gdb/c-exp.y

   1 /* YACC parser for C expressions, for GDB.
   2    Copyright (C) 1986, 1989, 1990, 1991, 1993, 1994
   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 <string.h>
  42 #include "expression.h"
  43 #include "value.h"
  44 #include "parser-defs.h"
  45 #include "language.h"
  46 #include "c-lang.h"
  47 #include "bfd.h" /* Required by objfiles.h.  */
  48 #include "symfile.h" /* Required by objfiles.h.  */
  49 #include "objfiles.h" /* For have_full_symbols and have_partial_symbols */
  50
  51 /* Remap normal yacc parser interface names (yyparse, yylex, yyerror, etc),
  52    as well as gratuitiously global symbol names, so we can have multiple
  53    yacc generated parsers in gdb.  Note that these are only the variables
  54    produced by yacc.  If other parser generators (bison, byacc, etc) produce
  55    additional global names that conflict at link time, then those parser
  56    generators need to be fixed instead of adding those names to this list. */
  57
  58 #define yymaxdepth c_maxdepth
  59 #define yyparse c_parse
  60 #define yylex   c_lex
  61 #define yyerror c_error
  62 #define yylval  c_lval
  63 #define yychar  c_char
  64 #define yydebug c_debug
  65 #define yypact  c_pact
  66 #define yyr1    c_r1
  67 #define yyr2    c_r2
  68 #define yydef   c_def
  69 #define yychk   c_chk
  70 #define yypgo   c_pgo
  71 #define yyact   c_act
  72 #define yyexca  c_exca
  73 #define yyerrflag c_errflag
  74 #define yynerrs c_nerrs
  75 #define yyps    c_ps
  76 #define yypv    c_pv
  77 #define yys     c_s
  78 #define yy_yys  c_yys
  79 #define yystate c_state
  80 #define yytmp   c_tmp
  81 #define yyv     c_v
  82 #define yy_yyv  c_yyv
  83 #define yyval   c_val
  84 #define yylloc  c_lloc
  85 #define yyreds  c_reds          /* With YYDEBUG defined */
  86 #define yytoks  c_toks          /* With YYDEBUG defined */
  87 #define yylhs   c_yylhs
  88 #define yylen   c_yylen
  89 #define yydefred c_yydefred
  90 #define yydgoto c_yydgoto
  91 #define yysindex c_yysindex
  92 #define yyrindex c_yyrindex
  93 #define yygindex c_yygindex
  94 #define yytable  c_yytable
  95 #define yycheck  c_yycheck
  96
  97 #ifndef YYDEBUG
  98 #define YYDEBUG 0               /* Default to no yydebug support */
  99 #endif
 100
 101 int
 102 yyparse PARAMS ((void));
 103
 104 static int
 105 yylex PARAMS ((void));
 106
 107 void
 108 yyerror PARAMS ((char *));
 109
 110 %}
 111
 112 /* Although the yacc "value" of an expression is not used,
 113    since the result is stored in the structure being created,
 114    other node types do have values.  */
 115
 116 %union
 117   {
 118     LONGEST lval;
 119     struct {
 120       LONGEST val;
 121       struct type *type;
 122     } typed_val_int;
 123     struct {
 124       DOUBLEST dval;
 125       struct type *type;
 126     } typed_val_float;
 127     struct symbol *sym;
 128     struct type *tval;
 129     struct stoken sval;
 130     struct ttype tsym;
 131     struct symtoken ssym;
 132     int voidval;
 133     struct block *bval;
 134     enum exp_opcode opcode;
 135     struct internalvar *ivar;
 136
 137     struct type **tvec;
 138     int *ivec;
 139   }
 140
 141 %{
 142 /* YYSTYPE gets defined by %union */
 143 static int
 144 parse_number PARAMS ((char *, int, int, YYSTYPE *));
 145 %}
 146
 147 %type <voidval> exp exp1 type_exp start variable qualified_name lcurly
 148 %type <lval> rcurly
 149 %type <tval> type typebase
 150 %type <tvec> nonempty_typelist
 151 /* %type <bval> block */
 152
 153 /* Fancy type parsing.  */
 154 %type <voidval> func_mod direct_abs_decl abs_decl
 155 %type <tval> ptype
 156 %type <lval> array_mod
 157
 158 %token <typed_val_int> INT
 159 %token <typed_val_float> FLOAT
 160
 161 /* Both NAME and TYPENAME tokens represent symbols in the input,
 162    and both convey their data as strings.
 163    But a TYPENAME is a string that happens to be defined as a typedef
 164    or builtin type name (such as int or char)
 165    and a NAME is any other symbol.
 166    Contexts where this distinction is not important can use the
 167    nonterminal "name", which matches either NAME or TYPENAME.  */
 168
 169 %token <sval> STRING
 170 %token <ssym> NAME /* BLOCKNAME defined below to give it higher precedence. */
 171 %token <tsym> TYPENAME
 172 %type <sval> name
 173 %type <ssym> name_not_typename
 174 %type <tsym> typename
 175
 176 /* A NAME_OR_INT is a symbol which is not known in the symbol table,
 177    but which would parse as a valid number in the current input radix.
 178    E.g. "c" when input_radix==16.  Depending on the parse, it will be
 179    turned into a name or into a number.  */
 180
 181 %token <ssym> NAME_OR_INT
 182
 183 %token STRUCT CLASS UNION ENUM SIZEOF UNSIGNED COLONCOLON
 184 %token TEMPLATE
 185 %token ERROR
 186
 187 /* Special type cases, put in to allow the parser to distinguish different
 188    legal basetypes.  */
 189 %token SIGNED_KEYWORD LONG SHORT INT_KEYWORD CONST_KEYWORD VOLATILE_KEYWORD DOUBLE_KEYWORD
 190
 191 %token <voidval> VARIABLE
 192
 193 %token <opcode> ASSIGN_MODIFY
 194
 195 /* C++ */
 196 %token THIS
 197
 198 %left ','
 199 %left ABOVE_COMMA
 200 %right '=' ASSIGN_MODIFY
 201 %right '?'
 202 %left OROR
 203 %left ANDAND
 204 %left '|'
 205 %left '^'
 206 %left '&'
 207 %left EQUAL NOTEQUAL
 208 %left '<' '>' LEQ GEQ
 209 %left LSH RSH
 210 %left '@'
 211 %left '+' '-'
 212 %left '*' '/' '%'
 213 %right UNARY INCREMENT DECREMENT
 214 %right ARROW '.' '[' '('
 215 %token <ssym> BLOCKNAME
 216 %type <bval> block
 217 %left COLONCOLON
 218
 219 \f
 220 %%
 221
 222 start   :       exp1
 223         |       type_exp
 224         ;
 225
 226 type_exp:       type
 227                         { write_exp_elt_opcode(OP_TYPE);
 228                           write_exp_elt_type($1);
 229                           write_exp_elt_opcode(OP_TYPE);}
 230         ;
 231
 232 /* Expressions, including the comma operator.  */
 233 exp1    :       exp
 234         |       exp1 ',' exp
 235                         { write_exp_elt_opcode (BINOP_COMMA); }
 236         ;
 237
 238 /* Expressions, not including the comma operator.  */
 239 exp     :       '*' exp    %prec UNARY
 240                         { write_exp_elt_opcode (UNOP_IND); }
 241
 242 exp     :       '&' exp    %prec UNARY
 243                         { write_exp_elt_opcode (UNOP_ADDR); }
 244
 245 exp     :       '-' exp    %prec UNARY
 246                         { write_exp_elt_opcode (UNOP_NEG); }
 247         ;
 248
 249 exp     :       '!' exp    %prec UNARY
 250                         { write_exp_elt_opcode (UNOP_LOGICAL_NOT); }
 251         ;
 252
 253 exp     :       '~' exp    %prec UNARY
 254                         { write_exp_elt_opcode (UNOP_COMPLEMENT); }
 255         ;
 256
 257 exp     :       INCREMENT exp    %prec UNARY
 258                         { write_exp_elt_opcode (UNOP_PREINCREMENT); }
 259         ;
 260
 261 exp     :       DECREMENT exp    %prec UNARY
 262                         { write_exp_elt_opcode (UNOP_PREDECREMENT); }
 263         ;
 264
 265 exp     :       exp INCREMENT    %prec UNARY
 266                         { write_exp_elt_opcode (UNOP_POSTINCREMENT); }
 267         ;
 268
 269 exp     :       exp DECREMENT    %prec UNARY
 270                         { write_exp_elt_opcode (UNOP_POSTDECREMENT); }
 271         ;
 272
 273 exp     :       SIZEOF exp       %prec UNARY
 274                         { write_exp_elt_opcode (UNOP_SIZEOF); }
 275         ;
 276
 277 exp     :       exp ARROW name
 278                         { write_exp_elt_opcode (STRUCTOP_PTR);
 279                           write_exp_string ($3);
 280                           write_exp_elt_opcode (STRUCTOP_PTR); }
 281         ;
 282
 283 exp     :       exp ARROW qualified_name
 284                         { /* exp->type::name becomes exp->*(&type::name) */
 285                           /* Note: this doesn't work if name is a
 286                              static member!  FIXME */
 287                           write_exp_elt_opcode (UNOP_ADDR);
 288                           write_exp_elt_opcode (STRUCTOP_MPTR); }
 289         ;
 290 exp     :       exp ARROW '*' exp
 291                         { write_exp_elt_opcode (STRUCTOP_MPTR); }
 292         ;
 293
 294 exp     :       exp '.' name
 295                         { write_exp_elt_opcode (STRUCTOP_STRUCT);
 296                           write_exp_string ($3);
 297                           write_exp_elt_opcode (STRUCTOP_STRUCT); }
 298         ;
 299
 300 /* start-sanitize-gm
 301 Need to find a better way to do this...
 302 exp     :       exp '@' name
 303                         { write_exp_elt_opcode (STRUCTOP_FIELD);
 304                           write_exp_string ($3);
 305                           write_exp_elt_opcode (STRUCTOP_FIELD);
 306                         }
 307  end-sanitize-gm */
 308
 309 exp     :       exp '.' qualified_name
 310                         { /* exp.type::name becomes exp.*(&type::name) */
 311                           /* Note: this doesn't work if name is a
 312                              static member!  FIXME */
 313                           write_exp_elt_opcode (UNOP_ADDR);
 314                           write_exp_elt_opcode (STRUCTOP_MEMBER); }
 315         ;
 316
 317 exp     :       exp '.' '*' exp
 318                         { write_exp_elt_opcode (STRUCTOP_MEMBER); }
 319         ;
 320
 321 exp     :       exp '[' exp1 ']'
 322                         { write_exp_elt_opcode (BINOP_SUBSCRIPT); }
 323         ;
 324
 325 exp     :       exp '('
 326                         /* This is to save the value of arglist_len
 327                            being accumulated by an outer function call.  */
 328                         { start_arglist (); }
 329                 arglist ')'     %prec ARROW
 330                         { write_exp_elt_opcode (OP_FUNCALL);
 331                           write_exp_elt_longcst ((LONGEST) end_arglist ());
 332                           write_exp_elt_opcode (OP_FUNCALL); }
 333         ;
 334
 335 lcurly  :       '{'
 336                         { start_arglist (); }
 337         ;
 338
 339 arglist :
 340         ;
 341
 342 arglist :       exp
 343                         { arglist_len = 1; }
 344         ;
 345
 346 arglist :       arglist ',' exp   %prec ABOVE_COMMA
 347                         { arglist_len++; }
 348         ;
 349
 350 rcurly  :       '}'
 351                         { $$ = end_arglist () - 1; }
 352         ;
 353 exp     :       lcurly arglist rcurly   %prec ARROW
 354                         { write_exp_elt_opcode (OP_ARRAY);
 355                           write_exp_elt_longcst ((LONGEST) 0);
 356                           write_exp_elt_longcst ((LONGEST) $3);
 357                           write_exp_elt_opcode (OP_ARRAY); }
 358         ;
 359
 360 exp     :       lcurly type rcurly exp  %prec UNARY
 361                         { write_exp_elt_opcode (UNOP_MEMVAL);
 362                           write_exp_elt_type ($2);
 363                           write_exp_elt_opcode (UNOP_MEMVAL); }
 364         ;
 365
 366 exp     :       '(' type ')' exp  %prec UNARY
 367                         { write_exp_elt_opcode (UNOP_CAST);
 368                           write_exp_elt_type ($2);
 369                           write_exp_elt_opcode (UNOP_CAST); }
 370         ;
 371
 372 exp     :       '(' exp1 ')'
 373                         { }
 374         ;
 375
 376 /* Binary operators in order of decreasing precedence.  */
 377
 378 exp     :       exp '@' exp
 379                         { write_exp_elt_opcode (BINOP_REPEAT); }
 380         ;
 381
 382 exp     :       exp '*' exp
 383                         { write_exp_elt_opcode (BINOP_MUL); }
 384         ;
 385
 386 exp     :       exp '/' exp
 387                         { write_exp_elt_opcode (BINOP_DIV); }
 388         ;
 389
 390 exp     :       exp '%' exp
 391                         { write_exp_elt_opcode (BINOP_REM); }
 392         ;
 393
 394 exp     :       exp '+' exp
 395                         { write_exp_elt_opcode (BINOP_ADD); }
 396         ;
 397
 398 exp     :       exp '-' exp
 399                         { write_exp_elt_opcode (BINOP_SUB); }
 400         ;
 401
 402 exp     :       exp LSH exp
 403                         { write_exp_elt_opcode (BINOP_LSH); }
 404         ;
 405
 406 exp     :       exp RSH exp
 407                         { write_exp_elt_opcode (BINOP_RSH); }
 408         ;
 409
 410 exp     :       exp EQUAL exp
 411                         { write_exp_elt_opcode (BINOP_EQUAL); }
 412         ;
 413
 414 exp     :       exp NOTEQUAL exp
 415                         { write_exp_elt_opcode (BINOP_NOTEQUAL); }
 416         ;
 417
 418 exp     :       exp LEQ exp
 419                         { write_exp_elt_opcode (BINOP_LEQ); }
 420         ;
 421
 422 exp     :       exp GEQ exp
 423                         { write_exp_elt_opcode (BINOP_GEQ); }
 424         ;
 425
 426 exp     :       exp '<' exp
 427                         { write_exp_elt_opcode (BINOP_LESS); }
 428         ;
 429
 430 exp     :       exp '>' exp
 431                         { write_exp_elt_opcode (BINOP_GTR); }
 432         ;
 433
 434 exp     :       exp '&' exp
 435                         { write_exp_elt_opcode (BINOP_BITWISE_AND); }
 436         ;
 437
 438 exp     :       exp '^' exp
 439                         { write_exp_elt_opcode (BINOP_BITWISE_XOR); }
 440         ;
 441
 442 exp     :       exp '|' exp
 443                         { write_exp_elt_opcode (BINOP_BITWISE_IOR); }
 444         ;
 445
 446 exp     :       exp ANDAND exp
 447                         { write_exp_elt_opcode (BINOP_LOGICAL_AND); }
 448         ;
 449
 450 exp     :       exp OROR exp
 451                         { write_exp_elt_opcode (BINOP_LOGICAL_OR); }
 452         ;
 453
 454 exp     :       exp '?' exp ':' exp     %prec '?'
 455                         { write_exp_elt_opcode (TERNOP_COND); }
 456         ;
 457
 458 exp     :       exp '=' exp
 459                         { write_exp_elt_opcode (BINOP_ASSIGN); }
 460         ;
 461
 462 exp     :       exp ASSIGN_MODIFY exp
 463                         { write_exp_elt_opcode (BINOP_ASSIGN_MODIFY);
 464                           write_exp_elt_opcode ($2);
 465                           write_exp_elt_opcode (BINOP_ASSIGN_MODIFY); }
 466         ;
 467
 468 exp     :       INT
 469                         { write_exp_elt_opcode (OP_LONG);
 470                           write_exp_elt_type ($1.type);
 471                           write_exp_elt_longcst ((LONGEST)($1.val));
 472                           write_exp_elt_opcode (OP_LONG); }
 473         ;
 474
 475 exp     :       NAME_OR_INT
 476                         { YYSTYPE val;
 477                           parse_number ($1.stoken.ptr, $1.stoken.length, 0, &val);
 478                           write_exp_elt_opcode (OP_LONG);
 479                           write_exp_elt_type (val.typed_val_int.type);
 480                           write_exp_elt_longcst ((LONGEST)val.typed_val_int.val);
 481                           write_exp_elt_opcode (OP_LONG);
 482                         }
 483         ;
 484
 485
 486 exp     :       FLOAT
 487                         { write_exp_elt_opcode (OP_DOUBLE);
 488                           write_exp_elt_type ($1.type);
 489                           write_exp_elt_dblcst ($1.dval);
 490                           write_exp_elt_opcode (OP_DOUBLE); }
 491         ;
 492
 493 exp     :       variable
 494         ;
 495
 496 exp     :       VARIABLE
 497                         /* Already written by write_dollar_variable. */
 498         ;
 499
 500 exp     :       SIZEOF '(' type ')'     %prec UNARY
 501                         { write_exp_elt_opcode (OP_LONG);
 502                           write_exp_elt_type (builtin_type_int);
 503                           CHECK_TYPEDEF ($3);
 504                           write_exp_elt_longcst ((LONGEST) TYPE_LENGTH ($3));
 505                           write_exp_elt_opcode (OP_LONG); }
 506         ;
 507
 508 exp     :       STRING
 509                         { /* C strings are converted into array constants with
 510                              an explicit null byte added at the end.  Thus
 511                              the array upper bound is the string length.
 512                              There is no such thing in C as a completely empty
 513                              string. */
 514                           char *sp = $1.ptr; int count = $1.length;
 515                           while (count-- > 0)
 516                             {
 517                               write_exp_elt_opcode (OP_LONG);
 518                               write_exp_elt_type (builtin_type_char);
 519                               write_exp_elt_longcst ((LONGEST)(*sp++));
 520                               write_exp_elt_opcode (OP_LONG);
 521                             }
 522                           write_exp_elt_opcode (OP_LONG);
 523                           write_exp_elt_type (builtin_type_char);
 524                           write_exp_elt_longcst ((LONGEST)'\0');
 525                           write_exp_elt_opcode (OP_LONG);
 526                           write_exp_elt_opcode (OP_ARRAY);
 527                           write_exp_elt_longcst ((LONGEST) 0);
 528                           write_exp_elt_longcst ((LONGEST) ($1.length));
 529                           write_exp_elt_opcode (OP_ARRAY); }
 530         ;
 531
 532 /* C++.  */
 533 exp     :       THIS
 534                         { write_exp_elt_opcode (OP_THIS);
 535                           write_exp_elt_opcode (OP_THIS); }
 536         ;
 537
 538 /* end of C++.  */
 539
 540 block   :       BLOCKNAME
 541                         {
 542                           if ($1.sym != 0)
 543                               $$ = SYMBOL_BLOCK_VALUE ($1.sym);
 544                           else
 545                             {
 546                               struct symtab *tem =
 547                                   lookup_symtab (copy_name ($1.stoken));
 548                               if (tem)
 549                                 $$ = BLOCKVECTOR_BLOCK (BLOCKVECTOR (tem), STATIC_BLOCK);
 550                               else
 551                                 error ("No file or function \"%s\".",
 552                                        copy_name ($1.stoken));
 553                             }
 554                         }
 555         ;
 556
 557 block   :       block COLONCOLON name
 558                         { struct symbol *tem
 559                             = lookup_symbol (copy_name ($3), $1,
 560                                              VAR_NAMESPACE, (int *) NULL,
 561                                              (struct symtab **) NULL);
 562                           if (!tem || SYMBOL_CLASS (tem) != LOC_BLOCK)
 563                             error ("No function \"%s\" in specified context.",
 564                                    copy_name ($3));
 565                           $$ = SYMBOL_BLOCK_VALUE (tem); }
 566         ;
 567
 568 variable:       block COLONCOLON name
 569                         { struct symbol *sym;
 570                           sym = lookup_symbol (copy_name ($3), $1,
 571                                                VAR_NAMESPACE, (int *) NULL,
 572                                                (struct symtab **) NULL);
 573                           if (sym == 0)
 574                             error ("No symbol \"%s\" in specified context.",
 575                                    copy_name ($3));
 576
 577                           write_exp_elt_opcode (OP_VAR_VALUE);
 578                           /* block_found is set by lookup_symbol.  */
 579                           write_exp_elt_block (block_found);
 580                           write_exp_elt_sym (sym);
 581                           write_exp_elt_opcode (OP_VAR_VALUE); }
 582         ;
 583
 584 qualified_name: typebase COLONCOLON name
 585                         {
 586                           struct type *type = $1;
 587                           if (TYPE_CODE (type) != TYPE_CODE_STRUCT
 588                               && TYPE_CODE (type) != TYPE_CODE_UNION)
 589                             error ("`%s' is not defined as an aggregate type.",
 590                                    TYPE_NAME (type));
 591
 592                           write_exp_elt_opcode (OP_SCOPE);
 593                           write_exp_elt_type (type);
 594                           write_exp_string ($3);
 595                           write_exp_elt_opcode (OP_SCOPE);
 596                         }
 597         |       typebase COLONCOLON '~' name
 598                         {
 599                           struct type *type = $1;
 600                           struct stoken tmp_token;
 601                           if (TYPE_CODE (type) != TYPE_CODE_STRUCT
 602                               && TYPE_CODE (type) != TYPE_CODE_UNION)
 603                             error ("`%s' is not defined as an aggregate type.",
 604                                    TYPE_NAME (type));
 605
 606                           if (!STREQ (type_name_no_tag (type), $4.ptr))
 607                             error ("invalid destructor `%s::~%s'",
 608                                    type_name_no_tag (type), $4.ptr);
 609
 610                           tmp_token.ptr = (char*) alloca ($4.length + 2);
 611                           tmp_token.length = $4.length + 1;
 612                           tmp_token.ptr[0] = '~';
 613                           memcpy (tmp_token.ptr+1, $4.ptr, $4.length);
 614                           tmp_token.ptr[tmp_token.length] = 0;
 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   unsigned LONGEST 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   unsigned LONGEST 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 && (unsigned LONGEST) prevn >= (unsigned LONGEST) 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 = (unsigned LONGEST)n >> 2;
1072   if (long_p == 0
1073       && (un >> (TARGET_INT_BIT - 2)) == 0)
1074     {
1075       high_bit = ((unsigned LONGEST)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 = ((unsigned LONGEST)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 = (((unsigned LONGEST)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           (unsigned LONGEST)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        if (c == '<')
1413          {
1414            int i = namelen;
1415            while (tokstart[++i] && tokstart[i] != '>');
1416            if (tokstart[i] == '>')
1417              namelen = i;
1418           }
1419        c = tokstart[++namelen];
1420      }
1421
1422   /* The token "if" terminates the expression and is NOT
1423      removed from the input stream.  */
1424   if (namelen == 2 && tokstart[0] == 'i' && tokstart[1] == 'f')
1425     {
1426       return 0;
1427     }
1428
1429   lexptr += namelen;
1430
1431   tryname:
1432
1433   /* Catch specific keywords.  Should be done with a data structure.  */
1434   switch (namelen)
1435     {
1436     case 8:
1437       if (STREQN (tokstart, "unsigned", 8))
1438         return UNSIGNED;
1439       if (current_language->la_language == language_cplus
1440           && STREQN (tokstart, "template", 8))
1441         return TEMPLATE;
1442       if (STREQN (tokstart, "volatile", 8))
1443         return VOLATILE_KEYWORD;
1444       break;
1445     case 6:
1446       if (STREQN (tokstart, "struct", 6))
1447         return STRUCT;
1448       if (STREQN (tokstart, "signed", 6))
1449         return SIGNED_KEYWORD;
1450       if (STREQN (tokstart, "sizeof", 6))
1451         return SIZEOF;
1452       if (STREQN (tokstart, "double", 6))
1453         return DOUBLE_KEYWORD;
1454       break;
1455     case 5:
1456       if (current_language->la_language == language_cplus
1457           && STREQN (tokstart, "class", 5))
1458         return CLASS;
1459       if (STREQN (tokstart, "union", 5))
1460         return UNION;
1461       if (STREQN (tokstart, "short", 5))
1462         return SHORT;
1463       if (STREQN (tokstart, "const", 5))
1464         return CONST_KEYWORD;
1465       break;
1466     case 4:
1467       if (STREQN (tokstart, "enum", 4))
1468         return ENUM;
1469       if (STREQN (tokstart, "long", 4))
1470         return LONG;
1471       if (current_language->la_language == language_cplus
1472           && STREQN (tokstart, "this", 4))
1473         {
1474           static const char this_name[] =
1475                                  { CPLUS_MARKER, 't', 'h', 'i', 's', '\0' };
1476
1477           if (lookup_symbol (this_name, expression_context_block,
1478                              VAR_NAMESPACE, (int *) NULL,
1479                              (struct symtab **) NULL))
1480             return THIS;
1481         }
1482       break;
1483     case 3:
1484       if (STREQN (tokstart, "int", 3))
1485         return INT_KEYWORD;
1486       break;
1487     default:
1488       break;
1489     }
1490
1491   yylval.sval.ptr = tokstart;
1492   yylval.sval.length = namelen;
1493
1494   if (*tokstart == '$')
1495     {
1496       write_dollar_variable (yylval.sval);
1497       return VARIABLE;
1498     }
1499
1500   /* Use token-type BLOCKNAME for symbols that happen to be defined as
1501      functions or symtabs.  If this is not so, then ...
1502      Use token-type TYPENAME for symbols that happen to be defined
1503      currently as names of types; NAME for other symbols.
1504      The caller is not constrained to care about the distinction.  */
1505   {
1506     char *tmp = copy_name (yylval.sval);
1507     struct symbol *sym;
1508     int is_a_field_of_this = 0;
1509     int hextype;
1510
1511     sym = lookup_symbol (tmp, expression_context_block,
1512                          VAR_NAMESPACE,
1513                          current_language->la_language == language_cplus
1514                          ? &is_a_field_of_this : (int *) NULL,
1515                          (struct symtab **) NULL);
1516     /* Call lookup_symtab, not lookup_partial_symtab, in case there are
1517        no psymtabs (coff, xcoff, or some future change to blow away the
1518        psymtabs once once symbols are read).  */
1519     if ((sym && SYMBOL_CLASS (sym) == LOC_BLOCK) ||
1520         lookup_symtab (tmp))
1521       {
1522         yylval.ssym.sym = sym;
1523         yylval.ssym.is_a_field_of_this = is_a_field_of_this;
1524         return BLOCKNAME;
1525       }
1526     if (sym && SYMBOL_CLASS (sym) == LOC_TYPEDEF)
1527         {
1528 #if 1
1529           /* Despite the following flaw, we need to keep this code enabled.
1530              Because we can get called from check_stub_method, if we don't
1531              handle nested types then it screws many operations in any
1532              program which uses nested types.  */
1533           /* In "A::x", if x is a member function of A and there happens
1534              to be a type (nested or not, since the stabs don't make that
1535              distinction) named x, then this code incorrectly thinks we
1536              are dealing with nested types rather than a member function.  */
1537
1538           char *p;
1539           char *namestart;
1540           struct symbol *best_sym;
1541
1542           /* Look ahead to detect nested types.  This probably should be
1543              done in the grammar, but trying seemed to introduce a lot
1544              of shift/reduce and reduce/reduce conflicts.  It's possible
1545              that it could be done, though.  Or perhaps a non-grammar, but
1546              less ad hoc, approach would work well.  */
1547
1548           /* Since we do not currently have any way of distinguishing
1549              a nested type from a non-nested one (the stabs don't tell
1550              us whether a type is nested), we just ignore the
1551              containing type.  */
1552
1553           p = lexptr;
1554           best_sym = sym;
1555           while (1)
1556             {
1557               /* Skip whitespace.  */
1558               while (*p == ' ' || *p == '\t' || *p == '\n')
1559                 ++p;
1560               if (*p == ':' && p[1] == ':')
1561                 {
1562                   /* Skip the `::'.  */
1563                   p += 2;
1564                   /* Skip whitespace.  */
1565                   while (*p == ' ' || *p == '\t' || *p == '\n')
1566                     ++p;
1567                   namestart = p;
1568                   while (*p == '_' || *p == '$' || (*p >= '0' && *p <= '9')
1569                          || (*p >= 'a' && *p <= 'z')
1570                          || (*p >= 'A' && *p <= 'Z'))
1571                     ++p;
1572                   if (p != namestart)
1573                     {
1574                       struct symbol *cur_sym;
1575                       /* As big as the whole rest of the expression, which is
1576                          at least big enough.  */
1577                       char *ncopy = alloca (strlen (tmp)+strlen (namestart)+3);
1578                       char *tmp1;
1579
1580                       tmp1 = ncopy;
1581                       memcpy (tmp1, tmp, strlen (tmp));
1582                       tmp1 += strlen (tmp);
1583                       memcpy (tmp1, "::", 2);
1584                       tmp1 += 2;
1585                       memcpy (tmp1, namestart, p - namestart);
1586                       tmp1[p - namestart] = '\0';
1587                       cur_sym = lookup_symbol (ncopy, expression_context_block,
1588                                                VAR_NAMESPACE, (int *) NULL,
1589                                                (struct symtab **) NULL);
1590                       if (cur_sym)
1591                         {
1592                           if (SYMBOL_CLASS (cur_sym) == LOC_TYPEDEF)
1593                             {
1594                               best_sym = cur_sym;
1595                               lexptr = p;
1596                             }
1597                           else
1598                             break;
1599                         }
1600                       else
1601                         break;
1602                     }
1603                   else
1604                     break;
1605                 }
1606               else
1607                 break;
1608             }
1609
1610           yylval.tsym.type = SYMBOL_TYPE (best_sym);
1611 #else /* not 0 */
1612           yylval.tsym.type = SYMBOL_TYPE (sym);
1613 #endif /* not 0 */
1614           return TYPENAME;
1615         }
1616     if ((yylval.tsym.type = lookup_primitive_typename (tmp)) != 0)
1617         return TYPENAME;
1618
1619     /* Input names that aren't symbols but ARE valid hex numbers,
1620        when the input radix permits them, can be names or numbers
1621        depending on the parse.  Note we support radixes > 16 here.  */
1622     if (!sym &&
1623         ((tokstart[0] >= 'a' && tokstart[0] < 'a' + input_radix - 10) ||
1624          (tokstart[0] >= 'A' && tokstart[0] < 'A' + input_radix - 10)))
1625       {
1626         YYSTYPE newlval;        /* Its value is ignored.  */
1627         hextype = parse_number (tokstart, namelen, 0, &newlval);
1628         if (hextype == INT)
1629           {
1630             yylval.ssym.sym = sym;
1631             yylval.ssym.is_a_field_of_this = is_a_field_of_this;
1632             return NAME_OR_INT;
1633           }
1634       }
1635
1636     /* Any other kind of symbol */
1637     yylval.ssym.sym = sym;
1638     yylval.ssym.is_a_field_of_this = is_a_field_of_this;
1639     return NAME;
1640   }
1641 }
1642
1643 void
1644 yyerror (msg)
1645      char *msg;
1646 {
1647   error ("A %s in expression, near `%s'.", (msg ? msg : "error"), lexptr);
1648 }