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bae7f79e ILT |
1 | // symtab.h -- the gold symbol table -*- C++ -*- |
2 | ||
4b95cf5c | 3 | // Copyright (C) 2006-2014 Free Software Foundation, Inc. |
6cb15b7f ILT |
4 | // Written by Ian Lance Taylor <iant@google.com>. |
5 | ||
6 | // This file is part of gold. | |
7 | ||
8 | // This program is free software; you can redistribute it and/or modify | |
9 | // it under the terms of the GNU General Public License as published by | |
10 | // the Free Software Foundation; either version 3 of the License, or | |
11 | // (at your option) any later version. | |
12 | ||
13 | // This program is distributed in the hope that it will be useful, | |
14 | // but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | // GNU General Public License for more details. | |
17 | ||
18 | // You should have received a copy of the GNU General Public License | |
19 | // along with this program; if not, write to the Free Software | |
20 | // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, | |
21 | // MA 02110-1301, USA. | |
22 | ||
bae7f79e ILT |
23 | // Symbol_table |
24 | // The symbol table. | |
25 | ||
f345227a ST |
26 | #ifndef GOLD_SYMTAB_H |
27 | #define GOLD_SYMTAB_H | |
28 | ||
bae7f79e ILT |
29 | #include <string> |
30 | #include <utility> | |
ead1e424 | 31 | #include <vector> |
bae7f79e ILT |
32 | |
33 | #include "elfcpp.h" | |
7e1edb90 | 34 | #include "parameters.h" |
14bfc3f5 | 35 | #include "stringpool.h" |
f6ce93d6 | 36 | #include "object.h" |
bae7f79e | 37 | |
bae7f79e ILT |
38 | namespace gold |
39 | { | |
40 | ||
7d9e3d98 | 41 | class Mapfile; |
14bfc3f5 | 42 | class Object; |
f6ce93d6 | 43 | class Relobj; |
dbe717ef | 44 | template<int size, bool big_endian> |
6fa2a40b | 45 | class Sized_relobj_file; |
89fc3421 CC |
46 | template<int size, bool big_endian> |
47 | class Sized_pluginobj; | |
f6ce93d6 | 48 | class Dynobj; |
dbe717ef ILT |
49 | template<int size, bool big_endian> |
50 | class Sized_dynobj; | |
cdc29364 CC |
51 | template<int size, bool big_endian> |
52 | class Sized_incrobj; | |
14b31740 | 53 | class Versions; |
09124467 | 54 | class Version_script_info; |
9a2d6984 | 55 | class Input_objects; |
ead1e424 | 56 | class Output_data; |
a3ad94ed | 57 | class Output_section; |
ead1e424 | 58 | class Output_segment; |
61ba1cf9 | 59 | class Output_file; |
d491d34e | 60 | class Output_symtab_xindex; |
6d03d481 | 61 | class Garbage_collection; |
ef15dade | 62 | class Icf; |
14bfc3f5 | 63 | |
14bfc3f5 | 64 | // The base class of an entry in the symbol table. The symbol table |
c9269dff | 65 | // can have a lot of entries, so we don't want this class too big. |
14bfc3f5 ILT |
66 | // Size dependent fields can be found in the template class |
67 | // Sized_symbol. Targets may support their own derived classes. | |
bae7f79e | 68 | |
bae7f79e ILT |
69 | class Symbol |
70 | { | |
71 | public: | |
ead1e424 ILT |
72 | // Because we want the class to be small, we don't use any virtual |
73 | // functions. But because symbols can be defined in different | |
74 | // places, we need to classify them. This enum is the different | |
75 | // sources of symbols we support. | |
76 | enum Source | |
77 | { | |
f6ce93d6 ILT |
78 | // Symbol defined in a relocatable or dynamic input file--this is |
79 | // the most common case. | |
ead1e424 ILT |
80 | FROM_OBJECT, |
81 | // Symbol defined in an Output_data, a special section created by | |
82 | // the target. | |
83 | IN_OUTPUT_DATA, | |
84 | // Symbol defined in an Output_segment, with no associated | |
85 | // section. | |
86 | IN_OUTPUT_SEGMENT, | |
87 | // Symbol value is constant. | |
f3e9c5c5 ILT |
88 | IS_CONSTANT, |
89 | // Symbol is undefined. | |
90 | IS_UNDEFINED | |
ead1e424 ILT |
91 | }; |
92 | ||
93 | // When the source is IN_OUTPUT_SEGMENT, we need to describe what | |
94 | // the offset means. | |
95 | enum Segment_offset_base | |
96 | { | |
97 | // From the start of the segment. | |
98 | SEGMENT_START, | |
99 | // From the end of the segment. | |
100 | SEGMENT_END, | |
101 | // From the filesz of the segment--i.e., after the loaded bytes | |
102 | // but before the bytes which are allocated but zeroed. | |
103 | SEGMENT_BSS | |
104 | }; | |
105 | ||
14bfc3f5 ILT |
106 | // Return the symbol name. |
107 | const char* | |
108 | name() const | |
109 | { return this->name_; } | |
110 | ||
a2b1aa12 ILT |
111 | // Return the (ANSI) demangled version of the name, if |
112 | // parameters.demangle() is true. Otherwise, return the name. This | |
113 | // is intended to be used only for logging errors, so it's not | |
114 | // super-efficient. | |
115 | std::string | |
116 | demangled_name() const; | |
117 | ||
14bfc3f5 ILT |
118 | // Return the symbol version. This will return NULL for an |
119 | // unversioned symbol. | |
120 | const char* | |
121 | version() const | |
122 | { return this->version_; } | |
123 | ||
32e2b61d AM |
124 | void |
125 | clear_version() | |
126 | { this->version_ = NULL; } | |
127 | ||
09124467 ILT |
128 | // Return whether this version is the default for this symbol name |
129 | // (eg, "foo@@V2" is a default version; "foo@V1" is not). Only | |
130 | // meaningful for versioned symbols. | |
131 | bool | |
132 | is_default() const | |
133 | { | |
134 | gold_assert(this->version_ != NULL); | |
135 | return this->is_def_; | |
136 | } | |
137 | ||
be3e6201 | 138 | // Set that this version is the default for this symbol name. |
09124467 | 139 | void |
be3e6201 ILT |
140 | set_is_default() |
141 | { this->is_def_ = true; } | |
09124467 | 142 | |
6d1c4efb ILT |
143 | // Return the symbol's name as name@version (or name@@version). |
144 | std::string | |
145 | versioned_name() const; | |
146 | ||
ead1e424 ILT |
147 | // Return the symbol source. |
148 | Source | |
149 | source() const | |
150 | { return this->source_; } | |
151 | ||
14bfc3f5 ILT |
152 | // Return the object with which this symbol is associated. |
153 | Object* | |
154 | object() const | |
ead1e424 | 155 | { |
a3ad94ed | 156 | gold_assert(this->source_ == FROM_OBJECT); |
ead1e424 ILT |
157 | return this->u_.from_object.object; |
158 | } | |
159 | ||
f6ce93d6 ILT |
160 | // Return the index of the section in the input relocatable or |
161 | // dynamic object file. | |
ead1e424 | 162 | unsigned int |
d491d34e | 163 | shndx(bool* is_ordinary) const |
ead1e424 | 164 | { |
a3ad94ed | 165 | gold_assert(this->source_ == FROM_OBJECT); |
d491d34e | 166 | *is_ordinary = this->is_ordinary_shndx_; |
16649710 | 167 | return this->u_.from_object.shndx; |
ead1e424 ILT |
168 | } |
169 | ||
170 | // Return the output data section with which this symbol is | |
171 | // associated, if the symbol was specially defined with respect to | |
172 | // an output data section. | |
173 | Output_data* | |
174 | output_data() const | |
175 | { | |
a3ad94ed | 176 | gold_assert(this->source_ == IN_OUTPUT_DATA); |
ead1e424 ILT |
177 | return this->u_.in_output_data.output_data; |
178 | } | |
179 | ||
180 | // If this symbol was defined with respect to an output data | |
181 | // section, return whether the value is an offset from end. | |
182 | bool | |
183 | offset_is_from_end() const | |
184 | { | |
a3ad94ed | 185 | gold_assert(this->source_ == IN_OUTPUT_DATA); |
ead1e424 ILT |
186 | return this->u_.in_output_data.offset_is_from_end; |
187 | } | |
188 | ||
189 | // Return the output segment with which this symbol is associated, | |
190 | // if the symbol was specially defined with respect to an output | |
191 | // segment. | |
192 | Output_segment* | |
193 | output_segment() const | |
194 | { | |
a3ad94ed | 195 | gold_assert(this->source_ == IN_OUTPUT_SEGMENT); |
ead1e424 ILT |
196 | return this->u_.in_output_segment.output_segment; |
197 | } | |
198 | ||
199 | // If this symbol was defined with respect to an output segment, | |
200 | // return the offset base. | |
201 | Segment_offset_base | |
202 | offset_base() const | |
203 | { | |
a3ad94ed | 204 | gold_assert(this->source_ == IN_OUTPUT_SEGMENT); |
ead1e424 ILT |
205 | return this->u_.in_output_segment.offset_base; |
206 | } | |
14bfc3f5 ILT |
207 | |
208 | // Return the symbol binding. | |
209 | elfcpp::STB | |
210 | binding() const | |
211 | { return this->binding_; } | |
212 | ||
1564db8d ILT |
213 | // Return the symbol type. |
214 | elfcpp::STT | |
215 | type() const | |
216 | { return this->type_; } | |
217 | ||
53d7974c L |
218 | // Return true for function symbol. |
219 | bool | |
220 | is_func() const | |
221 | { | |
222 | return (this->type_ == elfcpp::STT_FUNC | |
223 | || this->type_ == elfcpp::STT_GNU_IFUNC); | |
224 | } | |
225 | ||
1564db8d ILT |
226 | // Return the symbol visibility. |
227 | elfcpp::STV | |
228 | visibility() const | |
229 | { return this->visibility_; } | |
230 | ||
0602e05a ILT |
231 | // Set the visibility. |
232 | void | |
2ea97941 ILT |
233 | set_visibility(elfcpp::STV visibility) |
234 | { this->visibility_ = visibility; } | |
0602e05a ILT |
235 | |
236 | // Override symbol visibility. | |
237 | void | |
238 | override_visibility(elfcpp::STV); | |
239 | ||
ce279a62 | 240 | // Set whether the symbol was originally a weak undef or a regular undef |
d1bddd3c | 241 | // when resolved by a dynamic def or by a special symbol. |
ce279a62 CC |
242 | inline void |
243 | set_undef_binding(elfcpp::STB bind) | |
244 | { | |
245 | if (!this->undef_binding_set_ || this->undef_binding_weak_) | |
246 | { | |
247 | this->undef_binding_weak_ = bind == elfcpp::STB_WEAK; | |
248 | this->undef_binding_set_ = true; | |
249 | } | |
250 | } | |
251 | ||
d1bddd3c CC |
252 | // Return TRUE if a weak undef was resolved by a dynamic def or |
253 | // by a special symbol. | |
ce279a62 CC |
254 | inline bool |
255 | is_undef_binding_weak() const | |
256 | { return this->undef_binding_weak_; } | |
257 | ||
1564db8d ILT |
258 | // Return the non-visibility part of the st_other field. |
259 | unsigned char | |
ead1e424 ILT |
260 | nonvis() const |
261 | { return this->nonvis_; } | |
14bfc3f5 | 262 | |
9b12c500 CC |
263 | // Set the non-visibility part of the st_other field. |
264 | void | |
265 | set_nonvis(unsigned int nonvis) | |
266 | { this->nonvis_ = nonvis; } | |
267 | ||
1564db8d ILT |
268 | // Return whether this symbol is a forwarder. This will never be |
269 | // true of a symbol found in the hash table, but may be true of | |
270 | // symbol pointers attached to object files. | |
271 | bool | |
272 | is_forwarder() const | |
273 | { return this->is_forwarder_; } | |
274 | ||
275 | // Mark this symbol as a forwarder. | |
276 | void | |
277 | set_forwarder() | |
278 | { this->is_forwarder_ = true; } | |
279 | ||
aeddab66 ILT |
280 | // Return whether this symbol has an alias in the weak aliases table |
281 | // in Symbol_table. | |
282 | bool | |
283 | has_alias() const | |
284 | { return this->has_alias_; } | |
285 | ||
286 | // Mark this symbol as having an alias. | |
287 | void | |
288 | set_has_alias() | |
289 | { this->has_alias_ = true; } | |
290 | ||
c06b7b0b ILT |
291 | // Return whether this symbol needs an entry in the dynamic symbol |
292 | // table. | |
293 | bool | |
294 | needs_dynsym_entry() const | |
429c1569 ILT |
295 | { |
296 | return (this->needs_dynsym_entry_ | |
8d6d383d ILT |
297 | || (this->in_reg() |
298 | && this->in_dyn() | |
299 | && this->is_externally_visible())); | |
429c1569 | 300 | } |
c06b7b0b ILT |
301 | |
302 | // Mark this symbol as needing an entry in the dynamic symbol table. | |
303 | void | |
304 | set_needs_dynsym_entry() | |
305 | { this->needs_dynsym_entry_ = true; } | |
306 | ||
436ca963 ILT |
307 | // Return whether this symbol should be added to the dynamic symbol |
308 | // table. | |
309 | bool | |
ce97fa81 | 310 | should_add_dynsym_entry(Symbol_table*) const; |
436ca963 | 311 | |
008db82e ILT |
312 | // Return whether this symbol has been seen in a regular object. |
313 | bool | |
314 | in_reg() const | |
315 | { return this->in_reg_; } | |
316 | ||
317 | // Mark this symbol as having been seen in a regular object. | |
318 | void | |
319 | set_in_reg() | |
320 | { this->in_reg_ = true; } | |
321 | ||
1ebd95fd ILT |
322 | // Return whether this symbol has been seen in a dynamic object. |
323 | bool | |
324 | in_dyn() const | |
325 | { return this->in_dyn_; } | |
326 | ||
f6ce93d6 | 327 | // Mark this symbol as having been seen in a dynamic object. |
1564db8d ILT |
328 | void |
329 | set_in_dyn() | |
330 | { this->in_dyn_ = true; } | |
331 | ||
89fc3421 CC |
332 | // Return whether this symbol has been seen in a real ELF object. |
333 | // (IN_REG will return TRUE if the symbol has been seen in either | |
334 | // a real ELF object or an object claimed by a plugin.) | |
335 | bool | |
336 | in_real_elf() const | |
337 | { return this->in_real_elf_; } | |
338 | ||
339 | // Mark this symbol as having been seen in a real ELF object. | |
340 | void | |
341 | set_in_real_elf() | |
342 | { this->in_real_elf_ = true; } | |
343 | ||
880cd20d ILT |
344 | // Return whether this symbol was defined in a section that was |
345 | // discarded from the link. This is used to control some error | |
346 | // reporting. | |
347 | bool | |
348 | is_defined_in_discarded_section() const | |
349 | { return this->is_defined_in_discarded_section_; } | |
350 | ||
351 | // Mark this symbol as having been defined in a discarded section. | |
352 | void | |
353 | set_is_defined_in_discarded_section() | |
354 | { this->is_defined_in_discarded_section_ = true; } | |
355 | ||
c06b7b0b ILT |
356 | // Return the index of this symbol in the output file symbol table. |
357 | // A value of -1U means that this symbol is not going into the | |
358 | // output file. This starts out as zero, and is set to a non-zero | |
359 | // value by Symbol_table::finalize. It is an error to ask for the | |
360 | // symbol table index before it has been set. | |
361 | unsigned int | |
362 | symtab_index() const | |
363 | { | |
a3ad94ed | 364 | gold_assert(this->symtab_index_ != 0); |
c06b7b0b ILT |
365 | return this->symtab_index_; |
366 | } | |
367 | ||
368 | // Set the index of the symbol in the output file symbol table. | |
369 | void | |
370 | set_symtab_index(unsigned int index) | |
371 | { | |
a3ad94ed | 372 | gold_assert(index != 0); |
c06b7b0b ILT |
373 | this->symtab_index_ = index; |
374 | } | |
375 | ||
a3ad94ed ILT |
376 | // Return whether this symbol already has an index in the output |
377 | // file symbol table. | |
378 | bool | |
379 | has_symtab_index() const | |
380 | { return this->symtab_index_ != 0; } | |
381 | ||
c06b7b0b ILT |
382 | // Return the index of this symbol in the dynamic symbol table. A |
383 | // value of -1U means that this symbol is not going into the dynamic | |
384 | // symbol table. This starts out as zero, and is set to a non-zero | |
385 | // during Layout::finalize. It is an error to ask for the dynamic | |
386 | // symbol table index before it has been set. | |
387 | unsigned int | |
388 | dynsym_index() const | |
389 | { | |
a3ad94ed | 390 | gold_assert(this->dynsym_index_ != 0); |
c06b7b0b ILT |
391 | return this->dynsym_index_; |
392 | } | |
393 | ||
394 | // Set the index of the symbol in the dynamic symbol table. | |
395 | void | |
396 | set_dynsym_index(unsigned int index) | |
397 | { | |
a3ad94ed | 398 | gold_assert(index != 0); |
c06b7b0b ILT |
399 | this->dynsym_index_ = index; |
400 | } | |
401 | ||
16649710 ILT |
402 | // Return whether this symbol already has an index in the dynamic |
403 | // symbol table. | |
404 | bool | |
405 | has_dynsym_index() const | |
406 | { return this->dynsym_index_ != 0; } | |
407 | ||
ead1e424 | 408 | // Return whether this symbol has an entry in the GOT section. |
07f397ab | 409 | // For a TLS symbol, this GOT entry will hold its tp-relative offset. |
92e059d8 | 410 | bool |
0a65a3a7 CC |
411 | has_got_offset(unsigned int got_type) const |
412 | { return this->got_offsets_.get_offset(got_type) != -1U; } | |
ead1e424 ILT |
413 | |
414 | // Return the offset into the GOT section of this symbol. | |
415 | unsigned int | |
0a65a3a7 | 416 | got_offset(unsigned int got_type) const |
ead1e424 | 417 | { |
2ea97941 ILT |
418 | unsigned int got_offset = this->got_offsets_.get_offset(got_type); |
419 | gold_assert(got_offset != -1U); | |
420 | return got_offset; | |
ead1e424 ILT |
421 | } |
422 | ||
423 | // Set the GOT offset of this symbol. | |
424 | void | |
2ea97941 ILT |
425 | set_got_offset(unsigned int got_type, unsigned int got_offset) |
426 | { this->got_offsets_.set_offset(got_type, got_offset); } | |
07f397ab | 427 | |
0e70b911 CC |
428 | // Return the GOT offset list. |
429 | const Got_offset_list* | |
430 | got_offset_list() const | |
431 | { return this->got_offsets_.get_list(); } | |
432 | ||
a3ad94ed | 433 | // Return whether this symbol has an entry in the PLT section. |
ead1e424 | 434 | bool |
a3ad94ed | 435 | has_plt_offset() const |
880cd20d | 436 | { return this->plt_offset_ != -1U; } |
a3ad94ed ILT |
437 | |
438 | // Return the offset into the PLT section of this symbol. | |
439 | unsigned int | |
440 | plt_offset() const | |
441 | { | |
442 | gold_assert(this->has_plt_offset()); | |
443 | return this->plt_offset_; | |
444 | } | |
445 | ||
446 | // Set the PLT offset of this symbol. | |
447 | void | |
2ea97941 | 448 | set_plt_offset(unsigned int plt_offset) |
a3ad94ed | 449 | { |
880cd20d | 450 | gold_assert(plt_offset != -1U); |
2ea97941 | 451 | this->plt_offset_ = plt_offset; |
a3ad94ed ILT |
452 | } |
453 | ||
ab5c9e90 ILT |
454 | // Return whether this dynamic symbol needs a special value in the |
455 | // dynamic symbol table. | |
456 | bool | |
457 | needs_dynsym_value() const | |
458 | { return this->needs_dynsym_value_; } | |
459 | ||
460 | // Set that this dynamic symbol needs a special value in the dynamic | |
461 | // symbol table. | |
462 | void | |
463 | set_needs_dynsym_value() | |
464 | { | |
465 | gold_assert(this->object()->is_dynamic()); | |
466 | this->needs_dynsym_value_ = true; | |
467 | } | |
468 | ||
a3ad94ed ILT |
469 | // Return true if the final value of this symbol is known at link |
470 | // time. | |
471 | bool | |
b3b74ddc | 472 | final_value_is_known() const; |
ead1e424 | 473 | |
8a5e3e08 ILT |
474 | // Return true if SHNDX represents a common symbol. This depends on |
475 | // the target. | |
476 | static bool | |
477 | is_common_shndx(unsigned int shndx); | |
478 | ||
f6ce93d6 ILT |
479 | // Return whether this is a defined symbol (not undefined or |
480 | // common). | |
481 | bool | |
482 | is_defined() const | |
483 | { | |
d491d34e ILT |
484 | bool is_ordinary; |
485 | if (this->source_ != FROM_OBJECT) | |
f3e9c5c5 | 486 | return this->source_ != IS_UNDEFINED; |
2ea97941 | 487 | unsigned int shndx = this->shndx(&is_ordinary); |
d491d34e | 488 | return (is_ordinary |
2ea97941 ILT |
489 | ? shndx != elfcpp::SHN_UNDEF |
490 | : !Symbol::is_common_shndx(shndx)); | |
a3ad94ed ILT |
491 | } |
492 | ||
14b31740 | 493 | // Return true if this symbol is from a dynamic object. |
a3ad94ed | 494 | bool |
14b31740 | 495 | is_from_dynobj() const |
a3ad94ed | 496 | { |
14b31740 | 497 | return this->source_ == FROM_OBJECT && this->object()->is_dynamic(); |
f6ce93d6 ILT |
498 | } |
499 | ||
f3a2388f CC |
500 | // Return whether this is a placeholder symbol from a plugin object. |
501 | bool | |
502 | is_placeholder() const | |
503 | { | |
504 | return this->source_ == FROM_OBJECT && this->object()->pluginobj() != NULL; | |
505 | } | |
506 | ||
ead1e424 ILT |
507 | // Return whether this is an undefined symbol. |
508 | bool | |
509 | is_undefined() const | |
510 | { | |
d491d34e | 511 | bool is_ordinary; |
f3e9c5c5 ILT |
512 | return ((this->source_ == FROM_OBJECT |
513 | && this->shndx(&is_ordinary) == elfcpp::SHN_UNDEF | |
514 | && is_ordinary) | |
515 | || this->source_ == IS_UNDEFINED); | |
ead1e424 ILT |
516 | } |
517 | ||
86925eef CC |
518 | // Return whether this is a weak undefined symbol. |
519 | bool | |
520 | is_weak_undefined() const | |
d1bddd3c CC |
521 | { |
522 | return (this->is_undefined() | |
523 | && (this->binding() == elfcpp::STB_WEAK | |
524 | || this->is_undef_binding_weak())); | |
525 | } | |
526 | ||
527 | // Return whether this is a strong undefined symbol. | |
528 | bool | |
529 | is_strong_undefined() const | |
530 | { | |
531 | return (this->is_undefined() | |
532 | && this->binding() != elfcpp::STB_WEAK | |
533 | && !this->is_undef_binding_weak()); | |
534 | } | |
86925eef | 535 | |
86925eef CC |
536 | // Return whether this is an absolute symbol. |
537 | bool | |
538 | is_absolute() const | |
539 | { | |
d491d34e | 540 | bool is_ordinary; |
f3e9c5c5 ILT |
541 | return ((this->source_ == FROM_OBJECT |
542 | && this->shndx(&is_ordinary) == elfcpp::SHN_ABS | |
543 | && !is_ordinary) | |
544 | || this->source_ == IS_CONSTANT); | |
86925eef CC |
545 | } |
546 | ||
ead1e424 ILT |
547 | // Return whether this is a common symbol. |
548 | bool | |
549 | is_common() const | |
550 | { | |
8a5e3e08 ILT |
551 | if (this->source_ != FROM_OBJECT) |
552 | return false; | |
eda294df ILT |
553 | if (this->type_ == elfcpp::STT_COMMON) |
554 | return true; | |
d491d34e | 555 | bool is_ordinary; |
2ea97941 ILT |
556 | unsigned int shndx = this->shndx(&is_ordinary); |
557 | return !is_ordinary && Symbol::is_common_shndx(shndx); | |
ead1e424 | 558 | } |
92e059d8 | 559 | |
a6badf5a ILT |
560 | // Return whether this symbol can be seen outside this object. |
561 | bool | |
562 | is_externally_visible() const | |
563 | { | |
804eb480 ST |
564 | return ((this->visibility_ == elfcpp::STV_DEFAULT |
565 | || this->visibility_ == elfcpp::STV_PROTECTED) | |
566 | && !this->is_forced_local_); | |
a6badf5a ILT |
567 | } |
568 | ||
436ca963 ILT |
569 | // Return true if this symbol can be preempted by a definition in |
570 | // another link unit. | |
571 | bool | |
572 | is_preemptible() const | |
573 | { | |
386c048c ILT |
574 | // It doesn't make sense to ask whether a symbol defined in |
575 | // another object is preemptible. | |
576 | gold_assert(!this->is_from_dynobj()); | |
577 | ||
8fc19601 ILT |
578 | // It doesn't make sense to ask whether an undefined symbol |
579 | // is preemptible. | |
580 | gold_assert(!this->is_undefined()); | |
581 | ||
f1f70eae ILT |
582 | // If a symbol does not have default visibility, it can not be |
583 | // seen outside this link unit and therefore is not preemptible. | |
584 | if (this->visibility_ != elfcpp::STV_DEFAULT) | |
585 | return false; | |
586 | ||
587 | // If this symbol has been forced to be a local symbol by a | |
588 | // version script, then it is not visible outside this link unit | |
589 | // and is not preemptible. | |
590 | if (this->is_forced_local_) | |
591 | return false; | |
592 | ||
593 | // If we are not producing a shared library, then nothing is | |
594 | // preemptible. | |
595 | if (!parameters->options().shared()) | |
596 | return false; | |
597 | ||
fd834e57 CC |
598 | // If the symbol was named in a --dynamic-list script, it is preemptible. |
599 | if (parameters->options().in_dynamic_list(this->name())) | |
600 | return true; | |
601 | ||
602 | // If the user used -Bsymbolic or provided a --dynamic-list script, | |
603 | // then nothing (else) is preemptible. | |
604 | if (parameters->options().Bsymbolic() | |
605 | || parameters->options().have_dynamic_list()) | |
f1f70eae ILT |
606 | return false; |
607 | ||
608 | // If the user used -Bsymbolic-functions, then functions are not | |
609 | // preemptible. We explicitly check for not being STT_OBJECT, | |
610 | // rather than for being STT_FUNC, because that is what the GNU | |
611 | // linker does. | |
612 | if (this->type() != elfcpp::STT_OBJECT | |
613 | && parameters->options().Bsymbolic_functions()) | |
614 | return false; | |
615 | ||
616 | // Otherwise the symbol is preemptible. | |
617 | return true; | |
436ca963 ILT |
618 | } |
619 | ||
d61c6bd4 | 620 | // Return true if this symbol is a function that needs a PLT entry. |
d61c6bd4 ILT |
621 | bool |
622 | needs_plt_entry() const | |
623 | { | |
6d479619 CC |
624 | // An undefined symbol from an executable does not need a PLT entry. |
625 | if (this->is_undefined() && !parameters->options().shared()) | |
626 | return false; | |
627 | ||
7223e9ca ILT |
628 | // An STT_GNU_IFUNC symbol always needs a PLT entry, even when |
629 | // doing a static link. | |
630 | if (this->type() == elfcpp::STT_GNU_IFUNC) | |
631 | return true; | |
632 | ||
633 | // We only need a PLT entry for a function. | |
634 | if (!this->is_func()) | |
635 | return false; | |
636 | ||
637 | // If we're doing a static link or a -pie link, we don't create | |
638 | // PLT entries. | |
639 | if (parameters->doing_static_link() | |
640 | || parameters->options().pie()) | |
641 | return false; | |
642 | ||
643 | // We need a PLT entry if the function is defined in a dynamic | |
644 | // object, or is undefined when building a shared object, or if it | |
645 | // is subject to pre-emption. | |
646 | return (this->is_from_dynobj() | |
647 | || this->is_undefined() | |
648 | || this->is_preemptible()); | |
d61c6bd4 ILT |
649 | } |
650 | ||
0700cf32 ILT |
651 | // When determining whether a reference to a symbol needs a dynamic |
652 | // relocation, we need to know several things about the reference. | |
95a2c8d6 RS |
653 | // These flags may be or'ed together. 0 means that the symbol |
654 | // isn't referenced at all. | |
0700cf32 ILT |
655 | enum Reference_flags |
656 | { | |
95a2c8d6 RS |
657 | // A reference to the symbol's absolute address. This includes |
658 | // references that cause an absolute address to be stored in the GOT. | |
0700cf32 | 659 | ABSOLUTE_REF = 1, |
95a2c8d6 RS |
660 | // A reference that calculates the offset of the symbol from some |
661 | // anchor point, such as the PC or GOT. | |
662 | RELATIVE_REF = 2, | |
663 | // A TLS-related reference. | |
664 | TLS_REF = 4, | |
665 | // A reference that can always be treated as a function call. | |
88b8e639 AM |
666 | FUNCTION_CALL = 8, |
667 | // When set, says that dynamic relocations are needed even if a | |
668 | // symbol has a plt entry. | |
669 | FUNC_DESC_ABI = 16, | |
0700cf32 ILT |
670 | }; |
671 | ||
d61c6bd4 ILT |
672 | // Given a direct absolute or pc-relative static relocation against |
673 | // the global symbol, this function returns whether a dynamic relocation | |
674 | // is needed. | |
675 | ||
676 | bool | |
0700cf32 | 677 | needs_dynamic_reloc(int flags) const |
d61c6bd4 | 678 | { |
8fc19601 ILT |
679 | // No dynamic relocations in a static link! |
680 | if (parameters->doing_static_link()) | |
681 | return false; | |
682 | ||
6d479619 | 683 | // A reference to an undefined symbol from an executable should be |
f3c69fca CC |
684 | // statically resolved to 0, and does not need a dynamic relocation. |
685 | // This matches gnu ld behavior. | |
6d479619 | 686 | if (this->is_undefined() && !parameters->options().shared()) |
f3c69fca CC |
687 | return false; |
688 | ||
689 | // A reference to an absolute symbol does not need a dynamic relocation. | |
690 | if (this->is_absolute()) | |
86925eef CC |
691 | return false; |
692 | ||
d61c6bd4 | 693 | // An absolute reference within a position-independent output file |
0700cf32 ILT |
694 | // will need a dynamic relocation. |
695 | if ((flags & ABSOLUTE_REF) | |
8851ecca | 696 | && parameters->options().output_is_position_independent()) |
d61c6bd4 ILT |
697 | return true; |
698 | ||
699 | // A function call that can branch to a local PLT entry does not need | |
95a2c8d6 RS |
700 | // a dynamic relocation. |
701 | if ((flags & FUNCTION_CALL) && this->has_plt_offset()) | |
d61c6bd4 ILT |
702 | return false; |
703 | ||
704 | // A reference to any PLT entry in a non-position-independent executable | |
705 | // does not need a dynamic relocation. | |
88b8e639 AM |
706 | if (!(flags & FUNC_DESC_ABI) |
707 | && !parameters->options().output_is_position_independent() | |
d61c6bd4 ILT |
708 | && this->has_plt_offset()) |
709 | return false; | |
710 | ||
711 | // A reference to a symbol defined in a dynamic object or to a | |
712 | // symbol that is preemptible will need a dynamic relocation. | |
8fc19601 ILT |
713 | if (this->is_from_dynobj() |
714 | || this->is_undefined() | |
715 | || this->is_preemptible()) | |
d61c6bd4 ILT |
716 | return true; |
717 | ||
718 | // For all other cases, return FALSE. | |
719 | return false; | |
720 | } | |
721 | ||
de4c45bd | 722 | // Whether we should use the PLT offset associated with a symbol for |
95a2c8d6 | 723 | // a relocation. FLAGS is a set of Reference_flags. |
de4c45bd ILT |
724 | |
725 | bool | |
95a2c8d6 | 726 | use_plt_offset(int flags) const |
de4c45bd ILT |
727 | { |
728 | // If the symbol doesn't have a PLT offset, then naturally we | |
729 | // don't want to use it. | |
730 | if (!this->has_plt_offset()) | |
731 | return false; | |
732 | ||
7223e9ca ILT |
733 | // For a STT_GNU_IFUNC symbol we always have to use the PLT entry. |
734 | if (this->type() == elfcpp::STT_GNU_IFUNC) | |
735 | return true; | |
736 | ||
de4c45bd ILT |
737 | // If we are going to generate a dynamic relocation, then we will |
738 | // wind up using that, so no need to use the PLT entry. | |
95a2c8d6 | 739 | if (this->needs_dynamic_reloc(flags)) |
de4c45bd ILT |
740 | return false; |
741 | ||
742 | // If the symbol is from a dynamic object, we need to use the PLT | |
743 | // entry. | |
744 | if (this->is_from_dynobj()) | |
745 | return true; | |
746 | ||
747 | // If we are generating a shared object, and this symbol is | |
748 | // undefined or preemptible, we need to use the PLT entry. | |
749 | if (parameters->options().shared() | |
750 | && (this->is_undefined() || this->is_preemptible())) | |
751 | return true; | |
752 | ||
95a2c8d6 RS |
753 | // If this is a call to a weak undefined symbol, we need to use |
754 | // the PLT entry; the symbol may be defined by a library loaded | |
755 | // at runtime. | |
756 | if ((flags & FUNCTION_CALL) && this->is_weak_undefined()) | |
de4c45bd ILT |
757 | return true; |
758 | ||
759 | // Otherwise we can use the regular definition. | |
760 | return false; | |
761 | } | |
762 | ||
d61c6bd4 ILT |
763 | // Given a direct absolute static relocation against |
764 | // the global symbol, where a dynamic relocation is needed, this | |
765 | // function returns whether a relative dynamic relocation can be used. | |
766 | // The caller must determine separately whether the static relocation | |
767 | // is compatible with a relative relocation. | |
768 | ||
769 | bool | |
770 | can_use_relative_reloc(bool is_function_call) const | |
771 | { | |
772 | // A function call that can branch to a local PLT entry can | |
773 | // use a RELATIVE relocation. | |
774 | if (is_function_call && this->has_plt_offset()) | |
775 | return true; | |
776 | ||
777 | // A reference to a symbol defined in a dynamic object or to a | |
9b547ce6 | 778 | // symbol that is preemptible can not use a RELATIVE relocation. |
8fc19601 ILT |
779 | if (this->is_from_dynobj() |
780 | || this->is_undefined() | |
781 | || this->is_preemptible()) | |
d61c6bd4 ILT |
782 | return false; |
783 | ||
784 | // For all other cases, return TRUE. | |
785 | return true; | |
786 | } | |
787 | ||
77e65537 ILT |
788 | // Return the output section where this symbol is defined. Return |
789 | // NULL if the symbol has an absolute value. | |
790 | Output_section* | |
791 | output_section() const; | |
792 | ||
793 | // Set the symbol's output section. This is used for symbols | |
794 | // defined in scripts. This should only be called after the symbol | |
795 | // table has been finalized. | |
796 | void | |
797 | set_output_section(Output_section*); | |
a445fddf | 798 | |
d1bddd3c CC |
799 | // Set the symbol's output segment. This is used for pre-defined |
800 | // symbols whose segments aren't known until after layout is done | |
801 | // (e.g., __ehdr_start). | |
802 | void | |
803 | set_output_segment(Output_segment*, Segment_offset_base); | |
804 | ||
805 | // Set the symbol to undefined. This is used for pre-defined | |
806 | // symbols whose segments aren't known until after layout is done | |
807 | // (e.g., __ehdr_start). | |
808 | void | |
809 | set_undefined(); | |
810 | ||
f6ce93d6 ILT |
811 | // Return whether there should be a warning for references to this |
812 | // symbol. | |
813 | bool | |
814 | has_warning() const | |
815 | { return this->has_warning_; } | |
816 | ||
817 | // Mark this symbol as having a warning. | |
818 | void | |
819 | set_has_warning() | |
820 | { this->has_warning_ = true; } | |
821 | ||
46fe1623 ILT |
822 | // Return whether this symbol is defined by a COPY reloc from a |
823 | // dynamic object. | |
824 | bool | |
825 | is_copied_from_dynobj() const | |
826 | { return this->is_copied_from_dynobj_; } | |
827 | ||
828 | // Mark this symbol as defined by a COPY reloc. | |
829 | void | |
830 | set_is_copied_from_dynobj() | |
831 | { this->is_copied_from_dynobj_ = true; } | |
832 | ||
55a93433 ILT |
833 | // Return whether this symbol is forced to visibility STB_LOCAL |
834 | // by a "local:" entry in a version script. | |
835 | bool | |
836 | is_forced_local() const | |
837 | { return this->is_forced_local_; } | |
838 | ||
839 | // Mark this symbol as forced to STB_LOCAL visibility. | |
840 | void | |
841 | set_is_forced_local() | |
842 | { this->is_forced_local_ = true; } | |
843 | ||
966d4097 DK |
844 | // Return true if this may need a COPY relocation. |
845 | // References from an executable object to non-function symbols | |
846 | // defined in a dynamic object may need a COPY relocation. | |
847 | bool | |
848 | may_need_copy_reloc() const | |
849 | { | |
a82bef93 | 850 | return (parameters->options().copyreloc() |
966d4097 | 851 | && this->is_from_dynobj() |
53d7974c | 852 | && !this->is_func()); |
966d4097 DK |
853 | } |
854 | ||
5146f448 CC |
855 | // Return true if this symbol was predefined by the linker. |
856 | bool | |
857 | is_predefined() const | |
858 | { return this->is_predefined_; } | |
859 | ||
93acabad CC |
860 | // Return true if this is a C++ vtable symbol. |
861 | bool | |
862 | is_cxx_vtable() const | |
863 | { return is_prefix_of("_ZTV", this->name_); } | |
864 | ||
14bfc3f5 ILT |
865 | protected: |
866 | // Instances of this class should always be created at a specific | |
867 | // size. | |
868 | Symbol() | |
f6ce93d6 | 869 | { memset(this, 0, sizeof *this); } |
14bfc3f5 | 870 | |
ead1e424 ILT |
871 | // Initialize the general fields. |
872 | void | |
873 | init_fields(const char* name, const char* version, | |
874 | elfcpp::STT type, elfcpp::STB binding, | |
875 | elfcpp::STV visibility, unsigned char nonvis); | |
876 | ||
d491d34e ILT |
877 | // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the |
878 | // section index, IS_ORDINARY is whether it is a normal section | |
879 | // index rather than a special code. | |
14bfc3f5 ILT |
880 | template<int size, bool big_endian> |
881 | void | |
ca09d69a | 882 | init_base_object(const char* name, const char* version, Object* object, |
f3e9c5c5 ILT |
883 | const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx, |
884 | bool is_ordinary); | |
bae7f79e | 885 | |
ead1e424 ILT |
886 | // Initialize fields for an Output_data. |
887 | void | |
75517b77 ILT |
888 | init_base_output_data(const char* name, const char* version, Output_data*, |
889 | elfcpp::STT, elfcpp::STB, elfcpp::STV, | |
5146f448 CC |
890 | unsigned char nonvis, bool offset_is_from_end, |
891 | bool is_predefined); | |
ead1e424 ILT |
892 | |
893 | // Initialize fields for an Output_segment. | |
894 | void | |
75517b77 ILT |
895 | init_base_output_segment(const char* name, const char* version, |
896 | Output_segment* os, elfcpp::STT type, | |
897 | elfcpp::STB binding, elfcpp::STV visibility, | |
898 | unsigned char nonvis, | |
5146f448 CC |
899 | Segment_offset_base offset_base, |
900 | bool is_predefined); | |
ead1e424 ILT |
901 | |
902 | // Initialize fields for a constant. | |
903 | void | |
75517b77 ILT |
904 | init_base_constant(const char* name, const char* version, elfcpp::STT type, |
905 | elfcpp::STB binding, elfcpp::STV visibility, | |
5146f448 | 906 | unsigned char nonvis, bool is_predefined); |
f3e9c5c5 ILT |
907 | |
908 | // Initialize fields for an undefined symbol. | |
909 | void | |
75517b77 ILT |
910 | init_base_undefined(const char* name, const char* version, elfcpp::STT type, |
911 | elfcpp::STB binding, elfcpp::STV visibility, | |
912 | unsigned char nonvis); | |
ead1e424 | 913 | |
1564db8d ILT |
914 | // Override existing symbol. |
915 | template<int size, bool big_endian> | |
916 | void | |
d491d34e ILT |
917 | override_base(const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx, |
918 | bool is_ordinary, Object* object, const char* version); | |
1564db8d | 919 | |
86f2e683 ILT |
920 | // Override existing symbol with a special symbol. |
921 | void | |
922 | override_base_with_special(const Symbol* from); | |
923 | ||
75517b77 ILT |
924 | // Override symbol version. |
925 | void | |
926 | override_version(const char* version); | |
927 | ||
c7912668 ILT |
928 | // Allocate a common symbol by giving it a location in the output |
929 | // file. | |
930 | void | |
931 | allocate_base_common(Output_data*); | |
932 | ||
bae7f79e | 933 | private: |
14bfc3f5 ILT |
934 | Symbol(const Symbol&); |
935 | Symbol& operator=(const Symbol&); | |
936 | ||
937 | // Symbol name (expected to point into a Stringpool). | |
938 | const char* name_; | |
939 | // Symbol version (expected to point into a Stringpool). This may | |
940 | // be NULL. | |
bae7f79e | 941 | const char* version_; |
ead1e424 ILT |
942 | |
943 | union | |
944 | { | |
945 | // This struct is used if SOURCE_ == FROM_OBJECT. | |
946 | struct | |
947 | { | |
948 | // Object in which symbol is defined, or in which it was first | |
949 | // seen. | |
950 | Object* object; | |
951 | // Section number in object_ in which symbol is defined. | |
16649710 | 952 | unsigned int shndx; |
ead1e424 ILT |
953 | } from_object; |
954 | ||
955 | // This struct is used if SOURCE_ == IN_OUTPUT_DATA. | |
956 | struct | |
957 | { | |
958 | // Output_data in which symbol is defined. Before | |
959 | // Layout::finalize the symbol's value is an offset within the | |
960 | // Output_data. | |
961 | Output_data* output_data; | |
962 | // True if the offset is from the end, false if the offset is | |
963 | // from the beginning. | |
964 | bool offset_is_from_end; | |
965 | } in_output_data; | |
966 | ||
967 | // This struct is used if SOURCE_ == IN_OUTPUT_SEGMENT. | |
968 | struct | |
969 | { | |
970 | // Output_segment in which the symbol is defined. Before | |
971 | // Layout::finalize the symbol's value is an offset. | |
972 | Output_segment* output_segment; | |
973 | // The base to use for the offset before Layout::finalize. | |
974 | Segment_offset_base offset_base; | |
975 | } in_output_segment; | |
976 | } u_; | |
977 | ||
c06b7b0b ILT |
978 | // The index of this symbol in the output file. If the symbol is |
979 | // not going into the output file, this value is -1U. This field | |
980 | // starts as always holding zero. It is set to a non-zero value by | |
981 | // Symbol_table::finalize. | |
982 | unsigned int symtab_index_; | |
983 | ||
984 | // The index of this symbol in the dynamic symbol table. If the | |
985 | // symbol is not going into the dynamic symbol table, this value is | |
986 | // -1U. This field starts as always holding zero. It is set to a | |
987 | // non-zero value during Layout::finalize. | |
988 | unsigned int dynsym_index_; | |
989 | ||
880cd20d ILT |
990 | // The GOT section entries for this symbol. A symbol may have more |
991 | // than one GOT offset (e.g., when mixing modules compiled with two | |
992 | // different TLS models), but will usually have at most one. | |
0a65a3a7 | 993 | Got_offset_list got_offsets_; |
07f397ab | 994 | |
880cd20d ILT |
995 | // If this symbol has an entry in the PLT section, then this is the |
996 | // offset from the start of the PLT section. This is -1U if there | |
997 | // is no PLT entry. | |
a3ad94ed ILT |
998 | unsigned int plt_offset_; |
999 | ||
d491d34e | 1000 | // Symbol type (bits 0 to 3). |
bae7f79e | 1001 | elfcpp::STT type_ : 4; |
d491d34e | 1002 | // Symbol binding (bits 4 to 7). |
bae7f79e | 1003 | elfcpp::STB binding_ : 4; |
d491d34e | 1004 | // Symbol visibility (bits 8 to 9). |
14bfc3f5 | 1005 | elfcpp::STV visibility_ : 2; |
d491d34e | 1006 | // Rest of symbol st_other field (bits 10 to 15). |
ead1e424 | 1007 | unsigned int nonvis_ : 6; |
d491d34e | 1008 | // The type of symbol (bits 16 to 18). |
f6ce93d6 | 1009 | Source source_ : 3; |
880cd20d | 1010 | // True if this is the default version of the symbol (bit 19). |
1564db8d | 1011 | bool is_def_ : 1; |
14bfc3f5 ILT |
1012 | // True if this symbol really forwards to another symbol. This is |
1013 | // used when we discover after the fact that two different entries | |
1014 | // in the hash table really refer to the same symbol. This will | |
1015 | // never be set for a symbol found in the hash table, but may be set | |
1016 | // for a symbol found in the list of symbols attached to an Object. | |
1017 | // It forwards to the symbol found in the forwarders_ map of | |
880cd20d | 1018 | // Symbol_table (bit 20). |
1564db8d | 1019 | bool is_forwarder_ : 1; |
aeddab66 | 1020 | // True if the symbol has an alias in the weak_aliases table in |
880cd20d | 1021 | // Symbol_table (bit 21). |
aeddab66 | 1022 | bool has_alias_ : 1; |
d491d34e | 1023 | // True if this symbol needs to be in the dynamic symbol table (bit |
880cd20d | 1024 | // 22). |
c06b7b0b | 1025 | bool needs_dynsym_entry_ : 1; |
880cd20d | 1026 | // True if we've seen this symbol in a regular object (bit 23). |
008db82e | 1027 | bool in_reg_ : 1; |
880cd20d | 1028 | // True if we've seen this symbol in a dynamic object (bit 24). |
1564db8d | 1029 | bool in_dyn_ : 1; |
ab5c9e90 | 1030 | // True if this is a dynamic symbol which needs a special value in |
880cd20d | 1031 | // the dynamic symbol table (bit 25). |
ab5c9e90 | 1032 | bool needs_dynsym_value_ : 1; |
880cd20d | 1033 | // True if there is a warning for this symbol (bit 26). |
f6ce93d6 | 1034 | bool has_warning_ : 1; |
46fe1623 | 1035 | // True if we are using a COPY reloc for this symbol, so that the |
880cd20d | 1036 | // real definition lives in a dynamic object (bit 27). |
46fe1623 | 1037 | bool is_copied_from_dynobj_ : 1; |
55a93433 | 1038 | // True if this symbol was forced to local visibility by a version |
880cd20d | 1039 | // script (bit 28). |
55a93433 | 1040 | bool is_forced_local_ : 1; |
d491d34e ILT |
1041 | // True if the field u_.from_object.shndx is an ordinary section |
1042 | // index, not one of the special codes from SHN_LORESERVE to | |
880cd20d | 1043 | // SHN_HIRESERVE (bit 29). |
d491d34e | 1044 | bool is_ordinary_shndx_ : 1; |
f7c5b166 CC |
1045 | // True if we've seen this symbol in a "real" ELF object (bit 30). |
1046 | // If the symbol has been seen in a relocatable, non-IR, object file, | |
1047 | // it's known to be referenced from outside the IR. A reference from | |
1048 | // a dynamic object doesn't count as a "real" ELF, and we'll simply | |
1049 | // mark the symbol as "visible" from outside the IR. The compiler | |
1050 | // can use this distinction to guide its handling of COMDAT symbols. | |
89fc3421 | 1051 | bool in_real_elf_ : 1; |
880cd20d ILT |
1052 | // True if this symbol is defined in a section which was discarded |
1053 | // (bit 31). | |
1054 | bool is_defined_in_discarded_section_ : 1; | |
ce279a62 CC |
1055 | // True if UNDEF_BINDING_WEAK_ has been set (bit 32). |
1056 | bool undef_binding_set_ : 1; | |
1057 | // True if this symbol was a weak undef resolved by a dynamic def | |
d1bddd3c | 1058 | // or by a special symbol (bit 33). |
ce279a62 | 1059 | bool undef_binding_weak_ : 1; |
5146f448 CC |
1060 | // True if this symbol is a predefined linker symbol (bit 34). |
1061 | bool is_predefined_ : 1; | |
bae7f79e ILT |
1062 | }; |
1063 | ||
14bfc3f5 ILT |
1064 | // The parts of a symbol which are size specific. Using a template |
1065 | // derived class like this helps us use less space on a 32-bit system. | |
bae7f79e ILT |
1066 | |
1067 | template<int size> | |
14bfc3f5 ILT |
1068 | class Sized_symbol : public Symbol |
1069 | { | |
1070 | public: | |
1564db8d ILT |
1071 | typedef typename elfcpp::Elf_types<size>::Elf_Addr Value_type; |
1072 | typedef typename elfcpp::Elf_types<size>::Elf_WXword Size_type; | |
1073 | ||
14bfc3f5 ILT |
1074 | Sized_symbol() |
1075 | { } | |
1076 | ||
d491d34e ILT |
1077 | // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the |
1078 | // section index, IS_ORDINARY is whether it is a normal section | |
1079 | // index rather than a special code. | |
14bfc3f5 ILT |
1080 | template<bool big_endian> |
1081 | void | |
ca09d69a | 1082 | init_object(const char* name, const char* version, Object* object, |
f3e9c5c5 ILT |
1083 | const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx, |
1084 | bool is_ordinary); | |
14bfc3f5 | 1085 | |
ead1e424 ILT |
1086 | // Initialize fields for an Output_data. |
1087 | void | |
75517b77 ILT |
1088 | init_output_data(const char* name, const char* version, Output_data*, |
1089 | Value_type value, Size_type symsize, elfcpp::STT, | |
1090 | elfcpp::STB, elfcpp::STV, unsigned char nonvis, | |
5146f448 | 1091 | bool offset_is_from_end, bool is_predefined); |
ead1e424 ILT |
1092 | |
1093 | // Initialize fields for an Output_segment. | |
1094 | void | |
75517b77 ILT |
1095 | init_output_segment(const char* name, const char* version, Output_segment*, |
1096 | Value_type value, Size_type symsize, elfcpp::STT, | |
1097 | elfcpp::STB, elfcpp::STV, unsigned char nonvis, | |
5146f448 | 1098 | Segment_offset_base offset_base, bool is_predefined); |
ead1e424 ILT |
1099 | |
1100 | // Initialize fields for a constant. | |
1101 | void | |
75517b77 ILT |
1102 | init_constant(const char* name, const char* version, Value_type value, |
1103 | Size_type symsize, elfcpp::STT, elfcpp::STB, elfcpp::STV, | |
5146f448 | 1104 | unsigned char nonvis, bool is_predefined); |
f3e9c5c5 ILT |
1105 | |
1106 | // Initialize fields for an undefined symbol. | |
1107 | void | |
75517b77 ILT |
1108 | init_undefined(const char* name, const char* version, elfcpp::STT, |
1109 | elfcpp::STB, elfcpp::STV, unsigned char nonvis); | |
ead1e424 | 1110 | |
1564db8d ILT |
1111 | // Override existing symbol. |
1112 | template<bool big_endian> | |
1113 | void | |
d491d34e ILT |
1114 | override(const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx, |
1115 | bool is_ordinary, Object* object, const char* version); | |
1564db8d | 1116 | |
86f2e683 ILT |
1117 | // Override existing symbol with a special symbol. |
1118 | void | |
1119 | override_with_special(const Sized_symbol<size>*); | |
1120 | ||
1564db8d ILT |
1121 | // Return the symbol's value. |
1122 | Value_type | |
1123 | value() const | |
1124 | { return this->value_; } | |
1125 | ||
1126 | // Return the symbol's size (we can't call this 'size' because that | |
1127 | // is a template parameter). | |
1128 | Size_type | |
1129 | symsize() const | |
ead1e424 ILT |
1130 | { return this->symsize_; } |
1131 | ||
1132 | // Set the symbol size. This is used when resolving common symbols. | |
1133 | void | |
2ea97941 ILT |
1134 | set_symsize(Size_type symsize) |
1135 | { this->symsize_ = symsize; } | |
1564db8d | 1136 | |
75f65a3e ILT |
1137 | // Set the symbol value. This is called when we store the final |
1138 | // values of the symbols into the symbol table. | |
1139 | void | |
2ea97941 ILT |
1140 | set_value(Value_type value) |
1141 | { this->value_ = value; } | |
75f65a3e | 1142 | |
c7912668 ILT |
1143 | // Allocate a common symbol by giving it a location in the output |
1144 | // file. | |
1145 | void | |
1146 | allocate_common(Output_data*, Value_type value); | |
1147 | ||
14bfc3f5 ILT |
1148 | private: |
1149 | Sized_symbol(const Sized_symbol&); | |
1150 | Sized_symbol& operator=(const Sized_symbol&); | |
1151 | ||
ead1e424 ILT |
1152 | // Symbol value. Before Layout::finalize this is the offset in the |
1153 | // input section. This is set to the final value during | |
1154 | // Layout::finalize. | |
1564db8d | 1155 | Value_type value_; |
14bfc3f5 | 1156 | // Symbol size. |
ead1e424 ILT |
1157 | Size_type symsize_; |
1158 | }; | |
1159 | ||
1160 | // A struct describing a symbol defined by the linker, where the value | |
1161 | // of the symbol is defined based on an output section. This is used | |
1162 | // for symbols defined by the linker, like "_init_array_start". | |
1163 | ||
1164 | struct Define_symbol_in_section | |
1165 | { | |
1166 | // The symbol name. | |
1167 | const char* name; | |
1168 | // The name of the output section with which this symbol should be | |
1169 | // associated. If there is no output section with that name, the | |
1170 | // symbol will be defined as zero. | |
1171 | const char* output_section; | |
1172 | // The offset of the symbol within the output section. This is an | |
1173 | // offset from the start of the output section, unless start_at_end | |
1174 | // is true, in which case this is an offset from the end of the | |
1175 | // output section. | |
1176 | uint64_t value; | |
1177 | // The size of the symbol. | |
1178 | uint64_t size; | |
1179 | // The symbol type. | |
1180 | elfcpp::STT type; | |
1181 | // The symbol binding. | |
1182 | elfcpp::STB binding; | |
1183 | // The symbol visibility. | |
1184 | elfcpp::STV visibility; | |
1185 | // The rest of the st_other field. | |
1186 | unsigned char nonvis; | |
1187 | // If true, the value field is an offset from the end of the output | |
1188 | // section. | |
1189 | bool offset_is_from_end; | |
1190 | // If true, this symbol is defined only if we see a reference to it. | |
1191 | bool only_if_ref; | |
1192 | }; | |
1193 | ||
1194 | // A struct describing a symbol defined by the linker, where the value | |
1195 | // of the symbol is defined based on a segment. This is used for | |
1196 | // symbols defined by the linker, like "_end". We describe the | |
1197 | // segment with which the symbol should be associated by its | |
1198 | // characteristics. If no segment meets these characteristics, the | |
1199 | // symbol will be defined as zero. If there is more than one segment | |
1200 | // which meets these characteristics, we will use the first one. | |
1201 | ||
1202 | struct Define_symbol_in_segment | |
1203 | { | |
1204 | // The symbol name. | |
1205 | const char* name; | |
1206 | // The segment type where the symbol should be defined, typically | |
1207 | // PT_LOAD. | |
1208 | elfcpp::PT segment_type; | |
1209 | // Bitmask of segment flags which must be set. | |
1210 | elfcpp::PF segment_flags_set; | |
1211 | // Bitmask of segment flags which must be clear. | |
1212 | elfcpp::PF segment_flags_clear; | |
1213 | // The offset of the symbol within the segment. The offset is | |
1214 | // calculated from the position set by offset_base. | |
1215 | uint64_t value; | |
1216 | // The size of the symbol. | |
1217 | uint64_t size; | |
1218 | // The symbol type. | |
1219 | elfcpp::STT type; | |
1220 | // The symbol binding. | |
1221 | elfcpp::STB binding; | |
1222 | // The symbol visibility. | |
1223 | elfcpp::STV visibility; | |
1224 | // The rest of the st_other field. | |
1225 | unsigned char nonvis; | |
1226 | // The base from which we compute the offset. | |
1227 | Symbol::Segment_offset_base offset_base; | |
1228 | // If true, this symbol is defined only if we see a reference to it. | |
1229 | bool only_if_ref; | |
14bfc3f5 ILT |
1230 | }; |
1231 | ||
dc3714f3 AM |
1232 | // Specify an object/section/offset location. Used by ODR code. |
1233 | ||
1234 | struct Symbol_location | |
1235 | { | |
1236 | // Object where the symbol is defined. | |
1237 | Object* object; | |
1238 | // Section-in-object where the symbol is defined. | |
1239 | unsigned int shndx; | |
1240 | // For relocatable objects, offset-in-section where the symbol is defined. | |
1241 | // For dynamic objects, address where the symbol is defined. | |
1242 | off_t offset; | |
1243 | bool operator==(const Symbol_location& that) const | |
1244 | { | |
1245 | return (this->object == that.object | |
1246 | && this->shndx == that.shndx | |
1247 | && this->offset == that.offset); | |
1248 | } | |
1249 | }; | |
1250 | ||
f6ce93d6 ILT |
1251 | // This class manages warnings. Warnings are a GNU extension. When |
1252 | // we see a section named .gnu.warning.SYM in an object file, and if | |
1253 | // we wind using the definition of SYM from that object file, then we | |
1254 | // will issue a warning for any relocation against SYM from a | |
1255 | // different object file. The text of the warning is the contents of | |
1256 | // the section. This is not precisely the definition used by the old | |
1257 | // GNU linker; the old GNU linker treated an occurrence of | |
1258 | // .gnu.warning.SYM as defining a warning symbol. A warning symbol | |
1259 | // would trigger a warning on any reference. However, it was | |
1260 | // inconsistent in that a warning in a dynamic object only triggered | |
1261 | // if there was no definition in a regular object. This linker is | |
1262 | // different in that we only issue a warning if we use the symbol | |
1263 | // definition from the same object file as the warning section. | |
1264 | ||
1265 | class Warnings | |
1266 | { | |
1267 | public: | |
1268 | Warnings() | |
1269 | : warnings_() | |
1270 | { } | |
1271 | ||
cb295612 ILT |
1272 | // Add a warning for symbol NAME in object OBJ. WARNING is the text |
1273 | // of the warning. | |
f6ce93d6 ILT |
1274 | void |
1275 | add_warning(Symbol_table* symtab, const char* name, Object* obj, | |
cb295612 | 1276 | const std::string& warning); |
f6ce93d6 ILT |
1277 | |
1278 | // For each symbol for which we should give a warning, make a note | |
1279 | // on the symbol. | |
1280 | void | |
cb295612 | 1281 | note_warnings(Symbol_table* symtab); |
f6ce93d6 | 1282 | |
75f2446e ILT |
1283 | // Issue a warning for a reference to SYM at RELINFO's location. |
1284 | template<int size, bool big_endian> | |
f6ce93d6 | 1285 | void |
75f2446e ILT |
1286 | issue_warning(const Symbol* sym, const Relocate_info<size, big_endian>*, |
1287 | size_t relnum, off_t reloffset) const; | |
f6ce93d6 ILT |
1288 | |
1289 | private: | |
1290 | Warnings(const Warnings&); | |
1291 | Warnings& operator=(const Warnings&); | |
1292 | ||
1293 | // What we need to know to get the warning text. | |
1294 | struct Warning_location | |
1295 | { | |
1296 | // The object the warning is in. | |
1297 | Object* object; | |
cb295612 | 1298 | // The warning text. |
f6ce93d6 ILT |
1299 | std::string text; |
1300 | ||
1301 | Warning_location() | |
cb295612 | 1302 | : object(NULL), text() |
f6ce93d6 ILT |
1303 | { } |
1304 | ||
1305 | void | |
cb295612 | 1306 | set(Object* o, const std::string& t) |
f6ce93d6 ILT |
1307 | { |
1308 | this->object = o; | |
cb295612 | 1309 | this->text = t; |
f6ce93d6 | 1310 | } |
f6ce93d6 ILT |
1311 | }; |
1312 | ||
1313 | // A mapping from warning symbol names (canonicalized in | |
70e654ba | 1314 | // Symbol_table's namepool_ field) to warning information. |
f6ce93d6 ILT |
1315 | typedef Unordered_map<const char*, Warning_location> Warning_table; |
1316 | ||
1317 | Warning_table warnings_; | |
1318 | }; | |
1319 | ||
14bfc3f5 ILT |
1320 | // The main linker symbol table. |
1321 | ||
bae7f79e ILT |
1322 | class Symbol_table |
1323 | { | |
1324 | public: | |
99fff23b ILT |
1325 | // The different places where a symbol definition can come from. |
1326 | enum Defined | |
1327 | { | |
1328 | // Defined in an object file--the normal case. | |
1329 | OBJECT, | |
1330 | // Defined for a COPY reloc. | |
1331 | COPY, | |
1332 | // Defined on the command line using --defsym. | |
1333 | DEFSYM, | |
1334 | // Defined (so to speak) on the command line using -u. | |
1335 | UNDEFINED, | |
1336 | // Defined in a linker script. | |
1337 | SCRIPT, | |
1338 | // Predefined by the linker. | |
1339 | PREDEFINED, | |
5146f448 CC |
1340 | // Defined by the linker during an incremental base link, but not |
1341 | // a predefined symbol (e.g., common, defined in script). | |
1342 | INCREMENTAL_BASE, | |
99fff23b ILT |
1343 | }; |
1344 | ||
fc59c572 ILT |
1345 | // The order in which we sort common symbols. |
1346 | enum Sort_commons_order | |
1347 | { | |
1348 | SORT_COMMONS_BY_SIZE_DESCENDING, | |
1349 | SORT_COMMONS_BY_ALIGNMENT_DESCENDING, | |
1350 | SORT_COMMONS_BY_ALIGNMENT_ASCENDING | |
1351 | }; | |
1352 | ||
9b547ce6 | 1353 | // COUNT is an estimate of how many symbols will be inserted in the |
6d013333 ILT |
1354 | // symbol table. It's ok to put 0 if you don't know; a correct |
1355 | // guess will just save some CPU by reducing hashtable resizes. | |
09124467 | 1356 | Symbol_table(unsigned int count, const Version_script_info& version_script); |
bae7f79e | 1357 | |
1564db8d | 1358 | ~Symbol_table(); |
bae7f79e | 1359 | |
ef15dade | 1360 | void |
2ea97941 ILT |
1361 | set_icf(Icf* icf) |
1362 | { this->icf_ = icf;} | |
ef15dade ST |
1363 | |
1364 | Icf* | |
1365 | icf() const | |
1366 | { return this->icf_; } | |
1367 | ||
1368 | // Returns true if ICF determined that this is a duplicate section. | |
1369 | bool | |
1370 | is_section_folded(Object* obj, unsigned int shndx) const; | |
1371 | ||
6d03d481 | 1372 | void |
2ea97941 ILT |
1373 | set_gc(Garbage_collection* gc) |
1374 | { this->gc_ = gc; } | |
6d03d481 ST |
1375 | |
1376 | Garbage_collection* | |
ef15dade | 1377 | gc() const |
6d03d481 ST |
1378 | { return this->gc_; } |
1379 | ||
1380 | // During garbage collection, this keeps undefined symbols. | |
1381 | void | |
88a4108b | 1382 | gc_mark_undef_symbols(Layout*); |
6d03d481 | 1383 | |
7257cc92 | 1384 | // This tells garbage collection that this symbol is referenced. |
6d03d481 | 1385 | void |
7257cc92 | 1386 | gc_mark_symbol(Symbol* sym); |
6d03d481 ST |
1387 | |
1388 | // During garbage collection, this keeps sections that correspond to | |
1389 | // symbols seen in dynamic objects. | |
1390 | inline void | |
1391 | gc_mark_dyn_syms(Symbol* sym); | |
1392 | ||
dbe717ef | 1393 | // Add COUNT external symbols from the relocatable object RELOBJ to |
d491d34e ILT |
1394 | // the symbol table. SYMS is the symbols, SYMNDX_OFFSET is the |
1395 | // offset in the symbol table of the first symbol, SYM_NAMES is | |
1396 | // their names, SYM_NAME_SIZE is the size of SYM_NAMES. This sets | |
92de84a6 ILT |
1397 | // SYMPOINTERS to point to the symbols in the symbol table. It sets |
1398 | // *DEFINED to the number of defined symbols. | |
14bfc3f5 ILT |
1399 | template<int size, bool big_endian> |
1400 | void | |
6fa2a40b | 1401 | add_from_relobj(Sized_relobj_file<size, big_endian>* relobj, |
dbe717ef | 1402 | const unsigned char* syms, size_t count, |
d491d34e ILT |
1403 | size_t symndx_offset, const char* sym_names, |
1404 | size_t sym_name_size, | |
6fa2a40b | 1405 | typename Sized_relobj_file<size, big_endian>::Symbols*, |
92de84a6 | 1406 | size_t* defined); |
89fc3421 CC |
1407 | |
1408 | // Add one external symbol from the plugin object OBJ to the symbol table. | |
1409 | // Returns a pointer to the resolved symbol in the symbol table. | |
1410 | template<int size, bool big_endian> | |
1411 | Symbol* | |
1412 | add_from_pluginobj(Sized_pluginobj<size, big_endian>* obj, | |
1413 | const char* name, const char* ver, | |
1414 | elfcpp::Sym<size, big_endian>* sym); | |
14bfc3f5 | 1415 | |
dbe717ef ILT |
1416 | // Add COUNT dynamic symbols from the dynamic object DYNOBJ to the |
1417 | // symbol table. SYMS is the symbols. SYM_NAMES is their names. | |
1418 | // SYM_NAME_SIZE is the size of SYM_NAMES. The other parameters are | |
1419 | // symbol version data. | |
1420 | template<int size, bool big_endian> | |
1421 | void | |
1422 | add_from_dynobj(Sized_dynobj<size, big_endian>* dynobj, | |
1423 | const unsigned char* syms, size_t count, | |
1424 | const char* sym_names, size_t sym_name_size, | |
1425 | const unsigned char* versym, size_t versym_size, | |
92de84a6 | 1426 | const std::vector<const char*>*, |
6fa2a40b | 1427 | typename Sized_relobj_file<size, big_endian>::Symbols*, |
92de84a6 | 1428 | size_t* defined); |
dbe717ef | 1429 | |
cdc29364 CC |
1430 | // Add one external symbol from the incremental object OBJ to the symbol |
1431 | // table. Returns a pointer to the resolved symbol in the symbol table. | |
1432 | template<int size, bool big_endian> | |
26d3c67d | 1433 | Sized_symbol<size>* |
cdc29364 CC |
1434 | add_from_incrobj(Object* obj, const char* name, |
1435 | const char* ver, elfcpp::Sym<size, big_endian>* sym); | |
1436 | ||
ead1e424 ILT |
1437 | // Define a special symbol based on an Output_data. It is a |
1438 | // multiple definition error if this symbol is already defined. | |
14b31740 | 1439 | Symbol* |
99fff23b | 1440 | define_in_output_data(const char* name, const char* version, Defined, |
14b31740 | 1441 | Output_data*, uint64_t value, uint64_t symsize, |
ead1e424 ILT |
1442 | elfcpp::STT type, elfcpp::STB binding, |
1443 | elfcpp::STV visibility, unsigned char nonvis, | |
1444 | bool offset_is_from_end, bool only_if_ref); | |
1445 | ||
1446 | // Define a special symbol based on an Output_segment. It is a | |
1447 | // multiple definition error if this symbol is already defined. | |
14b31740 | 1448 | Symbol* |
99fff23b | 1449 | define_in_output_segment(const char* name, const char* version, Defined, |
9b07f471 | 1450 | Output_segment*, uint64_t value, uint64_t symsize, |
ead1e424 ILT |
1451 | elfcpp::STT type, elfcpp::STB binding, |
1452 | elfcpp::STV visibility, unsigned char nonvis, | |
1453 | Symbol::Segment_offset_base, bool only_if_ref); | |
1454 | ||
1455 | // Define a special symbol with a constant value. It is a multiple | |
1456 | // definition error if this symbol is already defined. | |
14b31740 | 1457 | Symbol* |
99fff23b | 1458 | define_as_constant(const char* name, const char* version, Defined, |
14b31740 ILT |
1459 | uint64_t value, uint64_t symsize, elfcpp::STT type, |
1460 | elfcpp::STB binding, elfcpp::STV visibility, | |
caa9d5d9 ILT |
1461 | unsigned char nonvis, bool only_if_ref, |
1462 | bool force_override); | |
ead1e424 | 1463 | |
a445fddf ILT |
1464 | // Define a set of symbols in output sections. If ONLY_IF_REF is |
1465 | // true, only define them if they are referenced. | |
ead1e424 | 1466 | void |
a445fddf ILT |
1467 | define_symbols(const Layout*, int count, const Define_symbol_in_section*, |
1468 | bool only_if_ref); | |
ead1e424 | 1469 | |
a445fddf ILT |
1470 | // Define a set of symbols in output segments. If ONLY_IF_REF is |
1471 | // true, only defined them if they are referenced. | |
ead1e424 | 1472 | void |
a445fddf ILT |
1473 | define_symbols(const Layout*, int count, const Define_symbol_in_segment*, |
1474 | bool only_if_ref); | |
ead1e424 | 1475 | |
46fe1623 ILT |
1476 | // Define SYM using a COPY reloc. POSD is the Output_data where the |
1477 | // symbol should be defined--typically a .dyn.bss section. VALUE is | |
1478 | // the offset within POSD. | |
1479 | template<int size> | |
1480 | void | |
9b07f471 | 1481 | define_with_copy_reloc(Sized_symbol<size>* sym, Output_data* posd, |
fe8718a4 | 1482 | typename elfcpp::Elf_types<size>::Elf_Addr); |
46fe1623 | 1483 | |
61ba1cf9 ILT |
1484 | // Look up a symbol. |
1485 | Symbol* | |
1486 | lookup(const char*, const char* version = NULL) const; | |
1487 | ||
14bfc3f5 | 1488 | // Return the real symbol associated with the forwarder symbol FROM. |
bae7f79e | 1489 | Symbol* |
c06b7b0b | 1490 | resolve_forwards(const Symbol* from) const; |
bae7f79e | 1491 | |
1564db8d ILT |
1492 | // Return the sized version of a symbol in this table. |
1493 | template<int size> | |
1494 | Sized_symbol<size>* | |
7d1a9ebb | 1495 | get_sized_symbol(Symbol*) const; |
1564db8d ILT |
1496 | |
1497 | template<int size> | |
1498 | const Sized_symbol<size>* | |
7d1a9ebb | 1499 | get_sized_symbol(const Symbol*) const; |
54dc6425 | 1500 | |
ead1e424 | 1501 | // Return the count of undefined symbols seen. |
114dfbe1 | 1502 | size_t |
ead1e424 ILT |
1503 | saw_undefined() const |
1504 | { return this->saw_undefined_; } | |
1505 | ||
1506 | // Allocate the common symbols | |
1507 | void | |
7d9e3d98 | 1508 | allocate_commons(Layout*, Mapfile*); |
ead1e424 | 1509 | |
cb295612 ILT |
1510 | // Add a warning for symbol NAME in object OBJ. WARNING is the text |
1511 | // of the warning. | |
f6ce93d6 | 1512 | void |
cb295612 ILT |
1513 | add_warning(const char* name, Object* obj, const std::string& warning) |
1514 | { this->warnings_.add_warning(this, name, obj, warning); } | |
f6ce93d6 ILT |
1515 | |
1516 | // Canonicalize a symbol name for use in the hash table. | |
1517 | const char* | |
1518 | canonicalize_name(const char* name) | |
cfd73a4e | 1519 | { return this->namepool_.add(name, true, NULL); } |
f6ce93d6 ILT |
1520 | |
1521 | // Possibly issue a warning for a reference to SYM at LOCATION which | |
1522 | // is in OBJ. | |
75f2446e | 1523 | template<int size, bool big_endian> |
f6ce93d6 | 1524 | void |
75f2446e ILT |
1525 | issue_warning(const Symbol* sym, |
1526 | const Relocate_info<size, big_endian>* relinfo, | |
1527 | size_t relnum, off_t reloffset) const | |
1528 | { this->warnings_.issue_warning(sym, relinfo, relnum, reloffset); } | |
f6ce93d6 | 1529 | |
70e654ba ILT |
1530 | // Check candidate_odr_violations_ to find symbols with the same name |
1531 | // but apparently different definitions (different source-file/line-no). | |
1532 | void | |
17a1d0a9 | 1533 | detect_odr_violations(const Task*, const char* output_file_name) const; |
70e654ba | 1534 | |
f3e9c5c5 ILT |
1535 | // Add any undefined symbols named on the command line to the symbol |
1536 | // table. | |
1537 | void | |
88a4108b | 1538 | add_undefined_symbols_from_command_line(Layout*); |
f3e9c5c5 | 1539 | |
46fe1623 ILT |
1540 | // SYM is defined using a COPY reloc. Return the dynamic object |
1541 | // where the original definition was found. | |
1542 | Dynobj* | |
1543 | get_copy_source(const Symbol* sym) const; | |
1544 | ||
a3ad94ed ILT |
1545 | // Set the dynamic symbol indexes. INDEX is the index of the first |
1546 | // global dynamic symbol. Pointers to the symbols are stored into | |
1547 | // the vector. The names are stored into the Stringpool. This | |
1548 | // returns an updated dynamic symbol index. | |
1549 | unsigned int | |
9b07f471 ILT |
1550 | set_dynsym_indexes(unsigned int index, std::vector<Symbol*>*, |
1551 | Stringpool*, Versions*); | |
a3ad94ed | 1552 | |
75f65a3e | 1553 | // Finalize the symbol table after we have set the final addresses |
c06b7b0b | 1554 | // of all the input sections. This sets the final symbol indexes, |
55a93433 ILT |
1555 | // values and adds the names to *POOL. *PLOCAL_SYMCOUNT is the |
1556 | // index of the first global symbol. OFF is the file offset of the | |
1557 | // global symbol table, DYNOFF is the offset of the globals in the | |
1558 | // dynamic symbol table, DYN_GLOBAL_INDEX is the index of the first | |
1559 | // global dynamic symbol, and DYNCOUNT is the number of global | |
1560 | // dynamic symbols. This records the parameters, and returns the | |
1561 | // new file offset. It updates *PLOCAL_SYMCOUNT if it created any | |
1562 | // local symbols. | |
75f65a3e | 1563 | off_t |
55a93433 | 1564 | finalize(off_t off, off_t dynoff, size_t dyn_global_index, size_t dyncount, |
ca09d69a | 1565 | Stringpool* pool, unsigned int* plocal_symcount); |
1564db8d | 1566 | |
cdc29364 CC |
1567 | // Set the final file offset of the symbol table. |
1568 | void | |
1569 | set_file_offset(off_t off) | |
1570 | { this->offset_ = off; } | |
1571 | ||
c0a62865 DK |
1572 | // Status code of Symbol_table::compute_final_value. |
1573 | enum Compute_final_value_status | |
1574 | { | |
1575 | // No error. | |
1576 | CFVS_OK, | |
9b547ce6 | 1577 | // Unsupported symbol section. |
c0a62865 DK |
1578 | CFVS_UNSUPPORTED_SYMBOL_SECTION, |
1579 | // No output section. | |
1580 | CFVS_NO_OUTPUT_SECTION | |
1581 | }; | |
1582 | ||
1583 | // Compute the final value of SYM and store status in location PSTATUS. | |
1584 | // During relaxation, this may be called multiple times for a symbol to | |
1585 | // compute its would-be final value in each relaxation pass. | |
1586 | ||
1587 | template<int size> | |
1588 | typename Sized_symbol<size>::Value_type | |
1589 | compute_final_value(const Sized_symbol<size>* sym, | |
1590 | Compute_final_value_status* pstatus) const; | |
1591 | ||
09ec0418 CC |
1592 | // Return the index of the first global symbol. |
1593 | unsigned int | |
1594 | first_global_index() const | |
1595 | { return this->first_global_index_; } | |
1596 | ||
1597 | // Return the total number of symbols in the symbol table. | |
1598 | unsigned int | |
1599 | output_count() const | |
1600 | { return this->output_count_; } | |
1601 | ||
61ba1cf9 ILT |
1602 | // Write out the global symbols. |
1603 | void | |
fd9d194f | 1604 | write_globals(const Stringpool*, const Stringpool*, |
d491d34e | 1605 | Output_symtab_xindex*, Output_symtab_xindex*, |
16649710 | 1606 | Output_file*) const; |
61ba1cf9 | 1607 | |
a3ad94ed ILT |
1608 | // Write out a section symbol. Return the updated offset. |
1609 | void | |
d491d34e ILT |
1610 | write_section_symbol(const Output_section*, Output_symtab_xindex*, |
1611 | Output_file*, off_t) const; | |
a3ad94ed | 1612 | |
0e70b911 CC |
1613 | // Loop over all symbols, applying the function F to each. |
1614 | template<int size, typename F> | |
1615 | void | |
1616 | for_all_symbols(F f) const | |
1617 | { | |
1618 | for (Symbol_table_type::const_iterator p = this->table_.begin(); | |
1619 | p != this->table_.end(); | |
1620 | ++p) | |
1621 | { | |
1622 | Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second); | |
1623 | f(sym); | |
1624 | } | |
1625 | } | |
1626 | ||
abaa3995 ILT |
1627 | // Dump statistical information to stderr. |
1628 | void | |
1629 | print_stats() const; | |
1630 | ||
09124467 ILT |
1631 | // Return the version script information. |
1632 | const Version_script_info& | |
1633 | version_script() const | |
1634 | { return version_script_; } | |
1635 | ||
bae7f79e ILT |
1636 | private: |
1637 | Symbol_table(const Symbol_table&); | |
1638 | Symbol_table& operator=(const Symbol_table&); | |
1639 | ||
155a0dd7 ILT |
1640 | // The type of the list of common symbols. |
1641 | typedef std::vector<Symbol*> Commons_type; | |
1642 | ||
8c500701 ILT |
1643 | // The type of the symbol hash table. |
1644 | ||
1645 | typedef std::pair<Stringpool::Key, Stringpool::Key> Symbol_table_key; | |
1646 | ||
a9bfd952 | 1647 | // The hash function. The key values are Stringpool keys. |
8c500701 ILT |
1648 | struct Symbol_table_hash |
1649 | { | |
a9bfd952 DK |
1650 | inline size_t |
1651 | operator()(const Symbol_table_key& key) const | |
1652 | { | |
1653 | return key.first ^ key.second; | |
1654 | } | |
8c500701 ILT |
1655 | }; |
1656 | ||
1657 | struct Symbol_table_eq | |
1658 | { | |
1659 | bool | |
1660 | operator()(const Symbol_table_key&, const Symbol_table_key&) const; | |
1661 | }; | |
1662 | ||
1663 | typedef Unordered_map<Symbol_table_key, Symbol*, Symbol_table_hash, | |
1664 | Symbol_table_eq> Symbol_table_type; | |
1665 | ||
71ff8986 ILT |
1666 | // A map from symbol name (as a pointer into the namepool) to all |
1667 | // the locations the symbols is (weakly) defined (and certain other | |
1668 | // conditions are met). This map will be used later to detect | |
1669 | // possible One Definition Rule (ODR) violations. | |
71ff8986 ILT |
1670 | struct Symbol_location_hash |
1671 | { | |
1672 | size_t operator()(const Symbol_location& loc) const | |
1673 | { return reinterpret_cast<uintptr_t>(loc.object) ^ loc.offset ^ loc.shndx; } | |
1674 | }; | |
1675 | ||
1676 | typedef Unordered_map<const char*, | |
1677 | Unordered_set<Symbol_location, Symbol_location_hash> > | |
1678 | Odr_map; | |
1679 | ||
14bfc3f5 ILT |
1680 | // Make FROM a forwarder symbol to TO. |
1681 | void | |
1682 | make_forwarder(Symbol* from, Symbol* to); | |
1683 | ||
1684 | // Add a symbol. | |
1685 | template<int size, bool big_endian> | |
aeddab66 | 1686 | Sized_symbol<size>* |
ca09d69a NC |
1687 | add_from_object(Object*, const char* name, Stringpool::Key name_key, |
1688 | const char* version, Stringpool::Key version_key, | |
70e654ba | 1689 | bool def, const elfcpp::Sym<size, big_endian>& sym, |
d491d34e ILT |
1690 | unsigned int st_shndx, bool is_ordinary, |
1691 | unsigned int orig_st_shndx); | |
14bfc3f5 | 1692 | |
8c500701 ILT |
1693 | // Define a default symbol. |
1694 | template<int size, bool big_endian> | |
1695 | void | |
1696 | define_default_version(Sized_symbol<size>*, bool, | |
1697 | Symbol_table_type::iterator); | |
1698 | ||
14bfc3f5 ILT |
1699 | // Resolve symbols. |
1700 | template<int size, bool big_endian> | |
aeddab66 | 1701 | void |
1564db8d ILT |
1702 | resolve(Sized_symbol<size>* to, |
1703 | const elfcpp::Sym<size, big_endian>& sym, | |
d491d34e ILT |
1704 | unsigned int st_shndx, bool is_ordinary, |
1705 | unsigned int orig_st_shndx, | |
14b31740 | 1706 | Object*, const char* version); |
14bfc3f5 | 1707 | |
1564db8d | 1708 | template<int size, bool big_endian> |
aeddab66 | 1709 | void |
95d14cd3 | 1710 | resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from); |
14b31740 | 1711 | |
0602e05a ILT |
1712 | // Record that a symbol is forced to be local by a version script or |
1713 | // by visibility. | |
55a93433 ILT |
1714 | void |
1715 | force_local(Symbol*); | |
1716 | ||
0864d551 ILT |
1717 | // Adjust NAME and *NAME_KEY for wrapping. |
1718 | const char* | |
029ba973 | 1719 | wrap_symbol(const char* name, Stringpool::Key* name_key); |
0864d551 | 1720 | |
86f2e683 ILT |
1721 | // Whether we should override a symbol, based on flags in |
1722 | // resolve.cc. | |
1723 | static bool | |
62855347 ILT |
1724 | should_override(const Symbol*, unsigned int, elfcpp::STT, Defined, |
1725 | Object*, bool*, bool*); | |
86f2e683 | 1726 | |
1ae4d23b ILT |
1727 | // Report a problem in symbol resolution. |
1728 | static void | |
1729 | report_resolve_problem(bool is_error, const char* msg, const Symbol* to, | |
99fff23b | 1730 | Defined, Object* object); |
1ae4d23b | 1731 | |
aeddab66 ILT |
1732 | // Override a symbol. |
1733 | template<int size, bool big_endian> | |
1734 | void | |
1735 | override(Sized_symbol<size>* tosym, | |
1736 | const elfcpp::Sym<size, big_endian>& fromsym, | |
d491d34e | 1737 | unsigned int st_shndx, bool is_ordinary, |
aeddab66 ILT |
1738 | Object* object, const char* version); |
1739 | ||
86f2e683 ILT |
1740 | // Whether we should override a symbol with a special symbol which |
1741 | // is automatically defined by the linker. | |
1742 | static bool | |
62855347 | 1743 | should_override_with_special(const Symbol*, elfcpp::STT, Defined); |
86f2e683 | 1744 | |
aeddab66 ILT |
1745 | // Override a symbol with a special symbol. |
1746 | template<int size> | |
1747 | void | |
1748 | override_with_special(Sized_symbol<size>* tosym, | |
1749 | const Sized_symbol<size>* fromsym); | |
1750 | ||
1751 | // Record all weak alias sets for a dynamic object. | |
1752 | template<int size> | |
1753 | void | |
1754 | record_weak_aliases(std::vector<Sized_symbol<size>*>*); | |
1755 | ||
14b31740 ILT |
1756 | // Define a special symbol. |
1757 | template<int size, bool big_endian> | |
1758 | Sized_symbol<size>* | |
9b07f471 | 1759 | define_special_symbol(const char** pname, const char** pversion, |
8c500701 ILT |
1760 | bool only_if_ref, Sized_symbol<size>** poldsym, |
1761 | bool* resolve_oldsym); | |
14bfc3f5 | 1762 | |
ead1e424 ILT |
1763 | // Define a symbol in an Output_data, sized version. |
1764 | template<int size> | |
14b31740 | 1765 | Sized_symbol<size>* |
99fff23b ILT |
1766 | do_define_in_output_data(const char* name, const char* version, Defined, |
1767 | Output_data*, | |
ead1e424 ILT |
1768 | typename elfcpp::Elf_types<size>::Elf_Addr value, |
1769 | typename elfcpp::Elf_types<size>::Elf_WXword ssize, | |
1770 | elfcpp::STT type, elfcpp::STB binding, | |
1771 | elfcpp::STV visibility, unsigned char nonvis, | |
1772 | bool offset_is_from_end, bool only_if_ref); | |
1773 | ||
1774 | // Define a symbol in an Output_segment, sized version. | |
1775 | template<int size> | |
14b31740 | 1776 | Sized_symbol<size>* |
ead1e424 | 1777 | do_define_in_output_segment( |
99fff23b | 1778 | const char* name, const char* version, Defined, Output_segment* os, |
ead1e424 ILT |
1779 | typename elfcpp::Elf_types<size>::Elf_Addr value, |
1780 | typename elfcpp::Elf_types<size>::Elf_WXword ssize, | |
1781 | elfcpp::STT type, elfcpp::STB binding, | |
1782 | elfcpp::STV visibility, unsigned char nonvis, | |
1783 | Symbol::Segment_offset_base offset_base, bool only_if_ref); | |
1784 | ||
1785 | // Define a symbol as a constant, sized version. | |
1786 | template<int size> | |
14b31740 | 1787 | Sized_symbol<size>* |
ead1e424 | 1788 | do_define_as_constant( |
99fff23b | 1789 | const char* name, const char* version, Defined, |
ead1e424 ILT |
1790 | typename elfcpp::Elf_types<size>::Elf_Addr value, |
1791 | typename elfcpp::Elf_types<size>::Elf_WXword ssize, | |
1792 | elfcpp::STT type, elfcpp::STB binding, | |
1793 | elfcpp::STV visibility, unsigned char nonvis, | |
caa9d5d9 | 1794 | bool only_if_ref, bool force_override); |
ead1e424 | 1795 | |
f3e9c5c5 ILT |
1796 | // Add any undefined symbols named on the command line to the symbol |
1797 | // table, sized version. | |
1798 | template<int size> | |
1799 | void | |
88a4108b ILT |
1800 | do_add_undefined_symbols_from_command_line(Layout*); |
1801 | ||
1802 | // Add one undefined symbol. | |
1803 | template<int size> | |
1804 | void | |
1805 | add_undefined_symbol_from_command_line(const char* name); | |
f3e9c5c5 | 1806 | |
8a5e3e08 ILT |
1807 | // Types of common symbols. |
1808 | ||
1809 | enum Commons_section_type | |
1810 | { | |
1811 | COMMONS_NORMAL, | |
1812 | COMMONS_TLS, | |
1813 | COMMONS_SMALL, | |
1814 | COMMONS_LARGE | |
1815 | }; | |
1816 | ||
ead1e424 ILT |
1817 | // Allocate the common symbols, sized version. |
1818 | template<int size> | |
1819 | void | |
fc59c572 | 1820 | do_allocate_commons(Layout*, Mapfile*, Sort_commons_order); |
155a0dd7 ILT |
1821 | |
1822 | // Allocate the common symbols from one list. | |
1823 | template<int size> | |
1824 | void | |
8a5e3e08 | 1825 | do_allocate_commons_list(Layout*, Commons_section_type, Commons_type*, |
fc59c572 | 1826 | Mapfile*, Sort_commons_order); |
ead1e424 | 1827 | |
71ff8986 ILT |
1828 | // Returns all of the lines attached to LOC, not just the one the |
1829 | // instruction actually came from. This helps the ODR checker avoid | |
1830 | // false positives. | |
1831 | static std::vector<std::string> | |
1832 | linenos_from_loc(const Task* task, const Symbol_location& loc); | |
1833 | ||
70e654ba ILT |
1834 | // Implement detect_odr_violations. |
1835 | template<int size, bool big_endian> | |
1836 | void | |
1837 | sized_detect_odr_violations() const; | |
1838 | ||
75f65a3e ILT |
1839 | // Finalize symbols specialized for size. |
1840 | template<int size> | |
1841 | off_t | |
55a93433 ILT |
1842 | sized_finalize(off_t, Stringpool*, unsigned int*); |
1843 | ||
1844 | // Finalize a symbol. Return whether it should be added to the | |
1845 | // symbol table. | |
1846 | template<int size> | |
1847 | bool | |
1848 | sized_finalize_symbol(Symbol*); | |
1849 | ||
1850 | // Add a symbol the final symtab by setting its index. | |
1851 | template<int size> | |
1852 | void | |
1853 | add_to_final_symtab(Symbol*, Stringpool*, unsigned int* pindex, off_t* poff); | |
75f65a3e | 1854 | |
61ba1cf9 ILT |
1855 | // Write globals specialized for size and endianness. |
1856 | template<int size, bool big_endian> | |
1857 | void | |
fd9d194f ILT |
1858 | sized_write_globals(const Stringpool*, const Stringpool*, |
1859 | Output_symtab_xindex*, Output_symtab_xindex*, | |
1860 | Output_file*) const; | |
16649710 ILT |
1861 | |
1862 | // Write out a symbol to P. | |
1863 | template<int size, bool big_endian> | |
1864 | void | |
ab5c9e90 ILT |
1865 | sized_write_symbol(Sized_symbol<size>*, |
1866 | typename elfcpp::Elf_types<size>::Elf_Addr value, | |
ce279a62 | 1867 | unsigned int shndx, elfcpp::STB, |
7d1a9ebb | 1868 | const Stringpool*, unsigned char* p) const; |
61ba1cf9 | 1869 | |
9a2d6984 ILT |
1870 | // Possibly warn about an undefined symbol from a dynamic object. |
1871 | void | |
fd9d194f | 1872 | warn_about_undefined_dynobj_symbol(Symbol*) const; |
9a2d6984 | 1873 | |
a3ad94ed ILT |
1874 | // Write out a section symbol, specialized for size and endianness. |
1875 | template<int size, bool big_endian> | |
1876 | void | |
d491d34e ILT |
1877 | sized_write_section_symbol(const Output_section*, Output_symtab_xindex*, |
1878 | Output_file*, off_t) const; | |
a3ad94ed | 1879 | |
55a93433 ILT |
1880 | // The type of the list of symbols which have been forced local. |
1881 | typedef std::vector<Symbol*> Forced_locals; | |
1882 | ||
46fe1623 ILT |
1883 | // A map from symbols with COPY relocs to the dynamic objects where |
1884 | // they are defined. | |
1885 | typedef Unordered_map<const Symbol*, Dynobj*> Copied_symbol_dynobjs; | |
1886 | ||
ead1e424 ILT |
1887 | // We increment this every time we see a new undefined symbol, for |
1888 | // use in archive groups. | |
114dfbe1 | 1889 | size_t saw_undefined_; |
c06b7b0b ILT |
1890 | // The index of the first global symbol in the output file. |
1891 | unsigned int first_global_index_; | |
75f65a3e ILT |
1892 | // The file offset within the output symtab section where we should |
1893 | // write the table. | |
1894 | off_t offset_; | |
61ba1cf9 | 1895 | // The number of global symbols we want to write out. |
55a93433 | 1896 | unsigned int output_count_; |
16649710 ILT |
1897 | // The file offset of the global dynamic symbols, or 0 if none. |
1898 | off_t dynamic_offset_; | |
16649710 ILT |
1899 | // The index of the first global dynamic symbol. |
1900 | unsigned int first_dynamic_global_index_; | |
16649710 | 1901 | // The number of global dynamic symbols, or 0 if none. |
55a93433 | 1902 | unsigned int dynamic_count_; |
54dc6425 | 1903 | // The symbol hash table. |
14bfc3f5 | 1904 | Symbol_table_type table_; |
54dc6425 ILT |
1905 | // A pool of symbol names. This is used for all global symbols. |
1906 | // Entries in the hash table point into this pool. | |
14bfc3f5 | 1907 | Stringpool namepool_; |
14bfc3f5 | 1908 | // Forwarding symbols. |
c06b7b0b | 1909 | Unordered_map<const Symbol*, Symbol*> forwarders_; |
aeddab66 ILT |
1910 | // Weak aliases. A symbol in this list points to the next alias. |
1911 | // The aliases point to each other in a circular list. | |
1912 | Unordered_map<Symbol*, Symbol*> weak_aliases_; | |
ead1e424 ILT |
1913 | // We don't expect there to be very many common symbols, so we keep |
1914 | // a list of them. When we find a common symbol we add it to this | |
1915 | // list. It is possible that by the time we process the list the | |
1916 | // symbol is no longer a common symbol. It may also have become a | |
1917 | // forwarder. | |
1918 | Commons_type commons_; | |
155a0dd7 ILT |
1919 | // This is like the commons_ field, except that it holds TLS common |
1920 | // symbols. | |
1921 | Commons_type tls_commons_; | |
8a5e3e08 ILT |
1922 | // This is for small common symbols. |
1923 | Commons_type small_commons_; | |
1924 | // This is for large common symbols. | |
1925 | Commons_type large_commons_; | |
55a93433 ILT |
1926 | // A list of symbols which have been forced to be local. We don't |
1927 | // expect there to be very many of them, so we keep a list of them | |
1928 | // rather than walking the whole table to find them. | |
1929 | Forced_locals forced_locals_; | |
f6ce93d6 ILT |
1930 | // Manage symbol warnings. |
1931 | Warnings warnings_; | |
70e654ba ILT |
1932 | // Manage potential One Definition Rule (ODR) violations. |
1933 | Odr_map candidate_odr_violations_; | |
1934 | ||
46fe1623 ILT |
1935 | // When we emit a COPY reloc for a symbol, we define it in an |
1936 | // Output_data. When it's time to emit version information for it, | |
1937 | // we need to know the dynamic object in which we found the original | |
1938 | // definition. This maps symbols with COPY relocs to the dynamic | |
1939 | // object where they were defined. | |
1940 | Copied_symbol_dynobjs copied_symbol_dynobjs_; | |
09124467 ILT |
1941 | // Information parsed from the version script, if any. |
1942 | const Version_script_info& version_script_; | |
6d03d481 | 1943 | Garbage_collection* gc_; |
ef15dade | 1944 | Icf* icf_; |
bae7f79e ILT |
1945 | }; |
1946 | ||
1564db8d ILT |
1947 | // We inline get_sized_symbol for efficiency. |
1948 | ||
1949 | template<int size> | |
1950 | Sized_symbol<size>* | |
7d1a9ebb | 1951 | Symbol_table::get_sized_symbol(Symbol* sym) const |
1564db8d | 1952 | { |
8851ecca | 1953 | gold_assert(size == parameters->target().get_size()); |
1564db8d ILT |
1954 | return static_cast<Sized_symbol<size>*>(sym); |
1955 | } | |
1956 | ||
1957 | template<int size> | |
1958 | const Sized_symbol<size>* | |
7d1a9ebb | 1959 | Symbol_table::get_sized_symbol(const Symbol* sym) const |
1564db8d | 1960 | { |
8851ecca | 1961 | gold_assert(size == parameters->target().get_size()); |
1564db8d ILT |
1962 | return static_cast<const Sized_symbol<size>*>(sym); |
1963 | } | |
1964 | ||
bae7f79e ILT |
1965 | } // End namespace gold. |
1966 | ||
1967 | #endif // !defined(GOLD_SYMTAB_H) |