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
   4    Free Software Foundation, Inc.
   5
   6    This file is part of GLD, the Gnu Linker.
   7
   8    GLD 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 2, or (at your option)
  11    any later version.
  12
  13    GLD 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 GLD; see the file COPYING.  If not, write to the Free
  20    Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
  21    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_struct
  51 {
  52   char *name;
  53   struct memory_region_struct *next;
  54   bfd_vma origin;
  55   bfd_size_type length;
  56   bfd_vma current;
  57   union lang_statement_union *last_os;
  58   flagword flags;
  59   flagword not_flags;
  60   bfd_boolean had_full_message;
  61 } lang_memory_region_type;
  62
  63 typedef struct lang_statement_header_struct
  64 {
  65   union lang_statement_union *next;
  66   enum statement_enum
  67   {
  68     lang_output_section_statement_enum,
  69     lang_assignment_statement_enum,
  70     lang_input_statement_enum,
  71     lang_address_statement_enum,
  72     lang_wild_statement_enum,
  73     lang_input_section_enum,
  74     lang_object_symbols_statement_enum,
  75     lang_fill_statement_enum,
  76     lang_data_statement_enum,
  77     lang_reloc_statement_enum,
  78     lang_target_statement_enum,
  79     lang_output_statement_enum,
  80     lang_padding_statement_enum,
  81     lang_group_statement_enum,
  82
  83     lang_afile_asection_pair_statement_enum,
  84     lang_constructors_statement_enum
  85   } type;
  86 } lang_statement_header_type;
  87
  88 typedef struct
  89 {
  90   lang_statement_header_type header;
  91   union etree_union *exp;
  92 } lang_assignment_statement_type;
  93
  94 typedef struct lang_target_statement_struct
  95 {
  96   lang_statement_header_type header;
  97   const char *target;
  98 } lang_target_statement_type;
  99
 100 typedef struct lang_output_statement_struct
 101 {
 102   lang_statement_header_type header;
 103   const char *name;
 104 } lang_output_statement_type;
 105
 106 /* Section types specified in a linker script.  */
 107
 108 enum section_type
 109 {
 110   normal_section,
 111   noload_section,
 112   noalloc_section
 113 };
 114
 115 /* This structure holds a list of program headers describing
 116    segments in which this section should be placed.  */
 117
 118 typedef struct lang_output_section_phdr_list
 119 {
 120   struct lang_output_section_phdr_list *next;
 121   const char *name;
 122   bfd_boolean used;
 123 } lang_output_section_phdr_list;
 124
 125 typedef struct lang_output_section_statement_struct
 126 {
 127   lang_statement_header_type header;
 128   lang_statement_list_type children;
 129   struct lang_output_section_statement_struct *next;
 130   struct lang_output_section_statement_struct *prev;
 131   const char *name;
 132   asection *bfd_section;
 133   lang_memory_region_type *region;
 134   lang_memory_region_type *lma_region;
 135   fill_type *fill;
 136   union etree_union *addr_tree;
 137   union etree_union *load_base;
 138
 139   /* If non-null, an expression to evaluate after setting the section's
 140      size.  The expression is evaluated inside REGION (above) with '.'
 141      set to the end of the section.  Used in the last overlay section
 142      to move '.' past all the overlaid sections.  */
 143   union etree_union *update_dot_tree;
 144
 145   lang_output_section_phdr_list *phdrs;
 146
 147   unsigned int block_value;
 148   int subsection_alignment;     /* Alignment of components.  */
 149   int section_alignment;        /* Alignment of start of section.  */
 150   int constraint;
 151   flagword flags;
 152   enum section_type sectype;
 153   unsigned int processed : 1;
 154   unsigned int all_input_readonly : 1;
 155   unsigned int ignored : 1;
 156 } lang_output_section_statement_type;
 157
 158 typedef struct
 159 {
 160   lang_statement_header_type header;
 161 } lang_common_statement_type;
 162
 163 typedef struct
 164 {
 165   lang_statement_header_type header;
 166 } lang_object_symbols_statement_type;
 167
 168 typedef struct
 169 {
 170   lang_statement_header_type header;
 171   fill_type *fill;
 172   int size;
 173   asection *output_section;
 174 } lang_fill_statement_type;
 175
 176 typedef struct
 177 {
 178   lang_statement_header_type header;
 179   unsigned int type;
 180   union etree_union *exp;
 181   bfd_vma value;
 182   asection *output_section;
 183   bfd_vma output_offset;
 184 } lang_data_statement_type;
 185
 186 /* Generate a reloc in the output file.  */
 187
 188 typedef struct
 189 {
 190   lang_statement_header_type header;
 191
 192   /* Reloc to generate.  */
 193   bfd_reloc_code_real_type reloc;
 194
 195   /* Reloc howto structure.  */
 196   reloc_howto_type *howto;
 197
 198   /* Section to generate reloc against.
 199      Exactly one of section and name must be NULL.  */
 200   asection *section;
 201
 202   /* Name of symbol to generate reloc against.
 203      Exactly one of section and name must be NULL.  */
 204   const char *name;
 205
 206   /* Expression for addend.  */
 207   union etree_union *addend_exp;
 208
 209   /* Resolved addend.  */
 210   bfd_vma addend_value;
 211
 212   /* Output section where reloc should be performed.  */
 213   asection *output_section;
 214
 215   /* Offset within output section.  */
 216   bfd_vma output_offset;
 217 } lang_reloc_statement_type;
 218
 219 typedef struct lang_input_statement_struct
 220 {
 221   lang_statement_header_type header;
 222   /* Name of this file.  */
 223   const char *filename;
 224   /* Name to use for the symbol giving address of text start.
 225      Usually the same as filename, but for a file spec'd with
 226      -l this is the -l switch itself rather than the filename.  */
 227   const char *local_sym_name;
 228
 229   bfd *the_bfd;
 230
 231   file_ptr passive_position;
 232
 233   /* Symbol table of the file.  */
 234   asymbol **asymbols;
 235   unsigned int symbol_count;
 236
 237   /* Point to the next file - whatever it is, wanders up and down
 238      archives */
 239   union lang_statement_union *next;
 240
 241   /* Point to the next file, but skips archive contents.  */
 242   union lang_statement_union *next_real_file;
 243
 244   const char *target;
 245
 246   unsigned int closed : 1;
 247   unsigned int is_archive : 1;
 248
 249   /* 1 means search a set of directories for this file.  */
 250   unsigned int search_dirs_flag : 1;
 251
 252   /* 1 means this was found in a search directory marked as sysrooted,
 253      if search_dirs_flag is false, otherwise, that it should be
 254      searched in ld_sysroot before any other location, as long as it
 255      starts with a slash.  */
 256   unsigned int sysrooted : 1;
 257
 258   /* 1 means this is base file of incremental load.
 259      Do not load this file's text or data.
 260      Also default text_start to after this file's bss.  */
 261   unsigned int just_syms_flag : 1;
 262
 263   /* Whether to search for this entry as a dynamic archive.  */
 264   unsigned int dynamic : 1;
 265
 266   /* Whether DT_NEEDED tags should be added for dynamic libraries in
 267      DT_NEEDED tags from this entry.  */
 268   unsigned int add_needed : 1;
 269
 270   /* Whether this entry should cause a DT_NEEDED tag only when
 271      satisfying references from regular files, or always.  */
 272   unsigned int as_needed : 1;
 273
 274   /* Whether to include the entire contents of an archive.  */
 275   unsigned int whole_archive : 1;
 276
 277   unsigned int loaded : 1;
 278
 279   unsigned int real : 1;
 280 } lang_input_statement_type;
 281
 282 typedef struct
 283 {
 284   lang_statement_header_type header;
 285   asection *section;
 286 } lang_input_section_type;
 287
 288 typedef struct
 289 {
 290   lang_statement_header_type header;
 291   asection *section;
 292   union lang_statement_union *file;
 293 } lang_afile_asection_pair_statement_type;
 294
 295 typedef struct lang_wild_statement_struct lang_wild_statement_type;
 296
 297 typedef void (*callback_t) (lang_wild_statement_type *, struct wildcard_list *,
 298                             asection *, lang_input_statement_type *, void *);
 299
 300 typedef void (*walk_wild_section_handler_t) (lang_wild_statement_type *,
 301                                              lang_input_statement_type *,
 302                                              callback_t callback,
 303                                              void *data);
 304
 305 typedef bfd_boolean (*lang_match_sec_type_func) (bfd *, const asection *,
 306                                                  bfd *, const asection *);
 307
 308 /* Binary search tree structure to efficiently sort sections by
 309    name.  */
 310 typedef struct lang_section_bst
 311 {
 312   asection *section;
 313   struct lang_section_bst *left;
 314   struct lang_section_bst *right;
 315 } lang_section_bst_type;
 316
 317 struct lang_wild_statement_struct
 318 {
 319   lang_statement_header_type header;
 320   const char *filename;
 321   bfd_boolean filenames_sorted;
 322   struct wildcard_list *section_list;
 323   bfd_boolean keep_sections;
 324   lang_statement_list_type children;
 325
 326   walk_wild_section_handler_t walk_wild_section_handler;
 327   struct wildcard_list *handler_data[4];
 328   lang_section_bst_type *tree;
 329 };
 330
 331 typedef struct lang_address_statement_struct
 332 {
 333   lang_statement_header_type header;
 334   const char *section_name;
 335   union etree_union *address;
 336   const segment_type *segment;
 337 } lang_address_statement_type;
 338
 339 typedef struct
 340 {
 341   lang_statement_header_type header;
 342   bfd_vma output_offset;
 343   size_t size;
 344   asection *output_section;
 345   fill_type *fill;
 346 } lang_padding_statement_type;
 347
 348 /* A group statement collects a set of libraries together.  The
 349    libraries are searched multiple times, until no new undefined
 350    symbols are found.  The effect is to search a group of libraries as
 351    though they were a single library.  */
 352
 353 typedef struct
 354 {
 355   lang_statement_header_type header;
 356   lang_statement_list_type children;
 357 } lang_group_statement_type;
 358
 359 typedef union lang_statement_union
 360 {
 361   lang_statement_header_type header;
 362   lang_wild_statement_type wild_statement;
 363   lang_data_statement_type data_statement;
 364   lang_reloc_statement_type reloc_statement;
 365   lang_address_statement_type address_statement;
 366   lang_output_section_statement_type output_section_statement;
 367   lang_afile_asection_pair_statement_type afile_asection_pair_statement;
 368   lang_assignment_statement_type assignment_statement;
 369   lang_input_statement_type input_statement;
 370   lang_target_statement_type target_statement;
 371   lang_output_statement_type output_statement;
 372   lang_input_section_type input_section;
 373   lang_common_statement_type common_statement;
 374   lang_object_symbols_statement_type object_symbols_statement;
 375   lang_fill_statement_type fill_statement;
 376   lang_padding_statement_type padding_statement;
 377   lang_group_statement_type group_statement;
 378 } lang_statement_union_type;
 379
 380 /* This structure holds information about a program header, from the
 381    PHDRS command in the linker script.  */
 382
 383 struct lang_phdr
 384 {
 385   struct lang_phdr *next;
 386   const char *name;
 387   unsigned long type;
 388   bfd_boolean filehdr;
 389   bfd_boolean phdrs;
 390   etree_type *at;
 391   etree_type *flags;
 392 };
 393
 394 extern struct lang_phdr *lang_phdr_list;
 395
 396 /* This structure is used to hold a list of sections which may not
 397    cross reference each other.  */
 398
 399 typedef struct lang_nocrossref
 400 {
 401   struct lang_nocrossref *next;
 402   const char *name;
 403 } lang_nocrossref_type;
 404
 405 /* The list of nocrossref lists.  */
 406
 407 struct lang_nocrossrefs
 408 {
 409   struct lang_nocrossrefs *next;
 410   lang_nocrossref_type *list;
 411 };
 412
 413 extern struct lang_nocrossrefs *nocrossref_list;
 414
 415 /* This structure is used to hold a list of input section names which
 416    will not match an output section in the linker script.  */
 417
 418 struct unique_sections
 419 {
 420   struct unique_sections *next;
 421   const char *name;
 422 };
 423
 424 /* This structure records symbols for which we need to keep track of
 425    definedness for use in the DEFINED () test.  */
 426
 427 struct lang_definedness_hash_entry
 428 {
 429   struct bfd_hash_entry root;
 430   int iteration;
 431 };
 432
 433 /* Used by place_orphan to keep track of orphan sections and statements.  */
 434
 435 struct orphan_save {
 436   const char *name;
 437   flagword flags;
 438   lang_output_section_statement_type *os;
 439   asection **section;
 440   lang_statement_union_type **stmt;
 441   lang_output_section_statement_type **os_tail;
 442 };
 443
 444 extern lang_output_section_statement_type *abs_output_section;
 445 extern lang_statement_list_type lang_output_section_statement;
 446 extern bfd_boolean lang_has_input_file;
 447 extern etree_type *base;
 448 extern lang_statement_list_type *stat_ptr;
 449 extern bfd_boolean delete_output_file_on_failure;
 450
 451 extern struct bfd_sym_chain entry_symbol;
 452 extern const char *entry_section;
 453 extern bfd_boolean entry_from_cmdline;
 454 extern lang_statement_list_type file_chain;
 455
 456 extern int lang_statement_iteration;
 457
 458 extern void lang_init
 459   (void);
 460 extern void lang_finish
 461   (void);
 462 extern lang_memory_region_type *lang_memory_region_lookup
 463   (const char *const, bfd_boolean);
 464 extern lang_memory_region_type *lang_memory_region_default
 465   (asection *);
 466 extern void lang_map
 467   (void);
 468 extern void lang_set_flags
 469   (lang_memory_region_type *, const char *, int);
 470 extern void lang_add_output
 471   (const char *, int from_script);
 472 extern lang_output_section_statement_type *lang_enter_output_section_statement
 473   (const char *output_section_statement_name,
 474    etree_type *address_exp,
 475    enum section_type sectype,
 476    etree_type *align,
 477    etree_type *subalign,
 478    etree_type *, int);
 479 extern void lang_final
 480   (void);
 481 extern void lang_process
 482   (void);
 483 extern void lang_section_start
 484   (const char *, union etree_union *, const segment_type *);
 485 extern void lang_add_entry
 486   (const char *, bfd_boolean);
 487 extern void lang_default_entry
 488   (const char *);
 489 extern void lang_add_target
 490   (const char *);
 491 extern void lang_add_wild
 492   (struct wildcard_spec *, struct wildcard_list *, bfd_boolean);
 493 extern void lang_add_map
 494   (const char *);
 495 extern void lang_add_fill
 496   (fill_type *);
 497 extern lang_assignment_statement_type *lang_add_assignment
 498   (union etree_union *);
 499 extern void lang_add_attribute
 500   (enum statement_enum);
 501 extern void lang_startup
 502   (const char *);
 503 extern void lang_float
 504   (bfd_boolean);
 505 extern void lang_leave_output_section_statement
 506   (fill_type *, const char *, lang_output_section_phdr_list *,
 507    const char *);
 508 extern void lang_abs_symbol_at_end_of
 509   (const char *, const char *);
 510 extern void lang_abs_symbol_at_beginning_of
 511   (const char *, const char *);
 512 extern void lang_statement_append
 513   (lang_statement_list_type *, lang_statement_union_type *,
 514    lang_statement_union_type **);
 515 extern void lang_for_each_input_file
 516   (void (*dothis) (lang_input_statement_type *));
 517 extern void lang_for_each_file
 518   (void (*dothis) (lang_input_statement_type *));
 519 extern void lang_reset_memory_regions
 520   (void);
 521 extern void lang_do_assignments
 522   (void);
 523
 524 #define LANG_FOR_EACH_INPUT_STATEMENT(statement)                        \
 525   lang_input_statement_type *statement;                                 \
 526   for (statement = (lang_input_statement_type *) file_chain.head;       \
 527        statement != (lang_input_statement_type *) NULL;                 \
 528        statement = (lang_input_statement_type *) statement->next)       \
 529
 530 extern void lang_process
 531   (void);
 532 extern void ldlang_add_file
 533   (lang_input_statement_type *);
 534 extern lang_output_section_statement_type *lang_output_section_find
 535   (const char * const);
 536 extern lang_output_section_statement_type *lang_output_section_find_by_flags
 537   (const asection *, lang_output_section_statement_type **,
 538    lang_match_sec_type_func);
 539 extern lang_output_section_statement_type *lang_insert_orphan
 540   (asection *, const char *, lang_output_section_statement_type *,
 541    struct orphan_save *, etree_type *, lang_statement_list_type *);
 542 extern lang_input_statement_type *lang_add_input_file
 543   (const char *, lang_input_file_enum_type, const char *);
 544 extern void lang_add_keepsyms_file
 545   (const char *);
 546 extern lang_output_section_statement_type *
 547   lang_output_section_statement_lookup
 548   (const char *const);
 549 extern void ldlang_add_undef
 550   (const char *const);
 551 extern void lang_add_output_format
 552   (const char *, const char *, const char *, int);
 553 extern void lang_list_init
 554   (lang_statement_list_type *);
 555 extern void lang_add_data
 556   (int type, union etree_union *);
 557 extern void lang_add_reloc
 558   (bfd_reloc_code_real_type, reloc_howto_type *, asection *, const char *,
 559    union etree_union *);
 560 extern void lang_for_each_statement
 561   (void (*) (lang_statement_union_type *));
 562 extern void *stat_alloc
 563   (size_t);
 564 extern void strip_excluded_output_sections
 565   (void);
 566 extern void dprint_statement
 567   (lang_statement_union_type *, int);
 568 extern void lang_size_sections
 569   (bfd_boolean *, bfd_boolean);
 570 extern void one_lang_size_sections_pass
 571   (bfd_boolean *, bfd_boolean);
 572 extern void lang_enter_group
 573   (void);
 574 extern void lang_leave_group
 575   (void);
 576 extern void lang_add_section
 577   (lang_statement_list_type *, asection *,
 578    lang_output_section_statement_type *);
 579 extern void lang_new_phdr
 580   (const char *, etree_type *, bfd_boolean, bfd_boolean, etree_type *,
 581    etree_type *);
 582 extern void lang_add_nocrossref
 583   (lang_nocrossref_type *);
 584 extern void lang_enter_overlay
 585   (etree_type *, etree_type *);
 586 extern void lang_enter_overlay_section
 587   (const char *);
 588 extern void lang_leave_overlay_section
 589   (fill_type *, lang_output_section_phdr_list *);
 590 extern void lang_leave_overlay
 591   (etree_type *, int, fill_type *, const char *,
 592    lang_output_section_phdr_list *, const char *);
 593
 594 extern struct bfd_elf_version_tree *lang_elf_version_info;
 595
 596 extern struct bfd_elf_version_expr *lang_new_vers_pattern
 597   (struct bfd_elf_version_expr *, const char *, const char *, bfd_boolean);
 598 extern struct bfd_elf_version_tree *lang_new_vers_node
 599   (struct bfd_elf_version_expr *, struct bfd_elf_version_expr *);
 600 extern struct bfd_elf_version_deps *lang_add_vers_depend
 601   (struct bfd_elf_version_deps *, const char *);
 602 extern void lang_register_vers_node
 603   (const char *, struct bfd_elf_version_tree *, struct bfd_elf_version_deps *);
 604 bfd_boolean unique_section_p
 605   (const asection *);
 606 extern void lang_add_unique
 607   (const char *);
 608 extern const char *lang_get_output_target
 609   (void);
 610 extern void lang_track_definedness (const char *);
 611 extern int lang_symbol_definition_iteration (const char *);
 612 extern void lang_update_definedness
 613   (const char *, struct bfd_link_hash_entry *);
 614
 615 extern void add_excluded_libs (const char *);
 616
 617 #endif