1 /* bfdlink.h -- header file for BFD link routines
2 Copyright (C) 1993-2022 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 enum notice_asneeded_action
{
51 /* Whether to generate ELF common symbols with the STT_COMMON type
52 during a relocatable link. */
53 enum bfd_link_elf_stt_common
60 /* Describes the type of hash table entry structure being used.
61 Different hash table structure have different fields and so
62 support different linking features. */
63 enum bfd_link_hash_table_type
65 bfd_link_generic_hash_table
,
66 bfd_link_elf_hash_table
69 /* These are the possible types of an entry in the BFD link hash
72 enum bfd_link_hash_type
74 bfd_link_hash_new
, /* Symbol is new. */
75 bfd_link_hash_undefined
, /* Symbol seen before, but undefined. */
76 bfd_link_hash_undefweak
, /* Symbol is weak and undefined. */
77 bfd_link_hash_defined
, /* Symbol is defined. */
78 bfd_link_hash_defweak
, /* Symbol is weak and defined. */
79 bfd_link_hash_common
, /* Symbol is common. */
80 bfd_link_hash_indirect
, /* Symbol is an indirect link. */
81 bfd_link_hash_warning
/* Like indirect, but warn if referenced. */
84 enum bfd_link_common_skip_ar_symbols
86 bfd_link_common_skip_none
,
87 bfd_link_common_skip_text
,
88 bfd_link_common_skip_data
,
89 bfd_link_common_skip_all
92 struct bfd_link_hash_common_entry
94 unsigned int alignment_power
; /* Alignment. */
95 asection
*section
; /* Symbol section. */
98 /* The linking routines use a hash table which uses this structure for
101 struct bfd_link_hash_entry
103 /* Base hash table entry structure. */
104 struct bfd_hash_entry root
;
106 /* Type of this entry. */
107 ENUM_BITFIELD (bfd_link_hash_type
) type
: 8;
109 /* Symbol is referenced in a normal regular object file,
110 as distinct from a LTO IR object file. */
111 unsigned int non_ir_ref_regular
: 1;
113 /* Symbol is referenced in a normal dynamic object file,
114 as distinct from a LTO IR object file. */
115 unsigned int non_ir_ref_dynamic
: 1;
117 /* The symbol, SYM, is referenced by __real_SYM in an object file. */
118 unsigned int ref_real
: 1;
120 /* Symbol is a built-in define. These will be overridden by PROVIDE
121 in a linker script. */
122 unsigned int linker_def
: 1;
124 /* Symbol defined in a linker script. */
125 unsigned int ldscript_def
: 1;
127 /* Symbol will be converted from absolute to section-relative. Set for
128 symbols defined by a script from "dot" (also SEGMENT_START or ORIGIN)
129 outside of an output section statement. */
130 unsigned int rel_from_abs
: 1;
132 /* A union of information depending upon the type. */
135 /* Nothing is kept for bfd_hash_new. */
136 /* bfd_link_hash_undefined, bfd_link_hash_undefweak. */
139 /* Undefined and common symbols are kept in a linked list through
140 this field. This field is present in all of the union element
141 so that we don't need to remove entries from the list when we
142 change their type. Removing entries would either require the
143 list to be doubly linked, which would waste more memory, or
144 require a traversal. When an undefined or common symbol is
145 created, it should be added to this list, the head of which is in
146 the link hash table itself. As symbols are defined, they need
147 not be removed from the list; anything which reads the list must
148 doublecheck the symbol type.
150 Weak symbols are not kept on this list.
152 Defined and defweak symbols use this field as a reference marker.
153 If the field is not NULL, or this structure is the tail of the
154 undefined symbol list, the symbol has been referenced. If the
155 symbol is undefined and becomes defined, this field will
156 automatically be non-NULL since the symbol will have been on the
157 undefined symbol list. */
158 struct bfd_link_hash_entry
*next
;
159 /* BFD symbol was found in. */
162 /* bfd_link_hash_defined, bfd_link_hash_defweak. */
165 struct bfd_link_hash_entry
*next
;
166 /* Symbol section. */
171 /* bfd_link_hash_indirect, bfd_link_hash_warning. */
174 struct bfd_link_hash_entry
*next
;
176 struct bfd_link_hash_entry
*link
;
177 /* Warning message (bfd_link_hash_warning only). */
180 /* bfd_link_hash_common. */
183 struct bfd_link_hash_entry
*next
;
184 /* The linker needs to know three things about common
185 symbols: the size, the alignment, and the section in
186 which the symbol should be placed. We store the size
187 here, and we allocate a small structure to hold the
188 section and the alignment. The alignment is stored as a
189 power of two. We don't store all the information
190 directly because we don't want to increase the size of
191 the union; this structure is a major space user in the
193 struct bfd_link_hash_common_entry
*p
;
194 /* Common symbol size. */
200 /* This is the link hash table. It is a derived class of
203 struct bfd_link_hash_table
205 /* The hash table itself. */
206 struct bfd_hash_table table
;
207 /* A linked list of undefined and common symbols, linked through the
208 next field in the bfd_link_hash_entry structure. */
209 struct bfd_link_hash_entry
*undefs
;
210 /* Entries are added to the tail of the undefs list. */
211 struct bfd_link_hash_entry
*undefs_tail
;
212 /* Function to free the hash table on closing BFD. */
213 void (*hash_table_free
) (bfd
*);
214 /* The type of the link hash table. */
215 enum bfd_link_hash_table_type type
;
218 /* Look up an entry in a link hash table. If FOLLOW is TRUE, this
219 follows bfd_link_hash_indirect and bfd_link_hash_warning links to
221 extern struct bfd_link_hash_entry
*bfd_link_hash_lookup
222 (struct bfd_link_hash_table
*, const char *, bool create
,
223 bool copy
, bool follow
);
225 /* Look up an entry in the main linker hash table if the symbol might
226 be wrapped. This should only be used for references to an
227 undefined symbol, not for definitions of a symbol. */
229 extern struct bfd_link_hash_entry
*bfd_wrapped_link_hash_lookup
230 (bfd
*, struct bfd_link_info
*, const char *, bool, bool, bool);
232 /* If H is a wrapped symbol, ie. the symbol name starts with "__wrap_"
233 and the remainder is found in wrap_hash, return the real symbol. */
235 extern struct bfd_link_hash_entry
*unwrap_hash_lookup
236 (struct bfd_link_info
*, bfd
*, struct bfd_link_hash_entry
*);
238 /* Traverse a link hash table. */
239 extern void bfd_link_hash_traverse
240 (struct bfd_link_hash_table
*,
241 bool (*) (struct bfd_link_hash_entry
*, void *),
244 /* Add an entry to the undefs list. */
245 extern void bfd_link_add_undef
246 (struct bfd_link_hash_table
*, struct bfd_link_hash_entry
*);
248 /* Remove symbols from the undefs list that don't belong there. */
249 extern void bfd_link_repair_undef_list
250 (struct bfd_link_hash_table
*table
);
252 /* Read symbols and cache symbol pointer array in outsymbols. */
253 extern bool bfd_generic_link_read_symbols (bfd
*);
255 /* Check the relocs in the BFD. Called after all the input
256 files have been loaded, and garbage collection has tagged
257 any unneeded sections. */
258 extern bool bfd_link_check_relocs (bfd
*,struct bfd_link_info
*);
262 struct bfd_sym_chain
*next
;
266 /* How to handle unresolved symbols.
267 There are four possibilities which are enumerated below: */
270 /* This is the initial value when then link_info structure is created.
271 It allows the various stages of the linker to determine whether they
272 allowed to set the value. */
278 /* How to handle DT_TEXTREL. */
280 enum textrel_check_method
283 textrel_check_warning
,
287 #define bfd_link_textrel_check(info) \
288 (info->textrel_check != textrel_check_none)
290 typedef enum {with_flags
, without_flags
} flag_type
;
292 /* A section flag list. */
293 struct flag_info_list
298 struct flag_info_list
*next
;
301 /* Section flag info. */
304 flagword only_with_flags
;
305 flagword not_with_flags
;
306 struct flag_info_list
*flag_list
;
307 bool flags_initialized
;
310 struct bfd_elf_dynamic_list
;
311 struct bfd_elf_version_tree
;
313 /* Types of output. */
323 #define bfd_link_pde(info) ((info)->type == type_pde)
324 #define bfd_link_dll(info) ((info)->type == type_dll)
325 #define bfd_link_relocatable(info) ((info)->type == type_relocatable)
326 #define bfd_link_pie(info) ((info)->type == type_pie)
327 #define bfd_link_executable(info) (bfd_link_pde (info) || bfd_link_pie (info))
328 #define bfd_link_pic(info) (bfd_link_dll (info) || bfd_link_pie (info))
330 /* This structure holds all the information needed to communicate
331 between BFD and the linker when doing a link. */
336 ENUM_BITFIELD (output_type
) type
: 2;
338 /* TRUE if BFD should pre-bind symbols in a shared object. */
339 unsigned int symbolic
: 1;
341 /* TRUE if BFD should export all symbols in the dynamic symbol table
342 of an executable, rather than only those used. */
343 unsigned int export_dynamic
: 1;
345 /* TRUE if a default symbol version should be created and used for
347 unsigned int create_default_symver
: 1;
349 /* TRUE if unreferenced sections should be removed. */
350 unsigned int gc_sections
: 1;
352 /* TRUE if exported symbols should be kept during section gc. */
353 unsigned int gc_keep_exported
: 1;
355 /* TRUE if every symbol should be reported back via the notice
357 unsigned int notice_all
: 1;
359 /* TRUE if the LTO plugin is active. */
360 unsigned int lto_plugin_active
: 1;
362 /* TRUE if all LTO IR symbols have been read. */
363 unsigned int lto_all_symbols_read
: 1;
365 /* TRUE if global symbols in discarded sections should be stripped. */
366 unsigned int strip_discarded
: 1;
368 /* TRUE if all data symbols should be dynamic. */
369 unsigned int dynamic_data
: 1;
371 /* TRUE if section groups should be resolved. */
372 unsigned int resolve_section_groups
: 1;
374 /* Set if output file is big-endian, or if that is unknown, from
375 the command line or first input file endianness. */
376 unsigned int big_endian
: 1;
378 /* Which symbols to strip. */
379 ENUM_BITFIELD (bfd_link_strip
) strip
: 2;
381 /* Which local symbols to discard. */
382 ENUM_BITFIELD (bfd_link_discard
) discard
: 2;
384 /* Whether to generate ELF common symbols with the STT_COMMON type. */
385 ENUM_BITFIELD (bfd_link_elf_stt_common
) elf_stt_common
: 2;
387 /* Criteria for skipping symbols when determining
388 whether to include an object from an archive. */
389 ENUM_BITFIELD (bfd_link_common_skip_ar_symbols
) common_skip_ar_symbols
: 2;
391 /* What to do with unresolved symbols in an object file.
392 When producing executables the default is GENERATE_ERROR.
393 When producing shared libraries the default is IGNORE. The
394 assumption with shared libraries is that the reference will be
395 resolved at load/execution time. */
396 ENUM_BITFIELD (report_method
) unresolved_syms_in_objects
: 2;
398 /* What to do with unresolved symbols in a shared library.
399 The same defaults apply. */
400 ENUM_BITFIELD (report_method
) unresolved_syms_in_shared_libs
: 2;
402 /* TRUE if unresolved symbols are to be warned, rather than errored. */
403 unsigned int warn_unresolved_syms
: 1;
405 /* TRUE if shared objects should be linked directly, not shared. */
406 unsigned int static_link
: 1;
408 /* TRUE if symbols should be retained in memory, FALSE if they
409 should be freed and reread. */
410 unsigned int keep_memory
: 1;
412 /* TRUE if BFD should generate relocation information in the final
414 unsigned int emitrelocations
: 1;
416 /* TRUE if PT_GNU_RELRO segment should be created. */
417 unsigned int relro
: 1;
419 /* TRUE if DT_RELR should be enabled for compact relative
421 unsigned int enable_dt_relr
: 1;
423 /* TRUE if separate code segment should be created. */
424 unsigned int separate_code
: 1;
426 /* Nonzero if .eh_frame_hdr section and PT_GNU_EH_FRAME ELF segment
427 should be created. 1 for DWARF2 tables, 2 for compact tables. */
428 unsigned int eh_frame_hdr_type
: 2;
430 /* What to do with DT_TEXTREL in output. */
431 ENUM_BITFIELD (textrel_check_method
) textrel_check
: 2;
433 /* TRUE if .hash section should be created. */
434 unsigned int emit_hash
: 1;
436 /* TRUE if .gnu.hash section should be created. */
437 unsigned int emit_gnu_hash
: 1;
439 /* If TRUE reduce memory overheads, at the expense of speed. This will
440 cause map file generation to use an O(N^2) algorithm and disable
441 caching ELF symbol buffer. */
442 unsigned int reduce_memory_overheads
: 1;
444 /* TRUE if the output file should be in a traditional format. This
445 is equivalent to the setting of the BFD_TRADITIONAL_FORMAT flag
446 on the output file, but may be checked when reading the input
448 unsigned int traditional_format
: 1;
450 /* TRUE if non-PLT relocs should be merged into one reloc section
451 and sorted so that relocs against the same symbol come together. */
452 unsigned int combreloc
: 1;
454 /* TRUE if a default symbol version should be created and used for
456 unsigned int default_imported_symver
: 1;
458 /* TRUE if the new ELF dynamic tags are enabled. */
459 unsigned int new_dtags
: 1;
461 /* FALSE if .eh_frame unwind info should be generated for PLT and other
462 linker created sections, TRUE if it should be omitted. */
463 unsigned int no_ld_generated_unwind_info
: 1;
465 /* TRUE if BFD should generate a "task linked" object file,
466 similar to relocatable but also with globals converted to
468 unsigned int task_link
: 1;
470 /* TRUE if ok to have multiple definitions, without warning. */
471 unsigned int allow_multiple_definition
: 1;
473 /* TRUE if multiple definition of absolute symbols (eg. from -R) should
475 unsigned int prohibit_multiple_definition_absolute
: 1;
477 /* TRUE if multiple definitions should only warn. */
478 unsigned int warn_multiple_definition
: 1;
480 /* TRUE if ok to have version with no definition. */
481 unsigned int allow_undefined_version
: 1;
483 /* TRUE if some symbols have to be dynamic, controlled by
484 --dynamic-list command line options. */
485 unsigned int dynamic
: 1;
487 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W|PF_X
489 unsigned int execstack
: 1;
491 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W
493 unsigned int noexecstack
: 1;
495 /* Tri-state variable:
496 0 => do not warn when creating an executable stack.
497 1 => always warn when creating an executable stack.
498 >1 => warn when creating an executable stack if execstack is 0. */
499 unsigned int warn_execstack
: 2;
501 /* TRUE if warnings should not be generated for TLS segments with eXecute
502 permission or LOAD segments with RWX permissions. */
503 unsigned int no_warn_rwx_segments
: 1;
505 /* TRUE if the stack can be made executable because of the absence of a
506 .note.GNU-stack section in an input file. Note - even if this field
507 is set, some targets may choose to ignore the setting and not create
508 an executable stack. */
509 unsigned int default_execstack
: 1;
511 /* TRUE if we want to produced optimized output files. This might
512 need much more time and therefore must be explicitly selected. */
513 unsigned int optimize
: 1;
515 /* TRUE if user should be informed of removed unreferenced sections. */
516 unsigned int print_gc_sections
: 1;
518 /* TRUE if we should warn alternate ELF machine code. */
519 unsigned int warn_alternate_em
: 1;
521 /* TRUE if the linker script contained an explicit PHDRS command. */
522 unsigned int user_phdrs
: 1;
524 /* TRUE if program headers ought to be loaded. */
525 unsigned int load_phdrs
: 1;
527 /* TRUE if we should check relocations after all input files have
529 unsigned int check_relocs_after_open_input
: 1;
531 /* TRUE if generation of .interp/PT_INTERP should be suppressed. */
532 unsigned int nointerp
: 1;
534 /* TRUE if common symbols should be treated as undefined. */
535 unsigned int inhibit_common_definition
: 1;
537 /* TRUE if "-Map map" is passed to linker. */
538 unsigned int has_map_file
: 1;
540 /* TRUE if "--enable-non-contiguous-regions" is passed to the
542 unsigned int non_contiguous_regions
: 1;
544 /* TRUE if "--enable-non-contiguous-regions-warnings" is passed to
546 unsigned int non_contiguous_regions_warnings
: 1;
548 /* TRUE if all symbol names should be unique. */
549 unsigned int unique_symbol
: 1;
551 /* TRUE if maxpagesize is set on command-line. */
552 unsigned int maxpagesize_is_set
: 1;
554 /* TRUE if commonpagesize is set on command-line. */
555 unsigned int commonpagesize_is_set
: 1;
557 /* Char that may appear as the first char of a symbol, but should be
558 skipped (like symbol_leading_char) when looking up symbols in
559 wrap_hash. Used by PowerPC Linux for 'dot' symbols. */
562 /* Separator between archive and filename in linker script filespecs. */
565 /* Default stack size. Zero means default (often zero itself), -1
566 means explicitly zero-sized. */
567 bfd_signed_vma stacksize
;
569 /* Enable or disable target specific optimizations.
571 Not all targets have optimizations to enable.
573 Normally these optimizations are disabled by default but some targets
574 prefer to enable them by default. So this field is a tri-state variable.
577 zero: Enable the optimizations (either from --relax being specified on
578 the command line or the backend's before_allocation emulation function.
580 positive: The user has requested that these optimizations be disabled.
581 (Via the --no-relax command line option).
583 negative: The optimizations are disabled. (Set when initializing the
584 args_type structure in ldmain.c:main. */
585 signed int disable_target_specific_optimizations
;
587 /* Function callbacks. */
588 const struct bfd_link_callbacks
*callbacks
;
590 /* Hash table handled by BFD. */
591 struct bfd_link_hash_table
*hash
;
593 /* Hash table of symbols to keep. This is NULL unless strip is
595 struct bfd_hash_table
*keep_hash
;
597 /* Hash table of symbols to report back via the notice callback. If
598 this is NULL, and notice_all is FALSE, then no symbols are
600 struct bfd_hash_table
*notice_hash
;
602 /* Hash table of symbols which are being wrapped (the --wrap linker
603 option). If this is NULL, no symbols are being wrapped. */
604 struct bfd_hash_table
*wrap_hash
;
606 /* Hash table of symbols which may be left unresolved during
607 a link. If this is NULL, no symbols can be left unresolved. */
608 struct bfd_hash_table
*ignore_hash
;
610 /* The output BFD. */
613 /* The import library generated. */
616 /* The list of input BFD's involved in the link. These are chained
617 together via the link.next field. */
619 bfd
**input_bfds_tail
;
621 /* If a symbol should be created for each input BFD, this is section
622 where those symbols should be placed. It must be a section in
623 the output BFD. It may be NULL, in which case no such symbols
624 will be created. This is to support CREATE_OBJECT_SYMBOLS in the
625 linker command language. */
626 asection
*create_object_symbols_section
;
628 /* List of global symbol names that are starting points for marking
629 sections against garbage collection. */
630 struct bfd_sym_chain
*gc_sym_list
;
632 /* If a base output file is wanted, then this points to it */
635 /* The function to call when the executable or shared object is
637 const char *init_function
;
639 /* The function to call when the executable or shared object is
641 const char *fini_function
;
643 /* Number of relaxation passes. Usually only one relaxation pass
644 is needed. But a backend can have as many relaxation passes as
645 necessary. During bfd_relax_section call, it is set to the
646 current pass, starting from 0. */
649 /* Number of relaxation trips. This number is incremented every
650 time the relaxation pass is restarted due to a previous
651 relaxation returning true in *AGAIN. */
654 /* > 0 to treat protected data defined in the shared library as
655 reference external. 0 to treat it as internal. -1 to let
656 backend to decide. */
657 int extern_protected_data
;
659 /* 1 to make undefined weak symbols dynamic when building a dynamic
660 object. 0 to resolve undefined weak symbols to zero. -1 to let
661 the backend decide. */
662 int dynamic_undefined_weak
;
664 /* Non-zero if auto-import thunks for DATA items in pei386 DLLs
665 should be generated/linked against. Set to 1 if this feature
666 is explicitly requested by the user, -1 if enabled by default. */
667 int pei386_auto_import
;
669 /* Non-zero if runtime relocs for DATA items with non-zero addends
670 in pei386 DLLs should be generated. Set to 1 if this feature
671 is explicitly requested by the user, -1 if enabled by default. */
672 int pei386_runtime_pseudo_reloc
;
674 /* How many spare .dynamic DT_NULL entries should be added? */
675 unsigned int spare_dynamic_tags
;
677 /* GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS control:
678 > 1: Turn on by -z indirect-extern-access or by backend.
679 == 1: Turn on by an input.
681 < 0: Turn on if it is set on any inputs or let backend to
683 int indirect_extern_access
;
685 /* Non-zero if executable should not contain copy relocs.
686 > 1: Implied by indirect_extern_access.
687 == 1: Turn on by -z nocopyreloc.
689 Setting this to non-zero may result in a non-sharable text
693 /* Pointer to the GNU_PROPERTY_1_NEEDED property in memory. */
694 bfd_byte
*needed_1_p
;
696 /* May be used to set DT_FLAGS for ELF. */
699 /* May be used to set DT_FLAGS_1 for ELF. */
702 /* May be used to set DT_GNU_FLAGS_1 for ELF. */
705 /* TRUE if references to __start_/__stop_ synthesized symbols do not
706 specially retain C identifier named sections. */
709 /* May be used to set ELF visibility for __start_* / __stop_. */
710 unsigned int start_stop_visibility
;
712 /* The maximum page size for ELF. */
715 /* The common page size for ELF. */
716 bfd_vma commonpagesize
;
718 /* Start and end of RELRO region. */
719 bfd_vma relro_start
, relro_end
;
721 /* List of symbols should be dynamic. */
722 struct bfd_elf_dynamic_list
*dynamic_list
;
724 /* The version information. */
725 struct bfd_elf_version_tree
*version_info
;
727 /* Size of cache. Backend can use it to keep strace cache size. */
728 bfd_size_type cache_size
;
730 /* The maximum cache size. Backend can use cache_size and and
731 max_cache_size to decide if keep_memory should be honored. */
732 bfd_size_type max_cache_size
;
735 /* Some forward-definitions used by some callbacks. */
737 struct elf_strtab_hash
;
738 struct elf_internal_sym
;
740 /* This structures holds a set of callback functions. These are called
741 by the BFD linker routines. */
743 struct bfd_link_callbacks
745 /* A function which is called when an object is added from an
746 archive. ABFD is the archive element being added. NAME is the
747 name of the symbol which caused the archive element to be pulled
748 in. This function may set *SUBSBFD to point to an alternative
749 BFD from which symbols should in fact be added in place of the
750 original BFD's symbols. Returns TRUE if the object should be
751 added, FALSE if it should be skipped. */
752 bool (*add_archive_element
)
753 (struct bfd_link_info
*, bfd
*abfd
, const char *name
, bfd
**subsbfd
);
754 /* A function which is called when a symbol is found with multiple
755 definitions. H is the symbol which is defined multiple times.
756 NBFD is the new BFD, NSEC is the new section, and NVAL is the new
757 value. NSEC may be bfd_com_section or bfd_ind_section. */
758 void (*multiple_definition
)
759 (struct bfd_link_info
*, struct bfd_link_hash_entry
*h
,
760 bfd
*nbfd
, asection
*nsec
, bfd_vma nval
);
761 /* A function which is called when a common symbol is defined
762 multiple times. H is the symbol appearing multiple times.
763 NBFD is the BFD of the new symbol. NTYPE is the type of the new
764 symbol, one of bfd_link_hash_defined, bfd_link_hash_common, or
765 bfd_link_hash_indirect. If NTYPE is bfd_link_hash_common, NSIZE
766 is the size of the new symbol. */
767 void (*multiple_common
)
768 (struct bfd_link_info
*, struct bfd_link_hash_entry
*h
,
769 bfd
*nbfd
, enum bfd_link_hash_type ntype
, bfd_vma nsize
);
770 /* A function which is called to add a symbol to a set. ENTRY is
771 the link hash table entry for the set itself (e.g.,
772 __CTOR_LIST__). RELOC is the relocation to use for an entry in
773 the set when generating a relocatable file, and is also used to
774 get the size of the entry when generating an executable file.
775 ABFD, SEC and VALUE identify the value to add to the set. */
777 (struct bfd_link_info
*, struct bfd_link_hash_entry
*entry
,
778 bfd_reloc_code_real_type reloc
, bfd
*abfd
, asection
*sec
, bfd_vma value
);
779 /* A function which is called when the name of a g++ constructor or
780 destructor is found. This is only called by some object file
781 formats. CONSTRUCTOR is TRUE for a constructor, FALSE for a
782 destructor. This will use BFD_RELOC_CTOR when generating a
783 relocatable file. NAME is the name of the symbol found. ABFD,
784 SECTION and VALUE are the value of the symbol. */
786 (struct bfd_link_info
*, bool constructor
, const char *name
,
787 bfd
*abfd
, asection
*sec
, bfd_vma value
);
788 /* A function which is called to issue a linker warning. For
789 example, this is called when there is a reference to a warning
790 symbol. WARNING is the warning to be issued. SYMBOL is the name
791 of the symbol which triggered the warning; it may be NULL if
792 there is none. ABFD, SECTION and ADDRESS identify the location
793 which trigerred the warning; either ABFD or SECTION or both may
794 be NULL if the location is not known. */
796 (struct bfd_link_info
*, const char *warning
, const char *symbol
,
797 bfd
*abfd
, asection
*section
, bfd_vma address
);
798 /* A function which is called when a relocation is attempted against
799 an undefined symbol. NAME is the symbol which is undefined.
800 ABFD, SECTION and ADDRESS identify the location from which the
801 reference is made. IS_FATAL indicates whether an undefined symbol is
802 a fatal error or not. In some cases SECTION may be NULL. */
803 void (*undefined_symbol
)
804 (struct bfd_link_info
*, const char *name
, bfd
*abfd
,
805 asection
*section
, bfd_vma address
, bool is_fatal
);
806 /* A function which is called when a reloc overflow occurs. ENTRY is
807 the link hash table entry for the symbol the reloc is against.
808 NAME is the name of the local symbol or section the reloc is
809 against, RELOC_NAME is the name of the relocation, and ADDEND is
810 any addend that is used. ABFD, SECTION and ADDRESS identify the
811 location at which the overflow occurs; if this is the result of a
812 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
813 ABFD will be NULL. */
814 void (*reloc_overflow
)
815 (struct bfd_link_info
*, struct bfd_link_hash_entry
*entry
,
816 const char *name
, const char *reloc_name
, bfd_vma addend
,
817 bfd
*abfd
, asection
*section
, bfd_vma address
);
818 /* A function which is called when a dangerous reloc is performed.
819 MESSAGE is an appropriate message.
820 ABFD, SECTION and ADDRESS identify the location at which the
821 problem occurred; if this is the result of a
822 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
823 ABFD will be NULL. */
824 void (*reloc_dangerous
)
825 (struct bfd_link_info
*, const char *message
,
826 bfd
*abfd
, asection
*section
, bfd_vma address
);
827 /* A function which is called when a reloc is found to be attached
828 to a symbol which is not being written out. NAME is the name of
829 the symbol. ABFD, SECTION and ADDRESS identify the location of
830 the reloc; if this is the result of a
831 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
832 ABFD will be NULL. */
833 void (*unattached_reloc
)
834 (struct bfd_link_info
*, const char *name
,
835 bfd
*abfd
, asection
*section
, bfd_vma address
);
836 /* A function which is called when a symbol in notice_hash is
837 defined or referenced. H is the symbol, INH the indirect symbol
838 if applicable. ABFD, SECTION and ADDRESS are the (new) value of
839 the symbol. If SECTION is bfd_und_section, this is a reference.
840 FLAGS are the symbol BSF_* flags. */
842 (struct bfd_link_info
*, struct bfd_link_hash_entry
*h
,
843 struct bfd_link_hash_entry
*inh
,
844 bfd
*abfd
, asection
*section
, bfd_vma address
, flagword flags
);
845 /* Error or warning link info message. */
847 (const char *fmt
, ...);
848 /* General link info message. */
850 (const char *fmt
, ...);
851 /* Message to be printed in linker map file. */
853 (const char *fmt
, ...);
854 /* This callback provides a chance for users of the BFD library to
855 override its decision about whether to place two adjacent sections
856 into the same segment. */
857 bool (*override_segment_assignment
)
858 (struct bfd_link_info
*, bfd
* abfd
,
859 asection
* current_section
, asection
* previous_section
,
861 /* This callback provides a chance for callers of the BFD to examine the
862 ELF (dynamic) string table once it is complete. */
863 void (*examine_strtab
)
864 (struct elf_strtab_hash
*symstrtab
);
865 /* This callback is called just before a symbol is swapped out, so that the
866 CTF machinery can look up symbols during construction. The name is
867 already an external strtab offset at this point. */
868 void (*ctf_new_symbol
)
869 (int symidx
, struct elf_internal_sym
*sym
);
870 /* Likewise, for dynamic symbols. */
871 void (*ctf_new_dynsym
)
872 (int symidx
, struct elf_internal_sym
*sym
);
873 /* This callback should emit the CTF section into a non-loadable section in
874 the output BFD named .ctf or a name beginning with ".ctf.". */
879 /* The linker builds link_order structures which tell the code how to
880 include input data in the output file. */
882 /* These are the types of link_order structures. */
884 enum bfd_link_order_type
886 bfd_undefined_link_order
, /* Undefined. */
887 bfd_indirect_link_order
, /* Built from a section. */
888 bfd_data_link_order
, /* Set to explicit data. */
889 bfd_section_reloc_link_order
, /* Relocate against a section. */
890 bfd_symbol_reloc_link_order
/* Relocate against a symbol. */
893 /* This is the link_order structure itself. These form a chain
894 attached to the output section whose contents they are describing. */
896 struct bfd_link_order
898 /* Next link_order in chain. */
899 struct bfd_link_order
*next
;
900 /* Type of link_order. */
901 enum bfd_link_order_type type
;
902 /* Offset within output section in bytes. */
904 /* Size within output section in octets. */
906 /* Type specific information. */
911 /* Section to include. If this is used, then
912 section->output_section must be the section the
913 link_order is attached to, section->output_offset must
914 equal the link_order offset field, and section->size
915 must equal the link_order size field. Maybe these
916 restrictions should be relaxed someday. */
921 /* Size of contents, or zero when contents should be filled by
922 the architecture-dependent fill function.
923 A non-zero value allows filling of the output section
924 with an arbitrary repeated pattern. */
926 /* Data to put into file. */
931 /* Description of reloc to generate. Used for
932 bfd_section_reloc_link_order and
933 bfd_symbol_reloc_link_order. */
934 struct bfd_link_order_reloc
*p
;
939 /* A linker order of type bfd_section_reloc_link_order or
940 bfd_symbol_reloc_link_order means to create a reloc against a
941 section or symbol, respectively. This is used to implement -Ur to
942 generate relocs for the constructor tables. The
943 bfd_link_order_reloc structure describes the reloc that BFD should
944 create. It is similar to a arelent, but I didn't use arelent
945 because the linker does not know anything about most symbols, and
946 any asymbol structure it creates will be partially meaningless.
947 This information could logically be in the bfd_link_order struct,
948 but I didn't want to waste the space since these types of relocs
949 are relatively rare. */
951 struct bfd_link_order_reloc
954 bfd_reloc_code_real_type reloc
;
958 /* For type bfd_section_reloc_link_order, this is the section
959 the reloc should be against. This must be a section in the
960 output BFD, not any of the input BFDs. */
962 /* For type bfd_symbol_reloc_link_order, this is the name of the
963 symbol the reloc should be against. */
967 /* Addend to use. The object file should contain zero. The BFD
968 backend is responsible for filling in the contents of the object
969 file correctly. For some object file formats (e.g., COFF) the
970 addend must be stored into in the object file, and for some
971 (e.g., SPARC a.out) it is kept in the reloc. */
975 /* Allocate a new link_order for a section. */
976 extern struct bfd_link_order
*bfd_new_link_order (bfd
*, asection
*);
978 struct bfd_section_already_linked
;
980 extern bool bfd_section_already_linked_table_init (void);
981 extern void bfd_section_already_linked_table_free (void);
982 extern bool _bfd_handle_already_linked
983 (struct bfd_section
*, struct bfd_section_already_linked
*,
984 struct bfd_link_info
*);
986 extern struct bfd_section
*_bfd_nearby_section
987 (bfd
*, struct bfd_section
*, bfd_vma
);
989 extern void _bfd_fix_excluded_sec_syms
990 (bfd
*, struct bfd_link_info
*);
992 /* These structures are used to describe version information for the
993 ELF linker. These structures could be manipulated entirely inside
994 BFD, but it would be a pain. Instead, the regular linker sets up
995 these structures, and then passes them into BFD. */
997 /* Glob pattern for a version. */
999 struct bfd_elf_version_expr
1001 /* Next glob pattern for this version. */
1002 struct bfd_elf_version_expr
*next
;
1004 const char *pattern
;
1005 /* Set if pattern is not a glob. */
1006 unsigned int literal
: 1;
1007 /* Defined by ".symver". */
1008 unsigned int symver
: 1;
1009 /* Defined by version script. */
1010 unsigned int script
: 1;
1012 #define BFD_ELF_VERSION_C_TYPE 1
1013 #define BFD_ELF_VERSION_CXX_TYPE 2
1014 #define BFD_ELF_VERSION_JAVA_TYPE 4
1015 unsigned int mask
: 3;
1018 struct bfd_elf_version_expr_head
1020 /* List of all patterns, both wildcards and non-wildcards. */
1021 struct bfd_elf_version_expr
*list
;
1022 /* Hash table for non-wildcards. */
1024 /* Remaining patterns. */
1025 struct bfd_elf_version_expr
*remaining
;
1026 /* What kind of pattern types are present in list (bitmask). */
1030 /* Version dependencies. */
1032 struct bfd_elf_version_deps
1034 /* Next dependency for this version. */
1035 struct bfd_elf_version_deps
*next
;
1036 /* The version which this version depends upon. */
1037 struct bfd_elf_version_tree
*version_needed
;
1040 /* A node in the version tree. */
1042 struct bfd_elf_version_tree
1045 struct bfd_elf_version_tree
*next
;
1046 /* Name of this version. */
1048 /* Version number. */
1049 unsigned int vernum
;
1050 /* Regular expressions for global symbols in this version. */
1051 struct bfd_elf_version_expr_head globals
;
1052 /* Regular expressions for local symbols in this version. */
1053 struct bfd_elf_version_expr_head locals
;
1054 /* List of versions which this version depends upon. */
1055 struct bfd_elf_version_deps
*deps
;
1056 /* Index of the version name. This is used within BFD. */
1057 unsigned int name_indx
;
1058 /* Whether this version tree was used. This is used within BFD. */
1060 /* Matching hook. */
1061 struct bfd_elf_version_expr
*(*match
)
1062 (struct bfd_elf_version_expr_head
*head
,
1063 struct bfd_elf_version_expr
*prev
, const char *sym
);
1066 struct bfd_elf_dynamic_list
1068 struct bfd_elf_version_expr_head head
;
1069 struct bfd_elf_version_expr
*(*match
)
1070 (struct bfd_elf_version_expr_head
*head
,
1071 struct bfd_elf_version_expr
*prev
, const char *sym
);