1 /* bfdlink.h -- header file for BFD link routines
2 Copyright (C) 1993-2015 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 /* Describes the type of hash table entry structure being used.
46 Different hash table structure have different fields and so
47 support different linking features. */
48 enum bfd_link_hash_table_type
50 bfd_link_generic_hash_table
,
51 bfd_link_elf_hash_table
54 /* These are the possible types of an entry in the BFD link hash
57 enum bfd_link_hash_type
59 bfd_link_hash_new
, /* Symbol is new. */
60 bfd_link_hash_undefined
, /* Symbol seen before, but undefined. */
61 bfd_link_hash_undefweak
, /* Symbol is weak and undefined. */
62 bfd_link_hash_defined
, /* Symbol is defined. */
63 bfd_link_hash_defweak
, /* Symbol is weak and defined. */
64 bfd_link_hash_common
, /* Symbol is common. */
65 bfd_link_hash_indirect
, /* Symbol is an indirect link. */
66 bfd_link_hash_warning
/* Like indirect, but warn if referenced. */
69 enum bfd_link_common_skip_ar_symbols
71 bfd_link_common_skip_none
,
72 bfd_link_common_skip_text
,
73 bfd_link_common_skip_data
,
74 bfd_link_common_skip_all
77 struct bfd_link_hash_common_entry
79 unsigned int alignment_power
; /* Alignment. */
80 asection
*section
; /* Symbol section. */
83 /* The linking routines use a hash table which uses this structure for
86 struct bfd_link_hash_entry
88 /* Base hash table entry structure. */
89 struct bfd_hash_entry root
;
91 /* Type of this entry. */
92 ENUM_BITFIELD (bfd_link_hash_type
) type
: 8;
94 /* Symbol is referenced in a normal object file, as distict from a LTO
96 unsigned int non_ir_ref
: 1;
98 /* Symbol is a built-in define. These will be overridden by PROVIDE
99 in a linker script. */
100 unsigned int linker_def
: 1;
102 /* A union of information depending upon the type. */
105 /* Nothing is kept for bfd_hash_new. */
106 /* bfd_link_hash_undefined, bfd_link_hash_undefweak. */
109 /* Undefined and common symbols are kept in a linked list through
110 this field. This field is present in all of the union element
111 so that we don't need to remove entries from the list when we
112 change their type. Removing entries would either require the
113 list to be doubly linked, which would waste more memory, or
114 require a traversal. When an undefined or common symbol is
115 created, it should be added to this list, the head of which is in
116 the link hash table itself. As symbols are defined, they need
117 not be removed from the list; anything which reads the list must
118 doublecheck the symbol type.
120 Weak symbols are not kept on this list.
122 Defined and defweak symbols use this field as a reference marker.
123 If the field is not NULL, or this structure is the tail of the
124 undefined symbol list, the symbol has been referenced. If the
125 symbol is undefined and becomes defined, this field will
126 automatically be non-NULL since the symbol will have been on the
127 undefined symbol list. */
128 struct bfd_link_hash_entry
*next
;
129 bfd
*abfd
; /* BFD symbol was found in. */
131 /* bfd_link_hash_defined, bfd_link_hash_defweak. */
134 struct bfd_link_hash_entry
*next
;
135 asection
*section
; /* Symbol section. */
136 bfd_vma value
; /* Symbol value. */
138 /* bfd_link_hash_indirect, bfd_link_hash_warning. */
141 struct bfd_link_hash_entry
*next
;
142 struct bfd_link_hash_entry
*link
; /* Real symbol. */
143 const char *warning
; /* Warning (bfd_link_hash_warning only). */
145 /* bfd_link_hash_common. */
148 struct bfd_link_hash_entry
*next
;
149 /* The linker needs to know three things about common
150 symbols: the size, the alignment, and the section in
151 which the symbol should be placed. We store the size
152 here, and we allocate a small structure to hold the
153 section and the alignment. The alignment is stored as a
154 power of two. We don't store all the information
155 directly because we don't want to increase the size of
156 the union; this structure is a major space user in the
158 struct bfd_link_hash_common_entry
*p
;
159 bfd_size_type size
; /* Common symbol size. */
164 /* This is the link hash table. It is a derived class of
167 struct bfd_link_hash_table
169 /* The hash table itself. */
170 struct bfd_hash_table table
;
171 /* A linked list of undefined and common symbols, linked through the
172 next field in the bfd_link_hash_entry structure. */
173 struct bfd_link_hash_entry
*undefs
;
174 /* Entries are added to the tail of the undefs list. */
175 struct bfd_link_hash_entry
*undefs_tail
;
176 /* Function to free the hash table on closing BFD. */
177 void (*hash_table_free
) (bfd
*);
178 /* The type of the link hash table. */
179 enum bfd_link_hash_table_type type
;
182 /* Look up an entry in a link hash table. If FOLLOW is TRUE, this
183 follows bfd_link_hash_indirect and bfd_link_hash_warning links to
185 extern struct bfd_link_hash_entry
*bfd_link_hash_lookup
186 (struct bfd_link_hash_table
*, const char *, bfd_boolean create
,
187 bfd_boolean copy
, bfd_boolean follow
);
189 /* Look up an entry in the main linker hash table if the symbol might
190 be wrapped. This should only be used for references to an
191 undefined symbol, not for definitions of a symbol. */
193 extern struct bfd_link_hash_entry
*bfd_wrapped_link_hash_lookup
194 (bfd
*, struct bfd_link_info
*, const char *, bfd_boolean
,
195 bfd_boolean
, bfd_boolean
);
197 /* If H is a wrapped symbol, ie. the symbol name starts with "__wrap_"
198 and the remainder is found in wrap_hash, return the real symbol. */
200 extern struct bfd_link_hash_entry
*unwrap_hash_lookup
201 (struct bfd_link_info
*, bfd
*, struct bfd_link_hash_entry
*);
203 /* Traverse a link hash table. */
204 extern void bfd_link_hash_traverse
205 (struct bfd_link_hash_table
*,
206 bfd_boolean (*) (struct bfd_link_hash_entry
*, void *),
209 /* Add an entry to the undefs list. */
210 extern void bfd_link_add_undef
211 (struct bfd_link_hash_table
*, struct bfd_link_hash_entry
*);
213 /* Remove symbols from the undefs list that don't belong there. */
214 extern void bfd_link_repair_undef_list
215 (struct bfd_link_hash_table
*table
);
217 /* Read symbols and cache symbol pointer array in outsymbols. */
218 extern bfd_boolean
bfd_generic_link_read_symbols (bfd
*);
222 struct bfd_sym_chain
*next
;
226 /* How to handle unresolved symbols.
227 There are four possibilities which are enumerated below: */
230 /* This is the initial value when then link_info structure is created.
231 It allows the various stages of the linker to determine whether they
232 allowed to set the value. */
239 typedef enum {with_flags
, without_flags
} flag_type
;
241 /* A section flag list. */
242 struct flag_info_list
247 struct flag_info_list
*next
;
250 /* Section flag info. */
253 flagword only_with_flags
;
254 flagword not_with_flags
;
255 struct flag_info_list
*flag_list
;
256 bfd_boolean flags_initialized
;
259 struct bfd_elf_dynamic_list
;
260 struct bfd_elf_version_tree
;
262 /* Types of output. */
271 #define bfd_link_executable(info) ((info)->type == type_executable)
272 #define bfd_link_dll(info) ((info)->type == type_dll)
273 #define bfd_link_relocatable(info) ((info)->type == type_relocatable)
274 #define bfd_link_pic(info) (info)->pic
275 #define bfd_link_pie(info) (bfd_link_executable (info) \
276 && bfd_link_pic (info))
278 /* This structure holds all the information needed to communicate
279 between BFD and the linker when doing a link. */
284 ENUM_BITFIELD (output_type
) type
: 2;
286 /* TRUE if BFD should generate a position independent object. */
287 unsigned int pic
: 1;
289 /* TRUE if BFD should pre-bind symbols in a shared object. */
290 unsigned int symbolic
: 1;
292 /* TRUE if executable should not contain copy relocs.
293 Setting this true may result in a non-sharable text segment. */
294 unsigned int nocopyreloc
: 1;
296 /* TRUE if BFD should export all symbols in the dynamic symbol table
297 of an executable, rather than only those used. */
298 unsigned int export_dynamic
: 1;
300 /* TRUE if a default symbol version should be created and used for
302 unsigned int create_default_symver
: 1;
304 /* TRUE if unreferenced sections should be removed. */
305 unsigned int gc_sections
: 1;
307 /* TRUE if every symbol should be reported back via the notice
309 unsigned int notice_all
: 1;
311 /* TRUE if the LTO plugin is active. */
312 unsigned int lto_plugin_active
: 1;
314 /* TRUE if global symbols in discarded sections should be stripped. */
315 unsigned int strip_discarded
: 1;
317 /* TRUE if all data symbols should be dynamic. */
318 unsigned int dynamic_data
: 1;
320 /* Which symbols to strip. */
321 ENUM_BITFIELD (bfd_link_strip
) strip
: 2;
323 /* Which local symbols to discard. */
324 ENUM_BITFIELD (bfd_link_discard
) discard
: 2;
326 /* Criteria for skipping symbols when determining
327 whether to include an object from an archive. */
328 ENUM_BITFIELD (bfd_link_common_skip_ar_symbols
) common_skip_ar_symbols
: 2;
330 /* What to do with unresolved symbols in an object file.
331 When producing executables the default is GENERATE_ERROR.
332 When producing shared libraries the default is IGNORE. The
333 assumption with shared libraries is that the reference will be
334 resolved at load/execution time. */
335 ENUM_BITFIELD (report_method
) unresolved_syms_in_objects
: 2;
337 /* What to do with unresolved symbols in a shared library.
338 The same defaults apply. */
339 ENUM_BITFIELD (report_method
) unresolved_syms_in_shared_libs
: 2;
341 /* TRUE if shared objects should be linked directly, not shared. */
342 unsigned int static_link
: 1;
344 /* TRUE if symbols should be retained in memory, FALSE if they
345 should be freed and reread. */
346 unsigned int keep_memory
: 1;
348 /* TRUE if BFD should generate relocation information in the final
350 unsigned int emitrelocations
: 1;
352 /* TRUE if PT_GNU_RELRO segment should be created. */
353 unsigned int relro
: 1;
355 /* Nonzero if .eh_frame_hdr section and PT_GNU_EH_FRAME ELF segment
356 should be created. 1 for DWARF2 tables, 2 for compact tables. */
357 unsigned int eh_frame_hdr_type
: 2;
359 /* TRUE if we should warn when adding a DT_TEXTREL to a shared object. */
360 unsigned int warn_shared_textrel
: 1;
362 /* TRUE if we should error when adding a DT_TEXTREL. */
363 unsigned int error_textrel
: 1;
365 /* TRUE if .hash section should be created. */
366 unsigned int emit_hash
: 1;
368 /* TRUE if .gnu.hash section should be created. */
369 unsigned int emit_gnu_hash
: 1;
371 /* If TRUE reduce memory overheads, at the expense of speed. This will
372 cause map file generation to use an O(N^2) algorithm and disable
373 caching ELF symbol buffer. */
374 unsigned int reduce_memory_overheads
: 1;
376 /* TRUE if the output file should be in a traditional format. This
377 is equivalent to the setting of the BFD_TRADITIONAL_FORMAT flag
378 on the output file, but may be checked when reading the input
380 unsigned int traditional_format
: 1;
382 /* TRUE if non-PLT relocs should be merged into one reloc section
383 and sorted so that relocs against the same symbol come together. */
384 unsigned int combreloc
: 1;
386 /* TRUE if a default symbol version should be created and used for
388 unsigned int default_imported_symver
: 1;
390 /* TRUE if the new ELF dynamic tags are enabled. */
391 unsigned int new_dtags
: 1;
393 /* FALSE if .eh_frame unwind info should be generated for PLT and other
394 linker created sections, TRUE if it should be omitted. */
395 unsigned int no_ld_generated_unwind_info
: 1;
397 /* TRUE if BFD should generate a "task linked" object file,
398 similar to relocatable but also with globals converted to
400 unsigned int task_link
: 1;
402 /* TRUE if ok to have multiple definition. */
403 unsigned int allow_multiple_definition
: 1;
405 /* TRUE if ok to have version with no definition. */
406 unsigned int allow_undefined_version
: 1;
408 /* TRUE if some symbols have to be dynamic, controlled by
409 --dynamic-list command line options. */
410 unsigned int dynamic
: 1;
412 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W|PF_X
414 unsigned int execstack
: 1;
416 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W
418 unsigned int noexecstack
: 1;
420 /* TRUE if we want to produced optimized output files. This might
421 need much more time and therefore must be explicitly selected. */
422 unsigned int optimize
: 1;
424 /* TRUE if user should be informed of removed unreferenced sections. */
425 unsigned int print_gc_sections
: 1;
427 /* TRUE if we should warn alternate ELF machine code. */
428 unsigned int warn_alternate_em
: 1;
430 /* TRUE if the linker script contained an explicit PHDRS command. */
431 unsigned int user_phdrs
: 1;
433 /* TRUE if BND prefix in PLT entries is always generated. */
434 unsigned int bndplt
: 1;
436 /* Char that may appear as the first char of a symbol, but should be
437 skipped (like symbol_leading_char) when looking up symbols in
438 wrap_hash. Used by PowerPC Linux for 'dot' symbols. */
441 /* Separator between archive and filename in linker script filespecs. */
444 /* Compress DWARF debug sections. */
445 enum compressed_debug_section_type compress_debug
;
447 /* Default stack size. Zero means default (often zero itself), -1
448 means explicitly zero-sized. */
449 bfd_signed_vma stacksize
;
451 /* Enable or disable target specific optimizations.
453 Not all targets have optimizations to enable.
455 Normally these optimizations are disabled by default but some targets
456 prefer to enable them by default. So this field is a tri-state variable.
459 zero: Enable the optimizations (either from --relax being specified on
460 the command line or the backend's before_allocation emulation function.
462 positive: The user has requested that these optimizations be disabled.
463 (Via the --no-relax command line option).
465 negative: The optimizations are disabled. (Set when initializing the
466 args_type structure in ldmain.c:main. */
467 signed int disable_target_specific_optimizations
;
469 /* Function callbacks. */
470 const struct bfd_link_callbacks
*callbacks
;
472 /* Hash table handled by BFD. */
473 struct bfd_link_hash_table
*hash
;
475 /* Hash table of symbols to keep. This is NULL unless strip is
477 struct bfd_hash_table
*keep_hash
;
479 /* Hash table of symbols to report back via the notice callback. If
480 this is NULL, and notice_all is FALSE, then no symbols are
482 struct bfd_hash_table
*notice_hash
;
484 /* Hash table of symbols which are being wrapped (the --wrap linker
485 option). If this is NULL, no symbols are being wrapped. */
486 struct bfd_hash_table
*wrap_hash
;
488 /* Hash table of symbols which may be left unresolved during
489 a link. If this is NULL, no symbols can be left unresolved. */
490 struct bfd_hash_table
*ignore_hash
;
492 /* The output BFD. */
495 /* The list of input BFD's involved in the link. These are chained
496 together via the link.next field. */
498 bfd
**input_bfds_tail
;
500 /* If a symbol should be created for each input BFD, this is section
501 where those symbols should be placed. It must be a section in
502 the output BFD. It may be NULL, in which case no such symbols
503 will be created. This is to support CREATE_OBJECT_SYMBOLS in the
504 linker command language. */
505 asection
*create_object_symbols_section
;
507 /* List of global symbol names that are starting points for marking
508 sections against garbage collection. */
509 struct bfd_sym_chain
*gc_sym_list
;
511 /* If a base output file is wanted, then this points to it */
514 /* The function to call when the executable or shared object is
516 const char *init_function
;
518 /* The function to call when the executable or shared object is
520 const char *fini_function
;
522 /* Number of relaxation passes. Usually only one relaxation pass
523 is needed. But a backend can have as many relaxation passes as
524 necessary. During bfd_relax_section call, it is set to the
525 current pass, starting from 0. */
528 /* Number of relaxation trips. This number is incremented every
529 time the relaxation pass is restarted due to a previous
530 relaxation returning true in *AGAIN. */
533 /* > 0 to treat protected data defined in the shared library as
534 reference external. 0 to treat it as internal. -1 to let
535 backend to decide. */
536 int extern_protected_data
;
538 /* Non-zero if auto-import thunks for DATA items in pei386 DLLs
539 should be generated/linked against. Set to 1 if this feature
540 is explicitly requested by the user, -1 if enabled by default. */
541 int pei386_auto_import
;
543 /* Non-zero if runtime relocs for DATA items with non-zero addends
544 in pei386 DLLs should be generated. Set to 1 if this feature
545 is explicitly requested by the user, -1 if enabled by default. */
546 int pei386_runtime_pseudo_reloc
;
548 /* How many spare .dynamic DT_NULL entries should be added? */
549 unsigned int spare_dynamic_tags
;
551 /* May be used to set DT_FLAGS for ELF. */
554 /* May be used to set DT_FLAGS_1 for ELF. */
557 /* Start and end of RELRO region. */
558 bfd_vma relro_start
, relro_end
;
560 /* List of symbols should be dynamic. */
561 struct bfd_elf_dynamic_list
*dynamic_list
;
563 /* The version information. */
564 struct bfd_elf_version_tree
*version_info
;
567 /* This structures holds a set of callback functions. These are called
568 by the BFD linker routines. Except for the info functions, the first
569 argument to each callback function is the bfd_link_info structure
570 being used and each function returns a boolean value. If the
571 function returns FALSE, then the BFD function which called it should
572 return with a failure indication. */
574 struct bfd_link_callbacks
576 /* A function which is called when an object is added from an
577 archive. ABFD is the archive element being added. NAME is the
578 name of the symbol which caused the archive element to be pulled
579 in. This function may set *SUBSBFD to point to an alternative
580 BFD from which symbols should in fact be added in place of the
581 original BFD's symbols. */
582 bfd_boolean (*add_archive_element
)
583 (struct bfd_link_info
*, bfd
*abfd
, const char *name
, bfd
**subsbfd
);
584 /* A function which is called when a symbol is found with multiple
585 definitions. H is the symbol which is defined multiple times.
586 NBFD is the new BFD, NSEC is the new section, and NVAL is the new
587 value. NSEC may be bfd_com_section or bfd_ind_section. */
588 bfd_boolean (*multiple_definition
)
589 (struct bfd_link_info
*, struct bfd_link_hash_entry
*h
,
590 bfd
*nbfd
, asection
*nsec
, bfd_vma nval
);
591 /* A function which is called when a common symbol is defined
592 multiple times. H is the symbol appearing multiple times.
593 NBFD is the BFD of the new symbol. NTYPE is the type of the new
594 symbol, one of bfd_link_hash_defined, bfd_link_hash_common, or
595 bfd_link_hash_indirect. If NTYPE is bfd_link_hash_common, NSIZE
596 is the size of the new symbol. */
597 bfd_boolean (*multiple_common
)
598 (struct bfd_link_info
*, struct bfd_link_hash_entry
*h
,
599 bfd
*nbfd
, enum bfd_link_hash_type ntype
, bfd_vma nsize
);
600 /* A function which is called to add a symbol to a set. ENTRY is
601 the link hash table entry for the set itself (e.g.,
602 __CTOR_LIST__). RELOC is the relocation to use for an entry in
603 the set when generating a relocatable file, and is also used to
604 get the size of the entry when generating an executable file.
605 ABFD, SEC and VALUE identify the value to add to the set. */
606 bfd_boolean (*add_to_set
)
607 (struct bfd_link_info
*, struct bfd_link_hash_entry
*entry
,
608 bfd_reloc_code_real_type reloc
, bfd
*abfd
, asection
*sec
, bfd_vma value
);
609 /* A function which is called when the name of a g++ constructor or
610 destructor is found. This is only called by some object file
611 formats. CONSTRUCTOR is TRUE for a constructor, FALSE for a
612 destructor. This will use BFD_RELOC_CTOR when generating a
613 relocatable file. NAME is the name of the symbol found. ABFD,
614 SECTION and VALUE are the value of the symbol. */
615 bfd_boolean (*constructor
)
616 (struct bfd_link_info
*, bfd_boolean constructor
, const char *name
,
617 bfd
*abfd
, asection
*sec
, bfd_vma value
);
618 /* A function which is called to issue a linker warning. For
619 example, this is called when there is a reference to a warning
620 symbol. WARNING is the warning to be issued. SYMBOL is the name
621 of the symbol which triggered the warning; it may be NULL if
622 there is none. ABFD, SECTION and ADDRESS identify the location
623 which trigerred the warning; either ABFD or SECTION or both may
624 be NULL if the location is not known. */
625 bfd_boolean (*warning
)
626 (struct bfd_link_info
*, const char *warning
, const char *symbol
,
627 bfd
*abfd
, asection
*section
, bfd_vma address
);
628 /* A function which is called when a relocation is attempted against
629 an undefined symbol. NAME is the symbol which is undefined.
630 ABFD, SECTION and ADDRESS identify the location from which the
631 reference is made. IS_FATAL indicates whether an undefined symbol is
632 a fatal error or not. In some cases SECTION may be NULL. */
633 bfd_boolean (*undefined_symbol
)
634 (struct bfd_link_info
*, const char *name
, bfd
*abfd
,
635 asection
*section
, bfd_vma address
, bfd_boolean is_fatal
);
636 /* A function which is called when a reloc overflow occurs. ENTRY is
637 the link hash table entry for the symbol the reloc is against.
638 NAME is the name of the local symbol or section the reloc is
639 against, RELOC_NAME is the name of the relocation, and ADDEND is
640 any addend that is used. ABFD, SECTION and ADDRESS identify the
641 location at which the overflow occurs; if this is the result of a
642 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
643 ABFD will be NULL. */
644 bfd_boolean (*reloc_overflow
)
645 (struct bfd_link_info
*, struct bfd_link_hash_entry
*entry
,
646 const char *name
, const char *reloc_name
, bfd_vma addend
,
647 bfd
*abfd
, asection
*section
, bfd_vma address
);
648 /* A function which is called when a dangerous reloc is performed.
649 MESSAGE is an appropriate message.
650 ABFD, SECTION and ADDRESS identify the location at which the
651 problem occurred; if this is the result of a
652 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
653 ABFD will be NULL. */
654 bfd_boolean (*reloc_dangerous
)
655 (struct bfd_link_info
*, const char *message
,
656 bfd
*abfd
, asection
*section
, bfd_vma address
);
657 /* A function which is called when a reloc is found to be attached
658 to a symbol which is not being written out. NAME is the name of
659 the symbol. ABFD, SECTION and ADDRESS identify the location of
660 the reloc; if this is the result of a
661 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
662 ABFD will be NULL. */
663 bfd_boolean (*unattached_reloc
)
664 (struct bfd_link_info
*, const char *name
,
665 bfd
*abfd
, asection
*section
, bfd_vma address
);
666 /* A function which is called when a symbol in notice_hash is
667 defined or referenced. H is the symbol, INH the indirect symbol
668 if applicable. ABFD, SECTION and ADDRESS are the (new) value of
669 the symbol. If SECTION is bfd_und_section, this is a reference.
670 FLAGS are the symbol BSF_* flags. */
671 bfd_boolean (*notice
)
672 (struct bfd_link_info
*, struct bfd_link_hash_entry
*h
,
673 struct bfd_link_hash_entry
*inh
,
674 bfd
*abfd
, asection
*section
, bfd_vma address
, flagword flags
);
675 /* Error or warning link info message. */
677 (const char *fmt
, ...);
678 /* General link info message. */
680 (const char *fmt
, ...);
681 /* Message to be printed in linker map file. */
683 (const char *fmt
, ...);
684 /* This callback provides a chance for users of the BFD library to
685 override its decision about whether to place two adjacent sections
686 into the same segment. */
687 bfd_boolean (*override_segment_assignment
)
688 (struct bfd_link_info
*, bfd
* abfd
,
689 asection
* current_section
, asection
* previous_section
,
690 bfd_boolean new_segment
);
693 /* The linker builds link_order structures which tell the code how to
694 include input data in the output file. */
696 /* These are the types of link_order structures. */
698 enum bfd_link_order_type
700 bfd_undefined_link_order
, /* Undefined. */
701 bfd_indirect_link_order
, /* Built from a section. */
702 bfd_data_link_order
, /* Set to explicit data. */
703 bfd_section_reloc_link_order
, /* Relocate against a section. */
704 bfd_symbol_reloc_link_order
/* Relocate against a symbol. */
707 /* This is the link_order structure itself. These form a chain
708 attached to the output section whose contents they are describing. */
710 struct bfd_link_order
712 /* Next link_order in chain. */
713 struct bfd_link_order
*next
;
714 /* Type of link_order. */
715 enum bfd_link_order_type type
;
716 /* Offset within output section. */
718 /* Size within output section. */
720 /* Type specific information. */
725 /* Section to include. If this is used, then
726 section->output_section must be the section the
727 link_order is attached to, section->output_offset must
728 equal the link_order offset field, and section->size
729 must equal the link_order size field. Maybe these
730 restrictions should be relaxed someday. */
735 /* Size of contents, or zero when contents should be filled by
736 the architecture-dependent fill function.
737 A non-zero value allows filling of the output section
738 with an arbitrary repeated pattern. */
740 /* Data to put into file. */
745 /* Description of reloc to generate. Used for
746 bfd_section_reloc_link_order and
747 bfd_symbol_reloc_link_order. */
748 struct bfd_link_order_reloc
*p
;
753 /* A linker order of type bfd_section_reloc_link_order or
754 bfd_symbol_reloc_link_order means to create a reloc against a
755 section or symbol, respectively. This is used to implement -Ur to
756 generate relocs for the constructor tables. The
757 bfd_link_order_reloc structure describes the reloc that BFD should
758 create. It is similar to a arelent, but I didn't use arelent
759 because the linker does not know anything about most symbols, and
760 any asymbol structure it creates will be partially meaningless.
761 This information could logically be in the bfd_link_order struct,
762 but I didn't want to waste the space since these types of relocs
763 are relatively rare. */
765 struct bfd_link_order_reloc
768 bfd_reloc_code_real_type reloc
;
772 /* For type bfd_section_reloc_link_order, this is the section
773 the reloc should be against. This must be a section in the
774 output BFD, not any of the input BFDs. */
776 /* For type bfd_symbol_reloc_link_order, this is the name of the
777 symbol the reloc should be against. */
781 /* Addend to use. The object file should contain zero. The BFD
782 backend is responsible for filling in the contents of the object
783 file correctly. For some object file formats (e.g., COFF) the
784 addend must be stored into in the object file, and for some
785 (e.g., SPARC a.out) it is kept in the reloc. */
789 /* Allocate a new link_order for a section. */
790 extern struct bfd_link_order
*bfd_new_link_order (bfd
*, asection
*);
792 /* These structures are used to describe version information for the
793 ELF linker. These structures could be manipulated entirely inside
794 BFD, but it would be a pain. Instead, the regular linker sets up
795 these structures, and then passes them into BFD. */
797 /* Glob pattern for a version. */
799 struct bfd_elf_version_expr
801 /* Next glob pattern for this version. */
802 struct bfd_elf_version_expr
*next
;
805 /* Set if pattern is not a glob. */
806 unsigned int literal
: 1;
807 /* Defined by ".symver". */
808 unsigned int symver
: 1;
809 /* Defined by version script. */
810 unsigned int script
: 1;
812 #define BFD_ELF_VERSION_C_TYPE 1
813 #define BFD_ELF_VERSION_CXX_TYPE 2
814 #define BFD_ELF_VERSION_JAVA_TYPE 4
815 unsigned int mask
: 3;
818 struct bfd_elf_version_expr_head
820 /* List of all patterns, both wildcards and non-wildcards. */
821 struct bfd_elf_version_expr
*list
;
822 /* Hash table for non-wildcards. */
824 /* Remaining patterns. */
825 struct bfd_elf_version_expr
*remaining
;
826 /* What kind of pattern types are present in list (bitmask). */
830 /* Version dependencies. */
832 struct bfd_elf_version_deps
834 /* Next dependency for this version. */
835 struct bfd_elf_version_deps
*next
;
836 /* The version which this version depends upon. */
837 struct bfd_elf_version_tree
*version_needed
;
840 /* A node in the version tree. */
842 struct bfd_elf_version_tree
845 struct bfd_elf_version_tree
*next
;
846 /* Name of this version. */
848 /* Version number. */
850 /* Regular expressions for global symbols in this version. */
851 struct bfd_elf_version_expr_head globals
;
852 /* Regular expressions for local symbols in this version. */
853 struct bfd_elf_version_expr_head locals
;
854 /* List of versions which this version depends upon. */
855 struct bfd_elf_version_deps
*deps
;
856 /* Index of the version name. This is used within BFD. */
857 unsigned int name_indx
;
858 /* Whether this version tree was used. This is used within BFD. */
861 struct bfd_elf_version_expr
*(*match
)
862 (struct bfd_elf_version_expr_head
*head
,
863 struct bfd_elf_version_expr
*prev
, const char *sym
);
866 struct bfd_elf_dynamic_list
868 struct bfd_elf_version_expr_head head
;
869 struct bfd_elf_version_expr
*(*match
)
870 (struct bfd_elf_version_expr_head
*head
,
871 struct bfd_elf_version_expr
*prev
, const char *sym
);