ld/ldlang.h

   1 /* ldlang.h - linker command language support
   2    Copyright (C) 1991-2016 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
 287   /* Set if added by the lto plugin add_input_file callback.  */
 288   unsigned int lto_output : 1;
 289 #endif /* ENABLE_PLUGINS */
 290
 291   /* Head of list of pushed flags.  */
 292   struct lang_input_statement_flags *pushed;
 293 };
 294
 295 typedef struct lang_input_statement_struct
 296 {
 297   lang_statement_header_type header;
 298   /* Name of this file.  */
 299   const char *filename;
 300   /* Name to use for the symbol giving address of text start.
 301      Usually the same as filename, but for a file spec'd with
 302      -l this is the -l switch itself rather than the filename.  */
 303   const char *local_sym_name;
 304
 305   bfd *the_bfd;
 306
 307   struct flag_info *section_flag_list;
 308
 309   /* Point to the next file - whatever it is, wanders up and down
 310      archives */
 311   union lang_statement_union *next;
 312
 313   /* Point to the next file, but skips archive contents.  */
 314   union lang_statement_union *next_real_file;
 315
 316   const char *target;
 317
 318   struct lang_input_statement_flags flags;
 319 } lang_input_statement_type;
 320
 321 typedef struct
 322 {
 323   lang_statement_header_type header;
 324   asection *section;
 325 } lang_input_section_type;
 326
 327 struct map_symbol_def {
 328   struct bfd_link_hash_entry *entry;
 329   struct map_symbol_def *next;
 330 };
 331
 332 /* For input sections, when writing a map file: head / tail of a linked
 333    list of hash table entries for symbols defined in this section.  */
 334 typedef struct input_section_userdata_struct
 335 {
 336   struct map_symbol_def *map_symbol_def_head;
 337   struct map_symbol_def **map_symbol_def_tail;
 338   unsigned long map_symbol_def_count;
 339 } input_section_userdata_type;
 340
 341 #define get_userdata(x) ((x)->userdata)
 342
 343
 344 typedef struct lang_wild_statement_struct lang_wild_statement_type;
 345
 346 typedef void (*callback_t) (lang_wild_statement_type *, struct wildcard_list *,
 347                             asection *, struct flag_info *,
 348                             lang_input_statement_type *, void *);
 349
 350 typedef void (*walk_wild_section_handler_t) (lang_wild_statement_type *,
 351                                              lang_input_statement_type *,
 352                                              callback_t callback,
 353                                              void *data);
 354
 355 typedef bfd_boolean (*lang_match_sec_type_func) (bfd *, const asection *,
 356                                                  bfd *, const asection *);
 357
 358 /* Binary search tree structure to efficiently sort sections by
 359    name.  */
 360 typedef struct lang_section_bst
 361 {
 362   asection *section;
 363   struct lang_section_bst *left;
 364   struct lang_section_bst *right;
 365 } lang_section_bst_type;
 366
 367 struct lang_wild_statement_struct
 368 {
 369   lang_statement_header_type header;
 370   const char *filename;
 371   bfd_boolean filenames_sorted;
 372   struct wildcard_list *section_list;
 373   bfd_boolean keep_sections;
 374   lang_statement_list_type children;
 375   struct name_list *exclude_name_list;
 376
 377   walk_wild_section_handler_t walk_wild_section_handler;
 378   struct wildcard_list *handler_data[4];
 379   lang_section_bst_type *tree;
 380   struct flag_info *section_flag_list;
 381 };
 382
 383 typedef struct lang_address_statement_struct
 384 {
 385   lang_statement_header_type header;
 386   const char *section_name;
 387   union etree_union *address;
 388   const segment_type *segment;
 389 } lang_address_statement_type;
 390
 391 typedef struct
 392 {
 393   lang_statement_header_type header;
 394   bfd_vma output_offset;
 395   bfd_size_type size;
 396   asection *output_section;
 397   fill_type *fill;
 398 } lang_padding_statement_type;
 399
 400 /* A group statement collects a set of libraries together.  The
 401    libraries are searched multiple times, until no new undefined
 402    symbols are found.  The effect is to search a group of libraries as
 403    though they were a single library.  */
 404
 405 typedef struct
 406 {
 407   lang_statement_header_type header;
 408   lang_statement_list_type children;
 409 } lang_group_statement_type;
 410
 411 typedef struct
 412 {
 413   lang_statement_header_type header;
 414   const char *where;
 415   bfd_boolean is_before;
 416 } lang_insert_statement_type;
 417
 418 typedef union lang_statement_union
 419 {
 420   lang_statement_header_type header;
 421   lang_wild_statement_type wild_statement;
 422   lang_data_statement_type data_statement;
 423   lang_reloc_statement_type reloc_statement;
 424   lang_address_statement_type address_statement;
 425   lang_output_section_statement_type output_section_statement;
 426   lang_assignment_statement_type assignment_statement;
 427   lang_input_statement_type input_statement;
 428   lang_target_statement_type target_statement;
 429   lang_output_statement_type output_statement;
 430   lang_input_section_type input_section;
 431   lang_common_statement_type common_statement;
 432   lang_object_symbols_statement_type object_symbols_statement;
 433   lang_fill_statement_type fill_statement;
 434   lang_padding_statement_type padding_statement;
 435   lang_group_statement_type group_statement;
 436   lang_insert_statement_type insert_statement;
 437 } lang_statement_union_type;
 438
 439 /* This structure holds information about a program header, from the
 440    PHDRS command in the linker script.  */
 441
 442 struct lang_phdr
 443 {
 444   struct lang_phdr *next;
 445   const char *name;
 446   unsigned long type;
 447   bfd_boolean filehdr;
 448   bfd_boolean phdrs;
 449   etree_type *at;
 450   etree_type *flags;
 451 };
 452
 453 /* This structure is used to hold a list of sections which may not
 454    cross reference each other.  */
 455
 456 typedef struct lang_nocrossref
 457 {
 458   struct lang_nocrossref *next;
 459   const char *name;
 460 } lang_nocrossref_type;
 461
 462 /* The list of nocrossref lists.  */
 463
 464 struct lang_nocrossrefs
 465 {
 466   struct lang_nocrossrefs *next;
 467   lang_nocrossref_type *list;
 468   bfd_boolean onlyfirst;
 469 };
 470
 471 /* This structure is used to hold a list of input section names which
 472    will not match an output section in the linker script.  */
 473
 474 struct unique_sections
 475 {
 476   struct unique_sections *next;
 477   const char *name;
 478 };
 479
 480 /* Used by place_orphan to keep track of orphan sections and statements.  */
 481
 482 struct orphan_save
 483 {
 484   const char *name;
 485   flagword flags;
 486   lang_output_section_statement_type *os;
 487   asection **section;
 488   lang_statement_union_type **stmt;
 489   lang_output_section_statement_type **os_tail;
 490 };
 491
 492 struct asneeded_minfo
 493 {
 494   struct asneeded_minfo *next;
 495   const char *soname;
 496   bfd *ref;
 497   const char *name;
 498 };
 499
 500 extern struct lang_phdr *lang_phdr_list;
 501 extern struct lang_nocrossrefs *nocrossref_list;
 502 extern const char *output_target;
 503 extern lang_output_section_statement_type *abs_output_section;
 504 extern lang_statement_list_type lang_output_section_statement;
 505 extern struct lang_input_statement_flags input_flags;
 506 extern bfd_boolean lang_has_input_file;
 507 extern lang_statement_list_type *stat_ptr;
 508 extern bfd_boolean delete_output_file_on_failure;
 509
 510 extern struct bfd_sym_chain entry_symbol;
 511 extern const char *entry_section;
 512 extern bfd_boolean entry_from_cmdline;
 513 extern lang_statement_list_type file_chain;
 514 extern lang_statement_list_type input_file_chain;
 515
 516 extern int lang_statement_iteration;
 517 extern struct asneeded_minfo **asneeded_list_tail;
 518
 519 extern void (*output_bfd_hash_table_free_fn) (struct bfd_link_hash_table *);
 520
 521 extern void lang_init
 522   (void);
 523 extern void lang_finish
 524   (void);
 525 extern lang_memory_region_type * lang_memory_region_lookup
 526   (const char * const, bfd_boolean);
 527 extern void lang_memory_region_alias
 528   (const char *, const char *);
 529 extern void lang_map
 530   (void);
 531 extern void lang_set_flags
 532   (lang_memory_region_type *, const char *, int);
 533 extern void lang_add_output
 534   (const char *, int from_script);
 535 extern lang_output_section_statement_type *lang_enter_output_section_statement
 536   (const char *, etree_type *, enum section_type, etree_type *, etree_type *,
 537    etree_type *, int, int);
 538 extern void lang_final
 539   (void);
 540 extern void lang_relax_sections
 541   (bfd_boolean);
 542 extern void lang_process
 543   (void);
 544 extern void lang_section_start
 545   (const char *, union etree_union *, const segment_type *);
 546 extern void lang_add_entry
 547   (const char *, bfd_boolean);
 548 extern void lang_default_entry
 549   (const char *);
 550 extern void lang_add_target
 551   (const char *);
 552 extern void lang_add_wild
 553   (struct wildcard_spec *, struct wildcard_list *, bfd_boolean);
 554 extern void lang_add_map
 555   (const char *);
 556 extern void lang_add_fill
 557   (fill_type *);
 558 extern lang_assignment_statement_type *lang_add_assignment
 559   (union etree_union *);
 560 extern void lang_add_attribute
 561   (enum statement_enum);
 562 extern void lang_startup
 563   (const char *);
 564 extern void lang_float
 565   (bfd_boolean);
 566 extern void lang_leave_output_section_statement
 567   (fill_type *, const char *, lang_output_section_phdr_list *,
 568    const char *);
 569 extern void lang_statement_append
 570   (lang_statement_list_type *, lang_statement_union_type *,
 571    lang_statement_union_type **);
 572 extern void lang_for_each_input_file
 573   (void (*dothis) (lang_input_statement_type *));
 574 extern void lang_for_each_file
 575   (void (*dothis) (lang_input_statement_type *));
 576 extern void lang_reset_memory_regions
 577   (void);
 578 extern void lang_do_assignments
 579   (lang_phase_type);
 580 extern asection *section_for_dot
 581   (void);
 582
 583 #define LANG_FOR_EACH_INPUT_STATEMENT(statement)                        \
 584   lang_input_statement_type *statement;                                 \
 585   for (statement = (lang_input_statement_type *) file_chain.head;       \
 586        statement != (lang_input_statement_type *) NULL;                 \
 587        statement = (lang_input_statement_type *) statement->next)       \
 588
 589 #define lang_output_section_find(NAME) \
 590   lang_output_section_statement_lookup (NAME, 0, FALSE)
 591
 592 extern void lang_process
 593   (void);
 594 extern void ldlang_add_file
 595   (lang_input_statement_type *);
 596 extern lang_output_section_statement_type *lang_output_section_find_by_flags
 597   (const asection *, flagword, lang_output_section_statement_type **,
 598    lang_match_sec_type_func);
 599 extern lang_output_section_statement_type *lang_insert_orphan
 600   (asection *, const char *, int, lang_output_section_statement_type *,
 601    struct orphan_save *, etree_type *, lang_statement_list_type *);
 602 extern lang_input_statement_type *lang_add_input_file
 603   (const char *, lang_input_file_enum_type, const char *);
 604 extern void lang_add_keepsyms_file
 605   (const char *);
 606 extern lang_output_section_statement_type *lang_output_section_get
 607   (const asection *);
 608 extern lang_output_section_statement_type *lang_output_section_statement_lookup
 609   (const char *, int, bfd_boolean);
 610 extern lang_output_section_statement_type *next_matching_output_section_statement
 611   (lang_output_section_statement_type *, int);
 612 extern void ldlang_add_undef
 613   (const char *const, bfd_boolean);
 614 extern void ldlang_add_require_defined
 615   (const char *const);
 616 extern void lang_add_output_format
 617   (const char *, const char *, const char *, int);
 618 extern void lang_list_init
 619   (lang_statement_list_type *);
 620 extern void push_stat_ptr
 621   (lang_statement_list_type *);
 622 extern void pop_stat_ptr
 623   (void);
 624 extern void lang_add_data
 625   (int type, union etree_union *);
 626 extern void lang_add_reloc
 627   (bfd_reloc_code_real_type, reloc_howto_type *, asection *, const char *,
 628    union etree_union *);
 629 extern void lang_for_each_statement
 630   (void (*) (lang_statement_union_type *));
 631 extern void lang_for_each_statement_worker
 632   (void (*) (lang_statement_union_type *), lang_statement_union_type *);
 633 extern void *stat_alloc
 634   (size_t);
 635 extern void strip_excluded_output_sections
 636   (void);
 637 extern void lang_clear_os_map
 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_add_nocrossref_to
 660   (lang_nocrossref_type *);
 661 extern void lang_enter_overlay
 662   (etree_type *, etree_type *);
 663 extern void lang_enter_overlay_section
 664   (const char *);
 665 extern void lang_leave_overlay_section
 666   (fill_type *, lang_output_section_phdr_list *);
 667 extern void lang_leave_overlay
 668   (etree_type *, int, fill_type *, const char *,
 669    lang_output_section_phdr_list *, const char *);
 670
 671 extern struct bfd_elf_version_expr *lang_new_vers_pattern
 672   (struct bfd_elf_version_expr *, const char *, const char *, bfd_boolean);
 673 extern struct bfd_elf_version_tree *lang_new_vers_node
 674   (struct bfd_elf_version_expr *, struct bfd_elf_version_expr *);
 675 extern struct bfd_elf_version_deps *lang_add_vers_depend
 676   (struct bfd_elf_version_deps *, const char *);
 677 extern void lang_register_vers_node
 678   (const char *, struct bfd_elf_version_tree *, struct bfd_elf_version_deps *);
 679 extern void lang_append_dynamic_list (struct bfd_elf_version_expr *);
 680 extern void lang_append_dynamic_list_cpp_typeinfo (void);
 681 extern void lang_append_dynamic_list_cpp_new (void);
 682 extern void lang_add_unique
 683   (const char *);
 684 extern const char *lang_get_output_target
 685   (void);
 686 extern void add_excluded_libs (const char *);
 687 extern bfd_boolean load_symbols
 688   (lang_input_statement_type *, lang_statement_list_type *);
 689
 690 extern bfd_boolean
 691 ldlang_override_segment_assignment
 692   (struct bfd_link_info *, bfd *, asection *, asection *, bfd_boolean);
 693
 694 extern void
 695 lang_ld_feature (char *);
 696
 697 extern void
 698 lang_print_memory_usage (void);
 699
 700 extern void
 701 lang_add_gc_name (const char *);
 702
 703 #endif