ld/ldlang.h

   1 /* ldlang.h - linker command language support
   2    Copyright 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
   3    2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012
   4    Free Software Foundation, Inc.
   5
   6    This file is part of the GNU Binutils.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21    MA 02110-1301, USA.  */
  22
  23 #ifndef LDLANG_H
  24 #define LDLANG_H
  25
  26 #define DEFAULT_MEMORY_REGION   "*default*"
  27
  28 typedef enum
  29 {
  30   lang_input_file_is_l_enum,
  31   lang_input_file_is_symbols_only_enum,
  32   lang_input_file_is_marker_enum,
  33   lang_input_file_is_fake_enum,
  34   lang_input_file_is_search_file_enum,
  35   lang_input_file_is_file_enum
  36 } lang_input_file_enum_type;
  37
  38 struct _fill_type
  39 {
  40   size_t size;
  41   unsigned char data[1];
  42 };
  43
  44 typedef struct statement_list
  45 {
  46   union lang_statement_union *  head;
  47   union lang_statement_union ** tail;
  48 } lang_statement_list_type;
  49
  50 typedef struct memory_region_name_struct
  51 {
  52   const char * name;
  53   struct memory_region_name_struct * next;
  54 } lang_memory_region_name;
  55
  56 typedef struct memory_region_struct
  57 {
  58   lang_memory_region_name name_list;
  59   struct memory_region_struct *next;
  60   bfd_vma origin;
  61   bfd_size_type length;
  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 there is a symbol relative to this section.  */
 167   unsigned int section_relative_symbol : 1;
 168 } lang_output_section_statement_type;
 169
 170 typedef struct
 171 {
 172   lang_statement_header_type header;
 173 } lang_common_statement_type;
 174
 175 typedef struct
 176 {
 177   lang_statement_header_type header;
 178 } lang_object_symbols_statement_type;
 179
 180 typedef struct
 181 {
 182   lang_statement_header_type header;
 183   fill_type *fill;
 184   int size;
 185   asection *output_section;
 186 } lang_fill_statement_type;
 187
 188 typedef struct
 189 {
 190   lang_statement_header_type header;
 191   unsigned int type;
 192   union etree_union *exp;
 193   bfd_vma value;
 194   asection *output_section;
 195   bfd_vma output_offset;
 196 } lang_data_statement_type;
 197
 198 /* Generate a reloc in the output file.  */
 199
 200 typedef struct
 201 {
 202   lang_statement_header_type header;
 203
 204   /* Reloc to generate.  */
 205   bfd_reloc_code_real_type reloc;
 206
 207   /* Reloc howto structure.  */
 208   reloc_howto_type *howto;
 209
 210   /* Section to generate reloc against.
 211      Exactly one of section and name must be NULL.  */
 212   asection *section;
 213
 214   /* Name of symbol to generate reloc against.
 215      Exactly one of section and name must be NULL.  */
 216   const char *name;
 217
 218   /* Expression for addend.  */
 219   union etree_union *addend_exp;
 220
 221   /* Resolved addend.  */
 222   bfd_vma addend_value;
 223
 224   /* Output section where reloc should be performed.  */
 225   asection *output_section;
 226
 227   /* Offset within output section.  */
 228   bfd_vma output_offset;
 229 } lang_reloc_statement_type;
 230
 231 struct lang_input_statement_flags
 232 {
 233   /* 1 means this file was specified in a -l option.  */
 234   unsigned int maybe_archive : 1;
 235
 236   /* 1 means search a set of directories for this file.  */
 237   unsigned int search_dirs : 1;
 238
 239   /* 1 means this was found when processing a script in the sysroot.  */
 240   unsigned int sysrooted : 1;
 241
 242   /* 1 means this is base file of incremental load.
 243      Do not load this file's text or data.
 244      Also default text_start to after this file's bss.  */
 245   unsigned int just_syms : 1;
 246
 247   /* Whether to search for this entry as a dynamic archive.  */
 248   unsigned int dynamic : 1;
 249
 250   /* Set if a DT_NEEDED tag should be added not just for the dynamic library
 251      explicitly given by this entry but also for any dynamic libraries in
 252      this entry's needed list.  */
 253   unsigned int add_DT_NEEDED_for_dynamic : 1;
 254
 255   /* Set if this entry should cause a DT_NEEDED tag only when some
 256      regular file references its symbols (ie. --as-needed is in effect).  */
 257   unsigned int add_DT_NEEDED_for_regular : 1;
 258
 259   /* Whether to include the entire contents of an archive.  */
 260   unsigned int whole_archive : 1;
 261
 262   /* Set when bfd opening is successful.  */
 263   unsigned int loaded : 1;
 264
 265   unsigned int real : 1;
 266
 267   /* Set if the file does not exist.  */
 268   unsigned int missing_file : 1;
 269
 270 #ifdef ENABLE_PLUGINS
 271   /* Set if the file was claimed by a plugin.  */
 272   unsigned int claimed : 1;
 273
 274   /* Set if the file was claimed from an archive.  */
 275   unsigned int claim_archive : 1;
 276
 277   /* Set if reloading an --as-needed lib.  */
 278   unsigned int reload : 1;
 279 #endif /* ENABLE_PLUGINS */
 280 };
 281
 282 typedef struct lang_input_statement_struct
 283 {
 284   lang_statement_header_type header;
 285   /* Name of this file.  */
 286   const char *filename;
 287   /* Name to use for the symbol giving address of text start.
 288      Usually the same as filename, but for a file spec'd with
 289      -l this is the -l switch itself rather than the filename.  */
 290   const char *local_sym_name;
 291
 292   bfd *the_bfd;
 293
 294   struct flag_info *section_flag_list;
 295
 296   /* Point to the next file - whatever it is, wanders up and down
 297      archives */
 298   union lang_statement_union *next;
 299
 300   /* Point to the next file, but skips archive contents.  */
 301   union lang_statement_union *next_real_file;
 302
 303   const char *target;
 304
 305   struct lang_input_statement_flags flags;
 306 } lang_input_statement_type;
 307
 308 typedef struct
 309 {
 310   lang_statement_header_type header;
 311   asection *section;
 312 } lang_input_section_type;
 313
 314 typedef struct lang_wild_statement_struct lang_wild_statement_type;
 315
 316 typedef void (*callback_t) (lang_wild_statement_type *, struct wildcard_list *,
 317                             asection *, lang_input_statement_type *, void *);
 318
 319 typedef void (*walk_wild_section_handler_t) (lang_wild_statement_type *,
 320                                              lang_input_statement_type *,
 321                                              callback_t callback,
 322                                              void *data);
 323
 324 typedef bfd_boolean (*lang_match_sec_type_func) (bfd *, const asection *,
 325                                                  bfd *, const asection *);
 326
 327 /* Binary search tree structure to efficiently sort sections by
 328    name.  */
 329 typedef struct lang_section_bst
 330 {
 331   asection *section;
 332   struct lang_section_bst *left;
 333   struct lang_section_bst *right;
 334 } lang_section_bst_type;
 335
 336 struct lang_wild_statement_struct
 337 {
 338   lang_statement_header_type header;
 339   const char *filename;
 340   bfd_boolean filenames_sorted;
 341   struct wildcard_list *section_list;
 342   bfd_boolean keep_sections;
 343   lang_statement_list_type children;
 344
 345   walk_wild_section_handler_t walk_wild_section_handler;
 346   struct wildcard_list *handler_data[4];
 347   lang_section_bst_type *tree;
 348   struct flag_info *section_flag_list;
 349 };
 350
 351 typedef struct lang_address_statement_struct
 352 {
 353   lang_statement_header_type header;
 354   const char *section_name;
 355   union etree_union *address;
 356   const segment_type *segment;
 357 } lang_address_statement_type;
 358
 359 typedef struct
 360 {
 361   lang_statement_header_type header;
 362   bfd_vma output_offset;
 363   bfd_size_type size;
 364   asection *output_section;
 365   fill_type *fill;
 366 } lang_padding_statement_type;
 367
 368 /* A group statement collects a set of libraries together.  The
 369    libraries are searched multiple times, until no new undefined
 370    symbols are found.  The effect is to search a group of libraries as
 371    though they were a single library.  */
 372
 373 typedef struct
 374 {
 375   lang_statement_header_type header;
 376   lang_statement_list_type children;
 377 } lang_group_statement_type;
 378
 379 typedef struct
 380 {
 381   lang_statement_header_type header;
 382   const char *where;
 383   bfd_boolean is_before;
 384 } lang_insert_statement_type;
 385
 386 typedef union lang_statement_union
 387 {
 388   lang_statement_header_type header;
 389   lang_wild_statement_type wild_statement;
 390   lang_data_statement_type data_statement;
 391   lang_reloc_statement_type reloc_statement;
 392   lang_address_statement_type address_statement;
 393   lang_output_section_statement_type output_section_statement;
 394   lang_assignment_statement_type assignment_statement;
 395   lang_input_statement_type input_statement;
 396   lang_target_statement_type target_statement;
 397   lang_output_statement_type output_statement;
 398   lang_input_section_type input_section;
 399   lang_common_statement_type common_statement;
 400   lang_object_symbols_statement_type object_symbols_statement;
 401   lang_fill_statement_type fill_statement;
 402   lang_padding_statement_type padding_statement;
 403   lang_group_statement_type group_statement;
 404   lang_insert_statement_type insert_statement;
 405 } lang_statement_union_type;
 406
 407 /* This structure holds information about a program header, from the
 408    PHDRS command in the linker script.  */
 409
 410 struct lang_phdr
 411 {
 412   struct lang_phdr *next;
 413   const char *name;
 414   unsigned long type;
 415   bfd_boolean filehdr;
 416   bfd_boolean phdrs;
 417   etree_type *at;
 418   etree_type *flags;
 419 };
 420
 421 /* This structure is used to hold a list of sections which may not
 422    cross reference each other.  */
 423
 424 typedef struct lang_nocrossref
 425 {
 426   struct lang_nocrossref *next;
 427   const char *name;
 428 } lang_nocrossref_type;
 429
 430 /* The list of nocrossref lists.  */
 431
 432 struct lang_nocrossrefs
 433 {
 434   struct lang_nocrossrefs *next;
 435   lang_nocrossref_type *list;
 436 };
 437
 438 /* This structure is used to hold a list of input section names which
 439    will not match an output section in the linker script.  */
 440
 441 struct unique_sections
 442 {
 443   struct unique_sections *next;
 444   const char *name;
 445 };
 446
 447 /* This structure records symbols for which we need to keep track of
 448    definedness for use in the DEFINED () test.  */
 449
 450 struct lang_definedness_hash_entry
 451 {
 452   struct bfd_hash_entry root;
 453   int iteration;
 454 };
 455
 456 /* Used by place_orphan to keep track of orphan sections and statements.  */
 457
 458 struct orphan_save
 459 {
 460   const char *name;
 461   flagword flags;
 462   lang_output_section_statement_type *os;
 463   asection **section;
 464   lang_statement_union_type **stmt;
 465   lang_output_section_statement_type **os_tail;
 466 };
 467
 468 extern struct lang_phdr *lang_phdr_list;
 469 extern struct lang_nocrossrefs *nocrossref_list;
 470 extern const char *output_target;
 471 extern lang_output_section_statement_type *abs_output_section;
 472 extern lang_statement_list_type lang_output_section_statement;
 473 extern struct lang_input_statement_flags input_flags;
 474 extern bfd_boolean lang_has_input_file;
 475 extern etree_type *base;
 476 extern lang_statement_list_type *stat_ptr;
 477 extern bfd_boolean delete_output_file_on_failure;
 478
 479 extern struct bfd_sym_chain entry_symbol;
 480 extern const char *entry_section;
 481 extern bfd_boolean entry_from_cmdline;
 482 extern lang_statement_list_type file_chain;
 483 extern lang_statement_list_type input_file_chain;
 484
 485 extern int lang_statement_iteration;
 486
 487 extern void lang_init
 488   (void);
 489 extern void lang_finish
 490   (void);
 491 extern lang_memory_region_type * lang_memory_region_lookup
 492   (const char * const, bfd_boolean);
 493 extern void lang_memory_region_alias
 494   (const char *, const char *);
 495 extern void lang_map
 496   (void);
 497 extern void lang_set_flags
 498   (lang_memory_region_type *, const char *, int);
 499 extern void lang_add_output
 500   (const char *, int from_script);
 501 extern lang_output_section_statement_type *lang_enter_output_section_statement
 502   (const char *output_section_statement_name,
 503    etree_type *address_exp,
 504    enum section_type sectype,
 505    etree_type *align,
 506    etree_type *subalign,
 507    etree_type *, int);
 508 extern void lang_final
 509   (void);
 510 extern void lang_relax_sections
 511   (bfd_boolean);
 512 extern void lang_process
 513   (void);
 514 extern void lang_section_start
 515   (const char *, union etree_union *, const segment_type *);
 516 extern void lang_add_entry
 517   (const char *, bfd_boolean);
 518 extern void lang_default_entry
 519   (const char *);
 520 extern void lang_add_target
 521   (const char *);
 522 extern void lang_add_wild
 523   (struct wildcard_spec *, struct wildcard_list *, bfd_boolean);
 524 extern void lang_add_map
 525   (const char *);
 526 extern void lang_add_fill
 527   (fill_type *);
 528 extern lang_assignment_statement_type *lang_add_assignment
 529   (union etree_union *);
 530 extern void lang_add_attribute
 531   (enum statement_enum);
 532 extern void lang_startup
 533   (const char *);
 534 extern void lang_float
 535   (bfd_boolean);
 536 extern void lang_leave_output_section_statement
 537   (fill_type *, const char *, lang_output_section_phdr_list *,
 538    const char *);
 539 extern void lang_abs_symbol_at_end_of
 540   (const char *, const char *);
 541 extern void lang_abs_symbol_at_beginning_of
 542   (const char *, const char *);
 543 extern void lang_statement_append
 544   (lang_statement_list_type *, lang_statement_union_type *,
 545    lang_statement_union_type **);
 546 extern void lang_for_each_input_file
 547   (void (*dothis) (lang_input_statement_type *));
 548 extern void lang_for_each_file
 549   (void (*dothis) (lang_input_statement_type *));
 550 extern void lang_reset_memory_regions
 551   (void);
 552 extern void lang_do_assignments
 553   (lang_phase_type);
 554
 555 #define LANG_FOR_EACH_INPUT_STATEMENT(statement)                        \
 556   lang_input_statement_type *statement;                                 \
 557   for (statement = (lang_input_statement_type *) file_chain.head;       \
 558        statement != (lang_input_statement_type *) NULL;                 \
 559        statement = (lang_input_statement_type *) statement->next)       \
 560
 561 #define lang_output_section_find(NAME) \
 562   lang_output_section_statement_lookup (NAME, 0, FALSE)
 563
 564 extern void lang_process
 565   (void);
 566 extern void ldlang_add_file
 567   (lang_input_statement_type *);
 568 extern lang_output_section_statement_type *lang_output_section_find_by_flags
 569   (const asection *, lang_output_section_statement_type **,
 570    lang_match_sec_type_func);
 571 extern lang_output_section_statement_type *lang_insert_orphan
 572   (asection *, const char *, int, lang_output_section_statement_type *,
 573    struct orphan_save *, etree_type *, lang_statement_list_type *);
 574 extern lang_input_statement_type *lang_add_input_file
 575   (const char *, lang_input_file_enum_type, const char *);
 576 extern void lang_add_keepsyms_file
 577   (const char *);
 578 extern lang_output_section_statement_type *lang_output_section_statement_lookup
 579   (const char *, int, bfd_boolean);
 580 extern lang_output_section_statement_type *next_matching_output_section_statement
 581   (lang_output_section_statement_type *, int);
 582 extern void ldlang_add_undef
 583   (const char *const, bfd_boolean);
 584 extern void lang_add_output_format
 585   (const char *, const char *, const char *, int);
 586 extern void lang_list_init
 587   (lang_statement_list_type *);
 588 extern void push_stat_ptr
 589   (lang_statement_list_type *);
 590 extern void pop_stat_ptr
 591   (void);
 592 extern void lang_add_data
 593   (int type, union etree_union *);
 594 extern void lang_add_reloc
 595   (bfd_reloc_code_real_type, reloc_howto_type *, asection *, const char *,
 596    union etree_union *);
 597 extern void lang_for_each_statement
 598   (void (*) (lang_statement_union_type *));
 599 extern void lang_for_each_statement_worker
 600   (void (*) (lang_statement_union_type *), lang_statement_union_type *);
 601 extern void *stat_alloc
 602   (size_t);
 603 extern void strip_excluded_output_sections
 604   (void);
 605 extern void dprint_statement
 606   (lang_statement_union_type *, int);
 607 extern void lang_size_sections
 608   (bfd_boolean *, bfd_boolean);
 609 extern void one_lang_size_sections_pass
 610   (bfd_boolean *, bfd_boolean);
 611 extern void lang_add_insert
 612   (const char *, int);
 613 extern void lang_enter_group
 614   (void);
 615 extern void lang_leave_group
 616   (void);
 617 extern void lang_add_section
 618   (lang_statement_list_type *, asection *,
 619    lang_output_section_statement_type *);
 620 extern void lang_new_phdr
 621   (const char *, etree_type *, bfd_boolean, bfd_boolean, etree_type *,
 622    etree_type *);
 623 extern void lang_add_nocrossref
 624   (lang_nocrossref_type *);
 625 extern void lang_enter_overlay
 626   (etree_type *, etree_type *);
 627 extern void lang_enter_overlay_section
 628   (const char *);
 629 extern void lang_leave_overlay_section
 630   (fill_type *, lang_output_section_phdr_list *);
 631 extern void lang_leave_overlay
 632   (etree_type *, int, fill_type *, const char *,
 633    lang_output_section_phdr_list *, const char *);
 634
 635 extern struct bfd_elf_version_expr *lang_new_vers_pattern
 636   (struct bfd_elf_version_expr *, const char *, const char *, bfd_boolean);
 637 extern struct bfd_elf_version_tree *lang_new_vers_node
 638   (struct bfd_elf_version_expr *, struct bfd_elf_version_expr *);
 639 extern struct bfd_elf_version_deps *lang_add_vers_depend
 640   (struct bfd_elf_version_deps *, const char *);
 641 extern void lang_register_vers_node
 642   (const char *, struct bfd_elf_version_tree *, struct bfd_elf_version_deps *);
 643 extern void lang_append_dynamic_list (struct bfd_elf_version_expr *);
 644 extern void lang_append_dynamic_list_cpp_typeinfo (void);
 645 extern void lang_append_dynamic_list_cpp_new (void);
 646 extern void lang_add_unique
 647   (const char *);
 648 extern const char *lang_get_output_target
 649   (void);
 650 extern void lang_track_definedness (const char *);
 651 extern int lang_symbol_definition_iteration (const char *);
 652 extern void lang_update_definedness
 653   (const char *, struct bfd_link_hash_entry *);
 654
 655 extern void add_excluded_libs (const char *);
 656 extern bfd_boolean load_symbols
 657   (lang_input_statement_type *, lang_statement_list_type *);
 658
 659 extern bfd_boolean
 660 ldlang_override_segment_assignment
 661   (struct bfd_link_info *, bfd *, asection *, asection *, bfd_boolean);
 662
 663 extern void
 664 lang_ld_feature (char *);
 665
 666 #endif