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