ld/ldgram.y

   1 /* A YACC grammer to parse a superset of the AT&T linker scripting languaue.
   2    Copyright (C) 1991 Free Software Foundation, Inc.
   3    Written by Steve Chamberlain of Cygnus Support (steve@cygnus.com).
   4
   5 This file is part of GNU ld.
   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., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  20
  21 %{
  22 /*
  23
  24  */
  25
  26 #define DONTDECLARE_MALLOC
  27
  28 #include "bfd.h"
  29 #include "sysdep.h"
  30 #include "ld.h"
  31 #include "ldexp.h"
  32 #include "ldver.h"
  33 #include "ldlang.h"
  34 #include "ldemul.h"
  35 #include "ldfile.h"
  36 #include "ldmisc.h"
  37 #include "mri.h"
  38
  39 #define YYDEBUG 1
  40
  41 boolean option_v;
  42 extern unsigned int lineno;
  43 extern boolean trace_files;
  44 extern boolean write_map;
  45 extern boolean option_longmap;
  46 boolean hex_mode;
  47
  48 strip_symbols_type strip_symbols=STRIP_NONE;
  49 discard_locals_type discard_locals=DISCARD_NONE;
  50
  51
  52 lang_memory_region_type *region;
  53
  54
  55 lang_memory_region_type *lang_memory_region_lookup();
  56 lang_output_section_statement_type *lang_output_section_statement_lookup();
  57
  58 #ifdef __STDC__
  59
  60 void lang_add_data(int type, union etree_union *exp);
  61 void lang_enter_output_section_statement(char *output_section_statement_name, etree_type *address_exp, int flags, bfd_vma block_value);
  62
  63 #else
  64
  65 void lang_add_data();
  66 void lang_enter_output_section_statement();
  67
  68 #endif /* __STDC__ */
  69
  70 extern args_type command_line;
  71 char *current_file;
  72 boolean ldgram_want_filename = true;
  73 boolean had_script = false;
  74 boolean force_make_executable = false;
  75
  76 boolean ldgram_in_script = false;
  77 boolean ldgram_had_equals = false;
  78 /* LOCALS */
  79
  80
  81 #define ERROR_NAME_MAX 20
  82 static char *error_names[ERROR_NAME_MAX];
  83 static int error_index;
  84 #define PUSH_ERROR(x) if (error_index < ERROR_NAME_MAX) error_names[error_index] = x; error_index++;
  85 #define POP_ERROR()   error_index--;
  86 %}
  87 %union {
  88   bfd_vma integer;
  89   int voidval;
  90   char *name;
  91   int token;
  92   union etree_union *etree;
  93 struct sec *section;
  94   struct lang_output_section_statement_struct *output_section_statement;
  95   union  lang_statement_union **statement_ptr;
  96   int lineno;
  97   struct {
  98     FILE *file;
  99     char *name;
 100     unsigned int lineno;
 101   } state;
 102
 103
 104 }
 105
 106 %type <etree> exp  opt_exp  mustbe_exp
 107 %type <integer> fill_opt opt_block opt_type
 108 %type <name> memspec_opt
 109 %token <integer> INT
 110 %token <name> NAME
 111 %type  <integer> length
 112
 113 %right <token> PLUSEQ MINUSEQ MULTEQ DIVEQ  '=' LSHIFTEQ RSHIFTEQ   ANDEQ OREQ
 114 %right <token> '?' ':'
 115 %left <token> OROR
 116 %left <token>  ANDAND
 117 %left <token> '|'
 118 %left <token>  '^'
 119 %left  <token> '&'
 120 %left <token>  EQ NE
 121 %left  <token> '<' '>' LE GE
 122 %left  <token> LSHIFT RSHIFT
 123
 124 %left  <token> '+' '-'
 125 %left  <token> '*' '/' '%'
 126
 127 /*%token <token> '+' '-' '*' '/' '%'*/
 128 %right UNARY
 129 %token END
 130 %left <token> '('
 131 %token <token> ALIGN_K BLOCK LONG SHORT BYTE
 132 %token SECTIONS
 133 %token '{' '}'
 134 %token SIZEOF_HEADERS OUTPUT_FORMAT FORCE_COMMON_ALLOCATION OUTPUT_ARCH
 135 %token SIZEOF_HEADERS
 136 %token MEMORY
 137 %token NOLOAD DSECT COPY INFO OVERLAY
 138 %token NAME DEFINED TARGET_K SEARCH_DIR MAP ENTRY
 139 %token OPTION_e OPTION_c OPTION_noinhibit_exec OPTION_s OPTION_S OPTION_sort_common
 140 %token OPTION_format  OPTION_F OPTION_u OPTION_Bstatic OPTION_N
 141 %token <integer> SIZEOF NEXT ADDR
 142 %token OPTION_d OPTION_dc OPTION_dp OPTION_x OPTION_X OPTION_defsym
 143 %token OPTION_v OPTION_V OPTION_M OPTION_t STARTUP HLL SYSLIB FLOAT  NOFLOAT
 144 %token OPTION_Map
 145 %token OPTION_n OPTION_r OPTION_o OPTION_b  OPTION_R OPTION_relax
 146 %token <name> OPTION_l OPTION_L  OPTION_T OPTION_Aarch OPTION_Tfile  OPTION_Texp
 147 %token OPTION_Ur
 148 %token ORIGIN FILL OPTION_g
 149 %token LENGTH    CREATE_OBJECT_SYMBOLS INPUT OUTPUT  CONSTRUCTORS
 150 %type <token> assign_op
 151
 152 %type <name>  filename
 153
 154
 155 %token CHIP LIST SECT ABSOLUTE  LOAD NEWLINE ENDWORD ORDER NAMEWORD FORMAT
 156
 157 %{
 158 ld_config_type config;
 159 %}
 160
 161 %%
 162
 163 file:   command_line  { lang_final(); };
 164
 165
 166 filename:  NAME;
 167
 168
 169 command_line:
 170                 command_line command_line_option
 171         |
 172         ;
 173
 174 command_line_option:
 175                 OPTION_Bstatic { }
 176         |       OPTION_v
 177                         {
 178                         ldversion(0);
 179                         option_v = true;
 180                         }
 181         |       OPTION_V
 182                         {
 183                         ldversion(1);
 184                         option_v = true;
 185                         }
 186         |       OPTION_t {
 187                         trace_files = true;
 188                         }
 189         |     OPTION_Map  NAME
 190                 {
 191                 write_map = true;
 192                 config.map_filename = $2;
 193                 }
 194         |       OPTION_M {
 195             config.map_filename = "-";
 196
 197                         }
 198         |       OPTION_n {
 199                         config.magic_demand_paged = false;
 200                         }
 201         |       OPTION_N {
 202                         config.text_read_only = false;
 203                         config.magic_demand_paged = false;
 204                         }
 205         |       OPTION_s {
 206                         strip_symbols = STRIP_ALL;
 207                         }
 208         |       OPTION_S {
 209                         strip_symbols = STRIP_DEBUGGER;
 210                         }
 211         |       OPTION_u NAME {
 212                         ldlang_add_undef($2);
 213                 }
 214
 215         |       OPTION_r {
 216                         config.relocateable_output = true;
 217                         config.build_constructors = false;
 218                         config.magic_demand_paged = false;
 219                         config.text_read_only = false;
 220                         }
 221         |       OPTION_Ur {
 222                         config.relocateable_output = true;
 223                         config.build_constructors = true;
 224                         config.magic_demand_paged = false;
 225                         config.text_read_only = false;
 226                       }
 227         |       OPTION_o filename
 228                         {
 229                         lang_add_output($2);
 230                         }
 231         |       OPTION_e NAME
 232                         { lang_add_entry($2);
 233                         }
 234         |       OPTION_X {
 235                         discard_locals = DISCARD_L;
 236                 }
 237         |       OPTION_x {
 238                         discard_locals = DISCARD_ALL;
 239                 }
 240
 241         |       OPTION_noinhibit_exec
 242                         {
 243                         force_make_executable = true;
 244                         }
 245         |      OPTION_sort_common {
 246         config.sort_common = true;
 247       }
 248         |      OPTION_d {
 249                           command_line.force_common_definition = true;
 250                         }
 251
 252         |      OPTION_relax {
 253                           command_line.relax = true;
 254                         }
 255         |      OPTION_dc
 256                          {
 257                           command_line.force_common_definition = true;
 258                         }
 259         |       OPTION_g
 260                         {
 261                         /* Ignored */
 262                         }
 263         |       OPTION_dp
 264                          {
 265                           command_line.force_common_definition = true;
 266                         }
 267         |       OPTION_format NAME
 268                    {
 269                           lang_add_target($2);
 270                    }
 271         |       OPTION_Texp
 272                 {
 273                         hex_mode  = 16;
 274                 }
 275                 INT
 276                 {
 277                         lang_section_start($1,exp_intop($3));
 278                         hex_mode = 0;
 279                 }
 280
 281         |       OPTION_Aarch
 282                 {
 283                         ldfile_add_arch($1);
 284                 }
 285         |        OPTION_b NAME
 286                         {
 287                         lang_add_target($2);
 288                         }
 289         |       OPTION_L
 290                         {
 291                         ldfile_add_library_path($1);
 292                         }
 293         |       OPTION_F
 294                 {
 295                 /* Ignore */
 296                 }
 297         |       NAME
 298                 { lang_add_input_file($1,lang_input_file_is_file_enum,
 299                                  (char *)NULL); }
 300         |       OPTION_c filename
 301                         { ldfile_open_command_file($2); } mri_script_file  END {  ldlex_command()};
 302
 303         |       OPTION_Tfile
 304                         { ldfile_open_command_file($1); } script_file
 305                         END {  ldlex_command();}
 306
 307         |       OPTION_T filename
 308                         { ldfile_open_command_file($2); } script_file
 309 END {  ldlex_command();}
 310
 311         |       OPTION_l
 312                         {
 313                           lang_add_input_file($1,
 314                                          lang_input_file_is_l_enum,
 315                                          (char *)NULL);
 316                         }
 317         |       OPTION_R filename
 318                         {
 319                         lang_add_input_file($2,
 320                                 lang_input_file_is_symbols_only_enum,
 321                                 (char *)NULL);
 322                         }
 323         |       OPTION_defsym  { ldlex_expression();
 324
 325                         }
 326                 NAME     '=' mustbe_exp  { ldlex_popstate();
 327                         lang_add_assignment(exp_assop($4,$3,$5));
 328                         }
 329         | '-' NAME
 330                  { info("%P%F Unrecognised option -%s\n", $2);  }
 331
 332         | '{' script_file '}'
 333         ;
 334
 335
 336 /* SYNTAX WITHIN AN MRI SCRIPT FILE */
 337 mri_script_file:
 338                 {       ldlex_mri_script();
 339                         PUSH_ERROR("MRI style script");
 340                 }
 341              mri_script_lines
 342                 {       ldlex_popstate();
 343                         POP_ERROR();
 344                 }
 345         ;
 346
 347 mri_script_lines:
 348                 mri_script_lines mri_script_command NEWLINE
 349           |
 350         ;
 351
 352 mri_script_command:
 353                 CHIP  exp
 354         |       CHIP  exp ',' exp
 355         |       NAME    {
 356                         einfo("%P%F: unrecognised keyword in MRI style script '%s'\n",$1);
 357                         }
 358         |       LIST    {
 359                         write_map = true;
 360                         config.map_filename = "-";
 361                         }
 362         |       ORDER ordernamelist
 363         |       ENDWORD
 364         |       FORMAT NAME
 365                         { mri_format($2); }
 366         |       SECT NAME ',' exp
 367                         { mri_output_section($2, $4);}
 368         |       SECT NAME  exp
 369                         { mri_output_section($2, $3);}
 370         |       SECT NAME '=' exp
 371                         { mri_output_section($2, $4);}
 372         |       ABSOLUTE mri_abs_name_list
 373         |       LOAD     mri_load_name_list
 374         |       NAMEWORD NAME
 375                         { mri_name($2); }
 376         |
 377         ;
 378
 379 ordernamelist:
 380               ordernamelist ',' NAME         { mri_order($3); }
 381         |     ordernamelist  NAME         { mri_order($2); }
 382         |
 383         ;
 384
 385 mri_load_name_list:
 386                 NAME
 387                         { mri_load($1); }
 388         |       mri_load_name_list ',' NAME { mri_load($3); }
 389         ;
 390
 391 mri_abs_name_list:
 392                 NAME
 393                         { mri_only_load($1); }
 394         |       mri_abs_name_list ','  NAME
 395                         { mri_only_load($3); }
 396         ;
 397
 398 script_file:
 399         {
 400          ldlex_both();
 401         }
 402        ifile_list
 403         {
 404         ldlex_popstate();
 405         }
 406         ;
 407
 408
 409 ifile_list:
 410        ifile_list ifile_p1
 411         |
 412         ;
 413
 414
 415
 416 ifile_p1:
 417                 memory
 418         |       sections
 419         |       startup
 420         |       high_level_library
 421         |       low_level_library
 422         |       floating_point_support
 423         |       statement_anywhere
 424         |        ';'
 425         |       TARGET_K '(' NAME ')'
 426                 { lang_add_target($3); }
 427         |       SEARCH_DIR '(' filename ')'
 428                 { ldfile_add_library_path($3); }
 429         |       OUTPUT '(' filename ')'
 430                 { lang_add_output($3); }
 431         | OUTPUT_FORMAT '(' NAME ')'
 432                   { lang_add_output_format($3); }
 433         | OUTPUT_ARCH '(' NAME ')'
 434                   { ldfile_set_output_arch($3); }
 435         |       FORCE_COMMON_ALLOCATION
 436                 { command_line.force_common_definition = true ; }
 437         |       INPUT '(' input_list ')'
 438         |       MAP '(' filename ')'
 439                 { lang_add_map($3); }
 440         ;
 441
 442 input_list:
 443                 NAME
 444                 { lang_add_input_file($1,lang_input_file_is_file_enum,
 445                                  (char *)NULL); }
 446         |       input_list ',' NAME
 447                 { lang_add_input_file($3,lang_input_file_is_file_enum,
 448                                  (char *)NULL); }
 449         |       input_list NAME
 450                 { lang_add_input_file($2,
 451 lang_input_file_is_file_enum,
 452                                  (char *)NULL); }
 453         ;
 454
 455 sections:
 456                 SECTIONS '{' sec_or_group_p1 '}'
 457         ;
 458
 459 sec_or_group_p1:
 460                 sec_or_group_p1 section
 461         |       sec_or_group_p1 statement_anywhere
 462         |
 463         ;
 464
 465 statement_anywhere:
 466                 ENTRY '(' NAME ')'
 467                 { lang_add_entry($3); }
 468         |       assignment end
 469         ;
 470
 471 file_NAME_list:
 472                 NAME
 473                         { lang_add_wild($1, current_file); }
 474         |       file_NAME_list opt_comma NAME
 475                         { lang_add_wild($3, current_file); }
 476         ;
 477
 478 input_section_spec:
 479                 NAME
 480                 {
 481                 lang_add_wild((char *)NULL, $1);
 482                 }
 483         |       '['
 484                         {
 485                         current_file = (char *)NULL;
 486                         }
 487                         file_NAME_list
 488                 ']'
 489         |       NAME
 490                         {
 491                         current_file =$1;
 492                         }
 493                 '(' file_NAME_list ')'
 494         |       '*'
 495                         {
 496                         current_file = (char *)NULL;
 497                         }
 498                 '(' file_NAME_list ')'
 499         ;
 500
 501 statement:
 502                 statement assignment end
 503         |       statement CREATE_OBJECT_SYMBOLS
 504                 {
 505
 506 lang_add_attribute(lang_object_symbols_statement_enum); }
 507         |       statement ';'
 508         |       statement CONSTRUCTORS
 509                 {
 510
 511 lang_add_attribute(lang_constructors_statement_enum); }
 512
 513         |       statement input_section_spec
 514         | statement length '(' exp ')'
 515                         {
 516                         lang_add_data($2,$4);
 517                         }
 518
 519         |       statement FILL '(' exp ')'
 520                         {
 521                           lang_add_fill
 522                             (exp_get_value_int($4,
 523                                                0,
 524                                                "fill value",
 525
 526 lang_first_phase_enum));
 527                         }
 528         |
 529         ;
 530
 531 length:
 532                 LONG
 533                         { $$ = $1; }
 534         |       SHORT
 535                         { $$ = $1; }
 536         |       BYTE
 537                         { $$ = $1; }
 538         ;
 539
 540 fill_opt:
 541           '=' mustbe_exp
 542                 {
 543                   $$ =   exp_get_value_int($2,
 544                                            0,
 545                                            "fill value",
 546                                            lang_first_phase_enum);
 547                 }
 548         |       { $$ = 0; }
 549         ;
 550
 551
 552
 553 assign_op:
 554                 PLUSEQ
 555                         { $$ = '+'; }
 556         |       MINUSEQ
 557                         { $$ = '-'; }
 558         |       MULTEQ
 559                         { $$ = '*'; }
 560         |       DIVEQ
 561                         { $$ = '/'; }
 562         |       LSHIFTEQ
 563                         { $$ = LSHIFT; }
 564         |       RSHIFTEQ
 565                         { $$ = RSHIFT; }
 566         |       ANDEQ
 567                         { $$ = '&'; }
 568         |       OREQ
 569                         { $$ = '|'; }
 570
 571         ;
 572
 573 end:    ';' | ','
 574         ;
 575
 576
 577 assignment:
 578                 NAME '=' mustbe_exp
 579                 {
 580                   lang_add_assignment(exp_assop($2,$1,$3));
 581                 }
 582         |       NAME assign_op mustbe_exp
 583                 {
 584
 585 lang_add_assignment(exp_assop('=',$1,exp_binop($2,exp_nameop(NAME,$1),$3)));
 586                 }
 587
 588         ;
 589
 590
 591 opt_comma:
 592                 ','     |       ;
 593
 594
 595 memory:
 596                 MEMORY '{' memory_spec memory_spec_list '}'
 597         ;
 598
 599 memory_spec_list:
 600                 memory_spec_list memory_spec
 601         |       memory_spec_list ',' memory_spec
 602         |
 603         ;
 604
 605
 606 memory_spec:            NAME
 607                         { region = lang_memory_region_lookup($1); }
 608                 attributes_opt ':'
 609                 origin_spec opt_comma length_spec
 610
 611         ; origin_spec:
 612         ORIGIN '=' mustbe_exp
 613                 { region->current =
 614                  region->origin =
 615                  exp_get_vma($3, 0L,"origin", lang_first_phase_enum);
 616 }
 617         ; length_spec:
 618              LENGTH '=' mustbe_exp
 619                { region->length = exp_get_vma($3,
 620                                                ~((bfd_vma)0),
 621                                                "length",
 622                                                lang_first_phase_enum);
 623                 }
 624
 625
 626 attributes_opt:
 627                   '(' NAME ')'
 628                         {
 629                         lang_set_flags(&region->flags, $2);
 630                         }
 631         |
 632
 633         ;
 634
 635 startup:
 636         STARTUP '(' filename ')'
 637                 { lang_startup($3); }
 638         ;
 639
 640 high_level_library:
 641                 HLL '(' high_level_library_NAME_list ')'
 642         |       HLL '(' ')'
 643                         { ldemul_hll((char *)NULL); }
 644         ;
 645
 646 high_level_library_NAME_list:
 647                 high_level_library_NAME_list opt_comma filename
 648                         { ldemul_hll($3); }
 649         |       filename
 650                         { ldemul_hll($1); }
 651
 652         ;
 653
 654 low_level_library:
 655         SYSLIB '(' low_level_library_NAME_list ')'
 656         ; low_level_library_NAME_list:
 657                 low_level_library_NAME_list opt_comma filename
 658                         { ldemul_syslib($3); }
 659         |
 660         ;
 661
 662 floating_point_support:
 663                 FLOAT
 664                         { lang_float(true); }
 665         |       NOFLOAT
 666                         { lang_float(false); }
 667         ;
 668
 669
 670 mustbe_exp:              { ldlex_expression(); }
 671                 exp
 672                          { ldlex_popstate(); $$=$2;}
 673         ;
 674
 675 exp     :
 676                 '-' exp %prec UNARY
 677                         { $$ = exp_unop('-', $2); }
 678         |       '(' exp ')'
 679                         { $$ = $2; }
 680         |       NEXT '(' exp ')' %prec UNARY
 681                         { $$ = exp_unop($1,$3); }
 682         |       '!' exp %prec UNARY
 683                         { $$ = exp_unop('!', $2); }
 684         |       '+' exp %prec UNARY
 685                         { $$ = $2; }
 686         |       '~' exp %prec UNARY
 687                         { $$ = exp_unop('~', $2);}
 688
 689         |       exp '*' exp
 690                         { $$ = exp_binop('*', $1, $3); }
 691         |       exp '/' exp
 692                         { $$ = exp_binop('/', $1, $3); }
 693         |       exp '%' exp
 694                         { $$ = exp_binop('%', $1, $3); }
 695         |       exp '+' exp
 696                         { $$ = exp_binop('+', $1, $3); }
 697         |       exp '-' exp
 698                         { $$ = exp_binop('-' , $1, $3); }
 699         |       exp LSHIFT exp
 700                         { $$ = exp_binop(LSHIFT , $1, $3); }
 701         |       exp RSHIFT exp
 702                         { $$ = exp_binop(RSHIFT , $1, $3); }
 703         |       exp EQ exp
 704                         { $$ = exp_binop(EQ , $1, $3); }
 705         |       exp NE exp
 706                         { $$ = exp_binop(NE , $1, $3); }
 707         |       exp LE exp
 708                         { $$ = exp_binop(LE , $1, $3); }
 709         |       exp GE exp
 710                         { $$ = exp_binop(GE , $1, $3); }
 711         |       exp '<' exp
 712                         { $$ = exp_binop('<' , $1, $3); }
 713         |       exp '>' exp
 714                         { $$ = exp_binop('>' , $1, $3); }
 715         |       exp '&' exp
 716                         { $$ = exp_binop('&' , $1, $3); }
 717         |       exp '^' exp
 718                         { $$ = exp_binop('^' , $1, $3); }
 719         |       exp '|' exp
 720                         { $$ = exp_binop('|' , $1, $3); }
 721         |       exp '?' exp ':' exp
 722                         { $$ = exp_trinop('?' , $1, $3, $5); }
 723         |       exp ANDAND exp
 724                         { $$ = exp_binop(ANDAND , $1, $3); }
 725         |       exp OROR exp
 726                         { $$ = exp_binop(OROR , $1, $3); }
 727         |       DEFINED '(' NAME ')'
 728                         { $$ = exp_nameop(DEFINED, $3); }
 729         |       INT
 730                         { $$ = exp_intop($1); }
 731         |       SIZEOF_HEADERS
 732                         { $$ = exp_nameop(SIZEOF_HEADERS,0); }
 733
 734         |       SIZEOF '(' NAME ')'
 735                         { $$ = exp_nameop(SIZEOF,$3); }
 736         |       ADDR '(' NAME ')'
 737                         { $$ = exp_nameop(ADDR,$3); }
 738         |       ALIGN_K '(' exp ')'
 739                         { $$ = exp_unop(ALIGN_K,$3); }
 740         |       NAME
 741                         { $$ = exp_nameop(NAME,$1); }
 742         ;
 743
 744
 745
 746
 747 section:        NAME            { ldlex_expression(); }
 748                 opt_exp         { ldlex_popstate(); }
 749                 opt_type opt_block ':' opt_things'{'
 750                 {
 751                 lang_enter_output_section_statement($1,$3,$5,$6);
 752                 }
 753                statement        '}'     fill_opt memspec_opt
 754                 {
 755                   lang_leave_output_section_statement($13, $14);
 756                 }
 757
 758         ;
 759
 760 opt_type:
 761           '(' NOLOAD ')' { $$ = SEC_NO_FLAGS; }
 762         | '(' DSECT ')' { $$ = 0; }
 763         | '(' COPY ')' { $$ = 0; }
 764         | '(' INFO ')' { $$ = 0; }
 765         | '(' OVERLAY ')' { $$ = 0; }
 766         | { $$ = SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS; }
 767         ;
 768
 769 opt_things:
 770       {
 771       };
 772
 773
 774 opt_exp:
 775                 exp
 776                         { $$ = $1; }
 777         |               { $$= (etree_type *)NULL; }
 778         ;
 779
 780 opt_block:
 781                 BLOCK '(' exp ')'
 782                 { $$ = exp_get_value_int($3,
 783                                          1L,
 784                                          "block",
 785                                          lang_first_phase_enum);
 786                 }
 787         |       { $$  = 1; }
 788         ;
 789
 790 memspec_opt:
 791                 '>' NAME
 792                 { $$ = $2; }
 793         |       { $$ = "*default*"; }
 794         ;
 795 %%
 796 void
 797 yyerror(arg)
 798 char *arg;
 799 {
 800   if (error_index> 0  && error_index < ERROR_NAME_MAX)
 801      einfo("%P%F: %S syntax error in %s\n",error_names[error_index-1]);
 802   else
 803      einfo("%P%F: %S syntax error\n");
 804 }