Commit | Line | Data |
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252b5132 | 1 | /* bfdlink.h -- header file for BFD link routines |
4b95cf5c | 2 | Copyright (C) 1993-2014 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 NC |
44 | |
45 | /* Describes the type of hash table entry structure being used. | |
46 | Different hash table structure have different fields and so | |
47 | support different linking features. */ | |
48 | enum bfd_link_hash_table_type | |
49 | { | |
50 | bfd_link_generic_hash_table, | |
51 | bfd_link_elf_hash_table | |
52 | }; | |
252b5132 RH |
53 | \f |
54 | /* These are the possible types of an entry in the BFD link hash | |
55 | table. */ | |
56 | ||
57 | enum bfd_link_hash_type | |
58 | { | |
59 | bfd_link_hash_new, /* Symbol is new. */ | |
60 | bfd_link_hash_undefined, /* Symbol seen before, but undefined. */ | |
61 | bfd_link_hash_undefweak, /* Symbol is weak and undefined. */ | |
62 | bfd_link_hash_defined, /* Symbol is defined. */ | |
63 | bfd_link_hash_defweak, /* Symbol is weak and defined. */ | |
64 | bfd_link_hash_common, /* Symbol is common. */ | |
65 | bfd_link_hash_indirect, /* Symbol is an indirect link. */ | |
66 | bfd_link_hash_warning /* Like indirect, but warn if referenced. */ | |
67 | }; | |
68 | ||
f88dc410 | 69 | enum bfd_link_common_skip_ar_symbols |
f7c33884 NC |
70 | { |
71 | bfd_link_common_skip_none, | |
72 | bfd_link_common_skip_text, | |
73 | bfd_link_common_skip_data, | |
74 | bfd_link_common_skip_all | |
75 | }; | |
76 | ||
a50b1753 NC |
77 | struct bfd_link_hash_common_entry |
78 | { | |
79 | unsigned int alignment_power; /* Alignment. */ | |
80 | asection *section; /* Symbol section. */ | |
81 | }; | |
82 | ||
252b5132 RH |
83 | /* The linking routines use a hash table which uses this structure for |
84 | its elements. */ | |
85 | ||
86 | struct bfd_link_hash_entry | |
87 | { | |
88 | /* Base hash table entry structure. */ | |
89 | struct bfd_hash_entry root; | |
6ad841a1 | 90 | |
252b5132 | 91 | /* Type of this entry. */ |
35ed3f94 AM |
92 | ENUM_BITFIELD (bfd_link_hash_type) type : 8; |
93 | ||
94 | unsigned int non_ir_ref : 1; | |
252b5132 | 95 | |
252b5132 RH |
96 | /* A union of information depending upon the type. */ |
97 | union | |
98 | { | |
99 | /* Nothing is kept for bfd_hash_new. */ | |
100 | /* bfd_link_hash_undefined, bfd_link_hash_undefweak. */ | |
101 | struct | |
102 | { | |
f6e332e6 AM |
103 | /* Undefined and common symbols are kept in a linked list through |
104 | this field. This field is present in all of the union element | |
105 | so that we don't need to remove entries from the list when we | |
106 | change their type. Removing entries would either require the | |
107 | list to be doubly linked, which would waste more memory, or | |
108 | require a traversal. When an undefined or common symbol is | |
109 | created, it should be added to this list, the head of which is in | |
110 | the link hash table itself. As symbols are defined, they need | |
111 | not be removed from the list; anything which reads the list must | |
112 | doublecheck the symbol type. | |
113 | ||
114 | Weak symbols are not kept on this list. | |
115 | ||
116 | Defined and defweak symbols use this field as a reference marker. | |
117 | If the field is not NULL, or this structure is the tail of the | |
118 | undefined symbol list, the symbol has been referenced. If the | |
119 | symbol is undefined and becomes defined, this field will | |
120 | automatically be non-NULL since the symbol will have been on the | |
121 | undefined symbol list. */ | |
122 | struct bfd_link_hash_entry *next; | |
252b5132 RH |
123 | bfd *abfd; /* BFD symbol was found in. */ |
124 | } undef; | |
125 | /* bfd_link_hash_defined, bfd_link_hash_defweak. */ | |
126 | struct | |
127 | { | |
f6e332e6 | 128 | struct bfd_link_hash_entry *next; |
252b5132 | 129 | asection *section; /* Symbol section. */ |
f6e332e6 | 130 | bfd_vma value; /* Symbol value. */ |
252b5132 RH |
131 | } def; |
132 | /* bfd_link_hash_indirect, bfd_link_hash_warning. */ | |
133 | struct | |
134 | { | |
f6e332e6 | 135 | struct bfd_link_hash_entry *next; |
252b5132 RH |
136 | struct bfd_link_hash_entry *link; /* Real symbol. */ |
137 | const char *warning; /* Warning (bfd_link_hash_warning only). */ | |
138 | } i; | |
139 | /* bfd_link_hash_common. */ | |
140 | struct | |
141 | { | |
f6e332e6 | 142 | struct bfd_link_hash_entry *next; |
252b5132 | 143 | /* The linker needs to know three things about common |
b34976b6 AM |
144 | symbols: the size, the alignment, and the section in |
145 | which the symbol should be placed. We store the size | |
146 | here, and we allocate a small structure to hold the | |
147 | section and the alignment. The alignment is stored as a | |
148 | power of two. We don't store all the information | |
149 | directly because we don't want to increase the size of | |
150 | the union; this structure is a major space user in the | |
151 | linker. */ | |
a50b1753 | 152 | struct bfd_link_hash_common_entry *p; |
f6e332e6 | 153 | bfd_size_type size; /* Common symbol size. */ |
252b5132 RH |
154 | } c; |
155 | } u; | |
156 | }; | |
157 | ||
158 | /* This is the link hash table. It is a derived class of | |
159 | bfd_hash_table. */ | |
160 | ||
161 | struct bfd_link_hash_table | |
162 | { | |
163 | /* The hash table itself. */ | |
164 | struct bfd_hash_table table; | |
252b5132 RH |
165 | /* A linked list of undefined and common symbols, linked through the |
166 | next field in the bfd_link_hash_entry structure. */ | |
167 | struct bfd_link_hash_entry *undefs; | |
168 | /* Entries are added to the tail of the undefs list. */ | |
169 | struct bfd_link_hash_entry *undefs_tail; | |
d495ab0d AM |
170 | /* Function to free the hash table on closing BFD. */ |
171 | void (*hash_table_free) (bfd *); | |
b9b171fb | 172 | /* The type of the link hash table. */ |
8ea2e4bd | 173 | enum bfd_link_hash_table_type type; |
252b5132 RH |
174 | }; |
175 | ||
b34976b6 | 176 | /* Look up an entry in a link hash table. If FOLLOW is TRUE, this |
252b5132 RH |
177 | follows bfd_link_hash_indirect and bfd_link_hash_warning links to |
178 | the real symbol. */ | |
179 | extern struct bfd_link_hash_entry *bfd_link_hash_lookup | |
8cf3f354 AM |
180 | (struct bfd_link_hash_table *, const char *, bfd_boolean create, |
181 | bfd_boolean copy, bfd_boolean follow); | |
252b5132 RH |
182 | |
183 | /* Look up an entry in the main linker hash table if the symbol might | |
184 | be wrapped. This should only be used for references to an | |
185 | undefined symbol, not for definitions of a symbol. */ | |
186 | ||
187 | extern struct bfd_link_hash_entry *bfd_wrapped_link_hash_lookup | |
8cf3f354 AM |
188 | (bfd *, struct bfd_link_info *, const char *, bfd_boolean, |
189 | bfd_boolean, bfd_boolean); | |
252b5132 | 190 | |
8a5da09b AM |
191 | /* If H is a wrapped symbol, ie. the symbol name starts with "__wrap_" |
192 | and the remainder is found in wrap_hash, return the real symbol. */ | |
193 | ||
194 | extern struct bfd_link_hash_entry *unwrap_hash_lookup | |
195 | (struct bfd_link_info *, bfd *, struct bfd_link_hash_entry *); | |
196 | ||
252b5132 RH |
197 | /* Traverse a link hash table. */ |
198 | extern void bfd_link_hash_traverse | |
8cf3f354 AM |
199 | (struct bfd_link_hash_table *, |
200 | bfd_boolean (*) (struct bfd_link_hash_entry *, void *), | |
201 | void *); | |
252b5132 RH |
202 | |
203 | /* Add an entry to the undefs list. */ | |
204 | extern void bfd_link_add_undef | |
8cf3f354 | 205 | (struct bfd_link_hash_table *, struct bfd_link_hash_entry *); |
7815cf4f | 206 | |
77cfaee6 AM |
207 | /* Remove symbols from the undefs list that don't belong there. */ |
208 | extern void bfd_link_repair_undef_list | |
209 | (struct bfd_link_hash_table *table); | |
210 | ||
5c1d2f5f AM |
211 | /* Read symbols and cache symbol pointer array in outsymbols. */ |
212 | extern bfd_boolean bfd_generic_link_read_symbols (bfd *); | |
213 | ||
7815cf4f AM |
214 | struct bfd_sym_chain |
215 | { | |
216 | struct bfd_sym_chain *next; | |
217 | const char *name; | |
218 | }; | |
252b5132 | 219 | \f |
560e09e9 NC |
220 | /* How to handle unresolved symbols. |
221 | There are four possibilities which are enumerated below: */ | |
222 | enum report_method | |
223 | { | |
224 | /* This is the initial value when then link_info structure is created. | |
225 | It allows the various stages of the linker to determine whether they | |
226 | allowed to set the value. */ | |
227 | RM_NOT_YET_SET = 0, | |
228 | RM_IGNORE, | |
229 | RM_GENERATE_WARNING, | |
230 | RM_GENERATE_ERROR | |
231 | }; | |
232 | ||
ae17ab41 CM |
233 | typedef enum {with_flags, without_flags} flag_type; |
234 | ||
235 | /* A section flag list. */ | |
236 | struct flag_info_list | |
237 | { | |
d324f6d6 | 238 | flag_type with; |
ae17ab41 CM |
239 | const char *name; |
240 | bfd_boolean valid; | |
241 | struct flag_info_list *next; | |
242 | }; | |
243 | ||
244 | /* Section flag info. */ | |
245 | struct flag_info | |
246 | { | |
247 | flagword only_with_flags; | |
248 | flagword not_with_flags; | |
249 | struct flag_info_list *flag_list; | |
250 | bfd_boolean flags_initialized; | |
251 | }; | |
252 | ||
55255dae | 253 | struct bfd_elf_dynamic_list; |
fd91d419 | 254 | struct bfd_elf_version_tree; |
55255dae | 255 | |
252b5132 RH |
256 | /* This structure holds all the information needed to communicate |
257 | between BFD and the linker when doing a link. */ | |
258 | ||
259 | struct bfd_link_info | |
260 | { | |
05aecedb AM |
261 | /* TRUE if BFD should generate a shared object (or a pie). */ |
262 | unsigned int shared: 1; | |
7815cf4f | 263 | |
05aecedb AM |
264 | /* TRUE if generating an executable, position independent or not. */ |
265 | unsigned int executable : 1; | |
7815cf4f | 266 | |
05aecedb AM |
267 | /* TRUE if generating a position independent executable. */ |
268 | unsigned int pie: 1; | |
7815cf4f | 269 | |
05aecedb AM |
270 | /* TRUE if BFD should generate a relocatable object file. */ |
271 | unsigned int relocatable: 1; | |
7815cf4f | 272 | |
b34976b6 | 273 | /* TRUE if BFD should pre-bind symbols in a shared object. */ |
cddd0089 | 274 | unsigned int symbolic: 1; |
7815cf4f | 275 | |
05aecedb AM |
276 | /* TRUE if executable should not contain copy relocs. |
277 | Setting this true may result in a non-sharable text segment. */ | |
278 | unsigned int nocopyreloc: 1; | |
279 | ||
b34976b6 | 280 | /* TRUE if BFD should export all symbols in the dynamic symbol table |
7be4069c | 281 | of an executable, rather than only those used. */ |
cddd0089 | 282 | unsigned int export_dynamic: 1; |
7815cf4f | 283 | |
fc0e6df6 PB |
284 | /* TRUE if a default symbol version should be created and used for |
285 | exported symbols. */ | |
3e3b46e5 PB |
286 | unsigned int create_default_symver: 1; |
287 | ||
05aecedb AM |
288 | /* TRUE if unreferenced sections should be removed. */ |
289 | unsigned int gc_sections: 1; | |
cddd0089 AM |
290 | |
291 | /* TRUE if every symbol should be reported back via the notice | |
292 | callback. */ | |
293 | unsigned int notice_all: 1; | |
294 | ||
61f41c3c AM |
295 | /* TRUE if the LTO plugin is active. */ |
296 | unsigned int lto_plugin_active: 1; | |
297 | ||
05aecedb AM |
298 | /* TRUE if we are loading LTO outputs. */ |
299 | unsigned int loading_lto_outputs: 1; | |
cddd0089 | 300 | |
05aecedb AM |
301 | /* TRUE if global symbols in discarded sections should be stripped. */ |
302 | unsigned int strip_discarded: 1; | |
cddd0089 | 303 | |
05aecedb AM |
304 | /* TRUE if all data symbols should be dynamic. */ |
305 | unsigned int dynamic_data: 1; | |
cddd0089 | 306 | |
05aecedb AM |
307 | /* Which symbols to strip. */ |
308 | ENUM_BITFIELD (bfd_link_strip) strip : 2; | |
31941635 | 309 | |
05aecedb AM |
310 | /* Which local symbols to discard. */ |
311 | ENUM_BITFIELD (bfd_link_discard) discard : 2; | |
c6b64018 | 312 | |
05aecedb AM |
313 | /* Criteria for skipping symbols when determining |
314 | whether to include an object from an archive. */ | |
315 | ENUM_BITFIELD (bfd_link_common_skip_ar_symbols) common_skip_ar_symbols : 2; | |
36af4a4e | 316 | |
05aecedb AM |
317 | /* What to do with unresolved symbols in an object file. |
318 | When producing executables the default is GENERATE_ERROR. | |
319 | When producing shared libraries the default is IGNORE. The | |
320 | assumption with shared libraries is that the reference will be | |
321 | resolved at load/execution time. */ | |
322 | ENUM_BITFIELD (report_method) unresolved_syms_in_objects : 2; | |
36af4a4e | 323 | |
05aecedb AM |
324 | /* What to do with unresolved symbols in a shared library. |
325 | The same defaults apply. */ | |
326 | ENUM_BITFIELD (report_method) unresolved_syms_in_shared_libs : 2; | |
9ee5e499 | 327 | |
05aecedb AM |
328 | /* TRUE if shared objects should be linked directly, not shared. */ |
329 | unsigned int static_link: 1; | |
330 | ||
331 | /* TRUE if symbols should be retained in memory, FALSE if they | |
332 | should be freed and reread. */ | |
333 | unsigned int keep_memory: 1; | |
334 | ||
335 | /* TRUE if BFD should generate relocation information in the final | |
336 | executable. */ | |
337 | unsigned int emitrelocations: 1; | |
9ee5e499 | 338 | |
8c37241b JJ |
339 | /* TRUE if PT_GNU_RELRO segment should be created. */ |
340 | unsigned int relro: 1; | |
341 | ||
05aecedb AM |
342 | /* TRUE if .eh_frame_hdr section and PT_GNU_EH_FRAME ELF segment |
343 | should be created. */ | |
344 | unsigned int eh_frame_hdr: 1; | |
345 | ||
8fdd7217 NC |
346 | /* TRUE if we should warn when adding a DT_TEXTREL to a shared object. */ |
347 | unsigned int warn_shared_textrel: 1; | |
348 | ||
c192a133 AM |
349 | /* TRUE if we should error when adding a DT_TEXTREL. */ |
350 | unsigned int error_textrel: 1; | |
351 | ||
fdc90cb4 JJ |
352 | /* TRUE if .hash section should be created. */ |
353 | unsigned int emit_hash: 1; | |
354 | ||
355 | /* TRUE if .gnu.hash section should be created. */ | |
356 | unsigned int emit_gnu_hash: 1; | |
357 | ||
c0f00686 L |
358 | /* If TRUE reduce memory overheads, at the expense of speed. This will |
359 | cause map file generation to use an O(N^2) algorithm and disable | |
360 | caching ELF symbol buffer. */ | |
361 | unsigned int reduce_memory_overheads: 1; | |
362 | ||
05aecedb AM |
363 | /* TRUE if the output file should be in a traditional format. This |
364 | is equivalent to the setting of the BFD_TRADITIONAL_FORMAT flag | |
365 | on the output file, but may be checked when reading the input | |
366 | files. */ | |
367 | unsigned int traditional_format: 1; | |
40b36307 | 368 | |
05aecedb AM |
369 | /* TRUE if non-PLT relocs should be merged into one reloc section |
370 | and sorted so that relocs against the same symbol come together. */ | |
371 | unsigned int combreloc: 1; | |
372 | ||
373 | /* TRUE if a default symbol version should be created and used for | |
374 | imported symbols. */ | |
375 | unsigned int default_imported_symver: 1; | |
376 | ||
377 | /* TRUE if the new ELF dynamic tags are enabled. */ | |
378 | unsigned int new_dtags: 1; | |
40b36307 | 379 | |
e41b3a13 JJ |
380 | /* FALSE if .eh_frame unwind info should be generated for PLT and other |
381 | linker created sections, TRUE if it should be omitted. */ | |
382 | unsigned int no_ld_generated_unwind_info: 1; | |
383 | ||
05aecedb AM |
384 | /* TRUE if BFD should generate a "task linked" object file, |
385 | similar to relocatable but also with globals converted to | |
386 | statics. */ | |
387 | unsigned int task_link: 1; | |
0c511000 | 388 | |
05aecedb AM |
389 | /* TRUE if ok to have multiple definition. */ |
390 | unsigned int allow_multiple_definition: 1; | |
ab24bc21 | 391 | |
05aecedb AM |
392 | /* TRUE if ok to have version with no definition. */ |
393 | unsigned int allow_undefined_version: 1; | |
560e09e9 | 394 | |
05aecedb AM |
395 | /* TRUE if some symbols have to be dynamic, controlled by |
396 | --dynamic-list command line options. */ | |
397 | unsigned int dynamic: 1; | |
560e09e9 | 398 | |
05aecedb AM |
399 | /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W|PF_X |
400 | flags. */ | |
401 | unsigned int execstack: 1; | |
7815cf4f | 402 | |
05aecedb AM |
403 | /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W |
404 | flags. */ | |
405 | unsigned int noexecstack: 1; | |
7815cf4f | 406 | |
05aecedb AM |
407 | /* TRUE if we want to produced optimized output files. This might |
408 | need much more time and therefore must be explicitly selected. */ | |
409 | unsigned int optimize: 1; | |
410 | ||
411 | /* TRUE if user should be informed of removed unreferenced sections. */ | |
412 | unsigned int print_gc_sections: 1; | |
413 | ||
414 | /* TRUE if we should warn alternate ELF machine code. */ | |
415 | unsigned int warn_alternate_em: 1; | |
7815cf4f | 416 | |
d324f6d6 RM |
417 | /* TRUE if the linker script contained an explicit PHDRS command. */ |
418 | unsigned int user_phdrs: 1; | |
419 | ||
b9cf773d AM |
420 | /* Char that may appear as the first char of a symbol, but should be |
421 | skipped (like symbol_leading_char) when looking up symbols in | |
422 | wrap_hash. Used by PowerPC Linux for 'dot' symbols. */ | |
423 | char wrap_char; | |
424 | ||
97407faf AM |
425 | /* Separator between archive and filename in linker script filespecs. */ |
426 | char path_separator; | |
427 | ||
04c3a755 NS |
428 | /* Default stack size. Zero means default (often zero itself), -1 |
429 | means explicitly zero-sized. */ | |
430 | bfd_signed_vma stacksize; | |
431 | ||
4f9d22a0 L |
432 | /* Enable or disable target specific optimizations. |
433 | ||
434 | Not all targets have optimizations to enable. | |
435 | ||
436 | Normally these optimizations are disabled by default but some targets | |
437 | prefer to enable them by default. So this field is a tri-state variable. | |
438 | The values are: | |
439 | ||
440 | zero: Enable the optimizations (either from --relax being specified on | |
441 | the command line or the backend's before_allocation emulation function. | |
442 | ||
443 | positive: The user has requested that these optimizations be disabled. | |
444 | (Via the --no-relax command line option). | |
445 | ||
446 | negative: The optimizations are disabled. (Set when initializing the | |
447 | args_type structure in ldmain.c:main. */ | |
448 | signed int disable_target_specific_optimizations; | |
449 | ||
cddd0089 AM |
450 | /* Function callbacks. */ |
451 | const struct bfd_link_callbacks *callbacks; | |
7815cf4f | 452 | |
252b5132 RH |
453 | /* Hash table handled by BFD. */ |
454 | struct bfd_link_hash_table *hash; | |
7815cf4f | 455 | |
252b5132 RH |
456 | /* Hash table of symbols to keep. This is NULL unless strip is |
457 | strip_some. */ | |
458 | struct bfd_hash_table *keep_hash; | |
7815cf4f | 459 | |
252b5132 | 460 | /* Hash table of symbols to report back via the notice callback. If |
b34976b6 | 461 | this is NULL, and notice_all is FALSE, then no symbols are |
252b5132 RH |
462 | reported back. */ |
463 | struct bfd_hash_table *notice_hash; | |
7815cf4f | 464 | |
252b5132 RH |
465 | /* Hash table of symbols which are being wrapped (the --wrap linker |
466 | option). If this is NULL, no symbols are being wrapped. */ | |
467 | struct bfd_hash_table *wrap_hash; | |
7815cf4f | 468 | |
0e86e20e AM |
469 | /* Hash table of symbols which may be left unresolved during |
470 | a link. If this is NULL, no symbols can be left unresolved. */ | |
471 | struct bfd_hash_table *ignore_hash; | |
472 | ||
f13a99db AM |
473 | /* The output BFD. */ |
474 | bfd *output_bfd; | |
475 | ||
cddd0089 | 476 | /* The list of input BFD's involved in the link. These are chained |
c72f2fb2 | 477 | together via the link.next field. */ |
cddd0089 | 478 | bfd *input_bfds; |
a9a4c53e | 479 | bfd **input_bfds_tail; |
cddd0089 AM |
480 | |
481 | /* If a symbol should be created for each input BFD, this is section | |
482 | where those symbols should be placed. It must be a section in | |
483 | the output BFD. It may be NULL, in which case no such symbols | |
484 | will be created. This is to support CREATE_OBJECT_SYMBOLS in the | |
485 | linker command language. */ | |
486 | asection *create_object_symbols_section; | |
487 | ||
488 | /* List of global symbol names that are starting points for marking | |
489 | sections against garbage collection. */ | |
490 | struct bfd_sym_chain *gc_sym_list; | |
491 | ||
252b5132 | 492 | /* If a base output file is wanted, then this points to it */ |
8cf3f354 | 493 | void *base_file; |
252b5132 | 494 | |
94883c63 MM |
495 | /* The function to call when the executable or shared object is |
496 | loaded. */ | |
497 | const char *init_function; | |
7815cf4f | 498 | |
94883c63 MM |
499 | /* The function to call when the executable or shared object is |
500 | unloaded. */ | |
501 | const char *fini_function; | |
9bfcb6d6 | 502 | |
fbbc3759 L |
503 | /* Number of relaxation passes. Usually only one relaxation pass |
504 | is needed. But a backend can have as many relaxation passes as | |
505 | necessary. During bfd_relax_section call, it is set to the | |
506 | current pass, starting from 0. */ | |
507 | int relax_pass; | |
508 | ||
4a828aab RH |
509 | /* Number of relaxation trips. This number is incremented every |
510 | time the relaxation pass is restarted due to a previous | |
511 | relaxation returning true in *AGAIN. */ | |
512 | int relax_trip; | |
513 | ||
b34976b6 | 514 | /* Non-zero if auto-import thunks for DATA items in pei386 DLLs |
e0076ab3 NC |
515 | should be generated/linked against. Set to 1 if this feature |
516 | is explicitly requested by the user, -1 if enabled by default. */ | |
517 | int pei386_auto_import; | |
db6751f2 | 518 | |
2fa9fc65 NC |
519 | /* Non-zero if runtime relocs for DATA items with non-zero addends |
520 | in pei386 DLLs should be generated. Set to 1 if this feature | |
521 | is explicitly requested by the user, -1 if enabled by default. */ | |
522 | int pei386_runtime_pseudo_reloc; | |
523 | ||
db6751f2 | 524 | /* How many spare .dynamic DT_NULL entries should be added? */ |
b7781dbe | 525 | unsigned int spare_dynamic_tags; |
f7c33884 | 526 | |
cddd0089 AM |
527 | /* May be used to set DT_FLAGS for ELF. */ |
528 | bfd_vma flags; | |
529 | ||
530 | /* May be used to set DT_FLAGS_1 for ELF. */ | |
531 | bfd_vma flags_1; | |
8c37241b JJ |
532 | |
533 | /* Start and end of RELRO region. */ | |
534 | bfd_vma relro_start, relro_end; | |
55255dae L |
535 | |
536 | /* List of symbols should be dynamic. */ | |
40b36307 | 537 | struct bfd_elf_dynamic_list *dynamic_list; |
fd91d419 L |
538 | |
539 | /* The version information. */ | |
540 | struct bfd_elf_version_tree *version_info; | |
252b5132 RH |
541 | }; |
542 | ||
49fa1e15 AM |
543 | /* This structures holds a set of callback functions. These are called |
544 | by the BFD linker routines. Except for the info functions, the first | |
e1fffbe6 AM |
545 | argument to each callback function is the bfd_link_info structure |
546 | being used and each function returns a boolean value. If the | |
547 | function returns FALSE, then the BFD function which called it should | |
548 | return with a failure indication. */ | |
252b5132 RH |
549 | |
550 | struct bfd_link_callbacks | |
551 | { | |
552 | /* A function which is called when an object is added from an | |
553 | archive. ABFD is the archive element being added. NAME is the | |
554 | name of the symbol which caused the archive element to be pulled | |
5d3236ee DK |
555 | in. This function may set *SUBSBFD to point to an alternative |
556 | BFD from which symbols should in fact be added in place of the | |
557 | original BFD's symbols. */ | |
b34976b6 | 558 | bfd_boolean (*add_archive_element) |
5d3236ee | 559 | (struct bfd_link_info *, bfd *abfd, const char *name, bfd **subsbfd); |
252b5132 | 560 | /* A function which is called when a symbol is found with multiple |
24f58f47 AM |
561 | definitions. H is the symbol which is defined multiple times. |
562 | NBFD is the new BFD, NSEC is the new section, and NVAL is the new | |
563 | value. NSEC may be bfd_com_section or bfd_ind_section. */ | |
b34976b6 | 564 | bfd_boolean (*multiple_definition) |
24f58f47 | 565 | (struct bfd_link_info *, struct bfd_link_hash_entry *h, |
8cf3f354 | 566 | bfd *nbfd, asection *nsec, bfd_vma nval); |
252b5132 | 567 | /* A function which is called when a common symbol is defined |
24f58f47 | 568 | multiple times. H is the symbol appearing multiple times. |
252b5132 RH |
569 | NBFD is the BFD of the new symbol. NTYPE is the type of the new |
570 | symbol, one of bfd_link_hash_defined, bfd_link_hash_common, or | |
571 | bfd_link_hash_indirect. If NTYPE is bfd_link_hash_common, NSIZE | |
572 | is the size of the new symbol. */ | |
b34976b6 | 573 | bfd_boolean (*multiple_common) |
24f58f47 | 574 | (struct bfd_link_info *, struct bfd_link_hash_entry *h, |
8cf3f354 | 575 | bfd *nbfd, enum bfd_link_hash_type ntype, bfd_vma nsize); |
252b5132 RH |
576 | /* A function which is called to add a symbol to a set. ENTRY is |
577 | the link hash table entry for the set itself (e.g., | |
578 | __CTOR_LIST__). RELOC is the relocation to use for an entry in | |
1049f94e | 579 | the set when generating a relocatable file, and is also used to |
252b5132 RH |
580 | get the size of the entry when generating an executable file. |
581 | ABFD, SEC and VALUE identify the value to add to the set. */ | |
b34976b6 | 582 | bfd_boolean (*add_to_set) |
8cf3f354 AM |
583 | (struct bfd_link_info *, struct bfd_link_hash_entry *entry, |
584 | bfd_reloc_code_real_type reloc, bfd *abfd, asection *sec, bfd_vma value); | |
252b5132 RH |
585 | /* A function which is called when the name of a g++ constructor or |
586 | destructor is found. This is only called by some object file | |
b34976b6 | 587 | formats. CONSTRUCTOR is TRUE for a constructor, FALSE for a |
252b5132 | 588 | destructor. This will use BFD_RELOC_CTOR when generating a |
1049f94e | 589 | relocatable file. NAME is the name of the symbol found. ABFD, |
252b5132 | 590 | SECTION and VALUE are the value of the symbol. */ |
b34976b6 | 591 | bfd_boolean (*constructor) |
8cf3f354 AM |
592 | (struct bfd_link_info *, bfd_boolean constructor, const char *name, |
593 | bfd *abfd, asection *sec, bfd_vma value); | |
252b5132 RH |
594 | /* A function which is called to issue a linker warning. For |
595 | example, this is called when there is a reference to a warning | |
596 | symbol. WARNING is the warning to be issued. SYMBOL is the name | |
597 | of the symbol which triggered the warning; it may be NULL if | |
598 | there is none. ABFD, SECTION and ADDRESS identify the location | |
599 | which trigerred the warning; either ABFD or SECTION or both may | |
600 | be NULL if the location is not known. */ | |
b34976b6 | 601 | bfd_boolean (*warning) |
8cf3f354 AM |
602 | (struct bfd_link_info *, const char *warning, const char *symbol, |
603 | bfd *abfd, asection *section, bfd_vma address); | |
252b5132 RH |
604 | /* A function which is called when a relocation is attempted against |
605 | an undefined symbol. NAME is the symbol which is undefined. | |
606 | ABFD, SECTION and ADDRESS identify the location from which the | |
e7f8eadb | 607 | reference is made. IS_FATAL indicates whether an undefined symbol is |
c086cbc6 | 608 | a fatal error or not. In some cases SECTION may be NULL. */ |
b34976b6 | 609 | bfd_boolean (*undefined_symbol) |
8cf3f354 | 610 | (struct bfd_link_info *, const char *name, bfd *abfd, |
e7f8eadb | 611 | asection *section, bfd_vma address, bfd_boolean is_fatal); |
dfeffb9f L |
612 | /* A function which is called when a reloc overflow occurs. ENTRY is |
613 | the link hash table entry for the symbol the reloc is against. | |
614 | NAME is the name of the local symbol or section the reloc is | |
615 | against, RELOC_NAME is the name of the relocation, and ADDEND is | |
616 | any addend that is used. ABFD, SECTION and ADDRESS identify the | |
252b5132 RH |
617 | location at which the overflow occurs; if this is the result of a |
618 | bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then | |
619 | ABFD will be NULL. */ | |
b34976b6 | 620 | bfd_boolean (*reloc_overflow) |
dfeffb9f L |
621 | (struct bfd_link_info *, struct bfd_link_hash_entry *entry, |
622 | const char *name, const char *reloc_name, bfd_vma addend, | |
623 | bfd *abfd, asection *section, bfd_vma address); | |
252b5132 | 624 | /* A function which is called when a dangerous reloc is performed. |
c17ae8a2 | 625 | MESSAGE is an appropriate message. |
252b5132 RH |
626 | ABFD, SECTION and ADDRESS identify the location at which the |
627 | problem occurred; if this is the result of a | |
628 | bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then | |
629 | ABFD will be NULL. */ | |
b34976b6 | 630 | bfd_boolean (*reloc_dangerous) |
8cf3f354 AM |
631 | (struct bfd_link_info *, const char *message, |
632 | bfd *abfd, asection *section, bfd_vma address); | |
252b5132 RH |
633 | /* A function which is called when a reloc is found to be attached |
634 | to a symbol which is not being written out. NAME is the name of | |
635 | the symbol. ABFD, SECTION and ADDRESS identify the location of | |
636 | the reloc; if this is the result of a | |
637 | bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then | |
638 | ABFD will be NULL. */ | |
b34976b6 | 639 | bfd_boolean (*unattached_reloc) |
8cf3f354 AM |
640 | (struct bfd_link_info *, const char *name, |
641 | bfd *abfd, asection *section, bfd_vma address); | |
252b5132 | 642 | /* A function which is called when a symbol in notice_hash is |
46135103 AM |
643 | defined or referenced. H is the symbol, INH the indirect symbol |
644 | if applicable. ABFD, SECTION and ADDRESS are the (new) value of | |
645 | the symbol. If SECTION is bfd_und_section, this is a reference. | |
646 | FLAGS are the symbol BSF_* flags. */ | |
b34976b6 | 647 | bfd_boolean (*notice) |
35ed3f94 | 648 | (struct bfd_link_info *, struct bfd_link_hash_entry *h, |
46135103 AM |
649 | struct bfd_link_hash_entry *inh, |
650 | bfd *abfd, asection *section, bfd_vma address, flagword flags); | |
49fa1e15 | 651 | /* Error or warning link info message. */ |
e1fffbe6 AM |
652 | void (*einfo) |
653 | (const char *fmt, ...); | |
49fa1e15 AM |
654 | /* General link info message. */ |
655 | void (*info) | |
656 | (const char *fmt, ...); | |
657 | /* Message to be printed in linker map file. */ | |
658 | void (*minfo) | |
659 | (const char *fmt, ...); | |
2889e75b NC |
660 | /* This callback provides a chance for users of the BFD library to |
661 | override its decision about whether to place two adjacent sections | |
662 | into the same segment. */ | |
663 | bfd_boolean (*override_segment_assignment) | |
664 | (struct bfd_link_info *, bfd * abfd, | |
665 | asection * current_section, asection * previous_section, | |
666 | bfd_boolean new_segment); | |
252b5132 RH |
667 | }; |
668 | \f | |
669 | /* The linker builds link_order structures which tell the code how to | |
670 | include input data in the output file. */ | |
671 | ||
672 | /* These are the types of link_order structures. */ | |
673 | ||
674 | enum bfd_link_order_type | |
675 | { | |
676 | bfd_undefined_link_order, /* Undefined. */ | |
677 | bfd_indirect_link_order, /* Built from a section. */ | |
252b5132 RH |
678 | bfd_data_link_order, /* Set to explicit data. */ |
679 | bfd_section_reloc_link_order, /* Relocate against a section. */ | |
680 | bfd_symbol_reloc_link_order /* Relocate against a symbol. */ | |
681 | }; | |
682 | ||
683 | /* This is the link_order structure itself. These form a chain | |
6ed89c00 | 684 | attached to the output section whose contents they are describing. */ |
252b5132 | 685 | |
b34976b6 | 686 | struct bfd_link_order |
252b5132 RH |
687 | { |
688 | /* Next link_order in chain. */ | |
689 | struct bfd_link_order *next; | |
690 | /* Type of link_order. */ | |
691 | enum bfd_link_order_type type; | |
692 | /* Offset within output section. */ | |
b34976b6 | 693 | bfd_vma offset; |
252b5132 RH |
694 | /* Size within output section. */ |
695 | bfd_size_type size; | |
696 | /* Type specific information. */ | |
b34976b6 | 697 | union |
252b5132 | 698 | { |
b34976b6 | 699 | struct |
252b5132 RH |
700 | { |
701 | /* Section to include. If this is used, then | |
702 | section->output_section must be the section the | |
703 | link_order is attached to, section->output_offset must | |
eea6121a | 704 | equal the link_order offset field, and section->size |
252b5132 RH |
705 | must equal the link_order size field. Maybe these |
706 | restrictions should be relaxed someday. */ | |
707 | asection *section; | |
708 | } indirect; | |
709 | struct | |
710 | { | |
d324f6d6 | 711 | /* Size of contents, or zero when contents should be filled by |
b7761f11 | 712 | the architecture-dependent fill function. |
9a1b9f82 AM |
713 | A non-zero value allows filling of the output section |
714 | with an arbitrary repeated pattern. */ | |
715 | unsigned int size; | |
716 | /* Data to put into file. */ | |
252b5132 RH |
717 | bfd_byte *contents; |
718 | } data; | |
719 | struct | |
720 | { | |
721 | /* Description of reloc to generate. Used for | |
722 | bfd_section_reloc_link_order and | |
723 | bfd_symbol_reloc_link_order. */ | |
724 | struct bfd_link_order_reloc *p; | |
725 | } reloc; | |
726 | } u; | |
727 | }; | |
728 | ||
729 | /* A linker order of type bfd_section_reloc_link_order or | |
730 | bfd_symbol_reloc_link_order means to create a reloc against a | |
731 | section or symbol, respectively. This is used to implement -Ur to | |
732 | generate relocs for the constructor tables. The | |
733 | bfd_link_order_reloc structure describes the reloc that BFD should | |
734 | create. It is similar to a arelent, but I didn't use arelent | |
735 | because the linker does not know anything about most symbols, and | |
736 | any asymbol structure it creates will be partially meaningless. | |
737 | This information could logically be in the bfd_link_order struct, | |
738 | but I didn't want to waste the space since these types of relocs | |
739 | are relatively rare. */ | |
740 | ||
741 | struct bfd_link_order_reloc | |
742 | { | |
743 | /* Reloc type. */ | |
744 | bfd_reloc_code_real_type reloc; | |
745 | ||
746 | union | |
747 | { | |
748 | /* For type bfd_section_reloc_link_order, this is the section | |
749 | the reloc should be against. This must be a section in the | |
750 | output BFD, not any of the input BFDs. */ | |
751 | asection *section; | |
752 | /* For type bfd_symbol_reloc_link_order, this is the name of the | |
753 | symbol the reloc should be against. */ | |
754 | const char *name; | |
755 | } u; | |
756 | ||
757 | /* Addend to use. The object file should contain zero. The BFD | |
758 | backend is responsible for filling in the contents of the object | |
759 | file correctly. For some object file formats (e.g., COFF) the | |
760 | addend must be stored into in the object file, and for some | |
761 | (e.g., SPARC a.out) it is kept in the reloc. */ | |
762 | bfd_vma addend; | |
763 | }; | |
764 | ||
765 | /* Allocate a new link_order for a section. */ | |
8cf3f354 | 766 | extern struct bfd_link_order *bfd_new_link_order (bfd *, asection *); |
252b5132 RH |
767 | |
768 | /* These structures are used to describe version information for the | |
769 | ELF linker. These structures could be manipulated entirely inside | |
770 | BFD, but it would be a pain. Instead, the regular linker sets up | |
771 | these structures, and then passes them into BFD. */ | |
772 | ||
108ba305 | 773 | /* Glob pattern for a version. */ |
252b5132 RH |
774 | |
775 | struct bfd_elf_version_expr | |
776 | { | |
108ba305 | 777 | /* Next glob pattern for this version. */ |
252b5132 | 778 | struct bfd_elf_version_expr *next; |
108ba305 | 779 | /* Glob pattern. */ |
252b5132 | 780 | const char *pattern; |
ae5a3597 AM |
781 | /* Set if pattern is not a glob. */ |
782 | unsigned int literal : 1; | |
31941635 | 783 | /* Defined by ".symver". */ |
108ba305 | 784 | unsigned int symver : 1; |
31941635 L |
785 | /* Defined by version script. */ |
786 | unsigned int script : 1; | |
108ba305 JJ |
787 | /* Pattern type. */ |
788 | #define BFD_ELF_VERSION_C_TYPE 1 | |
789 | #define BFD_ELF_VERSION_CXX_TYPE 2 | |
790 | #define BFD_ELF_VERSION_JAVA_TYPE 4 | |
791 | unsigned int mask : 3; | |
792 | }; | |
793 | ||
794 | struct bfd_elf_version_expr_head | |
795 | { | |
796 | /* List of all patterns, both wildcards and non-wildcards. */ | |
797 | struct bfd_elf_version_expr *list; | |
798 | /* Hash table for non-wildcards. */ | |
799 | void *htab; | |
800 | /* Remaining patterns. */ | |
801 | struct bfd_elf_version_expr *remaining; | |
802 | /* What kind of pattern types are present in list (bitmask). */ | |
803 | unsigned int mask; | |
252b5132 RH |
804 | }; |
805 | ||
806 | /* Version dependencies. */ | |
807 | ||
808 | struct bfd_elf_version_deps | |
809 | { | |
810 | /* Next dependency for this version. */ | |
811 | struct bfd_elf_version_deps *next; | |
812 | /* The version which this version depends upon. */ | |
813 | struct bfd_elf_version_tree *version_needed; | |
814 | }; | |
815 | ||
816 | /* A node in the version tree. */ | |
817 | ||
818 | struct bfd_elf_version_tree | |
819 | { | |
820 | /* Next version. */ | |
821 | struct bfd_elf_version_tree *next; | |
822 | /* Name of this version. */ | |
823 | const char *name; | |
824 | /* Version number. */ | |
825 | unsigned int vernum; | |
826 | /* Regular expressions for global symbols in this version. */ | |
108ba305 | 827 | struct bfd_elf_version_expr_head globals; |
252b5132 | 828 | /* Regular expressions for local symbols in this version. */ |
108ba305 | 829 | struct bfd_elf_version_expr_head locals; |
252b5132 RH |
830 | /* List of versions which this version depends upon. */ |
831 | struct bfd_elf_version_deps *deps; | |
832 | /* Index of the version name. This is used within BFD. */ | |
833 | unsigned int name_indx; | |
834 | /* Whether this version tree was used. This is used within BFD. */ | |
835 | int used; | |
108ba305 JJ |
836 | /* Matching hook. */ |
837 | struct bfd_elf_version_expr *(*match) | |
838 | (struct bfd_elf_version_expr_head *head, | |
839 | struct bfd_elf_version_expr *prev, const char *sym); | |
252b5132 RH |
840 | }; |
841 | ||
55255dae L |
842 | struct bfd_elf_dynamic_list |
843 | { | |
844 | struct bfd_elf_version_expr_head head; | |
845 | struct bfd_elf_version_expr *(*match) | |
846 | (struct bfd_elf_version_expr_head *head, | |
847 | struct bfd_elf_version_expr *prev, const char *sym); | |
848 | }; | |
849 | ||
252b5132 | 850 | #endif |