1 /* bfdlink.h -- header file for BFD link routines
2 Copyright (C) 1993-2020 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 /* Symbol is a built-in define. These will be overridden by PROVIDE
118 in a linker script. */
119 unsigned int linker_def
: 1;
121 /* Symbol defined in a linker script. */
122 unsigned int ldscript_def
: 1;
124 /* Symbol will be converted from absolute to section-relative. Set for
125 symbols defined by a script from "dot" (also SEGMENT_START or ORIGIN)
126 outside of an output section statement. */
127 unsigned int rel_from_abs
: 1;
129 /* A union of information depending upon the type. */
132 /* Nothing is kept for bfd_hash_new. */
133 /* bfd_link_hash_undefined, bfd_link_hash_undefweak. */
136 /* Undefined and common symbols are kept in a linked list through
137 this field. This field is present in all of the union element
138 so that we don't need to remove entries from the list when we
139 change their type. Removing entries would either require the
140 list to be doubly linked, which would waste more memory, or
141 require a traversal. When an undefined or common symbol is
142 created, it should be added to this list, the head of which is in
143 the link hash table itself. As symbols are defined, they need
144 not be removed from the list; anything which reads the list must
145 doublecheck the symbol type.
147 Weak symbols are not kept on this list.
149 Defined and defweak symbols use this field as a reference marker.
150 If the field is not NULL, or this structure is the tail of the
151 undefined symbol list, the symbol has been referenced. If the
152 symbol is undefined and becomes defined, this field will
153 automatically be non-NULL since the symbol will have been on the
154 undefined symbol list. */
155 struct bfd_link_hash_entry
*next
;
156 /* BFD symbol was found in. */
159 /* bfd_link_hash_defined, bfd_link_hash_defweak. */
162 struct bfd_link_hash_entry
*next
;
163 /* Symbol section. */
168 /* bfd_link_hash_indirect, bfd_link_hash_warning. */
171 struct bfd_link_hash_entry
*next
;
173 struct bfd_link_hash_entry
*link
;
174 /* Warning message (bfd_link_hash_warning only). */
177 /* bfd_link_hash_common. */
180 struct bfd_link_hash_entry
*next
;
181 /* The linker needs to know three things about common
182 symbols: the size, the alignment, and the section in
183 which the symbol should be placed. We store the size
184 here, and we allocate a small structure to hold the
185 section and the alignment. The alignment is stored as a
186 power of two. We don't store all the information
187 directly because we don't want to increase the size of
188 the union; this structure is a major space user in the
190 struct bfd_link_hash_common_entry
*p
;
191 /* Common symbol size. */
197 /* This is the link hash table. It is a derived class of
200 struct bfd_link_hash_table
202 /* The hash table itself. */
203 struct bfd_hash_table table
;
204 /* A linked list of undefined and common symbols, linked through the
205 next field in the bfd_link_hash_entry structure. */
206 struct bfd_link_hash_entry
*undefs
;
207 /* Entries are added to the tail of the undefs list. */
208 struct bfd_link_hash_entry
*undefs_tail
;
209 /* Function to free the hash table on closing BFD. */
210 void (*hash_table_free
) (bfd
*);
211 /* The type of the link hash table. */
212 enum bfd_link_hash_table_type type
;
215 /* Look up an entry in a link hash table. If FOLLOW is TRUE, this
216 follows bfd_link_hash_indirect and bfd_link_hash_warning links to
218 extern struct bfd_link_hash_entry
*bfd_link_hash_lookup
219 (struct bfd_link_hash_table
*, const char *, bfd_boolean create
,
220 bfd_boolean copy
, bfd_boolean follow
);
222 /* Look up an entry in the main linker hash table if the symbol might
223 be wrapped. This should only be used for references to an
224 undefined symbol, not for definitions of a symbol. */
226 extern struct bfd_link_hash_entry
*bfd_wrapped_link_hash_lookup
227 (bfd
*, struct bfd_link_info
*, const char *, bfd_boolean
,
228 bfd_boolean
, bfd_boolean
);
230 /* If H is a wrapped symbol, ie. the symbol name starts with "__wrap_"
231 and the remainder is found in wrap_hash, return the real symbol. */
233 extern struct bfd_link_hash_entry
*unwrap_hash_lookup
234 (struct bfd_link_info
*, bfd
*, struct bfd_link_hash_entry
*);
236 /* Traverse a link hash table. */
237 extern void bfd_link_hash_traverse
238 (struct bfd_link_hash_table
*,
239 bfd_boolean (*) (struct bfd_link_hash_entry
*, void *),
242 /* Add an entry to the undefs list. */
243 extern void bfd_link_add_undef
244 (struct bfd_link_hash_table
*, struct bfd_link_hash_entry
*);
246 /* Remove symbols from the undefs list that don't belong there. */
247 extern void bfd_link_repair_undef_list
248 (struct bfd_link_hash_table
*table
);
250 /* Read symbols and cache symbol pointer array in outsymbols. */
251 extern bfd_boolean
bfd_generic_link_read_symbols (bfd
*);
253 /* Check the relocs in the BFD. Called after all the input
254 files have been loaded, and garbage collection has tagged
255 any unneeded sections. */
256 extern bfd_boolean
bfd_link_check_relocs (bfd
*,struct bfd_link_info
*);
260 struct bfd_sym_chain
*next
;
264 /* How to handle unresolved symbols.
265 There are four possibilities which are enumerated below: */
268 /* This is the initial value when then link_info structure is created.
269 It allows the various stages of the linker to determine whether they
270 allowed to set the value. */
276 typedef enum {with_flags
, without_flags
} flag_type
;
278 /* A section flag list. */
279 struct flag_info_list
284 struct flag_info_list
*next
;
287 /* Section flag info. */
290 flagword only_with_flags
;
291 flagword not_with_flags
;
292 struct flag_info_list
*flag_list
;
293 bfd_boolean flags_initialized
;
296 struct bfd_elf_dynamic_list
;
297 struct bfd_elf_version_tree
;
299 /* Types of output. */
309 #define bfd_link_pde(info) ((info)->type == type_pde)
310 #define bfd_link_dll(info) ((info)->type == type_dll)
311 #define bfd_link_relocatable(info) ((info)->type == type_relocatable)
312 #define bfd_link_pie(info) ((info)->type == type_pie)
313 #define bfd_link_executable(info) (bfd_link_pde (info) || bfd_link_pie (info))
314 #define bfd_link_pic(info) (bfd_link_dll (info) || bfd_link_pie (info))
316 /* This structure holds all the information needed to communicate
317 between BFD and the linker when doing a link. */
322 ENUM_BITFIELD (output_type
) type
: 2;
324 /* TRUE if BFD should pre-bind symbols in a shared object. */
325 unsigned int symbolic
: 1;
327 /* TRUE if executable should not contain copy relocs.
328 Setting this true may result in a non-sharable text segment. */
329 unsigned int nocopyreloc
: 1;
331 /* TRUE if BFD should export all symbols in the dynamic symbol table
332 of an executable, rather than only those used. */
333 unsigned int export_dynamic
: 1;
335 /* TRUE if a default symbol version should be created and used for
337 unsigned int create_default_symver
: 1;
339 /* TRUE if unreferenced sections should be removed. */
340 unsigned int gc_sections
: 1;
342 /* TRUE if exported symbols should be kept during section gc. */
343 unsigned int gc_keep_exported
: 1;
345 /* TRUE if every symbol should be reported back via the notice
347 unsigned int notice_all
: 1;
349 /* TRUE if the LTO plugin is active. */
350 unsigned int lto_plugin_active
: 1;
352 /* TRUE if global symbols in discarded sections should be stripped. */
353 unsigned int strip_discarded
: 1;
355 /* TRUE if all data symbols should be dynamic. */
356 unsigned int dynamic_data
: 1;
358 /* TRUE if section groups should be resolved. */
359 unsigned int resolve_section_groups
: 1;
361 /* Set if output file is big-endian, or if that is unknown, from
362 the command line or first input file endianness. */
363 unsigned int big_endian
: 1;
365 /* Which symbols to strip. */
366 ENUM_BITFIELD (bfd_link_strip
) strip
: 2;
368 /* Which local symbols to discard. */
369 ENUM_BITFIELD (bfd_link_discard
) discard
: 2;
371 /* Whether to generate ELF common symbols with the STT_COMMON type. */
372 ENUM_BITFIELD (bfd_link_elf_stt_common
) elf_stt_common
: 2;
374 /* Criteria for skipping symbols when determining
375 whether to include an object from an archive. */
376 ENUM_BITFIELD (bfd_link_common_skip_ar_symbols
) common_skip_ar_symbols
: 2;
378 /* What to do with unresolved symbols in an object file.
379 When producing executables the default is GENERATE_ERROR.
380 When producing shared libraries the default is IGNORE. The
381 assumption with shared libraries is that the reference will be
382 resolved at load/execution time. */
383 ENUM_BITFIELD (report_method
) unresolved_syms_in_objects
: 2;
385 /* What to do with unresolved symbols in a shared library.
386 The same defaults apply. */
387 ENUM_BITFIELD (report_method
) unresolved_syms_in_shared_libs
: 2;
389 /* TRUE if unresolved symbols are to be warned, rather than errored. */
390 unsigned int warn_unresolved_syms
: 1;
392 /* TRUE if shared objects should be linked directly, not shared. */
393 unsigned int static_link
: 1;
395 /* TRUE if symbols should be retained in memory, FALSE if they
396 should be freed and reread. */
397 unsigned int keep_memory
: 1;
399 /* TRUE if BFD should generate relocation information in the final
401 unsigned int emitrelocations
: 1;
403 /* TRUE if PT_GNU_RELRO segment should be created. */
404 unsigned int relro
: 1;
406 /* TRUE if separate code segment should be created. */
407 unsigned int separate_code
: 1;
409 /* Nonzero if .eh_frame_hdr section and PT_GNU_EH_FRAME ELF segment
410 should be created. 1 for DWARF2 tables, 2 for compact tables. */
411 unsigned int eh_frame_hdr_type
: 2;
413 /* TRUE if we should warn when adding a DT_TEXTREL to a shared object. */
414 unsigned int warn_shared_textrel
: 1;
416 /* TRUE if we should error when adding a DT_TEXTREL. */
417 unsigned int error_textrel
: 1;
419 /* TRUE if .hash section should be created. */
420 unsigned int emit_hash
: 1;
422 /* TRUE if .gnu.hash section should be created. */
423 unsigned int emit_gnu_hash
: 1;
425 /* If TRUE reduce memory overheads, at the expense of speed. This will
426 cause map file generation to use an O(N^2) algorithm and disable
427 caching ELF symbol buffer. */
428 unsigned int reduce_memory_overheads
: 1;
430 /* TRUE if the output file should be in a traditional format. This
431 is equivalent to the setting of the BFD_TRADITIONAL_FORMAT flag
432 on the output file, but may be checked when reading the input
434 unsigned int traditional_format
: 1;
436 /* TRUE if non-PLT relocs should be merged into one reloc section
437 and sorted so that relocs against the same symbol come together. */
438 unsigned int combreloc
: 1;
440 /* TRUE if a default symbol version should be created and used for
442 unsigned int default_imported_symver
: 1;
444 /* TRUE if the new ELF dynamic tags are enabled. */
445 unsigned int new_dtags
: 1;
447 /* FALSE if .eh_frame unwind info should be generated for PLT and other
448 linker created sections, TRUE if it should be omitted. */
449 unsigned int no_ld_generated_unwind_info
: 1;
451 /* TRUE if BFD should generate a "task linked" object file,
452 similar to relocatable but also with globals converted to
454 unsigned int task_link
: 1;
456 /* TRUE if ok to have multiple definition. */
457 unsigned int allow_multiple_definition
: 1;
459 /* TRUE if ok to have prohibit multiple definition of absolute symbols. */
460 unsigned int prohibit_multiple_definition_absolute
: 1;
462 /* TRUE if ok to have version with no definition. */
463 unsigned int allow_undefined_version
: 1;
465 /* TRUE if some symbols have to be dynamic, controlled by
466 --dynamic-list command line options. */
467 unsigned int dynamic
: 1;
469 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W|PF_X
471 unsigned int execstack
: 1;
473 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W
475 unsigned int noexecstack
: 1;
477 /* TRUE if we want to produced optimized output files. This might
478 need much more time and therefore must be explicitly selected. */
479 unsigned int optimize
: 1;
481 /* TRUE if user should be informed of removed unreferenced sections. */
482 unsigned int print_gc_sections
: 1;
484 /* TRUE if we should warn alternate ELF machine code. */
485 unsigned int warn_alternate_em
: 1;
487 /* TRUE if the linker script contained an explicit PHDRS command. */
488 unsigned int user_phdrs
: 1;
490 /* TRUE if program headers ought to be loaded. */
491 unsigned int load_phdrs
: 1;
493 /* TRUE if we should check relocations after all input files have
495 unsigned int check_relocs_after_open_input
: 1;
497 /* TRUE if generation of .interp/PT_INTERP should be suppressed. */
498 unsigned int nointerp
: 1;
500 /* TRUE if common symbols should be treated as undefined. */
501 unsigned int inhibit_common_definition
: 1;
503 /* TRUE if "-Map map" is passed to linker. */
504 unsigned int has_map_file
: 1;
506 /* TRUE if "--enable-non-contiguous-regions" is passed to the
508 unsigned int non_contiguous_regions
: 1;
510 /* TRUE if "--enable-non-contiguous-regions-warnings" is passed to
512 unsigned int non_contiguous_regions_warnings
: 1;
514 /* Char that may appear as the first char of a symbol, but should be
515 skipped (like symbol_leading_char) when looking up symbols in
516 wrap_hash. Used by PowerPC Linux for 'dot' symbols. */
519 /* Separator between archive and filename in linker script filespecs. */
522 /* Compress DWARF debug sections. */
523 enum compressed_debug_section_type compress_debug
;
525 /* Default stack size. Zero means default (often zero itself), -1
526 means explicitly zero-sized. */
527 bfd_signed_vma stacksize
;
529 /* Enable or disable target specific optimizations.
531 Not all targets have optimizations to enable.
533 Normally these optimizations are disabled by default but some targets
534 prefer to enable them by default. So this field is a tri-state variable.
537 zero: Enable the optimizations (either from --relax being specified on
538 the command line or the backend's before_allocation emulation function.
540 positive: The user has requested that these optimizations be disabled.
541 (Via the --no-relax command line option).
543 negative: The optimizations are disabled. (Set when initializing the
544 args_type structure in ldmain.c:main. */
545 signed int disable_target_specific_optimizations
;
547 /* Function callbacks. */
548 const struct bfd_link_callbacks
*callbacks
;
550 /* Hash table handled by BFD. */
551 struct bfd_link_hash_table
*hash
;
553 /* Hash table of symbols to keep. This is NULL unless strip is
555 struct bfd_hash_table
*keep_hash
;
557 /* Hash table of symbols to report back via the notice callback. If
558 this is NULL, and notice_all is FALSE, then no symbols are
560 struct bfd_hash_table
*notice_hash
;
562 /* Hash table of symbols which are being wrapped (the --wrap linker
563 option). If this is NULL, no symbols are being wrapped. */
564 struct bfd_hash_table
*wrap_hash
;
566 /* Hash table of symbols which may be left unresolved during
567 a link. If this is NULL, no symbols can be left unresolved. */
568 struct bfd_hash_table
*ignore_hash
;
570 /* The output BFD. */
573 /* The import library generated. */
576 /* The list of input BFD's involved in the link. These are chained
577 together via the link.next field. */
579 bfd
**input_bfds_tail
;
581 /* If a symbol should be created for each input BFD, this is section
582 where those symbols should be placed. It must be a section in
583 the output BFD. It may be NULL, in which case no such symbols
584 will be created. This is to support CREATE_OBJECT_SYMBOLS in the
585 linker command language. */
586 asection
*create_object_symbols_section
;
588 /* List of global symbol names that are starting points for marking
589 sections against garbage collection. */
590 struct bfd_sym_chain
*gc_sym_list
;
592 /* If a base output file is wanted, then this points to it */
595 /* The function to call when the executable or shared object is
597 const char *init_function
;
599 /* The function to call when the executable or shared object is
601 const char *fini_function
;
603 /* Number of relaxation passes. Usually only one relaxation pass
604 is needed. But a backend can have as many relaxation passes as
605 necessary. During bfd_relax_section call, it is set to the
606 current pass, starting from 0. */
609 /* Number of relaxation trips. This number is incremented every
610 time the relaxation pass is restarted due to a previous
611 relaxation returning true in *AGAIN. */
614 /* > 0 to treat protected data defined in the shared library as
615 reference external. 0 to treat it as internal. -1 to let
616 backend to decide. */
617 int extern_protected_data
;
619 /* 1 to make undefined weak symbols dynamic when building a dynamic
620 object. 0 to resolve undefined weak symbols to zero. -1 to let
621 the backend decide. */
622 int dynamic_undefined_weak
;
624 /* Non-zero if auto-import thunks for DATA items in pei386 DLLs
625 should be generated/linked against. Set to 1 if this feature
626 is explicitly requested by the user, -1 if enabled by default. */
627 int pei386_auto_import
;
629 /* Non-zero if runtime relocs for DATA items with non-zero addends
630 in pei386 DLLs should be generated. Set to 1 if this feature
631 is explicitly requested by the user, -1 if enabled by default. */
632 int pei386_runtime_pseudo_reloc
;
634 /* How many spare .dynamic DT_NULL entries should be added? */
635 unsigned int spare_dynamic_tags
;
637 /* May be used to set DT_FLAGS for ELF. */
640 /* May be used to set DT_FLAGS_1 for ELF. */
643 /* Start and end of RELRO region. */
644 bfd_vma relro_start
, relro_end
;
646 /* List of symbols should be dynamic. */
647 struct bfd_elf_dynamic_list
*dynamic_list
;
649 /* The version information. */
650 struct bfd_elf_version_tree
*version_info
;
653 /* Some forward-definitions used by some callbacks. */
655 struct elf_strtab_hash
;
656 struct elf_sym_strtab
;
658 /* This structures holds a set of callback functions. These are called
659 by the BFD linker routines. */
661 struct bfd_link_callbacks
663 /* A function which is called when an object is added from an
664 archive. ABFD is the archive element being added. NAME is the
665 name of the symbol which caused the archive element to be pulled
666 in. This function may set *SUBSBFD to point to an alternative
667 BFD from which symbols should in fact be added in place of the
668 original BFD's symbols. Returns TRUE if the object should be
669 added, FALSE if it should be skipped. */
670 bfd_boolean (*add_archive_element
)
671 (struct bfd_link_info
*, bfd
*abfd
, const char *name
, bfd
**subsbfd
);
672 /* A function which is called when a symbol is found with multiple
673 definitions. H is the symbol which is defined multiple times.
674 NBFD is the new BFD, NSEC is the new section, and NVAL is the new
675 value. NSEC may be bfd_com_section or bfd_ind_section. */
676 void (*multiple_definition
)
677 (struct bfd_link_info
*, struct bfd_link_hash_entry
*h
,
678 bfd
*nbfd
, asection
*nsec
, bfd_vma nval
);
679 /* A function which is called when a common symbol is defined
680 multiple times. H is the symbol appearing multiple times.
681 NBFD is the BFD of the new symbol. NTYPE is the type of the new
682 symbol, one of bfd_link_hash_defined, bfd_link_hash_common, or
683 bfd_link_hash_indirect. If NTYPE is bfd_link_hash_common, NSIZE
684 is the size of the new symbol. */
685 void (*multiple_common
)
686 (struct bfd_link_info
*, struct bfd_link_hash_entry
*h
,
687 bfd
*nbfd
, enum bfd_link_hash_type ntype
, bfd_vma nsize
);
688 /* A function which is called to add a symbol to a set. ENTRY is
689 the link hash table entry for the set itself (e.g.,
690 __CTOR_LIST__). RELOC is the relocation to use for an entry in
691 the set when generating a relocatable file, and is also used to
692 get the size of the entry when generating an executable file.
693 ABFD, SEC and VALUE identify the value to add to the set. */
695 (struct bfd_link_info
*, struct bfd_link_hash_entry
*entry
,
696 bfd_reloc_code_real_type reloc
, bfd
*abfd
, asection
*sec
, bfd_vma value
);
697 /* A function which is called when the name of a g++ constructor or
698 destructor is found. This is only called by some object file
699 formats. CONSTRUCTOR is TRUE for a constructor, FALSE for a
700 destructor. This will use BFD_RELOC_CTOR when generating a
701 relocatable file. NAME is the name of the symbol found. ABFD,
702 SECTION and VALUE are the value of the symbol. */
704 (struct bfd_link_info
*, bfd_boolean constructor
, const char *name
,
705 bfd
*abfd
, asection
*sec
, bfd_vma value
);
706 /* A function which is called to issue a linker warning. For
707 example, this is called when there is a reference to a warning
708 symbol. WARNING is the warning to be issued. SYMBOL is the name
709 of the symbol which triggered the warning; it may be NULL if
710 there is none. ABFD, SECTION and ADDRESS identify the location
711 which trigerred the warning; either ABFD or SECTION or both may
712 be NULL if the location is not known. */
714 (struct bfd_link_info
*, const char *warning
, const char *symbol
,
715 bfd
*abfd
, asection
*section
, bfd_vma address
);
716 /* A function which is called when a relocation is attempted against
717 an undefined symbol. NAME is the symbol which is undefined.
718 ABFD, SECTION and ADDRESS identify the location from which the
719 reference is made. IS_FATAL indicates whether an undefined symbol is
720 a fatal error or not. In some cases SECTION may be NULL. */
721 void (*undefined_symbol
)
722 (struct bfd_link_info
*, const char *name
, bfd
*abfd
,
723 asection
*section
, bfd_vma address
, bfd_boolean is_fatal
);
724 /* A function which is called when a reloc overflow occurs. ENTRY is
725 the link hash table entry for the symbol the reloc is against.
726 NAME is the name of the local symbol or section the reloc is
727 against, RELOC_NAME is the name of the relocation, and ADDEND is
728 any addend that is used. ABFD, SECTION and ADDRESS identify the
729 location at which the overflow occurs; if this is the result of a
730 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
731 ABFD will be NULL. */
732 void (*reloc_overflow
)
733 (struct bfd_link_info
*, struct bfd_link_hash_entry
*entry
,
734 const char *name
, const char *reloc_name
, bfd_vma addend
,
735 bfd
*abfd
, asection
*section
, bfd_vma address
);
736 /* A function which is called when a dangerous reloc is performed.
737 MESSAGE is an appropriate message.
738 ABFD, SECTION and ADDRESS identify the location at which the
739 problem occurred; if this is the result of a
740 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
741 ABFD will be NULL. */
742 void (*reloc_dangerous
)
743 (struct bfd_link_info
*, const char *message
,
744 bfd
*abfd
, asection
*section
, bfd_vma address
);
745 /* A function which is called when a reloc is found to be attached
746 to a symbol which is not being written out. NAME is the name of
747 the symbol. ABFD, SECTION and ADDRESS identify the location of
748 the reloc; if this is the result of a
749 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
750 ABFD will be NULL. */
751 void (*unattached_reloc
)
752 (struct bfd_link_info
*, const char *name
,
753 bfd
*abfd
, asection
*section
, bfd_vma address
);
754 /* A function which is called when a symbol in notice_hash is
755 defined or referenced. H is the symbol, INH the indirect symbol
756 if applicable. ABFD, SECTION and ADDRESS are the (new) value of
757 the symbol. If SECTION is bfd_und_section, this is a reference.
758 FLAGS are the symbol BSF_* flags. */
759 bfd_boolean (*notice
)
760 (struct bfd_link_info
*, struct bfd_link_hash_entry
*h
,
761 struct bfd_link_hash_entry
*inh
,
762 bfd
*abfd
, asection
*section
, bfd_vma address
, flagword flags
);
763 /* Error or warning link info message. */
765 (const char *fmt
, ...);
766 /* General link info message. */
768 (const char *fmt
, ...);
769 /* Message to be printed in linker map file. */
771 (const char *fmt
, ...);
772 /* This callback provides a chance for users of the BFD library to
773 override its decision about whether to place two adjacent sections
774 into the same segment. */
775 bfd_boolean (*override_segment_assignment
)
776 (struct bfd_link_info
*, bfd
* abfd
,
777 asection
* current_section
, asection
* previous_section
,
778 bfd_boolean new_segment
);
779 /* This callback provides a chance for callers of the BFD to examine the
780 ELF string table and symbol table once they are complete and indexes and
782 void (*examine_strtab
)
783 (struct elf_sym_strtab
*syms
, bfd_size_type symcount
,
784 struct elf_strtab_hash
*symstrtab
);
785 /* This callback should emit the CTF section into a non-loadable section in
786 the output BFD named .ctf or a name beginning with ".ctf.". */
791 /* The linker builds link_order structures which tell the code how to
792 include input data in the output file. */
794 /* These are the types of link_order structures. */
796 enum bfd_link_order_type
798 bfd_undefined_link_order
, /* Undefined. */
799 bfd_indirect_link_order
, /* Built from a section. */
800 bfd_data_link_order
, /* Set to explicit data. */
801 bfd_section_reloc_link_order
, /* Relocate against a section. */
802 bfd_symbol_reloc_link_order
/* Relocate against a symbol. */
805 /* This is the link_order structure itself. These form a chain
806 attached to the output section whose contents they are describing. */
808 struct bfd_link_order
810 /* Next link_order in chain. */
811 struct bfd_link_order
*next
;
812 /* Type of link_order. */
813 enum bfd_link_order_type type
;
814 /* Offset within output section in bytes. */
816 /* Size within output section in octets. */
818 /* Type specific information. */
823 /* Section to include. If this is used, then
824 section->output_section must be the section the
825 link_order is attached to, section->output_offset must
826 equal the link_order offset field, and section->size
827 must equal the link_order size field. Maybe these
828 restrictions should be relaxed someday. */
833 /* Size of contents, or zero when contents should be filled by
834 the architecture-dependent fill function.
835 A non-zero value allows filling of the output section
836 with an arbitrary repeated pattern. */
838 /* Data to put into file. */
843 /* Description of reloc to generate. Used for
844 bfd_section_reloc_link_order and
845 bfd_symbol_reloc_link_order. */
846 struct bfd_link_order_reloc
*p
;
851 /* A linker order of type bfd_section_reloc_link_order or
852 bfd_symbol_reloc_link_order means to create a reloc against a
853 section or symbol, respectively. This is used to implement -Ur to
854 generate relocs for the constructor tables. The
855 bfd_link_order_reloc structure describes the reloc that BFD should
856 create. It is similar to a arelent, but I didn't use arelent
857 because the linker does not know anything about most symbols, and
858 any asymbol structure it creates will be partially meaningless.
859 This information could logically be in the bfd_link_order struct,
860 but I didn't want to waste the space since these types of relocs
861 are relatively rare. */
863 struct bfd_link_order_reloc
866 bfd_reloc_code_real_type reloc
;
870 /* For type bfd_section_reloc_link_order, this is the section
871 the reloc should be against. This must be a section in the
872 output BFD, not any of the input BFDs. */
874 /* For type bfd_symbol_reloc_link_order, this is the name of the
875 symbol the reloc should be against. */
879 /* Addend to use. The object file should contain zero. The BFD
880 backend is responsible for filling in the contents of the object
881 file correctly. For some object file formats (e.g., COFF) the
882 addend must be stored into in the object file, and for some
883 (e.g., SPARC a.out) it is kept in the reloc. */
887 /* Allocate a new link_order for a section. */
888 extern struct bfd_link_order
*bfd_new_link_order (bfd
*, asection
*);
890 struct bfd_section_already_linked
;
892 extern bfd_boolean
bfd_section_already_linked_table_init (void);
893 extern void bfd_section_already_linked_table_free (void);
894 extern bfd_boolean _bfd_handle_already_linked
895 (struct bfd_section
*, struct bfd_section_already_linked
*,
896 struct bfd_link_info
*);
898 extern struct bfd_section
*_bfd_nearby_section
899 (bfd
*, struct bfd_section
*, bfd_vma
);
901 extern void _bfd_fix_excluded_sec_syms
902 (bfd
*, struct bfd_link_info
*);
904 /* These structures are used to describe version information for the
905 ELF linker. These structures could be manipulated entirely inside
906 BFD, but it would be a pain. Instead, the regular linker sets up
907 these structures, and then passes them into BFD. */
909 /* Glob pattern for a version. */
911 struct bfd_elf_version_expr
913 /* Next glob pattern for this version. */
914 struct bfd_elf_version_expr
*next
;
917 /* Set if pattern is not a glob. */
918 unsigned int literal
: 1;
919 /* Defined by ".symver". */
920 unsigned int symver
: 1;
921 /* Defined by version script. */
922 unsigned int script
: 1;
924 #define BFD_ELF_VERSION_C_TYPE 1
925 #define BFD_ELF_VERSION_CXX_TYPE 2
926 #define BFD_ELF_VERSION_JAVA_TYPE 4
927 unsigned int mask
: 3;
930 struct bfd_elf_version_expr_head
932 /* List of all patterns, both wildcards and non-wildcards. */
933 struct bfd_elf_version_expr
*list
;
934 /* Hash table for non-wildcards. */
936 /* Remaining patterns. */
937 struct bfd_elf_version_expr
*remaining
;
938 /* What kind of pattern types are present in list (bitmask). */
942 /* Version dependencies. */
944 struct bfd_elf_version_deps
946 /* Next dependency for this version. */
947 struct bfd_elf_version_deps
*next
;
948 /* The version which this version depends upon. */
949 struct bfd_elf_version_tree
*version_needed
;
952 /* A node in the version tree. */
954 struct bfd_elf_version_tree
957 struct bfd_elf_version_tree
*next
;
958 /* Name of this version. */
960 /* Version number. */
962 /* Regular expressions for global symbols in this version. */
963 struct bfd_elf_version_expr_head globals
;
964 /* Regular expressions for local symbols in this version. */
965 struct bfd_elf_version_expr_head locals
;
966 /* List of versions which this version depends upon. */
967 struct bfd_elf_version_deps
*deps
;
968 /* Index of the version name. This is used within BFD. */
969 unsigned int name_indx
;
970 /* Whether this version tree was used. This is used within BFD. */
973 struct bfd_elf_version_expr
*(*match
)
974 (struct bfd_elf_version_expr_head
*head
,
975 struct bfd_elf_version_expr
*prev
, const char *sym
);
978 struct bfd_elf_dynamic_list
980 struct bfd_elf_version_expr_head head
;
981 struct bfd_elf_version_expr
*(*match
)
982 (struct bfd_elf_version_expr_head
*head
,
983 struct bfd_elf_version_expr
*prev
, const char *sym
);