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
   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 typedef struct lang_input_statement_struct
 232 {
 233   lang_statement_header_type header;
 234   /* Name of this file.  */
 235   const char *filename;
 236   /* Name to use for the symbol giving address of text start.
 237      Usually the same as filename, but for a file spec'd with
 238      -l this is the -l switch itself rather than the filename.  */
 239   const char *local_sym_name;
 240
 241   bfd *the_bfd;
 242
 243   /* Point to the next file - whatever it is, wanders up and down
 244      archives */
 245   union lang_statement_union *next;
 246
 247   /* Point to the next file, but skips archive contents.  */
 248   union lang_statement_union *next_real_file;
 249
 250   const char *target;
 251
 252   unsigned int maybe_archive : 1;
 253
 254   /* 1 means search a set of directories for this file.  */
 255   unsigned int search_dirs_flag : 1;
 256
 257   /* 1 means this was found in a search directory marked as sysrooted,
 258      if search_dirs_flag is false, otherwise, that it should be
 259      searched in ld_sysroot before any other location, as long as it
 260      starts with a slash.  */
 261   unsigned int sysrooted : 1;
 262
 263   /* 1 means this is base file of incremental load.
 264      Do not load this file's text or data.
 265      Also default text_start to after this file's bss.  */
 266   unsigned int just_syms_flag : 1;
 267
 268   /* Whether to search for this entry as a dynamic archive.  */
 269   unsigned int dynamic : 1;
 270
 271   /* Whether DT_NEEDED tags should be added for dynamic libraries in
 272      DT_NEEDED tags from this entry.  */
 273   unsigned int add_DT_NEEDED_for_dynamic : 1;
 274
 275   /* Whether this entry should cause a DT_NEEDED tag only when
 276      satisfying references from regular files, or always.  */
 277   unsigned int add_DT_NEEDED_for_regular : 1;
 278
 279   /* Whether to include the entire contents of an archive.  */
 280   unsigned int whole_archive : 1;
 281
 282   /* Set when bfd opening is successful.  */
 283   unsigned int loaded : 1;
 284
 285   unsigned int real : 1;
 286
 287   /* Set if the file does not exist.  */
 288   unsigned int missing_file : 1;
 289
 290 #ifdef ENABLE_PLUGINS
 291   /* Set if the file was claimed by a plugin.  */
 292   unsigned int claimed : 1;
 293
 294   /* Set if the file was claimed from an archive.  */
 295   unsigned int claim_archive : 1;
 296 #endif /* ENABLE_PLUGINS */
 297
 298 } lang_input_statement_type;
 299
 300 typedef struct
 301 {
 302   lang_statement_header_type header;
 303   asection *section;
 304 } lang_input_section_type;
 305
 306 typedef struct lang_wild_statement_struct lang_wild_statement_type;
 307
 308 typedef void (*callback_t) (lang_wild_statement_type *, struct wildcard_list *,
 309                             asection *, lang_input_statement_type *, void *);
 310
 311 typedef void (*walk_wild_section_handler_t) (lang_wild_statement_type *,
 312                                              lang_input_statement_type *,
 313                                              callback_t callback,
 314                                              void *data);
 315
 316 typedef bfd_boolean (*lang_match_sec_type_func) (bfd *, const asection *,
 317                                                  bfd *, const asection *);
 318
 319 /* Binary search tree structure to efficiently sort sections by
 320    name.  */
 321 typedef struct lang_section_bst
 322 {
 323   asection *section;
 324   struct lang_section_bst *left;
 325   struct lang_section_bst *right;
 326 } lang_section_bst_type;
 327
 328 struct lang_wild_statement_struct
 329 {
 330   lang_statement_header_type header;
 331   const char *filename;
 332   bfd_boolean filenames_sorted;
 333   struct wildcard_list *section_list;
 334   bfd_boolean keep_sections;
 335   lang_statement_list_type children;
 336
 337   walk_wild_section_handler_t walk_wild_section_handler;
 338   struct wildcard_list *handler_data[4];
 339   lang_section_bst_type *tree;
 340 };
 341
 342 typedef struct lang_address_statement_struct
 343 {
 344   lang_statement_header_type header;
 345   const char *section_name;
 346   union etree_union *address;
 347   const segment_type *segment;
 348 } lang_address_statement_type;
 349
 350 typedef struct
 351 {
 352   lang_statement_header_type header;
 353   bfd_vma output_offset;
 354   size_t size;
 355   asection *output_section;
 356   fill_type *fill;
 357 } lang_padding_statement_type;
 358
 359 /* A group statement collects a set of libraries together.  The
 360    libraries are searched multiple times, until no new undefined
 361    symbols are found.  The effect is to search a group of libraries as
 362    though they were a single library.  */
 363
 364 typedef struct
 365 {
 366   lang_statement_header_type header;
 367   lang_statement_list_type children;
 368 } lang_group_statement_type;
 369
 370 typedef struct
 371 {
 372   lang_statement_header_type header;
 373   const char *where;
 374   bfd_boolean is_before;
 375 } lang_insert_statement_type;
 376
 377 typedef union lang_statement_union
 378 {
 379   lang_statement_header_type header;
 380   lang_wild_statement_type wild_statement;
 381   lang_data_statement_type data_statement;
 382   lang_reloc_statement_type reloc_statement;
 383   lang_address_statement_type address_statement;
 384   lang_output_section_statement_type output_section_statement;
 385   lang_assignment_statement_type assignment_statement;
 386   lang_input_statement_type input_statement;
 387   lang_target_statement_type target_statement;
 388   lang_output_statement_type output_statement;
 389   lang_input_section_type input_section;
 390   lang_common_statement_type common_statement;
 391   lang_object_symbols_statement_type object_symbols_statement;
 392   lang_fill_statement_type fill_statement;
 393   lang_padding_statement_type padding_statement;
 394   lang_group_statement_type group_statement;
 395   lang_insert_statement_type insert_statement;
 396 } lang_statement_union_type;
 397
 398 /* This structure holds information about a program header, from the
 399    PHDRS command in the linker script.  */
 400
 401 struct lang_phdr
 402 {
 403   struct lang_phdr *next;
 404   const char *name;
 405   unsigned long type;
 406   bfd_boolean filehdr;
 407   bfd_boolean phdrs;
 408   etree_type *at;
 409   etree_type *flags;
 410 };
 411
 412 extern struct lang_phdr *lang_phdr_list;
 413
 414 /* This structure is used to hold a list of sections which may not
 415    cross reference each other.  */
 416
 417 typedef struct lang_nocrossref
 418 {
 419   struct lang_nocrossref *next;
 420   const char *name;
 421 } lang_nocrossref_type;
 422
 423 /* The list of nocrossref lists.  */
 424
 425 struct lang_nocrossrefs
 426 {
 427   struct lang_nocrossrefs *next;
 428   lang_nocrossref_type *list;
 429 };
 430
 431 extern struct lang_nocrossrefs *nocrossref_list;
 432
 433 /* This structure is used to hold a list of input section names which
 434    will not match an output section in the linker script.  */
 435
 436 struct unique_sections
 437 {
 438   struct unique_sections *next;
 439   const char *name;
 440 };
 441
 442 /* This structure records symbols for which we need to keep track of
 443    definedness for use in the DEFINED () test.  */
 444
 445 struct lang_definedness_hash_entry
 446 {
 447   struct bfd_hash_entry root;
 448   int iteration;
 449 };
 450
 451 /* Used by place_orphan to keep track of orphan sections and statements.  */
 452
 453 struct orphan_save
 454 {
 455   const char *name;
 456   flagword flags;
 457   lang_output_section_statement_type *os;
 458   asection **section;
 459   lang_statement_union_type **stmt;
 460   lang_output_section_statement_type **os_tail;
 461 };
 462
 463 extern const char *output_target;
 464 extern lang_output_section_statement_type *abs_output_section;
 465 extern lang_statement_list_type lang_output_section_statement;
 466 extern bfd_boolean lang_has_input_file;
 467 extern etree_type *base;
 468 extern lang_statement_list_type *stat_ptr;
 469 extern bfd_boolean delete_output_file_on_failure;
 470
 471 extern struct bfd_sym_chain entry_symbol;
 472 extern const char *entry_section;
 473 extern bfd_boolean entry_from_cmdline;
 474 extern lang_statement_list_type file_chain;
 475 extern lang_statement_list_type input_file_chain;
 476
 477 extern int lang_statement_iteration;
 478 extern bfd_boolean missing_file;
 479
 480 extern void lang_init
 481   (void);
 482 extern void lang_finish
 483   (void);
 484 extern lang_memory_region_type * lang_memory_region_lookup
 485   (const char * const, bfd_boolean);
 486 extern void lang_memory_region_alias
 487   (const char *, const char *);
 488 extern void lang_map
 489   (void);
 490 extern void lang_set_flags
 491   (lang_memory_region_type *, const char *, int);
 492 extern void lang_add_output
 493   (const char *, int from_script);
 494 extern lang_output_section_statement_type *lang_enter_output_section_statement
 495   (const char *output_section_statement_name,
 496    etree_type *address_exp,
 497    enum section_type sectype,
 498    etree_type *align,
 499    etree_type *subalign,
 500    etree_type *, int);
 501 extern void lang_final
 502   (void);
 503 extern void lang_relax_sections
 504   (bfd_boolean);
 505 extern void lang_process
 506   (void);
 507 extern void lang_section_start
 508   (const char *, union etree_union *, const segment_type *);
 509 extern void lang_add_entry
 510   (const char *, bfd_boolean);
 511 extern void lang_default_entry
 512   (const char *);
 513 extern void lang_add_target
 514   (const char *);
 515 extern void lang_add_wild
 516   (struct wildcard_spec *, struct wildcard_list *, bfd_boolean);
 517 extern void lang_add_map
 518   (const char *);
 519 extern void lang_add_fill
 520   (fill_type *);
 521 extern lang_assignment_statement_type *lang_add_assignment
 522   (union etree_union *);
 523 extern void lang_add_attribute
 524   (enum statement_enum);
 525 extern void lang_startup
 526   (const char *);
 527 extern void lang_float
 528   (bfd_boolean);
 529 extern void lang_leave_output_section_statement
 530   (fill_type *, const char *, lang_output_section_phdr_list *,
 531    const char *);
 532 extern void lang_abs_symbol_at_end_of
 533   (const char *, const char *);
 534 extern void lang_abs_symbol_at_beginning_of
 535   (const char *, const char *);
 536 extern void lang_statement_append
 537   (lang_statement_list_type *, lang_statement_union_type *,
 538    lang_statement_union_type **);
 539 extern void lang_for_each_input_file
 540   (void (*dothis) (lang_input_statement_type *));
 541 extern void lang_for_each_file
 542   (void (*dothis) (lang_input_statement_type *));
 543 extern void lang_reset_memory_regions
 544   (void);
 545 extern void lang_do_assignments
 546   (lang_phase_type);
 547
 548 #define LANG_FOR_EACH_INPUT_STATEMENT(statement)                        \
 549   lang_input_statement_type *statement;                                 \
 550   for (statement = (lang_input_statement_type *) file_chain.head;       \
 551        statement != (lang_input_statement_type *) NULL;                 \
 552        statement = (lang_input_statement_type *) statement->next)       \
 553
 554 #define lang_output_section_find(NAME) \
 555   lang_output_section_statement_lookup (NAME, 0, FALSE)
 556
 557 extern void lang_process
 558   (void);
 559 extern void ldlang_add_file
 560   (lang_input_statement_type *);
 561 extern lang_output_section_statement_type *lang_output_section_find_by_flags
 562   (const asection *, lang_output_section_statement_type **,
 563    lang_match_sec_type_func);
 564 extern lang_output_section_statement_type *lang_insert_orphan
 565   (asection *, const char *, int, lang_output_section_statement_type *,
 566    struct orphan_save *, etree_type *, lang_statement_list_type *);
 567 extern lang_input_statement_type *lang_add_input_file
 568   (const char *, lang_input_file_enum_type, const char *);
 569 extern void lang_add_keepsyms_file
 570   (const char *);
 571 extern lang_output_section_statement_type *lang_output_section_statement_lookup
 572   (const char *, int, bfd_boolean);
 573 extern lang_output_section_statement_type *next_matching_output_section_statement
 574   (lang_output_section_statement_type *, int);
 575 extern void ldlang_add_undef
 576   (const char *const, bfd_boolean);
 577 extern void lang_add_output_format
 578   (const char *, const char *, const char *, int);
 579 extern void lang_list_init
 580   (lang_statement_list_type *);
 581 extern void push_stat_ptr
 582   (lang_statement_list_type *);
 583 extern void pop_stat_ptr
 584   (void);
 585 extern void lang_add_data
 586   (int type, union etree_union *);
 587 extern void lang_add_reloc
 588   (bfd_reloc_code_real_type, reloc_howto_type *, asection *, const char *,
 589    union etree_union *);
 590 extern void lang_for_each_statement
 591   (void (*) (lang_statement_union_type *));
 592 extern void lang_for_each_statement_worker
 593   (void (*) (lang_statement_union_type *), lang_statement_union_type *);
 594 extern void *stat_alloc
 595   (size_t);
 596 extern void strip_excluded_output_sections
 597   (void);
 598 extern void dprint_statement
 599   (lang_statement_union_type *, int);
 600 extern void lang_size_sections
 601   (bfd_boolean *, bfd_boolean);
 602 extern void one_lang_size_sections_pass
 603   (bfd_boolean *, bfd_boolean);
 604 extern void lang_add_insert
 605   (const char *, int);
 606 extern void lang_enter_group
 607   (void);
 608 extern void lang_leave_group
 609   (void);
 610 extern void lang_add_section
 611   (lang_statement_list_type *, asection *,
 612    lang_output_section_statement_type *);
 613 extern void lang_new_phdr
 614   (const char *, etree_type *, bfd_boolean, bfd_boolean, etree_type *,
 615    etree_type *);
 616 extern void lang_add_nocrossref
 617   (lang_nocrossref_type *);
 618 extern void lang_enter_overlay
 619   (etree_type *, etree_type *);
 620 extern void lang_enter_overlay_section
 621   (const char *);
 622 extern void lang_leave_overlay_section
 623   (fill_type *, lang_output_section_phdr_list *);
 624 extern void lang_leave_overlay
 625   (etree_type *, int, fill_type *, const char *,
 626    lang_output_section_phdr_list *, const char *);
 627
 628 extern struct bfd_elf_version_tree *lang_elf_version_info;
 629
 630 extern struct bfd_elf_version_expr *lang_new_vers_pattern
 631   (struct bfd_elf_version_expr *, const char *, const char *, bfd_boolean);
 632 extern struct bfd_elf_version_tree *lang_new_vers_node
 633   (struct bfd_elf_version_expr *, struct bfd_elf_version_expr *);
 634 extern struct bfd_elf_version_deps *lang_add_vers_depend
 635   (struct bfd_elf_version_deps *, const char *);
 636 extern void lang_register_vers_node
 637   (const char *, struct bfd_elf_version_tree *, struct bfd_elf_version_deps *);
 638 extern void lang_append_dynamic_list (struct bfd_elf_version_expr *);
 639 extern void lang_append_dynamic_list_cpp_typeinfo (void);
 640 extern void lang_append_dynamic_list_cpp_new (void);
 641 extern void lang_add_unique
 642   (const char *);
 643 extern const char *lang_get_output_target
 644   (void);
 645 extern void lang_track_definedness (const char *);
 646 extern int lang_symbol_definition_iteration (const char *);
 647 extern void lang_update_definedness
 648   (const char *, struct bfd_link_hash_entry *);
 649
 650 extern void add_excluded_libs (const char *);
 651 extern bfd_boolean load_symbols
 652   (lang_input_statement_type *, lang_statement_list_type *);
 653
 654 extern bfd_boolean
 655 ldlang_override_segment_assignment
 656   (struct bfd_link_info *, bfd *, asection *, asection *, bfd_boolean);
 657
 658 extern void
 659 lang_ld_feature (char *);
 660
 661 #endif