ld/ldlang.h

   1 /* ldlang.h - linker command language support
   2    Copyright (C) 1991-2019 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_address_statement_enum,
  72   lang_assignment_statement_enum,
  73   lang_data_statement_enum,
  74   lang_fill_statement_enum,
  75   lang_group_statement_enum,
  76   lang_input_section_enum,
  77   lang_input_statement_enum,
  78   lang_insert_statement_enum,
  79   lang_output_section_statement_enum,
  80   lang_output_statement_enum,
  81   lang_padding_statement_enum,
  82   lang_reloc_statement_enum,
  83   lang_target_statement_enum,
  84   lang_wild_statement_enum,
  85   lang_constructors_statement_enum,
  86   lang_object_symbols_statement_enum
  87 };
  88
  89 typedef struct lang_statement_header_struct
  90 {
  91   /* Next pointer for statement_list statement list.  */
  92   union lang_statement_union *next;
  93   enum statement_enum type;
  94 } lang_statement_header_type;
  95
  96 typedef struct
  97 {
  98   lang_statement_header_type header;
  99   union etree_union *exp;
 100 } lang_assignment_statement_type;
 101
 102 typedef struct lang_target_statement_struct
 103 {
 104   lang_statement_header_type header;
 105   const char *target;
 106 } lang_target_statement_type;
 107
 108 typedef struct lang_output_statement_struct
 109 {
 110   lang_statement_header_type header;
 111   const char *name;
 112 } lang_output_statement_type;
 113
 114 /* Section types specified in a linker script.  */
 115
 116 enum section_type
 117 {
 118   normal_section,
 119   first_overlay_section,
 120   overlay_section,
 121   noload_section,
 122   noalloc_section
 123 };
 124
 125 /* This structure holds a list of program headers describing
 126    segments in which this section should be placed.  */
 127
 128 typedef struct lang_output_section_phdr_list
 129 {
 130   struct lang_output_section_phdr_list *next;
 131   const char *name;
 132   bfd_boolean used;
 133 } lang_output_section_phdr_list;
 134
 135 typedef struct lang_output_section_statement_struct
 136 {
 137   lang_statement_header_type header;
 138   lang_statement_list_type children;
 139   struct lang_output_section_statement_struct *next;
 140   struct lang_output_section_statement_struct *prev;
 141   const char *name;
 142   asection *bfd_section;
 143   lang_memory_region_type *region;
 144   lang_memory_region_type *lma_region;
 145   fill_type *fill;
 146   union etree_union *addr_tree;
 147   union etree_union *load_base;
 148   union etree_union *section_alignment;
 149   union etree_union *subsection_alignment;
 150
 151   /* If non-null, an expression to evaluate after setting the section's
 152      size.  The expression is evaluated inside REGION (above) with '.'
 153      set to the end of the section.  Used in the last overlay section
 154      to move '.' past all the overlaid sections.  */
 155   union etree_union *update_dot_tree;
 156
 157   lang_output_section_phdr_list *phdrs;
 158
 159   unsigned int block_value;
 160   int constraint;
 161   flagword flags;
 162   enum section_type sectype;
 163   unsigned int processed_vma : 1;
 164   unsigned int processed_lma : 1;
 165   unsigned int all_input_readonly : 1;
 166   /* If this section should be ignored.  */
 167   unsigned int ignored : 1;
 168   /* If this section should update "dot".  Prevents section being ignored.  */
 169   unsigned int update_dot : 1;
 170   /* If this section is after assignment to _end.  */
 171   unsigned int after_end : 1;
 172   /* If this section uses the alignment of its input sections.  */
 173   unsigned int align_lma_with_input : 1;
 174 } lang_output_section_statement_type;
 175
 176 typedef struct
 177 {
 178   lang_statement_header_type header;
 179   fill_type *fill;
 180   int size;
 181   asection *output_section;
 182 } lang_fill_statement_type;
 183
 184 typedef struct
 185 {
 186   lang_statement_header_type header;
 187   unsigned int type;
 188   union etree_union *exp;
 189   bfd_vma value;
 190   asection *output_section;
 191   bfd_vma output_offset;
 192 } lang_data_statement_type;
 193
 194 /* Generate a reloc in the output file.  */
 195
 196 typedef struct
 197 {
 198   lang_statement_header_type header;
 199
 200   /* Reloc to generate.  */
 201   bfd_reloc_code_real_type reloc;
 202
 203   /* Reloc howto structure.  */
 204   reloc_howto_type *howto;
 205
 206   /* Section to generate reloc against.
 207      Exactly one of section and name must be NULL.  */
 208   asection *section;
 209
 210   /* Name of symbol to generate reloc against.
 211      Exactly one of section and name must be NULL.  */
 212   const char *name;
 213
 214   /* Expression for addend.  */
 215   union etree_union *addend_exp;
 216
 217   /* Resolved addend.  */
 218   bfd_vma addend_value;
 219
 220   /* Output section where reloc should be performed.  */
 221   asection *output_section;
 222
 223   /* Offset within output section.  */
 224   bfd_vma output_offset;
 225 } lang_reloc_statement_type;
 226
 227 struct lang_input_statement_flags
 228 {
 229   /* 1 means this file was specified in a -l option.  */
 230   unsigned int maybe_archive : 1;
 231
 232   /* 1 means this file was specified in a -l:namespec option.  */
 233   unsigned int full_name_provided : 1;
 234
 235   /* 1 means search a set of directories for this file.  */
 236   unsigned int search_dirs : 1;
 237
 238   /* 1 means this was found when processing a script in the sysroot.  */
 239   unsigned int sysrooted : 1;
 240
 241   /* 1 means this is base file of incremental load.
 242      Do not load this file's text or data.
 243      Also default text_start to after this file's bss.  */
 244   unsigned int just_syms : 1;
 245
 246   /* Whether to search for this entry as a dynamic archive.  */
 247   unsigned int dynamic : 1;
 248
 249   /* Set if a DT_NEEDED tag should be added not just for the dynamic library
 250      explicitly given by this entry but also for any dynamic libraries in
 251      this entry's needed list.  */
 252   unsigned int add_DT_NEEDED_for_dynamic : 1;
 253
 254   /* Set if this entry should cause a DT_NEEDED tag only when some
 255      regular file references its symbols (ie. --as-needed is in effect).  */
 256   unsigned int add_DT_NEEDED_for_regular : 1;
 257
 258   /* Whether to include the entire contents of an archive.  */
 259   unsigned int whole_archive : 1;
 260
 261   /* Set when bfd opening is successful.  */
 262   unsigned int loaded : 1;
 263
 264   unsigned int real : 1;
 265
 266   /* Set if the file does not exist.  */
 267   unsigned int missing_file : 1;
 268
 269   /* Set if reloading an archive or --as-needed lib.  */
 270   unsigned int reload : 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 added by the lto plugin add_input_file callback.  */
 280   unsigned int lto_output : 1;
 281 #endif /* ENABLE_PLUGINS */
 282
 283   /* Head of list of pushed flags.  */
 284   struct lang_input_statement_flags *pushed;
 285 };
 286
 287 typedef struct lang_input_statement_struct
 288 {
 289   lang_statement_header_type header;
 290   /* Name of this file.  */
 291   const char *filename;
 292   /* Name to use for the symbol giving address of text start.
 293      Usually the same as filename, but for a file spec'd with
 294      -l this is the -l switch itself rather than the filename.  */
 295   const char *local_sym_name;
 296
 297   bfd *the_bfd;
 298
 299   struct flag_info *section_flag_list;
 300
 301   /* Next pointer for file_chain statement list.  */
 302   struct lang_input_statement_struct *next;
 303
 304   /* Next pointer for input_file_chain statement list.  */
 305   struct lang_input_statement_struct *next_real_file;
 306
 307   const char *target;
 308
 309   struct lang_input_statement_flags flags;
 310 } lang_input_statement_type;
 311
 312 typedef struct
 313 {
 314   lang_statement_header_type header;
 315   asection *section;
 316 } lang_input_section_type;
 317
 318 struct map_symbol_def {
 319   struct bfd_link_hash_entry *entry;
 320   struct map_symbol_def *next;
 321 };
 322
 323 /* For input sections, when writing a map file: head / tail of a linked
 324    list of hash table entries for symbols defined in this section.  */
 325 typedef struct input_section_userdata_struct
 326 {
 327   struct map_symbol_def *map_symbol_def_head;
 328   struct map_symbol_def **map_symbol_def_tail;
 329   unsigned long map_symbol_def_count;
 330 } input_section_userdata_type;
 331
 332 static inline bfd_boolean
 333 bfd_input_just_syms (const bfd *abfd)
 334 {
 335   lang_input_statement_type *is = bfd_usrdata (abfd);
 336   return is != NULL && is->flags.just_syms;
 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   struct name_list *exclude_name_list;
 371
 372   walk_wild_section_handler_t walk_wild_section_handler;
 373   struct wildcard_list *handler_data[4];
 374   lang_section_bst_type *tree;
 375   struct flag_info *section_flag_list;
 376 };
 377
 378 typedef struct lang_address_statement_struct
 379 {
 380   lang_statement_header_type header;
 381   const char *section_name;
 382   union etree_union *address;
 383   const segment_type *segment;
 384 } lang_address_statement_type;
 385
 386 typedef struct
 387 {
 388   lang_statement_header_type header;
 389   bfd_vma output_offset;
 390   bfd_size_type size;
 391   asection *output_section;
 392   fill_type *fill;
 393 } lang_padding_statement_type;
 394
 395 /* A group statement collects a set of libraries together.  The
 396    libraries are searched multiple times, until no new undefined
 397    symbols are found.  The effect is to search a group of libraries as
 398    though they were a single library.  */
 399
 400 typedef struct
 401 {
 402   lang_statement_header_type header;
 403   lang_statement_list_type children;
 404 } lang_group_statement_type;
 405
 406 typedef struct
 407 {
 408   lang_statement_header_type header;
 409   const char *where;
 410   bfd_boolean is_before;
 411 } lang_insert_statement_type;
 412
 413 typedef union lang_statement_union
 414 {
 415   lang_statement_header_type header;
 416   lang_address_statement_type address_statement;
 417   lang_assignment_statement_type assignment_statement;
 418   lang_data_statement_type data_statement;
 419   lang_fill_statement_type fill_statement;
 420   lang_group_statement_type group_statement;
 421   lang_input_section_type input_section;
 422   lang_input_statement_type input_statement;
 423   lang_insert_statement_type insert_statement;
 424   lang_output_section_statement_type output_section_statement;
 425   lang_output_statement_type output_statement;
 426   lang_padding_statement_type padding_statement;
 427   lang_reloc_statement_type reloc_statement;
 428   lang_target_statement_type target_statement;
 429   lang_wild_statement_type wild_statement;
 430 } lang_statement_union_type;
 431
 432 /* This structure holds information about a program header, from the
 433    PHDRS command in the linker script.  */
 434
 435 struct lang_phdr
 436 {
 437   struct lang_phdr *next;
 438   const char *name;
 439   unsigned long type;
 440   bfd_boolean filehdr;
 441   bfd_boolean phdrs;
 442   etree_type *at;
 443   etree_type *flags;
 444 };
 445
 446 /* This structure is used to hold a list of sections which may not
 447    cross reference each other.  */
 448
 449 typedef struct lang_nocrossref
 450 {
 451   struct lang_nocrossref *next;
 452   const char *name;
 453 } lang_nocrossref_type;
 454
 455 /* The list of nocrossref lists.  */
 456
 457 struct lang_nocrossrefs
 458 {
 459   struct lang_nocrossrefs *next;
 460   lang_nocrossref_type *list;
 461   bfd_boolean onlyfirst;
 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 /* Used by place_orphan to keep track of orphan sections and statements.  */
 474
 475 struct orphan_save
 476 {
 477   const char *name;
 478   flagword flags;
 479   lang_output_section_statement_type *os;
 480   asection **section;
 481   lang_statement_union_type **stmt;
 482   lang_output_section_statement_type **os_tail;
 483 };
 484
 485 struct asneeded_minfo
 486 {
 487   struct asneeded_minfo *next;
 488   const char *soname;
 489   bfd *ref;
 490   const char *name;
 491 };
 492
 493 extern struct lang_phdr *lang_phdr_list;
 494 extern struct lang_nocrossrefs *nocrossref_list;
 495 extern const char *output_target;
 496 extern lang_output_section_statement_type *abs_output_section;
 497 extern lang_statement_list_type lang_os_list;
 498 extern struct lang_input_statement_flags input_flags;
 499 extern bfd_boolean lang_has_input_file;
 500 extern lang_statement_list_type *stat_ptr;
 501 extern bfd_boolean delete_output_file_on_failure;
 502
 503 extern struct bfd_sym_chain entry_symbol;
 504 extern const char *entry_section;
 505 extern bfd_boolean entry_from_cmdline;
 506 extern lang_statement_list_type file_chain;
 507 extern lang_statement_list_type input_file_chain;
 508
 509 extern int lang_statement_iteration;
 510 extern struct asneeded_minfo **asneeded_list_tail;
 511
 512 extern void (*output_bfd_hash_table_free_fn) (struct bfd_link_hash_table *);
 513
 514 extern void lang_init
 515   (void);
 516 extern void lang_finish
 517   (void);
 518 extern lang_memory_region_type * lang_memory_region_lookup
 519   (const char * const, bfd_boolean);
 520 extern void lang_memory_region_alias
 521   (const char *, const char *);
 522 extern void lang_map
 523   (void);
 524 extern void lang_set_flags
 525   (lang_memory_region_type *, const char *, int);
 526 extern void lang_add_output
 527   (const char *, int from_script);
 528 extern lang_output_section_statement_type *lang_enter_output_section_statement
 529   (const char *, etree_type *, enum section_type, etree_type *, etree_type *,
 530    etree_type *, int, int);
 531 extern void lang_final
 532   (void);
 533 extern void lang_relax_sections
 534   (bfd_boolean);
 535 extern void lang_process
 536   (void);
 537 extern void lang_section_start
 538   (const char *, union etree_union *, const segment_type *);
 539 extern void lang_add_entry
 540   (const char *, bfd_boolean);
 541 extern void lang_default_entry
 542   (const char *);
 543 extern void lang_add_target
 544   (const char *);
 545 extern void lang_add_wild
 546   (struct wildcard_spec *, struct wildcard_list *, bfd_boolean);
 547 extern void lang_add_map
 548   (const char *);
 549 extern void lang_add_fill
 550   (fill_type *);
 551 extern lang_assignment_statement_type *lang_add_assignment
 552   (union etree_union *);
 553 extern void lang_add_attribute
 554   (enum statement_enum);
 555 extern void lang_startup
 556   (const char *);
 557 extern void lang_float
 558   (bfd_boolean);
 559 extern void lang_leave_output_section_statement
 560   (fill_type *, const char *, lang_output_section_phdr_list *,
 561    const char *);
 562 extern void lang_for_each_input_file
 563   (void (*dothis) (lang_input_statement_type *));
 564 extern void lang_for_each_file
 565   (void (*dothis) (lang_input_statement_type *));
 566 extern void lang_reset_memory_regions
 567   (void);
 568 extern void lang_do_assignments
 569   (lang_phase_type);
 570 extern asection *section_for_dot
 571   (void);
 572
 573 #define LANG_FOR_EACH_INPUT_STATEMENT(statement)                        \
 574   lang_input_statement_type *statement;                                 \
 575   for (statement = &file_chain.head->input_statement;                   \
 576        statement != NULL;                                               \
 577        statement = statement->next)
 578
 579 #define lang_output_section_find(NAME) \
 580   lang_output_section_statement_lookup (NAME, 0, FALSE)
 581
 582 extern void lang_process
 583   (void);
 584 extern void ldlang_add_file
 585   (lang_input_statement_type *);
 586 extern lang_output_section_statement_type *lang_output_section_find_by_flags
 587   (const asection *, flagword, lang_output_section_statement_type **,
 588    lang_match_sec_type_func);
 589 extern lang_output_section_statement_type *lang_insert_orphan
 590   (asection *, const char *, int, lang_output_section_statement_type *,
 591    struct orphan_save *, etree_type *, lang_statement_list_type *);
 592 extern lang_input_statement_type *lang_add_input_file
 593   (const char *, lang_input_file_enum_type, const char *);
 594 extern void lang_add_keepsyms_file
 595   (const char *);
 596 extern lang_output_section_statement_type *lang_output_section_get
 597   (const asection *);
 598 extern lang_output_section_statement_type *lang_output_section_statement_lookup
 599   (const char *, int, bfd_boolean);
 600 extern lang_output_section_statement_type *next_matching_output_section_statement
 601   (lang_output_section_statement_type *, int);
 602 extern void ldlang_add_undef
 603   (const char *const, bfd_boolean);
 604 extern void ldlang_add_require_defined
 605   (const char *const);
 606 extern void lang_add_output_format
 607   (const char *, const char *, const char *, int);
 608 extern void lang_list_init
 609   (lang_statement_list_type *);
 610 extern void push_stat_ptr
 611   (lang_statement_list_type *);
 612 extern void pop_stat_ptr
 613   (void);
 614 extern void lang_add_data
 615   (int type, union etree_union *);
 616 extern void lang_add_reloc
 617   (bfd_reloc_code_real_type, reloc_howto_type *, asection *, const char *,
 618    union etree_union *);
 619 extern void lang_for_each_statement
 620   (void (*) (lang_statement_union_type *));
 621 extern void lang_for_each_statement_worker
 622   (void (*) (lang_statement_union_type *), lang_statement_union_type *);
 623 extern void *stat_alloc
 624   (size_t);
 625 extern void strip_excluded_output_sections
 626   (void);
 627 extern void lang_clear_os_map
 628   (void);
 629 extern void dprint_statement
 630   (lang_statement_union_type *, int);
 631 extern void lang_size_sections
 632   (bfd_boolean *, bfd_boolean);
 633 extern void one_lang_size_sections_pass
 634   (bfd_boolean *, bfd_boolean);
 635 extern void lang_add_insert
 636   (const char *, int);
 637 extern void lang_enter_group
 638   (void);
 639 extern void lang_leave_group
 640   (void);
 641 extern void lang_add_section
 642   (lang_statement_list_type *, asection *,
 643    struct flag_info *, lang_output_section_statement_type *);
 644 extern void lang_new_phdr
 645   (const char *, etree_type *, bfd_boolean, bfd_boolean, etree_type *,
 646    etree_type *);
 647 extern void lang_add_nocrossref
 648   (lang_nocrossref_type *);
 649 extern void lang_add_nocrossref_to
 650   (lang_nocrossref_type *);
 651 extern void lang_enter_overlay
 652   (etree_type *, etree_type *);
 653 extern void lang_enter_overlay_section
 654   (const char *);
 655 extern void lang_leave_overlay_section
 656   (fill_type *, lang_output_section_phdr_list *);
 657 extern void lang_leave_overlay
 658   (etree_type *, int, fill_type *, const char *,
 659    lang_output_section_phdr_list *, const char *);
 660
 661 extern struct bfd_elf_version_expr *lang_new_vers_pattern
 662   (struct bfd_elf_version_expr *, const char *, const char *, bfd_boolean);
 663 extern struct bfd_elf_version_tree *lang_new_vers_node
 664   (struct bfd_elf_version_expr *, struct bfd_elf_version_expr *);
 665 extern struct bfd_elf_version_deps *lang_add_vers_depend
 666   (struct bfd_elf_version_deps *, const char *);
 667 extern void lang_register_vers_node
 668   (const char *, struct bfd_elf_version_tree *, struct bfd_elf_version_deps *);
 669 extern void lang_append_dynamic_list (struct bfd_elf_version_expr *);
 670 extern void lang_append_dynamic_list_cpp_typeinfo (void);
 671 extern void lang_append_dynamic_list_cpp_new (void);
 672 extern void lang_add_unique
 673   (const char *);
 674 extern const char *lang_get_output_target
 675   (void);
 676 extern void add_excluded_libs (const char *);
 677 extern bfd_boolean load_symbols
 678   (lang_input_statement_type *, lang_statement_list_type *);
 679
 680 extern bfd_boolean
 681 ldlang_override_segment_assignment
 682   (struct bfd_link_info *, bfd *, asection *, asection *, bfd_boolean);
 683
 684 extern void
 685 lang_ld_feature (char *);
 686
 687 extern void
 688 lang_print_memory_usage (void);
 689
 690 extern void
 691 lang_add_gc_name (const char *);
 692
 693 #endif