1 /* bfdlink.h -- header file for BFD link routines
2 Copyright (C) 1993-2016 Free Software Foundation, Inc.
3 Written by Steve Chamberlain and Ian Lance Taylor, Cygnus Support.
5 This file is part of BFD, the Binary File Descriptor library.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
20 MA 02110-1301, USA. */
25 /* Which symbols to strip during a link. */
28 strip_none, /* Don't strip any symbols. */
29 strip_debugger, /* Strip debugging symbols. */
30 strip_some, /* keep_hash is the list of symbols to keep. */
31 strip_all /* Strip all symbols. */
34 /* Which local symbols to discard during a link. This is irrelevant
35 if strip_all is used. */
38 discard_sec_merge, /* Discard local temporary symbols in SEC_MERGE
40 discard_none, /* Don't discard any locals. */
41 discard_l, /* Discard local temporary symbols. */
42 discard_all /* Discard all locals. */
45 /* Whether to generate ELF common symbols with the STT_COMMON type
46 during a relocatable link. */
47 enum bfd_link_elf_stt_common
54 /* Describes the type of hash table entry structure being used.
55 Different hash table structure have different fields and so
56 support different linking features. */
57 enum bfd_link_hash_table_type
59 bfd_link_generic_hash_table,
60 bfd_link_elf_hash_table
63 /* These are the possible types of an entry in the BFD link hash
66 enum bfd_link_hash_type
68 bfd_link_hash_new, /* Symbol is new. */
69 bfd_link_hash_undefined, /* Symbol seen before, but undefined. */
70 bfd_link_hash_undefweak, /* Symbol is weak and undefined. */
71 bfd_link_hash_defined, /* Symbol is defined. */
72 bfd_link_hash_defweak, /* Symbol is weak and defined. */
73 bfd_link_hash_common, /* Symbol is common. */
74 bfd_link_hash_indirect, /* Symbol is an indirect link. */
75 bfd_link_hash_warning /* Like indirect, but warn if referenced. */
78 enum bfd_link_common_skip_ar_symbols
80 bfd_link_common_skip_none,
81 bfd_link_common_skip_text,
82 bfd_link_common_skip_data,
83 bfd_link_common_skip_all
86 struct bfd_link_hash_common_entry
88 unsigned int alignment_power; /* Alignment. */
89 asection *section; /* Symbol section. */
92 /* The linking routines use a hash table which uses this structure for
95 struct bfd_link_hash_entry
97 /* Base hash table entry structure. */
98 struct bfd_hash_entry root;
100 /* Type of this entry. */
101 ENUM_BITFIELD (bfd_link_hash_type) type : 8;
103 /* Symbol is referenced in a normal object file, as distict from a LTO
105 unsigned int non_ir_ref : 1;
107 /* Symbol is a built-in define. These will be overridden by PROVIDE
108 in a linker script. */
109 unsigned int linker_def : 1;
111 /* A union of information depending upon the type. */
114 /* Nothing is kept for bfd_hash_new. */
115 /* bfd_link_hash_undefined, bfd_link_hash_undefweak. */
118 /* Undefined and common symbols are kept in a linked list through
119 this field. This field is present in all of the union element
120 so that we don't need to remove entries from the list when we
121 change their type. Removing entries would either require the
122 list to be doubly linked, which would waste more memory, or
123 require a traversal. When an undefined or common symbol is
124 created, it should be added to this list, the head of which is in
125 the link hash table itself. As symbols are defined, they need
126 not be removed from the list; anything which reads the list must
127 doublecheck the symbol type.
129 Weak symbols are not kept on this list.
131 Defined and defweak symbols use this field as a reference marker.
132 If the field is not NULL, or this structure is the tail of the
133 undefined symbol list, the symbol has been referenced. If the
134 symbol is undefined and becomes defined, this field will
135 automatically be non-NULL since the symbol will have been on the
136 undefined symbol list. */
137 struct bfd_link_hash_entry *next;
138 bfd *abfd; /* BFD symbol was found in. */
140 /* bfd_link_hash_defined, bfd_link_hash_defweak. */
143 struct bfd_link_hash_entry *next;
144 asection *section; /* Symbol section. */
145 bfd_vma value; /* Symbol value. */
147 /* bfd_link_hash_indirect, bfd_link_hash_warning. */
150 struct bfd_link_hash_entry *next;
151 struct bfd_link_hash_entry *link; /* Real symbol. */
152 const char *warning; /* Warning (bfd_link_hash_warning only). */
154 /* bfd_link_hash_common. */
157 struct bfd_link_hash_entry *next;
158 /* The linker needs to know three things about common
159 symbols: the size, the alignment, and the section in
160 which the symbol should be placed. We store the size
161 here, and we allocate a small structure to hold the
162 section and the alignment. The alignment is stored as a
163 power of two. We don't store all the information
164 directly because we don't want to increase the size of
165 the union; this structure is a major space user in the
167 struct bfd_link_hash_common_entry *p;
168 bfd_size_type size; /* Common symbol size. */
173 /* This is the link hash table. It is a derived class of
176 struct bfd_link_hash_table
178 /* The hash table itself. */
179 struct bfd_hash_table table;
180 /* A linked list of undefined and common symbols, linked through the
181 next field in the bfd_link_hash_entry structure. */
182 struct bfd_link_hash_entry *undefs;
183 /* Entries are added to the tail of the undefs list. */
184 struct bfd_link_hash_entry *undefs_tail;
185 /* Function to free the hash table on closing BFD. */
186 void (*hash_table_free) (bfd *);
187 /* The type of the link hash table. */
188 enum bfd_link_hash_table_type type;
191 /* Look up an entry in a link hash table. If FOLLOW is TRUE, this
192 follows bfd_link_hash_indirect and bfd_link_hash_warning links to
194 extern struct bfd_link_hash_entry *bfd_link_hash_lookup
195 (struct bfd_link_hash_table *, const char *, bfd_boolean create,
196 bfd_boolean copy, bfd_boolean follow);
198 /* Look up an entry in the main linker hash table if the symbol might
199 be wrapped. This should only be used for references to an
200 undefined symbol, not for definitions of a symbol. */
202 extern struct bfd_link_hash_entry *bfd_wrapped_link_hash_lookup
203 (bfd *, struct bfd_link_info *, const char *, bfd_boolean,
204 bfd_boolean, bfd_boolean);
206 /* If H is a wrapped symbol, ie. the symbol name starts with "__wrap_"
207 and the remainder is found in wrap_hash, return the real symbol. */
209 extern struct bfd_link_hash_entry *unwrap_hash_lookup
210 (struct bfd_link_info *, bfd *, struct bfd_link_hash_entry *);
212 /* Traverse a link hash table. */
213 extern void bfd_link_hash_traverse
214 (struct bfd_link_hash_table *,
215 bfd_boolean (*) (struct bfd_link_hash_entry *, void *),
218 /* Add an entry to the undefs list. */
219 extern void bfd_link_add_undef
220 (struct bfd_link_hash_table *, struct bfd_link_hash_entry *);
222 /* Remove symbols from the undefs list that don't belong there. */
223 extern void bfd_link_repair_undef_list
224 (struct bfd_link_hash_table *table);
226 /* Read symbols and cache symbol pointer array in outsymbols. */
227 extern bfd_boolean bfd_generic_link_read_symbols (bfd *);
229 /* Check the relocs in the BFD. Called after all the input
230 files have been loaded, and garbage collection has tagged
231 any unneeded sections. */
232 extern bfd_boolean bfd_link_check_relocs (bfd *,struct bfd_link_info *);
236 struct bfd_sym_chain *next;
240 /* How to handle unresolved symbols.
241 There are four possibilities which are enumerated below: */
244 /* This is the initial value when then link_info structure is created.
245 It allows the various stages of the linker to determine whether they
246 allowed to set the value. */
253 typedef enum {with_flags, without_flags} flag_type;
255 /* A section flag list. */
256 struct flag_info_list
261 struct flag_info_list *next;
264 /* Section flag info. */
267 flagword only_with_flags;
268 flagword not_with_flags;
269 struct flag_info_list *flag_list;
270 bfd_boolean flags_initialized;
273 struct bfd_elf_dynamic_list;
274 struct bfd_elf_version_tree;
276 /* Types of output. */
286 #define bfd_link_pde(info) ((info)->type == type_pde)
287 #define bfd_link_dll(info) ((info)->type == type_dll)
288 #define bfd_link_relocatable(info) ((info)->type == type_relocatable)
289 #define bfd_link_pie(info) ((info)->type == type_pie)
290 #define bfd_link_executable(info) (bfd_link_pde (info) || bfd_link_pie (info))
291 #define bfd_link_pic(info) (bfd_link_dll (info) || bfd_link_pie (info))
293 /* This structure holds all the information needed to communicate
294 between BFD and the linker when doing a link. */
299 ENUM_BITFIELD (output_type) type : 2;
301 /* TRUE if BFD should pre-bind symbols in a shared object. */
302 unsigned int symbolic: 1;
304 /* TRUE if executable should not contain copy relocs.
305 Setting this true may result in a non-sharable text segment. */
306 unsigned int nocopyreloc: 1;
308 /* TRUE if BFD should export all symbols in the dynamic symbol table
309 of an executable, rather than only those used. */
310 unsigned int export_dynamic: 1;
312 /* TRUE if a default symbol version should be created and used for
314 unsigned int create_default_symver: 1;
316 /* TRUE if unreferenced sections should be removed. */
317 unsigned int gc_sections: 1;
319 /* TRUE if every symbol should be reported back via the notice
321 unsigned int notice_all: 1;
323 /* TRUE if the LTO plugin is active. */
324 unsigned int lto_plugin_active: 1;
326 /* TRUE if global symbols in discarded sections should be stripped. */
327 unsigned int strip_discarded: 1;
329 /* TRUE if all data symbols should be dynamic. */
330 unsigned int dynamic_data: 1;
332 /* Which symbols to strip. */
333 ENUM_BITFIELD (bfd_link_strip) strip : 2;
335 /* Which local symbols to discard. */
336 ENUM_BITFIELD (bfd_link_discard) discard : 2;
338 /* Whether to generate ELF common symbols with the STT_COMMON type. */
339 ENUM_BITFIELD (bfd_link_elf_stt_common) elf_stt_common : 2;
341 /* Criteria for skipping symbols when determining
342 whether to include an object from an archive. */
343 ENUM_BITFIELD (bfd_link_common_skip_ar_symbols) common_skip_ar_symbols : 2;
345 /* What to do with unresolved symbols in an object file.
346 When producing executables the default is GENERATE_ERROR.
347 When producing shared libraries the default is IGNORE. The
348 assumption with shared libraries is that the reference will be
349 resolved at load/execution time. */
350 ENUM_BITFIELD (report_method) unresolved_syms_in_objects : 2;
352 /* What to do with unresolved symbols in a shared library.
353 The same defaults apply. */
354 ENUM_BITFIELD (report_method) unresolved_syms_in_shared_libs : 2;
356 /* TRUE if shared objects should be linked directly, not shared. */
357 unsigned int static_link: 1;
359 /* TRUE if symbols should be retained in memory, FALSE if they
360 should be freed and reread. */
361 unsigned int keep_memory: 1;
363 /* TRUE if BFD should generate relocation information in the final
365 unsigned int emitrelocations: 1;
367 /* TRUE if PT_GNU_RELRO segment should be created. */
368 unsigned int relro: 1;
370 /* Nonzero if .eh_frame_hdr section and PT_GNU_EH_FRAME ELF segment
371 should be created. 1 for DWARF2 tables, 2 for compact tables. */
372 unsigned int eh_frame_hdr_type: 2;
374 /* TRUE if we should warn when adding a DT_TEXTREL to a shared object. */
375 unsigned int warn_shared_textrel: 1;
377 /* TRUE if we should error when adding a DT_TEXTREL. */
378 unsigned int error_textrel: 1;
380 /* TRUE if .hash section should be created. */
381 unsigned int emit_hash: 1;
383 /* TRUE if .gnu.hash section should be created. */
384 unsigned int emit_gnu_hash: 1;
386 /* If TRUE reduce memory overheads, at the expense of speed. This will
387 cause map file generation to use an O(N^2) algorithm and disable
388 caching ELF symbol buffer. */
389 unsigned int reduce_memory_overheads: 1;
391 /* TRUE if the output file should be in a traditional format. This
392 is equivalent to the setting of the BFD_TRADITIONAL_FORMAT flag
393 on the output file, but may be checked when reading the input
395 unsigned int traditional_format: 1;
397 /* TRUE if non-PLT relocs should be merged into one reloc section
398 and sorted so that relocs against the same symbol come together. */
399 unsigned int combreloc: 1;
401 /* TRUE if a default symbol version should be created and used for
403 unsigned int default_imported_symver: 1;
405 /* TRUE if the new ELF dynamic tags are enabled. */
406 unsigned int new_dtags: 1;
408 /* FALSE if .eh_frame unwind info should be generated for PLT and other
409 linker created sections, TRUE if it should be omitted. */
410 unsigned int no_ld_generated_unwind_info: 1;
412 /* TRUE if BFD should generate a "task linked" object file,
413 similar to relocatable but also with globals converted to
415 unsigned int task_link: 1;
417 /* TRUE if ok to have multiple definition. */
418 unsigned int allow_multiple_definition: 1;
420 /* TRUE if ok to have version with no definition. */
421 unsigned int allow_undefined_version: 1;
423 /* TRUE if some symbols have to be dynamic, controlled by
424 --dynamic-list command line options. */
425 unsigned int dynamic: 1;
427 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W|PF_X
429 unsigned int execstack: 1;
431 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W
433 unsigned int noexecstack: 1;
435 /* TRUE if we want to produced optimized output files. This might
436 need much more time and therefore must be explicitly selected. */
437 unsigned int optimize: 1;
439 /* TRUE if user should be informed of removed unreferenced sections. */
440 unsigned int print_gc_sections: 1;
442 /* TRUE if we should warn alternate ELF machine code. */
443 unsigned int warn_alternate_em: 1;
445 /* TRUE if the linker script contained an explicit PHDRS command. */
446 unsigned int user_phdrs: 1;
448 /* TRUE if we should check relocations after all input files have
450 unsigned int check_relocs_after_open_input: 1;
452 /* TRUE if BND prefix in PLT entries is always generated. */
453 unsigned int bndplt: 1;
455 /* TRUE if generation of .interp/PT_INTERP should be suppressed. */
456 unsigned int nointerp: 1;
458 /* TRUE if we shouldn't check relocation overflow. */
459 unsigned int no_reloc_overflow_check: 1;
461 /* TRUE if generate a 1-byte NOP as suffix for x86 call instruction. */
462 unsigned int call_nop_as_suffix : 1;
464 /* The 1-byte NOP for x86 call instruction. */
467 /* Char that may appear as the first char of a symbol, but should be
468 skipped (like symbol_leading_char) when looking up symbols in
469 wrap_hash. Used by PowerPC Linux for 'dot' symbols. */
472 /* Separator between archive and filename in linker script filespecs. */
475 /* Compress DWARF debug sections. */
476 enum compressed_debug_section_type compress_debug;
478 /* Default stack size. Zero means default (often zero itself), -1
479 means explicitly zero-sized. */
480 bfd_signed_vma stacksize;
482 /* Enable or disable target specific optimizations.
484 Not all targets have optimizations to enable.
486 Normally these optimizations are disabled by default but some targets
487 prefer to enable them by default. So this field is a tri-state variable.
490 zero: Enable the optimizations (either from --relax being specified on
491 the command line or the backend's before_allocation emulation function.
493 positive: The user has requested that these optimizations be disabled.
494 (Via the --no-relax command line option).
496 negative: The optimizations are disabled. (Set when initializing the
497 args_type structure in ldmain.c:main. */
498 signed int disable_target_specific_optimizations;
500 /* Function callbacks. */
501 const struct bfd_link_callbacks *callbacks;
503 /* Hash table handled by BFD. */
504 struct bfd_link_hash_table *hash;
506 /* Hash table of symbols to keep. This is NULL unless strip is
508 struct bfd_hash_table *keep_hash;
510 /* Hash table of symbols to report back via the notice callback. If
511 this is NULL, and notice_all is FALSE, then no symbols are
513 struct bfd_hash_table *notice_hash;
515 /* Hash table of symbols which are being wrapped (the --wrap linker
516 option). If this is NULL, no symbols are being wrapped. */
517 struct bfd_hash_table *wrap_hash;
519 /* Hash table of symbols which may be left unresolved during
520 a link. If this is NULL, no symbols can be left unresolved. */
521 struct bfd_hash_table *ignore_hash;
523 /* The output BFD. */
526 /* The list of input BFD's involved in the link. These are chained
527 together via the link.next field. */
529 bfd **input_bfds_tail;
531 /* If a symbol should be created for each input BFD, this is section
532 where those symbols should be placed. It must be a section in
533 the output BFD. It may be NULL, in which case no such symbols
534 will be created. This is to support CREATE_OBJECT_SYMBOLS in the
535 linker command language. */
536 asection *create_object_symbols_section;
538 /* List of global symbol names that are starting points for marking
539 sections against garbage collection. */
540 struct bfd_sym_chain *gc_sym_list;
542 /* If a base output file is wanted, then this points to it */
545 /* The function to call when the executable or shared object is
547 const char *init_function;
549 /* The function to call when the executable or shared object is
551 const char *fini_function;
553 /* Number of relaxation passes. Usually only one relaxation pass
554 is needed. But a backend can have as many relaxation passes as
555 necessary. During bfd_relax_section call, it is set to the
556 current pass, starting from 0. */
559 /* Number of relaxation trips. This number is incremented every
560 time the relaxation pass is restarted due to a previous
561 relaxation returning true in *AGAIN. */
564 /* > 0 to treat protected data defined in the shared library as
565 reference external. 0 to treat it as internal. -1 to let
566 backend to decide. */
567 int extern_protected_data;
569 /* > 0 to treat undefined weak symbol in the executable as dynamic,
570 requiring dynamic relocation. */
571 int dynamic_undefined_weak;
573 /* Non-zero if auto-import thunks for DATA items in pei386 DLLs
574 should be generated/linked against. Set to 1 if this feature
575 is explicitly requested by the user, -1 if enabled by default. */
576 int pei386_auto_import;
578 /* Non-zero if runtime relocs for DATA items with non-zero addends
579 in pei386 DLLs should be generated. Set to 1 if this feature
580 is explicitly requested by the user, -1 if enabled by default. */
581 int pei386_runtime_pseudo_reloc;
583 /* How many spare .dynamic DT_NULL entries should be added? */
584 unsigned int spare_dynamic_tags;
586 /* May be used to set DT_FLAGS for ELF. */
589 /* May be used to set DT_FLAGS_1 for ELF. */
592 /* Start and end of RELRO region. */
593 bfd_vma relro_start, relro_end;
595 /* List of symbols should be dynamic. */
596 struct bfd_elf_dynamic_list *dynamic_list;
598 /* The version information. */
599 struct bfd_elf_version_tree *version_info;
602 /* This structures holds a set of callback functions. These are called
603 by the BFD linker routines. Except for the info functions, the first
604 argument to each callback function is the bfd_link_info structure
605 being used and each function returns a boolean value. If the
606 function returns FALSE, then the BFD function which called it should
607 return with a failure indication. */
609 struct bfd_link_callbacks
611 /* A function which is called when an object is added from an
612 archive. ABFD is the archive element being added. NAME is the
613 name of the symbol which caused the archive element to be pulled
614 in. This function may set *SUBSBFD to point to an alternative
615 BFD from which symbols should in fact be added in place of the
616 original BFD's symbols. */
617 bfd_boolean (*add_archive_element)
618 (struct bfd_link_info *, bfd *abfd, const char *name, bfd **subsbfd);
619 /* A function which is called when a symbol is found with multiple
620 definitions. H is the symbol which is defined multiple times.
621 NBFD is the new BFD, NSEC is the new section, and NVAL is the new
622 value. NSEC may be bfd_com_section or bfd_ind_section. */
623 bfd_boolean (*multiple_definition)
624 (struct bfd_link_info *, struct bfd_link_hash_entry *h,
625 bfd *nbfd, asection *nsec, bfd_vma nval);
626 /* A function which is called when a common symbol is defined
627 multiple times. H is the symbol appearing multiple times.
628 NBFD is the BFD of the new symbol. NTYPE is the type of the new
629 symbol, one of bfd_link_hash_defined, bfd_link_hash_common, or
630 bfd_link_hash_indirect. If NTYPE is bfd_link_hash_common, NSIZE
631 is the size of the new symbol. */
632 bfd_boolean (*multiple_common)
633 (struct bfd_link_info *, struct bfd_link_hash_entry *h,
634 bfd *nbfd, enum bfd_link_hash_type ntype, bfd_vma nsize);
635 /* A function which is called to add a symbol to a set. ENTRY is
636 the link hash table entry for the set itself (e.g.,
637 __CTOR_LIST__). RELOC is the relocation to use for an entry in
638 the set when generating a relocatable file, and is also used to
639 get the size of the entry when generating an executable file.
640 ABFD, SEC and VALUE identify the value to add to the set. */
641 bfd_boolean (*add_to_set)
642 (struct bfd_link_info *, struct bfd_link_hash_entry *entry,
643 bfd_reloc_code_real_type reloc, bfd *abfd, asection *sec, bfd_vma value);
644 /* A function which is called when the name of a g++ constructor or
645 destructor is found. This is only called by some object file
646 formats. CONSTRUCTOR is TRUE for a constructor, FALSE for a
647 destructor. This will use BFD_RELOC_CTOR when generating a
648 relocatable file. NAME is the name of the symbol found. ABFD,
649 SECTION and VALUE are the value of the symbol. */
650 bfd_boolean (*constructor)
651 (struct bfd_link_info *, bfd_boolean constructor, const char *name,
652 bfd *abfd, asection *sec, bfd_vma value);
653 /* A function which is called to issue a linker warning. For
654 example, this is called when there is a reference to a warning
655 symbol. WARNING is the warning to be issued. SYMBOL is the name
656 of the symbol which triggered the warning; it may be NULL if
657 there is none. ABFD, SECTION and ADDRESS identify the location
658 which trigerred the warning; either ABFD or SECTION or both may
659 be NULL if the location is not known. */
660 bfd_boolean (*warning)
661 (struct bfd_link_info *, const char *warning, const char *symbol,
662 bfd *abfd, asection *section, bfd_vma address);
663 /* A function which is called when a relocation is attempted against
664 an undefined symbol. NAME is the symbol which is undefined.
665 ABFD, SECTION and ADDRESS identify the location from which the
666 reference is made. IS_FATAL indicates whether an undefined symbol is
667 a fatal error or not. In some cases SECTION may be NULL. */
668 bfd_boolean (*undefined_symbol)
669 (struct bfd_link_info *, const char *name, bfd *abfd,
670 asection *section, bfd_vma address, bfd_boolean is_fatal);
671 /* A function which is called when a reloc overflow occurs. ENTRY is
672 the link hash table entry for the symbol the reloc is against.
673 NAME is the name of the local symbol or section the reloc is
674 against, RELOC_NAME is the name of the relocation, and ADDEND is
675 any addend that is used. ABFD, SECTION and ADDRESS identify the
676 location at which the overflow occurs; if this is the result of a
677 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
678 ABFD will be NULL. */
679 bfd_boolean (*reloc_overflow)
680 (struct bfd_link_info *, struct bfd_link_hash_entry *entry,
681 const char *name, const char *reloc_name, bfd_vma addend,
682 bfd *abfd, asection *section, bfd_vma address);
683 /* A function which is called when a dangerous reloc is performed.
684 MESSAGE is an appropriate message.
685 ABFD, SECTION and ADDRESS identify the location at which the
686 problem occurred; if this is the result of a
687 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
688 ABFD will be NULL. */
689 bfd_boolean (*reloc_dangerous)
690 (struct bfd_link_info *, const char *message,
691 bfd *abfd, asection *section, bfd_vma address);
692 /* A function which is called when a reloc is found to be attached
693 to a symbol which is not being written out. NAME is the name of
694 the symbol. ABFD, SECTION and ADDRESS identify the location of
695 the reloc; if this is the result of a
696 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
697 ABFD will be NULL. */
698 bfd_boolean (*unattached_reloc)
699 (struct bfd_link_info *, const char *name,
700 bfd *abfd, asection *section, bfd_vma address);
701 /* A function which is called when a symbol in notice_hash is
702 defined or referenced. H is the symbol, INH the indirect symbol
703 if applicable. ABFD, SECTION and ADDRESS are the (new) value of
704 the symbol. If SECTION is bfd_und_section, this is a reference.
705 FLAGS are the symbol BSF_* flags. */
706 bfd_boolean (*notice)
707 (struct bfd_link_info *, struct bfd_link_hash_entry *h,
708 struct bfd_link_hash_entry *inh,
709 bfd *abfd, asection *section, bfd_vma address, flagword flags);
710 /* Error or warning link info message. */
712 (const char *fmt, ...);
713 /* General link info message. */
715 (const char *fmt, ...);
716 /* Message to be printed in linker map file. */
718 (const char *fmt, ...);
719 /* This callback provides a chance for users of the BFD library to
720 override its decision about whether to place two adjacent sections
721 into the same segment. */
722 bfd_boolean (*override_segment_assignment)
723 (struct bfd_link_info *, bfd * abfd,
724 asection * current_section, asection * previous_section,
725 bfd_boolean new_segment);
728 /* The linker builds link_order structures which tell the code how to
729 include input data in the output file. */
731 /* These are the types of link_order structures. */
733 enum bfd_link_order_type
735 bfd_undefined_link_order, /* Undefined. */
736 bfd_indirect_link_order, /* Built from a section. */
737 bfd_data_link_order, /* Set to explicit data. */
738 bfd_section_reloc_link_order, /* Relocate against a section. */
739 bfd_symbol_reloc_link_order /* Relocate against a symbol. */
742 /* This is the link_order structure itself. These form a chain
743 attached to the output section whose contents they are describing. */
745 struct bfd_link_order
747 /* Next link_order in chain. */
748 struct bfd_link_order *next;
749 /* Type of link_order. */
750 enum bfd_link_order_type type;
751 /* Offset within output section. */
753 /* Size within output section. */
755 /* Type specific information. */
760 /* Section to include. If this is used, then
761 section->output_section must be the section the
762 link_order is attached to, section->output_offset must
763 equal the link_order offset field, and section->size
764 must equal the link_order size field. Maybe these
765 restrictions should be relaxed someday. */
770 /* Size of contents, or zero when contents should be filled by
771 the architecture-dependent fill function.
772 A non-zero value allows filling of the output section
773 with an arbitrary repeated pattern. */
775 /* Data to put into file. */
780 /* Description of reloc to generate. Used for
781 bfd_section_reloc_link_order and
782 bfd_symbol_reloc_link_order. */
783 struct bfd_link_order_reloc *p;
788 /* A linker order of type bfd_section_reloc_link_order or
789 bfd_symbol_reloc_link_order means to create a reloc against a
790 section or symbol, respectively. This is used to implement -Ur to
791 generate relocs for the constructor tables. The
792 bfd_link_order_reloc structure describes the reloc that BFD should
793 create. It is similar to a arelent, but I didn't use arelent
794 because the linker does not know anything about most symbols, and
795 any asymbol structure it creates will be partially meaningless.
796 This information could logically be in the bfd_link_order struct,
797 but I didn't want to waste the space since these types of relocs
798 are relatively rare. */
800 struct bfd_link_order_reloc
803 bfd_reloc_code_real_type reloc;
807 /* For type bfd_section_reloc_link_order, this is the section
808 the reloc should be against. This must be a section in the
809 output BFD, not any of the input BFDs. */
811 /* For type bfd_symbol_reloc_link_order, this is the name of the
812 symbol the reloc should be against. */
816 /* Addend to use. The object file should contain zero. The BFD
817 backend is responsible for filling in the contents of the object
818 file correctly. For some object file formats (e.g., COFF) the
819 addend must be stored into in the object file, and for some
820 (e.g., SPARC a.out) it is kept in the reloc. */
824 /* Allocate a new link_order for a section. */
825 extern struct bfd_link_order *bfd_new_link_order (bfd *, asection *);
827 /* These structures are used to describe version information for the
828 ELF linker. These structures could be manipulated entirely inside
829 BFD, but it would be a pain. Instead, the regular linker sets up
830 these structures, and then passes them into BFD. */
832 /* Glob pattern for a version. */
834 struct bfd_elf_version_expr
836 /* Next glob pattern for this version. */
837 struct bfd_elf_version_expr *next;
840 /* Set if pattern is not a glob. */
841 unsigned int literal : 1;
842 /* Defined by ".symver". */
843 unsigned int symver : 1;
844 /* Defined by version script. */
845 unsigned int script : 1;
847 #define BFD_ELF_VERSION_C_TYPE 1
848 #define BFD_ELF_VERSION_CXX_TYPE 2
849 #define BFD_ELF_VERSION_JAVA_TYPE 4
850 unsigned int mask : 3;
853 struct bfd_elf_version_expr_head
855 /* List of all patterns, both wildcards and non-wildcards. */
856 struct bfd_elf_version_expr *list;
857 /* Hash table for non-wildcards. */
859 /* Remaining patterns. */
860 struct bfd_elf_version_expr *remaining;
861 /* What kind of pattern types are present in list (bitmask). */
865 /* Version dependencies. */
867 struct bfd_elf_version_deps
869 /* Next dependency for this version. */
870 struct bfd_elf_version_deps *next;
871 /* The version which this version depends upon. */
872 struct bfd_elf_version_tree *version_needed;
875 /* A node in the version tree. */
877 struct bfd_elf_version_tree
880 struct bfd_elf_version_tree *next;
881 /* Name of this version. */
883 /* Version number. */
885 /* Regular expressions for global symbols in this version. */
886 struct bfd_elf_version_expr_head globals;
887 /* Regular expressions for local symbols in this version. */
888 struct bfd_elf_version_expr_head locals;
889 /* List of versions which this version depends upon. */
890 struct bfd_elf_version_deps *deps;
891 /* Index of the version name. This is used within BFD. */
892 unsigned int name_indx;
893 /* Whether this version tree was used. This is used within BFD. */
896 struct bfd_elf_version_expr *(*match)
897 (struct bfd_elf_version_expr_head *head,
898 struct bfd_elf_version_expr *prev, const char *sym);
901 struct bfd_elf_dynamic_list
903 struct bfd_elf_version_expr_head head;
904 struct bfd_elf_version_expr *(*match)
905 (struct bfd_elf_version_expr_head *head,
906 struct bfd_elf_version_expr *prev, const char *sym);