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 /* Symbol will be converted from absolute to section-relative. Set for
119 symbols defined by a script from "dot" (also SEGMENT_START or ORIGIN)
120 outside of an output section statement. */
121 unsigned int rel_from_abs : 1;
123 /* A union of information depending upon the type. */
126 /* Nothing is kept for bfd_hash_new. */
127 /* bfd_link_hash_undefined, bfd_link_hash_undefweak. */
130 /* Undefined and common symbols are kept in a linked list through
131 this field. This field is present in all of the union element
132 so that we don't need to remove entries from the list when we
133 change their type. Removing entries would either require the
134 list to be doubly linked, which would waste more memory, or
135 require a traversal. When an undefined or common symbol is
136 created, it should be added to this list, the head of which is in
137 the link hash table itself. As symbols are defined, they need
138 not be removed from the list; anything which reads the list must
139 doublecheck the symbol type.
141 Weak symbols are not kept on this list.
143 Defined and defweak symbols use this field as a reference marker.
144 If the field is not NULL, or this structure is the tail of the
145 undefined symbol list, the symbol has been referenced. If the
146 symbol is undefined and becomes defined, this field will
147 automatically be non-NULL since the symbol will have been on the
148 undefined symbol list. */
149 struct bfd_link_hash_entry *next;
150 /* BFD symbol was found in. */
153 /* bfd_link_hash_defined, bfd_link_hash_defweak. */
156 struct bfd_link_hash_entry *next;
157 /* Symbol section. */
162 /* bfd_link_hash_indirect, bfd_link_hash_warning. */
165 struct bfd_link_hash_entry *next;
167 struct bfd_link_hash_entry *link;
168 /* Warning message (bfd_link_hash_warning only). */
171 /* bfd_link_hash_common. */
174 struct bfd_link_hash_entry *next;
175 /* The linker needs to know three things about common
176 symbols: the size, the alignment, and the section in
177 which the symbol should be placed. We store the size
178 here, and we allocate a small structure to hold the
179 section and the alignment. The alignment is stored as a
180 power of two. We don't store all the information
181 directly because we don't want to increase the size of
182 the union; this structure is a major space user in the
184 struct bfd_link_hash_common_entry *p;
185 /* Common symbol size. */
191 /* This is the link hash table. It is a derived class of
194 struct bfd_link_hash_table
196 /* The hash table itself. */
197 struct bfd_hash_table table;
198 /* A linked list of undefined and common symbols, linked through the
199 next field in the bfd_link_hash_entry structure. */
200 struct bfd_link_hash_entry *undefs;
201 /* Entries are added to the tail of the undefs list. */
202 struct bfd_link_hash_entry *undefs_tail;
203 /* Function to free the hash table on closing BFD. */
204 void (*hash_table_free) (bfd *);
205 /* The type of the link hash table. */
206 enum bfd_link_hash_table_type type;
209 /* Look up an entry in a link hash table. If FOLLOW is TRUE, this
210 follows bfd_link_hash_indirect and bfd_link_hash_warning links to
212 extern struct bfd_link_hash_entry *bfd_link_hash_lookup
213 (struct bfd_link_hash_table *, const char *, bfd_boolean create,
214 bfd_boolean copy, bfd_boolean follow);
216 /* Look up an entry in the main linker hash table if the symbol might
217 be wrapped. This should only be used for references to an
218 undefined symbol, not for definitions of a symbol. */
220 extern struct bfd_link_hash_entry *bfd_wrapped_link_hash_lookup
221 (bfd *, struct bfd_link_info *, const char *, bfd_boolean,
222 bfd_boolean, bfd_boolean);
224 /* If H is a wrapped symbol, ie. the symbol name starts with "__wrap_"
225 and the remainder is found in wrap_hash, return the real symbol. */
227 extern struct bfd_link_hash_entry *unwrap_hash_lookup
228 (struct bfd_link_info *, bfd *, struct bfd_link_hash_entry *);
230 /* Traverse a link hash table. */
231 extern void bfd_link_hash_traverse
232 (struct bfd_link_hash_table *,
233 bfd_boolean (*) (struct bfd_link_hash_entry *, void *),
236 /* Add an entry to the undefs list. */
237 extern void bfd_link_add_undef
238 (struct bfd_link_hash_table *, struct bfd_link_hash_entry *);
240 /* Remove symbols from the undefs list that don't belong there. */
241 extern void bfd_link_repair_undef_list
242 (struct bfd_link_hash_table *table);
244 /* Read symbols and cache symbol pointer array in outsymbols. */
245 extern bfd_boolean bfd_generic_link_read_symbols (bfd *);
247 /* Check the relocs in the BFD. Called after all the input
248 files have been loaded, and garbage collection has tagged
249 any unneeded sections. */
250 extern bfd_boolean bfd_link_check_relocs (bfd *,struct bfd_link_info *);
254 struct bfd_sym_chain *next;
258 /* How to handle unresolved symbols.
259 There are four possibilities which are enumerated below: */
262 /* This is the initial value when then link_info structure is created.
263 It allows the various stages of the linker to determine whether they
264 allowed to set the value. */
271 typedef enum {with_flags, without_flags} flag_type;
273 /* A section flag list. */
274 struct flag_info_list
279 struct flag_info_list *next;
282 /* Section flag info. */
285 flagword only_with_flags;
286 flagword not_with_flags;
287 struct flag_info_list *flag_list;
288 bfd_boolean flags_initialized;
291 struct bfd_elf_dynamic_list;
292 struct bfd_elf_version_tree;
294 /* Types of output. */
304 #define bfd_link_pde(info) ((info)->type == type_pde)
305 #define bfd_link_dll(info) ((info)->type == type_dll)
306 #define bfd_link_relocatable(info) ((info)->type == type_relocatable)
307 #define bfd_link_pie(info) ((info)->type == type_pie)
308 #define bfd_link_executable(info) (bfd_link_pde (info) || bfd_link_pie (info))
309 #define bfd_link_pic(info) (bfd_link_dll (info) || bfd_link_pie (info))
311 /* This structure holds all the information needed to communicate
312 between BFD and the linker when doing a link. */
317 ENUM_BITFIELD (output_type) type : 2;
319 /* TRUE if BFD should pre-bind symbols in a shared object. */
320 unsigned int symbolic: 1;
322 /* TRUE if executable should not contain copy relocs.
323 Setting this true may result in a non-sharable text segment. */
324 unsigned int nocopyreloc: 1;
326 /* TRUE if BFD should export all symbols in the dynamic symbol table
327 of an executable, rather than only those used. */
328 unsigned int export_dynamic: 1;
330 /* TRUE if a default symbol version should be created and used for
332 unsigned int create_default_symver: 1;
334 /* TRUE if unreferenced sections should be removed. */
335 unsigned int gc_sections: 1;
337 /* TRUE if exported symbols should be kept during section gc. */
338 unsigned int gc_keep_exported: 1;
340 /* TRUE if every symbol should be reported back via the notice
342 unsigned int notice_all: 1;
344 /* TRUE if the LTO plugin is active. */
345 unsigned int lto_plugin_active: 1;
347 /* TRUE if global symbols in discarded sections should be stripped. */
348 unsigned int strip_discarded: 1;
350 /* TRUE if all data symbols should be dynamic. */
351 unsigned int dynamic_data: 1;
353 /* TRUE if section groups should be resolved. */
354 unsigned int resolve_section_groups: 1;
356 /* Which symbols to strip. */
357 ENUM_BITFIELD (bfd_link_strip) strip : 2;
359 /* Which local symbols to discard. */
360 ENUM_BITFIELD (bfd_link_discard) discard : 2;
362 /* Whether to generate ELF common symbols with the STT_COMMON type. */
363 ENUM_BITFIELD (bfd_link_elf_stt_common) elf_stt_common : 2;
365 /* Criteria for skipping symbols when determining
366 whether to include an object from an archive. */
367 ENUM_BITFIELD (bfd_link_common_skip_ar_symbols) common_skip_ar_symbols : 2;
369 /* What to do with unresolved symbols in an object file.
370 When producing executables the default is GENERATE_ERROR.
371 When producing shared libraries the default is IGNORE. The
372 assumption with shared libraries is that the reference will be
373 resolved at load/execution time. */
374 ENUM_BITFIELD (report_method) unresolved_syms_in_objects : 2;
376 /* What to do with unresolved symbols in a shared library.
377 The same defaults apply. */
378 ENUM_BITFIELD (report_method) unresolved_syms_in_shared_libs : 2;
380 /* TRUE if shared objects should be linked directly, not shared. */
381 unsigned int static_link: 1;
383 /* TRUE if symbols should be retained in memory, FALSE if they
384 should be freed and reread. */
385 unsigned int keep_memory: 1;
387 /* TRUE if BFD should generate relocation information in the final
389 unsigned int emitrelocations: 1;
391 /* TRUE if PT_GNU_RELRO segment should be created. */
392 unsigned int relro: 1;
394 /* TRUE if separate code segment should be created. */
395 unsigned int separate_code: 1;
397 /* Nonzero if .eh_frame_hdr section and PT_GNU_EH_FRAME ELF segment
398 should be created. 1 for DWARF2 tables, 2 for compact tables. */
399 unsigned int eh_frame_hdr_type: 2;
401 /* TRUE if we should warn when adding a DT_TEXTREL to a shared object. */
402 unsigned int warn_shared_textrel: 1;
404 /* TRUE if we should error when adding a DT_TEXTREL. */
405 unsigned int error_textrel: 1;
407 /* TRUE if .hash section should be created. */
408 unsigned int emit_hash: 1;
410 /* TRUE if .gnu.hash section should be created. */
411 unsigned int emit_gnu_hash: 1;
413 /* If TRUE reduce memory overheads, at the expense of speed. This will
414 cause map file generation to use an O(N^2) algorithm and disable
415 caching ELF symbol buffer. */
416 unsigned int reduce_memory_overheads: 1;
418 /* TRUE if the output file should be in a traditional format. This
419 is equivalent to the setting of the BFD_TRADITIONAL_FORMAT flag
420 on the output file, but may be checked when reading the input
422 unsigned int traditional_format: 1;
424 /* TRUE if non-PLT relocs should be merged into one reloc section
425 and sorted so that relocs against the same symbol come together. */
426 unsigned int combreloc: 1;
428 /* TRUE if a default symbol version should be created and used for
430 unsigned int default_imported_symver: 1;
432 /* TRUE if the new ELF dynamic tags are enabled. */
433 unsigned int new_dtags: 1;
435 /* FALSE if .eh_frame unwind info should be generated for PLT and other
436 linker created sections, TRUE if it should be omitted. */
437 unsigned int no_ld_generated_unwind_info: 1;
439 /* TRUE if BFD should generate a "task linked" object file,
440 similar to relocatable but also with globals converted to
442 unsigned int task_link: 1;
444 /* TRUE if ok to have multiple definition. */
445 unsigned int allow_multiple_definition: 1;
447 /* TRUE if ok to have prohibit multiple definition of absolute symbols. */
448 unsigned int prohibit_multiple_definition_absolute: 1;
450 /* TRUE if ok to have version with no definition. */
451 unsigned int allow_undefined_version: 1;
453 /* TRUE if some symbols have to be dynamic, controlled by
454 --dynamic-list command line options. */
455 unsigned int dynamic: 1;
457 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W|PF_X
459 unsigned int execstack: 1;
461 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W
463 unsigned int noexecstack: 1;
465 /* TRUE if we want to produced optimized output files. This might
466 need much more time and therefore must be explicitly selected. */
467 unsigned int optimize: 1;
469 /* TRUE if user should be informed of removed unreferenced sections. */
470 unsigned int print_gc_sections: 1;
472 /* TRUE if we should warn alternate ELF machine code. */
473 unsigned int warn_alternate_em: 1;
475 /* TRUE if the linker script contained an explicit PHDRS command. */
476 unsigned int user_phdrs: 1;
478 /* TRUE if we should check relocations after all input files have
480 unsigned int check_relocs_after_open_input: 1;
482 /* TRUE if BND prefix in PLT entries is always generated. */
483 unsigned int bndplt: 1;
485 /* TRUE if IBT-enabled PLT entries should be generated. */
486 unsigned int ibtplt: 1;
488 /* TRUE if GNU_PROPERTY_X86_FEATURE_1_IBT should be generated. */
491 /* TRUE if GNU_PROPERTY_X86_FEATURE_1_SHSTK should be generated. */
492 unsigned int shstk: 1;
494 /* TRUE if generation of .interp/PT_INTERP should be suppressed. */
495 unsigned int nointerp: 1;
497 /* TRUE if we shouldn't check relocation overflow. */
498 unsigned int no_reloc_overflow_check: 1;
500 /* TRUE if generate a 1-byte NOP as suffix for x86 call instruction. */
501 unsigned int call_nop_as_suffix : 1;
503 /* TRUE if common symbols should be treated as undefined. */
504 unsigned int inhibit_common_definition : 1;
506 /* The 1-byte NOP for x86 call instruction. */
509 /* Char that may appear as the first char of a symbol, but should be
510 skipped (like symbol_leading_char) when looking up symbols in
511 wrap_hash. Used by PowerPC Linux for 'dot' symbols. */
514 /* Separator between archive and filename in linker script filespecs. */
517 /* Compress DWARF debug sections. */
518 enum compressed_debug_section_type compress_debug;
520 /* Default stack size. Zero means default (often zero itself), -1
521 means explicitly zero-sized. */
522 bfd_signed_vma stacksize;
524 /* Enable or disable target specific optimizations.
526 Not all targets have optimizations to enable.
528 Normally these optimizations are disabled by default but some targets
529 prefer to enable them by default. So this field is a tri-state variable.
532 zero: Enable the optimizations (either from --relax being specified on
533 the command line or the backend's before_allocation emulation function.
535 positive: The user has requested that these optimizations be disabled.
536 (Via the --no-relax command line option).
538 negative: The optimizations are disabled. (Set when initializing the
539 args_type structure in ldmain.c:main. */
540 signed int disable_target_specific_optimizations;
542 /* Function callbacks. */
543 const struct bfd_link_callbacks *callbacks;
545 /* Hash table handled by BFD. */
546 struct bfd_link_hash_table *hash;
548 /* Hash table of symbols to keep. This is NULL unless strip is
550 struct bfd_hash_table *keep_hash;
552 /* Hash table of symbols to report back via the notice callback. If
553 this is NULL, and notice_all is FALSE, then no symbols are
555 struct bfd_hash_table *notice_hash;
557 /* Hash table of symbols which are being wrapped (the --wrap linker
558 option). If this is NULL, no symbols are being wrapped. */
559 struct bfd_hash_table *wrap_hash;
561 /* Hash table of symbols which may be left unresolved during
562 a link. If this is NULL, no symbols can be left unresolved. */
563 struct bfd_hash_table *ignore_hash;
565 /* The output BFD. */
568 /* The import library generated. */
571 /* The list of input BFD's involved in the link. These are chained
572 together via the link.next field. */
574 bfd **input_bfds_tail;
576 /* If a symbol should be created for each input BFD, this is section
577 where those symbols should be placed. It must be a section in
578 the output BFD. It may be NULL, in which case no such symbols
579 will be created. This is to support CREATE_OBJECT_SYMBOLS in the
580 linker command language. */
581 asection *create_object_symbols_section;
583 /* List of global symbol names that are starting points for marking
584 sections against garbage collection. */
585 struct bfd_sym_chain *gc_sym_list;
587 /* If a base output file is wanted, then this points to it */
590 /* The function to call when the executable or shared object is
592 const char *init_function;
594 /* The function to call when the executable or shared object is
596 const char *fini_function;
598 /* Number of relaxation passes. Usually only one relaxation pass
599 is needed. But a backend can have as many relaxation passes as
600 necessary. During bfd_relax_section call, it is set to the
601 current pass, starting from 0. */
604 /* Number of relaxation trips. This number is incremented every
605 time the relaxation pass is restarted due to a previous
606 relaxation returning true in *AGAIN. */
609 /* > 0 to treat protected data defined in the shared library as
610 reference external. 0 to treat it as internal. -1 to let
611 backend to decide. */
612 int extern_protected_data;
614 /* 1 to make undefined weak symbols dynamic when building a dynamic
615 object. 0 to resolve undefined weak symbols to zero. -1 to let
616 the backend decide. */
617 int dynamic_undefined_weak;
619 /* Non-zero if auto-import thunks for DATA items in pei386 DLLs
620 should be generated/linked against. Set to 1 if this feature
621 is explicitly requested by the user, -1 if enabled by default. */
622 int pei386_auto_import;
624 /* Non-zero if runtime relocs for DATA items with non-zero addends
625 in pei386 DLLs should be generated. Set to 1 if this feature
626 is explicitly requested by the user, -1 if enabled by default. */
627 int pei386_runtime_pseudo_reloc;
629 /* How many spare .dynamic DT_NULL entries should be added? */
630 unsigned int spare_dynamic_tags;
632 /* May be used to set DT_FLAGS for ELF. */
635 /* May be used to set DT_FLAGS_1 for ELF. */
638 /* Start and end of RELRO region. */
639 bfd_vma relro_start, relro_end;
641 /* List of symbols should be dynamic. */
642 struct bfd_elf_dynamic_list *dynamic_list;
644 /* The version information. */
645 struct bfd_elf_version_tree *version_info;
648 /* This structures holds a set of callback functions. These are called
649 by the BFD linker routines. */
651 struct bfd_link_callbacks
653 /* A function which is called when an object is added from an
654 archive. ABFD is the archive element being added. NAME is the
655 name of the symbol which caused the archive element to be pulled
656 in. This function may set *SUBSBFD to point to an alternative
657 BFD from which symbols should in fact be added in place of the
658 original BFD's symbols. Returns TRUE if the object should be
659 added, FALSE if it should be skipped. */
660 bfd_boolean (*add_archive_element)
661 (struct bfd_link_info *, bfd *abfd, const char *name, bfd **subsbfd);
662 /* A function which is called when a symbol is found with multiple
663 definitions. H is the symbol which is defined multiple times.
664 NBFD is the new BFD, NSEC is the new section, and NVAL is the new
665 value. NSEC may be bfd_com_section or bfd_ind_section. */
666 void (*multiple_definition)
667 (struct bfd_link_info *, struct bfd_link_hash_entry *h,
668 bfd *nbfd, asection *nsec, bfd_vma nval);
669 /* A function which is called when a common symbol is defined
670 multiple times. H is the symbol appearing multiple times.
671 NBFD is the BFD of the new symbol. NTYPE is the type of the new
672 symbol, one of bfd_link_hash_defined, bfd_link_hash_common, or
673 bfd_link_hash_indirect. If NTYPE is bfd_link_hash_common, NSIZE
674 is the size of the new symbol. */
675 void (*multiple_common)
676 (struct bfd_link_info *, struct bfd_link_hash_entry *h,
677 bfd *nbfd, enum bfd_link_hash_type ntype, bfd_vma nsize);
678 /* A function which is called to add a symbol to a set. ENTRY is
679 the link hash table entry for the set itself (e.g.,
680 __CTOR_LIST__). RELOC is the relocation to use for an entry in
681 the set when generating a relocatable file, and is also used to
682 get the size of the entry when generating an executable file.
683 ABFD, SEC and VALUE identify the value to add to the set. */
685 (struct bfd_link_info *, struct bfd_link_hash_entry *entry,
686 bfd_reloc_code_real_type reloc, bfd *abfd, asection *sec, bfd_vma value);
687 /* A function which is called when the name of a g++ constructor or
688 destructor is found. This is only called by some object file
689 formats. CONSTRUCTOR is TRUE for a constructor, FALSE for a
690 destructor. This will use BFD_RELOC_CTOR when generating a
691 relocatable file. NAME is the name of the symbol found. ABFD,
692 SECTION and VALUE are the value of the symbol. */
694 (struct bfd_link_info *, bfd_boolean constructor, const char *name,
695 bfd *abfd, asection *sec, bfd_vma value);
696 /* A function which is called to issue a linker warning. For
697 example, this is called when there is a reference to a warning
698 symbol. WARNING is the warning to be issued. SYMBOL is the name
699 of the symbol which triggered the warning; it may be NULL if
700 there is none. ABFD, SECTION and ADDRESS identify the location
701 which trigerred the warning; either ABFD or SECTION or both may
702 be NULL if the location is not known. */
704 (struct bfd_link_info *, const char *warning, const char *symbol,
705 bfd *abfd, asection *section, bfd_vma address);
706 /* A function which is called when a relocation is attempted against
707 an undefined symbol. NAME is the symbol which is undefined.
708 ABFD, SECTION and ADDRESS identify the location from which the
709 reference is made. IS_FATAL indicates whether an undefined symbol is
710 a fatal error or not. In some cases SECTION may be NULL. */
711 void (*undefined_symbol)
712 (struct bfd_link_info *, const char *name, bfd *abfd,
713 asection *section, bfd_vma address, bfd_boolean is_fatal);
714 /* A function which is called when a reloc overflow occurs. ENTRY is
715 the link hash table entry for the symbol the reloc is against.
716 NAME is the name of the local symbol or section the reloc is
717 against, RELOC_NAME is the name of the relocation, and ADDEND is
718 any addend that is used. ABFD, SECTION and ADDRESS identify the
719 location at which the overflow occurs; if this is the result of a
720 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
721 ABFD will be NULL. */
722 void (*reloc_overflow)
723 (struct bfd_link_info *, struct bfd_link_hash_entry *entry,
724 const char *name, const char *reloc_name, bfd_vma addend,
725 bfd *abfd, asection *section, bfd_vma address);
726 /* A function which is called when a dangerous reloc is performed.
727 MESSAGE is an appropriate message.
728 ABFD, SECTION and ADDRESS identify the location at which the
729 problem occurred; if this is the result of a
730 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
731 ABFD will be NULL. */
732 void (*reloc_dangerous)
733 (struct bfd_link_info *, const char *message,
734 bfd *abfd, asection *section, bfd_vma address);
735 /* A function which is called when a reloc is found to be attached
736 to a symbol which is not being written out. NAME is the name of
737 the symbol. ABFD, SECTION and ADDRESS identify the location of
738 the reloc; if this is the result of a
739 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
740 ABFD will be NULL. */
741 void (*unattached_reloc)
742 (struct bfd_link_info *, const char *name,
743 bfd *abfd, asection *section, bfd_vma address);
744 /* A function which is called when a symbol in notice_hash is
745 defined or referenced. H is the symbol, INH the indirect symbol
746 if applicable. ABFD, SECTION and ADDRESS are the (new) value of
747 the symbol. If SECTION is bfd_und_section, this is a reference.
748 FLAGS are the symbol BSF_* flags. */
749 bfd_boolean (*notice)
750 (struct bfd_link_info *, struct bfd_link_hash_entry *h,
751 struct bfd_link_hash_entry *inh,
752 bfd *abfd, asection *section, bfd_vma address, flagword flags);
753 /* Error or warning link info message. */
755 (const char *fmt, ...);
756 /* General link info message. */
758 (const char *fmt, ...);
759 /* Message to be printed in linker map file. */
761 (const char *fmt, ...);
762 /* This callback provides a chance for users of the BFD library to
763 override its decision about whether to place two adjacent sections
764 into the same segment. */
765 bfd_boolean (*override_segment_assignment)
766 (struct bfd_link_info *, bfd * abfd,
767 asection * current_section, asection * previous_section,
768 bfd_boolean new_segment);
771 /* The linker builds link_order structures which tell the code how to
772 include input data in the output file. */
774 /* These are the types of link_order structures. */
776 enum bfd_link_order_type
778 bfd_undefined_link_order, /* Undefined. */
779 bfd_indirect_link_order, /* Built from a section. */
780 bfd_data_link_order, /* Set to explicit data. */
781 bfd_section_reloc_link_order, /* Relocate against a section. */
782 bfd_symbol_reloc_link_order /* Relocate against a symbol. */
785 /* This is the link_order structure itself. These form a chain
786 attached to the output section whose contents they are describing. */
788 struct bfd_link_order
790 /* Next link_order in chain. */
791 struct bfd_link_order *next;
792 /* Type of link_order. */
793 enum bfd_link_order_type type;
794 /* Offset within output section. */
796 /* Size within output section. */
798 /* Type specific information. */
803 /* Section to include. If this is used, then
804 section->output_section must be the section the
805 link_order is attached to, section->output_offset must
806 equal the link_order offset field, and section->size
807 must equal the link_order size field. Maybe these
808 restrictions should be relaxed someday. */
813 /* Size of contents, or zero when contents should be filled by
814 the architecture-dependent fill function.
815 A non-zero value allows filling of the output section
816 with an arbitrary repeated pattern. */
818 /* Data to put into file. */
823 /* Description of reloc to generate. Used for
824 bfd_section_reloc_link_order and
825 bfd_symbol_reloc_link_order. */
826 struct bfd_link_order_reloc *p;
831 /* A linker order of type bfd_section_reloc_link_order or
832 bfd_symbol_reloc_link_order means to create a reloc against a
833 section or symbol, respectively. This is used to implement -Ur to
834 generate relocs for the constructor tables. The
835 bfd_link_order_reloc structure describes the reloc that BFD should
836 create. It is similar to a arelent, but I didn't use arelent
837 because the linker does not know anything about most symbols, and
838 any asymbol structure it creates will be partially meaningless.
839 This information could logically be in the bfd_link_order struct,
840 but I didn't want to waste the space since these types of relocs
841 are relatively rare. */
843 struct bfd_link_order_reloc
846 bfd_reloc_code_real_type reloc;
850 /* For type bfd_section_reloc_link_order, this is the section
851 the reloc should be against. This must be a section in the
852 output BFD, not any of the input BFDs. */
854 /* For type bfd_symbol_reloc_link_order, this is the name of the
855 symbol the reloc should be against. */
859 /* Addend to use. The object file should contain zero. The BFD
860 backend is responsible for filling in the contents of the object
861 file correctly. For some object file formats (e.g., COFF) the
862 addend must be stored into in the object file, and for some
863 (e.g., SPARC a.out) it is kept in the reloc. */
867 /* Allocate a new link_order for a section. */
868 extern struct bfd_link_order *bfd_new_link_order (bfd *, asection *);
870 /* These structures are used to describe version information for the
871 ELF linker. These structures could be manipulated entirely inside
872 BFD, but it would be a pain. Instead, the regular linker sets up
873 these structures, and then passes them into BFD. */
875 /* Glob pattern for a version. */
877 struct bfd_elf_version_expr
879 /* Next glob pattern for this version. */
880 struct bfd_elf_version_expr *next;
883 /* Set if pattern is not a glob. */
884 unsigned int literal : 1;
885 /* Defined by ".symver". */
886 unsigned int symver : 1;
887 /* Defined by version script. */
888 unsigned int script : 1;
890 #define BFD_ELF_VERSION_C_TYPE 1
891 #define BFD_ELF_VERSION_CXX_TYPE 2
892 #define BFD_ELF_VERSION_JAVA_TYPE 4
893 unsigned int mask : 3;
896 struct bfd_elf_version_expr_head
898 /* List of all patterns, both wildcards and non-wildcards. */
899 struct bfd_elf_version_expr *list;
900 /* Hash table for non-wildcards. */
902 /* Remaining patterns. */
903 struct bfd_elf_version_expr *remaining;
904 /* What kind of pattern types are present in list (bitmask). */
908 /* Version dependencies. */
910 struct bfd_elf_version_deps
912 /* Next dependency for this version. */
913 struct bfd_elf_version_deps *next;
914 /* The version which this version depends upon. */
915 struct bfd_elf_version_tree *version_needed;
918 /* A node in the version tree. */
920 struct bfd_elf_version_tree
923 struct bfd_elf_version_tree *next;
924 /* Name of this version. */
926 /* Version number. */
928 /* Regular expressions for global symbols in this version. */
929 struct bfd_elf_version_expr_head globals;
930 /* Regular expressions for local symbols in this version. */
931 struct bfd_elf_version_expr_head locals;
932 /* List of versions which this version depends upon. */
933 struct bfd_elf_version_deps *deps;
934 /* Index of the version name. This is used within BFD. */
935 unsigned int name_indx;
936 /* Whether this version tree was used. This is used within BFD. */
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);
944 struct bfd_elf_dynamic_list
946 struct bfd_elf_version_expr_head head;
947 struct bfd_elf_version_expr *(*match)
948 (struct bfd_elf_version_expr_head *head,
949 struct bfd_elf_version_expr *prev, const char *sym);