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