ld/ldlang.h

   1 /* ldlang.h - linker command language support
   2    Copyright (C) 1991-2014 Free Software Foundation, Inc.
   3
   4    This file is part of the GNU Binutils.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  19    MA 02110-1301, USA.  */
  20
  21 #ifndef LDLANG_H
  22 #define LDLANG_H
  23
  24 #define DEFAULT_MEMORY_REGION   "*default*"
  25
  26 typedef enum
  27 {
  28   lang_input_file_is_l_enum,
  29   lang_input_file_is_symbols_only_enum,
  30   lang_input_file_is_marker_enum,
  31   lang_input_file_is_fake_enum,
  32   lang_input_file_is_search_file_enum,
  33   lang_input_file_is_file_enum
  34 } lang_input_file_enum_type;
  35
  36 struct _fill_type
  37 {
  38   size_t size;
  39   unsigned char data[1];
  40 };
  41
  42 typedef struct statement_list
  43 {
  44   union lang_statement_union *  head;
  45   union lang_statement_union ** tail;
  46 } lang_statement_list_type;
  47
  48 typedef struct memory_region_name_struct
  49 {
  50   const char * name;
  51   struct memory_region_name_struct * next;
  52 } lang_memory_region_name;
  53
  54 typedef struct memory_region_struct
  55 {
  56   lang_memory_region_name name_list;
  57   struct memory_region_struct *next;
  58   bfd_vma origin;
  59   bfd_size_type length;
  60   bfd_vma current;
  61   union lang_statement_union *last_os;
  62   flagword flags;
  63   flagword not_flags;
  64   bfd_boolean had_full_message;
  65 } lang_memory_region_type;
  66
  67 enum statement_enum
  68 {
  69   lang_output_section_statement_enum,
  70   lang_assignment_statement_enum,
  71   lang_input_statement_enum,
  72   lang_address_statement_enum,
  73   lang_wild_statement_enum,
  74   lang_input_section_enum,
  75   lang_object_symbols_statement_enum,
  76   lang_fill_statement_enum,
  77   lang_data_statement_enum,
  78   lang_reloc_statement_enum,
  79   lang_target_statement_enum,
  80   lang_output_statement_enum,
  81   lang_padding_statement_enum,
  82   lang_group_statement_enum,
  83   lang_insert_statement_enum,
  84   lang_constructors_statement_enum
  85 };
  86
  87 typedef struct lang_statement_header_struct
  88 {
  89   union lang_statement_union *next;
  90   enum statement_enum type;
  91 } lang_statement_header_type;
  92
  93 typedef struct
  94 {
  95   lang_statement_header_type header;
  96   union etree_union *exp;
  97 } lang_assignment_statement_type;
  98
  99 typedef struct lang_target_statement_struct
 100 {
 101   lang_statement_header_type header;
 102   const char *target;
 103 } lang_target_statement_type;
 104
 105 typedef struct lang_output_statement_struct
 106 {
 107   lang_statement_header_type header;
 108   const char *name;
 109 } lang_output_statement_type;
 110
 111 /* Section types specified in a linker script.  */
 112
 113 enum section_type
 114 {
 115   normal_section,
 116   overlay_section,
 117   noload_section,
 118   noalloc_section
 119 };
 120
 121 /* This structure holds a list of program headers describing
 122    segments in which this section should be placed.  */
 123
 124 typedef struct lang_output_section_phdr_list
 125 {
 126   struct lang_output_section_phdr_list *next;
 127   const char *name;
 128   bfd_boolean used;
 129 } lang_output_section_phdr_list;
 130
 131 typedef struct lang_output_section_statement_struct
 132 {
 133   lang_statement_header_type header;
 134   lang_statement_list_type children;
 135   struct lang_output_section_statement_struct *next;
 136   struct lang_output_section_statement_struct *prev;
 137   const char *name;
 138   asection *bfd_section;
 139   lang_memory_region_type *region;
 140   lang_memory_region_type *lma_region;
 141   fill_type *fill;
 142   union etree_union *addr_tree;
 143   union etree_union *load_base;
 144
 145   /* If non-null, an expression to evaluate after setting the section's
 146      size.  The expression is evaluated inside REGION (above) with '.'
 147      set to the end of the section.  Used in the last overlay section
 148      to move '.' past all the overlaid sections.  */
 149   union etree_union *update_dot_tree;
 150
 151   lang_output_section_phdr_list *phdrs;
 152
 153   unsigned int block_value;
 154   int subsection_alignment;     /* Alignment of components.  */
 155   int section_alignment;        /* Alignment of start of section.  */
 156   int constraint;
 157   flagword flags;
 158   enum section_type sectype;
 159   unsigned int processed_vma : 1;
 160   unsigned int processed_lma : 1;
 161   unsigned int all_input_readonly : 1;
 162   /* If this section should be ignored.  */
 163   unsigned int ignored : 1;
 164   /* If this section should update "dot".  Prevents section being ignored.  */
 165   unsigned int update_dot : 1;
 166   /* If this section is after assignment to _end.  */
 167   unsigned int after_end : 1;
 168   /* If this section uses the alignment of its input sections.  */
 169   unsigned int align_lma_with_input : 1;
 170 } lang_output_section_statement_type;
 171
 172 typedef struct
 173 {
 174   lang_statement_header_type header;
 175 } lang_common_statement_type;
 176
 177 typedef struct
 178 {
 179   lang_statement_header_type header;
 180 } lang_object_symbols_statement_type;
 181
 182 typedef struct
 183 {
 184   lang_statement_header_type header;
 185   fill_type *fill;
 186   int size;
 187   asection *output_section;
 188 } lang_fill_statement_type;
 189
 190 typedef struct
 191 {
 192   lang_statement_header_type header;
 193   unsigned int type;
 194   union etree_union *exp;
 195   bfd_vma value;
 196   asection *output_section;
 197   bfd_vma output_offset;
 198 } lang_data_statement_type;
 199
 200 /* Generate a reloc in the output file.  */
 201
 202 typedef struct
 203 {
 204   lang_statement_header_type header;
 205
 206   /* Reloc to generate.  */
 207   bfd_reloc_code_real_type reloc;
 208
 209   /* Reloc howto structure.  */
 210   reloc_howto_type *howto;
 211
 212   /* Section to generate reloc against.
 213      Exactly one of section and name must be NULL.  */
 214   asection *section;
 215
 216   /* Name of symbol to generate reloc against.
 217      Exactly one of section and name must be NULL.  */
 218   const char *name;
 219
 220   /* Expression for addend.  */
 221   union etree_union *addend_exp;
 222
 223   /* Resolved addend.  */
 224   bfd_vma addend_value;
 225
 226   /* Output section where reloc should be performed.  */
 227   asection *output_section;
 228
 229   /* Offset within output section.  */
 230   bfd_vma output_offset;
 231 } lang_reloc_statement_type;
 232
 233 struct lang_input_statement_flags
 234 {
 235   /* 1 means this file was specified in a -l option.  */
 236   unsigned int maybe_archive : 1;
 237
 238   /* 1 means this file was specified in a -l:namespec option.  */
 239   unsigned int full_name_provided : 1;
 240
 241   /* 1 means search a set of directories for this file.  */
 242   unsigned int search_dirs : 1;
 243
 244   /* 1 means this was found when processing a script in the sysroot.  */
 245   unsigned int sysrooted : 1;
 246
 247   /* 1 means this is base file of incremental load.
 248      Do not load this file's text or data.
 249      Also default text_start to after this file's bss.  */
 250   unsigned int just_syms : 1;
 251
 252   /* Whether to search for this entry as a dynamic archive.  */
 253   unsigned int dynamic : 1;
 254
 255   /* Set if a DT_NEEDED tag should be added not just for the dynamic library
 256      explicitly given by this entry but also for any dynamic libraries in
 257      this entry's needed list.  */
 258   unsigned int add_DT_NEEDED_for_dynamic : 1;
 259
 260   /* Set if this entry should cause a DT_NEEDED tag only when some
 261      regular file references its symbols (ie. --as-needed is in effect).  */
 262   unsigned int add_DT_NEEDED_for_regular : 1;
 263
 264   /* Whether to include the entire contents of an archive.  */
 265   unsigned int whole_archive : 1;
 266
 267   /* Set when bfd opening is successful.  */
 268   unsigned int loaded : 1;
 269
 270   unsigned int real : 1;
 271
 272   /* Set if the file does not exist.  */
 273   unsigned int missing_file : 1;
 274
 275 #ifdef ENABLE_PLUGINS
 276   /* Set if the file was claimed by a plugin.  */
 277   unsigned int claimed : 1;
 278
 279   /* Set if the file was claimed from an archive.  */
 280   unsigned int claim_archive : 1;
 281
 282   /* Set if reloading an --as-needed lib.  */
 283   unsigned int reload : 1;
 284 #endif /* ENABLE_PLUGINS */
 285 };
 286
 287 typedef struct lang_input_statement_struct
 288 {
 289   lang_statement_header_type header;
 290   /* Name of this file.  */
 291   const char *filename;
 292   /* Name to use for the symbol giving address of text start.
 293      Usually the same as filename, but for a file spec'd with
 294      -l this is the -l switch itself rather than the filename.  */
 295   const char *local_sym_name;
 296
 297   bfd *the_bfd;
 298
 299   struct flag_info *section_flag_list;
 300
 301   /* Point to the next file - whatever it is, wanders up and down
 302      archives */
 303   union lang_statement_union *next;
 304
 305   /* Point to the next file, but skips archive contents.  */
 306   union lang_statement_union *next_real_file;
 307
 308   const char *target;
 309
 310   struct lang_input_statement_flags flags;
 311 } lang_input_statement_type;
 312
 313 typedef struct
 314 {
 315   lang_statement_header_type header;
 316   asection *section;
 317 } lang_input_section_type;
 318
 319 struct map_symbol_def {
 320   struct bfd_link_hash_entry *entry;
 321   struct map_symbol_def *next;
 322 };
 323
 324 /* For input sections, when writing a map file: head / tail of a linked
 325    list of hash table entries for symbols defined in this section.  */
 326 typedef struct input_section_userdata_struct
 327 {
 328   struct map_symbol_def *map_symbol_def_head;
 329   struct map_symbol_def **map_symbol_def_tail;
 330   unsigned long map_symbol_def_count;
 331 } input_section_userdata_type;
 332
 333 #define get_userdata(x) ((x)->userdata)
 334
 335
 336 typedef struct lang_wild_statement_struct lang_wild_statement_type;
 337
 338 typedef void (*callback_t) (lang_wild_statement_type *, struct wildcard_list *,
 339                             asection *, struct flag_info *,
 340                             lang_input_statement_type *, void *);
 341
 342 typedef void (*walk_wild_section_handler_t) (lang_wild_statement_type *,
 343                                              lang_input_statement_type *,
 344                                              callback_t callback,
 345                                              void *data);
 346
 347 typedef bfd_boolean (*lang_match_sec_type_func) (bfd *, const asection *,
 348                                                  bfd *, const asection *);
 349
 350 /* Binary search tree structure to efficiently sort sections by
 351    name.  */
 352 typedef struct lang_section_bst
 353 {
 354   asection *section;
 355   struct lang_section_bst *left;
 356   struct lang_section_bst *right;
 357 } lang_section_bst_type;
 358
 359 struct lang_wild_statement_struct
 360 {
 361   lang_statement_header_type header;
 362   const char *filename;
 363   bfd_boolean filenames_sorted;
 364   struct wildcard_list *section_list;
 365   bfd_boolean keep_sections;
 366   lang_statement_list_type children;
 367
 368   walk_wild_section_handler_t walk_wild_section_handler;
 369   struct wildcard_list *handler_data[4];
 370   lang_section_bst_type *tree;
 371   struct flag_info *section_flag_list;
 372 };
 373
 374 typedef struct lang_address_statement_struct
 375 {
 376   lang_statement_header_type header;
 377   const char *section_name;
 378   union etree_union *address;
 379   const segment_type *segment;
 380 } lang_address_statement_type;
 381
 382 typedef struct
 383 {
 384   lang_statement_header_type header;
 385   bfd_vma output_offset;
 386   bfd_size_type size;
 387   asection *output_section;
 388   fill_type *fill;
 389 } lang_padding_statement_type;
 390
 391 /* A group statement collects a set of libraries together.  The
 392    libraries are searched multiple times, until no new undefined
 393    symbols are found.  The effect is to search a group of libraries as
 394    though they were a single library.  */
 395
 396 typedef struct
 397 {
 398   lang_statement_header_type header;
 399   lang_statement_list_type children;
 400 } lang_group_statement_type;
 401
 402 typedef struct
 403 {
 404   lang_statement_header_type header;
 405   const char *where;
 406   bfd_boolean is_before;
 407 } lang_insert_statement_type;
 408
 409 typedef union lang_statement_union
 410 {
 411   lang_statement_header_type header;
 412   lang_wild_statement_type wild_statement;
 413   lang_data_statement_type data_statement;
 414   lang_reloc_statement_type reloc_statement;
 415   lang_address_statement_type address_statement;
 416   lang_output_section_statement_type output_section_statement;
 417   lang_assignment_statement_type assignment_statement;
 418   lang_input_statement_type input_statement;
 419   lang_target_statement_type target_statement;
 420   lang_output_statement_type output_statement;
 421   lang_input_section_type input_section;
 422   lang_common_statement_type common_statement;
 423   lang_object_symbols_statement_type object_symbols_statement;
 424   lang_fill_statement_type fill_statement;
 425   lang_padding_statement_type padding_statement;
 426   lang_group_statement_type group_statement;
 427   lang_insert_statement_type insert_statement;
 428 } lang_statement_union_type;
 429
 430 /* This structure holds information about a program header, from the
 431    PHDRS command in the linker script.  */
 432
 433 struct lang_phdr
 434 {
 435   struct lang_phdr *next;
 436   const char *name;
 437   unsigned long type;
 438   bfd_boolean filehdr;
 439   bfd_boolean phdrs;
 440   etree_type *at;
 441   etree_type *flags;
 442 };
 443
 444 /* This structure is used to hold a list of sections which may not
 445    cross reference each other.  */
 446
 447 typedef struct lang_nocrossref
 448 {
 449   struct lang_nocrossref *next;
 450   const char *name;
 451 } lang_nocrossref_type;
 452
 453 /* The list of nocrossref lists.  */
 454
 455 struct lang_nocrossrefs
 456 {
 457   struct lang_nocrossrefs *next;
 458   lang_nocrossref_type *list;
 459 };
 460
 461 /* This structure is used to hold a list of input section names which
 462    will not match an output section in the linker script.  */
 463
 464 struct unique_sections
 465 {
 466   struct unique_sections *next;
 467   const char *name;
 468 };
 469
 470 /* This structure records symbols for which we need to keep track of
 471    definedness for use in the DEFINED () test.  */
 472
 473 struct lang_definedness_hash_entry
 474 {
 475   struct bfd_hash_entry root;
 476   unsigned int by_object : 1;
 477   unsigned int by_script : 1;
 478   unsigned int iteration : 1;
 479 };
 480
 481 /* Used by place_orphan to keep track of orphan sections and statements.  */
 482
 483 struct orphan_save
 484 {
 485   const char *name;
 486   flagword flags;
 487   lang_output_section_statement_type *os;
 488   asection **section;
 489   lang_statement_union_type **stmt;
 490   lang_output_section_statement_type **os_tail;
 491 };
 492
 493 struct asneeded_minfo
 494 {
 495   struct asneeded_minfo *next;
 496   const char *soname;
 497   bfd *ref;
 498   const char *name;
 499 };
 500
 501 extern struct lang_phdr *lang_phdr_list;
 502 extern struct lang_nocrossrefs *nocrossref_list;
 503 extern const char *output_target;
 504 extern lang_output_section_statement_type *abs_output_section;
 505 extern lang_statement_list_type lang_output_section_statement;
 506 extern struct lang_input_statement_flags input_flags;
 507 extern bfd_boolean lang_has_input_file;
 508 extern lang_statement_list_type *stat_ptr;
 509 extern bfd_boolean delete_output_file_on_failure;
 510
 511 extern struct bfd_sym_chain entry_symbol;
 512 extern const char *entry_section;
 513 extern bfd_boolean entry_from_cmdline;
 514 extern lang_statement_list_type file_chain;
 515 extern lang_statement_list_type input_file_chain;
 516
 517 extern int lang_statement_iteration;
 518 extern struct asneeded_minfo **asneeded_list_tail;
 519
 520 extern void (*output_bfd_hash_table_free_fn) (struct bfd_link_hash_table *);
 521
 522 extern void lang_init
 523   (void);
 524 extern void lang_finish
 525   (void);
 526 extern lang_memory_region_type * lang_memory_region_lookup
 527   (const char * const, bfd_boolean);
 528 extern void lang_memory_region_alias
 529   (const char *, const char *);
 530 extern void lang_map
 531   (void);
 532 extern void lang_set_flags
 533   (lang_memory_region_type *, const char *, int);
 534 extern void lang_add_output
 535   (const char *, int from_script);
 536 extern lang_output_section_statement_type *lang_enter_output_section_statement
 537   (const char *, etree_type *, enum section_type, etree_type *, etree_type *,
 538    etree_type *, int, int);
 539 extern void lang_final
 540   (void);
 541 extern void lang_relax_sections
 542   (bfd_boolean);
 543 extern void lang_process
 544   (void);
 545 extern void lang_section_start
 546   (const char *, union etree_union *, const segment_type *);
 547 extern void lang_add_entry
 548   (const char *, bfd_boolean);
 549 extern void lang_default_entry
 550   (const char *);
 551 extern void lang_add_target
 552   (const char *);
 553 extern void lang_add_wild
 554   (struct wildcard_spec *, struct wildcard_list *, bfd_boolean);
 555 extern void lang_add_map
 556   (const char *);
 557 extern void lang_add_fill
 558   (fill_type *);
 559 extern lang_assignment_statement_type *lang_add_assignment
 560   (union etree_union *);
 561 extern void lang_add_attribute
 562   (enum statement_enum);
 563 extern void lang_startup
 564   (const char *);
 565 extern void lang_float
 566   (bfd_boolean);
 567 extern void lang_leave_output_section_statement
 568   (fill_type *, const char *, lang_output_section_phdr_list *,
 569    const char *);
 570 extern void lang_statement_append
 571   (lang_statement_list_type *, lang_statement_union_type *,
 572    lang_statement_union_type **);
 573 extern void lang_for_each_input_file
 574   (void (*dothis) (lang_input_statement_type *));
 575 extern void lang_for_each_file
 576   (void (*dothis) (lang_input_statement_type *));
 577 extern void lang_reset_memory_regions
 578   (void);
 579 extern void lang_do_assignments
 580   (lang_phase_type);
 581 extern asection *section_for_dot
 582   (void);
 583
 584 #define LANG_FOR_EACH_INPUT_STATEMENT(statement)                        \
 585   lang_input_statement_type *statement;                                 \
 586   for (statement = (lang_input_statement_type *) file_chain.head;       \
 587        statement != (lang_input_statement_type *) NULL;                 \
 588        statement = (lang_input_statement_type *) statement->next)       \
 589
 590 #define lang_output_section_find(NAME) \
 591   lang_output_section_statement_lookup (NAME, 0, FALSE)
 592
 593 extern void lang_process
 594   (void);
 595 extern void ldlang_add_file
 596   (lang_input_statement_type *);
 597 extern lang_output_section_statement_type *lang_output_section_find_by_flags
 598   (const asection *, lang_output_section_statement_type **,
 599    lang_match_sec_type_func);
 600 extern lang_output_section_statement_type *lang_insert_orphan
 601   (asection *, const char *, int, lang_output_section_statement_type *,
 602    struct orphan_save *, etree_type *, lang_statement_list_type *);
 603 extern lang_input_statement_type *lang_add_input_file
 604   (const char *, lang_input_file_enum_type, const char *);
 605 extern void lang_add_keepsyms_file
 606   (const char *);
 607 extern lang_output_section_statement_type *lang_output_section_get
 608   (const asection *);
 609 extern lang_output_section_statement_type *lang_output_section_statement_lookup
 610   (const char *, int, bfd_boolean);
 611 extern lang_output_section_statement_type *next_matching_output_section_statement
 612   (lang_output_section_statement_type *, int);
 613 extern void ldlang_add_undef
 614   (const char *const, bfd_boolean);
 615 extern void lang_add_output_format
 616   (const char *, const char *, const char *, int);
 617 extern void lang_list_init
 618   (lang_statement_list_type *);
 619 extern void push_stat_ptr
 620   (lang_statement_list_type *);
 621 extern void pop_stat_ptr
 622   (void);
 623 extern void lang_add_data
 624   (int type, union etree_union *);
 625 extern void lang_add_reloc
 626   (bfd_reloc_code_real_type, reloc_howto_type *, asection *, const char *,
 627    union etree_union *);
 628 extern void lang_for_each_statement
 629   (void (*) (lang_statement_union_type *));
 630 extern void lang_for_each_statement_worker
 631   (void (*) (lang_statement_union_type *), lang_statement_union_type *);
 632 extern void *stat_alloc
 633   (size_t);
 634 extern void strip_excluded_output_sections
 635   (void);
 636 extern void dprint_statement
 637   (lang_statement_union_type *, int);
 638 extern void lang_size_sections
 639   (bfd_boolean *, bfd_boolean);
 640 extern void one_lang_size_sections_pass
 641   (bfd_boolean *, bfd_boolean);
 642 extern void lang_add_insert
 643   (const char *, int);
 644 extern void lang_enter_group
 645   (void);
 646 extern void lang_leave_group
 647   (void);
 648 extern void lang_add_section
 649   (lang_statement_list_type *, asection *,
 650    struct flag_info *, lang_output_section_statement_type *);
 651 extern void lang_new_phdr
 652   (const char *, etree_type *, bfd_boolean, bfd_boolean, etree_type *,
 653    etree_type *);
 654 extern void lang_add_nocrossref
 655   (lang_nocrossref_type *);
 656 extern void lang_enter_overlay
 657   (etree_type *, etree_type *);
 658 extern void lang_enter_overlay_section
 659   (const char *);
 660 extern void lang_leave_overlay_section
 661   (fill_type *, lang_output_section_phdr_list *);
 662 extern void lang_leave_overlay
 663   (etree_type *, int, fill_type *, const char *,
 664    lang_output_section_phdr_list *, const char *);
 665
 666 extern struct bfd_elf_version_expr *lang_new_vers_pattern
 667   (struct bfd_elf_version_expr *, const char *, const char *, bfd_boolean);
 668 extern struct bfd_elf_version_tree *lang_new_vers_node
 669   (struct bfd_elf_version_expr *, struct bfd_elf_version_expr *);
 670 extern struct bfd_elf_version_deps *lang_add_vers_depend
 671   (struct bfd_elf_version_deps *, const char *);
 672 extern void lang_register_vers_node
 673   (const char *, struct bfd_elf_version_tree *, struct bfd_elf_version_deps *);
 674 extern void lang_append_dynamic_list (struct bfd_elf_version_expr *);
 675 extern void lang_append_dynamic_list_cpp_typeinfo (void);
 676 extern void lang_append_dynamic_list_cpp_new (void);
 677 extern void lang_add_unique
 678   (const char *);
 679 extern const char *lang_get_output_target
 680   (void);
 681 extern struct lang_definedness_hash_entry *lang_symbol_defined (const char *);
 682 extern void lang_update_definedness
 683   (const char *, struct bfd_link_hash_entry *);
 684
 685 extern void add_excluded_libs (const char *);
 686 extern bfd_boolean load_symbols
 687   (lang_input_statement_type *, lang_statement_list_type *);
 688
 689 extern bfd_boolean
 690 ldlang_override_segment_assignment
 691   (struct bfd_link_info *, bfd *, asection *, asection *, bfd_boolean);
 692
 693 extern void
 694 lang_ld_feature (char *);
 695
 696 #endif