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252b5132 | 1 | /* bfdlink.h -- header file for BFD link routines |
6f2750fe | 2 | Copyright (C) 1993-2016 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 | |
252b5132 RH |
111 | /* A union of information depending upon the type. */ |
112 | union | |
113 | { | |
114 | /* Nothing is kept for bfd_hash_new. */ | |
115 | /* bfd_link_hash_undefined, bfd_link_hash_undefweak. */ | |
116 | struct | |
117 | { | |
f6e332e6 AM |
118 | /* Undefined and common symbols are kept in a linked list through |
119 | this field. This field is present in all of the union element | |
120 | so that we don't need to remove entries from the list when we | |
121 | change their type. Removing entries would either require the | |
122 | list to be doubly linked, which would waste more memory, or | |
123 | require a traversal. When an undefined or common symbol is | |
124 | created, it should be added to this list, the head of which is in | |
125 | the link hash table itself. As symbols are defined, they need | |
126 | not be removed from the list; anything which reads the list must | |
127 | doublecheck the symbol type. | |
128 | ||
129 | Weak symbols are not kept on this list. | |
130 | ||
131 | Defined and defweak symbols use this field as a reference marker. | |
132 | If the field is not NULL, or this structure is the tail of the | |
133 | undefined symbol list, the symbol has been referenced. If the | |
134 | symbol is undefined and becomes defined, this field will | |
135 | automatically be non-NULL since the symbol will have been on the | |
136 | undefined symbol list. */ | |
137 | struct bfd_link_hash_entry *next; | |
a6a4679f AM |
138 | /* BFD symbol was found in. */ |
139 | bfd *abfd; | |
140 | /* For __start_<name> and __stop_<name> symbols, the first | |
141 | input section matching the name. */ | |
142 | asection *section; | |
252b5132 RH |
143 | } undef; |
144 | /* bfd_link_hash_defined, bfd_link_hash_defweak. */ | |
145 | struct | |
146 | { | |
f6e332e6 | 147 | struct bfd_link_hash_entry *next; |
a6a4679f AM |
148 | /* Symbol section. */ |
149 | asection *section; | |
150 | /* Symbol value. */ | |
151 | bfd_vma value; | |
252b5132 RH |
152 | } def; |
153 | /* bfd_link_hash_indirect, bfd_link_hash_warning. */ | |
154 | struct | |
155 | { | |
f6e332e6 | 156 | struct bfd_link_hash_entry *next; |
a6a4679f AM |
157 | /* Real symbol. */ |
158 | struct bfd_link_hash_entry *link; | |
159 | /* Warning message (bfd_link_hash_warning only). */ | |
160 | const char *warning; | |
252b5132 RH |
161 | } i; |
162 | /* bfd_link_hash_common. */ | |
163 | struct | |
164 | { | |
f6e332e6 | 165 | struct bfd_link_hash_entry *next; |
252b5132 | 166 | /* The linker needs to know three things about common |
b34976b6 AM |
167 | symbols: the size, the alignment, and the section in |
168 | which the symbol should be placed. We store the size | |
169 | here, and we allocate a small structure to hold the | |
170 | section and the alignment. The alignment is stored as a | |
171 | power of two. We don't store all the information | |
172 | directly because we don't want to increase the size of | |
173 | the union; this structure is a major space user in the | |
174 | linker. */ | |
a50b1753 | 175 | struct bfd_link_hash_common_entry *p; |
a6a4679f AM |
176 | /* Common symbol size. */ |
177 | bfd_size_type size; | |
252b5132 RH |
178 | } c; |
179 | } u; | |
180 | }; | |
181 | ||
182 | /* This is the link hash table. It is a derived class of | |
183 | bfd_hash_table. */ | |
184 | ||
185 | struct bfd_link_hash_table | |
186 | { | |
187 | /* The hash table itself. */ | |
188 | struct bfd_hash_table table; | |
252b5132 RH |
189 | /* A linked list of undefined and common symbols, linked through the |
190 | next field in the bfd_link_hash_entry structure. */ | |
191 | struct bfd_link_hash_entry *undefs; | |
192 | /* Entries are added to the tail of the undefs list. */ | |
193 | struct bfd_link_hash_entry *undefs_tail; | |
d495ab0d AM |
194 | /* Function to free the hash table on closing BFD. */ |
195 | void (*hash_table_free) (bfd *); | |
b9b171fb | 196 | /* The type of the link hash table. */ |
8ea2e4bd | 197 | enum bfd_link_hash_table_type type; |
252b5132 RH |
198 | }; |
199 | ||
b34976b6 | 200 | /* Look up an entry in a link hash table. If FOLLOW is TRUE, this |
252b5132 RH |
201 | follows bfd_link_hash_indirect and bfd_link_hash_warning links to |
202 | the real symbol. */ | |
203 | extern struct bfd_link_hash_entry *bfd_link_hash_lookup | |
8cf3f354 AM |
204 | (struct bfd_link_hash_table *, const char *, bfd_boolean create, |
205 | bfd_boolean copy, bfd_boolean follow); | |
252b5132 RH |
206 | |
207 | /* Look up an entry in the main linker hash table if the symbol might | |
208 | be wrapped. This should only be used for references to an | |
209 | undefined symbol, not for definitions of a symbol. */ | |
210 | ||
211 | extern struct bfd_link_hash_entry *bfd_wrapped_link_hash_lookup | |
8cf3f354 AM |
212 | (bfd *, struct bfd_link_info *, const char *, bfd_boolean, |
213 | bfd_boolean, bfd_boolean); | |
252b5132 | 214 | |
8a5da09b AM |
215 | /* If H is a wrapped symbol, ie. the symbol name starts with "__wrap_" |
216 | and the remainder is found in wrap_hash, return the real symbol. */ | |
217 | ||
218 | extern struct bfd_link_hash_entry *unwrap_hash_lookup | |
219 | (struct bfd_link_info *, bfd *, struct bfd_link_hash_entry *); | |
220 | ||
252b5132 RH |
221 | /* Traverse a link hash table. */ |
222 | extern void bfd_link_hash_traverse | |
8cf3f354 AM |
223 | (struct bfd_link_hash_table *, |
224 | bfd_boolean (*) (struct bfd_link_hash_entry *, void *), | |
225 | void *); | |
252b5132 RH |
226 | |
227 | /* Add an entry to the undefs list. */ | |
228 | extern void bfd_link_add_undef | |
8cf3f354 | 229 | (struct bfd_link_hash_table *, struct bfd_link_hash_entry *); |
7815cf4f | 230 | |
77cfaee6 AM |
231 | /* Remove symbols from the undefs list that don't belong there. */ |
232 | extern void bfd_link_repair_undef_list | |
233 | (struct bfd_link_hash_table *table); | |
234 | ||
5c1d2f5f AM |
235 | /* Read symbols and cache symbol pointer array in outsymbols. */ |
236 | extern bfd_boolean bfd_generic_link_read_symbols (bfd *); | |
237 | ||
4f3b23b3 NC |
238 | /* Check the relocs in the BFD. Called after all the input |
239 | files have been loaded, and garbage collection has tagged | |
240 | any unneeded sections. */ | |
241 | extern bfd_boolean bfd_link_check_relocs (bfd *,struct bfd_link_info *); | |
242 | ||
7815cf4f AM |
243 | struct bfd_sym_chain |
244 | { | |
245 | struct bfd_sym_chain *next; | |
246 | const char *name; | |
247 | }; | |
252b5132 | 248 | \f |
560e09e9 NC |
249 | /* How to handle unresolved symbols. |
250 | There are four possibilities which are enumerated below: */ | |
251 | enum report_method | |
252 | { | |
253 | /* This is the initial value when then link_info structure is created. | |
254 | It allows the various stages of the linker to determine whether they | |
255 | allowed to set the value. */ | |
256 | RM_NOT_YET_SET = 0, | |
257 | RM_IGNORE, | |
258 | RM_GENERATE_WARNING, | |
259 | RM_GENERATE_ERROR | |
260 | }; | |
261 | ||
ae17ab41 CM |
262 | typedef enum {with_flags, without_flags} flag_type; |
263 | ||
264 | /* A section flag list. */ | |
265 | struct flag_info_list | |
266 | { | |
d324f6d6 | 267 | flag_type with; |
ae17ab41 CM |
268 | const char *name; |
269 | bfd_boolean valid; | |
270 | struct flag_info_list *next; | |
271 | }; | |
272 | ||
273 | /* Section flag info. */ | |
274 | struct flag_info | |
275 | { | |
276 | flagword only_with_flags; | |
277 | flagword not_with_flags; | |
278 | struct flag_info_list *flag_list; | |
279 | bfd_boolean flags_initialized; | |
280 | }; | |
281 | ||
55255dae | 282 | struct bfd_elf_dynamic_list; |
fd91d419 | 283 | struct bfd_elf_version_tree; |
55255dae | 284 | |
0e1862bb L |
285 | /* Types of output. */ |
286 | ||
287 | enum output_type | |
288 | { | |
64d94ba0 | 289 | type_pde, |
64d94ba0 | 290 | type_pie, |
5f329d5b | 291 | type_relocatable, |
0e1862bb | 292 | type_dll, |
0e1862bb L |
293 | }; |
294 | ||
64d94ba0 | 295 | #define bfd_link_pde(info) ((info)->type == type_pde) |
0e1862bb L |
296 | #define bfd_link_dll(info) ((info)->type == type_dll) |
297 | #define bfd_link_relocatable(info) ((info)->type == type_relocatable) | |
64d94ba0 AM |
298 | #define bfd_link_pie(info) ((info)->type == type_pie) |
299 | #define bfd_link_executable(info) (bfd_link_pde (info) || bfd_link_pie (info)) | |
300 | #define bfd_link_pic(info) (bfd_link_dll (info) || bfd_link_pie (info)) | |
0e1862bb | 301 | |
252b5132 RH |
302 | /* This structure holds all the information needed to communicate |
303 | between BFD and the linker when doing a link. */ | |
304 | ||
305 | struct bfd_link_info | |
306 | { | |
0e1862bb L |
307 | /* Output type. */ |
308 | ENUM_BITFIELD (output_type) type : 2; | |
7815cf4f | 309 | |
b34976b6 | 310 | /* TRUE if BFD should pre-bind symbols in a shared object. */ |
cddd0089 | 311 | unsigned int symbolic: 1; |
7815cf4f | 312 | |
05aecedb AM |
313 | /* TRUE if executable should not contain copy relocs. |
314 | Setting this true may result in a non-sharable text segment. */ | |
315 | unsigned int nocopyreloc: 1; | |
316 | ||
b34976b6 | 317 | /* TRUE if BFD should export all symbols in the dynamic symbol table |
7be4069c | 318 | of an executable, rather than only those used. */ |
cddd0089 | 319 | unsigned int export_dynamic: 1; |
7815cf4f | 320 | |
fc0e6df6 PB |
321 | /* TRUE if a default symbol version should be created and used for |
322 | exported symbols. */ | |
3e3b46e5 PB |
323 | unsigned int create_default_symver: 1; |
324 | ||
05aecedb AM |
325 | /* TRUE if unreferenced sections should be removed. */ |
326 | unsigned int gc_sections: 1; | |
cddd0089 AM |
327 | |
328 | /* TRUE if every symbol should be reported back via the notice | |
329 | callback. */ | |
330 | unsigned int notice_all: 1; | |
331 | ||
61f41c3c AM |
332 | /* TRUE if the LTO plugin is active. */ |
333 | unsigned int lto_plugin_active: 1; | |
334 | ||
05aecedb AM |
335 | /* TRUE if global symbols in discarded sections should be stripped. */ |
336 | unsigned int strip_discarded: 1; | |
cddd0089 | 337 | |
05aecedb AM |
338 | /* TRUE if all data symbols should be dynamic. */ |
339 | unsigned int dynamic_data: 1; | |
cddd0089 | 340 | |
05aecedb AM |
341 | /* Which symbols to strip. */ |
342 | ENUM_BITFIELD (bfd_link_strip) strip : 2; | |
31941635 | 343 | |
05aecedb AM |
344 | /* Which local symbols to discard. */ |
345 | ENUM_BITFIELD (bfd_link_discard) discard : 2; | |
c6b64018 | 346 | |
b8871f35 L |
347 | /* Whether to generate ELF common symbols with the STT_COMMON type. */ |
348 | ENUM_BITFIELD (bfd_link_elf_stt_common) elf_stt_common : 2; | |
349 | ||
05aecedb AM |
350 | /* Criteria for skipping symbols when determining |
351 | whether to include an object from an archive. */ | |
352 | ENUM_BITFIELD (bfd_link_common_skip_ar_symbols) common_skip_ar_symbols : 2; | |
36af4a4e | 353 | |
05aecedb AM |
354 | /* What to do with unresolved symbols in an object file. |
355 | When producing executables the default is GENERATE_ERROR. | |
356 | When producing shared libraries the default is IGNORE. The | |
357 | assumption with shared libraries is that the reference will be | |
358 | resolved at load/execution time. */ | |
359 | ENUM_BITFIELD (report_method) unresolved_syms_in_objects : 2; | |
36af4a4e | 360 | |
05aecedb AM |
361 | /* What to do with unresolved symbols in a shared library. |
362 | The same defaults apply. */ | |
363 | ENUM_BITFIELD (report_method) unresolved_syms_in_shared_libs : 2; | |
9ee5e499 | 364 | |
05aecedb AM |
365 | /* TRUE if shared objects should be linked directly, not shared. */ |
366 | unsigned int static_link: 1; | |
367 | ||
368 | /* TRUE if symbols should be retained in memory, FALSE if they | |
369 | should be freed and reread. */ | |
370 | unsigned int keep_memory: 1; | |
371 | ||
372 | /* TRUE if BFD should generate relocation information in the final | |
373 | executable. */ | |
374 | unsigned int emitrelocations: 1; | |
9ee5e499 | 375 | |
8c37241b JJ |
376 | /* TRUE if PT_GNU_RELRO segment should be created. */ |
377 | unsigned int relro: 1; | |
378 | ||
2f0c68f2 CM |
379 | /* Nonzero if .eh_frame_hdr section and PT_GNU_EH_FRAME ELF segment |
380 | should be created. 1 for DWARF2 tables, 2 for compact tables. */ | |
381 | unsigned int eh_frame_hdr_type: 2; | |
05aecedb | 382 | |
8fdd7217 NC |
383 | /* TRUE if we should warn when adding a DT_TEXTREL to a shared object. */ |
384 | unsigned int warn_shared_textrel: 1; | |
385 | ||
c192a133 AM |
386 | /* TRUE if we should error when adding a DT_TEXTREL. */ |
387 | unsigned int error_textrel: 1; | |
388 | ||
fdc90cb4 JJ |
389 | /* TRUE if .hash section should be created. */ |
390 | unsigned int emit_hash: 1; | |
391 | ||
392 | /* TRUE if .gnu.hash section should be created. */ | |
393 | unsigned int emit_gnu_hash: 1; | |
394 | ||
c0f00686 L |
395 | /* If TRUE reduce memory overheads, at the expense of speed. This will |
396 | cause map file generation to use an O(N^2) algorithm and disable | |
397 | caching ELF symbol buffer. */ | |
398 | unsigned int reduce_memory_overheads: 1; | |
399 | ||
05aecedb AM |
400 | /* TRUE if the output file should be in a traditional format. This |
401 | is equivalent to the setting of the BFD_TRADITIONAL_FORMAT flag | |
402 | on the output file, but may be checked when reading the input | |
403 | files. */ | |
404 | unsigned int traditional_format: 1; | |
40b36307 | 405 | |
05aecedb AM |
406 | /* TRUE if non-PLT relocs should be merged into one reloc section |
407 | and sorted so that relocs against the same symbol come together. */ | |
408 | unsigned int combreloc: 1; | |
409 | ||
410 | /* TRUE if a default symbol version should be created and used for | |
411 | imported symbols. */ | |
412 | unsigned int default_imported_symver: 1; | |
413 | ||
414 | /* TRUE if the new ELF dynamic tags are enabled. */ | |
415 | unsigned int new_dtags: 1; | |
40b36307 | 416 | |
e41b3a13 JJ |
417 | /* FALSE if .eh_frame unwind info should be generated for PLT and other |
418 | linker created sections, TRUE if it should be omitted. */ | |
419 | unsigned int no_ld_generated_unwind_info: 1; | |
420 | ||
05aecedb AM |
421 | /* TRUE if BFD should generate a "task linked" object file, |
422 | similar to relocatable but also with globals converted to | |
423 | statics. */ | |
424 | unsigned int task_link: 1; | |
0c511000 | 425 | |
05aecedb AM |
426 | /* TRUE if ok to have multiple definition. */ |
427 | unsigned int allow_multiple_definition: 1; | |
ab24bc21 | 428 | |
05aecedb AM |
429 | /* TRUE if ok to have version with no definition. */ |
430 | unsigned int allow_undefined_version: 1; | |
560e09e9 | 431 | |
05aecedb AM |
432 | /* TRUE if some symbols have to be dynamic, controlled by |
433 | --dynamic-list command line options. */ | |
434 | unsigned int dynamic: 1; | |
560e09e9 | 435 | |
05aecedb AM |
436 | /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W|PF_X |
437 | flags. */ | |
438 | unsigned int execstack: 1; | |
7815cf4f | 439 | |
05aecedb AM |
440 | /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W |
441 | flags. */ | |
442 | unsigned int noexecstack: 1; | |
7815cf4f | 443 | |
05aecedb AM |
444 | /* TRUE if we want to produced optimized output files. This might |
445 | need much more time and therefore must be explicitly selected. */ | |
446 | unsigned int optimize: 1; | |
447 | ||
448 | /* TRUE if user should be informed of removed unreferenced sections. */ | |
449 | unsigned int print_gc_sections: 1; | |
450 | ||
451 | /* TRUE if we should warn alternate ELF machine code. */ | |
452 | unsigned int warn_alternate_em: 1; | |
7815cf4f | 453 | |
d324f6d6 RM |
454 | /* TRUE if the linker script contained an explicit PHDRS command. */ |
455 | unsigned int user_phdrs: 1; | |
456 | ||
d9689752 L |
457 | /* TRUE if we should check relocations after all input files have |
458 | been opened. */ | |
459 | unsigned int check_relocs_after_open_input: 1; | |
460 | ||
d258b828 IZ |
461 | /* TRUE if BND prefix in PLT entries is always generated. */ |
462 | unsigned int bndplt: 1; | |
463 | ||
9b8b325a RF |
464 | /* TRUE if generation of .interp/PT_INTERP should be suppressed. */ |
465 | unsigned int nointerp: 1; | |
466 | ||
4c10bbaa L |
467 | /* TRUE if we shouldn't check relocation overflow. */ |
468 | unsigned int no_reloc_overflow_check: 1; | |
469 | ||
caa65211 L |
470 | /* TRUE if generate a 1-byte NOP as suffix for x86 call instruction. */ |
471 | unsigned int call_nop_as_suffix : 1; | |
472 | ||
473 | /* The 1-byte NOP for x86 call instruction. */ | |
474 | char call_nop_byte; | |
475 | ||
b9cf773d AM |
476 | /* Char that may appear as the first char of a symbol, but should be |
477 | skipped (like symbol_leading_char) when looking up symbols in | |
478 | wrap_hash. Used by PowerPC Linux for 'dot' symbols. */ | |
479 | char wrap_char; | |
480 | ||
97407faf AM |
481 | /* Separator between archive and filename in linker script filespecs. */ |
482 | char path_separator; | |
483 | ||
0ce398f1 L |
484 | /* Compress DWARF debug sections. */ |
485 | enum compressed_debug_section_type compress_debug; | |
486 | ||
04c3a755 NS |
487 | /* Default stack size. Zero means default (often zero itself), -1 |
488 | means explicitly zero-sized. */ | |
489 | bfd_signed_vma stacksize; | |
490 | ||
4f9d22a0 L |
491 | /* Enable or disable target specific optimizations. |
492 | ||
493 | Not all targets have optimizations to enable. | |
494 | ||
495 | Normally these optimizations are disabled by default but some targets | |
496 | prefer to enable them by default. So this field is a tri-state variable. | |
497 | The values are: | |
498 | ||
499 | zero: Enable the optimizations (either from --relax being specified on | |
500 | the command line or the backend's before_allocation emulation function. | |
501 | ||
502 | positive: The user has requested that these optimizations be disabled. | |
503 | (Via the --no-relax command line option). | |
504 | ||
505 | negative: The optimizations are disabled. (Set when initializing the | |
506 | args_type structure in ldmain.c:main. */ | |
507 | signed int disable_target_specific_optimizations; | |
508 | ||
cddd0089 AM |
509 | /* Function callbacks. */ |
510 | const struct bfd_link_callbacks *callbacks; | |
7815cf4f | 511 | |
252b5132 RH |
512 | /* Hash table handled by BFD. */ |
513 | struct bfd_link_hash_table *hash; | |
7815cf4f | 514 | |
252b5132 RH |
515 | /* Hash table of symbols to keep. This is NULL unless strip is |
516 | strip_some. */ | |
517 | struct bfd_hash_table *keep_hash; | |
7815cf4f | 518 | |
252b5132 | 519 | /* Hash table of symbols to report back via the notice callback. If |
b34976b6 | 520 | this is NULL, and notice_all is FALSE, then no symbols are |
252b5132 RH |
521 | reported back. */ |
522 | struct bfd_hash_table *notice_hash; | |
7815cf4f | 523 | |
252b5132 RH |
524 | /* Hash table of symbols which are being wrapped (the --wrap linker |
525 | option). If this is NULL, no symbols are being wrapped. */ | |
526 | struct bfd_hash_table *wrap_hash; | |
7815cf4f | 527 | |
0e86e20e AM |
528 | /* Hash table of symbols which may be left unresolved during |
529 | a link. If this is NULL, no symbols can be left unresolved. */ | |
530 | struct bfd_hash_table *ignore_hash; | |
531 | ||
f13a99db AM |
532 | /* The output BFD. */ |
533 | bfd *output_bfd; | |
534 | ||
cddd0089 | 535 | /* The list of input BFD's involved in the link. These are chained |
c72f2fb2 | 536 | together via the link.next field. */ |
cddd0089 | 537 | bfd *input_bfds; |
a9a4c53e | 538 | bfd **input_bfds_tail; |
cddd0089 AM |
539 | |
540 | /* If a symbol should be created for each input BFD, this is section | |
541 | where those symbols should be placed. It must be a section in | |
542 | the output BFD. It may be NULL, in which case no such symbols | |
543 | will be created. This is to support CREATE_OBJECT_SYMBOLS in the | |
544 | linker command language. */ | |
545 | asection *create_object_symbols_section; | |
546 | ||
547 | /* List of global symbol names that are starting points for marking | |
548 | sections against garbage collection. */ | |
549 | struct bfd_sym_chain *gc_sym_list; | |
550 | ||
252b5132 | 551 | /* If a base output file is wanted, then this points to it */ |
8cf3f354 | 552 | void *base_file; |
252b5132 | 553 | |
94883c63 MM |
554 | /* The function to call when the executable or shared object is |
555 | loaded. */ | |
556 | const char *init_function; | |
7815cf4f | 557 | |
94883c63 MM |
558 | /* The function to call when the executable or shared object is |
559 | unloaded. */ | |
560 | const char *fini_function; | |
9bfcb6d6 | 561 | |
fbbc3759 L |
562 | /* Number of relaxation passes. Usually only one relaxation pass |
563 | is needed. But a backend can have as many relaxation passes as | |
564 | necessary. During bfd_relax_section call, it is set to the | |
565 | current pass, starting from 0. */ | |
566 | int relax_pass; | |
567 | ||
4a828aab RH |
568 | /* Number of relaxation trips. This number is incremented every |
569 | time the relaxation pass is restarted due to a previous | |
570 | relaxation returning true in *AGAIN. */ | |
571 | int relax_trip; | |
572 | ||
889c2a67 L |
573 | /* > 0 to treat protected data defined in the shared library as |
574 | reference external. 0 to treat it as internal. -1 to let | |
575 | backend to decide. */ | |
576 | int extern_protected_data; | |
577 | ||
aec6b87e L |
578 | /* > 0 to treat undefined weak symbol in the executable as dynamic, |
579 | requiring dynamic relocation. */ | |
580 | int dynamic_undefined_weak; | |
581 | ||
b34976b6 | 582 | /* Non-zero if auto-import thunks for DATA items in pei386 DLLs |
e0076ab3 NC |
583 | should be generated/linked against. Set to 1 if this feature |
584 | is explicitly requested by the user, -1 if enabled by default. */ | |
585 | int pei386_auto_import; | |
db6751f2 | 586 | |
2fa9fc65 NC |
587 | /* Non-zero if runtime relocs for DATA items with non-zero addends |
588 | in pei386 DLLs should be generated. Set to 1 if this feature | |
589 | is explicitly requested by the user, -1 if enabled by default. */ | |
590 | int pei386_runtime_pseudo_reloc; | |
591 | ||
db6751f2 | 592 | /* How many spare .dynamic DT_NULL entries should be added? */ |
b7781dbe | 593 | unsigned int spare_dynamic_tags; |
f7c33884 | 594 | |
cddd0089 AM |
595 | /* May be used to set DT_FLAGS for ELF. */ |
596 | bfd_vma flags; | |
597 | ||
598 | /* May be used to set DT_FLAGS_1 for ELF. */ | |
599 | bfd_vma flags_1; | |
8c37241b JJ |
600 | |
601 | /* Start and end of RELRO region. */ | |
602 | bfd_vma relro_start, relro_end; | |
55255dae L |
603 | |
604 | /* List of symbols should be dynamic. */ | |
40b36307 | 605 | struct bfd_elf_dynamic_list *dynamic_list; |
fd91d419 L |
606 | |
607 | /* The version information. */ | |
608 | struct bfd_elf_version_tree *version_info; | |
252b5132 RH |
609 | }; |
610 | ||
49fa1e15 AM |
611 | /* This structures holds a set of callback functions. These are called |
612 | by the BFD linker routines. Except for the info functions, the first | |
e1fffbe6 AM |
613 | argument to each callback function is the bfd_link_info structure |
614 | being used and each function returns a boolean value. If the | |
615 | function returns FALSE, then the BFD function which called it should | |
616 | return with a failure indication. */ | |
252b5132 RH |
617 | |
618 | struct bfd_link_callbacks | |
619 | { | |
620 | /* A function which is called when an object is added from an | |
621 | archive. ABFD is the archive element being added. NAME is the | |
622 | name of the symbol which caused the archive element to be pulled | |
5d3236ee DK |
623 | in. This function may set *SUBSBFD to point to an alternative |
624 | BFD from which symbols should in fact be added in place of the | |
625 | original BFD's symbols. */ | |
b34976b6 | 626 | bfd_boolean (*add_archive_element) |
5d3236ee | 627 | (struct bfd_link_info *, bfd *abfd, const char *name, bfd **subsbfd); |
252b5132 | 628 | /* A function which is called when a symbol is found with multiple |
24f58f47 AM |
629 | definitions. H is the symbol which is defined multiple times. |
630 | NBFD is the new BFD, NSEC is the new section, and NVAL is the new | |
631 | value. NSEC may be bfd_com_section or bfd_ind_section. */ | |
b34976b6 | 632 | bfd_boolean (*multiple_definition) |
24f58f47 | 633 | (struct bfd_link_info *, struct bfd_link_hash_entry *h, |
8cf3f354 | 634 | bfd *nbfd, asection *nsec, bfd_vma nval); |
252b5132 | 635 | /* A function which is called when a common symbol is defined |
24f58f47 | 636 | multiple times. H is the symbol appearing multiple times. |
252b5132 RH |
637 | NBFD is the BFD of the new symbol. NTYPE is the type of the new |
638 | symbol, one of bfd_link_hash_defined, bfd_link_hash_common, or | |
639 | bfd_link_hash_indirect. If NTYPE is bfd_link_hash_common, NSIZE | |
640 | is the size of the new symbol. */ | |
b34976b6 | 641 | bfd_boolean (*multiple_common) |
24f58f47 | 642 | (struct bfd_link_info *, struct bfd_link_hash_entry *h, |
8cf3f354 | 643 | bfd *nbfd, enum bfd_link_hash_type ntype, bfd_vma nsize); |
252b5132 RH |
644 | /* A function which is called to add a symbol to a set. ENTRY is |
645 | the link hash table entry for the set itself (e.g., | |
646 | __CTOR_LIST__). RELOC is the relocation to use for an entry in | |
1049f94e | 647 | the set when generating a relocatable file, and is also used to |
252b5132 RH |
648 | get the size of the entry when generating an executable file. |
649 | ABFD, SEC and VALUE identify the value to add to the set. */ | |
b34976b6 | 650 | bfd_boolean (*add_to_set) |
8cf3f354 AM |
651 | (struct bfd_link_info *, struct bfd_link_hash_entry *entry, |
652 | bfd_reloc_code_real_type reloc, bfd *abfd, asection *sec, bfd_vma value); | |
252b5132 RH |
653 | /* A function which is called when the name of a g++ constructor or |
654 | destructor is found. This is only called by some object file | |
b34976b6 | 655 | formats. CONSTRUCTOR is TRUE for a constructor, FALSE for a |
252b5132 | 656 | destructor. This will use BFD_RELOC_CTOR when generating a |
1049f94e | 657 | relocatable file. NAME is the name of the symbol found. ABFD, |
252b5132 | 658 | SECTION and VALUE are the value of the symbol. */ |
b34976b6 | 659 | bfd_boolean (*constructor) |
8cf3f354 AM |
660 | (struct bfd_link_info *, bfd_boolean constructor, const char *name, |
661 | bfd *abfd, asection *sec, bfd_vma value); | |
252b5132 RH |
662 | /* A function which is called to issue a linker warning. For |
663 | example, this is called when there is a reference to a warning | |
664 | symbol. WARNING is the warning to be issued. SYMBOL is the name | |
665 | of the symbol which triggered the warning; it may be NULL if | |
666 | there is none. ABFD, SECTION and ADDRESS identify the location | |
667 | which trigerred the warning; either ABFD or SECTION or both may | |
668 | be NULL if the location is not known. */ | |
b34976b6 | 669 | bfd_boolean (*warning) |
8cf3f354 AM |
670 | (struct bfd_link_info *, const char *warning, const char *symbol, |
671 | bfd *abfd, asection *section, bfd_vma address); | |
252b5132 RH |
672 | /* A function which is called when a relocation is attempted against |
673 | an undefined symbol. NAME is the symbol which is undefined. | |
674 | ABFD, SECTION and ADDRESS identify the location from which the | |
e7f8eadb | 675 | reference is made. IS_FATAL indicates whether an undefined symbol is |
c086cbc6 | 676 | a fatal error or not. In some cases SECTION may be NULL. */ |
b34976b6 | 677 | bfd_boolean (*undefined_symbol) |
8cf3f354 | 678 | (struct bfd_link_info *, const char *name, bfd *abfd, |
e7f8eadb | 679 | asection *section, bfd_vma address, bfd_boolean is_fatal); |
dfeffb9f L |
680 | /* A function which is called when a reloc overflow occurs. ENTRY is |
681 | the link hash table entry for the symbol the reloc is against. | |
682 | NAME is the name of the local symbol or section the reloc is | |
683 | against, RELOC_NAME is the name of the relocation, and ADDEND is | |
684 | any addend that is used. ABFD, SECTION and ADDRESS identify the | |
252b5132 RH |
685 | location at which the overflow occurs; if this is the result of a |
686 | bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then | |
687 | ABFD will be NULL. */ | |
b34976b6 | 688 | bfd_boolean (*reloc_overflow) |
dfeffb9f L |
689 | (struct bfd_link_info *, struct bfd_link_hash_entry *entry, |
690 | const char *name, const char *reloc_name, bfd_vma addend, | |
691 | bfd *abfd, asection *section, bfd_vma address); | |
252b5132 | 692 | /* A function which is called when a dangerous reloc is performed. |
c17ae8a2 | 693 | MESSAGE is an appropriate message. |
252b5132 RH |
694 | ABFD, SECTION and ADDRESS identify the location at which the |
695 | problem occurred; if this is the result of a | |
696 | bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then | |
697 | ABFD will be NULL. */ | |
b34976b6 | 698 | bfd_boolean (*reloc_dangerous) |
8cf3f354 AM |
699 | (struct bfd_link_info *, const char *message, |
700 | bfd *abfd, asection *section, bfd_vma address); | |
252b5132 RH |
701 | /* A function which is called when a reloc is found to be attached |
702 | to a symbol which is not being written out. NAME is the name of | |
703 | the symbol. ABFD, SECTION and ADDRESS identify the location of | |
704 | the reloc; if this is the result of a | |
705 | bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then | |
706 | ABFD will be NULL. */ | |
b34976b6 | 707 | bfd_boolean (*unattached_reloc) |
8cf3f354 AM |
708 | (struct bfd_link_info *, const char *name, |
709 | bfd *abfd, asection *section, bfd_vma address); | |
252b5132 | 710 | /* A function which is called when a symbol in notice_hash is |
46135103 AM |
711 | defined or referenced. H is the symbol, INH the indirect symbol |
712 | if applicable. ABFD, SECTION and ADDRESS are the (new) value of | |
713 | the symbol. If SECTION is bfd_und_section, this is a reference. | |
714 | FLAGS are the symbol BSF_* flags. */ | |
b34976b6 | 715 | bfd_boolean (*notice) |
35ed3f94 | 716 | (struct bfd_link_info *, struct bfd_link_hash_entry *h, |
46135103 AM |
717 | struct bfd_link_hash_entry *inh, |
718 | bfd *abfd, asection *section, bfd_vma address, flagword flags); | |
49fa1e15 | 719 | /* Error or warning link info message. */ |
e1fffbe6 AM |
720 | void (*einfo) |
721 | (const char *fmt, ...); | |
49fa1e15 AM |
722 | /* General link info message. */ |
723 | void (*info) | |
724 | (const char *fmt, ...); | |
725 | /* Message to be printed in linker map file. */ | |
726 | void (*minfo) | |
727 | (const char *fmt, ...); | |
2889e75b NC |
728 | /* This callback provides a chance for users of the BFD library to |
729 | override its decision about whether to place two adjacent sections | |
730 | into the same segment. */ | |
731 | bfd_boolean (*override_segment_assignment) | |
732 | (struct bfd_link_info *, bfd * abfd, | |
733 | asection * current_section, asection * previous_section, | |
734 | bfd_boolean new_segment); | |
252b5132 RH |
735 | }; |
736 | \f | |
737 | /* The linker builds link_order structures which tell the code how to | |
738 | include input data in the output file. */ | |
739 | ||
740 | /* These are the types of link_order structures. */ | |
741 | ||
742 | enum bfd_link_order_type | |
743 | { | |
744 | bfd_undefined_link_order, /* Undefined. */ | |
745 | bfd_indirect_link_order, /* Built from a section. */ | |
252b5132 RH |
746 | bfd_data_link_order, /* Set to explicit data. */ |
747 | bfd_section_reloc_link_order, /* Relocate against a section. */ | |
748 | bfd_symbol_reloc_link_order /* Relocate against a symbol. */ | |
749 | }; | |
750 | ||
751 | /* This is the link_order structure itself. These form a chain | |
6ed89c00 | 752 | attached to the output section whose contents they are describing. */ |
252b5132 | 753 | |
b34976b6 | 754 | struct bfd_link_order |
252b5132 RH |
755 | { |
756 | /* Next link_order in chain. */ | |
757 | struct bfd_link_order *next; | |
758 | /* Type of link_order. */ | |
759 | enum bfd_link_order_type type; | |
760 | /* Offset within output section. */ | |
b34976b6 | 761 | bfd_vma offset; |
252b5132 RH |
762 | /* Size within output section. */ |
763 | bfd_size_type size; | |
764 | /* Type specific information. */ | |
b34976b6 | 765 | union |
252b5132 | 766 | { |
b34976b6 | 767 | struct |
252b5132 RH |
768 | { |
769 | /* Section to include. If this is used, then | |
770 | section->output_section must be the section the | |
771 | link_order is attached to, section->output_offset must | |
eea6121a | 772 | equal the link_order offset field, and section->size |
252b5132 RH |
773 | must equal the link_order size field. Maybe these |
774 | restrictions should be relaxed someday. */ | |
775 | asection *section; | |
776 | } indirect; | |
777 | struct | |
778 | { | |
d324f6d6 | 779 | /* Size of contents, or zero when contents should be filled by |
b7761f11 | 780 | the architecture-dependent fill function. |
9a1b9f82 AM |
781 | A non-zero value allows filling of the output section |
782 | with an arbitrary repeated pattern. */ | |
783 | unsigned int size; | |
784 | /* Data to put into file. */ | |
252b5132 RH |
785 | bfd_byte *contents; |
786 | } data; | |
787 | struct | |
788 | { | |
789 | /* Description of reloc to generate. Used for | |
790 | bfd_section_reloc_link_order and | |
791 | bfd_symbol_reloc_link_order. */ | |
792 | struct bfd_link_order_reloc *p; | |
793 | } reloc; | |
794 | } u; | |
795 | }; | |
796 | ||
797 | /* A linker order of type bfd_section_reloc_link_order or | |
798 | bfd_symbol_reloc_link_order means to create a reloc against a | |
799 | section or symbol, respectively. This is used to implement -Ur to | |
800 | generate relocs for the constructor tables. The | |
801 | bfd_link_order_reloc structure describes the reloc that BFD should | |
802 | create. It is similar to a arelent, but I didn't use arelent | |
803 | because the linker does not know anything about most symbols, and | |
804 | any asymbol structure it creates will be partially meaningless. | |
805 | This information could logically be in the bfd_link_order struct, | |
806 | but I didn't want to waste the space since these types of relocs | |
807 | are relatively rare. */ | |
808 | ||
809 | struct bfd_link_order_reloc | |
810 | { | |
811 | /* Reloc type. */ | |
812 | bfd_reloc_code_real_type reloc; | |
813 | ||
814 | union | |
815 | { | |
816 | /* For type bfd_section_reloc_link_order, this is the section | |
817 | the reloc should be against. This must be a section in the | |
818 | output BFD, not any of the input BFDs. */ | |
819 | asection *section; | |
820 | /* For type bfd_symbol_reloc_link_order, this is the name of the | |
821 | symbol the reloc should be against. */ | |
822 | const char *name; | |
823 | } u; | |
824 | ||
825 | /* Addend to use. The object file should contain zero. The BFD | |
826 | backend is responsible for filling in the contents of the object | |
827 | file correctly. For some object file formats (e.g., COFF) the | |
828 | addend must be stored into in the object file, and for some | |
829 | (e.g., SPARC a.out) it is kept in the reloc. */ | |
830 | bfd_vma addend; | |
831 | }; | |
832 | ||
833 | /* Allocate a new link_order for a section. */ | |
8cf3f354 | 834 | extern struct bfd_link_order *bfd_new_link_order (bfd *, asection *); |
252b5132 RH |
835 | |
836 | /* These structures are used to describe version information for the | |
837 | ELF linker. These structures could be manipulated entirely inside | |
838 | BFD, but it would be a pain. Instead, the regular linker sets up | |
839 | these structures, and then passes them into BFD. */ | |
840 | ||
108ba305 | 841 | /* Glob pattern for a version. */ |
252b5132 RH |
842 | |
843 | struct bfd_elf_version_expr | |
844 | { | |
108ba305 | 845 | /* Next glob pattern for this version. */ |
252b5132 | 846 | struct bfd_elf_version_expr *next; |
108ba305 | 847 | /* Glob pattern. */ |
252b5132 | 848 | const char *pattern; |
ae5a3597 AM |
849 | /* Set if pattern is not a glob. */ |
850 | unsigned int literal : 1; | |
31941635 | 851 | /* Defined by ".symver". */ |
108ba305 | 852 | unsigned int symver : 1; |
31941635 L |
853 | /* Defined by version script. */ |
854 | unsigned int script : 1; | |
108ba305 JJ |
855 | /* Pattern type. */ |
856 | #define BFD_ELF_VERSION_C_TYPE 1 | |
857 | #define BFD_ELF_VERSION_CXX_TYPE 2 | |
858 | #define BFD_ELF_VERSION_JAVA_TYPE 4 | |
859 | unsigned int mask : 3; | |
860 | }; | |
861 | ||
862 | struct bfd_elf_version_expr_head | |
863 | { | |
864 | /* List of all patterns, both wildcards and non-wildcards. */ | |
865 | struct bfd_elf_version_expr *list; | |
866 | /* Hash table for non-wildcards. */ | |
867 | void *htab; | |
868 | /* Remaining patterns. */ | |
869 | struct bfd_elf_version_expr *remaining; | |
870 | /* What kind of pattern types are present in list (bitmask). */ | |
871 | unsigned int mask; | |
252b5132 RH |
872 | }; |
873 | ||
874 | /* Version dependencies. */ | |
875 | ||
876 | struct bfd_elf_version_deps | |
877 | { | |
878 | /* Next dependency for this version. */ | |
879 | struct bfd_elf_version_deps *next; | |
880 | /* The version which this version depends upon. */ | |
881 | struct bfd_elf_version_tree *version_needed; | |
882 | }; | |
883 | ||
884 | /* A node in the version tree. */ | |
885 | ||
886 | struct bfd_elf_version_tree | |
887 | { | |
888 | /* Next version. */ | |
889 | struct bfd_elf_version_tree *next; | |
890 | /* Name of this version. */ | |
891 | const char *name; | |
892 | /* Version number. */ | |
893 | unsigned int vernum; | |
894 | /* Regular expressions for global symbols in this version. */ | |
108ba305 | 895 | struct bfd_elf_version_expr_head globals; |
252b5132 | 896 | /* Regular expressions for local symbols in this version. */ |
108ba305 | 897 | struct bfd_elf_version_expr_head locals; |
252b5132 RH |
898 | /* List of versions which this version depends upon. */ |
899 | struct bfd_elf_version_deps *deps; | |
900 | /* Index of the version name. This is used within BFD. */ | |
901 | unsigned int name_indx; | |
902 | /* Whether this version tree was used. This is used within BFD. */ | |
903 | int used; | |
108ba305 JJ |
904 | /* Matching hook. */ |
905 | struct bfd_elf_version_expr *(*match) | |
906 | (struct bfd_elf_version_expr_head *head, | |
907 | struct bfd_elf_version_expr *prev, const char *sym); | |
252b5132 RH |
908 | }; |
909 | ||
55255dae L |
910 | struct bfd_elf_dynamic_list |
911 | { | |
912 | struct bfd_elf_version_expr_head head; | |
913 | struct bfd_elf_version_expr *(*match) | |
914 | (struct bfd_elf_version_expr_head *head, | |
915 | struct bfd_elf_version_expr *prev, const char *sym); | |
916 | }; | |
917 | ||
252b5132 | 918 | #endif |