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 search a set of directories for this file.  */
 239   unsigned int search_dirs : 1;
 240
 241   /* 1 means this was found when processing a script in the sysroot.  */
 242   unsigned int sysrooted : 1;
 243
 244   /* 1 means this is base file of incremental load.
 245      Do not load this file's text or data.
 246      Also default text_start to after this file's bss.  */
 247   unsigned int just_syms : 1;
 248
 249   /* Whether to search for this entry as a dynamic archive.  */
 250   unsigned int dynamic : 1;
 251
 252   /* Set if a DT_NEEDED tag should be added not just for the dynamic library
 253      explicitly given by this entry but also for any dynamic libraries in
 254      this entry's needed list.  */
 255   unsigned int add_DT_NEEDED_for_dynamic : 1;
 256
 257   /* Set if this entry should cause a DT_NEEDED tag only when some
 258      regular file references its symbols (ie. --as-needed is in effect).  */
 259   unsigned int add_DT_NEEDED_for_regular : 1;
 260
 261   /* Whether to include the entire contents of an archive.  */
 262   unsigned int whole_archive : 1;
 263
 264   /* Set when bfd opening is successful.  */
 265   unsigned int loaded : 1;
 266
 267   unsigned int real : 1;
 268
 269   /* Set if the file does not exist.  */
 270   unsigned int missing_file : 1;
 271
 272 #ifdef ENABLE_PLUGINS
 273   /* Set if the file was claimed by a plugin.  */
 274   unsigned int claimed : 1;
 275
 276   /* Set if the file was claimed from an archive.  */
 277   unsigned int claim_archive : 1;
 278
 279   /* Set if reloading an --as-needed lib.  */
 280   unsigned int reload : 1;
 281 #endif /* ENABLE_PLUGINS */
 282 };
 283
 284 typedef struct lang_input_statement_struct
 285 {
 286   lang_statement_header_type header;
 287   /* Name of this file.  */
 288   const char *filename;
 289   /* Name to use for the symbol giving address of text start.
 290      Usually the same as filename, but for a file spec'd with
 291      -l this is the -l switch itself rather than the filename.  */
 292   const char *local_sym_name;
 293
 294   bfd *the_bfd;
 295
 296   struct flag_info *section_flag_list;
 297
 298   /* Point to the next file - whatever it is, wanders up and down
 299      archives */
 300   union lang_statement_union *next;
 301
 302   /* Point to the next file, but skips archive contents.  */
 303   union lang_statement_union *next_real_file;
 304
 305   const char *target;
 306
 307   struct lang_input_statement_flags flags;
 308 } lang_input_statement_type;
 309
 310 typedef struct
 311 {
 312   lang_statement_header_type header;
 313   asection *section;
 314 } lang_input_section_type;
 315
 316 struct map_symbol_def {
 317   struct bfd_link_hash_entry *entry;
 318   struct map_symbol_def *next;
 319 };
 320
 321 /* For input sections, when writing a map file: head / tail of a linked
 322    list of hash table entries for symbols defined in this section.  */
 323 typedef struct input_section_userdata_struct
 324 {
 325   struct map_symbol_def *map_symbol_def_head;
 326   struct map_symbol_def **map_symbol_def_tail;
 327   unsigned long map_symbol_def_count;
 328 } input_section_userdata_type;
 329
 330 #define get_userdata(x) ((x)->userdata)
 331
 332
 333 typedef struct lang_wild_statement_struct lang_wild_statement_type;
 334
 335 typedef void (*callback_t) (lang_wild_statement_type *, struct wildcard_list *,
 336                             asection *, struct flag_info *,
 337                             lang_input_statement_type *, void *);
 338
 339 typedef void (*walk_wild_section_handler_t) (lang_wild_statement_type *,
 340                                              lang_input_statement_type *,
 341                                              callback_t callback,
 342                                              void *data);
 343
 344 typedef bfd_boolean (*lang_match_sec_type_func) (bfd *, const asection *,
 345                                                  bfd *, const asection *);
 346
 347 /* Binary search tree structure to efficiently sort sections by
 348    name.  */
 349 typedef struct lang_section_bst
 350 {
 351   asection *section;
 352   struct lang_section_bst *left;
 353   struct lang_section_bst *right;
 354 } lang_section_bst_type;
 355
 356 struct lang_wild_statement_struct
 357 {
 358   lang_statement_header_type header;
 359   const char *filename;
 360   bfd_boolean filenames_sorted;
 361   struct wildcard_list *section_list;
 362   bfd_boolean keep_sections;
 363   lang_statement_list_type children;
 364
 365   walk_wild_section_handler_t walk_wild_section_handler;
 366   struct wildcard_list *handler_data[4];
 367   lang_section_bst_type *tree;
 368   struct flag_info *section_flag_list;
 369 };
 370
 371 typedef struct lang_address_statement_struct
 372 {
 373   lang_statement_header_type header;
 374   const char *section_name;
 375   union etree_union *address;
 376   const segment_type *segment;
 377 } lang_address_statement_type;
 378
 379 typedef struct
 380 {
 381   lang_statement_header_type header;
 382   bfd_vma output_offset;
 383   bfd_size_type size;
 384   asection *output_section;
 385   fill_type *fill;
 386 } lang_padding_statement_type;
 387
 388 /* A group statement collects a set of libraries together.  The
 389    libraries are searched multiple times, until no new undefined
 390    symbols are found.  The effect is to search a group of libraries as
 391    though they were a single library.  */
 392
 393 typedef struct
 394 {
 395   lang_statement_header_type header;
 396   lang_statement_list_type children;
 397 } lang_group_statement_type;
 398
 399 typedef struct
 400 {
 401   lang_statement_header_type header;
 402   const char *where;
 403   bfd_boolean is_before;
 404 } lang_insert_statement_type;
 405
 406 typedef union lang_statement_union
 407 {
 408   lang_statement_header_type header;
 409   lang_wild_statement_type wild_statement;
 410   lang_data_statement_type data_statement;
 411   lang_reloc_statement_type reloc_statement;
 412   lang_address_statement_type address_statement;
 413   lang_output_section_statement_type output_section_statement;
 414   lang_assignment_statement_type assignment_statement;
 415   lang_input_statement_type input_statement;
 416   lang_target_statement_type target_statement;
 417   lang_output_statement_type output_statement;
 418   lang_input_section_type input_section;
 419   lang_common_statement_type common_statement;
 420   lang_object_symbols_statement_type object_symbols_statement;
 421   lang_fill_statement_type fill_statement;
 422   lang_padding_statement_type padding_statement;
 423   lang_group_statement_type group_statement;
 424   lang_insert_statement_type insert_statement;
 425 } lang_statement_union_type;
 426
 427 /* This structure holds information about a program header, from the
 428    PHDRS command in the linker script.  */
 429
 430 struct lang_phdr
 431 {
 432   struct lang_phdr *next;
 433   const char *name;
 434   unsigned long type;
 435   bfd_boolean filehdr;
 436   bfd_boolean phdrs;
 437   etree_type *at;
 438   etree_type *flags;
 439 };
 440
 441 /* This structure is used to hold a list of sections which may not
 442    cross reference each other.  */
 443
 444 typedef struct lang_nocrossref
 445 {
 446   struct lang_nocrossref *next;
 447   const char *name;
 448 } lang_nocrossref_type;
 449
 450 /* The list of nocrossref lists.  */
 451
 452 struct lang_nocrossrefs
 453 {
 454   struct lang_nocrossrefs *next;
 455   lang_nocrossref_type *list;
 456 };
 457
 458 /* This structure is used to hold a list of input section names which
 459    will not match an output section in the linker script.  */
 460
 461 struct unique_sections
 462 {
 463   struct unique_sections *next;
 464   const char *name;
 465 };
 466
 467 /* This structure records symbols for which we need to keep track of
 468    definedness for use in the DEFINED () test.  */
 469
 470 struct lang_definedness_hash_entry
 471 {
 472   struct bfd_hash_entry root;
 473   unsigned int by_object : 1;
 474   unsigned int by_script : 1;
 475   unsigned int iteration : 1;
 476 };
 477
 478 /* Used by place_orphan to keep track of orphan sections and statements.  */
 479
 480 struct orphan_save
 481 {
 482   const char *name;
 483   flagword flags;
 484   lang_output_section_statement_type *os;
 485   asection **section;
 486   lang_statement_union_type **stmt;
 487   lang_output_section_statement_type **os_tail;
 488 };
 489
 490 struct asneeded_minfo
 491 {
 492   struct asneeded_minfo *next;
 493   const char *soname;
 494   bfd *ref;
 495   const char *name;
 496 };
 497
 498 extern struct lang_phdr *lang_phdr_list;
 499 extern struct lang_nocrossrefs *nocrossref_list;
 500 extern const char *output_target;
 501 extern lang_output_section_statement_type *abs_output_section;
 502 extern lang_statement_list_type lang_output_section_statement;
 503 extern struct lang_input_statement_flags input_flags;
 504 extern bfd_boolean lang_has_input_file;
 505 extern etree_type *base;
 506 extern lang_statement_list_type *stat_ptr;
 507 extern bfd_boolean delete_output_file_on_failure;
 508
 509 extern struct bfd_sym_chain entry_symbol;
 510 extern const char *entry_section;
 511 extern bfd_boolean entry_from_cmdline;
 512 extern lang_statement_list_type file_chain;
 513 extern lang_statement_list_type input_file_chain;
 514
 515 extern int lang_statement_iteration;
 516 extern struct asneeded_minfo **asneeded_list_tail;
 517
 518 extern void lang_init
 519   (void);
 520 extern void lang_finish
 521   (void);
 522 extern lang_memory_region_type * lang_memory_region_lookup
 523   (const char * const, bfd_boolean);
 524 extern void lang_memory_region_alias
 525   (const char *, const char *);
 526 extern void lang_map
 527   (void);
 528 extern void lang_set_flags
 529   (lang_memory_region_type *, const char *, int);
 530 extern void lang_add_output
 531   (const char *, int from_script);
 532 extern lang_output_section_statement_type *lang_enter_output_section_statement
 533   (const char *, etree_type *, enum section_type, etree_type *, etree_type *,
 534    etree_type *, int, int);
 535 extern void lang_final
 536   (void);
 537 extern void lang_relax_sections
 538   (bfd_boolean);
 539 extern void lang_process
 540   (void);
 541 extern void lang_section_start
 542   (const char *, union etree_union *, const segment_type *);
 543 extern void lang_add_entry
 544   (const char *, bfd_boolean);
 545 extern void lang_default_entry
 546   (const char *);
 547 extern void lang_add_target
 548   (const char *);
 549 extern void lang_add_wild
 550   (struct wildcard_spec *, struct wildcard_list *, bfd_boolean);
 551 extern void lang_add_map
 552   (const char *);
 553 extern void lang_add_fill
 554   (fill_type *);
 555 extern lang_assignment_statement_type *lang_add_assignment
 556   (union etree_union *);
 557 extern void lang_add_attribute
 558   (enum statement_enum);
 559 extern void lang_startup
 560   (const char *);
 561 extern void lang_float
 562   (bfd_boolean);
 563 extern void lang_leave_output_section_statement
 564   (fill_type *, const char *, lang_output_section_phdr_list *,
 565    const char *);
 566 extern void lang_statement_append
 567   (lang_statement_list_type *, lang_statement_union_type *,
 568    lang_statement_union_type **);
 569 extern void lang_for_each_input_file
 570   (void (*dothis) (lang_input_statement_type *));
 571 extern void lang_for_each_file
 572   (void (*dothis) (lang_input_statement_type *));
 573 extern void lang_reset_memory_regions
 574   (void);
 575 extern void lang_do_assignments
 576   (lang_phase_type);
 577 extern asection *section_for_dot
 578   (void);
 579
 580 #define LANG_FOR_EACH_INPUT_STATEMENT(statement)                        \
 581   lang_input_statement_type *statement;                                 \
 582   for (statement = (lang_input_statement_type *) file_chain.head;       \
 583        statement != (lang_input_statement_type *) NULL;                 \
 584        statement = (lang_input_statement_type *) statement->next)       \
 585
 586 #define lang_output_section_find(NAME) \
 587   lang_output_section_statement_lookup (NAME, 0, FALSE)
 588
 589 extern void lang_process
 590   (void);
 591 extern void ldlang_add_file
 592   (lang_input_statement_type *);
 593 extern lang_output_section_statement_type *lang_output_section_find_by_flags
 594   (const asection *, lang_output_section_statement_type **,
 595    lang_match_sec_type_func);
 596 extern lang_output_section_statement_type *lang_insert_orphan
 597   (asection *, const char *, int, lang_output_section_statement_type *,
 598    struct orphan_save *, etree_type *, lang_statement_list_type *);
 599 extern lang_input_statement_type *lang_add_input_file
 600   (const char *, lang_input_file_enum_type, const char *);
 601 extern void lang_add_keepsyms_file
 602   (const char *);
 603 extern lang_output_section_statement_type *lang_output_section_get
 604   (const asection *);
 605 extern lang_output_section_statement_type *lang_output_section_statement_lookup
 606   (const char *, int, bfd_boolean);
 607 extern lang_output_section_statement_type *next_matching_output_section_statement
 608   (lang_output_section_statement_type *, int);
 609 extern void ldlang_add_undef
 610   (const char *const, bfd_boolean);
 611 extern void lang_add_output_format
 612   (const char *, const char *, const char *, int);
 613 extern void lang_list_init
 614   (lang_statement_list_type *);
 615 extern void push_stat_ptr
 616   (lang_statement_list_type *);
 617 extern void pop_stat_ptr
 618   (void);
 619 extern void lang_add_data
 620   (int type, union etree_union *);
 621 extern void lang_add_reloc
 622   (bfd_reloc_code_real_type, reloc_howto_type *, asection *, const char *,
 623    union etree_union *);
 624 extern void lang_for_each_statement
 625   (void (*) (lang_statement_union_type *));
 626 extern void lang_for_each_statement_worker
 627   (void (*) (lang_statement_union_type *), lang_statement_union_type *);
 628 extern void *stat_alloc
 629   (size_t);
 630 extern void strip_excluded_output_sections
 631   (void);
 632 extern void dprint_statement
 633   (lang_statement_union_type *, int);
 634 extern void lang_size_sections
 635   (bfd_boolean *, bfd_boolean);
 636 extern void one_lang_size_sections_pass
 637   (bfd_boolean *, bfd_boolean);
 638 extern void lang_add_insert
 639   (const char *, int);
 640 extern void lang_enter_group
 641   (void);
 642 extern void lang_leave_group
 643   (void);
 644 extern void lang_add_section
 645   (lang_statement_list_type *, asection *,
 646    struct flag_info *, lang_output_section_statement_type *);
 647 extern void lang_new_phdr
 648   (const char *, etree_type *, bfd_boolean, bfd_boolean, etree_type *,
 649    etree_type *);
 650 extern void lang_add_nocrossref
 651   (lang_nocrossref_type *);
 652 extern void lang_enter_overlay
 653   (etree_type *, etree_type *);
 654 extern void lang_enter_overlay_section
 655   (const char *);
 656 extern void lang_leave_overlay_section
 657   (fill_type *, lang_output_section_phdr_list *);
 658 extern void lang_leave_overlay
 659   (etree_type *, int, fill_type *, const char *,
 660    lang_output_section_phdr_list *, const char *);
 661
 662 extern struct bfd_elf_version_expr *lang_new_vers_pattern
 663   (struct bfd_elf_version_expr *, const char *, const char *, bfd_boolean);
 664 extern struct bfd_elf_version_tree *lang_new_vers_node
 665   (struct bfd_elf_version_expr *, struct bfd_elf_version_expr *);
 666 extern struct bfd_elf_version_deps *lang_add_vers_depend
 667   (struct bfd_elf_version_deps *, const char *);
 668 extern void lang_register_vers_node
 669   (const char *, struct bfd_elf_version_tree *, struct bfd_elf_version_deps *);
 670 extern void lang_append_dynamic_list (struct bfd_elf_version_expr *);
 671 extern void lang_append_dynamic_list_cpp_typeinfo (void);
 672 extern void lang_append_dynamic_list_cpp_new (void);
 673 extern void lang_add_unique
 674   (const char *);
 675 extern const char *lang_get_output_target
 676   (void);
 677 extern struct lang_definedness_hash_entry *lang_symbol_defined (const char *);
 678 extern void lang_update_definedness
 679   (const char *, struct bfd_link_hash_entry *);
 680
 681 extern void add_excluded_libs (const char *);
 682 extern bfd_boolean load_symbols
 683   (lang_input_statement_type *, lang_statement_list_type *);
 684
 685 extern bfd_boolean
 686 ldlang_override_segment_assignment
 687   (struct bfd_link_info *, bfd *, asection *, asection *, bfd_boolean);
 688
 689 extern void
 690 lang_ld_feature (char *);
 691
 692 #endif