1 /* bfdlink.h -- header file for BFD link routines
2 Copyright (C) 1993-2017 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 object file, as distict from a LTO
105 unsigned int non_ir_ref : 1;
107 /* Symbol is a built-in define. These will be overridden by PROVIDE
108 in a linker script. */
109 unsigned int linker_def : 1;
111 /* Symbol defined in a linker script. */
112 unsigned int ldscript_def : 1;
114 /* A union of information depending upon the type. */
117 /* Nothing is kept for bfd_hash_new. */
118 /* bfd_link_hash_undefined, bfd_link_hash_undefweak. */
121 /* Undefined and common symbols are kept in a linked list through
122 this field. This field is present in all of the union element
123 so that we don't need to remove entries from the list when we
124 change their type. Removing entries would either require the
125 list to be doubly linked, which would waste more memory, or
126 require a traversal. When an undefined or common symbol is
127 created, it should be added to this list, the head of which is in
128 the link hash table itself. As symbols are defined, they need
129 not be removed from the list; anything which reads the list must
130 doublecheck the symbol type.
132 Weak symbols are not kept on this list.
134 Defined and defweak symbols use this field as a reference marker.
135 If the field is not NULL, or this structure is the tail of the
136 undefined symbol list, the symbol has been referenced. If the
137 symbol is undefined and becomes defined, this field will
138 automatically be non-NULL since the symbol will have been on the
139 undefined symbol list. */
140 struct bfd_link_hash_entry *next;
141 /* BFD symbol was found in. */
143 /* For __start_<name> and __stop_<name> symbols, the first
144 input section matching the name. */
147 /* bfd_link_hash_defined, bfd_link_hash_defweak. */
150 struct bfd_link_hash_entry *next;
151 /* Symbol section. */
156 /* bfd_link_hash_indirect, bfd_link_hash_warning. */
159 struct bfd_link_hash_entry *next;
161 struct bfd_link_hash_entry *link;
162 /* Warning message (bfd_link_hash_warning only). */
165 /* bfd_link_hash_common. */
168 struct bfd_link_hash_entry *next;
169 /* The linker needs to know three things about common
170 symbols: the size, the alignment, and the section in
171 which the symbol should be placed. We store the size
172 here, and we allocate a small structure to hold the
173 section and the alignment. The alignment is stored as a
174 power of two. We don't store all the information
175 directly because we don't want to increase the size of
176 the union; this structure is a major space user in the
178 struct bfd_link_hash_common_entry *p;
179 /* Common symbol size. */
185 /* This is the link hash table. It is a derived class of
188 struct bfd_link_hash_table
190 /* The hash table itself. */
191 struct bfd_hash_table table;
192 /* A linked list of undefined and common symbols, linked through the
193 next field in the bfd_link_hash_entry structure. */
194 struct bfd_link_hash_entry *undefs;
195 /* Entries are added to the tail of the undefs list. */
196 struct bfd_link_hash_entry *undefs_tail;
197 /* Function to free the hash table on closing BFD. */
198 void (*hash_table_free) (bfd *);
199 /* The type of the link hash table. */
200 enum bfd_link_hash_table_type type;
203 /* Look up an entry in a link hash table. If FOLLOW is TRUE, this
204 follows bfd_link_hash_indirect and bfd_link_hash_warning links to
206 extern struct bfd_link_hash_entry *bfd_link_hash_lookup
207 (struct bfd_link_hash_table *, const char *, bfd_boolean create,
208 bfd_boolean copy, bfd_boolean follow);
210 /* Look up an entry in the main linker hash table if the symbol might
211 be wrapped. This should only be used for references to an
212 undefined symbol, not for definitions of a symbol. */
214 extern struct bfd_link_hash_entry *bfd_wrapped_link_hash_lookup
215 (bfd *, struct bfd_link_info *, const char *, bfd_boolean,
216 bfd_boolean, bfd_boolean);
218 /* If H is a wrapped symbol, ie. the symbol name starts with "__wrap_"
219 and the remainder is found in wrap_hash, return the real symbol. */
221 extern struct bfd_link_hash_entry *unwrap_hash_lookup
222 (struct bfd_link_info *, bfd *, struct bfd_link_hash_entry *);
224 /* Traverse a link hash table. */
225 extern void bfd_link_hash_traverse
226 (struct bfd_link_hash_table *,
227 bfd_boolean (*) (struct bfd_link_hash_entry *, void *),
230 /* Add an entry to the undefs list. */
231 extern void bfd_link_add_undef
232 (struct bfd_link_hash_table *, struct bfd_link_hash_entry *);
234 /* Remove symbols from the undefs list that don't belong there. */
235 extern void bfd_link_repair_undef_list
236 (struct bfd_link_hash_table *table);
238 /* Read symbols and cache symbol pointer array in outsymbols. */
239 extern bfd_boolean bfd_generic_link_read_symbols (bfd *);
241 /* Check the relocs in the BFD. Called after all the input
242 files have been loaded, and garbage collection has tagged
243 any unneeded sections. */
244 extern bfd_boolean bfd_link_check_relocs (bfd *,struct bfd_link_info *);
248 struct bfd_sym_chain *next;
252 /* How to handle unresolved symbols.
253 There are four possibilities which are enumerated below: */
256 /* This is the initial value when then link_info structure is created.
257 It allows the various stages of the linker to determine whether they
258 allowed to set the value. */
265 typedef enum {with_flags, without_flags} flag_type;
267 /* A section flag list. */
268 struct flag_info_list
273 struct flag_info_list *next;
276 /* Section flag info. */
279 flagword only_with_flags;
280 flagword not_with_flags;
281 struct flag_info_list *flag_list;
282 bfd_boolean flags_initialized;
285 struct bfd_elf_dynamic_list;
286 struct bfd_elf_version_tree;
288 /* Types of output. */
298 #define bfd_link_pde(info) ((info)->type == type_pde)
299 #define bfd_link_dll(info) ((info)->type == type_dll)
300 #define bfd_link_relocatable(info) ((info)->type == type_relocatable)
301 #define bfd_link_pie(info) ((info)->type == type_pie)
302 #define bfd_link_executable(info) (bfd_link_pde (info) || bfd_link_pie (info))
303 #define bfd_link_pic(info) (bfd_link_dll (info) || bfd_link_pie (info))
305 /* This structure holds all the information needed to communicate
306 between BFD and the linker when doing a link. */
311 ENUM_BITFIELD (output_type) type : 2;
313 /* TRUE if BFD should pre-bind symbols in a shared object. */
314 unsigned int symbolic: 1;
316 /* TRUE if executable should not contain copy relocs.
317 Setting this true may result in a non-sharable text segment. */
318 unsigned int nocopyreloc: 1;
320 /* TRUE if BFD should export all symbols in the dynamic symbol table
321 of an executable, rather than only those used. */
322 unsigned int export_dynamic: 1;
324 /* TRUE if a default symbol version should be created and used for
326 unsigned int create_default_symver: 1;
328 /* TRUE if unreferenced sections should be removed. */
329 unsigned int gc_sections: 1;
331 /* TRUE if exported symbols should be kept during section gc. */
332 unsigned int gc_keep_exported: 1;
334 /* TRUE if every symbol should be reported back via the notice
336 unsigned int notice_all: 1;
338 /* TRUE if the LTO plugin is active. */
339 unsigned int lto_plugin_active: 1;
341 /* TRUE if global symbols in discarded sections should be stripped. */
342 unsigned int strip_discarded: 1;
344 /* TRUE if all data symbols should be dynamic. */
345 unsigned int dynamic_data: 1;
347 /* Which symbols to strip. */
348 ENUM_BITFIELD (bfd_link_strip) strip : 2;
350 /* Which local symbols to discard. */
351 ENUM_BITFIELD (bfd_link_discard) discard : 2;
353 /* Whether to generate ELF common symbols with the STT_COMMON type. */
354 ENUM_BITFIELD (bfd_link_elf_stt_common) elf_stt_common : 2;
356 /* Criteria for skipping symbols when determining
357 whether to include an object from an archive. */
358 ENUM_BITFIELD (bfd_link_common_skip_ar_symbols) common_skip_ar_symbols : 2;
360 /* What to do with unresolved symbols in an object file.
361 When producing executables the default is GENERATE_ERROR.
362 When producing shared libraries the default is IGNORE. The
363 assumption with shared libraries is that the reference will be
364 resolved at load/execution time. */
365 ENUM_BITFIELD (report_method) unresolved_syms_in_objects : 2;
367 /* What to do with unresolved symbols in a shared library.
368 The same defaults apply. */
369 ENUM_BITFIELD (report_method) unresolved_syms_in_shared_libs : 2;
371 /* TRUE if shared objects should be linked directly, not shared. */
372 unsigned int static_link: 1;
374 /* TRUE if symbols should be retained in memory, FALSE if they
375 should be freed and reread. */
376 unsigned int keep_memory: 1;
378 /* TRUE if BFD should generate relocation information in the final
380 unsigned int emitrelocations: 1;
382 /* TRUE if PT_GNU_RELRO segment should be created. */
383 unsigned int relro: 1;
385 /* Nonzero if .eh_frame_hdr section and PT_GNU_EH_FRAME ELF segment
386 should be created. 1 for DWARF2 tables, 2 for compact tables. */
387 unsigned int eh_frame_hdr_type: 2;
389 /* TRUE if we should warn when adding a DT_TEXTREL to a shared object. */
390 unsigned int warn_shared_textrel: 1;
392 /* TRUE if we should error when adding a DT_TEXTREL. */
393 unsigned int error_textrel: 1;
395 /* TRUE if .hash section should be created. */
396 unsigned int emit_hash: 1;
398 /* TRUE if .gnu.hash section should be created. */
399 unsigned int emit_gnu_hash: 1;
401 /* If TRUE reduce memory overheads, at the expense of speed. This will
402 cause map file generation to use an O(N^2) algorithm and disable
403 caching ELF symbol buffer. */
404 unsigned int reduce_memory_overheads: 1;
406 /* TRUE if the output file should be in a traditional format. This
407 is equivalent to the setting of the BFD_TRADITIONAL_FORMAT flag
408 on the output file, but may be checked when reading the input
410 unsigned int traditional_format: 1;
412 /* TRUE if non-PLT relocs should be merged into one reloc section
413 and sorted so that relocs against the same symbol come together. */
414 unsigned int combreloc: 1;
416 /* TRUE if a default symbol version should be created and used for
418 unsigned int default_imported_symver: 1;
420 /* TRUE if the new ELF dynamic tags are enabled. */
421 unsigned int new_dtags: 1;
423 /* FALSE if .eh_frame unwind info should be generated for PLT and other
424 linker created sections, TRUE if it should be omitted. */
425 unsigned int no_ld_generated_unwind_info: 1;
427 /* TRUE if BFD should generate a "task linked" object file,
428 similar to relocatable but also with globals converted to
430 unsigned int task_link: 1;
432 /* TRUE if ok to have multiple definition. */
433 unsigned int allow_multiple_definition: 1;
435 /* TRUE if ok to have version with no definition. */
436 unsigned int allow_undefined_version: 1;
438 /* TRUE if some symbols have to be dynamic, controlled by
439 --dynamic-list command line options. */
440 unsigned int dynamic: 1;
442 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W|PF_X
444 unsigned int execstack: 1;
446 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W
448 unsigned int noexecstack: 1;
450 /* TRUE if we want to produced optimized output files. This might
451 need much more time and therefore must be explicitly selected. */
452 unsigned int optimize: 1;
454 /* TRUE if user should be informed of removed unreferenced sections. */
455 unsigned int print_gc_sections: 1;
457 /* TRUE if we should warn alternate ELF machine code. */
458 unsigned int warn_alternate_em: 1;
460 /* TRUE if the linker script contained an explicit PHDRS command. */
461 unsigned int user_phdrs: 1;
463 /* TRUE if we should check relocations after all input files have
465 unsigned int check_relocs_after_open_input: 1;
467 /* TRUE if BND prefix in PLT entries is always generated. */
468 unsigned int bndplt: 1;
470 /* TRUE if generation of .interp/PT_INTERP should be suppressed. */
471 unsigned int nointerp: 1;
473 /* TRUE if we shouldn't check relocation overflow. */
474 unsigned int no_reloc_overflow_check: 1;
476 /* TRUE if generate a 1-byte NOP as suffix for x86 call instruction. */
477 unsigned int call_nop_as_suffix : 1;
479 /* The 1-byte NOP for x86 call instruction. */
482 /* Char that may appear as the first char of a symbol, but should be
483 skipped (like symbol_leading_char) when looking up symbols in
484 wrap_hash. Used by PowerPC Linux for 'dot' symbols. */
487 /* Separator between archive and filename in linker script filespecs. */
490 /* Compress DWARF debug sections. */
491 enum compressed_debug_section_type compress_debug;
493 /* Default stack size. Zero means default (often zero itself), -1
494 means explicitly zero-sized. */
495 bfd_signed_vma stacksize;
497 /* Enable or disable target specific optimizations.
499 Not all targets have optimizations to enable.
501 Normally these optimizations are disabled by default but some targets
502 prefer to enable them by default. So this field is a tri-state variable.
505 zero: Enable the optimizations (either from --relax being specified on
506 the command line or the backend's before_allocation emulation function.
508 positive: The user has requested that these optimizations be disabled.
509 (Via the --no-relax command line option).
511 negative: The optimizations are disabled. (Set when initializing the
512 args_type structure in ldmain.c:main. */
513 signed int disable_target_specific_optimizations;
515 /* Function callbacks. */
516 const struct bfd_link_callbacks *callbacks;
518 /* Hash table handled by BFD. */
519 struct bfd_link_hash_table *hash;
521 /* Hash table of symbols to keep. This is NULL unless strip is
523 struct bfd_hash_table *keep_hash;
525 /* Hash table of symbols to report back via the notice callback. If
526 this is NULL, and notice_all is FALSE, then no symbols are
528 struct bfd_hash_table *notice_hash;
530 /* Hash table of symbols which are being wrapped (the --wrap linker
531 option). If this is NULL, no symbols are being wrapped. */
532 struct bfd_hash_table *wrap_hash;
534 /* Hash table of symbols which may be left unresolved during
535 a link. If this is NULL, no symbols can be left unresolved. */
536 struct bfd_hash_table *ignore_hash;
538 /* The output BFD. */
541 /* The import library generated. */
544 /* The list of input BFD's involved in the link. These are chained
545 together via the link.next field. */
547 bfd **input_bfds_tail;
549 /* If a symbol should be created for each input BFD, this is section
550 where those symbols should be placed. It must be a section in
551 the output BFD. It may be NULL, in which case no such symbols
552 will be created. This is to support CREATE_OBJECT_SYMBOLS in the
553 linker command language. */
554 asection *create_object_symbols_section;
556 /* List of global symbol names that are starting points for marking
557 sections against garbage collection. */
558 struct bfd_sym_chain *gc_sym_list;
560 /* If a base output file is wanted, then this points to it */
563 /* The function to call when the executable or shared object is
565 const char *init_function;
567 /* The function to call when the executable or shared object is
569 const char *fini_function;
571 /* Number of relaxation passes. Usually only one relaxation pass
572 is needed. But a backend can have as many relaxation passes as
573 necessary. During bfd_relax_section call, it is set to the
574 current pass, starting from 0. */
577 /* Number of relaxation trips. This number is incremented every
578 time the relaxation pass is restarted due to a previous
579 relaxation returning true in *AGAIN. */
582 /* > 0 to treat protected data defined in the shared library as
583 reference external. 0 to treat it as internal. -1 to let
584 backend to decide. */
585 int extern_protected_data;
587 /* 1 to make undefined weak symbols dynamic when building a dynamic
588 object. 0 to resolve undefined weak symbols to zero. -1 to let
589 the backend decide. */
590 int dynamic_undefined_weak;
592 /* Non-zero if auto-import thunks for DATA items in pei386 DLLs
593 should be generated/linked against. Set to 1 if this feature
594 is explicitly requested by the user, -1 if enabled by default. */
595 int pei386_auto_import;
597 /* Non-zero if runtime relocs for DATA items with non-zero addends
598 in pei386 DLLs should be generated. Set to 1 if this feature
599 is explicitly requested by the user, -1 if enabled by default. */
600 int pei386_runtime_pseudo_reloc;
602 /* How many spare .dynamic DT_NULL entries should be added? */
603 unsigned int spare_dynamic_tags;
605 /* May be used to set DT_FLAGS for ELF. */
608 /* May be used to set DT_FLAGS_1 for ELF. */
611 /* Start and end of RELRO region. */
612 bfd_vma relro_start, relro_end;
614 /* List of symbols should be dynamic. */
615 struct bfd_elf_dynamic_list *dynamic_list;
617 /* The version information. */
618 struct bfd_elf_version_tree *version_info;
621 /* This structures holds a set of callback functions. These are called
622 by the BFD linker routines. */
624 struct bfd_link_callbacks
626 /* A function which is called when an object is added from an
627 archive. ABFD is the archive element being added. NAME is the
628 name of the symbol which caused the archive element to be pulled
629 in. This function may set *SUBSBFD to point to an alternative
630 BFD from which symbols should in fact be added in place of the
631 original BFD's symbols. Returns TRUE if the object should be
632 added, FALSE if it should be skipped. */
633 bfd_boolean (*add_archive_element)
634 (struct bfd_link_info *, bfd *abfd, const char *name, bfd **subsbfd);
635 /* A function which is called when a symbol is found with multiple
636 definitions. H is the symbol which is defined multiple times.
637 NBFD is the new BFD, NSEC is the new section, and NVAL is the new
638 value. NSEC may be bfd_com_section or bfd_ind_section. */
639 void (*multiple_definition)
640 (struct bfd_link_info *, struct bfd_link_hash_entry *h,
641 bfd *nbfd, asection *nsec, bfd_vma nval);
642 /* A function which is called when a common symbol is defined
643 multiple times. H is the symbol appearing multiple times.
644 NBFD is the BFD of the new symbol. NTYPE is the type of the new
645 symbol, one of bfd_link_hash_defined, bfd_link_hash_common, or
646 bfd_link_hash_indirect. If NTYPE is bfd_link_hash_common, NSIZE
647 is the size of the new symbol. */
648 void (*multiple_common)
649 (struct bfd_link_info *, struct bfd_link_hash_entry *h,
650 bfd *nbfd, enum bfd_link_hash_type ntype, bfd_vma nsize);
651 /* A function which is called to add a symbol to a set. ENTRY is
652 the link hash table entry for the set itself (e.g.,
653 __CTOR_LIST__). RELOC is the relocation to use for an entry in
654 the set when generating a relocatable file, and is also used to
655 get the size of the entry when generating an executable file.
656 ABFD, SEC and VALUE identify the value to add to the set. */
658 (struct bfd_link_info *, struct bfd_link_hash_entry *entry,
659 bfd_reloc_code_real_type reloc, bfd *abfd, asection *sec, bfd_vma value);
660 /* A function which is called when the name of a g++ constructor or
661 destructor is found. This is only called by some object file
662 formats. CONSTRUCTOR is TRUE for a constructor, FALSE for a
663 destructor. This will use BFD_RELOC_CTOR when generating a
664 relocatable file. NAME is the name of the symbol found. ABFD,
665 SECTION and VALUE are the value of the symbol. */
667 (struct bfd_link_info *, bfd_boolean constructor, const char *name,
668 bfd *abfd, asection *sec, bfd_vma value);
669 /* A function which is called to issue a linker warning. For
670 example, this is called when there is a reference to a warning
671 symbol. WARNING is the warning to be issued. SYMBOL is the name
672 of the symbol which triggered the warning; it may be NULL if
673 there is none. ABFD, SECTION and ADDRESS identify the location
674 which trigerred the warning; either ABFD or SECTION or both may
675 be NULL if the location is not known. */
677 (struct bfd_link_info *, const char *warning, const char *symbol,
678 bfd *abfd, asection *section, bfd_vma address);
679 /* A function which is called when a relocation is attempted against
680 an undefined symbol. NAME is the symbol which is undefined.
681 ABFD, SECTION and ADDRESS identify the location from which the
682 reference is made. IS_FATAL indicates whether an undefined symbol is
683 a fatal error or not. In some cases SECTION may be NULL. */
684 void (*undefined_symbol)
685 (struct bfd_link_info *, const char *name, bfd *abfd,
686 asection *section, bfd_vma address, bfd_boolean is_fatal);
687 /* A function which is called when a reloc overflow occurs. ENTRY is
688 the link hash table entry for the symbol the reloc is against.
689 NAME is the name of the local symbol or section the reloc is
690 against, RELOC_NAME is the name of the relocation, and ADDEND is
691 any addend that is used. ABFD, SECTION and ADDRESS identify the
692 location at which the overflow occurs; if this is the result of a
693 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
694 ABFD will be NULL. */
695 void (*reloc_overflow)
696 (struct bfd_link_info *, struct bfd_link_hash_entry *entry,
697 const char *name, const char *reloc_name, bfd_vma addend,
698 bfd *abfd, asection *section, bfd_vma address);
699 /* A function which is called when a dangerous reloc is performed.
700 MESSAGE is an appropriate message.
701 ABFD, SECTION and ADDRESS identify the location at which the
702 problem occurred; if this is the result of a
703 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
704 ABFD will be NULL. */
705 void (*reloc_dangerous)
706 (struct bfd_link_info *, const char *message,
707 bfd *abfd, asection *section, bfd_vma address);
708 /* A function which is called when a reloc is found to be attached
709 to a symbol which is not being written out. NAME is the name of
710 the symbol. ABFD, SECTION and ADDRESS identify the location of
711 the reloc; 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 (*unattached_reloc)
715 (struct bfd_link_info *, const char *name,
716 bfd *abfd, asection *section, bfd_vma address);
717 /* A function which is called when a symbol in notice_hash is
718 defined or referenced. H is the symbol, INH the indirect symbol
719 if applicable. ABFD, SECTION and ADDRESS are the (new) value of
720 the symbol. If SECTION is bfd_und_section, this is a reference.
721 FLAGS are the symbol BSF_* flags. */
722 bfd_boolean (*notice)
723 (struct bfd_link_info *, struct bfd_link_hash_entry *h,
724 struct bfd_link_hash_entry *inh,
725 bfd *abfd, asection *section, bfd_vma address, flagword flags);
726 /* Error or warning link info message. */
728 (const char *fmt, ...);
729 /* General link info message. */
731 (const char *fmt, ...);
732 /* Message to be printed in linker map file. */
734 (const char *fmt, ...);
735 /* This callback provides a chance for users of the BFD library to
736 override its decision about whether to place two adjacent sections
737 into the same segment. */
738 bfd_boolean (*override_segment_assignment)
739 (struct bfd_link_info *, bfd * abfd,
740 asection * current_section, asection * previous_section,
741 bfd_boolean new_segment);
744 /* The linker builds link_order structures which tell the code how to
745 include input data in the output file. */
747 /* These are the types of link_order structures. */
749 enum bfd_link_order_type
751 bfd_undefined_link_order, /* Undefined. */
752 bfd_indirect_link_order, /* Built from a section. */
753 bfd_data_link_order, /* Set to explicit data. */
754 bfd_section_reloc_link_order, /* Relocate against a section. */
755 bfd_symbol_reloc_link_order /* Relocate against a symbol. */
758 /* This is the link_order structure itself. These form a chain
759 attached to the output section whose contents they are describing. */
761 struct bfd_link_order
763 /* Next link_order in chain. */
764 struct bfd_link_order *next;
765 /* Type of link_order. */
766 enum bfd_link_order_type type;
767 /* Offset within output section. */
769 /* Size within output section. */
771 /* Type specific information. */
776 /* Section to include. If this is used, then
777 section->output_section must be the section the
778 link_order is attached to, section->output_offset must
779 equal the link_order offset field, and section->size
780 must equal the link_order size field. Maybe these
781 restrictions should be relaxed someday. */
786 /* Size of contents, or zero when contents should be filled by
787 the architecture-dependent fill function.
788 A non-zero value allows filling of the output section
789 with an arbitrary repeated pattern. */
791 /* Data to put into file. */
796 /* Description of reloc to generate. Used for
797 bfd_section_reloc_link_order and
798 bfd_symbol_reloc_link_order. */
799 struct bfd_link_order_reloc *p;
804 /* A linker order of type bfd_section_reloc_link_order or
805 bfd_symbol_reloc_link_order means to create a reloc against a
806 section or symbol, respectively. This is used to implement -Ur to
807 generate relocs for the constructor tables. The
808 bfd_link_order_reloc structure describes the reloc that BFD should
809 create. It is similar to a arelent, but I didn't use arelent
810 because the linker does not know anything about most symbols, and
811 any asymbol structure it creates will be partially meaningless.
812 This information could logically be in the bfd_link_order struct,
813 but I didn't want to waste the space since these types of relocs
814 are relatively rare. */
816 struct bfd_link_order_reloc
819 bfd_reloc_code_real_type reloc;
823 /* For type bfd_section_reloc_link_order, this is the section
824 the reloc should be against. This must be a section in the
825 output BFD, not any of the input BFDs. */
827 /* For type bfd_symbol_reloc_link_order, this is the name of the
828 symbol the reloc should be against. */
832 /* Addend to use. The object file should contain zero. The BFD
833 backend is responsible for filling in the contents of the object
834 file correctly. For some object file formats (e.g., COFF) the
835 addend must be stored into in the object file, and for some
836 (e.g., SPARC a.out) it is kept in the reloc. */
840 /* Allocate a new link_order for a section. */
841 extern struct bfd_link_order *bfd_new_link_order (bfd *, asection *);
843 /* These structures are used to describe version information for the
844 ELF linker. These structures could be manipulated entirely inside
845 BFD, but it would be a pain. Instead, the regular linker sets up
846 these structures, and then passes them into BFD. */
848 /* Glob pattern for a version. */
850 struct bfd_elf_version_expr
852 /* Next glob pattern for this version. */
853 struct bfd_elf_version_expr *next;
856 /* Set if pattern is not a glob. */
857 unsigned int literal : 1;
858 /* Defined by ".symver". */
859 unsigned int symver : 1;
860 /* Defined by version script. */
861 unsigned int script : 1;
863 #define BFD_ELF_VERSION_C_TYPE 1
864 #define BFD_ELF_VERSION_CXX_TYPE 2
865 #define BFD_ELF_VERSION_JAVA_TYPE 4
866 unsigned int mask : 3;
869 struct bfd_elf_version_expr_head
871 /* List of all patterns, both wildcards and non-wildcards. */
872 struct bfd_elf_version_expr *list;
873 /* Hash table for non-wildcards. */
875 /* Remaining patterns. */
876 struct bfd_elf_version_expr *remaining;
877 /* What kind of pattern types are present in list (bitmask). */
881 /* Version dependencies. */
883 struct bfd_elf_version_deps
885 /* Next dependency for this version. */
886 struct bfd_elf_version_deps *next;
887 /* The version which this version depends upon. */
888 struct bfd_elf_version_tree *version_needed;
891 /* A node in the version tree. */
893 struct bfd_elf_version_tree
896 struct bfd_elf_version_tree *next;
897 /* Name of this version. */
899 /* Version number. */
901 /* Regular expressions for global symbols in this version. */
902 struct bfd_elf_version_expr_head globals;
903 /* Regular expressions for local symbols in this version. */
904 struct bfd_elf_version_expr_head locals;
905 /* List of versions which this version depends upon. */
906 struct bfd_elf_version_deps *deps;
907 /* Index of the version name. This is used within BFD. */
908 unsigned int name_indx;
909 /* Whether this version tree was used. This is used within BFD. */
912 struct bfd_elf_version_expr *(*match)
913 (struct bfd_elf_version_expr_head *head,
914 struct bfd_elf_version_expr *prev, const char *sym);
917 struct bfd_elf_dynamic_list
919 struct bfd_elf_version_expr_head head;
920 struct bfd_elf_version_expr *(*match)
921 (struct bfd_elf_version_expr_head *head,
922 struct bfd_elf_version_expr *prev, const char *sym);