ld/ldlang.h

   1 /* ldlang.h - linker command language support
   2    Copyright 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
   3    2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
   4    Free Software Foundation, Inc.
   5
   6    This file is part of the GNU Binutils.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21    MA 02110-1301, USA.  */
  22
  23 #ifndef LDLANG_H
  24 #define LDLANG_H
  25
  26 #define DEFAULT_MEMORY_REGION   "*default*"
  27
  28 typedef enum
  29 {
  30   lang_input_file_is_l_enum,
  31   lang_input_file_is_symbols_only_enum,
  32   lang_input_file_is_marker_enum,
  33   lang_input_file_is_fake_enum,
  34   lang_input_file_is_search_file_enum,
  35   lang_input_file_is_file_enum
  36 } lang_input_file_enum_type;
  37
  38 struct _fill_type
  39 {
  40   size_t size;
  41   unsigned char data[1];
  42 };
  43
  44 typedef struct statement_list
  45 {
  46   union lang_statement_union *  head;
  47   union lang_statement_union ** tail;
  48 } lang_statement_list_type;
  49
  50 typedef struct memory_region_name_struct
  51 {
  52   const char * name;
  53   struct memory_region_name_struct * next;
  54 } lang_memory_region_name;
  55
  56 typedef struct memory_region_struct
  57 {
  58   lang_memory_region_name name_list;
  59   struct memory_region_struct *next;
  60   bfd_vma origin;
  61   bfd_size_type length;
  62   bfd_vma current;
  63   union lang_statement_union *last_os;
  64   flagword flags;
  65   flagword not_flags;
  66   bfd_boolean had_full_message;
  67 } lang_memory_region_type;
  68
  69 enum statement_enum
  70 {
  71   lang_output_section_statement_enum,
  72   lang_assignment_statement_enum,
  73   lang_input_statement_enum,
  74   lang_address_statement_enum,
  75   lang_wild_statement_enum,
  76   lang_input_section_enum,
  77   lang_object_symbols_statement_enum,
  78   lang_fill_statement_enum,
  79   lang_data_statement_enum,
  80   lang_reloc_statement_enum,
  81   lang_target_statement_enum,
  82   lang_output_statement_enum,
  83   lang_padding_statement_enum,
  84   lang_group_statement_enum,
  85   lang_insert_statement_enum,
  86   lang_constructors_statement_enum
  87 };
  88
  89 typedef struct lang_statement_header_struct
  90 {
  91   union lang_statement_union *next;
  92   enum statement_enum type;
  93 } lang_statement_header_type;
  94
  95 typedef struct
  96 {
  97   lang_statement_header_type header;
  98   union etree_union *exp;
  99 } lang_assignment_statement_type;
 100
 101 typedef struct lang_target_statement_struct
 102 {
 103   lang_statement_header_type header;
 104   const char *target;
 105 } lang_target_statement_type;
 106
 107 typedef struct lang_output_statement_struct
 108 {
 109   lang_statement_header_type header;
 110   const char *name;
 111 } lang_output_statement_type;
 112
 113 /* Section types specified in a linker script.  */
 114
 115 enum section_type
 116 {
 117   normal_section,
 118   overlay_section,
 119   noload_section,
 120   noalloc_section
 121 };
 122
 123 /* This structure holds a list of program headers describing
 124    segments in which this section should be placed.  */
 125
 126 typedef struct lang_output_section_phdr_list
 127 {
 128   struct lang_output_section_phdr_list *next;
 129   const char *name;
 130   bfd_boolean used;
 131 } lang_output_section_phdr_list;
 132
 133 typedef struct lang_output_section_statement_struct
 134 {
 135   lang_statement_header_type header;
 136   lang_statement_list_type children;
 137   struct lang_output_section_statement_struct *next;
 138   struct lang_output_section_statement_struct *prev;
 139   const char *name;
 140   asection *bfd_section;
 141   lang_memory_region_type *region;
 142   lang_memory_region_type *lma_region;
 143   fill_type *fill;
 144   union etree_union *addr_tree;
 145   union etree_union *load_base;
 146
 147   /* If non-null, an expression to evaluate after setting the section's
 148      size.  The expression is evaluated inside REGION (above) with '.'
 149      set to the end of the section.  Used in the last overlay section
 150      to move '.' past all the overlaid sections.  */
 151   union etree_union *update_dot_tree;
 152
 153   lang_output_section_phdr_list *phdrs;
 154
 155   unsigned int block_value;
 156   int subsection_alignment;     /* Alignment of components.  */
 157   int section_alignment;        /* Alignment of start of section.  */
 158   int constraint;
 159   flagword flags;
 160   enum section_type sectype;
 161   unsigned int processed_vma : 1;
 162   unsigned int processed_lma : 1;
 163   unsigned int all_input_readonly : 1;
 164   /* If this section should be ignored.  */
 165   unsigned int ignored : 1;
 166   /* If there is a symbol relative to this section.  */
 167   unsigned int section_relative_symbol : 1;
 168 } lang_output_section_statement_type;
 169
 170 typedef struct
 171 {
 172   lang_statement_header_type header;
 173 } lang_common_statement_type;
 174
 175 typedef struct
 176 {
 177   lang_statement_header_type header;
 178 } lang_object_symbols_statement_type;
 179
 180 typedef struct
 181 {
 182   lang_statement_header_type header;
 183   fill_type *fill;
 184   int size;
 185   asection *output_section;
 186 } lang_fill_statement_type;
 187
 188 typedef struct
 189 {
 190   lang_statement_header_type header;
 191   unsigned int type;
 192   union etree_union *exp;
 193   bfd_vma value;
 194   asection *output_section;
 195   bfd_vma output_offset;
 196 } lang_data_statement_type;
 197
 198 /* Generate a reloc in the output file.  */
 199
 200 typedef struct
 201 {
 202   lang_statement_header_type header;
 203
 204   /* Reloc to generate.  */
 205   bfd_reloc_code_real_type reloc;
 206
 207   /* Reloc howto structure.  */
 208   reloc_howto_type *howto;
 209
 210   /* Section to generate reloc against.
 211      Exactly one of section and name must be NULL.  */
 212   asection *section;
 213
 214   /* Name of symbol to generate reloc against.
 215      Exactly one of section and name must be NULL.  */
 216   const char *name;
 217
 218   /* Expression for addend.  */
 219   union etree_union *addend_exp;
 220
 221   /* Resolved addend.  */
 222   bfd_vma addend_value;
 223
 224   /* Output section where reloc should be performed.  */
 225   asection *output_section;
 226
 227   /* Offset within output section.  */
 228   bfd_vma output_offset;
 229 } lang_reloc_statement_type;
 230
 231 typedef struct lang_input_statement_struct
 232 {
 233   lang_statement_header_type header;
 234   /* Name of this file.  */
 235   const char *filename;
 236   /* Name to use for the symbol giving address of text start.
 237      Usually the same as filename, but for a file spec'd with
 238      -l this is the -l switch itself rather than the filename.  */
 239   const char *local_sym_name;
 240
 241   bfd *the_bfd;
 242
 243   struct flag_info *section_flag_list;
 244
 245   /* Point to the next file - whatever it is, wanders up and down
 246      archives */
 247   union lang_statement_union *next;
 248
 249   /* Point to the next file, but skips archive contents.  */
 250   union lang_statement_union *next_real_file;
 251
 252   const char *target;
 253
 254   unsigned int maybe_archive : 1;
 255
 256   /* 1 means search a set of directories for this file.  */
 257   unsigned int search_dirs_flag : 1;
 258
 259   /* 1 means this was found in a search directory marked as sysrooted,
 260      if search_dirs_flag is false, otherwise, that it should be
 261      searched in ld_sysroot before any other location, as long as it
 262      starts with a slash.  */
 263   unsigned int sysrooted : 1;
 264
 265   /* 1 means this is base file of incremental load.
 266      Do not load this file's text or data.
 267      Also default text_start to after this file's bss.  */
 268   unsigned int just_syms_flag : 1;
 269
 270   /* Whether to search for this entry as a dynamic archive.  */
 271   unsigned int dynamic : 1;
 272
 273   /* Whether DT_NEEDED tags should be added for dynamic libraries in
 274      DT_NEEDED tags from this entry.  */
 275   unsigned int add_DT_NEEDED_for_dynamic : 1;
 276
 277   /* Whether this entry should cause a DT_NEEDED tag only when
 278      satisfying references from regular files, or always.  */
 279   unsigned int add_DT_NEEDED_for_regular : 1;
 280
 281   /* Whether to include the entire contents of an archive.  */
 282   unsigned int whole_archive : 1;
 283
 284   /* Set when bfd opening is successful.  */
 285   unsigned int loaded : 1;
 286
 287   unsigned int real : 1;
 288
 289   /* Set if the file does not exist.  */
 290   unsigned int missing_file : 1;
 291
 292 #ifdef ENABLE_PLUGINS
 293   /* Set if the file was claimed by a plugin.  */
 294   unsigned int claimed : 1;
 295
 296   /* Set if the file was claimed from an archive.  */
 297   unsigned int claim_archive : 1;
 298 #endif /* ENABLE_PLUGINS */
 299
 300 } lang_input_statement_type;
 301
 302 typedef struct
 303 {
 304   lang_statement_header_type header;
 305   asection *section;
 306 } lang_input_section_type;
 307
 308 typedef struct lang_wild_statement_struct lang_wild_statement_type;
 309
 310 typedef void (*callback_t) (lang_wild_statement_type *, struct wildcard_list *,
 311                             asection *, lang_input_statement_type *, void *);
 312
 313 typedef void (*walk_wild_section_handler_t) (lang_wild_statement_type *,
 314                                              lang_input_statement_type *,
 315                                              callback_t callback,
 316                                              void *data);
 317
 318 typedef bfd_boolean (*lang_match_sec_type_func) (bfd *, const asection *,
 319                                                  bfd *, const asection *);
 320
 321 /* Binary search tree structure to efficiently sort sections by
 322    name.  */
 323 typedef struct lang_section_bst
 324 {
 325   asection *section;
 326   struct lang_section_bst *left;
 327   struct lang_section_bst *right;
 328 } lang_section_bst_type;
 329
 330 struct lang_wild_statement_struct
 331 {
 332   lang_statement_header_type header;
 333   const char *filename;
 334   bfd_boolean filenames_sorted;
 335   struct wildcard_list *section_list;
 336   bfd_boolean keep_sections;
 337   lang_statement_list_type children;
 338
 339   walk_wild_section_handler_t walk_wild_section_handler;
 340   struct wildcard_list *handler_data[4];
 341   lang_section_bst_type *tree;
 342   struct flag_info *section_flag_list;
 343 };
 344
 345 typedef struct lang_address_statement_struct
 346 {
 347   lang_statement_header_type header;
 348   const char *section_name;
 349   union etree_union *address;
 350   const segment_type *segment;
 351 } lang_address_statement_type;
 352
 353 typedef struct
 354 {
 355   lang_statement_header_type header;
 356   bfd_vma output_offset;
 357   size_t size;
 358   asection *output_section;
 359   fill_type *fill;
 360 } lang_padding_statement_type;
 361
 362 /* A group statement collects a set of libraries together.  The
 363    libraries are searched multiple times, until no new undefined
 364    symbols are found.  The effect is to search a group of libraries as
 365    though they were a single library.  */
 366
 367 typedef struct
 368 {
 369   lang_statement_header_type header;
 370   lang_statement_list_type children;
 371 } lang_group_statement_type;
 372
 373 typedef struct
 374 {
 375   lang_statement_header_type header;
 376   const char *where;
 377   bfd_boolean is_before;
 378 } lang_insert_statement_type;
 379
 380 typedef union lang_statement_union
 381 {
 382   lang_statement_header_type header;
 383   lang_wild_statement_type wild_statement;
 384   lang_data_statement_type data_statement;
 385   lang_reloc_statement_type reloc_statement;
 386   lang_address_statement_type address_statement;
 387   lang_output_section_statement_type output_section_statement;
 388   lang_assignment_statement_type assignment_statement;
 389   lang_input_statement_type input_statement;
 390   lang_target_statement_type target_statement;
 391   lang_output_statement_type output_statement;
 392   lang_input_section_type input_section;
 393   lang_common_statement_type common_statement;
 394   lang_object_symbols_statement_type object_symbols_statement;
 395   lang_fill_statement_type fill_statement;
 396   lang_padding_statement_type padding_statement;
 397   lang_group_statement_type group_statement;
 398   lang_insert_statement_type insert_statement;
 399 } lang_statement_union_type;
 400
 401 /* This structure holds information about a program header, from the
 402    PHDRS command in the linker script.  */
 403
 404 struct lang_phdr
 405 {
 406   struct lang_phdr *next;
 407   const char *name;
 408   unsigned long type;
 409   bfd_boolean filehdr;
 410   bfd_boolean phdrs;
 411   etree_type *at;
 412   etree_type *flags;
 413 };
 414
 415 extern struct lang_phdr *lang_phdr_list;
 416
 417 /* This structure is used to hold a list of sections which may not
 418    cross reference each other.  */
 419
 420 typedef struct lang_nocrossref
 421 {
 422   struct lang_nocrossref *next;
 423   const char *name;
 424 } lang_nocrossref_type;
 425
 426 /* The list of nocrossref lists.  */
 427
 428 struct lang_nocrossrefs
 429 {
 430   struct lang_nocrossrefs *next;
 431   lang_nocrossref_type *list;
 432 };
 433
 434 extern struct lang_nocrossrefs *nocrossref_list;
 435
 436 /* This structure is used to hold a list of input section names which
 437    will not match an output section in the linker script.  */
 438
 439 struct unique_sections
 440 {
 441   struct unique_sections *next;
 442   const char *name;
 443 };
 444
 445 /* This structure records symbols for which we need to keep track of
 446    definedness for use in the DEFINED () test.  */
 447
 448 struct lang_definedness_hash_entry
 449 {
 450   struct bfd_hash_entry root;
 451   int iteration;
 452 };
 453
 454 /* Used by place_orphan to keep track of orphan sections and statements.  */
 455
 456 struct orphan_save
 457 {
 458   const char *name;
 459   flagword flags;
 460   lang_output_section_statement_type *os;
 461   asection **section;
 462   lang_statement_union_type **stmt;
 463   lang_output_section_statement_type **os_tail;
 464 };
 465
 466 extern const char *output_target;
 467 extern lang_output_section_statement_type *abs_output_section;
 468 extern lang_statement_list_type lang_output_section_statement;
 469 extern bfd_boolean lang_has_input_file;
 470 extern etree_type *base;
 471 extern lang_statement_list_type *stat_ptr;
 472 extern bfd_boolean delete_output_file_on_failure;
 473
 474 extern struct bfd_sym_chain entry_symbol;
 475 extern const char *entry_section;
 476 extern bfd_boolean entry_from_cmdline;
 477 extern lang_statement_list_type file_chain;
 478 extern lang_statement_list_type input_file_chain;
 479
 480 extern int lang_statement_iteration;
 481 extern bfd_boolean missing_file;
 482
 483 extern void lang_init
 484   (void);
 485 extern void lang_finish
 486   (void);
 487 extern lang_memory_region_type * lang_memory_region_lookup
 488   (const char * const, bfd_boolean);
 489 extern void lang_memory_region_alias
 490   (const char *, const char *);
 491 extern void lang_map
 492   (void);
 493 extern void lang_set_flags
 494   (lang_memory_region_type *, const char *, int);
 495 extern void lang_add_output
 496   (const char *, int from_script);
 497 extern lang_output_section_statement_type *lang_enter_output_section_statement
 498   (const char *output_section_statement_name,
 499    etree_type *address_exp,
 500    enum section_type sectype,
 501    etree_type *align,
 502    etree_type *subalign,
 503    etree_type *, int);
 504 extern void lang_final
 505   (void);
 506 extern void lang_relax_sections
 507   (bfd_boolean);
 508 extern void lang_process
 509   (void);
 510 extern void lang_section_start
 511   (const char *, union etree_union *, const segment_type *);
 512 extern void lang_add_entry
 513   (const char *, bfd_boolean);
 514 extern void lang_default_entry
 515   (const char *);
 516 extern void lang_add_target
 517   (const char *);
 518 extern void lang_add_wild
 519   (struct wildcard_spec *, struct wildcard_list *, bfd_boolean);
 520 extern void lang_add_map
 521   (const char *);
 522 extern void lang_add_fill
 523   (fill_type *);
 524 extern lang_assignment_statement_type *lang_add_assignment
 525   (union etree_union *);
 526 extern void lang_add_attribute
 527   (enum statement_enum);
 528 extern void lang_startup
 529   (const char *);
 530 extern void lang_float
 531   (bfd_boolean);
 532 extern void lang_leave_output_section_statement
 533   (fill_type *, const char *, lang_output_section_phdr_list *,
 534    const char *);
 535 extern void lang_abs_symbol_at_end_of
 536   (const char *, const char *);
 537 extern void lang_abs_symbol_at_beginning_of
 538   (const char *, const char *);
 539 extern void lang_statement_append
 540   (lang_statement_list_type *, lang_statement_union_type *,
 541    lang_statement_union_type **);
 542 extern void lang_for_each_input_file
 543   (void (*dothis) (lang_input_statement_type *));
 544 extern void lang_for_each_file
 545   (void (*dothis) (lang_input_statement_type *));
 546 extern void lang_reset_memory_regions
 547   (void);
 548 extern void lang_do_assignments
 549   (lang_phase_type);
 550
 551 #define LANG_FOR_EACH_INPUT_STATEMENT(statement)                        \
 552   lang_input_statement_type *statement;                                 \
 553   for (statement = (lang_input_statement_type *) file_chain.head;       \
 554        statement != (lang_input_statement_type *) NULL;                 \
 555        statement = (lang_input_statement_type *) statement->next)       \
 556
 557 #define lang_output_section_find(NAME) \
 558   lang_output_section_statement_lookup (NAME, 0, FALSE)
 559
 560 extern void lang_process
 561   (void);
 562 extern void ldlang_add_file
 563   (lang_input_statement_type *);
 564 extern lang_output_section_statement_type *lang_output_section_find_by_flags
 565   (const asection *, lang_output_section_statement_type **,
 566    lang_match_sec_type_func);
 567 extern lang_output_section_statement_type *lang_insert_orphan
 568   (asection *, const char *, int, lang_output_section_statement_type *,
 569    struct orphan_save *, etree_type *, lang_statement_list_type *);
 570 extern lang_input_statement_type *lang_add_input_file
 571   (const char *, lang_input_file_enum_type, const char *);
 572 extern void lang_add_keepsyms_file
 573   (const char *);
 574 extern lang_output_section_statement_type *lang_output_section_statement_lookup
 575   (const char *, int, bfd_boolean);
 576 extern lang_output_section_statement_type *next_matching_output_section_statement
 577   (lang_output_section_statement_type *, int);
 578 extern void ldlang_add_undef
 579   (const char *const, bfd_boolean);
 580 extern void lang_add_output_format
 581   (const char *, const char *, const char *, int);
 582 extern void lang_list_init
 583   (lang_statement_list_type *);
 584 extern void push_stat_ptr
 585   (lang_statement_list_type *);
 586 extern void pop_stat_ptr
 587   (void);
 588 extern void lang_add_data
 589   (int type, union etree_union *);
 590 extern void lang_add_reloc
 591   (bfd_reloc_code_real_type, reloc_howto_type *, asection *, const char *,
 592    union etree_union *);
 593 extern void lang_for_each_statement
 594   (void (*) (lang_statement_union_type *));
 595 extern void lang_for_each_statement_worker
 596   (void (*) (lang_statement_union_type *), lang_statement_union_type *);
 597 extern void *stat_alloc
 598   (size_t);
 599 extern void strip_excluded_output_sections
 600   (void);
 601 extern void dprint_statement
 602   (lang_statement_union_type *, int);
 603 extern void lang_size_sections
 604   (bfd_boolean *, bfd_boolean);
 605 extern void one_lang_size_sections_pass
 606   (bfd_boolean *, bfd_boolean);
 607 extern void lang_add_insert
 608   (const char *, int);
 609 extern void lang_enter_group
 610   (void);
 611 extern void lang_leave_group
 612   (void);
 613 extern void lang_add_section
 614   (lang_statement_list_type *, asection *,
 615    lang_output_section_statement_type *);
 616 extern void lang_new_phdr
 617   (const char *, etree_type *, bfd_boolean, bfd_boolean, etree_type *,
 618    etree_type *);
 619 extern void lang_add_nocrossref
 620   (lang_nocrossref_type *);
 621 extern void lang_enter_overlay
 622   (etree_type *, etree_type *);
 623 extern void lang_enter_overlay_section
 624   (const char *);
 625 extern void lang_leave_overlay_section
 626   (fill_type *, lang_output_section_phdr_list *);
 627 extern void lang_leave_overlay
 628   (etree_type *, int, fill_type *, const char *,
 629    lang_output_section_phdr_list *, const char *);
 630
 631 extern struct bfd_elf_version_tree *lang_elf_version_info;
 632
 633 extern struct bfd_elf_version_expr *lang_new_vers_pattern
 634   (struct bfd_elf_version_expr *, const char *, const char *, bfd_boolean);
 635 extern struct bfd_elf_version_tree *lang_new_vers_node
 636   (struct bfd_elf_version_expr *, struct bfd_elf_version_expr *);
 637 extern struct bfd_elf_version_deps *lang_add_vers_depend
 638   (struct bfd_elf_version_deps *, const char *);
 639 extern void lang_register_vers_node
 640   (const char *, struct bfd_elf_version_tree *, struct bfd_elf_version_deps *);
 641 extern void lang_append_dynamic_list (struct bfd_elf_version_expr *);
 642 extern void lang_append_dynamic_list_cpp_typeinfo (void);
 643 extern void lang_append_dynamic_list_cpp_new (void);
 644 extern void lang_add_unique
 645   (const char *);
 646 extern const char *lang_get_output_target
 647   (void);
 648 extern void lang_track_definedness (const char *);
 649 extern int lang_symbol_definition_iteration (const char *);
 650 extern void lang_update_definedness
 651   (const char *, struct bfd_link_hash_entry *);
 652
 653 extern void add_excluded_libs (const char *);
 654 extern bfd_boolean load_symbols
 655   (lang_input_statement_type *, lang_statement_list_type *);
 656
 657 extern bfd_boolean
 658 ldlang_override_segment_assignment
 659   (struct bfd_link_info *, bfd *, asection *, asection *, bfd_boolean);
 660
 661 extern void
 662 lang_ld_feature (char *);
 663
 664 #endif