gdb/c-exp.y

   1 /* YACC parser for C expressions, for GDB.
   2    Copyright (C) 1986, 1989, 1990, 1991, 1993, 1994, 1996, 1997
   3    Free Software Foundation, Inc.
   4
   5 This file is part of GDB.
   6
   7 This program is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2 of the License, or
  10 (at your option) any later version.
  11
  12 This program is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with this program; if not, write to the Free Software
  19 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  20
  21 /* Parse a C expression from text in a string,
  22    and return the result as a  struct expression  pointer.
  23    That structure contains arithmetic operations in reverse polish,
  24    with constants represented by operations that are followed by special data.
  25    See expression.h for the details of the format.
  26    What is important here is that it can be built up sequentially
  27    during the process of parsing; the lower levels of the tree always
  28    come first in the result.
  29
  30    Note that malloc's and realloc's in this file are transformed to
  31    xmalloc and xrealloc respectively by the same sed command in the
  32    makefile that remaps any other malloc/realloc inserted by the parser
  33    generator.  Doing this with #defines and trying to control the interaction
  34    with include files (<malloc.h> and <stdlib.h> for example) just became
  35    too messy, particularly when such includes can be inserted at random
  36    times by the parser generator.  */
  37
  38 %{
  39
  40 #include "defs.h"
  41 #include "gdb_string.h"
  42 #include <ctype.h>
  43 #include "expression.h"
  44 #include "value.h"
  45 #include "parser-defs.h"
  46 #include "language.h"
  47 #include "c-lang.h"
  48 #include "bfd.h" /* Required by objfiles.h.  */
  49 #include "symfile.h" /* Required by objfiles.h.  */
  50 #include "objfiles.h" /* For have_full_symbols and have_partial_symbols */
  51
  52 /* Remap normal yacc parser interface names (yyparse, yylex, yyerror, etc),
  53    as well as gratuitiously global symbol names, so we can have multiple
  54    yacc generated parsers in gdb.  Note that these are only the variables
  55    produced by yacc.  If other parser generators (bison, byacc, etc) produce
  56    additional global names that conflict at link time, then those parser
  57    generators need to be fixed instead of adding those names to this list. */
  58
  59 #define yymaxdepth c_maxdepth
  60 #define yyparse c_parse
  61 #define yylex   c_lex
  62 #define yyerror c_error
  63 #define yylval  c_lval
  64 #define yychar  c_char
  65 #define yydebug c_debug
  66 #define yypact  c_pact
  67 #define yyr1    c_r1
  68 #define yyr2    c_r2
  69 #define yydef   c_def
  70 #define yychk   c_chk
  71 #define yypgo   c_pgo
  72 #define yyact   c_act
  73 #define yyexca  c_exca
  74 #define yyerrflag c_errflag
  75 #define yynerrs c_nerrs
  76 #define yyps    c_ps
  77 #define yypv    c_pv
  78 #define yys     c_s
  79 #define yy_yys  c_yys
  80 #define yystate c_state
  81 #define yytmp   c_tmp
  82 #define yyv     c_v
  83 #define yy_yyv  c_yyv
  84 #define yyval   c_val
  85 #define yylloc  c_lloc
  86 #define yyreds  c_reds          /* With YYDEBUG defined */
  87 #define yytoks  c_toks          /* With YYDEBUG defined */
  88 #define yylhs   c_yylhs
  89 #define yylen   c_yylen
  90 #define yydefred c_yydefred
  91 #define yydgoto c_yydgoto
  92 #define yysindex c_yysindex
  93 #define yyrindex c_yyrindex
  94 #define yygindex c_yygindex
  95 #define yytable  c_yytable
  96 #define yycheck  c_yycheck
  97
  98 #ifndef YYDEBUG
  99 #define YYDEBUG 0               /* Default to no yydebug support */
 100 #endif
 101
 102 int
 103 yyparse PARAMS ((void));
 104
 105 static int
 106 yylex PARAMS ((void));
 107
 108 void
 109 yyerror PARAMS ((char *));
 110
 111 %}
 112
 113 /* Although the yacc "value" of an expression is not used,
 114    since the result is stored in the structure being created,
 115    other node types do have values.  */
 116
 117 %union
 118   {
 119     LONGEST lval;
 120     struct {
 121       LONGEST val;
 122       struct type *type;
 123     } typed_val_int;
 124     struct {
 125       DOUBLEST dval;
 126       struct type *type;
 127     } typed_val_float;
 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 %{
 143 /* YYSTYPE gets defined by %union */
 144 static int
 145 parse_number PARAMS ((char *, int, int, YYSTYPE *));
 146 %}
 147
 148 %type <voidval> exp exp1 type_exp start variable qualified_name lcurly
 149 %type <lval> rcurly
 150 %type <tval> type typebase
 151 %type <tvec> nonempty_typelist
 152 /* %type <bval> block */
 153
 154 /* Fancy type parsing.  */
 155 %type <voidval> func_mod direct_abs_decl abs_decl
 156 %type <tval> ptype
 157 %type <lval> array_mod
 158
 159 %token <typed_val_int> INT
 160 %token <typed_val_float> FLOAT
 161
 162 /* Both NAME and TYPENAME tokens represent symbols in the input,
 163    and both convey their data as strings.
 164    But a TYPENAME is a string that happens to be defined as a typedef
 165    or builtin type name (such as int or char)
 166    and a NAME is any other symbol.
 167    Contexts where this distinction is not important can use the
 168    nonterminal "name", which matches either NAME or TYPENAME.  */
 169
 170 %token <sval> STRING
 171 %token <ssym> NAME /* BLOCKNAME defined below to give it higher precedence. */
 172 %token <tsym> TYPENAME
 173 %type <sval> name
 174 %type <ssym> name_not_typename
 175 %type <tsym> typename
 176
 177 /* A NAME_OR_INT is a symbol which is not known in the symbol table,
 178    but which would parse as a valid number in the current input radix.
 179    E.g. "c" when input_radix==16.  Depending on the parse, it will be
 180    turned into a name or into a number.  */
 181
 182 %token <ssym> NAME_OR_INT
 183
 184 %token STRUCT CLASS UNION ENUM SIZEOF UNSIGNED COLONCOLON
 185 %token TEMPLATE
 186 %token ERROR
 187
 188 /* Special type cases, put in to allow the parser to distinguish different
 189    legal basetypes.  */
 190 %token SIGNED_KEYWORD LONG SHORT INT_KEYWORD CONST_KEYWORD VOLATILE_KEYWORD DOUBLE_KEYWORD
 191
 192 %token <voidval> VARIABLE
 193
 194 %token <opcode> ASSIGN_MODIFY
 195
 196 /* C++ */
 197 %token THIS
 198
 199 %left ','
 200 %left ABOVE_COMMA
 201 %right '=' ASSIGN_MODIFY
 202 %right '?'
 203 %left OROR
 204 %left ANDAND
 205 %left '|'
 206 %left '^'
 207 %left '&'
 208 %left EQUAL NOTEQUAL
 209 %left '<' '>' LEQ GEQ
 210 %left LSH RSH
 211 %left '@'
 212 %left '+' '-'
 213 %left '*' '/' '%'
 214 %right UNARY INCREMENT DECREMENT
 215 %right ARROW '.' '[' '('
 216 %token <ssym> BLOCKNAME
 217 %type <bval> block
 218 %left COLONCOLON
 219
 220 \f
 221 %%
 222
 223 start   :       exp1
 224         |       type_exp
 225         ;
 226
 227 type_exp:       type
 228                         { write_exp_elt_opcode(OP_TYPE);
 229                           write_exp_elt_type($1);
 230                           write_exp_elt_opcode(OP_TYPE);}
 231         ;
 232
 233 /* Expressions, including the comma operator.  */
 234 exp1    :       exp
 235         |       exp1 ',' exp
 236                         { write_exp_elt_opcode (BINOP_COMMA); }
 237         ;
 238
 239 /* Expressions, not including the comma operator.  */
 240 exp     :       '*' exp    %prec UNARY
 241                         { write_exp_elt_opcode (UNOP_IND); }
 242
 243 exp     :       '&' exp    %prec UNARY
 244                         { write_exp_elt_opcode (UNOP_ADDR); }
 245
 246 exp     :       '-' exp    %prec UNARY
 247                         { write_exp_elt_opcode (UNOP_NEG); }
 248         ;
 249
 250 exp     :       '!' exp    %prec UNARY
 251                         { write_exp_elt_opcode (UNOP_LOGICAL_NOT); }
 252         ;
 253
 254 exp     :       '~' exp    %prec UNARY
 255                         { write_exp_elt_opcode (UNOP_COMPLEMENT); }
 256         ;
 257
 258 exp     :       INCREMENT exp    %prec UNARY
 259                         { write_exp_elt_opcode (UNOP_PREINCREMENT); }
 260         ;
 261
 262 exp     :       DECREMENT exp    %prec UNARY
 263                         { write_exp_elt_opcode (UNOP_PREDECREMENT); }
 264         ;
 265
 266 exp     :       exp INCREMENT    %prec UNARY
 267                         { write_exp_elt_opcode (UNOP_POSTINCREMENT); }
 268         ;
 269
 270 exp     :       exp DECREMENT    %prec UNARY
 271                         { write_exp_elt_opcode (UNOP_POSTDECREMENT); }
 272         ;
 273
 274 exp     :       SIZEOF exp       %prec UNARY
 275                         { write_exp_elt_opcode (UNOP_SIZEOF); }
 276         ;
 277
 278 exp     :       exp ARROW name
 279                         { write_exp_elt_opcode (STRUCTOP_PTR);
 280                           write_exp_string ($3);
 281                           write_exp_elt_opcode (STRUCTOP_PTR); }
 282         ;
 283
 284 exp     :       exp ARROW qualified_name
 285                         { /* exp->type::name becomes exp->*(&type::name) */
 286                           /* Note: this doesn't work if name is a
 287                              static member!  FIXME */
 288                           write_exp_elt_opcode (UNOP_ADDR);
 289                           write_exp_elt_opcode (STRUCTOP_MPTR); }
 290         ;
 291 exp     :       exp ARROW '*' exp
 292                         { write_exp_elt_opcode (STRUCTOP_MPTR); }
 293         ;
 294
 295 exp     :       exp '.' name
 296                         { write_exp_elt_opcode (STRUCTOP_STRUCT);
 297                           write_exp_string ($3);
 298                           write_exp_elt_opcode (STRUCTOP_STRUCT); }
 299         ;
 300
 301 /* start-sanitize-gm
 302 Need to find a better way to do this...
 303 exp     :       exp '@' name
 304                         { write_exp_elt_opcode (STRUCTOP_FIELD);
 305                           write_exp_string ($3);
 306                           write_exp_elt_opcode (STRUCTOP_FIELD);
 307                         }
 308  end-sanitize-gm */
 309
 310 exp     :       exp '.' qualified_name
 311                         { /* exp.type::name becomes exp.*(&type::name) */
 312                           /* Note: this doesn't work if name is a
 313                              static member!  FIXME */
 314                           write_exp_elt_opcode (UNOP_ADDR);
 315                           write_exp_elt_opcode (STRUCTOP_MEMBER); }
 316         ;
 317
 318 exp     :       exp '.' '*' exp
 319                         { write_exp_elt_opcode (STRUCTOP_MEMBER); }
 320         ;
 321
 322 exp     :       exp '[' exp1 ']'
 323                         { write_exp_elt_opcode (BINOP_SUBSCRIPT); }
 324         ;
 325
 326 exp     :       exp '('
 327                         /* This is to save the value of arglist_len
 328                            being accumulated by an outer function call.  */
 329                         { start_arglist (); }
 330                 arglist ')'     %prec ARROW
 331                         { write_exp_elt_opcode (OP_FUNCALL);
 332                           write_exp_elt_longcst ((LONGEST) end_arglist ());
 333                           write_exp_elt_opcode (OP_FUNCALL); }
 334         ;
 335
 336 lcurly  :       '{'
 337                         { start_arglist (); }
 338         ;
 339
 340 arglist :
 341         ;
 342
 343 arglist :       exp
 344                         { arglist_len = 1; }
 345         ;
 346
 347 arglist :       arglist ',' exp   %prec ABOVE_COMMA
 348                         { arglist_len++; }
 349         ;
 350
 351 rcurly  :       '}'
 352                         { $$ = end_arglist () - 1; }
 353         ;
 354 exp     :       lcurly arglist rcurly   %prec ARROW
 355                         { write_exp_elt_opcode (OP_ARRAY);
 356                           write_exp_elt_longcst ((LONGEST) 0);
 357                           write_exp_elt_longcst ((LONGEST) $3);
 358                           write_exp_elt_opcode (OP_ARRAY); }
 359         ;
 360
 361 exp     :       lcurly type rcurly exp  %prec UNARY
 362                         { write_exp_elt_opcode (UNOP_MEMVAL);
 363                           write_exp_elt_type ($2);
 364                           write_exp_elt_opcode (UNOP_MEMVAL); }
 365         ;
 366
 367 exp     :       '(' type ')' exp  %prec UNARY
 368                         { write_exp_elt_opcode (UNOP_CAST);
 369                           write_exp_elt_type ($2);
 370                           write_exp_elt_opcode (UNOP_CAST); }
 371         ;
 372
 373 exp     :       '(' exp1 ')'
 374                         { }
 375         ;
 376
 377 /* Binary operators in order of decreasing precedence.  */
 378
 379 exp     :       exp '@' exp
 380                         { write_exp_elt_opcode (BINOP_REPEAT); }
 381         ;
 382
 383 exp     :       exp '*' exp
 384                         { write_exp_elt_opcode (BINOP_MUL); }
 385         ;
 386
 387 exp     :       exp '/' exp
 388                         { write_exp_elt_opcode (BINOP_DIV); }
 389         ;
 390
 391 exp     :       exp '%' exp
 392                         { write_exp_elt_opcode (BINOP_REM); }
 393         ;
 394
 395 exp     :       exp '+' exp
 396                         { write_exp_elt_opcode (BINOP_ADD); }
 397         ;
 398
 399 exp     :       exp '-' exp
 400                         { write_exp_elt_opcode (BINOP_SUB); }
 401         ;
 402
 403 exp     :       exp LSH exp
 404                         { write_exp_elt_opcode (BINOP_LSH); }
 405         ;
 406
 407 exp     :       exp RSH exp
 408                         { write_exp_elt_opcode (BINOP_RSH); }
 409         ;
 410
 411 exp     :       exp EQUAL exp
 412                         { write_exp_elt_opcode (BINOP_EQUAL); }
 413         ;
 414
 415 exp     :       exp NOTEQUAL exp
 416                         { write_exp_elt_opcode (BINOP_NOTEQUAL); }
 417         ;
 418
 419 exp     :       exp LEQ exp
 420                         { write_exp_elt_opcode (BINOP_LEQ); }
 421         ;
 422
 423 exp     :       exp GEQ exp
 424                         { write_exp_elt_opcode (BINOP_GEQ); }
 425         ;
 426
 427 exp     :       exp '<' exp
 428                         { write_exp_elt_opcode (BINOP_LESS); }
 429         ;
 430
 431 exp     :       exp '>' exp
 432                         { write_exp_elt_opcode (BINOP_GTR); }
 433         ;
 434
 435 exp     :       exp '&' exp
 436                         { write_exp_elt_opcode (BINOP_BITWISE_AND); }
 437         ;
 438
 439 exp     :       exp '^' exp
 440                         { write_exp_elt_opcode (BINOP_BITWISE_XOR); }
 441         ;
 442
 443 exp     :       exp '|' exp
 444                         { write_exp_elt_opcode (BINOP_BITWISE_IOR); }
 445         ;
 446
 447 exp     :       exp ANDAND exp
 448                         { write_exp_elt_opcode (BINOP_LOGICAL_AND); }
 449         ;
 450
 451 exp     :       exp OROR exp
 452                         { write_exp_elt_opcode (BINOP_LOGICAL_OR); }
 453         ;
 454
 455 exp     :       exp '?' exp ':' exp     %prec '?'
 456                         { write_exp_elt_opcode (TERNOP_COND); }
 457         ;
 458
 459 exp     :       exp '=' exp
 460                         { write_exp_elt_opcode (BINOP_ASSIGN); }
 461         ;
 462
 463 exp     :       exp ASSIGN_MODIFY exp
 464                         { write_exp_elt_opcode (BINOP_ASSIGN_MODIFY);
 465                           write_exp_elt_opcode ($2);
 466                           write_exp_elt_opcode (BINOP_ASSIGN_MODIFY); }
 467         ;
 468
 469 exp     :       INT
 470                         { write_exp_elt_opcode (OP_LONG);
 471                           write_exp_elt_type ($1.type);
 472                           write_exp_elt_longcst ((LONGEST)($1.val));
 473                           write_exp_elt_opcode (OP_LONG); }
 474         ;
 475
 476 exp     :       NAME_OR_INT
 477                         { YYSTYPE val;
 478                           parse_number ($1.stoken.ptr, $1.stoken.length, 0, &val);
 479                           write_exp_elt_opcode (OP_LONG);
 480                           write_exp_elt_type (val.typed_val_int.type);
 481                           write_exp_elt_longcst ((LONGEST)val.typed_val_int.val);
 482                           write_exp_elt_opcode (OP_LONG);
 483                         }
 484         ;
 485
 486
 487 exp     :       FLOAT
 488                         { write_exp_elt_opcode (OP_DOUBLE);
 489                           write_exp_elt_type ($1.type);
 490                           write_exp_elt_dblcst ($1.dval);
 491                           write_exp_elt_opcode (OP_DOUBLE); }
 492         ;
 493
 494 exp     :       variable
 495         ;
 496
 497 exp     :       VARIABLE
 498                         /* Already written by write_dollar_variable. */
 499         ;
 500
 501 exp     :       SIZEOF '(' type ')'     %prec UNARY
 502                         { write_exp_elt_opcode (OP_LONG);
 503                           write_exp_elt_type (builtin_type_int);
 504                           CHECK_TYPEDEF ($3);
 505                           write_exp_elt_longcst ((LONGEST) TYPE_LENGTH ($3));
 506                           write_exp_elt_opcode (OP_LONG); }
 507         ;
 508
 509 exp     :       STRING
 510                         { /* C strings are converted into array constants with
 511                              an explicit null byte added at the end.  Thus
 512                              the array upper bound is the string length.
 513                              There is no such thing in C as a completely empty
 514                              string. */
 515                           char *sp = $1.ptr; int count = $1.length;
 516                           while (count-- > 0)
 517                             {
 518                               write_exp_elt_opcode (OP_LONG);
 519                               write_exp_elt_type (builtin_type_char);
 520                               write_exp_elt_longcst ((LONGEST)(*sp++));
 521                               write_exp_elt_opcode (OP_LONG);
 522                             }
 523                           write_exp_elt_opcode (OP_LONG);
 524                           write_exp_elt_type (builtin_type_char);
 525                           write_exp_elt_longcst ((LONGEST)'\0');
 526                           write_exp_elt_opcode (OP_LONG);
 527                           write_exp_elt_opcode (OP_ARRAY);
 528                           write_exp_elt_longcst ((LONGEST) 0);
 529                           write_exp_elt_longcst ((LONGEST) ($1.length));
 530                           write_exp_elt_opcode (OP_ARRAY); }
 531         ;
 532
 533 /* C++.  */
 534 exp     :       THIS
 535                         { write_exp_elt_opcode (OP_THIS);
 536                           write_exp_elt_opcode (OP_THIS); }
 537         ;
 538
 539 /* end of C++.  */
 540
 541 block   :       BLOCKNAME
 542                         {
 543                           if ($1.sym != 0)
 544                               $$ = SYMBOL_BLOCK_VALUE ($1.sym);
 545                           else
 546                             {
 547                               struct symtab *tem =
 548                                   lookup_symtab (copy_name ($1.stoken));
 549                               if (tem)
 550                                 $$ = BLOCKVECTOR_BLOCK (BLOCKVECTOR (tem), STATIC_BLOCK);
 551                               else
 552                                 error ("No file or function \"%s\".",
 553                                        copy_name ($1.stoken));
 554                             }
 555                         }
 556         ;
 557
 558 block   :       block COLONCOLON name
 559                         { struct symbol *tem
 560                             = lookup_symbol (copy_name ($3), $1,
 561                                              VAR_NAMESPACE, (int *) NULL,
 562                                              (struct symtab **) NULL);
 563                           if (!tem || SYMBOL_CLASS (tem) != LOC_BLOCK)
 564                             error ("No function \"%s\" in specified context.",
 565                                    copy_name ($3));
 566                           $$ = SYMBOL_BLOCK_VALUE (tem); }
 567         ;
 568
 569 variable:       block COLONCOLON name
 570                         { struct symbol *sym;
 571                           sym = lookup_symbol (copy_name ($3), $1,
 572                                                VAR_NAMESPACE, (int *) NULL,
 573                                                (struct symtab **) NULL);
 574                           if (sym == 0)
 575                             error ("No symbol \"%s\" in specified context.",
 576                                    copy_name ($3));
 577
 578                           write_exp_elt_opcode (OP_VAR_VALUE);
 579                           /* block_found is set by lookup_symbol.  */
 580                           write_exp_elt_block (block_found);
 581                           write_exp_elt_sym (sym);
 582                           write_exp_elt_opcode (OP_VAR_VALUE); }
 583         ;
 584
 585 qualified_name: typebase COLONCOLON name
 586                         {
 587                           struct type *type = $1;
 588                           if (TYPE_CODE (type) != TYPE_CODE_STRUCT
 589                               && TYPE_CODE (type) != TYPE_CODE_UNION)
 590                             error ("`%s' is not defined as an aggregate type.",
 591                                    TYPE_NAME (type));
 592
 593                           write_exp_elt_opcode (OP_SCOPE);
 594                           write_exp_elt_type (type);
 595                           write_exp_string ($3);
 596                           write_exp_elt_opcode (OP_SCOPE);
 597                         }
 598         |       typebase COLONCOLON '~' name
 599                         {
 600                           struct type *type = $1;
 601                           struct stoken tmp_token;
 602                           if (TYPE_CODE (type) != TYPE_CODE_STRUCT
 603                               && TYPE_CODE (type) != TYPE_CODE_UNION)
 604                             error ("`%s' is not defined as an aggregate type.",
 605                                    TYPE_NAME (type));
 606
 607                           tmp_token.ptr = (char*) alloca ($4.length + 2);
 608                           tmp_token.length = $4.length + 1;
 609                           tmp_token.ptr[0] = '~';
 610                           memcpy (tmp_token.ptr+1, $4.ptr, $4.length);
 611                           tmp_token.ptr[tmp_token.length] = 0;
 612
 613                           /* Check for valid destructor name.  */
 614                           destructor_name_p (tmp_token.ptr, type);
 615                           write_exp_elt_opcode (OP_SCOPE);
 616                           write_exp_elt_type (type);
 617                           write_exp_string (tmp_token);
 618                           write_exp_elt_opcode (OP_SCOPE);
 619                         }
 620         ;
 621
 622 variable:       qualified_name
 623         |       COLONCOLON name
 624                         {
 625                           char *name = copy_name ($2);
 626                           struct symbol *sym;
 627                           struct minimal_symbol *msymbol;
 628
 629                           sym =
 630                             lookup_symbol (name, (const struct block *) NULL,
 631                                            VAR_NAMESPACE, (int *) NULL,
 632                                            (struct symtab **) NULL);
 633                           if (sym)
 634                             {
 635                               write_exp_elt_opcode (OP_VAR_VALUE);
 636                               write_exp_elt_block (NULL);
 637                               write_exp_elt_sym (sym);
 638                               write_exp_elt_opcode (OP_VAR_VALUE);
 639                               break;
 640                             }
 641
 642                           msymbol = lookup_minimal_symbol (name, NULL, NULL);
 643                           if (msymbol != NULL)
 644                             {
 645                               write_exp_msymbol (msymbol,
 646                                                  lookup_function_type (builtin_type_int),
 647                                                  builtin_type_int);
 648                             }
 649                           else
 650                             if (!have_full_symbols () && !have_partial_symbols ())
 651                               error ("No symbol table is loaded.  Use the \"file\" command.");
 652                             else
 653                               error ("No symbol \"%s\" in current context.", name);
 654                         }
 655         ;
 656
 657 variable:       name_not_typename
 658                         { struct symbol *sym = $1.sym;
 659
 660                           if (sym)
 661                             {
 662                               if (symbol_read_needs_frame (sym))
 663                                 {
 664                                   if (innermost_block == 0 ||
 665                                       contained_in (block_found,
 666                                                     innermost_block))
 667                                     innermost_block = block_found;
 668                                 }
 669
 670                               write_exp_elt_opcode (OP_VAR_VALUE);
 671                               /* We want to use the selected frame, not
 672                                  another more inner frame which happens to
 673                                  be in the same block.  */
 674                               write_exp_elt_block (NULL);
 675                               write_exp_elt_sym (sym);
 676                               write_exp_elt_opcode (OP_VAR_VALUE);
 677                             }
 678                           else if ($1.is_a_field_of_this)
 679                             {
 680                               /* C++: it hangs off of `this'.  Must
 681                                  not inadvertently convert from a method call
 682                                  to data ref.  */
 683                               if (innermost_block == 0 ||
 684                                   contained_in (block_found, innermost_block))
 685                                 innermost_block = block_found;
 686                               write_exp_elt_opcode (OP_THIS);
 687                               write_exp_elt_opcode (OP_THIS);
 688                               write_exp_elt_opcode (STRUCTOP_PTR);
 689                               write_exp_string ($1.stoken);
 690                               write_exp_elt_opcode (STRUCTOP_PTR);
 691                             }
 692                           else
 693                             {
 694                               struct minimal_symbol *msymbol;
 695                               register char *arg = copy_name ($1.stoken);
 696
 697                               msymbol =
 698                                 lookup_minimal_symbol (arg, NULL, NULL);
 699                               if (msymbol != NULL)
 700                                 {
 701                                   write_exp_msymbol (msymbol,
 702                                                      lookup_function_type (builtin_type_int),
 703                                                      builtin_type_int);
 704                                 }
 705                               else if (!have_full_symbols () && !have_partial_symbols ())
 706                                 error ("No symbol table is loaded.  Use the \"file\" command.");
 707                               else
 708                                 error ("No symbol \"%s\" in current context.",
 709                                        copy_name ($1.stoken));
 710                             }
 711                         }
 712         ;
 713
 714
 715 ptype   :       typebase
 716         /* "const" and "volatile" are curently ignored.  A type qualifier
 717            before the type is currently handled in the typebase rule.
 718            The reason for recognizing these here (shift/reduce conflicts)
 719            might be obsolete now that some pointer to member rules have
 720            been deleted.  */
 721         |       typebase CONST_KEYWORD
 722         |       typebase VOLATILE_KEYWORD
 723         |       typebase abs_decl
 724                 { $$ = follow_types ($1); }
 725         |       typebase CONST_KEYWORD abs_decl
 726                 { $$ = follow_types ($1); }
 727         |       typebase VOLATILE_KEYWORD abs_decl
 728                 { $$ = follow_types ($1); }
 729         ;
 730
 731 abs_decl:       '*'
 732                         { push_type (tp_pointer); $$ = 0; }
 733         |       '*' abs_decl
 734                         { push_type (tp_pointer); $$ = $2; }
 735         |       '&'
 736                         { push_type (tp_reference); $$ = 0; }
 737         |       '&' abs_decl
 738                         { push_type (tp_reference); $$ = $2; }
 739         |       direct_abs_decl
 740         ;
 741
 742 direct_abs_decl: '(' abs_decl ')'
 743                         { $$ = $2; }
 744         |       direct_abs_decl array_mod
 745                         {
 746                           push_type_int ($2);
 747                           push_type (tp_array);
 748                         }
 749         |       array_mod
 750                         {
 751                           push_type_int ($1);
 752                           push_type (tp_array);
 753                           $$ = 0;
 754                         }
 755
 756         |       direct_abs_decl func_mod
 757                         { push_type (tp_function); }
 758         |       func_mod
 759                         { push_type (tp_function); }
 760         ;
 761
 762 array_mod:      '[' ']'
 763                         { $$ = -1; }
 764         |       '[' INT ']'
 765                         { $$ = $2.val; }
 766         ;
 767
 768 func_mod:       '(' ')'
 769                         { $$ = 0; }
 770         |       '(' nonempty_typelist ')'
 771                         { free ((PTR)$2); $$ = 0; }
 772         ;
 773
 774 /* We used to try to recognize more pointer to member types here, but
 775    that didn't work (shift/reduce conflicts meant that these rules never
 776    got executed).  The problem is that
 777      int (foo::bar::baz::bizzle)
 778    is a function type but
 779      int (foo::bar::baz::bizzle::*)
 780    is a pointer to member type.  Stroustrup loses again!  */
 781
 782 type    :       ptype
 783         |       typebase COLONCOLON '*'
 784                         { $$ = lookup_member_type (builtin_type_int, $1); }
 785         ;
 786
 787 typebase  /* Implements (approximately): (type-qualifier)* type-specifier */
 788         :       TYPENAME
 789                         { $$ = $1.type; }
 790         |       INT_KEYWORD
 791                         { $$ = builtin_type_int; }
 792         |       LONG
 793                         { $$ = builtin_type_long; }
 794         |       SHORT
 795                         { $$ = builtin_type_short; }
 796         |       LONG INT_KEYWORD
 797                         { $$ = builtin_type_long; }
 798         |       UNSIGNED LONG INT_KEYWORD
 799                         { $$ = builtin_type_unsigned_long; }
 800         |       LONG LONG
 801                         { $$ = builtin_type_long_long; }
 802         |       LONG LONG INT_KEYWORD
 803                         { $$ = builtin_type_long_long; }
 804         |       UNSIGNED LONG LONG
 805                         { $$ = builtin_type_unsigned_long_long; }
 806         |       UNSIGNED LONG LONG INT_KEYWORD
 807                         { $$ = builtin_type_unsigned_long_long; }
 808         |       SHORT INT_KEYWORD
 809                         { $$ = builtin_type_short; }
 810         |       UNSIGNED SHORT INT_KEYWORD
 811                         { $$ = builtin_type_unsigned_short; }
 812         |       DOUBLE_KEYWORD
 813                         { $$ = builtin_type_double; }
 814         |       LONG DOUBLE_KEYWORD
 815                         { $$ = builtin_type_long_double; }
 816         |       STRUCT name
 817                         { $$ = lookup_struct (copy_name ($2),
 818                                               expression_context_block); }
 819         |       CLASS name
 820                         { $$ = lookup_struct (copy_name ($2),
 821                                               expression_context_block); }
 822         |       UNION name
 823                         { $$ = lookup_union (copy_name ($2),
 824                                              expression_context_block); }
 825         |       ENUM name
 826                         { $$ = lookup_enum (copy_name ($2),
 827                                             expression_context_block); }
 828         |       UNSIGNED typename
 829                         { $$ = lookup_unsigned_typename (TYPE_NAME($2.type)); }
 830         |       UNSIGNED
 831                         { $$ = builtin_type_unsigned_int; }
 832         |       SIGNED_KEYWORD typename
 833                         { $$ = lookup_signed_typename (TYPE_NAME($2.type)); }
 834         |       SIGNED_KEYWORD
 835                         { $$ = builtin_type_int; }
 836         |       TEMPLATE name '<' type '>'
 837                         { $$ = lookup_template_type(copy_name($2), $4,
 838                                                     expression_context_block);
 839                         }
 840         /* "const" and "volatile" are curently ignored.  A type qualifier
 841            after the type is handled in the ptype rule.  I think these could
 842            be too.  */
 843         |       CONST_KEYWORD typebase { $$ = $2; }
 844         |       VOLATILE_KEYWORD typebase { $$ = $2; }
 845         ;
 846
 847 typename:       TYPENAME
 848         |       INT_KEYWORD
 849                 {
 850                   $$.stoken.ptr = "int";
 851                   $$.stoken.length = 3;
 852                   $$.type = builtin_type_int;
 853                 }
 854         |       LONG
 855                 {
 856                   $$.stoken.ptr = "long";
 857                   $$.stoken.length = 4;
 858                   $$.type = builtin_type_long;
 859                 }
 860         |       SHORT
 861                 {
 862                   $$.stoken.ptr = "short";
 863                   $$.stoken.length = 5;
 864                   $$.type = builtin_type_short;
 865                 }
 866         ;
 867
 868 nonempty_typelist
 869         :       type
 870                 { $$ = (struct type **) malloc (sizeof (struct type *) * 2);
 871                   $<ivec>$[0] = 1;      /* Number of types in vector */
 872                   $$[1] = $1;
 873                 }
 874         |       nonempty_typelist ',' type
 875                 { int len = sizeof (struct type *) * (++($<ivec>1[0]) + 1);
 876                   $$ = (struct type **) realloc ((char *) $1, len);
 877                   $$[$<ivec>$[0]] = $3;
 878                 }
 879         ;
 880
 881 name    :       NAME { $$ = $1.stoken; }
 882         |       BLOCKNAME { $$ = $1.stoken; }
 883         |       TYPENAME { $$ = $1.stoken; }
 884         |       NAME_OR_INT  { $$ = $1.stoken; }
 885         ;
 886
 887 name_not_typename :     NAME
 888         |       BLOCKNAME
 889 /* These would be useful if name_not_typename was useful, but it is just
 890    a fake for "variable", so these cause reduce/reduce conflicts because
 891    the parser can't tell whether NAME_OR_INT is a name_not_typename (=variable,
 892    =exp) or just an exp.  If name_not_typename was ever used in an lvalue
 893    context where only a name could occur, this might be useful.
 894         |       NAME_OR_INT
 895  */
 896         ;
 897
 898 %%
 899
 900 /* Take care of parsing a number (anything that starts with a digit).
 901    Set yylval and return the token type; update lexptr.
 902    LEN is the number of characters in it.  */
 903
 904 /*** Needs some error checking for the float case ***/
 905
 906 static int
 907 parse_number (p, len, parsed_float, putithere)
 908      register char *p;
 909      register int len;
 910      int parsed_float;
 911      YYSTYPE *putithere;
 912 {
 913   /* FIXME: Shouldn't these be unsigned?  We don't deal with negative values
 914      here, and we do kind of silly things like cast to unsigned.  */
 915   register LONGEST n = 0;
 916   register LONGEST prevn = 0;
 917   ULONGEST un;
 918
 919   register int i = 0;
 920   register int c;
 921   register int base = input_radix;
 922   int unsigned_p = 0;
 923
 924   /* Number of "L" suffixes encountered.  */
 925   int long_p = 0;
 926
 927   /* We have found a "L" or "U" suffix.  */
 928   int found_suffix = 0;
 929
 930   ULONGEST high_bit;
 931   struct type *signed_type;
 932   struct type *unsigned_type;
 933
 934   if (parsed_float)
 935     {
 936       char c;
 937
 938       /* It's a float since it contains a point or an exponent.  */
 939
 940       if (sizeof (putithere->typed_val_float.dval) <= sizeof (float))
 941         sscanf (p, "%g", &putithere->typed_val_float.dval);
 942       else if (sizeof (putithere->typed_val_float.dval) <= sizeof (double))
 943         sscanf (p, "%lg", &putithere->typed_val_float.dval);
 944       else
 945         {
 946 #ifdef PRINTF_HAS_LONG_DOUBLE
 947           sscanf (p, "%Lg", &putithere->typed_val_float.dval);
 948 #else
 949           /* Scan it into a double, then assign it to the long double.
 950              This at least wins with values representable in the range
 951              of doubles. */
 952           double temp;
 953           sscanf (p, "%lg", &temp);
 954           putithere->typed_val_float.dval = temp;
 955 #endif
 956         }
 957
 958       /* See if it has `f' or `l' suffix (float or long double).  */
 959
 960       c = tolower (p[len - 1]);
 961
 962       if (c == 'f')
 963         putithere->typed_val_float.type = builtin_type_float;
 964       else if (c == 'l')
 965         putithere->typed_val_float.type = builtin_type_long_double;
 966       else if (isdigit (c) || c == '.')
 967         putithere->typed_val_float.type = builtin_type_double;
 968       else
 969         return ERROR;
 970
 971       return FLOAT;
 972     }
 973
 974   /* Handle base-switching prefixes 0x, 0t, 0d, 0 */
 975   if (p[0] == '0')
 976     switch (p[1])
 977       {
 978       case 'x':
 979       case 'X':
 980         if (len >= 3)
 981           {
 982             p += 2;
 983             base = 16;
 984             len -= 2;
 985           }
 986         break;
 987
 988       case 't':
 989       case 'T':
 990       case 'd':
 991       case 'D':
 992         if (len >= 3)
 993           {
 994             p += 2;
 995             base = 10;
 996             len -= 2;
 997           }
 998         break;
 999
1000       default:
1001         base = 8;
1002         break;
1003       }
1004
1005   while (len-- > 0)
1006     {
1007       c = *p++;
1008       if (c >= 'A' && c <= 'Z')
1009         c += 'a' - 'A';
1010       if (c != 'l' && c != 'u')
1011         n *= base;
1012       if (c >= '0' && c <= '9')
1013         {
1014           if (found_suffix)
1015             return ERROR;
1016           n += i = c - '0';
1017         }
1018       else
1019         {
1020           if (base > 10 && c >= 'a' && c <= 'f')
1021             {
1022               if (found_suffix)
1023                 return ERROR;
1024               n += i = c - 'a' + 10;
1025             }
1026           else if (c == 'l')
1027             {
1028               ++long_p;
1029               found_suffix = 1;
1030             }
1031           else if (c == 'u')
1032             {
1033               unsigned_p = 1;
1034               found_suffix = 1;
1035             }
1036           else
1037             return ERROR;       /* Char not a digit */
1038         }
1039       if (i >= base)
1040         return ERROR;           /* Invalid digit in this base */
1041
1042       /* Portably test for overflow (only works for nonzero values, so make
1043          a second check for zero).  FIXME: Can't we just make n and prevn
1044          unsigned and avoid this?  */
1045       if (c != 'l' && c != 'u' && (prevn >= n) && n != 0)
1046         unsigned_p = 1;         /* Try something unsigned */
1047
1048       /* Portably test for unsigned overflow.
1049          FIXME: This check is wrong; for example it doesn't find overflow
1050          on 0x123456789 when LONGEST is 32 bits.  */
1051       if (c != 'l' && c != 'u' && n != 0)
1052         {
1053           if ((unsigned_p && (ULONGEST) prevn >= (ULONGEST) n))
1054             error ("Numeric constant too large.");
1055         }
1056       prevn = n;
1057     }
1058
1059   /* An integer constant is an int, a long, or a long long.  An L
1060      suffix forces it to be long; an LL suffix forces it to be long
1061      long.  If not forced to a larger size, it gets the first type of
1062      the above that it fits in.  To figure out whether it fits, we
1063      shift it right and see whether anything remains.  Note that we
1064      can't shift sizeof (LONGEST) * HOST_CHAR_BIT bits or more in one
1065      operation, because many compilers will warn about such a shift
1066      (which always produces a zero result).  Sometimes TARGET_INT_BIT
1067      or TARGET_LONG_BIT will be that big, sometimes not.  To deal with
1068      the case where it is we just always shift the value more than
1069      once, with fewer bits each time.  */
1070
1071   un = (ULONGEST)n >> 2;
1072   if (long_p == 0
1073       && (un >> (TARGET_INT_BIT - 2)) == 0)
1074     {
1075       high_bit = ((ULONGEST)1) << (TARGET_INT_BIT-1);
1076
1077       /* A large decimal (not hex or octal) constant (between INT_MAX
1078          and UINT_MAX) is a long or unsigned long, according to ANSI,
1079          never an unsigned int, but this code treats it as unsigned
1080          int.  This probably should be fixed.  GCC gives a warning on
1081          such constants.  */
1082
1083       unsigned_type = builtin_type_unsigned_int;
1084       signed_type = builtin_type_int;
1085     }
1086   else if (long_p <= 1
1087            && (un >> (TARGET_LONG_BIT - 2)) == 0)
1088     {
1089       high_bit = ((ULONGEST)1) << (TARGET_LONG_BIT-1);
1090       unsigned_type = builtin_type_unsigned_long;
1091       signed_type = builtin_type_long;
1092     }
1093   else
1094     {
1095       high_bit = (((ULONGEST)1)
1096                   << (TARGET_LONG_LONG_BIT - 32 - 1)
1097                   << 16
1098                   << 16);
1099       if (high_bit == 0)
1100         /* A long long does not fit in a LONGEST.  */
1101         high_bit =
1102           (ULONGEST)1 << (sizeof (LONGEST) * HOST_CHAR_BIT - 1);
1103       unsigned_type = builtin_type_unsigned_long_long;
1104       signed_type = builtin_type_long_long;
1105     }
1106
1107    putithere->typed_val_int.val = n;
1108
1109    /* If the high bit of the worked out type is set then this number
1110       has to be unsigned. */
1111
1112    if (unsigned_p || (n & high_bit))
1113      {
1114        putithere->typed_val_int.type = unsigned_type;
1115      }
1116    else
1117      {
1118        putithere->typed_val_int.type = signed_type;
1119      }
1120
1121    return INT;
1122 }
1123
1124 struct token
1125 {
1126   char *operator;
1127   int token;
1128   enum exp_opcode opcode;
1129 };
1130
1131 static const struct token tokentab3[] =
1132   {
1133     {">>=", ASSIGN_MODIFY, BINOP_RSH},
1134     {"<<=", ASSIGN_MODIFY, BINOP_LSH}
1135   };
1136
1137 static const struct token tokentab2[] =
1138   {
1139     {"+=", ASSIGN_MODIFY, BINOP_ADD},
1140     {"-=", ASSIGN_MODIFY, BINOP_SUB},
1141     {"*=", ASSIGN_MODIFY, BINOP_MUL},
1142     {"/=", ASSIGN_MODIFY, BINOP_DIV},
1143     {"%=", ASSIGN_MODIFY, BINOP_REM},
1144     {"|=", ASSIGN_MODIFY, BINOP_BITWISE_IOR},
1145     {"&=", ASSIGN_MODIFY, BINOP_BITWISE_AND},
1146     {"^=", ASSIGN_MODIFY, BINOP_BITWISE_XOR},
1147     {"++", INCREMENT, BINOP_END},
1148     {"--", DECREMENT, BINOP_END},
1149     {"->", ARROW, BINOP_END},
1150     {"&&", ANDAND, BINOP_END},
1151     {"||", OROR, BINOP_END},
1152     {"::", COLONCOLON, BINOP_END},
1153     {"<<", LSH, BINOP_END},
1154     {">>", RSH, BINOP_END},
1155     {"==", EQUAL, BINOP_END},
1156     {"!=", NOTEQUAL, BINOP_END},
1157     {"<=", LEQ, BINOP_END},
1158     {">=", GEQ, BINOP_END}
1159   };
1160
1161 /* Read one token, getting characters through lexptr.  */
1162
1163 static int
1164 yylex ()
1165 {
1166   int c;
1167   int namelen;
1168   unsigned int i;
1169   char *tokstart;
1170   char *tokptr;
1171   int tempbufindex;
1172   static char *tempbuf;
1173   static int tempbufsize;
1174
1175  retry:
1176
1177   tokstart = lexptr;
1178   /* See if it is a special token of length 3.  */
1179   for (i = 0; i < sizeof tokentab3 / sizeof tokentab3[0]; i++)
1180     if (STREQN (tokstart, tokentab3[i].operator, 3))
1181       {
1182         lexptr += 3;
1183         yylval.opcode = tokentab3[i].opcode;
1184         return tokentab3[i].token;
1185       }
1186
1187   /* See if it is a special token of length 2.  */
1188   for (i = 0; i < sizeof tokentab2 / sizeof tokentab2[0]; i++)
1189     if (STREQN (tokstart, tokentab2[i].operator, 2))
1190       {
1191         lexptr += 2;
1192         yylval.opcode = tokentab2[i].opcode;
1193         return tokentab2[i].token;
1194       }
1195
1196   switch (c = *tokstart)
1197     {
1198     case 0:
1199       return 0;
1200
1201     case ' ':
1202     case '\t':
1203     case '\n':
1204       lexptr++;
1205       goto retry;
1206
1207     case '\'':
1208       /* We either have a character constant ('0' or '\177' for example)
1209          or we have a quoted symbol reference ('foo(int,int)' in C++
1210          for example). */
1211       lexptr++;
1212       c = *lexptr++;
1213       if (c == '\\')
1214         c = parse_escape (&lexptr);
1215       else if (c == '\'')
1216         error ("Empty character constant.");
1217
1218       yylval.typed_val_int.val = c;
1219       yylval.typed_val_int.type = builtin_type_char;
1220
1221       c = *lexptr++;
1222       if (c != '\'')
1223         {
1224           namelen = skip_quoted (tokstart) - tokstart;
1225           if (namelen > 2)
1226             {
1227               lexptr = tokstart + namelen;
1228               if (lexptr[-1] != '\'')
1229                 error ("Unmatched single quote.");
1230               namelen -= 2;
1231               tokstart++;
1232               goto tryname;
1233             }
1234           error ("Invalid character constant.");
1235         }
1236       return INT;
1237
1238     case '(':
1239       paren_depth++;
1240       lexptr++;
1241       return c;
1242
1243     case ')':
1244       if (paren_depth == 0)
1245         return 0;
1246       paren_depth--;
1247       lexptr++;
1248       return c;
1249
1250     case ',':
1251       if (comma_terminates && paren_depth == 0)
1252         return 0;
1253       lexptr++;
1254       return c;
1255
1256     case '.':
1257       /* Might be a floating point number.  */
1258       if (lexptr[1] < '0' || lexptr[1] > '9')
1259         goto symbol;            /* Nope, must be a symbol. */
1260       /* FALL THRU into number case.  */
1261
1262     case '0':
1263     case '1':
1264     case '2':
1265     case '3':
1266     case '4':
1267     case '5':
1268     case '6':
1269     case '7':
1270     case '8':
1271     case '9':
1272       {
1273         /* It's a number.  */
1274         int got_dot = 0, got_e = 0, toktype;
1275         register char *p = tokstart;
1276         int hex = input_radix > 10;
1277
1278         if (c == '0' && (p[1] == 'x' || p[1] == 'X'))
1279           {
1280             p += 2;
1281             hex = 1;
1282           }
1283         else if (c == '0' && (p[1]=='t' || p[1]=='T' || p[1]=='d' || p[1]=='D'))
1284           {
1285             p += 2;
1286             hex = 0;
1287           }
1288
1289         for (;; ++p)
1290           {
1291             /* This test includes !hex because 'e' is a valid hex digit
1292                and thus does not indicate a floating point number when
1293                the radix is hex.  */
1294             if (!hex && !got_e && (*p == 'e' || *p == 'E'))
1295               got_dot = got_e = 1;
1296             /* This test does not include !hex, because a '.' always indicates
1297                a decimal floating point number regardless of the radix.  */
1298             else if (!got_dot && *p == '.')
1299               got_dot = 1;
1300             else if (got_e && (p[-1] == 'e' || p[-1] == 'E')
1301                      && (*p == '-' || *p == '+'))
1302               /* This is the sign of the exponent, not the end of the
1303                  number.  */
1304               continue;
1305             /* We will take any letters or digits.  parse_number will
1306                complain if past the radix, or if L or U are not final.  */
1307             else if ((*p < '0' || *p > '9')
1308                      && ((*p < 'a' || *p > 'z')
1309                                   && (*p < 'A' || *p > 'Z')))
1310               break;
1311           }
1312         toktype = parse_number (tokstart, p - tokstart, got_dot|got_e, &yylval);
1313         if (toktype == ERROR)
1314           {
1315             char *err_copy = (char *) alloca (p - tokstart + 1);
1316
1317             memcpy (err_copy, tokstart, p - tokstart);
1318             err_copy[p - tokstart] = 0;
1319             error ("Invalid number \"%s\".", err_copy);
1320           }
1321         lexptr = p;
1322         return toktype;
1323       }
1324
1325     case '+':
1326     case '-':
1327     case '*':
1328     case '/':
1329     case '%':
1330     case '|':
1331     case '&':
1332     case '^':
1333     case '~':
1334     case '!':
1335     case '@':
1336     case '<':
1337     case '>':
1338     case '[':
1339     case ']':
1340     case '?':
1341     case ':':
1342     case '=':
1343     case '{':
1344     case '}':
1345     symbol:
1346       lexptr++;
1347       return c;
1348
1349     case '"':
1350
1351       /* Build the gdb internal form of the input string in tempbuf,
1352          translating any standard C escape forms seen.  Note that the
1353          buffer is null byte terminated *only* for the convenience of
1354          debugging gdb itself and printing the buffer contents when
1355          the buffer contains no embedded nulls.  Gdb does not depend
1356          upon the buffer being null byte terminated, it uses the length
1357          string instead.  This allows gdb to handle C strings (as well
1358          as strings in other languages) with embedded null bytes */
1359
1360       tokptr = ++tokstart;
1361       tempbufindex = 0;
1362
1363       do {
1364         /* Grow the static temp buffer if necessary, including allocating
1365            the first one on demand. */
1366         if (tempbufindex + 1 >= tempbufsize)
1367           {
1368             tempbuf = (char *) realloc (tempbuf, tempbufsize += 64);
1369           }
1370         switch (*tokptr)
1371           {
1372           case '\0':
1373           case '"':
1374             /* Do nothing, loop will terminate. */
1375             break;
1376           case '\\':
1377             tokptr++;
1378             c = parse_escape (&tokptr);
1379             if (c == -1)
1380               {
1381                 continue;
1382               }
1383             tempbuf[tempbufindex++] = c;
1384             break;
1385           default:
1386             tempbuf[tempbufindex++] = *tokptr++;
1387             break;
1388           }
1389       } while ((*tokptr != '"') && (*tokptr != '\0'));
1390       if (*tokptr++ != '"')
1391         {
1392           error ("Unterminated string in expression.");
1393         }
1394       tempbuf[tempbufindex] = '\0';     /* See note above */
1395       yylval.sval.ptr = tempbuf;
1396       yylval.sval.length = tempbufindex;
1397       lexptr = tokptr;
1398       return (STRING);
1399     }
1400
1401   if (!(c == '_' || c == '$'
1402         || (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')))
1403     /* We must have come across a bad character (e.g. ';').  */
1404     error ("Invalid character '%c' in expression.", c);
1405
1406   /* It's a name.  See how long it is.  */
1407   namelen = 0;
1408   for (c = tokstart[namelen];
1409        (c == '_' || c == '$' || (c >= '0' && c <= '9')
1410         || (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '<');)
1411     {
1412       /* Template parameter lists are part of the name.
1413          FIXME: This mishandles `print $a<4&&$a>3'.  */
1414
1415       if (c == '<')
1416         {
1417           int i = namelen;
1418           int nesting_level = 1;
1419           while (tokstart[++i])
1420             {
1421               if (tokstart[i] == '<')
1422                 nesting_level++;
1423               else if (tokstart[i] == '>')
1424                 {
1425                   if (--nesting_level == 0)
1426                     break;
1427                 }
1428             }
1429           if (tokstart[i] == '>')
1430             namelen = i;
1431           else
1432             break;
1433         }
1434       c = tokstart[++namelen];
1435     }
1436
1437   /* The token "if" terminates the expression and is NOT
1438      removed from the input stream.  */
1439   if (namelen == 2 && tokstart[0] == 'i' && tokstart[1] == 'f')
1440     {
1441       return 0;
1442     }
1443
1444   lexptr += namelen;
1445
1446   tryname:
1447
1448   /* Catch specific keywords.  Should be done with a data structure.  */
1449   switch (namelen)
1450     {
1451     case 8:
1452       if (STREQN (tokstart, "unsigned", 8))
1453         return UNSIGNED;
1454       if (current_language->la_language == language_cplus
1455           && STREQN (tokstart, "template", 8))
1456         return TEMPLATE;
1457       if (STREQN (tokstart, "volatile", 8))
1458         return VOLATILE_KEYWORD;
1459       break;
1460     case 6:
1461       if (STREQN (tokstart, "struct", 6))
1462         return STRUCT;
1463       if (STREQN (tokstart, "signed", 6))
1464         return SIGNED_KEYWORD;
1465       if (STREQN (tokstart, "sizeof", 6))
1466         return SIZEOF;
1467       if (STREQN (tokstart, "double", 6))
1468         return DOUBLE_KEYWORD;
1469       break;
1470     case 5:
1471       if (current_language->la_language == language_cplus
1472           && STREQN (tokstart, "class", 5))
1473         return CLASS;
1474       if (STREQN (tokstart, "union", 5))
1475         return UNION;
1476       if (STREQN (tokstart, "short", 5))
1477         return SHORT;
1478       if (STREQN (tokstart, "const", 5))
1479         return CONST_KEYWORD;
1480       break;
1481     case 4:
1482       if (STREQN (tokstart, "enum", 4))
1483         return ENUM;
1484       if (STREQN (tokstart, "long", 4))
1485         return LONG;
1486       if (current_language->la_language == language_cplus
1487           && STREQN (tokstart, "this", 4))
1488         {
1489           static const char this_name[] =
1490                                  { CPLUS_MARKER, 't', 'h', 'i', 's', '\0' };
1491
1492           if (lookup_symbol (this_name, expression_context_block,
1493                              VAR_NAMESPACE, (int *) NULL,
1494                              (struct symtab **) NULL))
1495             return THIS;
1496         }
1497       break;
1498     case 3:
1499       if (STREQN (tokstart, "int", 3))
1500         return INT_KEYWORD;
1501       break;
1502     default:
1503       break;
1504     }
1505
1506   yylval.sval.ptr = tokstart;
1507   yylval.sval.length = namelen;
1508
1509   if (*tokstart == '$')
1510     {
1511       write_dollar_variable (yylval.sval);
1512       return VARIABLE;
1513     }
1514
1515   /* Use token-type BLOCKNAME for symbols that happen to be defined as
1516      functions or symtabs.  If this is not so, then ...
1517      Use token-type TYPENAME for symbols that happen to be defined
1518      currently as names of types; NAME for other symbols.
1519      The caller is not constrained to care about the distinction.  */
1520   {
1521     char *tmp = copy_name (yylval.sval);
1522     struct symbol *sym;
1523     int is_a_field_of_this = 0;
1524     int hextype;
1525
1526     sym = lookup_symbol (tmp, expression_context_block,
1527                          VAR_NAMESPACE,
1528                          current_language->la_language == language_cplus
1529                          ? &is_a_field_of_this : (int *) NULL,
1530                          (struct symtab **) NULL);
1531     /* Call lookup_symtab, not lookup_partial_symtab, in case there are
1532        no psymtabs (coff, xcoff, or some future change to blow away the
1533        psymtabs once once symbols are read).  */
1534     if ((sym && SYMBOL_CLASS (sym) == LOC_BLOCK) ||
1535         lookup_symtab (tmp))
1536       {
1537         yylval.ssym.sym = sym;
1538         yylval.ssym.is_a_field_of_this = is_a_field_of_this;
1539         return BLOCKNAME;
1540       }
1541     if (sym && SYMBOL_CLASS (sym) == LOC_TYPEDEF)
1542         {
1543 #if 1
1544           /* Despite the following flaw, we need to keep this code enabled.
1545              Because we can get called from check_stub_method, if we don't
1546              handle nested types then it screws many operations in any
1547              program which uses nested types.  */
1548           /* In "A::x", if x is a member function of A and there happens
1549              to be a type (nested or not, since the stabs don't make that
1550              distinction) named x, then this code incorrectly thinks we
1551              are dealing with nested types rather than a member function.  */
1552
1553           char *p;
1554           char *namestart;
1555           struct symbol *best_sym;
1556
1557           /* Look ahead to detect nested types.  This probably should be
1558              done in the grammar, but trying seemed to introduce a lot
1559              of shift/reduce and reduce/reduce conflicts.  It's possible
1560              that it could be done, though.  Or perhaps a non-grammar, but
1561              less ad hoc, approach would work well.  */
1562
1563           /* Since we do not currently have any way of distinguishing
1564              a nested type from a non-nested one (the stabs don't tell
1565              us whether a type is nested), we just ignore the
1566              containing type.  */
1567
1568           p = lexptr;
1569           best_sym = sym;
1570           while (1)
1571             {
1572               /* Skip whitespace.  */
1573               while (*p == ' ' || *p == '\t' || *p == '\n')
1574                 ++p;
1575               if (*p == ':' && p[1] == ':')
1576                 {
1577                   /* Skip the `::'.  */
1578                   p += 2;
1579                   /* Skip whitespace.  */
1580                   while (*p == ' ' || *p == '\t' || *p == '\n')
1581                     ++p;
1582                   namestart = p;
1583                   while (*p == '_' || *p == '$' || (*p >= '0' && *p <= '9')
1584                          || (*p >= 'a' && *p <= 'z')
1585                          || (*p >= 'A' && *p <= 'Z'))
1586                     ++p;
1587                   if (p != namestart)
1588                     {
1589                       struct symbol *cur_sym;
1590                       /* As big as the whole rest of the expression, which is
1591                          at least big enough.  */
1592                       char *ncopy = alloca (strlen (tmp)+strlen (namestart)+3);
1593                       char *tmp1;
1594
1595                       tmp1 = ncopy;
1596                       memcpy (tmp1, tmp, strlen (tmp));
1597                       tmp1 += strlen (tmp);
1598                       memcpy (tmp1, "::", 2);
1599                       tmp1 += 2;
1600                       memcpy (tmp1, namestart, p - namestart);
1601                       tmp1[p - namestart] = '\0';
1602                       cur_sym = lookup_symbol (ncopy, expression_context_block,
1603                                                VAR_NAMESPACE, (int *) NULL,
1604                                                (struct symtab **) NULL);
1605                       if (cur_sym)
1606                         {
1607                           if (SYMBOL_CLASS (cur_sym) == LOC_TYPEDEF)
1608                             {
1609                               best_sym = cur_sym;
1610                               lexptr = p;
1611                             }
1612                           else
1613                             break;
1614                         }
1615                       else
1616                         break;
1617                     }
1618                   else
1619                     break;
1620                 }
1621               else
1622                 break;
1623             }
1624
1625           yylval.tsym.type = SYMBOL_TYPE (best_sym);
1626 #else /* not 0 */
1627           yylval.tsym.type = SYMBOL_TYPE (sym);
1628 #endif /* not 0 */
1629           return TYPENAME;
1630         }
1631     if ((yylval.tsym.type = lookup_primitive_typename (tmp)) != 0)
1632         return TYPENAME;
1633
1634     /* Input names that aren't symbols but ARE valid hex numbers,
1635        when the input radix permits them, can be names or numbers
1636        depending on the parse.  Note we support radixes > 16 here.  */
1637     if (!sym &&
1638         ((tokstart[0] >= 'a' && tokstart[0] < 'a' + input_radix - 10) ||
1639          (tokstart[0] >= 'A' && tokstart[0] < 'A' + input_radix - 10)))
1640       {
1641         YYSTYPE newlval;        /* Its value is ignored.  */
1642         hextype = parse_number (tokstart, namelen, 0, &newlval);
1643         if (hextype == INT)
1644           {
1645             yylval.ssym.sym = sym;
1646             yylval.ssym.is_a_field_of_this = is_a_field_of_this;
1647             return NAME_OR_INT;
1648           }
1649       }
1650
1651     /* Any other kind of symbol */
1652     yylval.ssym.sym = sym;
1653     yylval.ssym.is_a_field_of_this = is_a_field_of_this;
1654     return NAME;
1655   }
1656 }
1657
1658 void
1659 yyerror (msg)
1660      char *msg;
1661 {
1662   error ("A %s in expression, near `%s'.", (msg ? msg : "error"), lexptr);
1663 }