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. */
277 typedef enum {with_flags
, without_flags
} flag_type
;
279 /* A section flag list. */
280 struct flag_info_list
285 struct flag_info_list
*next
;
288 /* Section flag info. */
291 flagword only_with_flags
;
292 flagword not_with_flags
;
293 struct flag_info_list
*flag_list
;
294 bfd_boolean flags_initialized
;
297 struct bfd_elf_dynamic_list
;
298 struct bfd_elf_version_tree
;
300 /* Types of output. */
310 #define bfd_link_pde(info) ((info)->type == type_pde)
311 #define bfd_link_dll(info) ((info)->type == type_dll)
312 #define bfd_link_relocatable(info) ((info)->type == type_relocatable)
313 #define bfd_link_pie(info) ((info)->type == type_pie)
314 #define bfd_link_executable(info) (bfd_link_pde (info) || bfd_link_pie (info))
315 #define bfd_link_pic(info) (bfd_link_dll (info) || bfd_link_pie (info))
317 /* This structure holds all the information needed to communicate
318 between BFD and the linker when doing a link. */
323 ENUM_BITFIELD (output_type
) type
: 2;
325 /* TRUE if BFD should pre-bind symbols in a shared object. */
326 unsigned int symbolic
: 1;
328 /* TRUE if executable should not contain copy relocs.
329 Setting this true may result in a non-sharable text segment. */
330 unsigned int nocopyreloc
: 1;
332 /* TRUE if BFD should export all symbols in the dynamic symbol table
333 of an executable, rather than only those used. */
334 unsigned int export_dynamic
: 1;
336 /* TRUE if a default symbol version should be created and used for
338 unsigned int create_default_symver
: 1;
340 /* TRUE if unreferenced sections should be removed. */
341 unsigned int gc_sections
: 1;
343 /* TRUE if exported symbols should be kept during section gc. */
344 unsigned int gc_keep_exported
: 1;
346 /* TRUE if every symbol should be reported back via the notice
348 unsigned int notice_all
: 1;
350 /* TRUE if the LTO plugin is active. */
351 unsigned int lto_plugin_active
: 1;
353 /* TRUE if global symbols in discarded sections should be stripped. */
354 unsigned int strip_discarded
: 1;
356 /* TRUE if all data symbols should be dynamic. */
357 unsigned int dynamic_data
: 1;
359 /* TRUE if section groups should be resolved. */
360 unsigned int resolve_section_groups
: 1;
362 /* Set if output file is big-endian, or if that is unknown, from
363 the command line or first input file endianness. */
364 unsigned int big_endian
: 1;
366 /* Which symbols to strip. */
367 ENUM_BITFIELD (bfd_link_strip
) strip
: 2;
369 /* Which local symbols to discard. */
370 ENUM_BITFIELD (bfd_link_discard
) discard
: 2;
372 /* Whether to generate ELF common symbols with the STT_COMMON type. */
373 ENUM_BITFIELD (bfd_link_elf_stt_common
) elf_stt_common
: 2;
375 /* Criteria for skipping symbols when determining
376 whether to include an object from an archive. */
377 ENUM_BITFIELD (bfd_link_common_skip_ar_symbols
) common_skip_ar_symbols
: 2;
379 /* What to do with unresolved symbols in an object file.
380 When producing executables the default is GENERATE_ERROR.
381 When producing shared libraries the default is IGNORE. The
382 assumption with shared libraries is that the reference will be
383 resolved at load/execution time. */
384 ENUM_BITFIELD (report_method
) unresolved_syms_in_objects
: 2;
386 /* What to do with unresolved symbols in a shared library.
387 The same defaults apply. */
388 ENUM_BITFIELD (report_method
) unresolved_syms_in_shared_libs
: 2;
390 /* TRUE if shared objects should be linked directly, not shared. */
391 unsigned int static_link
: 1;
393 /* TRUE if symbols should be retained in memory, FALSE if they
394 should be freed and reread. */
395 unsigned int keep_memory
: 1;
397 /* TRUE if BFD should generate relocation information in the final
399 unsigned int emitrelocations
: 1;
401 /* TRUE if PT_GNU_RELRO segment should be created. */
402 unsigned int relro
: 1;
404 /* TRUE if separate code segment should be created. */
405 unsigned int separate_code
: 1;
407 /* Nonzero if .eh_frame_hdr section and PT_GNU_EH_FRAME ELF segment
408 should be created. 1 for DWARF2 tables, 2 for compact tables. */
409 unsigned int eh_frame_hdr_type
: 2;
411 /* TRUE if we should warn when adding a DT_TEXTREL to a shared object. */
412 unsigned int warn_shared_textrel
: 1;
414 /* TRUE if we should error when adding a DT_TEXTREL. */
415 unsigned int error_textrel
: 1;
417 /* TRUE if .hash section should be created. */
418 unsigned int emit_hash
: 1;
420 /* TRUE if .gnu.hash section should be created. */
421 unsigned int emit_gnu_hash
: 1;
423 /* If TRUE reduce memory overheads, at the expense of speed. This will
424 cause map file generation to use an O(N^2) algorithm and disable
425 caching ELF symbol buffer. */
426 unsigned int reduce_memory_overheads
: 1;
428 /* TRUE if the output file should be in a traditional format. This
429 is equivalent to the setting of the BFD_TRADITIONAL_FORMAT flag
430 on the output file, but may be checked when reading the input
432 unsigned int traditional_format
: 1;
434 /* TRUE if non-PLT relocs should be merged into one reloc section
435 and sorted so that relocs against the same symbol come together. */
436 unsigned int combreloc
: 1;
438 /* TRUE if a default symbol version should be created and used for
440 unsigned int default_imported_symver
: 1;
442 /* TRUE if the new ELF dynamic tags are enabled. */
443 unsigned int new_dtags
: 1;
445 /* FALSE if .eh_frame unwind info should be generated for PLT and other
446 linker created sections, TRUE if it should be omitted. */
447 unsigned int no_ld_generated_unwind_info
: 1;
449 /* TRUE if BFD should generate a "task linked" object file,
450 similar to relocatable but also with globals converted to
452 unsigned int task_link
: 1;
454 /* TRUE if ok to have multiple definition. */
455 unsigned int allow_multiple_definition
: 1;
457 /* TRUE if ok to have prohibit multiple definition of absolute symbols. */
458 unsigned int prohibit_multiple_definition_absolute
: 1;
460 /* TRUE if ok to have version with no definition. */
461 unsigned int allow_undefined_version
: 1;
463 /* TRUE if some symbols have to be dynamic, controlled by
464 --dynamic-list command line options. */
465 unsigned int dynamic
: 1;
467 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W|PF_X
469 unsigned int execstack
: 1;
471 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W
473 unsigned int noexecstack
: 1;
475 /* TRUE if we want to produced optimized output files. This might
476 need much more time and therefore must be explicitly selected. */
477 unsigned int optimize
: 1;
479 /* TRUE if user should be informed of removed unreferenced sections. */
480 unsigned int print_gc_sections
: 1;
482 /* TRUE if we should warn alternate ELF machine code. */
483 unsigned int warn_alternate_em
: 1;
485 /* TRUE if the linker script contained an explicit PHDRS command. */
486 unsigned int user_phdrs
: 1;
488 /* TRUE if program headers ought to be loaded. */
489 unsigned int load_phdrs
: 1;
491 /* TRUE if we should check relocations after all input files have
493 unsigned int check_relocs_after_open_input
: 1;
495 /* TRUE if generation of .interp/PT_INTERP should be suppressed. */
496 unsigned int nointerp
: 1;
498 /* TRUE if common symbols should be treated as undefined. */
499 unsigned int inhibit_common_definition
: 1;
501 /* TRUE if "-Map map" is passed to linker. */
502 unsigned int has_map_file
: 1;
504 /* TRUE if "--enable-non-contiguous-regions" is passed to the
506 unsigned int non_contiguous_regions
: 1;
508 /* TRUE if "--enable-non-contiguous-regions-warnings" is passed to
510 unsigned int non_contiguous_regions_warnings
: 1;
512 /* Char that may appear as the first char of a symbol, but should be
513 skipped (like symbol_leading_char) when looking up symbols in
514 wrap_hash. Used by PowerPC Linux for 'dot' symbols. */
517 /* Separator between archive and filename in linker script filespecs. */
520 /* Compress DWARF debug sections. */
521 enum compressed_debug_section_type compress_debug
;
523 /* Default stack size. Zero means default (often zero itself), -1
524 means explicitly zero-sized. */
525 bfd_signed_vma stacksize
;
527 /* Enable or disable target specific optimizations.
529 Not all targets have optimizations to enable.
531 Normally these optimizations are disabled by default but some targets
532 prefer to enable them by default. So this field is a tri-state variable.
535 zero: Enable the optimizations (either from --relax being specified on
536 the command line or the backend's before_allocation emulation function.
538 positive: The user has requested that these optimizations be disabled.
539 (Via the --no-relax command line option).
541 negative: The optimizations are disabled. (Set when initializing the
542 args_type structure in ldmain.c:main. */
543 signed int disable_target_specific_optimizations
;
545 /* Function callbacks. */
546 const struct bfd_link_callbacks
*callbacks
;
548 /* Hash table handled by BFD. */
549 struct bfd_link_hash_table
*hash
;
551 /* Hash table of symbols to keep. This is NULL unless strip is
553 struct bfd_hash_table
*keep_hash
;
555 /* Hash table of symbols to report back via the notice callback. If
556 this is NULL, and notice_all is FALSE, then no symbols are
558 struct bfd_hash_table
*notice_hash
;
560 /* Hash table of symbols which are being wrapped (the --wrap linker
561 option). If this is NULL, no symbols are being wrapped. */
562 struct bfd_hash_table
*wrap_hash
;
564 /* Hash table of symbols which may be left unresolved during
565 a link. If this is NULL, no symbols can be left unresolved. */
566 struct bfd_hash_table
*ignore_hash
;
568 /* The output BFD. */
571 /* The import library generated. */
574 /* The list of input BFD's involved in the link. These are chained
575 together via the link.next field. */
577 bfd
**input_bfds_tail
;
579 /* If a symbol should be created for each input BFD, this is section
580 where those symbols should be placed. It must be a section in
581 the output BFD. It may be NULL, in which case no such symbols
582 will be created. This is to support CREATE_OBJECT_SYMBOLS in the
583 linker command language. */
584 asection
*create_object_symbols_section
;
586 /* List of global symbol names that are starting points for marking
587 sections against garbage collection. */
588 struct bfd_sym_chain
*gc_sym_list
;
590 /* If a base output file is wanted, then this points to it */
593 /* The function to call when the executable or shared object is
595 const char *init_function
;
597 /* The function to call when the executable or shared object is
599 const char *fini_function
;
601 /* Number of relaxation passes. Usually only one relaxation pass
602 is needed. But a backend can have as many relaxation passes as
603 necessary. During bfd_relax_section call, it is set to the
604 current pass, starting from 0. */
607 /* Number of relaxation trips. This number is incremented every
608 time the relaxation pass is restarted due to a previous
609 relaxation returning true in *AGAIN. */
612 /* > 0 to treat protected data defined in the shared library as
613 reference external. 0 to treat it as internal. -1 to let
614 backend to decide. */
615 int extern_protected_data
;
617 /* 1 to make undefined weak symbols dynamic when building a dynamic
618 object. 0 to resolve undefined weak symbols to zero. -1 to let
619 the backend decide. */
620 int dynamic_undefined_weak
;
622 /* Non-zero if auto-import thunks for DATA items in pei386 DLLs
623 should be generated/linked against. Set to 1 if this feature
624 is explicitly requested by the user, -1 if enabled by default. */
625 int pei386_auto_import
;
627 /* Non-zero if runtime relocs for DATA items with non-zero addends
628 in pei386 DLLs should be generated. Set to 1 if this feature
629 is explicitly requested by the user, -1 if enabled by default. */
630 int pei386_runtime_pseudo_reloc
;
632 /* How many spare .dynamic DT_NULL entries should be added? */
633 unsigned int spare_dynamic_tags
;
635 /* May be used to set DT_FLAGS for ELF. */
638 /* May be used to set DT_FLAGS_1 for ELF. */
641 /* Start and end of RELRO region. */
642 bfd_vma relro_start
, relro_end
;
644 /* List of symbols should be dynamic. */
645 struct bfd_elf_dynamic_list
*dynamic_list
;
647 /* The version information. */
648 struct bfd_elf_version_tree
*version_info
;
651 /* Some forward-definitions used by some callbacks. */
653 struct elf_strtab_hash
;
654 struct elf_sym_strtab
;
656 /* This structures holds a set of callback functions. These are called
657 by the BFD linker routines. */
659 struct bfd_link_callbacks
661 /* A function which is called when an object is added from an
662 archive. ABFD is the archive element being added. NAME is the
663 name of the symbol which caused the archive element to be pulled
664 in. This function may set *SUBSBFD to point to an alternative
665 BFD from which symbols should in fact be added in place of the
666 original BFD's symbols. Returns TRUE if the object should be
667 added, FALSE if it should be skipped. */
668 bfd_boolean (*add_archive_element
)
669 (struct bfd_link_info
*, bfd
*abfd
, const char *name
, bfd
**subsbfd
);
670 /* A function which is called when a symbol is found with multiple
671 definitions. H is the symbol which is defined multiple times.
672 NBFD is the new BFD, NSEC is the new section, and NVAL is the new
673 value. NSEC may be bfd_com_section or bfd_ind_section. */
674 void (*multiple_definition
)
675 (struct bfd_link_info
*, struct bfd_link_hash_entry
*h
,
676 bfd
*nbfd
, asection
*nsec
, bfd_vma nval
);
677 /* A function which is called when a common symbol is defined
678 multiple times. H is the symbol appearing multiple times.
679 NBFD is the BFD of the new symbol. NTYPE is the type of the new
680 symbol, one of bfd_link_hash_defined, bfd_link_hash_common, or
681 bfd_link_hash_indirect. If NTYPE is bfd_link_hash_common, NSIZE
682 is the size of the new symbol. */
683 void (*multiple_common
)
684 (struct bfd_link_info
*, struct bfd_link_hash_entry
*h
,
685 bfd
*nbfd
, enum bfd_link_hash_type ntype
, bfd_vma nsize
);
686 /* A function which is called to add a symbol to a set. ENTRY is
687 the link hash table entry for the set itself (e.g.,
688 __CTOR_LIST__). RELOC is the relocation to use for an entry in
689 the set when generating a relocatable file, and is also used to
690 get the size of the entry when generating an executable file.
691 ABFD, SEC and VALUE identify the value to add to the set. */
693 (struct bfd_link_info
*, struct bfd_link_hash_entry
*entry
,
694 bfd_reloc_code_real_type reloc
, bfd
*abfd
, asection
*sec
, bfd_vma value
);
695 /* A function which is called when the name of a g++ constructor or
696 destructor is found. This is only called by some object file
697 formats. CONSTRUCTOR is TRUE for a constructor, FALSE for a
698 destructor. This will use BFD_RELOC_CTOR when generating a
699 relocatable file. NAME is the name of the symbol found. ABFD,
700 SECTION and VALUE are the value of the symbol. */
702 (struct bfd_link_info
*, bfd_boolean constructor
, const char *name
,
703 bfd
*abfd
, asection
*sec
, bfd_vma value
);
704 /* A function which is called to issue a linker warning. For
705 example, this is called when there is a reference to a warning
706 symbol. WARNING is the warning to be issued. SYMBOL is the name
707 of the symbol which triggered the warning; it may be NULL if
708 there is none. ABFD, SECTION and ADDRESS identify the location
709 which trigerred the warning; either ABFD or SECTION or both may
710 be NULL if the location is not known. */
712 (struct bfd_link_info
*, const char *warning
, const char *symbol
,
713 bfd
*abfd
, asection
*section
, bfd_vma address
);
714 /* A function which is called when a relocation is attempted against
715 an undefined symbol. NAME is the symbol which is undefined.
716 ABFD, SECTION and ADDRESS identify the location from which the
717 reference is made. IS_FATAL indicates whether an undefined symbol is
718 a fatal error or not. In some cases SECTION may be NULL. */
719 void (*undefined_symbol
)
720 (struct bfd_link_info
*, const char *name
, bfd
*abfd
,
721 asection
*section
, bfd_vma address
, bfd_boolean is_fatal
);
722 /* A function which is called when a reloc overflow occurs. ENTRY is
723 the link hash table entry for the symbol the reloc is against.
724 NAME is the name of the local symbol or section the reloc is
725 against, RELOC_NAME is the name of the relocation, and ADDEND is
726 any addend that is used. ABFD, SECTION and ADDRESS identify the
727 location at which the overflow occurs; if this is the result of a
728 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
729 ABFD will be NULL. */
730 void (*reloc_overflow
)
731 (struct bfd_link_info
*, struct bfd_link_hash_entry
*entry
,
732 const char *name
, const char *reloc_name
, bfd_vma addend
,
733 bfd
*abfd
, asection
*section
, bfd_vma address
);
734 /* A function which is called when a dangerous reloc is performed.
735 MESSAGE is an appropriate message.
736 ABFD, SECTION and ADDRESS identify the location at which the
737 problem occurred; if this is the result of a
738 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
739 ABFD will be NULL. */
740 void (*reloc_dangerous
)
741 (struct bfd_link_info
*, const char *message
,
742 bfd
*abfd
, asection
*section
, bfd_vma address
);
743 /* A function which is called when a reloc is found to be attached
744 to a symbol which is not being written out. NAME is the name of
745 the symbol. ABFD, SECTION and ADDRESS identify the location of
746 the reloc; if this is the result of a
747 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
748 ABFD will be NULL. */
749 void (*unattached_reloc
)
750 (struct bfd_link_info
*, const char *name
,
751 bfd
*abfd
, asection
*section
, bfd_vma address
);
752 /* A function which is called when a symbol in notice_hash is
753 defined or referenced. H is the symbol, INH the indirect symbol
754 if applicable. ABFD, SECTION and ADDRESS are the (new) value of
755 the symbol. If SECTION is bfd_und_section, this is a reference.
756 FLAGS are the symbol BSF_* flags. */
757 bfd_boolean (*notice
)
758 (struct bfd_link_info
*, struct bfd_link_hash_entry
*h
,
759 struct bfd_link_hash_entry
*inh
,
760 bfd
*abfd
, asection
*section
, bfd_vma address
, flagword flags
);
761 /* Error or warning link info message. */
763 (const char *fmt
, ...);
764 /* General link info message. */
766 (const char *fmt
, ...);
767 /* Message to be printed in linker map file. */
769 (const char *fmt
, ...);
770 /* This callback provides a chance for users of the BFD library to
771 override its decision about whether to place two adjacent sections
772 into the same segment. */
773 bfd_boolean (*override_segment_assignment
)
774 (struct bfd_link_info
*, bfd
* abfd
,
775 asection
* current_section
, asection
* previous_section
,
776 bfd_boolean new_segment
);
777 /* This callback provides a chance for callers of the BFD to examine the
778 ELF string table and symbol table once they are complete and indexes and
780 void (*examine_strtab
)
781 (struct elf_sym_strtab
*syms
, bfd_size_type symcount
,
782 struct elf_strtab_hash
*symstrtab
);
783 /* This callback should emit the CTF section into a non-loadable section in
784 the output BFD named .ctf or a name beginning with ".ctf.". */
789 /* The linker builds link_order structures which tell the code how to
790 include input data in the output file. */
792 /* These are the types of link_order structures. */
794 enum bfd_link_order_type
796 bfd_undefined_link_order
, /* Undefined. */
797 bfd_indirect_link_order
, /* Built from a section. */
798 bfd_data_link_order
, /* Set to explicit data. */
799 bfd_section_reloc_link_order
, /* Relocate against a section. */
800 bfd_symbol_reloc_link_order
/* Relocate against a symbol. */
803 /* This is the link_order structure itself. These form a chain
804 attached to the output section whose contents they are describing. */
806 struct bfd_link_order
808 /* Next link_order in chain. */
809 struct bfd_link_order
*next
;
810 /* Type of link_order. */
811 enum bfd_link_order_type type
;
812 /* Offset within output section in bytes. */
814 /* Size within output section in octets. */
816 /* Type specific information. */
821 /* Section to include. If this is used, then
822 section->output_section must be the section the
823 link_order is attached to, section->output_offset must
824 equal the link_order offset field, and section->size
825 must equal the link_order size field. Maybe these
826 restrictions should be relaxed someday. */
831 /* Size of contents, or zero when contents should be filled by
832 the architecture-dependent fill function.
833 A non-zero value allows filling of the output section
834 with an arbitrary repeated pattern. */
836 /* Data to put into file. */
841 /* Description of reloc to generate. Used for
842 bfd_section_reloc_link_order and
843 bfd_symbol_reloc_link_order. */
844 struct bfd_link_order_reloc
*p
;
849 /* A linker order of type bfd_section_reloc_link_order or
850 bfd_symbol_reloc_link_order means to create a reloc against a
851 section or symbol, respectively. This is used to implement -Ur to
852 generate relocs for the constructor tables. The
853 bfd_link_order_reloc structure describes the reloc that BFD should
854 create. It is similar to a arelent, but I didn't use arelent
855 because the linker does not know anything about most symbols, and
856 any asymbol structure it creates will be partially meaningless.
857 This information could logically be in the bfd_link_order struct,
858 but I didn't want to waste the space since these types of relocs
859 are relatively rare. */
861 struct bfd_link_order_reloc
864 bfd_reloc_code_real_type reloc
;
868 /* For type bfd_section_reloc_link_order, this is the section
869 the reloc should be against. This must be a section in the
870 output BFD, not any of the input BFDs. */
872 /* For type bfd_symbol_reloc_link_order, this is the name of the
873 symbol the reloc should be against. */
877 /* Addend to use. The object file should contain zero. The BFD
878 backend is responsible for filling in the contents of the object
879 file correctly. For some object file formats (e.g., COFF) the
880 addend must be stored into in the object file, and for some
881 (e.g., SPARC a.out) it is kept in the reloc. */
885 /* Allocate a new link_order for a section. */
886 extern struct bfd_link_order
*bfd_new_link_order (bfd
*, asection
*);
888 struct bfd_section_already_linked
;
890 extern bfd_boolean
bfd_section_already_linked_table_init (void);
891 extern void bfd_section_already_linked_table_free (void);
892 extern bfd_boolean _bfd_handle_already_linked
893 (struct bfd_section
*, struct bfd_section_already_linked
*,
894 struct bfd_link_info
*);
896 extern struct bfd_section
*_bfd_nearby_section
897 (bfd
*, struct bfd_section
*, bfd_vma
);
899 extern void _bfd_fix_excluded_sec_syms
900 (bfd
*, struct bfd_link_info
*);
902 /* These structures are used to describe version information for the
903 ELF linker. These structures could be manipulated entirely inside
904 BFD, but it would be a pain. Instead, the regular linker sets up
905 these structures, and then passes them into BFD. */
907 /* Glob pattern for a version. */
909 struct bfd_elf_version_expr
911 /* Next glob pattern for this version. */
912 struct bfd_elf_version_expr
*next
;
915 /* Set if pattern is not a glob. */
916 unsigned int literal
: 1;
917 /* Defined by ".symver". */
918 unsigned int symver
: 1;
919 /* Defined by version script. */
920 unsigned int script
: 1;
922 #define BFD_ELF_VERSION_C_TYPE 1
923 #define BFD_ELF_VERSION_CXX_TYPE 2
924 #define BFD_ELF_VERSION_JAVA_TYPE 4
925 unsigned int mask
: 3;
928 struct bfd_elf_version_expr_head
930 /* List of all patterns, both wildcards and non-wildcards. */
931 struct bfd_elf_version_expr
*list
;
932 /* Hash table for non-wildcards. */
934 /* Remaining patterns. */
935 struct bfd_elf_version_expr
*remaining
;
936 /* What kind of pattern types are present in list (bitmask). */
940 /* Version dependencies. */
942 struct bfd_elf_version_deps
944 /* Next dependency for this version. */
945 struct bfd_elf_version_deps
*next
;
946 /* The version which this version depends upon. */
947 struct bfd_elf_version_tree
*version_needed
;
950 /* A node in the version tree. */
952 struct bfd_elf_version_tree
955 struct bfd_elf_version_tree
*next
;
956 /* Name of this version. */
958 /* Version number. */
960 /* Regular expressions for global symbols in this version. */
961 struct bfd_elf_version_expr_head globals
;
962 /* Regular expressions for local symbols in this version. */
963 struct bfd_elf_version_expr_head locals
;
964 /* List of versions which this version depends upon. */
965 struct bfd_elf_version_deps
*deps
;
966 /* Index of the version name. This is used within BFD. */
967 unsigned int name_indx
;
968 /* Whether this version tree was used. This is used within BFD. */
971 struct bfd_elf_version_expr
*(*match
)
972 (struct bfd_elf_version_expr_head
*head
,
973 struct bfd_elf_version_expr
*prev
, const char *sym
);
976 struct bfd_elf_dynamic_list
978 struct bfd_elf_version_expr_head head
;
979 struct bfd_elf_version_expr
*(*match
)
980 (struct bfd_elf_version_expr_head
*head
,
981 struct bfd_elf_version_expr
*prev
, const char *sym
);