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