gdb/ch-exp.y

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