gdb/ch-exp.y

   1 /* YACC grammar for Chill expressions, for GDB.
   2    Copyright (C) 1992 Free Software Foundation, Inc.
   3
   4 This file is part of GDB.
   5
   6 This program is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2 of the License, or
   9 (at your option) any later version.
  10
  11 This program is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with this program; if not, write to the Free Software
  18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20 /* Parse a Chill expression from text in a string,
  21    and return the result as a  struct expression  pointer.
  22    That structure contains arithmetic operations in reverse polish,
  23    with constants represented by operations that are followed by special data.
  24    See expression.h for the details of the format.
  25    What is important here is that it can be built up sequentially
  26    during the process of parsing; the lower levels of the tree always
  27    come first in the result.
  28
  29    Note that malloc's and realloc's in this file are transformed to
  30    xmalloc and xrealloc respectively by the same sed command in the
  31    makefile that remaps any other malloc/realloc inserted by the parser
  32    generator.  Doing this with #defines and trying to control the interaction
  33    with include files (<malloc.h> and <stdlib.h> for example) just became
  34    too messy, particularly when such includes can be inserted at random
  35    times by the parser generator.
  36
  37    Also note that the language accepted by this parser is more liberal
  38    than the one accepted by an actual Chill compiler.  For example, the
  39    language rule that a simple name string can not be one of the reserved
  40    simple name strings is not enforced (e.g "case" is not treated as a
  41    reserved name).  Another example is that Chill is a strongly typed
  42    language, and certain expressions that violate the type constraints
  43    may still be evaluated if gdb can do so in a meaningful manner, while
  44    such expressions would be rejected by the compiler.  The reason for
  45    this more liberal behavior is the philosophy that the debugger
  46    is intended to be a tool that is used by the programmer when things
  47    go wrong, and as such, it should provide as few artificial barriers
  48    to it's use as possible.  If it can do something meaningful, even
  49    something that violates language contraints that are enforced by the
  50    compiler, it should do so without complaint.
  51
  52  */
  53
  54 %{
  55
  56 #include "defs.h"
  57 #include "expression.h"
  58 #include "language.h"
  59 #include "value.h"
  60 #include "parser-defs.h"
  61 #include "ch-lang.h"
  62
  63 /* Remap normal yacc parser interface names (yyparse, yylex, yyerror, etc),
  64    as well as gratuitiously global symbol names, so we can have multiple
  65    yacc generated parsers in gdb.  Note that these are only the variables
  66    produced by yacc.  If other parser generators (bison, byacc, etc) produce
  67    additional global names that conflict at link time, then those parser
  68    generators need to be fixed instead of adding those names to this list. */
  69
  70 #define yymaxdepth chill_maxdepth
  71 #define yyparse chill_parse
  72 #define yylex   chill_lex
  73 #define yyerror chill_error
  74 #define yylval  chill_lval
  75 #define yychar  chill_char
  76 #define yydebug chill_debug
  77 #define yypact  chill_pact
  78 #define yyr1    chill_r1
  79 #define yyr2    chill_r2
  80 #define yydef   chill_def
  81 #define yychk   chill_chk
  82 #define yypgo   chill_pgo
  83 #define yyact   chill_act
  84 #define yyexca  chill_exca
  85 #define yyerrflag chill_errflag
  86 #define yynerrs chill_nerrs
  87 #define yyps    chill_ps
  88 #define yypv    chill_pv
  89 #define yys     chill_s
  90 #define yy_yys  chill_yys
  91 #define yystate chill_state
  92 #define yytmp   chill_tmp
  93 #define yyv     chill_v
  94 #define yy_yyv  chill_yyv
  95 #define yyval   chill_val
  96 #define yylloc  chill_lloc
  97 #define yyreds  chill_reds              /* With YYDEBUG defined */
  98 #define yytoks  chill_toks              /* With YYDEBUG defined */
  99
 100 #ifndef YYDEBUG
 101 #define YYDEBUG 0               /* Default to no yydebug support */
 102 #endif
 103
 104 int
 105 yyparse PARAMS ((void));
 106
 107 static int
 108 yylex PARAMS ((void));
 109
 110 void
 111 yyerror PARAMS ((char *));
 112
 113 %}
 114
 115 /* Although the yacc "value" of an expression is not used,
 116    since the result is stored in the structure being created,
 117    other node types do have values.  */
 118
 119 %union
 120   {
 121     LONGEST lval;
 122     unsigned LONGEST ulval;
 123     struct {
 124       LONGEST val;
 125       struct type *type;
 126     } typed_val;
 127     double dval;
 128     struct symbol *sym;
 129     struct type *tval;
 130     struct stoken sval;
 131     struct ttype tsym;
 132     struct symtoken ssym;
 133     int voidval;
 134     struct block *bval;
 135     enum exp_opcode opcode;
 136     struct internalvar *ivar;
 137
 138     struct type **tvec;
 139     int *ivec;
 140   }
 141
 142 %token <voidval> FIXME
 143
 144 %token <typed_val>      INTEGER_LITERAL
 145 %token <ulval>          BOOLEAN_LITERAL
 146 %token <typed_val>      CHARACTER_LITERAL
 147 %token <dval>           FLOAT_LITERAL
 148 %token <ssym>           GENERAL_PROCEDURE_NAME
 149 %token <ssym>           LOCATION_NAME
 150 %token <voidval>        SET_LITERAL
 151 %token <voidval>        EMPTINESS_LITERAL
 152 %token <sval>           CHARACTER_STRING_LITERAL
 153 %token <sval>           BIT_STRING_LITERAL
 154
 155 %token <voidval>        STRING
 156 %token <voidval>        CONSTANT
 157 %token <voidval>        '.'
 158 %token <voidval>        ';'
 159 %token <voidval>        ':'
 160 %token <voidval>        CASE
 161 %token <voidval>        OF
 162 %token <voidval>        ESAC
 163 %token <voidval>        LOGIOR
 164 %token <voidval>        ORIF
 165 %token <voidval>        LOGXOR
 166 %token <voidval>        LOGAND
 167 %token <voidval>        ANDIF
 168 %token <voidval>        '='
 169 %token <voidval>        NOTEQUAL
 170 %token <voidval>        '>'
 171 %token <voidval>        GTR
 172 %token <voidval>        '<'
 173 %token <voidval>        LEQ
 174 %token <voidval>        IN
 175 %token <voidval>        '+'
 176 %token <voidval>        '-'
 177 %token <voidval>        '*'
 178 %token <voidval>        '/'
 179 %token <voidval>        SLASH_SLASH
 180 %token <voidval>        MOD
 181 %token <voidval>        REM
 182 %token <voidval>        NOT
 183 %token <voidval>        POINTER
 184 %token <voidval>        RECEIVE
 185 %token <voidval>        SC
 186 %token <voidval>        '['
 187 %token <voidval>        ']'
 188 %token <voidval>        '('
 189 %token <voidval>        ')'
 190 %token <voidval>        UP
 191 %token <voidval>        IF
 192 %token <voidval>        THEN
 193 %token <voidval>        ELSE
 194 %token <voidval>        FI
 195 %token <voidval>        ELSIF
 196 %token <voidval>        ILLEGAL_TOKEN
 197 %token <voidval>        NUM
 198 %token <voidval>        PRED
 199 %token <voidval>        SUCC
 200 %token <voidval>        ABS
 201 %token <voidval>        CARD
 202 %token <voidval>        MAX
 203 %token <voidval>        MIN
 204 %token <voidval>        SIZE
 205 %token <voidval>        UPPER
 206 %token <voidval>        LOWER
 207 %token <voidval>        LENGTH
 208
 209 /* Tokens which are not Chill tokens used in expressions, but rather GDB
 210    specific things that we recognize in the same context as Chill tokens
 211    (register names for example). */
 212
 213 %token <lval>           GDB_REGNAME     /* Machine register name */
 214 %token <lval>           GDB_LAST        /* Value history */
 215 %token <ivar>           GDB_VARIABLE    /* Convenience variable */
 216 %token <voidval>        GDB_ASSIGNMENT  /* Assign value to somewhere */
 217
 218 %type <voidval>         location
 219 %type <voidval>         access_name
 220 %type <voidval>         primitive_value
 221 %type <voidval>         location_contents
 222 %type <voidval>         value_name
 223 %type <voidval>         literal
 224 %type <voidval>         tuple
 225 %type <voidval>         value_string_element
 226 %type <voidval>         value_string_slice
 227 %type <voidval>         value_array_element
 228 %type <voidval>         value_array_slice
 229 %type <voidval>         value_structure_field
 230 %type <voidval>         expression_conversion
 231 %type <voidval>         value_procedure_call
 232 %type <voidval>         value_built_in_routine_call
 233 %type <voidval>         chill_value_built_in_routine_call
 234 %type <voidval>         start_expression
 235 %type <voidval>         zero_adic_operator
 236 %type <voidval>         parenthesised_expression
 237 %type <voidval>         value
 238 %type <voidval>         undefined_value
 239 %type <voidval>         expression
 240 %type <voidval>         conditional_expression
 241 %type <voidval>         then_alternative
 242 %type <voidval>         else_alternative
 243 %type <voidval>         sub_expression
 244 %type <voidval>         value_case_alternative
 245 %type <voidval>         operand_0
 246 %type <voidval>         operand_1
 247 %type <voidval>         operand_2
 248 %type <voidval>         operand_3
 249 %type <voidval>         operand_4
 250 %type <voidval>         operand_5
 251 %type <voidval>         operand_6
 252 %type <voidval>         integer_literal_expression
 253 %type <voidval>         synonym_name
 254 %type <voidval>         value_enumeration_name
 255 %type <voidval>         value_do_with_name
 256 %type <voidval>         value_receive_name
 257 %type <voidval>         string_primitive_value
 258 %type <voidval>         start_element
 259 %type <voidval>         left_element
 260 %type <voidval>         right_element
 261 %type <voidval>         slice_size
 262 %type <voidval>         array_primitive_value
 263 %type <voidval>         expression_list
 264 %type <voidval>         lower_element
 265 %type <voidval>         upper_element
 266 %type <voidval>         first_element
 267 %type <voidval>         structure_primitive_value
 268 %type <voidval>         field_name
 269 %type <voidval>         mode_argument
 270 %type <voidval>         upper_lower_argument
 271 %type <voidval>         length_argument
 272 %type <voidval>         mode_name
 273 %type <voidval>         array_mode_name
 274 %type <voidval>         string_mode_name
 275 %type <voidval>         variant_structure_mode_name
 276 %type <voidval>         boolean_expression
 277 %type <voidval>         case_selector_list
 278 %type <voidval>         subexpression
 279 %type <voidval>         case_label_specification
 280 %type <voidval>         buffer_location
 281
 282 %type <voidval>         single_assignment_action
 283
 284 %%
 285
 286 /* Z.200, 5.3.1 */
 287
 288 value           :       expression
 289                         {
 290                           $$ = 0;       /* FIXME */
 291                         }
 292                 |       undefined_value
 293                         {
 294                           $$ = 0;       /* FIXME */
 295                         }
 296                 ;
 297
 298 undefined_value :       FIXME
 299                         {
 300                           $$ = 0;       /* FIXME */
 301                         }
 302                 ;
 303
 304 /* Z.200, 4.2.1 */
 305
 306 location        :       access_name
 307                         {
 308                           $$ = 0;       /* FIXME */
 309                         }
 310                 |       FIXME
 311                         {
 312                           $$ = 0;       /* FIXME */
 313                         }
 314                 ;
 315
 316 /* Z.200, 4.2.2 */
 317
 318 access_name     :       LOCATION_NAME
 319                         {
 320                           write_exp_elt_opcode (OP_VAR_VALUE);
 321                           write_exp_elt_sym ($1.sym);
 322                           write_exp_elt_opcode (OP_VAR_VALUE);
 323                         }
 324                 |       GDB_LAST                /* gdb specific */
 325                         {
 326                           write_exp_elt_opcode (OP_LAST);
 327                           write_exp_elt_longcst ($1);
 328                           write_exp_elt_opcode (OP_LAST);
 329                         }
 330                 |       GDB_REGNAME             /* gdb specific */
 331                         {
 332                           write_exp_elt_opcode (OP_REGISTER);
 333                           write_exp_elt_longcst ($1);
 334                           write_exp_elt_opcode (OP_REGISTER);
 335                         }
 336                 |       GDB_VARIABLE    /* gdb specific */
 337                         {
 338                           write_exp_elt_opcode (OP_INTERNALVAR);
 339                           write_exp_elt_intern ($1);
 340                           write_exp_elt_opcode (OP_INTERNALVAR);
 341                         }
 342                 |       FIXME
 343                         {
 344                           $$ = 0;       /* FIXME */
 345                         }
 346                 ;
 347
 348 /* Z.200, 4.2.8 */
 349
 350 expression_list :       expression
 351                         {
 352                           arglist_len = 1;
 353                         }
 354                 |       expression_list ',' expression
 355                         {
 356                           arglist_len++;
 357                         }
 358
 359 /* Z.200, 5.2.1 */
 360
 361 primitive_value :       location_contents
 362                         {
 363                           $$ = 0;       /* FIXME */
 364                         }
 365                 |       value_name
 366                         {
 367                           $$ = 0;       /* FIXME */
 368                         }
 369                 |       literal
 370                         {
 371                           $$ = 0;       /* FIXME */
 372                         }
 373                 |       tuple
 374                         {
 375                           $$ = 0;       /* FIXME */
 376                         }
 377                 |       value_string_element
 378                         {
 379                           $$ = 0;       /* FIXME */
 380                         }
 381                 |       value_string_slice
 382                         {
 383                           $$ = 0;       /* FIXME */
 384                         }
 385                 |       value_array_element
 386                         {
 387                           $$ = 0;       /* FIXME */
 388                         }
 389                 |       value_array_slice
 390                         {
 391                           $$ = 0;       /* FIXME */
 392                         }
 393                 |       value_structure_field
 394                         {
 395                           $$ = 0;       /* FIXME */
 396                         }
 397                 |       expression_conversion
 398                         {
 399                           $$ = 0;       /* FIXME */
 400                         }
 401                 |       value_procedure_call
 402                         {
 403                           $$ = 0;       /* FIXME */
 404                         }
 405                 |       value_built_in_routine_call
 406                         {
 407                           $$ = 0;       /* FIXME */
 408                         }
 409                 |       start_expression
 410                         {
 411                           $$ = 0;       /* FIXME */
 412                         }
 413                 |       zero_adic_operator
 414                         {
 415                           $$ = 0;       /* FIXME */
 416                         }
 417                 |       parenthesised_expression
 418                         {
 419                           $$ = 0;       /* FIXME */
 420                         }
 421                 ;
 422
 423 /* Z.200, 5.2.2 */
 424
 425 location_contents:      location
 426                         {
 427                           $$ = 0;       /* FIXME */
 428                         }
 429                 ;
 430
 431 /* Z.200, 5.2.3 */
 432
 433 value_name      :       synonym_name
 434                         {
 435                           $$ = 0;       /* FIXME */
 436                         }
 437                 |       value_enumeration_name
 438                         {
 439                           $$ = 0;       /* FIXME */
 440                         }
 441                 |       value_do_with_name
 442                         {
 443                           $$ = 0;       /* FIXME */
 444                         }
 445                 |       value_receive_name
 446                         {
 447                           $$ = 0;       /* FIXME */
 448                         }
 449                 |       GENERAL_PROCEDURE_NAME
 450                         {
 451                           write_exp_elt_opcode (OP_VAR_VALUE);
 452                           write_exp_elt_sym ($1.sym);
 453                           write_exp_elt_opcode (OP_VAR_VALUE);
 454                         }
 455                 ;
 456
 457 /* Z.200, 5.2.4.1 */
 458
 459 literal         :       INTEGER_LITERAL
 460                         {
 461                           write_exp_elt_opcode (OP_LONG);
 462                           write_exp_elt_type ($1.type);
 463                           write_exp_elt_longcst ((LONGEST) ($1.val));
 464                           write_exp_elt_opcode (OP_LONG);
 465                         }
 466                 |       BOOLEAN_LITERAL
 467                         {
 468                           write_exp_elt_opcode (OP_BOOL);
 469                           write_exp_elt_longcst ((LONGEST) $1);
 470                           write_exp_elt_opcode (OP_BOOL);
 471                         }
 472                 |       CHARACTER_LITERAL
 473                         {
 474                           write_exp_elt_opcode (OP_LONG);
 475                           write_exp_elt_type ($1.type);
 476                           write_exp_elt_longcst ((LONGEST) ($1.val));
 477                           write_exp_elt_opcode (OP_LONG);
 478                         }
 479                 |       FLOAT_LITERAL
 480                         {
 481                           write_exp_elt_opcode (OP_DOUBLE);
 482                           write_exp_elt_type (builtin_type_double);
 483                           write_exp_elt_dblcst ($1);
 484                           write_exp_elt_opcode (OP_DOUBLE);
 485                         }
 486                 |       SET_LITERAL
 487                         {
 488                           $$ = 0;       /* FIXME */
 489                         }
 490                 |       EMPTINESS_LITERAL
 491                         {
 492                           $$ = 0;       /* FIXME */
 493                         }
 494                 |       CHARACTER_STRING_LITERAL
 495                         {
 496                           write_exp_elt_opcode (OP_STRING);
 497                           write_exp_string ($1);
 498                           write_exp_elt_opcode (OP_STRING);
 499                         }
 500                 |       BIT_STRING_LITERAL
 501                         {
 502                           write_exp_elt_opcode (OP_BITSTRING);
 503                           write_exp_bitstring ($1);
 504                           write_exp_elt_opcode (OP_BITSTRING);
 505                         }
 506                 ;
 507
 508 /* Z.200, 5.2.5 */
 509
 510 tuple           :       FIXME
 511                         {
 512                           $$ = 0;       /* FIXME */
 513                         }
 514                 ;
 515
 516
 517 /* Z.200, 5.2.6 */
 518
 519 value_string_element:   string_primitive_value '(' start_element ')'
 520                         {
 521                           $$ = 0;       /* FIXME */
 522                         }
 523                 ;
 524
 525 /* Z.200, 5.2.7 */
 526
 527 value_string_slice:     string_primitive_value '(' left_element ':' right_element ')'
 528                         {
 529                           $$ = 0;       /* FIXME */
 530                         }
 531                 |       string_primitive_value '(' start_element UP slice_size ')'
 532                         {
 533                           $$ = 0;       /* FIXME */
 534                         }
 535                 ;
 536
 537 /* Z.200, 5.2.8 */
 538
 539 value_array_element:    array_primitive_value '('
 540                                 /* This is to save the value of arglist_len
 541                                    being accumulated for each dimension. */
 542                                 { start_arglist (); }
 543                         expression_list ')'
 544                         {
 545                           write_exp_elt_opcode (MULTI_SUBSCRIPT);
 546                           write_exp_elt_longcst ((LONGEST) end_arglist ());
 547                           write_exp_elt_opcode (MULTI_SUBSCRIPT);
 548                         }
 549                 ;
 550
 551 /* Z.200, 5.2.9 */
 552
 553 value_array_slice:      array_primitive_value '(' lower_element ':' upper_element ')'
 554                         {
 555                           $$ = 0;       /* FIXME */
 556                         }
 557                 |       array_primitive_value '(' first_element UP slice_size ')'
 558                         {
 559                           $$ = 0;       /* FIXME */
 560                         }
 561                 ;
 562
 563 /* Z.200, 5.2.10 */
 564
 565 value_structure_field:  structure_primitive_value '.' field_name
 566                         {
 567                           $$ = 0;       /* FIXME */
 568                         }
 569                 ;
 570
 571 /* Z.200, 5.2.11 */
 572
 573 expression_conversion:  mode_name '(' expression ')'
 574                         {
 575                           $$ = 0;       /* FIXME */
 576                         }
 577                 ;
 578
 579 /* Z.200, 5.2.12 */
 580
 581 value_procedure_call:   FIXME
 582                         {
 583                           $$ = 0;       /* FIXME */
 584                         }
 585                 ;
 586
 587 /* Z.200, 5.2.13 */
 588
 589 value_built_in_routine_call:    chill_value_built_in_routine_call
 590                         {
 591                           $$ = 0;       /* FIXME */
 592                         }
 593                 ;
 594
 595 /* Z.200, 5.2.14 */
 596
 597 start_expression:       FIXME
 598                         {
 599                           $$ = 0;       /* FIXME */
 600                         }       /* Not in GNU-Chill */
 601                 ;
 602
 603 /* Z.200, 5.2.15 */
 604
 605 zero_adic_operator:     FIXME
 606                         {
 607                           $$ = 0;       /* FIXME */
 608                         }
 609                 ;
 610
 611 /* Z.200, 5.2.16 */
 612
 613 parenthesised_expression:       '(' expression ')'
 614                         {
 615                           $$ = 0;       /* FIXME */
 616                         }
 617                 ;
 618
 619 /* Z.200, 5.3.2 */
 620
 621 expression      :       operand_0
 622                         {
 623                           $$ = 0;       /* FIXME */
 624                         }
 625                 |       conditional_expression
 626                         {
 627                           $$ = 0;       /* FIXME */
 628                         }
 629                 ;
 630
 631 conditional_expression : IF boolean_expression then_alternative else_alternative FI
 632                         {
 633                           $$ = 0;       /* FIXME */
 634                         }
 635                 |       CASE case_selector_list OF value_case_alternative '[' ELSE sub_expression ']' ESAC
 636                         {
 637                           $$ = 0;       /* FIXME */
 638                         }
 639                 ;
 640
 641 then_alternative:       THEN subexpression
 642                         {
 643                           $$ = 0;       /* FIXME */
 644                         }
 645                 ;
 646
 647 else_alternative:       ELSE subexpression
 648                         {
 649                           $$ = 0;       /* FIXME */
 650                         }
 651                 |       ELSIF boolean_expression then_alternative else_alternative
 652                         {
 653                           $$ = 0;       /* FIXME */
 654                         }
 655                 ;
 656
 657 sub_expression  :       expression
 658                         {
 659                           $$ = 0;       /* FIXME */
 660                         }
 661                 ;
 662
 663 value_case_alternative: case_label_specification ':' sub_expression ';'
 664                         {
 665                           $$ = 0;       /* FIXME */
 666                         }
 667                 ;
 668
 669 /* Z.200, 5.3.3 */
 670
 671 operand_0       :       operand_1
 672                         {
 673                           $$ = 0;       /* FIXME */
 674                         }
 675                 |       operand_0 LOGIOR operand_1
 676                         {
 677                           write_exp_elt_opcode (BINOP_BITWISE_IOR);
 678                         }
 679                 |       operand_0 ORIF operand_1
 680                         {
 681                           $$ = 0;       /* FIXME */
 682                         }
 683                 |       operand_0 LOGXOR operand_1
 684                         {
 685                           write_exp_elt_opcode (BINOP_BITWISE_XOR);
 686                         }
 687                 |       single_assignment_action
 688                         {
 689                           $$ = 0;       /* FIXME */
 690                         }
 691                 ;
 692
 693 /* Z.200, 5.3.4 */
 694
 695 operand_1       :       operand_2
 696                         {
 697                           $$ = 0;       /* FIXME */
 698                         }
 699                 |       operand_1 LOGAND operand_2
 700                         {
 701                           write_exp_elt_opcode (BINOP_BITWISE_AND);
 702                         }
 703                 |       operand_1 ANDIF operand_2
 704                         {
 705                           $$ = 0;       /* FIXME */
 706                         }
 707                 ;
 708
 709 /* Z.200, 5.3.5 */
 710
 711 operand_2       :       operand_3
 712                         {
 713                           $$ = 0;       /* FIXME */
 714                         }
 715                 |       operand_2 '=' operand_3
 716                         {
 717                           write_exp_elt_opcode (BINOP_EQUAL);
 718                         }
 719                 |       operand_2 NOTEQUAL operand_3
 720                         {
 721                           write_exp_elt_opcode (BINOP_NOTEQUAL);
 722                         }
 723                 |       operand_2 '>' operand_3
 724                         {
 725                           write_exp_elt_opcode (BINOP_GTR);
 726                         }
 727                 |       operand_2 GTR operand_3
 728                         {
 729                           write_exp_elt_opcode (BINOP_GEQ);
 730                         }
 731                 |       operand_2 '<' operand_3
 732                         {
 733                           write_exp_elt_opcode (BINOP_LESS);
 734                         }
 735                 |       operand_2 LEQ operand_3
 736                         {
 737                           write_exp_elt_opcode (BINOP_LEQ);
 738                         }
 739                 |       operand_2 IN operand_3
 740                         {
 741                           $$ = 0;       /* FIXME */
 742                         }
 743                 ;
 744
 745
 746 /* Z.200, 5.3.6 */
 747
 748 operand_3       :       operand_4
 749                         {
 750                           $$ = 0;       /* FIXME */
 751                         }
 752                 |       operand_3 '+' operand_4
 753                         {
 754                           write_exp_elt_opcode (BINOP_ADD);
 755                         }
 756                 |       operand_3 '-' operand_4
 757                         {
 758                           write_exp_elt_opcode (BINOP_SUB);
 759                         }
 760                 |       operand_3 SLASH_SLASH operand_4
 761                         {
 762                           $$ = 0;       /* FIXME */
 763                         }
 764                 ;
 765
 766 /* Z.200, 5.3.7 */
 767
 768 operand_4       :       operand_5
 769                         {
 770                           $$ = 0;       /* FIXME */
 771                         }
 772                 |       operand_4 '*' operand_5
 773                         {
 774                           write_exp_elt_opcode (BINOP_MUL);
 775                         }
 776                 |       operand_4 '/' operand_5
 777                         {
 778                           write_exp_elt_opcode (BINOP_DIV);
 779                         }
 780                 |       operand_4 MOD operand_5
 781                         {
 782                           write_exp_elt_opcode (BINOP_MOD);
 783                         }
 784                 |       operand_4 REM operand_5
 785                         {
 786                           write_exp_elt_opcode (BINOP_REM);
 787                         }
 788                 ;
 789
 790 /* Z.200, 5.3.8 */
 791
 792 operand_5       :       operand_6
 793                         {
 794                           $$ = 0;       /* FIXME */
 795                         }
 796                 |       '-' operand_6
 797                         {
 798                           write_exp_elt_opcode (UNOP_NEG);
 799                         }
 800                 |       NOT operand_6
 801                         {
 802                           write_exp_elt_opcode (UNOP_LOGICAL_NOT);
 803                         }
 804                 |       '(' integer_literal_expression ')' operand_6
 805                         {
 806                           $$ = 0;       /* FIXME */
 807                         }
 808                 ;
 809
 810 /* Z.200, 5.3.9 */
 811
 812 operand_6       :       POINTER location
 813                         {
 814                           $$ = 0;       /* FIXME */
 815                         }
 816                 |       RECEIVE buffer_location
 817                         {
 818                           $$ = 0;       /* FIXME */
 819                         }
 820                 |       primitive_value
 821                         {
 822                           $$ = 0;       /* FIXME */
 823                         }
 824                 ;
 825
 826
 827 /* Z.200, 6.2 */
 828
 829 single_assignment_action :
 830                         location GDB_ASSIGNMENT value
 831                         {
 832                           write_exp_elt_opcode (BINOP_ASSIGN);
 833                         }
 834                 ;
 835
 836 /* Z.200, 6.20.3 */
 837
 838 chill_value_built_in_routine_call :
 839                         NUM '(' expression ')'
 840                         {
 841                           $$ = 0;       /* FIXME */
 842                         }
 843                 |       PRED '(' expression ')'
 844                         {
 845                           $$ = 0;       /* FIXME */
 846                         }
 847                 |       SUCC '(' expression ')'
 848                         {
 849                           $$ = 0;       /* FIXME */
 850                         }
 851                 |       ABS '(' expression ')'
 852                         {
 853                           $$ = 0;       /* FIXME */
 854                         }
 855                 |       CARD '(' expression ')'
 856                         {
 857                           $$ = 0;       /* FIXME */
 858                         }
 859                 |       MAX '(' expression ')'
 860                         {
 861                           $$ = 0;       /* FIXME */
 862                         }
 863                 |       MIN '(' expression ')'
 864                         {
 865                           $$ = 0;       /* FIXME */
 866                         }
 867                 |       SIZE '(' location ')'
 868                         {
 869                           $$ = 0;       /* FIXME */
 870                         }
 871                 |       SIZE '(' mode_argument ')'
 872                         {
 873                           $$ = 0;       /* FIXME */
 874                         }
 875                 |       UPPER '(' upper_lower_argument ')'
 876                         {
 877                           $$ = 0;       /* FIXME */
 878                         }
 879                 |       LOWER '(' upper_lower_argument ')'
 880                         {
 881                           $$ = 0;       /* FIXME */
 882                         }
 883                 |       LENGTH '(' length_argument ')'
 884                         {
 885                           $$ = 0;       /* FIXME */
 886                         }
 887                 ;
 888
 889 mode_argument :         mode_name
 890                         {
 891                           $$ = 0;       /* FIXME */
 892                         }
 893                 |       array_mode_name '(' expression ')'
 894                         {
 895                           $$ = 0;       /* FIXME */
 896                         }
 897                 |       string_mode_name '(' expression ')'
 898                         {
 899                           $$ = 0;       /* FIXME */
 900                         }
 901                 |       variant_structure_mode_name '(' expression_list ')'
 902                         {
 903                           $$ = 0;       /* FIXME */
 904                         }
 905                 ;
 906
 907 upper_lower_argument :  location
 908                         {
 909                           $$ = 0;       /* FIXME */
 910                         }
 911                 |       expression
 912                         {
 913                           $$ = 0;       /* FIXME */
 914                         }
 915                 |       mode_name
 916                         {
 917                           $$ = 0;       /* FIXME */
 918                         }
 919                 ;
 920
 921 length_argument :       location
 922                         {
 923                           $$ = 0;       /* FIXME */
 924                         }
 925                 |       expression
 926                         {
 927                           $$ = 0;       /* FIXME */
 928                         }
 929                 ;
 930
 931 /* Z.200, 12.4.3 */
 932 /* FIXME:  For now we just accept only a single integer literal. */
 933
 934 integer_literal_expression:
 935                         INTEGER_LITERAL
 936                         {
 937                           $$ = 0;
 938                         }
 939                 ;
 940
 941 /* Z.200, 12.4.3 */
 942
 943 array_primitive_value : primitive_value
 944                         {
 945                           $$ = 0;
 946                         }
 947                 ;
 948
 949
 950 /* Things which still need productions... */
 951
 952 array_mode_name         :       FIXME { $$ = 0; }
 953 string_mode_name        :       FIXME { $$ = 0; }
 954 variant_structure_mode_name:    FIXME { $$ = 0; }
 955 synonym_name            :       FIXME { $$ = 0; }
 956 value_enumeration_name  :       FIXME { $$ = 0; }
 957 value_do_with_name      :       FIXME { $$ = 0; }
 958 value_receive_name      :       FIXME { $$ = 0; }
 959 string_primitive_value  :       FIXME { $$ = 0; }
 960 start_element           :       FIXME { $$ = 0; }
 961 left_element            :       FIXME { $$ = 0; }
 962 right_element           :       FIXME { $$ = 0; }
 963 slice_size              :       FIXME { $$ = 0; }
 964 lower_element           :       FIXME { $$ = 0; }
 965 upper_element           :       FIXME { $$ = 0; }
 966 first_element           :       FIXME { $$ = 0; }
 967 structure_primitive_value:      FIXME { $$ = 0; }
 968 field_name              :       FIXME { $$ = 0; }
 969 mode_name               :       FIXME { $$ = 0; }
 970 boolean_expression      :       FIXME { $$ = 0; }
 971 case_selector_list      :       FIXME { $$ = 0; }
 972 subexpression           :       FIXME { $$ = 0; }
 973 case_label_specification:       FIXME { $$ = 0; }
 974 buffer_location         :       FIXME { $$ = 0; }
 975
 976 %%
 977
 978 /* Implementation of a dynamically expandable buffer for processing input
 979    characters acquired through lexptr and building a value to return in
 980    yylval. */
 981
 982 static char *tempbuf;           /* Current buffer contents */
 983 static int tempbufsize;         /* Size of allocated buffer */
 984 static int tempbufindex;        /* Current index into buffer */
 985
 986 #define GROWBY_MIN_SIZE 64      /* Minimum amount to grow buffer by */
 987
 988 #define CHECKBUF(size) \
 989   do { \
 990     if (tempbufindex + (size) >= tempbufsize) \
 991       { \
 992         growbuf_by_size (size); \
 993       } \
 994   } while (0);
 995
 996 /* Grow the static temp buffer if necessary, including allocating the first one
 997    on demand. */
 998
 999 static void
1000 growbuf_by_size (count)
1001      int count;
1002 {
1003   int growby;
1004
1005   growby = max (count, GROWBY_MIN_SIZE);
1006   tempbufsize += growby;
1007   if (tempbuf == NULL)
1008     {
1009       tempbuf = (char *) malloc (tempbufsize);
1010     }
1011   else
1012     {
1013       tempbuf = (char *) realloc (tempbuf, tempbufsize);
1014     }
1015 }
1016
1017 /* Try to consume a simple name string token.  If successful, returns
1018    a pointer to a nullbyte terminated copy of the name that can be used
1019    in symbol table lookups.  If not successful, returns NULL. */
1020
1021 static char *
1022 match_simple_name_string ()
1023 {
1024   char *tokptr = lexptr;
1025
1026   if (isalpha (*tokptr))
1027     {
1028       do {
1029         tokptr++;
1030       } while (isalpha (*tokptr) || isdigit (*tokptr) || (*tokptr == '_'));
1031       yylval.sval.ptr = lexptr;
1032       yylval.sval.length = tokptr - lexptr;
1033       lexptr = tokptr;
1034       return (copy_name (yylval.sval));
1035     }
1036   return (NULL);
1037 }
1038
1039 /* Start looking for a value composed of valid digits as set by the base
1040    in use.  Note that '_' characters are valid anywhere, in any quantity,
1041    and are simply ignored.  Since we must find at least one valid digit,
1042    or reject this token as an integer literal, we keep track of how many
1043    digits we have encountered. */
1044
1045 static int
1046 decode_integer_value (base, tokptrptr, ivalptr)
1047   int base;
1048   char **tokptrptr;
1049   int *ivalptr;
1050 {
1051   char *tokptr = *tokptrptr;
1052   int temp;
1053   int digits = 0;
1054
1055   while (*tokptr != '\0')
1056     {
1057       temp = tolower (*tokptr);
1058       tokptr++;
1059       switch (temp)
1060         {
1061         case '_':
1062           continue;
1063         case '0':  case '1':  case '2':  case '3':  case '4':
1064         case '5':  case '6':  case '7':  case '8':  case '9':
1065           temp -= '0';
1066           break;
1067         case 'a':  case 'b':  case 'c':  case 'd':  case 'e': case 'f':
1068           temp -= 'a';
1069           temp += 10;
1070           break;
1071         default:
1072           temp = base;
1073           break;
1074         }
1075       if (temp < base)
1076         {
1077           digits++;
1078           *ivalptr *= base;
1079           *ivalptr += temp;
1080         }
1081       else
1082         {
1083           /* Found something not in domain for current base. */
1084           tokptr--;     /* Unconsume what gave us indigestion. */
1085           break;
1086         }
1087     }
1088
1089   /* If we didn't find any digits, then we don't have a valid integer
1090      value, so reject the entire token.  Otherwise, update the lexical
1091      scan pointer, and return non-zero for success. */
1092
1093   if (digits == 0)
1094     {
1095       return (0);
1096     }
1097   else
1098     {
1099       *tokptrptr = tokptr;
1100       return (1);
1101     }
1102 }
1103
1104 static int
1105 decode_integer_literal (valptr, tokptrptr)
1106   int *valptr;
1107   char **tokptrptr;
1108 {
1109   char *tokptr = *tokptrptr;
1110   int base = 0;
1111   int ival = 0;
1112   int explicit_base = 0;
1113
1114   /* Look for an explicit base specifier, which is optional. */
1115
1116   switch (*tokptr)
1117     {
1118     case 'd':
1119     case 'D':
1120       explicit_base++;
1121       base = 10;
1122       tokptr++;
1123       break;
1124     case 'b':
1125     case 'B':
1126       explicit_base++;
1127       base = 2;
1128       tokptr++;
1129       break;
1130     case 'h':
1131     case 'H':
1132       explicit_base++;
1133       base = 16;
1134       tokptr++;
1135       break;
1136     case 'o':
1137     case 'O':
1138       explicit_base++;
1139       base = 8;
1140       tokptr++;
1141       break;
1142     default:
1143       base = 10;
1144       break;
1145     }
1146
1147   /* If we found an explicit base ensure that the character after the
1148      explicit base is a single quote. */
1149
1150   if (explicit_base && (*tokptr++ != '\''))
1151     {
1152       return (0);
1153     }
1154
1155   /* Attempt to decode whatever follows as an integer value in the
1156      indicated base, updating the token pointer in the process and
1157      computing the value into ival.  Also, if we have an explicit
1158      base, then the next character must not be a single quote, or we
1159      have a bitstring literal, so reject the entire token in this case.
1160      Otherwise, update the lexical scan pointer, and return non-zero
1161      for success. */
1162
1163   if (!decode_integer_value (base, &tokptr, &ival))
1164     {
1165       return (0);
1166     }
1167   else if (explicit_base && (*tokptr == '\''))
1168     {
1169       return (0);
1170     }
1171   else
1172     {
1173       *valptr = ival;
1174       *tokptrptr = tokptr;
1175       return (1);
1176     }
1177 }
1178
1179 /*  If it wasn't for the fact that floating point values can contain '_'
1180     characters, we could just let strtod do all the hard work by letting it
1181     try to consume as much of the current token buffer as possible and
1182     find a legal conversion.  Unfortunately we need to filter out the '_'
1183     characters before calling strtod, which we do by copying the other
1184     legal chars to a local buffer to be converted.  However since we also
1185     need to keep track of where the last unconsumed character in the input
1186     buffer is, we have transfer only as many characters as may compose a
1187     legal floating point value. */
1188
1189 static int
1190 match_float_literal ()
1191 {
1192   char *tokptr = lexptr;
1193   char *buf;
1194   char *copy;
1195   char ch;
1196   double dval;
1197   extern double strtod ();
1198
1199   /* Make local buffer in which to build the string to convert.  This is
1200      required because underscores are valid in chill floating point numbers
1201      but not in the string passed to strtod to convert.  The string will be
1202      no longer than our input string. */
1203
1204   copy = buf = (char *) alloca (strlen (tokptr) + 1);
1205
1206   /* Transfer all leading digits to the conversion buffer, discarding any
1207      underscores. */
1208
1209   while (isdigit (*tokptr) || *tokptr == '_')
1210     {
1211       if (*tokptr != '_')
1212         {
1213           *copy++ = *tokptr;
1214         }
1215       tokptr++;
1216     }
1217
1218   /* Now accept either a '.', or one of [eEdD].  Dot is legal regardless
1219      of whether we found any leading digits, and we simply accept it and
1220      continue on to look for the fractional part and/or exponent.  One of
1221      [eEdD] is legal only if we have seen digits, and means that there
1222      is no fractional part.  If we find neither of these, then this is
1223      not a floating point number, so return failure. */
1224
1225   switch (*tokptr++)
1226     {
1227       case '.':
1228         /* Accept and then look for fractional part and/or exponent. */
1229         *copy++ = '.';
1230         break;
1231
1232       case 'e':
1233       case 'E':
1234       case 'd':
1235       case 'D':
1236         if (copy == buf)
1237           {
1238             return (0);
1239           }
1240         *copy++ = 'e';
1241         goto collect_exponent;
1242         break;
1243
1244       default:
1245         return (0);
1246         break;
1247     }
1248
1249   /* We found a '.', copy any fractional digits to the conversion buffer, up
1250      to the first nondigit, non-underscore character. */
1251
1252   while (isdigit (*tokptr) || *tokptr == '_')
1253     {
1254       if (*tokptr != '_')
1255         {
1256           *copy++ = *tokptr;
1257         }
1258       tokptr++;
1259     }
1260
1261   /* Look for an exponent, which must start with one of [eEdD].  If none
1262      is found, jump directly to trying to convert what we have collected
1263      so far. */
1264
1265   switch (*tokptr)
1266     {
1267       case 'e':
1268       case 'E':
1269       case 'd':
1270       case 'D':
1271         *copy++ = 'e';
1272         tokptr++;
1273         break;
1274       default:
1275         goto convert_float;
1276         break;
1277     }
1278
1279   /* Accept an optional '-' or '+' following one of [eEdD]. */
1280
1281   collect_exponent:
1282   if (*tokptr == '+' || *tokptr == '-')
1283     {
1284       *copy++ = *tokptr++;
1285     }
1286
1287   /* Now copy an exponent into the conversion buffer.  Note that at the
1288      moment underscores are *not* allowed in exponents. */
1289
1290   while (isdigit (*tokptr))
1291     {
1292       *copy++ = *tokptr++;
1293     }
1294
1295   /* If we transfered any chars to the conversion buffer, try to interpret its
1296      contents as a floating point value.  If any characters remain, then we
1297      must not have a valid floating point string. */
1298
1299   convert_float:
1300   *copy = '\0';
1301   if (copy != buf)
1302       {
1303         dval = strtod (buf, &copy);
1304         if (*copy == '\0')
1305           {
1306             yylval.dval = dval;
1307             lexptr = tokptr;
1308             return (FLOAT_LITERAL);
1309           }
1310       }
1311   return (0);
1312 }
1313
1314 /* Recognize a string literal.  A string literal is a nonzero sequence
1315    of characters enclosed in matching single or double quotes, except that
1316    a single character inside single quotes is a character literal, which
1317    we reject as a string literal.  To embed the terminator character inside
1318    a string, it is simply doubled (I.E. "this""is""one""string") */
1319
1320 static int
1321 match_string_literal ()
1322 {
1323   char *tokptr = lexptr;
1324
1325   for (tempbufindex = 0, tokptr++; *tokptr != '\0'; tokptr++)
1326     {
1327       CHECKBUF (1);
1328       if (*tokptr == *lexptr)
1329         {
1330           if (*(tokptr + 1) == *lexptr)
1331             {
1332               tokptr++;
1333             }
1334           else
1335             {
1336               break;
1337             }
1338         }
1339       tempbuf[tempbufindex++] = *tokptr;
1340     }
1341   if (*tokptr == '\0'                                   /* no terminator */
1342       || tempbufindex == 0                              /* no string */
1343       || (tempbufindex == 1 && *tokptr == '\''))        /* char literal */
1344     {
1345       return (0);
1346     }
1347   else
1348     {
1349       tempbuf[tempbufindex] = '\0';
1350       yylval.sval.ptr = tempbuf;
1351       yylval.sval.length = tempbufindex;
1352       lexptr = ++tokptr;
1353       return (CHARACTER_STRING_LITERAL);
1354     }
1355 }
1356
1357 /* Recognize a character literal.  A character literal is single character
1358    or a control sequence, enclosed in single quotes.  A control sequence
1359    is a comma separated list of one or more integer literals, enclosed
1360    in parenthesis and introduced with a circumflex character.
1361
1362    EX:  'a'  '^(7)'  '^(7,8)'
1363
1364    As a GNU chill extension, the syntax C'xx' is also recognized as a
1365    character literal, where xx is a hex value for the character.
1366
1367    Note that more than a single character, enclosed in single quotes, is
1368    a string literal.
1369
1370    Returns CHARACTER_LITERAL if a match is found.
1371    */
1372
1373 static int
1374 match_character_literal ()
1375 {
1376   char *tokptr = lexptr;
1377   int ival = 0;
1378
1379   if ((tolower (*tokptr) == 'c') && (*(tokptr + 1) == '\''))
1380     {
1381       /* We have a GNU chill extension form, so skip the leading "C'",
1382          decode the hex value, and then ensure that we have a trailing
1383          single quote character. */
1384       tokptr += 2;
1385       if (!decode_integer_value (16, &tokptr, &ival) || (*tokptr != '\''))
1386         {
1387           return (0);
1388         }
1389       tokptr++;
1390     }
1391   else if (*tokptr == '\'')
1392     {
1393       tokptr++;
1394
1395       /* Determine which form we have, either a control sequence or the
1396          single character form. */
1397
1398       if ((*tokptr == '^') && (*(tokptr + 1) == '('))
1399         {
1400           /* Match and decode a control sequence.  Return zero if we don't
1401              find a valid integer literal, or if the next unconsumed character
1402              after the integer literal is not the trailing ')'.
1403              FIXME:  We currently don't handle the multiple integer literal
1404              form. */
1405           tokptr += 2;
1406           if (!decode_integer_literal (&ival, &tokptr) || (*tokptr++ != ')'))
1407             {
1408               return (0);
1409             }
1410         }
1411       else
1412         {
1413           ival = *tokptr++;
1414         }
1415
1416       /* The trailing quote has not yet been consumed.  If we don't find
1417          it, then we have no match. */
1418
1419       if (*tokptr++ != '\'')
1420         {
1421           return (0);
1422         }
1423     }
1424   else
1425     {
1426       /* Not a character literal. */
1427       return (0);
1428     }
1429   yylval.typed_val.val = ival;
1430   yylval.typed_val.type = builtin_type_chill_char;
1431   lexptr = tokptr;
1432   return (CHARACTER_LITERAL);
1433 }
1434
1435 /* Recognize an integer literal, as specified in Z.200 sec 5.2.4.2.
1436    Note that according to 5.2.4.2, a single "_" is also a valid integer
1437    literal, however GNU-chill requires there to be at least one "digit"
1438    in any integer literal. */
1439
1440 static int
1441 match_integer_literal ()
1442 {
1443   char *tokptr = lexptr;
1444   int ival;
1445
1446   if (!decode_integer_literal (&ival, &tokptr))
1447     {
1448       return (0);
1449     }
1450   else
1451     {
1452       yylval.typed_val.val = ival;
1453       yylval.typed_val.type = builtin_type_int;
1454       lexptr = tokptr;
1455       return (INTEGER_LITERAL);
1456     }
1457 }
1458
1459 /* Recognize a bit-string literal, as specified in Z.200 sec 5.2.4.8
1460    Note that according to 5.2.4.8, a single "_" is also a valid bit-string
1461    literal, however GNU-chill requires there to be at least one "digit"
1462    in any bit-string literal. */
1463
1464 static int
1465 match_bitstring_literal ()
1466 {
1467   char *tokptr = lexptr;
1468   int mask;
1469   int bitoffset = 0;
1470   int bitcount = 0;
1471   int base;
1472   int digit;
1473
1474   tempbufindex = 0;
1475
1476   /* Look for the required explicit base specifier. */
1477
1478   switch (*tokptr++)
1479     {
1480     case 'b':
1481     case 'B':
1482       base = 2;
1483       break;
1484     case 'o':
1485     case 'O':
1486       base = 8;
1487       break;
1488     case 'h':
1489     case 'H':
1490       base = 16;
1491       break;
1492     default:
1493       return (0);
1494       break;
1495     }
1496
1497   /* Ensure that the character after the explicit base is a single quote. */
1498
1499   if (*tokptr++ != '\'')
1500     {
1501       return (0);
1502     }
1503
1504   while (*tokptr != '\0' && *tokptr != '\'')
1505     {
1506       digit = tolower (*tokptr);
1507       tokptr++;
1508       switch (digit)
1509         {
1510           case '_':
1511             continue;
1512           case '0':  case '1':  case '2':  case '3':  case '4':
1513           case '5':  case '6':  case '7':  case '8':  case '9':
1514             digit -= '0';
1515             break;
1516           case 'a':  case 'b':  case 'c':  case 'd':  case 'e': case 'f':
1517             digit -= 'a';
1518             digit += 10;
1519             break;
1520           default:
1521             return (0);
1522             break;
1523         }
1524       if (digit >= base)
1525         {
1526           /* Found something not in domain for current base. */
1527           return (0);
1528         }
1529       else
1530         {
1531           /* Extract bits from digit, starting with the msbit appropriate for
1532              the current base, and packing them into the bitstring byte,
1533              starting at the lsbit. */
1534           for (mask = (base >> 1); mask > 0; mask >>= 1)
1535             {
1536               bitcount++;
1537               CHECKBUF (1);
1538               if (digit & mask)
1539                 {
1540                   tempbuf[tempbufindex] |= (1 << bitoffset);
1541                 }
1542               bitoffset++;
1543               if (bitoffset == HOST_CHAR_BIT)
1544                 {
1545                   bitoffset = 0;
1546                   tempbufindex++;
1547                 }
1548             }
1549         }
1550     }
1551
1552   /* Verify that we consumed everything up to the trailing single quote,
1553      and that we found some bits (IE not just underbars). */
1554
1555   if (*tokptr++ != '\'')
1556     {
1557       return (0);
1558     }
1559   else
1560     {
1561       yylval.sval.ptr = tempbuf;
1562       yylval.sval.length = bitcount;
1563       lexptr = tokptr;
1564       return (BIT_STRING_LITERAL);
1565     }
1566 }
1567
1568 /* Recognize tokens that start with '$'.  These include:
1569
1570         $regname        A native register name or a "standard
1571                         register name".
1572                         Return token GDB_REGNAME.
1573
1574         $variable       A convenience variable with a name chosen
1575                         by the user.
1576                         Return token GDB_VARIABLE.
1577
1578         $digits         Value history with index <digits>, starting
1579                         from the first value which has index 1.
1580                         Return GDB_LAST.
1581
1582         $$digits        Value history with index <digits> relative
1583                         to the last value.  I.E. $$0 is the last
1584                         value, $$1 is the one previous to that, $$2
1585                         is the one previous to $$1, etc.
1586                         Return token GDB_LAST.
1587
1588         $ | $0 | $$0    The last value in the value history.
1589                         Return token GDB_LAST.
1590
1591         $$              An abbreviation for the second to the last
1592                         value in the value history, I.E. $$1
1593                         Return token GDB_LAST.
1594
1595     Note that we currently assume that register names and convenience
1596     variables follow the convention of starting with a letter or '_'.
1597
1598    */
1599
1600 static int
1601 match_dollar_tokens ()
1602 {
1603   char *tokptr;
1604   int regno;
1605   int namelength;
1606   int negate;
1607   int ival;
1608
1609   /* We will always have a successful match, even if it is just for
1610      a single '$', the abbreviation for $$0.  So advance lexptr. */
1611
1612   tokptr = ++lexptr;
1613
1614   if (*tokptr == '_' || isalpha (*tokptr))
1615     {
1616       /* Look for a match with a native register name, usually something
1617          like "r0" for example. */
1618
1619       for (regno = 0; regno < NUM_REGS; regno++)
1620         {
1621           namelength = strlen (reg_names[regno]);
1622           if (STREQN (tokptr, reg_names[regno], namelength)
1623               && !isalnum (tokptr[namelength]))
1624             {
1625               yylval.lval = regno;
1626               lexptr += namelength + 1;
1627               return (GDB_REGNAME);
1628             }
1629         }
1630
1631       /* Look for a match with a standard register name, usually something
1632          like "pc", which gdb always recognizes as the program counter
1633          regardless of what the native register name is. */
1634
1635       for (regno = 0; regno < num_std_regs; regno++)
1636         {
1637           namelength = strlen (std_regs[regno].name);
1638           if (STREQN (tokptr, std_regs[regno].name, namelength)
1639               && !isalnum (tokptr[namelength]))
1640             {
1641               yylval.lval = std_regs[regno].regnum;
1642               lexptr += namelength;
1643               return (GDB_REGNAME);
1644             }
1645         }
1646
1647       /* Attempt to match against a convenience variable.  Note that
1648          this will always succeed, because if no variable of that name
1649          already exists, the lookup_internalvar will create one for us.
1650          Also note that both lexptr and tokptr currently point to the
1651          start of the input string we are trying to match, and that we
1652          have already tested the first character for non-numeric, so we
1653          don't have to treat it specially. */
1654
1655       while (*tokptr == '_' || isalnum (*tokptr))
1656         {
1657           tokptr++;
1658         }
1659       yylval.sval.ptr = lexptr;
1660       yylval.sval.length = tokptr - lexptr;
1661       yylval.ivar = lookup_internalvar (copy_name (yylval.sval));
1662       lexptr = tokptr;
1663       return (GDB_VARIABLE);
1664     }
1665
1666   /* Since we didn't match against a register name or convenience
1667      variable, our only choice left is a history value. */
1668
1669   if (*tokptr == '$')
1670     {
1671       negate = 1;
1672       ival = 1;
1673       tokptr++;
1674     }
1675   else
1676     {
1677       negate = 0;
1678       ival = 0;
1679     }
1680
1681   /* Attempt to decode more characters as an integer value giving
1682      the index in the history list.  If successful, the value will
1683      overwrite ival (currently 0 or 1), and if not, ival will be
1684      left alone, which is good since it is currently correct for
1685      the '$' or '$$' case. */
1686
1687   decode_integer_literal (&ival, &tokptr);
1688   yylval.lval = negate ? -ival : ival;
1689   lexptr = tokptr;
1690   return (GDB_LAST);
1691 }
1692
1693 struct token
1694 {
1695   char *operator;
1696   int token;
1697 };
1698
1699 static const struct token tokentab6[] =
1700 {
1701     { "LENGTH", LENGTH }
1702 };
1703
1704 static const struct token tokentab5[] =
1705 {
1706     { "LOWER", LOWER },
1707     { "UPPER", UPPER },
1708     { "ANDIF", ANDIF }
1709 };
1710
1711 static const struct token tokentab4[] =
1712 {
1713     { "PRED", PRED },
1714     { "SUCC", SUCC },
1715     { "CARD", CARD },
1716     { "SIZE", SIZE },
1717     { "ORIF", ORIF }
1718 };
1719
1720 static const struct token tokentab3[] =
1721 {
1722     { "NUM", NUM },
1723     { "ABS", ABS },
1724     { "MAX", MAX },
1725     { "MIN", MIN },
1726     { "MOD", MOD },
1727     { "REM", REM },
1728     { "NOT", NOT },
1729     { "XOR", LOGXOR },
1730     { "AND", LOGAND }
1731 };
1732
1733 static const struct token tokentab2[] =
1734 {
1735     { ":=", GDB_ASSIGNMENT },
1736     { "//", SLASH_SLASH },
1737     { "/=", NOTEQUAL },
1738     { "<=", LEQ },
1739     { ">=", GTR },
1740     { "IN", IN },
1741     { "OR", LOGIOR }
1742 };
1743
1744 /* Read one token, getting characters through lexptr.  */
1745 /* This is where we will check to make sure that the language and the
1746    operators used are compatible.  */
1747
1748 static int
1749 yylex ()
1750 {
1751     unsigned int i;
1752     int token;
1753     char *simplename;
1754     struct symbol *sym;
1755
1756     /* Skip over any leading whitespace. */
1757     while (isspace (*lexptr))
1758         {
1759             lexptr++;
1760         }
1761     /* Look for special single character cases which can't be the first
1762        character of some other multicharacter token. */
1763     switch (*lexptr)
1764         {
1765             case '\0':
1766                 return (0);
1767             case ',':
1768             case '=':
1769             case ';':
1770             case '!':
1771             case '+':
1772             case '-':
1773             case '*':
1774             case '/':
1775             case '(':
1776             case ')':
1777             case '[':
1778             case ']':
1779                 return (*lexptr++);
1780         }
1781     /* Look for characters which start a particular kind of multicharacter
1782        token, such as a character literal, register name, convenience
1783        variable name, string literal, etc. */
1784     switch (*lexptr)
1785       {
1786         case '\'':
1787         case '\"':
1788           /* First try to match a string literal, which is any nonzero
1789              sequence of characters enclosed in matching single or double
1790              quotes, except that a single character inside single quotes
1791              is a character literal, so we have to catch that case also. */
1792           token = match_string_literal ();
1793           if (token != 0)
1794             {
1795               return (token);
1796             }
1797           if (*lexptr == '\'')
1798             {
1799               token = match_character_literal ();
1800               if (token != 0)
1801                 {
1802                   return (token);
1803                 }
1804             }
1805           break;
1806         case 'C':
1807         case 'c':
1808           token = match_character_literal ();
1809           if (token != 0)
1810             {
1811               return (token);
1812             }
1813           break;
1814         case '$':
1815           token = match_dollar_tokens ();
1816           if (token != 0)
1817             {
1818               return (token);
1819             }
1820           break;
1821       }
1822     /* See if it is a special token of length 6.  */
1823     for (i = 0; i < sizeof (tokentab6) / sizeof (tokentab6[0]); i++)
1824         {
1825             if (STREQN (lexptr, tokentab6[i].operator, 6))
1826                 {
1827                     lexptr += 6;
1828                     return (tokentab6[i].token);
1829                 }
1830         }
1831     /* See if it is a special token of length 5.  */
1832     for (i = 0; i < sizeof (tokentab5) / sizeof (tokentab5[0]); i++)
1833         {
1834             if (STREQN (lexptr, tokentab5[i].operator, 5))
1835                 {
1836                     lexptr += 5;
1837                     return (tokentab5[i].token);
1838                 }
1839         }
1840     /* See if it is a special token of length 4.  */
1841     for (i = 0; i < sizeof (tokentab4) / sizeof (tokentab4[0]); i++)
1842         {
1843             if (STREQN (lexptr, tokentab4[i].operator, 4))
1844                 {
1845                     lexptr += 4;
1846                     return (tokentab4[i].token);
1847                 }
1848         }
1849     /* See if it is a special token of length 3.  */
1850     for (i = 0; i < sizeof (tokentab3) / sizeof (tokentab3[0]); i++)
1851         {
1852             if (STREQN (lexptr, tokentab3[i].operator, 3))
1853                 {
1854                     lexptr += 3;
1855                     return (tokentab3[i].token);
1856                 }
1857         }
1858     /* See if it is a special token of length 2.  */
1859     for (i = 0; i < sizeof (tokentab2) / sizeof (tokentab2[0]); i++)
1860         {
1861             if (STREQN (lexptr, tokentab2[i].operator, 2))
1862                 {
1863                     lexptr += 2;
1864                     return (tokentab2[i].token);
1865                 }
1866         }
1867     /* Look for single character cases which which could be the first
1868        character of some other multicharacter token, but aren't, or we
1869        would already have found it. */
1870     switch (*lexptr)
1871         {
1872             case ':':
1873             case '/':
1874             case '<':
1875             case '>':
1876                 return (*lexptr++);
1877         }
1878     /* Look for other special tokens. */
1879     if (STREQN (lexptr, "TRUE", 4)) /* FIXME:  What about lowercase? */
1880         {
1881             yylval.ulval = 1;
1882             lexptr += 4;
1883             return (BOOLEAN_LITERAL);
1884         }
1885     if (STREQN (lexptr, "FALSE", 5)) /* FIXME:  What about lowercase? */
1886         {
1887             yylval.ulval = 0;
1888             lexptr += 5;
1889             return (BOOLEAN_LITERAL);
1890         }
1891     /* Look for a float literal before looking for an integer literal, so
1892        we match as much of the input stream as possible. */
1893     token = match_float_literal ();
1894     if (token != 0)
1895         {
1896             return (token);
1897         }
1898     token = match_bitstring_literal ();
1899     if (token != 0)
1900         {
1901             return (token);
1902         }
1903     token = match_integer_literal ();
1904     if (token != 0)
1905         {
1906             return (token);
1907         }
1908
1909     /* Try to match a simple name string, and if a match is found, then
1910        further classify what sort of name it is and return an appropriate
1911        token.  Note that attempting to match a simple name string consumes
1912        the token from lexptr, so we can't back out if we later find that
1913        we can't classify what sort of name it is. */
1914
1915     simplename = match_simple_name_string ();
1916     if (simplename != NULL)
1917       {
1918         sym = lookup_symbol (simplename, expression_context_block,
1919                              VAR_NAMESPACE, (int *) NULL,
1920                              (struct symtab **) NULL);
1921         if (sym != NULL)
1922           {
1923             yylval.ssym.stoken.ptr = NULL;
1924             yylval.ssym.stoken.length = 0;
1925             yylval.ssym.sym = sym;
1926             yylval.ssym.is_a_field_of_this = 0; /* FIXME, C++'ism */
1927             switch (SYMBOL_CLASS (sym))
1928               {
1929               case LOC_BLOCK:
1930                 /* Found a procedure name. */
1931                 return (GENERAL_PROCEDURE_NAME);
1932               case LOC_STATIC:
1933                 /* Found a global or local static variable. */
1934                 return (LOCATION_NAME);
1935               case LOC_REGISTER:
1936               case LOC_ARG:
1937               case LOC_REF_ARG:
1938               case LOC_REGPARM:
1939               case LOC_LOCAL:
1940               case LOC_LOCAL_ARG:
1941                 if (innermost_block == NULL
1942                     || contained_in (block_found, innermost_block))
1943                   {
1944                     innermost_block = block_found;
1945                   }
1946                 return (LOCATION_NAME);
1947                 break;
1948               case LOC_CONST:
1949               case LOC_LABEL:
1950                 return (LOCATION_NAME);
1951                 break;
1952               case LOC_UNDEF:
1953               case LOC_TYPEDEF:
1954               case LOC_CONST_BYTES:
1955                 error ("Symbol \"%s\" names no location.", simplename);
1956                 break;
1957               }
1958           }
1959         else if (!have_full_symbols () && !have_partial_symbols ())
1960           {
1961             error ("No symbol table is loaded.  Use the \"file\" command.");
1962           }
1963         else
1964           {
1965             error ("No symbol \"%s\" in current context.", simplename);
1966           }
1967       }
1968
1969     /* Catch single character tokens which are not part of some
1970        longer token. */
1971
1972     switch (*lexptr)
1973       {
1974         case '.':                       /* Not float for example. */
1975           return (*lexptr++);
1976       }
1977
1978     return (ILLEGAL_TOKEN);
1979 }
1980
1981 void
1982 yyerror (msg)
1983      char *msg; /* unused */
1984 {
1985   printf ("Parsing:  %s\n", lexptr);
1986   if (yychar < 256)
1987     {
1988       error ("Invalid syntax in expression near character '%c'.", yychar);
1989     }
1990   else
1991     {
1992       error ("Invalid syntax in expression");
1993     }
1994 }