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, 2009, 2010
   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_name_struct
  51 {
  52   const char * name;
  53   struct memory_region_name_struct * next;
  54 } lang_memory_region_name;
  55
  56 typedef struct memory_region_struct
  57 {
  58   lang_memory_region_name name_list;
  59   struct memory_region_struct *next;
  60   bfd_vma origin;
  61   bfd_size_type length;
  62   bfd_vma current;
  63   union lang_statement_union *last_os;
  64   flagword flags;
  65   flagword not_flags;
  66   bfd_boolean had_full_message;
  67 } lang_memory_region_type;
  68
  69 enum statement_enum
  70 {
  71   lang_output_section_statement_enum,
  72   lang_assignment_statement_enum,
  73   lang_input_statement_enum,
  74   lang_address_statement_enum,
  75   lang_wild_statement_enum,
  76   lang_input_section_enum,
  77   lang_object_symbols_statement_enum,
  78   lang_fill_statement_enum,
  79   lang_data_statement_enum,
  80   lang_reloc_statement_enum,
  81   lang_target_statement_enum,
  82   lang_output_statement_enum,
  83   lang_padding_statement_enum,
  84   lang_group_statement_enum,
  85   lang_insert_statement_enum,
  86   lang_constructors_statement_enum
  87 };
  88
  89 typedef struct lang_statement_header_struct
  90 {
  91   union lang_statement_union *next;
  92   enum statement_enum type;
  93 } lang_statement_header_type;
  94
  95 typedef struct
  96 {
  97   lang_statement_header_type header;
  98   union etree_union *exp;
  99 } lang_assignment_statement_type;
 100
 101 typedef struct lang_target_statement_struct
 102 {
 103   lang_statement_header_type header;
 104   const char *target;
 105 } lang_target_statement_type;
 106
 107 typedef struct lang_output_statement_struct
 108 {
 109   lang_statement_header_type header;
 110   const char *name;
 111 } lang_output_statement_type;
 112
 113 /* Section types specified in a linker script.  */
 114
 115 enum section_type
 116 {
 117   normal_section,
 118   overlay_section,
 119   noload_section,
 120   noalloc_section
 121 };
 122
 123 /* This structure holds a list of program headers describing
 124    segments in which this section should be placed.  */
 125
 126 typedef struct lang_output_section_phdr_list
 127 {
 128   struct lang_output_section_phdr_list *next;
 129   const char *name;
 130   bfd_boolean used;
 131 } lang_output_section_phdr_list;
 132
 133 typedef struct lang_output_section_statement_struct
 134 {
 135   lang_statement_header_type header;
 136   lang_statement_list_type children;
 137   struct lang_output_section_statement_struct *next;
 138   struct lang_output_section_statement_struct *prev;
 139   const char *name;
 140   asection *bfd_section;
 141   lang_memory_region_type *region;
 142   lang_memory_region_type *lma_region;
 143   fill_type *fill;
 144   union etree_union *addr_tree;
 145   union etree_union *load_base;
 146
 147   /* If non-null, an expression to evaluate after setting the section's
 148      size.  The expression is evaluated inside REGION (above) with '.'
 149      set to the end of the section.  Used in the last overlay section
 150      to move '.' past all the overlaid sections.  */
 151   union etree_union *update_dot_tree;
 152
 153   lang_output_section_phdr_list *phdrs;
 154
 155   unsigned int block_value;
 156   int subsection_alignment;     /* Alignment of components.  */
 157   int section_alignment;        /* Alignment of start of section.  */
 158   int constraint;
 159   flagword flags;
 160   enum section_type sectype;
 161   unsigned int processed_vma : 1;
 162   unsigned int processed_lma : 1;
 163   unsigned int all_input_readonly : 1;
 164   /* If this section should be ignored.  */
 165   unsigned int ignored : 1;
 166   /* If there is a symbol relative to this section.  */
 167   unsigned int section_relative_symbol : 1;
 168 } lang_output_section_statement_type;
 169
 170 typedef struct
 171 {
 172   lang_statement_header_type header;
 173 } lang_common_statement_type;
 174
 175 typedef struct
 176 {
 177   lang_statement_header_type header;
 178 } lang_object_symbols_statement_type;
 179
 180 typedef struct
 181 {
 182   lang_statement_header_type header;
 183   fill_type *fill;
 184   int size;
 185   asection *output_section;
 186 } lang_fill_statement_type;
 187
 188 typedef struct
 189 {
 190   lang_statement_header_type header;
 191   unsigned int type;
 192   union etree_union *exp;
 193   bfd_vma value;
 194   asection *output_section;
 195   bfd_vma output_offset;
 196 } lang_data_statement_type;
 197
 198 /* Generate a reloc in the output file.  */
 199
 200 typedef struct
 201 {
 202   lang_statement_header_type header;
 203
 204   /* Reloc to generate.  */
 205   bfd_reloc_code_real_type reloc;
 206
 207   /* Reloc howto structure.  */
 208   reloc_howto_type *howto;
 209
 210   /* Section to generate reloc against.
 211      Exactly one of section and name must be NULL.  */
 212   asection *section;
 213
 214   /* Name of symbol to generate reloc against.
 215      Exactly one of section and name must be NULL.  */
 216   const char *name;
 217
 218   /* Expression for addend.  */
 219   union etree_union *addend_exp;
 220
 221   /* Resolved addend.  */
 222   bfd_vma addend_value;
 223
 224   /* Output section where reloc should be performed.  */
 225   asection *output_section;
 226
 227   /* Offset within output section.  */
 228   bfd_vma output_offset;
 229 } lang_reloc_statement_type;
 230
 231 typedef struct lang_input_statement_struct
 232 {
 233   lang_statement_header_type header;
 234   /* Name of this file.  */
 235   const char *filename;
 236   /* Name to use for the symbol giving address of text start.
 237      Usually the same as filename, but for a file spec'd with
 238      -l this is the -l switch itself rather than the filename.  */
 239   const char *local_sym_name;
 240
 241   bfd *the_bfd;
 242
 243   /* Point to the next file - whatever it is, wanders up and down
 244      archives */
 245   union lang_statement_union *next;
 246
 247   /* Point to the next file, but skips archive contents.  */
 248   union lang_statement_union *next_real_file;
 249
 250   const char *target;
 251
 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_DT_NEEDED_for_dynamic : 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 add_DT_NEEDED_for_regular : 1;
 278
 279   /* Whether to include the entire contents of an archive.  */
 280   unsigned int whole_archive : 1;
 281
 282   /* Set when bfd opening is successful.  */
 283   unsigned int loaded : 1;
 284
 285   unsigned int real : 1;
 286
 287   /* Set if the file does not exist.  */
 288   unsigned int missing_file : 1;
 289 } lang_input_statement_type;
 290
 291 typedef struct
 292 {
 293   lang_statement_header_type header;
 294   asection *section;
 295 } lang_input_section_type;
 296
 297 typedef struct lang_wild_statement_struct lang_wild_statement_type;
 298
 299 typedef void (*callback_t) (lang_wild_statement_type *, struct wildcard_list *,
 300                             asection *, lang_input_statement_type *, void *);
 301
 302 typedef void (*walk_wild_section_handler_t) (lang_wild_statement_type *,
 303                                              lang_input_statement_type *,
 304                                              callback_t callback,
 305                                              void *data);
 306
 307 typedef bfd_boolean (*lang_match_sec_type_func) (bfd *, const asection *,
 308                                                  bfd *, const asection *);
 309
 310 /* Binary search tree structure to efficiently sort sections by
 311    name.  */
 312 typedef struct lang_section_bst
 313 {
 314   asection *section;
 315   struct lang_section_bst *left;
 316   struct lang_section_bst *right;
 317 } lang_section_bst_type;
 318
 319 struct lang_wild_statement_struct
 320 {
 321   lang_statement_header_type header;
 322   const char *filename;
 323   bfd_boolean filenames_sorted;
 324   struct wildcard_list *section_list;
 325   bfd_boolean keep_sections;
 326   lang_statement_list_type children;
 327
 328   walk_wild_section_handler_t walk_wild_section_handler;
 329   struct wildcard_list *handler_data[4];
 330   lang_section_bst_type *tree;
 331 };
 332
 333 typedef struct lang_address_statement_struct
 334 {
 335   lang_statement_header_type header;
 336   const char *section_name;
 337   union etree_union *address;
 338   const segment_type *segment;
 339 } lang_address_statement_type;
 340
 341 typedef struct
 342 {
 343   lang_statement_header_type header;
 344   bfd_vma output_offset;
 345   size_t size;
 346   asection *output_section;
 347   fill_type *fill;
 348 } lang_padding_statement_type;
 349
 350 /* A group statement collects a set of libraries together.  The
 351    libraries are searched multiple times, until no new undefined
 352    symbols are found.  The effect is to search a group of libraries as
 353    though they were a single library.  */
 354
 355 typedef struct
 356 {
 357   lang_statement_header_type header;
 358   lang_statement_list_type children;
 359 } lang_group_statement_type;
 360
 361 typedef struct
 362 {
 363   lang_statement_header_type header;
 364   const char *where;
 365   bfd_boolean is_before;
 366 } lang_insert_statement_type;
 367
 368 typedef union lang_statement_union
 369 {
 370   lang_statement_header_type header;
 371   lang_wild_statement_type wild_statement;
 372   lang_data_statement_type data_statement;
 373   lang_reloc_statement_type reloc_statement;
 374   lang_address_statement_type address_statement;
 375   lang_output_section_statement_type output_section_statement;
 376   lang_assignment_statement_type assignment_statement;
 377   lang_input_statement_type input_statement;
 378   lang_target_statement_type target_statement;
 379   lang_output_statement_type output_statement;
 380   lang_input_section_type input_section;
 381   lang_common_statement_type common_statement;
 382   lang_object_symbols_statement_type object_symbols_statement;
 383   lang_fill_statement_type fill_statement;
 384   lang_padding_statement_type padding_statement;
 385   lang_group_statement_type group_statement;
 386   lang_insert_statement_type insert_statement;
 387 } lang_statement_union_type;
 388
 389 /* This structure holds information about a program header, from the
 390    PHDRS command in the linker script.  */
 391
 392 struct lang_phdr
 393 {
 394   struct lang_phdr *next;
 395   const char *name;
 396   unsigned long type;
 397   bfd_boolean filehdr;
 398   bfd_boolean phdrs;
 399   etree_type *at;
 400   etree_type *flags;
 401 };
 402
 403 extern struct lang_phdr *lang_phdr_list;
 404
 405 /* This structure is used to hold a list of sections which may not
 406    cross reference each other.  */
 407
 408 typedef struct lang_nocrossref
 409 {
 410   struct lang_nocrossref *next;
 411   const char *name;
 412 } lang_nocrossref_type;
 413
 414 /* The list of nocrossref lists.  */
 415
 416 struct lang_nocrossrefs
 417 {
 418   struct lang_nocrossrefs *next;
 419   lang_nocrossref_type *list;
 420 };
 421
 422 extern struct lang_nocrossrefs *nocrossref_list;
 423
 424 /* This structure is used to hold a list of input section names which
 425    will not match an output section in the linker script.  */
 426
 427 struct unique_sections
 428 {
 429   struct unique_sections *next;
 430   const char *name;
 431 };
 432
 433 /* This structure records symbols for which we need to keep track of
 434    definedness for use in the DEFINED () test.  */
 435
 436 struct lang_definedness_hash_entry
 437 {
 438   struct bfd_hash_entry root;
 439   int iteration;
 440 };
 441
 442 /* Used by place_orphan to keep track of orphan sections and statements.  */
 443
 444 struct orphan_save
 445 {
 446   const char *name;
 447   flagword flags;
 448   lang_output_section_statement_type *os;
 449   asection **section;
 450   lang_statement_union_type **stmt;
 451   lang_output_section_statement_type **os_tail;
 452 };
 453
 454 extern const char *output_target;
 455 extern lang_output_section_statement_type *abs_output_section;
 456 extern lang_statement_list_type lang_output_section_statement;
 457 extern bfd_boolean lang_has_input_file;
 458 extern etree_type *base;
 459 extern lang_statement_list_type *stat_ptr;
 460 extern bfd_boolean delete_output_file_on_failure;
 461
 462 extern struct bfd_sym_chain entry_symbol;
 463 extern const char *entry_section;
 464 extern bfd_boolean entry_from_cmdline;
 465 extern lang_statement_list_type file_chain;
 466 extern lang_statement_list_type input_file_chain;
 467
 468 extern int lang_statement_iteration;
 469 extern bfd_boolean missing_file;
 470
 471 extern void lang_init
 472   (void);
 473 extern void lang_finish
 474   (void);
 475 extern lang_memory_region_type * lang_memory_region_lookup
 476   (const char * const, bfd_boolean);
 477 extern void lang_memory_region_alias
 478   (const char *, const char *);
 479 extern void lang_map
 480   (void);
 481 extern void lang_set_flags
 482   (lang_memory_region_type *, const char *, int);
 483 extern void lang_add_output
 484   (const char *, int from_script);
 485 extern lang_output_section_statement_type *lang_enter_output_section_statement
 486   (const char *output_section_statement_name,
 487    etree_type *address_exp,
 488    enum section_type sectype,
 489    etree_type *align,
 490    etree_type *subalign,
 491    etree_type *, int);
 492 extern void lang_final
 493   (void);
 494 extern void lang_relax_sections
 495   (bfd_boolean);
 496 extern void lang_process
 497   (void);
 498 extern void lang_section_start
 499   (const char *, union etree_union *, const segment_type *);
 500 extern void lang_add_entry
 501   (const char *, bfd_boolean);
 502 extern void lang_default_entry
 503   (const char *);
 504 extern void lang_add_target
 505   (const char *);
 506 extern void lang_add_wild
 507   (struct wildcard_spec *, struct wildcard_list *, bfd_boolean);
 508 extern void lang_add_map
 509   (const char *);
 510 extern void lang_add_fill
 511   (fill_type *);
 512 extern lang_assignment_statement_type *lang_add_assignment
 513   (union etree_union *);
 514 extern void lang_add_attribute
 515   (enum statement_enum);
 516 extern void lang_startup
 517   (const char *);
 518 extern void lang_float
 519   (bfd_boolean);
 520 extern void lang_leave_output_section_statement
 521   (fill_type *, const char *, lang_output_section_phdr_list *,
 522    const char *);
 523 extern void lang_abs_symbol_at_end_of
 524   (const char *, const char *);
 525 extern void lang_abs_symbol_at_beginning_of
 526   (const char *, const char *);
 527 extern void lang_statement_append
 528   (lang_statement_list_type *, lang_statement_union_type *,
 529    lang_statement_union_type **);
 530 extern void lang_for_each_input_file
 531   (void (*dothis) (lang_input_statement_type *));
 532 extern void lang_for_each_file
 533   (void (*dothis) (lang_input_statement_type *));
 534 extern void lang_reset_memory_regions
 535   (void);
 536 extern void lang_do_assignments
 537   (void);
 538
 539 #define LANG_FOR_EACH_INPUT_STATEMENT(statement)                        \
 540   lang_input_statement_type *statement;                                 \
 541   for (statement = (lang_input_statement_type *) file_chain.head;       \
 542        statement != (lang_input_statement_type *) NULL;                 \
 543        statement = (lang_input_statement_type *) statement->next)       \
 544
 545 #define lang_output_section_find(NAME) \
 546   lang_output_section_statement_lookup (NAME, 0, FALSE)
 547
 548 extern void lang_process
 549   (void);
 550 extern void ldlang_add_file
 551   (lang_input_statement_type *);
 552 extern lang_output_section_statement_type *lang_output_section_find_by_flags
 553   (const asection *, lang_output_section_statement_type **,
 554    lang_match_sec_type_func);
 555 extern lang_output_section_statement_type *lang_insert_orphan
 556   (asection *, const char *, int, lang_output_section_statement_type *,
 557    struct orphan_save *, etree_type *, lang_statement_list_type *);
 558 extern lang_input_statement_type *lang_add_input_file
 559   (const char *, lang_input_file_enum_type, const char *);
 560 extern void lang_add_keepsyms_file
 561   (const char *);
 562 extern lang_output_section_statement_type *lang_output_section_statement_lookup
 563   (const char *, int, bfd_boolean);
 564 extern lang_output_section_statement_type *next_matching_output_section_statement
 565   (lang_output_section_statement_type *, int);
 566 extern void ldlang_add_undef
 567   (const char *const);
 568 extern void lang_add_output_format
 569   (const char *, const char *, const char *, int);
 570 extern void lang_list_init
 571   (lang_statement_list_type *);
 572 extern void push_stat_ptr
 573   (lang_statement_list_type *);
 574 extern void pop_stat_ptr
 575   (void);
 576 extern void lang_add_data
 577   (int type, union etree_union *);
 578 extern void lang_add_reloc
 579   (bfd_reloc_code_real_type, reloc_howto_type *, asection *, const char *,
 580    union etree_union *);
 581 extern void lang_for_each_statement
 582   (void (*) (lang_statement_union_type *));
 583 extern void *stat_alloc
 584   (size_t);
 585 extern void strip_excluded_output_sections
 586   (void);
 587 extern void dprint_statement
 588   (lang_statement_union_type *, int);
 589 extern void lang_size_sections
 590   (bfd_boolean *, bfd_boolean);
 591 extern void one_lang_size_sections_pass
 592   (bfd_boolean *, bfd_boolean);
 593 extern void lang_add_insert
 594   (const char *, int);
 595 extern void lang_enter_group
 596   (void);
 597 extern void lang_leave_group
 598   (void);
 599 extern void lang_add_section
 600   (lang_statement_list_type *, asection *,
 601    lang_output_section_statement_type *);
 602 extern void lang_new_phdr
 603   (const char *, etree_type *, bfd_boolean, bfd_boolean, etree_type *,
 604    etree_type *);
 605 extern void lang_add_nocrossref
 606   (lang_nocrossref_type *);
 607 extern void lang_enter_overlay
 608   (etree_type *, etree_type *);
 609 extern void lang_enter_overlay_section
 610   (const char *);
 611 extern void lang_leave_overlay_section
 612   (fill_type *, lang_output_section_phdr_list *);
 613 extern void lang_leave_overlay
 614   (etree_type *, int, fill_type *, const char *,
 615    lang_output_section_phdr_list *, const char *);
 616
 617 extern struct bfd_elf_version_tree *lang_elf_version_info;
 618
 619 extern struct bfd_elf_version_expr *lang_new_vers_pattern
 620   (struct bfd_elf_version_expr *, const char *, const char *, bfd_boolean);
 621 extern struct bfd_elf_version_tree *lang_new_vers_node
 622   (struct bfd_elf_version_expr *, struct bfd_elf_version_expr *);
 623 extern struct bfd_elf_version_deps *lang_add_vers_depend
 624   (struct bfd_elf_version_deps *, const char *);
 625 extern void lang_register_vers_node
 626   (const char *, struct bfd_elf_version_tree *, struct bfd_elf_version_deps *);
 627 extern void lang_append_dynamic_list (struct bfd_elf_version_expr *);
 628 extern void lang_append_dynamic_list_cpp_typeinfo (void);
 629 extern void lang_append_dynamic_list_cpp_new (void);
 630 extern void lang_add_unique
 631   (const char *);
 632 extern const char *lang_get_output_target
 633   (void);
 634 extern void lang_track_definedness (const char *);
 635 extern int lang_symbol_definition_iteration (const char *);
 636 extern void lang_update_definedness
 637   (const char *, struct bfd_link_hash_entry *);
 638
 639 extern void add_excluded_libs (const char *);
 640 extern bfd_boolean load_symbols
 641   (lang_input_statement_type *, lang_statement_list_type *);
 642
 643 extern bfd_boolean
 644 ldlang_override_segment_assignment
 645   (struct bfd_link_info *, bfd *, asection *, asection *, bfd_boolean);
 646
 647 #endif