ld/ldlang.h

   1 /* ldlang.h - linker command language support
   2    Copyright 1991-2013 Free Software Foundation, Inc.
   3
   4    This file is part of the GNU Binutils.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  19    MA 02110-1301, USA.  */
  20
  21 #ifndef LDLANG_H
  22 #define LDLANG_H
  23
  24 #define DEFAULT_MEMORY_REGION   "*default*"
  25
  26 typedef enum
  27 {
  28   lang_input_file_is_l_enum,
  29   lang_input_file_is_symbols_only_enum,
  30   lang_input_file_is_marker_enum,
  31   lang_input_file_is_fake_enum,
  32   lang_input_file_is_search_file_enum,
  33   lang_input_file_is_file_enum
  34 } lang_input_file_enum_type;
  35
  36 struct _fill_type
  37 {
  38   size_t size;
  39   unsigned char data[1];
  40 };
  41
  42 typedef struct statement_list
  43 {
  44   union lang_statement_union *  head;
  45   union lang_statement_union ** tail;
  46 } lang_statement_list_type;
  47
  48 typedef struct memory_region_name_struct
  49 {
  50   const char * name;
  51   struct memory_region_name_struct * next;
  52 } lang_memory_region_name;
  53
  54 typedef struct memory_region_struct
  55 {
  56   lang_memory_region_name name_list;
  57   struct memory_region_struct *next;
  58   bfd_vma origin;
  59   bfd_size_type length;
  60   bfd_vma current;
  61   union lang_statement_union *last_os;
  62   flagword flags;
  63   flagword not_flags;
  64   bfd_boolean had_full_message;
  65 } lang_memory_region_type;
  66
  67 enum statement_enum
  68 {
  69   lang_output_section_statement_enum,
  70   lang_assignment_statement_enum,
  71   lang_input_statement_enum,
  72   lang_address_statement_enum,
  73   lang_wild_statement_enum,
  74   lang_input_section_enum,
  75   lang_object_symbols_statement_enum,
  76   lang_fill_statement_enum,
  77   lang_data_statement_enum,
  78   lang_reloc_statement_enum,
  79   lang_target_statement_enum,
  80   lang_output_statement_enum,
  81   lang_padding_statement_enum,
  82   lang_group_statement_enum,
  83   lang_insert_statement_enum,
  84   lang_constructors_statement_enum
  85 };
  86
  87 typedef struct lang_statement_header_struct
  88 {
  89   union lang_statement_union *next;
  90   enum statement_enum type;
  91 } lang_statement_header_type;
  92
  93 typedef struct
  94 {
  95   lang_statement_header_type header;
  96   union etree_union *exp;
  97 } lang_assignment_statement_type;
  98
  99 typedef struct lang_target_statement_struct
 100 {
 101   lang_statement_header_type header;
 102   const char *target;
 103 } lang_target_statement_type;
 104
 105 typedef struct lang_output_statement_struct
 106 {
 107   lang_statement_header_type header;
 108   const char *name;
 109 } lang_output_statement_type;
 110
 111 /* Section types specified in a linker script.  */
 112
 113 enum section_type
 114 {
 115   normal_section,
 116   overlay_section,
 117   noload_section,
 118   noalloc_section
 119 };
 120
 121 /* This structure holds a list of program headers describing
 122    segments in which this section should be placed.  */
 123
 124 typedef struct lang_output_section_phdr_list
 125 {
 126   struct lang_output_section_phdr_list *next;
 127   const char *name;
 128   bfd_boolean used;
 129 } lang_output_section_phdr_list;
 130
 131 typedef struct lang_output_section_statement_struct
 132 {
 133   lang_statement_header_type header;
 134   lang_statement_list_type children;
 135   struct lang_output_section_statement_struct *next;
 136   struct lang_output_section_statement_struct *prev;
 137   const char *name;
 138   asection *bfd_section;
 139   lang_memory_region_type *region;
 140   lang_memory_region_type *lma_region;
 141   fill_type *fill;
 142   union etree_union *addr_tree;
 143   union etree_union *load_base;
 144
 145   /* If non-null, an expression to evaluate after setting the section's
 146      size.  The expression is evaluated inside REGION (above) with '.'
 147      set to the end of the section.  Used in the last overlay section
 148      to move '.' past all the overlaid sections.  */
 149   union etree_union *update_dot_tree;
 150
 151   lang_output_section_phdr_list *phdrs;
 152
 153   unsigned int block_value;
 154   int subsection_alignment;     /* Alignment of components.  */
 155   int section_alignment;        /* Alignment of start of section.  */
 156   int constraint;
 157   flagword flags;
 158   enum section_type sectype;
 159   unsigned int processed_vma : 1;
 160   unsigned int processed_lma : 1;
 161   unsigned int all_input_readonly : 1;
 162   /* If this section should be ignored.  */
 163   unsigned int ignored : 1;
 164   /* If this section should update "dot".  Prevents section being ignored.  */
 165   unsigned int update_dot : 1;
 166   /* If this section is after assignment to _end.  */
 167   unsigned int after_end : 1;
 168   /* If this section uses the alignment of its input sections.  */
 169   unsigned int align_lma_with_input : 1;
 170 } lang_output_section_statement_type;
 171
 172 typedef struct
 173 {
 174   lang_statement_header_type header;
 175 } lang_common_statement_type;
 176
 177 typedef struct
 178 {
 179   lang_statement_header_type header;
 180 } lang_object_symbols_statement_type;
 181
 182 typedef struct
 183 {
 184   lang_statement_header_type header;
 185   fill_type *fill;
 186   int size;
 187   asection *output_section;
 188 } lang_fill_statement_type;
 189
 190 typedef struct
 191 {
 192   lang_statement_header_type header;
 193   unsigned int type;
 194   union etree_union *exp;
 195   bfd_vma value;
 196   asection *output_section;
 197   bfd_vma output_offset;
 198 } lang_data_statement_type;
 199
 200 /* Generate a reloc in the output file.  */
 201
 202 typedef struct
 203 {
 204   lang_statement_header_type header;
 205
 206   /* Reloc to generate.  */
 207   bfd_reloc_code_real_type reloc;
 208
 209   /* Reloc howto structure.  */
 210   reloc_howto_type *howto;
 211
 212   /* Section to generate reloc against.
 213      Exactly one of section and name must be NULL.  */
 214   asection *section;
 215
 216   /* Name of symbol to generate reloc against.
 217      Exactly one of section and name must be NULL.  */
 218   const char *name;
 219
 220   /* Expression for addend.  */
 221   union etree_union *addend_exp;
 222
 223   /* Resolved addend.  */
 224   bfd_vma addend_value;
 225
 226   /* Output section where reloc should be performed.  */
 227   asection *output_section;
 228
 229   /* Offset within output section.  */
 230   bfd_vma output_offset;
 231 } lang_reloc_statement_type;
 232
 233 struct lang_input_statement_flags
 234 {
 235   /* 1 means this file was specified in a -l option.  */
 236   unsigned int maybe_archive : 1;
 237
 238   /* 1 means search a set of directories for this file.  */
 239   unsigned int search_dirs : 1;
 240
 241   /* 1 means this was found when processing a script in the sysroot.  */
 242   unsigned int sysrooted : 1;
 243
 244   /* 1 means this is base file of incremental load.
 245      Do not load this file's text or data.
 246      Also default text_start to after this file's bss.  */
 247   unsigned int just_syms : 1;
 248
 249   /* Whether to search for this entry as a dynamic archive.  */
 250   unsigned int dynamic : 1;
 251
 252   /* Set if a DT_NEEDED tag should be added not just for the dynamic library
 253      explicitly given by this entry but also for any dynamic libraries in
 254      this entry's needed list.  */
 255   unsigned int add_DT_NEEDED_for_dynamic : 1;
 256
 257   /* Set if this entry should cause a DT_NEEDED tag only when some
 258      regular file references its symbols (ie. --as-needed is in effect).  */
 259   unsigned int add_DT_NEEDED_for_regular : 1;
 260
 261   /* Whether to include the entire contents of an archive.  */
 262   unsigned int whole_archive : 1;
 263
 264   /* Set when bfd opening is successful.  */
 265   unsigned int loaded : 1;
 266
 267   unsigned int real : 1;
 268
 269   /* Set if the file does not exist.  */
 270   unsigned int missing_file : 1;
 271
 272 #ifdef ENABLE_PLUGINS
 273   /* Set if the file was claimed by a plugin.  */
 274   unsigned int claimed : 1;
 275
 276   /* Set if the file was claimed from an archive.  */
 277   unsigned int claim_archive : 1;
 278
 279   /* Set if reloading an --as-needed lib.  */
 280   unsigned int reload : 1;
 281 #endif /* ENABLE_PLUGINS */
 282 };
 283
 284 typedef struct lang_input_statement_struct
 285 {
 286   lang_statement_header_type header;
 287   /* Name of this file.  */
 288   const char *filename;
 289   /* Name to use for the symbol giving address of text start.
 290      Usually the same as filename, but for a file spec'd with
 291      -l this is the -l switch itself rather than the filename.  */
 292   const char *local_sym_name;
 293
 294   bfd *the_bfd;
 295
 296   struct flag_info *section_flag_list;
 297
 298   /* Point to the next file - whatever it is, wanders up and down
 299      archives */
 300   union lang_statement_union *next;
 301
 302   /* Point to the next file, but skips archive contents.  */
 303   union lang_statement_union *next_real_file;
 304
 305   const char *target;
 306
 307   struct lang_input_statement_flags flags;
 308 } lang_input_statement_type;
 309
 310 typedef struct
 311 {
 312   lang_statement_header_type header;
 313   asection *section;
 314 } lang_input_section_type;
 315
 316 typedef struct lang_wild_statement_struct lang_wild_statement_type;
 317
 318 typedef void (*callback_t) (lang_wild_statement_type *, struct wildcard_list *,
 319                             asection *, struct flag_info *,
 320                             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 *, etree_type *, enum section_type, etree_type *, etree_type *,
 506    etree_type *, int, int);
 507 extern void lang_final
 508   (void);
 509 extern void lang_relax_sections
 510   (bfd_boolean);
 511 extern void lang_process
 512   (void);
 513 extern void lang_section_start
 514   (const char *, union etree_union *, const segment_type *);
 515 extern void lang_add_entry
 516   (const char *, bfd_boolean);
 517 extern void lang_default_entry
 518   (const char *);
 519 extern void lang_add_target
 520   (const char *);
 521 extern void lang_add_wild
 522   (struct wildcard_spec *, struct wildcard_list *, bfd_boolean);
 523 extern void lang_add_map
 524   (const char *);
 525 extern void lang_add_fill
 526   (fill_type *);
 527 extern lang_assignment_statement_type *lang_add_assignment
 528   (union etree_union *);
 529 extern void lang_add_attribute
 530   (enum statement_enum);
 531 extern void lang_startup
 532   (const char *);
 533 extern void lang_float
 534   (bfd_boolean);
 535 extern void lang_leave_output_section_statement
 536   (fill_type *, const char *, lang_output_section_phdr_list *,
 537    const char *);
 538 extern void lang_statement_append
 539   (lang_statement_list_type *, lang_statement_union_type *,
 540    lang_statement_union_type **);
 541 extern void lang_for_each_input_file
 542   (void (*dothis) (lang_input_statement_type *));
 543 extern void lang_for_each_file
 544   (void (*dothis) (lang_input_statement_type *));
 545 extern void lang_reset_memory_regions
 546   (void);
 547 extern void lang_do_assignments
 548   (lang_phase_type);
 549 extern asection *section_for_dot
 550   (void);
 551
 552 #define LANG_FOR_EACH_INPUT_STATEMENT(statement)                        \
 553   lang_input_statement_type *statement;                                 \
 554   for (statement = (lang_input_statement_type *) file_chain.head;       \
 555        statement != (lang_input_statement_type *) NULL;                 \
 556        statement = (lang_input_statement_type *) statement->next)       \
 557
 558 #define lang_output_section_find(NAME) \
 559   lang_output_section_statement_lookup (NAME, 0, FALSE)
 560
 561 extern void lang_process
 562   (void);
 563 extern void ldlang_add_file
 564   (lang_input_statement_type *);
 565 extern lang_output_section_statement_type *lang_output_section_find_by_flags
 566   (const asection *, lang_output_section_statement_type **,
 567    lang_match_sec_type_func);
 568 extern lang_output_section_statement_type *lang_insert_orphan
 569   (asection *, const char *, int, lang_output_section_statement_type *,
 570    struct orphan_save *, etree_type *, lang_statement_list_type *);
 571 extern lang_input_statement_type *lang_add_input_file
 572   (const char *, lang_input_file_enum_type, const char *);
 573 extern void lang_add_keepsyms_file
 574   (const char *);
 575 extern lang_output_section_statement_type *lang_output_section_statement_lookup
 576   (const char *, int, bfd_boolean);
 577 extern lang_output_section_statement_type *next_matching_output_section_statement
 578   (lang_output_section_statement_type *, int);
 579 extern void ldlang_add_undef
 580   (const char *const, bfd_boolean);
 581 extern void lang_add_output_format
 582   (const char *, const char *, const char *, int);
 583 extern void lang_list_init
 584   (lang_statement_list_type *);
 585 extern void push_stat_ptr
 586   (lang_statement_list_type *);
 587 extern void pop_stat_ptr
 588   (void);
 589 extern void lang_add_data
 590   (int type, union etree_union *);
 591 extern void lang_add_reloc
 592   (bfd_reloc_code_real_type, reloc_howto_type *, asection *, const char *,
 593    union etree_union *);
 594 extern void lang_for_each_statement
 595   (void (*) (lang_statement_union_type *));
 596 extern void lang_for_each_statement_worker
 597   (void (*) (lang_statement_union_type *), lang_statement_union_type *);
 598 extern void *stat_alloc
 599   (size_t);
 600 extern void strip_excluded_output_sections
 601   (void);
 602 extern void dprint_statement
 603   (lang_statement_union_type *, int);
 604 extern void lang_size_sections
 605   (bfd_boolean *, bfd_boolean);
 606 extern void one_lang_size_sections_pass
 607   (bfd_boolean *, bfd_boolean);
 608 extern void lang_add_insert
 609   (const char *, int);
 610 extern void lang_enter_group
 611   (void);
 612 extern void lang_leave_group
 613   (void);
 614 extern void lang_add_section
 615   (lang_statement_list_type *, asection *,
 616    struct flag_info *, lang_output_section_statement_type *);
 617 extern void lang_new_phdr
 618   (const char *, etree_type *, bfd_boolean, bfd_boolean, etree_type *,
 619    etree_type *);
 620 extern void lang_add_nocrossref
 621   (lang_nocrossref_type *);
 622 extern void lang_enter_overlay
 623   (etree_type *, etree_type *);
 624 extern void lang_enter_overlay_section
 625   (const char *);
 626 extern void lang_leave_overlay_section
 627   (fill_type *, lang_output_section_phdr_list *);
 628 extern void lang_leave_overlay
 629   (etree_type *, int, fill_type *, const char *,
 630    lang_output_section_phdr_list *, const char *);
 631
 632 extern struct bfd_elf_version_expr *lang_new_vers_pattern
 633   (struct bfd_elf_version_expr *, const char *, const char *, bfd_boolean);
 634 extern struct bfd_elf_version_tree *lang_new_vers_node
 635   (struct bfd_elf_version_expr *, struct bfd_elf_version_expr *);
 636 extern struct bfd_elf_version_deps *lang_add_vers_depend
 637   (struct bfd_elf_version_deps *, const char *);
 638 extern void lang_register_vers_node
 639   (const char *, struct bfd_elf_version_tree *, struct bfd_elf_version_deps *);
 640 extern void lang_append_dynamic_list (struct bfd_elf_version_expr *);
 641 extern void lang_append_dynamic_list_cpp_typeinfo (void);
 642 extern void lang_append_dynamic_list_cpp_new (void);
 643 extern void lang_add_unique
 644   (const char *);
 645 extern const char *lang_get_output_target
 646   (void);
 647 extern void lang_track_definedness (const char *);
 648 extern int lang_symbol_definition_iteration (const char *);
 649 extern void lang_update_definedness
 650   (const char *, struct bfd_link_hash_entry *);
 651
 652 extern void add_excluded_libs (const char *);
 653 extern bfd_boolean load_symbols
 654   (lang_input_statement_type *, lang_statement_list_type *);
 655
 656 extern bfd_boolean
 657 ldlang_override_segment_assignment
 658   (struct bfd_link_info *, bfd *, asection *, asection *, bfd_boolean);
 659
 660 extern void
 661 lang_ld_feature (char *);
 662
 663 #endif