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252b5132 | 1 | /* bfdlink.h -- header file for BFD link routines |
2571583a | 2 | Copyright (C) 1993-2017 Free Software Foundation, Inc. |
252b5132 RH |
3 | Written by Steve Chamberlain and Ian Lance Taylor, Cygnus Support. |
4 | ||
e0076ab3 | 5 | This file is part of BFD, the Binary File Descriptor library. |
252b5132 | 6 | |
e0076ab3 NC |
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 | |
a208b53c | 9 | the Free Software Foundation; either version 3 of the License, or |
e0076ab3 | 10 | (at your option) any later version. |
252b5132 | 11 | |
e0076ab3 NC |
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. | |
252b5132 | 16 | |
e0076ab3 NC |
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 | |
a208b53c NC |
19 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
20 | MA 02110-1301, USA. */ | |
252b5132 RH |
21 | |
22 | #ifndef BFDLINK_H | |
23 | #define BFDLINK_H | |
24 | ||
25 | /* Which symbols to strip during a link. */ | |
26 | enum bfd_link_strip | |
27 | { | |
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. */ | |
32 | }; | |
33 | ||
34 | /* Which local symbols to discard during a link. This is irrelevant | |
35 | if strip_all is used. */ | |
36 | enum bfd_link_discard | |
37 | { | |
f5fa8ca2 JJ |
38 | discard_sec_merge, /* Discard local temporary symbols in SEC_MERGE |
39 | sections. */ | |
252b5132 RH |
40 | discard_none, /* Don't discard any locals. */ |
41 | discard_l, /* Discard local temporary symbols. */ | |
42 | discard_all /* Discard all locals. */ | |
43 | }; | |
8ea2e4bd | 44 | |
b8871f35 L |
45 | /* Whether to generate ELF common symbols with the STT_COMMON type |
46 | during a relocatable link. */ | |
47 | enum bfd_link_elf_stt_common | |
48 | { | |
49 | unchanged, | |
50 | elf_stt_common, | |
51 | no_elf_stt_common | |
52 | }; | |
53 | ||
8ea2e4bd NC |
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 | |
58 | { | |
59 | bfd_link_generic_hash_table, | |
60 | bfd_link_elf_hash_table | |
61 | }; | |
252b5132 RH |
62 | \f |
63 | /* These are the possible types of an entry in the BFD link hash | |
64 | table. */ | |
65 | ||
66 | enum bfd_link_hash_type | |
67 | { | |
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. */ | |
76 | }; | |
77 | ||
f88dc410 | 78 | enum bfd_link_common_skip_ar_symbols |
f7c33884 NC |
79 | { |
80 | bfd_link_common_skip_none, | |
81 | bfd_link_common_skip_text, | |
82 | bfd_link_common_skip_data, | |
83 | bfd_link_common_skip_all | |
84 | }; | |
85 | ||
a50b1753 NC |
86 | struct bfd_link_hash_common_entry |
87 | { | |
88 | unsigned int alignment_power; /* Alignment. */ | |
89 | asection *section; /* Symbol section. */ | |
90 | }; | |
91 | ||
252b5132 RH |
92 | /* The linking routines use a hash table which uses this structure for |
93 | its elements. */ | |
94 | ||
95 | struct bfd_link_hash_entry | |
96 | { | |
97 | /* Base hash table entry structure. */ | |
98 | struct bfd_hash_entry root; | |
6ad841a1 | 99 | |
252b5132 | 100 | /* Type of this entry. */ |
35ed3f94 AM |
101 | ENUM_BITFIELD (bfd_link_hash_type) type : 8; |
102 | ||
12b2843a AM |
103 | /* Symbol is referenced in a normal object file, as distict from a LTO |
104 | IR object file. */ | |
35ed3f94 | 105 | unsigned int non_ir_ref : 1; |
12b2843a AM |
106 | |
107 | /* Symbol is a built-in define. These will be overridden by PROVIDE | |
108 | in a linker script. */ | |
109 | unsigned int linker_def : 1; | |
252b5132 | 110 | |
76359541 TP |
111 | /* Symbol defined in a linker script. */ |
112 | unsigned int ldscript_def : 1; | |
113 | ||
252b5132 RH |
114 | /* A union of information depending upon the type. */ |
115 | union | |
116 | { | |
117 | /* Nothing is kept for bfd_hash_new. */ | |
118 | /* bfd_link_hash_undefined, bfd_link_hash_undefweak. */ | |
119 | struct | |
120 | { | |
f6e332e6 AM |
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. | |
131 | ||
132 | Weak symbols are not kept on this list. | |
133 | ||
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; | |
a6a4679f AM |
141 | /* BFD symbol was found in. */ |
142 | bfd *abfd; | |
143 | /* For __start_<name> and __stop_<name> symbols, the first | |
144 | input section matching the name. */ | |
145 | asection *section; | |
252b5132 RH |
146 | } undef; |
147 | /* bfd_link_hash_defined, bfd_link_hash_defweak. */ | |
148 | struct | |
149 | { | |
f6e332e6 | 150 | struct bfd_link_hash_entry *next; |
a6a4679f AM |
151 | /* Symbol section. */ |
152 | asection *section; | |
153 | /* Symbol value. */ | |
154 | bfd_vma value; | |
252b5132 RH |
155 | } def; |
156 | /* bfd_link_hash_indirect, bfd_link_hash_warning. */ | |
157 | struct | |
158 | { | |
f6e332e6 | 159 | struct bfd_link_hash_entry *next; |
a6a4679f AM |
160 | /* Real symbol. */ |
161 | struct bfd_link_hash_entry *link; | |
162 | /* Warning message (bfd_link_hash_warning only). */ | |
163 | const char *warning; | |
252b5132 RH |
164 | } i; |
165 | /* bfd_link_hash_common. */ | |
166 | struct | |
167 | { | |
f6e332e6 | 168 | struct bfd_link_hash_entry *next; |
252b5132 | 169 | /* The linker needs to know three things about common |
b34976b6 AM |
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 | |
177 | linker. */ | |
a50b1753 | 178 | struct bfd_link_hash_common_entry *p; |
a6a4679f AM |
179 | /* Common symbol size. */ |
180 | bfd_size_type size; | |
252b5132 RH |
181 | } c; |
182 | } u; | |
183 | }; | |
184 | ||
185 | /* This is the link hash table. It is a derived class of | |
186 | bfd_hash_table. */ | |
187 | ||
188 | struct bfd_link_hash_table | |
189 | { | |
190 | /* The hash table itself. */ | |
191 | struct bfd_hash_table table; | |
252b5132 RH |
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; | |
d495ab0d AM |
197 | /* Function to free the hash table on closing BFD. */ |
198 | void (*hash_table_free) (bfd *); | |
b9b171fb | 199 | /* The type of the link hash table. */ |
8ea2e4bd | 200 | enum bfd_link_hash_table_type type; |
252b5132 RH |
201 | }; |
202 | ||
b34976b6 | 203 | /* Look up an entry in a link hash table. If FOLLOW is TRUE, this |
252b5132 RH |
204 | follows bfd_link_hash_indirect and bfd_link_hash_warning links to |
205 | the real symbol. */ | |
206 | extern struct bfd_link_hash_entry *bfd_link_hash_lookup | |
8cf3f354 AM |
207 | (struct bfd_link_hash_table *, const char *, bfd_boolean create, |
208 | bfd_boolean copy, bfd_boolean follow); | |
252b5132 RH |
209 | |
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. */ | |
213 | ||
214 | extern struct bfd_link_hash_entry *bfd_wrapped_link_hash_lookup | |
8cf3f354 AM |
215 | (bfd *, struct bfd_link_info *, const char *, bfd_boolean, |
216 | bfd_boolean, bfd_boolean); | |
252b5132 | 217 | |
8a5da09b AM |
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. */ | |
220 | ||
221 | extern struct bfd_link_hash_entry *unwrap_hash_lookup | |
222 | (struct bfd_link_info *, bfd *, struct bfd_link_hash_entry *); | |
223 | ||
252b5132 RH |
224 | /* Traverse a link hash table. */ |
225 | extern void bfd_link_hash_traverse | |
8cf3f354 AM |
226 | (struct bfd_link_hash_table *, |
227 | bfd_boolean (*) (struct bfd_link_hash_entry *, void *), | |
228 | void *); | |
252b5132 RH |
229 | |
230 | /* Add an entry to the undefs list. */ | |
231 | extern void bfd_link_add_undef | |
8cf3f354 | 232 | (struct bfd_link_hash_table *, struct bfd_link_hash_entry *); |
7815cf4f | 233 | |
77cfaee6 AM |
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); | |
237 | ||
5c1d2f5f AM |
238 | /* Read symbols and cache symbol pointer array in outsymbols. */ |
239 | extern bfd_boolean bfd_generic_link_read_symbols (bfd *); | |
240 | ||
4f3b23b3 NC |
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 *); | |
245 | ||
7815cf4f AM |
246 | struct bfd_sym_chain |
247 | { | |
248 | struct bfd_sym_chain *next; | |
249 | const char *name; | |
250 | }; | |
252b5132 | 251 | \f |
560e09e9 NC |
252 | /* How to handle unresolved symbols. |
253 | There are four possibilities which are enumerated below: */ | |
254 | enum report_method | |
255 | { | |
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. */ | |
259 | RM_NOT_YET_SET = 0, | |
260 | RM_IGNORE, | |
261 | RM_GENERATE_WARNING, | |
262 | RM_GENERATE_ERROR | |
263 | }; | |
264 | ||
ae17ab41 CM |
265 | typedef enum {with_flags, without_flags} flag_type; |
266 | ||
267 | /* A section flag list. */ | |
268 | struct flag_info_list | |
269 | { | |
d324f6d6 | 270 | flag_type with; |
ae17ab41 CM |
271 | const char *name; |
272 | bfd_boolean valid; | |
273 | struct flag_info_list *next; | |
274 | }; | |
275 | ||
276 | /* Section flag info. */ | |
277 | struct flag_info | |
278 | { | |
279 | flagword only_with_flags; | |
280 | flagword not_with_flags; | |
281 | struct flag_info_list *flag_list; | |
282 | bfd_boolean flags_initialized; | |
283 | }; | |
284 | ||
55255dae | 285 | struct bfd_elf_dynamic_list; |
fd91d419 | 286 | struct bfd_elf_version_tree; |
55255dae | 287 | |
0e1862bb L |
288 | /* Types of output. */ |
289 | ||
290 | enum output_type | |
291 | { | |
64d94ba0 | 292 | type_pde, |
64d94ba0 | 293 | type_pie, |
5f329d5b | 294 | type_relocatable, |
0e1862bb | 295 | type_dll, |
0e1862bb L |
296 | }; |
297 | ||
64d94ba0 | 298 | #define bfd_link_pde(info) ((info)->type == type_pde) |
0e1862bb L |
299 | #define bfd_link_dll(info) ((info)->type == type_dll) |
300 | #define bfd_link_relocatable(info) ((info)->type == type_relocatable) | |
64d94ba0 AM |
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)) | |
0e1862bb | 304 | |
252b5132 RH |
305 | /* This structure holds all the information needed to communicate |
306 | between BFD and the linker when doing a link. */ | |
307 | ||
308 | struct bfd_link_info | |
309 | { | |
0e1862bb L |
310 | /* Output type. */ |
311 | ENUM_BITFIELD (output_type) type : 2; | |
7815cf4f | 312 | |
b34976b6 | 313 | /* TRUE if BFD should pre-bind symbols in a shared object. */ |
cddd0089 | 314 | unsigned int symbolic: 1; |
7815cf4f | 315 | |
05aecedb AM |
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; | |
319 | ||
b34976b6 | 320 | /* TRUE if BFD should export all symbols in the dynamic symbol table |
7be4069c | 321 | of an executable, rather than only those used. */ |
cddd0089 | 322 | unsigned int export_dynamic: 1; |
7815cf4f | 323 | |
fc0e6df6 PB |
324 | /* TRUE if a default symbol version should be created and used for |
325 | exported symbols. */ | |
3e3b46e5 PB |
326 | unsigned int create_default_symver: 1; |
327 | ||
05aecedb AM |
328 | /* TRUE if unreferenced sections should be removed. */ |
329 | unsigned int gc_sections: 1; | |
cddd0089 | 330 | |
22185505 | 331 | /* TRUE if exported symbols should be kept during section gc. */ |
332 | unsigned int gc_keep_exported: 1; | |
333 | ||
cddd0089 AM |
334 | /* TRUE if every symbol should be reported back via the notice |
335 | callback. */ | |
336 | unsigned int notice_all: 1; | |
337 | ||
61f41c3c AM |
338 | /* TRUE if the LTO plugin is active. */ |
339 | unsigned int lto_plugin_active: 1; | |
340 | ||
05aecedb AM |
341 | /* TRUE if global symbols in discarded sections should be stripped. */ |
342 | unsigned int strip_discarded: 1; | |
cddd0089 | 343 | |
05aecedb AM |
344 | /* TRUE if all data symbols should be dynamic. */ |
345 | unsigned int dynamic_data: 1; | |
cddd0089 | 346 | |
05aecedb AM |
347 | /* Which symbols to strip. */ |
348 | ENUM_BITFIELD (bfd_link_strip) strip : 2; | |
31941635 | 349 | |
05aecedb AM |
350 | /* Which local symbols to discard. */ |
351 | ENUM_BITFIELD (bfd_link_discard) discard : 2; | |
c6b64018 | 352 | |
b8871f35 L |
353 | /* Whether to generate ELF common symbols with the STT_COMMON type. */ |
354 | ENUM_BITFIELD (bfd_link_elf_stt_common) elf_stt_common : 2; | |
355 | ||
05aecedb AM |
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; | |
36af4a4e | 359 | |
05aecedb AM |
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; | |
36af4a4e | 366 | |
05aecedb AM |
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; | |
9ee5e499 | 370 | |
05aecedb AM |
371 | /* TRUE if shared objects should be linked directly, not shared. */ |
372 | unsigned int static_link: 1; | |
373 | ||
374 | /* TRUE if symbols should be retained in memory, FALSE if they | |
375 | should be freed and reread. */ | |
376 | unsigned int keep_memory: 1; | |
377 | ||
378 | /* TRUE if BFD should generate relocation information in the final | |
379 | executable. */ | |
380 | unsigned int emitrelocations: 1; | |
9ee5e499 | 381 | |
8c37241b JJ |
382 | /* TRUE if PT_GNU_RELRO segment should be created. */ |
383 | unsigned int relro: 1; | |
384 | ||
2f0c68f2 CM |
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; | |
05aecedb | 388 | |
8fdd7217 NC |
389 | /* TRUE if we should warn when adding a DT_TEXTREL to a shared object. */ |
390 | unsigned int warn_shared_textrel: 1; | |
391 | ||
c192a133 AM |
392 | /* TRUE if we should error when adding a DT_TEXTREL. */ |
393 | unsigned int error_textrel: 1; | |
394 | ||
fdc90cb4 JJ |
395 | /* TRUE if .hash section should be created. */ |
396 | unsigned int emit_hash: 1; | |
397 | ||
398 | /* TRUE if .gnu.hash section should be created. */ | |
399 | unsigned int emit_gnu_hash: 1; | |
400 | ||
c0f00686 L |
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; | |
405 | ||
05aecedb AM |
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 | |
409 | files. */ | |
410 | unsigned int traditional_format: 1; | |
40b36307 | 411 | |
05aecedb AM |
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; | |
415 | ||
416 | /* TRUE if a default symbol version should be created and used for | |
417 | imported symbols. */ | |
418 | unsigned int default_imported_symver: 1; | |
419 | ||
420 | /* TRUE if the new ELF dynamic tags are enabled. */ | |
421 | unsigned int new_dtags: 1; | |
40b36307 | 422 | |
e41b3a13 JJ |
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; | |
426 | ||
05aecedb AM |
427 | /* TRUE if BFD should generate a "task linked" object file, |
428 | similar to relocatable but also with globals converted to | |
429 | statics. */ | |
430 | unsigned int task_link: 1; | |
0c511000 | 431 | |
05aecedb AM |
432 | /* TRUE if ok to have multiple definition. */ |
433 | unsigned int allow_multiple_definition: 1; | |
ab24bc21 | 434 | |
05aecedb AM |
435 | /* TRUE if ok to have version with no definition. */ |
436 | unsigned int allow_undefined_version: 1; | |
560e09e9 | 437 | |
05aecedb AM |
438 | /* TRUE if some symbols have to be dynamic, controlled by |
439 | --dynamic-list command line options. */ | |
440 | unsigned int dynamic: 1; | |
560e09e9 | 441 | |
05aecedb AM |
442 | /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W|PF_X |
443 | flags. */ | |
444 | unsigned int execstack: 1; | |
7815cf4f | 445 | |
05aecedb AM |
446 | /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W |
447 | flags. */ | |
448 | unsigned int noexecstack: 1; | |
7815cf4f | 449 | |
05aecedb AM |
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; | |
453 | ||
454 | /* TRUE if user should be informed of removed unreferenced sections. */ | |
455 | unsigned int print_gc_sections: 1; | |
456 | ||
457 | /* TRUE if we should warn alternate ELF machine code. */ | |
458 | unsigned int warn_alternate_em: 1; | |
7815cf4f | 459 | |
d324f6d6 RM |
460 | /* TRUE if the linker script contained an explicit PHDRS command. */ |
461 | unsigned int user_phdrs: 1; | |
462 | ||
d9689752 L |
463 | /* TRUE if we should check relocations after all input files have |
464 | been opened. */ | |
465 | unsigned int check_relocs_after_open_input: 1; | |
466 | ||
d258b828 IZ |
467 | /* TRUE if BND prefix in PLT entries is always generated. */ |
468 | unsigned int bndplt: 1; | |
469 | ||
9b8b325a RF |
470 | /* TRUE if generation of .interp/PT_INTERP should be suppressed. */ |
471 | unsigned int nointerp: 1; | |
472 | ||
4c10bbaa L |
473 | /* TRUE if we shouldn't check relocation overflow. */ |
474 | unsigned int no_reloc_overflow_check: 1; | |
475 | ||
caa65211 L |
476 | /* TRUE if generate a 1-byte NOP as suffix for x86 call instruction. */ |
477 | unsigned int call_nop_as_suffix : 1; | |
478 | ||
479 | /* The 1-byte NOP for x86 call instruction. */ | |
480 | char call_nop_byte; | |
481 | ||
b9cf773d AM |
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. */ | |
485 | char wrap_char; | |
486 | ||
97407faf AM |
487 | /* Separator between archive and filename in linker script filespecs. */ |
488 | char path_separator; | |
489 | ||
0ce398f1 L |
490 | /* Compress DWARF debug sections. */ |
491 | enum compressed_debug_section_type compress_debug; | |
492 | ||
04c3a755 NS |
493 | /* Default stack size. Zero means default (often zero itself), -1 |
494 | means explicitly zero-sized. */ | |
495 | bfd_signed_vma stacksize; | |
496 | ||
4f9d22a0 L |
497 | /* Enable or disable target specific optimizations. |
498 | ||
499 | Not all targets have optimizations to enable. | |
500 | ||
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. | |
503 | The values are: | |
504 | ||
505 | zero: Enable the optimizations (either from --relax being specified on | |
506 | the command line or the backend's before_allocation emulation function. | |
507 | ||
508 | positive: The user has requested that these optimizations be disabled. | |
509 | (Via the --no-relax command line option). | |
510 | ||
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; | |
514 | ||
cddd0089 AM |
515 | /* Function callbacks. */ |
516 | const struct bfd_link_callbacks *callbacks; | |
7815cf4f | 517 | |
252b5132 RH |
518 | /* Hash table handled by BFD. */ |
519 | struct bfd_link_hash_table *hash; | |
7815cf4f | 520 | |
252b5132 RH |
521 | /* Hash table of symbols to keep. This is NULL unless strip is |
522 | strip_some. */ | |
523 | struct bfd_hash_table *keep_hash; | |
7815cf4f | 524 | |
252b5132 | 525 | /* Hash table of symbols to report back via the notice callback. If |
b34976b6 | 526 | this is NULL, and notice_all is FALSE, then no symbols are |
252b5132 RH |
527 | reported back. */ |
528 | struct bfd_hash_table *notice_hash; | |
7815cf4f | 529 | |
252b5132 RH |
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; | |
7815cf4f | 533 | |
0e86e20e AM |
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; | |
537 | ||
f13a99db AM |
538 | /* The output BFD. */ |
539 | bfd *output_bfd; | |
540 | ||
76359541 TP |
541 | /* The import library generated. */ |
542 | bfd *out_implib_bfd; | |
543 | ||
cddd0089 | 544 | /* The list of input BFD's involved in the link. These are chained |
c72f2fb2 | 545 | together via the link.next field. */ |
cddd0089 | 546 | bfd *input_bfds; |
a9a4c53e | 547 | bfd **input_bfds_tail; |
cddd0089 AM |
548 | |
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; | |
555 | ||
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; | |
559 | ||
252b5132 | 560 | /* If a base output file is wanted, then this points to it */ |
8cf3f354 | 561 | void *base_file; |
252b5132 | 562 | |
94883c63 MM |
563 | /* The function to call when the executable or shared object is |
564 | loaded. */ | |
565 | const char *init_function; | |
7815cf4f | 566 | |
94883c63 MM |
567 | /* The function to call when the executable or shared object is |
568 | unloaded. */ | |
569 | const char *fini_function; | |
9bfcb6d6 | 570 | |
fbbc3759 L |
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. */ | |
575 | int relax_pass; | |
576 | ||
4a828aab RH |
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. */ | |
580 | int relax_trip; | |
581 | ||
889c2a67 L |
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; | |
586 | ||
aec6b87e L |
587 | /* > 0 to treat undefined weak symbol in the executable as dynamic, |
588 | requiring dynamic relocation. */ | |
589 | int dynamic_undefined_weak; | |
590 | ||
b34976b6 | 591 | /* Non-zero if auto-import thunks for DATA items in pei386 DLLs |
e0076ab3 NC |
592 | should be generated/linked against. Set to 1 if this feature |
593 | is explicitly requested by the user, -1 if enabled by default. */ | |
594 | int pei386_auto_import; | |
db6751f2 | 595 | |
2fa9fc65 NC |
596 | /* Non-zero if runtime relocs for DATA items with non-zero addends |
597 | in pei386 DLLs should be generated. Set to 1 if this feature | |
598 | is explicitly requested by the user, -1 if enabled by default. */ | |
599 | int pei386_runtime_pseudo_reloc; | |
600 | ||
db6751f2 | 601 | /* How many spare .dynamic DT_NULL entries should be added? */ |
b7781dbe | 602 | unsigned int spare_dynamic_tags; |
f7c33884 | 603 | |
cddd0089 AM |
604 | /* May be used to set DT_FLAGS for ELF. */ |
605 | bfd_vma flags; | |
606 | ||
607 | /* May be used to set DT_FLAGS_1 for ELF. */ | |
608 | bfd_vma flags_1; | |
8c37241b JJ |
609 | |
610 | /* Start and end of RELRO region. */ | |
611 | bfd_vma relro_start, relro_end; | |
55255dae L |
612 | |
613 | /* List of symbols should be dynamic. */ | |
40b36307 | 614 | struct bfd_elf_dynamic_list *dynamic_list; |
fd91d419 L |
615 | |
616 | /* The version information. */ | |
617 | struct bfd_elf_version_tree *version_info; | |
252b5132 RH |
618 | }; |
619 | ||
49fa1e15 | 620 | /* This structures holds a set of callback functions. These are called |
1a72702b | 621 | by the BFD linker routines. */ |
252b5132 RH |
622 | |
623 | struct bfd_link_callbacks | |
624 | { | |
625 | /* A function which is called when an object is added from an | |
626 | archive. ABFD is the archive element being added. NAME is the | |
627 | name of the symbol which caused the archive element to be pulled | |
5d3236ee DK |
628 | in. This function may set *SUBSBFD to point to an alternative |
629 | BFD from which symbols should in fact be added in place of the | |
1a72702b AM |
630 | original BFD's symbols. Returns TRUE if the object should be |
631 | added, FALSE if it should be skipped. */ | |
b34976b6 | 632 | bfd_boolean (*add_archive_element) |
5d3236ee | 633 | (struct bfd_link_info *, bfd *abfd, const char *name, bfd **subsbfd); |
252b5132 | 634 | /* A function which is called when a symbol is found with multiple |
24f58f47 AM |
635 | definitions. H is the symbol which is defined multiple times. |
636 | NBFD is the new BFD, NSEC is the new section, and NVAL is the new | |
637 | value. NSEC may be bfd_com_section or bfd_ind_section. */ | |
1a72702b | 638 | void (*multiple_definition) |
24f58f47 | 639 | (struct bfd_link_info *, struct bfd_link_hash_entry *h, |
8cf3f354 | 640 | bfd *nbfd, asection *nsec, bfd_vma nval); |
252b5132 | 641 | /* A function which is called when a common symbol is defined |
24f58f47 | 642 | multiple times. H is the symbol appearing multiple times. |
252b5132 RH |
643 | NBFD is the BFD of the new symbol. NTYPE is the type of the new |
644 | symbol, one of bfd_link_hash_defined, bfd_link_hash_common, or | |
645 | bfd_link_hash_indirect. If NTYPE is bfd_link_hash_common, NSIZE | |
646 | is the size of the new symbol. */ | |
1a72702b | 647 | void (*multiple_common) |
24f58f47 | 648 | (struct bfd_link_info *, struct bfd_link_hash_entry *h, |
8cf3f354 | 649 | bfd *nbfd, enum bfd_link_hash_type ntype, bfd_vma nsize); |
252b5132 RH |
650 | /* A function which is called to add a symbol to a set. ENTRY is |
651 | the link hash table entry for the set itself (e.g., | |
652 | __CTOR_LIST__). RELOC is the relocation to use for an entry in | |
1049f94e | 653 | the set when generating a relocatable file, and is also used to |
252b5132 RH |
654 | get the size of the entry when generating an executable file. |
655 | ABFD, SEC and VALUE identify the value to add to the set. */ | |
1a72702b | 656 | void (*add_to_set) |
8cf3f354 AM |
657 | (struct bfd_link_info *, struct bfd_link_hash_entry *entry, |
658 | bfd_reloc_code_real_type reloc, bfd *abfd, asection *sec, bfd_vma value); | |
252b5132 RH |
659 | /* A function which is called when the name of a g++ constructor or |
660 | destructor is found. This is only called by some object file | |
b34976b6 | 661 | formats. CONSTRUCTOR is TRUE for a constructor, FALSE for a |
252b5132 | 662 | destructor. This will use BFD_RELOC_CTOR when generating a |
1049f94e | 663 | relocatable file. NAME is the name of the symbol found. ABFD, |
252b5132 | 664 | SECTION and VALUE are the value of the symbol. */ |
1a72702b | 665 | void (*constructor) |
8cf3f354 AM |
666 | (struct bfd_link_info *, bfd_boolean constructor, const char *name, |
667 | bfd *abfd, asection *sec, bfd_vma value); | |
252b5132 RH |
668 | /* A function which is called to issue a linker warning. For |
669 | example, this is called when there is a reference to a warning | |
670 | symbol. WARNING is the warning to be issued. SYMBOL is the name | |
671 | of the symbol which triggered the warning; it may be NULL if | |
672 | there is none. ABFD, SECTION and ADDRESS identify the location | |
673 | which trigerred the warning; either ABFD or SECTION or both may | |
674 | be NULL if the location is not known. */ | |
1a72702b | 675 | void (*warning) |
8cf3f354 AM |
676 | (struct bfd_link_info *, const char *warning, const char *symbol, |
677 | bfd *abfd, asection *section, bfd_vma address); | |
252b5132 RH |
678 | /* A function which is called when a relocation is attempted against |
679 | an undefined symbol. NAME is the symbol which is undefined. | |
680 | ABFD, SECTION and ADDRESS identify the location from which the | |
e7f8eadb | 681 | reference is made. IS_FATAL indicates whether an undefined symbol is |
c086cbc6 | 682 | a fatal error or not. In some cases SECTION may be NULL. */ |
1a72702b | 683 | void (*undefined_symbol) |
8cf3f354 | 684 | (struct bfd_link_info *, const char *name, bfd *abfd, |
e7f8eadb | 685 | asection *section, bfd_vma address, bfd_boolean is_fatal); |
dfeffb9f L |
686 | /* A function which is called when a reloc overflow occurs. ENTRY is |
687 | the link hash table entry for the symbol the reloc is against. | |
688 | NAME is the name of the local symbol or section the reloc is | |
689 | against, RELOC_NAME is the name of the relocation, and ADDEND is | |
690 | any addend that is used. ABFD, SECTION and ADDRESS identify the | |
252b5132 RH |
691 | location at which the overflow occurs; if this is the result of a |
692 | bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then | |
693 | ABFD will be NULL. */ | |
1a72702b | 694 | void (*reloc_overflow) |
dfeffb9f L |
695 | (struct bfd_link_info *, struct bfd_link_hash_entry *entry, |
696 | const char *name, const char *reloc_name, bfd_vma addend, | |
697 | bfd *abfd, asection *section, bfd_vma address); | |
252b5132 | 698 | /* A function which is called when a dangerous reloc is performed. |
c17ae8a2 | 699 | MESSAGE is an appropriate message. |
252b5132 RH |
700 | ABFD, SECTION and ADDRESS identify the location at which the |
701 | problem occurred; if this is the result of a | |
702 | bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then | |
703 | ABFD will be NULL. */ | |
1a72702b | 704 | void (*reloc_dangerous) |
8cf3f354 AM |
705 | (struct bfd_link_info *, const char *message, |
706 | bfd *abfd, asection *section, bfd_vma address); | |
252b5132 RH |
707 | /* A function which is called when a reloc is found to be attached |
708 | to a symbol which is not being written out. NAME is the name of | |
709 | the symbol. ABFD, SECTION and ADDRESS identify the location of | |
710 | the reloc; if this is the result of a | |
711 | bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then | |
712 | ABFD will be NULL. */ | |
1a72702b | 713 | void (*unattached_reloc) |
8cf3f354 AM |
714 | (struct bfd_link_info *, const char *name, |
715 | bfd *abfd, asection *section, bfd_vma address); | |
252b5132 | 716 | /* A function which is called when a symbol in notice_hash is |
46135103 AM |
717 | defined or referenced. H is the symbol, INH the indirect symbol |
718 | if applicable. ABFD, SECTION and ADDRESS are the (new) value of | |
719 | the symbol. If SECTION is bfd_und_section, this is a reference. | |
720 | FLAGS are the symbol BSF_* flags. */ | |
b34976b6 | 721 | bfd_boolean (*notice) |
35ed3f94 | 722 | (struct bfd_link_info *, struct bfd_link_hash_entry *h, |
46135103 AM |
723 | struct bfd_link_hash_entry *inh, |
724 | bfd *abfd, asection *section, bfd_vma address, flagword flags); | |
49fa1e15 | 725 | /* Error or warning link info message. */ |
e1fffbe6 AM |
726 | void (*einfo) |
727 | (const char *fmt, ...); | |
49fa1e15 AM |
728 | /* General link info message. */ |
729 | void (*info) | |
730 | (const char *fmt, ...); | |
731 | /* Message to be printed in linker map file. */ | |
732 | void (*minfo) | |
733 | (const char *fmt, ...); | |
2889e75b NC |
734 | /* This callback provides a chance for users of the BFD library to |
735 | override its decision about whether to place two adjacent sections | |
736 | into the same segment. */ | |
737 | bfd_boolean (*override_segment_assignment) | |
738 | (struct bfd_link_info *, bfd * abfd, | |
739 | asection * current_section, asection * previous_section, | |
740 | bfd_boolean new_segment); | |
252b5132 RH |
741 | }; |
742 | \f | |
743 | /* The linker builds link_order structures which tell the code how to | |
744 | include input data in the output file. */ | |
745 | ||
746 | /* These are the types of link_order structures. */ | |
747 | ||
748 | enum bfd_link_order_type | |
749 | { | |
750 | bfd_undefined_link_order, /* Undefined. */ | |
751 | bfd_indirect_link_order, /* Built from a section. */ | |
252b5132 RH |
752 | bfd_data_link_order, /* Set to explicit data. */ |
753 | bfd_section_reloc_link_order, /* Relocate against a section. */ | |
754 | bfd_symbol_reloc_link_order /* Relocate against a symbol. */ | |
755 | }; | |
756 | ||
757 | /* This is the link_order structure itself. These form a chain | |
6ed89c00 | 758 | attached to the output section whose contents they are describing. */ |
252b5132 | 759 | |
b34976b6 | 760 | struct bfd_link_order |
252b5132 RH |
761 | { |
762 | /* Next link_order in chain. */ | |
763 | struct bfd_link_order *next; | |
764 | /* Type of link_order. */ | |
765 | enum bfd_link_order_type type; | |
766 | /* Offset within output section. */ | |
b34976b6 | 767 | bfd_vma offset; |
252b5132 RH |
768 | /* Size within output section. */ |
769 | bfd_size_type size; | |
770 | /* Type specific information. */ | |
b34976b6 | 771 | union |
252b5132 | 772 | { |
b34976b6 | 773 | struct |
252b5132 RH |
774 | { |
775 | /* Section to include. If this is used, then | |
776 | section->output_section must be the section the | |
777 | link_order is attached to, section->output_offset must | |
eea6121a | 778 | equal the link_order offset field, and section->size |
252b5132 RH |
779 | must equal the link_order size field. Maybe these |
780 | restrictions should be relaxed someday. */ | |
781 | asection *section; | |
782 | } indirect; | |
783 | struct | |
784 | { | |
d324f6d6 | 785 | /* Size of contents, or zero when contents should be filled by |
b7761f11 | 786 | the architecture-dependent fill function. |
9a1b9f82 AM |
787 | A non-zero value allows filling of the output section |
788 | with an arbitrary repeated pattern. */ | |
789 | unsigned int size; | |
790 | /* Data to put into file. */ | |
252b5132 RH |
791 | bfd_byte *contents; |
792 | } data; | |
793 | struct | |
794 | { | |
795 | /* Description of reloc to generate. Used for | |
796 | bfd_section_reloc_link_order and | |
797 | bfd_symbol_reloc_link_order. */ | |
798 | struct bfd_link_order_reloc *p; | |
799 | } reloc; | |
800 | } u; | |
801 | }; | |
802 | ||
803 | /* A linker order of type bfd_section_reloc_link_order or | |
804 | bfd_symbol_reloc_link_order means to create a reloc against a | |
805 | section or symbol, respectively. This is used to implement -Ur to | |
806 | generate relocs for the constructor tables. The | |
807 | bfd_link_order_reloc structure describes the reloc that BFD should | |
808 | create. It is similar to a arelent, but I didn't use arelent | |
809 | because the linker does not know anything about most symbols, and | |
810 | any asymbol structure it creates will be partially meaningless. | |
811 | This information could logically be in the bfd_link_order struct, | |
812 | but I didn't want to waste the space since these types of relocs | |
813 | are relatively rare. */ | |
814 | ||
815 | struct bfd_link_order_reloc | |
816 | { | |
817 | /* Reloc type. */ | |
818 | bfd_reloc_code_real_type reloc; | |
819 | ||
820 | union | |
821 | { | |
822 | /* For type bfd_section_reloc_link_order, this is the section | |
823 | the reloc should be against. This must be a section in the | |
824 | output BFD, not any of the input BFDs. */ | |
825 | asection *section; | |
826 | /* For type bfd_symbol_reloc_link_order, this is the name of the | |
827 | symbol the reloc should be against. */ | |
828 | const char *name; | |
829 | } u; | |
830 | ||
831 | /* Addend to use. The object file should contain zero. The BFD | |
832 | backend is responsible for filling in the contents of the object | |
833 | file correctly. For some object file formats (e.g., COFF) the | |
834 | addend must be stored into in the object file, and for some | |
835 | (e.g., SPARC a.out) it is kept in the reloc. */ | |
836 | bfd_vma addend; | |
837 | }; | |
838 | ||
839 | /* Allocate a new link_order for a section. */ | |
8cf3f354 | 840 | extern struct bfd_link_order *bfd_new_link_order (bfd *, asection *); |
252b5132 RH |
841 | |
842 | /* These structures are used to describe version information for the | |
843 | ELF linker. These structures could be manipulated entirely inside | |
844 | BFD, but it would be a pain. Instead, the regular linker sets up | |
845 | these structures, and then passes them into BFD. */ | |
846 | ||
108ba305 | 847 | /* Glob pattern for a version. */ |
252b5132 RH |
848 | |
849 | struct bfd_elf_version_expr | |
850 | { | |
108ba305 | 851 | /* Next glob pattern for this version. */ |
252b5132 | 852 | struct bfd_elf_version_expr *next; |
108ba305 | 853 | /* Glob pattern. */ |
252b5132 | 854 | const char *pattern; |
ae5a3597 AM |
855 | /* Set if pattern is not a glob. */ |
856 | unsigned int literal : 1; | |
31941635 | 857 | /* Defined by ".symver". */ |
108ba305 | 858 | unsigned int symver : 1; |
31941635 L |
859 | /* Defined by version script. */ |
860 | unsigned int script : 1; | |
108ba305 JJ |
861 | /* Pattern type. */ |
862 | #define BFD_ELF_VERSION_C_TYPE 1 | |
863 | #define BFD_ELF_VERSION_CXX_TYPE 2 | |
864 | #define BFD_ELF_VERSION_JAVA_TYPE 4 | |
865 | unsigned int mask : 3; | |
866 | }; | |
867 | ||
868 | struct bfd_elf_version_expr_head | |
869 | { | |
870 | /* List of all patterns, both wildcards and non-wildcards. */ | |
871 | struct bfd_elf_version_expr *list; | |
872 | /* Hash table for non-wildcards. */ | |
873 | void *htab; | |
874 | /* Remaining patterns. */ | |
875 | struct bfd_elf_version_expr *remaining; | |
876 | /* What kind of pattern types are present in list (bitmask). */ | |
877 | unsigned int mask; | |
252b5132 RH |
878 | }; |
879 | ||
880 | /* Version dependencies. */ | |
881 | ||
882 | struct bfd_elf_version_deps | |
883 | { | |
884 | /* Next dependency for this version. */ | |
885 | struct bfd_elf_version_deps *next; | |
886 | /* The version which this version depends upon. */ | |
887 | struct bfd_elf_version_tree *version_needed; | |
888 | }; | |
889 | ||
890 | /* A node in the version tree. */ | |
891 | ||
892 | struct bfd_elf_version_tree | |
893 | { | |
894 | /* Next version. */ | |
895 | struct bfd_elf_version_tree *next; | |
896 | /* Name of this version. */ | |
897 | const char *name; | |
898 | /* Version number. */ | |
899 | unsigned int vernum; | |
900 | /* Regular expressions for global symbols in this version. */ | |
108ba305 | 901 | struct bfd_elf_version_expr_head globals; |
252b5132 | 902 | /* Regular expressions for local symbols in this version. */ |
108ba305 | 903 | struct bfd_elf_version_expr_head locals; |
252b5132 RH |
904 | /* List of versions which this version depends upon. */ |
905 | struct bfd_elf_version_deps *deps; | |
906 | /* Index of the version name. This is used within BFD. */ | |
907 | unsigned int name_indx; | |
908 | /* Whether this version tree was used. This is used within BFD. */ | |
909 | int used; | |
108ba305 JJ |
910 | /* Matching hook. */ |
911 | struct bfd_elf_version_expr *(*match) | |
912 | (struct bfd_elf_version_expr_head *head, | |
913 | struct bfd_elf_version_expr *prev, const char *sym); | |
252b5132 RH |
914 | }; |
915 | ||
55255dae L |
916 | struct bfd_elf_dynamic_list |
917 | { | |
918 | struct bfd_elf_version_expr_head head; | |
919 | struct bfd_elf_version_expr *(*match) | |
920 | (struct bfd_elf_version_expr_head *head, | |
921 | struct bfd_elf_version_expr *prev, const char *sym); | |
922 | }; | |
923 | ||
252b5132 | 924 | #endif |