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, 2011, 2012
   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 struct lang_input_statement_flags
 232 {
 233   /* 1 means this file was specified in a -l option.  */
 234   unsigned int maybe_archive : 1;
 235
 236   /* 1 means search a set of directories for this file.  */
 237   unsigned int search_dirs : 1;
 238
 239   /* 1 means this was found in a search directory marked as sysrooted,
 240      if search_dirs is false, otherwise, that it should be
 241      searched in ld_sysroot before any other location, as long as it
 242      starts with a slash.  */
 243   unsigned int sysrooted : 1;
 244
 245   /* 1 means this is base file of incremental load.
 246      Do not load this file's text or data.
 247      Also default text_start to after this file's bss.  */
 248   unsigned int just_syms : 1;
 249
 250   /* Whether to search for this entry as a dynamic archive.  */
 251   unsigned int dynamic : 1;
 252
 253   /* Set if a DT_NEEDED tag should be added not just for the dynamic library
 254      explicitly given by this entry but also for any dynamic libraries in
 255      this entry's needed list.  */
 256   unsigned int add_DT_NEEDED_for_dynamic : 1;
 257
 258   /* Set if this entry should cause a DT_NEEDED tag only when some
 259      regular file references its symbols (ie. --as-needed is in effect).  */
 260   unsigned int add_DT_NEEDED_for_regular : 1;
 261
 262   /* Whether to include the entire contents of an archive.  */
 263   unsigned int whole_archive : 1;
 264
 265   /* Set when bfd opening is successful.  */
 266   unsigned int loaded : 1;
 267
 268   unsigned int real : 1;
 269
 270   /* Set if the file does not exist.  */
 271   unsigned int missing_file : 1;
 272
 273 #ifdef ENABLE_PLUGINS
 274   /* Set if the file was claimed by a plugin.  */
 275   unsigned int claimed : 1;
 276
 277   /* Set if the file was claimed from an archive.  */
 278   unsigned int claim_archive : 1;
 279
 280   /* Set if reloading an --as-needed lib.  */
 281   unsigned int reload : 1;
 282 #endif /* ENABLE_PLUGINS */
 283 };
 284
 285 typedef struct lang_input_statement_struct
 286 {
 287   lang_statement_header_type header;
 288   /* Name of this file.  */
 289   const char *filename;
 290   /* Name to use for the symbol giving address of text start.
 291      Usually the same as filename, but for a file spec'd with
 292      -l this is the -l switch itself rather than the filename.  */
 293   const char *local_sym_name;
 294
 295   bfd *the_bfd;
 296
 297   struct flag_info *section_flag_list;
 298
 299   /* Point to the next file - whatever it is, wanders up and down
 300      archives */
 301   union lang_statement_union *next;
 302
 303   /* Point to the next file, but skips archive contents.  */
 304   union lang_statement_union *next_real_file;
 305
 306   const char *target;
 307
 308   struct lang_input_statement_flags flags;
 309 } lang_input_statement_type;
 310
 311 typedef struct
 312 {
 313   lang_statement_header_type header;
 314   asection *section;
 315 } lang_input_section_type;
 316
 317 typedef struct lang_wild_statement_struct lang_wild_statement_type;
 318
 319 typedef void (*callback_t) (lang_wild_statement_type *, struct wildcard_list *,
 320                             asection *, lang_input_statement_type *, void *);
 321
 322 typedef void (*walk_wild_section_handler_t) (lang_wild_statement_type *,
 323                                              lang_input_statement_type *,
 324                                              callback_t callback,
 325                                              void *data);
 326
 327 typedef bfd_boolean (*lang_match_sec_type_func) (bfd *, const asection *,
 328                                                  bfd *, const asection *);
 329
 330 /* Binary search tree structure to efficiently sort sections by
 331    name.  */
 332 typedef struct lang_section_bst
 333 {
 334   asection *section;
 335   struct lang_section_bst *left;
 336   struct lang_section_bst *right;
 337 } lang_section_bst_type;
 338
 339 struct lang_wild_statement_struct
 340 {
 341   lang_statement_header_type header;
 342   const char *filename;
 343   bfd_boolean filenames_sorted;
 344   struct wildcard_list *section_list;
 345   bfd_boolean keep_sections;
 346   lang_statement_list_type children;
 347
 348   walk_wild_section_handler_t walk_wild_section_handler;
 349   struct wildcard_list *handler_data[4];
 350   lang_section_bst_type *tree;
 351   struct flag_info *section_flag_list;
 352 };
 353
 354 typedef struct lang_address_statement_struct
 355 {
 356   lang_statement_header_type header;
 357   const char *section_name;
 358   union etree_union *address;
 359   const segment_type *segment;
 360 } lang_address_statement_type;
 361
 362 typedef struct
 363 {
 364   lang_statement_header_type header;
 365   bfd_vma output_offset;
 366   bfd_size_type size;
 367   asection *output_section;
 368   fill_type *fill;
 369 } lang_padding_statement_type;
 370
 371 /* A group statement collects a set of libraries together.  The
 372    libraries are searched multiple times, until no new undefined
 373    symbols are found.  The effect is to search a group of libraries as
 374    though they were a single library.  */
 375
 376 typedef struct
 377 {
 378   lang_statement_header_type header;
 379   lang_statement_list_type children;
 380 } lang_group_statement_type;
 381
 382 typedef struct
 383 {
 384   lang_statement_header_type header;
 385   const char *where;
 386   bfd_boolean is_before;
 387 } lang_insert_statement_type;
 388
 389 typedef union lang_statement_union
 390 {
 391   lang_statement_header_type header;
 392   lang_wild_statement_type wild_statement;
 393   lang_data_statement_type data_statement;
 394   lang_reloc_statement_type reloc_statement;
 395   lang_address_statement_type address_statement;
 396   lang_output_section_statement_type output_section_statement;
 397   lang_assignment_statement_type assignment_statement;
 398   lang_input_statement_type input_statement;
 399   lang_target_statement_type target_statement;
 400   lang_output_statement_type output_statement;
 401   lang_input_section_type input_section;
 402   lang_common_statement_type common_statement;
 403   lang_object_symbols_statement_type object_symbols_statement;
 404   lang_fill_statement_type fill_statement;
 405   lang_padding_statement_type padding_statement;
 406   lang_group_statement_type group_statement;
 407   lang_insert_statement_type insert_statement;
 408 } lang_statement_union_type;
 409
 410 /* This structure holds information about a program header, from the
 411    PHDRS command in the linker script.  */
 412
 413 struct lang_phdr
 414 {
 415   struct lang_phdr *next;
 416   const char *name;
 417   unsigned long type;
 418   bfd_boolean filehdr;
 419   bfd_boolean phdrs;
 420   etree_type *at;
 421   etree_type *flags;
 422 };
 423
 424 /* This structure is used to hold a list of sections which may not
 425    cross reference each other.  */
 426
 427 typedef struct lang_nocrossref
 428 {
 429   struct lang_nocrossref *next;
 430   const char *name;
 431 } lang_nocrossref_type;
 432
 433 /* The list of nocrossref lists.  */
 434
 435 struct lang_nocrossrefs
 436 {
 437   struct lang_nocrossrefs *next;
 438   lang_nocrossref_type *list;
 439 };
 440
 441 /* This structure is used to hold a list of input section names which
 442    will not match an output section in the linker script.  */
 443
 444 struct unique_sections
 445 {
 446   struct unique_sections *next;
 447   const char *name;
 448 };
 449
 450 /* This structure records symbols for which we need to keep track of
 451    definedness for use in the DEFINED () test.  */
 452
 453 struct lang_definedness_hash_entry
 454 {
 455   struct bfd_hash_entry root;
 456   int iteration;
 457 };
 458
 459 /* Used by place_orphan to keep track of orphan sections and statements.  */
 460
 461 struct orphan_save
 462 {
 463   const char *name;
 464   flagword flags;
 465   lang_output_section_statement_type *os;
 466   asection **section;
 467   lang_statement_union_type **stmt;
 468   lang_output_section_statement_type **os_tail;
 469 };
 470
 471 extern struct lang_phdr *lang_phdr_list;
 472 extern struct lang_nocrossrefs *nocrossref_list;
 473 extern const char *output_target;
 474 extern lang_output_section_statement_type *abs_output_section;
 475 extern lang_statement_list_type lang_output_section_statement;
 476 extern struct lang_input_statement_flags input_flags;
 477 extern bfd_boolean lang_has_input_file;
 478 extern etree_type *base;
 479 extern lang_statement_list_type *stat_ptr;
 480 extern bfd_boolean delete_output_file_on_failure;
 481
 482 extern struct bfd_sym_chain entry_symbol;
 483 extern const char *entry_section;
 484 extern bfd_boolean entry_from_cmdline;
 485 extern lang_statement_list_type file_chain;
 486 extern lang_statement_list_type input_file_chain;
 487
 488 extern int lang_statement_iteration;
 489
 490 extern void lang_init
 491   (void);
 492 extern void lang_finish
 493   (void);
 494 extern lang_memory_region_type * lang_memory_region_lookup
 495   (const char * const, bfd_boolean);
 496 extern void lang_memory_region_alias
 497   (const char *, const char *);
 498 extern void lang_map
 499   (void);
 500 extern void lang_set_flags
 501   (lang_memory_region_type *, const char *, int);
 502 extern void lang_add_output
 503   (const char *, int from_script);
 504 extern lang_output_section_statement_type *lang_enter_output_section_statement
 505   (const char *output_section_statement_name,
 506    etree_type *address_exp,
 507    enum section_type sectype,
 508    etree_type *align,
 509    etree_type *subalign,
 510    etree_type *, int);
 511 extern void lang_final
 512   (void);
 513 extern void lang_relax_sections
 514   (bfd_boolean);
 515 extern void lang_process
 516   (void);
 517 extern void lang_section_start
 518   (const char *, union etree_union *, const segment_type *);
 519 extern void lang_add_entry
 520   (const char *, bfd_boolean);
 521 extern void lang_default_entry
 522   (const char *);
 523 extern void lang_add_target
 524   (const char *);
 525 extern void lang_add_wild
 526   (struct wildcard_spec *, struct wildcard_list *, bfd_boolean);
 527 extern void lang_add_map
 528   (const char *);
 529 extern void lang_add_fill
 530   (fill_type *);
 531 extern lang_assignment_statement_type *lang_add_assignment
 532   (union etree_union *);
 533 extern void lang_add_attribute
 534   (enum statement_enum);
 535 extern void lang_startup
 536   (const char *);
 537 extern void lang_float
 538   (bfd_boolean);
 539 extern void lang_leave_output_section_statement
 540   (fill_type *, const char *, lang_output_section_phdr_list *,
 541    const char *);
 542 extern void lang_abs_symbol_at_end_of
 543   (const char *, const char *);
 544 extern void lang_abs_symbol_at_beginning_of
 545   (const char *, const char *);
 546 extern void lang_statement_append
 547   (lang_statement_list_type *, lang_statement_union_type *,
 548    lang_statement_union_type **);
 549 extern void lang_for_each_input_file
 550   (void (*dothis) (lang_input_statement_type *));
 551 extern void lang_for_each_file
 552   (void (*dothis) (lang_input_statement_type *));
 553 extern void lang_reset_memory_regions
 554   (void);
 555 extern void lang_do_assignments
 556   (lang_phase_type);
 557
 558 #define LANG_FOR_EACH_INPUT_STATEMENT(statement)                        \
 559   lang_input_statement_type *statement;                                 \
 560   for (statement = (lang_input_statement_type *) file_chain.head;       \
 561        statement != (lang_input_statement_type *) NULL;                 \
 562        statement = (lang_input_statement_type *) statement->next)       \
 563
 564 #define lang_output_section_find(NAME) \
 565   lang_output_section_statement_lookup (NAME, 0, FALSE)
 566
 567 extern void lang_process
 568   (void);
 569 extern void ldlang_add_file
 570   (lang_input_statement_type *);
 571 extern lang_output_section_statement_type *lang_output_section_find_by_flags
 572   (const asection *, lang_output_section_statement_type **,
 573    lang_match_sec_type_func);
 574 extern lang_output_section_statement_type *lang_insert_orphan
 575   (asection *, const char *, int, lang_output_section_statement_type *,
 576    struct orphan_save *, etree_type *, lang_statement_list_type *);
 577 extern lang_input_statement_type *lang_add_input_file
 578   (const char *, lang_input_file_enum_type, const char *);
 579 extern void lang_add_keepsyms_file
 580   (const char *);
 581 extern lang_output_section_statement_type *lang_output_section_statement_lookup
 582   (const char *, int, bfd_boolean);
 583 extern lang_output_section_statement_type *next_matching_output_section_statement
 584   (lang_output_section_statement_type *, int);
 585 extern void ldlang_add_undef
 586   (const char *const, bfd_boolean);
 587 extern void lang_add_output_format
 588   (const char *, const char *, const char *, int);
 589 extern void lang_list_init
 590   (lang_statement_list_type *);
 591 extern void push_stat_ptr
 592   (lang_statement_list_type *);
 593 extern void pop_stat_ptr
 594   (void);
 595 extern void lang_add_data
 596   (int type, union etree_union *);
 597 extern void lang_add_reloc
 598   (bfd_reloc_code_real_type, reloc_howto_type *, asection *, const char *,
 599    union etree_union *);
 600 extern void lang_for_each_statement
 601   (void (*) (lang_statement_union_type *));
 602 extern void lang_for_each_statement_worker
 603   (void (*) (lang_statement_union_type *), lang_statement_union_type *);
 604 extern void *stat_alloc
 605   (size_t);
 606 extern void strip_excluded_output_sections
 607   (void);
 608 extern void dprint_statement
 609   (lang_statement_union_type *, int);
 610 extern void lang_size_sections
 611   (bfd_boolean *, bfd_boolean);
 612 extern void one_lang_size_sections_pass
 613   (bfd_boolean *, bfd_boolean);
 614 extern void lang_add_insert
 615   (const char *, int);
 616 extern void lang_enter_group
 617   (void);
 618 extern void lang_leave_group
 619   (void);
 620 extern void lang_add_section
 621   (lang_statement_list_type *, asection *,
 622    lang_output_section_statement_type *);
 623 extern void lang_new_phdr
 624   (const char *, etree_type *, bfd_boolean, bfd_boolean, etree_type *,
 625    etree_type *);
 626 extern void lang_add_nocrossref
 627   (lang_nocrossref_type *);
 628 extern void lang_enter_overlay
 629   (etree_type *, etree_type *);
 630 extern void lang_enter_overlay_section
 631   (const char *);
 632 extern void lang_leave_overlay_section
 633   (fill_type *, lang_output_section_phdr_list *);
 634 extern void lang_leave_overlay
 635   (etree_type *, int, fill_type *, const char *,
 636    lang_output_section_phdr_list *, const char *);
 637
 638 extern struct bfd_elf_version_expr *lang_new_vers_pattern
 639   (struct bfd_elf_version_expr *, const char *, const char *, bfd_boolean);
 640 extern struct bfd_elf_version_tree *lang_new_vers_node
 641   (struct bfd_elf_version_expr *, struct bfd_elf_version_expr *);
 642 extern struct bfd_elf_version_deps *lang_add_vers_depend
 643   (struct bfd_elf_version_deps *, const char *);
 644 extern void lang_register_vers_node
 645   (const char *, struct bfd_elf_version_tree *, struct bfd_elf_version_deps *);
 646 extern void lang_append_dynamic_list (struct bfd_elf_version_expr *);
 647 extern void lang_append_dynamic_list_cpp_typeinfo (void);
 648 extern void lang_append_dynamic_list_cpp_new (void);
 649 extern void lang_add_unique
 650   (const char *);
 651 extern const char *lang_get_output_target
 652   (void);
 653 extern void lang_track_definedness (const char *);
 654 extern int lang_symbol_definition_iteration (const char *);
 655 extern void lang_update_definedness
 656   (const char *, struct bfd_link_hash_entry *);
 657
 658 extern void add_excluded_libs (const char *);
 659 extern bfd_boolean load_symbols
 660   (lang_input_statement_type *, lang_statement_list_type *);
 661
 662 extern bfd_boolean
 663 ldlang_override_segment_assignment
 664   (struct bfd_link_info *, bfd *, asection *, asection *, bfd_boolean);
 665
 666 extern void
 667 lang_ld_feature (char *);
 668
 669 #endif