gdb/ch-exp.y

   1 /* YACC grammar for Chill expressions, for GDB.
   2    Copyright 1992, 1993 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_24
 166 %token <voidval> FIXME_25
 167 %token <voidval> FIXME_26
 168 %token <voidval> FIXME_27
 169 %token <voidval> FIXME_28
 170 %token <voidval> FIXME_29
 171 %token <voidval> FIXME_30
 172
 173 %token <typed_val>      INTEGER_LITERAL
 174 %token <ulval>          BOOLEAN_LITERAL
 175 %token <typed_val>      CHARACTER_LITERAL
 176 %token <dval>           FLOAT_LITERAL
 177 %token <ssym>           GENERAL_PROCEDURE_NAME
 178 %token <ssym>           LOCATION_NAME
 179 %token <voidval>        SET_LITERAL
 180 %token <voidval>        EMPTINESS_LITERAL
 181 %token <sval>           CHARACTER_STRING_LITERAL
 182 %token <sval>           BIT_STRING_LITERAL
 183 %token <tsym>           TYPENAME
 184 %token <sval>           FIELD_NAME
 185
 186 %token <voidval>        '.'
 187 %token <voidval>        ';'
 188 %token <voidval>        ':'
 189 %token <voidval>        CASE
 190 %token <voidval>        OF
 191 %token <voidval>        ESAC
 192 %token <voidval>        LOGIOR
 193 %token <voidval>        ORIF
 194 %token <voidval>        LOGXOR
 195 %token <voidval>        LOGAND
 196 %token <voidval>        ANDIF
 197 %token <voidval>        '='
 198 %token <voidval>        NOTEQUAL
 199 %token <voidval>        '>'
 200 %token <voidval>        GTR
 201 %token <voidval>        '<'
 202 %token <voidval>        LEQ
 203 %token <voidval>        IN
 204 %token <voidval>        '+'
 205 %token <voidval>        '-'
 206 %token <voidval>        '*'
 207 %token <voidval>        '/'
 208 %token <voidval>        SLASH_SLASH
 209 %token <voidval>        MOD
 210 %token <voidval>        REM
 211 %token <voidval>        NOT
 212 %token <voidval>        POINTER
 213 %token <voidval>        RECEIVE
 214 %token <voidval>        '['
 215 %token <voidval>        ']'
 216 %token <voidval>        '('
 217 %token <voidval>        ')'
 218 %token <voidval>        UP
 219 %token <voidval>        IF
 220 %token <voidval>        THEN
 221 %token <voidval>        ELSE
 222 %token <voidval>        FI
 223 %token <voidval>        ELSIF
 224 %token <voidval>        ILLEGAL_TOKEN
 225 %token <voidval>        NUM
 226 %token <voidval>        PRED
 227 %token <voidval>        SUCC
 228 %token <voidval>        ABS
 229 %token <voidval>        CARD
 230 %token <voidval>        MAX_TOKEN
 231 %token <voidval>        MIN_TOKEN
 232 %token <voidval>        SIZE
 233 %token <voidval>        UPPER
 234 %token <voidval>        LOWER
 235 %token <voidval>        LENGTH
 236
 237 /* Tokens which are not Chill tokens used in expressions, but rather GDB
 238    specific things that we recognize in the same context as Chill tokens
 239    (register names for example). */
 240
 241 %token <lval>           GDB_REGNAME     /* Machine register name */
 242 %token <lval>           GDB_LAST        /* Value history */
 243 %token <ivar>           GDB_VARIABLE    /* Convenience variable */
 244 %token <voidval>        GDB_ASSIGNMENT  /* Assign value to somewhere */
 245
 246 %type <voidval>         location
 247 %type <voidval>         access_name
 248 %type <voidval>         primitive_value
 249 %type <voidval>         location_contents
 250 %type <voidval>         value_name
 251 %type <voidval>         literal
 252 %type <voidval>         tuple
 253 %type <voidval>         value_string_element
 254 %type <voidval>         value_string_slice
 255 %type <voidval>         value_array_element
 256 %type <voidval>         value_array_slice
 257 %type <voidval>         value_structure_field
 258 %type <voidval>         expression_conversion
 259 %type <voidval>         value_procedure_call
 260 %type <voidval>         value_built_in_routine_call
 261 %type <voidval>         chill_value_built_in_routine_call
 262 %type <voidval>         start_expression
 263 %type <voidval>         zero_adic_operator
 264 %type <voidval>         parenthesised_expression
 265 %type <voidval>         value
 266 %type <voidval>         undefined_value
 267 %type <voidval>         expression
 268 %type <voidval>         conditional_expression
 269 %type <voidval>         then_alternative
 270 %type <voidval>         else_alternative
 271 %type <voidval>         sub_expression
 272 %type <voidval>         value_case_alternative
 273 %type <voidval>         operand_0
 274 %type <voidval>         operand_1
 275 %type <voidval>         operand_2
 276 %type <voidval>         operand_3
 277 %type <voidval>         operand_4
 278 %type <voidval>         operand_5
 279 %type <voidval>         operand_6
 280 %type <voidval>         synonym_name
 281 %type <voidval>         value_enumeration_name
 282 %type <voidval>         value_do_with_name
 283 %type <voidval>         value_receive_name
 284 %type <voidval>         string_primitive_value
 285 %type <voidval>         start_element
 286 %type <voidval>         left_element
 287 %type <voidval>         right_element
 288 %type <voidval>         slice_size
 289 %type <voidval>         array_primitive_value
 290 %type <voidval>         expression_list
 291 %type <voidval>         lower_element
 292 %type <voidval>         upper_element
 293 %type <voidval>         first_element
 294 %type <voidval>         mode_argument
 295 %type <voidval>         upper_lower_argument
 296 %type <voidval>         length_argument
 297 %type <voidval>         array_mode_name
 298 %type <voidval>         string_mode_name
 299 %type <voidval>         variant_structure_mode_name
 300 %type <voidval>         boolean_expression
 301 %type <voidval>         case_selector_list
 302 %type <voidval>         subexpression
 303 %type <voidval>         case_label_specification
 304 %type <voidval>         buffer_location
 305 %type <voidval>         single_assignment_action
 306 %type <tsym>            mode_name
 307
 308 %%
 309
 310 /* Z.200, 5.3.1 */
 311
 312 start   :       value { }
 313         |       mode_name
 314                         { write_exp_elt_opcode(OP_TYPE);
 315                           write_exp_elt_type($1.type);
 316                           write_exp_elt_opcode(OP_TYPE);}
 317         ;
 318
 319 value           :       expression
 320                         {
 321                           $$ = 0;       /* FIXME */
 322                         }
 323                 |       undefined_value
 324                         {
 325                           $$ = 0;       /* FIXME */
 326                         }
 327                 ;
 328
 329 undefined_value :       FIXME_01
 330                         {
 331                           $$ = 0;       /* FIXME */
 332                         }
 333                 ;
 334
 335 /* Z.200, 4.2.1 */
 336
 337 location        :       access_name
 338                 |       primitive_value POINTER
 339                         {
 340                           write_exp_elt_opcode (UNOP_IND);
 341                         }
 342                 ;
 343
 344 /* Z.200, 4.2.2 */
 345
 346 access_name     :       LOCATION_NAME
 347                         {
 348                           write_exp_elt_opcode (OP_VAR_VALUE);
 349                           write_exp_elt_block (NULL);
 350                           write_exp_elt_sym ($1.sym);
 351                           write_exp_elt_opcode (OP_VAR_VALUE);
 352                         }
 353                 |       GDB_LAST                /* gdb specific */
 354                         {
 355                           write_exp_elt_opcode (OP_LAST);
 356                           write_exp_elt_longcst ($1);
 357                           write_exp_elt_opcode (OP_LAST);
 358                         }
 359                 |       GDB_REGNAME             /* gdb specific */
 360                         {
 361                           write_exp_elt_opcode (OP_REGISTER);
 362                           write_exp_elt_longcst ($1);
 363                           write_exp_elt_opcode (OP_REGISTER);
 364                         }
 365                 |       GDB_VARIABLE    /* gdb specific */
 366                         {
 367                           write_exp_elt_opcode (OP_INTERNALVAR);
 368                           write_exp_elt_intern ($1);
 369                           write_exp_elt_opcode (OP_INTERNALVAR);
 370                         }
 371                 |       FIXME_03
 372                         {
 373                           $$ = 0;       /* FIXME */
 374                         }
 375                 ;
 376
 377 /* Z.200, 4.2.8 */
 378
 379 expression_list :       expression
 380                         {
 381                           arglist_len = 1;
 382                         }
 383                 |       expression_list ',' expression
 384                         {
 385                           arglist_len++;
 386                         }
 387
 388 /* Z.200, 5.2.1 */
 389
 390 primitive_value :       location_contents
 391                         {
 392                           $$ = 0;       /* FIXME */
 393                         }
 394                 |       value_name
 395                         {
 396                           $$ = 0;       /* FIXME */
 397                         }
 398                 |       literal
 399                         {
 400                           $$ = 0;       /* FIXME */
 401                         }
 402                 |       tuple
 403                         {
 404                           $$ = 0;       /* FIXME */
 405                         }
 406                 |       value_string_element
 407                         {
 408                           $$ = 0;       /* FIXME */
 409                         }
 410                 |       value_string_slice
 411                         {
 412                           $$ = 0;       /* FIXME */
 413                         }
 414                 |       value_array_element
 415                         {
 416                           $$ = 0;       /* FIXME */
 417                         }
 418                 |       value_array_slice
 419                         {
 420                           $$ = 0;       /* FIXME */
 421                         }
 422                 |       value_structure_field
 423                         {
 424                           $$ = 0;       /* FIXME */
 425                         }
 426                 |       expression_conversion
 427                         {
 428                           $$ = 0;       /* FIXME */
 429                         }
 430                 |       value_procedure_call
 431                         {
 432                           $$ = 0;       /* FIXME */
 433                         }
 434                 |       value_built_in_routine_call
 435                         {
 436                           $$ = 0;       /* FIXME */
 437                         }
 438                 |       start_expression
 439                         {
 440                           $$ = 0;       /* FIXME */
 441                         }
 442                 |       zero_adic_operator
 443                         {
 444                           $$ = 0;       /* FIXME */
 445                         }
 446                 |       parenthesised_expression
 447                         {
 448                           $$ = 0;       /* FIXME */
 449                         }
 450                 ;
 451
 452 /* Z.200, 5.2.2 */
 453
 454 location_contents:      location
 455                         {
 456                           $$ = 0;       /* FIXME */
 457                         }
 458                 ;
 459
 460 /* Z.200, 5.2.3 */
 461
 462 value_name      :       synonym_name
 463                         {
 464                           $$ = 0;       /* FIXME */
 465                         }
 466                 |       value_enumeration_name
 467                         {
 468                           $$ = 0;       /* FIXME */
 469                         }
 470                 |       value_do_with_name
 471                         {
 472                           $$ = 0;       /* FIXME */
 473                         }
 474                 |       value_receive_name
 475                         {
 476                           $$ = 0;       /* FIXME */
 477                         }
 478                 |       GENERAL_PROCEDURE_NAME
 479                         {
 480                           write_exp_elt_opcode (OP_VAR_VALUE);
 481                           write_exp_elt_block (NULL);
 482                           write_exp_elt_sym ($1.sym);
 483                           write_exp_elt_opcode (OP_VAR_VALUE);
 484                         }
 485                 ;
 486
 487 /* Z.200, 5.2.4.1 */
 488
 489 literal         :       INTEGER_LITERAL
 490                         {
 491                           write_exp_elt_opcode (OP_LONG);
 492                           write_exp_elt_type ($1.type);
 493                           write_exp_elt_longcst ((LONGEST) ($1.val));
 494                           write_exp_elt_opcode (OP_LONG);
 495                         }
 496                 |       BOOLEAN_LITERAL
 497                         {
 498                           write_exp_elt_opcode (OP_BOOL);
 499                           write_exp_elt_longcst ((LONGEST) $1);
 500                           write_exp_elt_opcode (OP_BOOL);
 501                         }
 502                 |       CHARACTER_LITERAL
 503                         {
 504                           write_exp_elt_opcode (OP_LONG);
 505                           write_exp_elt_type ($1.type);
 506                           write_exp_elt_longcst ((LONGEST) ($1.val));
 507                           write_exp_elt_opcode (OP_LONG);
 508                         }
 509                 |       FLOAT_LITERAL
 510                         {
 511                           write_exp_elt_opcode (OP_DOUBLE);
 512                           write_exp_elt_type (builtin_type_double);
 513                           write_exp_elt_dblcst ($1);
 514                           write_exp_elt_opcode (OP_DOUBLE);
 515                         }
 516                 |       SET_LITERAL
 517                         {
 518                           $$ = 0;       /* FIXME */
 519                         }
 520                 |       EMPTINESS_LITERAL
 521                         {
 522                           $$ = 0;       /* FIXME */
 523                         }
 524                 |       CHARACTER_STRING_LITERAL
 525                         {
 526                           write_exp_elt_opcode (OP_STRING);
 527                           write_exp_string ($1);
 528                           write_exp_elt_opcode (OP_STRING);
 529                         }
 530                 |       BIT_STRING_LITERAL
 531                         {
 532                           write_exp_elt_opcode (OP_BITSTRING);
 533                           write_exp_bitstring ($1);
 534                           write_exp_elt_opcode (OP_BITSTRING);
 535                         }
 536                 ;
 537
 538 /* Z.200, 5.2.5 */
 539
 540 tuple           :       FIXME_04
 541                         {
 542                           $$ = 0;       /* FIXME */
 543                         }
 544                 ;
 545
 546
 547 /* Z.200, 5.2.6 */
 548
 549 value_string_element:   string_primitive_value '(' start_element ')'
 550                         {
 551                           $$ = 0;       /* FIXME */
 552                         }
 553                 ;
 554
 555 /* Z.200, 5.2.7 */
 556
 557 value_string_slice:     string_primitive_value '(' left_element ':' right_element ')'
 558                         {
 559                           $$ = 0;       /* FIXME */
 560                         }
 561                 |       string_primitive_value '(' start_element UP slice_size ')'
 562                         {
 563                           $$ = 0;       /* FIXME */
 564                         }
 565                 ;
 566
 567 /* Z.200, 5.2.8 */
 568
 569 value_array_element:    array_primitive_value '('
 570                                 /* This is to save the value of arglist_len
 571                                    being accumulated for each dimension. */
 572                                 { start_arglist (); }
 573                         expression_list ')'
 574                         {
 575                           write_exp_elt_opcode (MULTI_SUBSCRIPT);
 576                           write_exp_elt_longcst ((LONGEST) end_arglist ());
 577                           write_exp_elt_opcode (MULTI_SUBSCRIPT);
 578                         }
 579                 ;
 580
 581 /* Z.200, 5.2.9 */
 582
 583 value_array_slice:      array_primitive_value '(' lower_element ':' upper_element ')'
 584                         {
 585                           $$ = 0;       /* FIXME */
 586                         }
 587                 |       array_primitive_value '(' first_element UP slice_size ')'
 588                         {
 589                           $$ = 0;       /* FIXME */
 590                         }
 591                 ;
 592
 593 /* Z.200, 5.2.10 */
 594
 595 value_structure_field:  primitive_value FIELD_NAME
 596                         { write_exp_elt_opcode (STRUCTOP_STRUCT);
 597                           write_exp_string ($2);
 598                           write_exp_elt_opcode (STRUCTOP_STRUCT);
 599                         }
 600                 ;
 601
 602 /* Z.200, 5.2.11 */
 603
 604 expression_conversion:  mode_name parenthesised_expression
 605                         {
 606                           write_exp_elt_opcode (UNOP_CAST);
 607                           write_exp_elt_type ($1.type);
 608                           write_exp_elt_opcode (UNOP_CAST);
 609                         }
 610                 ;
 611
 612 /* Z.200, 5.2.12 */
 613
 614 value_procedure_call:   FIXME_05
 615                         {
 616                           $$ = 0;       /* FIXME */
 617                         }
 618                 ;
 619
 620 /* Z.200, 5.2.13 */
 621
 622 value_built_in_routine_call:    chill_value_built_in_routine_call
 623                         {
 624                           $$ = 0;       /* FIXME */
 625                         }
 626                 ;
 627
 628 /* Z.200, 5.2.14 */
 629
 630 start_expression:       FIXME_06
 631                         {
 632                           $$ = 0;       /* FIXME */
 633                         }       /* Not in GNU-Chill */
 634                 ;
 635
 636 /* Z.200, 5.2.15 */
 637
 638 zero_adic_operator:     FIXME_07
 639                         {
 640                           $$ = 0;       /* FIXME */
 641                         }
 642                 ;
 643
 644 /* Z.200, 5.2.16 */
 645
 646 parenthesised_expression:       '(' expression ')'
 647                         {
 648                           $$ = 0;       /* FIXME */
 649                         }
 650                 ;
 651
 652 /* Z.200, 5.3.2 */
 653
 654 expression      :       operand_0
 655                         {
 656                           $$ = 0;       /* FIXME */
 657                         }
 658                 |       single_assignment_action
 659                         {
 660                           $$ = 0;       /* FIXME */
 661                         }
 662                 |       conditional_expression
 663                         {
 664                           $$ = 0;       /* FIXME */
 665                         }
 666                 ;
 667
 668 conditional_expression : IF boolean_expression then_alternative else_alternative FI
 669                         {
 670                           $$ = 0;       /* FIXME */
 671                         }
 672                 |       CASE case_selector_list OF value_case_alternative '[' ELSE sub_expression ']' ESAC
 673                         {
 674                           $$ = 0;       /* FIXME */
 675                         }
 676                 ;
 677
 678 then_alternative:       THEN subexpression
 679                         {
 680                           $$ = 0;       /* FIXME */
 681                         }
 682                 ;
 683
 684 else_alternative:       ELSE subexpression
 685                         {
 686                           $$ = 0;       /* FIXME */
 687                         }
 688                 |       ELSIF boolean_expression then_alternative else_alternative
 689                         {
 690                           $$ = 0;       /* FIXME */
 691                         }
 692                 ;
 693
 694 sub_expression  :       expression
 695                         {
 696                           $$ = 0;       /* FIXME */
 697                         }
 698                 ;
 699
 700 value_case_alternative: case_label_specification ':' sub_expression ';'
 701                         {
 702                           $$ = 0;       /* FIXME */
 703                         }
 704                 ;
 705
 706 /* Z.200, 5.3.3 */
 707
 708 operand_0       :       operand_1
 709                         {
 710                           $$ = 0;       /* FIXME */
 711                         }
 712                 |       operand_0 LOGIOR operand_1
 713                         {
 714                           write_exp_elt_opcode (BINOP_BITWISE_IOR);
 715                         }
 716                 |       operand_0 ORIF operand_1
 717                         {
 718                           $$ = 0;       /* FIXME */
 719                         }
 720                 |       operand_0 LOGXOR operand_1
 721                         {
 722                           write_exp_elt_opcode (BINOP_BITWISE_XOR);
 723                         }
 724                 ;
 725
 726 /* Z.200, 5.3.4 */
 727
 728 operand_1       :       operand_2
 729                         {
 730                           $$ = 0;       /* FIXME */
 731                         }
 732                 |       operand_1 LOGAND operand_2
 733                         {
 734                           write_exp_elt_opcode (BINOP_BITWISE_AND);
 735                         }
 736                 |       operand_1 ANDIF operand_2
 737                         {
 738                           $$ = 0;       /* FIXME */
 739                         }
 740                 ;
 741
 742 /* Z.200, 5.3.5 */
 743
 744 operand_2       :       operand_3
 745                         {
 746                           $$ = 0;       /* FIXME */
 747                         }
 748                 |       operand_2 '=' operand_3
 749                         {
 750                           write_exp_elt_opcode (BINOP_EQUAL);
 751                         }
 752                 |       operand_2 NOTEQUAL operand_3
 753                         {
 754                           write_exp_elt_opcode (BINOP_NOTEQUAL);
 755                         }
 756                 |       operand_2 '>' operand_3
 757                         {
 758                           write_exp_elt_opcode (BINOP_GTR);
 759                         }
 760                 |       operand_2 GTR operand_3
 761                         {
 762                           write_exp_elt_opcode (BINOP_GEQ);
 763                         }
 764                 |       operand_2 '<' operand_3
 765                         {
 766                           write_exp_elt_opcode (BINOP_LESS);
 767                         }
 768                 |       operand_2 LEQ operand_3
 769                         {
 770                           write_exp_elt_opcode (BINOP_LEQ);
 771                         }
 772                 |       operand_2 IN operand_3
 773                         {
 774                           $$ = 0;       /* FIXME */
 775                         }
 776                 ;
 777
 778
 779 /* Z.200, 5.3.6 */
 780
 781 operand_3       :       operand_4
 782                         {
 783                           $$ = 0;       /* FIXME */
 784                         }
 785                 |       operand_3 '+' operand_4
 786                         {
 787                           write_exp_elt_opcode (BINOP_ADD);
 788                         }
 789                 |       operand_3 '-' operand_4
 790                         {
 791                           write_exp_elt_opcode (BINOP_SUB);
 792                         }
 793                 |       operand_3 SLASH_SLASH operand_4
 794                         {
 795                           write_exp_elt_opcode (BINOP_CONCAT);
 796                         }
 797                 ;
 798
 799 /* Z.200, 5.3.7 */
 800
 801 operand_4       :       operand_5
 802                         {
 803                           $$ = 0;       /* FIXME */
 804                         }
 805                 |       operand_4 '*' operand_5
 806                         {
 807                           write_exp_elt_opcode (BINOP_MUL);
 808                         }
 809                 |       operand_4 '/' operand_5
 810                         {
 811                           write_exp_elt_opcode (BINOP_DIV);
 812                         }
 813                 |       operand_4 MOD operand_5
 814                         {
 815                           write_exp_elt_opcode (BINOP_MOD);
 816                         }
 817                 |       operand_4 REM operand_5
 818                         {
 819                           write_exp_elt_opcode (BINOP_REM);
 820                         }
 821                 ;
 822
 823 /* Z.200, 5.3.8 */
 824
 825 operand_5       :       operand_6
 826                         {
 827                           $$ = 0;       /* FIXME */
 828                         }
 829                 |       '-' operand_6
 830                         {
 831                           write_exp_elt_opcode (UNOP_NEG);
 832                         }
 833                 |       NOT operand_6
 834                         {
 835                           write_exp_elt_opcode (UNOP_LOGICAL_NOT);
 836                         }
 837                 |       parenthesised_expression literal
 838 /* We require the string operand to be a literal, to avoid some
 839    nasty parsing ambiguities. */
 840                         {
 841                           write_exp_elt_opcode (BINOP_CONCAT);
 842                         }
 843                 ;
 844
 845 /* Z.200, 5.3.9 */
 846
 847 operand_6       :       POINTER location
 848                         {
 849                           write_exp_elt_opcode (UNOP_ADDR);
 850                         }
 851                 |       RECEIVE buffer_location
 852                         {
 853                           $$ = 0;       /* FIXME */
 854                         }
 855                 |       primitive_value
 856                         {
 857                           $$ = 0;       /* FIXME */
 858                         }
 859                 ;
 860
 861
 862 /* Z.200, 6.2 */
 863
 864 single_assignment_action :
 865                         location GDB_ASSIGNMENT value
 866                         {
 867                           write_exp_elt_opcode (BINOP_ASSIGN);
 868                         }
 869                 ;
 870
 871 /* Z.200, 6.20.3 */
 872
 873 chill_value_built_in_routine_call :
 874                         NUM '(' expression ')'
 875                         {
 876                           $$ = 0;       /* FIXME */
 877                         }
 878                 |       PRED '(' expression ')'
 879                         {
 880                           $$ = 0;       /* FIXME */
 881                         }
 882                 |       SUCC '(' expression ')'
 883                         {
 884                           $$ = 0;       /* FIXME */
 885                         }
 886                 |       ABS '(' expression ')'
 887                         {
 888                           $$ = 0;       /* FIXME */
 889                         }
 890                 |       CARD '(' expression ')'
 891                         {
 892                           $$ = 0;       /* FIXME */
 893                         }
 894                 |       MAX_TOKEN '(' expression ')'
 895                         {
 896                           $$ = 0;       /* FIXME */
 897                         }
 898                 |       MIN_TOKEN '(' expression ')'
 899                         {
 900                           $$ = 0;       /* FIXME */
 901                         }
 902                 |       SIZE '(' location ')'
 903                         {
 904                           $$ = 0;       /* FIXME */
 905                         }
 906                 |       SIZE '(' mode_argument ')'
 907                         {
 908                           $$ = 0;       /* FIXME */
 909                         }
 910                 |       UPPER '(' upper_lower_argument ')'
 911                         {
 912                           $$ = 0;       /* FIXME */
 913                         }
 914                 |       LOWER '(' upper_lower_argument ')'
 915                         {
 916                           $$ = 0;       /* FIXME */
 917                         }
 918                 |       LENGTH '(' length_argument ')'
 919                         {
 920                           $$ = 0;       /* FIXME */
 921                         }
 922                 ;
 923
 924 mode_argument :         mode_name
 925                         {
 926                           $$ = 0;       /* FIXME */
 927                         }
 928                 |       array_mode_name '(' expression ')'
 929                         {
 930                           $$ = 0;       /* FIXME */
 931                         }
 932                 |       string_mode_name '(' expression ')'
 933                         {
 934                           $$ = 0;       /* FIXME */
 935                         }
 936                 |       variant_structure_mode_name '(' expression_list ')'
 937                         {
 938                           $$ = 0;       /* FIXME */
 939                         }
 940                 ;
 941
 942 mode_name :             TYPENAME
 943                 ;
 944
 945 upper_lower_argument :  expression
 946                         {
 947                           $$ = 0;       /* FIXME */
 948                         }
 949                 |       mode_name
 950                         {
 951                           $$ = 0;       /* FIXME */
 952                         }
 953                 ;
 954
 955 length_argument :       expression
 956                         {
 957                           $$ = 0;       /* FIXME */
 958                         }
 959                 ;
 960
 961 /* Z.200, 12.4.3 */
 962
 963 array_primitive_value : primitive_value
 964                         {
 965                           $$ = 0;
 966                         }
 967                 ;
 968
 969
 970 /* Things which still need productions... */
 971
 972 array_mode_name         :       FIXME_08 { $$ = 0; }
 973 string_mode_name        :       FIXME_09 { $$ = 0; }
 974 variant_structure_mode_name:    FIXME_10 { $$ = 0; }
 975 synonym_name            :       FIXME_11 { $$ = 0; }
 976 value_enumeration_name  :       FIXME_12 { $$ = 0; }
 977 value_do_with_name      :       FIXME_13 { $$ = 0; }
 978 value_receive_name      :       FIXME_14 { $$ = 0; }
 979 string_primitive_value  :       FIXME_15 { $$ = 0; }
 980 start_element           :       FIXME_16 { $$ = 0; }
 981 left_element            :       FIXME_17 { $$ = 0; }
 982 right_element           :       FIXME_18 { $$ = 0; }
 983 slice_size              :       FIXME_19 { $$ = 0; }
 984 lower_element           :       FIXME_20 { $$ = 0; }
 985 upper_element           :       FIXME_21 { $$ = 0; }
 986 first_element           :       FIXME_22 { $$ = 0; }
 987 boolean_expression      :       FIXME_26 { $$ = 0; }
 988 case_selector_list      :       FIXME_27 { $$ = 0; }
 989 subexpression           :       FIXME_28 { $$ = 0; }
 990 case_label_specification:       FIXME_29 { $$ = 0; }
 991 buffer_location         :       FIXME_30 { $$ = 0; }
 992
 993 %%
 994
 995 /* Implementation of a dynamically expandable buffer for processing input
 996    characters acquired through lexptr and building a value to return in
 997    yylval. */
 998
 999 static char *tempbuf;           /* Current buffer contents */
1000 static int tempbufsize;         /* Size of allocated buffer */
1001 static int tempbufindex;        /* Current index into buffer */
1002
1003 #define GROWBY_MIN_SIZE 64      /* Minimum amount to grow buffer by */
1004
1005 #define CHECKBUF(size) \
1006   do { \
1007     if (tempbufindex + (size) >= tempbufsize) \
1008       { \
1009         growbuf_by_size (size); \
1010       } \
1011   } while (0);
1012
1013 /* Grow the static temp buffer if necessary, including allocating the first one
1014    on demand. */
1015
1016 static void
1017 growbuf_by_size (count)
1018      int count;
1019 {
1020   int growby;
1021
1022   growby = max (count, GROWBY_MIN_SIZE);
1023   tempbufsize += growby;
1024   if (tempbuf == NULL)
1025     {
1026       tempbuf = (char *) malloc (tempbufsize);
1027     }
1028   else
1029     {
1030       tempbuf = (char *) realloc (tempbuf, tempbufsize);
1031     }
1032 }
1033
1034 /* Try to consume a simple name string token.  If successful, returns
1035    a pointer to a nullbyte terminated copy of the name that can be used
1036    in symbol table lookups.  If not successful, returns NULL. */
1037
1038 static char *
1039 match_simple_name_string ()
1040 {
1041   char *tokptr = lexptr;
1042
1043   if (isalpha (*tokptr))
1044     {
1045       char *result;
1046       do {
1047         tokptr++;
1048       } while (isalnum (*tokptr) || (*tokptr == '_'));
1049       yylval.sval.ptr = lexptr;
1050       yylval.sval.length = tokptr - lexptr;
1051       lexptr = tokptr;
1052       result = copy_name (yylval.sval);
1053       for (tokptr = result; *tokptr; tokptr++)
1054         if (isupper (*tokptr))
1055           *tokptr = tolower(*tokptr);
1056       return result;
1057     }
1058   return (NULL);
1059 }
1060
1061 /* Start looking for a value composed of valid digits as set by the base
1062    in use.  Note that '_' characters are valid anywhere, in any quantity,
1063    and are simply ignored.  Since we must find at least one valid digit,
1064    or reject this token as an integer literal, we keep track of how many
1065    digits we have encountered. */
1066
1067 static int
1068 decode_integer_value (base, tokptrptr, ivalptr)
1069   int base;
1070   char **tokptrptr;
1071   int *ivalptr;
1072 {
1073   char *tokptr = *tokptrptr;
1074   int temp;
1075   int digits = 0;
1076
1077   while (*tokptr != '\0')
1078     {
1079       temp = tolower (*tokptr);
1080       tokptr++;
1081       switch (temp)
1082         {
1083         case '_':
1084           continue;
1085         case '0':  case '1':  case '2':  case '3':  case '4':
1086         case '5':  case '6':  case '7':  case '8':  case '9':
1087           temp -= '0';
1088           break;
1089         case 'a':  case 'b':  case 'c':  case 'd':  case 'e': case 'f':
1090           temp -= 'a';
1091           temp += 10;
1092           break;
1093         default:
1094           temp = base;
1095           break;
1096         }
1097       if (temp < base)
1098         {
1099           digits++;
1100           *ivalptr *= base;
1101           *ivalptr += temp;
1102         }
1103       else
1104         {
1105           /* Found something not in domain for current base. */
1106           tokptr--;     /* Unconsume what gave us indigestion. */
1107           break;
1108         }
1109     }
1110
1111   /* If we didn't find any digits, then we don't have a valid integer
1112      value, so reject the entire token.  Otherwise, update the lexical
1113      scan pointer, and return non-zero for success. */
1114
1115   if (digits == 0)
1116     {
1117       return (0);
1118     }
1119   else
1120     {
1121       *tokptrptr = tokptr;
1122       return (1);
1123     }
1124 }
1125
1126 static int
1127 decode_integer_literal (valptr, tokptrptr)
1128   int *valptr;
1129   char **tokptrptr;
1130 {
1131   char *tokptr = *tokptrptr;
1132   int base = 0;
1133   int ival = 0;
1134   int explicit_base = 0;
1135
1136   /* Look for an explicit base specifier, which is optional. */
1137
1138   switch (*tokptr)
1139     {
1140     case 'd':
1141     case 'D':
1142       explicit_base++;
1143       base = 10;
1144       tokptr++;
1145       break;
1146     case 'b':
1147     case 'B':
1148       explicit_base++;
1149       base = 2;
1150       tokptr++;
1151       break;
1152     case 'h':
1153     case 'H':
1154       explicit_base++;
1155       base = 16;
1156       tokptr++;
1157       break;
1158     case 'o':
1159     case 'O':
1160       explicit_base++;
1161       base = 8;
1162       tokptr++;
1163       break;
1164     default:
1165       base = 10;
1166       break;
1167     }
1168
1169   /* If we found an explicit base ensure that the character after the
1170      explicit base is a single quote. */
1171
1172   if (explicit_base && (*tokptr++ != '\''))
1173     {
1174       return (0);
1175     }
1176
1177   /* Attempt to decode whatever follows as an integer value in the
1178      indicated base, updating the token pointer in the process and
1179      computing the value into ival.  Also, if we have an explicit
1180      base, then the next character must not be a single quote, or we
1181      have a bitstring literal, so reject the entire token in this case.
1182      Otherwise, update the lexical scan pointer, and return non-zero
1183      for success. */
1184
1185   if (!decode_integer_value (base, &tokptr, &ival))
1186     {
1187       return (0);
1188     }
1189   else if (explicit_base && (*tokptr == '\''))
1190     {
1191       return (0);
1192     }
1193   else
1194     {
1195       *valptr = ival;
1196       *tokptrptr = tokptr;
1197       return (1);
1198     }
1199 }
1200
1201 /*  If it wasn't for the fact that floating point values can contain '_'
1202     characters, we could just let strtod do all the hard work by letting it
1203     try to consume as much of the current token buffer as possible and
1204     find a legal conversion.  Unfortunately we need to filter out the '_'
1205     characters before calling strtod, which we do by copying the other
1206     legal chars to a local buffer to be converted.  However since we also
1207     need to keep track of where the last unconsumed character in the input
1208     buffer is, we have transfer only as many characters as may compose a
1209     legal floating point value. */
1210
1211 static int
1212 match_float_literal ()
1213 {
1214   char *tokptr = lexptr;
1215   char *buf;
1216   char *copy;
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 idtokentab[] =
1731 {
1732     { "length", LENGTH },
1733     { "lower", LOWER },
1734     { "upper", UPPER },
1735     { "andif", ANDIF },
1736     { "pred", PRED },
1737     { "succ", SUCC },
1738     { "card", CARD },
1739     { "size", SIZE },
1740     { "orif", ORIF },
1741     { "num", NUM },
1742     { "abs", ABS },
1743     { "max", MAX_TOKEN },
1744     { "min", MIN_TOKEN },
1745     { "mod", MOD },
1746     { "rem", REM },
1747     { "not", NOT },
1748     { "xor", LOGXOR },
1749     { "and", LOGAND },
1750     { "in", IN },
1751     { "or", LOGIOR }
1752 };
1753
1754 static const struct token tokentab2[] =
1755 {
1756     { ":=", GDB_ASSIGNMENT },
1757     { "//", SLASH_SLASH },
1758     { "->", POINTER },
1759     { "/=", NOTEQUAL },
1760     { "<=", LEQ },
1761     { ">=", GTR }
1762 };
1763
1764 /* Read one token, getting characters through lexptr.  */
1765 /* This is where we will check to make sure that the language and the
1766    operators used are compatible.  */
1767
1768 static int
1769 yylex ()
1770 {
1771     unsigned int i;
1772     int token;
1773     char *simplename;
1774     struct symbol *sym;
1775
1776     /* Skip over any leading whitespace. */
1777     while (isspace (*lexptr))
1778         {
1779             lexptr++;
1780         }
1781     /* Look for special single character cases which can't be the first
1782        character of some other multicharacter token. */
1783     switch (*lexptr)
1784         {
1785             case '\0':
1786                 return (0);
1787             case ',':
1788             case '=':
1789             case ';':
1790             case '!':
1791             case '+':
1792             case '*':
1793             case '(':
1794             case ')':
1795             case '[':
1796             case ']':
1797                 return (*lexptr++);
1798         }
1799     /* Look for characters which start a particular kind of multicharacter
1800        token, such as a character literal, register name, convenience
1801        variable name, string literal, etc. */
1802     switch (*lexptr)
1803       {
1804         case '\'':
1805         case '\"':
1806           /* First try to match a string literal, which is any nonzero
1807              sequence of characters enclosed in matching single or double
1808              quotes, except that a single character inside single quotes
1809              is a character literal, so we have to catch that case also. */
1810           token = match_string_literal ();
1811           if (token != 0)
1812             {
1813               return (token);
1814             }
1815           if (*lexptr == '\'')
1816             {
1817               token = match_character_literal ();
1818               if (token != 0)
1819                 {
1820                   return (token);
1821                 }
1822             }
1823           break;
1824         case 'C':
1825         case 'c':
1826           token = match_character_literal ();
1827           if (token != 0)
1828             {
1829               return (token);
1830             }
1831           break;
1832         case '$':
1833           token = match_dollar_tokens ();
1834           if (token != 0)
1835             {
1836               return (token);
1837             }
1838           break;
1839       }
1840     /* See if it is a special token of length 2.  */
1841     for (i = 0; i < sizeof (tokentab2) / sizeof (tokentab2[0]); i++)
1842         {
1843             if (STREQN (lexptr, tokentab2[i].operator, 2))
1844                 {
1845                     lexptr += 2;
1846                     return (tokentab2[i].token);
1847                 }
1848         }
1849     /* Look for single character cases which which could be the first
1850        character of some other multicharacter token, but aren't, or we
1851        would already have found it. */
1852     switch (*lexptr)
1853         {
1854             case '-':
1855             case ':':
1856             case '/':
1857             case '<':
1858             case '>':
1859                 return (*lexptr++);
1860         }
1861     /* Look for a float literal before looking for an integer literal, so
1862        we match as much of the input stream as possible. */
1863     token = match_float_literal ();
1864     if (token != 0)
1865         {
1866             return (token);
1867         }
1868     token = match_bitstring_literal ();
1869     if (token != 0)
1870         {
1871             return (token);
1872         }
1873     token = match_integer_literal ();
1874     if (token != 0)
1875         {
1876             return (token);
1877         }
1878
1879     /* Try to match a simple name string, and if a match is found, then
1880        further classify what sort of name it is and return an appropriate
1881        token.  Note that attempting to match a simple name string consumes
1882        the token from lexptr, so we can't back out if we later find that
1883        we can't classify what sort of name it is. */
1884
1885     simplename = match_simple_name_string ();
1886
1887     if (simplename != NULL)
1888       {
1889         /* See if it is a reserved identifier. */
1890         for (i = 0; i < sizeof (idtokentab) / sizeof (idtokentab[0]); i++)
1891             {
1892                 if (STREQ (simplename, idtokentab[i].operator))
1893                     {
1894                         return (idtokentab[i].token);
1895                     }
1896             }
1897
1898         /* Look for other special tokens. */
1899         if (STREQ (simplename, "true"))
1900             {
1901                 yylval.ulval = 1;
1902                 return (BOOLEAN_LITERAL);
1903             }
1904         if (STREQ (simplename, "false"))
1905             {
1906                 yylval.ulval = 0;
1907                 return (BOOLEAN_LITERAL);
1908             }
1909
1910         sym = lookup_symbol (simplename, expression_context_block,
1911                              VAR_NAMESPACE, (int *) NULL,
1912                              (struct symtab **) NULL);
1913         if (sym != NULL)
1914           {
1915             yylval.ssym.stoken.ptr = NULL;
1916             yylval.ssym.stoken.length = 0;
1917             yylval.ssym.sym = sym;
1918             yylval.ssym.is_a_field_of_this = 0; /* FIXME, C++'ism */
1919             switch (SYMBOL_CLASS (sym))
1920               {
1921               case LOC_BLOCK:
1922                 /* Found a procedure name. */
1923                 return (GENERAL_PROCEDURE_NAME);
1924               case LOC_STATIC:
1925                 /* Found a global or local static variable. */
1926                 return (LOCATION_NAME);
1927               case LOC_REGISTER:
1928               case LOC_ARG:
1929               case LOC_REF_ARG:
1930               case LOC_REGPARM:
1931               case LOC_REGPARM_ADDR:
1932               case LOC_LOCAL:
1933               case LOC_LOCAL_ARG:
1934               case LOC_BASEREG:
1935               case LOC_BASEREG_ARG:
1936                 if (innermost_block == NULL
1937                     || contained_in (block_found, innermost_block))
1938                   {
1939                     innermost_block = block_found;
1940                   }
1941                 return (LOCATION_NAME);
1942                 break;
1943               case LOC_CONST:
1944               case LOC_LABEL:
1945                 return (LOCATION_NAME);
1946                 break;
1947               case LOC_TYPEDEF:
1948                 yylval.tsym.type = SYMBOL_TYPE (sym);
1949                 return TYPENAME;
1950               case LOC_UNDEF:
1951               case LOC_CONST_BYTES:
1952               case LOC_OPTIMIZED_OUT:
1953                 error ("Symbol \"%s\" names no location.", simplename);
1954                 break;
1955               }
1956           }
1957         else if (!have_full_symbols () && !have_partial_symbols ())
1958           {
1959             error ("No symbol table is loaded.  Use the \"file\" command.");
1960           }
1961         else
1962           {
1963             error ("No symbol \"%s\" in current context.", simplename);
1964           }
1965       }
1966
1967     /* Catch single character tokens which are not part of some
1968        longer token. */
1969
1970     switch (*lexptr)
1971       {
1972         case '.':                       /* Not float for example. */
1973           lexptr++;
1974           while (isspace (*lexptr)) lexptr++;
1975           simplename = match_simple_name_string ();
1976           if (!simplename)
1977             return '.';
1978           return FIELD_NAME;
1979       }
1980
1981     return (ILLEGAL_TOKEN);
1982 }
1983
1984 void
1985 yyerror (msg)
1986      char *msg; /* unused */
1987 {
1988   printf ("Parsing:  %s\n", lexptr);
1989   if (yychar < 256)
1990     {
1991       error ("Invalid syntax in expression near character '%c'.", yychar);
1992     }
1993   else
1994     {
1995       error ("Invalid syntax in expression");
1996     }
1997 }