gdb/jv-exp.y

   1 /* YACC parser for Java expressions, for GDB.
   2    Copyright (C) 1997, 1998, 1999, 2000, 2006, 2007, 2008, 2009
   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 3 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, see <http://www.gnu.org/licenses/>.  */
  19
  20 /* Parse a Java expression from text in a string,
  21    and return the result as a  struct expression  pointer.
  22    That structure contains arithmetic operations in reverse polish,
  23    with constants represented by operations that are followed by special data.
  24    See expression.h for the details of the format.
  25    What is important here is that it can be built up sequentially
  26    during the process of parsing; the lower levels of the tree always
  27    come first in the result.  Well, almost always; see ArrayAccess.
  28
  29    Note that malloc's and realloc's in this file are transformed to
  30    xmalloc and xrealloc respectively by the same sed command in the
  31    makefile that remaps any other malloc/realloc inserted by the parser
  32    generator.  Doing this with #defines and trying to control the interaction
  33    with include files (<malloc.h> and <stdlib.h> for example) just became
  34    too messy, particularly when such includes can be inserted at random
  35    times by the parser generator.  */
  36
  37 %{
  38
  39 #include "defs.h"
  40 #include "gdb_string.h"
  41 #include <ctype.h>
  42 #include "expression.h"
  43 #include "value.h"
  44 #include "parser-defs.h"
  45 #include "language.h"
  46 #include "jv-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 #include "block.h"
  51
  52 #define parse_type builtin_type (parse_gdbarch)
  53 #define parse_java_type builtin_java_type (parse_gdbarch)
  54
  55 /* Remap normal yacc parser interface names (yyparse, yylex, yyerror, etc),
  56    as well as gratuitiously global symbol names, so we can have multiple
  57    yacc generated parsers in gdb.  Note that these are only the variables
  58    produced by yacc.  If other parser generators (bison, byacc, etc) produce
  59    additional global names that conflict at link time, then those parser
  60    generators need to be fixed instead of adding those names to this list. */
  61
  62 #define yymaxdepth java_maxdepth
  63 #define yyparse java_parse
  64 #define yylex   java_lex
  65 #define yyerror java_error
  66 #define yylval  java_lval
  67 #define yychar  java_char
  68 #define yydebug java_debug
  69 #define yypact  java_pact
  70 #define yyr1    java_r1
  71 #define yyr2    java_r2
  72 #define yydef   java_def
  73 #define yychk   java_chk
  74 #define yypgo   java_pgo
  75 #define yyact   java_act
  76 #define yyexca  java_exca
  77 #define yyerrflag java_errflag
  78 #define yynerrs java_nerrs
  79 #define yyps    java_ps
  80 #define yypv    java_pv
  81 #define yys     java_s
  82 #define yy_yys  java_yys
  83 #define yystate java_state
  84 #define yytmp   java_tmp
  85 #define yyv     java_v
  86 #define yy_yyv  java_yyv
  87 #define yyval   java_val
  88 #define yylloc  java_lloc
  89 #define yyreds  java_reds               /* With YYDEBUG defined */
  90 #define yytoks  java_toks               /* With YYDEBUG defined */
  91 #define yyname  java_name               /* With YYDEBUG defined */
  92 #define yyrule  java_rule               /* With YYDEBUG defined */
  93 #define yylhs   java_yylhs
  94 #define yylen   java_yylen
  95 #define yydefred java_yydefred
  96 #define yydgoto java_yydgoto
  97 #define yysindex java_yysindex
  98 #define yyrindex java_yyrindex
  99 #define yygindex java_yygindex
 100 #define yytable  java_yytable
 101 #define yycheck  java_yycheck
 102
 103 #ifndef YYDEBUG
 104 #define YYDEBUG 1               /* Default to yydebug support */
 105 #endif
 106
 107 #define YYFPRINTF parser_fprintf
 108
 109 int yyparse (void);
 110
 111 static int yylex (void);
 112
 113 void yyerror (char *);
 114
 115 static struct type *java_type_from_name (struct stoken);
 116 static void push_expression_name (struct stoken);
 117 static void push_fieldnames (struct stoken);
 118
 119 static struct expression *copy_exp (struct expression *, int);
 120 static void insert_exp (int, struct expression *);
 121
 122 %}
 123
 124 /* Although the yacc "value" of an expression is not used,
 125    since the result is stored in the structure being created,
 126    other node types do have values.  */
 127
 128 %union
 129   {
 130     LONGEST lval;
 131     struct {
 132       LONGEST val;
 133       struct type *type;
 134     } typed_val_int;
 135     struct {
 136       DOUBLEST dval;
 137       struct type *type;
 138     } typed_val_float;
 139     struct symbol *sym;
 140     struct type *tval;
 141     struct stoken sval;
 142     struct ttype tsym;
 143     struct symtoken ssym;
 144     struct block *bval;
 145     enum exp_opcode opcode;
 146     struct internalvar *ivar;
 147     int *ivec;
 148   }
 149
 150 %{
 151 /* YYSTYPE gets defined by %union */
 152 static int parse_number (char *, int, int, YYSTYPE *);
 153 %}
 154
 155 %type <lval> rcurly Dims Dims_opt
 156 %type <tval> ClassOrInterfaceType ClassType /* ReferenceType Type ArrayType */
 157 %type <tval> IntegralType FloatingPointType NumericType PrimitiveType ArrayType PrimitiveOrArrayType
 158
 159 %token <typed_val_int> INTEGER_LITERAL
 160 %token <typed_val_float> FLOATING_POINT_LITERAL
 161
 162 %token <sval> IDENTIFIER
 163 %token <sval> STRING_LITERAL
 164 %token <lval> BOOLEAN_LITERAL
 165 %token <tsym> TYPENAME
 166 %type <sval> Name SimpleName QualifiedName ForcedName
 167
 168 /* A NAME_OR_INT is a symbol which is not known in the symbol table,
 169    but which would parse as a valid number in the current input radix.
 170    E.g. "c" when input_radix==16.  Depending on the parse, it will be
 171    turned into a name or into a number.  */
 172
 173 %token <sval> NAME_OR_INT
 174
 175 %token ERROR
 176
 177 /* Special type cases, put in to allow the parser to distinguish different
 178    legal basetypes.  */
 179 %token LONG SHORT BYTE INT CHAR BOOLEAN DOUBLE FLOAT
 180
 181 %token VARIABLE
 182
 183 %token <opcode> ASSIGN_MODIFY
 184
 185 %token SUPER NEW
 186
 187 %left ','
 188 %right '=' ASSIGN_MODIFY
 189 %right '?'
 190 %left OROR
 191 %left ANDAND
 192 %left '|'
 193 %left '^'
 194 %left '&'
 195 %left EQUAL NOTEQUAL
 196 %left '<' '>' LEQ GEQ
 197 %left LSH RSH
 198 %left '+' '-'
 199 %left '*' '/' '%'
 200 %right INCREMENT DECREMENT
 201 %right '.' '[' '('
 202
 203 \f
 204 %%
 205
 206 start   :       exp1
 207         |       type_exp
 208         ;
 209
 210 type_exp:       PrimitiveOrArrayType
 211                 {
 212                   write_exp_elt_opcode(OP_TYPE);
 213                   write_exp_elt_type($1);
 214                   write_exp_elt_opcode(OP_TYPE);
 215                 }
 216         ;
 217
 218 PrimitiveOrArrayType:
 219                 PrimitiveType
 220         |       ArrayType
 221         ;
 222
 223 StringLiteral:
 224         STRING_LITERAL
 225                 {
 226                   write_exp_elt_opcode (OP_STRING);
 227                   write_exp_string ($1);
 228                   write_exp_elt_opcode (OP_STRING);
 229                 }
 230 ;
 231
 232 Literal:
 233         INTEGER_LITERAL
 234                 { write_exp_elt_opcode (OP_LONG);
 235                   write_exp_elt_type ($1.type);
 236                   write_exp_elt_longcst ((LONGEST)($1.val));
 237                   write_exp_elt_opcode (OP_LONG); }
 238 |       NAME_OR_INT
 239                 { YYSTYPE val;
 240                   parse_number ($1.ptr, $1.length, 0, &val);
 241                   write_exp_elt_opcode (OP_LONG);
 242                   write_exp_elt_type (val.typed_val_int.type);
 243                   write_exp_elt_longcst ((LONGEST)val.typed_val_int.val);
 244                   write_exp_elt_opcode (OP_LONG);
 245                 }
 246 |       FLOATING_POINT_LITERAL
 247                 { write_exp_elt_opcode (OP_DOUBLE);
 248                   write_exp_elt_type ($1.type);
 249                   write_exp_elt_dblcst ($1.dval);
 250                   write_exp_elt_opcode (OP_DOUBLE); }
 251 |       BOOLEAN_LITERAL
 252                 { write_exp_elt_opcode (OP_LONG);
 253                   write_exp_elt_type (parse_java_type->builtin_boolean);
 254                   write_exp_elt_longcst ((LONGEST)$1);
 255                   write_exp_elt_opcode (OP_LONG); }
 256 |       StringLiteral
 257         ;
 258
 259 /* UNUSED:
 260 Type:
 261         PrimitiveType
 262 |       ReferenceType
 263 ;
 264 */
 265
 266 PrimitiveType:
 267         NumericType
 268 |       BOOLEAN
 269                 { $$ = parse_java_type->builtin_boolean; }
 270 ;
 271
 272 NumericType:
 273         IntegralType
 274 |       FloatingPointType
 275 ;
 276
 277 IntegralType:
 278         BYTE
 279                 { $$ = parse_java_type->builtin_byte; }
 280 |       SHORT
 281                 { $$ = parse_java_type->builtin_short; }
 282 |       INT
 283                 { $$ = parse_java_type->builtin_int; }
 284 |       LONG
 285                 { $$ = parse_java_type->builtin_long; }
 286 |       CHAR
 287                 { $$ = parse_java_type->builtin_char; }
 288 ;
 289
 290 FloatingPointType:
 291         FLOAT
 292                 { $$ = parse_java_type->builtin_float; }
 293 |       DOUBLE
 294                 { $$ = parse_java_type->builtin_double; }
 295 ;
 296
 297 /* UNUSED:
 298 ReferenceType:
 299         ClassOrInterfaceType
 300 |       ArrayType
 301 ;
 302 */
 303
 304 ClassOrInterfaceType:
 305         Name
 306                 { $$ = java_type_from_name ($1); }
 307 ;
 308
 309 ClassType:
 310         ClassOrInterfaceType
 311 ;
 312
 313 ArrayType:
 314         PrimitiveType Dims
 315                 { $$ = java_array_type ($1, $2); }
 316 |       Name Dims
 317                 { $$ = java_array_type (java_type_from_name ($1), $2); }
 318 ;
 319
 320 Name:
 321         IDENTIFIER
 322 |       QualifiedName
 323 ;
 324
 325 ForcedName:
 326         SimpleName
 327 |       QualifiedName
 328 ;
 329
 330 SimpleName:
 331         IDENTIFIER
 332 |       NAME_OR_INT
 333 ;
 334
 335 QualifiedName:
 336         Name '.' SimpleName
 337                 { $$.length = $1.length + $3.length + 1;
 338                   if ($1.ptr + $1.length + 1 == $3.ptr
 339                       && $1.ptr[$1.length] == '.')
 340                     $$.ptr = $1.ptr;  /* Optimization. */
 341                   else
 342                     {
 343                       $$.ptr = (char *) malloc ($$.length + 1);
 344                       make_cleanup (free, $$.ptr);
 345                       sprintf ($$.ptr, "%.*s.%.*s",
 346                                $1.length, $1.ptr, $3.length, $3.ptr);
 347                 } }
 348 ;
 349
 350 /*
 351 type_exp:       type
 352                         { write_exp_elt_opcode(OP_TYPE);
 353                           write_exp_elt_type($1);
 354                           write_exp_elt_opcode(OP_TYPE);}
 355         ;
 356         */
 357
 358 /* Expressions, including the comma operator.  */
 359 exp1    :       Expression
 360         |       exp1 ',' Expression
 361                         { write_exp_elt_opcode (BINOP_COMMA); }
 362         ;
 363
 364 Primary:
 365         PrimaryNoNewArray
 366 |       ArrayCreationExpression
 367 ;
 368
 369 PrimaryNoNewArray:
 370         Literal
 371 |       '(' Expression ')'
 372 |       ClassInstanceCreationExpression
 373 |       FieldAccess
 374 |       MethodInvocation
 375 |       ArrayAccess
 376 |       lcurly ArgumentList rcurly
 377                 { write_exp_elt_opcode (OP_ARRAY);
 378                   write_exp_elt_longcst ((LONGEST) 0);
 379                   write_exp_elt_longcst ((LONGEST) $3);
 380                   write_exp_elt_opcode (OP_ARRAY); }
 381 ;
 382
 383 lcurly:
 384         '{'
 385                 { start_arglist (); }
 386 ;
 387
 388 rcurly:
 389         '}'
 390                 { $$ = end_arglist () - 1; }
 391 ;
 392
 393 ClassInstanceCreationExpression:
 394         NEW ClassType '(' ArgumentList_opt ')'
 395                 { internal_error (__FILE__, __LINE__,
 396                                   _("FIXME - ClassInstanceCreationExpression")); }
 397 ;
 398
 399 ArgumentList:
 400         Expression
 401                 { arglist_len = 1; }
 402 |       ArgumentList ',' Expression
 403                 { arglist_len++; }
 404 ;
 405
 406 ArgumentList_opt:
 407         /* EMPTY */
 408                 { arglist_len = 0; }
 409 | ArgumentList
 410 ;
 411
 412 ArrayCreationExpression:
 413         NEW PrimitiveType DimExprs Dims_opt
 414                 { internal_error (__FILE__, __LINE__,
 415                                   _("FIXME - ArrayCreationExpression")); }
 416 |       NEW ClassOrInterfaceType DimExprs Dims_opt
 417                 { internal_error (__FILE__, __LINE__,
 418                                   _("FIXME - ArrayCreationExpression")); }
 419 ;
 420
 421 DimExprs:
 422         DimExpr
 423 |       DimExprs DimExpr
 424 ;
 425
 426 DimExpr:
 427         '[' Expression ']'
 428 ;
 429
 430 Dims:
 431         '[' ']'
 432                 { $$ = 1; }
 433 |       Dims '[' ']'
 434         { $$ = $1 + 1; }
 435 ;
 436
 437 Dims_opt:
 438         Dims
 439 |       /* EMPTY */
 440                 { $$ = 0; }
 441 ;
 442
 443 FieldAccess:
 444         Primary '.' SimpleName
 445                 { push_fieldnames ($3); }
 446 |       VARIABLE '.' SimpleName
 447                 { push_fieldnames ($3); }
 448 /*|     SUPER '.' SimpleName { FIXME } */
 449 ;
 450
 451 FuncStart:
 452         Name '('
 453                 { push_expression_name ($1); }
 454 ;
 455
 456 MethodInvocation:
 457         FuncStart
 458                 { start_arglist(); }
 459         ArgumentList_opt ')'
 460                 { write_exp_elt_opcode (OP_FUNCALL);
 461                   write_exp_elt_longcst ((LONGEST) end_arglist ());
 462                   write_exp_elt_opcode (OP_FUNCALL); }
 463 |       Primary '.' SimpleName '(' ArgumentList_opt ')'
 464                 { error (_("Form of method invocation not implemented")); }
 465 |       SUPER '.' SimpleName '(' ArgumentList_opt ')'
 466                 { error (_("Form of method invocation not implemented")); }
 467 ;
 468
 469 ArrayAccess:
 470         Name '[' Expression ']'
 471                 {
 472                   /* Emit code for the Name now, then exchange it in the
 473                      expout array with the Expression's code.  We could
 474                      introduce a OP_SWAP code or a reversed version of
 475                      BINOP_SUBSCRIPT, but that makes the rest of GDB pay
 476                      for our parsing kludges.  */
 477                   struct expression *name_expr;
 478
 479                   push_expression_name ($1);
 480                   name_expr = copy_exp (expout, expout_ptr);
 481                   expout_ptr -= name_expr->nelts;
 482                   insert_exp (expout_ptr-length_of_subexp (expout, expout_ptr),
 483                               name_expr);
 484                   free (name_expr);
 485                   write_exp_elt_opcode (BINOP_SUBSCRIPT);
 486                 }
 487 |       VARIABLE '[' Expression ']'
 488                 { write_exp_elt_opcode (BINOP_SUBSCRIPT); }
 489 |       PrimaryNoNewArray '[' Expression ']'
 490                 { write_exp_elt_opcode (BINOP_SUBSCRIPT); }
 491 ;
 492
 493 PostfixExpression:
 494         Primary
 495 |       Name
 496                 { push_expression_name ($1); }
 497 |       VARIABLE
 498                 /* Already written by write_dollar_variable. */
 499 |       PostIncrementExpression
 500 |       PostDecrementExpression
 501 ;
 502
 503 PostIncrementExpression:
 504         PostfixExpression INCREMENT
 505                 { write_exp_elt_opcode (UNOP_POSTINCREMENT); }
 506 ;
 507
 508 PostDecrementExpression:
 509         PostfixExpression DECREMENT
 510                 { write_exp_elt_opcode (UNOP_POSTDECREMENT); }
 511 ;
 512
 513 UnaryExpression:
 514         PreIncrementExpression
 515 |       PreDecrementExpression
 516 |       '+' UnaryExpression
 517 |       '-' UnaryExpression
 518                 { write_exp_elt_opcode (UNOP_NEG); }
 519 |       '*' UnaryExpression
 520                 { write_exp_elt_opcode (UNOP_IND); } /*FIXME not in Java  */
 521 |       UnaryExpressionNotPlusMinus
 522 ;
 523
 524 PreIncrementExpression:
 525         INCREMENT UnaryExpression
 526                 { write_exp_elt_opcode (UNOP_PREINCREMENT); }
 527 ;
 528
 529 PreDecrementExpression:
 530         DECREMENT UnaryExpression
 531                 { write_exp_elt_opcode (UNOP_PREDECREMENT); }
 532 ;
 533
 534 UnaryExpressionNotPlusMinus:
 535         PostfixExpression
 536 |       '~' UnaryExpression
 537                 { write_exp_elt_opcode (UNOP_COMPLEMENT); }
 538 |       '!' UnaryExpression
 539                 { write_exp_elt_opcode (UNOP_LOGICAL_NOT); }
 540 |       CastExpression
 541         ;
 542
 543 CastExpression:
 544         '(' PrimitiveType Dims_opt ')' UnaryExpression
 545                 { write_exp_elt_opcode (UNOP_CAST);
 546                   write_exp_elt_type (java_array_type ($2, $3));
 547                   write_exp_elt_opcode (UNOP_CAST); }
 548 |       '(' Expression ')' UnaryExpressionNotPlusMinus
 549                 {
 550                   int exp_size = expout_ptr;
 551                   int last_exp_size = length_of_subexp(expout, expout_ptr);
 552                   struct type *type;
 553                   int i;
 554                   int base = expout_ptr - last_exp_size - 3;
 555                   if (base < 0 || expout->elts[base+2].opcode != OP_TYPE)
 556                     error (_("Invalid cast expression"));
 557                   type = expout->elts[base+1].type;
 558                   /* Remove the 'Expression' and slide the
 559                      UnaryExpressionNotPlusMinus down to replace it. */
 560                   for (i = 0;  i < last_exp_size;  i++)
 561                     expout->elts[base + i] = expout->elts[base + i + 3];
 562                   expout_ptr -= 3;
 563                   if (TYPE_CODE (type) == TYPE_CODE_STRUCT)
 564                     type = lookup_pointer_type (type);
 565                   write_exp_elt_opcode (UNOP_CAST);
 566                   write_exp_elt_type (type);
 567                   write_exp_elt_opcode (UNOP_CAST);
 568                 }
 569 |       '(' Name Dims ')' UnaryExpressionNotPlusMinus
 570                 { write_exp_elt_opcode (UNOP_CAST);
 571                   write_exp_elt_type (java_array_type (java_type_from_name ($2), $3));
 572                   write_exp_elt_opcode (UNOP_CAST); }
 573 ;
 574
 575
 576 MultiplicativeExpression:
 577         UnaryExpression
 578 |       MultiplicativeExpression '*' UnaryExpression
 579                 { write_exp_elt_opcode (BINOP_MUL); }
 580 |       MultiplicativeExpression '/' UnaryExpression
 581                 { write_exp_elt_opcode (BINOP_DIV); }
 582 |       MultiplicativeExpression '%' UnaryExpression
 583                 { write_exp_elt_opcode (BINOP_REM); }
 584 ;
 585
 586 AdditiveExpression:
 587         MultiplicativeExpression
 588 |       AdditiveExpression '+' MultiplicativeExpression
 589                 { write_exp_elt_opcode (BINOP_ADD); }
 590 |       AdditiveExpression '-' MultiplicativeExpression
 591                 { write_exp_elt_opcode (BINOP_SUB); }
 592 ;
 593
 594 ShiftExpression:
 595         AdditiveExpression
 596 |       ShiftExpression LSH AdditiveExpression
 597                 { write_exp_elt_opcode (BINOP_LSH); }
 598 |       ShiftExpression RSH AdditiveExpression
 599                 { write_exp_elt_opcode (BINOP_RSH); }
 600 /* |    ShiftExpression >>> AdditiveExpression { FIXME } */
 601 ;
 602
 603 RelationalExpression:
 604         ShiftExpression
 605 |       RelationalExpression '<' ShiftExpression
 606                 { write_exp_elt_opcode (BINOP_LESS); }
 607 |       RelationalExpression '>' ShiftExpression
 608                 { write_exp_elt_opcode (BINOP_GTR); }
 609 |       RelationalExpression LEQ ShiftExpression
 610                 { write_exp_elt_opcode (BINOP_LEQ); }
 611 |       RelationalExpression GEQ ShiftExpression
 612                 { write_exp_elt_opcode (BINOP_GEQ); }
 613 /* | RelationalExpresion INSTANCEOF ReferenceType { FIXME } */
 614 ;
 615
 616 EqualityExpression:
 617         RelationalExpression
 618 |       EqualityExpression EQUAL RelationalExpression
 619                 { write_exp_elt_opcode (BINOP_EQUAL); }
 620 |       EqualityExpression NOTEQUAL RelationalExpression
 621                 { write_exp_elt_opcode (BINOP_NOTEQUAL); }
 622 ;
 623
 624 AndExpression:
 625         EqualityExpression
 626 |       AndExpression '&' EqualityExpression
 627                 { write_exp_elt_opcode (BINOP_BITWISE_AND); }
 628 ;
 629
 630 ExclusiveOrExpression:
 631         AndExpression
 632 |       ExclusiveOrExpression '^' AndExpression
 633                 { write_exp_elt_opcode (BINOP_BITWISE_XOR); }
 634 ;
 635 InclusiveOrExpression:
 636         ExclusiveOrExpression
 637 |       InclusiveOrExpression '|' ExclusiveOrExpression
 638                 { write_exp_elt_opcode (BINOP_BITWISE_IOR); }
 639 ;
 640
 641 ConditionalAndExpression:
 642         InclusiveOrExpression
 643 |       ConditionalAndExpression ANDAND InclusiveOrExpression
 644                 { write_exp_elt_opcode (BINOP_LOGICAL_AND); }
 645 ;
 646
 647 ConditionalOrExpression:
 648         ConditionalAndExpression
 649 |       ConditionalOrExpression OROR ConditionalAndExpression
 650                 { write_exp_elt_opcode (BINOP_LOGICAL_OR); }
 651 ;
 652
 653 ConditionalExpression:
 654         ConditionalOrExpression
 655 |       ConditionalOrExpression '?' Expression ':' ConditionalExpression
 656                 { write_exp_elt_opcode (TERNOP_COND); }
 657 ;
 658
 659 AssignmentExpression:
 660         ConditionalExpression
 661 |       Assignment
 662 ;
 663
 664 Assignment:
 665         LeftHandSide '=' ConditionalExpression
 666                 { write_exp_elt_opcode (BINOP_ASSIGN); }
 667 |       LeftHandSide ASSIGN_MODIFY ConditionalExpression
 668                 { write_exp_elt_opcode (BINOP_ASSIGN_MODIFY);
 669                   write_exp_elt_opcode ($2);
 670                   write_exp_elt_opcode (BINOP_ASSIGN_MODIFY); }
 671 ;
 672
 673 LeftHandSide:
 674         ForcedName
 675                 { push_expression_name ($1); }
 676 |       VARIABLE
 677                 /* Already written by write_dollar_variable. */
 678 |       FieldAccess
 679 |       ArrayAccess
 680 ;
 681
 682
 683 Expression:
 684         AssignmentExpression
 685 ;
 686
 687 %%
 688 /* Take care of parsing a number (anything that starts with a digit).
 689    Set yylval and return the token type; update lexptr.
 690    LEN is the number of characters in it.  */
 691
 692 /*** Needs some error checking for the float case ***/
 693
 694 static int
 695 parse_number (char *p, int len, int parsed_float, YYSTYPE *putithere)
 696 {
 697   ULONGEST n = 0;
 698   ULONGEST limit, limit_div_base;
 699
 700   int c;
 701   int base = input_radix;
 702
 703   struct type *type;
 704
 705   if (parsed_float)
 706     {
 707       /* It's a float since it contains a point or an exponent.  */
 708       char c;
 709       int num = 0;      /* number of tokens scanned by scanf */
 710       char saved_char = p[len];
 711
 712       p[len] = 0;       /* null-terminate the token */
 713       num = sscanf (p, "%" DOUBLEST_SCAN_FORMAT "%c",
 714                     &putithere->typed_val_float.dval, &c);
 715       p[len] = saved_char;      /* restore the input stream */
 716       if (num != 1)             /* check scanf found ONLY a float ... */
 717         return ERROR;
 718       /* See if it has `f' or `d' suffix (float or double).  */
 719
 720       c = tolower (p[len - 1]);
 721
 722       if (c == 'f' || c == 'F')
 723         putithere->typed_val_float.type = parse_type->builtin_float;
 724       else if (isdigit (c) || c == '.' || c == 'd' || c == 'D')
 725         putithere->typed_val_float.type = parse_type->builtin_double;
 726       else
 727         return ERROR;
 728
 729       return FLOATING_POINT_LITERAL;
 730     }
 731
 732   /* Handle base-switching prefixes 0x, 0t, 0d, 0 */
 733   if (p[0] == '0')
 734     switch (p[1])
 735       {
 736       case 'x':
 737       case 'X':
 738         if (len >= 3)
 739           {
 740             p += 2;
 741             base = 16;
 742             len -= 2;
 743           }
 744         break;
 745
 746       case 't':
 747       case 'T':
 748       case 'd':
 749       case 'D':
 750         if (len >= 3)
 751           {
 752             p += 2;
 753             base = 10;
 754             len -= 2;
 755           }
 756         break;
 757
 758       default:
 759         base = 8;
 760         break;
 761       }
 762
 763   c = p[len-1];
 764   /* A paranoid calculation of (1<<64)-1. */
 765   limit = (ULONGEST)0xffffffff;
 766   limit = ((limit << 16) << 16) | limit;
 767   if (c == 'l' || c == 'L')
 768     {
 769       type = parse_java_type->builtin_long;
 770       len--;
 771     }
 772   else
 773     {
 774       type = parse_java_type->builtin_int;
 775     }
 776   limit_div_base = limit / (ULONGEST) base;
 777
 778   while (--len >= 0)
 779     {
 780       c = *p++;
 781       if (c >= '0' && c <= '9')
 782         c -= '0';
 783       else if (c >= 'A' && c <= 'Z')
 784         c -= 'A' - 10;
 785       else if (c >= 'a' && c <= 'z')
 786         c -= 'a' - 10;
 787       else
 788         return ERROR;   /* Char not a digit */
 789       if (c >= base)
 790         return ERROR;
 791       if (n > limit_div_base
 792           || (n *= base) > limit - c)
 793         error (_("Numeric constant too large"));
 794       n += c;
 795         }
 796
 797   /* If the type is bigger than a 32-bit signed integer can be, implicitly
 798      promote to long.  Java does not do this, so mark it as
 799      parse_type->builtin_uint64 rather than parse_java_type->builtin_long.
 800      0x80000000 will become -0x80000000 instead of 0x80000000L, because we
 801      don't know the sign at this point.  */
 802   if (type == parse_java_type->builtin_int && n > (ULONGEST)0x80000000)
 803     type = parse_type->builtin_uint64;
 804
 805   putithere->typed_val_int.val = n;
 806   putithere->typed_val_int.type = type;
 807
 808   return INTEGER_LITERAL;
 809 }
 810
 811 struct token
 812 {
 813   char *operator;
 814   int token;
 815   enum exp_opcode opcode;
 816 };
 817
 818 static const struct token tokentab3[] =
 819   {
 820     {">>=", ASSIGN_MODIFY, BINOP_RSH},
 821     {"<<=", ASSIGN_MODIFY, BINOP_LSH}
 822   };
 823
 824 static const struct token tokentab2[] =
 825   {
 826     {"+=", ASSIGN_MODIFY, BINOP_ADD},
 827     {"-=", ASSIGN_MODIFY, BINOP_SUB},
 828     {"*=", ASSIGN_MODIFY, BINOP_MUL},
 829     {"/=", ASSIGN_MODIFY, BINOP_DIV},
 830     {"%=", ASSIGN_MODIFY, BINOP_REM},
 831     {"|=", ASSIGN_MODIFY, BINOP_BITWISE_IOR},
 832     {"&=", ASSIGN_MODIFY, BINOP_BITWISE_AND},
 833     {"^=", ASSIGN_MODIFY, BINOP_BITWISE_XOR},
 834     {"++", INCREMENT, BINOP_END},
 835     {"--", DECREMENT, BINOP_END},
 836     {"&&", ANDAND, BINOP_END},
 837     {"||", OROR, BINOP_END},
 838     {"<<", LSH, BINOP_END},
 839     {">>", RSH, BINOP_END},
 840     {"==", EQUAL, BINOP_END},
 841     {"!=", NOTEQUAL, BINOP_END},
 842     {"<=", LEQ, BINOP_END},
 843     {">=", GEQ, BINOP_END}
 844   };
 845
 846 /* Read one token, getting characters through lexptr.  */
 847
 848 static int
 849 yylex (void)
 850 {
 851   int c;
 852   int namelen;
 853   unsigned int i;
 854   char *tokstart;
 855   char *tokptr;
 856   int tempbufindex;
 857   static char *tempbuf;
 858   static int tempbufsize;
 859
 860  retry:
 861
 862   prev_lexptr = lexptr;
 863
 864   tokstart = lexptr;
 865   /* See if it is a special token of length 3.  */
 866   for (i = 0; i < sizeof tokentab3 / sizeof tokentab3[0]; i++)
 867     if (strncmp (tokstart, tokentab3[i].operator, 3) == 0)
 868       {
 869         lexptr += 3;
 870         yylval.opcode = tokentab3[i].opcode;
 871         return tokentab3[i].token;
 872       }
 873
 874   /* See if it is a special token of length 2.  */
 875   for (i = 0; i < sizeof tokentab2 / sizeof tokentab2[0]; i++)
 876     if (strncmp (tokstart, tokentab2[i].operator, 2) == 0)
 877       {
 878         lexptr += 2;
 879         yylval.opcode = tokentab2[i].opcode;
 880         return tokentab2[i].token;
 881       }
 882
 883   switch (c = *tokstart)
 884     {
 885     case 0:
 886       return 0;
 887
 888     case ' ':
 889     case '\t':
 890     case '\n':
 891       lexptr++;
 892       goto retry;
 893
 894     case '\'':
 895       /* We either have a character constant ('0' or '\177' for example)
 896          or we have a quoted symbol reference ('foo(int,int)' in C++
 897          for example). */
 898       lexptr++;
 899       c = *lexptr++;
 900       if (c == '\\')
 901         c = parse_escape (&lexptr);
 902       else if (c == '\'')
 903         error (_("Empty character constant"));
 904
 905       yylval.typed_val_int.val = c;
 906       yylval.typed_val_int.type = parse_java_type->builtin_char;
 907
 908       c = *lexptr++;
 909       if (c != '\'')
 910         {
 911           namelen = skip_quoted (tokstart) - tokstart;
 912           if (namelen > 2)
 913             {
 914               lexptr = tokstart + namelen;
 915               if (lexptr[-1] != '\'')
 916                 error (_("Unmatched single quote"));
 917               namelen -= 2;
 918               tokstart++;
 919               goto tryname;
 920             }
 921           error (_("Invalid character constant"));
 922         }
 923       return INTEGER_LITERAL;
 924
 925     case '(':
 926       paren_depth++;
 927       lexptr++;
 928       return c;
 929
 930     case ')':
 931       if (paren_depth == 0)
 932         return 0;
 933       paren_depth--;
 934       lexptr++;
 935       return c;
 936
 937     case ',':
 938       if (comma_terminates && paren_depth == 0)
 939         return 0;
 940       lexptr++;
 941       return c;
 942
 943     case '.':
 944       /* Might be a floating point number.  */
 945       if (lexptr[1] < '0' || lexptr[1] > '9')
 946         goto symbol;            /* Nope, must be a symbol. */
 947       /* FALL THRU into number case.  */
 948
 949     case '0':
 950     case '1':
 951     case '2':
 952     case '3':
 953     case '4':
 954     case '5':
 955     case '6':
 956     case '7':
 957     case '8':
 958     case '9':
 959       {
 960         /* It's a number.  */
 961         int got_dot = 0, got_e = 0, toktype;
 962         char *p = tokstart;
 963         int hex = input_radix > 10;
 964
 965         if (c == '0' && (p[1] == 'x' || p[1] == 'X'))
 966           {
 967             p += 2;
 968             hex = 1;
 969           }
 970         else if (c == '0' && (p[1]=='t' || p[1]=='T' || p[1]=='d' || p[1]=='D'))
 971           {
 972             p += 2;
 973             hex = 0;
 974           }
 975
 976         for (;; ++p)
 977           {
 978             /* This test includes !hex because 'e' is a valid hex digit
 979                and thus does not indicate a floating point number when
 980                the radix is hex.  */
 981             if (!hex && !got_e && (*p == 'e' || *p == 'E'))
 982               got_dot = got_e = 1;
 983             /* This test does not include !hex, because a '.' always indicates
 984                a decimal floating point number regardless of the radix.  */
 985             else if (!got_dot && *p == '.')
 986               got_dot = 1;
 987             else if (got_e && (p[-1] == 'e' || p[-1] == 'E')
 988                      && (*p == '-' || *p == '+'))
 989               /* This is the sign of the exponent, not the end of the
 990                  number.  */
 991               continue;
 992             /* We will take any letters or digits.  parse_number will
 993                complain if past the radix, or if L or U are not final.  */
 994             else if ((*p < '0' || *p > '9')
 995                      && ((*p < 'a' || *p > 'z')
 996                                   && (*p < 'A' || *p > 'Z')))
 997               break;
 998           }
 999         toktype = parse_number (tokstart, p - tokstart, got_dot|got_e, &yylval);
1000         if (toktype == ERROR)
1001           {
1002             char *err_copy = (char *) alloca (p - tokstart + 1);
1003
1004             memcpy (err_copy, tokstart, p - tokstart);
1005             err_copy[p - tokstart] = 0;
1006             error (_("Invalid number \"%s\""), err_copy);
1007           }
1008         lexptr = p;
1009         return toktype;
1010       }
1011
1012     case '+':
1013     case '-':
1014     case '*':
1015     case '/':
1016     case '%':
1017     case '|':
1018     case '&':
1019     case '^':
1020     case '~':
1021     case '!':
1022     case '<':
1023     case '>':
1024     case '[':
1025     case ']':
1026     case '?':
1027     case ':':
1028     case '=':
1029     case '{':
1030     case '}':
1031     symbol:
1032       lexptr++;
1033       return c;
1034
1035     case '"':
1036
1037       /* Build the gdb internal form of the input string in tempbuf,
1038          translating any standard C escape forms seen.  Note that the
1039          buffer is null byte terminated *only* for the convenience of
1040          debugging gdb itself and printing the buffer contents when
1041          the buffer contains no embedded nulls.  Gdb does not depend
1042          upon the buffer being null byte terminated, it uses the length
1043          string instead.  This allows gdb to handle C strings (as well
1044          as strings in other languages) with embedded null bytes */
1045
1046       tokptr = ++tokstart;
1047       tempbufindex = 0;
1048
1049       do {
1050         /* Grow the static temp buffer if necessary, including allocating
1051            the first one on demand. */
1052         if (tempbufindex + 1 >= tempbufsize)
1053           {
1054             tempbuf = (char *) realloc (tempbuf, tempbufsize += 64);
1055           }
1056         switch (*tokptr)
1057           {
1058           case '\0':
1059           case '"':
1060             /* Do nothing, loop will terminate. */
1061             break;
1062           case '\\':
1063             tokptr++;
1064             c = parse_escape (&tokptr);
1065             if (c == -1)
1066               {
1067                 continue;
1068               }
1069             tempbuf[tempbufindex++] = c;
1070             break;
1071           default:
1072             tempbuf[tempbufindex++] = *tokptr++;
1073             break;
1074           }
1075       } while ((*tokptr != '"') && (*tokptr != '\0'));
1076       if (*tokptr++ != '"')
1077         {
1078           error (_("Unterminated string in expression"));
1079         }
1080       tempbuf[tempbufindex] = '\0';     /* See note above */
1081       yylval.sval.ptr = tempbuf;
1082       yylval.sval.length = tempbufindex;
1083       lexptr = tokptr;
1084       return (STRING_LITERAL);
1085     }
1086
1087   if (!(c == '_' || c == '$'
1088         || (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')))
1089     /* We must have come across a bad character (e.g. ';').  */
1090     error (_("Invalid character '%c' in expression"), c);
1091
1092   /* It's a name.  See how long it is.  */
1093   namelen = 0;
1094   for (c = tokstart[namelen];
1095        (c == '_'
1096         || c == '$'
1097         || (c >= '0' && c <= '9')
1098         || (c >= 'a' && c <= 'z')
1099         || (c >= 'A' && c <= 'Z')
1100         || c == '<');
1101        )
1102     {
1103       if (c == '<')
1104         {
1105           int i = namelen;
1106           while (tokstart[++i] && tokstart[i] != '>');
1107           if (tokstart[i] == '>')
1108             namelen = i;
1109         }
1110        c = tokstart[++namelen];
1111      }
1112
1113   /* The token "if" terminates the expression and is NOT
1114      removed from the input stream.  */
1115   if (namelen == 2 && tokstart[0] == 'i' && tokstart[1] == 'f')
1116     {
1117       return 0;
1118     }
1119
1120   lexptr += namelen;
1121
1122   tryname:
1123
1124   /* Catch specific keywords.  Should be done with a data structure.  */
1125   switch (namelen)
1126     {
1127     case 7:
1128       if (strncmp (tokstart, "boolean", 7) == 0)
1129         return BOOLEAN;
1130       break;
1131     case 6:
1132       if (strncmp (tokstart, "double", 6) == 0)
1133         return DOUBLE;
1134       break;
1135     case 5:
1136       if (strncmp (tokstart, "short", 5) == 0)
1137         return SHORT;
1138       if (strncmp (tokstart, "false", 5) == 0)
1139         {
1140           yylval.lval = 0;
1141           return BOOLEAN_LITERAL;
1142         }
1143       if (strncmp (tokstart, "super", 5) == 0)
1144         return SUPER;
1145       if (strncmp (tokstart, "float", 5) == 0)
1146         return FLOAT;
1147       break;
1148     case 4:
1149       if (strncmp (tokstart, "long", 4) == 0)
1150         return LONG;
1151       if (strncmp (tokstart, "byte", 4) == 0)
1152         return BYTE;
1153       if (strncmp (tokstart, "char", 4) == 0)
1154         return CHAR;
1155       if (strncmp (tokstart, "true", 4) == 0)
1156         {
1157           yylval.lval = 1;
1158           return BOOLEAN_LITERAL;
1159         }
1160       break;
1161     case 3:
1162       if (strncmp (tokstart, "int", 3) == 0)
1163         return INT;
1164       if (strncmp (tokstart, "new", 3) == 0)
1165         return NEW;
1166       break;
1167     default:
1168       break;
1169     }
1170
1171   yylval.sval.ptr = tokstart;
1172   yylval.sval.length = namelen;
1173
1174   if (*tokstart == '$')
1175     {
1176       write_dollar_variable (yylval.sval);
1177       return VARIABLE;
1178     }
1179
1180   /* Input names that aren't symbols but ARE valid hex numbers,
1181      when the input radix permits them, can be names or numbers
1182      depending on the parse.  Note we support radixes > 16 here.  */
1183   if (((tokstart[0] >= 'a' && tokstart[0] < 'a' + input_radix - 10) ||
1184        (tokstart[0] >= 'A' && tokstart[0] < 'A' + input_radix - 10)))
1185     {
1186       YYSTYPE newlval;  /* Its value is ignored.  */
1187       int hextype = parse_number (tokstart, namelen, 0, &newlval);
1188       if (hextype == INTEGER_LITERAL)
1189         return NAME_OR_INT;
1190     }
1191   return IDENTIFIER;
1192 }
1193
1194 void
1195 yyerror (char *msg)
1196 {
1197   if (prev_lexptr)
1198     lexptr = prev_lexptr;
1199
1200   if (msg)
1201     error (_("%s: near `%s'"), msg, lexptr);
1202   else
1203     error (_("error in expression, near `%s'"), lexptr);
1204 }
1205
1206 static struct type *
1207 java_type_from_name (struct stoken name)
1208 {
1209   char *tmp = copy_name (name);
1210   struct type *typ = java_lookup_class (tmp);
1211   if (typ == NULL || TYPE_CODE (typ) != TYPE_CODE_STRUCT)
1212     error (_("No class named `%s'"), tmp);
1213   return typ;
1214 }
1215
1216 /* If NAME is a valid variable name in this scope, push it and return 1.
1217    Otherwise, return 0. */
1218
1219 static int
1220 push_variable (struct stoken name)
1221 {
1222   char *tmp = copy_name (name);
1223   int is_a_field_of_this = 0;
1224   struct symbol *sym;
1225   sym = lookup_symbol (tmp, expression_context_block, VAR_DOMAIN,
1226                        &is_a_field_of_this);
1227   if (sym && SYMBOL_CLASS (sym) != LOC_TYPEDEF)
1228     {
1229       if (symbol_read_needs_frame (sym))
1230         {
1231           if (innermost_block == 0 ||
1232               contained_in (block_found, innermost_block))
1233             innermost_block = block_found;
1234         }
1235
1236       write_exp_elt_opcode (OP_VAR_VALUE);
1237       /* We want to use the selected frame, not another more inner frame
1238          which happens to be in the same block.  */
1239       write_exp_elt_block (NULL);
1240       write_exp_elt_sym (sym);
1241       write_exp_elt_opcode (OP_VAR_VALUE);
1242       return 1;
1243     }
1244   if (is_a_field_of_this)
1245     {
1246       /* it hangs off of `this'.  Must not inadvertently convert from a
1247          method call to data ref.  */
1248       if (innermost_block == 0 ||
1249           contained_in (block_found, innermost_block))
1250         innermost_block = block_found;
1251       write_exp_elt_opcode (OP_THIS);
1252       write_exp_elt_opcode (OP_THIS);
1253       write_exp_elt_opcode (STRUCTOP_PTR);
1254       write_exp_string (name);
1255       write_exp_elt_opcode (STRUCTOP_PTR);
1256       return 1;
1257     }
1258   return 0;
1259 }
1260
1261 /* Assuming a reference expression has been pushed, emit the
1262    STRUCTOP_PTR ops to access the field named NAME.  If NAME is a
1263    qualified name (has '.'), generate a field access for each part. */
1264
1265 static void
1266 push_fieldnames (struct stoken name)
1267 {
1268   int i;
1269   struct stoken token;
1270   token.ptr = name.ptr;
1271   for (i = 0;  ;  i++)
1272     {
1273       if (i == name.length || name.ptr[i] == '.')
1274         {
1275           /* token.ptr is start of current field name. */
1276           token.length = &name.ptr[i] - token.ptr;
1277           write_exp_elt_opcode (STRUCTOP_PTR);
1278           write_exp_string (token);
1279           write_exp_elt_opcode (STRUCTOP_PTR);
1280           token.ptr += token.length + 1;
1281         }
1282       if (i >= name.length)
1283         break;
1284     }
1285 }
1286
1287 /* Helper routine for push_expression_name.
1288    Handle a qualified name, where DOT_INDEX is the index of the first '.' */
1289
1290 static void
1291 push_qualified_expression_name (struct stoken name, int dot_index)
1292 {
1293   struct stoken token;
1294   char *tmp;
1295   struct type *typ;
1296
1297   token.ptr = name.ptr;
1298   token.length = dot_index;
1299
1300   if (push_variable (token))
1301     {
1302       token.ptr = name.ptr + dot_index + 1;
1303       token.length = name.length - dot_index - 1;
1304       push_fieldnames (token);
1305       return;
1306     }
1307
1308   token.ptr = name.ptr;
1309   for (;;)
1310     {
1311       token.length = dot_index;
1312       tmp = copy_name (token);
1313       typ = java_lookup_class (tmp);
1314       if (typ != NULL)
1315         {
1316           if (dot_index == name.length)
1317             {
1318               write_exp_elt_opcode(OP_TYPE);
1319               write_exp_elt_type(typ);
1320               write_exp_elt_opcode(OP_TYPE);
1321               return;
1322             }
1323           dot_index++;  /* Skip '.' */
1324           name.ptr += dot_index;
1325           name.length -= dot_index;
1326           dot_index = 0;
1327           while (dot_index < name.length && name.ptr[dot_index] != '.')
1328             dot_index++;
1329           token.ptr = name.ptr;
1330           token.length = dot_index;
1331           write_exp_elt_opcode (OP_SCOPE);
1332           write_exp_elt_type (typ);
1333           write_exp_string (token);
1334           write_exp_elt_opcode (OP_SCOPE);
1335           if (dot_index < name.length)
1336             {
1337               dot_index++;
1338               name.ptr += dot_index;
1339               name.length -= dot_index;
1340               push_fieldnames (name);
1341             }
1342           return;
1343         }
1344       else if (dot_index >= name.length)
1345         break;
1346       dot_index++;  /* Skip '.' */
1347       while (dot_index < name.length && name.ptr[dot_index] != '.')
1348         dot_index++;
1349     }
1350   error (_("unknown type `%.*s'"), name.length, name.ptr);
1351 }
1352
1353 /* Handle Name in an expression (or LHS).
1354    Handle VAR, TYPE, TYPE.FIELD1....FIELDN and VAR.FIELD1....FIELDN. */
1355
1356 static void
1357 push_expression_name (struct stoken name)
1358 {
1359   char *tmp;
1360   struct type *typ;
1361   char *ptr;
1362   int i;
1363
1364   for (i = 0;  i < name.length;  i++)
1365     {
1366       if (name.ptr[i] == '.')
1367         {
1368           /* It's a Qualified Expression Name. */
1369           push_qualified_expression_name (name, i);
1370           return;
1371         }
1372     }
1373
1374   /* It's a Simple Expression Name. */
1375
1376   if (push_variable (name))
1377     return;
1378   tmp = copy_name (name);
1379   typ = java_lookup_class (tmp);
1380   if (typ != NULL)
1381     {
1382       write_exp_elt_opcode(OP_TYPE);
1383       write_exp_elt_type(typ);
1384       write_exp_elt_opcode(OP_TYPE);
1385     }
1386   else
1387     {
1388       struct minimal_symbol *msymbol;
1389
1390       msymbol = lookup_minimal_symbol (tmp, NULL, NULL);
1391       if (msymbol != NULL)
1392         write_exp_msymbol (msymbol);
1393       else if (!have_full_symbols () && !have_partial_symbols ())
1394         error (_("No symbol table is loaded.  Use the \"file\" command"));
1395       else
1396         error (_("No symbol \"%s\" in current context"), tmp);
1397     }
1398
1399 }
1400
1401
1402 /* The following two routines, copy_exp and insert_exp, aren't specific to
1403    Java, so they could go in parse.c, but their only purpose is to support
1404    the parsing kludges we use in this file, so maybe it's best to isolate
1405    them here.  */
1406
1407 /* Copy the expression whose last element is at index ENDPOS - 1 in EXPR
1408    into a freshly malloc'ed struct expression.  Its language_defn is set
1409    to null.  */
1410 static struct expression *
1411 copy_exp (struct expression *expr, int endpos)
1412 {
1413   int len = length_of_subexp (expr, endpos);
1414   struct expression *new
1415     = (struct expression *) malloc (sizeof (*new) + EXP_ELEM_TO_BYTES (len));
1416   new->nelts = len;
1417   memcpy (new->elts, expr->elts + endpos - len, EXP_ELEM_TO_BYTES (len));
1418   new->language_defn = 0;
1419
1420   return new;
1421 }
1422
1423 /* Insert the expression NEW into the current expression (expout) at POS.  */
1424 static void
1425 insert_exp (int pos, struct expression *new)
1426 {
1427   int newlen = new->nelts;
1428
1429   /* Grow expout if necessary.  In this function's only use at present,
1430      this should never be necessary.  */
1431   if (expout_ptr + newlen > expout_size)
1432     {
1433       expout_size = max (expout_size * 2, expout_ptr + newlen + 10);
1434       expout = (struct expression *)
1435         realloc ((char *) expout, (sizeof (struct expression)
1436                                     + EXP_ELEM_TO_BYTES (expout_size)));
1437     }
1438
1439   {
1440     int i;
1441
1442     for (i = expout_ptr - 1; i >= pos; i--)
1443       expout->elts[i + newlen] = expout->elts[i];
1444   }
1445
1446   memcpy (expout->elts + pos, new->elts, EXP_ELEM_TO_BYTES (newlen));
1447   expout_ptr += newlen;
1448 }