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
   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_insert_statement_enum,
  83     lang_constructors_statement_enum
  84   } type;
  85 } lang_statement_header_type;
  86
  87 typedef struct
  88 {
  89   lang_statement_header_type header;
  90   union etree_union *exp;
  91 } lang_assignment_statement_type;
  92
  93 typedef struct lang_target_statement_struct
  94 {
  95   lang_statement_header_type header;
  96   const char *target;
  97 } lang_target_statement_type;
  98
  99 typedef struct lang_output_statement_struct
 100 {
 101   lang_statement_header_type header;
 102   const char *name;
 103 } lang_output_statement_type;
 104
 105 /* Section types specified in a linker script.  */
 106
 107 enum section_type
 108 {
 109   normal_section,
 110   overlay_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_vma : 1;
 154   unsigned int processed_lma : 1;
 155   unsigned int all_input_readonly : 1;
 156   /* If this section should be ignored.  */
 157   unsigned int ignored : 1;
 158   /* If there is a symbol relative to this section.  */
 159   unsigned int section_relative_symbol : 1;
 160 } lang_output_section_statement_type;
 161
 162 typedef struct
 163 {
 164   lang_statement_header_type header;
 165 } lang_common_statement_type;
 166
 167 typedef struct
 168 {
 169   lang_statement_header_type header;
 170 } lang_object_symbols_statement_type;
 171
 172 typedef struct
 173 {
 174   lang_statement_header_type header;
 175   fill_type *fill;
 176   int size;
 177   asection *output_section;
 178 } lang_fill_statement_type;
 179
 180 typedef struct
 181 {
 182   lang_statement_header_type header;
 183   unsigned int type;
 184   union etree_union *exp;
 185   bfd_vma value;
 186   asection *output_section;
 187   bfd_vma output_offset;
 188 } lang_data_statement_type;
 189
 190 /* Generate a reloc in the output file.  */
 191
 192 typedef struct
 193 {
 194   lang_statement_header_type header;
 195
 196   /* Reloc to generate.  */
 197   bfd_reloc_code_real_type reloc;
 198
 199   /* Reloc howto structure.  */
 200   reloc_howto_type *howto;
 201
 202   /* Section to generate reloc against.
 203      Exactly one of section and name must be NULL.  */
 204   asection *section;
 205
 206   /* Name of symbol to generate reloc against.
 207      Exactly one of section and name must be NULL.  */
 208   const char *name;
 209
 210   /* Expression for addend.  */
 211   union etree_union *addend_exp;
 212
 213   /* Resolved addend.  */
 214   bfd_vma addend_value;
 215
 216   /* Output section where reloc should be performed.  */
 217   asection *output_section;
 218
 219   /* Offset within output section.  */
 220   bfd_vma output_offset;
 221 } lang_reloc_statement_type;
 222
 223 typedef struct lang_input_statement_struct
 224 {
 225   lang_statement_header_type header;
 226   /* Name of this file.  */
 227   const char *filename;
 228   /* Name to use for the symbol giving address of text start.
 229      Usually the same as filename, but for a file spec'd with
 230      -l this is the -l switch itself rather than the filename.  */
 231   const char *local_sym_name;
 232
 233   bfd *the_bfd;
 234
 235   /* Point to the next file - whatever it is, wanders up and down
 236      archives */
 237   union lang_statement_union *next;
 238
 239   /* Point to the next file, but skips archive contents.  */
 240   union lang_statement_union *next_real_file;
 241
 242   const char *target;
 243
 244   unsigned int is_archive : 1;
 245
 246   /* 1 means search a set of directories for this file.  */
 247   unsigned int search_dirs_flag : 1;
 248
 249   /* 1 means this was found in a search directory marked as sysrooted,
 250      if search_dirs_flag is false, otherwise, that it should be
 251      searched in ld_sysroot before any other location, as long as it
 252      starts with a slash.  */
 253   unsigned int sysrooted : 1;
 254
 255   /* 1 means this is base file of incremental load.
 256      Do not load this file's text or data.
 257      Also default text_start to after this file's bss.  */
 258   unsigned int just_syms_flag : 1;
 259
 260   /* Whether to search for this entry as a dynamic archive.  */
 261   unsigned int dynamic : 1;
 262
 263   /* Whether DT_NEEDED tags should be added for dynamic libraries in
 264      DT_NEEDED tags from this entry.  */
 265   unsigned int add_needed : 1;
 266
 267   /* Whether this entry should cause a DT_NEEDED tag only when
 268      satisfying references from regular files, or always.  */
 269   unsigned int as_needed : 1;
 270
 271   /* Whether to include the entire contents of an archive.  */
 272   unsigned int whole_archive : 1;
 273
 274   unsigned int loaded : 1;
 275
 276   unsigned int real : 1;
 277 } lang_input_statement_type;
 278
 279 typedef struct
 280 {
 281   lang_statement_header_type header;
 282   asection *section;
 283 } lang_input_section_type;
 284
 285 typedef struct lang_wild_statement_struct lang_wild_statement_type;
 286
 287 typedef void (*callback_t) (lang_wild_statement_type *, struct wildcard_list *,
 288                             asection *, lang_input_statement_type *, void *);
 289
 290 typedef void (*walk_wild_section_handler_t) (lang_wild_statement_type *,
 291                                              lang_input_statement_type *,
 292                                              callback_t callback,
 293                                              void *data);
 294
 295 typedef bfd_boolean (*lang_match_sec_type_func) (bfd *, const asection *,
 296                                                  bfd *, const asection *);
 297
 298 /* Binary search tree structure to efficiently sort sections by
 299    name.  */
 300 typedef struct lang_section_bst
 301 {
 302   asection *section;
 303   struct lang_section_bst *left;
 304   struct lang_section_bst *right;
 305 } lang_section_bst_type;
 306
 307 struct lang_wild_statement_struct
 308 {
 309   lang_statement_header_type header;
 310   const char *filename;
 311   bfd_boolean filenames_sorted;
 312   struct wildcard_list *section_list;
 313   bfd_boolean keep_sections;
 314   lang_statement_list_type children;
 315
 316   walk_wild_section_handler_t walk_wild_section_handler;
 317   struct wildcard_list *handler_data[4];
 318   lang_section_bst_type *tree;
 319 };
 320
 321 typedef struct lang_address_statement_struct
 322 {
 323   lang_statement_header_type header;
 324   const char *section_name;
 325   union etree_union *address;
 326   const segment_type *segment;
 327 } lang_address_statement_type;
 328
 329 typedef struct
 330 {
 331   lang_statement_header_type header;
 332   bfd_vma output_offset;
 333   size_t size;
 334   asection *output_section;
 335   fill_type *fill;
 336 } lang_padding_statement_type;
 337
 338 /* A group statement collects a set of libraries together.  The
 339    libraries are searched multiple times, until no new undefined
 340    symbols are found.  The effect is to search a group of libraries as
 341    though they were a single library.  */
 342
 343 typedef struct
 344 {
 345   lang_statement_header_type header;
 346   lang_statement_list_type children;
 347 } lang_group_statement_type;
 348
 349 typedef struct
 350 {
 351   lang_statement_header_type header;
 352   const char *where;
 353   bfd_boolean is_before;
 354 } lang_insert_statement_type;
 355
 356 typedef union lang_statement_union
 357 {
 358   lang_statement_header_type header;
 359   lang_wild_statement_type wild_statement;
 360   lang_data_statement_type data_statement;
 361   lang_reloc_statement_type reloc_statement;
 362   lang_address_statement_type address_statement;
 363   lang_output_section_statement_type output_section_statement;
 364   lang_assignment_statement_type assignment_statement;
 365   lang_input_statement_type input_statement;
 366   lang_target_statement_type target_statement;
 367   lang_output_statement_type output_statement;
 368   lang_input_section_type input_section;
 369   lang_common_statement_type common_statement;
 370   lang_object_symbols_statement_type object_symbols_statement;
 371   lang_fill_statement_type fill_statement;
 372   lang_padding_statement_type padding_statement;
 373   lang_group_statement_type group_statement;
 374   lang_insert_statement_type insert_statement;
 375 } lang_statement_union_type;
 376
 377 /* This structure holds information about a program header, from the
 378    PHDRS command in the linker script.  */
 379
 380 struct lang_phdr
 381 {
 382   struct lang_phdr *next;
 383   const char *name;
 384   unsigned long type;
 385   bfd_boolean filehdr;
 386   bfd_boolean phdrs;
 387   etree_type *at;
 388   etree_type *flags;
 389 };
 390
 391 extern struct lang_phdr *lang_phdr_list;
 392
 393 /* This structure is used to hold a list of sections which may not
 394    cross reference each other.  */
 395
 396 typedef struct lang_nocrossref
 397 {
 398   struct lang_nocrossref *next;
 399   const char *name;
 400 } lang_nocrossref_type;
 401
 402 /* The list of nocrossref lists.  */
 403
 404 struct lang_nocrossrefs
 405 {
 406   struct lang_nocrossrefs *next;
 407   lang_nocrossref_type *list;
 408 };
 409
 410 extern struct lang_nocrossrefs *nocrossref_list;
 411
 412 /* This structure is used to hold a list of input section names which
 413    will not match an output section in the linker script.  */
 414
 415 struct unique_sections
 416 {
 417   struct unique_sections *next;
 418   const char *name;
 419 };
 420
 421 /* This structure records symbols for which we need to keep track of
 422    definedness for use in the DEFINED () test.  */
 423
 424 struct lang_definedness_hash_entry
 425 {
 426   struct bfd_hash_entry root;
 427   int iteration;
 428 };
 429
 430 /* Used by place_orphan to keep track of orphan sections and statements.  */
 431
 432 struct orphan_save {
 433   const char *name;
 434   flagword flags;
 435   lang_output_section_statement_type *os;
 436   asection **section;
 437   lang_statement_union_type **stmt;
 438   lang_output_section_statement_type **os_tail;
 439 };
 440
 441 extern lang_output_section_statement_type *abs_output_section;
 442 extern lang_statement_list_type lang_output_section_statement;
 443 extern bfd_boolean lang_has_input_file;
 444 extern etree_type *base;
 445 extern lang_statement_list_type *stat_ptr;
 446 extern bfd_boolean delete_output_file_on_failure;
 447
 448 extern struct bfd_sym_chain entry_symbol;
 449 extern const char *entry_section;
 450 extern bfd_boolean entry_from_cmdline;
 451 extern lang_statement_list_type file_chain;
 452 extern lang_statement_list_type input_file_chain;
 453
 454 extern int lang_statement_iteration;
 455
 456 extern void lang_init
 457   (void);
 458 extern void lang_finish
 459   (void);
 460 extern lang_memory_region_type *lang_memory_region_lookup
 461   (const char *const, bfd_boolean);
 462 extern lang_memory_region_type *lang_memory_region_default
 463   (asection *);
 464 extern void lang_map
 465   (void);
 466 extern void lang_set_flags
 467   (lang_memory_region_type *, const char *, int);
 468 extern void lang_add_output
 469   (const char *, int from_script);
 470 extern lang_output_section_statement_type *lang_enter_output_section_statement
 471   (const char *output_section_statement_name,
 472    etree_type *address_exp,
 473    enum section_type sectype,
 474    etree_type *align,
 475    etree_type *subalign,
 476    etree_type *, int);
 477 extern void lang_final
 478   (void);
 479 extern void lang_process
 480   (void);
 481 extern void lang_section_start
 482   (const char *, union etree_union *, const segment_type *);
 483 extern void lang_add_entry
 484   (const char *, bfd_boolean);
 485 extern void lang_default_entry
 486   (const char *);
 487 extern void lang_add_target
 488   (const char *);
 489 extern void lang_add_wild
 490   (struct wildcard_spec *, struct wildcard_list *, bfd_boolean);
 491 extern void lang_add_map
 492   (const char *);
 493 extern void lang_add_fill
 494   (fill_type *);
 495 extern lang_assignment_statement_type *lang_add_assignment
 496   (union etree_union *);
 497 extern void lang_add_attribute
 498   (enum statement_enum);
 499 extern void lang_startup
 500   (const char *);
 501 extern void lang_float
 502   (bfd_boolean);
 503 extern void lang_leave_output_section_statement
 504   (fill_type *, const char *, lang_output_section_phdr_list *,
 505    const char *);
 506 extern void lang_abs_symbol_at_end_of
 507   (const char *, const char *);
 508 extern void lang_abs_symbol_at_beginning_of
 509   (const char *, const char *);
 510 extern void lang_statement_append
 511   (lang_statement_list_type *, lang_statement_union_type *,
 512    lang_statement_union_type **);
 513 extern void lang_for_each_input_file
 514   (void (*dothis) (lang_input_statement_type *));
 515 extern void lang_for_each_file
 516   (void (*dothis) (lang_input_statement_type *));
 517 extern void lang_reset_memory_regions
 518   (void);
 519 extern void lang_do_assignments
 520   (void);
 521
 522 #define LANG_FOR_EACH_INPUT_STATEMENT(statement)                        \
 523   lang_input_statement_type *statement;                                 \
 524   for (statement = (lang_input_statement_type *) file_chain.head;       \
 525        statement != (lang_input_statement_type *) NULL;                 \
 526        statement = (lang_input_statement_type *) statement->next)       \
 527
 528 #define lang_output_section_find(NAME) \
 529   lang_output_section_statement_lookup (NAME, 0, FALSE)
 530
 531 extern void lang_process
 532   (void);
 533 extern void ldlang_add_file
 534   (lang_input_statement_type *);
 535 extern lang_output_section_statement_type *lang_output_section_find_by_flags
 536   (const asection *, lang_output_section_statement_type **,
 537    lang_match_sec_type_func);
 538 extern lang_output_section_statement_type *lang_insert_orphan
 539   (asection *, const char *, int, lang_output_section_statement_type *,
 540    struct orphan_save *, etree_type *, lang_statement_list_type *);
 541 extern lang_input_statement_type *lang_add_input_file
 542   (const char *, lang_input_file_enum_type, const char *);
 543 extern void lang_add_keepsyms_file
 544   (const char *);
 545 extern lang_output_section_statement_type *lang_output_section_statement_lookup
 546   (const char *const, int, bfd_boolean);
 547 extern void ldlang_add_undef
 548   (const char *const);
 549 extern void lang_add_output_format
 550   (const char *, const char *, const char *, int);
 551 extern void lang_list_init
 552   (lang_statement_list_type *);
 553 extern void lang_add_data
 554   (int type, union etree_union *);
 555 extern void lang_add_reloc
 556   (bfd_reloc_code_real_type, reloc_howto_type *, asection *, const char *,
 557    union etree_union *);
 558 extern void lang_for_each_statement
 559   (void (*) (lang_statement_union_type *));
 560 extern void *stat_alloc
 561   (size_t);
 562 extern void strip_excluded_output_sections
 563   (void);
 564 extern void dprint_statement
 565   (lang_statement_union_type *, int);
 566 extern void lang_size_sections
 567   (bfd_boolean *, bfd_boolean);
 568 extern void one_lang_size_sections_pass
 569   (bfd_boolean *, bfd_boolean);
 570 extern void lang_add_insert
 571   (const char *, int);
 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 extern void lang_append_dynamic_list (struct bfd_elf_version_expr *);
 605 extern void lang_append_dynamic_list_cpp_typeinfo (void);
 606 extern void lang_append_dynamic_list_cpp_new (void);
 607 extern void lang_add_unique
 608   (const char *);
 609 extern const char *lang_get_output_target
 610   (void);
 611 extern void lang_track_definedness (const char *);
 612 extern int lang_symbol_definition_iteration (const char *);
 613 extern void lang_update_definedness
 614   (const char *, struct bfd_link_hash_entry *);
 615
 616 extern void add_excluded_libs (const char *);
 617 extern bfd_boolean load_symbols
 618   (lang_input_statement_type *, lang_statement_list_type *);
 619
 620 extern bfd_boolean
 621 ldlang_override_segment_assignment
 622   (struct bfd_link_info *, bfd *, asection *, asection *, bfd_boolean);
 623
 624 #endif