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