ld/ldlang.h

   1 /* ldlang.h - linker command language support
   2    Copyright (C) 1991-2018 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   /* 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   overlay_section,
 120   noload_section,
 121   noalloc_section
 122 };
 123
 124 /* This structure holds a list of program headers describing
 125    segments in which this section should be placed.  */
 126
 127 typedef struct lang_output_section_phdr_list
 128 {
 129   struct lang_output_section_phdr_list *next;
 130   const char *name;
 131   bfd_boolean used;
 132 } lang_output_section_phdr_list;
 133
 134 typedef struct lang_output_section_statement_struct
 135 {
 136   lang_statement_header_type header;
 137   lang_statement_list_type children;
 138   struct lang_output_section_statement_struct *next;
 139   struct lang_output_section_statement_struct *prev;
 140   const char *name;
 141   asection *bfd_section;
 142   lang_memory_region_type *region;
 143   lang_memory_region_type *lma_region;
 144   fill_type *fill;
 145   union etree_union *addr_tree;
 146   union etree_union *load_base;
 147   union etree_union *section_alignment;
 148   union etree_union *subsection_alignment;
 149
 150   /* If non-null, an expression to evaluate after setting the section's
 151      size.  The expression is evaluated inside REGION (above) with '.'
 152      set to the end of the section.  Used in the last overlay section
 153      to move '.' past all the overlaid sections.  */
 154   union etree_union *update_dot_tree;
 155
 156   lang_output_section_phdr_list *phdrs;
 157
 158   unsigned int block_value;
 159   int constraint;
 160   flagword flags;
 161   enum section_type sectype;
 162   unsigned int processed_vma : 1;
 163   unsigned int processed_lma : 1;
 164   unsigned int all_input_readonly : 1;
 165   /* If this section should be ignored.  */
 166   unsigned int ignored : 1;
 167   /* If this section should update "dot".  Prevents section being ignored.  */
 168   unsigned int update_dot : 1;
 169   /* If this section is after assignment to _end.  */
 170   unsigned int after_end : 1;
 171   /* If this section uses the alignment of its input sections.  */
 172   unsigned int align_lma_with_input : 1;
 173 } lang_output_section_statement_type;
 174
 175 typedef struct
 176 {
 177   lang_statement_header_type header;
 178 } lang_common_statement_type;
 179
 180 typedef struct
 181 {
 182   lang_statement_header_type header;
 183 } lang_object_symbols_statement_type;
 184
 185 typedef struct
 186 {
 187   lang_statement_header_type header;
 188   fill_type *fill;
 189   int size;
 190   asection *output_section;
 191 } lang_fill_statement_type;
 192
 193 typedef struct
 194 {
 195   lang_statement_header_type header;
 196   unsigned int type;
 197   union etree_union *exp;
 198   bfd_vma value;
 199   asection *output_section;
 200   bfd_vma output_offset;
 201 } lang_data_statement_type;
 202
 203 /* Generate a reloc in the output file.  */
 204
 205 typedef struct
 206 {
 207   lang_statement_header_type header;
 208
 209   /* Reloc to generate.  */
 210   bfd_reloc_code_real_type reloc;
 211
 212   /* Reloc howto structure.  */
 213   reloc_howto_type *howto;
 214
 215   /* Section to generate reloc against.
 216      Exactly one of section and name must be NULL.  */
 217   asection *section;
 218
 219   /* Name of symbol to generate reloc against.
 220      Exactly one of section and name must be NULL.  */
 221   const char *name;
 222
 223   /* Expression for addend.  */
 224   union etree_union *addend_exp;
 225
 226   /* Resolved addend.  */
 227   bfd_vma addend_value;
 228
 229   /* Output section where reloc should be performed.  */
 230   asection *output_section;
 231
 232   /* Offset within output section.  */
 233   bfd_vma output_offset;
 234 } lang_reloc_statement_type;
 235
 236 struct lang_input_statement_flags
 237 {
 238   /* 1 means this file was specified in a -l option.  */
 239   unsigned int maybe_archive : 1;
 240
 241   /* 1 means this file was specified in a -l:namespec option.  */
 242   unsigned int full_name_provided : 1;
 243
 244   /* 1 means search a set of directories for this file.  */
 245   unsigned int search_dirs : 1;
 246
 247   /* 1 means this was found when processing a script in the sysroot.  */
 248   unsigned int sysrooted : 1;
 249
 250   /* 1 means this is base file of incremental load.
 251      Do not load this file's text or data.
 252      Also default text_start to after this file's bss.  */
 253   unsigned int just_syms : 1;
 254
 255   /* Whether to search for this entry as a dynamic archive.  */
 256   unsigned int dynamic : 1;
 257
 258   /* Set if a DT_NEEDED tag should be added not just for the dynamic library
 259      explicitly given by this entry but also for any dynamic libraries in
 260      this entry's needed list.  */
 261   unsigned int add_DT_NEEDED_for_dynamic : 1;
 262
 263   /* Set if this entry should cause a DT_NEEDED tag only when some
 264      regular file references its symbols (ie. --as-needed is in effect).  */
 265   unsigned int add_DT_NEEDED_for_regular : 1;
 266
 267   /* Whether to include the entire contents of an archive.  */
 268   unsigned int whole_archive : 1;
 269
 270   /* Set when bfd opening is successful.  */
 271   unsigned int loaded : 1;
 272
 273   unsigned int real : 1;
 274
 275   /* Set if the file does not exist.  */
 276   unsigned int missing_file : 1;
 277
 278   /* Set if reloading an archive or --as-needed lib.  */
 279   unsigned int reload : 1;
 280
 281 #ifdef ENABLE_PLUGINS
 282   /* Set if the file was claimed by a plugin.  */
 283   unsigned int claimed : 1;
 284
 285   /* Set if the file was claimed from an archive.  */
 286   unsigned int claim_archive : 1;
 287
 288   /* Set if added by the lto plugin add_input_file callback.  */
 289   unsigned int lto_output : 1;
 290 #endif /* ENABLE_PLUGINS */
 291
 292   /* Head of list of pushed flags.  */
 293   struct lang_input_statement_flags *pushed;
 294 };
 295
 296 typedef struct lang_input_statement_struct
 297 {
 298   lang_statement_header_type header;
 299   /* Name of this file.  */
 300   const char *filename;
 301   /* Name to use for the symbol giving address of text start.
 302      Usually the same as filename, but for a file spec'd with
 303      -l this is the -l switch itself rather than the filename.  */
 304   const char *local_sym_name;
 305
 306   bfd *the_bfd;
 307
 308   struct flag_info *section_flag_list;
 309
 310   /* Next pointer for file_chain statement list.  */
 311   union lang_statement_union *next;
 312
 313   /* Next pointer for input_file_chain statement list.  */
 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 = &file_chain.head->input_statement;                   \
 586        statement != NULL;                                               \
 587        statement = &statement->next->input_statement)
 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