ld/ldlang.h

   1 /* ldlang.h - linker command language support
   2    Copyright (C) 1991-2016 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
 147   /* If non-null, an expression to evaluate after setting the section's
 148      size.  The expression is evaluated inside REGION (above) with '.'
 149      set to the end of the section.  Used in the last overlay section
 150      to move '.' past all the overlaid sections.  */
 151   union etree_union *update_dot_tree;
 152
 153   lang_output_section_phdr_list *phdrs;
 154
 155   unsigned int block_value;
 156   int subsection_alignment;     /* Alignment of components.  */
 157   int section_alignment;        /* Alignment of start of section.  */
 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      archives */
 311   union lang_statement_union *next;
 312
 313   /* Point to the next file, but skips archive contents.  */
 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
 376   walk_wild_section_handler_t walk_wild_section_handler;
 377   struct wildcard_list *handler_data[4];
 378   lang_section_bst_type *tree;
 379   struct flag_info *section_flag_list;
 380 };
 381
 382 typedef struct lang_address_statement_struct
 383 {
 384   lang_statement_header_type header;
 385   const char *section_name;
 386   union etree_union *address;
 387   const segment_type *segment;
 388 } lang_address_statement_type;
 389
 390 typedef struct
 391 {
 392   lang_statement_header_type header;
 393   bfd_vma output_offset;
 394   bfd_size_type size;
 395   asection *output_section;
 396   fill_type *fill;
 397 } lang_padding_statement_type;
 398
 399 /* A group statement collects a set of libraries together.  The
 400    libraries are searched multiple times, until no new undefined
 401    symbols are found.  The effect is to search a group of libraries as
 402    though they were a single library.  */
 403
 404 typedef struct
 405 {
 406   lang_statement_header_type header;
 407   lang_statement_list_type children;
 408 } lang_group_statement_type;
 409
 410 typedef struct
 411 {
 412   lang_statement_header_type header;
 413   const char *where;
 414   bfd_boolean is_before;
 415 } lang_insert_statement_type;
 416
 417 typedef union lang_statement_union
 418 {
 419   lang_statement_header_type header;
 420   lang_wild_statement_type wild_statement;
 421   lang_data_statement_type data_statement;
 422   lang_reloc_statement_type reloc_statement;
 423   lang_address_statement_type address_statement;
 424   lang_output_section_statement_type output_section_statement;
 425   lang_assignment_statement_type assignment_statement;
 426   lang_input_statement_type input_statement;
 427   lang_target_statement_type target_statement;
 428   lang_output_statement_type output_statement;
 429   lang_input_section_type input_section;
 430   lang_common_statement_type common_statement;
 431   lang_object_symbols_statement_type object_symbols_statement;
 432   lang_fill_statement_type fill_statement;
 433   lang_padding_statement_type padding_statement;
 434   lang_group_statement_type group_statement;
 435   lang_insert_statement_type insert_statement;
 436 } lang_statement_union_type;
 437
 438 /* This structure holds information about a program header, from the
 439    PHDRS command in the linker script.  */
 440
 441 struct lang_phdr
 442 {
 443   struct lang_phdr *next;
 444   const char *name;
 445   unsigned long type;
 446   bfd_boolean filehdr;
 447   bfd_boolean phdrs;
 448   etree_type *at;
 449   etree_type *flags;
 450 };
 451
 452 /* This structure is used to hold a list of sections which may not
 453    cross reference each other.  */
 454
 455 typedef struct lang_nocrossref
 456 {
 457   struct lang_nocrossref *next;
 458   const char *name;
 459 } lang_nocrossref_type;
 460
 461 /* The list of nocrossref lists.  */
 462
 463 struct lang_nocrossrefs
 464 {
 465   struct lang_nocrossrefs *next;
 466   lang_nocrossref_type *list;
 467   bfd_boolean onlyfirst;
 468 };
 469
 470 /* This structure is used to hold a list of input section names which
 471    will not match an output section in the linker script.  */
 472
 473 struct unique_sections
 474 {
 475   struct unique_sections *next;
 476   const char *name;
 477 };
 478
 479 /* Used by place_orphan to keep track of orphan sections and statements.  */
 480
 481 struct orphan_save
 482 {
 483   const char *name;
 484   flagword flags;
 485   lang_output_section_statement_type *os;
 486   asection **section;
 487   lang_statement_union_type **stmt;
 488   lang_output_section_statement_type **os_tail;
 489 };
 490
 491 struct asneeded_minfo
 492 {
 493   struct asneeded_minfo *next;
 494   const char *soname;
 495   bfd *ref;
 496   const char *name;
 497 };
 498
 499 extern struct lang_phdr *lang_phdr_list;
 500 extern struct lang_nocrossrefs *nocrossref_list;
 501 extern const char *output_target;
 502 extern lang_output_section_statement_type *abs_output_section;
 503 extern lang_statement_list_type lang_output_section_statement;
 504 extern struct lang_input_statement_flags input_flags;
 505 extern bfd_boolean lang_has_input_file;
 506 extern lang_statement_list_type *stat_ptr;
 507 extern bfd_boolean delete_output_file_on_failure;
 508
 509 extern struct bfd_sym_chain entry_symbol;
 510 extern const char *entry_section;
 511 extern bfd_boolean entry_from_cmdline;
 512 extern lang_statement_list_type file_chain;
 513 extern lang_statement_list_type input_file_chain;
 514
 515 extern int lang_statement_iteration;
 516 extern struct asneeded_minfo **asneeded_list_tail;
 517
 518 extern void (*output_bfd_hash_table_free_fn) (struct bfd_link_hash_table *);
 519
 520 extern void lang_init
 521   (void);
 522 extern void lang_finish
 523   (void);
 524 extern lang_memory_region_type * lang_memory_region_lookup
 525   (const char * const, bfd_boolean);
 526 extern void lang_memory_region_alias
 527   (const char *, const char *);
 528 extern void lang_map
 529   (void);
 530 extern void lang_set_flags
 531   (lang_memory_region_type *, const char *, int);
 532 extern void lang_add_output
 533   (const char *, int from_script);
 534 extern lang_output_section_statement_type *lang_enter_output_section_statement
 535   (const char *, etree_type *, enum section_type, etree_type *, etree_type *,
 536    etree_type *, int, int);
 537 extern void lang_final
 538   (void);
 539 extern void lang_relax_sections
 540   (bfd_boolean);
 541 extern void lang_process
 542   (void);
 543 extern void lang_section_start
 544   (const char *, union etree_union *, const segment_type *);
 545 extern void lang_add_entry
 546   (const char *, bfd_boolean);
 547 extern void lang_default_entry
 548   (const char *);
 549 extern void lang_add_target
 550   (const char *);
 551 extern void lang_add_wild
 552   (struct wildcard_spec *, struct wildcard_list *, bfd_boolean);
 553 extern void lang_add_map
 554   (const char *);
 555 extern void lang_add_fill
 556   (fill_type *);
 557 extern lang_assignment_statement_type *lang_add_assignment
 558   (union etree_union *);
 559 extern void lang_add_attribute
 560   (enum statement_enum);
 561 extern void lang_startup
 562   (const char *);
 563 extern void lang_float
 564   (bfd_boolean);
 565 extern void lang_leave_output_section_statement
 566   (fill_type *, const char *, lang_output_section_phdr_list *,
 567    const char *);
 568 extern void lang_statement_append
 569   (lang_statement_list_type *, lang_statement_union_type *,
 570    lang_statement_union_type **);
 571 extern void lang_for_each_input_file
 572   (void (*dothis) (lang_input_statement_type *));
 573 extern void lang_for_each_file
 574   (void (*dothis) (lang_input_statement_type *));
 575 extern void lang_reset_memory_regions
 576   (void);
 577 extern void lang_do_assignments
 578   (lang_phase_type);
 579 extern asection *section_for_dot
 580   (void);
 581
 582 #define LANG_FOR_EACH_INPUT_STATEMENT(statement)                        \
 583   lang_input_statement_type *statement;                                 \
 584   for (statement = (lang_input_statement_type *) file_chain.head;       \
 585        statement != (lang_input_statement_type *) NULL;                 \
 586        statement = (lang_input_statement_type *) statement->next)       \
 587
 588 #define lang_output_section_find(NAME) \
 589   lang_output_section_statement_lookup (NAME, 0, FALSE)
 590
 591 extern void lang_process
 592   (void);
 593 extern void ldlang_add_file
 594   (lang_input_statement_type *);
 595 extern lang_output_section_statement_type *lang_output_section_find_by_flags
 596   (const asection *, flagword, lang_output_section_statement_type **,
 597    lang_match_sec_type_func);
 598 extern lang_output_section_statement_type *lang_insert_orphan
 599   (asection *, const char *, int, lang_output_section_statement_type *,
 600    struct orphan_save *, etree_type *, lang_statement_list_type *);
 601 extern lang_input_statement_type *lang_add_input_file
 602   (const char *, lang_input_file_enum_type, const char *);
 603 extern void lang_add_keepsyms_file
 604   (const char *);
 605 extern lang_output_section_statement_type *lang_output_section_get
 606   (const asection *);
 607 extern lang_output_section_statement_type *lang_output_section_statement_lookup
 608   (const char *, int, bfd_boolean);
 609 extern lang_output_section_statement_type *next_matching_output_section_statement
 610   (lang_output_section_statement_type *, int);
 611 extern void ldlang_add_undef
 612   (const char *const, bfd_boolean);
 613 extern void ldlang_add_require_defined
 614   (const char *const);
 615 extern void lang_add_output_format
 616   (const char *, const char *, const char *, int);
 617 extern void lang_list_init
 618   (lang_statement_list_type *);
 619 extern void push_stat_ptr
 620   (lang_statement_list_type *);
 621 extern void pop_stat_ptr
 622   (void);
 623 extern void lang_add_data
 624   (int type, union etree_union *);
 625 extern void lang_add_reloc
 626   (bfd_reloc_code_real_type, reloc_howto_type *, asection *, const char *,
 627    union etree_union *);
 628 extern void lang_for_each_statement
 629   (void (*) (lang_statement_union_type *));
 630 extern void lang_for_each_statement_worker
 631   (void (*) (lang_statement_union_type *), lang_statement_union_type *);
 632 extern void *stat_alloc
 633   (size_t);
 634 extern void strip_excluded_output_sections
 635   (void);
 636 extern void lang_clear_os_map
 637   (void);
 638 extern void dprint_statement
 639   (lang_statement_union_type *, int);
 640 extern void lang_size_sections
 641   (bfd_boolean *, bfd_boolean);
 642 extern void one_lang_size_sections_pass
 643   (bfd_boolean *, bfd_boolean);
 644 extern void lang_add_insert
 645   (const char *, int);
 646 extern void lang_enter_group
 647   (void);
 648 extern void lang_leave_group
 649   (void);
 650 extern void lang_add_section
 651   (lang_statement_list_type *, asection *,
 652    struct flag_info *, lang_output_section_statement_type *);
 653 extern void lang_new_phdr
 654   (const char *, etree_type *, bfd_boolean, bfd_boolean, etree_type *,
 655    etree_type *);
 656 extern void lang_add_nocrossref
 657   (lang_nocrossref_type *);
 658 extern void lang_add_nocrossref_to
 659   (lang_nocrossref_type *);
 660 extern void lang_enter_overlay
 661   (etree_type *, etree_type *);
 662 extern void lang_enter_overlay_section
 663   (const char *);
 664 extern void lang_leave_overlay_section
 665   (fill_type *, lang_output_section_phdr_list *);
 666 extern void lang_leave_overlay
 667   (etree_type *, int, fill_type *, const char *,
 668    lang_output_section_phdr_list *, const char *);
 669
 670 extern struct bfd_elf_version_expr *lang_new_vers_pattern
 671   (struct bfd_elf_version_expr *, const char *, const char *, bfd_boolean);
 672 extern struct bfd_elf_version_tree *lang_new_vers_node
 673   (struct bfd_elf_version_expr *, struct bfd_elf_version_expr *);
 674 extern struct bfd_elf_version_deps *lang_add_vers_depend
 675   (struct bfd_elf_version_deps *, const char *);
 676 extern void lang_register_vers_node
 677   (const char *, struct bfd_elf_version_tree *, struct bfd_elf_version_deps *);
 678 extern void lang_append_dynamic_list (struct bfd_elf_version_expr *);
 679 extern void lang_append_dynamic_list_cpp_typeinfo (void);
 680 extern void lang_append_dynamic_list_cpp_new (void);
 681 extern void lang_add_unique
 682   (const char *);
 683 extern const char *lang_get_output_target
 684   (void);
 685 extern void add_excluded_libs (const char *);
 686 extern bfd_boolean load_symbols
 687   (lang_input_statement_type *, lang_statement_list_type *);
 688
 689 extern bfd_boolean
 690 ldlang_override_segment_assignment
 691   (struct bfd_link_info *, bfd *, asection *, asection *, bfd_boolean);
 692
 693 extern void
 694 lang_ld_feature (char *);
 695
 696 extern void
 697 lang_print_memory_usage (void);
 698
 699 extern void
 700 lang_add_gc_name (const char *);
 701
 702 #endif