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   /* Set if reloading an archive or --as-needed lib.  */
 276   unsigned int reload : 1;
 277
 278 #ifdef ENABLE_PLUGINS
 279   /* Set if the file was claimed by a plugin.  */
 280   unsigned int claimed : 1;
 281
 282   /* Set if the file was claimed from an archive.  */
 283   unsigned int claim_archive : 1;
 284 #endif /* ENABLE_PLUGINS */
 285
 286   /* Head of list of pushed flags.  */
 287   struct lang_input_statement_flags *pushed;
 288 };
 289
 290 typedef struct lang_input_statement_struct
 291 {
 292   lang_statement_header_type header;
 293   /* Name of this file.  */
 294   const char *filename;
 295   /* Name to use for the symbol giving address of text start.
 296      Usually the same as filename, but for a file spec'd with
 297      -l this is the -l switch itself rather than the filename.  */
 298   const char *local_sym_name;
 299
 300   bfd *the_bfd;
 301
 302   struct flag_info *section_flag_list;
 303
 304   /* Point to the next file - whatever it is, wanders up and down
 305      archives */
 306   union lang_statement_union *next;
 307
 308   /* Point to the next file, but skips archive contents.  */
 309   union lang_statement_union *next_real_file;
 310
 311   const char *target;
 312
 313   struct lang_input_statement_flags flags;
 314 } lang_input_statement_type;
 315
 316 typedef struct
 317 {
 318   lang_statement_header_type header;
 319   asection *section;
 320 } lang_input_section_type;
 321
 322 struct map_symbol_def {
 323   struct bfd_link_hash_entry *entry;
 324   struct map_symbol_def *next;
 325 };
 326
 327 /* For input sections, when writing a map file: head / tail of a linked
 328    list of hash table entries for symbols defined in this section.  */
 329 typedef struct input_section_userdata_struct
 330 {
 331   struct map_symbol_def *map_symbol_def_head;
 332   struct map_symbol_def **map_symbol_def_tail;
 333   unsigned long map_symbol_def_count;
 334 } input_section_userdata_type;
 335
 336 #define get_userdata(x) ((x)->userdata)
 337
 338
 339 typedef struct lang_wild_statement_struct lang_wild_statement_type;
 340
 341 typedef void (*callback_t) (lang_wild_statement_type *, struct wildcard_list *,
 342                             asection *, struct flag_info *,
 343                             lang_input_statement_type *, void *);
 344
 345 typedef void (*walk_wild_section_handler_t) (lang_wild_statement_type *,
 346                                              lang_input_statement_type *,
 347                                              callback_t callback,
 348                                              void *data);
 349
 350 typedef bfd_boolean (*lang_match_sec_type_func) (bfd *, const asection *,
 351                                                  bfd *, const asection *);
 352
 353 /* Binary search tree structure to efficiently sort sections by
 354    name.  */
 355 typedef struct lang_section_bst
 356 {
 357   asection *section;
 358   struct lang_section_bst *left;
 359   struct lang_section_bst *right;
 360 } lang_section_bst_type;
 361
 362 struct lang_wild_statement_struct
 363 {
 364   lang_statement_header_type header;
 365   const char *filename;
 366   bfd_boolean filenames_sorted;
 367   struct wildcard_list *section_list;
 368   bfd_boolean keep_sections;
 369   lang_statement_list_type children;
 370
 371   walk_wild_section_handler_t walk_wild_section_handler;
 372   struct wildcard_list *handler_data[4];
 373   lang_section_bst_type *tree;
 374   struct flag_info *section_flag_list;
 375 };
 376
 377 typedef struct lang_address_statement_struct
 378 {
 379   lang_statement_header_type header;
 380   const char *section_name;
 381   union etree_union *address;
 382   const segment_type *segment;
 383 } lang_address_statement_type;
 384
 385 typedef struct
 386 {
 387   lang_statement_header_type header;
 388   bfd_vma output_offset;
 389   bfd_size_type size;
 390   asection *output_section;
 391   fill_type *fill;
 392 } lang_padding_statement_type;
 393
 394 /* A group statement collects a set of libraries together.  The
 395    libraries are searched multiple times, until no new undefined
 396    symbols are found.  The effect is to search a group of libraries as
 397    though they were a single library.  */
 398
 399 typedef struct
 400 {
 401   lang_statement_header_type header;
 402   lang_statement_list_type children;
 403 } lang_group_statement_type;
 404
 405 typedef struct
 406 {
 407   lang_statement_header_type header;
 408   const char *where;
 409   bfd_boolean is_before;
 410 } lang_insert_statement_type;
 411
 412 typedef union lang_statement_union
 413 {
 414   lang_statement_header_type header;
 415   lang_wild_statement_type wild_statement;
 416   lang_data_statement_type data_statement;
 417   lang_reloc_statement_type reloc_statement;
 418   lang_address_statement_type address_statement;
 419   lang_output_section_statement_type output_section_statement;
 420   lang_assignment_statement_type assignment_statement;
 421   lang_input_statement_type input_statement;
 422   lang_target_statement_type target_statement;
 423   lang_output_statement_type output_statement;
 424   lang_input_section_type input_section;
 425   lang_common_statement_type common_statement;
 426   lang_object_symbols_statement_type object_symbols_statement;
 427   lang_fill_statement_type fill_statement;
 428   lang_padding_statement_type padding_statement;
 429   lang_group_statement_type group_statement;
 430   lang_insert_statement_type insert_statement;
 431 } lang_statement_union_type;
 432
 433 /* This structure holds information about a program header, from the
 434    PHDRS command in the linker script.  */
 435
 436 struct lang_phdr
 437 {
 438   struct lang_phdr *next;
 439   const char *name;
 440   unsigned long type;
 441   bfd_boolean filehdr;
 442   bfd_boolean phdrs;
 443   etree_type *at;
 444   etree_type *flags;
 445 };
 446
 447 /* This structure is used to hold a list of sections which may not
 448    cross reference each other.  */
 449
 450 typedef struct lang_nocrossref
 451 {
 452   struct lang_nocrossref *next;
 453   const char *name;
 454 } lang_nocrossref_type;
 455
 456 /* The list of nocrossref lists.  */
 457
 458 struct lang_nocrossrefs
 459 {
 460   struct lang_nocrossrefs *next;
 461   lang_nocrossref_type *list;
 462 };
 463
 464 /* This structure is used to hold a list of input section names which
 465    will not match an output section in the linker script.  */
 466
 467 struct unique_sections
 468 {
 469   struct unique_sections *next;
 470   const char *name;
 471 };
 472
 473 /* This structure records symbols for which we need to keep track of
 474    definedness for use in the DEFINED () test.  */
 475
 476 struct lang_definedness_hash_entry
 477 {
 478   struct bfd_hash_entry root;
 479   unsigned int by_object : 1;
 480   unsigned int by_script : 1;
 481   unsigned int iteration : 1;
 482 };
 483
 484 /* Used by place_orphan to keep track of orphan sections and statements.  */
 485
 486 struct orphan_save
 487 {
 488   const char *name;
 489   flagword flags;
 490   lang_output_section_statement_type *os;
 491   asection **section;
 492   lang_statement_union_type **stmt;
 493   lang_output_section_statement_type **os_tail;
 494 };
 495
 496 struct asneeded_minfo
 497 {
 498   struct asneeded_minfo *next;
 499   const char *soname;
 500   bfd *ref;
 501   const char *name;
 502 };
 503
 504 extern struct lang_phdr *lang_phdr_list;
 505 extern struct lang_nocrossrefs *nocrossref_list;
 506 extern const char *output_target;
 507 extern lang_output_section_statement_type *abs_output_section;
 508 extern lang_statement_list_type lang_output_section_statement;
 509 extern struct lang_input_statement_flags input_flags;
 510 extern bfd_boolean lang_has_input_file;
 511 extern lang_statement_list_type *stat_ptr;
 512 extern bfd_boolean delete_output_file_on_failure;
 513
 514 extern struct bfd_sym_chain entry_symbol;
 515 extern const char *entry_section;
 516 extern bfd_boolean entry_from_cmdline;
 517 extern lang_statement_list_type file_chain;
 518 extern lang_statement_list_type input_file_chain;
 519
 520 extern int lang_statement_iteration;
 521 extern struct asneeded_minfo **asneeded_list_tail;
 522
 523 extern void (*output_bfd_hash_table_free_fn) (struct bfd_link_hash_table *);
 524
 525 extern void lang_init
 526   (void);
 527 extern void lang_finish
 528   (void);
 529 extern lang_memory_region_type * lang_memory_region_lookup
 530   (const char * const, bfd_boolean);
 531 extern void lang_memory_region_alias
 532   (const char *, const char *);
 533 extern void lang_map
 534   (void);
 535 extern void lang_set_flags
 536   (lang_memory_region_type *, const char *, int);
 537 extern void lang_add_output
 538   (const char *, int from_script);
 539 extern lang_output_section_statement_type *lang_enter_output_section_statement
 540   (const char *, etree_type *, enum section_type, etree_type *, etree_type *,
 541    etree_type *, int, int);
 542 extern void lang_final
 543   (void);
 544 extern void lang_relax_sections
 545   (bfd_boolean);
 546 extern void lang_process
 547   (void);
 548 extern void lang_section_start
 549   (const char *, union etree_union *, const segment_type *);
 550 extern void lang_add_entry
 551   (const char *, bfd_boolean);
 552 extern void lang_default_entry
 553   (const char *);
 554 extern void lang_add_target
 555   (const char *);
 556 extern void lang_add_wild
 557   (struct wildcard_spec *, struct wildcard_list *, bfd_boolean);
 558 extern void lang_add_map
 559   (const char *);
 560 extern void lang_add_fill
 561   (fill_type *);
 562 extern lang_assignment_statement_type *lang_add_assignment
 563   (union etree_union *);
 564 extern void lang_add_attribute
 565   (enum statement_enum);
 566 extern void lang_startup
 567   (const char *);
 568 extern void lang_float
 569   (bfd_boolean);
 570 extern void lang_leave_output_section_statement
 571   (fill_type *, const char *, lang_output_section_phdr_list *,
 572    const char *);
 573 extern void lang_statement_append
 574   (lang_statement_list_type *, lang_statement_union_type *,
 575    lang_statement_union_type **);
 576 extern void lang_for_each_input_file
 577   (void (*dothis) (lang_input_statement_type *));
 578 extern void lang_for_each_file
 579   (void (*dothis) (lang_input_statement_type *));
 580 extern void lang_reset_memory_regions
 581   (void);
 582 extern void lang_do_assignments
 583   (lang_phase_type);
 584 extern asection *section_for_dot
 585   (void);
 586
 587 #define LANG_FOR_EACH_INPUT_STATEMENT(statement)                        \
 588   lang_input_statement_type *statement;                                 \
 589   for (statement = (lang_input_statement_type *) file_chain.head;       \
 590        statement != (lang_input_statement_type *) NULL;                 \
 591        statement = (lang_input_statement_type *) statement->next)       \
 592
 593 #define lang_output_section_find(NAME) \
 594   lang_output_section_statement_lookup (NAME, 0, FALSE)
 595
 596 extern void lang_process
 597   (void);
 598 extern void ldlang_add_file
 599   (lang_input_statement_type *);
 600 extern lang_output_section_statement_type *lang_output_section_find_by_flags
 601   (const asection *, lang_output_section_statement_type **,
 602    lang_match_sec_type_func);
 603 extern lang_output_section_statement_type *lang_insert_orphan
 604   (asection *, const char *, int, lang_output_section_statement_type *,
 605    struct orphan_save *, etree_type *, lang_statement_list_type *);
 606 extern lang_input_statement_type *lang_add_input_file
 607   (const char *, lang_input_file_enum_type, const char *);
 608 extern void lang_add_keepsyms_file
 609   (const char *);
 610 extern lang_output_section_statement_type *lang_output_section_get
 611   (const asection *);
 612 extern lang_output_section_statement_type *lang_output_section_statement_lookup
 613   (const char *, int, bfd_boolean);
 614 extern lang_output_section_statement_type *next_matching_output_section_statement
 615   (lang_output_section_statement_type *, int);
 616 extern void ldlang_add_undef
 617   (const char *const, bfd_boolean);
 618 extern void lang_add_output_format
 619   (const char *, const char *, const char *, int);
 620 extern void lang_list_init
 621   (lang_statement_list_type *);
 622 extern void push_stat_ptr
 623   (lang_statement_list_type *);
 624 extern void pop_stat_ptr
 625   (void);
 626 extern void lang_add_data
 627   (int type, union etree_union *);
 628 extern void lang_add_reloc
 629   (bfd_reloc_code_real_type, reloc_howto_type *, asection *, const char *,
 630    union etree_union *);
 631 extern void lang_for_each_statement
 632   (void (*) (lang_statement_union_type *));
 633 extern void lang_for_each_statement_worker
 634   (void (*) (lang_statement_union_type *), lang_statement_union_type *);
 635 extern void *stat_alloc
 636   (size_t);
 637 extern void strip_excluded_output_sections
 638   (void);
 639 extern void dprint_statement
 640   (lang_statement_union_type *, int);
 641 extern void lang_size_sections
 642   (bfd_boolean *, bfd_boolean);
 643 extern void one_lang_size_sections_pass
 644   (bfd_boolean *, bfd_boolean);
 645 extern void lang_add_insert
 646   (const char *, int);
 647 extern void lang_enter_group
 648   (void);
 649 extern void lang_leave_group
 650   (void);
 651 extern void lang_add_section
 652   (lang_statement_list_type *, asection *,
 653    struct flag_info *, lang_output_section_statement_type *);
 654 extern void lang_new_phdr
 655   (const char *, etree_type *, bfd_boolean, bfd_boolean, etree_type *,
 656    etree_type *);
 657 extern void lang_add_nocrossref
 658   (lang_nocrossref_type *);
 659 extern void lang_enter_overlay
 660   (etree_type *, etree_type *);
 661 extern void lang_enter_overlay_section
 662   (const char *);
 663 extern void lang_leave_overlay_section
 664   (fill_type *, lang_output_section_phdr_list *);
 665 extern void lang_leave_overlay
 666   (etree_type *, int, fill_type *, const char *,
 667    lang_output_section_phdr_list *, const char *);
 668
 669 extern struct bfd_elf_version_expr *lang_new_vers_pattern
 670   (struct bfd_elf_version_expr *, const char *, const char *, bfd_boolean);
 671 extern struct bfd_elf_version_tree *lang_new_vers_node
 672   (struct bfd_elf_version_expr *, struct bfd_elf_version_expr *);
 673 extern struct bfd_elf_version_deps *lang_add_vers_depend
 674   (struct bfd_elf_version_deps *, const char *);
 675 extern void lang_register_vers_node
 676   (const char *, struct bfd_elf_version_tree *, struct bfd_elf_version_deps *);
 677 extern void lang_append_dynamic_list (struct bfd_elf_version_expr *);
 678 extern void lang_append_dynamic_list_cpp_typeinfo (void);
 679 extern void lang_append_dynamic_list_cpp_new (void);
 680 extern void lang_add_unique
 681   (const char *);
 682 extern const char *lang_get_output_target
 683   (void);
 684 extern struct lang_definedness_hash_entry *lang_symbol_defined (const char *);
 685 extern void lang_update_definedness
 686   (const char *, struct bfd_link_hash_entry *);
 687
 688 extern void add_excluded_libs (const char *);
 689 extern bfd_boolean load_symbols
 690   (lang_input_statement_type *, lang_statement_list_type *);
 691
 692 extern bfd_boolean
 693 ldlang_override_segment_assignment
 694   (struct bfd_link_info *, bfd *, asection *, asection *, bfd_boolean);
 695
 696 extern void
 697 lang_ld_feature (char *);
 698
 699 #endif