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