ld/ldlang.h

   1 /* ldlang.h - linker command language support
   2    Copyright (C) 1991-2015 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   union etree_union *origin_exp;
  59   bfd_vma origin;
  60   bfd_size_type length;
  61   union etree_union *length_exp;
  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 this section should update "dot".  Prevents section being ignored.  */
 167   unsigned int update_dot : 1;
 168   /* If this section is after assignment to _end.  */
 169   unsigned int after_end : 1;
 170   /* If this section uses the alignment of its input sections.  */
 171   unsigned int align_lma_with_input : 1;
 172 } lang_output_section_statement_type;
 173
 174 typedef struct
 175 {
 176   lang_statement_header_type header;
 177 } lang_common_statement_type;
 178
 179 typedef struct
 180 {
 181   lang_statement_header_type header;
 182 } lang_object_symbols_statement_type;
 183
 184 typedef struct
 185 {
 186   lang_statement_header_type header;
 187   fill_type *fill;
 188   int size;
 189   asection *output_section;
 190 } lang_fill_statement_type;
 191
 192 typedef struct
 193 {
 194   lang_statement_header_type header;
 195   unsigned int type;
 196   union etree_union *exp;
 197   bfd_vma value;
 198   asection *output_section;
 199   bfd_vma output_offset;
 200 } lang_data_statement_type;
 201
 202 /* Generate a reloc in the output file.  */
 203
 204 typedef struct
 205 {
 206   lang_statement_header_type header;
 207
 208   /* Reloc to generate.  */
 209   bfd_reloc_code_real_type reloc;
 210
 211   /* Reloc howto structure.  */
 212   reloc_howto_type *howto;
 213
 214   /* Section to generate reloc against.
 215      Exactly one of section and name must be NULL.  */
 216   asection *section;
 217
 218   /* Name of symbol to generate reloc against.
 219      Exactly one of section and name must be NULL.  */
 220   const char *name;
 221
 222   /* Expression for addend.  */
 223   union etree_union *addend_exp;
 224
 225   /* Resolved addend.  */
 226   bfd_vma addend_value;
 227
 228   /* Output section where reloc should be performed.  */
 229   asection *output_section;
 230
 231   /* Offset within output section.  */
 232   bfd_vma output_offset;
 233 } lang_reloc_statement_type;
 234
 235 struct lang_input_statement_flags
 236 {
 237   /* 1 means this file was specified in a -l option.  */
 238   unsigned int maybe_archive : 1;
 239
 240   /* 1 means this file was specified in a -l:namespec option.  */
 241   unsigned int full_name_provided : 1;
 242
 243   /* 1 means search a set of directories for this file.  */
 244   unsigned int search_dirs : 1;
 245
 246   /* 1 means this was found when processing a script in the sysroot.  */
 247   unsigned int sysrooted : 1;
 248
 249   /* 1 means this is base file of incremental load.
 250      Do not load this file's text or data.
 251      Also default text_start to after this file's bss.  */
 252   unsigned int just_syms : 1;
 253
 254   /* Whether to search for this entry as a dynamic archive.  */
 255   unsigned int dynamic : 1;
 256
 257   /* Set if a DT_NEEDED tag should be added not just for the dynamic library
 258      explicitly given by this entry but also for any dynamic libraries in
 259      this entry's needed list.  */
 260   unsigned int add_DT_NEEDED_for_dynamic : 1;
 261
 262   /* Set if this entry should cause a DT_NEEDED tag only when some
 263      regular file references its symbols (ie. --as-needed is in effect).  */
 264   unsigned int add_DT_NEEDED_for_regular : 1;
 265
 266   /* Whether to include the entire contents of an archive.  */
 267   unsigned int whole_archive : 1;
 268
 269   /* Set when bfd opening is successful.  */
 270   unsigned int loaded : 1;
 271
 272   unsigned int real : 1;
 273
 274   /* Set if the file does not exist.  */
 275   unsigned int missing_file : 1;
 276
 277   /* Set if reloading an archive or --as-needed lib.  */
 278   unsigned int reload : 1;
 279
 280 #ifdef ENABLE_PLUGINS
 281   /* Set if the file was claimed by a plugin.  */
 282   unsigned int claimed : 1;
 283
 284   /* Set if the file was claimed from an archive.  */
 285   unsigned int claim_archive : 1;
 286 #endif /* ENABLE_PLUGINS */
 287
 288   /* Head of list of pushed flags.  */
 289   struct lang_input_statement_flags *pushed;
 290 };
 291
 292 typedef struct lang_input_statement_struct
 293 {
 294   lang_statement_header_type header;
 295   /* Name of this file.  */
 296   const char *filename;
 297   /* Name to use for the symbol giving address of text start.
 298      Usually the same as filename, but for a file spec'd with
 299      -l this is the -l switch itself rather than the filename.  */
 300   const char *local_sym_name;
 301
 302   bfd *the_bfd;
 303
 304   struct flag_info *section_flag_list;
 305
 306   /* Point to the next file - whatever it is, wanders up and down
 307      archives */
 308   union lang_statement_union *next;
 309
 310   /* Point to the next file, but skips archive contents.  */
 311   union lang_statement_union *next_real_file;
 312
 313   const char *target;
 314
 315   struct lang_input_statement_flags flags;
 316 } lang_input_statement_type;
 317
 318 typedef struct
 319 {
 320   lang_statement_header_type header;
 321   asection *section;
 322 } lang_input_section_type;
 323
 324 struct map_symbol_def {
 325   struct bfd_link_hash_entry *entry;
 326   struct map_symbol_def *next;
 327 };
 328
 329 /* For input sections, when writing a map file: head / tail of a linked
 330    list of hash table entries for symbols defined in this section.  */
 331 typedef struct input_section_userdata_struct
 332 {
 333   struct map_symbol_def *map_symbol_def_head;
 334   struct map_symbol_def **map_symbol_def_tail;
 335   unsigned long map_symbol_def_count;
 336 } input_section_userdata_type;
 337
 338 #define get_userdata(x) ((x)->userdata)
 339
 340
 341 typedef struct lang_wild_statement_struct lang_wild_statement_type;
 342
 343 typedef void (*callback_t) (lang_wild_statement_type *, struct wildcard_list *,
 344                             asection *, struct flag_info *,
 345                             lang_input_statement_type *, void *);
 346
 347 typedef void (*walk_wild_section_handler_t) (lang_wild_statement_type *,
 348                                              lang_input_statement_type *,
 349                                              callback_t callback,
 350                                              void *data);
 351
 352 typedef bfd_boolean (*lang_match_sec_type_func) (bfd *, const asection *,
 353                                                  bfd *, const asection *);
 354
 355 /* Binary search tree structure to efficiently sort sections by
 356    name.  */
 357 typedef struct lang_section_bst
 358 {
 359   asection *section;
 360   struct lang_section_bst *left;
 361   struct lang_section_bst *right;
 362 } lang_section_bst_type;
 363
 364 struct lang_wild_statement_struct
 365 {
 366   lang_statement_header_type header;
 367   const char *filename;
 368   bfd_boolean filenames_sorted;
 369   struct wildcard_list *section_list;
 370   bfd_boolean keep_sections;
 371   lang_statement_list_type children;
 372
 373   walk_wild_section_handler_t walk_wild_section_handler;
 374   struct wildcard_list *handler_data[4];
 375   lang_section_bst_type *tree;
 376   struct flag_info *section_flag_list;
 377 };
 378
 379 typedef struct lang_address_statement_struct
 380 {
 381   lang_statement_header_type header;
 382   const char *section_name;
 383   union etree_union *address;
 384   const segment_type *segment;
 385 } lang_address_statement_type;
 386
 387 typedef struct
 388 {
 389   lang_statement_header_type header;
 390   bfd_vma output_offset;
 391   bfd_size_type size;
 392   asection *output_section;
 393   fill_type *fill;
 394 } lang_padding_statement_type;
 395
 396 /* A group statement collects a set of libraries together.  The
 397    libraries are searched multiple times, until no new undefined
 398    symbols are found.  The effect is to search a group of libraries as
 399    though they were a single library.  */
 400
 401 typedef struct
 402 {
 403   lang_statement_header_type header;
 404   lang_statement_list_type children;
 405 } lang_group_statement_type;
 406
 407 typedef struct
 408 {
 409   lang_statement_header_type header;
 410   const char *where;
 411   bfd_boolean is_before;
 412 } lang_insert_statement_type;
 413
 414 typedef union lang_statement_union
 415 {
 416   lang_statement_header_type header;
 417   lang_wild_statement_type wild_statement;
 418   lang_data_statement_type data_statement;
 419   lang_reloc_statement_type reloc_statement;
 420   lang_address_statement_type address_statement;
 421   lang_output_section_statement_type output_section_statement;
 422   lang_assignment_statement_type assignment_statement;
 423   lang_input_statement_type input_statement;
 424   lang_target_statement_type target_statement;
 425   lang_output_statement_type output_statement;
 426   lang_input_section_type input_section;
 427   lang_common_statement_type common_statement;
 428   lang_object_symbols_statement_type object_symbols_statement;
 429   lang_fill_statement_type fill_statement;
 430   lang_padding_statement_type padding_statement;
 431   lang_group_statement_type group_statement;
 432   lang_insert_statement_type insert_statement;
 433 } lang_statement_union_type;
 434
 435 /* This structure holds information about a program header, from the
 436    PHDRS command in the linker script.  */
 437
 438 struct lang_phdr
 439 {
 440   struct lang_phdr *next;
 441   const char *name;
 442   unsigned long type;
 443   bfd_boolean filehdr;
 444   bfd_boolean phdrs;
 445   etree_type *at;
 446   etree_type *flags;
 447 };
 448
 449 /* This structure is used to hold a list of sections which may not
 450    cross reference each other.  */
 451
 452 typedef struct lang_nocrossref
 453 {
 454   struct lang_nocrossref *next;
 455   const char *name;
 456 } lang_nocrossref_type;
 457
 458 /* The list of nocrossref lists.  */
 459
 460 struct lang_nocrossrefs
 461 {
 462   struct lang_nocrossrefs *next;
 463   lang_nocrossref_type *list;
 464 };
 465
 466 /* This structure is used to hold a list of input section names which
 467    will not match an output section in the linker script.  */
 468
 469 struct unique_sections
 470 {
 471   struct unique_sections *next;
 472   const char *name;
 473 };
 474
 475 /* Used by place_orphan to keep track of orphan sections and statements.  */
 476
 477 struct orphan_save
 478 {
 479   const char *name;
 480   flagword flags;
 481   lang_output_section_statement_type *os;
 482   asection **section;
 483   lang_statement_union_type **stmt;
 484   lang_output_section_statement_type **os_tail;
 485 };
 486
 487 struct asneeded_minfo
 488 {
 489   struct asneeded_minfo *next;
 490   const char *soname;
 491   bfd *ref;
 492   const char *name;
 493 };
 494
 495 extern struct lang_phdr *lang_phdr_list;
 496 extern struct lang_nocrossrefs *nocrossref_list;
 497 extern const char *output_target;
 498 extern lang_output_section_statement_type *abs_output_section;
 499 extern lang_statement_list_type lang_output_section_statement;
 500 extern struct lang_input_statement_flags input_flags;
 501 extern bfd_boolean lang_has_input_file;
 502 extern lang_statement_list_type *stat_ptr;
 503 extern bfd_boolean delete_output_file_on_failure;
 504
 505 extern struct bfd_sym_chain entry_symbol;
 506 extern const char *entry_section;
 507 extern bfd_boolean entry_from_cmdline;
 508 extern lang_statement_list_type file_chain;
 509 extern lang_statement_list_type input_file_chain;
 510
 511 extern int lang_statement_iteration;
 512 extern struct asneeded_minfo **asneeded_list_tail;
 513
 514 extern void (*output_bfd_hash_table_free_fn) (struct bfd_link_hash_table *);
 515
 516 extern void lang_init
 517   (void);
 518 extern void lang_finish
 519   (void);
 520 extern lang_memory_region_type * lang_memory_region_lookup
 521   (const char * const, bfd_boolean);
 522 extern void lang_memory_region_alias
 523   (const char *, const char *);
 524 extern void lang_map
 525   (void);
 526 extern void lang_set_flags
 527   (lang_memory_region_type *, const char *, int);
 528 extern void lang_add_output
 529   (const char *, int from_script);
 530 extern lang_output_section_statement_type *lang_enter_output_section_statement
 531   (const char *, etree_type *, enum section_type, etree_type *, etree_type *,
 532    etree_type *, int, int);
 533 extern void lang_final
 534   (void);
 535 extern void lang_relax_sections
 536   (bfd_boolean);
 537 extern void lang_process
 538   (void);
 539 extern void lang_section_start
 540   (const char *, union etree_union *, const segment_type *);
 541 extern void lang_add_entry
 542   (const char *, bfd_boolean);
 543 extern void lang_default_entry
 544   (const char *);
 545 extern void lang_add_target
 546   (const char *);
 547 extern void lang_add_wild
 548   (struct wildcard_spec *, struct wildcard_list *, bfd_boolean);
 549 extern void lang_add_map
 550   (const char *);
 551 extern void lang_add_fill
 552   (fill_type *);
 553 extern lang_assignment_statement_type *lang_add_assignment
 554   (union etree_union *);
 555 extern void lang_add_attribute
 556   (enum statement_enum);
 557 extern void lang_startup
 558   (const char *);
 559 extern void lang_float
 560   (bfd_boolean);
 561 extern void lang_leave_output_section_statement
 562   (fill_type *, const char *, lang_output_section_phdr_list *,
 563    const char *);
 564 extern void lang_statement_append
 565   (lang_statement_list_type *, lang_statement_union_type *,
 566    lang_statement_union_type **);
 567 extern void lang_for_each_input_file
 568   (void (*dothis) (lang_input_statement_type *));
 569 extern void lang_for_each_file
 570   (void (*dothis) (lang_input_statement_type *));
 571 extern void lang_reset_memory_regions
 572   (void);
 573 extern void lang_do_assignments
 574   (lang_phase_type);
 575 extern asection *section_for_dot
 576   (void);
 577
 578 #define LANG_FOR_EACH_INPUT_STATEMENT(statement)                        \
 579   lang_input_statement_type *statement;                                 \
 580   for (statement = (lang_input_statement_type *) file_chain.head;       \
 581        statement != (lang_input_statement_type *) NULL;                 \
 582        statement = (lang_input_statement_type *) statement->next)       \
 583
 584 #define lang_output_section_find(NAME) \
 585   lang_output_section_statement_lookup (NAME, 0, FALSE)
 586
 587 extern void lang_process
 588   (void);
 589 extern void ldlang_add_file
 590   (lang_input_statement_type *);
 591 extern lang_output_section_statement_type *lang_output_section_find_by_flags
 592   (const asection *, lang_output_section_statement_type **,
 593    lang_match_sec_type_func);
 594 extern lang_output_section_statement_type *lang_insert_orphan
 595   (asection *, const char *, int, lang_output_section_statement_type *,
 596    struct orphan_save *, etree_type *, lang_statement_list_type *);
 597 extern lang_input_statement_type *lang_add_input_file
 598   (const char *, lang_input_file_enum_type, const char *);
 599 extern void lang_add_keepsyms_file
 600   (const char *);
 601 extern lang_output_section_statement_type *lang_output_section_get
 602   (const asection *);
 603 extern lang_output_section_statement_type *lang_output_section_statement_lookup
 604   (const char *, int, bfd_boolean);
 605 extern lang_output_section_statement_type *next_matching_output_section_statement
 606   (lang_output_section_statement_type *, int);
 607 extern void ldlang_add_undef
 608   (const char *const, bfd_boolean);
 609 extern void lang_add_output_format
 610   (const char *, const char *, const char *, int);
 611 extern void lang_list_init
 612   (lang_statement_list_type *);
 613 extern void push_stat_ptr
 614   (lang_statement_list_type *);
 615 extern void pop_stat_ptr
 616   (void);
 617 extern void lang_add_data
 618   (int type, union etree_union *);
 619 extern void lang_add_reloc
 620   (bfd_reloc_code_real_type, reloc_howto_type *, asection *, const char *,
 621    union etree_union *);
 622 extern void lang_for_each_statement
 623   (void (*) (lang_statement_union_type *));
 624 extern void lang_for_each_statement_worker
 625   (void (*) (lang_statement_union_type *), lang_statement_union_type *);
 626 extern void *stat_alloc
 627   (size_t);
 628 extern void strip_excluded_output_sections
 629   (void);
 630 extern void lang_clear_os_map
 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 void add_excluded_libs (const char *);
 678 extern bfd_boolean load_symbols
 679   (lang_input_statement_type *, lang_statement_list_type *);
 680
 681 extern bfd_boolean
 682 ldlang_override_segment_assignment
 683   (struct bfd_link_info *, bfd *, asection *, asection *, bfd_boolean);
 684
 685 extern void
 686 lang_ld_feature (char *);
 687
 688 #endif