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_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   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 } lang_common_statement_type;
 180
 181 typedef struct
 182 {
 183   lang_statement_header_type header;
 184 } lang_object_symbols_statement_type;
 185
 186 typedef struct
 187 {
 188   lang_statement_header_type header;
 189   fill_type *fill;
 190   int size;
 191   asection *output_section;
 192 } lang_fill_statement_type;
 193
 194 typedef struct
 195 {
 196   lang_statement_header_type header;
 197   unsigned int type;
 198   union etree_union *exp;
 199   bfd_vma value;
 200   asection *output_section;
 201   bfd_vma output_offset;
 202 } lang_data_statement_type;
 203
 204 /* Generate a reloc in the output file.  */
 205
 206 typedef struct
 207 {
 208   lang_statement_header_type header;
 209
 210   /* Reloc to generate.  */
 211   bfd_reloc_code_real_type reloc;
 212
 213   /* Reloc howto structure.  */
 214   reloc_howto_type *howto;
 215
 216   /* Section to generate reloc against.
 217      Exactly one of section and name must be NULL.  */
 218   asection *section;
 219
 220   /* Name of symbol to generate reloc against.
 221      Exactly one of section and name must be NULL.  */
 222   const char *name;
 223
 224   /* Expression for addend.  */
 225   union etree_union *addend_exp;
 226
 227   /* Resolved addend.  */
 228   bfd_vma addend_value;
 229
 230   /* Output section where reloc should be performed.  */
 231   asection *output_section;
 232
 233   /* Offset within output section.  */
 234   bfd_vma output_offset;
 235 } lang_reloc_statement_type;
 236
 237 struct lang_input_statement_flags
 238 {
 239   /* 1 means this file was specified in a -l option.  */
 240   unsigned int maybe_archive : 1;
 241
 242   /* 1 means this file was specified in a -l:namespec option.  */
 243   unsigned int full_name_provided : 1;
 244
 245   /* 1 means search a set of directories for this file.  */
 246   unsigned int search_dirs : 1;
 247
 248   /* 1 means this was found when processing a script in the sysroot.  */
 249   unsigned int sysrooted : 1;
 250
 251   /* 1 means this is base file of incremental load.
 252      Do not load this file's text or data.
 253      Also default text_start to after this file's bss.  */
 254   unsigned int just_syms : 1;
 255
 256   /* Whether to search for this entry as a dynamic archive.  */
 257   unsigned int dynamic : 1;
 258
 259   /* Set if a DT_NEEDED tag should be added not just for the dynamic library
 260      explicitly given by this entry but also for any dynamic libraries in
 261      this entry's needed list.  */
 262   unsigned int add_DT_NEEDED_for_dynamic : 1;
 263
 264   /* Set if this entry should cause a DT_NEEDED tag only when some
 265      regular file references its symbols (ie. --as-needed is in effect).  */
 266   unsigned int add_DT_NEEDED_for_regular : 1;
 267
 268   /* Whether to include the entire contents of an archive.  */
 269   unsigned int whole_archive : 1;
 270
 271   /* Set when bfd opening is successful.  */
 272   unsigned int loaded : 1;
 273
 274   unsigned int real : 1;
 275
 276   /* Set if the file does not exist.  */
 277   unsigned int missing_file : 1;
 278
 279   /* Set if reloading an archive or --as-needed lib.  */
 280   unsigned int reload : 1;
 281
 282 #ifdef ENABLE_PLUGINS
 283   /* Set if the file was claimed by a plugin.  */
 284   unsigned int claimed : 1;
 285
 286   /* Set if the file was claimed from an archive.  */
 287   unsigned int claim_archive : 1;
 288
 289   /* Set if added by the lto plugin add_input_file callback.  */
 290   unsigned int lto_output : 1;
 291 #endif /* ENABLE_PLUGINS */
 292
 293   /* Head of list of pushed flags.  */
 294   struct lang_input_statement_flags *pushed;
 295 };
 296
 297 typedef struct lang_input_statement_struct
 298 {
 299   lang_statement_header_type header;
 300   /* Name of this file.  */
 301   const char *filename;
 302   /* Name to use for the symbol giving address of text start.
 303      Usually the same as filename, but for a file spec'd with
 304      -l this is the -l switch itself rather than the filename.  */
 305   const char *local_sym_name;
 306
 307   bfd *the_bfd;
 308
 309   struct flag_info *section_flag_list;
 310
 311   /* Next pointer for file_chain statement list.  */
 312   struct lang_input_statement_struct *next;
 313
 314   /* Next pointer for input_file_chain statement list.  */
 315   struct lang_input_statement_struct *next_real_file;
 316
 317   const char *target;
 318
 319   struct lang_input_statement_flags flags;
 320 } lang_input_statement_type;
 321
 322 typedef struct
 323 {
 324   lang_statement_header_type header;
 325   asection *section;
 326 } lang_input_section_type;
 327
 328 struct map_symbol_def {
 329   struct bfd_link_hash_entry *entry;
 330   struct map_symbol_def *next;
 331 };
 332
 333 /* For input sections, when writing a map file: head / tail of a linked
 334    list of hash table entries for symbols defined in this section.  */
 335 typedef struct input_section_userdata_struct
 336 {
 337   struct map_symbol_def *map_symbol_def_head;
 338   struct map_symbol_def **map_symbol_def_tail;
 339   unsigned long map_symbol_def_count;
 340 } input_section_userdata_type;
 341
 342 #define get_userdata(x) ((x)->userdata)
 343
 344
 345 typedef struct lang_wild_statement_struct lang_wild_statement_type;
 346
 347 typedef void (*callback_t) (lang_wild_statement_type *, struct wildcard_list *,
 348                             asection *, struct flag_info *,
 349                             lang_input_statement_type *, void *);
 350
 351 typedef void (*walk_wild_section_handler_t) (lang_wild_statement_type *,
 352                                              lang_input_statement_type *,
 353                                              callback_t callback,
 354                                              void *data);
 355
 356 typedef bfd_boolean (*lang_match_sec_type_func) (bfd *, const asection *,
 357                                                  bfd *, const asection *);
 358
 359 /* Binary search tree structure to efficiently sort sections by
 360    name.  */
 361 typedef struct lang_section_bst
 362 {
 363   asection *section;
 364   struct lang_section_bst *left;
 365   struct lang_section_bst *right;
 366 } lang_section_bst_type;
 367
 368 struct lang_wild_statement_struct
 369 {
 370   lang_statement_header_type header;
 371   const char *filename;
 372   bfd_boolean filenames_sorted;
 373   struct wildcard_list *section_list;
 374   bfd_boolean keep_sections;
 375   lang_statement_list_type children;
 376   struct name_list *exclude_name_list;
 377
 378   walk_wild_section_handler_t walk_wild_section_handler;
 379   struct wildcard_list *handler_data[4];
 380   lang_section_bst_type *tree;
 381   struct flag_info *section_flag_list;
 382 };
 383
 384 typedef struct lang_address_statement_struct
 385 {
 386   lang_statement_header_type header;
 387   const char *section_name;
 388   union etree_union *address;
 389   const segment_type *segment;
 390 } lang_address_statement_type;
 391
 392 typedef struct
 393 {
 394   lang_statement_header_type header;
 395   bfd_vma output_offset;
 396   bfd_size_type size;
 397   asection *output_section;
 398   fill_type *fill;
 399 } lang_padding_statement_type;
 400
 401 /* A group statement collects a set of libraries together.  The
 402    libraries are searched multiple times, until no new undefined
 403    symbols are found.  The effect is to search a group of libraries as
 404    though they were a single library.  */
 405
 406 typedef struct
 407 {
 408   lang_statement_header_type header;
 409   lang_statement_list_type children;
 410 } lang_group_statement_type;
 411
 412 typedef struct
 413 {
 414   lang_statement_header_type header;
 415   const char *where;
 416   bfd_boolean is_before;
 417 } lang_insert_statement_type;
 418
 419 typedef union lang_statement_union
 420 {
 421   lang_statement_header_type header;
 422   lang_wild_statement_type wild_statement;
 423   lang_data_statement_type data_statement;
 424   lang_reloc_statement_type reloc_statement;
 425   lang_address_statement_type address_statement;
 426   lang_output_section_statement_type output_section_statement;
 427   lang_assignment_statement_type assignment_statement;
 428   lang_input_statement_type input_statement;
 429   lang_target_statement_type target_statement;
 430   lang_output_statement_type output_statement;
 431   lang_input_section_type input_section;
 432   lang_common_statement_type common_statement;
 433   lang_object_symbols_statement_type object_symbols_statement;
 434   lang_fill_statement_type fill_statement;
 435   lang_padding_statement_type padding_statement;
 436   lang_group_statement_type group_statement;
 437   lang_insert_statement_type insert_statement;
 438 } lang_statement_union_type;
 439
 440 /* This structure holds information about a program header, from the
 441    PHDRS command in the linker script.  */
 442
 443 struct lang_phdr
 444 {
 445   struct lang_phdr *next;
 446   const char *name;
 447   unsigned long type;
 448   bfd_boolean filehdr;
 449   bfd_boolean phdrs;
 450   etree_type *at;
 451   etree_type *flags;
 452 };
 453
 454 /* This structure is used to hold a list of sections which may not
 455    cross reference each other.  */
 456
 457 typedef struct lang_nocrossref
 458 {
 459   struct lang_nocrossref *next;
 460   const char *name;
 461 } lang_nocrossref_type;
 462
 463 /* The list of nocrossref lists.  */
 464
 465 struct lang_nocrossrefs
 466 {
 467   struct lang_nocrossrefs *next;
 468   lang_nocrossref_type *list;
 469   bfd_boolean onlyfirst;
 470 };
 471
 472 /* This structure is used to hold a list of input section names which
 473    will not match an output section in the linker script.  */
 474
 475 struct unique_sections
 476 {
 477   struct unique_sections *next;
 478   const char *name;
 479 };
 480
 481 /* Used by place_orphan to keep track of orphan sections and statements.  */
 482
 483 struct orphan_save
 484 {
 485   const char *name;
 486   flagword flags;
 487   lang_output_section_statement_type *os;
 488   asection **section;
 489   lang_statement_union_type **stmt;
 490   lang_output_section_statement_type **os_tail;
 491 };
 492
 493 struct asneeded_minfo
 494 {
 495   struct asneeded_minfo *next;
 496   const char *soname;
 497   bfd *ref;
 498   const char *name;
 499 };
 500
 501 extern struct lang_phdr *lang_phdr_list;
 502 extern struct lang_nocrossrefs *nocrossref_list;
 503 extern const char *output_target;
 504 extern lang_output_section_statement_type *abs_output_section;
 505 extern lang_statement_list_type lang_os_list;
 506 extern struct lang_input_statement_flags input_flags;
 507 extern bfd_boolean lang_has_input_file;
 508 extern lang_statement_list_type *stat_ptr;
 509 extern bfd_boolean delete_output_file_on_failure;
 510
 511 extern struct bfd_sym_chain entry_symbol;
 512 extern const char *entry_section;
 513 extern bfd_boolean entry_from_cmdline;
 514 extern lang_statement_list_type file_chain;
 515 extern lang_statement_list_type input_file_chain;
 516
 517 extern int lang_statement_iteration;
 518 extern struct asneeded_minfo **asneeded_list_tail;
 519
 520 extern void (*output_bfd_hash_table_free_fn) (struct bfd_link_hash_table *);
 521
 522 extern void lang_init
 523   (void);
 524 extern void lang_finish
 525   (void);
 526 extern lang_memory_region_type * lang_memory_region_lookup
 527   (const char * const, bfd_boolean);
 528 extern void lang_memory_region_alias
 529   (const char *, const char *);
 530 extern void lang_map
 531   (void);
 532 extern void lang_set_flags
 533   (lang_memory_region_type *, const char *, int);
 534 extern void lang_add_output
 535   (const char *, int from_script);
 536 extern lang_output_section_statement_type *lang_enter_output_section_statement
 537   (const char *, etree_type *, enum section_type, etree_type *, etree_type *,
 538    etree_type *, int, int);
 539 extern void lang_final
 540   (void);
 541 extern void lang_relax_sections
 542   (bfd_boolean);
 543 extern void lang_process
 544   (void);
 545 extern void lang_section_start
 546   (const char *, union etree_union *, const segment_type *);
 547 extern void lang_add_entry
 548   (const char *, bfd_boolean);
 549 extern void lang_default_entry
 550   (const char *);
 551 extern void lang_add_target
 552   (const char *);
 553 extern void lang_add_wild
 554   (struct wildcard_spec *, struct wildcard_list *, bfd_boolean);
 555 extern void lang_add_map
 556   (const char *);
 557 extern void lang_add_fill
 558   (fill_type *);
 559 extern lang_assignment_statement_type *lang_add_assignment
 560   (union etree_union *);
 561 extern void lang_add_attribute
 562   (enum statement_enum);
 563 extern void lang_startup
 564   (const char *);
 565 extern void lang_float
 566   (bfd_boolean);
 567 extern void lang_leave_output_section_statement
 568   (fill_type *, const char *, lang_output_section_phdr_list *,
 569    const char *);
 570 extern void lang_for_each_input_file
 571   (void (*dothis) (lang_input_statement_type *));
 572 extern void lang_for_each_file
 573   (void (*dothis) (lang_input_statement_type *));
 574 extern void lang_reset_memory_regions
 575   (void);
 576 extern void lang_do_assignments
 577   (lang_phase_type);
 578 extern asection *section_for_dot
 579   (void);
 580
 581 #define LANG_FOR_EACH_INPUT_STATEMENT(statement)                        \
 582   lang_input_statement_type *statement;                                 \
 583   for (statement = &file_chain.head->input_statement;                   \
 584        statement != NULL;                                               \
 585        statement = statement->next)
 586
 587 #define lang_output_section_find(NAME) \
 588   lang_output_section_statement_lookup (NAME, 0, FALSE)
 589
 590 extern void lang_process
 591   (void);
 592 extern void ldlang_add_file
 593   (lang_input_statement_type *);
 594 extern lang_output_section_statement_type *lang_output_section_find_by_flags
 595   (const asection *, flagword, lang_output_section_statement_type **,
 596    lang_match_sec_type_func);
 597 extern lang_output_section_statement_type *lang_insert_orphan
 598   (asection *, const char *, int, lang_output_section_statement_type *,
 599    struct orphan_save *, etree_type *, lang_statement_list_type *);
 600 extern lang_input_statement_type *lang_add_input_file
 601   (const char *, lang_input_file_enum_type, const char *);
 602 extern void lang_add_keepsyms_file
 603   (const char *);
 604 extern lang_output_section_statement_type *lang_output_section_get
 605   (const asection *);
 606 extern lang_output_section_statement_type *lang_output_section_statement_lookup
 607   (const char *, int, bfd_boolean);
 608 extern lang_output_section_statement_type *next_matching_output_section_statement
 609   (lang_output_section_statement_type *, int);
 610 extern void ldlang_add_undef
 611   (const char *const, bfd_boolean);
 612 extern void ldlang_add_require_defined
 613   (const char *const);
 614 extern void lang_add_output_format
 615   (const char *, const char *, const char *, int);
 616 extern void lang_list_init
 617   (lang_statement_list_type *);
 618 extern void push_stat_ptr
 619   (lang_statement_list_type *);
 620 extern void pop_stat_ptr
 621   (void);
 622 extern void lang_add_data
 623   (int type, union etree_union *);
 624 extern void lang_add_reloc
 625   (bfd_reloc_code_real_type, reloc_howto_type *, asection *, const char *,
 626    union etree_union *);
 627 extern void lang_for_each_statement
 628   (void (*) (lang_statement_union_type *));
 629 extern void lang_for_each_statement_worker
 630   (void (*) (lang_statement_union_type *), lang_statement_union_type *);
 631 extern void *stat_alloc
 632   (size_t);
 633 extern void strip_excluded_output_sections
 634   (void);
 635 extern void lang_clear_os_map
 636   (void);
 637 extern void dprint_statement
 638   (lang_statement_union_type *, int);
 639 extern void lang_size_sections
 640   (bfd_boolean *, bfd_boolean);
 641 extern void one_lang_size_sections_pass
 642   (bfd_boolean *, bfd_boolean);
 643 extern void lang_add_insert
 644   (const char *, int);
 645 extern void lang_enter_group
 646   (void);
 647 extern void lang_leave_group
 648   (void);
 649 extern void lang_add_section
 650   (lang_statement_list_type *, asection *,
 651    struct flag_info *, lang_output_section_statement_type *);
 652 extern void lang_new_phdr
 653   (const char *, etree_type *, bfd_boolean, bfd_boolean, etree_type *,
 654    etree_type *);
 655 extern void lang_add_nocrossref
 656   (lang_nocrossref_type *);
 657 extern void lang_add_nocrossref_to
 658   (lang_nocrossref_type *);
 659 extern void lang_enter_overlay
 660   (etree_type *, etree_type *);
 661 extern void lang_enter_overlay_section
 662   (const char *);
 663 extern void lang_leave_overlay_section
 664   (fill_type *, lang_output_section_phdr_list *);
 665 extern void lang_leave_overlay
 666   (etree_type *, int, fill_type *, const char *,
 667    lang_output_section_phdr_list *, const char *);
 668
 669 extern struct bfd_elf_version_expr *lang_new_vers_pattern
 670   (struct bfd_elf_version_expr *, const char *, const char *, bfd_boolean);
 671 extern struct bfd_elf_version_tree *lang_new_vers_node
 672   (struct bfd_elf_version_expr *, struct bfd_elf_version_expr *);
 673 extern struct bfd_elf_version_deps *lang_add_vers_depend
 674   (struct bfd_elf_version_deps *, const char *);
 675 extern void lang_register_vers_node
 676   (const char *, struct bfd_elf_version_tree *, struct bfd_elf_version_deps *);
 677 extern void lang_append_dynamic_list (struct bfd_elf_version_expr *);
 678 extern void lang_append_dynamic_list_cpp_typeinfo (void);
 679 extern void lang_append_dynamic_list_cpp_new (void);
 680 extern void lang_add_unique
 681   (const char *);
 682 extern const char *lang_get_output_target
 683   (void);
 684 extern void add_excluded_libs (const char *);
 685 extern bfd_boolean load_symbols
 686   (lang_input_statement_type *, lang_statement_list_type *);
 687
 688 extern bfd_boolean
 689 ldlang_override_segment_assignment
 690   (struct bfd_link_info *, bfd *, asection *, asection *, bfd_boolean);
 691
 692 extern void
 693 lang_ld_feature (char *);
 694
 695 extern void
 696 lang_print_memory_usage (void);
 697
 698 extern void
 699 lang_add_gc_name (const char *);
 700
 701 #endif