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
   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_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     lang_constructors_statement_enum
  83   } type;
  84 } lang_statement_header_type;
  85
  86 typedef struct
  87 {
  88   lang_statement_header_type header;
  89   union etree_union *exp;
  90 } lang_assignment_statement_type;
  91
  92 typedef struct lang_target_statement_struct
  93 {
  94   lang_statement_header_type header;
  95   const char *target;
  96 } lang_target_statement_type;
  97
  98 typedef struct lang_output_statement_struct
  99 {
 100   lang_statement_header_type header;
 101   const char *name;
 102 } lang_output_statement_type;
 103
 104 /* Section types specified in a linker script.  */
 105
 106 enum section_type
 107 {
 108   normal_section,
 109   overlay_section,
 110   noload_section,
 111   noalloc_section
 112 };
 113
 114 /* This structure holds a list of program headers describing
 115    segments in which this section should be placed.  */
 116
 117 typedef struct lang_output_section_phdr_list
 118 {
 119   struct lang_output_section_phdr_list *next;
 120   const char *name;
 121   bfd_boolean used;
 122 } lang_output_section_phdr_list;
 123
 124 typedef struct lang_output_section_statement_struct
 125 {
 126   lang_statement_header_type header;
 127   lang_statement_list_type children;
 128   struct lang_output_section_statement_struct *next;
 129   struct lang_output_section_statement_struct *prev;
 130   const char *name;
 131   asection *bfd_section;
 132   lang_memory_region_type *region;
 133   lang_memory_region_type *lma_region;
 134   fill_type *fill;
 135   union etree_union *addr_tree;
 136   union etree_union *load_base;
 137
 138   /* If non-null, an expression to evaluate after setting the section's
 139      size.  The expression is evaluated inside REGION (above) with '.'
 140      set to the end of the section.  Used in the last overlay section
 141      to move '.' past all the overlaid sections.  */
 142   union etree_union *update_dot_tree;
 143
 144   lang_output_section_phdr_list *phdrs;
 145
 146   unsigned int block_value;
 147   int subsection_alignment;     /* Alignment of components.  */
 148   int section_alignment;        /* Alignment of start of section.  */
 149   int constraint;
 150   flagword flags;
 151   enum section_type sectype;
 152   unsigned int processed_vma : 1;
 153   unsigned int processed_lma : 1;
 154   unsigned int all_input_readonly : 1;
 155   /* If this section should be ignored.  */
 156   unsigned int ignored : 1;
 157   /* If there is a symbol relative to this section.  */
 158   unsigned int section_relative_symbol : 1;
 159 } lang_output_section_statement_type;
 160
 161 typedef struct
 162 {
 163   lang_statement_header_type header;
 164 } lang_common_statement_type;
 165
 166 typedef struct
 167 {
 168   lang_statement_header_type header;
 169 } lang_object_symbols_statement_type;
 170
 171 typedef struct
 172 {
 173   lang_statement_header_type header;
 174   fill_type *fill;
 175   int size;
 176   asection *output_section;
 177 } lang_fill_statement_type;
 178
 179 typedef struct
 180 {
 181   lang_statement_header_type header;
 182   unsigned int type;
 183   union etree_union *exp;
 184   bfd_vma value;
 185   asection *output_section;
 186   bfd_vma output_offset;
 187 } lang_data_statement_type;
 188
 189 /* Generate a reloc in the output file.  */
 190
 191 typedef struct
 192 {
 193   lang_statement_header_type header;
 194
 195   /* Reloc to generate.  */
 196   bfd_reloc_code_real_type reloc;
 197
 198   /* Reloc howto structure.  */
 199   reloc_howto_type *howto;
 200
 201   /* Section to generate reloc against.
 202      Exactly one of section and name must be NULL.  */
 203   asection *section;
 204
 205   /* Name of symbol to generate reloc against.
 206      Exactly one of section and name must be NULL.  */
 207   const char *name;
 208
 209   /* Expression for addend.  */
 210   union etree_union *addend_exp;
 211
 212   /* Resolved addend.  */
 213   bfd_vma addend_value;
 214
 215   /* Output section where reloc should be performed.  */
 216   asection *output_section;
 217
 218   /* Offset within output section.  */
 219   bfd_vma output_offset;
 220 } lang_reloc_statement_type;
 221
 222 typedef struct lang_input_statement_struct
 223 {
 224   lang_statement_header_type header;
 225   /* Name of this file.  */
 226   const char *filename;
 227   /* Name to use for the symbol giving address of text start.
 228      Usually the same as filename, but for a file spec'd with
 229      -l this is the -l switch itself rather than the filename.  */
 230   const char *local_sym_name;
 231
 232   bfd *the_bfd;
 233
 234   file_ptr passive_position;
 235
 236   /* Symbol table of the file.  */
 237   asymbol **asymbols;
 238   unsigned int symbol_count;
 239
 240   /* Point to the next file - whatever it is, wanders up and down
 241      archives */
 242   union lang_statement_union *next;
 243
 244   /* Point to the next file, but skips archive contents.  */
 245   union lang_statement_union *next_real_file;
 246
 247   const char *target;
 248
 249   unsigned int closed : 1;
 250   unsigned int is_archive : 1;
 251
 252   /* 1 means search a set of directories for this file.  */
 253   unsigned int search_dirs_flag : 1;
 254
 255   /* 1 means this was found in a search directory marked as sysrooted,
 256      if search_dirs_flag is false, otherwise, that it should be
 257      searched in ld_sysroot before any other location, as long as it
 258      starts with a slash.  */
 259   unsigned int sysrooted : 1;
 260
 261   /* 1 means this is base file of incremental load.
 262      Do not load this file's text or data.
 263      Also default text_start to after this file's bss.  */
 264   unsigned int just_syms_flag : 1;
 265
 266   /* Whether to search for this entry as a dynamic archive.  */
 267   unsigned int dynamic : 1;
 268
 269   /* Whether DT_NEEDED tags should be added for dynamic libraries in
 270      DT_NEEDED tags from this entry.  */
 271   unsigned int add_needed : 1;
 272
 273   /* Whether this entry should cause a DT_NEEDED tag only when
 274      satisfying references from regular files, or always.  */
 275   unsigned int as_needed : 1;
 276
 277   /* Whether to include the entire contents of an archive.  */
 278   unsigned int whole_archive : 1;
 279
 280   unsigned int loaded : 1;
 281
 282   unsigned int real : 1;
 283 } lang_input_statement_type;
 284
 285 typedef struct
 286 {
 287   lang_statement_header_type header;
 288   asection *section;
 289 } lang_input_section_type;
 290
 291 typedef struct lang_wild_statement_struct lang_wild_statement_type;
 292
 293 typedef void (*callback_t) (lang_wild_statement_type *, struct wildcard_list *,
 294                             asection *, lang_input_statement_type *, void *);
 295
 296 typedef void (*walk_wild_section_handler_t) (lang_wild_statement_type *,
 297                                              lang_input_statement_type *,
 298                                              callback_t callback,
 299                                              void *data);
 300
 301 typedef bfd_boolean (*lang_match_sec_type_func) (bfd *, const asection *,
 302                                                  bfd *, const asection *);
 303
 304 /* Binary search tree structure to efficiently sort sections by
 305    name.  */
 306 typedef struct lang_section_bst
 307 {
 308   asection *section;
 309   struct lang_section_bst *left;
 310   struct lang_section_bst *right;
 311 } lang_section_bst_type;
 312
 313 struct lang_wild_statement_struct
 314 {
 315   lang_statement_header_type header;
 316   const char *filename;
 317   bfd_boolean filenames_sorted;
 318   struct wildcard_list *section_list;
 319   bfd_boolean keep_sections;
 320   lang_statement_list_type children;
 321
 322   walk_wild_section_handler_t walk_wild_section_handler;
 323   struct wildcard_list *handler_data[4];
 324   lang_section_bst_type *tree;
 325 };
 326
 327 typedef struct lang_address_statement_struct
 328 {
 329   lang_statement_header_type header;
 330   const char *section_name;
 331   union etree_union *address;
 332   const segment_type *segment;
 333 } lang_address_statement_type;
 334
 335 typedef struct
 336 {
 337   lang_statement_header_type header;
 338   bfd_vma output_offset;
 339   size_t size;
 340   asection *output_section;
 341   fill_type *fill;
 342 } lang_padding_statement_type;
 343
 344 /* A group statement collects a set of libraries together.  The
 345    libraries are searched multiple times, until no new undefined
 346    symbols are found.  The effect is to search a group of libraries as
 347    though they were a single library.  */
 348
 349 typedef struct
 350 {
 351   lang_statement_header_type header;
 352   lang_statement_list_type children;
 353 } lang_group_statement_type;
 354
 355 typedef union lang_statement_union
 356 {
 357   lang_statement_header_type header;
 358   lang_wild_statement_type wild_statement;
 359   lang_data_statement_type data_statement;
 360   lang_reloc_statement_type reloc_statement;
 361   lang_address_statement_type address_statement;
 362   lang_output_section_statement_type output_section_statement;
 363   lang_assignment_statement_type assignment_statement;
 364   lang_input_statement_type input_statement;
 365   lang_target_statement_type target_statement;
 366   lang_output_statement_type output_statement;
 367   lang_input_section_type input_section;
 368   lang_common_statement_type common_statement;
 369   lang_object_symbols_statement_type object_symbols_statement;
 370   lang_fill_statement_type fill_statement;
 371   lang_padding_statement_type padding_statement;
 372   lang_group_statement_type group_statement;
 373 } lang_statement_union_type;
 374
 375 /* This structure holds information about a program header, from the
 376    PHDRS command in the linker script.  */
 377
 378 struct lang_phdr
 379 {
 380   struct lang_phdr *next;
 381   const char *name;
 382   unsigned long type;
 383   bfd_boolean filehdr;
 384   bfd_boolean phdrs;
 385   etree_type *at;
 386   etree_type *flags;
 387 };
 388
 389 extern struct lang_phdr *lang_phdr_list;
 390
 391 /* This structure is used to hold a list of sections which may not
 392    cross reference each other.  */
 393
 394 typedef struct lang_nocrossref
 395 {
 396   struct lang_nocrossref *next;
 397   const char *name;
 398 } lang_nocrossref_type;
 399
 400 /* The list of nocrossref lists.  */
 401
 402 struct lang_nocrossrefs
 403 {
 404   struct lang_nocrossrefs *next;
 405   lang_nocrossref_type *list;
 406 };
 407
 408 extern struct lang_nocrossrefs *nocrossref_list;
 409
 410 /* This structure is used to hold a list of input section names which
 411    will not match an output section in the linker script.  */
 412
 413 struct unique_sections
 414 {
 415   struct unique_sections *next;
 416   const char *name;
 417 };
 418
 419 /* This structure records symbols for which we need to keep track of
 420    definedness for use in the DEFINED () test.  */
 421
 422 struct lang_definedness_hash_entry
 423 {
 424   struct bfd_hash_entry root;
 425   int iteration;
 426 };
 427
 428 /* Used by place_orphan to keep track of orphan sections and statements.  */
 429
 430 struct orphan_save {
 431   const char *name;
 432   flagword flags;
 433   lang_output_section_statement_type *os;
 434   asection **section;
 435   lang_statement_union_type **stmt;
 436   lang_output_section_statement_type **os_tail;
 437 };
 438
 439 extern lang_output_section_statement_type *abs_output_section;
 440 extern lang_statement_list_type lang_output_section_statement;
 441 extern bfd_boolean lang_has_input_file;
 442 extern etree_type *base;
 443 extern lang_statement_list_type *stat_ptr;
 444 extern bfd_boolean delete_output_file_on_failure;
 445
 446 extern struct bfd_sym_chain entry_symbol;
 447 extern const char *entry_section;
 448 extern bfd_boolean entry_from_cmdline;
 449 extern lang_statement_list_type file_chain;
 450 extern lang_statement_list_type input_file_chain;
 451
 452 extern int lang_statement_iteration;
 453
 454 extern void lang_init
 455   (void);
 456 extern void lang_finish
 457   (void);
 458 extern lang_memory_region_type *lang_memory_region_lookup
 459   (const char *const, bfd_boolean);
 460 extern lang_memory_region_type *lang_memory_region_default
 461   (asection *);
 462 extern void lang_map
 463   (void);
 464 extern void lang_set_flags
 465   (lang_memory_region_type *, const char *, int);
 466 extern void lang_add_output
 467   (const char *, int from_script);
 468 extern lang_output_section_statement_type *lang_enter_output_section_statement
 469   (const char *output_section_statement_name,
 470    etree_type *address_exp,
 471    enum section_type sectype,
 472    etree_type *align,
 473    etree_type *subalign,
 474    etree_type *, int);
 475 extern void lang_final
 476   (void);
 477 extern void lang_process
 478   (void);
 479 extern void lang_section_start
 480   (const char *, union etree_union *, const segment_type *);
 481 extern void lang_add_entry
 482   (const char *, bfd_boolean);
 483 extern void lang_default_entry
 484   (const char *);
 485 extern void lang_add_target
 486   (const char *);
 487 extern void lang_add_wild
 488   (struct wildcard_spec *, struct wildcard_list *, bfd_boolean);
 489 extern void lang_add_map
 490   (const char *);
 491 extern void lang_add_fill
 492   (fill_type *);
 493 extern lang_assignment_statement_type *lang_add_assignment
 494   (union etree_union *);
 495 extern void lang_add_attribute
 496   (enum statement_enum);
 497 extern void lang_startup
 498   (const char *);
 499 extern void lang_float
 500   (bfd_boolean);
 501 extern void lang_leave_output_section_statement
 502   (fill_type *, const char *, lang_output_section_phdr_list *,
 503    const char *);
 504 extern void lang_abs_symbol_at_end_of
 505   (const char *, const char *);
 506 extern void lang_abs_symbol_at_beginning_of
 507   (const char *, const char *);
 508 extern void lang_statement_append
 509   (lang_statement_list_type *, lang_statement_union_type *,
 510    lang_statement_union_type **);
 511 extern void lang_for_each_input_file
 512   (void (*dothis) (lang_input_statement_type *));
 513 extern void lang_for_each_file
 514   (void (*dothis) (lang_input_statement_type *));
 515 extern void lang_reset_memory_regions
 516   (void);
 517 extern void lang_do_assignments
 518   (void);
 519
 520 #define LANG_FOR_EACH_INPUT_STATEMENT(statement)                        \
 521   lang_input_statement_type *statement;                                 \
 522   for (statement = (lang_input_statement_type *) file_chain.head;       \
 523        statement != (lang_input_statement_type *) NULL;                 \
 524        statement = (lang_input_statement_type *) statement->next)       \
 525
 526 extern void lang_process
 527   (void);
 528 extern void ldlang_add_file
 529   (lang_input_statement_type *);
 530 extern lang_output_section_statement_type *lang_output_section_find
 531   (const char * const);
 532 extern lang_output_section_statement_type *lang_output_section_find_by_flags
 533   (const asection *, lang_output_section_statement_type **,
 534    lang_match_sec_type_func);
 535 extern lang_output_section_statement_type *lang_insert_orphan
 536   (asection *, const char *, lang_output_section_statement_type *,
 537    struct orphan_save *, etree_type *, lang_statement_list_type *);
 538 extern lang_input_statement_type *lang_add_input_file
 539   (const char *, lang_input_file_enum_type, const char *);
 540 extern void lang_add_keepsyms_file
 541   (const char *);
 542 extern lang_output_section_statement_type *
 543   lang_output_section_statement_lookup
 544   (const char *const);
 545 extern void ldlang_add_undef
 546   (const char *const);
 547 extern void lang_add_output_format
 548   (const char *, const char *, const char *, int);
 549 extern void lang_list_init
 550   (lang_statement_list_type *);
 551 extern void lang_add_data
 552   (int type, union etree_union *);
 553 extern void lang_add_reloc
 554   (bfd_reloc_code_real_type, reloc_howto_type *, asection *, const char *,
 555    union etree_union *);
 556 extern void lang_for_each_statement
 557   (void (*) (lang_statement_union_type *));
 558 extern void *stat_alloc
 559   (size_t);
 560 extern void strip_excluded_output_sections
 561   (void);
 562 extern void dprint_statement
 563   (lang_statement_union_type *, int);
 564 extern void lang_size_sections
 565   (bfd_boolean *, bfd_boolean);
 566 extern void one_lang_size_sections_pass
 567   (bfd_boolean *, bfd_boolean);
 568 extern void lang_enter_group
 569   (void);
 570 extern void lang_leave_group
 571   (void);
 572 extern void lang_add_section
 573   (lang_statement_list_type *, asection *,
 574    lang_output_section_statement_type *);
 575 extern void lang_new_phdr
 576   (const char *, etree_type *, bfd_boolean, bfd_boolean, etree_type *,
 577    etree_type *);
 578 extern void lang_add_nocrossref
 579   (lang_nocrossref_type *);
 580 extern void lang_enter_overlay
 581   (etree_type *, etree_type *);
 582 extern void lang_enter_overlay_section
 583   (const char *);
 584 extern void lang_leave_overlay_section
 585   (fill_type *, lang_output_section_phdr_list *);
 586 extern void lang_leave_overlay
 587   (etree_type *, int, fill_type *, const char *,
 588    lang_output_section_phdr_list *, const char *);
 589
 590 extern struct bfd_elf_version_tree *lang_elf_version_info;
 591
 592 extern struct bfd_elf_version_expr *lang_new_vers_pattern
 593   (struct bfd_elf_version_expr *, const char *, const char *, bfd_boolean);
 594 extern struct bfd_elf_version_tree *lang_new_vers_node
 595   (struct bfd_elf_version_expr *, struct bfd_elf_version_expr *);
 596 extern struct bfd_elf_version_deps *lang_add_vers_depend
 597   (struct bfd_elf_version_deps *, const char *);
 598 extern void lang_register_vers_node
 599   (const char *, struct bfd_elf_version_tree *, struct bfd_elf_version_deps *);
 600 extern void lang_append_dynamic_list (struct bfd_elf_version_expr *);
 601 extern void lang_append_dynamic_list_cpp_typeinfo (void);
 602 extern void lang_append_dynamic_list_cpp_new (void);
 603 bfd_boolean unique_section_p
 604   (const asection *);
 605 extern void lang_add_unique
 606   (const char *);
 607 extern const char *lang_get_output_target
 608   (void);
 609 extern void lang_track_definedness (const char *);
 610 extern int lang_symbol_definition_iteration (const char *);
 611 extern void lang_update_definedness
 612   (const char *, struct bfd_link_hash_entry *);
 613
 614 extern void add_excluded_libs (const char *);
 615 extern bfd_boolean load_symbols
 616   (lang_input_statement_type *, lang_statement_list_type *);
 617
 618 extern bfd_boolean
 619 ldlang_override_segment_assignment
 620   (struct bfd_link_info *, bfd *, asection *, asection *, bfd_boolean);
 621
 622 #endif