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   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   union etree_union *section_alignment;
 147   union etree_union *subsection_alignment;
 148
 149   /* If non-null, an expression to evaluate after setting the section's
 150      size.  The expression is evaluated inside REGION (above) with '.'
 151      set to the end of the section.  Used in the last overlay section
 152      to move '.' past all the overlaid sections.  */
 153   union etree_union *update_dot_tree;
 154
 155   lang_output_section_phdr_list *phdrs;
 156
 157   unsigned int block_value;
 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      archive elements.  If this input_statement is for an archive, it
 311      won't be on file_chain (which uses this list pointer), but if
 312      any elements have been extracted from the archive, it will point
 313      to the input_statement for the last such element.  */
 314   union lang_statement_union *next;
 315
 316   /* Point to the next file, but skips archive contents.  Used by
 317      input_file_chain.  */
 318   union lang_statement_union *next_real_file;
 319
 320   const char *target;
 321
 322   struct lang_input_statement_flags flags;
 323 } lang_input_statement_type;
 324
 325 typedef struct
 326 {
 327   lang_statement_header_type header;
 328   asection *section;
 329 } lang_input_section_type;
 330
 331 struct map_symbol_def {
 332   struct bfd_link_hash_entry *entry;
 333   struct map_symbol_def *next;
 334 };
 335
 336 /* For input sections, when writing a map file: head / tail of a linked
 337    list of hash table entries for symbols defined in this section.  */
 338 typedef struct input_section_userdata_struct
 339 {
 340   struct map_symbol_def *map_symbol_def_head;
 341   struct map_symbol_def **map_symbol_def_tail;
 342   unsigned long map_symbol_def_count;
 343 } input_section_userdata_type;
 344
 345 #define get_userdata(x) ((x)->userdata)
 346
 347
 348 typedef struct lang_wild_statement_struct lang_wild_statement_type;
 349
 350 typedef void (*callback_t) (lang_wild_statement_type *, struct wildcard_list *,
 351                             asection *, struct flag_info *,
 352                             lang_input_statement_type *, void *);
 353
 354 typedef void (*walk_wild_section_handler_t) (lang_wild_statement_type *,
 355                                              lang_input_statement_type *,
 356                                              callback_t callback,
 357                                              void *data);
 358
 359 typedef bfd_boolean (*lang_match_sec_type_func) (bfd *, const asection *,
 360                                                  bfd *, const asection *);
 361
 362 /* Binary search tree structure to efficiently sort sections by
 363    name.  */
 364 typedef struct lang_section_bst
 365 {
 366   asection *section;
 367   struct lang_section_bst *left;
 368   struct lang_section_bst *right;
 369 } lang_section_bst_type;
 370
 371 struct lang_wild_statement_struct
 372 {
 373   lang_statement_header_type header;
 374   const char *filename;
 375   bfd_boolean filenames_sorted;
 376   struct wildcard_list *section_list;
 377   bfd_boolean keep_sections;
 378   lang_statement_list_type children;
 379   struct name_list *exclude_name_list;
 380
 381   walk_wild_section_handler_t walk_wild_section_handler;
 382   struct wildcard_list *handler_data[4];
 383   lang_section_bst_type *tree;
 384   struct flag_info *section_flag_list;
 385 };
 386
 387 typedef struct lang_address_statement_struct
 388 {
 389   lang_statement_header_type header;
 390   const char *section_name;
 391   union etree_union *address;
 392   const segment_type *segment;
 393 } lang_address_statement_type;
 394
 395 typedef struct
 396 {
 397   lang_statement_header_type header;
 398   bfd_vma output_offset;
 399   bfd_size_type size;
 400   asection *output_section;
 401   fill_type *fill;
 402 } lang_padding_statement_type;
 403
 404 /* A group statement collects a set of libraries together.  The
 405    libraries are searched multiple times, until no new undefined
 406    symbols are found.  The effect is to search a group of libraries as
 407    though they were a single library.  */
 408
 409 typedef struct
 410 {
 411   lang_statement_header_type header;
 412   lang_statement_list_type children;
 413 } lang_group_statement_type;
 414
 415 typedef struct
 416 {
 417   lang_statement_header_type header;
 418   const char *where;
 419   bfd_boolean is_before;
 420 } lang_insert_statement_type;
 421
 422 typedef union lang_statement_union
 423 {
 424   lang_statement_header_type header;
 425   lang_wild_statement_type wild_statement;
 426   lang_data_statement_type data_statement;
 427   lang_reloc_statement_type reloc_statement;
 428   lang_address_statement_type address_statement;
 429   lang_output_section_statement_type output_section_statement;
 430   lang_assignment_statement_type assignment_statement;
 431   lang_input_statement_type input_statement;
 432   lang_target_statement_type target_statement;
 433   lang_output_statement_type output_statement;
 434   lang_input_section_type input_section;
 435   lang_common_statement_type common_statement;
 436   lang_object_symbols_statement_type object_symbols_statement;
 437   lang_fill_statement_type fill_statement;
 438   lang_padding_statement_type padding_statement;
 439   lang_group_statement_type group_statement;
 440   lang_insert_statement_type insert_statement;
 441 } lang_statement_union_type;
 442
 443 /* This structure holds information about a program header, from the
 444    PHDRS command in the linker script.  */
 445
 446 struct lang_phdr
 447 {
 448   struct lang_phdr *next;
 449   const char *name;
 450   unsigned long type;
 451   bfd_boolean filehdr;
 452   bfd_boolean phdrs;
 453   etree_type *at;
 454   etree_type *flags;
 455 };
 456
 457 /* This structure is used to hold a list of sections which may not
 458    cross reference each other.  */
 459
 460 typedef struct lang_nocrossref
 461 {
 462   struct lang_nocrossref *next;
 463   const char *name;
 464 } lang_nocrossref_type;
 465
 466 /* The list of nocrossref lists.  */
 467
 468 struct lang_nocrossrefs
 469 {
 470   struct lang_nocrossrefs *next;
 471   lang_nocrossref_type *list;
 472   bfd_boolean onlyfirst;
 473 };
 474
 475 /* This structure is used to hold a list of input section names which
 476    will not match an output section in the linker script.  */
 477
 478 struct unique_sections
 479 {
 480   struct unique_sections *next;
 481   const char *name;
 482 };
 483
 484 /* Used by place_orphan to keep track of orphan sections and statements.  */
 485
 486 struct orphan_save
 487 {
 488   const char *name;
 489   flagword flags;
 490   lang_output_section_statement_type *os;
 491   asection **section;
 492   lang_statement_union_type **stmt;
 493   lang_output_section_statement_type **os_tail;
 494 };
 495
 496 struct asneeded_minfo
 497 {
 498   struct asneeded_minfo *next;
 499   const char *soname;
 500   bfd *ref;
 501   const char *name;
 502 };
 503
 504 extern struct lang_phdr *lang_phdr_list;
 505 extern struct lang_nocrossrefs *nocrossref_list;
 506 extern const char *output_target;
 507 extern lang_output_section_statement_type *abs_output_section;
 508 extern lang_statement_list_type lang_output_section_statement;
 509 extern struct lang_input_statement_flags input_flags;
 510 extern bfd_boolean lang_has_input_file;
 511 extern lang_statement_list_type *stat_ptr;
 512 extern bfd_boolean delete_output_file_on_failure;
 513
 514 extern struct bfd_sym_chain entry_symbol;
 515 extern const char *entry_section;
 516 extern bfd_boolean entry_from_cmdline;
 517 extern lang_statement_list_type file_chain;
 518 extern lang_statement_list_type input_file_chain;
 519
 520 extern int lang_statement_iteration;
 521 extern struct asneeded_minfo **asneeded_list_tail;
 522
 523 extern void (*output_bfd_hash_table_free_fn) (struct bfd_link_hash_table *);
 524
 525 extern void lang_init
 526   (void);
 527 extern void lang_finish
 528   (void);
 529 extern lang_memory_region_type * lang_memory_region_lookup
 530   (const char * const, bfd_boolean);
 531 extern void lang_memory_region_alias
 532   (const char *, const char *);
 533 extern void lang_map
 534   (void);
 535 extern void lang_set_flags
 536   (lang_memory_region_type *, const char *, int);
 537 extern void lang_add_output
 538   (const char *, int from_script);
 539 extern lang_output_section_statement_type *lang_enter_output_section_statement
 540   (const char *, etree_type *, enum section_type, etree_type *, etree_type *,
 541    etree_type *, int, int);
 542 extern void lang_final
 543   (void);
 544 extern void lang_relax_sections
 545   (bfd_boolean);
 546 extern void lang_process
 547   (void);
 548 extern void lang_section_start
 549   (const char *, union etree_union *, const segment_type *);
 550 extern void lang_add_entry
 551   (const char *, bfd_boolean);
 552 extern void lang_default_entry
 553   (const char *);
 554 extern void lang_add_target
 555   (const char *);
 556 extern void lang_add_wild
 557   (struct wildcard_spec *, struct wildcard_list *, bfd_boolean);
 558 extern void lang_add_map
 559   (const char *);
 560 extern void lang_add_fill
 561   (fill_type *);
 562 extern lang_assignment_statement_type *lang_add_assignment
 563   (union etree_union *);
 564 extern void lang_add_attribute
 565   (enum statement_enum);
 566 extern void lang_startup
 567   (const char *);
 568 extern void lang_float
 569   (bfd_boolean);
 570 extern void lang_leave_output_section_statement
 571   (fill_type *, const char *, lang_output_section_phdr_list *,
 572    const char *);
 573 extern void lang_statement_append
 574   (lang_statement_list_type *, lang_statement_union_type *,
 575    lang_statement_union_type **);
 576 extern void lang_for_each_input_file
 577   (void (*dothis) (lang_input_statement_type *));
 578 extern void lang_for_each_file
 579   (void (*dothis) (lang_input_statement_type *));
 580 extern void lang_reset_memory_regions
 581   (void);
 582 extern void lang_do_assignments
 583   (lang_phase_type);
 584 extern asection *section_for_dot
 585   (void);
 586
 587 #define LANG_FOR_EACH_INPUT_STATEMENT(statement)                        \
 588   lang_input_statement_type *statement;                                 \
 589   for (statement = &file_chain.head->input_statement;                   \
 590        statement != NULL;                                               \
 591        statement = &statement->next->input_statement)
 592
 593 #define lang_output_section_find(NAME) \
 594   lang_output_section_statement_lookup (NAME, 0, FALSE)
 595
 596 extern void lang_process
 597   (void);
 598 extern void ldlang_add_file
 599   (lang_input_statement_type *);
 600 extern lang_output_section_statement_type *lang_output_section_find_by_flags
 601   (const asection *, flagword, lang_output_section_statement_type **,
 602    lang_match_sec_type_func);
 603 extern lang_output_section_statement_type *lang_insert_orphan
 604   (asection *, const char *, int, lang_output_section_statement_type *,
 605    struct orphan_save *, etree_type *, lang_statement_list_type *);
 606 extern lang_input_statement_type *lang_add_input_file
 607   (const char *, lang_input_file_enum_type, const char *);
 608 extern void lang_add_keepsyms_file
 609   (const char *);
 610 extern lang_output_section_statement_type *lang_output_section_get
 611   (const asection *);
 612 extern lang_output_section_statement_type *lang_output_section_statement_lookup
 613   (const char *, int, bfd_boolean);
 614 extern lang_output_section_statement_type *next_matching_output_section_statement
 615   (lang_output_section_statement_type *, int);
 616 extern void ldlang_add_undef
 617   (const char *const, bfd_boolean);
 618 extern void ldlang_add_require_defined
 619   (const char *const);
 620 extern void lang_add_output_format
 621   (const char *, const char *, const char *, int);
 622 extern void lang_list_init
 623   (lang_statement_list_type *);
 624 extern void push_stat_ptr
 625   (lang_statement_list_type *);
 626 extern void pop_stat_ptr
 627   (void);
 628 extern void lang_add_data
 629   (int type, union etree_union *);
 630 extern void lang_add_reloc
 631   (bfd_reloc_code_real_type, reloc_howto_type *, asection *, const char *,
 632    union etree_union *);
 633 extern void lang_for_each_statement
 634   (void (*) (lang_statement_union_type *));
 635 extern void lang_for_each_statement_worker
 636   (void (*) (lang_statement_union_type *), lang_statement_union_type *);
 637 extern void *stat_alloc
 638   (size_t);
 639 extern void strip_excluded_output_sections
 640   (void);
 641 extern void lang_clear_os_map
 642   (void);
 643 extern void dprint_statement
 644   (lang_statement_union_type *, int);
 645 extern void lang_size_sections
 646   (bfd_boolean *, bfd_boolean);
 647 extern void one_lang_size_sections_pass
 648   (bfd_boolean *, bfd_boolean);
 649 extern void lang_add_insert
 650   (const char *, int);
 651 extern void lang_enter_group
 652   (void);
 653 extern void lang_leave_group
 654   (void);
 655 extern void lang_add_section
 656   (lang_statement_list_type *, asection *,
 657    struct flag_info *, lang_output_section_statement_type *);
 658 extern void lang_new_phdr
 659   (const char *, etree_type *, bfd_boolean, bfd_boolean, etree_type *,
 660    etree_type *);
 661 extern void lang_add_nocrossref
 662   (lang_nocrossref_type *);
 663 extern void lang_add_nocrossref_to
 664   (lang_nocrossref_type *);
 665 extern void lang_enter_overlay
 666   (etree_type *, etree_type *);
 667 extern void lang_enter_overlay_section
 668   (const char *);
 669 extern void lang_leave_overlay_section
 670   (fill_type *, lang_output_section_phdr_list *);
 671 extern void lang_leave_overlay
 672   (etree_type *, int, fill_type *, const char *,
 673    lang_output_section_phdr_list *, const char *);
 674
 675 extern struct bfd_elf_version_expr *lang_new_vers_pattern
 676   (struct bfd_elf_version_expr *, const char *, const char *, bfd_boolean);
 677 extern struct bfd_elf_version_tree *lang_new_vers_node
 678   (struct bfd_elf_version_expr *, struct bfd_elf_version_expr *);
 679 extern struct bfd_elf_version_deps *lang_add_vers_depend
 680   (struct bfd_elf_version_deps *, const char *);
 681 extern void lang_register_vers_node
 682   (const char *, struct bfd_elf_version_tree *, struct bfd_elf_version_deps *);
 683 extern void lang_append_dynamic_list (struct bfd_elf_version_expr *);
 684 extern void lang_append_dynamic_list_cpp_typeinfo (void);
 685 extern void lang_append_dynamic_list_cpp_new (void);
 686 extern void lang_add_unique
 687   (const char *);
 688 extern const char *lang_get_output_target
 689   (void);
 690 extern void add_excluded_libs (const char *);
 691 extern bfd_boolean load_symbols
 692   (lang_input_statement_type *, lang_statement_list_type *);
 693
 694 extern bfd_boolean
 695 ldlang_override_segment_assignment
 696   (struct bfd_link_info *, bfd *, asection *, asection *, bfd_boolean);
 697
 698 extern void
 699 lang_ld_feature (char *);
 700
 701 extern void
 702 lang_print_memory_usage (void);
 703
 704 extern void
 705 lang_add_gc_name (const char *);
 706
 707 #endif