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 maybe_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
 290   /* Set if the file was claimed by a plugin.  */
 291   unsigned int claimed : 1;
 292
 293 } lang_input_statement_type;
 294
 295 typedef struct
 296 {
 297   lang_statement_header_type header;
 298   asection *section;
 299 } lang_input_section_type;
 300
 301 typedef struct lang_wild_statement_struct lang_wild_statement_type;
 302
 303 typedef void (*callback_t) (lang_wild_statement_type *, struct wildcard_list *,
 304                             asection *, lang_input_statement_type *, void *);
 305
 306 typedef void (*walk_wild_section_handler_t) (lang_wild_statement_type *,
 307                                              lang_input_statement_type *,
 308                                              callback_t callback,
 309                                              void *data);
 310
 311 typedef bfd_boolean (*lang_match_sec_type_func) (bfd *, const asection *,
 312                                                  bfd *, const asection *);
 313
 314 /* Binary search tree structure to efficiently sort sections by
 315    name.  */
 316 typedef struct lang_section_bst
 317 {
 318   asection *section;
 319   struct lang_section_bst *left;
 320   struct lang_section_bst *right;
 321 } lang_section_bst_type;
 322
 323 struct lang_wild_statement_struct
 324 {
 325   lang_statement_header_type header;
 326   const char *filename;
 327   bfd_boolean filenames_sorted;
 328   struct wildcard_list *section_list;
 329   bfd_boolean keep_sections;
 330   lang_statement_list_type children;
 331
 332   walk_wild_section_handler_t walk_wild_section_handler;
 333   struct wildcard_list *handler_data[4];
 334   lang_section_bst_type *tree;
 335 };
 336
 337 typedef struct lang_address_statement_struct
 338 {
 339   lang_statement_header_type header;
 340   const char *section_name;
 341   union etree_union *address;
 342   const segment_type *segment;
 343 } lang_address_statement_type;
 344
 345 typedef struct
 346 {
 347   lang_statement_header_type header;
 348   bfd_vma output_offset;
 349   size_t size;
 350   asection *output_section;
 351   fill_type *fill;
 352 } lang_padding_statement_type;
 353
 354 /* A group statement collects a set of libraries together.  The
 355    libraries are searched multiple times, until no new undefined
 356    symbols are found.  The effect is to search a group of libraries as
 357    though they were a single library.  */
 358
 359 typedef struct
 360 {
 361   lang_statement_header_type header;
 362   lang_statement_list_type children;
 363 } lang_group_statement_type;
 364
 365 typedef struct
 366 {
 367   lang_statement_header_type header;
 368   const char *where;
 369   bfd_boolean is_before;
 370 } lang_insert_statement_type;
 371
 372 typedef union lang_statement_union
 373 {
 374   lang_statement_header_type header;
 375   lang_wild_statement_type wild_statement;
 376   lang_data_statement_type data_statement;
 377   lang_reloc_statement_type reloc_statement;
 378   lang_address_statement_type address_statement;
 379   lang_output_section_statement_type output_section_statement;
 380   lang_assignment_statement_type assignment_statement;
 381   lang_input_statement_type input_statement;
 382   lang_target_statement_type target_statement;
 383   lang_output_statement_type output_statement;
 384   lang_input_section_type input_section;
 385   lang_common_statement_type common_statement;
 386   lang_object_symbols_statement_type object_symbols_statement;
 387   lang_fill_statement_type fill_statement;
 388   lang_padding_statement_type padding_statement;
 389   lang_group_statement_type group_statement;
 390   lang_insert_statement_type insert_statement;
 391 } lang_statement_union_type;
 392
 393 /* This structure holds information about a program header, from the
 394    PHDRS command in the linker script.  */
 395
 396 struct lang_phdr
 397 {
 398   struct lang_phdr *next;
 399   const char *name;
 400   unsigned long type;
 401   bfd_boolean filehdr;
 402   bfd_boolean phdrs;
 403   etree_type *at;
 404   etree_type *flags;
 405 };
 406
 407 extern struct lang_phdr *lang_phdr_list;
 408
 409 /* This structure is used to hold a list of sections which may not
 410    cross reference each other.  */
 411
 412 typedef struct lang_nocrossref
 413 {
 414   struct lang_nocrossref *next;
 415   const char *name;
 416 } lang_nocrossref_type;
 417
 418 /* The list of nocrossref lists.  */
 419
 420 struct lang_nocrossrefs
 421 {
 422   struct lang_nocrossrefs *next;
 423   lang_nocrossref_type *list;
 424 };
 425
 426 extern struct lang_nocrossrefs *nocrossref_list;
 427
 428 /* This structure is used to hold a list of input section names which
 429    will not match an output section in the linker script.  */
 430
 431 struct unique_sections
 432 {
 433   struct unique_sections *next;
 434   const char *name;
 435 };
 436
 437 /* This structure records symbols for which we need to keep track of
 438    definedness for use in the DEFINED () test.  */
 439
 440 struct lang_definedness_hash_entry
 441 {
 442   struct bfd_hash_entry root;
 443   int iteration;
 444 };
 445
 446 /* Used by place_orphan to keep track of orphan sections and statements.  */
 447
 448 struct orphan_save
 449 {
 450   const char *name;
 451   flagword flags;
 452   lang_output_section_statement_type *os;
 453   asection **section;
 454   lang_statement_union_type **stmt;
 455   lang_output_section_statement_type **os_tail;
 456 };
 457
 458 extern const char *output_target;
 459 extern lang_output_section_statement_type *abs_output_section;
 460 extern lang_statement_list_type lang_output_section_statement;
 461 extern bfd_boolean lang_has_input_file;
 462 extern etree_type *base;
 463 extern lang_statement_list_type *stat_ptr;
 464 extern bfd_boolean delete_output_file_on_failure;
 465
 466 extern struct bfd_sym_chain entry_symbol;
 467 extern const char *entry_section;
 468 extern bfd_boolean entry_from_cmdline;
 469 extern lang_statement_list_type file_chain;
 470 extern lang_statement_list_type input_file_chain;
 471
 472 extern int ld_compatibility;
 473 extern int lang_statement_iteration;
 474 extern bfd_boolean missing_file;
 475
 476 extern void lang_init
 477   (void);
 478 extern void lang_finish
 479   (void);
 480 extern lang_memory_region_type * lang_memory_region_lookup
 481   (const char * const, bfd_boolean);
 482 extern void lang_memory_region_alias
 483   (const char *, const char *);
 484 extern void lang_map
 485   (void);
 486 extern void lang_set_flags
 487   (lang_memory_region_type *, const char *, int);
 488 extern void lang_add_output
 489   (const char *, int from_script);
 490 extern lang_output_section_statement_type *lang_enter_output_section_statement
 491   (const char *output_section_statement_name,
 492    etree_type *address_exp,
 493    enum section_type sectype,
 494    etree_type *align,
 495    etree_type *subalign,
 496    etree_type *, int);
 497 extern void lang_final
 498   (void);
 499 extern void lang_relax_sections
 500   (bfd_boolean);
 501 extern void lang_process
 502   (void);
 503 extern void lang_section_start
 504   (const char *, union etree_union *, const segment_type *);
 505 extern void lang_add_entry
 506   (const char *, bfd_boolean);
 507 extern void lang_default_entry
 508   (const char *);
 509 extern void lang_add_target
 510   (const char *);
 511 extern void lang_add_wild
 512   (struct wildcard_spec *, struct wildcard_list *, bfd_boolean);
 513 extern void lang_add_map
 514   (const char *);
 515 extern void lang_add_fill
 516   (fill_type *);
 517 extern lang_assignment_statement_type *lang_add_assignment
 518   (union etree_union *);
 519 extern void lang_add_attribute
 520   (enum statement_enum);
 521 extern void lang_startup
 522   (const char *);
 523 extern void lang_float
 524   (bfd_boolean);
 525 extern void lang_leave_output_section_statement
 526   (fill_type *, const char *, lang_output_section_phdr_list *,
 527    const char *);
 528 extern void lang_abs_symbol_at_end_of
 529   (const char *, const char *);
 530 extern void lang_abs_symbol_at_beginning_of
 531   (const char *, const char *);
 532 extern void lang_statement_append
 533   (lang_statement_list_type *, lang_statement_union_type *,
 534    lang_statement_union_type **);
 535 extern void lang_for_each_input_file
 536   (void (*dothis) (lang_input_statement_type *));
 537 extern void lang_for_each_file
 538   (void (*dothis) (lang_input_statement_type *));
 539 extern void lang_reset_memory_regions
 540   (void);
 541 extern void lang_do_assignments
 542   (void);
 543
 544 #define LANG_FOR_EACH_INPUT_STATEMENT(statement)                        \
 545   lang_input_statement_type *statement;                                 \
 546   for (statement = (lang_input_statement_type *) file_chain.head;       \
 547        statement != (lang_input_statement_type *) NULL;                 \
 548        statement = (lang_input_statement_type *) statement->next)       \
 549
 550 #define lang_output_section_find(NAME) \
 551   lang_output_section_statement_lookup (NAME, 0, FALSE)
 552
 553 extern void lang_process
 554   (void);
 555 extern void ldlang_add_file
 556   (lang_input_statement_type *);
 557 extern lang_output_section_statement_type *lang_output_section_find_by_flags
 558   (const asection *, lang_output_section_statement_type **,
 559    lang_match_sec_type_func);
 560 extern lang_output_section_statement_type *lang_insert_orphan
 561   (asection *, const char *, int, lang_output_section_statement_type *,
 562    struct orphan_save *, etree_type *, lang_statement_list_type *);
 563 extern lang_input_statement_type *lang_add_input_file
 564   (const char *, lang_input_file_enum_type, const char *);
 565 extern void lang_add_keepsyms_file
 566   (const char *);
 567 extern lang_output_section_statement_type *lang_output_section_statement_lookup
 568   (const char *, int, bfd_boolean);
 569 extern lang_output_section_statement_type *next_matching_output_section_statement
 570   (lang_output_section_statement_type *, int);
 571 extern void ldlang_add_undef
 572   (const char *const, bfd_boolean);
 573 extern void lang_add_output_format
 574   (const char *, const char *, const char *, int);
 575 extern void lang_list_init
 576   (lang_statement_list_type *);
 577 extern void push_stat_ptr
 578   (lang_statement_list_type *);
 579 extern void pop_stat_ptr
 580   (void);
 581 extern void lang_add_data
 582   (int type, union etree_union *);
 583 extern void lang_add_reloc
 584   (bfd_reloc_code_real_type, reloc_howto_type *, asection *, const char *,
 585    union etree_union *);
 586 extern void lang_for_each_statement
 587   (void (*) (lang_statement_union_type *));
 588 extern void lang_for_each_statement_worker
 589   (void (*) (lang_statement_union_type *), lang_statement_union_type *);
 590 extern void *stat_alloc
 591   (size_t);
 592 extern void strip_excluded_output_sections
 593   (void);
 594 extern void dprint_statement
 595   (lang_statement_union_type *, int);
 596 extern void lang_size_sections
 597   (bfd_boolean *, bfd_boolean);
 598 extern void one_lang_size_sections_pass
 599   (bfd_boolean *, bfd_boolean);
 600 extern void lang_add_insert
 601   (const char *, int);
 602 extern void lang_enter_group
 603   (void);
 604 extern void lang_leave_group
 605   (void);
 606 extern void lang_add_section
 607   (lang_statement_list_type *, asection *,
 608    lang_output_section_statement_type *);
 609 extern void lang_new_phdr
 610   (const char *, etree_type *, bfd_boolean, bfd_boolean, etree_type *,
 611    etree_type *);
 612 extern void lang_add_nocrossref
 613   (lang_nocrossref_type *);
 614 extern void lang_enter_overlay
 615   (etree_type *, etree_type *);
 616 extern void lang_enter_overlay_section
 617   (const char *);
 618 extern void lang_leave_overlay_section
 619   (fill_type *, lang_output_section_phdr_list *);
 620 extern void lang_leave_overlay
 621   (etree_type *, int, fill_type *, const char *,
 622    lang_output_section_phdr_list *, const char *);
 623
 624 extern struct bfd_elf_version_tree *lang_elf_version_info;
 625
 626 extern struct bfd_elf_version_expr *lang_new_vers_pattern
 627   (struct bfd_elf_version_expr *, const char *, const char *, bfd_boolean);
 628 extern struct bfd_elf_version_tree *lang_new_vers_node
 629   (struct bfd_elf_version_expr *, struct bfd_elf_version_expr *);
 630 extern struct bfd_elf_version_deps *lang_add_vers_depend
 631   (struct bfd_elf_version_deps *, const char *);
 632 extern void lang_register_vers_node
 633   (const char *, struct bfd_elf_version_tree *, struct bfd_elf_version_deps *);
 634 extern void lang_append_dynamic_list (struct bfd_elf_version_expr *);
 635 extern void lang_append_dynamic_list_cpp_typeinfo (void);
 636 extern void lang_append_dynamic_list_cpp_new (void);
 637 extern void lang_add_unique
 638   (const char *);
 639 extern const char *lang_get_output_target
 640   (void);
 641 extern void lang_track_definedness (const char *);
 642 extern int lang_symbol_definition_iteration (const char *);
 643 extern void lang_update_definedness
 644   (const char *, struct bfd_link_hash_entry *);
 645
 646 extern void add_excluded_libs (const char *);
 647 extern bfd_boolean load_symbols
 648   (lang_input_statement_type *, lang_statement_list_type *);
 649
 650 extern bfd_boolean
 651 ldlang_override_segment_assignment
 652   (struct bfd_link_info *, bfd *, asection *, asection *, bfd_boolean);
 653
 654 #endif