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 /* Remap normal yacc parser interface names (yyparse, yylex, yyerror, etc),
  64    as well as gratuitiously global symbol names, so we can have multiple
  65    yacc generated parsers in gdb.  Note that these are only the variables
  66    produced by yacc.  If other parser generators (bison, byacc, etc) produce
  67    additional global names that conflict at link time, then those parser
  68    generators need to be fixed instead of adding those names to this list. */
  69
  70 #define yymaxdepth chill_maxdepth
  71 #define yyparse chill_parse
  72 #define yylex   chill_lex
  73 #define yyerror chill_error
  74 #define yylval  chill_lval
  75 #define yychar  chill_char
  76 #define yydebug chill_debug
  77 #define yypact  chill_pact
  78 #define yyr1    chill_r1
  79 #define yyr2    chill_r2
  80 #define yydef   chill_def
  81 #define yychk   chill_chk
  82 #define yypgo   chill_pgo
  83 #define yyact   chill_act
  84 #define yyexca  chill_exca
  85 #define yyerrflag chill_errflag
  86 #define yynerrs chill_nerrs
  87 #define yyps    chill_ps
  88 #define yypv    chill_pv
  89 #define yys     chill_s
  90 #define yy_yys  chill_yys
  91 #define yystate chill_state
  92 #define yytmp   chill_tmp
  93 #define yyv     chill_v
  94 #define yy_yyv  chill_yyv
  95 #define yyval   chill_val
  96 #define yylloc  chill_lloc
  97 #define yyreds  chill_reds              /* With YYDEBUG defined */
  98 #define yytoks  chill_toks              /* With YYDEBUG defined */
  99
 100 #ifndef YYDEBUG
 101 #define YYDEBUG 0               /* Default to no yydebug support */
 102 #endif
 103
 104 int
 105 yyparse PARAMS ((void));
 106
 107 static int
 108 yylex PARAMS ((void));
 109
 110 void
 111 yyerror PARAMS ((char *));
 112
 113 %}
 114
 115 /* Although the yacc "value" of an expression is not used,
 116    since the result is stored in the structure being created,
 117    other node types do have values.  */
 118
 119 %union
 120   {
 121     LONGEST lval;
 122     unsigned LONGEST ulval;
 123     struct {
 124       LONGEST val;
 125       struct type *type;
 126     } typed_val;
 127     double dval;
 128     struct symbol *sym;
 129     struct type *tval;
 130     struct stoken sval;
 131     struct ttype tsym;
 132     struct symtoken ssym;
 133     int voidval;
 134     struct block *bval;
 135     enum exp_opcode opcode;
 136     struct internalvar *ivar;
 137
 138     struct type **tvec;
 139     int *ivec;
 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 /* Tokens which are not Chill tokens used in expressions, but rather GDB
 198    specific things that we recognize in the same context as Chill tokens
 199    (register names for example). */
 200
 201 %token <lval>           GDB_REGNAME     /* Machine register name */
 202 %token <lval>           GDB_LAST        /* Value history */
 203 %token <ivar>           GDB_VARIABLE    /* Convenience variable */
 204 %token <voidval>        GDB_ASSIGNMENT  /* Assign value to somewhere */
 205
 206 %type <voidval>         location
 207 %type <voidval>         access_name
 208 %type <voidval>         primitive_value
 209 %type <voidval>         location_contents
 210 %type <voidval>         value_name
 211 %type <voidval>         literal
 212 %type <voidval>         tuple
 213 %type <voidval>         value_string_element
 214 %type <voidval>         value_string_slice
 215 %type <voidval>         value_array_element
 216 %type <voidval>         value_array_slice
 217 %type <voidval>         value_structure_field
 218 %type <voidval>         expression_conversion
 219 %type <voidval>         value_procedure_call
 220 %type <voidval>         value_built_in_routine_call
 221 %type <voidval>         start_expression
 222 %type <voidval>         zero_adic_operator
 223 %type <voidval>         parenthesised_expression
 224 %type <voidval>         value
 225 %type <voidval>         undefined_value
 226 %type <voidval>         expression
 227 %type <voidval>         conditional_expression
 228 %type <voidval>         then_alternative
 229 %type <voidval>         else_alternative
 230 %type <voidval>         sub_expression
 231 %type <voidval>         value_case_alternative
 232 %type <voidval>         operand_0
 233 %type <voidval>         operand_1
 234 %type <voidval>         operand_2
 235 %type <voidval>         operand_3
 236 %type <voidval>         operand_4
 237 %type <voidval>         operand_5
 238 %type <voidval>         operand_6
 239 %type <voidval>         integer_literal_expression
 240 %type <voidval>         synonym_name
 241 %type <voidval>         value_enumeration_name
 242 %type <voidval>         value_do_with_name
 243 %type <voidval>         value_receive_name
 244 %type <voidval>         string_primitive_value
 245 %type <voidval>         start_element
 246 %type <voidval>         left_element
 247 %type <voidval>         right_element
 248 %type <voidval>         slice_size
 249 %type <voidval>         array_primitive_value
 250 %type <voidval>         expression_list
 251 %type <voidval>         lower_element
 252 %type <voidval>         upper_element
 253 %type <voidval>         first_element
 254 %type <voidval>         structure_primitive_value
 255 %type <voidval>         field_name
 256 %type <voidval>         mode_name
 257 %type <voidval>         boolean_expression
 258 %type <voidval>         case_selector_list
 259 %type <voidval>         subexpression
 260 %type <voidval>         case_label_specification
 261 %type <voidval>         buffer_location
 262
 263 %type <voidval>         single_assignment_action
 264
 265 %%
 266
 267 /* Z.200, 5.3.1 */
 268
 269 value           :       expression
 270                         {
 271                           $$ = 0;       /* FIXME */
 272                         }
 273                 |       undefined_value
 274                         {
 275                           $$ = 0;       /* FIXME */
 276                         }
 277                 ;
 278
 279 undefined_value :       FIXME
 280                         {
 281                           $$ = 0;       /* FIXME */
 282                         }
 283                 ;
 284
 285 /* Z.200, 4.2.1 */
 286
 287 location        :       access_name
 288                         {
 289                           $$ = 0;       /* FIXME */
 290                         }
 291                 |       FIXME
 292                         {
 293                           $$ = 0;       /* FIXME */
 294                         }
 295                 ;
 296
 297 /* Z.200, 4.2.2 */
 298
 299 access_name     :       LOCATION_NAME
 300                         {
 301                           write_exp_elt_opcode (OP_VAR_VALUE);
 302                           write_exp_elt_sym ($1.sym);
 303                           write_exp_elt_opcode (OP_VAR_VALUE);
 304                         }
 305                 |       GDB_LAST                /* gdb specific */
 306                         {
 307                           write_exp_elt_opcode (OP_LAST);
 308                           write_exp_elt_longcst ($1);
 309                           write_exp_elt_opcode (OP_LAST);
 310                         }
 311                 |       GDB_REGNAME             /* gdb specific */
 312                         {
 313                           write_exp_elt_opcode (OP_REGISTER);
 314                           write_exp_elt_longcst ($1);
 315                           write_exp_elt_opcode (OP_REGISTER);
 316                         }
 317                 |       GDB_VARIABLE    /* gdb specific */
 318                         {
 319                           write_exp_elt_opcode (OP_INTERNALVAR);
 320                           write_exp_elt_intern ($1);
 321                           write_exp_elt_opcode (OP_INTERNALVAR);
 322                         }
 323                 |       FIXME
 324                         {
 325                           $$ = 0;       /* FIXME */
 326                         }
 327                 ;
 328
 329 /* Z.200, 4.2.8 */
 330
 331 expression_list :       expression
 332                         {
 333                           arglist_len = 1;
 334                         }
 335                 |       expression_list ',' expression
 336                         {
 337                           arglist_len++;
 338                         }
 339
 340 /* Z.200, 5.2.1 */
 341
 342 primitive_value :       location_contents
 343                         {
 344                           $$ = 0;       /* FIXME */
 345                         }
 346                 |       value_name
 347                         {
 348                           $$ = 0;       /* FIXME */
 349                         }
 350                 |       literal
 351                         {
 352                           $$ = 0;       /* FIXME */
 353                         }
 354                 |       tuple
 355                         {
 356                           $$ = 0;       /* FIXME */
 357                         }
 358                 |       value_string_element
 359                         {
 360                           $$ = 0;       /* FIXME */
 361                         }
 362                 |       value_string_slice
 363                         {
 364                           $$ = 0;       /* FIXME */
 365                         }
 366                 |       value_array_element
 367                         {
 368                           $$ = 0;       /* FIXME */
 369                         }
 370                 |       value_array_slice
 371                         {
 372                           $$ = 0;       /* FIXME */
 373                         }
 374                 |       value_structure_field
 375                         {
 376                           $$ = 0;       /* FIXME */
 377                         }
 378                 |       expression_conversion
 379                         {
 380                           $$ = 0;       /* FIXME */
 381                         }
 382                 |       value_procedure_call
 383                         {
 384                           $$ = 0;       /* FIXME */
 385                         }
 386                 |       value_built_in_routine_call
 387                         {
 388                           $$ = 0;       /* FIXME */
 389                         }
 390                 |       start_expression
 391                         {
 392                           $$ = 0;       /* FIXME */
 393                         }
 394                 |       zero_adic_operator
 395                         {
 396                           $$ = 0;       /* FIXME */
 397                         }
 398                 |       parenthesised_expression
 399                         {
 400                           $$ = 0;       /* FIXME */
 401                         }
 402                 ;
 403
 404 /* Z.200, 5.2.2 */
 405
 406 location_contents:      location
 407                         {
 408                           $$ = 0;       /* FIXME */
 409                         }
 410                 ;
 411
 412 /* Z.200, 5.2.3 */
 413
 414 value_name      :       synonym_name
 415                         {
 416                           $$ = 0;       /* FIXME */
 417                         }
 418                 |       value_enumeration_name
 419                         {
 420                           $$ = 0;       /* FIXME */
 421                         }
 422                 |       value_do_with_name
 423                         {
 424                           $$ = 0;       /* FIXME */
 425                         }
 426                 |       value_receive_name
 427                         {
 428                           $$ = 0;       /* FIXME */
 429                         }
 430                 |       GENERAL_PROCEDURE_NAME
 431                         {
 432                           write_exp_elt_opcode (OP_VAR_VALUE);
 433                           write_exp_elt_sym ($1.sym);
 434                           write_exp_elt_opcode (OP_VAR_VALUE);
 435                         }
 436                 ;
 437
 438 /* Z.200, 5.2.4.1 */
 439
 440 literal         :       INTEGER_LITERAL
 441                         {
 442                           write_exp_elt_opcode (OP_LONG);
 443                           write_exp_elt_type ($1.type);
 444                           write_exp_elt_longcst ((LONGEST) ($1.val));
 445                           write_exp_elt_opcode (OP_LONG);
 446                         }
 447                 |       BOOLEAN_LITERAL
 448                         {
 449                           write_exp_elt_opcode (OP_BOOL);
 450                           write_exp_elt_longcst ((LONGEST) $1);
 451                           write_exp_elt_opcode (OP_BOOL);
 452                         }
 453                 |       CHARACTER_LITERAL
 454                         {
 455                           write_exp_elt_opcode (OP_LONG);
 456                           write_exp_elt_type ($1.type);
 457                           write_exp_elt_longcst ((LONGEST) ($1.val));
 458                           write_exp_elt_opcode (OP_LONG);
 459                         }
 460                 |       SET_LITERAL
 461                         {
 462                           $$ = 0;       /* FIXME */
 463                         }
 464                 |       EMPTINESS_LITERAL
 465                         {
 466                           $$ = 0;       /* FIXME */
 467                         }
 468                 |       CHARACTER_STRING_LITERAL
 469                         {
 470                           $$ = 0;       /* FIXME */
 471                         }
 472                 |       BIT_STRING_LITERAL
 473                         {
 474                           $$ = 0;       /* FIXME */
 475                         }
 476                 ;
 477
 478 /* Z.200, 5.2.5 */
 479
 480 tuple           :       FIXME
 481                         {
 482                           $$ = 0;       /* FIXME */
 483                         }
 484                 ;
 485
 486
 487 /* Z.200, 5.2.6 */
 488
 489 value_string_element:   string_primitive_value '(' start_element ')'
 490                         {
 491                           $$ = 0;       /* FIXME */
 492                         }
 493                 ;
 494
 495 /* Z.200, 5.2.7 */
 496
 497 value_string_slice:     string_primitive_value '(' left_element ':' right_element ')'
 498                         {
 499                           $$ = 0;       /* FIXME */
 500                         }
 501                 |       string_primitive_value '(' start_element UP slice_size ')'
 502                         {
 503                           $$ = 0;       /* FIXME */
 504                         }
 505                 ;
 506
 507 /* Z.200, 5.2.8 */
 508
 509 value_array_element:    array_primitive_value '('
 510                                 /* This is to save the value of arglist_len
 511                                    being accumulated for each dimension. */
 512                                 { start_arglist (); }
 513                         expression_list ')'
 514                         {
 515                           write_exp_elt_opcode (MULTI_SUBSCRIPT);
 516                           write_exp_elt_longcst ((LONGEST) end_arglist ());
 517                           write_exp_elt_opcode (MULTI_SUBSCRIPT);
 518                         }
 519                 ;
 520
 521 /* Z.200, 5.2.9 */
 522
 523 value_array_slice:      array_primitive_value '(' lower_element ':' upper_element ')'
 524                         {
 525                           $$ = 0;       /* FIXME */
 526                         }
 527                 |       array_primitive_value '(' first_element UP slice_size ')'
 528                         {
 529                           $$ = 0;       /* FIXME */
 530                         }
 531                 ;
 532
 533 /* Z.200, 5.2.10 */
 534
 535 value_structure_field:  structure_primitive_value '.' field_name
 536                         {
 537                           $$ = 0;       /* FIXME */
 538                         }
 539                 ;
 540
 541 /* Z.200, 5.2.11 */
 542
 543 expression_conversion:  mode_name '(' expression ')'
 544                         {
 545                           $$ = 0;       /* FIXME */
 546                         }
 547                 ;
 548
 549 /* Z.200, 5.2.12 */
 550
 551 value_procedure_call:   FIXME
 552                         {
 553                           $$ = 0;       /* FIXME */
 554                         }
 555                 ;
 556
 557 /* Z.200, 5.2.13 */
 558
 559 value_built_in_routine_call:    FIXME
 560                         {
 561                           $$ = 0;       /* FIXME */
 562                         }
 563                 ;
 564
 565 /* Z.200, 5.2.14 */
 566
 567 start_expression:       FIXME
 568                         {
 569                           $$ = 0;       /* FIXME */
 570                         }       /* Not in GNU-Chill */
 571                 ;
 572
 573 /* Z.200, 5.2.15 */
 574
 575 zero_adic_operator:     FIXME
 576                         {
 577                           $$ = 0;       /* FIXME */
 578                         }
 579                 ;
 580
 581 /* Z.200, 5.2.16 */
 582
 583 parenthesised_expression:       '(' expression ')'
 584                         {
 585                           $$ = 0;       /* FIXME */
 586                         }
 587                 ;
 588
 589 /* Z.200, 5.3.2 */
 590
 591 expression      :       operand_0
 592                         {
 593                           $$ = 0;       /* FIXME */
 594                         }
 595                 |       conditional_expression
 596                         {
 597                           $$ = 0;       /* FIXME */
 598                         }
 599                 ;
 600
 601 conditional_expression : IF boolean_expression then_alternative else_alternative FI
 602                         {
 603                           $$ = 0;       /* FIXME */
 604                         }
 605                 |       CASE case_selector_list OF value_case_alternative '[' ELSE sub_expression ']' ESAC
 606                         {
 607                           $$ = 0;       /* FIXME */
 608                         }
 609                 ;
 610
 611 then_alternative:       THEN subexpression
 612                         {
 613                           $$ = 0;       /* FIXME */
 614                         }
 615                 ;
 616
 617 else_alternative:       ELSE subexpression
 618                         {
 619                           $$ = 0;       /* FIXME */
 620                         }
 621                 |       ELSIF boolean_expression then_alternative else_alternative
 622                         {
 623                           $$ = 0;       /* FIXME */
 624                         }
 625                 ;
 626
 627 sub_expression  :       expression
 628                         {
 629                           $$ = 0;       /* FIXME */
 630                         }
 631                 ;
 632
 633 value_case_alternative: case_label_specification ':' sub_expression ';'
 634                         {
 635                           $$ = 0;       /* FIXME */
 636                         }
 637                 ;
 638
 639 /* Z.200, 5.3.3 */
 640
 641 operand_0       :       operand_1
 642                         {
 643                           $$ = 0;       /* FIXME */
 644                         }
 645                 |       operand_0 LOGIOR operand_1
 646                         {
 647                           write_exp_elt_opcode (BINOP_BITWISE_IOR);
 648                         }
 649                 |       operand_0 ORIF operand_1
 650                         {
 651                           $$ = 0;       /* FIXME */
 652                         }
 653                 |       operand_0 LOGXOR operand_1
 654                         {
 655                           write_exp_elt_opcode (BINOP_BITWISE_XOR);
 656                         }
 657                 |       single_assignment_action
 658                         {
 659                           $$ = 0;       /* FIXME */
 660                         }
 661                 ;
 662
 663 /* Z.200, 5.3.4 */
 664
 665 operand_1       :       operand_2
 666                         {
 667                           $$ = 0;       /* FIXME */
 668                         }
 669                 |       operand_1 LOGAND operand_2
 670                         {
 671                           write_exp_elt_opcode (BINOP_BITWISE_AND);
 672                         }
 673                 |       operand_1 ANDIF operand_2
 674                         {
 675                           $$ = 0;       /* FIXME */
 676                         }
 677                 ;
 678
 679 /* Z.200, 5.3.5 */
 680
 681 operand_2       :       operand_3
 682                         {
 683                           $$ = 0;       /* FIXME */
 684                         }
 685                 |       operand_2 '=' operand_3
 686                         {
 687                           write_exp_elt_opcode (BINOP_EQUAL);
 688                         }
 689                 |       operand_2 NOTEQUAL operand_3
 690                         {
 691                           write_exp_elt_opcode (BINOP_NOTEQUAL);
 692                         }
 693                 |       operand_2 '>' operand_3
 694                         {
 695                           write_exp_elt_opcode (BINOP_GTR);
 696                         }
 697                 |       operand_2 GTR operand_3
 698                         {
 699                           write_exp_elt_opcode (BINOP_GEQ);
 700                         }
 701                 |       operand_2 '<' operand_3
 702                         {
 703                           write_exp_elt_opcode (BINOP_LESS);
 704                         }
 705                 |       operand_2 LEQ operand_3
 706                         {
 707                           write_exp_elt_opcode (BINOP_LEQ);
 708                         }
 709                 |       operand_2 IN operand_3
 710                         {
 711                           $$ = 0;       /* FIXME */
 712                         }
 713                 ;
 714
 715
 716 /* Z.200, 5.3.6 */
 717
 718 operand_3       :       operand_4
 719                         {
 720                           $$ = 0;       /* FIXME */
 721                         }
 722                 |       operand_3 '+' operand_4
 723                         {
 724                           write_exp_elt_opcode (BINOP_ADD);
 725                         }
 726                 |       operand_3 '-' operand_4
 727                         {
 728                           write_exp_elt_opcode (BINOP_SUB);
 729                         }
 730                 |       operand_3 SLASH_SLASH operand_4
 731                         {
 732                           $$ = 0;       /* FIXME */
 733                         }
 734                 ;
 735
 736 /* Z.200, 5.3.7 */
 737
 738 operand_4       :       operand_5
 739                         {
 740                           $$ = 0;       /* FIXME */
 741                         }
 742                 |       operand_4 '*' operand_5
 743                         {
 744                           write_exp_elt_opcode (BINOP_MUL);
 745                         }
 746                 |       operand_4 '/' operand_5
 747                         {
 748                           write_exp_elt_opcode (BINOP_DIV);
 749                         }
 750                 |       operand_4 MOD operand_5
 751                         {
 752                           $$ = 0;       /* FIXME */
 753                         }
 754                 |       operand_4 REM operand_5
 755                         {
 756                           $$ = 0;       /* FIXME */
 757                         }
 758                 ;
 759
 760 /* Z.200, 5.3.8 */
 761
 762 operand_5       :       operand_6
 763                         {
 764                           $$ = 0;       /* FIXME */
 765                         }
 766                 |       '-' operand_6
 767                         {
 768                           write_exp_elt_opcode (UNOP_NEG);
 769                         }
 770                 |       NOT operand_6
 771                         {
 772                           write_exp_elt_opcode (UNOP_LOGICAL_NOT);
 773                         }
 774                 |       '(' integer_literal_expression ')' operand_6
 775                         {
 776                           $$ = 0;       /* FIXME */
 777                         }
 778                 ;
 779
 780 /* Z.200, 5.3.9 */
 781
 782 operand_6       :       POINTER location
 783                         {
 784                           $$ = 0;       /* FIXME */
 785                         }
 786                 |       RECEIVE buffer_location
 787                         {
 788                           $$ = 0;       /* FIXME */
 789                         }
 790                 |       primitive_value
 791                         {
 792                           $$ = 0;       /* FIXME */
 793                         }
 794                 ;
 795
 796
 797 /* Z.200, 6.2 */
 798
 799 single_assignment_action :      location GDB_ASSIGNMENT value
 800                         {
 801                           write_exp_elt_opcode (BINOP_ASSIGN);
 802                         }
 803
 804 /* Z.200, 12.4.3 */
 805 /* FIXME:  For now we just accept only a single integer literal. */
 806
 807 integer_literal_expression:
 808                         INTEGER_LITERAL
 809                         {
 810                           $$ = 0;
 811                         }
 812
 813 /* Z.200, 12.4.3 */
 814
 815 array_primitive_value : primitive_value
 816                         {
 817                           $$ = 0;
 818                         }
 819
 820
 821 /* Things which still need productions... */
 822
 823 synonym_name            :       FIXME { $$ = 0; }
 824 value_enumeration_name  :       FIXME { $$ = 0; }
 825 value_do_with_name      :       FIXME { $$ = 0; }
 826 value_receive_name      :       FIXME { $$ = 0; }
 827 string_primitive_value  :       FIXME { $$ = 0; }
 828 start_element           :       FIXME { $$ = 0; }
 829 left_element            :       FIXME { $$ = 0; }
 830 right_element           :       FIXME { $$ = 0; }
 831 slice_size              :       FIXME { $$ = 0; }
 832 lower_element           :       FIXME { $$ = 0; }
 833 upper_element           :       FIXME { $$ = 0; }
 834 first_element           :       FIXME { $$ = 0; }
 835 structure_primitive_value:      FIXME { $$ = 0; }
 836 field_name              :       FIXME { $$ = 0; }
 837 mode_name               :       FIXME { $$ = 0; }
 838 boolean_expression      :       FIXME { $$ = 0; }
 839 case_selector_list      :       FIXME { $$ = 0; }
 840 subexpression           :       FIXME { $$ = 0; }
 841 case_label_specification:       FIXME { $$ = 0; }
 842 buffer_location         :       FIXME { $$ = 0; }
 843
 844 %%
 845
 846 /* Try to consume a simple name string token.  If successful, returns
 847    a pointer to a nullbyte terminated copy of the name that can be used
 848    in symbol table lookups.  If not successful, returns NULL. */
 849
 850 static char *
 851 match_simple_name_string ()
 852 {
 853   char *tokptr = lexptr;
 854
 855   if (isalpha (*tokptr))
 856     {
 857       do {
 858         tokptr++;
 859       } while (isalpha (*tokptr) || isdigit (*tokptr) || (*tokptr == '_'));
 860       yylval.sval.ptr = lexptr;
 861       yylval.sval.length = tokptr - lexptr;
 862       lexptr = tokptr;
 863       return (copy_name (yylval.sval));
 864     }
 865   return (NULL);
 866 }
 867
 868 /* Start looking for a value composed of valid digits as set by the base
 869    in use.  Note that '_' characters are valid anywhere, in any quantity,
 870    and are simply ignored.  Since we must find at least one valid digit,
 871    or reject this token as an integer literal, we keep track of how many
 872    digits we have encountered. */
 873
 874 static int
 875 decode_integer_value (base, tokptrptr, ivalptr)
 876   int base;
 877   char **tokptrptr;
 878   int *ivalptr;
 879 {
 880   char *tokptr = *tokptrptr;
 881   int temp;
 882   int digits = 0;
 883
 884   while (*tokptr != '\0')
 885     {
 886       temp = tolower (*tokptr);
 887       tokptr++;
 888       switch (temp)
 889         {
 890         case '_':
 891           continue;
 892         case '0':  case '1':  case '2':  case '3':  case '4':
 893         case '5':  case '6':  case '7':  case '8':  case '9':
 894           temp -= '0';
 895           break;
 896         case 'a':  case 'b':  case 'c':  case 'd':  case 'e': case 'f':
 897           temp -= 'a';
 898           temp += 10;
 899           break;
 900         default:
 901           temp = base;
 902           break;
 903         }
 904       if (temp < base)
 905         {
 906           digits++;
 907           *ivalptr *= base;
 908           *ivalptr += temp;
 909         }
 910       else
 911         {
 912           /* Found something not in domain for current base. */
 913           tokptr--;     /* Unconsume what gave us indigestion. */
 914           break;
 915         }
 916     }
 917
 918   /* If we didn't find any digits, then we don't have a valid integer
 919      value, so reject the entire token.  Otherwise, update the lexical
 920      scan pointer, and return non-zero for success. */
 921
 922   if (digits == 0)
 923     {
 924       return (0);
 925     }
 926   else
 927     {
 928       *tokptrptr = tokptr;
 929       return (1);
 930     }
 931 }
 932
 933 static int
 934 decode_integer_literal (valptr, tokptrptr)
 935   int *valptr;
 936   char **tokptrptr;
 937 {
 938   char *tokptr = *tokptrptr;
 939   int base = 0;
 940   int ival = 0;
 941   int explicit_base = 0;
 942
 943   /* Look for an explicit base specifier, which is optional. */
 944
 945   switch (*tokptr)
 946     {
 947     case 'd':
 948     case 'D':
 949       explicit_base++;
 950       base = 10;
 951       tokptr++;
 952       break;
 953     case 'b':
 954     case 'B':
 955       explicit_base++;
 956       base = 2;
 957       tokptr++;
 958       break;
 959     case 'h':
 960     case 'H':
 961       explicit_base++;
 962       base = 16;
 963       tokptr++;
 964       break;
 965     case 'o':
 966     case 'O':
 967       explicit_base++;
 968       base = 8;
 969       tokptr++;
 970       break;
 971     default:
 972       base = 10;
 973       break;
 974     }
 975
 976   /* If we found an explicit base ensure that the character after the
 977      explicit base is a single quote. */
 978
 979   if (explicit_base && (*tokptr++ != '\''))
 980     {
 981       return (0);
 982     }
 983
 984   /* Attempt to decode whatever follows as an integer value in the
 985      indicated base, updating the token pointer in the process and
 986      computing the value into ival.  Also, if we have an explicit
 987      base, then the next character must not be a single quote, or we
 988      have a bitstring literal, so reject the entire token in this case.
 989      Otherwise, update the lexical scan pointer, and return non-zero
 990      for success. */
 991
 992   if (!decode_integer_value (base, &tokptr, &ival))
 993     {
 994       return (0);
 995     }
 996   else if (explicit_base && (*tokptr == '\''))
 997     {
 998       return (0);
 999     }
1000   else
1001     {
1002       *valptr = ival;
1003       *tokptrptr = tokptr;
1004       return (1);
1005     }
1006 }
1007
1008 /* Recognize a character literal.  A character literal is single character
1009    or a control sequence, enclosed in single quotes.  A control sequence
1010    is a comma separated list of one or more integer literals, enclosed
1011    in parenthesis and introduced with a circumflex character.
1012
1013    EX:  'a'  '^(7)'  '^(7,8)'
1014
1015    As a GNU chill extension, the syntax C'xx' is also recognized as a
1016    character literal, where xx is a hex value for the character.
1017
1018    Returns CHARACTER_LITERAL if a match is found.
1019    */
1020
1021 static int
1022 match_character_literal ()
1023 {
1024   char *tokptr = lexptr;
1025   int ival = 0;
1026
1027   if ((tolower (*tokptr) == 'c') && (*(tokptr + 1) == '\''))
1028     {
1029       /* We have a GNU chill extension form, so skip the leading "C'",
1030          decode the hex value, and then ensure that we have a trailing
1031          single quote character. */
1032       tokptr += 2;
1033       if (!decode_integer_value (16, &tokptr, &ival) || (*tokptr != '\''))
1034         {
1035           return (0);
1036         }
1037       tokptr++;
1038     }
1039   else if (*tokptr == '\'')
1040     {
1041       tokptr++;
1042
1043       /* Determine which form we have, either a control sequence or the
1044          single character form. */
1045
1046       if ((*tokptr == '^') && (*(tokptr + 1) == '('))
1047         {
1048           /* Match and decode a control sequence.  Return zero if we don't
1049              find a valid integer literal, or if the next unconsumed character
1050              after the integer literal is not the trailing ')'.
1051              FIXME:  We currently don't handle the multiple integer literal
1052              form. */
1053           tokptr += 2;
1054           if (!decode_integer_literal (&ival, &tokptr) || (*tokptr++ != ')'))
1055             {
1056               return (0);
1057             }
1058         }
1059       else
1060         {
1061           ival = *tokptr++;
1062         }
1063
1064       /* The trailing quote has not yet been consumed.  If we don't find
1065          it, then we have no match. */
1066
1067       if (*tokptr++ != '\'')
1068         {
1069           return (0);
1070         }
1071     }
1072   else
1073     {
1074       /* Not a character literal. */
1075       return (0);
1076     }
1077   yylval.typed_val.val = ival;
1078   yylval.typed_val.type = builtin_type_chill_char;
1079   lexptr = tokptr;
1080   return (CHARACTER_LITERAL);
1081 }
1082
1083 /* Recognize an integer literal, as specified in Z.200 sec 5.2.4.2.
1084    Note that according to 5.2.4.2, a single "_" is also a valid integer
1085    literal, however GNU-chill requires there to be at least one "digit"
1086    in any integer literal. */
1087
1088 static int
1089 match_integer_literal ()
1090 {
1091   char *tokptr = lexptr;
1092   int ival;
1093
1094   if (!decode_integer_literal (&ival, &tokptr))
1095     {
1096       return (0);
1097     }
1098   else
1099     {
1100       yylval.typed_val.val = ival;
1101       yylval.typed_val.type = builtin_type_int;
1102       lexptr = tokptr;
1103       return (INTEGER_LITERAL);
1104     }
1105 }
1106
1107 /* Recognize tokens that start with '$'.  These include:
1108
1109         $regname        A native register name or a "standard
1110                         register name".
1111                         Return token GDB_REGNAME.
1112
1113         $variable       A convenience variable with a name chosen
1114                         by the user.
1115                         Return token GDB_VARIABLE.
1116
1117         $digits         Value history with index <digits>, starting
1118                         from the first value which has index 1.
1119                         Return GDB_LAST.
1120
1121         $$digits        Value history with index <digits> relative
1122                         to the last value.  I.E. $$0 is the last
1123                         value, $$1 is the one previous to that, $$2
1124                         is the one previous to $$1, etc.
1125                         Return token GDB_LAST.
1126
1127         $ | $0 | $$0    The last value in the value history.
1128                         Return token GDB_LAST.
1129
1130         $$              An abbreviation for the second to the last
1131                         value in the value history, I.E. $$1
1132                         Return token GDB_LAST.
1133
1134     Note that we currently assume that register names and convenience
1135     variables follow the convention of starting with a letter or '_'.
1136
1137    */
1138
1139 static int
1140 match_dollar_tokens ()
1141 {
1142   char *tokptr;
1143   int regno;
1144   int namelength;
1145   int negate;
1146   int ival;
1147
1148   /* We will always have a successful match, even if it is just for
1149      a single '$', the abbreviation for $$0.  So advance lexptr. */
1150
1151   tokptr = ++lexptr;
1152
1153   if (*tokptr == '_' || isalpha (*tokptr))
1154     {
1155       /* Look for a match with a native register name, usually something
1156          like "r0" for example. */
1157
1158       for (regno = 0; regno < NUM_REGS; regno++)
1159         {
1160           namelength = strlen (reg_names[regno]);
1161           if (STREQN (tokptr, reg_names[regno], namelength)
1162               && !isalnum (tokptr[namelength]))
1163             {
1164               yylval.lval = regno;
1165               lexptr += namelength + 1;
1166               return (GDB_REGNAME);
1167             }
1168         }
1169
1170       /* Look for a match with a standard register name, usually something
1171          like "pc", which gdb always recognizes as the program counter
1172          regardless of what the native register name is. */
1173
1174       for (regno = 0; regno < num_std_regs; regno++)
1175         {
1176           namelength = strlen (std_regs[regno].name);
1177           if (STREQN (tokptr, std_regs[regno].name, namelength)
1178               && !isalnum (tokptr[namelength]))
1179             {
1180               yylval.lval = std_regs[regno].regnum;
1181               lexptr += namelength;
1182               return (GDB_REGNAME);
1183             }
1184         }
1185
1186       /* Attempt to match against a convenience variable.  Note that
1187          this will always succeed, because if no variable of that name
1188          already exists, the lookup_internalvar will create one for us.
1189          Also note that both lexptr and tokptr currently point to the
1190          start of the input string we are trying to match, and that we
1191          have already tested the first character for non-numeric, so we
1192          don't have to treat it specially. */
1193
1194       while (*tokptr == '_' || isalnum (*tokptr))
1195         {
1196           tokptr++;
1197         }
1198       yylval.sval.ptr = lexptr;
1199       yylval.sval.length = tokptr - lexptr;
1200       yylval.ivar = lookup_internalvar (copy_name (yylval.sval));
1201       lexptr = tokptr;
1202       return (GDB_VARIABLE);
1203     }
1204
1205   /* Since we didn't match against a register name or convenience
1206      variable, our only choice left is a history value. */
1207
1208   if (*tokptr == '$')
1209     {
1210       negate = 1;
1211       ival = 1;
1212       tokptr++;
1213     }
1214   else
1215     {
1216       negate = 0;
1217       ival = 0;
1218     }
1219
1220   /* Attempt to decode more characters as an integer value giving
1221      the index in the history list.  If successful, the value will
1222      overwrite ival (currently 0 or 1), and if not, ival will be
1223      left alone, which is good since it is currently correct for
1224      the '$' or '$$' case. */
1225
1226   decode_integer_literal (&ival, &tokptr);
1227   yylval.lval = negate ? -ival : ival;
1228   lexptr = tokptr;
1229   return (GDB_LAST);
1230 }
1231
1232 #if 0
1233 static void convert_float ()
1234 {
1235     extern double strtod ();
1236     double d;
1237     char        tmp[256];
1238     char        *p = yytext, *p1 = tmp;
1239     char        c;
1240
1241     while (c = *p++)
1242     {
1243         switch (c)
1244         {
1245         case '_':
1246             break;
1247         case 'E':
1248         case 'd':
1249         case 'D':
1250             *p1++ = 'e';
1251             break;
1252         default:
1253             *p1++ = c;
1254             break;
1255         }
1256     }
1257     *p1 = '\0';
1258     d = strtod (tmp, &p1);
1259     if (*p1)
1260     {
1261         /* add error handling here */
1262         ;
1263     }
1264     yylval.dval = d;
1265 }
1266 #endif
1267
1268 /* Take care of parsing a number (anything that starts with a digit).
1269    Set yylval and return the token type; update lexptr.
1270    LEN is the number of characters in it.  */
1271
1272 /*** Needs some error checking for the float case ***/
1273
1274 struct token
1275 {
1276   char *operator;
1277   int token;
1278 };
1279
1280 static const struct token tokentab5[] =
1281 {
1282     { "ANDIF", ANDIF }
1283 };
1284
1285 static const struct token tokentab4[] =
1286 {
1287     { "ORIF", ORIF }
1288 };
1289
1290 static const struct token tokentab3[] =
1291 {
1292     { "NOT", NOT },
1293     { "XOR", LOGXOR },
1294     { "AND", LOGAND }
1295 };
1296
1297 static const struct token tokentab2[] =
1298 {
1299     { ":=", GDB_ASSIGNMENT },
1300     { "//", SLASH_SLASH },
1301     { "/=", NOTEQUAL },
1302     { "<=", LEQ },
1303     { ">=", GTR },
1304     { "IN", IN },
1305     { "OR", LOGIOR }
1306 };
1307
1308 /* Read one token, getting characters through lexptr.  */
1309 /* This is where we will check to make sure that the language and the
1310    operators used are compatible.  */
1311
1312 static int
1313 yylex ()
1314 {
1315     unsigned int i;
1316     int token;
1317     char *simplename;
1318     struct symbol *sym;
1319
1320     /* Skip over any leading whitespace. */
1321     while (isspace (*lexptr))
1322         {
1323             lexptr++;
1324         }
1325     /* Look for special single character cases which can't be the first
1326        character of some other multicharacter token. */
1327     switch (*lexptr)
1328         {
1329             case '\0':
1330                 return (0);
1331             case ',':
1332             case '.':
1333             case '=':
1334             case ';':
1335             case '!':
1336             case '+':
1337             case '-':
1338             case '*':
1339             case '/':
1340             case '(':
1341             case ')':
1342             case '[':
1343             case ']':
1344                 return (*lexptr++);
1345         }
1346     /* Look for characters which start a particular kind of multicharacter
1347        token, such as a character literal, register name, convenience
1348        variable name, etc. */
1349     switch (*lexptr)
1350       {
1351         case 'C':
1352         case 'c':
1353         case '\'':
1354           token = match_character_literal ();
1355           if (token != 0)
1356             {
1357               return (token);
1358             }
1359           break;
1360         case '$':
1361           token = match_dollar_tokens ();
1362           if (token != 0)
1363             {
1364               return (token);
1365             }
1366           break;
1367       }
1368     /* See if it is a special token of length 5.  */
1369     for (i = 0; i < sizeof (tokentab5) / sizeof (tokentab5[0]); i++)
1370         {
1371             if (STREQN (lexptr, tokentab5[i].operator, 5))
1372                 {
1373                     lexptr += 5;
1374                     return (tokentab5[i].token);
1375                 }
1376         }
1377     /* See if it is a special token of length 4.  */
1378     for (i = 0; i < sizeof (tokentab4) / sizeof (tokentab4[0]); i++)
1379         {
1380             if (STREQN (lexptr, tokentab4[i].operator, 4))
1381                 {
1382                     lexptr += 4;
1383                     return (tokentab4[i].token);
1384                 }
1385         }
1386     /* See if it is a special token of length 3.  */
1387     for (i = 0; i < sizeof (tokentab3) / sizeof (tokentab3[0]); i++)
1388         {
1389             if (STREQN (lexptr, tokentab3[i].operator, 3))
1390                 {
1391                     lexptr += 3;
1392                     return (tokentab3[i].token);
1393                 }
1394         }
1395     /* See if it is a special token of length 2.  */
1396     for (i = 0; i < sizeof (tokentab2) / sizeof (tokentab2[0]); i++)
1397         {
1398             if (STREQN (lexptr, tokentab2[i].operator, 2))
1399                 {
1400                     lexptr += 2;
1401                     return (tokentab2[i].token);
1402                 }
1403         }
1404     /* Look for single character cases which which could be the first
1405        character of some other multicharacter token, but aren't, or we
1406        would already have found it. */
1407     switch (*lexptr)
1408         {
1409             case ':':
1410             case '/':
1411             case '<':
1412             case '>':
1413                 return (*lexptr++);
1414         }
1415     /* Look for other special tokens. */
1416     if (STREQN (lexptr, "TRUE", 4)) /* FIXME:  What about lowercase? */
1417         {
1418             yylval.ulval = 1;
1419             lexptr += 4;
1420             return (BOOLEAN_LITERAL);
1421         }
1422     if (STREQN (lexptr, "FALSE", 5)) /* FIXME:  What about lowercase? */
1423         {
1424             yylval.ulval = 0;
1425             lexptr += 5;
1426             return (BOOLEAN_LITERAL);
1427         }
1428     token = match_integer_literal ();
1429     if (token != 0)
1430         {
1431             return (token);
1432         }
1433
1434     /* Try to match a simple name string, and if a match is found, then
1435        further classify what sort of name it is and return an appropriate
1436        token.  Note that attempting to match a simple name string consumes
1437        the token from lexptr, so we can't back out if we later find that
1438        we can't classify what sort of name it is. */
1439
1440     simplename = match_simple_name_string ();
1441     if (simplename != NULL)
1442       {
1443         sym = lookup_symbol (simplename, expression_context_block,
1444                              VAR_NAMESPACE, (int *) NULL,
1445                              (struct symtab **) NULL);
1446         if (sym != NULL)
1447           {
1448             yylval.ssym.stoken.ptr = NULL;
1449             yylval.ssym.stoken.length = 0;
1450             yylval.ssym.sym = sym;
1451             yylval.ssym.is_a_field_of_this = 0; /* FIXME, C++'ism */
1452             switch (SYMBOL_CLASS (sym))
1453               {
1454               case LOC_BLOCK:
1455                 /* Found a procedure name. */
1456                 return (GENERAL_PROCEDURE_NAME);
1457               case LOC_STATIC:
1458                 /* Found a global or local static variable. */
1459                 return (LOCATION_NAME);
1460               case LOC_UNDEF:
1461               case LOC_CONST:
1462               case LOC_REGISTER:
1463               case LOC_ARG:
1464               case LOC_REF_ARG:
1465               case LOC_REGPARM:
1466               case LOC_LOCAL:
1467               case LOC_TYPEDEF:
1468               case LOC_LABEL:
1469               case LOC_CONST_BYTES:
1470               case LOC_LOCAL_ARG:
1471                 break;
1472               }
1473           }
1474         else if (!have_full_symbols () && !have_partial_symbols ())
1475           {
1476             error ("No symbol table is loaded.  Use the \"file\" command.");
1477           }
1478         else
1479           {
1480             error ("No symbol \"%s\" in current context.", simplename);
1481           }
1482       }
1483
1484     return (ILLEGAL_TOKEN);
1485 }
1486
1487 void
1488 yyerror (msg)
1489      char *msg; /* unused */
1490 {
1491   printf ("Parsing:  %s\n", lexptr);
1492   if (yychar < 256)
1493     {
1494       error ("Invalid syntax in expression near character '%c'.", yychar);
1495     }
1496   else
1497     {
1498       error ("Invalid syntax in expression");
1499     }
1500 }