gdb/ch-exp.y

   1 /* YACC grammar for Chill expressions, for GDB.
   2    Copyright (C) 1992 Free Software Foundation, Inc.
   3
   4 This file is part of GDB.
   5
   6 This program is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2 of the License, or
   9 (at your option) any later version.
  10
  11 This program is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with this program; if not, write to the Free Software
  18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20 /* Parse a Chill expression from text in a string,
  21    and return the result as a  struct expression  pointer.
  22    That structure contains arithmetic operations in reverse polish,
  23    with constants represented by operations that are followed by special data.
  24    See expression.h for the details of the format.
  25    What is important here is that it can be built up sequentially
  26    during the process of parsing; the lower levels of the tree always
  27    come first in the result.
  28
  29    Note that malloc's and realloc's in this file are transformed to
  30    xmalloc and xrealloc respectively by the same sed command in the
  31    makefile that remaps any other malloc/realloc inserted by the parser
  32    generator.  Doing this with #defines and trying to control the interaction
  33    with include files (<malloc.h> and <stdlib.h> for example) just became
  34    too messy, particularly when such includes can be inserted at random
  35    times by the parser generator.
  36
  37    Also note that the language accepted by this parser is more liberal
  38    than the one accepted by an actual Chill compiler.  For example, the
  39    language rule that a simple name string can not be one of the reserved
  40    simple name strings is not enforced (e.g "case" is not treated as a
  41    reserved name).  Another example is that Chill is a strongly typed
  42    language, and certain expressions that violate the type constraints
  43    may still be evaluated if gdb can do so in a meaningful manner, while
  44    such expressions would be rejected by the compiler.  The reason for
  45    this more liberal behavior is the philosophy that the debugger
  46    is intended to be a tool that is used by the programmer when things
  47    go wrong, and as such, it should provide as few artificial barriers
  48    to it's use as possible.  If it can do something meaningful, even
  49    something that violates language contraints that are enforced by the
  50    compiler, it should do so without complaint.
  51
  52  */
  53
  54 %{
  55
  56 #include "defs.h"
  57 #include <ctype.h>
  58 #include "expression.h"
  59 #include "language.h"
  60 #include "value.h"
  61 #include "parser-defs.h"
  62 #include "ch-lang.h"
  63
  64 /* Remap normal yacc parser interface names (yyparse, yylex, yyerror, etc),
  65    as well as gratuitiously global symbol names, so we can have multiple
  66    yacc generated parsers in gdb.  Note that these are only the variables
  67    produced by yacc.  If other parser generators (bison, byacc, etc) produce
  68    additional global names that conflict at link time, then those parser
  69    generators need to be fixed instead of adding those names to this list. */
  70
  71 #define yymaxdepth chill_maxdepth
  72 #define yyparse chill_parse
  73 #define yylex   chill_lex
  74 #define yyerror chill_error
  75 #define yylval  chill_lval
  76 #define yychar  chill_char
  77 #define yydebug chill_debug
  78 #define yypact  chill_pact
  79 #define yyr1    chill_r1
  80 #define yyr2    chill_r2
  81 #define yydef   chill_def
  82 #define yychk   chill_chk
  83 #define yypgo   chill_pgo
  84 #define yyact   chill_act
  85 #define yyexca  chill_exca
  86 #define yyerrflag chill_errflag
  87 #define yynerrs chill_nerrs
  88 #define yyps    chill_ps
  89 #define yypv    chill_pv
  90 #define yys     chill_s
  91 #define yy_yys  chill_yys
  92 #define yystate chill_state
  93 #define yytmp   chill_tmp
  94 #define yyv     chill_v
  95 #define yy_yyv  chill_yyv
  96 #define yyval   chill_val
  97 #define yylloc  chill_lloc
  98 #define yyreds  chill_reds              /* With YYDEBUG defined */
  99 #define yytoks  chill_toks              /* With YYDEBUG defined */
 100
 101 #ifndef YYDEBUG
 102 #define YYDEBUG 0               /* Default to no yydebug support */
 103 #endif
 104
 105 int
 106 yyparse PARAMS ((void));
 107
 108 static int
 109 yylex PARAMS ((void));
 110
 111 void
 112 yyerror PARAMS ((char *));
 113
 114 %}
 115
 116 /* Although the yacc "value" of an expression is not used,
 117    since the result is stored in the structure being created,
 118    other node types do have values.  */
 119
 120 %union
 121   {
 122     LONGEST lval;
 123     unsigned LONGEST ulval;
 124     struct {
 125       LONGEST val;
 126       struct type *type;
 127     } typed_val;
 128     double dval;
 129     struct symbol *sym;
 130     struct type *tval;
 131     struct stoken sval;
 132     struct ttype tsym;
 133     struct symtoken ssym;
 134     int voidval;
 135     struct block *bval;
 136     enum exp_opcode opcode;
 137     struct internalvar *ivar;
 138
 139     struct type **tvec;
 140     int *ivec;
 141   }
 142
 143 %token <voidval> FIXME_01
 144 %token <voidval> FIXME_02
 145 %token <voidval> FIXME_03
 146 %token <voidval> FIXME_04
 147 %token <voidval> FIXME_05
 148 %token <voidval> FIXME_06
 149 %token <voidval> FIXME_07
 150 %token <voidval> FIXME_08
 151 %token <voidval> FIXME_09
 152 %token <voidval> FIXME_10
 153 %token <voidval> FIXME_11
 154 %token <voidval> FIXME_12
 155 %token <voidval> FIXME_13
 156 %token <voidval> FIXME_14
 157 %token <voidval> FIXME_15
 158 %token <voidval> FIXME_16
 159 %token <voidval> FIXME_17
 160 %token <voidval> FIXME_18
 161 %token <voidval> FIXME_19
 162 %token <voidval> FIXME_20
 163 %token <voidval> FIXME_21
 164 %token <voidval> FIXME_22
 165 %token <voidval> FIXME_23
 166 %token <voidval> FIXME_24
 167 %token <voidval> FIXME_25
 168 %token <voidval> FIXME_26
 169 %token <voidval> FIXME_27
 170 %token <voidval> FIXME_28
 171 %token <voidval> FIXME_29
 172 %token <voidval> FIXME_30
 173
 174 %token <typed_val>      INTEGER_LITERAL
 175 %token <ulval>          BOOLEAN_LITERAL
 176 %token <typed_val>      CHARACTER_LITERAL
 177 %token <dval>           FLOAT_LITERAL
 178 %token <ssym>           GENERAL_PROCEDURE_NAME
 179 %token <ssym>           LOCATION_NAME
 180 %token <voidval>        SET_LITERAL
 181 %token <voidval>        EMPTINESS_LITERAL
 182 %token <sval>           CHARACTER_STRING_LITERAL
 183 %token <sval>           BIT_STRING_LITERAL
 184 %token <tsym>           TYPENAME
 185 %token <sval>           FIELD_NAME
 186
 187 %token <voidval>        '.'
 188 %token <voidval>        ';'
 189 %token <voidval>        ':'
 190 %token <voidval>        CASE
 191 %token <voidval>        OF
 192 %token <voidval>        ESAC
 193 %token <voidval>        LOGIOR
 194 %token <voidval>        ORIF
 195 %token <voidval>        LOGXOR
 196 %token <voidval>        LOGAND
 197 %token <voidval>        ANDIF
 198 %token <voidval>        '='
 199 %token <voidval>        NOTEQUAL
 200 %token <voidval>        '>'
 201 %token <voidval>        GTR
 202 %token <voidval>        '<'
 203 %token <voidval>        LEQ
 204 %token <voidval>        IN
 205 %token <voidval>        '+'
 206 %token <voidval>        '-'
 207 %token <voidval>        '*'
 208 %token <voidval>        '/'
 209 %token <voidval>        SLASH_SLASH
 210 %token <voidval>        MOD
 211 %token <voidval>        REM
 212 %token <voidval>        NOT
 213 %token <voidval>        POINTER
 214 %token <voidval>        RECEIVE
 215 %token <voidval>        '['
 216 %token <voidval>        ']'
 217 %token <voidval>        '('
 218 %token <voidval>        ')'
 219 %token <voidval>        UP
 220 %token <voidval>        IF
 221 %token <voidval>        THEN
 222 %token <voidval>        ELSE
 223 %token <voidval>        FI
 224 %token <voidval>        ELSIF
 225 %token <voidval>        ILLEGAL_TOKEN
 226 %token <voidval>        NUM
 227 %token <voidval>        PRED
 228 %token <voidval>        SUCC
 229 %token <voidval>        ABS
 230 %token <voidval>        CARD
 231 %token <voidval>        MAX
 232 %token <voidval>        MIN
 233 %token <voidval>        SIZE
 234 %token <voidval>        UPPER
 235 %token <voidval>        LOWER
 236 %token <voidval>        LENGTH
 237
 238 /* Tokens which are not Chill tokens used in expressions, but rather GDB
 239    specific things that we recognize in the same context as Chill tokens
 240    (register names for example). */
 241
 242 %token <lval>           GDB_REGNAME     /* Machine register name */
 243 %token <lval>           GDB_LAST        /* Value history */
 244 %token <ivar>           GDB_VARIABLE    /* Convenience variable */
 245 %token <voidval>        GDB_ASSIGNMENT  /* Assign value to somewhere */
 246
 247 %type <voidval>         location
 248 %type <voidval>         access_name
 249 %type <voidval>         primitive_value
 250 %type <voidval>         location_contents
 251 %type <voidval>         value_name
 252 %type <voidval>         literal
 253 %type <voidval>         tuple
 254 %type <voidval>         value_string_element
 255 %type <voidval>         value_string_slice
 256 %type <voidval>         value_array_element
 257 %type <voidval>         value_array_slice
 258 %type <voidval>         value_structure_field
 259 %type <voidval>         expression_conversion
 260 %type <voidval>         value_procedure_call
 261 %type <voidval>         value_built_in_routine_call
 262 %type <voidval>         chill_value_built_in_routine_call
 263 %type <voidval>         start_expression
 264 %type <voidval>         zero_adic_operator
 265 %type <voidval>         parenthesised_expression
 266 %type <voidval>         value
 267 %type <voidval>         undefined_value
 268 %type <voidval>         expression
 269 %type <voidval>         conditional_expression
 270 %type <voidval>         then_alternative
 271 %type <voidval>         else_alternative
 272 %type <voidval>         sub_expression
 273 %type <voidval>         value_case_alternative
 274 %type <voidval>         operand_0
 275 %type <voidval>         operand_1
 276 %type <voidval>         operand_2
 277 %type <voidval>         operand_3
 278 %type <voidval>         operand_4
 279 %type <voidval>         operand_5
 280 %type <voidval>         operand_6
 281 %type <voidval>         synonym_name
 282 %type <voidval>         value_enumeration_name
 283 %type <voidval>         value_do_with_name
 284 %type <voidval>         value_receive_name
 285 %type <voidval>         string_primitive_value
 286 %type <voidval>         start_element
 287 %type <voidval>         left_element
 288 %type <voidval>         right_element
 289 %type <voidval>         slice_size
 290 %type <voidval>         array_primitive_value
 291 %type <voidval>         expression_list
 292 %type <voidval>         lower_element
 293 %type <voidval>         upper_element
 294 %type <voidval>         first_element
 295 %type <voidval>         structure_primitive_value
 296 %type <voidval>         mode_argument
 297 %type <voidval>         upper_lower_argument
 298 %type <voidval>         length_argument
 299 %type <voidval>         array_mode_name
 300 %type <voidval>         string_mode_name
 301 %type <voidval>         variant_structure_mode_name
 302 %type <voidval>         boolean_expression
 303 %type <voidval>         case_selector_list
 304 %type <voidval>         subexpression
 305 %type <voidval>         case_label_specification
 306 %type <voidval>         buffer_location
 307 %type <voidval>         single_assignment_action
 308 %type <tsym>            mode_name
 309
 310 %%
 311
 312 /* Z.200, 5.3.1 */
 313
 314 start   :       value
 315         |       mode_name
 316                         { write_exp_elt_opcode(OP_TYPE);
 317                           write_exp_elt_type($1.type);
 318                           write_exp_elt_opcode(OP_TYPE);}
 319         ;
 320
 321 value           :       expression
 322                         {
 323                           $$ = 0;       /* FIXME */
 324                         }
 325                 |       undefined_value
 326                         {
 327                           $$ = 0;       /* FIXME */
 328                         }
 329                 ;
 330
 331 undefined_value :       FIXME_01
 332                         {
 333                           $$ = 0;       /* FIXME */
 334                         }
 335                 ;
 336
 337 /* Z.200, 4.2.1 */
 338
 339 location        :       access_name
 340                 |       primitive_value POINTER
 341                         {
 342                           write_exp_elt_opcode (UNOP_IND);
 343                         }
 344                 ;
 345
 346 /* Z.200, 4.2.2 */
 347
 348 access_name     :       LOCATION_NAME
 349                         {
 350                           write_exp_elt_opcode (OP_VAR_VALUE);
 351                           write_exp_elt_sym ($1.sym);
 352                           write_exp_elt_opcode (OP_VAR_VALUE);
 353                         }
 354                 |       GDB_LAST                /* gdb specific */
 355                         {
 356                           write_exp_elt_opcode (OP_LAST);
 357                           write_exp_elt_longcst ($1);
 358                           write_exp_elt_opcode (OP_LAST);
 359                         }
 360                 |       GDB_REGNAME             /* gdb specific */
 361                         {
 362                           write_exp_elt_opcode (OP_REGISTER);
 363                           write_exp_elt_longcst ($1);
 364                           write_exp_elt_opcode (OP_REGISTER);
 365                         }
 366                 |       GDB_VARIABLE    /* gdb specific */
 367                         {
 368                           write_exp_elt_opcode (OP_INTERNALVAR);
 369                           write_exp_elt_intern ($1);
 370                           write_exp_elt_opcode (OP_INTERNALVAR);
 371                         }
 372                 |       FIXME_03
 373                         {
 374                           $$ = 0;       /* FIXME */
 375                         }
 376                 ;
 377
 378 /* Z.200, 4.2.8 */
 379
 380 expression_list :       expression
 381                         {
 382                           arglist_len = 1;
 383                         }
 384                 |       expression_list ',' expression
 385                         {
 386                           arglist_len++;
 387                         }
 388
 389 /* Z.200, 5.2.1 */
 390
 391 primitive_value :       location_contents
 392                         {
 393                           $$ = 0;       /* FIXME */
 394                         }
 395                 |       value_name
 396                         {
 397                           $$ = 0;       /* FIXME */
 398                         }
 399                 |       literal
 400                         {
 401                           $$ = 0;       /* FIXME */
 402                         }
 403                 |       tuple
 404                         {
 405                           $$ = 0;       /* FIXME */
 406                         }
 407                 |       value_string_element
 408                         {
 409                           $$ = 0;       /* FIXME */
 410                         }
 411                 |       value_string_slice
 412                         {
 413                           $$ = 0;       /* FIXME */
 414                         }
 415                 |       value_array_element
 416                         {
 417                           $$ = 0;       /* FIXME */
 418                         }
 419                 |       value_array_slice
 420                         {
 421                           $$ = 0;       /* FIXME */
 422                         }
 423                 |       value_structure_field
 424                         {
 425                           $$ = 0;       /* FIXME */
 426                         }
 427                 |       expression_conversion
 428                         {
 429                           $$ = 0;       /* FIXME */
 430                         }
 431                 |       value_procedure_call
 432                         {
 433                           $$ = 0;       /* FIXME */
 434                         }
 435                 |       value_built_in_routine_call
 436                         {
 437                           $$ = 0;       /* FIXME */
 438                         }
 439                 |       start_expression
 440                         {
 441                           $$ = 0;       /* FIXME */
 442                         }
 443                 |       zero_adic_operator
 444                         {
 445                           $$ = 0;       /* FIXME */
 446                         }
 447                 |       parenthesised_expression
 448                         {
 449                           $$ = 0;       /* FIXME */
 450                         }
 451                 ;
 452
 453 /* Z.200, 5.2.2 */
 454
 455 location_contents:      location
 456                         {
 457                           $$ = 0;       /* FIXME */
 458                         }
 459                 ;
 460
 461 /* Z.200, 5.2.3 */
 462
 463 value_name      :       synonym_name
 464                         {
 465                           $$ = 0;       /* FIXME */
 466                         }
 467                 |       value_enumeration_name
 468                         {
 469                           $$ = 0;       /* FIXME */
 470                         }
 471                 |       value_do_with_name
 472                         {
 473                           $$ = 0;       /* FIXME */
 474                         }
 475                 |       value_receive_name
 476                         {
 477                           $$ = 0;       /* FIXME */
 478                         }
 479                 |       GENERAL_PROCEDURE_NAME
 480                         {
 481                           write_exp_elt_opcode (OP_VAR_VALUE);
 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                           $$ = 0;       /* FIXME */
 893                         }
 894                 |       MAX '(' expression ')'
 895                         {
 896                           $$ = 0;       /* FIXME */
 897                         }
 898                 |       MIN '(' 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 { $$ = 0; }
 987 structure_primitive_value:      FIXME_23 { $$ = 0; }
 988 boolean_expression      :       FIXME_26 { $$ = 0; }
 989 case_selector_list      :       FIXME_27 { $$ = 0; }
 990 subexpression           :       FIXME_28 { $$ = 0; }
 991 case_label_specification:       FIXME_29 { $$ = 0; }
 992 buffer_location         :       FIXME_30 { $$ = 0; }
 993
 994 %%
 995
 996 /* Implementation of a dynamically expandable buffer for processing input
 997    characters acquired through lexptr and building a value to return in
 998    yylval. */
 999
1000 static char *tempbuf;           /* Current buffer contents */
1001 static int tempbufsize;         /* Size of allocated buffer */
1002 static int tempbufindex;        /* Current index into buffer */
1003
1004 #define GROWBY_MIN_SIZE 64      /* Minimum amount to grow buffer by */
1005
1006 #define CHECKBUF(size) \
1007   do { \
1008     if (tempbufindex + (size) >= tempbufsize) \
1009       { \
1010         growbuf_by_size (size); \
1011       } \
1012   } while (0);
1013
1014 /* Grow the static temp buffer if necessary, including allocating the first one
1015    on demand. */
1016
1017 static void
1018 growbuf_by_size (count)
1019      int count;
1020 {
1021   int growby;
1022
1023   growby = max (count, GROWBY_MIN_SIZE);
1024   tempbufsize += growby;
1025   if (tempbuf == NULL)
1026     {
1027       tempbuf = (char *) malloc (tempbufsize);
1028     }
1029   else
1030     {
1031       tempbuf = (char *) realloc (tempbuf, tempbufsize);
1032     }
1033 }
1034
1035 /* Try to consume a simple name string token.  If successful, returns
1036    a pointer to a nullbyte terminated copy of the name that can be used
1037    in symbol table lookups.  If not successful, returns NULL. */
1038
1039 static char *
1040 match_simple_name_string ()
1041 {
1042   char *tokptr = lexptr;
1043
1044   if (isalpha (*tokptr))
1045     {
1046       do {
1047         tokptr++;
1048       } while (isalpha (*tokptr) || isdigit (*tokptr) || (*tokptr == '_'));
1049       yylval.sval.ptr = lexptr;
1050       yylval.sval.length = tokptr - lexptr;
1051       lexptr = tokptr;
1052       return (copy_name (yylval.sval));
1053     }
1054   return (NULL);
1055 }
1056
1057 /* Start looking for a value composed of valid digits as set by the base
1058    in use.  Note that '_' characters are valid anywhere, in any quantity,
1059    and are simply ignored.  Since we must find at least one valid digit,
1060    or reject this token as an integer literal, we keep track of how many
1061    digits we have encountered. */
1062
1063 static int
1064 decode_integer_value (base, tokptrptr, ivalptr)
1065   int base;
1066   char **tokptrptr;
1067   int *ivalptr;
1068 {
1069   char *tokptr = *tokptrptr;
1070   int temp;
1071   int digits = 0;
1072
1073   while (*tokptr != '\0')
1074     {
1075       temp = tolower (*tokptr);
1076       tokptr++;
1077       switch (temp)
1078         {
1079         case '_':
1080           continue;
1081         case '0':  case '1':  case '2':  case '3':  case '4':
1082         case '5':  case '6':  case '7':  case '8':  case '9':
1083           temp -= '0';
1084           break;
1085         case 'a':  case 'b':  case 'c':  case 'd':  case 'e': case 'f':
1086           temp -= 'a';
1087           temp += 10;
1088           break;
1089         default:
1090           temp = base;
1091           break;
1092         }
1093       if (temp < base)
1094         {
1095           digits++;
1096           *ivalptr *= base;
1097           *ivalptr += temp;
1098         }
1099       else
1100         {
1101           /* Found something not in domain for current base. */
1102           tokptr--;     /* Unconsume what gave us indigestion. */
1103           break;
1104         }
1105     }
1106
1107   /* If we didn't find any digits, then we don't have a valid integer
1108      value, so reject the entire token.  Otherwise, update the lexical
1109      scan pointer, and return non-zero for success. */
1110
1111   if (digits == 0)
1112     {
1113       return (0);
1114     }
1115   else
1116     {
1117       *tokptrptr = tokptr;
1118       return (1);
1119     }
1120 }
1121
1122 static int
1123 decode_integer_literal (valptr, tokptrptr)
1124   int *valptr;
1125   char **tokptrptr;
1126 {
1127   char *tokptr = *tokptrptr;
1128   int base = 0;
1129   int ival = 0;
1130   int explicit_base = 0;
1131
1132   /* Look for an explicit base specifier, which is optional. */
1133
1134   switch (*tokptr)
1135     {
1136     case 'd':
1137     case 'D':
1138       explicit_base++;
1139       base = 10;
1140       tokptr++;
1141       break;
1142     case 'b':
1143     case 'B':
1144       explicit_base++;
1145       base = 2;
1146       tokptr++;
1147       break;
1148     case 'h':
1149     case 'H':
1150       explicit_base++;
1151       base = 16;
1152       tokptr++;
1153       break;
1154     case 'o':
1155     case 'O':
1156       explicit_base++;
1157       base = 8;
1158       tokptr++;
1159       break;
1160     default:
1161       base = 10;
1162       break;
1163     }
1164
1165   /* If we found an explicit base ensure that the character after the
1166      explicit base is a single quote. */
1167
1168   if (explicit_base && (*tokptr++ != '\''))
1169     {
1170       return (0);
1171     }
1172
1173   /* Attempt to decode whatever follows as an integer value in the
1174      indicated base, updating the token pointer in the process and
1175      computing the value into ival.  Also, if we have an explicit
1176      base, then the next character must not be a single quote, or we
1177      have a bitstring literal, so reject the entire token in this case.
1178      Otherwise, update the lexical scan pointer, and return non-zero
1179      for success. */
1180
1181   if (!decode_integer_value (base, &tokptr, &ival))
1182     {
1183       return (0);
1184     }
1185   else if (explicit_base && (*tokptr == '\''))
1186     {
1187       return (0);
1188     }
1189   else
1190     {
1191       *valptr = ival;
1192       *tokptrptr = tokptr;
1193       return (1);
1194     }
1195 }
1196
1197 /*  If it wasn't for the fact that floating point values can contain '_'
1198     characters, we could just let strtod do all the hard work by letting it
1199     try to consume as much of the current token buffer as possible and
1200     find a legal conversion.  Unfortunately we need to filter out the '_'
1201     characters before calling strtod, which we do by copying the other
1202     legal chars to a local buffer to be converted.  However since we also
1203     need to keep track of where the last unconsumed character in the input
1204     buffer is, we have transfer only as many characters as may compose a
1205     legal floating point value. */
1206
1207 static int
1208 match_float_literal ()
1209 {
1210   char *tokptr = lexptr;
1211   char *buf;
1212   char *copy;
1213   char ch;
1214   double dval;
1215   extern double strtod ();
1216
1217   /* Make local buffer in which to build the string to convert.  This is
1218      required because underscores are valid in chill floating point numbers
1219      but not in the string passed to strtod to convert.  The string will be
1220      no longer than our input string. */
1221
1222   copy = buf = (char *) alloca (strlen (tokptr) + 1);
1223
1224   /* Transfer all leading digits to the conversion buffer, discarding any
1225      underscores. */
1226
1227   while (isdigit (*tokptr) || *tokptr == '_')
1228     {
1229       if (*tokptr != '_')
1230         {
1231           *copy++ = *tokptr;
1232         }
1233       tokptr++;
1234     }
1235
1236   /* Now accept either a '.', or one of [eEdD].  Dot is legal regardless
1237      of whether we found any leading digits, and we simply accept it and
1238      continue on to look for the fractional part and/or exponent.  One of
1239      [eEdD] is legal only if we have seen digits, and means that there
1240      is no fractional part.  If we find neither of these, then this is
1241      not a floating point number, so return failure. */
1242
1243   switch (*tokptr++)
1244     {
1245       case '.':
1246         /* Accept and then look for fractional part and/or exponent. */
1247         *copy++ = '.';
1248         break;
1249
1250       case 'e':
1251       case 'E':
1252       case 'd':
1253       case 'D':
1254         if (copy == buf)
1255           {
1256             return (0);
1257           }
1258         *copy++ = 'e';
1259         goto collect_exponent;
1260         break;
1261
1262       default:
1263         return (0);
1264         break;
1265     }
1266
1267   /* We found a '.', copy any fractional digits to the conversion buffer, up
1268      to the first nondigit, non-underscore character. */
1269
1270   while (isdigit (*tokptr) || *tokptr == '_')
1271     {
1272       if (*tokptr != '_')
1273         {
1274           *copy++ = *tokptr;
1275         }
1276       tokptr++;
1277     }
1278
1279   /* Look for an exponent, which must start with one of [eEdD].  If none
1280      is found, jump directly to trying to convert what we have collected
1281      so far. */
1282
1283   switch (*tokptr)
1284     {
1285       case 'e':
1286       case 'E':
1287       case 'd':
1288       case 'D':
1289         *copy++ = 'e';
1290         tokptr++;
1291         break;
1292       default:
1293         goto convert_float;
1294         break;
1295     }
1296
1297   /* Accept an optional '-' or '+' following one of [eEdD]. */
1298
1299   collect_exponent:
1300   if (*tokptr == '+' || *tokptr == '-')
1301     {
1302       *copy++ = *tokptr++;
1303     }
1304
1305   /* Now copy an exponent into the conversion buffer.  Note that at the
1306      moment underscores are *not* allowed in exponents. */
1307
1308   while (isdigit (*tokptr))
1309     {
1310       *copy++ = *tokptr++;
1311     }
1312
1313   /* If we transfered any chars to the conversion buffer, try to interpret its
1314      contents as a floating point value.  If any characters remain, then we
1315      must not have a valid floating point string. */
1316
1317   convert_float:
1318   *copy = '\0';
1319   if (copy != buf)
1320       {
1321         dval = strtod (buf, &copy);
1322         if (*copy == '\0')
1323           {
1324             yylval.dval = dval;
1325             lexptr = tokptr;
1326             return (FLOAT_LITERAL);
1327           }
1328       }
1329   return (0);
1330 }
1331
1332 /* Recognize a string literal.  A string literal is a nonzero sequence
1333    of characters enclosed in matching single or double quotes, except that
1334    a single character inside single quotes is a character literal, which
1335    we reject as a string literal.  To embed the terminator character inside
1336    a string, it is simply doubled (I.E. "this""is""one""string") */
1337
1338 static int
1339 match_string_literal ()
1340 {
1341   char *tokptr = lexptr;
1342
1343   for (tempbufindex = 0, tokptr++; *tokptr != '\0'; tokptr++)
1344     {
1345       CHECKBUF (1);
1346       if (*tokptr == *lexptr)
1347         {
1348           if (*(tokptr + 1) == *lexptr)
1349             {
1350               tokptr++;
1351             }
1352           else
1353             {
1354               break;
1355             }
1356         }
1357       tempbuf[tempbufindex++] = *tokptr;
1358     }
1359   if (*tokptr == '\0'                                   /* no terminator */
1360       || tempbufindex == 0                              /* no string */
1361       || (tempbufindex == 1 && *tokptr == '\''))        /* char literal */
1362     {
1363       return (0);
1364     }
1365   else
1366     {
1367       tempbuf[tempbufindex] = '\0';
1368       yylval.sval.ptr = tempbuf;
1369       yylval.sval.length = tempbufindex;
1370       lexptr = ++tokptr;
1371       return (CHARACTER_STRING_LITERAL);
1372     }
1373 }
1374
1375 /* Recognize a character literal.  A character literal is single character
1376    or a control sequence, enclosed in single quotes.  A control sequence
1377    is a comma separated list of one or more integer literals, enclosed
1378    in parenthesis and introduced with a circumflex character.
1379
1380    EX:  'a'  '^(7)'  '^(7,8)'
1381
1382    As a GNU chill extension, the syntax C'xx' is also recognized as a
1383    character literal, where xx is a hex value for the character.
1384
1385    Note that more than a single character, enclosed in single quotes, is
1386    a string literal.
1387
1388    Also note that the control sequence form is not in GNU Chill since it
1389    is ambiguous with the string literal form using single quotes.  I.E.
1390    is '^(7)' a character literal or a string literal.  In theory it it
1391    possible to tell by context, but GNU Chill doesn't accept the control
1392    sequence form, so neither do we (for now the code is disabled).
1393
1394    Returns CHARACTER_LITERAL if a match is found.
1395    */
1396
1397 static int
1398 match_character_literal ()
1399 {
1400   char *tokptr = lexptr;
1401   int ival = 0;
1402
1403   if ((tolower (*tokptr) == 'c') && (*(tokptr + 1) == '\''))
1404     {
1405       /* We have a GNU chill extension form, so skip the leading "C'",
1406          decode the hex value, and then ensure that we have a trailing
1407          single quote character. */
1408       tokptr += 2;
1409       if (!decode_integer_value (16, &tokptr, &ival) || (*tokptr != '\''))
1410         {
1411           return (0);
1412         }
1413       tokptr++;
1414     }
1415   else if (*tokptr == '\'')
1416     {
1417       tokptr++;
1418
1419       /* Determine which form we have, either a control sequence or the
1420          single character form. */
1421
1422       if ((*tokptr == '^') && (*(tokptr + 1) == '('))
1423         {
1424 #if 0     /* Disable, see note above. -fnf */
1425           /* Match and decode a control sequence.  Return zero if we don't
1426              find a valid integer literal, or if the next unconsumed character
1427              after the integer literal is not the trailing ')'.
1428              FIXME:  We currently don't handle the multiple integer literal
1429              form. */
1430           tokptr += 2;
1431           if (!decode_integer_literal (&ival, &tokptr) || (*tokptr++ != ')'))
1432             {
1433               return (0);
1434             }
1435 #else
1436           return (0);
1437 #endif
1438         }
1439       else
1440         {
1441           ival = *tokptr++;
1442         }
1443
1444       /* The trailing quote has not yet been consumed.  If we don't find
1445          it, then we have no match. */
1446
1447       if (*tokptr++ != '\'')
1448         {
1449           return (0);
1450         }
1451     }
1452   else
1453     {
1454       /* Not a character literal. */
1455       return (0);
1456     }
1457   yylval.typed_val.val = ival;
1458   yylval.typed_val.type = builtin_type_chill_char;
1459   lexptr = tokptr;
1460   return (CHARACTER_LITERAL);
1461 }
1462
1463 /* Recognize an integer literal, as specified in Z.200 sec 5.2.4.2.
1464    Note that according to 5.2.4.2, a single "_" is also a valid integer
1465    literal, however GNU-chill requires there to be at least one "digit"
1466    in any integer literal. */
1467
1468 static int
1469 match_integer_literal ()
1470 {
1471   char *tokptr = lexptr;
1472   int ival;
1473
1474   if (!decode_integer_literal (&ival, &tokptr))
1475     {
1476       return (0);
1477     }
1478   else
1479     {
1480       yylval.typed_val.val = ival;
1481       yylval.typed_val.type = builtin_type_int;
1482       lexptr = tokptr;
1483       return (INTEGER_LITERAL);
1484     }
1485 }
1486
1487 /* Recognize a bit-string literal, as specified in Z.200 sec 5.2.4.8
1488    Note that according to 5.2.4.8, a single "_" is also a valid bit-string
1489    literal, however GNU-chill requires there to be at least one "digit"
1490    in any bit-string literal. */
1491
1492 static int
1493 match_bitstring_literal ()
1494 {
1495   char *tokptr = lexptr;
1496   int mask;
1497   int bitoffset = 0;
1498   int bitcount = 0;
1499   int base;
1500   int digit;
1501
1502   tempbufindex = 0;
1503
1504   /* Look for the required explicit base specifier. */
1505
1506   switch (*tokptr++)
1507     {
1508     case 'b':
1509     case 'B':
1510       base = 2;
1511       break;
1512     case 'o':
1513     case 'O':
1514       base = 8;
1515       break;
1516     case 'h':
1517     case 'H':
1518       base = 16;
1519       break;
1520     default:
1521       return (0);
1522       break;
1523     }
1524
1525   /* Ensure that the character after the explicit base is a single quote. */
1526
1527   if (*tokptr++ != '\'')
1528     {
1529       return (0);
1530     }
1531
1532   while (*tokptr != '\0' && *tokptr != '\'')
1533     {
1534       digit = tolower (*tokptr);
1535       tokptr++;
1536       switch (digit)
1537         {
1538           case '_':
1539             continue;
1540           case '0':  case '1':  case '2':  case '3':  case '4':
1541           case '5':  case '6':  case '7':  case '8':  case '9':
1542             digit -= '0';
1543             break;
1544           case 'a':  case 'b':  case 'c':  case 'd':  case 'e': case 'f':
1545             digit -= 'a';
1546             digit += 10;
1547             break;
1548           default:
1549             return (0);
1550             break;
1551         }
1552       if (digit >= base)
1553         {
1554           /* Found something not in domain for current base. */
1555           return (0);
1556         }
1557       else
1558         {
1559           /* Extract bits from digit, starting with the msbit appropriate for
1560              the current base, and packing them into the bitstring byte,
1561              starting at the lsbit. */
1562           for (mask = (base >> 1); mask > 0; mask >>= 1)
1563             {
1564               bitcount++;
1565               CHECKBUF (1);
1566               if (digit & mask)
1567                 {
1568                   tempbuf[tempbufindex] |= (1 << bitoffset);
1569                 }
1570               bitoffset++;
1571               if (bitoffset == HOST_CHAR_BIT)
1572                 {
1573                   bitoffset = 0;
1574                   tempbufindex++;
1575                 }
1576             }
1577         }
1578     }
1579
1580   /* Verify that we consumed everything up to the trailing single quote,
1581      and that we found some bits (IE not just underbars). */
1582
1583   if (*tokptr++ != '\'')
1584     {
1585       return (0);
1586     }
1587   else
1588     {
1589       yylval.sval.ptr = tempbuf;
1590       yylval.sval.length = bitcount;
1591       lexptr = tokptr;
1592       return (BIT_STRING_LITERAL);
1593     }
1594 }
1595
1596 /* Recognize tokens that start with '$'.  These include:
1597
1598         $regname        A native register name or a "standard
1599                         register name".
1600                         Return token GDB_REGNAME.
1601
1602         $variable       A convenience variable with a name chosen
1603                         by the user.
1604                         Return token GDB_VARIABLE.
1605
1606         $digits         Value history with index <digits>, starting
1607                         from the first value which has index 1.
1608                         Return GDB_LAST.
1609
1610         $$digits        Value history with index <digits> relative
1611                         to the last value.  I.E. $$0 is the last
1612                         value, $$1 is the one previous to that, $$2
1613                         is the one previous to $$1, etc.
1614                         Return token GDB_LAST.
1615
1616         $ | $0 | $$0    The last value in the value history.
1617                         Return token GDB_LAST.
1618
1619         $$              An abbreviation for the second to the last
1620                         value in the value history, I.E. $$1
1621                         Return token GDB_LAST.
1622
1623     Note that we currently assume that register names and convenience
1624     variables follow the convention of starting with a letter or '_'.
1625
1626    */
1627
1628 static int
1629 match_dollar_tokens ()
1630 {
1631   char *tokptr;
1632   int regno;
1633   int namelength;
1634   int negate;
1635   int ival;
1636
1637   /* We will always have a successful match, even if it is just for
1638      a single '$', the abbreviation for $$0.  So advance lexptr. */
1639
1640   tokptr = ++lexptr;
1641
1642   if (*tokptr == '_' || isalpha (*tokptr))
1643     {
1644       /* Look for a match with a native register name, usually something
1645          like "r0" for example. */
1646
1647       for (regno = 0; regno < NUM_REGS; regno++)
1648         {
1649           namelength = strlen (reg_names[regno]);
1650           if (STREQN (tokptr, reg_names[regno], namelength)
1651               && !isalnum (tokptr[namelength]))
1652             {
1653               yylval.lval = regno;
1654               lexptr += namelength + 1;
1655               return (GDB_REGNAME);
1656             }
1657         }
1658
1659       /* Look for a match with a standard register name, usually something
1660          like "pc", which gdb always recognizes as the program counter
1661          regardless of what the native register name is. */
1662
1663       for (regno = 0; regno < num_std_regs; regno++)
1664         {
1665           namelength = strlen (std_regs[regno].name);
1666           if (STREQN (tokptr, std_regs[regno].name, namelength)
1667               && !isalnum (tokptr[namelength]))
1668             {
1669               yylval.lval = std_regs[regno].regnum;
1670               lexptr += namelength;
1671               return (GDB_REGNAME);
1672             }
1673         }
1674
1675       /* Attempt to match against a convenience variable.  Note that
1676          this will always succeed, because if no variable of that name
1677          already exists, the lookup_internalvar will create one for us.
1678          Also note that both lexptr and tokptr currently point to the
1679          start of the input string we are trying to match, and that we
1680          have already tested the first character for non-numeric, so we
1681          don't have to treat it specially. */
1682
1683       while (*tokptr == '_' || isalnum (*tokptr))
1684         {
1685           tokptr++;
1686         }
1687       yylval.sval.ptr = lexptr;
1688       yylval.sval.length = tokptr - lexptr;
1689       yylval.ivar = lookup_internalvar (copy_name (yylval.sval));
1690       lexptr = tokptr;
1691       return (GDB_VARIABLE);
1692     }
1693
1694   /* Since we didn't match against a register name or convenience
1695      variable, our only choice left is a history value. */
1696
1697   if (*tokptr == '$')
1698     {
1699       negate = 1;
1700       ival = 1;
1701       tokptr++;
1702     }
1703   else
1704     {
1705       negate = 0;
1706       ival = 0;
1707     }
1708
1709   /* Attempt to decode more characters as an integer value giving
1710      the index in the history list.  If successful, the value will
1711      overwrite ival (currently 0 or 1), and if not, ival will be
1712      left alone, which is good since it is currently correct for
1713      the '$' or '$$' case. */
1714
1715   decode_integer_literal (&ival, &tokptr);
1716   yylval.lval = negate ? -ival : ival;
1717   lexptr = tokptr;
1718   return (GDB_LAST);
1719 }
1720
1721 struct token
1722 {
1723   char *operator;
1724   int token;
1725 };
1726
1727 static const struct token tokentab6[] =
1728 {
1729     { "LENGTH", LENGTH }
1730 };
1731
1732 static const struct token tokentab5[] =
1733 {
1734     { "LOWER", LOWER },
1735     { "UPPER", UPPER },
1736     { "ANDIF", ANDIF }
1737 };
1738
1739 static const struct token tokentab4[] =
1740 {
1741     { "PRED", PRED },
1742     { "SUCC", SUCC },
1743     { "CARD", CARD },
1744     { "SIZE", SIZE },
1745     { "ORIF", ORIF }
1746 };
1747
1748 static const struct token tokentab3[] =
1749 {
1750     { "NUM", NUM },
1751     { "ABS", ABS },
1752     { "MAX", MAX },
1753     { "MIN", MIN },
1754     { "MOD", MOD },
1755     { "REM", REM },
1756     { "NOT", NOT },
1757     { "XOR", LOGXOR },
1758     { "AND", LOGAND }
1759 };
1760
1761 static const struct token tokentab2[] =
1762 {
1763     { ":=", GDB_ASSIGNMENT },
1764     { "//", SLASH_SLASH },
1765     { "->", POINTER },
1766     { "/=", NOTEQUAL },
1767     { "<=", LEQ },
1768     { ">=", GTR },
1769     { "IN", IN },
1770     { "OR", LOGIOR }
1771 };
1772
1773 /* Read one token, getting characters through lexptr.  */
1774 /* This is where we will check to make sure that the language and the
1775    operators used are compatible.  */
1776
1777 static int
1778 yylex ()
1779 {
1780     unsigned int i;
1781     int token;
1782     char *simplename;
1783     struct symbol *sym;
1784
1785     /* Skip over any leading whitespace. */
1786     while (isspace (*lexptr))
1787         {
1788             lexptr++;
1789         }
1790     /* Look for special single character cases which can't be the first
1791        character of some other multicharacter token. */
1792     switch (*lexptr)
1793         {
1794             case '\0':
1795                 return (0);
1796             case ',':
1797             case '=':
1798             case ';':
1799             case '!':
1800             case '+':
1801             case '*':
1802             case '(':
1803             case ')':
1804             case '[':
1805             case ']':
1806                 return (*lexptr++);
1807         }
1808     /* Look for characters which start a particular kind of multicharacter
1809        token, such as a character literal, register name, convenience
1810        variable name, string literal, etc. */
1811     switch (*lexptr)
1812       {
1813         case '\'':
1814         case '\"':
1815           /* First try to match a string literal, which is any nonzero
1816              sequence of characters enclosed in matching single or double
1817              quotes, except that a single character inside single quotes
1818              is a character literal, so we have to catch that case also. */
1819           token = match_string_literal ();
1820           if (token != 0)
1821             {
1822               return (token);
1823             }
1824           if (*lexptr == '\'')
1825             {
1826               token = match_character_literal ();
1827               if (token != 0)
1828                 {
1829                   return (token);
1830                 }
1831             }
1832           break;
1833         case 'C':
1834         case 'c':
1835           token = match_character_literal ();
1836           if (token != 0)
1837             {
1838               return (token);
1839             }
1840           break;
1841         case '$':
1842           token = match_dollar_tokens ();
1843           if (token != 0)
1844             {
1845               return (token);
1846             }
1847           break;
1848       }
1849     /* See if it is a special token of length 6.  */
1850     for (i = 0; i < sizeof (tokentab6) / sizeof (tokentab6[0]); i++)
1851         {
1852             if (STREQN (lexptr, tokentab6[i].operator, 6))
1853                 {
1854                     lexptr += 6;
1855                     return (tokentab6[i].token);
1856                 }
1857         }
1858     /* See if it is a special token of length 5.  */
1859     for (i = 0; i < sizeof (tokentab5) / sizeof (tokentab5[0]); i++)
1860         {
1861             if (STREQN (lexptr, tokentab5[i].operator, 5))
1862                 {
1863                     lexptr += 5;
1864                     return (tokentab5[i].token);
1865                 }
1866         }
1867     /* See if it is a special token of length 4.  */
1868     for (i = 0; i < sizeof (tokentab4) / sizeof (tokentab4[0]); i++)
1869         {
1870             if (STREQN (lexptr, tokentab4[i].operator, 4))
1871                 {
1872                     lexptr += 4;
1873                     return (tokentab4[i].token);
1874                 }
1875         }
1876     /* See if it is a special token of length 3.  */
1877     for (i = 0; i < sizeof (tokentab3) / sizeof (tokentab3[0]); i++)
1878         {
1879             if (STREQN (lexptr, tokentab3[i].operator, 3))
1880                 {
1881                     lexptr += 3;
1882                     return (tokentab3[i].token);
1883                 }
1884         }
1885     /* See if it is a special token of length 2.  */
1886     for (i = 0; i < sizeof (tokentab2) / sizeof (tokentab2[0]); i++)
1887         {
1888             if (STREQN (lexptr, tokentab2[i].operator, 2))
1889                 {
1890                     lexptr += 2;
1891                     return (tokentab2[i].token);
1892                 }
1893         }
1894     /* Look for single character cases which which could be the first
1895        character of some other multicharacter token, but aren't, or we
1896        would already have found it. */
1897     switch (*lexptr)
1898         {
1899             case '-':
1900             case ':':
1901             case '/':
1902             case '<':
1903             case '>':
1904                 return (*lexptr++);
1905         }
1906     /* Look for other special tokens. */
1907     if (STREQN (lexptr, "TRUE", 4)) /* FIXME:  What about lowercase? */
1908         {
1909             yylval.ulval = 1;
1910             lexptr += 4;
1911             return (BOOLEAN_LITERAL);
1912         }
1913     if (STREQN (lexptr, "FALSE", 5)) /* FIXME:  What about lowercase? */
1914         {
1915             yylval.ulval = 0;
1916             lexptr += 5;
1917             return (BOOLEAN_LITERAL);
1918         }
1919     /* Look for a float literal before looking for an integer literal, so
1920        we match as much of the input stream as possible. */
1921     token = match_float_literal ();
1922     if (token != 0)
1923         {
1924             return (token);
1925         }
1926     token = match_bitstring_literal ();
1927     if (token != 0)
1928         {
1929             return (token);
1930         }
1931     token = match_integer_literal ();
1932     if (token != 0)
1933         {
1934             return (token);
1935         }
1936
1937     /* Try to match a simple name string, and if a match is found, then
1938        further classify what sort of name it is and return an appropriate
1939        token.  Note that attempting to match a simple name string consumes
1940        the token from lexptr, so we can't back out if we later find that
1941        we can't classify what sort of name it is. */
1942
1943     simplename = match_simple_name_string ();
1944     if (simplename != NULL)
1945       {
1946         sym = lookup_symbol (simplename, expression_context_block,
1947                              VAR_NAMESPACE, (int *) NULL,
1948                              (struct symtab **) NULL);
1949         if (sym != NULL)
1950           {
1951             yylval.ssym.stoken.ptr = NULL;
1952             yylval.ssym.stoken.length = 0;
1953             yylval.ssym.sym = sym;
1954             yylval.ssym.is_a_field_of_this = 0; /* FIXME, C++'ism */
1955             switch (SYMBOL_CLASS (sym))
1956               {
1957               case LOC_BLOCK:
1958                 /* Found a procedure name. */
1959                 return (GENERAL_PROCEDURE_NAME);
1960               case LOC_STATIC:
1961                 /* Found a global or local static variable. */
1962                 return (LOCATION_NAME);
1963               case LOC_REGISTER:
1964               case LOC_ARG:
1965               case LOC_REF_ARG:
1966               case LOC_REGPARM:
1967               case LOC_LOCAL:
1968               case LOC_LOCAL_ARG:
1969                 if (innermost_block == NULL
1970                     || contained_in (block_found, innermost_block))
1971                   {
1972                     innermost_block = block_found;
1973                   }
1974                 return (LOCATION_NAME);
1975                 break;
1976               case LOC_CONST:
1977               case LOC_LABEL:
1978                 return (LOCATION_NAME);
1979                 break;
1980               case LOC_TYPEDEF:
1981                 yylval.tsym.type = SYMBOL_TYPE (sym);
1982                 return TYPENAME;
1983               case LOC_UNDEF:
1984               case LOC_CONST_BYTES:
1985               case LOC_OPTIMIZED_OUT:
1986                 error ("Symbol \"%s\" names no location.", simplename);
1987                 break;
1988               }
1989           }
1990         else if (!have_full_symbols () && !have_partial_symbols ())
1991           {
1992             error ("No symbol table is loaded.  Use the \"file\" command.");
1993           }
1994         else
1995           {
1996             error ("No symbol \"%s\" in current context.", simplename);
1997           }
1998       }
1999
2000     /* Catch single character tokens which are not part of some
2001        longer token. */
2002
2003     switch (*lexptr)
2004       {
2005         case '.':                       /* Not float for example. */
2006           lexptr++;
2007           while (isspace (*lexptr)) lexptr++;
2008           simplename = match_simple_name_string ();
2009           if (!simplename)
2010             return '.';
2011           return FIELD_NAME;
2012       }
2013
2014     return (ILLEGAL_TOKEN);
2015 }
2016
2017 void
2018 yyerror (msg)
2019      char *msg; /* unused */
2020 {
2021   printf ("Parsing:  %s\n", lexptr);
2022   if (yychar < 256)
2023     {
2024       error ("Invalid syntax in expression near character '%c'.", yychar);
2025     }
2026   else
2027     {
2028       error ("Invalid syntax in expression");
2029     }
2030 }