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