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bae7f79e ILT |
1 | // symtab.h -- the gold symbol table -*- C++ -*- |
2 | ||
6f2750fe | 3 | // Copyright (C) 2006-2016 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 | |
b45e00b3 CC |
143 | // Set that this version is not the default for this symbol name. |
144 | void | |
145 | set_is_not_default() | |
146 | { this->is_def_ = false; } | |
147 | ||
6d1c4efb ILT |
148 | // Return the symbol's name as name@version (or name@@version). |
149 | std::string | |
150 | versioned_name() const; | |
151 | ||
ead1e424 ILT |
152 | // Return the symbol source. |
153 | Source | |
154 | source() const | |
155 | { return this->source_; } | |
156 | ||
14bfc3f5 ILT |
157 | // Return the object with which this symbol is associated. |
158 | Object* | |
159 | object() const | |
ead1e424 | 160 | { |
a3ad94ed | 161 | gold_assert(this->source_ == FROM_OBJECT); |
ead1e424 ILT |
162 | return this->u_.from_object.object; |
163 | } | |
164 | ||
f6ce93d6 ILT |
165 | // Return the index of the section in the input relocatable or |
166 | // dynamic object file. | |
ead1e424 | 167 | unsigned int |
d491d34e | 168 | shndx(bool* is_ordinary) const |
ead1e424 | 169 | { |
a3ad94ed | 170 | gold_assert(this->source_ == FROM_OBJECT); |
d491d34e | 171 | *is_ordinary = this->is_ordinary_shndx_; |
16649710 | 172 | return this->u_.from_object.shndx; |
ead1e424 ILT |
173 | } |
174 | ||
175 | // Return the output data section with which this symbol is | |
176 | // associated, if the symbol was specially defined with respect to | |
177 | // an output data section. | |
178 | Output_data* | |
179 | output_data() const | |
180 | { | |
a3ad94ed | 181 | gold_assert(this->source_ == IN_OUTPUT_DATA); |
ead1e424 ILT |
182 | return this->u_.in_output_data.output_data; |
183 | } | |
184 | ||
185 | // If this symbol was defined with respect to an output data | |
186 | // section, return whether the value is an offset from end. | |
187 | bool | |
188 | offset_is_from_end() const | |
189 | { | |
a3ad94ed | 190 | gold_assert(this->source_ == IN_OUTPUT_DATA); |
ead1e424 ILT |
191 | return this->u_.in_output_data.offset_is_from_end; |
192 | } | |
193 | ||
194 | // Return the output segment with which this symbol is associated, | |
195 | // if the symbol was specially defined with respect to an output | |
196 | // segment. | |
197 | Output_segment* | |
198 | output_segment() const | |
199 | { | |
a3ad94ed | 200 | gold_assert(this->source_ == IN_OUTPUT_SEGMENT); |
ead1e424 ILT |
201 | return this->u_.in_output_segment.output_segment; |
202 | } | |
203 | ||
204 | // If this symbol was defined with respect to an output segment, | |
205 | // return the offset base. | |
206 | Segment_offset_base | |
207 | offset_base() const | |
208 | { | |
a3ad94ed | 209 | gold_assert(this->source_ == IN_OUTPUT_SEGMENT); |
ead1e424 ILT |
210 | return this->u_.in_output_segment.offset_base; |
211 | } | |
14bfc3f5 ILT |
212 | |
213 | // Return the symbol binding. | |
214 | elfcpp::STB | |
215 | binding() const | |
216 | { return this->binding_; } | |
217 | ||
1564db8d ILT |
218 | // Return the symbol type. |
219 | elfcpp::STT | |
220 | type() const | |
221 | { return this->type_; } | |
222 | ||
e051745c CC |
223 | // Set the symbol type. |
224 | void | |
225 | set_type(elfcpp::STT type) | |
226 | { this->type_ = type; } | |
227 | ||
53d7974c L |
228 | // Return true for function symbol. |
229 | bool | |
230 | is_func() const | |
231 | { | |
232 | return (this->type_ == elfcpp::STT_FUNC | |
233 | || this->type_ == elfcpp::STT_GNU_IFUNC); | |
234 | } | |
235 | ||
1564db8d ILT |
236 | // Return the symbol visibility. |
237 | elfcpp::STV | |
238 | visibility() const | |
239 | { return this->visibility_; } | |
240 | ||
0602e05a ILT |
241 | // Set the visibility. |
242 | void | |
2ea97941 ILT |
243 | set_visibility(elfcpp::STV visibility) |
244 | { this->visibility_ = visibility; } | |
0602e05a ILT |
245 | |
246 | // Override symbol visibility. | |
247 | void | |
248 | override_visibility(elfcpp::STV); | |
249 | ||
ce279a62 | 250 | // Set whether the symbol was originally a weak undef or a regular undef |
d1bddd3c | 251 | // when resolved by a dynamic def or by a special symbol. |
ce279a62 CC |
252 | inline void |
253 | set_undef_binding(elfcpp::STB bind) | |
254 | { | |
255 | if (!this->undef_binding_set_ || this->undef_binding_weak_) | |
256 | { | |
257 | this->undef_binding_weak_ = bind == elfcpp::STB_WEAK; | |
258 | this->undef_binding_set_ = true; | |
259 | } | |
260 | } | |
261 | ||
d1bddd3c CC |
262 | // Return TRUE if a weak undef was resolved by a dynamic def or |
263 | // by a special symbol. | |
ce279a62 CC |
264 | inline bool |
265 | is_undef_binding_weak() const | |
266 | { return this->undef_binding_weak_; } | |
267 | ||
1564db8d ILT |
268 | // Return the non-visibility part of the st_other field. |
269 | unsigned char | |
ead1e424 ILT |
270 | nonvis() const |
271 | { return this->nonvis_; } | |
14bfc3f5 | 272 | |
9b12c500 CC |
273 | // Set the non-visibility part of the st_other field. |
274 | void | |
275 | set_nonvis(unsigned int nonvis) | |
276 | { this->nonvis_ = nonvis; } | |
277 | ||
1564db8d ILT |
278 | // Return whether this symbol is a forwarder. This will never be |
279 | // true of a symbol found in the hash table, but may be true of | |
280 | // symbol pointers attached to object files. | |
281 | bool | |
282 | is_forwarder() const | |
283 | { return this->is_forwarder_; } | |
284 | ||
285 | // Mark this symbol as a forwarder. | |
286 | void | |
287 | set_forwarder() | |
288 | { this->is_forwarder_ = true; } | |
289 | ||
aeddab66 ILT |
290 | // Return whether this symbol has an alias in the weak aliases table |
291 | // in Symbol_table. | |
292 | bool | |
293 | has_alias() const | |
294 | { return this->has_alias_; } | |
295 | ||
296 | // Mark this symbol as having an alias. | |
297 | void | |
298 | set_has_alias() | |
299 | { this->has_alias_ = true; } | |
300 | ||
c06b7b0b ILT |
301 | // Return whether this symbol needs an entry in the dynamic symbol |
302 | // table. | |
303 | bool | |
304 | needs_dynsym_entry() const | |
429c1569 ILT |
305 | { |
306 | return (this->needs_dynsym_entry_ | |
8d6d383d ILT |
307 | || (this->in_reg() |
308 | && this->in_dyn() | |
309 | && this->is_externally_visible())); | |
429c1569 | 310 | } |
c06b7b0b ILT |
311 | |
312 | // Mark this symbol as needing an entry in the dynamic symbol table. | |
313 | void | |
314 | set_needs_dynsym_entry() | |
315 | { this->needs_dynsym_entry_ = true; } | |
316 | ||
436ca963 ILT |
317 | // Return whether this symbol should be added to the dynamic symbol |
318 | // table. | |
319 | bool | |
ce97fa81 | 320 | should_add_dynsym_entry(Symbol_table*) const; |
436ca963 | 321 | |
008db82e ILT |
322 | // Return whether this symbol has been seen in a regular object. |
323 | bool | |
324 | in_reg() const | |
325 | { return this->in_reg_; } | |
326 | ||
327 | // Mark this symbol as having been seen in a regular object. | |
328 | void | |
329 | set_in_reg() | |
330 | { this->in_reg_ = true; } | |
331 | ||
1ebd95fd ILT |
332 | // Return whether this symbol has been seen in a dynamic object. |
333 | bool | |
334 | in_dyn() const | |
335 | { return this->in_dyn_; } | |
336 | ||
f6ce93d6 | 337 | // Mark this symbol as having been seen in a dynamic object. |
1564db8d ILT |
338 | void |
339 | set_in_dyn() | |
340 | { this->in_dyn_ = true; } | |
341 | ||
89fc3421 CC |
342 | // Return whether this symbol has been seen in a real ELF object. |
343 | // (IN_REG will return TRUE if the symbol has been seen in either | |
344 | // a real ELF object or an object claimed by a plugin.) | |
345 | bool | |
346 | in_real_elf() const | |
347 | { return this->in_real_elf_; } | |
348 | ||
349 | // Mark this symbol as having been seen in a real ELF object. | |
350 | void | |
351 | set_in_real_elf() | |
352 | { this->in_real_elf_ = true; } | |
353 | ||
880cd20d ILT |
354 | // Return whether this symbol was defined in a section that was |
355 | // discarded from the link. This is used to control some error | |
356 | // reporting. | |
357 | bool | |
358 | is_defined_in_discarded_section() const | |
359 | { return this->is_defined_in_discarded_section_; } | |
360 | ||
361 | // Mark this symbol as having been defined in a discarded section. | |
362 | void | |
363 | set_is_defined_in_discarded_section() | |
364 | { this->is_defined_in_discarded_section_ = true; } | |
365 | ||
c06b7b0b ILT |
366 | // Return the index of this symbol in the output file symbol table. |
367 | // A value of -1U means that this symbol is not going into the | |
368 | // output file. This starts out as zero, and is set to a non-zero | |
369 | // value by Symbol_table::finalize. It is an error to ask for the | |
370 | // symbol table index before it has been set. | |
371 | unsigned int | |
372 | symtab_index() const | |
373 | { | |
a3ad94ed | 374 | gold_assert(this->symtab_index_ != 0); |
c06b7b0b ILT |
375 | return this->symtab_index_; |
376 | } | |
377 | ||
378 | // Set the index of the symbol in the output file symbol table. | |
379 | void | |
380 | set_symtab_index(unsigned int index) | |
381 | { | |
a3ad94ed | 382 | gold_assert(index != 0); |
c06b7b0b ILT |
383 | this->symtab_index_ = index; |
384 | } | |
385 | ||
a3ad94ed ILT |
386 | // Return whether this symbol already has an index in the output |
387 | // file symbol table. | |
388 | bool | |
389 | has_symtab_index() const | |
390 | { return this->symtab_index_ != 0; } | |
391 | ||
c06b7b0b ILT |
392 | // Return the index of this symbol in the dynamic symbol table. A |
393 | // value of -1U means that this symbol is not going into the dynamic | |
394 | // symbol table. This starts out as zero, and is set to a non-zero | |
395 | // during Layout::finalize. It is an error to ask for the dynamic | |
396 | // symbol table index before it has been set. | |
397 | unsigned int | |
398 | dynsym_index() const | |
399 | { | |
a3ad94ed | 400 | gold_assert(this->dynsym_index_ != 0); |
c06b7b0b ILT |
401 | return this->dynsym_index_; |
402 | } | |
403 | ||
404 | // Set the index of the symbol in the dynamic symbol table. | |
405 | void | |
406 | set_dynsym_index(unsigned int index) | |
407 | { | |
a3ad94ed | 408 | gold_assert(index != 0); |
c06b7b0b ILT |
409 | this->dynsym_index_ = index; |
410 | } | |
411 | ||
16649710 ILT |
412 | // Return whether this symbol already has an index in the dynamic |
413 | // symbol table. | |
414 | bool | |
415 | has_dynsym_index() const | |
416 | { return this->dynsym_index_ != 0; } | |
417 | ||
ead1e424 | 418 | // Return whether this symbol has an entry in the GOT section. |
07f397ab | 419 | // For a TLS symbol, this GOT entry will hold its tp-relative offset. |
92e059d8 | 420 | bool |
0a65a3a7 CC |
421 | has_got_offset(unsigned int got_type) const |
422 | { return this->got_offsets_.get_offset(got_type) != -1U; } | |
ead1e424 ILT |
423 | |
424 | // Return the offset into the GOT section of this symbol. | |
425 | unsigned int | |
0a65a3a7 | 426 | got_offset(unsigned int got_type) const |
ead1e424 | 427 | { |
2ea97941 ILT |
428 | unsigned int got_offset = this->got_offsets_.get_offset(got_type); |
429 | gold_assert(got_offset != -1U); | |
430 | return got_offset; | |
ead1e424 ILT |
431 | } |
432 | ||
433 | // Set the GOT offset of this symbol. | |
434 | void | |
2ea97941 ILT |
435 | set_got_offset(unsigned int got_type, unsigned int got_offset) |
436 | { this->got_offsets_.set_offset(got_type, got_offset); } | |
07f397ab | 437 | |
0e70b911 CC |
438 | // Return the GOT offset list. |
439 | const Got_offset_list* | |
440 | got_offset_list() const | |
441 | { return this->got_offsets_.get_list(); } | |
442 | ||
a3ad94ed | 443 | // Return whether this symbol has an entry in the PLT section. |
ead1e424 | 444 | bool |
a3ad94ed | 445 | has_plt_offset() const |
880cd20d | 446 | { return this->plt_offset_ != -1U; } |
a3ad94ed ILT |
447 | |
448 | // Return the offset into the PLT section of this symbol. | |
449 | unsigned int | |
450 | plt_offset() const | |
451 | { | |
452 | gold_assert(this->has_plt_offset()); | |
453 | return this->plt_offset_; | |
454 | } | |
455 | ||
456 | // Set the PLT offset of this symbol. | |
457 | void | |
2ea97941 | 458 | set_plt_offset(unsigned int plt_offset) |
a3ad94ed | 459 | { |
880cd20d | 460 | gold_assert(plt_offset != -1U); |
2ea97941 | 461 | this->plt_offset_ = plt_offset; |
a3ad94ed ILT |
462 | } |
463 | ||
ab5c9e90 ILT |
464 | // Return whether this dynamic symbol needs a special value in the |
465 | // dynamic symbol table. | |
466 | bool | |
467 | needs_dynsym_value() const | |
468 | { return this->needs_dynsym_value_; } | |
469 | ||
470 | // Set that this dynamic symbol needs a special value in the dynamic | |
471 | // symbol table. | |
472 | void | |
473 | set_needs_dynsym_value() | |
474 | { | |
475 | gold_assert(this->object()->is_dynamic()); | |
476 | this->needs_dynsym_value_ = true; | |
477 | } | |
478 | ||
a3ad94ed ILT |
479 | // Return true if the final value of this symbol is known at link |
480 | // time. | |
481 | bool | |
b3b74ddc | 482 | final_value_is_known() const; |
ead1e424 | 483 | |
8a5e3e08 ILT |
484 | // Return true if SHNDX represents a common symbol. This depends on |
485 | // the target. | |
486 | static bool | |
487 | is_common_shndx(unsigned int shndx); | |
488 | ||
f6ce93d6 ILT |
489 | // Return whether this is a defined symbol (not undefined or |
490 | // common). | |
491 | bool | |
492 | is_defined() const | |
493 | { | |
d491d34e ILT |
494 | bool is_ordinary; |
495 | if (this->source_ != FROM_OBJECT) | |
f3e9c5c5 | 496 | return this->source_ != IS_UNDEFINED; |
2ea97941 | 497 | unsigned int shndx = this->shndx(&is_ordinary); |
d491d34e | 498 | return (is_ordinary |
2ea97941 ILT |
499 | ? shndx != elfcpp::SHN_UNDEF |
500 | : !Symbol::is_common_shndx(shndx)); | |
a3ad94ed ILT |
501 | } |
502 | ||
14b31740 | 503 | // Return true if this symbol is from a dynamic object. |
a3ad94ed | 504 | bool |
14b31740 | 505 | is_from_dynobj() const |
a3ad94ed | 506 | { |
14b31740 | 507 | return this->source_ == FROM_OBJECT && this->object()->is_dynamic(); |
f6ce93d6 ILT |
508 | } |
509 | ||
f3a2388f CC |
510 | // Return whether this is a placeholder symbol from a plugin object. |
511 | bool | |
512 | is_placeholder() const | |
513 | { | |
514 | return this->source_ == FROM_OBJECT && this->object()->pluginobj() != NULL; | |
515 | } | |
516 | ||
ead1e424 ILT |
517 | // Return whether this is an undefined symbol. |
518 | bool | |
519 | is_undefined() const | |
520 | { | |
d491d34e | 521 | bool is_ordinary; |
f3e9c5c5 ILT |
522 | return ((this->source_ == FROM_OBJECT |
523 | && this->shndx(&is_ordinary) == elfcpp::SHN_UNDEF | |
524 | && is_ordinary) | |
525 | || this->source_ == IS_UNDEFINED); | |
ead1e424 ILT |
526 | } |
527 | ||
86925eef CC |
528 | // Return whether this is a weak undefined symbol. |
529 | bool | |
530 | is_weak_undefined() const | |
d1bddd3c CC |
531 | { |
532 | return (this->is_undefined() | |
533 | && (this->binding() == elfcpp::STB_WEAK | |
a100d66f ST |
534 | || this->is_undef_binding_weak() |
535 | || parameters->options().weak_unresolved_symbols())); | |
d1bddd3c CC |
536 | } |
537 | ||
538 | // Return whether this is a strong undefined symbol. | |
539 | bool | |
540 | is_strong_undefined() const | |
541 | { | |
542 | return (this->is_undefined() | |
543 | && this->binding() != elfcpp::STB_WEAK | |
a100d66f ST |
544 | && !this->is_undef_binding_weak() |
545 | && !parameters->options().weak_unresolved_symbols()); | |
d1bddd3c | 546 | } |
86925eef | 547 | |
86925eef CC |
548 | // Return whether this is an absolute symbol. |
549 | bool | |
550 | is_absolute() const | |
551 | { | |
d491d34e | 552 | bool is_ordinary; |
f3e9c5c5 ILT |
553 | return ((this->source_ == FROM_OBJECT |
554 | && this->shndx(&is_ordinary) == elfcpp::SHN_ABS | |
555 | && !is_ordinary) | |
556 | || this->source_ == IS_CONSTANT); | |
86925eef CC |
557 | } |
558 | ||
ead1e424 ILT |
559 | // Return whether this is a common symbol. |
560 | bool | |
561 | is_common() const | |
562 | { | |
8a5e3e08 ILT |
563 | if (this->source_ != FROM_OBJECT) |
564 | return false; | |
d491d34e | 565 | bool is_ordinary; |
2ea97941 ILT |
566 | unsigned int shndx = this->shndx(&is_ordinary); |
567 | return !is_ordinary && Symbol::is_common_shndx(shndx); | |
ead1e424 | 568 | } |
92e059d8 | 569 | |
a6badf5a ILT |
570 | // Return whether this symbol can be seen outside this object. |
571 | bool | |
572 | is_externally_visible() const | |
573 | { | |
804eb480 ST |
574 | return ((this->visibility_ == elfcpp::STV_DEFAULT |
575 | || this->visibility_ == elfcpp::STV_PROTECTED) | |
576 | && !this->is_forced_local_); | |
a6badf5a ILT |
577 | } |
578 | ||
436ca963 ILT |
579 | // Return true if this symbol can be preempted by a definition in |
580 | // another link unit. | |
581 | bool | |
582 | is_preemptible() const | |
583 | { | |
386c048c ILT |
584 | // It doesn't make sense to ask whether a symbol defined in |
585 | // another object is preemptible. | |
586 | gold_assert(!this->is_from_dynobj()); | |
587 | ||
8fc19601 ILT |
588 | // It doesn't make sense to ask whether an undefined symbol |
589 | // is preemptible. | |
590 | gold_assert(!this->is_undefined()); | |
591 | ||
f1f70eae ILT |
592 | // If a symbol does not have default visibility, it can not be |
593 | // seen outside this link unit and therefore is not preemptible. | |
594 | if (this->visibility_ != elfcpp::STV_DEFAULT) | |
595 | return false; | |
596 | ||
597 | // If this symbol has been forced to be a local symbol by a | |
598 | // version script, then it is not visible outside this link unit | |
599 | // and is not preemptible. | |
600 | if (this->is_forced_local_) | |
601 | return false; | |
602 | ||
603 | // If we are not producing a shared library, then nothing is | |
604 | // preemptible. | |
605 | if (!parameters->options().shared()) | |
606 | return false; | |
607 | ||
fd834e57 CC |
608 | // If the symbol was named in a --dynamic-list script, it is preemptible. |
609 | if (parameters->options().in_dynamic_list(this->name())) | |
610 | return true; | |
611 | ||
e9c1bdad CC |
612 | // If the user used -Bsymbolic, then nothing (else) is preemptible. |
613 | if (parameters->options().Bsymbolic()) | |
f1f70eae ILT |
614 | return false; |
615 | ||
616 | // If the user used -Bsymbolic-functions, then functions are not | |
617 | // preemptible. We explicitly check for not being STT_OBJECT, | |
618 | // rather than for being STT_FUNC, because that is what the GNU | |
619 | // linker does. | |
620 | if (this->type() != elfcpp::STT_OBJECT | |
621 | && parameters->options().Bsymbolic_functions()) | |
622 | return false; | |
623 | ||
624 | // Otherwise the symbol is preemptible. | |
625 | return true; | |
436ca963 ILT |
626 | } |
627 | ||
d61c6bd4 | 628 | // Return true if this symbol is a function that needs a PLT entry. |
d61c6bd4 ILT |
629 | bool |
630 | needs_plt_entry() const | |
631 | { | |
6d479619 CC |
632 | // An undefined symbol from an executable does not need a PLT entry. |
633 | if (this->is_undefined() && !parameters->options().shared()) | |
634 | return false; | |
635 | ||
7223e9ca ILT |
636 | // An STT_GNU_IFUNC symbol always needs a PLT entry, even when |
637 | // doing a static link. | |
638 | if (this->type() == elfcpp::STT_GNU_IFUNC) | |
639 | return true; | |
640 | ||
641 | // We only need a PLT entry for a function. | |
642 | if (!this->is_func()) | |
643 | return false; | |
644 | ||
645 | // If we're doing a static link or a -pie link, we don't create | |
646 | // PLT entries. | |
647 | if (parameters->doing_static_link() | |
648 | || parameters->options().pie()) | |
649 | return false; | |
650 | ||
651 | // We need a PLT entry if the function is defined in a dynamic | |
652 | // object, or is undefined when building a shared object, or if it | |
653 | // is subject to pre-emption. | |
654 | return (this->is_from_dynobj() | |
655 | || this->is_undefined() | |
656 | || this->is_preemptible()); | |
d61c6bd4 ILT |
657 | } |
658 | ||
0700cf32 ILT |
659 | // When determining whether a reference to a symbol needs a dynamic |
660 | // relocation, we need to know several things about the reference. | |
95a2c8d6 RS |
661 | // These flags may be or'ed together. 0 means that the symbol |
662 | // isn't referenced at all. | |
0700cf32 ILT |
663 | enum Reference_flags |
664 | { | |
95a2c8d6 RS |
665 | // A reference to the symbol's absolute address. This includes |
666 | // references that cause an absolute address to be stored in the GOT. | |
0700cf32 | 667 | ABSOLUTE_REF = 1, |
95a2c8d6 RS |
668 | // A reference that calculates the offset of the symbol from some |
669 | // anchor point, such as the PC or GOT. | |
670 | RELATIVE_REF = 2, | |
671 | // A TLS-related reference. | |
672 | TLS_REF = 4, | |
673 | // A reference that can always be treated as a function call. | |
88b8e639 AM |
674 | FUNCTION_CALL = 8, |
675 | // When set, says that dynamic relocations are needed even if a | |
676 | // symbol has a plt entry. | |
677 | FUNC_DESC_ABI = 16, | |
0700cf32 ILT |
678 | }; |
679 | ||
d61c6bd4 ILT |
680 | // Given a direct absolute or pc-relative static relocation against |
681 | // the global symbol, this function returns whether a dynamic relocation | |
682 | // is needed. | |
683 | ||
684 | bool | |
0700cf32 | 685 | needs_dynamic_reloc(int flags) const |
d61c6bd4 | 686 | { |
8fc19601 ILT |
687 | // No dynamic relocations in a static link! |
688 | if (parameters->doing_static_link()) | |
689 | return false; | |
690 | ||
6d479619 | 691 | // A reference to an undefined symbol from an executable should be |
f3c69fca CC |
692 | // statically resolved to 0, and does not need a dynamic relocation. |
693 | // This matches gnu ld behavior. | |
6d479619 | 694 | if (this->is_undefined() && !parameters->options().shared()) |
f3c69fca CC |
695 | return false; |
696 | ||
697 | // A reference to an absolute symbol does not need a dynamic relocation. | |
698 | if (this->is_absolute()) | |
86925eef CC |
699 | return false; |
700 | ||
d61c6bd4 | 701 | // An absolute reference within a position-independent output file |
0700cf32 ILT |
702 | // will need a dynamic relocation. |
703 | if ((flags & ABSOLUTE_REF) | |
8851ecca | 704 | && parameters->options().output_is_position_independent()) |
d61c6bd4 ILT |
705 | return true; |
706 | ||
707 | // A function call that can branch to a local PLT entry does not need | |
95a2c8d6 RS |
708 | // a dynamic relocation. |
709 | if ((flags & FUNCTION_CALL) && this->has_plt_offset()) | |
d61c6bd4 ILT |
710 | return false; |
711 | ||
712 | // A reference to any PLT entry in a non-position-independent executable | |
713 | // does not need a dynamic relocation. | |
88b8e639 AM |
714 | if (!(flags & FUNC_DESC_ABI) |
715 | && !parameters->options().output_is_position_independent() | |
d61c6bd4 ILT |
716 | && this->has_plt_offset()) |
717 | return false; | |
718 | ||
719 | // A reference to a symbol defined in a dynamic object or to a | |
720 | // symbol that is preemptible will need a dynamic relocation. | |
8fc19601 ILT |
721 | if (this->is_from_dynobj() |
722 | || this->is_undefined() | |
723 | || this->is_preemptible()) | |
d61c6bd4 ILT |
724 | return true; |
725 | ||
726 | // For all other cases, return FALSE. | |
727 | return false; | |
728 | } | |
729 | ||
de4c45bd | 730 | // Whether we should use the PLT offset associated with a symbol for |
95a2c8d6 | 731 | // a relocation. FLAGS is a set of Reference_flags. |
de4c45bd ILT |
732 | |
733 | bool | |
95a2c8d6 | 734 | use_plt_offset(int flags) const |
de4c45bd ILT |
735 | { |
736 | // If the symbol doesn't have a PLT offset, then naturally we | |
737 | // don't want to use it. | |
738 | if (!this->has_plt_offset()) | |
739 | return false; | |
740 | ||
7223e9ca ILT |
741 | // For a STT_GNU_IFUNC symbol we always have to use the PLT entry. |
742 | if (this->type() == elfcpp::STT_GNU_IFUNC) | |
743 | return true; | |
744 | ||
de4c45bd ILT |
745 | // If we are going to generate a dynamic relocation, then we will |
746 | // wind up using that, so no need to use the PLT entry. | |
95a2c8d6 | 747 | if (this->needs_dynamic_reloc(flags)) |
de4c45bd ILT |
748 | return false; |
749 | ||
750 | // If the symbol is from a dynamic object, we need to use the PLT | |
751 | // entry. | |
752 | if (this->is_from_dynobj()) | |
753 | return true; | |
754 | ||
755 | // If we are generating a shared object, and this symbol is | |
756 | // undefined or preemptible, we need to use the PLT entry. | |
757 | if (parameters->options().shared() | |
758 | && (this->is_undefined() || this->is_preemptible())) | |
759 | return true; | |
760 | ||
95a2c8d6 RS |
761 | // If this is a call to a weak undefined symbol, we need to use |
762 | // the PLT entry; the symbol may be defined by a library loaded | |
763 | // at runtime. | |
764 | if ((flags & FUNCTION_CALL) && this->is_weak_undefined()) | |
de4c45bd ILT |
765 | return true; |
766 | ||
767 | // Otherwise we can use the regular definition. | |
768 | return false; | |
769 | } | |
770 | ||
d61c6bd4 ILT |
771 | // Given a direct absolute static relocation against |
772 | // the global symbol, where a dynamic relocation is needed, this | |
773 | // function returns whether a relative dynamic relocation can be used. | |
774 | // The caller must determine separately whether the static relocation | |
775 | // is compatible with a relative relocation. | |
776 | ||
777 | bool | |
778 | can_use_relative_reloc(bool is_function_call) const | |
779 | { | |
780 | // A function call that can branch to a local PLT entry can | |
781 | // use a RELATIVE relocation. | |
782 | if (is_function_call && this->has_plt_offset()) | |
783 | return true; | |
784 | ||
785 | // A reference to a symbol defined in a dynamic object or to a | |
9b547ce6 | 786 | // symbol that is preemptible can not use a RELATIVE relocation. |
8fc19601 ILT |
787 | if (this->is_from_dynobj() |
788 | || this->is_undefined() | |
789 | || this->is_preemptible()) | |
d61c6bd4 ILT |
790 | return false; |
791 | ||
792 | // For all other cases, return TRUE. | |
793 | return true; | |
794 | } | |
795 | ||
77e65537 ILT |
796 | // Return the output section where this symbol is defined. Return |
797 | // NULL if the symbol has an absolute value. | |
798 | Output_section* | |
799 | output_section() const; | |
800 | ||
801 | // Set the symbol's output section. This is used for symbols | |
802 | // defined in scripts. This should only be called after the symbol | |
803 | // table has been finalized. | |
804 | void | |
805 | set_output_section(Output_section*); | |
a445fddf | 806 | |
d1bddd3c CC |
807 | // Set the symbol's output segment. This is used for pre-defined |
808 | // symbols whose segments aren't known until after layout is done | |
809 | // (e.g., __ehdr_start). | |
810 | void | |
811 | set_output_segment(Output_segment*, Segment_offset_base); | |
812 | ||
813 | // Set the symbol to undefined. This is used for pre-defined | |
814 | // symbols whose segments aren't known until after layout is done | |
815 | // (e.g., __ehdr_start). | |
816 | void | |
817 | set_undefined(); | |
818 | ||
f6ce93d6 ILT |
819 | // Return whether there should be a warning for references to this |
820 | // symbol. | |
821 | bool | |
822 | has_warning() const | |
823 | { return this->has_warning_; } | |
824 | ||
825 | // Mark this symbol as having a warning. | |
826 | void | |
827 | set_has_warning() | |
828 | { this->has_warning_ = true; } | |
829 | ||
46fe1623 ILT |
830 | // Return whether this symbol is defined by a COPY reloc from a |
831 | // dynamic object. | |
832 | bool | |
833 | is_copied_from_dynobj() const | |
834 | { return this->is_copied_from_dynobj_; } | |
835 | ||
836 | // Mark this symbol as defined by a COPY reloc. | |
837 | void | |
838 | set_is_copied_from_dynobj() | |
839 | { this->is_copied_from_dynobj_ = true; } | |
840 | ||
55a93433 ILT |
841 | // Return whether this symbol is forced to visibility STB_LOCAL |
842 | // by a "local:" entry in a version script. | |
843 | bool | |
844 | is_forced_local() const | |
845 | { return this->is_forced_local_; } | |
846 | ||
847 | // Mark this symbol as forced to STB_LOCAL visibility. | |
848 | void | |
849 | set_is_forced_local() | |
850 | { this->is_forced_local_ = true; } | |
851 | ||
966d4097 DK |
852 | // Return true if this may need a COPY relocation. |
853 | // References from an executable object to non-function symbols | |
854 | // defined in a dynamic object may need a COPY relocation. | |
855 | bool | |
856 | may_need_copy_reloc() const | |
857 | { | |
a82bef93 | 858 | return (parameters->options().copyreloc() |
966d4097 | 859 | && this->is_from_dynobj() |
53d7974c | 860 | && !this->is_func()); |
966d4097 DK |
861 | } |
862 | ||
5146f448 CC |
863 | // Return true if this symbol was predefined by the linker. |
864 | bool | |
865 | is_predefined() const | |
866 | { return this->is_predefined_; } | |
867 | ||
93acabad CC |
868 | // Return true if this is a C++ vtable symbol. |
869 | bool | |
870 | is_cxx_vtable() const | |
871 | { return is_prefix_of("_ZTV", this->name_); } | |
872 | ||
14bfc3f5 ILT |
873 | protected: |
874 | // Instances of this class should always be created at a specific | |
875 | // size. | |
876 | Symbol() | |
f6ce93d6 | 877 | { memset(this, 0, sizeof *this); } |
14bfc3f5 | 878 | |
ead1e424 ILT |
879 | // Initialize the general fields. |
880 | void | |
881 | init_fields(const char* name, const char* version, | |
882 | elfcpp::STT type, elfcpp::STB binding, | |
883 | elfcpp::STV visibility, unsigned char nonvis); | |
884 | ||
d491d34e ILT |
885 | // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the |
886 | // section index, IS_ORDINARY is whether it is a normal section | |
887 | // index rather than a special code. | |
14bfc3f5 ILT |
888 | template<int size, bool big_endian> |
889 | void | |
ca09d69a | 890 | init_base_object(const char* name, const char* version, Object* object, |
f3e9c5c5 ILT |
891 | const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx, |
892 | bool is_ordinary); | |
bae7f79e | 893 | |
ead1e424 ILT |
894 | // Initialize fields for an Output_data. |
895 | void | |
75517b77 ILT |
896 | init_base_output_data(const char* name, const char* version, Output_data*, |
897 | elfcpp::STT, elfcpp::STB, elfcpp::STV, | |
5146f448 CC |
898 | unsigned char nonvis, bool offset_is_from_end, |
899 | bool is_predefined); | |
ead1e424 ILT |
900 | |
901 | // Initialize fields for an Output_segment. | |
902 | void | |
75517b77 ILT |
903 | init_base_output_segment(const char* name, const char* version, |
904 | Output_segment* os, elfcpp::STT type, | |
905 | elfcpp::STB binding, elfcpp::STV visibility, | |
906 | unsigned char nonvis, | |
5146f448 CC |
907 | Segment_offset_base offset_base, |
908 | bool is_predefined); | |
ead1e424 ILT |
909 | |
910 | // Initialize fields for a constant. | |
911 | void | |
75517b77 ILT |
912 | init_base_constant(const char* name, const char* version, elfcpp::STT type, |
913 | elfcpp::STB binding, elfcpp::STV visibility, | |
5146f448 | 914 | unsigned char nonvis, bool is_predefined); |
f3e9c5c5 ILT |
915 | |
916 | // Initialize fields for an undefined symbol. | |
917 | void | |
75517b77 ILT |
918 | init_base_undefined(const char* name, const char* version, elfcpp::STT type, |
919 | elfcpp::STB binding, elfcpp::STV visibility, | |
920 | unsigned char nonvis); | |
ead1e424 | 921 | |
1564db8d ILT |
922 | // Override existing symbol. |
923 | template<int size, bool big_endian> | |
924 | void | |
d491d34e ILT |
925 | override_base(const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx, |
926 | bool is_ordinary, Object* object, const char* version); | |
1564db8d | 927 | |
86f2e683 ILT |
928 | // Override existing symbol with a special symbol. |
929 | void | |
930 | override_base_with_special(const Symbol* from); | |
931 | ||
75517b77 ILT |
932 | // Override symbol version. |
933 | void | |
934 | override_version(const char* version); | |
935 | ||
c7912668 ILT |
936 | // Allocate a common symbol by giving it a location in the output |
937 | // file. | |
938 | void | |
939 | allocate_base_common(Output_data*); | |
940 | ||
bae7f79e | 941 | private: |
14bfc3f5 ILT |
942 | Symbol(const Symbol&); |
943 | Symbol& operator=(const Symbol&); | |
944 | ||
945 | // Symbol name (expected to point into a Stringpool). | |
946 | const char* name_; | |
947 | // Symbol version (expected to point into a Stringpool). This may | |
948 | // be NULL. | |
bae7f79e | 949 | const char* version_; |
ead1e424 ILT |
950 | |
951 | union | |
952 | { | |
953 | // This struct is used if SOURCE_ == FROM_OBJECT. | |
954 | struct | |
955 | { | |
956 | // Object in which symbol is defined, or in which it was first | |
957 | // seen. | |
958 | Object* object; | |
959 | // Section number in object_ in which symbol is defined. | |
16649710 | 960 | unsigned int shndx; |
ead1e424 ILT |
961 | } from_object; |
962 | ||
963 | // This struct is used if SOURCE_ == IN_OUTPUT_DATA. | |
964 | struct | |
965 | { | |
966 | // Output_data in which symbol is defined. Before | |
967 | // Layout::finalize the symbol's value is an offset within the | |
968 | // Output_data. | |
969 | Output_data* output_data; | |
970 | // True if the offset is from the end, false if the offset is | |
971 | // from the beginning. | |
972 | bool offset_is_from_end; | |
973 | } in_output_data; | |
974 | ||
975 | // This struct is used if SOURCE_ == IN_OUTPUT_SEGMENT. | |
976 | struct | |
977 | { | |
978 | // Output_segment in which the symbol is defined. Before | |
979 | // Layout::finalize the symbol's value is an offset. | |
980 | Output_segment* output_segment; | |
981 | // The base to use for the offset before Layout::finalize. | |
982 | Segment_offset_base offset_base; | |
983 | } in_output_segment; | |
984 | } u_; | |
985 | ||
c06b7b0b ILT |
986 | // The index of this symbol in the output file. If the symbol is |
987 | // not going into the output file, this value is -1U. This field | |
988 | // starts as always holding zero. It is set to a non-zero value by | |
989 | // Symbol_table::finalize. | |
990 | unsigned int symtab_index_; | |
991 | ||
992 | // The index of this symbol in the dynamic symbol table. If the | |
993 | // symbol is not going into the dynamic symbol table, this value is | |
994 | // -1U. This field starts as always holding zero. It is set to a | |
995 | // non-zero value during Layout::finalize. | |
996 | unsigned int dynsym_index_; | |
997 | ||
880cd20d ILT |
998 | // The GOT section entries for this symbol. A symbol may have more |
999 | // than one GOT offset (e.g., when mixing modules compiled with two | |
1000 | // different TLS models), but will usually have at most one. | |
0a65a3a7 | 1001 | Got_offset_list got_offsets_; |
07f397ab | 1002 | |
880cd20d ILT |
1003 | // If this symbol has an entry in the PLT section, then this is the |
1004 | // offset from the start of the PLT section. This is -1U if there | |
1005 | // is no PLT entry. | |
a3ad94ed ILT |
1006 | unsigned int plt_offset_; |
1007 | ||
d491d34e | 1008 | // Symbol type (bits 0 to 3). |
bae7f79e | 1009 | elfcpp::STT type_ : 4; |
d491d34e | 1010 | // Symbol binding (bits 4 to 7). |
bae7f79e | 1011 | elfcpp::STB binding_ : 4; |
d491d34e | 1012 | // Symbol visibility (bits 8 to 9). |
14bfc3f5 | 1013 | elfcpp::STV visibility_ : 2; |
d491d34e | 1014 | // Rest of symbol st_other field (bits 10 to 15). |
ead1e424 | 1015 | unsigned int nonvis_ : 6; |
d491d34e | 1016 | // The type of symbol (bits 16 to 18). |
f6ce93d6 | 1017 | Source source_ : 3; |
880cd20d | 1018 | // True if this is the default version of the symbol (bit 19). |
1564db8d | 1019 | bool is_def_ : 1; |
14bfc3f5 ILT |
1020 | // True if this symbol really forwards to another symbol. This is |
1021 | // used when we discover after the fact that two different entries | |
1022 | // in the hash table really refer to the same symbol. This will | |
1023 | // never be set for a symbol found in the hash table, but may be set | |
1024 | // for a symbol found in the list of symbols attached to an Object. | |
1025 | // It forwards to the symbol found in the forwarders_ map of | |
880cd20d | 1026 | // Symbol_table (bit 20). |
1564db8d | 1027 | bool is_forwarder_ : 1; |
aeddab66 | 1028 | // True if the symbol has an alias in the weak_aliases table in |
880cd20d | 1029 | // Symbol_table (bit 21). |
aeddab66 | 1030 | bool has_alias_ : 1; |
d491d34e | 1031 | // True if this symbol needs to be in the dynamic symbol table (bit |
880cd20d | 1032 | // 22). |
c06b7b0b | 1033 | bool needs_dynsym_entry_ : 1; |
880cd20d | 1034 | // True if we've seen this symbol in a regular object (bit 23). |
008db82e | 1035 | bool in_reg_ : 1; |
880cd20d | 1036 | // True if we've seen this symbol in a dynamic object (bit 24). |
1564db8d | 1037 | bool in_dyn_ : 1; |
ab5c9e90 | 1038 | // True if this is a dynamic symbol which needs a special value in |
880cd20d | 1039 | // the dynamic symbol table (bit 25). |
ab5c9e90 | 1040 | bool needs_dynsym_value_ : 1; |
880cd20d | 1041 | // True if there is a warning for this symbol (bit 26). |
f6ce93d6 | 1042 | bool has_warning_ : 1; |
46fe1623 | 1043 | // True if we are using a COPY reloc for this symbol, so that the |
880cd20d | 1044 | // real definition lives in a dynamic object (bit 27). |
46fe1623 | 1045 | bool is_copied_from_dynobj_ : 1; |
55a93433 | 1046 | // True if this symbol was forced to local visibility by a version |
880cd20d | 1047 | // script (bit 28). |
55a93433 | 1048 | bool is_forced_local_ : 1; |
d491d34e ILT |
1049 | // True if the field u_.from_object.shndx is an ordinary section |
1050 | // index, not one of the special codes from SHN_LORESERVE to | |
880cd20d | 1051 | // SHN_HIRESERVE (bit 29). |
d491d34e | 1052 | bool is_ordinary_shndx_ : 1; |
f7c5b166 CC |
1053 | // True if we've seen this symbol in a "real" ELF object (bit 30). |
1054 | // If the symbol has been seen in a relocatable, non-IR, object file, | |
1055 | // it's known to be referenced from outside the IR. A reference from | |
1056 | // a dynamic object doesn't count as a "real" ELF, and we'll simply | |
1057 | // mark the symbol as "visible" from outside the IR. The compiler | |
1058 | // can use this distinction to guide its handling of COMDAT symbols. | |
89fc3421 | 1059 | bool in_real_elf_ : 1; |
880cd20d ILT |
1060 | // True if this symbol is defined in a section which was discarded |
1061 | // (bit 31). | |
1062 | bool is_defined_in_discarded_section_ : 1; | |
ce279a62 CC |
1063 | // True if UNDEF_BINDING_WEAK_ has been set (bit 32). |
1064 | bool undef_binding_set_ : 1; | |
1065 | // True if this symbol was a weak undef resolved by a dynamic def | |
d1bddd3c | 1066 | // or by a special symbol (bit 33). |
ce279a62 | 1067 | bool undef_binding_weak_ : 1; |
5146f448 CC |
1068 | // True if this symbol is a predefined linker symbol (bit 34). |
1069 | bool is_predefined_ : 1; | |
bae7f79e ILT |
1070 | }; |
1071 | ||
14bfc3f5 ILT |
1072 | // The parts of a symbol which are size specific. Using a template |
1073 | // derived class like this helps us use less space on a 32-bit system. | |
bae7f79e ILT |
1074 | |
1075 | template<int size> | |
14bfc3f5 ILT |
1076 | class Sized_symbol : public Symbol |
1077 | { | |
1078 | public: | |
1564db8d ILT |
1079 | typedef typename elfcpp::Elf_types<size>::Elf_Addr Value_type; |
1080 | typedef typename elfcpp::Elf_types<size>::Elf_WXword Size_type; | |
1081 | ||
14bfc3f5 ILT |
1082 | Sized_symbol() |
1083 | { } | |
1084 | ||
d491d34e ILT |
1085 | // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the |
1086 | // section index, IS_ORDINARY is whether it is a normal section | |
1087 | // index rather than a special code. | |
14bfc3f5 ILT |
1088 | template<bool big_endian> |
1089 | void | |
ca09d69a | 1090 | init_object(const char* name, const char* version, Object* object, |
f3e9c5c5 ILT |
1091 | const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx, |
1092 | bool is_ordinary); | |
14bfc3f5 | 1093 | |
ead1e424 ILT |
1094 | // Initialize fields for an Output_data. |
1095 | void | |
75517b77 ILT |
1096 | init_output_data(const char* name, const char* version, Output_data*, |
1097 | Value_type value, Size_type symsize, elfcpp::STT, | |
1098 | elfcpp::STB, elfcpp::STV, unsigned char nonvis, | |
5146f448 | 1099 | bool offset_is_from_end, bool is_predefined); |
ead1e424 ILT |
1100 | |
1101 | // Initialize fields for an Output_segment. | |
1102 | void | |
75517b77 ILT |
1103 | init_output_segment(const char* name, const char* version, Output_segment*, |
1104 | Value_type value, Size_type symsize, elfcpp::STT, | |
1105 | elfcpp::STB, elfcpp::STV, unsigned char nonvis, | |
5146f448 | 1106 | Segment_offset_base offset_base, bool is_predefined); |
ead1e424 ILT |
1107 | |
1108 | // Initialize fields for a constant. | |
1109 | void | |
75517b77 ILT |
1110 | init_constant(const char* name, const char* version, Value_type value, |
1111 | Size_type symsize, elfcpp::STT, elfcpp::STB, elfcpp::STV, | |
5146f448 | 1112 | unsigned char nonvis, bool is_predefined); |
f3e9c5c5 ILT |
1113 | |
1114 | // Initialize fields for an undefined symbol. | |
1115 | void | |
75517b77 ILT |
1116 | init_undefined(const char* name, const char* version, elfcpp::STT, |
1117 | elfcpp::STB, elfcpp::STV, unsigned char nonvis); | |
ead1e424 | 1118 | |
1564db8d ILT |
1119 | // Override existing symbol. |
1120 | template<bool big_endian> | |
1121 | void | |
d491d34e ILT |
1122 | override(const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx, |
1123 | bool is_ordinary, Object* object, const char* version); | |
1564db8d | 1124 | |
86f2e683 ILT |
1125 | // Override existing symbol with a special symbol. |
1126 | void | |
1127 | override_with_special(const Sized_symbol<size>*); | |
1128 | ||
1564db8d ILT |
1129 | // Return the symbol's value. |
1130 | Value_type | |
1131 | value() const | |
1132 | { return this->value_; } | |
1133 | ||
1134 | // Return the symbol's size (we can't call this 'size' because that | |
1135 | // is a template parameter). | |
1136 | Size_type | |
1137 | symsize() const | |
ead1e424 ILT |
1138 | { return this->symsize_; } |
1139 | ||
1140 | // Set the symbol size. This is used when resolving common symbols. | |
1141 | void | |
2ea97941 ILT |
1142 | set_symsize(Size_type symsize) |
1143 | { this->symsize_ = symsize; } | |
1564db8d | 1144 | |
75f65a3e ILT |
1145 | // Set the symbol value. This is called when we store the final |
1146 | // values of the symbols into the symbol table. | |
1147 | void | |
2ea97941 ILT |
1148 | set_value(Value_type value) |
1149 | { this->value_ = value; } | |
75f65a3e | 1150 | |
c7912668 ILT |
1151 | // Allocate a common symbol by giving it a location in the output |
1152 | // file. | |
1153 | void | |
1154 | allocate_common(Output_data*, Value_type value); | |
1155 | ||
14bfc3f5 ILT |
1156 | private: |
1157 | Sized_symbol(const Sized_symbol&); | |
1158 | Sized_symbol& operator=(const Sized_symbol&); | |
1159 | ||
ead1e424 ILT |
1160 | // Symbol value. Before Layout::finalize this is the offset in the |
1161 | // input section. This is set to the final value during | |
1162 | // Layout::finalize. | |
1564db8d | 1163 | Value_type value_; |
14bfc3f5 | 1164 | // Symbol size. |
ead1e424 ILT |
1165 | Size_type symsize_; |
1166 | }; | |
1167 | ||
1168 | // A struct describing a symbol defined by the linker, where the value | |
1169 | // of the symbol is defined based on an output section. This is used | |
1170 | // for symbols defined by the linker, like "_init_array_start". | |
1171 | ||
1172 | struct Define_symbol_in_section | |
1173 | { | |
1174 | // The symbol name. | |
1175 | const char* name; | |
1176 | // The name of the output section with which this symbol should be | |
1177 | // associated. If there is no output section with that name, the | |
1178 | // symbol will be defined as zero. | |
1179 | const char* output_section; | |
1180 | // The offset of the symbol within the output section. This is an | |
1181 | // offset from the start of the output section, unless start_at_end | |
1182 | // is true, in which case this is an offset from the end of the | |
1183 | // output section. | |
1184 | uint64_t value; | |
1185 | // The size of the symbol. | |
1186 | uint64_t size; | |
1187 | // The symbol type. | |
1188 | elfcpp::STT type; | |
1189 | // The symbol binding. | |
1190 | elfcpp::STB binding; | |
1191 | // The symbol visibility. | |
1192 | elfcpp::STV visibility; | |
1193 | // The rest of the st_other field. | |
1194 | unsigned char nonvis; | |
1195 | // If true, the value field is an offset from the end of the output | |
1196 | // section. | |
1197 | bool offset_is_from_end; | |
1198 | // If true, this symbol is defined only if we see a reference to it. | |
1199 | bool only_if_ref; | |
1200 | }; | |
1201 | ||
1202 | // A struct describing a symbol defined by the linker, where the value | |
1203 | // of the symbol is defined based on a segment. This is used for | |
1204 | // symbols defined by the linker, like "_end". We describe the | |
1205 | // segment with which the symbol should be associated by its | |
1206 | // characteristics. If no segment meets these characteristics, the | |
1207 | // symbol will be defined as zero. If there is more than one segment | |
1208 | // which meets these characteristics, we will use the first one. | |
1209 | ||
1210 | struct Define_symbol_in_segment | |
1211 | { | |
1212 | // The symbol name. | |
1213 | const char* name; | |
1214 | // The segment type where the symbol should be defined, typically | |
1215 | // PT_LOAD. | |
1216 | elfcpp::PT segment_type; | |
1217 | // Bitmask of segment flags which must be set. | |
1218 | elfcpp::PF segment_flags_set; | |
1219 | // Bitmask of segment flags which must be clear. | |
1220 | elfcpp::PF segment_flags_clear; | |
1221 | // The offset of the symbol within the segment. The offset is | |
1222 | // calculated from the position set by offset_base. | |
1223 | uint64_t value; | |
1224 | // The size of the symbol. | |
1225 | uint64_t size; | |
1226 | // The symbol type. | |
1227 | elfcpp::STT type; | |
1228 | // The symbol binding. | |
1229 | elfcpp::STB binding; | |
1230 | // The symbol visibility. | |
1231 | elfcpp::STV visibility; | |
1232 | // The rest of the st_other field. | |
1233 | unsigned char nonvis; | |
1234 | // The base from which we compute the offset. | |
1235 | Symbol::Segment_offset_base offset_base; | |
1236 | // If true, this symbol is defined only if we see a reference to it. | |
1237 | bool only_if_ref; | |
14bfc3f5 ILT |
1238 | }; |
1239 | ||
dc3714f3 AM |
1240 | // Specify an object/section/offset location. Used by ODR code. |
1241 | ||
1242 | struct Symbol_location | |
1243 | { | |
1244 | // Object where the symbol is defined. | |
1245 | Object* object; | |
1246 | // Section-in-object where the symbol is defined. | |
1247 | unsigned int shndx; | |
1248 | // For relocatable objects, offset-in-section where the symbol is defined. | |
1249 | // For dynamic objects, address where the symbol is defined. | |
1250 | off_t offset; | |
1251 | bool operator==(const Symbol_location& that) const | |
1252 | { | |
1253 | return (this->object == that.object | |
1254 | && this->shndx == that.shndx | |
1255 | && this->offset == that.offset); | |
1256 | } | |
1257 | }; | |
1258 | ||
f6ce93d6 ILT |
1259 | // This class manages warnings. Warnings are a GNU extension. When |
1260 | // we see a section named .gnu.warning.SYM in an object file, and if | |
1261 | // we wind using the definition of SYM from that object file, then we | |
1262 | // will issue a warning for any relocation against SYM from a | |
1263 | // different object file. The text of the warning is the contents of | |
1264 | // the section. This is not precisely the definition used by the old | |
1265 | // GNU linker; the old GNU linker treated an occurrence of | |
1266 | // .gnu.warning.SYM as defining a warning symbol. A warning symbol | |
1267 | // would trigger a warning on any reference. However, it was | |
1268 | // inconsistent in that a warning in a dynamic object only triggered | |
1269 | // if there was no definition in a regular object. This linker is | |
1270 | // different in that we only issue a warning if we use the symbol | |
1271 | // definition from the same object file as the warning section. | |
1272 | ||
1273 | class Warnings | |
1274 | { | |
1275 | public: | |
1276 | Warnings() | |
1277 | : warnings_() | |
1278 | { } | |
1279 | ||
cb295612 ILT |
1280 | // Add a warning for symbol NAME in object OBJ. WARNING is the text |
1281 | // of the warning. | |
f6ce93d6 ILT |
1282 | void |
1283 | add_warning(Symbol_table* symtab, const char* name, Object* obj, | |
cb295612 | 1284 | const std::string& warning); |
f6ce93d6 ILT |
1285 | |
1286 | // For each symbol for which we should give a warning, make a note | |
1287 | // on the symbol. | |
1288 | void | |
cb295612 | 1289 | note_warnings(Symbol_table* symtab); |
f6ce93d6 | 1290 | |
75f2446e ILT |
1291 | // Issue a warning for a reference to SYM at RELINFO's location. |
1292 | template<int size, bool big_endian> | |
f6ce93d6 | 1293 | void |
75f2446e ILT |
1294 | issue_warning(const Symbol* sym, const Relocate_info<size, big_endian>*, |
1295 | size_t relnum, off_t reloffset) const; | |
f6ce93d6 ILT |
1296 | |
1297 | private: | |
1298 | Warnings(const Warnings&); | |
1299 | Warnings& operator=(const Warnings&); | |
1300 | ||
1301 | // What we need to know to get the warning text. | |
1302 | struct Warning_location | |
1303 | { | |
1304 | // The object the warning is in. | |
1305 | Object* object; | |
cb295612 | 1306 | // The warning text. |
f6ce93d6 ILT |
1307 | std::string text; |
1308 | ||
1309 | Warning_location() | |
cb295612 | 1310 | : object(NULL), text() |
f6ce93d6 ILT |
1311 | { } |
1312 | ||
1313 | void | |
cb295612 | 1314 | set(Object* o, const std::string& t) |
f6ce93d6 ILT |
1315 | { |
1316 | this->object = o; | |
cb295612 | 1317 | this->text = t; |
f6ce93d6 | 1318 | } |
f6ce93d6 ILT |
1319 | }; |
1320 | ||
1321 | // A mapping from warning symbol names (canonicalized in | |
70e654ba | 1322 | // Symbol_table's namepool_ field) to warning information. |
f6ce93d6 ILT |
1323 | typedef Unordered_map<const char*, Warning_location> Warning_table; |
1324 | ||
1325 | Warning_table warnings_; | |
1326 | }; | |
1327 | ||
14bfc3f5 ILT |
1328 | // The main linker symbol table. |
1329 | ||
bae7f79e ILT |
1330 | class Symbol_table |
1331 | { | |
1332 | public: | |
99fff23b ILT |
1333 | // The different places where a symbol definition can come from. |
1334 | enum Defined | |
1335 | { | |
1336 | // Defined in an object file--the normal case. | |
1337 | OBJECT, | |
1338 | // Defined for a COPY reloc. | |
1339 | COPY, | |
1340 | // Defined on the command line using --defsym. | |
1341 | DEFSYM, | |
1342 | // Defined (so to speak) on the command line using -u. | |
1343 | UNDEFINED, | |
1344 | // Defined in a linker script. | |
1345 | SCRIPT, | |
1346 | // Predefined by the linker. | |
1347 | PREDEFINED, | |
5146f448 CC |
1348 | // Defined by the linker during an incremental base link, but not |
1349 | // a predefined symbol (e.g., common, defined in script). | |
1350 | INCREMENTAL_BASE, | |
99fff23b ILT |
1351 | }; |
1352 | ||
fc59c572 ILT |
1353 | // The order in which we sort common symbols. |
1354 | enum Sort_commons_order | |
1355 | { | |
1356 | SORT_COMMONS_BY_SIZE_DESCENDING, | |
1357 | SORT_COMMONS_BY_ALIGNMENT_DESCENDING, | |
1358 | SORT_COMMONS_BY_ALIGNMENT_ASCENDING | |
1359 | }; | |
1360 | ||
9b547ce6 | 1361 | // COUNT is an estimate of how many symbols will be inserted in the |
6d013333 ILT |
1362 | // symbol table. It's ok to put 0 if you don't know; a correct |
1363 | // guess will just save some CPU by reducing hashtable resizes. | |
09124467 | 1364 | Symbol_table(unsigned int count, const Version_script_info& version_script); |
bae7f79e | 1365 | |
1564db8d | 1366 | ~Symbol_table(); |
bae7f79e | 1367 | |
ef15dade | 1368 | void |
2ea97941 ILT |
1369 | set_icf(Icf* icf) |
1370 | { this->icf_ = icf;} | |
ef15dade ST |
1371 | |
1372 | Icf* | |
1373 | icf() const | |
1374 | { return this->icf_; } | |
1375 | ||
1376 | // Returns true if ICF determined that this is a duplicate section. | |
1377 | bool | |
efc6fa12 | 1378 | is_section_folded(Relobj* obj, unsigned int shndx) const; |
ef15dade | 1379 | |
6d03d481 | 1380 | void |
2ea97941 ILT |
1381 | set_gc(Garbage_collection* gc) |
1382 | { this->gc_ = gc; } | |
6d03d481 ST |
1383 | |
1384 | Garbage_collection* | |
ef15dade | 1385 | gc() const |
6d03d481 ST |
1386 | { return this->gc_; } |
1387 | ||
1388 | // During garbage collection, this keeps undefined symbols. | |
1389 | void | |
88a4108b | 1390 | gc_mark_undef_symbols(Layout*); |
6d03d481 | 1391 | |
7257cc92 | 1392 | // This tells garbage collection that this symbol is referenced. |
6d03d481 | 1393 | void |
7257cc92 | 1394 | gc_mark_symbol(Symbol* sym); |
6d03d481 ST |
1395 | |
1396 | // During garbage collection, this keeps sections that correspond to | |
1397 | // symbols seen in dynamic objects. | |
1398 | inline void | |
1399 | gc_mark_dyn_syms(Symbol* sym); | |
1400 | ||
dbe717ef | 1401 | // Add COUNT external symbols from the relocatable object RELOBJ to |
d491d34e ILT |
1402 | // the symbol table. SYMS is the symbols, SYMNDX_OFFSET is the |
1403 | // offset in the symbol table of the first symbol, SYM_NAMES is | |
1404 | // their names, SYM_NAME_SIZE is the size of SYM_NAMES. This sets | |
92de84a6 ILT |
1405 | // SYMPOINTERS to point to the symbols in the symbol table. It sets |
1406 | // *DEFINED to the number of defined symbols. | |
14bfc3f5 ILT |
1407 | template<int size, bool big_endian> |
1408 | void | |
6fa2a40b | 1409 | add_from_relobj(Sized_relobj_file<size, big_endian>* relobj, |
dbe717ef | 1410 | const unsigned char* syms, size_t count, |
d491d34e ILT |
1411 | size_t symndx_offset, const char* sym_names, |
1412 | size_t sym_name_size, | |
6fa2a40b | 1413 | typename Sized_relobj_file<size, big_endian>::Symbols*, |
92de84a6 | 1414 | size_t* defined); |
89fc3421 CC |
1415 | |
1416 | // Add one external symbol from the plugin object OBJ to the symbol table. | |
1417 | // Returns a pointer to the resolved symbol in the symbol table. | |
1418 | template<int size, bool big_endian> | |
1419 | Symbol* | |
1420 | add_from_pluginobj(Sized_pluginobj<size, big_endian>* obj, | |
1421 | const char* name, const char* ver, | |
1422 | elfcpp::Sym<size, big_endian>* sym); | |
14bfc3f5 | 1423 | |
dbe717ef ILT |
1424 | // Add COUNT dynamic symbols from the dynamic object DYNOBJ to the |
1425 | // symbol table. SYMS is the symbols. SYM_NAMES is their names. | |
1426 | // SYM_NAME_SIZE is the size of SYM_NAMES. The other parameters are | |
1427 | // symbol version data. | |
1428 | template<int size, bool big_endian> | |
1429 | void | |
1430 | add_from_dynobj(Sized_dynobj<size, big_endian>* dynobj, | |
1431 | const unsigned char* syms, size_t count, | |
1432 | const char* sym_names, size_t sym_name_size, | |
1433 | const unsigned char* versym, size_t versym_size, | |
92de84a6 | 1434 | const std::vector<const char*>*, |
6fa2a40b | 1435 | typename Sized_relobj_file<size, big_endian>::Symbols*, |
92de84a6 | 1436 | size_t* defined); |
dbe717ef | 1437 | |
cdc29364 CC |
1438 | // Add one external symbol from the incremental object OBJ to the symbol |
1439 | // table. Returns a pointer to the resolved symbol in the symbol table. | |
1440 | template<int size, bool big_endian> | |
26d3c67d | 1441 | Sized_symbol<size>* |
cdc29364 CC |
1442 | add_from_incrobj(Object* obj, const char* name, |
1443 | const char* ver, elfcpp::Sym<size, big_endian>* sym); | |
1444 | ||
ead1e424 ILT |
1445 | // Define a special symbol based on an Output_data. It is a |
1446 | // multiple definition error if this symbol is already defined. | |
14b31740 | 1447 | Symbol* |
99fff23b | 1448 | define_in_output_data(const char* name, const char* version, Defined, |
14b31740 | 1449 | Output_data*, uint64_t value, uint64_t symsize, |
ead1e424 ILT |
1450 | elfcpp::STT type, elfcpp::STB binding, |
1451 | elfcpp::STV visibility, unsigned char nonvis, | |
1452 | bool offset_is_from_end, bool only_if_ref); | |
1453 | ||
1454 | // Define a special symbol based on an Output_segment. It is a | |
1455 | // multiple definition error if this symbol is already defined. | |
14b31740 | 1456 | Symbol* |
99fff23b | 1457 | define_in_output_segment(const char* name, const char* version, Defined, |
9b07f471 | 1458 | Output_segment*, uint64_t value, uint64_t symsize, |
ead1e424 ILT |
1459 | elfcpp::STT type, elfcpp::STB binding, |
1460 | elfcpp::STV visibility, unsigned char nonvis, | |
1461 | Symbol::Segment_offset_base, bool only_if_ref); | |
1462 | ||
1463 | // Define a special symbol with a constant value. It is a multiple | |
1464 | // definition error if this symbol is already defined. | |
14b31740 | 1465 | Symbol* |
99fff23b | 1466 | define_as_constant(const char* name, const char* version, Defined, |
14b31740 ILT |
1467 | uint64_t value, uint64_t symsize, elfcpp::STT type, |
1468 | elfcpp::STB binding, elfcpp::STV visibility, | |
caa9d5d9 ILT |
1469 | unsigned char nonvis, bool only_if_ref, |
1470 | bool force_override); | |
ead1e424 | 1471 | |
a445fddf ILT |
1472 | // Define a set of symbols in output sections. If ONLY_IF_REF is |
1473 | // true, only define them if they are referenced. | |
ead1e424 | 1474 | void |
a445fddf ILT |
1475 | define_symbols(const Layout*, int count, const Define_symbol_in_section*, |
1476 | bool only_if_ref); | |
ead1e424 | 1477 | |
a445fddf ILT |
1478 | // Define a set of symbols in output segments. If ONLY_IF_REF is |
1479 | // true, only defined them if they are referenced. | |
ead1e424 | 1480 | void |
a445fddf ILT |
1481 | define_symbols(const Layout*, int count, const Define_symbol_in_segment*, |
1482 | bool only_if_ref); | |
ead1e424 | 1483 | |
46fe1623 ILT |
1484 | // Define SYM using a COPY reloc. POSD is the Output_data where the |
1485 | // symbol should be defined--typically a .dyn.bss section. VALUE is | |
1486 | // the offset within POSD. | |
1487 | template<int size> | |
1488 | void | |
9b07f471 | 1489 | define_with_copy_reloc(Sized_symbol<size>* sym, Output_data* posd, |
fe8718a4 | 1490 | typename elfcpp::Elf_types<size>::Elf_Addr); |
46fe1623 | 1491 | |
61ba1cf9 ILT |
1492 | // Look up a symbol. |
1493 | Symbol* | |
1494 | lookup(const char*, const char* version = NULL) const; | |
1495 | ||
14bfc3f5 | 1496 | // Return the real symbol associated with the forwarder symbol FROM. |
bae7f79e | 1497 | Symbol* |
c06b7b0b | 1498 | resolve_forwards(const Symbol* from) const; |
bae7f79e | 1499 | |
1564db8d ILT |
1500 | // Return the sized version of a symbol in this table. |
1501 | template<int size> | |
1502 | Sized_symbol<size>* | |
7d1a9ebb | 1503 | get_sized_symbol(Symbol*) const; |
1564db8d ILT |
1504 | |
1505 | template<int size> | |
1506 | const Sized_symbol<size>* | |
7d1a9ebb | 1507 | get_sized_symbol(const Symbol*) const; |
54dc6425 | 1508 | |
ead1e424 | 1509 | // Return the count of undefined symbols seen. |
114dfbe1 | 1510 | size_t |
ead1e424 ILT |
1511 | saw_undefined() const |
1512 | { return this->saw_undefined_; } | |
1513 | ||
1514 | // Allocate the common symbols | |
1515 | void | |
7d9e3d98 | 1516 | allocate_commons(Layout*, Mapfile*); |
ead1e424 | 1517 | |
cb295612 ILT |
1518 | // Add a warning for symbol NAME in object OBJ. WARNING is the text |
1519 | // of the warning. | |
f6ce93d6 | 1520 | void |
cb295612 ILT |
1521 | add_warning(const char* name, Object* obj, const std::string& warning) |
1522 | { this->warnings_.add_warning(this, name, obj, warning); } | |
f6ce93d6 ILT |
1523 | |
1524 | // Canonicalize a symbol name for use in the hash table. | |
1525 | const char* | |
1526 | canonicalize_name(const char* name) | |
cfd73a4e | 1527 | { return this->namepool_.add(name, true, NULL); } |
f6ce93d6 ILT |
1528 | |
1529 | // Possibly issue a warning for a reference to SYM at LOCATION which | |
1530 | // is in OBJ. | |
75f2446e | 1531 | template<int size, bool big_endian> |
f6ce93d6 | 1532 | void |
75f2446e ILT |
1533 | issue_warning(const Symbol* sym, |
1534 | const Relocate_info<size, big_endian>* relinfo, | |
1535 | size_t relnum, off_t reloffset) const | |
1536 | { this->warnings_.issue_warning(sym, relinfo, relnum, reloffset); } | |
f6ce93d6 | 1537 | |
70e654ba ILT |
1538 | // Check candidate_odr_violations_ to find symbols with the same name |
1539 | // but apparently different definitions (different source-file/line-no). | |
1540 | void | |
17a1d0a9 | 1541 | detect_odr_violations(const Task*, const char* output_file_name) const; |
70e654ba | 1542 | |
f3e9c5c5 ILT |
1543 | // Add any undefined symbols named on the command line to the symbol |
1544 | // table. | |
1545 | void | |
88a4108b | 1546 | add_undefined_symbols_from_command_line(Layout*); |
f3e9c5c5 | 1547 | |
46fe1623 ILT |
1548 | // SYM is defined using a COPY reloc. Return the dynamic object |
1549 | // where the original definition was found. | |
1550 | Dynobj* | |
1551 | get_copy_source(const Symbol* sym) const; | |
1552 | ||
a3ad94ed ILT |
1553 | // Set the dynamic symbol indexes. INDEX is the index of the first |
1554 | // global dynamic symbol. Pointers to the symbols are stored into | |
1555 | // the vector. The names are stored into the Stringpool. This | |
1556 | // returns an updated dynamic symbol index. | |
1557 | unsigned int | |
9b07f471 ILT |
1558 | set_dynsym_indexes(unsigned int index, std::vector<Symbol*>*, |
1559 | Stringpool*, Versions*); | |
a3ad94ed | 1560 | |
75f65a3e | 1561 | // Finalize the symbol table after we have set the final addresses |
c06b7b0b | 1562 | // of all the input sections. This sets the final symbol indexes, |
55a93433 ILT |
1563 | // values and adds the names to *POOL. *PLOCAL_SYMCOUNT is the |
1564 | // index of the first global symbol. OFF is the file offset of the | |
1565 | // global symbol table, DYNOFF is the offset of the globals in the | |
1566 | // dynamic symbol table, DYN_GLOBAL_INDEX is the index of the first | |
1567 | // global dynamic symbol, and DYNCOUNT is the number of global | |
1568 | // dynamic symbols. This records the parameters, and returns the | |
1569 | // new file offset. It updates *PLOCAL_SYMCOUNT if it created any | |
1570 | // local symbols. | |
75f65a3e | 1571 | off_t |
55a93433 | 1572 | finalize(off_t off, off_t dynoff, size_t dyn_global_index, size_t dyncount, |
ca09d69a | 1573 | Stringpool* pool, unsigned int* plocal_symcount); |
1564db8d | 1574 | |
cdc29364 CC |
1575 | // Set the final file offset of the symbol table. |
1576 | void | |
1577 | set_file_offset(off_t off) | |
1578 | { this->offset_ = off; } | |
1579 | ||
c0a62865 DK |
1580 | // Status code of Symbol_table::compute_final_value. |
1581 | enum Compute_final_value_status | |
1582 | { | |
1583 | // No error. | |
1584 | CFVS_OK, | |
9b547ce6 | 1585 | // Unsupported symbol section. |
c0a62865 DK |
1586 | CFVS_UNSUPPORTED_SYMBOL_SECTION, |
1587 | // No output section. | |
1588 | CFVS_NO_OUTPUT_SECTION | |
1589 | }; | |
1590 | ||
1591 | // Compute the final value of SYM and store status in location PSTATUS. | |
1592 | // During relaxation, this may be called multiple times for a symbol to | |
1593 | // compute its would-be final value in each relaxation pass. | |
1594 | ||
1595 | template<int size> | |
1596 | typename Sized_symbol<size>::Value_type | |
1597 | compute_final_value(const Sized_symbol<size>* sym, | |
1598 | Compute_final_value_status* pstatus) const; | |
1599 | ||
09ec0418 CC |
1600 | // Return the index of the first global symbol. |
1601 | unsigned int | |
1602 | first_global_index() const | |
1603 | { return this->first_global_index_; } | |
1604 | ||
1605 | // Return the total number of symbols in the symbol table. | |
1606 | unsigned int | |
1607 | output_count() const | |
1608 | { return this->output_count_; } | |
1609 | ||
61ba1cf9 ILT |
1610 | // Write out the global symbols. |
1611 | void | |
fd9d194f | 1612 | write_globals(const Stringpool*, const Stringpool*, |
d491d34e | 1613 | Output_symtab_xindex*, Output_symtab_xindex*, |
16649710 | 1614 | Output_file*) const; |
61ba1cf9 | 1615 | |
a3ad94ed ILT |
1616 | // Write out a section symbol. Return the updated offset. |
1617 | void | |
d491d34e ILT |
1618 | write_section_symbol(const Output_section*, Output_symtab_xindex*, |
1619 | Output_file*, off_t) const; | |
a3ad94ed | 1620 | |
0e70b911 CC |
1621 | // Loop over all symbols, applying the function F to each. |
1622 | template<int size, typename F> | |
1623 | void | |
1624 | for_all_symbols(F f) const | |
1625 | { | |
1626 | for (Symbol_table_type::const_iterator p = this->table_.begin(); | |
1627 | p != this->table_.end(); | |
1628 | ++p) | |
1629 | { | |
1630 | Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second); | |
1631 | f(sym); | |
1632 | } | |
1633 | } | |
1634 | ||
abaa3995 ILT |
1635 | // Dump statistical information to stderr. |
1636 | void | |
1637 | print_stats() const; | |
1638 | ||
09124467 ILT |
1639 | // Return the version script information. |
1640 | const Version_script_info& | |
1641 | version_script() const | |
1642 | { return version_script_; } | |
1643 | ||
bae7f79e ILT |
1644 | private: |
1645 | Symbol_table(const Symbol_table&); | |
1646 | Symbol_table& operator=(const Symbol_table&); | |
1647 | ||
155a0dd7 ILT |
1648 | // The type of the list of common symbols. |
1649 | typedef std::vector<Symbol*> Commons_type; | |
1650 | ||
8c500701 ILT |
1651 | // The type of the symbol hash table. |
1652 | ||
1653 | typedef std::pair<Stringpool::Key, Stringpool::Key> Symbol_table_key; | |
1654 | ||
a9bfd952 | 1655 | // The hash function. The key values are Stringpool keys. |
8c500701 ILT |
1656 | struct Symbol_table_hash |
1657 | { | |
a9bfd952 DK |
1658 | inline size_t |
1659 | operator()(const Symbol_table_key& key) const | |
1660 | { | |
1661 | return key.first ^ key.second; | |
1662 | } | |
8c500701 ILT |
1663 | }; |
1664 | ||
1665 | struct Symbol_table_eq | |
1666 | { | |
1667 | bool | |
1668 | operator()(const Symbol_table_key&, const Symbol_table_key&) const; | |
1669 | }; | |
1670 | ||
1671 | typedef Unordered_map<Symbol_table_key, Symbol*, Symbol_table_hash, | |
1672 | Symbol_table_eq> Symbol_table_type; | |
1673 | ||
71ff8986 ILT |
1674 | // A map from symbol name (as a pointer into the namepool) to all |
1675 | // the locations the symbols is (weakly) defined (and certain other | |
1676 | // conditions are met). This map will be used later to detect | |
1677 | // possible One Definition Rule (ODR) violations. | |
71ff8986 ILT |
1678 | struct Symbol_location_hash |
1679 | { | |
1680 | size_t operator()(const Symbol_location& loc) const | |
1681 | { return reinterpret_cast<uintptr_t>(loc.object) ^ loc.offset ^ loc.shndx; } | |
1682 | }; | |
1683 | ||
1684 | typedef Unordered_map<const char*, | |
1685 | Unordered_set<Symbol_location, Symbol_location_hash> > | |
1686 | Odr_map; | |
1687 | ||
14bfc3f5 ILT |
1688 | // Make FROM a forwarder symbol to TO. |
1689 | void | |
1690 | make_forwarder(Symbol* from, Symbol* to); | |
1691 | ||
1692 | // Add a symbol. | |
1693 | template<int size, bool big_endian> | |
aeddab66 | 1694 | Sized_symbol<size>* |
ca09d69a NC |
1695 | add_from_object(Object*, const char* name, Stringpool::Key name_key, |
1696 | const char* version, Stringpool::Key version_key, | |
70e654ba | 1697 | bool def, const elfcpp::Sym<size, big_endian>& sym, |
d491d34e ILT |
1698 | unsigned int st_shndx, bool is_ordinary, |
1699 | unsigned int orig_st_shndx); | |
14bfc3f5 | 1700 | |
8c500701 ILT |
1701 | // Define a default symbol. |
1702 | template<int size, bool big_endian> | |
1703 | void | |
1704 | define_default_version(Sized_symbol<size>*, bool, | |
1705 | Symbol_table_type::iterator); | |
1706 | ||
14bfc3f5 ILT |
1707 | // Resolve symbols. |
1708 | template<int size, bool big_endian> | |
aeddab66 | 1709 | void |
1564db8d ILT |
1710 | resolve(Sized_symbol<size>* to, |
1711 | const elfcpp::Sym<size, big_endian>& sym, | |
d491d34e ILT |
1712 | unsigned int st_shndx, bool is_ordinary, |
1713 | unsigned int orig_st_shndx, | |
b45e00b3 CC |
1714 | Object*, const char* version, |
1715 | bool is_default_version); | |
14bfc3f5 | 1716 | |
1564db8d | 1717 | template<int size, bool big_endian> |
aeddab66 | 1718 | void |
95d14cd3 | 1719 | resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from); |
14b31740 | 1720 | |
0602e05a ILT |
1721 | // Record that a symbol is forced to be local by a version script or |
1722 | // by visibility. | |
55a93433 ILT |
1723 | void |
1724 | force_local(Symbol*); | |
1725 | ||
0864d551 ILT |
1726 | // Adjust NAME and *NAME_KEY for wrapping. |
1727 | const char* | |
029ba973 | 1728 | wrap_symbol(const char* name, Stringpool::Key* name_key); |
0864d551 | 1729 | |
86f2e683 ILT |
1730 | // Whether we should override a symbol, based on flags in |
1731 | // resolve.cc. | |
1732 | static bool | |
62855347 | 1733 | should_override(const Symbol*, unsigned int, elfcpp::STT, Defined, |
b45e00b3 | 1734 | Object*, bool*, bool*, bool); |
86f2e683 | 1735 | |
1ae4d23b ILT |
1736 | // Report a problem in symbol resolution. |
1737 | static void | |
1738 | report_resolve_problem(bool is_error, const char* msg, const Symbol* to, | |
99fff23b | 1739 | Defined, Object* object); |
1ae4d23b | 1740 | |
aeddab66 ILT |
1741 | // Override a symbol. |
1742 | template<int size, bool big_endian> | |
1743 | void | |
1744 | override(Sized_symbol<size>* tosym, | |
1745 | const elfcpp::Sym<size, big_endian>& fromsym, | |
d491d34e | 1746 | unsigned int st_shndx, bool is_ordinary, |
aeddab66 ILT |
1747 | Object* object, const char* version); |
1748 | ||
86f2e683 ILT |
1749 | // Whether we should override a symbol with a special symbol which |
1750 | // is automatically defined by the linker. | |
1751 | static bool | |
62855347 | 1752 | should_override_with_special(const Symbol*, elfcpp::STT, Defined); |
86f2e683 | 1753 | |
aeddab66 ILT |
1754 | // Override a symbol with a special symbol. |
1755 | template<int size> | |
1756 | void | |
1757 | override_with_special(Sized_symbol<size>* tosym, | |
1758 | const Sized_symbol<size>* fromsym); | |
1759 | ||
1760 | // Record all weak alias sets for a dynamic object. | |
1761 | template<int size> | |
1762 | void | |
1763 | record_weak_aliases(std::vector<Sized_symbol<size>*>*); | |
1764 | ||
14b31740 ILT |
1765 | // Define a special symbol. |
1766 | template<int size, bool big_endian> | |
1767 | Sized_symbol<size>* | |
9b07f471 | 1768 | define_special_symbol(const char** pname, const char** pversion, |
8c500701 ILT |
1769 | bool only_if_ref, Sized_symbol<size>** poldsym, |
1770 | bool* resolve_oldsym); | |
14bfc3f5 | 1771 | |
ead1e424 ILT |
1772 | // Define a symbol in an Output_data, sized version. |
1773 | template<int size> | |
14b31740 | 1774 | Sized_symbol<size>* |
99fff23b ILT |
1775 | do_define_in_output_data(const char* name, const char* version, Defined, |
1776 | Output_data*, | |
ead1e424 ILT |
1777 | typename elfcpp::Elf_types<size>::Elf_Addr value, |
1778 | typename elfcpp::Elf_types<size>::Elf_WXword ssize, | |
1779 | elfcpp::STT type, elfcpp::STB binding, | |
1780 | elfcpp::STV visibility, unsigned char nonvis, | |
1781 | bool offset_is_from_end, bool only_if_ref); | |
1782 | ||
1783 | // Define a symbol in an Output_segment, sized version. | |
1784 | template<int size> | |
14b31740 | 1785 | Sized_symbol<size>* |
ead1e424 | 1786 | do_define_in_output_segment( |
99fff23b | 1787 | const char* name, const char* version, Defined, Output_segment* os, |
ead1e424 ILT |
1788 | typename elfcpp::Elf_types<size>::Elf_Addr value, |
1789 | typename elfcpp::Elf_types<size>::Elf_WXword ssize, | |
1790 | elfcpp::STT type, elfcpp::STB binding, | |
1791 | elfcpp::STV visibility, unsigned char nonvis, | |
1792 | Symbol::Segment_offset_base offset_base, bool only_if_ref); | |
1793 | ||
1794 | // Define a symbol as a constant, sized version. | |
1795 | template<int size> | |
14b31740 | 1796 | Sized_symbol<size>* |
ead1e424 | 1797 | do_define_as_constant( |
99fff23b | 1798 | const char* name, const char* version, Defined, |
ead1e424 ILT |
1799 | typename elfcpp::Elf_types<size>::Elf_Addr value, |
1800 | typename elfcpp::Elf_types<size>::Elf_WXword ssize, | |
1801 | elfcpp::STT type, elfcpp::STB binding, | |
1802 | elfcpp::STV visibility, unsigned char nonvis, | |
caa9d5d9 | 1803 | bool only_if_ref, bool force_override); |
ead1e424 | 1804 | |
f3e9c5c5 ILT |
1805 | // Add any undefined symbols named on the command line to the symbol |
1806 | // table, sized version. | |
1807 | template<int size> | |
1808 | void | |
88a4108b ILT |
1809 | do_add_undefined_symbols_from_command_line(Layout*); |
1810 | ||
1811 | // Add one undefined symbol. | |
1812 | template<int size> | |
1813 | void | |
1814 | add_undefined_symbol_from_command_line(const char* name); | |
f3e9c5c5 | 1815 | |
8a5e3e08 ILT |
1816 | // Types of common symbols. |
1817 | ||
1818 | enum Commons_section_type | |
1819 | { | |
1820 | COMMONS_NORMAL, | |
1821 | COMMONS_TLS, | |
1822 | COMMONS_SMALL, | |
1823 | COMMONS_LARGE | |
1824 | }; | |
1825 | ||
ead1e424 ILT |
1826 | // Allocate the common symbols, sized version. |
1827 | template<int size> | |
1828 | void | |
fc59c572 | 1829 | do_allocate_commons(Layout*, Mapfile*, Sort_commons_order); |
155a0dd7 ILT |
1830 | |
1831 | // Allocate the common symbols from one list. | |
1832 | template<int size> | |
1833 | void | |
8a5e3e08 | 1834 | do_allocate_commons_list(Layout*, Commons_section_type, Commons_type*, |
fc59c572 | 1835 | Mapfile*, Sort_commons_order); |
ead1e424 | 1836 | |
71ff8986 ILT |
1837 | // Returns all of the lines attached to LOC, not just the one the |
1838 | // instruction actually came from. This helps the ODR checker avoid | |
1839 | // false positives. | |
1840 | static std::vector<std::string> | |
1841 | linenos_from_loc(const Task* task, const Symbol_location& loc); | |
1842 | ||
70e654ba ILT |
1843 | // Implement detect_odr_violations. |
1844 | template<int size, bool big_endian> | |
1845 | void | |
1846 | sized_detect_odr_violations() const; | |
1847 | ||
75f65a3e ILT |
1848 | // Finalize symbols specialized for size. |
1849 | template<int size> | |
1850 | off_t | |
55a93433 ILT |
1851 | sized_finalize(off_t, Stringpool*, unsigned int*); |
1852 | ||
1853 | // Finalize a symbol. Return whether it should be added to the | |
1854 | // symbol table. | |
1855 | template<int size> | |
1856 | bool | |
1857 | sized_finalize_symbol(Symbol*); | |
1858 | ||
1859 | // Add a symbol the final symtab by setting its index. | |
1860 | template<int size> | |
1861 | void | |
1862 | add_to_final_symtab(Symbol*, Stringpool*, unsigned int* pindex, off_t* poff); | |
75f65a3e | 1863 | |
61ba1cf9 ILT |
1864 | // Write globals specialized for size and endianness. |
1865 | template<int size, bool big_endian> | |
1866 | void | |
fd9d194f ILT |
1867 | sized_write_globals(const Stringpool*, const Stringpool*, |
1868 | Output_symtab_xindex*, Output_symtab_xindex*, | |
1869 | Output_file*) const; | |
16649710 ILT |
1870 | |
1871 | // Write out a symbol to P. | |
1872 | template<int size, bool big_endian> | |
1873 | void | |
ab5c9e90 ILT |
1874 | sized_write_symbol(Sized_symbol<size>*, |
1875 | typename elfcpp::Elf_types<size>::Elf_Addr value, | |
ce279a62 | 1876 | unsigned int shndx, elfcpp::STB, |
7d1a9ebb | 1877 | const Stringpool*, unsigned char* p) const; |
61ba1cf9 | 1878 | |
9a2d6984 ILT |
1879 | // Possibly warn about an undefined symbol from a dynamic object. |
1880 | void | |
fd9d194f | 1881 | warn_about_undefined_dynobj_symbol(Symbol*) const; |
9a2d6984 | 1882 | |
a3ad94ed ILT |
1883 | // Write out a section symbol, specialized for size and endianness. |
1884 | template<int size, bool big_endian> | |
1885 | void | |
d491d34e ILT |
1886 | sized_write_section_symbol(const Output_section*, Output_symtab_xindex*, |
1887 | Output_file*, off_t) const; | |
a3ad94ed | 1888 | |
55a93433 ILT |
1889 | // The type of the list of symbols which have been forced local. |
1890 | typedef std::vector<Symbol*> Forced_locals; | |
1891 | ||
46fe1623 ILT |
1892 | // A map from symbols with COPY relocs to the dynamic objects where |
1893 | // they are defined. | |
1894 | typedef Unordered_map<const Symbol*, Dynobj*> Copied_symbol_dynobjs; | |
1895 | ||
ead1e424 ILT |
1896 | // We increment this every time we see a new undefined symbol, for |
1897 | // use in archive groups. | |
114dfbe1 | 1898 | size_t saw_undefined_; |
c06b7b0b ILT |
1899 | // The index of the first global symbol in the output file. |
1900 | unsigned int first_global_index_; | |
75f65a3e ILT |
1901 | // The file offset within the output symtab section where we should |
1902 | // write the table. | |
1903 | off_t offset_; | |
61ba1cf9 | 1904 | // The number of global symbols we want to write out. |
55a93433 | 1905 | unsigned int output_count_; |
16649710 ILT |
1906 | // The file offset of the global dynamic symbols, or 0 if none. |
1907 | off_t dynamic_offset_; | |
16649710 ILT |
1908 | // The index of the first global dynamic symbol. |
1909 | unsigned int first_dynamic_global_index_; | |
16649710 | 1910 | // The number of global dynamic symbols, or 0 if none. |
55a93433 | 1911 | unsigned int dynamic_count_; |
54dc6425 | 1912 | // The symbol hash table. |
14bfc3f5 | 1913 | Symbol_table_type table_; |
54dc6425 ILT |
1914 | // A pool of symbol names. This is used for all global symbols. |
1915 | // Entries in the hash table point into this pool. | |
14bfc3f5 | 1916 | Stringpool namepool_; |
14bfc3f5 | 1917 | // Forwarding symbols. |
c06b7b0b | 1918 | Unordered_map<const Symbol*, Symbol*> forwarders_; |
aeddab66 ILT |
1919 | // Weak aliases. A symbol in this list points to the next alias. |
1920 | // The aliases point to each other in a circular list. | |
1921 | Unordered_map<Symbol*, Symbol*> weak_aliases_; | |
ead1e424 ILT |
1922 | // We don't expect there to be very many common symbols, so we keep |
1923 | // a list of them. When we find a common symbol we add it to this | |
1924 | // list. It is possible that by the time we process the list the | |
1925 | // symbol is no longer a common symbol. It may also have become a | |
1926 | // forwarder. | |
1927 | Commons_type commons_; | |
155a0dd7 ILT |
1928 | // This is like the commons_ field, except that it holds TLS common |
1929 | // symbols. | |
1930 | Commons_type tls_commons_; | |
8a5e3e08 ILT |
1931 | // This is for small common symbols. |
1932 | Commons_type small_commons_; | |
1933 | // This is for large common symbols. | |
1934 | Commons_type large_commons_; | |
55a93433 ILT |
1935 | // A list of symbols which have been forced to be local. We don't |
1936 | // expect there to be very many of them, so we keep a list of them | |
1937 | // rather than walking the whole table to find them. | |
1938 | Forced_locals forced_locals_; | |
f6ce93d6 ILT |
1939 | // Manage symbol warnings. |
1940 | Warnings warnings_; | |
70e654ba ILT |
1941 | // Manage potential One Definition Rule (ODR) violations. |
1942 | Odr_map candidate_odr_violations_; | |
1943 | ||
46fe1623 ILT |
1944 | // When we emit a COPY reloc for a symbol, we define it in an |
1945 | // Output_data. When it's time to emit version information for it, | |
1946 | // we need to know the dynamic object in which we found the original | |
1947 | // definition. This maps symbols with COPY relocs to the dynamic | |
1948 | // object where they were defined. | |
1949 | Copied_symbol_dynobjs copied_symbol_dynobjs_; | |
09124467 ILT |
1950 | // Information parsed from the version script, if any. |
1951 | const Version_script_info& version_script_; | |
6d03d481 | 1952 | Garbage_collection* gc_; |
ef15dade | 1953 | Icf* icf_; |
bae7f79e ILT |
1954 | }; |
1955 | ||
1564db8d ILT |
1956 | // We inline get_sized_symbol for efficiency. |
1957 | ||
1958 | template<int size> | |
1959 | Sized_symbol<size>* | |
7d1a9ebb | 1960 | Symbol_table::get_sized_symbol(Symbol* sym) const |
1564db8d | 1961 | { |
8851ecca | 1962 | gold_assert(size == parameters->target().get_size()); |
1564db8d ILT |
1963 | return static_cast<Sized_symbol<size>*>(sym); |
1964 | } | |
1965 | ||
1966 | template<int size> | |
1967 | const Sized_symbol<size>* | |
7d1a9ebb | 1968 | Symbol_table::get_sized_symbol(const Symbol* sym) const |
1564db8d | 1969 | { |
8851ecca | 1970 | gold_assert(size == parameters->target().get_size()); |
1564db8d ILT |
1971 | return static_cast<const Sized_symbol<size>*>(sym); |
1972 | } | |
1973 | ||
bae7f79e ILT |
1974 | } // End namespace gold. |
1975 | ||
1976 | #endif // !defined(GOLD_SYMTAB_H) |