp_elt_opcode (BINOP_LEQ);
 658                         }
 659                 |       operand_2 IN operand_3
 660                         {
 661                           $$ = 0;       /* FIXME */
 662                         }
 663                 ;
 664
 665
 666 /* Z.200, 5.3.6 */
 667
 668 operand_3       :       operand_4
 669                         {
 670                           $$ = 0;       /* FIXME */
 671                         }
 672                 |       operand_3 '+' operand_4
 673                         {
 674                           write_exp_elt_opcode (BINOP_ADD);
 675                         }
 676                 |       operand_3 '-' operand_4
 677                         {
 678                           write_exp_elt_opcode (BINOP_SUB);
 679                         }
 680                 |       operand_3 SLASH_SLASH operand_4
 681                         {
 682                           $$ = 0;       /* FIXME */
 683                         }
 684                 ;
 685
 686 /* Z.200, 5.3.7 */
 687
 688 operand_4       :       operand_5
 689                         {
 690                           $$ = 0;       /* FIXME */
 691                         }
 692                 |       operand_4 '*' operand_5
 693                         {
 694                           write_exp_elt_opcode (BINOP_MUL);
 695                         }
 696                 |       operand_4 '/' operand_5
 697                         {
 698                           write_exp_elt_opcode (BINOP_DIV);
 699                         }
 700                 |       operand_4 MOD operand_5
 701                         {
 702                           $$ = 0;       /* FIXME */
 703                         }
 704                 |       operand_4 REM operand_5
 705                         {
 706                           $$ = 0;       /* FIXME */
 707                         }
 708                 ;
 709
 710 /* Z.200, 5.3.8 */
 711
 712 operand_5       :       operand_6
 713                         {
 714                           $$ = 0;       /* FIXME */
 715                         }
 716                 |       '-' operand_6
 717                         {
 718                           write_exp_elt_opcode (UNOP_NEG);
 719                         }
 720                 |       NOT operand_6
 721                         {
 722                           write_exp_elt_opcode (UNOP_LOGICAL_NOT);
 723                         }
 724                 |       '(' integer_literal_expression ')' operand_6
 725                         {
 726                           $$ = 0;       /* FIXME */
 727                         }
 728                 ;
 729
 730 /* Z.200, 5.3.9 */
 731
 732 operand_6       :       POINTER location
 733                         {
 734                           $$ = 0;       /* FIXME */
 735                         }
 736                 |       RECEIVE buffer_location
 737                         {
 738                           $$ = 0;       /* FIXME */
 739                         }
 740                 |       primitive_value
 741                         {
 742                           $$ = 0;       /* FIXME */
 743                         }
 744                 ;
 745
 746
 747 /* Z.200, 12.4.3 */
 748 /* FIXME:  For now we just accept only a single integer literal. */
 749
 750 integer_literal_expression:
 751                         INTEGER_LITERAL
 752                         {
 753                           $$ = 0;
 754                         }
 755
 756 /* Things which still need productions... */
 757 synonym_name            :       FIXME { $$ = 0; }
 758 value_enumeration_name  :       FIXME { $$ = 0; }
 759 value_do_with_name      :       FIXME { $$ = 0; }
 760 value_receive_name      :       FIXME { $$ = 0; }
 761 string_primitive_value  :       FIXME { $$ = 0; }
 762 start_element           :       FIXME { $$ = 0; }
 763 left_element            :       FIXME { $$ = 0; }
 764 right_element           :       FIXME { $$ = 0; }
 765 slice_size              :       FIXME { $$ = 0; }
 766 array_primitive_value   :       FIXME { $$ = 0; }
 767 expression_list         :       FIXME { $$ = 0; }
 768 lower_element           :       FIXME { $$ = 0; }
 769 upper_element           :       FIXME { $$ = 0; }
 770 first_element           :       FIXME { $$ = 0; }
 771 structure_primitive_value:      FIXME { $$ = 0; }
 772 field_name              :       FIXME { $$ = 0; }
 773 mode_name               :       FIXME { $$ = 0; }
 774 boolean_expression      :       FIXME { $$ = 0; }
 775 case_selector_list      :       FIXME { $$ = 0; }
 776 subexpression           :       FIXME { $$ = 0; }
 777 case_label_specification:       FIXME { $$ = 0; }
 778 buffer_location         :       FIXME { $$ = 0; }
 779
 780 %%
 781
 782 /* Try to consume a simple name string token.  If successful, returns
 783    a pointer to a nullbyte terminated copy of the name that can be used
 784    in symbol table lookups.  If not successful, returns NULL. */
 785
 786 static char *
 787 match_simple_name_string ()
 788 {
 789   char *tokptr = lexptr;
 790
 791   if (isalpha (*tokptr))
 792     {
 793       do {
 794         tokptr++;
 795       } while (isalpha (*tokptr) || isdigit (*tokptr) || (*tokptr == '_'));
 796       yylval.sval.ptr = lexptr;
 797       yylval.sval.length = tokptr - lexptr;
 798       lexptr = tokptr;
 799       return (copy_name (yylval.sval));
 800     }
 801   return (NULL);
 802 }
 803
 804 /* Start looking for a value composed of valid digits as set by the base
 805    in use.  Note that '_' characters are valid anywhere, in any quantity,
 806    and are simply ignored.  Since we must find at least one valid digit,
 807    or reject this token as an integer literal, we keep track of how many
 808    digits we have encountered. */
 809
 810 static int
 811 decode_integer_value (base, tokptrptr, ivalptr)
 812   int base;
 813   char **tokptrptr;
 814   int *ivalptr;
 815 {
 816   char *tokptr = *tokptrptr;
 817   int temp;
 818   int digits = 0;
 819
 820   while (*tokptr != '\0')
 821     {
 822       temp = tolower (*tokptr);
 823       tokptr++;
 824       switch (temp)
 825         {
 826         case '_':
 827           continue;
 828         case '0':  case '1':  case '2':  case '3':  case '4':
 829         case '5':  case '6':  case '7':  case '8':  case '9':
 830           temp -= '0';
 831           break;
 832         case 'a':  case 'b':  case 'c':  case 'd':  case 'e': case 'f':
 833           temp -= 'a';
 834           temp += 10;
 835           break;
 836         default:
 837           temp = base;
 838           break;
 839         }
 840       if (temp < base)
 841         {
 842           digits++;
 843           *ivalptr *= base;
 844           *ivalptr += temp;
 845         }
 846       else
 847         {
 848           /* Found something not in domain for current base. */
 849           tokptr--;     /* Unconsume what gave us indigestion. */
 850           break;
 851         }
 852     }
 853
 854   /* If we didn't find any digits, then we don't have a valid integer
 855      value, so reject the entire token.  Otherwise, update the lexical
 856      scan pointer, and return non-zero for success. */
 857
 858   if (digits == 0)
 859     {
 860       return (0);
 861     }
 862   else
 863     {
 864       *tokptrptr = tokptr;
 865       return (1);
 866     }
 867 }
 868
 869 static int
 870 decode_integer_literal (valptr, tokptrptr)
 871   int *valptr;
 872   char **tokptrptr;
 873 {
 874   char *tokptr = *tokptrptr;
 875   int base = 0;
 876   int ival = 0;
 877   int digits = 0;
 878   int temp;
 879   int explicit_base = 0;
 880
 881   /* Look for an explicit base specifier, which is optional. */
 882
 883   switch (*tokptr)
 884     {
 885     case 'd':
 886     case 'D':
 887       explicit_base++;
 888       base = 10;
 889       tokptr++;
 890       break;
 891     case 'b':
 892     case 'B':
 893       explicit_base++;
 894       base = 2;
 895       tokptr++;
 896       break;
 897     case 'h':
 898     case 'H':
 899       explicit_base++;
 900       base = 16;
 901       tokptr++;
 902       break;
 903     case 'o':
 904     case 'O':
 905       explicit_base++;
 906       base = 8;
 907       tokptr++;
 908       break;
 909     default:
 910       base = 10;
 911       break;
 912     }
 913
 914   /* If we found an explicit base ensure that the character after the
 915      explicit base is a single quote. */
 916
 917   if (explicit_base && (*tokptr++ != '\''))
 918     {
 919       return (0);
 920     }
 921
 922   /* Attempt to decode whatever follows as an integer value in the
 923      indicated base, updating the token pointer in the process and
 924      computing the value into ival.  Also, if we have an explicit
 925      base, then the next character must not be a single quote, or we
 926      have a bitstring literal, so reject the entire token in this case.
 927      Otherwise, update the lexical scan pointer, and return non-zero
 928      for success. */
 929
 930   if (!decode_integer_value (base, &tokptr, &ival))
 931     {
 932       return (0);
 933     }
 934   else if (explicit_base && (*tokptr == '\''))
 935     {
 936       return (0);
 937     }
 938   else
 939     {
 940       *valptr = ival;
 941       *tokptrptr = tokptr;
 942       return (1);
 943     }
 944 }
 945
 946 /* Recognize a character literal.  A character literal is single character
 947    or a control sequence, enclosed in single quotes.  A control sequence
 948    is a comma separated list of one or more integer literals, enclosed
 949    in parenthesis and introduced with a circumflex character.
 950
 951    EX:  'a'  '^(7)'  '^(7,8)'
 952
 953    As a GNU chill extension, the syntax C'xx' is also recognized as a
 954    character literal, where xx is a hex value for the character.
 955
 956    Returns CHARACTER_LITERAL if a match is found.
 957    */
 958
 959 static int
 960 match_character_literal ()
 961 {
 962   char *tokptr = lexptr;
 963   int ival = 0;
 964
 965   if ((tolower (*tokptr) == 'c') && (*(tokptr + 1) == '\''))
 966     {
 967       /* We have a GNU chill extension form, so skip the leading "C'",
 968          decode the hex value, and then ensure that we have a trailing
 969          single quote character. */
 970       tokptr += 2;
 971       if (!decode_integer_value (16, &tokptr, &ival) || (*tokptr != '\''))
 972         {
 973           return (0);
 974         }
 975       tokptr++;
 976     }
 977   else if (*tokptr == '\'')
 978     {
 979       tokptr++;
 980
 981       /* Determine which form we have, either a control sequence or the
 982          single character form. */
 983
 984       if ((*tokptr == '^') && (*(tokptr + 1) == '('))
 985         {
 986           /* Match and decode a control sequence.  Return zero if we don't
 987              find a valid integer literal, or if the next unconsumed character
 988              after the integer literal is not the trailing ')'.
 989              FIXME:  We currently don't handle the multiple integer literal
 990              form. */
 991           tokptr += 2;
 992           if (!decode_integer_literal (&ival, &tokptr) || (*tokptr++ != ')'))
 993             {
 994               return (0);
 995             }
 996         }
 997       else
 998         {
 999           ival = *tokptr++;
1000         }
1001
1002       /* The trailing quote has not yet been consumed.  If we don't find
1003          it, then we have no match. */
1004
1005       if (*tokptr++ != '\'')
1006         {
1007           return (0);
1008         }
1009     }
1010   else
1011     {
1012       /* Not a character literal. */
1013       return (0);
1014     }
1015   yylval.typed_val.val = ival;
1016   yylval.typed_val.type = builtin_type_chill_char;
1017   lexptr = tokptr;
1018   return (CHARACTER_LITERAL);
1019 }
1020
1021 /* Recognize an integer literal, as specified in Z.200 sec 5.2.4.2.
1022    Note that according to 5.2.4.2, a single "_" is also a valid integer
1023    literal, however GNU-chill requires there to be at least one "digit"
1024    in any integer literal. */
1025
1026 static int
1027 match_integer_literal ()
1028 {
1029   char *tokptr = lexptr;
1030   int ival;
1031
1032   if (!decode_integer_literal (&ival, &tokptr))
1033     {
1034       return (0);
1035     }
1036   else
1037     {
1038       yylval.typed_val.val = ival;
1039       yylval.typed_val.type = builtin_type_int;
1040       lexptr = tokptr;
1041       return (INTEGER_LITERAL);
1042     }
1043 }
1044
1045 static void convert_float ()
1046 {
1047 #if 0
1048     extern double strtod ();
1049     double d;
1050     char        tmp[256];
1051     char        *p = yytext, *p1 = tmp;
1052     char        c;
1053
1054     while (c = *p++)
1055     {
1056         switch (c)
1057         {
1058         case '_':
1059             break;
1060         case 'E':
1061         case 'd':
1062         case 'D':
1063             *p1++ = 'e';
1064             break;
1065         default:
1066             *p1++ = c;
1067             break;
1068         }
1069     }
1070     *p1 = '\0';
1071     d = strtod (tmp, &p1);
1072     if (*p1)
1073     {
1074         /* add error handling here */
1075         ;
1076     }
1077     yylval.dval = d;
1078 #endif
1079 }
1080
1081 /* Take care of parsing a number (anything that starts with a digit).
1082    Set yylval and return the token type; update lexptr.
1083    LEN is the number of characters in it.  */
1084
1085 /*** Needs some error checking for the float case ***/
1086
1087 static int
1088 parse_number ()
1089 {
1090 }
1091
1092 struct token
1093 {
1094   char *operator;
1095   int token;
1096 };
1097
1098 const static struct token tokentab5[] =
1099 {
1100     { "ANDIF", ANDIF }
1101 };
1102
1103 const static struct token tokentab4[] =
1104 {
1105     { "ORIF", ORIF }
1106 };
1107
1108 const static struct token tokentab3[] =
1109 {
1110     { "NOT", NOT },
1111     { "XOR", LOGXOR },
1112     { "AND", LOGAND }
1113 };
1114
1115 const static struct token tokentab2[] =
1116 {
1117     { "//", SLASH_SLASH },
1118     { "/=", NOTEQUAL },
1119     { "<=", LEQ },
1120     { ">=", GTR },
1121     { "IN", IN },
1122     { "OR", LOGIOR }
1123 };
1124
1125 /* Read one token, getting characters through lexptr.  */
1126 /* This is where we will check to make sure that the language and the
1127    operators used are compatible.  */
1128
1129 static int
1130 yylex ()
1131 {
1132     unsigned int i;
1133     int token;
1134     char *simplename;
1135     struct symbol *sym;
1136
1137     /* Skip over any leading whitespace. */
1138     while (isspace (*lexptr))
1139         {
1140             lexptr++;
1141         }
1142     /* Look for special single character cases which can't be the first
1143        character of some other multicharacter token. */
1144     switch (*lexptr)
1145         {
1146             case '\0':
1147                 return (0);
1148             case '.':
1149             case '=':
1150             case ':':
1151             case ';':
1152             case '!':
1153             case '+':
1154             case '-':
1155             case '*':
1156             case '/':
1157             case '(':
1158             case ')':
1159             case '[':
1160             case ']':
1161                 return (*lexptr++);
1162         }
1163     /* Look for characters which start a particular kind of multicharacter
1164        token, such as a character literal. */
1165     switch (*lexptr)
1166       {
1167         case 'C':
1168         case 'c':
1169         case '\'':
1170           token = match_character_literal ();
1171           if (token != 0)
1172             {
1173               return (token);
1174             }
1175           break;
1176       }
1177     /* See if it is a special token of length 5.  */
1178     for (i = 0; i < sizeof (tokentab5) / sizeof (tokentab5[0]); i++)
1179         {
1180             if (strncmp (lexptr, tokentab5[i].operator, 5) == 0)
1181                 {
1182                     lexptr += 5;
1183                     return (tokentab5[i].token);
1184                 }
1185         }
1186     /* See if it is a special token of length 4.  */
1187     for (i = 0; i < sizeof (tokentab4) / sizeof (tokentab4[0]); i++)
1188         {
1189             if (strncmp (lexptr, tokentab4[i].operator, 4) == 0)
1190                 {
1191                     lexptr += 4;
1192                     return (tokentab4[i].token);
1193                 }
1194         }
1195     /* See if it is a special token of length 3.  */
1196     for (i = 0; i < sizeof (tokentab3) / sizeof (tokentab3[0]); i++)
1197         {
1198             if (strncmp (lexptr, tokentab3[i].operator, 3) == 0)
1199                 {
1200                     lexptr += 3;
1201                     return (tokentab3[i].token);
1202                 }
1203         }
1204     /* See if it is a special token of length 2.  */
1205     for (i = 0; i < sizeof (tokentab2) / sizeof (tokentab2[0]); i++)
1206         {
1207             if (strncmp (lexptr, tokentab2[i].operator, 2) == 0)
1208                 {
1209                     lexptr += 2;
1210                     return (tokentab2[i].token);
1211                 }
1212         }
1213     /* Look for single character cases which which could be the first
1214        character of some other multicharacter token, but aren't, or we
1215        would already have found it. */
1216     switch (*lexptr)
1217         {
1218             case '/':
1219             case '<':
1220             case '>':
1221                 return (*lexptr++);
1222         }
1223     /* Look for other special tokens. */
1224     if (strncmp (lexptr, "TRUE", 4) == 0) /* FIXME:  What about lowercase? */
1225         {
1226             yylval.ulval = 1;
1227             lexptr += 4;
1228             return (BOOLEAN_LITERAL);
1229         }
1230     if (strncmp (lexptr, "FALSE", 5) == 0) /* FIXME:  What about lowercase? */
1231         {
1232             yylval.ulval = 0;
1233             lexptr += 5;
1234             return (BOOLEAN_LITERAL);
1235         }
1236     token = match_integer_literal ();
1237     if (token != 0)
1238         {
1239             return (token);
1240         }
1241
1242     /* Try to match a simple name string, and if a match is found, then
1243        further classify what sort of name it is and return an appropriate
1244        token.  Note that attempting to match a simple name string consumes
1245        the token from lexptr, so we can't back out if we later find that
1246        we can't classify what sort of name it is. */
1247
1248     simplename = match_simple_name_string ();
1249     if (simplename != NULL)
1250       {
1251         sym = lookup_symbol (simplename, expression_context_block,
1252                              VAR_NAMESPACE, (int *) NULL,
1253                              (struct symtab **) NULL);
1254         if (sym != NULL)
1255           {
1256             yylval.ssym.stoken.ptr = NULL;
1257             yylval.ssym.stoken.length = 0;
1258             yylval.ssym.sym = sym;
1259             yylval.ssym.is_a_field_of_this = 0; /* FIXME, C++'ism */
1260             switch (SYMBOL_CLASS (sym))
1261               {
1262               case LOC_BLOCK:
1263                 /* Found a procedure name. */
1264                 return (GENERAL_PROCEDURE_NAME);
1265               case LOC_STATIC:
1266                 /* Found a global or local static variable. */
1267                 return (LOCATION_NAME);
1268               }
1269           }
1270         else if (!have_full_symbols () && !have_partial_symbols ())
1271           {
1272             error ("No symbol table is loaded.  Use the \"file\" command.");
1273           }
1274         else
1275           {
1276             error ("No symbol \"%s\" in current context.", simplename);
1277           }
1278       }
1279
1280     return (ILLEGAL_TOKEN);
1281 }
1282
1283 void
1284 yyerror (msg)
1285      char *msg; /* unused */
1286 {
1287   printf ("Parsing:  %s\n", lexptr);
1288   if (yychar < 256)
1289     {
1290       error ("Invalid syntax in expression near character '%c'.", yychar);
1291     }
1292   else
1293     {
1294       error ("Invalid syntax in expression");
1295     }
1296 }