1 /* bfdlink.h -- header file for BFD link routines
2 Copyright (C) 1993-2018 Free Software Foundation, Inc.
3 Written by Steve Chamberlain and Ian Lance Taylor, Cygnus Support.
5 This file is part of BFD, the Binary File Descriptor library.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
20 MA 02110-1301, USA. */
25 /* Which symbols to strip during a link. */
28 strip_none
, /* Don't strip any symbols. */
29 strip_debugger
, /* Strip debugging symbols. */
30 strip_some
, /* keep_hash is the list of symbols to keep. */
31 strip_all
/* Strip all symbols. */
34 /* Which local symbols to discard during a link. This is irrelevant
35 if strip_all is used. */
38 discard_sec_merge
, /* Discard local temporary symbols in SEC_MERGE
40 discard_none
, /* Don't discard any locals. */
41 discard_l
, /* Discard local temporary symbols. */
42 discard_all
/* Discard all locals. */
45 /* Whether to generate ELF common symbols with the STT_COMMON type
46 during a relocatable link. */
47 enum bfd_link_elf_stt_common
54 /* Describes the type of hash table entry structure being used.
55 Different hash table structure have different fields and so
56 support different linking features. */
57 enum bfd_link_hash_table_type
59 bfd_link_generic_hash_table
,
60 bfd_link_elf_hash_table
63 /* These are the possible types of an entry in the BFD link hash
66 enum bfd_link_hash_type
68 bfd_link_hash_new
, /* Symbol is new. */
69 bfd_link_hash_undefined
, /* Symbol seen before, but undefined. */
70 bfd_link_hash_undefweak
, /* Symbol is weak and undefined. */
71 bfd_link_hash_defined
, /* Symbol is defined. */
72 bfd_link_hash_defweak
, /* Symbol is weak and defined. */
73 bfd_link_hash_common
, /* Symbol is common. */
74 bfd_link_hash_indirect
, /* Symbol is an indirect link. */
75 bfd_link_hash_warning
/* Like indirect, but warn if referenced. */
78 enum bfd_link_common_skip_ar_symbols
80 bfd_link_common_skip_none
,
81 bfd_link_common_skip_text
,
82 bfd_link_common_skip_data
,
83 bfd_link_common_skip_all
86 struct bfd_link_hash_common_entry
88 unsigned int alignment_power
; /* Alignment. */
89 asection
*section
; /* Symbol section. */
92 /* The linking routines use a hash table which uses this structure for
95 struct bfd_link_hash_entry
97 /* Base hash table entry structure. */
98 struct bfd_hash_entry root
;
100 /* Type of this entry. */
101 ENUM_BITFIELD (bfd_link_hash_type
) type
: 8;
103 /* Symbol is referenced in a normal regular object file,
104 as distinct from a LTO IR object file. */
105 unsigned int non_ir_ref_regular
: 1;
107 /* Symbol is referenced in a normal dynamic object file,
108 as distinct from a LTO IR object file. */
109 unsigned int non_ir_ref_dynamic
: 1;
111 /* Symbol is a built-in define. These will be overridden by PROVIDE
112 in a linker script. */
113 unsigned int linker_def
: 1;
115 /* Symbol defined in a linker script. */
116 unsigned int ldscript_def
: 1;
118 /* A union of information depending upon the type. */
121 /* Nothing is kept for bfd_hash_new. */
122 /* bfd_link_hash_undefined, bfd_link_hash_undefweak. */
125 /* Undefined and common symbols are kept in a linked list through
126 this field. This field is present in all of the union element
127 so that we don't need to remove entries from the list when we
128 change their type. Removing entries would either require the
129 list to be doubly linked, which would waste more memory, or
130 require a traversal. When an undefined or common symbol is
131 created, it should be added to this list, the head of which is in
132 the link hash table itself. As symbols are defined, they need
133 not be removed from the list; anything which reads the list must
134 doublecheck the symbol type.
136 Weak symbols are not kept on this list.
138 Defined and defweak symbols use this field as a reference marker.
139 If the field is not NULL, or this structure is the tail of the
140 undefined symbol list, the symbol has been referenced. If the
141 symbol is undefined and becomes defined, this field will
142 automatically be non-NULL since the symbol will have been on the
143 undefined symbol list. */
144 struct bfd_link_hash_entry
*next
;
145 /* BFD symbol was found in. */
148 /* bfd_link_hash_defined, bfd_link_hash_defweak. */
151 struct bfd_link_hash_entry
*next
;
152 /* Symbol section. */
157 /* bfd_link_hash_indirect, bfd_link_hash_warning. */
160 struct bfd_link_hash_entry
*next
;
162 struct bfd_link_hash_entry
*link
;
163 /* Warning message (bfd_link_hash_warning only). */
166 /* bfd_link_hash_common. */
169 struct bfd_link_hash_entry
*next
;
170 /* The linker needs to know three things about common
171 symbols: the size, the alignment, and the section in
172 which the symbol should be placed. We store the size
173 here, and we allocate a small structure to hold the
174 section and the alignment. The alignment is stored as a
175 power of two. We don't store all the information
176 directly because we don't want to increase the size of
177 the union; this structure is a major space user in the
179 struct bfd_link_hash_common_entry
*p
;
180 /* Common symbol size. */
186 /* This is the link hash table. It is a derived class of
189 struct bfd_link_hash_table
191 /* The hash table itself. */
192 struct bfd_hash_table table
;
193 /* A linked list of undefined and common symbols, linked through the
194 next field in the bfd_link_hash_entry structure. */
195 struct bfd_link_hash_entry
*undefs
;
196 /* Entries are added to the tail of the undefs list. */
197 struct bfd_link_hash_entry
*undefs_tail
;
198 /* Function to free the hash table on closing BFD. */
199 void (*hash_table_free
) (bfd
*);
200 /* The type of the link hash table. */
201 enum bfd_link_hash_table_type type
;
204 /* Look up an entry in a link hash table. If FOLLOW is TRUE, this
205 follows bfd_link_hash_indirect and bfd_link_hash_warning links to
207 extern struct bfd_link_hash_entry
*bfd_link_hash_lookup
208 (struct bfd_link_hash_table
*, const char *, bfd_boolean create
,
209 bfd_boolean copy
, bfd_boolean follow
);
211 /* Look up an entry in the main linker hash table if the symbol might
212 be wrapped. This should only be used for references to an
213 undefined symbol, not for definitions of a symbol. */
215 extern struct bfd_link_hash_entry
*bfd_wrapped_link_hash_lookup
216 (bfd
*, struct bfd_link_info
*, const char *, bfd_boolean
,
217 bfd_boolean
, bfd_boolean
);
219 /* If H is a wrapped symbol, ie. the symbol name starts with "__wrap_"
220 and the remainder is found in wrap_hash, return the real symbol. */
222 extern struct bfd_link_hash_entry
*unwrap_hash_lookup
223 (struct bfd_link_info
*, bfd
*, struct bfd_link_hash_entry
*);
225 /* Traverse a link hash table. */
226 extern void bfd_link_hash_traverse
227 (struct bfd_link_hash_table
*,
228 bfd_boolean (*) (struct bfd_link_hash_entry
*, void *),
231 /* Add an entry to the undefs list. */
232 extern void bfd_link_add_undef
233 (struct bfd_link_hash_table
*, struct bfd_link_hash_entry
*);
235 /* Remove symbols from the undefs list that don't belong there. */
236 extern void bfd_link_repair_undef_list
237 (struct bfd_link_hash_table
*table
);
239 /* Read symbols and cache symbol pointer array in outsymbols. */
240 extern bfd_boolean
bfd_generic_link_read_symbols (bfd
*);
242 /* Check the relocs in the BFD. Called after all the input
243 files have been loaded, and garbage collection has tagged
244 any unneeded sections. */
245 extern bfd_boolean
bfd_link_check_relocs (bfd
*,struct bfd_link_info
*);
249 struct bfd_sym_chain
*next
;
253 /* How to handle unresolved symbols.
254 There are four possibilities which are enumerated below: */
257 /* This is the initial value when then link_info structure is created.
258 It allows the various stages of the linker to determine whether they
259 allowed to set the value. */
266 typedef enum {with_flags
, without_flags
} flag_type
;
268 /* A section flag list. */
269 struct flag_info_list
274 struct flag_info_list
*next
;
277 /* Section flag info. */
280 flagword only_with_flags
;
281 flagword not_with_flags
;
282 struct flag_info_list
*flag_list
;
283 bfd_boolean flags_initialized
;
286 struct bfd_elf_dynamic_list
;
287 struct bfd_elf_version_tree
;
289 /* Types of output. */
299 #define bfd_link_pde(info) ((info)->type == type_pde)
300 #define bfd_link_dll(info) ((info)->type == type_dll)
301 #define bfd_link_relocatable(info) ((info)->type == type_relocatable)
302 #define bfd_link_pie(info) ((info)->type == type_pie)
303 #define bfd_link_executable(info) (bfd_link_pde (info) || bfd_link_pie (info))
304 #define bfd_link_pic(info) (bfd_link_dll (info) || bfd_link_pie (info))
306 /* This structure holds all the information needed to communicate
307 between BFD and the linker when doing a link. */
312 ENUM_BITFIELD (output_type
) type
: 2;
314 /* TRUE if BFD should pre-bind symbols in a shared object. */
315 unsigned int symbolic
: 1;
317 /* TRUE if executable should not contain copy relocs.
318 Setting this true may result in a non-sharable text segment. */
319 unsigned int nocopyreloc
: 1;
321 /* TRUE if BFD should export all symbols in the dynamic symbol table
322 of an executable, rather than only those used. */
323 unsigned int export_dynamic
: 1;
325 /* TRUE if a default symbol version should be created and used for
327 unsigned int create_default_symver
: 1;
329 /* TRUE if unreferenced sections should be removed. */
330 unsigned int gc_sections
: 1;
332 /* TRUE if exported symbols should be kept during section gc. */
333 unsigned int gc_keep_exported
: 1;
335 /* TRUE if every symbol should be reported back via the notice
337 unsigned int notice_all
: 1;
339 /* TRUE if the LTO plugin is active. */
340 unsigned int lto_plugin_active
: 1;
342 /* TRUE if global symbols in discarded sections should be stripped. */
343 unsigned int strip_discarded
: 1;
345 /* TRUE if all data symbols should be dynamic. */
346 unsigned int dynamic_data
: 1;
348 /* TRUE if section groups should be resolved. */
349 unsigned int resolve_section_groups
: 1;
351 /* Which symbols to strip. */
352 ENUM_BITFIELD (bfd_link_strip
) strip
: 2;
354 /* Which local symbols to discard. */
355 ENUM_BITFIELD (bfd_link_discard
) discard
: 2;
357 /* Whether to generate ELF common symbols with the STT_COMMON type. */
358 ENUM_BITFIELD (bfd_link_elf_stt_common
) elf_stt_common
: 2;
360 /* Criteria for skipping symbols when determining
361 whether to include an object from an archive. */
362 ENUM_BITFIELD (bfd_link_common_skip_ar_symbols
) common_skip_ar_symbols
: 2;
364 /* What to do with unresolved symbols in an object file.
365 When producing executables the default is GENERATE_ERROR.
366 When producing shared libraries the default is IGNORE. The
367 assumption with shared libraries is that the reference will be
368 resolved at load/execution time. */
369 ENUM_BITFIELD (report_method
) unresolved_syms_in_objects
: 2;
371 /* What to do with unresolved symbols in a shared library.
372 The same defaults apply. */
373 ENUM_BITFIELD (report_method
) unresolved_syms_in_shared_libs
: 2;
375 /* TRUE if shared objects should be linked directly, not shared. */
376 unsigned int static_link
: 1;
378 /* TRUE if symbols should be retained in memory, FALSE if they
379 should be freed and reread. */
380 unsigned int keep_memory
: 1;
382 /* TRUE if BFD should generate relocation information in the final
384 unsigned int emitrelocations
: 1;
386 /* TRUE if PT_GNU_RELRO segment should be created. */
387 unsigned int relro
: 1;
389 /* TRUE if separate code segment should be created. */
390 unsigned int separate_code
: 1;
392 /* Nonzero if .eh_frame_hdr section and PT_GNU_EH_FRAME ELF segment
393 should be created. 1 for DWARF2 tables, 2 for compact tables. */
394 unsigned int eh_frame_hdr_type
: 2;
396 /* TRUE if we should warn when adding a DT_TEXTREL to a shared object. */
397 unsigned int warn_shared_textrel
: 1;
399 /* TRUE if we should error when adding a DT_TEXTREL. */
400 unsigned int error_textrel
: 1;
402 /* TRUE if .hash section should be created. */
403 unsigned int emit_hash
: 1;
405 /* TRUE if .gnu.hash section should be created. */
406 unsigned int emit_gnu_hash
: 1;
408 /* If TRUE reduce memory overheads, at the expense of speed. This will
409 cause map file generation to use an O(N^2) algorithm and disable
410 caching ELF symbol buffer. */
411 unsigned int reduce_memory_overheads
: 1;
413 /* TRUE if the output file should be in a traditional format. This
414 is equivalent to the setting of the BFD_TRADITIONAL_FORMAT flag
415 on the output file, but may be checked when reading the input
417 unsigned int traditional_format
: 1;
419 /* TRUE if non-PLT relocs should be merged into one reloc section
420 and sorted so that relocs against the same symbol come together. */
421 unsigned int combreloc
: 1;
423 /* TRUE if a default symbol version should be created and used for
425 unsigned int default_imported_symver
: 1;
427 /* TRUE if the new ELF dynamic tags are enabled. */
428 unsigned int new_dtags
: 1;
430 /* FALSE if .eh_frame unwind info should be generated for PLT and other
431 linker created sections, TRUE if it should be omitted. */
432 unsigned int no_ld_generated_unwind_info
: 1;
434 /* TRUE if BFD should generate a "task linked" object file,
435 similar to relocatable but also with globals converted to
437 unsigned int task_link
: 1;
439 /* TRUE if ok to have multiple definition. */
440 unsigned int allow_multiple_definition
: 1;
442 /* TRUE if ok to have version with no definition. */
443 unsigned int allow_undefined_version
: 1;
445 /* TRUE if some symbols have to be dynamic, controlled by
446 --dynamic-list command line options. */
447 unsigned int dynamic
: 1;
449 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W|PF_X
451 unsigned int execstack
: 1;
453 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W
455 unsigned int noexecstack
: 1;
457 /* TRUE if we want to produced optimized output files. This might
458 need much more time and therefore must be explicitly selected. */
459 unsigned int optimize
: 1;
461 /* TRUE if user should be informed of removed unreferenced sections. */
462 unsigned int print_gc_sections
: 1;
464 /* TRUE if we should warn alternate ELF machine code. */
465 unsigned int warn_alternate_em
: 1;
467 /* TRUE if the linker script contained an explicit PHDRS command. */
468 unsigned int user_phdrs
: 1;
470 /* TRUE if we should check relocations after all input files have
472 unsigned int check_relocs_after_open_input
: 1;
474 /* TRUE if BND prefix in PLT entries is always generated. */
475 unsigned int bndplt
: 1;
477 /* TRUE if IBT-enabled PLT entries should be generated. */
478 unsigned int ibtplt
: 1;
480 /* TRUE if GNU_PROPERTY_X86_FEATURE_1_IBT should be generated. */
483 /* TRUE if GNU_PROPERTY_X86_FEATURE_1_SHSTK should be generated. */
484 unsigned int shstk
: 1;
486 /* TRUE if generation of .interp/PT_INTERP should be suppressed. */
487 unsigned int nointerp
: 1;
489 /* TRUE if we shouldn't check relocation overflow. */
490 unsigned int no_reloc_overflow_check
: 1;
492 /* TRUE if generate a 1-byte NOP as suffix for x86 call instruction. */
493 unsigned int call_nop_as_suffix
: 1;
495 /* TRUE if common symbols should be treated as undefined. */
496 unsigned int inhibit_common_definition
: 1;
498 /* The 1-byte NOP for x86 call instruction. */
501 /* Char that may appear as the first char of a symbol, but should be
502 skipped (like symbol_leading_char) when looking up symbols in
503 wrap_hash. Used by PowerPC Linux for 'dot' symbols. */
506 /* Separator between archive and filename in linker script filespecs. */
509 /* Compress DWARF debug sections. */
510 enum compressed_debug_section_type compress_debug
;
512 /* Default stack size. Zero means default (often zero itself), -1
513 means explicitly zero-sized. */
514 bfd_signed_vma stacksize
;
516 /* Enable or disable target specific optimizations.
518 Not all targets have optimizations to enable.
520 Normally these optimizations are disabled by default but some targets
521 prefer to enable them by default. So this field is a tri-state variable.
524 zero: Enable the optimizations (either from --relax being specified on
525 the command line or the backend's before_allocation emulation function.
527 positive: The user has requested that these optimizations be disabled.
528 (Via the --no-relax command line option).
530 negative: The optimizations are disabled. (Set when initializing the
531 args_type structure in ldmain.c:main. */
532 signed int disable_target_specific_optimizations
;
534 /* Function callbacks. */
535 const struct bfd_link_callbacks
*callbacks
;
537 /* Hash table handled by BFD. */
538 struct bfd_link_hash_table
*hash
;
540 /* Hash table of symbols to keep. This is NULL unless strip is
542 struct bfd_hash_table
*keep_hash
;
544 /* Hash table of symbols to report back via the notice callback. If
545 this is NULL, and notice_all is FALSE, then no symbols are
547 struct bfd_hash_table
*notice_hash
;
549 /* Hash table of symbols which are being wrapped (the --wrap linker
550 option). If this is NULL, no symbols are being wrapped. */
551 struct bfd_hash_table
*wrap_hash
;
553 /* Hash table of symbols which may be left unresolved during
554 a link. If this is NULL, no symbols can be left unresolved. */
555 struct bfd_hash_table
*ignore_hash
;
557 /* The output BFD. */
560 /* The import library generated. */
563 /* The list of input BFD's involved in the link. These are chained
564 together via the link.next field. */
566 bfd
**input_bfds_tail
;
568 /* If a symbol should be created for each input BFD, this is section
569 where those symbols should be placed. It must be a section in
570 the output BFD. It may be NULL, in which case no such symbols
571 will be created. This is to support CREATE_OBJECT_SYMBOLS in the
572 linker command language. */
573 asection
*create_object_symbols_section
;
575 /* List of global symbol names that are starting points for marking
576 sections against garbage collection. */
577 struct bfd_sym_chain
*gc_sym_list
;
579 /* If a base output file is wanted, then this points to it */
582 /* The function to call when the executable or shared object is
584 const char *init_function
;
586 /* The function to call when the executable or shared object is
588 const char *fini_function
;
590 /* Number of relaxation passes. Usually only one relaxation pass
591 is needed. But a backend can have as many relaxation passes as
592 necessary. During bfd_relax_section call, it is set to the
593 current pass, starting from 0. */
596 /* Number of relaxation trips. This number is incremented every
597 time the relaxation pass is restarted due to a previous
598 relaxation returning true in *AGAIN. */
601 /* > 0 to treat protected data defined in the shared library as
602 reference external. 0 to treat it as internal. -1 to let
603 backend to decide. */
604 int extern_protected_data
;
606 /* 1 to make undefined weak symbols dynamic when building a dynamic
607 object. 0 to resolve undefined weak symbols to zero. -1 to let
608 the backend decide. */
609 int dynamic_undefined_weak
;
611 /* Non-zero if auto-import thunks for DATA items in pei386 DLLs
612 should be generated/linked against. Set to 1 if this feature
613 is explicitly requested by the user, -1 if enabled by default. */
614 int pei386_auto_import
;
616 /* Non-zero if runtime relocs for DATA items with non-zero addends
617 in pei386 DLLs should be generated. Set to 1 if this feature
618 is explicitly requested by the user, -1 if enabled by default. */
619 int pei386_runtime_pseudo_reloc
;
621 /* How many spare .dynamic DT_NULL entries should be added? */
622 unsigned int spare_dynamic_tags
;
624 /* May be used to set DT_FLAGS for ELF. */
627 /* May be used to set DT_FLAGS_1 for ELF. */
630 /* Start and end of RELRO region. */
631 bfd_vma relro_start
, relro_end
;
633 /* List of symbols should be dynamic. */
634 struct bfd_elf_dynamic_list
*dynamic_list
;
636 /* The version information. */
637 struct bfd_elf_version_tree
*version_info
;
640 /* This structures holds a set of callback functions. These are called
641 by the BFD linker routines. */
643 struct bfd_link_callbacks
645 /* A function which is called when an object is added from an
646 archive. ABFD is the archive element being added. NAME is the
647 name of the symbol which caused the archive element to be pulled
648 in. This function may set *SUBSBFD to point to an alternative
649 BFD from which symbols should in fact be added in place of the
650 original BFD's symbols. Returns TRUE if the object should be
651 added, FALSE if it should be skipped. */
652 bfd_boolean (*add_archive_element
)
653 (struct bfd_link_info
*, bfd
*abfd
, const char *name
, bfd
**subsbfd
);
654 /* A function which is called when a symbol is found with multiple
655 definitions. H is the symbol which is defined multiple times.
656 NBFD is the new BFD, NSEC is the new section, and NVAL is the new
657 value. NSEC may be bfd_com_section or bfd_ind_section. */
658 void (*multiple_definition
)
659 (struct bfd_link_info
*, struct bfd_link_hash_entry
*h
,
660 bfd
*nbfd
, asection
*nsec
, bfd_vma nval
);
661 /* A function which is called when a common symbol is defined
662 multiple times. H is the symbol appearing multiple times.
663 NBFD is the BFD of the new symbol. NTYPE is the type of the new
664 symbol, one of bfd_link_hash_defined, bfd_link_hash_common, or
665 bfd_link_hash_indirect. If NTYPE is bfd_link_hash_common, NSIZE
666 is the size of the new symbol. */
667 void (*multiple_common
)
668 (struct bfd_link_info
*, struct bfd_link_hash_entry
*h
,
669 bfd
*nbfd
, enum bfd_link_hash_type ntype
, bfd_vma nsize
);
670 /* A function which is called to add a symbol to a set. ENTRY is
671 the link hash table entry for the set itself (e.g.,
672 __CTOR_LIST__). RELOC is the relocation to use for an entry in
673 the set when generating a relocatable file, and is also used to
674 get the size of the entry when generating an executable file.
675 ABFD, SEC and VALUE identify the value to add to the set. */
677 (struct bfd_link_info
*, struct bfd_link_hash_entry
*entry
,
678 bfd_reloc_code_real_type reloc
, bfd
*abfd
, asection
*sec
, bfd_vma value
);
679 /* A function which is called when the name of a g++ constructor or
680 destructor is found. This is only called by some object file
681 formats. CONSTRUCTOR is TRUE for a constructor, FALSE for a
682 destructor. This will use BFD_RELOC_CTOR when generating a
683 relocatable file. NAME is the name of the symbol found. ABFD,
684 SECTION and VALUE are the value of the symbol. */
686 (struct bfd_link_info
*, bfd_boolean constructor
, const char *name
,
687 bfd
*abfd
, asection
*sec
, bfd_vma value
);
688 /* A function which is called to issue a linker warning. For
689 example, this is called when there is a reference to a warning
690 symbol. WARNING is the warning to be issued. SYMBOL is the name
691 of the symbol which triggered the warning; it may be NULL if
692 there is none. ABFD, SECTION and ADDRESS identify the location
693 which trigerred the warning; either ABFD or SECTION or both may
694 be NULL if the location is not known. */
696 (struct bfd_link_info
*, const char *warning
, const char *symbol
,
697 bfd
*abfd
, asection
*section
, bfd_vma address
);
698 /* A function which is called when a relocation is attempted against
699 an undefined symbol. NAME is the symbol which is undefined.
700 ABFD, SECTION and ADDRESS identify the location from which the
701 reference is made. IS_FATAL indicates whether an undefined symbol is
702 a fatal error or not. In some cases SECTION may be NULL. */
703 void (*undefined_symbol
)
704 (struct bfd_link_info
*, const char *name
, bfd
*abfd
,
705 asection
*section
, bfd_vma address
, bfd_boolean is_fatal
);
706 /* A function which is called when a reloc overflow occurs. ENTRY is
707 the link hash table entry for the symbol the reloc is against.
708 NAME is the name of the local symbol or section the reloc is
709 against, RELOC_NAME is the name of the relocation, and ADDEND is
710 any addend that is used. ABFD, SECTION and ADDRESS identify the
711 location at which the overflow occurs; if this is the result of a
712 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
713 ABFD will be NULL. */
714 void (*reloc_overflow
)
715 (struct bfd_link_info
*, struct bfd_link_hash_entry
*entry
,
716 const char *name
, const char *reloc_name
, bfd_vma addend
,
717 bfd
*abfd
, asection
*section
, bfd_vma address
);
718 /* A function which is called when a dangerous reloc is performed.
719 MESSAGE is an appropriate message.
720 ABFD, SECTION and ADDRESS identify the location at which the
721 problem occurred; if this is the result of a
722 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
723 ABFD will be NULL. */
724 void (*reloc_dangerous
)
725 (struct bfd_link_info
*, const char *message
,
726 bfd
*abfd
, asection
*section
, bfd_vma address
);
727 /* A function which is called when a reloc is found to be attached
728 to a symbol which is not being written out. NAME is the name of
729 the symbol. ABFD, SECTION and ADDRESS identify the location of
730 the reloc; if this is the result of a
731 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
732 ABFD will be NULL. */
733 void (*unattached_reloc
)
734 (struct bfd_link_info
*, const char *name
,
735 bfd
*abfd
, asection
*section
, bfd_vma address
);
736 /* A function which is called when a symbol in notice_hash is
737 defined or referenced. H is the symbol, INH the indirect symbol
738 if applicable. ABFD, SECTION and ADDRESS are the (new) value of
739 the symbol. If SECTION is bfd_und_section, this is a reference.
740 FLAGS are the symbol BSF_* flags. */
741 bfd_boolean (*notice
)
742 (struct bfd_link_info
*, struct bfd_link_hash_entry
*h
,
743 struct bfd_link_hash_entry
*inh
,
744 bfd
*abfd
, asection
*section
, bfd_vma address
, flagword flags
);
745 /* Error or warning link info message. */
747 (const char *fmt
, ...);
748 /* General link info message. */
750 (const char *fmt
, ...);
751 /* Message to be printed in linker map file. */
753 (const char *fmt
, ...);
754 /* This callback provides a chance for users of the BFD library to
755 override its decision about whether to place two adjacent sections
756 into the same segment. */
757 bfd_boolean (*override_segment_assignment
)
758 (struct bfd_link_info
*, bfd
* abfd
,
759 asection
* current_section
, asection
* previous_section
,
760 bfd_boolean new_segment
);
763 /* The linker builds link_order structures which tell the code how to
764 include input data in the output file. */
766 /* These are the types of link_order structures. */
768 enum bfd_link_order_type
770 bfd_undefined_link_order
, /* Undefined. */
771 bfd_indirect_link_order
, /* Built from a section. */
772 bfd_data_link_order
, /* Set to explicit data. */
773 bfd_section_reloc_link_order
, /* Relocate against a section. */
774 bfd_symbol_reloc_link_order
/* Relocate against a symbol. */
777 /* This is the link_order structure itself. These form a chain
778 attached to the output section whose contents they are describing. */
780 struct bfd_link_order
782 /* Next link_order in chain. */
783 struct bfd_link_order
*next
;
784 /* Type of link_order. */
785 enum bfd_link_order_type type
;
786 /* Offset within output section. */
788 /* Size within output section. */
790 /* Type specific information. */
795 /* Section to include. If this is used, then
796 section->output_section must be the section the
797 link_order is attached to, section->output_offset must
798 equal the link_order offset field, and section->size
799 must equal the link_order size field. Maybe these
800 restrictions should be relaxed someday. */
805 /* Size of contents, or zero when contents should be filled by
806 the architecture-dependent fill function.
807 A non-zero value allows filling of the output section
808 with an arbitrary repeated pattern. */
810 /* Data to put into file. */
815 /* Description of reloc to generate. Used for
816 bfd_section_reloc_link_order and
817 bfd_symbol_reloc_link_order. */
818 struct bfd_link_order_reloc
*p
;
823 /* A linker order of type bfd_section_reloc_link_order or
824 bfd_symbol_reloc_link_order means to create a reloc against a
825 section or symbol, respectively. This is used to implement -Ur to
826 generate relocs for the constructor tables. The
827 bfd_link_order_reloc structure describes the reloc that BFD should
828 create. It is similar to a arelent, but I didn't use arelent
829 because the linker does not know anything about most symbols, and
830 any asymbol structure it creates will be partially meaningless.
831 This information could logically be in the bfd_link_order struct,
832 but I didn't want to waste the space since these types of relocs
833 are relatively rare. */
835 struct bfd_link_order_reloc
838 bfd_reloc_code_real_type reloc
;
842 /* For type bfd_section_reloc_link_order, this is the section
843 the reloc should be against. This must be a section in the
844 output BFD, not any of the input BFDs. */
846 /* For type bfd_symbol_reloc_link_order, this is the name of the
847 symbol the reloc should be against. */
851 /* Addend to use. The object file should contain zero. The BFD
852 backend is responsible for filling in the contents of the object
853 file correctly. For some object file formats (e.g., COFF) the
854 addend must be stored into in the object file, and for some
855 (e.g., SPARC a.out) it is kept in the reloc. */
859 /* Allocate a new link_order for a section. */
860 extern struct bfd_link_order
*bfd_new_link_order (bfd
*, asection
*);
862 /* These structures are used to describe version information for the
863 ELF linker. These structures could be manipulated entirely inside
864 BFD, but it would be a pain. Instead, the regular linker sets up
865 these structures, and then passes them into BFD. */
867 /* Glob pattern for a version. */
869 struct bfd_elf_version_expr
871 /* Next glob pattern for this version. */
872 struct bfd_elf_version_expr
*next
;
875 /* Set if pattern is not a glob. */
876 unsigned int literal
: 1;
877 /* Defined by ".symver". */
878 unsigned int symver
: 1;
879 /* Defined by version script. */
880 unsigned int script
: 1;
882 #define BFD_ELF_VERSION_C_TYPE 1
883 #define BFD_ELF_VERSION_CXX_TYPE 2
884 #define BFD_ELF_VERSION_JAVA_TYPE 4
885 unsigned int mask
: 3;
888 struct bfd_elf_version_expr_head
890 /* List of all patterns, both wildcards and non-wildcards. */
891 struct bfd_elf_version_expr
*list
;
892 /* Hash table for non-wildcards. */
894 /* Remaining patterns. */
895 struct bfd_elf_version_expr
*remaining
;
896 /* What kind of pattern types are present in list (bitmask). */
900 /* Version dependencies. */
902 struct bfd_elf_version_deps
904 /* Next dependency for this version. */
905 struct bfd_elf_version_deps
*next
;
906 /* The version which this version depends upon. */
907 struct bfd_elf_version_tree
*version_needed
;
910 /* A node in the version tree. */
912 struct bfd_elf_version_tree
915 struct bfd_elf_version_tree
*next
;
916 /* Name of this version. */
918 /* Version number. */
920 /* Regular expressions for global symbols in this version. */
921 struct bfd_elf_version_expr_head globals
;
922 /* Regular expressions for local symbols in this version. */
923 struct bfd_elf_version_expr_head locals
;
924 /* List of versions which this version depends upon. */
925 struct bfd_elf_version_deps
*deps
;
926 /* Index of the version name. This is used within BFD. */
927 unsigned int name_indx
;
928 /* Whether this version tree was used. This is used within BFD. */
931 struct bfd_elf_version_expr
*(*match
)
932 (struct bfd_elf_version_expr_head
*head
,
933 struct bfd_elf_version_expr
*prev
, const char *sym
);
936 struct bfd_elf_dynamic_list
938 struct bfd_elf_version_expr_head head
;
939 struct bfd_elf_version_expr
*(*match
)
940 (struct bfd_elf_version_expr_head
*head
,
941 struct bfd_elf_version_expr
*prev
, const char *sym
);