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 /* For input sections, when writing a map file: head / tail of a linked
 317    list of hash table entries for symbols defined in this section.  */
 318 typedef struct input_section_userdata_struct
 319 {
 320   struct map_symbol_def *map_symbol_def_head;
 321   struct map_symbol_def **map_symbol_def_tail;
 322   unsigned long map_symbol_def_count;
 323 } input_section_userdata_type;
 324
 325 #define get_userdata(x) ((x)->userdata)
 326
 327
 328 typedef struct lang_wild_statement_struct lang_wild_statement_type;
 329
 330 typedef void (*callback_t) (lang_wild_statement_type *, struct wildcard_list *,
 331                             asection *, struct flag_info *,
 332                             lang_input_statement_type *, void *);
 333
 334 typedef void (*walk_wild_section_handler_t) (lang_wild_statement_type *,
 335                                              lang_input_statement_type *,
 336                                              callback_t callback,
 337                                              void *data);
 338
 339 typedef bfd_boolean (*lang_match_sec_type_func) (bfd *, const asection *,
 340                                                  bfd *, const asection *);
 341
 342 /* Binary search tree structure to efficiently sort sections by
 343    name.  */
 344 typedef struct lang_section_bst
 345 {
 346   asection *section;
 347   struct lang_section_bst *left;
 348   struct lang_section_bst *right;
 349 } lang_section_bst_type;
 350
 351 struct lang_wild_statement_struct
 352 {
 353   lang_statement_header_type header;
 354   const char *filename;
 355   bfd_boolean filenames_sorted;
 356   struct wildcard_list *section_list;
 357   bfd_boolean keep_sections;
 358   lang_statement_list_type children;
 359
 360   walk_wild_section_handler_t walk_wild_section_handler;
 361   struct wildcard_list *handler_data[4];
 362   lang_section_bst_type *tree;
 363   struct flag_info *section_flag_list;
 364 };
 365
 366 typedef struct lang_address_statement_struct
 367 {
 368   lang_statement_header_type header;
 369   const char *section_name;
 370   union etree_union *address;
 371   const segment_type *segment;
 372 } lang_address_statement_type;
 373
 374 typedef struct
 375 {
 376   lang_statement_header_type header;
 377   bfd_vma output_offset;
 378   bfd_size_type size;
 379   asection *output_section;
 380   fill_type *fill;
 381 } lang_padding_statement_type;
 382
 383 /* A group statement collects a set of libraries together.  The
 384    libraries are searched multiple times, until no new undefined
 385    symbols are found.  The effect is to search a group of libraries as
 386    though they were a single library.  */
 387
 388 typedef struct
 389 {
 390   lang_statement_header_type header;
 391   lang_statement_list_type children;
 392 } lang_group_statement_type;
 393
 394 typedef struct
 395 {
 396   lang_statement_header_type header;
 397   const char *where;
 398   bfd_boolean is_before;
 399 } lang_insert_statement_type;
 400
 401 typedef union lang_statement_union
 402 {
 403   lang_statement_header_type header;
 404   lang_wild_statement_type wild_statement;
 405   lang_data_statement_type data_statement;
 406   lang_reloc_statement_type reloc_statement;
 407   lang_address_statement_type address_statement;
 408   lang_output_section_statement_type output_section_statement;
 409   lang_assignment_statement_type assignment_statement;
 410   lang_input_statement_type input_statement;
 411   lang_target_statement_type target_statement;
 412   lang_output_statement_type output_statement;
 413   lang_input_section_type input_section;
 414   lang_common_statement_type common_statement;
 415   lang_object_symbols_statement_type object_symbols_statement;
 416   lang_fill_statement_type fill_statement;
 417   lang_padding_statement_type padding_statement;
 418   lang_group_statement_type group_statement;
 419   lang_insert_statement_type insert_statement;
 420 } lang_statement_union_type;
 421
 422 /* This structure holds information about a program header, from the
 423    PHDRS command in the linker script.  */
 424
 425 struct lang_phdr
 426 {
 427   struct lang_phdr *next;
 428   const char *name;
 429   unsigned long type;
 430   bfd_boolean filehdr;
 431   bfd_boolean phdrs;
 432   etree_type *at;
 433   etree_type *flags;
 434 };
 435
 436 /* This structure is used to hold a list of sections which may not
 437    cross reference each other.  */
 438
 439 typedef struct lang_nocrossref
 440 {
 441   struct lang_nocrossref *next;
 442   const char *name;
 443 } lang_nocrossref_type;
 444
 445 /* The list of nocrossref lists.  */
 446
 447 struct lang_nocrossrefs
 448 {
 449   struct lang_nocrossrefs *next;
 450   lang_nocrossref_type *list;
 451 };
 452
 453 /* This structure is used to hold a list of input section names which
 454    will not match an output section in the linker script.  */
 455
 456 struct unique_sections
 457 {
 458   struct unique_sections *next;
 459   const char *name;
 460 };
 461
 462 /* This structure records symbols for which we need to keep track of
 463    definedness for use in the DEFINED () test.  */
 464
 465 struct lang_definedness_hash_entry
 466 {
 467   struct bfd_hash_entry root;
 468   unsigned int by_object : 1;
 469   unsigned int by_script : 1;
 470   unsigned int iteration : 1;
 471 };
 472
 473 /* Used by place_orphan to keep track of orphan sections and statements.  */
 474
 475 struct orphan_save
 476 {
 477   const char *name;
 478   flagword flags;
 479   lang_output_section_statement_type *os;
 480   asection **section;
 481   lang_statement_union_type **stmt;
 482   lang_output_section_statement_type **os_tail;
 483 };
 484
 485 extern struct lang_phdr *lang_phdr_list;
 486 extern struct lang_nocrossrefs *nocrossref_list;
 487 extern const char *output_target;
 488 extern lang_output_section_statement_type *abs_output_section;
 489 extern lang_statement_list_type lang_output_section_statement;
 490 extern struct lang_input_statement_flags input_flags;
 491 extern bfd_boolean lang_has_input_file;
 492 extern etree_type *base;
 493 extern lang_statement_list_type *stat_ptr;
 494 extern bfd_boolean delete_output_file_on_failure;
 495
 496 extern struct bfd_sym_chain entry_symbol;
 497 extern const char *entry_section;
 498 extern bfd_boolean entry_from_cmdline;
 499 extern lang_statement_list_type file_chain;
 500 extern lang_statement_list_type input_file_chain;
 501
 502 extern int lang_statement_iteration;
 503
 504 extern void lang_init
 505   (void);
 506 extern void lang_finish
 507   (void);
 508 extern lang_memory_region_type * lang_memory_region_lookup
 509   (const char * const, bfd_boolean);
 510 extern void lang_memory_region_alias
 511   (const char *, const char *);
 512 extern void lang_map
 513   (void);
 514 extern void lang_set_flags
 515   (lang_memory_region_type *, const char *, int);
 516 extern void lang_add_output
 517   (const char *, int from_script);
 518 extern lang_output_section_statement_type *lang_enter_output_section_statement
 519   (const char *, etree_type *, enum section_type, etree_type *, etree_type *,
 520    etree_type *, int, int);
 521 extern void lang_final
 522   (void);
 523 extern void lang_relax_sections
 524   (bfd_boolean);
 525 extern void lang_process
 526   (void);
 527 extern void lang_section_start
 528   (const char *, union etree_union *, const segment_type *);
 529 extern void lang_add_entry
 530   (const char *, bfd_boolean);
 531 extern void lang_default_entry
 532   (const char *);
 533 extern void lang_add_target
 534   (const char *);
 535 extern void lang_add_wild
 536   (struct wildcard_spec *, struct wildcard_list *, bfd_boolean);
 537 extern void lang_add_map
 538   (const char *);
 539 extern void lang_add_fill
 540   (fill_type *);
 541 extern lang_assignment_statement_type *lang_add_assignment
 542   (union etree_union *);
 543 extern void lang_add_attribute
 544   (enum statement_enum);
 545 extern void lang_startup
 546   (const char *);
 547 extern void lang_float
 548   (bfd_boolean);
 549 extern void lang_leave_output_section_statement
 550   (fill_type *, const char *, lang_output_section_phdr_list *,
 551    const char *);
 552 extern void lang_statement_append
 553   (lang_statement_list_type *, lang_statement_union_type *,
 554    lang_statement_union_type **);
 555 extern void lang_for_each_input_file
 556   (void (*dothis) (lang_input_statement_type *));
 557 extern void lang_for_each_file
 558   (void (*dothis) (lang_input_statement_type *));
 559 extern void lang_reset_memory_regions
 560   (void);
 561 extern void lang_do_assignments
 562   (lang_phase_type);
 563 extern asection *section_for_dot
 564   (void);
 565
 566 #define LANG_FOR_EACH_INPUT_STATEMENT(statement)                        \
 567   lang_input_statement_type *statement;                                 \
 568   for (statement = (lang_input_statement_type *) file_chain.head;       \
 569        statement != (lang_input_statement_type *) NULL;                 \
 570        statement = (lang_input_statement_type *) statement->next)       \
 571
 572 #define lang_output_section_find(NAME) \
 573   lang_output_section_statement_lookup (NAME, 0, FALSE)
 574
 575 extern void lang_process
 576   (void);
 577 extern void ldlang_add_file
 578   (lang_input_statement_type *);
 579 extern lang_output_section_statement_type *lang_output_section_find_by_flags
 580   (const asection *, lang_output_section_statement_type **,
 581    lang_match_sec_type_func);
 582 extern lang_output_section_statement_type *lang_insert_orphan
 583   (asection *, const char *, int, lang_output_section_statement_type *,
 584    struct orphan_save *, etree_type *, lang_statement_list_type *);
 585 extern lang_input_statement_type *lang_add_input_file
 586   (const char *, lang_input_file_enum_type, const char *);
 587 extern void lang_add_keepsyms_file
 588   (const char *);
 589 extern lang_output_section_statement_type *lang_output_section_get
 590   (const asection *);
 591 extern lang_output_section_statement_type *lang_output_section_statement_lookup
 592   (const char *, int, bfd_boolean);
 593 extern lang_output_section_statement_type *next_matching_output_section_statement
 594   (lang_output_section_statement_type *, int);
 595 extern void ldlang_add_undef
 596   (const char *const, bfd_boolean);
 597 extern void lang_add_output_format
 598   (const char *, const char *, const char *, int);
 599 extern void lang_list_init
 600   (lang_statement_list_type *);
 601 extern void push_stat_ptr
 602   (lang_statement_list_type *);
 603 extern void pop_stat_ptr
 604   (void);
 605 extern void lang_add_data
 606   (int type, union etree_union *);
 607 extern void lang_add_reloc
 608   (bfd_reloc_code_real_type, reloc_howto_type *, asection *, const char *,
 609    union etree_union *);
 610 extern void lang_for_each_statement
 611   (void (*) (lang_statement_union_type *));
 612 extern void lang_for_each_statement_worker
 613   (void (*) (lang_statement_union_type *), lang_statement_union_type *);
 614 extern void *stat_alloc
 615   (size_t);
 616 extern void strip_excluded_output_sections
 617   (void);
 618 extern void dprint_statement
 619   (lang_statement_union_type *, int);
 620 extern void lang_size_sections
 621   (bfd_boolean *, bfd_boolean);
 622 extern void one_lang_size_sections_pass
 623   (bfd_boolean *, bfd_boolean);
 624 extern void lang_add_insert
 625   (const char *, int);
 626 extern void lang_enter_group
 627   (void);
 628 extern void lang_leave_group
 629   (void);
 630 extern void lang_add_section
 631   (lang_statement_list_type *, asection *,
 632    struct flag_info *, lang_output_section_statement_type *);
 633 extern void lang_new_phdr
 634   (const char *, etree_type *, bfd_boolean, bfd_boolean, etree_type *,
 635    etree_type *);
 636 extern void lang_add_nocrossref
 637   (lang_nocrossref_type *);
 638 extern void lang_enter_overlay
 639   (etree_type *, etree_type *);
 640 extern void lang_enter_overlay_section
 641   (const char *);
 642 extern void lang_leave_overlay_section
 643   (fill_type *, lang_output_section_phdr_list *);
 644 extern void lang_leave_overlay
 645   (etree_type *, int, fill_type *, const char *,
 646    lang_output_section_phdr_list *, const char *);
 647
 648 extern struct bfd_elf_version_expr *lang_new_vers_pattern
 649   (struct bfd_elf_version_expr *, const char *, const char *, bfd_boolean);
 650 extern struct bfd_elf_version_tree *lang_new_vers_node
 651   (struct bfd_elf_version_expr *, struct bfd_elf_version_expr *);
 652 extern struct bfd_elf_version_deps *lang_add_vers_depend
 653   (struct bfd_elf_version_deps *, const char *);
 654 extern void lang_register_vers_node
 655   (const char *, struct bfd_elf_version_tree *, struct bfd_elf_version_deps *);
 656 extern void lang_append_dynamic_list (struct bfd_elf_version_expr *);
 657 extern void lang_append_dynamic_list_cpp_typeinfo (void);
 658 extern void lang_append_dynamic_list_cpp_new (void);
 659 extern void lang_add_unique
 660   (const char *);
 661 extern const char *lang_get_output_target
 662   (void);
 663 extern struct lang_definedness_hash_entry *lang_symbol_defined (const char *);
 664 extern void lang_update_definedness
 665   (const char *, struct bfd_link_hash_entry *);
 666
 667 extern void add_excluded_libs (const char *);
 668 extern bfd_boolean load_symbols
 669   (lang_input_statement_type *, lang_statement_list_type *);
 670
 671 extern bfd_boolean
 672 ldlang_override_segment_assignment
 673   (struct bfd_link_info *, bfd *, asection *, asection *, bfd_boolean);
 674
 675 extern void
 676 lang_ld_feature (char *);
 677
 678 #endif