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 <ctype.h>
  58 #include "expression.h"
  59 #include "language.h"
  60 #include "value.h"
  61 #include "parser-defs.h"
  62 #include "ch-lang.h"
  63
  64 /* Remap normal yacc parser interface names (yyparse, yylex, yyerror, etc),
  65    as well as gratuitiously global symbol names, so we can have multiple
  66    yacc generated parsers in gdb.  Note that these are only the variables
  67    produced by yacc.  If other parser generators (bison, byacc, etc) produce
  68    additional global names that conflict at link time, then those parser
  69    generators need to be fixed instead of adding those names to this list. */
  70
  71 #define yymaxdepth chill_maxdepth
  72 #define yyparse chill_parse
  73 #define yylex   chill_lex
  74 #define yyerror chill_error
  75 #define yylval  chill_lval
  76 #define yychar  chill_char
  77 #define yydebug chill_debug
  78 #define yypact  chill_pact
  79 #define yyr1    chill_r1
  80 #define yyr2    chill_r2
  81 #define yydef   chill_def
  82 #define yychk   chill_chk
  83 #define yypgo   chill_pgo
  84 #define yyact   chill_act
  85 #define yyexca  chill_exca
  86 #define yyerrflag chill_errflag
  87 #define yynerrs chill_nerrs
  88 #define yyps    chill_ps
  89 #define yypv    chill_pv
  90 #define yys     chill_s
  91 #define yy_yys  chill_yys
  92 #define yystate chill_state
  93 #define yytmp   chill_tmp
  94 #define yyv     chill_v
  95 #define yy_yyv  chill_yyv
  96 #define yyval   chill_val
  97 #define yylloc  chill_lloc
  98 #define yyreds  chill_reds              /* With YYDEBUG defined */
  99 #define yytoks  chill_toks              /* With YYDEBUG defined */
 100
 101 #ifndef YYDEBUG
 102 #define YYDEBUG 0               /* Default to no yydebug support */
 103 #endif
 104
 105 int
 106 yyparse PARAMS ((void));
 107
 108 static int
 109 yylex PARAMS ((void));
 110
 111 void
 112 yyerror PARAMS ((char *));
 113
 114 %}
 115
 116 /* Although the yacc "value" of an expression is not used,
 117    since the result is stored in the structure being created,
 118    other node types do have values.  */
 119
 120 %union
 121   {
 122     LONGEST lval;
 123     unsigned LONGEST ulval;
 124     struct {
 125       LONGEST val;
 126       struct type *type;
 127     } typed_val;
 128     double dval;
 129     struct symbol *sym;
 130     struct type *tval;
 131     struct stoken sval;
 132     struct ttype tsym;
 133     struct symtoken ssym;
 134     int voidval;
 135     struct block *bval;
 136     enum exp_opcode opcode;
 137     struct internalvar *ivar;
 138
 139     struct type **tvec;
 140     int *ivec;
 141   }
 142
 143 %token <voidval> FIXME_01
 144 %token <voidval> FIXME_02
 145 %token <voidval> FIXME_03
 146 %token <voidval> FIXME_04
 147 %token <voidval> FIXME_05
 148 %token <voidval> FIXME_06
 149 %token <voidval> FIXME_07
 150 %token <voidval> FIXME_08
 151 %token <voidval> FIXME_09
 152 %token <voidval> FIXME_10
 153 %token <voidval> FIXME_11
 154 %token <voidval> FIXME_12
 155 %token <voidval> FIXME_13
 156 %token <voidval> FIXME_14
 157 %token <voidval> FIXME_15
 158 %token <voidval> FIXME_16
 159 %token <voidval> FIXME_17
 160 %token <voidval> FIXME_18
 161 %token <voidval> FIXME_19
 162 %token <voidval> FIXME_20
 163 %token <voidval> FIXME_21
 164 %token <voidval> FIXME_22
 165 %token <voidval> FIXME_23
 166 %token <voidval> FIXME_24
 167 %token <voidval> FIXME_25
 168 %token <voidval> FIXME_26
 169 %token <voidval> FIXME_27
 170 %token <voidval> FIXME_28
 171 %token <voidval> FIXME_29
 172 %token <voidval> FIXME_30
 173
 174 %token <typed_val>      INTEGER_LITERAL
 175 %token <ulval>          BOOLEAN_LITERAL
 176 %token <typed_val>      CHARACTER_LITERAL
 177 %token <dval>           FLOAT_LITERAL
 178 %token <ssym>           GENERAL_PROCEDURE_NAME
 179 %token <ssym>           LOCATION_NAME
 180 %token <voidval>        SET_LITERAL
 181 %token <voidval>        EMPTINESS_LITERAL
 182 %token <sval>           CHARACTER_STRING_LITERAL
 183 %token <sval>           BIT_STRING_LITERAL
 184 %token <tsym>           TYPENAME
 185 %token <sval>           FIELD_NAME
 186
 187 %token <voidval>        '.'
 188 %token <voidval>        ';'
 189 %token <voidval>        ':'
 190 %token <voidval>        CASE
 191 %token <voidval>        OF
 192 %token <voidval>        ESAC
 193 %token <voidval>        LOGIOR
 194 %token <voidval>        ORIF
 195 %token <voidval>        LOGXOR
 196 %token <voidval>        LOGAND
 197 %token <voidval>        ANDIF
 198 %token <voidval>        '='
 199 %token <voidval>        NOTEQUAL
 200 %token <voidval>        '>'
 201 %token <voidval>        GTR
 202 %token <voidval>        '<'
 203 %token <voidval>        LEQ
 204 %token <voidval>        IN
 205 %token <voidval>        '+'
 206 %token <voidval>        '-'
 207 %token <voidval>        '*'
 208 %token <voidval>        '/'
 209 %token <voidval>        SLASH_SLASH
 210 %token <voidval>        MOD
 211 %token <voidval>        REM
 212 %token <voidval>        NOT
 213 %token <voidval>        POINTER
 214 %token <voidval>        RECEIVE
 215 %token <voidval>        '['
 216 %token <voidval>        ']'
 217 %token <voidval>        '('
 218 %token <voidval>        ')'
 219 %token <voidval>        UP
 220 %token <voidval>        IF
 221 %token <voidval>        THEN
 222 %token <voidval>        ELSE
 223 %token <voidval>        FI
 224 %token <voidval>        ELSIF
 225 %token <voidval>        ILLEGAL_TOKEN
 226 %token <voidval>        NUM
 227 %token <voidval>        PRED
 228 %token <voidval>        SUCC
 229 %token <voidval>        ABS
 230 %token <voidval>        CARD
 231 %token <voidval>        MAX
 232 %token <voidval>        MIN
 233 %token <voidval>        SIZE
 234 %token <voidval>        UPPER
 235 %token <voidval>        LOWER
 236 %token <voidval>        LENGTH
 237
 238 /* Tokens which are not Chill tokens used in expressions, but rather GDB
 239    specific things that we recognize in the same context as Chill tokens
 240    (register names for example). */
 241
 242 %token <lval>           GDB_REGNAME     /* Machine register name */
 243 %token <lval>           GDB_LAST        /* Value history */
 244 %token <ivar>           GDB_VARIABLE    /* Convenience variable */
 245 %token <voidval>        GDB_ASSIGNMENT  /* Assign value to somewhere */
 246
 247 %type <voidval>         location
 248 %type <voidval>         access_name
 249 %type <voidval>         primitive_value
 250 %type <voidval>         location_contents
 251 %type <voidval>         value_name
 252 %type <voidval>         literal
 253 %type <voidval>         tuple
 254 %type <voidval>         value_string_element
 255 %type <voidval>         value_string_slice
 256 %type <voidval>         value_array_element
 257 %type <voidval>         value_array_slice
 258 %type <voidval>         value_structure_field
 259 %type <voidval>         expression_conversion
 260 %type <voidval>         value_procedure_call
 261 %type <voidval>         value_built_in_routine_call
 262 %type <voidval>         chill_value_built_in_routine_call
 263 %type <voidval>         start_expression
 264 %type <voidval>         zero_adic_operator
 265 %type <voidval>         parenthesised_expression
 266 %type <voidval>         value
 267 %type <voidval>         undefined_value
 268 %type <voidval>         expression
 269 %type <voidval>         conditional_expression
 270 %type <voidval>         then_alternative
 271 %type <voidval>         else_alternative
 272 %type <voidval>         sub_expression
 273 %type <voidval>         value_case_alternative
 274 %type <voidval>         operand_0
 275 %type <voidval>         operand_1
 276 %type <voidval>         operand_2
 277 %type <voidval>         operand_3
 278 %type <voidval>         operand_4
 279 %type <voidval>         operand_5
 280 %type <voidval>         operand_6
 281 %type <voidval>         synonym_name
 282 %type <voidval>         value_enumeration_name
 283 %type <voidval>         value_do_with_name
 284 %type <voidval>         value_receive_name
 285 %type <voidval>         string_primitive_value
 286 %type <voidval>         start_element
 287 %type <voidval>         left_element
 288 %type <voidval>         right_element
 289 %type <voidval>         slice_size
 290 %type <voidval>         array_primitive_value
 291 %type <voidval>         expression_list
 292 %type <voidval>         lower_element
 293 %type <voidval>         upper_element
 294 %type <voidval>         first_element
 295 %type <voidval>         structure_primitive_value
 296 %type <voidval>         mode_argument
 297 %type <voidval>         upper_lower_argument
 298 %type <voidval>         length_argument
 299 %type <voidval>         array_mode_name
 300 %type <voidval>         string_mode_name
 301 %type <voidval>         variant_structure_mode_name
 302 %type <voidval>         boolean_expression
 303 %type <voidval>         case_selector_list
 304 %type <voidval>         subexpression
 305 %type <voidval>         case_label_specification
 306 %type <voidval>         buffer_location
 307 %type <voidval>         single_assignment_action
 308 %type <tsym>            mode_name
 309
 310 %%
 311
 312 /* Z.200, 5.3.1 */
 313
 314 start   :       value
 315         |       mode_name
 316                         { write_exp_elt_opcode(OP_TYPE);
 317                           write_exp_elt_type($1.type);
 318                           write_exp_elt_opcode(OP_TYPE);}
 319         ;
 320
 321 value           :       expression
 322                         {
 323                           $$ = 0;       /* FIXME */
 324                         }
 325                 |       undefined_value
 326                         {
 327                           $$ = 0;       /* FIXME */
 328                         }
 329                 ;
 330
 331 undefined_value :       FIXME_01
 332                         {
 333                           $$ = 0;       /* FIXME */
 334                         }
 335                 ;
 336
 337 /* Z.200, 4.2.1 */
 338
 339 location        :       access_name
 340                         {
 341                           $$ = 0;       /* FIXME */
 342                         }
 343                 |       primitive_value POINTER
 344                         {
 345                           write_exp_elt_opcode (UNOP_IND);
 346                         }
 347                 ;
 348
 349 /* Z.200, 4.2.2 */
 350
 351 access_name     :       LOCATION_NAME
 352                         {
 353                           write_exp_elt_opcode (OP_VAR_VALUE);
 354                           write_exp_elt_sym ($1.sym);
 355                           write_exp_elt_opcode (OP_VAR_VALUE);
 356                         }
 357                 |       GDB_LAST                /* gdb specific */
 358                         {
 359                           write_exp_elt_opcode (OP_LAST);
 360                           write_exp_elt_longcst ($1);
 361                           write_exp_elt_opcode (OP_LAST);
 362                         }
 363                 |       GDB_REGNAME             /* gdb specific */
 364                         {
 365                           write_exp_elt_opcode (OP_REGISTER);
 366                           write_exp_elt_longcst ($1);
 367                           write_exp_elt_opcode (OP_REGISTER);
 368                         }
 369                 |       GDB_VARIABLE    /* gdb specific */
 370                         {
 371                           write_exp_elt_opcode (OP_INTERNALVAR);
 372                           write_exp_elt_intern ($1);
 373                           write_exp_elt_opcode (OP_INTERNALVAR);
 374                         }
 375                 |       FIXME_03
 376                         {
 377                           $$ = 0;       /* FIXME */
 378                         }
 379                 ;
 380
 381 /* Z.200, 4.2.8 */
 382
 383 expression_list :       expression
 384                         {
 385                           arglist_len = 1;
 386                         }
 387                 |       expression_list ',' expression
 388                         {
 389                           arglist_len++;
 390                         }
 391
 392 /* Z.200, 5.2.1 */
 393
 394 primitive_value :       location_contents
 395                         {
 396                           $$ = 0;       /* FIXME */
 397                         }
 398                 |       value_name
 399                         {
 400                           $$ = 0;       /* FIXME */
 401                         }
 402                 |       literal
 403                         {
 404                           $$ = 0;       /* FIXME */
 405                         }
 406                 |       tuple
 407                         {
 408                           $$ = 0;       /* FIXME */
 409                         }
 410                 |       value_string_element
 411                         {
 412                           $$ = 0;       /* FIXME */
 413                         }
 414                 |       value_string_slice
 415                         {
 416                           $$ = 0;       /* FIXME */
 417                         }
 418                 |       value_array_element
 419                         {
 420                           $$ = 0;       /* FIXME */
 421                         }
 422                 |       value_array_slice
 423                         {
 424                           $$ = 0;       /* FIXME */
 425                         }
 426                 |       value_structure_field
 427                         {
 428                           $$ = 0;       /* FIXME */
 429                         }
 430                 |       expression_conversion
 431                         {
 432                           $$ = 0;       /* FIXME */
 433                         }
 434                 |       value_procedure_call
 435                         {
 436                           $$ = 0;       /* FIXME */
 437                         }
 438                 |       value_built_in_routine_call
 439                         {
 440                           $$ = 0;       /* FIXME */
 441                         }
 442                 |       start_expression
 443                         {
 444                           $$ = 0;       /* FIXME */
 445                         }
 446                 |       zero_adic_operator
 447                         {
 448                           $$ = 0;       /* FIXME */
 449                         }
 450                 |       parenthesised_expression
 451                         {
 452                           $$ = 0;       /* FIXME */
 453                         }
 454                 ;
 455
 456 /* Z.200, 5.2.2 */
 457
 458 location_contents:      location
 459                         {
 460                           $$ = 0;       /* FIXME */
 461                         }
 462                 ;
 463
 464 /* Z.200, 5.2.3 */
 465
 466 value_name      :       synonym_name
 467                         {
 468                           $$ = 0;       /* FIXME */
 469                         }
 470                 |       value_enumeration_name
 471                         {
 472                           $$ = 0;       /* FIXME */
 473                         }
 474                 |       value_do_with_name
 475                         {
 476                           $$ = 0;       /* FIXME */
 477                         }
 478                 |       value_receive_name
 479                         {
 480                           $$ = 0;       /* FIXME */
 481                         }
 482                 |       GENERAL_PROCEDURE_NAME
 483                         {
 484                           write_exp_elt_opcode (OP_VAR_VALUE);
 485                           write_exp_elt_sym ($1.sym);
 486                           write_exp_elt_opcode (OP_VAR_VALUE);
 487                         }
 488                 ;
 489
 490 /* Z.200, 5.2.4.1 */
 491
 492 literal         :       INTEGER_LITERAL
 493                         {
 494                           write_exp_elt_opcode (OP_LONG);
 495                           write_exp_elt_type ($1.type);
 496                           write_exp_elt_longcst ((LONGEST) ($1.val));
 497                           write_exp_elt_opcode (OP_LONG);
 498                         }
 499                 |       BOOLEAN_LITERAL
 500                         {
 501                           write_exp_elt_opcode (OP_BOOL);
 502                           write_exp_elt_longcst ((LONGEST) $1);
 503                           write_exp_elt_opcode (OP_BOOL);
 504                         }
 505                 |       CHARACTER_LITERAL
 506                         {
 507                           write_exp_elt_opcode (OP_LONG);
 508                           write_exp_elt_type ($1.type);
 509                           write_exp_elt_longcst ((LONGEST) ($1.val));
 510                           write_exp_elt_opcode (OP_LONG);
 511                         }
 512                 |       FLOAT_LITERAL
 513                         {
 514                           write_exp_elt_opcode (OP_DOUBLE);
 515                           write_exp_elt_type (builtin_type_double);
 516                           write_exp_elt_dblcst ($1);
 517                           write_exp_elt_opcode (OP_DOUBLE);
 518                         }
 519                 |       SET_LITERAL
 520                         {
 521                           $$ = 0;       /* FIXME */
 522                         }
 523                 |       EMPTINESS_LITERAL
 524                         {
 525                           $$ = 0;       /* FIXME */
 526                         }
 527                 |       CHARACTER_STRING_LITERAL
 528                         {
 529                           write_exp_elt_opcode (OP_STRING);
 530                           write_exp_string ($1);
 531                           write_exp_elt_opcode (OP_STRING);
 532                         }
 533                 |       BIT_STRING_LITERAL
 534                         {
 535                           write_exp_elt_opcode (OP_BITSTRING);
 536                           write_exp_bitstring ($1);
 537                           write_exp_elt_opcode (OP_BITSTRING);
 538                         }
 539                 ;
 540
 541 /* Z.200, 5.2.5 */
 542
 543 tuple           :       FIXME_04
 544                         {
 545                           $$ = 0;       /* FIXME */
 546                         }
 547                 ;
 548
 549
 550 /* Z.200, 5.2.6 */
 551
 552 value_string_element:   string_primitive_value '(' start_element ')'
 553                         {
 554                           $$ = 0;       /* FIXME */
 555                         }
 556                 ;
 557
 558 /* Z.200, 5.2.7 */
 559
 560 value_string_slice:     string_primitive_value '(' left_element ':' right_element ')'
 561                         {
 562                           $$ = 0;       /* FIXME */
 563                         }
 564                 |       string_primitive_value '(' start_element UP slice_size ')'
 565                         {
 566                           $$ = 0;       /* FIXME */
 567                         }
 568                 ;
 569
 570 /* Z.200, 5.2.8 */
 571
 572 value_array_element:    array_primitive_value '('
 573                                 /* This is to save the value of arglist_len
 574                                    being accumulated for each dimension. */
 575                                 { start_arglist (); }
 576                         expression_list ')'
 577                         {
 578                           write_exp_elt_opcode (MULTI_SUBSCRIPT);
 579                           write_exp_elt_longcst ((LONGEST) end_arglist ());
 580                           write_exp_elt_opcode (MULTI_SUBSCRIPT);
 581                         }
 582                 ;
 583
 584 /* Z.200, 5.2.9 */
 585
 586 value_array_slice:      array_primitive_value '(' lower_element ':' upper_element ')'
 587                         {
 588                           $$ = 0;       /* FIXME */
 589                         }
 590                 |       array_primitive_value '(' first_element UP slice_size ')'
 591                         {
 592                           $$ = 0;       /* FIXME */
 593                         }
 594                 ;
 595
 596 /* Z.200, 5.2.10 */
 597
 598 value_structure_field:  primitive_value FIELD_NAME
 599                         { write_exp_elt_opcode (STRUCTOP_STRUCT);
 600                           write_exp_string ($2);
 601                           write_exp_elt_opcode (STRUCTOP_STRUCT);
 602                         }
 603                 ;
 604
 605 /* Z.200, 5.2.11 */
 606
 607 expression_conversion:  mode_name parenthesised_expression
 608                         {
 609                           write_exp_elt_opcode (UNOP_CAST);
 610                           write_exp_elt_type ($1.type);
 611                           write_exp_elt_opcode (UNOP_CAST);
 612                         }
 613                 ;
 614
 615 /* Z.200, 5.2.12 */
 616
 617 value_procedure_call:   FIXME_05
 618                         {
 619                           $$ = 0;       /* FIXME */
 620                         }
 621                 ;
 622
 623 /* Z.200, 5.2.13 */
 624
 625 value_built_in_routine_call:    chill_value_built_in_routine_call
 626                         {
 627                           $$ = 0;       /* FIXME */
 628                         }
 629                 ;
 630
 631 /* Z.200, 5.2.14 */
 632
 633 start_expression:       FIXME_06
 634                         {
 635                           $$ = 0;       /* FIXME */
 636                         }       /* Not in GNU-Chill */
 637                 ;
 638
 639 /* Z.200, 5.2.15 */
 640
 641 zero_adic_operator:     FIXME_07
 642                         {
 643                           $$ = 0;       /* FIXME */
 644                         }
 645                 ;
 646
 647 /* Z.200, 5.2.16 */
 648
 649 parenthesised_expression:       '(' expression ')'
 650                         {
 651                           $$ = 0;       /* FIXME */
 652                         }
 653                 ;
 654
 655 /* Z.200, 5.3.2 */
 656
 657 expression      :       operand_0
 658                         {
 659                           $$ = 0;       /* FIXME */
 660                         }
 661                 |       single_assignment_action
 662                         {
 663                           $$ = 0;       /* FIXME */
 664                         }
 665                 |       conditional_expression
 666                         {
 667                           $$ = 0;       /* FIXME */
 668                         }
 669                 ;
 670
 671 conditional_expression : IF boolean_expression then_alternative else_alternative FI
 672                         {
 673                           $$ = 0;       /* FIXME */
 674                         }
 675                 |       CASE case_selector_list OF value_case_alternative '[' ELSE sub_expression ']' ESAC
 676                         {
 677                           $$ = 0;       /* FIXME */
 678                         }
 679                 ;
 680
 681 then_alternative:       THEN subexpression
 682                         {
 683                           $$ = 0;       /* FIXME */
 684                         }
 685                 ;
 686
 687 else_alternative:       ELSE subexpression
 688                         {
 689                           $$ = 0;       /* FIXME */
 690                         }
 691                 |       ELSIF boolean_expression then_alternative else_alternative
 692                         {
 693                           $$ = 0;       /* FIXME */
 694                         }
 695                 ;
 696
 697 sub_expression  :       expression
 698                         {
 699                           $$ = 0;       /* FIXME */
 700                         }
 701                 ;
 702
 703 value_case_alternative: case_label_specification ':' sub_expression ';'
 704                         {
 705                           $$ = 0;       /* FIXME */
 706                         }
 707                 ;
 708
 709 /* Z.200, 5.3.3 */
 710
 711 operand_0       :       operand_1
 712                         {
 713                           $$ = 0;       /* FIXME */
 714                         }
 715                 |       operand_0 LOGIOR operand_1
 716                         {
 717                           write_exp_elt_opcode (BINOP_BITWISE_IOR);
 718                         }
 719                 |       operand_0 ORIF operand_1
 720                         {
 721                           $$ = 0;       /* FIXME */
 722                         }
 723                 |       operand_0 LOGXOR operand_1
 724                         {
 725                           write_exp_elt_opcode (BINOP_BITWISE_XOR);
 726                         }
 727                 ;
 728
 729 /* Z.200, 5.3.4 */
 730
 731 operand_1       :       operand_2
 732                         {
 733                           $$ = 0;       /* FIXME */
 734                         }
 735                 |       operand_1 LOGAND operand_2
 736                         {
 737                           write_exp_elt_opcode (BINOP_BITWISE_AND);
 738                         }
 739                 |       operand_1 ANDIF operand_2
 740                         {
 741                           $$ = 0;       /* FIXME */
 742                         }
 743                 ;
 744
 745 /* Z.200, 5.3.5 */
 746
 747 operand_2       :       operand_3
 748                         {
 749                           $$ = 0;       /* FIXME */
 750                         }
 751                 |       operand_2 '=' operand_3
 752                         {
 753                           write_exp_elt_opcode (BINOP_EQUAL);
 754                         }
 755                 |       operand_2 NOTEQUAL operand_3
 756                         {
 757                           write_exp_elt_opcode (BINOP_NOTEQUAL);
 758                         }
 759                 |       operand_2 '>' operand_3
 760                         {
 761                           write_exp_elt_opcode (BINOP_GTR);
 762                         }
 763                 |       operand_2 GTR operand_3
 764                         {
 765                           write_exp_elt_opcode (BINOP_GEQ);
 766                         }
 767                 |       operand_2 '<' operand_3
 768                         {
 769                           write_exp_elt_opcode (BINOP_LESS);
 770                         }
 771                 |       operand_2 LEQ operand_3
 772                         {
 773                           write_exp_elt_opcode (BINOP_LEQ);
 774                         }
 775                 |       operand_2 IN operand_3
 776                         {
 777                           $$ = 0;       /* FIXME */
 778                         }
 779                 ;
 780
 781
 782 /* Z.200, 5.3.6 */
 783
 784 operand_3       :       operand_4
 785                         {
 786                           $$ = 0;       /* FIXME */
 787                         }
 788                 |       operand_3 '+' operand_4
 789                         {
 790                           write_exp_elt_opcode (BINOP_ADD);
 791                         }
 792                 |       operand_3 '-' operand_4
 793                         {
 794                           write_exp_elt_opcode (BINOP_SUB);
 795                         }
 796                 |       operand_3 SLASH_SLASH operand_4
 797                         {
 798                           write_exp_elt_opcode (BINOP_CONCAT);
 799                         }
 800                 ;
 801
 802 /* Z.200, 5.3.7 */
 803
 804 operand_4       :       operand_5
 805                         {
 806                           $$ = 0;       /* FIXME */
 807                         }
 808                 |       operand_4 '*' operand_5
 809                         {
 810                           write_exp_elt_opcode (BINOP_MUL);
 811                         }
 812                 |       operand_4 '/' operand_5
 813                         {
 814                           write_exp_elt_opcode (BINOP_DIV);
 815                         }
 816                 |       operand_4 MOD operand_5
 817                         {
 818                           write_exp_elt_opcode (BINOP_MOD);
 819                         }
 820                 |       operand_4 REM operand_5
 821                         {
 822                           write_exp_elt_opcode (BINOP_REM);
 823                         }
 824                 ;
 825
 826 /* Z.200, 5.3.8 */
 827
 828 operand_5       :       operand_6
 829                         {
 830                           $$ = 0;       /* FIXME */
 831                         }
 832                 |       '-' operand_6
 833                         {
 834                           write_exp_elt_opcode (UNOP_NEG);
 835                         }
 836                 |       NOT operand_6
 837                         {
 838                           write_exp_elt_opcode (UNOP_LOGICAL_NOT);
 839                         }
 840                 |       parenthesised_expression CHARACTER_STRING_LITERAL
 841 /* We require the string operand to be a literal, to avoid some
 842    nasty parsing ambiguities. */
 843                         {
 844                           write_exp_elt_opcode (BINOP_CONCAT);
 845                         }
 846                 ;
 847
 848 /* Z.200, 5.3.9 */
 849
 850 operand_6       :       POINTER location
 851                         {
 852                           write_exp_elt_opcode (UNOP_ADDR);
 853                         }
 854                 |       RECEIVE buffer_location
 855                         {
 856                           $$ = 0;       /* FIXME */
 857                         }
 858                 |       primitive_value
 859                         {
 860                           $$ = 0;       /* FIXME */
 861                         }
 862                 ;
 863
 864
 865 /* Z.200, 6.2 */
 866
 867 single_assignment_action :
 868                         location GDB_ASSIGNMENT value
 869                         {
 870                           write_exp_elt_opcode (BINOP_ASSIGN);
 871                         }
 872                 ;
 873
 874 /* Z.200, 6.20.3 */
 875
 876 chill_value_built_in_routine_call :
 877                         NUM '(' expression ')'
 878                         {
 879                           $$ = 0;       /* FIXME */
 880                         }
 881                 |       PRED '(' expression ')'
 882                         {
 883                           $$ = 0;       /* FIXME */
 884                         }
 885                 |       SUCC '(' expression ')'
 886                         {
 887                           $$ = 0;       /* FIXME */
 888                         }
 889                 |       ABS '(' expression ')'
 890                         {
 891                           $$ = 0;       /* FIXME */
 892                         }
 893                 |       CARD '(' expression ')'
 894                         {
 895                           $$ = 0;       /* FIXME */
 896                         }
 897                 |       MAX '(' expression ')'
 898                         {
 899                           $$ = 0;       /* FIXME */
 900                         }
 901                 |       MIN '(' expression ')'
 902                         {
 903                           $$ = 0;       /* FIXME */
 904                         }
 905                 |       SIZE '(' location ')'
 906                         {
 907                           $$ = 0;       /* FIXME */
 908                         }
 909                 |       SIZE '(' mode_argument ')'
 910                         {
 911                           $$ = 0;       /* FIXME */
 912                         }
 913                 |       UPPER '(' upper_lower_argument ')'
 914                         {
 915                           $$ = 0;       /* FIXME */
 916                         }
 917                 |       LOWER '(' upper_lower_argument ')'
 918                         {
 919                           $$ = 0;       /* FIXME */
 920                         }
 921                 |       LENGTH '(' length_argument ')'
 922                         {
 923                           $$ = 0;       /* FIXME */
 924                         }
 925                 ;
 926
 927 mode_argument :         mode_name
 928                         {
 929                           $$ = 0;       /* FIXME */
 930                         }
 931                 |       array_mode_name '(' expression ')'
 932                         {
 933                           $$ = 0;       /* FIXME */
 934                         }
 935                 |       string_mode_name '(' expression ')'
 936                         {
 937                           $$ = 0;       /* FIXME */
 938                         }
 939                 |       variant_structure_mode_name '(' expression_list ')'
 940                         {
 941                           $$ = 0;       /* FIXME */
 942                         }
 943                 ;
 944
 945 mode_name :             TYPENAME
 946                 ;
 947
 948 upper_lower_argument :  expression
 949                         {
 950                           $$ = 0;       /* FIXME */
 951                         }
 952                 |       mode_name
 953                         {
 954                           $$ = 0;       /* FIXME */
 955                         }
 956                 ;
 957
 958 length_argument :       expression
 959                         {
 960                           $$ = 0;       /* FIXME */
 961                         }
 962                 ;
 963
 964 /* Z.200, 12.4.3 */
 965
 966 array_primitive_value : primitive_value
 967                         {
 968                           $$ = 0;
 969                         }
 970                 ;
 971
 972
 973 /* Things which still need productions... */
 974
 975 array_mode_name         :       FIXME_08 { $$ = 0; }
 976 string_mode_name        :       FIXME_09 { $$ = 0; }
 977 variant_structure_mode_name:    FIXME_10 { $$ = 0; }
 978 synonym_name            :       FIXME_11 { $$ = 0; }
 979 value_enumeration_name  :       FIXME_12 { $$ = 0; }
 980 value_do_with_name      :       FIXME_13 { $$ = 0; }
 981 value_receive_name      :       FIXME_14 { $$ = 0; }
 982 string_primitive_value  :       FIXME_15 { $$ = 0; }
 983 start_element           :       FIXME_16 { $$ = 0; }
 984 left_element            :       FIXME_17 { $$ = 0; }
 985 right_element           :       FIXME_18 { $$ = 0; }
 986 slice_size              :       FIXME_19 { $$ = 0; }
 987 lower_element           :       FIXME_20 { $$ = 0; }
 988 upper_element           :       FIXME_21 { $$ = 0; }
 989 first_element           :       FIXME_22 { $$ = 0; }
 990 structure_primitive_value:      FIXME_23 { $$ = 0; }
 991 boolean_expression      :       FIXME_26 { $$ = 0; }
 992 case_selector_list      :       FIXME_27 { $$ = 0; }
 993 subexpression           :       FIXME_28 { $$ = 0; }
 994 case_label_specification:       FIXME_29 { $$ = 0; }
 995 buffer_location         :       FIXME_30 { $$ = 0; }
 996
 997 %%
 998
 999 /* Implementation of a dynamically expandable buffer for processing input
1000    characters acquired through lexptr and building a value to return in
1001    yylval. */
1002
1003 static char *tempbuf;           /* Current buffer contents */
1004 static int tempbufsize;         /* Size of allocated buffer */
1005 static int tempbufindex;        /* Current index into buffer */
1006
1007 #define GROWBY_MIN_SIZE 64      /* Minimum amount to grow buffer by */
1008
1009 #define CHECKBUF(size) \
1010   do { \
1011     if (tempbufindex + (size) >= tempbufsize) \
1012       { \
1013         growbuf_by_size (size); \
1014       } \
1015   } while (0);
1016
1017 /* Grow the static temp buffer if necessary, including allocating the first one
1018    on demand. */
1019
1020 static void
1021 growbuf_by_size (count)
1022      int count;
1023 {
1024   int growby;
1025
1026   growby = max (count, GROWBY_MIN_SIZE);
1027   tempbufsize += growby;
1028   if (tempbuf == NULL)
1029     {
1030       tempbuf = (char *) malloc (tempbufsize);
1031     }
1032   else
1033     {
1034       tempbuf = (char *) realloc (tempbuf, tempbufsize);
1035     }
1036 }
1037
1038 /* Try to consume a simple name string token.  If successful, returns
1039    a pointer to a nullbyte terminated copy of the name that can be used
1040    in symbol table lookups.  If not successful, returns NULL. */
1041
1042 static char *
1043 match_simple_name_string ()
1044 {
1045   char *tokptr = lexptr;
1046
1047   if (isalpha (*tokptr))
1048     {
1049       do {
1050         tokptr++;
1051       } while (isalpha (*tokptr) || isdigit (*tokptr) || (*tokptr == '_'));
1052       yylval.sval.ptr = lexptr;
1053       yylval.sval.length = tokptr - lexptr;
1054       lexptr = tokptr;
1055       return (copy_name (yylval.sval));
1056     }
1057   return (NULL);
1058 }
1059
1060 /* Start looking for a value composed of valid digits as set by the base
1061    in use.  Note that '_' characters are valid anywhere, in any quantity,
1062    and are simply ignored.  Since we must find at least one valid digit,
1063    or reject this token as an integer literal, we keep track of how many
1064    digits we have encountered. */
1065
1066 static int
1067 decode_integer_value (base, tokptrptr, ivalptr)
1068   int base;
1069   char **tokptrptr;
1070   int *ivalptr;
1071 {
1072   char *tokptr = *tokptrptr;
1073   int temp;
1074   int digits = 0;
1075
1076   while (*tokptr != '\0')
1077     {
1078       temp = tolower (*tokptr);
1079       tokptr++;
1080       switch (temp)
1081         {
1082         case '_':
1083           continue;
1084         case '0':  case '1':  case '2':  case '3':  case '4':
1085         case '5':  case '6':  case '7':  case '8':  case '9':
1086           temp -= '0';
1087           break;
1088         case 'a':  case 'b':  case 'c':  case 'd':  case 'e': case 'f':
1089           temp -= 'a';
1090           temp += 10;
1091           break;
1092         default:
1093           temp = base;
1094           break;
1095         }
1096       if (temp < base)
1097         {
1098           digits++;
1099           *ivalptr *= base;
1100           *ivalptr += temp;
1101         }
1102       else
1103         {
1104           /* Found something not in domain for current base. */
1105           tokptr--;     /* Unconsume what gave us indigestion. */
1106           break;
1107         }
1108     }
1109
1110   /* If we didn't find any digits, then we don't have a valid integer
1111      value, so reject the entire token.  Otherwise, update the lexical
1112      scan pointer, and return non-zero for success. */
1113
1114   if (digits == 0)
1115     {
1116       return (0);
1117     }
1118   else
1119     {
1120       *tokptrptr = tokptr;
1121       return (1);
1122     }
1123 }
1124
1125 static int
1126 decode_integer_literal (valptr, tokptrptr)
1127   int *valptr;
1128   char **tokptrptr;
1129 {
1130   char *tokptr = *tokptrptr;
1131   int base = 0;
1132   int ival = 0;
1133   int explicit_base = 0;
1134
1135   /* Look for an explicit base specifier, which is optional. */
1136
1137   switch (*tokptr)
1138     {
1139     case 'd':
1140     case 'D':
1141       explicit_base++;
1142       base = 10;
1143       tokptr++;
1144       break;
1145     case 'b':
1146     case 'B':
1147       explicit_base++;
1148       base = 2;
1149       tokptr++;
1150       break;
1151     case 'h':
1152     case 'H':
1153       explicit_base++;
1154       base = 16;
1155       tokptr++;
1156       break;
1157     case 'o':
1158     case 'O':
1159       explicit_base++;
1160       base = 8;
1161       tokptr++;
1162       break;
1163     default:
1164       base = 10;
1165       break;
1166     }
1167
1168   /* If we found an explicit base ensure that the character after the
1169      explicit base is a single quote. */
1170
1171   if (explicit_base && (*tokptr++ != '\''))
1172     {
1173       return (0);
1174     }
1175
1176   /* Attempt to decode whatever follows as an integer value in the
1177      indicated base, updating the token pointer in the process and
1178      computing the value into ival.  Also, if we have an explicit
1179      base, then the next character must not be a single quote, or we
1180      have a bitstring literal, so reject the entire token in this case.
1181      Otherwise, update the lexical scan pointer, and return non-zero
1182      for success. */
1183
1184   if (!decode_integer_value (base, &tokptr, &ival))
1185     {
1186       return (0);
1187     }
1188   else if (explicit_base && (*tokptr == '\''))
1189     {
1190       return (0);
1191     }
1192   else
1193     {
1194       *valptr = ival;
1195       *tokptrptr = tokptr;
1196       return (1);
1197     }
1198 }
1199
1200 /*  If it wasn't for the fact that floating point values can contain '_'
1201     characters, we could just let strtod do all the hard work by letting it
1202     try to consume as much of the current token buffer as possible and
1203     find a legal conversion.  Unfortunately we need to filter out the '_'
1204     characters before calling strtod, which we do by copying the other
1205     legal chars to a local buffer to be converted.  However since we also
1206     need to keep track of where the last unconsumed character in the input
1207     buffer is, we have transfer only as many characters as may compose a
1208     legal floating point value. */
1209
1210 static int
1211 match_float_literal ()
1212 {
1213   char *tokptr = lexptr;
1214   char *buf;
1215   char *copy;
1216   char ch;
1217   double dval;
1218   extern double strtod ();
1219
1220   /* Make local buffer in which to build the string to convert.  This is
1221      required because underscores are valid in chill floating point numbers
1222      but not in the string passed to strtod to convert.  The string will be
1223      no longer than our input string. */
1224
1225   copy = buf = (char *) alloca (strlen (tokptr) + 1);
1226
1227   /* Transfer all leading digits to the conversion buffer, discarding any
1228      underscores. */
1229
1230   while (isdigit (*tokptr) || *tokptr == '_')
1231     {
1232       if (*tokptr != '_')
1233         {
1234           *copy++ = *tokptr;
1235         }
1236       tokptr++;
1237     }
1238
1239   /* Now accept either a '.', or one of [eEdD].  Dot is legal regardless
1240      of whether we found any leading digits, and we simply accept it and
1241      continue on to look for the fractional part and/or exponent.  One of
1242      [eEdD] is legal only if we have seen digits, and means that there
1243      is no fractional part.  If we find neither of these, then this is
1244      not a floating point number, so return failure. */
1245
1246   switch (*tokptr++)
1247     {
1248       case '.':
1249         /* Accept and then look for fractional part and/or exponent. */
1250         *copy++ = '.';
1251         break;
1252
1253       case 'e':
1254       case 'E':
1255       case 'd':
1256       case 'D':
1257         if (copy == buf)
1258           {
1259             return (0);
1260           }
1261         *copy++ = 'e';
1262         goto collect_exponent;
1263         break;
1264
1265       default:
1266         return (0);
1267         break;
1268     }
1269
1270   /* We found a '.', copy any fractional digits to the conversion buffer, up
1271      to the first nondigit, non-underscore character. */
1272
1273   while (isdigit (*tokptr) || *tokptr == '_')
1274     {
1275       if (*tokptr != '_')
1276         {
1277           *copy++ = *tokptr;
1278         }
1279       tokptr++;
1280     }
1281
1282   /* Look for an exponent, which must start with one of [eEdD].  If none
1283      is found, jump directly to trying to convert what we have collected
1284      so far. */
1285
1286   switch (*tokptr)
1287     {
1288       case 'e':
1289       case 'E':
1290       case 'd':
1291       case 'D':
1292         *copy++ = 'e';
1293         tokptr++;
1294         break;
1295       default:
1296         goto convert_float;
1297         break;
1298     }
1299
1300   /* Accept an optional '-' or '+' following one of [eEdD]. */
1301
1302   collect_exponent:
1303   if (*tokptr == '+' || *tokptr == '-')
1304     {
1305       *copy++ = *tokptr++;
1306     }
1307
1308   /* Now copy an exponent into the conversion buffer.  Note that at the
1309      moment underscores are *not* allowed in exponents. */
1310
1311   while (isdigit (*tokptr))
1312     {
1313       *copy++ = *tokptr++;
1314     }
1315
1316   /* If we transfered any chars to the conversion buffer, try to interpret its
1317      contents as a floating point value.  If any characters remain, then we
1318      must not have a valid floating point string. */
1319
1320   convert_float:
1321   *copy = '\0';
1322   if (copy != buf)
1323       {
1324         dval = strtod (buf, &copy);
1325         if (*copy == '\0')
1326           {
1327             yylval.dval = dval;
1328             lexptr = tokptr;
1329             return (FLOAT_LITERAL);
1330           }
1331       }
1332   return (0);
1333 }
1334
1335 /* Recognize a string literal.  A string literal is a nonzero sequence
1336    of characters enclosed in matching single or double quotes, except that
1337    a single character inside single quotes is a character literal, which
1338    we reject as a string literal.  To embed the terminator character inside
1339    a string, it is simply doubled (I.E. "this""is""one""string") */
1340
1341 static int
1342 match_string_literal ()
1343 {
1344   char *tokptr = lexptr;
1345
1346   for (tempbufindex = 0, tokptr++; *tokptr != '\0'; tokptr++)
1347     {
1348       CHECKBUF (1);
1349       if (*tokptr == *lexptr)
1350         {
1351           if (*(tokptr + 1) == *lexptr)
1352             {
1353               tokptr++;
1354             }
1355           else
1356             {
1357               break;
1358             }
1359         }
1360       tempbuf[tempbufindex++] = *tokptr;
1361     }
1362   if (*tokptr == '\0'                                   /* no terminator */
1363       || tempbufindex == 0                              /* no string */
1364       || (tempbufindex == 1 && *tokptr == '\''))        /* char literal */
1365     {
1366       return (0);
1367     }
1368   else
1369     {
1370       tempbuf[tempbufindex] = '\0';
1371       yylval.sval.ptr = tempbuf;
1372       yylval.sval.length = tempbufindex;
1373       lexptr = ++tokptr;
1374       return (CHARACTER_STRING_LITERAL);
1375     }
1376 }
1377
1378 /* Recognize a character literal.  A character literal is single character
1379    or a control sequence, enclosed in single quotes.  A control sequence
1380    is a comma separated list of one or more integer literals, enclosed
1381    in parenthesis and introduced with a circumflex character.
1382
1383    EX:  'a'  '^(7)'  '^(7,8)'
1384
1385    As a GNU chill extension, the syntax C'xx' is also recognized as a
1386    character literal, where xx is a hex value for the character.
1387
1388    Note that more than a single character, enclosed in single quotes, is
1389    a string literal.
1390
1391    Also note that the control sequence form is not in GNU Chill since it
1392    is ambiguous with the string literal form using single quotes.  I.E.
1393    is '^(7)' a character literal or a string literal.  In theory it it
1394    possible to tell by context, but GNU Chill doesn't accept the control
1395    sequence form, so neither do we (for now the code is disabled).
1396
1397    Returns CHARACTER_LITERAL if a match is found.
1398    */
1399
1400 static int
1401 match_character_literal ()
1402 {
1403   char *tokptr = lexptr;
1404   int ival = 0;
1405
1406   if ((tolower (*tokptr) == 'c') && (*(tokptr + 1) == '\''))
1407     {
1408       /* We have a GNU chill extension form, so skip the leading "C'",
1409          decode the hex value, and then ensure that we have a trailing
1410          single quote character. */
1411       tokptr += 2;
1412       if (!decode_integer_value (16, &tokptr, &ival) || (*tokptr != '\''))
1413         {
1414           return (0);
1415         }
1416       tokptr++;
1417     }
1418   else if (*tokptr == '\'')
1419     {
1420       tokptr++;
1421
1422       /* Determine which form we have, either a control sequence or the
1423          single character form. */
1424
1425       if ((*tokptr == '^') && (*(tokptr + 1) == '('))
1426         {
1427 #if 0     /* Disable, see note above. -fnf */
1428           /* Match and decode a control sequence.  Return zero if we don't
1429              find a valid integer literal, or if the next unconsumed character
1430              after the integer literal is not the trailing ')'.
1431              FIXME:  We currently don't handle the multiple integer literal
1432              form. */
1433           tokptr += 2;
1434           if (!decode_integer_literal (&ival, &tokptr) || (*tokptr++ != ')'))
1435             {
1436               return (0);
1437             }
1438 #else
1439           return (0);
1440 #endif
1441         }
1442       else
1443         {
1444           ival = *tokptr++;
1445         }
1446
1447       /* The trailing quote has not yet been consumed.  If we don't find
1448          it, then we have no match. */
1449
1450       if (*tokptr++ != '\'')
1451         {
1452           return (0);
1453         }
1454     }
1455   else
1456     {
1457       /* Not a character literal. */
1458       return (0);
1459     }
1460   yylval.typed_val.val = ival;
1461   yylval.typed_val.type = builtin_type_chill_char;
1462   lexptr = tokptr;
1463   return (CHARACTER_LITERAL);
1464 }
1465
1466 /* Recognize an integer literal, as specified in Z.200 sec 5.2.4.2.
1467    Note that according to 5.2.4.2, a single "_" is also a valid integer
1468    literal, however GNU-chill requires there to be at least one "digit"
1469    in any integer literal. */
1470
1471 static int
1472 match_integer_literal ()
1473 {
1474   char *tokptr = lexptr;
1475   int ival;
1476
1477   if (!decode_integer_literal (&ival, &tokptr))
1478     {
1479       return (0);
1480     }
1481   else
1482     {
1483       yylval.typed_val.val = ival;
1484       yylval.typed_val.type = builtin_type_int;
1485       lexptr = tokptr;
1486       return (INTEGER_LITERAL);
1487     }
1488 }
1489
1490 /* Recognize a bit-string literal, as specified in Z.200 sec 5.2.4.8
1491    Note that according to 5.2.4.8, a single "_" is also a valid bit-string
1492    literal, however GNU-chill requires there to be at least one "digit"
1493    in any bit-string literal. */
1494
1495 static int
1496 match_bitstring_literal ()
1497 {
1498   char *tokptr = lexptr;
1499   int mask;
1500   int bitoffset = 0;
1501   int bitcount = 0;
1502   int base;
1503   int digit;
1504
1505   tempbufindex = 0;
1506
1507   /* Look for the required explicit base specifier. */
1508
1509   switch (*tokptr++)
1510     {
1511     case 'b':
1512     case 'B':
1513       base = 2;
1514       break;
1515     case 'o':
1516     case 'O':
1517       base = 8;
1518       break;
1519     case 'h':
1520     case 'H':
1521       base = 16;
1522       break;
1523     default:
1524       return (0);
1525       break;
1526     }
1527
1528   /* Ensure that the character after the explicit base is a single quote. */
1529
1530   if (*tokptr++ != '\'')
1531     {
1532       return (0);
1533     }
1534
1535   while (*tokptr != '\0' && *tokptr != '\'')
1536     {
1537       digit = tolower (*tokptr);
1538       tokptr++;
1539       switch (digit)
1540         {
1541           case '_':
1542             continue;
1543           case '0':  case '1':  case '2':  case '3':  case '4':
1544           case '5':  case '6':  case '7':  case '8':  case '9':
1545             digit -= '0';
1546             break;
1547           case 'a':  case 'b':  case 'c':  case 'd':  case 'e': case 'f':
1548             digit -= 'a';
1549             digit += 10;
1550             break;
1551           default:
1552             return (0);
1553             break;
1554         }
1555       if (digit >= base)
1556         {
1557           /* Found something not in domain for current base. */
1558           return (0);
1559         }
1560       else
1561         {
1562           /* Extract bits from digit, starting with the msbit appropriate for
1563              the current base, and packing them into the bitstring byte,
1564              starting at the lsbit. */
1565           for (mask = (base >> 1); mask > 0; mask >>= 1)
1566             {
1567               bitcount++;
1568               CHECKBUF (1);
1569               if (digit & mask)
1570                 {
1571                   tempbuf[tempbufindex] |= (1 << bitoffset);
1572                 }
1573               bitoffset++;
1574               if (bitoffset == HOST_CHAR_BIT)
1575                 {
1576                   bitoffset = 0;
1577                   tempbufindex++;
1578                 }
1579             }
1580         }
1581     }
1582
1583   /* Verify that we consumed everything up to the trailing single quote,
1584      and that we found some bits (IE not just underbars). */
1585
1586   if (*tokptr++ != '\'')
1587     {
1588       return (0);
1589     }
1590   else
1591     {
1592       yylval.sval.ptr = tempbuf;
1593       yylval.sval.length = bitcount;
1594       lexptr = tokptr;
1595       return (BIT_STRING_LITERAL);
1596     }
1597 }
1598
1599 /* Recognize tokens that start with '$'.  These include:
1600
1601         $regname        A native register name or a "standard
1602                         register name".
1603                         Return token GDB_REGNAME.
1604
1605         $variable       A convenience variable with a name chosen
1606                         by the user.
1607                         Return token GDB_VARIABLE.
1608
1609         $digits         Value history with index <digits>, starting
1610                         from the first value which has index 1.
1611                         Return GDB_LAST.
1612
1613         $$digits        Value history with index <digits> relative
1614                         to the last value.  I.E. $$0 is the last
1615                         value, $$1 is the one previous to that, $$2
1616                         is the one previous to $$1, etc.
1617                         Return token GDB_LAST.
1618
1619         $ | $0 | $$0    The last value in the value history.
1620                         Return token GDB_LAST.
1621
1622         $$              An abbreviation for the second to the last
1623                         value in the value history, I.E. $$1
1624                         Return token GDB_LAST.
1625
1626     Note that we currently assume that register names and convenience
1627     variables follow the convention of starting with a letter or '_'.
1628
1629    */
1630
1631 static int
1632 match_dollar_tokens ()
1633 {
1634   char *tokptr;
1635   int regno;
1636   int namelength;
1637   int negate;
1638   int ival;
1639
1640   /* We will always have a successful match, even if it is just for
1641      a single '$', the abbreviation for $$0.  So advance lexptr. */
1642
1643   tokptr = ++lexptr;
1644
1645   if (*tokptr == '_' || isalpha (*tokptr))
1646     {
1647       /* Look for a match with a native register name, usually something
1648          like "r0" for example. */
1649
1650       for (regno = 0; regno < NUM_REGS; regno++)
1651         {
1652           namelength = strlen (reg_names[regno]);
1653           if (STREQN (tokptr, reg_names[regno], namelength)
1654               && !isalnum (tokptr[namelength]))
1655             {
1656               yylval.lval = regno;
1657               lexptr += namelength + 1;
1658               return (GDB_REGNAME);
1659             }
1660         }
1661
1662       /* Look for a match with a standard register name, usually something
1663          like "pc", which gdb always recognizes as the program counter
1664          regardless of what the native register name is. */
1665
1666       for (regno = 0; regno < num_std_regs; regno++)
1667         {
1668           namelength = strlen (std_regs[regno].name);
1669           if (STREQN (tokptr, std_regs[regno].name, namelength)
1670               && !isalnum (tokptr[namelength]))
1671             {
1672               yylval.lval = std_regs[regno].regnum;
1673               lexptr += namelength;
1674               return (GDB_REGNAME);
1675             }
1676         }
1677
1678       /* Attempt to match against a convenience variable.  Note that
1679          this will always succeed, because if no variable of that name
1680          already exists, the lookup_internalvar will create one for us.
1681          Also note that both lexptr and tokptr currently point to the
1682          start of the input string we are trying to match, and that we
1683          have already tested the first character for non-numeric, so we
1684          don't have to treat it specially. */
1685
1686       while (*tokptr == '_' || isalnum (*tokptr))
1687         {
1688           tokptr++;
1689         }
1690       yylval.sval.ptr = lexptr;
1691       yylval.sval.length = tokptr - lexptr;
1692       yylval.ivar = lookup_internalvar (copy_name (yylval.sval));
1693       lexptr = tokptr;
1694       return (GDB_VARIABLE);
1695     }
1696
1697   /* Since we didn't match against a register name or convenience
1698      variable, our only choice left is a history value. */
1699
1700   if (*tokptr == '$')
1701     {
1702       negate = 1;
1703       ival = 1;
1704       tokptr++;
1705     }
1706   else
1707     {
1708       negate = 0;
1709       ival = 0;
1710     }
1711
1712   /* Attempt to decode more characters as an integer value giving
1713      the index in the history list.  If successful, the value will
1714      overwrite ival (currently 0 or 1), and if not, ival will be
1715      left alone, which is good since it is currently correct for
1716      the '$' or '$$' case. */
1717
1718   decode_integer_literal (&ival, &tokptr);
1719   yylval.lval = negate ? -ival : ival;
1720   lexptr = tokptr;
1721   return (GDB_LAST);
1722 }
1723
1724 struct token
1725 {
1726   char *operator;
1727   int token;
1728 };
1729
1730 static const struct token tokentab6[] =
1731 {
1732     { "LENGTH", LENGTH }
1733 };
1734
1735 static const struct token tokentab5[] =
1736 {
1737     { "LOWER", LOWER },
1738     { "UPPER", UPPER },
1739     { "ANDIF", ANDIF }
1740 };
1741
1742 static const struct token tokentab4[] =
1743 {
1744     { "PRED", PRED },
1745     { "SUCC", SUCC },
1746     { "CARD", CARD },
1747     { "SIZE", SIZE },
1748     { "ORIF", ORIF }
1749 };
1750
1751 static const struct token tokentab3[] =
1752 {
1753     { "NUM", NUM },
1754     { "ABS", ABS },
1755     { "MAX", MAX },
1756     { "MIN", MIN },
1757     { "MOD", MOD },
1758     { "REM", REM },
1759     { "NOT", NOT },
1760     { "XOR", LOGXOR },
1761     { "AND", LOGAND }
1762 };
1763
1764 static const struct token tokentab2[] =
1765 {
1766     { ":=", GDB_ASSIGNMENT },
1767     { "//", SLASH_SLASH },
1768     { "->", POINTER },
1769     { "/=", NOTEQUAL },
1770     { "<=", LEQ },
1771     { ">=", GTR },
1772     { "IN", IN },
1773     { "OR", LOGIOR }
1774 };
1775
1776 /* Read one token, getting characters through lexptr.  */
1777 /* This is where we will check to make sure that the language and the
1778    operators used are compatible.  */
1779
1780 static int
1781 yylex ()
1782 {
1783     unsigned int i;
1784     int token;
1785     char *simplename;
1786     struct symbol *sym;
1787
1788     /* Skip over any leading whitespace. */
1789     while (isspace (*lexptr))
1790         {
1791             lexptr++;
1792         }
1793     /* Look for special single character cases which can't be the first
1794        character of some other multicharacter token. */
1795     switch (*lexptr)
1796         {
1797             case '\0':
1798                 return (0);
1799             case ',':
1800             case '=':
1801             case ';':
1802             case '!':
1803             case '+':
1804             case '*':
1805             case '(':
1806             case ')':
1807             case '[':
1808             case ']':
1809                 return (*lexptr++);
1810         }
1811     /* Look for characters which start a particular kind of multicharacter
1812        token, such as a character literal, register name, convenience
1813        variable name, string literal, etc. */
1814     switch (*lexptr)
1815       {
1816         case '\'':
1817         case '\"':
1818           /* First try to match a string literal, which is any nonzero
1819              sequence of characters enclosed in matching single or double
1820              quotes, except that a single character inside single quotes
1821              is a character literal, so we have to catch that case also. */
1822           token = match_string_literal ();
1823           if (token != 0)
1824             {
1825               return (token);
1826             }
1827           if (*lexptr == '\'')
1828             {
1829               token = match_character_literal ();
1830               if (token != 0)
1831                 {
1832                   return (token);
1833                 }
1834             }
1835           break;
1836         case 'C':
1837         case 'c':
1838           token = match_character_literal ();
1839           if (token != 0)
1840             {
1841               return (token);
1842             }
1843           break;
1844         case '$':
1845           token = match_dollar_tokens ();
1846           if (token != 0)
1847             {
1848               return (token);
1849             }
1850           break;
1851       }
1852     /* See if it is a special token of length 6.  */
1853     for (i = 0; i < sizeof (tokentab6) / sizeof (tokentab6[0]); i++)
1854         {
1855             if (STREQN (lexptr, tokentab6[i].operator, 6))
1856                 {
1857                     lexptr += 6;
1858                     return (tokentab6[i].token);
1859                 }
1860         }
1861     /* See if it is a special token of length 5.  */
1862     for (i = 0; i < sizeof (tokentab5) / sizeof (tokentab5[0]); i++)
1863         {
1864             if (STREQN (lexptr, tokentab5[i].operator, 5))
1865                 {
1866                     lexptr += 5;
1867                     return (tokentab5[i].token);
1868                 }
1869         }
1870     /* See if it is a special token of length 4.  */
1871     for (i = 0; i < sizeof (tokentab4) / sizeof (tokentab4[0]); i++)
1872         {
1873             if (STREQN (lexptr, tokentab4[i].operator, 4))
1874                 {
1875                     lexptr += 4;
1876                     return (tokentab4[i].token);
1877                 }
1878         }
1879     /* See if it is a special token of length 3.  */
1880     for (i = 0; i < sizeof (tokentab3) / sizeof (tokentab3[0]); i++)
1881         {
1882             if (STREQN (lexptr, tokentab3[i].operator, 3))
1883                 {
1884                     lexptr += 3;
1885                     return (tokentab3[i].token);
1886                 }
1887         }
1888     /* See if it is a special token of length 2.  */
1889     for (i = 0; i < sizeof (tokentab2) / sizeof (tokentab2[0]); i++)
1890         {
1891             if (STREQN (lexptr, tokentab2[i].operator, 2))
1892                 {
1893                     lexptr += 2;
1894                     return (tokentab2[i].token);
1895                 }
1896         }
1897     /* Look for single character cases which which could be the first
1898        character of some other multicharacter token, but aren't, or we
1899        would already have found it. */
1900     switch (*lexptr)
1901         {
1902             case '-':
1903             case ':':
1904             case '/':
1905             case '<':
1906             case '>':
1907                 return (*lexptr++);
1908         }
1909     /* Look for other special tokens. */
1910     if (STREQN (lexptr, "TRUE", 4)) /* FIXME:  What about lowercase? */
1911         {
1912             yylval.ulval = 1;
1913             lexptr += 4;
1914             return (BOOLEAN_LITERAL);
1915         }
1916     if (STREQN (lexptr, "FALSE", 5)) /* FIXME:  What about lowercase? */
1917         {
1918             yylval.ulval = 0;
1919             lexptr += 5;
1920             return (BOOLEAN_LITERAL);
1921         }
1922     /* Look for a float literal before looking for an integer literal, so
1923        we match as much of the input stream as possible. */
1924     token = match_float_literal ();
1925     if (token != 0)
1926         {
1927             return (token);
1928         }
1929     token = match_bitstring_literal ();
1930     if (token != 0)
1931         {
1932             return (token);
1933         }
1934     token = match_integer_literal ();
1935     if (token != 0)
1936         {
1937             return (token);
1938         }
1939
1940     /* Try to match a simple name string, and if a match is found, then
1941        further classify what sort of name it is and return an appropriate
1942        token.  Note that attempting to match a simple name string consumes
1943        the token from lexptr, so we can't back out if we later find that
1944        we can't classify what sort of name it is. */
1945
1946     simplename = match_simple_name_string ();
1947     if (simplename != NULL)
1948       {
1949         sym = lookup_symbol (simplename, expression_context_block,
1950                              VAR_NAMESPACE, (int *) NULL,
1951                              (struct symtab **) NULL);
1952         if (sym != NULL)
1953           {
1954             yylval.ssym.stoken.ptr = NULL;
1955             yylval.ssym.stoken.length = 0;
1956             yylval.ssym.sym = sym;
1957             yylval.ssym.is_a_field_of_this = 0; /* FIXME, C++'ism */
1958             switch (SYMBOL_CLASS (sym))
1959               {
1960               case LOC_BLOCK:
1961                 /* Found a procedure name. */
1962                 return (GENERAL_PROCEDURE_NAME);
1963               case LOC_STATIC:
1964                 /* Found a global or local static variable. */
1965                 return (LOCATION_NAME);
1966               case LOC_REGISTER:
1967               case LOC_ARG:
1968               case LOC_REF_ARG:
1969               case LOC_REGPARM:
1970               case LOC_LOCAL:
1971               case LOC_LOCAL_ARG:
1972                 if (innermost_block == NULL
1973                     || contained_in (block_found, innermost_block))
1974                   {
1975                     innermost_block = block_found;
1976                   }
1977                 return (LOCATION_NAME);
1978                 break;
1979               case LOC_CONST:
1980               case LOC_LABEL:
1981                 return (LOCATION_NAME);
1982                 break;
1983               case LOC_TYPEDEF:
1984                 yylval.tsym.type = SYMBOL_TYPE (sym);
1985                 return TYPENAME;
1986               case LOC_UNDEF:
1987               case LOC_CONST_BYTES:
1988               case LOC_OPTIMIZED_OUT:
1989                 error ("Symbol \"%s\" names no location.", simplename);
1990                 break;
1991               }
1992           }
1993         else if (!have_full_symbols () && !have_partial_symbols ())
1994           {
1995             error ("No symbol table is loaded.  Use the \"file\" command.");
1996           }
1997         else
1998           {
1999             error ("No symbol \"%s\" in current context.", simplename);
2000           }
2001       }
2002
2003     /* Catch single character tokens which are not part of some
2004        longer token. */
2005
2006     switch (*lexptr)
2007       {
2008         case '.':                       /* Not float for example. */
2009           lexptr++;
2010           while (isspace (*lexptr)) lexptr++;
2011           simplename = match_simple_name_string ();
2012           if (!simplename)
2013             return '.';
2014           return FIELD_NAME;
2015       }
2016
2017     return (ILLEGAL_TOKEN);
2018 }
2019
2020 void
2021 yyerror (msg)
2022      char *msg; /* unused */
2023 {
2024   printf ("Parsing:  %s\n", lexptr);
2025   if (yychar < 256)
2026     {
2027       error ("Invalid syntax in expression near character '%c'.", yychar);
2028     }
2029   else
2030     {
2031       error ("Invalid syntax in expression");
2032     }
2033 }