parser.y

   1 %{
   2 /*
   3  * $Id: parser.y,v 1.14 2007/11/11 22:35:51 khansen Exp $
   4  * $Log: parser.y,v $
   5  * Revision 1.14  2007/11/11 22:35:51  khansen
   6  * compile on mac
   7  *
   8  * Revision 1.13  2007/08/19 11:19:47  khansen
   9  * --case-insensitive option
  10  *
  11  * Revision 1.12  2007/08/12 18:59:00  khansen
  12  * ability to generate pure 6502 binary
  13  *
  14  * Revision 1.11  2007/08/11 01:25:50  khansen
  15  * includepaths support (-I option)
  16  *
  17  * Revision 1.10  2007/07/22 13:34:38  khansen
  18  * convert tabs to whitespaces
  19  *
  20  * Revision 1.9  2005/01/05 02:28:40  kenth
  21  * anonymous union parsing
  22  *
  23  * Revision 1.8  2004/12/29 21:45:26  kenth
  24  * xorcyst 1.4.2
  25  * static indexing
  26  *
  27  * Revision 1.7  2004/12/19 19:59:14  kenth
  28  * xorcyst 1.4.0
  29  *
  30  * Revision 1.6  2004/12/16 13:22:27  kenth
  31  * xorcyst 1.3.5
  32  *
  33  * Revision 1.5  2004/12/14 01:50:42  kenth
  34  * xorcyst 1.3.0
  35  *
  36  * Revision 1.4  2004/12/11 02:12:41  kenth
  37  * xorcyst 1.2.0
  38  *
  39  * Revision 1.3  2004/12/09 11:17:15  kenth
  40  * added: warning_statement, error_statement
  41  *
  42  * Revision 1.2  2004/12/06 05:06:21  kenth
  43  * xorcyst 1.1.0
  44  *
  45  * Revision 1.1  2004/06/30 07:57:03  kenth
  46  * Initial revision
  47  *
  48  */
  49 #include <stdlib.h>
  50 #include <stdio.h>
  51 #include <string.h>
  52 #include "symtab.h"
  53 #include "loc.h"
  54 #include "xasm.h"
  55 //#define YYDEBUG 1
  56 int yyparse(void);
  57 void yyerror(const char *);   /* In lexer */
  58 int yylex(void);    /* In lexer */
  59 int yypushandrestart(const char *, int);   /* In lexer */
  60 void __yy_memcpy(char *, char *, int);
  61 extern char *yytext;    /* In lexer */
  62 extern YYLTYPE yylloc;  /* In lexer */
  63 char *scan_include(int); /* In lexer */
  64 extern astnode *root_node;  /* Root of the generated parse tree */
  65 void handle_incsrc(astnode *);  /* See below */
  66 void handle_incbin(astnode *);  /* See below */
  67 %}
  68
  69 %union {
  70     long integer;
  71     int mnemonic;
  72     const char *string;
  73     const char *label;
  74     const char *ident;
  75     astnode *node;
  76 };
  77
  78 %error-verbose
  79
  80 %token <integer> INTEGER_LITERAL
  81 %token <string> STRING_LITERAL
  82 %token <string> FILE_PATH
  83 %token <ident> IDENTIFIER
  84 %token <ident> LOCAL_ID
  85 %token <ident> FORWARD_BRANCH
  86 %token <ident> BACKWARD_BRANCH
  87 %token <label> LABEL
  88 %token <label> LOCAL_LABEL
  89 %token <mnemonic> MNEMONIC
  90
  91 %type <node> identifier identifier_opt local_id assembly_unit statement labelable_statement statement_list if_statement elif_statement elif_statement_list elif_statement_list_opt ifdef_statement ifndef_statement macro_decl_statement macro_statement instruction_statement data_statement storage_statement null_statement incsrc_statement incbin_statement equ_statement assign_statement public_statement extrn_statement dataseg_statement codeseg_statement charmap_statement struc_decl_statement union_decl_statement enum_decl_statement record_decl_statement instruction expression extended_expression expression_opt arithmetic_expression comparison_expression literal label label_decl identifier_list expression_list file_specifier param_list_opt arg_list_opt else_part_opt scope_access struc_access struc_initializer field_initializer_list field_initializer_list_opt field_initializer datatype storage named_data_statement unnamed_data_statement named_storage_statement unnamed_storage_statement proc_statement rept_statement label_statement message_statement warning_statement error_statement while_statement define_statement align_statement org_statement symbol_type enum_item_list enum_item record_field_list record_field sizeof_arg label_addr_part_opt label_type_part_opt from_part_opt indexed_identifier
  92
  93 %token _LABEL_ BYTE CHAR WORD DWORD DSB DSW DSD DATASEG CODESEG IF IFDEF IFNDEF ELSE ELIF ENDIF INCSRC INCBIN MACRO REPT WHILE ENDM ALIGN EQU DEFINE END PUBLIC EXTRN CHARMAP STRUC UNION ENDS RECORD ENUM ENDE PROC ENDP SIZEOF MASK TAG MESSAGE WARNING ERROR ZEROPAGE ORG
  94
  95 %token '\n'
  96 %token ':'
  97 %token '@'
  98 %token SCOPE_OP
  99 %token 'A' 'X' 'Y'
 100 %token '='
 101 %token '$'
 102 %token '{' '}'
 103 %token '[' ']'
 104 %left ','
 105 %token '.'
 106 %right '#'
 107 %right LO_OP HI_OP
 108 %left '|'
 109 %left '^'
 110 %left '&'
 111 %left EQ_OP NE_OP
 112 %left LE_OP GE_OP '>' '<'
 113 %left SHL_OP SHR_OP
 114 %left '+' '-'
 115 %right UMINUS
 116 %left '*' '/' '%'
 117 %right '!' '~'
 118 %left '('
 119 %right ')'
 120 %start assembly_unit
 121 %%
 122 assembly_unit:
 123     statement_list end_opt { root_node = astnode_create_list($1); }
 124     ;
 125
 126 end_opt:
 127     END line_tail { ; }
 128     | /* empty */
 129     ;
 130
 131 statement_list:
 132     labelable_statement { $$ = $1; }
 133     | statement_list labelable_statement {
 134          if ($1 != NULL) { $$ = $1; astnode_add_sibling($$, $2); }
 135          else { $$ = $2; }
 136         }
 137     ;
 138
 139 labelable_statement:
 140     label_decl statement { $$ = $1; astnode_add_sibling($$, $2); }
 141     | statement { $$ = $1; }
 142     ;
 143
 144 statement:
 145     if_statement { $$ = $1; }
 146     | ifdef_statement { $$ = $1; }
 147     | ifndef_statement { $$ = $1; }
 148     | macro_decl_statement { $$ = $1; }
 149     | macro_statement { $$ = $1; }
 150     | incsrc_statement { $$ = $1; }
 151     | incbin_statement { $$ = $1; }
 152     | equ_statement { $$ = $1; }
 153     | assign_statement { $$ = $1; }
 154     | public_statement { $$ = $1; }
 155     | extrn_statement { $$ = $1; }
 156     | instruction_statement { $$ = $1; }
 157     | data_statement { $$ = $1; }
 158     | storage_statement { $$ = $1; }
 159     | dataseg_statement { $$ = $1; }
 160     | codeseg_statement { $$ = $1; }
 161     | charmap_statement { $$ = $1; }
 162     | struc_decl_statement { $$ = $1; }
 163     | union_decl_statement { $$ = $1; }
 164     | enum_decl_statement { $$ = $1; }
 165     | record_decl_statement { $$ = $1; }
 166     | proc_statement { $$ = $1; }
 167     | rept_statement { $$ = $1; }
 168     | while_statement { $$ = $1; }
 169     | label_statement { $$ = $1; }
 170     | message_statement { $$ = $1; }
 171     | warning_statement { $$ = $1; }
 172     | error_statement { $$ = $1; }
 173     | define_statement { $$ = $1; }
 174     | align_statement { $$ = $1; }
 175     | org_statement { $$ = $1; }
 176     | null_statement { $$ = $1; }
 177     | error line_tail { $$ = NULL; }
 178     ;
 179
 180 org_statement:
 181     ORG expression line_tail { $$ = astnode_create_org($2, @$); }
 182     ;
 183
 184 align_statement:
 185     ALIGN identifier_list expression line_tail { $$ = astnode_create_align($2, $3, @$); }
 186     ;
 187
 188 warning_statement:
 189     WARNING expression line_tail { $$ = astnode_create_warning($2, @$); }
 190     ;
 191
 192 error_statement:
 193     ERROR expression line_tail { $$ = astnode_create_error($2, @$); }
 194     ;
 195
 196 message_statement:
 197     MESSAGE expression line_tail { $$ = astnode_create_message($2, @$); }
 198     ;
 199
 200 label_statement:
 201     _LABEL_ identifier label_addr_part_opt label_type_part_opt line_tail { $$ = astnode_create_label($2->label, $3, $4, @$); }
 202     ;
 203
 204 label_addr_part_opt:
 205     '=' expression { $$ = $2; }
 206     | { $$ = NULL; }
 207     ;
 208
 209 label_type_part_opt:
 210     ':' symbol_type { $$ = $2; }
 211     | { $$ = NULL; }
 212     ;
 213
 214 while_statement:
 215     WHILE expression line_tail statement_list ENDM line_tail { $$ = astnode_create_while($2, $4, @$); }
 216     ;
 217
 218 rept_statement:
 219     REPT expression line_tail statement_list ENDM line_tail { $$ = astnode_create_rept($2, $4, @$); }
 220     ;
 221
 222 proc_statement:
 223     PROC identifier line_tail statement_list ENDP line_tail { $$ = astnode_create_proc($2, $4, @$); }
 224     ;
 225
 226 struc_decl_statement:
 227     STRUC identifier line_tail statement_list ENDS line_tail { $$ = astnode_create_struc_decl($2, $4, @$); }
 228     ;
 229
 230 union_decl_statement:
 231     UNION identifier_opt line_tail statement_list ENDS line_tail { $$ = astnode_create_union_decl($2, $4, @$); }
 232     ;
 233
 234 enum_decl_statement:
 235     ENUM identifier line_tail enum_item_list ENDE line_tail { $$ = astnode_create_enum_decl($2, $4, @$); }
 236     ;
 237
 238 enum_item_list:
 239     enum_item { $$ = $1; }
 240     | enum_item_list enum_item { $$ = $1; astnode_add_sibling($$, $2); }
 241     ;
 242
 243 enum_item:
 244     assign_statement { $$ = $1; }
 245     | identifier line_tail { $$ = $1; }
 246     ;
 247
 248 record_decl_statement:
 249     RECORD identifier record_field_list line_tail { $$ = astnode_create_record_decl($2, $3, @$); }
 250     ;
 251
 252 record_field_list:
 253     record_field { $$ = $1; }
 254     | record_field_list ',' record_field { $$ = $1; astnode_add_sibling($$, $3); }
 255     ;
 256
 257 record_field:
 258     identifier ':' expression { $$ = astnode_create_bitfield_decl($1, $3, @$); }
 259     ;
 260
 261 charmap_statement:
 262     CHARMAP file_specifier line_tail { $$ = astnode_create_charmap($2, @$); }
 263     ;
 264
 265 dataseg_statement:
 266     DATASEG line_tail { $$ = astnode_create_dataseg(0, @$); }
 267     | DATASEG ZEROPAGE line_tail { $$ = astnode_create_dataseg(ZEROPAGE_FLAG, @$); }
 268
 269 codeseg_statement:
 270     CODESEG line_tail { $$ = astnode_create_codeseg(@$); }
 271     ;
 272
 273 null_statement:
 274     line_tail { $$ = NULL; }
 275     ;
 276
 277 label_decl:
 278     label { $$ = $1; }
 279     ;
 280
 281 line_tail:
 282     newline { ; }
 283     | ':' { ; }
 284     ;
 285
 286 newline:
 287     '\n' { ; }
 288     ;
 289
 290 instruction_statement:
 291     instruction line_tail { $$ = $1; }
 292     ;
 293
 294 instruction:
 295     MNEMONIC { $$ = astnode_create_instruction($1, IMPLIED_MODE, NULL, @$); }
 296     | MNEMONIC 'A' { $$ = astnode_create_instruction($1, ACCUMULATOR_MODE, NULL, @$); }
 297     | MNEMONIC '#' expression { $$ = astnode_create_instruction($1, IMMEDIATE_MODE, $3, @$); }
 298     | MNEMONIC expression { $$ = astnode_create_instruction($1, ABSOLUTE_MODE, $2, @$); }
 299     | MNEMONIC expression ',' 'X' { $$ = astnode_create_instruction($1, ABSOLUTE_X_MODE, $2, @$); }
 300     | MNEMONIC expression ',' 'Y' { $$ = astnode_create_instruction($1, ABSOLUTE_Y_MODE, $2, @$); }
 301     | MNEMONIC '[' expression ',' 'X' ']' { $$ = astnode_create_instruction($1, PREINDEXED_INDIRECT_MODE, $3, @$); }
 302     | MNEMONIC '[' expression ']' ',' 'Y' { $$ = astnode_create_instruction($1, POSTINDEXED_INDIRECT_MODE, $3, @$); }
 303     | MNEMONIC '[' expression ']' { $$ = astnode_create_instruction($1, INDIRECT_MODE, $3, @$); }
 304     ;
 305
 306 expression:
 307     indexed_identifier { $$ = $1; }
 308     | SIZEOF sizeof_arg { $$ = astnode_create_sizeof($2, @$); }
 309     | scope_access { $$ = $1; }
 310     | struc_access { $$ = $1; }
 311     | local_id { $$ = $1; }
 312     | literal { $$ = $1; }
 313     | '$' { $$ = astnode_create_pc(@$); }
 314     | arithmetic_expression { $$ = $1; }
 315     | comparison_expression { $$ = $1; }
 316     | '(' expression ')' { $$ = $2; }
 317     | '+' { $$ = astnode_create_forward_branch("+", @$); }
 318     | '-' { $$ = astnode_create_backward_branch("-", @$); }
 319     | FORWARD_BRANCH { $$ = astnode_create_forward_branch($1, @$); }
 320     | BACKWARD_BRANCH { $$ = astnode_create_backward_branch($1, @$); }
 321     | MASK scope_access { $$ = astnode_create_mask($2, @$); }
 322     ;
 323
 324 indexed_identifier:
 325     identifier { $$ = $1; }
 326     | identifier '[' expression ']' { $$ = astnode_create_index($1, $3, @$); }
 327     | identifier '(' expression ')' { $$ = astnode_create_index($1, $3, @$); }
 328     ;
 329
 330 extended_expression:
 331     expression { $$ = $1; }
 332     | struc_initializer { $$ = $1; }
 333     ;
 334
 335 sizeof_arg:
 336     identifier { $$ = $1; }
 337     | datatype { $$ = $1; }
 338     ;
 339
 340 expression_opt:
 341     expression { $$ = $1; }
 342     | { $$ = NULL; }
 343     ;
 344
 345 scope_access:
 346     identifier SCOPE_OP identifier { $$ = astnode_create_scope($1, $3, @$); }
 347     ;
 348
 349 struc_access:
 350     indexed_identifier '.' struc_access { $$ = astnode_create_dot($1, $3, @$); }
 351     | indexed_identifier '.' indexed_identifier { $$ = astnode_create_dot($1, $3, @$); }
 352     ;
 353
 354 struc_initializer:
 355     '{' field_initializer_list_opt '}' { $$ = astnode_create_struc($2, @$); }
 356     ;
 357
 358 field_initializer_list_opt:
 359     field_initializer_list { $$ = $1; }
 360     | { $$ = NULL; }
 361     ;
 362
 363 field_initializer_list:
 364     field_initializer { $$ = $1; }
 365     | field_initializer_list ',' field_initializer { $$ = $1; astnode_add_sibling($$, $3); }
 366     ;
 367
 368 field_initializer:
 369     extended_expression { $$ = $1; }
 370     | { $$ = astnode_create_null(@$); }
 371     ;
 372
 373 local_id:
 374     LOCAL_ID { $$ = astnode_create_local_id($1, @$); }
 375     ;
 376
 377 arithmetic_expression:
 378     expression '+' expression { $$ = astnode_create_arithmetic(PLUS_OPERATOR, $1, $3, @$); }
 379     | expression '-' expression { $$ = astnode_create_arithmetic(MINUS_OPERATOR, $1, $3, @$); }
 380     | expression '*' expression { $$ = astnode_create_arithmetic(MUL_OPERATOR, $1, $3, @$); }
 381     | expression '/' expression { $$ = astnode_create_arithmetic(DIV_OPERATOR, $1, $3, @$); }
 382     | expression '%' expression { $$ = astnode_create_arithmetic(MOD_OPERATOR, $1, $3, @$); }
 383     | expression '&' expression { $$ = astnode_create_arithmetic(AND_OPERATOR, $1, $3, @$); }
 384     | expression '|' expression { $$ = astnode_create_arithmetic(OR_OPERATOR, $1, $3, @$); }
 385     | expression '^' expression { $$ = astnode_create_arithmetic(XOR_OPERATOR, $1, $3, @$); }
 386     | expression SHL_OP expression { $$ = astnode_create_arithmetic(SHL_OPERATOR, $1, $3, @$); }
 387     | expression SHR_OP expression { $$ = astnode_create_arithmetic(SHR_OPERATOR, $1, $3, @$); }
 388     | '~' expression { $$ = astnode_create_arithmetic(NEG_OPERATOR, $2, NULL, @$); }
 389     | '!' expression { $$ = astnode_create_arithmetic(NOT_OPERATOR, $2, NULL, @$); }
 390     | '^' identifier { $$ = astnode_create_arithmetic(BANK_OPERATOR, $2, NULL, @$); }
 391     | '<' expression %prec LO_OP { $$ = astnode_create_arithmetic(LO_OPERATOR, $2, NULL, @$); }
 392     | '>' expression %prec HI_OP { $$ = astnode_create_arithmetic(HI_OPERATOR, $2, NULL, @$); }
 393     | '-' expression %prec UMINUS { $$ = astnode_create_arithmetic(UMINUS_OPERATOR, $2, NULL, @$); }
 394     ;
 395
 396 comparison_expression:
 397     expression EQ_OP expression { $$ = astnode_create_arithmetic(EQ_OPERATOR, $1, $3, @$); }
 398     | expression NE_OP expression { $$ = astnode_create_arithmetic(NE_OPERATOR, $1, $3, @$); }
 399     | expression '>' expression { $$ = astnode_create_arithmetic(GT_OPERATOR, $1, $3, @$); }
 400     | expression '<' expression { $$ = astnode_create_arithmetic(LT_OPERATOR, $1, $3, @$); }
 401     | expression GE_OP expression { $$ = astnode_create_arithmetic(GE_OPERATOR, $1, $3, @$); }
 402     | expression LE_OP expression { $$ = astnode_create_arithmetic(LE_OPERATOR, $1, $3, @$); }
 403     ;
 404
 405 label:
 406     LABEL { $$ = astnode_create_label($1, NULL, NULL, @$); }
 407     | LOCAL_LABEL { $$ = astnode_create_local_label($1, @$); }
 408     | '+' { $$ = astnode_create_forward_branch_decl("+", @$); }
 409     | '-' { $$ = astnode_create_backward_branch_decl("-", @$); }
 410     | FORWARD_BRANCH { $$ = astnode_create_forward_branch_decl($1, @$); }
 411     | BACKWARD_BRANCH { $$ = astnode_create_backward_branch_decl($1, @$); }
 412     ;
 413
 414 identifier:
 415     IDENTIFIER { $$ = astnode_create_identifier($1, @$); }
 416     ;
 417
 418 identifier_opt:
 419     identifier { $$ = $1; }
 420     | { $$ = astnode_create_null(@$); }
 421     ;
 422
 423 literal:
 424     INTEGER_LITERAL { $$ = astnode_create_integer($1, @$); }
 425     | STRING_LITERAL { $$ = astnode_create_string($1, @$); }
 426     ;
 427
 428 if_statement:
 429     IF expression line_tail statement_list elif_statement_list_opt else_part_opt ENDIF line_tail { $$ = astnode_create_if($2, $4, $5, $6, @$); }
 430     ;
 431
 432 elif_statement_list_opt:
 433     elif_statement_list { $$ = $1; }
 434     | { $$ = NULL; }
 435     ;
 436
 437 elif_statement_list:
 438     elif_statement { $$ = $1; }
 439     | elif_statement_list elif_statement { $$ = $1; astnode_add_sibling($$, $2); }
 440     ;
 441
 442 elif_statement:
 443     ELIF expression line_tail statement_list { $$ = astnode_create_case($2, $4, @$); }
 444     ;
 445
 446 else_part_opt:
 447     ELSE line_tail statement_list { $$ = $3; }
 448     | { $$ = NULL; }
 449     ;
 450
 451 ifdef_statement:
 452     IFDEF identifier line_tail statement_list else_part_opt ENDIF line_tail { $$ = astnode_create_ifdef($2, $4, $5, @$); }
 453     ;
 454
 455 ifndef_statement:
 456     IFNDEF identifier line_tail statement_list else_part_opt ENDIF line_tail { $$ = astnode_create_ifndef($2, $4, $5, @$); }
 457     ;
 458
 459 data_statement:
 460     named_data_statement line_tail { $$ = $1; }
 461     | unnamed_data_statement line_tail { $$ = $1; }
 462     ;
 463
 464 named_data_statement:
 465     identifier unnamed_data_statement { $$ = astnode_create_var_decl(0, $1, $2, @$); }
 466     | ZEROPAGE identifier unnamed_data_statement { $$ = astnode_create_var_decl(ZEROPAGE_FLAG, $2, $3, @$); }
 467     | PUBLIC identifier unnamed_data_statement { $$ = astnode_create_var_decl(PUBLIC_FLAG, $2, $3, @$); }
 468     | ZEROPAGE PUBLIC identifier unnamed_data_statement { $$ = astnode_create_var_decl(ZEROPAGE_FLAG | PUBLIC_FLAG, $3, $4, @$); }
 469     | PUBLIC ZEROPAGE identifier unnamed_data_statement { $$ = astnode_create_var_decl(PUBLIC_FLAG | ZEROPAGE_FLAG, $3, $4, @$); }
 470     ;
 471
 472 unnamed_data_statement:
 473     datatype expression_list { $$ = astnode_create_data($1, $2, @$); }
 474     | datatype { $$ = astnode_create_storage($1, NULL, @$); }
 475     | datatype '[' expression ']' { $$ = astnode_create_storage($1, $3, @$); }
 476     ;
 477
 478 datatype:
 479     BYTE { $$ = astnode_create_datatype(BYTE_DATATYPE, NULL, @$); }
 480     | CHAR { $$ = astnode_create_datatype(CHAR_DATATYPE, NULL, @$); }
 481     | WORD { $$ = astnode_create_datatype(WORD_DATATYPE, NULL, @$); }
 482     | DWORD { $$ = astnode_create_datatype(DWORD_DATATYPE, NULL, @$); }
 483     | TAG identifier { $$ = astnode_create_datatype(USER_DATATYPE, $2, @$); }
 484     | '.' identifier { $$ = astnode_create_datatype(USER_DATATYPE, $2, @$); }
 485     ;
 486
 487 expression_list:
 488     extended_expression { $$ = $1; }
 489     | expression_list ',' extended_expression { $$ = $1; astnode_add_sibling($$, $3); }
 490     ;
 491
 492 incsrc_statement:
 493     INCSRC file_specifier line_tail { $$ = astnode_create_incsrc($2, @$); handle_incsrc($$); }
 494     ;
 495
 496 incbin_statement:
 497     INCBIN file_specifier line_tail { $$ = astnode_create_incbin($2, @$); handle_incbin($$); }
 498     ;
 499
 500 file_specifier:
 501     STRING_LITERAL { $$ = astnode_create_string($1, @$); }
 502     | '<' { $$ = astnode_create_file_path(scan_include('>'), @$); }
 503     ;
 504
 505 macro_decl_statement:
 506     MACRO identifier param_list_opt line_tail statement_list ENDM line_tail { $$ = astnode_create_macro_decl($2, $3, $5, @$); }
 507     ;
 508
 509 param_list_opt:
 510     identifier_list { $$ = $1; }
 511     | { $$ = NULL; }
 512     ;
 513
 514 macro_statement:
 515     identifier arg_list_opt line_tail { $$ = astnode_create_macro($1, $2, @$); }
 516     ;
 517
 518 arg_list_opt:
 519     expression_list { $$ = $1; }
 520     | { $$ = NULL; }
 521     ;
 522
 523 identifier_list:
 524     identifier { $$ = $1; }
 525     | identifier_list ',' identifier { $$ = $1; astnode_add_sibling($$, $3); }
 526     ;
 527
 528 equ_statement:
 529     identifier EQU extended_expression line_tail { $$ = astnode_create_equ($1, $3, @$); }
 530     ;
 531
 532 assign_statement:
 533     identifier '=' extended_expression line_tail { $$ = astnode_create_assign($1, $3, @$); }
 534     ;
 535
 536 define_statement:
 537     DEFINE identifier line_tail { $$ = astnode_create_equ($2, astnode_create_integer(0, @$), @$); }
 538     | DEFINE identifier extended_expression line_tail { $$ = astnode_create_equ($2, $3, @$); }
 539     ;
 540
 541 public_statement:
 542     PUBLIC identifier_list line_tail { $$ = astnode_create_public($2, @$); }
 543     ;
 544
 545 extrn_statement:
 546     EXTRN identifier_list ':' symbol_type from_part_opt line_tail { $$ = astnode_create_extrn($2, $4, $5, @$); }
 547     ;
 548
 549 from_part_opt:
 550     '@' identifier { $$ = $2; }
 551     | { $$ = NULL; }
 552     ;
 553
 554 symbol_type:
 555     datatype { $$ = $1; }
 556     | identifier { $$ = astnode_create_datatype(USER_DATATYPE, $1, @$); }
 557     | PROC { $$ = astnode_create_integer(PROC_SYMBOL, @$); }
 558     | _LABEL_ { $$ = astnode_create_integer(LABEL_SYMBOL, @$); }
 559     ;
 560
 561 storage_statement:
 562     named_storage_statement { $$ = $1; }
 563     | unnamed_storage_statement { $$ = $1; }
 564     ;
 565
 566 named_storage_statement:
 567     identifier unnamed_storage_statement { $$ = astnode_create_var_decl(0, $1, $2, @$); }
 568     | ZEROPAGE identifier unnamed_storage_statement { $$ = astnode_create_var_decl(ZEROPAGE_FLAG, $2, $3, @$); }
 569     | PUBLIC identifier unnamed_storage_statement { $$ = astnode_create_var_decl(PUBLIC_FLAG, $2, $3, @$); }
 570     | ZEROPAGE PUBLIC identifier unnamed_storage_statement { $$ = astnode_create_var_decl(ZEROPAGE_FLAG | PUBLIC_FLAG, $3, $4, @$); }
 571     | PUBLIC ZEROPAGE identifier unnamed_storage_statement { $$ = astnode_create_var_decl(PUBLIC_FLAG | ZEROPAGE_FLAG, $3, $4, @$); }
 572     ;
 573
 574 unnamed_storage_statement:
 575     storage expression_opt line_tail { $$ = astnode_create_storage($1, $2, @$); }
 576     ;
 577
 578 storage:
 579     DSB { $$ = astnode_create_datatype(BYTE_DATATYPE, NULL, @$); }
 580     | DSW { $$ = astnode_create_datatype(WORD_DATATYPE, NULL, @$); }
 581     | DSD { $$ = astnode_create_datatype(DWORD_DATATYPE, NULL, @$); }
 582     ;
 583 %%
 584 /**
 585  * Takes care of switching to a new scanner input stream when a "incsrc" statement
 586  * has been encountered.
 587  * The current stream is pushed on a stack, and will be popped when EOF is reached
 588  * in the new stream.
 589  * @param n A node of type INCSRC_NODE
 590  */
 591 void handle_incsrc(astnode *n)
 592 {
 593     char errs[512];
 594     /* Get the node which describes the file to include */
 595     astnode *file = astnode_get_child(n, 0);
 596     int quoted_form = (astnode_get_type(file) == STRING_NODE) ? 1 : 0;
 597     switch (yypushandrestart(file->string, quoted_form)) {
 598         case 0:
 599         /* Success */
 600         break;
 601         case 1:
 602         /* Failed to open file */
 603         sprintf(errs, "could not open '%s' for reading", file->string);
 604         yyerror(errs);
 605         break;
 606         case 2:
 607         /* Stack overflow */
 608         yyerror("Maximum include nesting level reached");
 609         break;
 610     }
 611 }
 612
 613 // TODO: This shouldn't be done here but rather in astproc module.
 614
 615 FILE *open_included_file(const char *, int, char **);
 616
 617 /**
 618  * Takes care of including the binary contents of the file specified by a parsed
 619  * "incbin" statement.
 620  * Calls yyerror() if the file can't be included for some reason.
 621  * @param n A node of type INCBIN_NODE
 622  */
 623 void handle_incbin(astnode *n)
 624 {
 625     FILE *fp;
 626     unsigned char *data;
 627     int size;
 628     char errs[512];
 629     /* Get the node which describes the file to include */
 630     astnode *file = astnode_get_child(n, 0);
 631     const char *filename = file->string;
 632     int quoted_form = (astnode_get_type(file) == STRING_NODE) ? 1 : 0;
 633     /* Try to open it */
 634     fp = open_included_file(filename, quoted_form, NULL);
 635     if (fp) {
 636         /* Get filesize */
 637         fseek(fp, 0, SEEK_END);
 638         size = ftell(fp);
 639         rewind(fp);
 640         if (size > 0) {
 641             /* Allocate buffer to hold file contents */
 642             data = (unsigned char *)malloc(size);
 643             /* Read file contents into buffer */
 644             fread(data, 1, size, fp);
 645             /* Insert binary node */
 646             astnode_add_sibling(n, astnode_create_binary(data, size, n->loc) );
 647         }
 648         /* Close file */
 649         fclose(fp);
 650     } else {
 651         /* Couldn't open file */
 652         sprintf(errs, "could not open '%s' for reading", file->string);
 653         yyerror(errs);
 654     }
 655 }