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   overlay_section,
 112   noload_section,
 113   noalloc_section
 114 };
 115
 116 /* This structure holds a list of program headers describing
 117    segments in which this section should be placed.  */
 118
 119 typedef struct lang_output_section_phdr_list
 120 {
 121   struct lang_output_section_phdr_list *next;
 122   const char *name;
 123   bfd_boolean used;
 124 } lang_output_section_phdr_list;
 125
 126 typedef struct lang_output_section_statement_struct
 127 {
 128   lang_statement_header_type header;
 129   lang_statement_list_type children;
 130   struct lang_output_section_statement_struct *next;
 131   struct lang_output_section_statement_struct *prev;
 132   const char *name;
 133   asection *bfd_section;
 134   lang_memory_region_type *region;
 135   lang_memory_region_type *lma_region;
 136   fill_type *fill;
 137   union etree_union *addr_tree;
 138   union etree_union *load_base;
 139
 140   /* If non-null, an expression to evaluate after setting the section's
 141      size.  The expression is evaluated inside REGION (above) with '.'
 142      set to the end of the section.  Used in the last overlay section
 143      to move '.' past all the overlaid sections.  */
 144   union etree_union *update_dot_tree;
 145
 146   lang_output_section_phdr_list *phdrs;
 147
 148   unsigned int block_value;
 149   int subsection_alignment;     /* Alignment of components.  */
 150   int section_alignment;        /* Alignment of start of section.  */
 151   int constraint;
 152   flagword flags;
 153   enum section_type sectype;
 154   unsigned int processed_vma : 1;
 155   unsigned int processed_lma : 1;
 156   unsigned int all_input_readonly : 1;
 157   /* If this section should be ignored.  */
 158   unsigned int ignored : 1;
 159   /* If there is a symbol relative to this section.  */
 160   unsigned int section_relative_symbol : 1;
 161 } lang_output_section_statement_type;
 162
 163 typedef struct
 164 {
 165   lang_statement_header_type header;
 166 } lang_common_statement_type;
 167
 168 typedef struct
 169 {
 170   lang_statement_header_type header;
 171 } lang_object_symbols_statement_type;
 172
 173 typedef struct
 174 {
 175   lang_statement_header_type header;
 176   fill_type *fill;
 177   int size;
 178   asection *output_section;
 179 } lang_fill_statement_type;
 180
 181 typedef struct
 182 {
 183   lang_statement_header_type header;
 184   unsigned int type;
 185   union etree_union *exp;
 186   bfd_vma value;
 187   asection *output_section;
 188   bfd_vma output_offset;
 189 } lang_data_statement_type;
 190
 191 /* Generate a reloc in the output file.  */
 192
 193 typedef struct
 194 {
 195   lang_statement_header_type header;
 196
 197   /* Reloc to generate.  */
 198   bfd_reloc_code_real_type reloc;
 199
 200   /* Reloc howto structure.  */
 201   reloc_howto_type *howto;
 202
 203   /* Section to generate reloc against.
 204      Exactly one of section and name must be NULL.  */
 205   asection *section;
 206
 207   /* Name of symbol to generate reloc against.
 208      Exactly one of section and name must be NULL.  */
 209   const char *name;
 210
 211   /* Expression for addend.  */
 212   union etree_union *addend_exp;
 213
 214   /* Resolved addend.  */
 215   bfd_vma addend_value;
 216
 217   /* Output section where reloc should be performed.  */
 218   asection *output_section;
 219
 220   /* Offset within output section.  */
 221   bfd_vma output_offset;
 222 } lang_reloc_statement_type;
 223
 224 typedef struct lang_input_statement_struct
 225 {
 226   lang_statement_header_type header;
 227   /* Name of this file.  */
 228   const char *filename;
 229   /* Name to use for the symbol giving address of text start.
 230      Usually the same as filename, but for a file spec'd with
 231      -l this is the -l switch itself rather than the filename.  */
 232   const char *local_sym_name;
 233
 234   bfd *the_bfd;
 235
 236   file_ptr passive_position;
 237
 238   /* Symbol table of the file.  */
 239   asymbol **asymbols;
 240   unsigned int symbol_count;
 241
 242   /* Point to the next file - whatever it is, wanders up and down
 243      archives */
 244   union lang_statement_union *next;
 245
 246   /* Point to the next file, but skips archive contents.  */
 247   union lang_statement_union *next_real_file;
 248
 249   const char *target;
 250
 251   unsigned int closed : 1;
 252   unsigned int is_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_needed : 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 as_needed : 1;
 278
 279   /* Whether to include the entire contents of an archive.  */
 280   unsigned int whole_archive : 1;
 281
 282   unsigned int loaded : 1;
 283
 284   unsigned int real : 1;
 285 } lang_input_statement_type;
 286
 287 typedef struct
 288 {
 289   lang_statement_header_type header;
 290   asection *section;
 291 } lang_input_section_type;
 292
 293 typedef struct
 294 {
 295   lang_statement_header_type header;
 296   asection *section;
 297   union lang_statement_union *file;
 298 } lang_afile_asection_pair_statement_type;
 299
 300 typedef struct lang_wild_statement_struct lang_wild_statement_type;
 301
 302 typedef void (*callback_t) (lang_wild_statement_type *, struct wildcard_list *,
 303                             asection *, lang_input_statement_type *, void *);
 304
 305 typedef void (*walk_wild_section_handler_t) (lang_wild_statement_type *,
 306                                              lang_input_statement_type *,
 307                                              callback_t callback,
 308                                              void *data);
 309
 310 typedef bfd_boolean (*lang_match_sec_type_func) (bfd *, const asection *,
 311                                                  bfd *, const asection *);
 312
 313 /* Binary search tree structure to efficiently sort sections by
 314    name.  */
 315 typedef struct lang_section_bst
 316 {
 317   asection *section;
 318   struct lang_section_bst *left;
 319   struct lang_section_bst *right;
 320 } lang_section_bst_type;
 321
 322 struct lang_wild_statement_struct
 323 {
 324   lang_statement_header_type header;
 325   const char *filename;
 326   bfd_boolean filenames_sorted;
 327   struct wildcard_list *section_list;
 328   bfd_boolean keep_sections;
 329   lang_statement_list_type children;
 330
 331   walk_wild_section_handler_t walk_wild_section_handler;
 332   struct wildcard_list *handler_data[4];
 333   lang_section_bst_type *tree;
 334 };
 335
 336 typedef struct lang_address_statement_struct
 337 {
 338   lang_statement_header_type header;
 339   const char *section_name;
 340   union etree_union *address;
 341   const segment_type *segment;
 342 } lang_address_statement_type;
 343
 344 typedef struct
 345 {
 346   lang_statement_header_type header;
 347   bfd_vma output_offset;
 348   size_t size;
 349   asection *output_section;
 350   fill_type *fill;
 351 } lang_padding_statement_type;
 352
 353 /* A group statement collects a set of libraries together.  The
 354    libraries are searched multiple times, until no new undefined
 355    symbols are found.  The effect is to search a group of libraries as
 356    though they were a single library.  */
 357
 358 typedef struct
 359 {
 360   lang_statement_header_type header;
 361   lang_statement_list_type children;
 362 } lang_group_statement_type;
 363
 364 typedef union lang_statement_union
 365 {
 366   lang_statement_header_type header;
 367   lang_wild_statement_type wild_statement;
 368   lang_data_statement_type data_statement;
 369   lang_reloc_statement_type reloc_statement;
 370   lang_address_statement_type address_statement;
 371   lang_output_section_statement_type output_section_statement;
 372   lang_afile_asection_pair_statement_type afile_asection_pair_statement;
 373   lang_assignment_statement_type assignment_statement;
 374   lang_input_statement_type input_statement;
 375   lang_target_statement_type target_statement;
 376   lang_output_statement_type output_statement;
 377   lang_input_section_type input_section;
 378   lang_common_statement_type common_statement;
 379   lang_object_symbols_statement_type object_symbols_statement;
 380   lang_fill_statement_type fill_statement;
 381   lang_padding_statement_type padding_statement;
 382   lang_group_statement_type group_statement;
 383 } lang_statement_union_type;
 384
 385 /* This structure holds information about a program header, from the
 386    PHDRS command in the linker script.  */
 387
 388 struct lang_phdr
 389 {
 390   struct lang_phdr *next;
 391   const char *name;
 392   unsigned long type;
 393   bfd_boolean filehdr;
 394   bfd_boolean phdrs;
 395   etree_type *at;
 396   etree_type *flags;
 397 };
 398
 399 extern struct lang_phdr *lang_phdr_list;
 400
 401 /* This structure is used to hold a list of sections which may not
 402    cross reference each other.  */
 403
 404 typedef struct lang_nocrossref
 405 {
 406   struct lang_nocrossref *next;
 407   const char *name;
 408 } lang_nocrossref_type;
 409
 410 /* The list of nocrossref lists.  */
 411
 412 struct lang_nocrossrefs
 413 {
 414   struct lang_nocrossrefs *next;
 415   lang_nocrossref_type *list;
 416 };
 417
 418 extern struct lang_nocrossrefs *nocrossref_list;
 419
 420 /* This structure is used to hold a list of input section names which
 421    will not match an output section in the linker script.  */
 422
 423 struct unique_sections
 424 {
 425   struct unique_sections *next;
 426   const char *name;
 427 };
 428
 429 /* This structure records symbols for which we need to keep track of
 430    definedness for use in the DEFINED () test.  */
 431
 432 struct lang_definedness_hash_entry
 433 {
 434   struct bfd_hash_entry root;
 435   int iteration;
 436 };
 437
 438 /* Used by place_orphan to keep track of orphan sections and statements.  */
 439
 440 struct orphan_save {
 441   const char *name;
 442   flagword flags;
 443   lang_output_section_statement_type *os;
 444   asection **section;
 445   lang_statement_union_type **stmt;
 446   lang_output_section_statement_type **os_tail;
 447 };
 448
 449 extern lang_output_section_statement_type *abs_output_section;
 450 extern lang_statement_list_type lang_output_section_statement;
 451 extern bfd_boolean lang_has_input_file;
 452 extern etree_type *base;
 453 extern lang_statement_list_type *stat_ptr;
 454 extern bfd_boolean delete_output_file_on_failure;
 455
 456 extern struct bfd_sym_chain entry_symbol;
 457 extern const char *entry_section;
 458 extern bfd_boolean entry_from_cmdline;
 459 extern lang_statement_list_type file_chain;
 460 extern lang_statement_list_type input_file_chain;
 461
 462 extern int lang_statement_iteration;
 463
 464 extern void lang_init
 465   (void);
 466 extern void lang_finish
 467   (void);
 468 extern lang_memory_region_type *lang_memory_region_lookup
 469   (const char *const, bfd_boolean);
 470 extern lang_memory_region_type *lang_memory_region_default
 471   (asection *);
 472 extern void lang_map
 473   (void);
 474 extern void lang_set_flags
 475   (lang_memory_region_type *, const char *, int);
 476 extern void lang_add_output
 477   (const char *, int from_script);
 478 extern lang_output_section_statement_type *lang_enter_output_section_statement
 479   (const char *output_section_statement_name,
 480    etree_type *address_exp,
 481    enum section_type sectype,
 482    etree_type *align,
 483    etree_type *subalign,
 484    etree_type *, int);
 485 extern void lang_final
 486   (void);
 487 extern void lang_process
 488   (void);
 489 extern void lang_section_start
 490   (const char *, union etree_union *, const segment_type *);
 491 extern void lang_add_entry
 492   (const char *, bfd_boolean);
 493 extern void lang_default_entry
 494   (const char *);
 495 extern void lang_add_target
 496   (const char *);
 497 extern void lang_add_wild
 498   (struct wildcard_spec *, struct wildcard_list *, bfd_boolean);
 499 extern void lang_add_map
 500   (const char *);
 501 extern void lang_add_fill
 502   (fill_type *);
 503 extern lang_assignment_statement_type *lang_add_assignment
 504   (union etree_union *);
 505 extern void lang_add_attribute
 506   (enum statement_enum);
 507 extern void lang_startup
 508   (const char *);
 509 extern void lang_float
 510   (bfd_boolean);
 511 extern void lang_leave_output_section_statement
 512   (fill_type *, const char *, lang_output_section_phdr_list *,
 513    const char *);
 514 extern void lang_abs_symbol_at_end_of
 515   (const char *, const char *);
 516 extern void lang_abs_symbol_at_beginning_of
 517   (const char *, const char *);
 518 extern void lang_statement_append
 519   (lang_statement_list_type *, lang_statement_union_type *,
 520    lang_statement_union_type **);
 521 extern void lang_for_each_input_file
 522   (void (*dothis) (lang_input_statement_type *));
 523 extern void lang_for_each_file
 524   (void (*dothis) (lang_input_statement_type *));
 525 extern void lang_reset_memory_regions
 526   (void);
 527 extern void lang_do_assignments
 528   (void);
 529
 530 #define LANG_FOR_EACH_INPUT_STATEMENT(statement)                        \
 531   lang_input_statement_type *statement;                                 \
 532   for (statement = (lang_input_statement_type *) file_chain.head;       \
 533        statement != (lang_input_statement_type *) NULL;                 \
 534        statement = (lang_input_statement_type *) statement->next)       \
 535
 536 extern void lang_process
 537   (void);
 538 extern void ldlang_add_file
 539   (lang_input_statement_type *);
 540 extern lang_output_section_statement_type *lang_output_section_find
 541   (const char * const);
 542 extern lang_output_section_statement_type *lang_output_section_find_by_flags
 543   (const asection *, lang_output_section_statement_type **,
 544    lang_match_sec_type_func);
 545 extern lang_output_section_statement_type *lang_insert_orphan
 546   (asection *, const char *, lang_output_section_statement_type *,
 547    struct orphan_save *, etree_type *, lang_statement_list_type *);
 548 extern lang_input_statement_type *lang_add_input_file
 549   (const char *, lang_input_file_enum_type, const char *);
 550 extern void lang_add_keepsyms_file
 551   (const char *);
 552 extern lang_output_section_statement_type *
 553   lang_output_section_statement_lookup
 554   (const char *const);
 555 extern void ldlang_add_undef
 556   (const char *const);
 557 extern void lang_add_output_format
 558   (const char *, const char *, const char *, int);
 559 extern void lang_list_init
 560   (lang_statement_list_type *);
 561 extern void lang_add_data
 562   (int type, union etree_union *);
 563 extern void lang_add_reloc
 564   (bfd_reloc_code_real_type, reloc_howto_type *, asection *, const char *,
 565    union etree_union *);
 566 extern void lang_for_each_statement
 567   (void (*) (lang_statement_union_type *));
 568 extern void *stat_alloc
 569   (size_t);
 570 extern void strip_excluded_output_sections
 571   (void);
 572 extern void dprint_statement
 573   (lang_statement_union_type *, int);
 574 extern void lang_size_sections
 575   (bfd_boolean *, bfd_boolean);
 576 extern void one_lang_size_sections_pass
 577   (bfd_boolean *, bfd_boolean);
 578 extern void lang_enter_group
 579   (void);
 580 extern void lang_leave_group
 581   (void);
 582 extern void lang_add_section
 583   (lang_statement_list_type *, asection *,
 584    lang_output_section_statement_type *);
 585 extern void lang_new_phdr
 586   (const char *, etree_type *, bfd_boolean, bfd_boolean, etree_type *,
 587    etree_type *);
 588 extern void lang_add_nocrossref
 589   (lang_nocrossref_type *);
 590 extern void lang_enter_overlay
 591   (etree_type *, etree_type *);
 592 extern void lang_enter_overlay_section
 593   (const char *);
 594 extern void lang_leave_overlay_section
 595   (fill_type *, lang_output_section_phdr_list *);
 596 extern void lang_leave_overlay
 597   (etree_type *, int, fill_type *, const char *,
 598    lang_output_section_phdr_list *, const char *);
 599
 600 extern struct bfd_elf_version_tree *lang_elf_version_info;
 601
 602 extern struct bfd_elf_version_expr *lang_new_vers_pattern
 603   (struct bfd_elf_version_expr *, const char *, const char *, bfd_boolean);
 604 extern struct bfd_elf_version_tree *lang_new_vers_node
 605   (struct bfd_elf_version_expr *, struct bfd_elf_version_expr *);
 606 extern struct bfd_elf_version_deps *lang_add_vers_depend
 607   (struct bfd_elf_version_deps *, const char *);
 608 extern void lang_register_vers_node
 609   (const char *, struct bfd_elf_version_tree *, struct bfd_elf_version_deps *);
 610 extern void lang_append_dynamic_list (struct bfd_elf_version_expr *);
 611 extern void lang_append_dynamic_list_cpp_typeinfo (void);
 612 extern void lang_append_dynamic_list_cpp_new (void);
 613 bfd_boolean unique_section_p
 614   (const asection *);
 615 extern void lang_add_unique
 616   (const char *);
 617 extern const char *lang_get_output_target
 618   (void);
 619 extern void lang_track_definedness (const char *);
 620 extern int lang_symbol_definition_iteration (const char *);
 621 extern void lang_update_definedness
 622   (const char *, struct bfd_link_hash_entry *);
 623
 624 extern void add_excluded_libs (const char *);
 625 extern bfd_boolean load_symbols
 626   (lang_input_statement_type *, lang_statement_list_type *);
 627
 628 extern bfd_boolean
 629 ldlang_override_segment_assignment
 630   (struct bfd_link_info *, bfd *, asection *, asection *, bfd_boolean);
 631
 632 #endif