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