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bae7f79e ILT |
1 | // symtab.h -- the gold symbol table -*- C++ -*- |
2 | ||
880cd20d | 3 | // Copyright 2006, 2007, 2008, 2009, 2010 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 ILT |
44 | template<int size, bool big_endian> |
45 | class Sized_relobj; | |
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 ILT |
64 | // The base class of an entry in the symbol table. The symbol table |
65 | // can have a lot of entries, so we don't want this class to big. | |
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 | ||
09124467 ILT |
124 | // Return whether this version is the default for this symbol name |
125 | // (eg, "foo@@V2" is a default version; "foo@V1" is not). Only | |
126 | // meaningful for versioned symbols. | |
127 | bool | |
128 | is_default() const | |
129 | { | |
130 | gold_assert(this->version_ != NULL); | |
131 | return this->is_def_; | |
132 | } | |
133 | ||
be3e6201 | 134 | // Set that this version is the default for this symbol name. |
09124467 | 135 | void |
be3e6201 ILT |
136 | set_is_default() |
137 | { this->is_def_ = true; } | |
09124467 | 138 | |
ead1e424 ILT |
139 | // Return the symbol source. |
140 | Source | |
141 | source() const | |
142 | { return this->source_; } | |
143 | ||
14bfc3f5 ILT |
144 | // Return the object with which this symbol is associated. |
145 | Object* | |
146 | object() const | |
ead1e424 | 147 | { |
a3ad94ed | 148 | gold_assert(this->source_ == FROM_OBJECT); |
ead1e424 ILT |
149 | return this->u_.from_object.object; |
150 | } | |
151 | ||
f6ce93d6 ILT |
152 | // Return the index of the section in the input relocatable or |
153 | // dynamic object file. | |
ead1e424 | 154 | unsigned int |
d491d34e | 155 | shndx(bool* is_ordinary) const |
ead1e424 | 156 | { |
a3ad94ed | 157 | gold_assert(this->source_ == FROM_OBJECT); |
d491d34e | 158 | *is_ordinary = this->is_ordinary_shndx_; |
16649710 | 159 | return this->u_.from_object.shndx; |
ead1e424 ILT |
160 | } |
161 | ||
162 | // Return the output data section with which this symbol is | |
163 | // associated, if the symbol was specially defined with respect to | |
164 | // an output data section. | |
165 | Output_data* | |
166 | output_data() const | |
167 | { | |
a3ad94ed | 168 | gold_assert(this->source_ == IN_OUTPUT_DATA); |
ead1e424 ILT |
169 | return this->u_.in_output_data.output_data; |
170 | } | |
171 | ||
172 | // If this symbol was defined with respect to an output data | |
173 | // section, return whether the value is an offset from end. | |
174 | bool | |
175 | offset_is_from_end() const | |
176 | { | |
a3ad94ed | 177 | gold_assert(this->source_ == IN_OUTPUT_DATA); |
ead1e424 ILT |
178 | return this->u_.in_output_data.offset_is_from_end; |
179 | } | |
180 | ||
181 | // Return the output segment with which this symbol is associated, | |
182 | // if the symbol was specially defined with respect to an output | |
183 | // segment. | |
184 | Output_segment* | |
185 | output_segment() const | |
186 | { | |
a3ad94ed | 187 | gold_assert(this->source_ == IN_OUTPUT_SEGMENT); |
ead1e424 ILT |
188 | return this->u_.in_output_segment.output_segment; |
189 | } | |
190 | ||
191 | // If this symbol was defined with respect to an output segment, | |
192 | // return the offset base. | |
193 | Segment_offset_base | |
194 | offset_base() const | |
195 | { | |
a3ad94ed | 196 | gold_assert(this->source_ == IN_OUTPUT_SEGMENT); |
ead1e424 ILT |
197 | return this->u_.in_output_segment.offset_base; |
198 | } | |
14bfc3f5 ILT |
199 | |
200 | // Return the symbol binding. | |
201 | elfcpp::STB | |
202 | binding() const | |
203 | { return this->binding_; } | |
204 | ||
1564db8d ILT |
205 | // Return the symbol type. |
206 | elfcpp::STT | |
207 | type() const | |
208 | { return this->type_; } | |
209 | ||
53d7974c L |
210 | // Return true for function symbol. |
211 | bool | |
212 | is_func() const | |
213 | { | |
214 | return (this->type_ == elfcpp::STT_FUNC | |
215 | || this->type_ == elfcpp::STT_GNU_IFUNC); | |
216 | } | |
217 | ||
1564db8d ILT |
218 | // Return the symbol visibility. |
219 | elfcpp::STV | |
220 | visibility() const | |
221 | { return this->visibility_; } | |
222 | ||
0602e05a ILT |
223 | // Set the visibility. |
224 | void | |
2ea97941 ILT |
225 | set_visibility(elfcpp::STV visibility) |
226 | { this->visibility_ = visibility; } | |
0602e05a ILT |
227 | |
228 | // Override symbol visibility. | |
229 | void | |
230 | override_visibility(elfcpp::STV); | |
231 | ||
ce279a62 CC |
232 | // Set whether the symbol was originally a weak undef or a regular undef |
233 | // when resolved by a dynamic def. | |
234 | inline void | |
235 | set_undef_binding(elfcpp::STB bind) | |
236 | { | |
237 | if (!this->undef_binding_set_ || this->undef_binding_weak_) | |
238 | { | |
239 | this->undef_binding_weak_ = bind == elfcpp::STB_WEAK; | |
240 | this->undef_binding_set_ = true; | |
241 | } | |
242 | } | |
243 | ||
244 | // Return TRUE if a weak undef was resolved by a dynamic def. | |
245 | inline bool | |
246 | is_undef_binding_weak() const | |
247 | { return this->undef_binding_weak_; } | |
248 | ||
1564db8d ILT |
249 | // Return the non-visibility part of the st_other field. |
250 | unsigned char | |
ead1e424 ILT |
251 | nonvis() const |
252 | { return this->nonvis_; } | |
14bfc3f5 | 253 | |
1564db8d ILT |
254 | // Return whether this symbol is a forwarder. This will never be |
255 | // true of a symbol found in the hash table, but may be true of | |
256 | // symbol pointers attached to object files. | |
257 | bool | |
258 | is_forwarder() const | |
259 | { return this->is_forwarder_; } | |
260 | ||
261 | // Mark this symbol as a forwarder. | |
262 | void | |
263 | set_forwarder() | |
264 | { this->is_forwarder_ = true; } | |
265 | ||
aeddab66 ILT |
266 | // Return whether this symbol has an alias in the weak aliases table |
267 | // in Symbol_table. | |
268 | bool | |
269 | has_alias() const | |
270 | { return this->has_alias_; } | |
271 | ||
272 | // Mark this symbol as having an alias. | |
273 | void | |
274 | set_has_alias() | |
275 | { this->has_alias_ = true; } | |
276 | ||
c06b7b0b ILT |
277 | // Return whether this symbol needs an entry in the dynamic symbol |
278 | // table. | |
279 | bool | |
280 | needs_dynsym_entry() const | |
429c1569 ILT |
281 | { |
282 | return (this->needs_dynsym_entry_ | |
8d6d383d ILT |
283 | || (this->in_reg() |
284 | && this->in_dyn() | |
285 | && this->is_externally_visible())); | |
429c1569 | 286 | } |
c06b7b0b ILT |
287 | |
288 | // Mark this symbol as needing an entry in the dynamic symbol table. | |
289 | void | |
290 | set_needs_dynsym_entry() | |
291 | { this->needs_dynsym_entry_ = true; } | |
292 | ||
436ca963 ILT |
293 | // Return whether this symbol should be added to the dynamic symbol |
294 | // table. | |
295 | bool | |
ce97fa81 | 296 | should_add_dynsym_entry(Symbol_table*) const; |
436ca963 | 297 | |
008db82e ILT |
298 | // Return whether this symbol has been seen in a regular object. |
299 | bool | |
300 | in_reg() const | |
301 | { return this->in_reg_; } | |
302 | ||
303 | // Mark this symbol as having been seen in a regular object. | |
304 | void | |
305 | set_in_reg() | |
306 | { this->in_reg_ = true; } | |
307 | ||
1ebd95fd ILT |
308 | // Return whether this symbol has been seen in a dynamic object. |
309 | bool | |
310 | in_dyn() const | |
311 | { return this->in_dyn_; } | |
312 | ||
f6ce93d6 | 313 | // Mark this symbol as having been seen in a dynamic object. |
1564db8d ILT |
314 | void |
315 | set_in_dyn() | |
316 | { this->in_dyn_ = true; } | |
317 | ||
89fc3421 CC |
318 | // Return whether this symbol has been seen in a real ELF object. |
319 | // (IN_REG will return TRUE if the symbol has been seen in either | |
320 | // a real ELF object or an object claimed by a plugin.) | |
321 | bool | |
322 | in_real_elf() const | |
323 | { return this->in_real_elf_; } | |
324 | ||
325 | // Mark this symbol as having been seen in a real ELF object. | |
326 | void | |
327 | set_in_real_elf() | |
328 | { this->in_real_elf_ = true; } | |
329 | ||
880cd20d ILT |
330 | // Return whether this symbol was defined in a section that was |
331 | // discarded from the link. This is used to control some error | |
332 | // reporting. | |
333 | bool | |
334 | is_defined_in_discarded_section() const | |
335 | { return this->is_defined_in_discarded_section_; } | |
336 | ||
337 | // Mark this symbol as having been defined in a discarded section. | |
338 | void | |
339 | set_is_defined_in_discarded_section() | |
340 | { this->is_defined_in_discarded_section_ = true; } | |
341 | ||
c06b7b0b ILT |
342 | // Return the index of this symbol in the output file symbol table. |
343 | // A value of -1U means that this symbol is not going into the | |
344 | // output file. This starts out as zero, and is set to a non-zero | |
345 | // value by Symbol_table::finalize. It is an error to ask for the | |
346 | // symbol table index before it has been set. | |
347 | unsigned int | |
348 | symtab_index() const | |
349 | { | |
a3ad94ed | 350 | gold_assert(this->symtab_index_ != 0); |
c06b7b0b ILT |
351 | return this->symtab_index_; |
352 | } | |
353 | ||
354 | // Set the index of the symbol in the output file symbol table. | |
355 | void | |
356 | set_symtab_index(unsigned int index) | |
357 | { | |
a3ad94ed | 358 | gold_assert(index != 0); |
c06b7b0b ILT |
359 | this->symtab_index_ = index; |
360 | } | |
361 | ||
a3ad94ed ILT |
362 | // Return whether this symbol already has an index in the output |
363 | // file symbol table. | |
364 | bool | |
365 | has_symtab_index() const | |
366 | { return this->symtab_index_ != 0; } | |
367 | ||
c06b7b0b ILT |
368 | // Return the index of this symbol in the dynamic symbol table. A |
369 | // value of -1U means that this symbol is not going into the dynamic | |
370 | // symbol table. This starts out as zero, and is set to a non-zero | |
371 | // during Layout::finalize. It is an error to ask for the dynamic | |
372 | // symbol table index before it has been set. | |
373 | unsigned int | |
374 | dynsym_index() const | |
375 | { | |
a3ad94ed | 376 | gold_assert(this->dynsym_index_ != 0); |
c06b7b0b ILT |
377 | return this->dynsym_index_; |
378 | } | |
379 | ||
380 | // Set the index of the symbol in the dynamic symbol table. | |
381 | void | |
382 | set_dynsym_index(unsigned int index) | |
383 | { | |
a3ad94ed | 384 | gold_assert(index != 0); |
c06b7b0b ILT |
385 | this->dynsym_index_ = index; |
386 | } | |
387 | ||
16649710 ILT |
388 | // Return whether this symbol already has an index in the dynamic |
389 | // symbol table. | |
390 | bool | |
391 | has_dynsym_index() const | |
392 | { return this->dynsym_index_ != 0; } | |
393 | ||
ead1e424 | 394 | // Return whether this symbol has an entry in the GOT section. |
07f397ab | 395 | // For a TLS symbol, this GOT entry will hold its tp-relative offset. |
92e059d8 | 396 | bool |
0a65a3a7 CC |
397 | has_got_offset(unsigned int got_type) const |
398 | { return this->got_offsets_.get_offset(got_type) != -1U; } | |
ead1e424 ILT |
399 | |
400 | // Return the offset into the GOT section of this symbol. | |
401 | unsigned int | |
0a65a3a7 | 402 | got_offset(unsigned int got_type) const |
ead1e424 | 403 | { |
2ea97941 ILT |
404 | unsigned int got_offset = this->got_offsets_.get_offset(got_type); |
405 | gold_assert(got_offset != -1U); | |
406 | return got_offset; | |
ead1e424 ILT |
407 | } |
408 | ||
409 | // Set the GOT offset of this symbol. | |
410 | void | |
2ea97941 ILT |
411 | set_got_offset(unsigned int got_type, unsigned int got_offset) |
412 | { this->got_offsets_.set_offset(got_type, got_offset); } | |
07f397ab | 413 | |
0e70b911 CC |
414 | // Return the GOT offset list. |
415 | const Got_offset_list* | |
416 | got_offset_list() const | |
417 | { return this->got_offsets_.get_list(); } | |
418 | ||
a3ad94ed | 419 | // Return whether this symbol has an entry in the PLT section. |
ead1e424 | 420 | bool |
a3ad94ed | 421 | has_plt_offset() const |
880cd20d | 422 | { return this->plt_offset_ != -1U; } |
a3ad94ed ILT |
423 | |
424 | // Return the offset into the PLT section of this symbol. | |
425 | unsigned int | |
426 | plt_offset() const | |
427 | { | |
428 | gold_assert(this->has_plt_offset()); | |
429 | return this->plt_offset_; | |
430 | } | |
431 | ||
432 | // Set the PLT offset of this symbol. | |
433 | void | |
2ea97941 | 434 | set_plt_offset(unsigned int plt_offset) |
a3ad94ed | 435 | { |
880cd20d | 436 | gold_assert(plt_offset != -1U); |
2ea97941 | 437 | this->plt_offset_ = plt_offset; |
a3ad94ed ILT |
438 | } |
439 | ||
ab5c9e90 ILT |
440 | // Return whether this dynamic symbol needs a special value in the |
441 | // dynamic symbol table. | |
442 | bool | |
443 | needs_dynsym_value() const | |
444 | { return this->needs_dynsym_value_; } | |
445 | ||
446 | // Set that this dynamic symbol needs a special value in the dynamic | |
447 | // symbol table. | |
448 | void | |
449 | set_needs_dynsym_value() | |
450 | { | |
451 | gold_assert(this->object()->is_dynamic()); | |
452 | this->needs_dynsym_value_ = true; | |
453 | } | |
454 | ||
a3ad94ed ILT |
455 | // Return true if the final value of this symbol is known at link |
456 | // time. | |
457 | bool | |
b3b74ddc | 458 | final_value_is_known() const; |
ead1e424 | 459 | |
8a5e3e08 ILT |
460 | // Return true if SHNDX represents a common symbol. This depends on |
461 | // the target. | |
462 | static bool | |
463 | is_common_shndx(unsigned int shndx); | |
464 | ||
f6ce93d6 ILT |
465 | // Return whether this is a defined symbol (not undefined or |
466 | // common). | |
467 | bool | |
468 | is_defined() const | |
469 | { | |
d491d34e ILT |
470 | bool is_ordinary; |
471 | if (this->source_ != FROM_OBJECT) | |
f3e9c5c5 | 472 | return this->source_ != IS_UNDEFINED; |
2ea97941 | 473 | unsigned int shndx = this->shndx(&is_ordinary); |
d491d34e | 474 | return (is_ordinary |
2ea97941 ILT |
475 | ? shndx != elfcpp::SHN_UNDEF |
476 | : !Symbol::is_common_shndx(shndx)); | |
a3ad94ed ILT |
477 | } |
478 | ||
14b31740 | 479 | // Return true if this symbol is from a dynamic object. |
a3ad94ed | 480 | bool |
14b31740 | 481 | is_from_dynobj() const |
a3ad94ed | 482 | { |
14b31740 | 483 | return this->source_ == FROM_OBJECT && this->object()->is_dynamic(); |
f6ce93d6 ILT |
484 | } |
485 | ||
f3a2388f CC |
486 | // Return whether this is a placeholder symbol from a plugin object. |
487 | bool | |
488 | is_placeholder() const | |
489 | { | |
490 | return this->source_ == FROM_OBJECT && this->object()->pluginobj() != NULL; | |
491 | } | |
492 | ||
ead1e424 ILT |
493 | // Return whether this is an undefined symbol. |
494 | bool | |
495 | is_undefined() const | |
496 | { | |
d491d34e | 497 | bool is_ordinary; |
f3e9c5c5 ILT |
498 | return ((this->source_ == FROM_OBJECT |
499 | && this->shndx(&is_ordinary) == elfcpp::SHN_UNDEF | |
500 | && is_ordinary) | |
501 | || this->source_ == IS_UNDEFINED); | |
ead1e424 ILT |
502 | } |
503 | ||
86925eef CC |
504 | // Return whether this is a weak undefined symbol. |
505 | bool | |
506 | is_weak_undefined() const | |
f3e9c5c5 | 507 | { return this->is_undefined() && this->binding() == elfcpp::STB_WEAK; } |
86925eef | 508 | |
86925eef CC |
509 | // Return whether this is an absolute symbol. |
510 | bool | |
511 | is_absolute() const | |
512 | { | |
d491d34e | 513 | bool is_ordinary; |
f3e9c5c5 ILT |
514 | return ((this->source_ == FROM_OBJECT |
515 | && this->shndx(&is_ordinary) == elfcpp::SHN_ABS | |
516 | && !is_ordinary) | |
517 | || this->source_ == IS_CONSTANT); | |
86925eef CC |
518 | } |
519 | ||
ead1e424 ILT |
520 | // Return whether this is a common symbol. |
521 | bool | |
522 | is_common() const | |
523 | { | |
8a5e3e08 ILT |
524 | if (this->source_ != FROM_OBJECT) |
525 | return false; | |
eda294df ILT |
526 | if (this->type_ == elfcpp::STT_COMMON) |
527 | return true; | |
d491d34e | 528 | bool is_ordinary; |
2ea97941 ILT |
529 | unsigned int shndx = this->shndx(&is_ordinary); |
530 | return !is_ordinary && Symbol::is_common_shndx(shndx); | |
ead1e424 | 531 | } |
92e059d8 | 532 | |
a6badf5a ILT |
533 | // Return whether this symbol can be seen outside this object. |
534 | bool | |
535 | is_externally_visible() const | |
536 | { | |
537 | return (this->visibility_ == elfcpp::STV_DEFAULT | |
538 | || this->visibility_ == elfcpp::STV_PROTECTED); | |
539 | } | |
540 | ||
436ca963 ILT |
541 | // Return true if this symbol can be preempted by a definition in |
542 | // another link unit. | |
543 | bool | |
544 | is_preemptible() const | |
545 | { | |
386c048c ILT |
546 | // It doesn't make sense to ask whether a symbol defined in |
547 | // another object is preemptible. | |
548 | gold_assert(!this->is_from_dynobj()); | |
549 | ||
8fc19601 ILT |
550 | // It doesn't make sense to ask whether an undefined symbol |
551 | // is preemptible. | |
552 | gold_assert(!this->is_undefined()); | |
553 | ||
f1f70eae ILT |
554 | // If a symbol does not have default visibility, it can not be |
555 | // seen outside this link unit and therefore is not preemptible. | |
556 | if (this->visibility_ != elfcpp::STV_DEFAULT) | |
557 | return false; | |
558 | ||
559 | // If this symbol has been forced to be a local symbol by a | |
560 | // version script, then it is not visible outside this link unit | |
561 | // and is not preemptible. | |
562 | if (this->is_forced_local_) | |
563 | return false; | |
564 | ||
565 | // If we are not producing a shared library, then nothing is | |
566 | // preemptible. | |
567 | if (!parameters->options().shared()) | |
568 | return false; | |
569 | ||
570 | // If the user used -Bsymbolic, then nothing is preemptible. | |
571 | if (parameters->options().Bsymbolic()) | |
572 | return false; | |
573 | ||
574 | // If the user used -Bsymbolic-functions, then functions are not | |
575 | // preemptible. We explicitly check for not being STT_OBJECT, | |
576 | // rather than for being STT_FUNC, because that is what the GNU | |
577 | // linker does. | |
578 | if (this->type() != elfcpp::STT_OBJECT | |
579 | && parameters->options().Bsymbolic_functions()) | |
580 | return false; | |
581 | ||
582 | // Otherwise the symbol is preemptible. | |
583 | return true; | |
436ca963 ILT |
584 | } |
585 | ||
d61c6bd4 | 586 | // Return true if this symbol is a function that needs a PLT entry. |
d61c6bd4 ILT |
587 | bool |
588 | needs_plt_entry() const | |
589 | { | |
6d479619 CC |
590 | // An undefined symbol from an executable does not need a PLT entry. |
591 | if (this->is_undefined() && !parameters->options().shared()) | |
592 | return false; | |
593 | ||
7223e9ca ILT |
594 | // An STT_GNU_IFUNC symbol always needs a PLT entry, even when |
595 | // doing a static link. | |
596 | if (this->type() == elfcpp::STT_GNU_IFUNC) | |
597 | return true; | |
598 | ||
599 | // We only need a PLT entry for a function. | |
600 | if (!this->is_func()) | |
601 | return false; | |
602 | ||
603 | // If we're doing a static link or a -pie link, we don't create | |
604 | // PLT entries. | |
605 | if (parameters->doing_static_link() | |
606 | || parameters->options().pie()) | |
607 | return false; | |
608 | ||
609 | // We need a PLT entry if the function is defined in a dynamic | |
610 | // object, or is undefined when building a shared object, or if it | |
611 | // is subject to pre-emption. | |
612 | return (this->is_from_dynobj() | |
613 | || this->is_undefined() | |
614 | || this->is_preemptible()); | |
d61c6bd4 ILT |
615 | } |
616 | ||
0700cf32 ILT |
617 | // When determining whether a reference to a symbol needs a dynamic |
618 | // relocation, we need to know several things about the reference. | |
95a2c8d6 RS |
619 | // These flags may be or'ed together. 0 means that the symbol |
620 | // isn't referenced at all. | |
0700cf32 ILT |
621 | enum Reference_flags |
622 | { | |
95a2c8d6 RS |
623 | // A reference to the symbol's absolute address. This includes |
624 | // references that cause an absolute address to be stored in the GOT. | |
0700cf32 | 625 | ABSOLUTE_REF = 1, |
95a2c8d6 RS |
626 | // A reference that calculates the offset of the symbol from some |
627 | // anchor point, such as the PC or GOT. | |
628 | RELATIVE_REF = 2, | |
629 | // A TLS-related reference. | |
630 | TLS_REF = 4, | |
631 | // A reference that can always be treated as a function call. | |
632 | FUNCTION_CALL = 8 | |
0700cf32 ILT |
633 | }; |
634 | ||
d61c6bd4 ILT |
635 | // Given a direct absolute or pc-relative static relocation against |
636 | // the global symbol, this function returns whether a dynamic relocation | |
637 | // is needed. | |
638 | ||
639 | bool | |
0700cf32 | 640 | needs_dynamic_reloc(int flags) const |
d61c6bd4 | 641 | { |
8fc19601 ILT |
642 | // No dynamic relocations in a static link! |
643 | if (parameters->doing_static_link()) | |
644 | return false; | |
645 | ||
6d479619 | 646 | // A reference to an undefined symbol from an executable should be |
f3c69fca CC |
647 | // statically resolved to 0, and does not need a dynamic relocation. |
648 | // This matches gnu ld behavior. | |
6d479619 | 649 | if (this->is_undefined() && !parameters->options().shared()) |
f3c69fca CC |
650 | return false; |
651 | ||
652 | // A reference to an absolute symbol does not need a dynamic relocation. | |
653 | if (this->is_absolute()) | |
86925eef CC |
654 | return false; |
655 | ||
d61c6bd4 | 656 | // An absolute reference within a position-independent output file |
0700cf32 ILT |
657 | // will need a dynamic relocation. |
658 | if ((flags & ABSOLUTE_REF) | |
8851ecca | 659 | && parameters->options().output_is_position_independent()) |
d61c6bd4 ILT |
660 | return true; |
661 | ||
662 | // A function call that can branch to a local PLT entry does not need | |
95a2c8d6 RS |
663 | // a dynamic relocation. |
664 | if ((flags & FUNCTION_CALL) && this->has_plt_offset()) | |
d61c6bd4 ILT |
665 | return false; |
666 | ||
667 | // A reference to any PLT entry in a non-position-independent executable | |
668 | // does not need a dynamic relocation. | |
8851ecca | 669 | if (!parameters->options().output_is_position_independent() |
d61c6bd4 ILT |
670 | && this->has_plt_offset()) |
671 | return false; | |
672 | ||
673 | // A reference to a symbol defined in a dynamic object or to a | |
674 | // symbol that is preemptible will need a dynamic relocation. | |
8fc19601 ILT |
675 | if (this->is_from_dynobj() |
676 | || this->is_undefined() | |
677 | || this->is_preemptible()) | |
d61c6bd4 ILT |
678 | return true; |
679 | ||
680 | // For all other cases, return FALSE. | |
681 | return false; | |
682 | } | |
683 | ||
de4c45bd | 684 | // Whether we should use the PLT offset associated with a symbol for |
95a2c8d6 | 685 | // a relocation. FLAGS is a set of Reference_flags. |
de4c45bd ILT |
686 | |
687 | bool | |
95a2c8d6 | 688 | use_plt_offset(int flags) const |
de4c45bd ILT |
689 | { |
690 | // If the symbol doesn't have a PLT offset, then naturally we | |
691 | // don't want to use it. | |
692 | if (!this->has_plt_offset()) | |
693 | return false; | |
694 | ||
7223e9ca ILT |
695 | // For a STT_GNU_IFUNC symbol we always have to use the PLT entry. |
696 | if (this->type() == elfcpp::STT_GNU_IFUNC) | |
697 | return true; | |
698 | ||
de4c45bd ILT |
699 | // If we are going to generate a dynamic relocation, then we will |
700 | // wind up using that, so no need to use the PLT entry. | |
95a2c8d6 | 701 | if (this->needs_dynamic_reloc(flags)) |
de4c45bd ILT |
702 | return false; |
703 | ||
704 | // If the symbol is from a dynamic object, we need to use the PLT | |
705 | // entry. | |
706 | if (this->is_from_dynobj()) | |
707 | return true; | |
708 | ||
709 | // If we are generating a shared object, and this symbol is | |
710 | // undefined or preemptible, we need to use the PLT entry. | |
711 | if (parameters->options().shared() | |
712 | && (this->is_undefined() || this->is_preemptible())) | |
713 | return true; | |
714 | ||
95a2c8d6 RS |
715 | // If this is a call to a weak undefined symbol, we need to use |
716 | // the PLT entry; the symbol may be defined by a library loaded | |
717 | // at runtime. | |
718 | if ((flags & FUNCTION_CALL) && this->is_weak_undefined()) | |
de4c45bd ILT |
719 | return true; |
720 | ||
721 | // Otherwise we can use the regular definition. | |
722 | return false; | |
723 | } | |
724 | ||
d61c6bd4 ILT |
725 | // Given a direct absolute static relocation against |
726 | // the global symbol, where a dynamic relocation is needed, this | |
727 | // function returns whether a relative dynamic relocation can be used. | |
728 | // The caller must determine separately whether the static relocation | |
729 | // is compatible with a relative relocation. | |
730 | ||
731 | bool | |
732 | can_use_relative_reloc(bool is_function_call) const | |
733 | { | |
734 | // A function call that can branch to a local PLT entry can | |
735 | // use a RELATIVE relocation. | |
736 | if (is_function_call && this->has_plt_offset()) | |
737 | return true; | |
738 | ||
739 | // A reference to a symbol defined in a dynamic object or to a | |
9b547ce6 | 740 | // symbol that is preemptible can not use a RELATIVE relocation. |
8fc19601 ILT |
741 | if (this->is_from_dynobj() |
742 | || this->is_undefined() | |
743 | || this->is_preemptible()) | |
d61c6bd4 ILT |
744 | return false; |
745 | ||
746 | // For all other cases, return TRUE. | |
747 | return true; | |
748 | } | |
749 | ||
77e65537 ILT |
750 | // Return the output section where this symbol is defined. Return |
751 | // NULL if the symbol has an absolute value. | |
752 | Output_section* | |
753 | output_section() const; | |
754 | ||
755 | // Set the symbol's output section. This is used for symbols | |
756 | // defined in scripts. This should only be called after the symbol | |
757 | // table has been finalized. | |
758 | void | |
759 | set_output_section(Output_section*); | |
a445fddf | 760 | |
f6ce93d6 ILT |
761 | // Return whether there should be a warning for references to this |
762 | // symbol. | |
763 | bool | |
764 | has_warning() const | |
765 | { return this->has_warning_; } | |
766 | ||
767 | // Mark this symbol as having a warning. | |
768 | void | |
769 | set_has_warning() | |
770 | { this->has_warning_ = true; } | |
771 | ||
46fe1623 ILT |
772 | // Return whether this symbol is defined by a COPY reloc from a |
773 | // dynamic object. | |
774 | bool | |
775 | is_copied_from_dynobj() const | |
776 | { return this->is_copied_from_dynobj_; } | |
777 | ||
778 | // Mark this symbol as defined by a COPY reloc. | |
779 | void | |
780 | set_is_copied_from_dynobj() | |
781 | { this->is_copied_from_dynobj_ = true; } | |
782 | ||
55a93433 ILT |
783 | // Return whether this symbol is forced to visibility STB_LOCAL |
784 | // by a "local:" entry in a version script. | |
785 | bool | |
786 | is_forced_local() const | |
787 | { return this->is_forced_local_; } | |
788 | ||
789 | // Mark this symbol as forced to STB_LOCAL visibility. | |
790 | void | |
791 | set_is_forced_local() | |
792 | { this->is_forced_local_ = true; } | |
793 | ||
966d4097 DK |
794 | // Return true if this may need a COPY relocation. |
795 | // References from an executable object to non-function symbols | |
796 | // defined in a dynamic object may need a COPY relocation. | |
797 | bool | |
798 | may_need_copy_reloc() const | |
799 | { | |
d89051bd | 800 | return (!parameters->options().output_is_position_independent() |
966d4097 DK |
801 | && parameters->options().copyreloc() |
802 | && this->is_from_dynobj() | |
53d7974c | 803 | && !this->is_func()); |
966d4097 DK |
804 | } |
805 | ||
14bfc3f5 ILT |
806 | protected: |
807 | // Instances of this class should always be created at a specific | |
808 | // size. | |
809 | Symbol() | |
f6ce93d6 | 810 | { memset(this, 0, sizeof *this); } |
14bfc3f5 | 811 | |
ead1e424 ILT |
812 | // Initialize the general fields. |
813 | void | |
814 | init_fields(const char* name, const char* version, | |
815 | elfcpp::STT type, elfcpp::STB binding, | |
816 | elfcpp::STV visibility, unsigned char nonvis); | |
817 | ||
d491d34e ILT |
818 | // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the |
819 | // section index, IS_ORDINARY is whether it is a normal section | |
820 | // index rather than a special code. | |
14bfc3f5 ILT |
821 | template<int size, bool big_endian> |
822 | void | |
ca09d69a | 823 | init_base_object(const char* name, const char* version, Object* object, |
f3e9c5c5 ILT |
824 | const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx, |
825 | bool is_ordinary); | |
bae7f79e | 826 | |
ead1e424 ILT |
827 | // Initialize fields for an Output_data. |
828 | void | |
75517b77 ILT |
829 | init_base_output_data(const char* name, const char* version, Output_data*, |
830 | elfcpp::STT, elfcpp::STB, elfcpp::STV, | |
831 | unsigned char nonvis, bool offset_is_from_end); | |
ead1e424 ILT |
832 | |
833 | // Initialize fields for an Output_segment. | |
834 | void | |
75517b77 ILT |
835 | init_base_output_segment(const char* name, const char* version, |
836 | Output_segment* os, elfcpp::STT type, | |
837 | elfcpp::STB binding, elfcpp::STV visibility, | |
838 | unsigned char nonvis, | |
f3e9c5c5 | 839 | Segment_offset_base offset_base); |
ead1e424 ILT |
840 | |
841 | // Initialize fields for a constant. | |
842 | void | |
75517b77 ILT |
843 | init_base_constant(const char* name, const char* version, elfcpp::STT type, |
844 | elfcpp::STB binding, elfcpp::STV visibility, | |
845 | unsigned char nonvis); | |
f3e9c5c5 ILT |
846 | |
847 | // Initialize fields for an undefined symbol. | |
848 | void | |
75517b77 ILT |
849 | init_base_undefined(const char* name, const char* version, elfcpp::STT type, |
850 | elfcpp::STB binding, elfcpp::STV visibility, | |
851 | unsigned char nonvis); | |
ead1e424 | 852 | |
1564db8d ILT |
853 | // Override existing symbol. |
854 | template<int size, bool big_endian> | |
855 | void | |
d491d34e ILT |
856 | override_base(const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx, |
857 | bool is_ordinary, Object* object, const char* version); | |
1564db8d | 858 | |
86f2e683 ILT |
859 | // Override existing symbol with a special symbol. |
860 | void | |
861 | override_base_with_special(const Symbol* from); | |
862 | ||
75517b77 ILT |
863 | // Override symbol version. |
864 | void | |
865 | override_version(const char* version); | |
866 | ||
c7912668 ILT |
867 | // Allocate a common symbol by giving it a location in the output |
868 | // file. | |
869 | void | |
870 | allocate_base_common(Output_data*); | |
871 | ||
bae7f79e | 872 | private: |
14bfc3f5 ILT |
873 | Symbol(const Symbol&); |
874 | Symbol& operator=(const Symbol&); | |
875 | ||
876 | // Symbol name (expected to point into a Stringpool). | |
877 | const char* name_; | |
878 | // Symbol version (expected to point into a Stringpool). This may | |
879 | // be NULL. | |
bae7f79e | 880 | const char* version_; |
ead1e424 ILT |
881 | |
882 | union | |
883 | { | |
884 | // This struct is used if SOURCE_ == FROM_OBJECT. | |
885 | struct | |
886 | { | |
887 | // Object in which symbol is defined, or in which it was first | |
888 | // seen. | |
889 | Object* object; | |
890 | // Section number in object_ in which symbol is defined. | |
16649710 | 891 | unsigned int shndx; |
ead1e424 ILT |
892 | } from_object; |
893 | ||
894 | // This struct is used if SOURCE_ == IN_OUTPUT_DATA. | |
895 | struct | |
896 | { | |
897 | // Output_data in which symbol is defined. Before | |
898 | // Layout::finalize the symbol's value is an offset within the | |
899 | // Output_data. | |
900 | Output_data* output_data; | |
901 | // True if the offset is from the end, false if the offset is | |
902 | // from the beginning. | |
903 | bool offset_is_from_end; | |
904 | } in_output_data; | |
905 | ||
906 | // This struct is used if SOURCE_ == IN_OUTPUT_SEGMENT. | |
907 | struct | |
908 | { | |
909 | // Output_segment in which the symbol is defined. Before | |
910 | // Layout::finalize the symbol's value is an offset. | |
911 | Output_segment* output_segment; | |
912 | // The base to use for the offset before Layout::finalize. | |
913 | Segment_offset_base offset_base; | |
914 | } in_output_segment; | |
915 | } u_; | |
916 | ||
c06b7b0b ILT |
917 | // The index of this symbol in the output file. If the symbol is |
918 | // not going into the output file, this value is -1U. This field | |
919 | // starts as always holding zero. It is set to a non-zero value by | |
920 | // Symbol_table::finalize. | |
921 | unsigned int symtab_index_; | |
922 | ||
923 | // The index of this symbol in the dynamic symbol table. If the | |
924 | // symbol is not going into the dynamic symbol table, this value is | |
925 | // -1U. This field starts as always holding zero. It is set to a | |
926 | // non-zero value during Layout::finalize. | |
927 | unsigned int dynsym_index_; | |
928 | ||
880cd20d ILT |
929 | // The GOT section entries for this symbol. A symbol may have more |
930 | // than one GOT offset (e.g., when mixing modules compiled with two | |
931 | // different TLS models), but will usually have at most one. | |
0a65a3a7 | 932 | Got_offset_list got_offsets_; |
07f397ab | 933 | |
880cd20d ILT |
934 | // If this symbol has an entry in the PLT section, then this is the |
935 | // offset from the start of the PLT section. This is -1U if there | |
936 | // is no PLT entry. | |
a3ad94ed ILT |
937 | unsigned int plt_offset_; |
938 | ||
d491d34e | 939 | // Symbol type (bits 0 to 3). |
bae7f79e | 940 | elfcpp::STT type_ : 4; |
d491d34e | 941 | // Symbol binding (bits 4 to 7). |
bae7f79e | 942 | elfcpp::STB binding_ : 4; |
d491d34e | 943 | // Symbol visibility (bits 8 to 9). |
14bfc3f5 | 944 | elfcpp::STV visibility_ : 2; |
d491d34e | 945 | // Rest of symbol st_other field (bits 10 to 15). |
ead1e424 | 946 | unsigned int nonvis_ : 6; |
d491d34e | 947 | // The type of symbol (bits 16 to 18). |
f6ce93d6 | 948 | Source source_ : 3; |
880cd20d | 949 | // True if this is the default version of the symbol (bit 19). |
1564db8d | 950 | bool is_def_ : 1; |
14bfc3f5 ILT |
951 | // True if this symbol really forwards to another symbol. This is |
952 | // used when we discover after the fact that two different entries | |
953 | // in the hash table really refer to the same symbol. This will | |
954 | // never be set for a symbol found in the hash table, but may be set | |
955 | // for a symbol found in the list of symbols attached to an Object. | |
956 | // It forwards to the symbol found in the forwarders_ map of | |
880cd20d | 957 | // Symbol_table (bit 20). |
1564db8d | 958 | bool is_forwarder_ : 1; |
aeddab66 | 959 | // True if the symbol has an alias in the weak_aliases table in |
880cd20d | 960 | // Symbol_table (bit 21). |
aeddab66 | 961 | bool has_alias_ : 1; |
d491d34e | 962 | // True if this symbol needs to be in the dynamic symbol table (bit |
880cd20d | 963 | // 22). |
c06b7b0b | 964 | bool needs_dynsym_entry_ : 1; |
880cd20d | 965 | // True if we've seen this symbol in a regular object (bit 23). |
008db82e | 966 | bool in_reg_ : 1; |
880cd20d | 967 | // True if we've seen this symbol in a dynamic object (bit 24). |
1564db8d | 968 | bool in_dyn_ : 1; |
ab5c9e90 | 969 | // True if this is a dynamic symbol which needs a special value in |
880cd20d | 970 | // the dynamic symbol table (bit 25). |
ab5c9e90 | 971 | bool needs_dynsym_value_ : 1; |
880cd20d | 972 | // True if there is a warning for this symbol (bit 26). |
f6ce93d6 | 973 | bool has_warning_ : 1; |
46fe1623 | 974 | // True if we are using a COPY reloc for this symbol, so that the |
880cd20d | 975 | // real definition lives in a dynamic object (bit 27). |
46fe1623 | 976 | bool is_copied_from_dynobj_ : 1; |
55a93433 | 977 | // True if this symbol was forced to local visibility by a version |
880cd20d | 978 | // script (bit 28). |
55a93433 | 979 | bool is_forced_local_ : 1; |
d491d34e ILT |
980 | // True if the field u_.from_object.shndx is an ordinary section |
981 | // index, not one of the special codes from SHN_LORESERVE to | |
880cd20d | 982 | // SHN_HIRESERVE (bit 29). |
d491d34e | 983 | bool is_ordinary_shndx_ : 1; |
880cd20d | 984 | // True if we've seen this symbol in a real ELF object (bit 30). |
89fc3421 | 985 | bool in_real_elf_ : 1; |
880cd20d ILT |
986 | // True if this symbol is defined in a section which was discarded |
987 | // (bit 31). | |
988 | bool is_defined_in_discarded_section_ : 1; | |
ce279a62 CC |
989 | // True if UNDEF_BINDING_WEAK_ has been set (bit 32). |
990 | bool undef_binding_set_ : 1; | |
991 | // True if this symbol was a weak undef resolved by a dynamic def | |
992 | // (bit 33). | |
993 | bool undef_binding_weak_ : 1; | |
bae7f79e ILT |
994 | }; |
995 | ||
14bfc3f5 ILT |
996 | // The parts of a symbol which are size specific. Using a template |
997 | // derived class like this helps us use less space on a 32-bit system. | |
bae7f79e ILT |
998 | |
999 | template<int size> | |
14bfc3f5 ILT |
1000 | class Sized_symbol : public Symbol |
1001 | { | |
1002 | public: | |
1564db8d ILT |
1003 | typedef typename elfcpp::Elf_types<size>::Elf_Addr Value_type; |
1004 | typedef typename elfcpp::Elf_types<size>::Elf_WXword Size_type; | |
1005 | ||
14bfc3f5 ILT |
1006 | Sized_symbol() |
1007 | { } | |
1008 | ||
d491d34e ILT |
1009 | // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the |
1010 | // section index, IS_ORDINARY is whether it is a normal section | |
1011 | // index rather than a special code. | |
14bfc3f5 ILT |
1012 | template<bool big_endian> |
1013 | void | |
ca09d69a | 1014 | init_object(const char* name, const char* version, Object* object, |
f3e9c5c5 ILT |
1015 | const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx, |
1016 | bool is_ordinary); | |
14bfc3f5 | 1017 | |
ead1e424 ILT |
1018 | // Initialize fields for an Output_data. |
1019 | void | |
75517b77 ILT |
1020 | init_output_data(const char* name, const char* version, Output_data*, |
1021 | Value_type value, Size_type symsize, elfcpp::STT, | |
1022 | elfcpp::STB, elfcpp::STV, unsigned char nonvis, | |
1023 | bool offset_is_from_end); | |
ead1e424 ILT |
1024 | |
1025 | // Initialize fields for an Output_segment. | |
1026 | void | |
75517b77 ILT |
1027 | init_output_segment(const char* name, const char* version, Output_segment*, |
1028 | Value_type value, Size_type symsize, elfcpp::STT, | |
1029 | elfcpp::STB, elfcpp::STV, unsigned char nonvis, | |
1030 | Segment_offset_base offset_base); | |
ead1e424 ILT |
1031 | |
1032 | // Initialize fields for a constant. | |
1033 | void | |
75517b77 ILT |
1034 | init_constant(const char* name, const char* version, Value_type value, |
1035 | Size_type symsize, elfcpp::STT, elfcpp::STB, elfcpp::STV, | |
1036 | unsigned char nonvis); | |
f3e9c5c5 ILT |
1037 | |
1038 | // Initialize fields for an undefined symbol. | |
1039 | void | |
75517b77 ILT |
1040 | init_undefined(const char* name, const char* version, elfcpp::STT, |
1041 | elfcpp::STB, elfcpp::STV, unsigned char nonvis); | |
ead1e424 | 1042 | |
1564db8d ILT |
1043 | // Override existing symbol. |
1044 | template<bool big_endian> | |
1045 | void | |
d491d34e ILT |
1046 | override(const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx, |
1047 | bool is_ordinary, Object* object, const char* version); | |
1564db8d | 1048 | |
86f2e683 ILT |
1049 | // Override existing symbol with a special symbol. |
1050 | void | |
1051 | override_with_special(const Sized_symbol<size>*); | |
1052 | ||
1564db8d ILT |
1053 | // Return the symbol's value. |
1054 | Value_type | |
1055 | value() const | |
1056 | { return this->value_; } | |
1057 | ||
1058 | // Return the symbol's size (we can't call this 'size' because that | |
1059 | // is a template parameter). | |
1060 | Size_type | |
1061 | symsize() const | |
ead1e424 ILT |
1062 | { return this->symsize_; } |
1063 | ||
1064 | // Set the symbol size. This is used when resolving common symbols. | |
1065 | void | |
2ea97941 ILT |
1066 | set_symsize(Size_type symsize) |
1067 | { this->symsize_ = symsize; } | |
1564db8d | 1068 | |
75f65a3e ILT |
1069 | // Set the symbol value. This is called when we store the final |
1070 | // values of the symbols into the symbol table. | |
1071 | void | |
2ea97941 ILT |
1072 | set_value(Value_type value) |
1073 | { this->value_ = value; } | |
75f65a3e | 1074 | |
c7912668 ILT |
1075 | // Allocate a common symbol by giving it a location in the output |
1076 | // file. | |
1077 | void | |
1078 | allocate_common(Output_data*, Value_type value); | |
1079 | ||
14bfc3f5 ILT |
1080 | private: |
1081 | Sized_symbol(const Sized_symbol&); | |
1082 | Sized_symbol& operator=(const Sized_symbol&); | |
1083 | ||
ead1e424 ILT |
1084 | // Symbol value. Before Layout::finalize this is the offset in the |
1085 | // input section. This is set to the final value during | |
1086 | // Layout::finalize. | |
1564db8d | 1087 | Value_type value_; |
14bfc3f5 | 1088 | // Symbol size. |
ead1e424 ILT |
1089 | Size_type symsize_; |
1090 | }; | |
1091 | ||
1092 | // A struct describing a symbol defined by the linker, where the value | |
1093 | // of the symbol is defined based on an output section. This is used | |
1094 | // for symbols defined by the linker, like "_init_array_start". | |
1095 | ||
1096 | struct Define_symbol_in_section | |
1097 | { | |
1098 | // The symbol name. | |
1099 | const char* name; | |
1100 | // The name of the output section with which this symbol should be | |
1101 | // associated. If there is no output section with that name, the | |
1102 | // symbol will be defined as zero. | |
1103 | const char* output_section; | |
1104 | // The offset of the symbol within the output section. This is an | |
1105 | // offset from the start of the output section, unless start_at_end | |
1106 | // is true, in which case this is an offset from the end of the | |
1107 | // output section. | |
1108 | uint64_t value; | |
1109 | // The size of the symbol. | |
1110 | uint64_t size; | |
1111 | // The symbol type. | |
1112 | elfcpp::STT type; | |
1113 | // The symbol binding. | |
1114 | elfcpp::STB binding; | |
1115 | // The symbol visibility. | |
1116 | elfcpp::STV visibility; | |
1117 | // The rest of the st_other field. | |
1118 | unsigned char nonvis; | |
1119 | // If true, the value field is an offset from the end of the output | |
1120 | // section. | |
1121 | bool offset_is_from_end; | |
1122 | // If true, this symbol is defined only if we see a reference to it. | |
1123 | bool only_if_ref; | |
1124 | }; | |
1125 | ||
1126 | // A struct describing a symbol defined by the linker, where the value | |
1127 | // of the symbol is defined based on a segment. This is used for | |
1128 | // symbols defined by the linker, like "_end". We describe the | |
1129 | // segment with which the symbol should be associated by its | |
1130 | // characteristics. If no segment meets these characteristics, the | |
1131 | // symbol will be defined as zero. If there is more than one segment | |
1132 | // which meets these characteristics, we will use the first one. | |
1133 | ||
1134 | struct Define_symbol_in_segment | |
1135 | { | |
1136 | // The symbol name. | |
1137 | const char* name; | |
1138 | // The segment type where the symbol should be defined, typically | |
1139 | // PT_LOAD. | |
1140 | elfcpp::PT segment_type; | |
1141 | // Bitmask of segment flags which must be set. | |
1142 | elfcpp::PF segment_flags_set; | |
1143 | // Bitmask of segment flags which must be clear. | |
1144 | elfcpp::PF segment_flags_clear; | |
1145 | // The offset of the symbol within the segment. The offset is | |
1146 | // calculated from the position set by offset_base. | |
1147 | uint64_t value; | |
1148 | // The size of the symbol. | |
1149 | uint64_t size; | |
1150 | // The symbol type. | |
1151 | elfcpp::STT type; | |
1152 | // The symbol binding. | |
1153 | elfcpp::STB binding; | |
1154 | // The symbol visibility. | |
1155 | elfcpp::STV visibility; | |
1156 | // The rest of the st_other field. | |
1157 | unsigned char nonvis; | |
1158 | // The base from which we compute the offset. | |
1159 | Symbol::Segment_offset_base offset_base; | |
1160 | // If true, this symbol is defined only if we see a reference to it. | |
1161 | bool only_if_ref; | |
14bfc3f5 ILT |
1162 | }; |
1163 | ||
f6ce93d6 ILT |
1164 | // This class manages warnings. Warnings are a GNU extension. When |
1165 | // we see a section named .gnu.warning.SYM in an object file, and if | |
1166 | // we wind using the definition of SYM from that object file, then we | |
1167 | // will issue a warning for any relocation against SYM from a | |
1168 | // different object file. The text of the warning is the contents of | |
1169 | // the section. This is not precisely the definition used by the old | |
1170 | // GNU linker; the old GNU linker treated an occurrence of | |
1171 | // .gnu.warning.SYM as defining a warning symbol. A warning symbol | |
1172 | // would trigger a warning on any reference. However, it was | |
1173 | // inconsistent in that a warning in a dynamic object only triggered | |
1174 | // if there was no definition in a regular object. This linker is | |
1175 | // different in that we only issue a warning if we use the symbol | |
1176 | // definition from the same object file as the warning section. | |
1177 | ||
1178 | class Warnings | |
1179 | { | |
1180 | public: | |
1181 | Warnings() | |
1182 | : warnings_() | |
1183 | { } | |
1184 | ||
cb295612 ILT |
1185 | // Add a warning for symbol NAME in object OBJ. WARNING is the text |
1186 | // of the warning. | |
f6ce93d6 ILT |
1187 | void |
1188 | add_warning(Symbol_table* symtab, const char* name, Object* obj, | |
cb295612 | 1189 | const std::string& warning); |
f6ce93d6 ILT |
1190 | |
1191 | // For each symbol for which we should give a warning, make a note | |
1192 | // on the symbol. | |
1193 | void | |
cb295612 | 1194 | note_warnings(Symbol_table* symtab); |
f6ce93d6 | 1195 | |
75f2446e ILT |
1196 | // Issue a warning for a reference to SYM at RELINFO's location. |
1197 | template<int size, bool big_endian> | |
f6ce93d6 | 1198 | void |
75f2446e ILT |
1199 | issue_warning(const Symbol* sym, const Relocate_info<size, big_endian>*, |
1200 | size_t relnum, off_t reloffset) const; | |
f6ce93d6 ILT |
1201 | |
1202 | private: | |
1203 | Warnings(const Warnings&); | |
1204 | Warnings& operator=(const Warnings&); | |
1205 | ||
1206 | // What we need to know to get the warning text. | |
1207 | struct Warning_location | |
1208 | { | |
1209 | // The object the warning is in. | |
1210 | Object* object; | |
cb295612 | 1211 | // The warning text. |
f6ce93d6 ILT |
1212 | std::string text; |
1213 | ||
1214 | Warning_location() | |
cb295612 | 1215 | : object(NULL), text() |
f6ce93d6 ILT |
1216 | { } |
1217 | ||
1218 | void | |
cb295612 | 1219 | set(Object* o, const std::string& t) |
f6ce93d6 ILT |
1220 | { |
1221 | this->object = o; | |
cb295612 | 1222 | this->text = t; |
f6ce93d6 | 1223 | } |
f6ce93d6 ILT |
1224 | }; |
1225 | ||
1226 | // A mapping from warning symbol names (canonicalized in | |
70e654ba | 1227 | // Symbol_table's namepool_ field) to warning information. |
f6ce93d6 ILT |
1228 | typedef Unordered_map<const char*, Warning_location> Warning_table; |
1229 | ||
1230 | Warning_table warnings_; | |
1231 | }; | |
1232 | ||
14bfc3f5 ILT |
1233 | // The main linker symbol table. |
1234 | ||
bae7f79e ILT |
1235 | class Symbol_table |
1236 | { | |
1237 | public: | |
99fff23b ILT |
1238 | // The different places where a symbol definition can come from. |
1239 | enum Defined | |
1240 | { | |
1241 | // Defined in an object file--the normal case. | |
1242 | OBJECT, | |
1243 | // Defined for a COPY reloc. | |
1244 | COPY, | |
1245 | // Defined on the command line using --defsym. | |
1246 | DEFSYM, | |
1247 | // Defined (so to speak) on the command line using -u. | |
1248 | UNDEFINED, | |
1249 | // Defined in a linker script. | |
1250 | SCRIPT, | |
1251 | // Predefined by the linker. | |
1252 | PREDEFINED, | |
1253 | }; | |
1254 | ||
fc59c572 ILT |
1255 | // The order in which we sort common symbols. |
1256 | enum Sort_commons_order | |
1257 | { | |
1258 | SORT_COMMONS_BY_SIZE_DESCENDING, | |
1259 | SORT_COMMONS_BY_ALIGNMENT_DESCENDING, | |
1260 | SORT_COMMONS_BY_ALIGNMENT_ASCENDING | |
1261 | }; | |
1262 | ||
9b547ce6 | 1263 | // COUNT is an estimate of how many symbols will be inserted in the |
6d013333 ILT |
1264 | // symbol table. It's ok to put 0 if you don't know; a correct |
1265 | // guess will just save some CPU by reducing hashtable resizes. | |
09124467 | 1266 | Symbol_table(unsigned int count, const Version_script_info& version_script); |
bae7f79e | 1267 | |
1564db8d | 1268 | ~Symbol_table(); |
bae7f79e | 1269 | |
ef15dade | 1270 | void |
2ea97941 ILT |
1271 | set_icf(Icf* icf) |
1272 | { this->icf_ = icf;} | |
ef15dade ST |
1273 | |
1274 | Icf* | |
1275 | icf() const | |
1276 | { return this->icf_; } | |
1277 | ||
1278 | // Returns true if ICF determined that this is a duplicate section. | |
1279 | bool | |
1280 | is_section_folded(Object* obj, unsigned int shndx) const; | |
1281 | ||
6d03d481 | 1282 | void |
2ea97941 ILT |
1283 | set_gc(Garbage_collection* gc) |
1284 | { this->gc_ = gc; } | |
6d03d481 ST |
1285 | |
1286 | Garbage_collection* | |
ef15dade | 1287 | gc() const |
6d03d481 ST |
1288 | { return this->gc_; } |
1289 | ||
1290 | // During garbage collection, this keeps undefined symbols. | |
1291 | void | |
88a4108b | 1292 | gc_mark_undef_symbols(Layout*); |
6d03d481 ST |
1293 | |
1294 | // During garbage collection, this ensures externally visible symbols | |
1295 | // are not treated as garbage while building shared objects. | |
1296 | void | |
1297 | gc_mark_symbol_for_shlib(Symbol* sym); | |
1298 | ||
1299 | // During garbage collection, this keeps sections that correspond to | |
1300 | // symbols seen in dynamic objects. | |
1301 | inline void | |
1302 | gc_mark_dyn_syms(Symbol* sym); | |
1303 | ||
dbe717ef | 1304 | // Add COUNT external symbols from the relocatable object RELOBJ to |
d491d34e ILT |
1305 | // the symbol table. SYMS is the symbols, SYMNDX_OFFSET is the |
1306 | // offset in the symbol table of the first symbol, SYM_NAMES is | |
1307 | // their names, SYM_NAME_SIZE is the size of SYM_NAMES. This sets | |
92de84a6 ILT |
1308 | // SYMPOINTERS to point to the symbols in the symbol table. It sets |
1309 | // *DEFINED to the number of defined symbols. | |
14bfc3f5 ILT |
1310 | template<int size, bool big_endian> |
1311 | void | |
dbe717ef ILT |
1312 | add_from_relobj(Sized_relobj<size, big_endian>* relobj, |
1313 | const unsigned char* syms, size_t count, | |
d491d34e ILT |
1314 | size_t symndx_offset, const char* sym_names, |
1315 | size_t sym_name_size, | |
92de84a6 ILT |
1316 | typename Sized_relobj<size, big_endian>::Symbols*, |
1317 | size_t* defined); | |
89fc3421 CC |
1318 | |
1319 | // Add one external symbol from the plugin object OBJ to the symbol table. | |
1320 | // Returns a pointer to the resolved symbol in the symbol table. | |
1321 | template<int size, bool big_endian> | |
1322 | Symbol* | |
1323 | add_from_pluginobj(Sized_pluginobj<size, big_endian>* obj, | |
1324 | const char* name, const char* ver, | |
1325 | elfcpp::Sym<size, big_endian>* sym); | |
14bfc3f5 | 1326 | |
dbe717ef ILT |
1327 | // Add COUNT dynamic symbols from the dynamic object DYNOBJ to the |
1328 | // symbol table. SYMS is the symbols. SYM_NAMES is their names. | |
1329 | // SYM_NAME_SIZE is the size of SYM_NAMES. The other parameters are | |
1330 | // symbol version data. | |
1331 | template<int size, bool big_endian> | |
1332 | void | |
1333 | add_from_dynobj(Sized_dynobj<size, big_endian>* dynobj, | |
1334 | const unsigned char* syms, size_t count, | |
1335 | const char* sym_names, size_t sym_name_size, | |
1336 | const unsigned char* versym, size_t versym_size, | |
92de84a6 ILT |
1337 | const std::vector<const char*>*, |
1338 | typename Sized_relobj<size, big_endian>::Symbols*, | |
1339 | size_t* defined); | |
dbe717ef | 1340 | |
cdc29364 CC |
1341 | // Add one external symbol from the incremental object OBJ to the symbol |
1342 | // table. Returns a pointer to the resolved symbol in the symbol table. | |
1343 | template<int size, bool big_endian> | |
1344 | Symbol* | |
1345 | add_from_incrobj(Object* obj, const char* name, | |
1346 | const char* ver, elfcpp::Sym<size, big_endian>* sym); | |
1347 | ||
ead1e424 ILT |
1348 | // Define a special symbol based on an Output_data. It is a |
1349 | // multiple definition error if this symbol is already defined. | |
14b31740 | 1350 | Symbol* |
99fff23b | 1351 | define_in_output_data(const char* name, const char* version, Defined, |
14b31740 | 1352 | Output_data*, uint64_t value, uint64_t symsize, |
ead1e424 ILT |
1353 | elfcpp::STT type, elfcpp::STB binding, |
1354 | elfcpp::STV visibility, unsigned char nonvis, | |
1355 | bool offset_is_from_end, bool only_if_ref); | |
1356 | ||
1357 | // Define a special symbol based on an Output_segment. It is a | |
1358 | // multiple definition error if this symbol is already defined. | |
14b31740 | 1359 | Symbol* |
99fff23b | 1360 | define_in_output_segment(const char* name, const char* version, Defined, |
9b07f471 | 1361 | Output_segment*, uint64_t value, uint64_t symsize, |
ead1e424 ILT |
1362 | elfcpp::STT type, elfcpp::STB binding, |
1363 | elfcpp::STV visibility, unsigned char nonvis, | |
1364 | Symbol::Segment_offset_base, bool only_if_ref); | |
1365 | ||
1366 | // Define a special symbol with a constant value. It is a multiple | |
1367 | // definition error if this symbol is already defined. | |
14b31740 | 1368 | Symbol* |
99fff23b | 1369 | define_as_constant(const char* name, const char* version, Defined, |
14b31740 ILT |
1370 | uint64_t value, uint64_t symsize, elfcpp::STT type, |
1371 | elfcpp::STB binding, elfcpp::STV visibility, | |
caa9d5d9 ILT |
1372 | unsigned char nonvis, bool only_if_ref, |
1373 | bool force_override); | |
ead1e424 | 1374 | |
a445fddf ILT |
1375 | // Define a set of symbols in output sections. If ONLY_IF_REF is |
1376 | // true, only define them if they are referenced. | |
ead1e424 | 1377 | void |
a445fddf ILT |
1378 | define_symbols(const Layout*, int count, const Define_symbol_in_section*, |
1379 | bool only_if_ref); | |
ead1e424 | 1380 | |
a445fddf ILT |
1381 | // Define a set of symbols in output segments. If ONLY_IF_REF is |
1382 | // true, only defined them if they are referenced. | |
ead1e424 | 1383 | void |
a445fddf ILT |
1384 | define_symbols(const Layout*, int count, const Define_symbol_in_segment*, |
1385 | bool only_if_ref); | |
ead1e424 | 1386 | |
46fe1623 ILT |
1387 | // Define SYM using a COPY reloc. POSD is the Output_data where the |
1388 | // symbol should be defined--typically a .dyn.bss section. VALUE is | |
1389 | // the offset within POSD. | |
1390 | template<int size> | |
1391 | void | |
9b07f471 | 1392 | define_with_copy_reloc(Sized_symbol<size>* sym, Output_data* posd, |
fe8718a4 | 1393 | typename elfcpp::Elf_types<size>::Elf_Addr); |
46fe1623 | 1394 | |
61ba1cf9 ILT |
1395 | // Look up a symbol. |
1396 | Symbol* | |
1397 | lookup(const char*, const char* version = NULL) const; | |
1398 | ||
14bfc3f5 | 1399 | // Return the real symbol associated with the forwarder symbol FROM. |
bae7f79e | 1400 | Symbol* |
c06b7b0b | 1401 | resolve_forwards(const Symbol* from) const; |
bae7f79e | 1402 | |
1564db8d ILT |
1403 | // Return the sized version of a symbol in this table. |
1404 | template<int size> | |
1405 | Sized_symbol<size>* | |
7d1a9ebb | 1406 | get_sized_symbol(Symbol*) const; |
1564db8d ILT |
1407 | |
1408 | template<int size> | |
1409 | const Sized_symbol<size>* | |
7d1a9ebb | 1410 | get_sized_symbol(const Symbol*) const; |
54dc6425 | 1411 | |
ead1e424 | 1412 | // Return the count of undefined symbols seen. |
114dfbe1 | 1413 | size_t |
ead1e424 ILT |
1414 | saw_undefined() const |
1415 | { return this->saw_undefined_; } | |
1416 | ||
1417 | // Allocate the common symbols | |
1418 | void | |
7d9e3d98 | 1419 | allocate_commons(Layout*, Mapfile*); |
ead1e424 | 1420 | |
cb295612 ILT |
1421 | // Add a warning for symbol NAME in object OBJ. WARNING is the text |
1422 | // of the warning. | |
f6ce93d6 | 1423 | void |
cb295612 ILT |
1424 | add_warning(const char* name, Object* obj, const std::string& warning) |
1425 | { this->warnings_.add_warning(this, name, obj, warning); } | |
f6ce93d6 ILT |
1426 | |
1427 | // Canonicalize a symbol name for use in the hash table. | |
1428 | const char* | |
1429 | canonicalize_name(const char* name) | |
cfd73a4e | 1430 | { return this->namepool_.add(name, true, NULL); } |
f6ce93d6 ILT |
1431 | |
1432 | // Possibly issue a warning for a reference to SYM at LOCATION which | |
1433 | // is in OBJ. | |
75f2446e | 1434 | template<int size, bool big_endian> |
f6ce93d6 | 1435 | void |
75f2446e ILT |
1436 | issue_warning(const Symbol* sym, |
1437 | const Relocate_info<size, big_endian>* relinfo, | |
1438 | size_t relnum, off_t reloffset) const | |
1439 | { this->warnings_.issue_warning(sym, relinfo, relnum, reloffset); } | |
f6ce93d6 | 1440 | |
70e654ba ILT |
1441 | // Check candidate_odr_violations_ to find symbols with the same name |
1442 | // but apparently different definitions (different source-file/line-no). | |
1443 | void | |
17a1d0a9 | 1444 | detect_odr_violations(const Task*, const char* output_file_name) const; |
70e654ba | 1445 | |
f3e9c5c5 ILT |
1446 | // Add any undefined symbols named on the command line to the symbol |
1447 | // table. | |
1448 | void | |
88a4108b | 1449 | add_undefined_symbols_from_command_line(Layout*); |
f3e9c5c5 | 1450 | |
46fe1623 ILT |
1451 | // SYM is defined using a COPY reloc. Return the dynamic object |
1452 | // where the original definition was found. | |
1453 | Dynobj* | |
1454 | get_copy_source(const Symbol* sym) const; | |
1455 | ||
a3ad94ed ILT |
1456 | // Set the dynamic symbol indexes. INDEX is the index of the first |
1457 | // global dynamic symbol. Pointers to the symbols are stored into | |
1458 | // the vector. The names are stored into the Stringpool. This | |
1459 | // returns an updated dynamic symbol index. | |
1460 | unsigned int | |
9b07f471 ILT |
1461 | set_dynsym_indexes(unsigned int index, std::vector<Symbol*>*, |
1462 | Stringpool*, Versions*); | |
a3ad94ed | 1463 | |
75f65a3e | 1464 | // Finalize the symbol table after we have set the final addresses |
c06b7b0b | 1465 | // of all the input sections. This sets the final symbol indexes, |
55a93433 ILT |
1466 | // values and adds the names to *POOL. *PLOCAL_SYMCOUNT is the |
1467 | // index of the first global symbol. OFF is the file offset of the | |
1468 | // global symbol table, DYNOFF is the offset of the globals in the | |
1469 | // dynamic symbol table, DYN_GLOBAL_INDEX is the index of the first | |
1470 | // global dynamic symbol, and DYNCOUNT is the number of global | |
1471 | // dynamic symbols. This records the parameters, and returns the | |
1472 | // new file offset. It updates *PLOCAL_SYMCOUNT if it created any | |
1473 | // local symbols. | |
75f65a3e | 1474 | off_t |
55a93433 | 1475 | finalize(off_t off, off_t dynoff, size_t dyn_global_index, size_t dyncount, |
ca09d69a | 1476 | Stringpool* pool, unsigned int* plocal_symcount); |
1564db8d | 1477 | |
cdc29364 CC |
1478 | // Set the final file offset of the symbol table. |
1479 | void | |
1480 | set_file_offset(off_t off) | |
1481 | { this->offset_ = off; } | |
1482 | ||
c0a62865 DK |
1483 | // Status code of Symbol_table::compute_final_value. |
1484 | enum Compute_final_value_status | |
1485 | { | |
1486 | // No error. | |
1487 | CFVS_OK, | |
9b547ce6 | 1488 | // Unsupported symbol section. |
c0a62865 DK |
1489 | CFVS_UNSUPPORTED_SYMBOL_SECTION, |
1490 | // No output section. | |
1491 | CFVS_NO_OUTPUT_SECTION | |
1492 | }; | |
1493 | ||
1494 | // Compute the final value of SYM and store status in location PSTATUS. | |
1495 | // During relaxation, this may be called multiple times for a symbol to | |
1496 | // compute its would-be final value in each relaxation pass. | |
1497 | ||
1498 | template<int size> | |
1499 | typename Sized_symbol<size>::Value_type | |
1500 | compute_final_value(const Sized_symbol<size>* sym, | |
1501 | Compute_final_value_status* pstatus) const; | |
1502 | ||
09ec0418 CC |
1503 | // Return the index of the first global symbol. |
1504 | unsigned int | |
1505 | first_global_index() const | |
1506 | { return this->first_global_index_; } | |
1507 | ||
1508 | // Return the total number of symbols in the symbol table. | |
1509 | unsigned int | |
1510 | output_count() const | |
1511 | { return this->output_count_; } | |
1512 | ||
61ba1cf9 ILT |
1513 | // Write out the global symbols. |
1514 | void | |
fd9d194f | 1515 | write_globals(const Stringpool*, const Stringpool*, |
d491d34e | 1516 | Output_symtab_xindex*, Output_symtab_xindex*, |
16649710 | 1517 | Output_file*) const; |
61ba1cf9 | 1518 | |
a3ad94ed ILT |
1519 | // Write out a section symbol. Return the updated offset. |
1520 | void | |
d491d34e ILT |
1521 | write_section_symbol(const Output_section*, Output_symtab_xindex*, |
1522 | Output_file*, off_t) const; | |
a3ad94ed | 1523 | |
0e70b911 CC |
1524 | // Loop over all symbols, applying the function F to each. |
1525 | template<int size, typename F> | |
1526 | void | |
1527 | for_all_symbols(F f) const | |
1528 | { | |
1529 | for (Symbol_table_type::const_iterator p = this->table_.begin(); | |
1530 | p != this->table_.end(); | |
1531 | ++p) | |
1532 | { | |
1533 | Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second); | |
1534 | f(sym); | |
1535 | } | |
1536 | } | |
1537 | ||
abaa3995 ILT |
1538 | // Dump statistical information to stderr. |
1539 | void | |
1540 | print_stats() const; | |
1541 | ||
09124467 ILT |
1542 | // Return the version script information. |
1543 | const Version_script_info& | |
1544 | version_script() const | |
1545 | { return version_script_; } | |
1546 | ||
bae7f79e ILT |
1547 | private: |
1548 | Symbol_table(const Symbol_table&); | |
1549 | Symbol_table& operator=(const Symbol_table&); | |
1550 | ||
155a0dd7 ILT |
1551 | // The type of the list of common symbols. |
1552 | typedef std::vector<Symbol*> Commons_type; | |
1553 | ||
8c500701 ILT |
1554 | // The type of the symbol hash table. |
1555 | ||
1556 | typedef std::pair<Stringpool::Key, Stringpool::Key> Symbol_table_key; | |
1557 | ||
a9bfd952 | 1558 | // The hash function. The key values are Stringpool keys. |
8c500701 ILT |
1559 | struct Symbol_table_hash |
1560 | { | |
a9bfd952 DK |
1561 | inline size_t |
1562 | operator()(const Symbol_table_key& key) const | |
1563 | { | |
1564 | return key.first ^ key.second; | |
1565 | } | |
8c500701 ILT |
1566 | }; |
1567 | ||
1568 | struct Symbol_table_eq | |
1569 | { | |
1570 | bool | |
1571 | operator()(const Symbol_table_key&, const Symbol_table_key&) const; | |
1572 | }; | |
1573 | ||
1574 | typedef Unordered_map<Symbol_table_key, Symbol*, Symbol_table_hash, | |
1575 | Symbol_table_eq> Symbol_table_type; | |
1576 | ||
71ff8986 ILT |
1577 | // A map from symbol name (as a pointer into the namepool) to all |
1578 | // the locations the symbols is (weakly) defined (and certain other | |
1579 | // conditions are met). This map will be used later to detect | |
1580 | // possible One Definition Rule (ODR) violations. | |
1581 | struct Symbol_location | |
1582 | { | |
1583 | Object* object; // Object where the symbol is defined. | |
1584 | unsigned int shndx; // Section-in-object where the symbol is defined. | |
1585 | off_t offset; // Offset-in-section where the symbol is defined. | |
1586 | bool operator==(const Symbol_location& that) const | |
1587 | { | |
1588 | return (this->object == that.object | |
1589 | && this->shndx == that.shndx | |
1590 | && this->offset == that.offset); | |
1591 | } | |
1592 | }; | |
1593 | ||
1594 | struct Symbol_location_hash | |
1595 | { | |
1596 | size_t operator()(const Symbol_location& loc) const | |
1597 | { return reinterpret_cast<uintptr_t>(loc.object) ^ loc.offset ^ loc.shndx; } | |
1598 | }; | |
1599 | ||
1600 | typedef Unordered_map<const char*, | |
1601 | Unordered_set<Symbol_location, Symbol_location_hash> > | |
1602 | Odr_map; | |
1603 | ||
14bfc3f5 ILT |
1604 | // Make FROM a forwarder symbol to TO. |
1605 | void | |
1606 | make_forwarder(Symbol* from, Symbol* to); | |
1607 | ||
1608 | // Add a symbol. | |
1609 | template<int size, bool big_endian> | |
aeddab66 | 1610 | Sized_symbol<size>* |
ca09d69a NC |
1611 | add_from_object(Object*, const char* name, Stringpool::Key name_key, |
1612 | const char* version, Stringpool::Key version_key, | |
70e654ba | 1613 | bool def, const elfcpp::Sym<size, big_endian>& sym, |
d491d34e ILT |
1614 | unsigned int st_shndx, bool is_ordinary, |
1615 | unsigned int orig_st_shndx); | |
14bfc3f5 | 1616 | |
8c500701 ILT |
1617 | // Define a default symbol. |
1618 | template<int size, bool big_endian> | |
1619 | void | |
1620 | define_default_version(Sized_symbol<size>*, bool, | |
1621 | Symbol_table_type::iterator); | |
1622 | ||
14bfc3f5 ILT |
1623 | // Resolve symbols. |
1624 | template<int size, bool big_endian> | |
aeddab66 | 1625 | void |
1564db8d ILT |
1626 | resolve(Sized_symbol<size>* to, |
1627 | const elfcpp::Sym<size, big_endian>& sym, | |
d491d34e ILT |
1628 | unsigned int st_shndx, bool is_ordinary, |
1629 | unsigned int orig_st_shndx, | |
14b31740 | 1630 | Object*, const char* version); |
14bfc3f5 | 1631 | |
1564db8d | 1632 | template<int size, bool big_endian> |
aeddab66 | 1633 | void |
95d14cd3 | 1634 | resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from); |
14b31740 | 1635 | |
0602e05a ILT |
1636 | // Record that a symbol is forced to be local by a version script or |
1637 | // by visibility. | |
55a93433 ILT |
1638 | void |
1639 | force_local(Symbol*); | |
1640 | ||
0864d551 ILT |
1641 | // Adjust NAME and *NAME_KEY for wrapping. |
1642 | const char* | |
029ba973 | 1643 | wrap_symbol(const char* name, Stringpool::Key* name_key); |
0864d551 | 1644 | |
86f2e683 ILT |
1645 | // Whether we should override a symbol, based on flags in |
1646 | // resolve.cc. | |
1647 | static bool | |
ce279a62 | 1648 | should_override(const Symbol*, unsigned int, Defined, Object*, bool*, bool*); |
86f2e683 | 1649 | |
1ae4d23b ILT |
1650 | // Report a problem in symbol resolution. |
1651 | static void | |
1652 | report_resolve_problem(bool is_error, const char* msg, const Symbol* to, | |
99fff23b | 1653 | Defined, Object* object); |
1ae4d23b | 1654 | |
aeddab66 ILT |
1655 | // Override a symbol. |
1656 | template<int size, bool big_endian> | |
1657 | void | |
1658 | override(Sized_symbol<size>* tosym, | |
1659 | const elfcpp::Sym<size, big_endian>& fromsym, | |
d491d34e | 1660 | unsigned int st_shndx, bool is_ordinary, |
aeddab66 ILT |
1661 | Object* object, const char* version); |
1662 | ||
86f2e683 ILT |
1663 | // Whether we should override a symbol with a special symbol which |
1664 | // is automatically defined by the linker. | |
1665 | static bool | |
99fff23b | 1666 | should_override_with_special(const Symbol*, Defined); |
86f2e683 | 1667 | |
aeddab66 ILT |
1668 | // Override a symbol with a special symbol. |
1669 | template<int size> | |
1670 | void | |
1671 | override_with_special(Sized_symbol<size>* tosym, | |
1672 | const Sized_symbol<size>* fromsym); | |
1673 | ||
1674 | // Record all weak alias sets for a dynamic object. | |
1675 | template<int size> | |
1676 | void | |
1677 | record_weak_aliases(std::vector<Sized_symbol<size>*>*); | |
1678 | ||
14b31740 ILT |
1679 | // Define a special symbol. |
1680 | template<int size, bool big_endian> | |
1681 | Sized_symbol<size>* | |
9b07f471 | 1682 | define_special_symbol(const char** pname, const char** pversion, |
8c500701 ILT |
1683 | bool only_if_ref, Sized_symbol<size>** poldsym, |
1684 | bool* resolve_oldsym); | |
14bfc3f5 | 1685 | |
ead1e424 ILT |
1686 | // Define a symbol in an Output_data, sized version. |
1687 | template<int size> | |
14b31740 | 1688 | Sized_symbol<size>* |
99fff23b ILT |
1689 | do_define_in_output_data(const char* name, const char* version, Defined, |
1690 | Output_data*, | |
ead1e424 ILT |
1691 | typename elfcpp::Elf_types<size>::Elf_Addr value, |
1692 | typename elfcpp::Elf_types<size>::Elf_WXword ssize, | |
1693 | elfcpp::STT type, elfcpp::STB binding, | |
1694 | elfcpp::STV visibility, unsigned char nonvis, | |
1695 | bool offset_is_from_end, bool only_if_ref); | |
1696 | ||
1697 | // Define a symbol in an Output_segment, sized version. | |
1698 | template<int size> | |
14b31740 | 1699 | Sized_symbol<size>* |
ead1e424 | 1700 | do_define_in_output_segment( |
99fff23b | 1701 | const char* name, const char* version, Defined, Output_segment* os, |
ead1e424 ILT |
1702 | typename elfcpp::Elf_types<size>::Elf_Addr value, |
1703 | typename elfcpp::Elf_types<size>::Elf_WXword ssize, | |
1704 | elfcpp::STT type, elfcpp::STB binding, | |
1705 | elfcpp::STV visibility, unsigned char nonvis, | |
1706 | Symbol::Segment_offset_base offset_base, bool only_if_ref); | |
1707 | ||
1708 | // Define a symbol as a constant, sized version. | |
1709 | template<int size> | |
14b31740 | 1710 | Sized_symbol<size>* |
ead1e424 | 1711 | do_define_as_constant( |
99fff23b | 1712 | const char* name, const char* version, Defined, |
ead1e424 ILT |
1713 | typename elfcpp::Elf_types<size>::Elf_Addr value, |
1714 | typename elfcpp::Elf_types<size>::Elf_WXword ssize, | |
1715 | elfcpp::STT type, elfcpp::STB binding, | |
1716 | elfcpp::STV visibility, unsigned char nonvis, | |
caa9d5d9 | 1717 | bool only_if_ref, bool force_override); |
ead1e424 | 1718 | |
f3e9c5c5 ILT |
1719 | // Add any undefined symbols named on the command line to the symbol |
1720 | // table, sized version. | |
1721 | template<int size> | |
1722 | void | |
88a4108b ILT |
1723 | do_add_undefined_symbols_from_command_line(Layout*); |
1724 | ||
1725 | // Add one undefined symbol. | |
1726 | template<int size> | |
1727 | void | |
1728 | add_undefined_symbol_from_command_line(const char* name); | |
f3e9c5c5 | 1729 | |
8a5e3e08 ILT |
1730 | // Types of common symbols. |
1731 | ||
1732 | enum Commons_section_type | |
1733 | { | |
1734 | COMMONS_NORMAL, | |
1735 | COMMONS_TLS, | |
1736 | COMMONS_SMALL, | |
1737 | COMMONS_LARGE | |
1738 | }; | |
1739 | ||
ead1e424 ILT |
1740 | // Allocate the common symbols, sized version. |
1741 | template<int size> | |
1742 | void | |
fc59c572 | 1743 | do_allocate_commons(Layout*, Mapfile*, Sort_commons_order); |
155a0dd7 ILT |
1744 | |
1745 | // Allocate the common symbols from one list. | |
1746 | template<int size> | |
1747 | void | |
8a5e3e08 | 1748 | do_allocate_commons_list(Layout*, Commons_section_type, Commons_type*, |
fc59c572 | 1749 | Mapfile*, Sort_commons_order); |
ead1e424 | 1750 | |
71ff8986 ILT |
1751 | // Returns all of the lines attached to LOC, not just the one the |
1752 | // instruction actually came from. This helps the ODR checker avoid | |
1753 | // false positives. | |
1754 | static std::vector<std::string> | |
1755 | linenos_from_loc(const Task* task, const Symbol_location& loc); | |
1756 | ||
70e654ba ILT |
1757 | // Implement detect_odr_violations. |
1758 | template<int size, bool big_endian> | |
1759 | void | |
1760 | sized_detect_odr_violations() const; | |
1761 | ||
75f65a3e ILT |
1762 | // Finalize symbols specialized for size. |
1763 | template<int size> | |
1764 | off_t | |
55a93433 ILT |
1765 | sized_finalize(off_t, Stringpool*, unsigned int*); |
1766 | ||
1767 | // Finalize a symbol. Return whether it should be added to the | |
1768 | // symbol table. | |
1769 | template<int size> | |
1770 | bool | |
1771 | sized_finalize_symbol(Symbol*); | |
1772 | ||
1773 | // Add a symbol the final symtab by setting its index. | |
1774 | template<int size> | |
1775 | void | |
1776 | add_to_final_symtab(Symbol*, Stringpool*, unsigned int* pindex, off_t* poff); | |
75f65a3e | 1777 | |
61ba1cf9 ILT |
1778 | // Write globals specialized for size and endianness. |
1779 | template<int size, bool big_endian> | |
1780 | void | |
fd9d194f ILT |
1781 | sized_write_globals(const Stringpool*, const Stringpool*, |
1782 | Output_symtab_xindex*, Output_symtab_xindex*, | |
1783 | Output_file*) const; | |
16649710 ILT |
1784 | |
1785 | // Write out a symbol to P. | |
1786 | template<int size, bool big_endian> | |
1787 | void | |
ab5c9e90 ILT |
1788 | sized_write_symbol(Sized_symbol<size>*, |
1789 | typename elfcpp::Elf_types<size>::Elf_Addr value, | |
ce279a62 | 1790 | unsigned int shndx, elfcpp::STB, |
7d1a9ebb | 1791 | const Stringpool*, unsigned char* p) const; |
61ba1cf9 | 1792 | |
9a2d6984 ILT |
1793 | // Possibly warn about an undefined symbol from a dynamic object. |
1794 | void | |
fd9d194f | 1795 | warn_about_undefined_dynobj_symbol(Symbol*) const; |
9a2d6984 | 1796 | |
a3ad94ed ILT |
1797 | // Write out a section symbol, specialized for size and endianness. |
1798 | template<int size, bool big_endian> | |
1799 | void | |
d491d34e ILT |
1800 | sized_write_section_symbol(const Output_section*, Output_symtab_xindex*, |
1801 | Output_file*, off_t) const; | |
a3ad94ed | 1802 | |
55a93433 ILT |
1803 | // The type of the list of symbols which have been forced local. |
1804 | typedef std::vector<Symbol*> Forced_locals; | |
1805 | ||
46fe1623 ILT |
1806 | // A map from symbols with COPY relocs to the dynamic objects where |
1807 | // they are defined. | |
1808 | typedef Unordered_map<const Symbol*, Dynobj*> Copied_symbol_dynobjs; | |
1809 | ||
ead1e424 ILT |
1810 | // We increment this every time we see a new undefined symbol, for |
1811 | // use in archive groups. | |
114dfbe1 | 1812 | size_t saw_undefined_; |
c06b7b0b ILT |
1813 | // The index of the first global symbol in the output file. |
1814 | unsigned int first_global_index_; | |
75f65a3e ILT |
1815 | // The file offset within the output symtab section where we should |
1816 | // write the table. | |
1817 | off_t offset_; | |
61ba1cf9 | 1818 | // The number of global symbols we want to write out. |
55a93433 | 1819 | unsigned int output_count_; |
16649710 ILT |
1820 | // The file offset of the global dynamic symbols, or 0 if none. |
1821 | off_t dynamic_offset_; | |
16649710 ILT |
1822 | // The index of the first global dynamic symbol. |
1823 | unsigned int first_dynamic_global_index_; | |
16649710 | 1824 | // The number of global dynamic symbols, or 0 if none. |
55a93433 | 1825 | unsigned int dynamic_count_; |
54dc6425 | 1826 | // The symbol hash table. |
14bfc3f5 | 1827 | Symbol_table_type table_; |
54dc6425 ILT |
1828 | // A pool of symbol names. This is used for all global symbols. |
1829 | // Entries in the hash table point into this pool. | |
14bfc3f5 | 1830 | Stringpool namepool_; |
14bfc3f5 | 1831 | // Forwarding symbols. |
c06b7b0b | 1832 | Unordered_map<const Symbol*, Symbol*> forwarders_; |
aeddab66 ILT |
1833 | // Weak aliases. A symbol in this list points to the next alias. |
1834 | // The aliases point to each other in a circular list. | |
1835 | Unordered_map<Symbol*, Symbol*> weak_aliases_; | |
ead1e424 ILT |
1836 | // We don't expect there to be very many common symbols, so we keep |
1837 | // a list of them. When we find a common symbol we add it to this | |
1838 | // list. It is possible that by the time we process the list the | |
1839 | // symbol is no longer a common symbol. It may also have become a | |
1840 | // forwarder. | |
1841 | Commons_type commons_; | |
155a0dd7 ILT |
1842 | // This is like the commons_ field, except that it holds TLS common |
1843 | // symbols. | |
1844 | Commons_type tls_commons_; | |
8a5e3e08 ILT |
1845 | // This is for small common symbols. |
1846 | Commons_type small_commons_; | |
1847 | // This is for large common symbols. | |
1848 | Commons_type large_commons_; | |
55a93433 ILT |
1849 | // A list of symbols which have been forced to be local. We don't |
1850 | // expect there to be very many of them, so we keep a list of them | |
1851 | // rather than walking the whole table to find them. | |
1852 | Forced_locals forced_locals_; | |
f6ce93d6 ILT |
1853 | // Manage symbol warnings. |
1854 | Warnings warnings_; | |
70e654ba ILT |
1855 | // Manage potential One Definition Rule (ODR) violations. |
1856 | Odr_map candidate_odr_violations_; | |
1857 | ||
46fe1623 ILT |
1858 | // When we emit a COPY reloc for a symbol, we define it in an |
1859 | // Output_data. When it's time to emit version information for it, | |
1860 | // we need to know the dynamic object in which we found the original | |
1861 | // definition. This maps symbols with COPY relocs to the dynamic | |
1862 | // object where they were defined. | |
1863 | Copied_symbol_dynobjs copied_symbol_dynobjs_; | |
09124467 ILT |
1864 | // Information parsed from the version script, if any. |
1865 | const Version_script_info& version_script_; | |
6d03d481 | 1866 | Garbage_collection* gc_; |
ef15dade | 1867 | Icf* icf_; |
bae7f79e ILT |
1868 | }; |
1869 | ||
1564db8d ILT |
1870 | // We inline get_sized_symbol for efficiency. |
1871 | ||
1872 | template<int size> | |
1873 | Sized_symbol<size>* | |
7d1a9ebb | 1874 | Symbol_table::get_sized_symbol(Symbol* sym) const |
1564db8d | 1875 | { |
8851ecca | 1876 | gold_assert(size == parameters->target().get_size()); |
1564db8d ILT |
1877 | return static_cast<Sized_symbol<size>*>(sym); |
1878 | } | |
1879 | ||
1880 | template<int size> | |
1881 | const Sized_symbol<size>* | |
7d1a9ebb | 1882 | Symbol_table::get_sized_symbol(const Symbol* sym) const |
1564db8d | 1883 | { |
8851ecca | 1884 | gold_assert(size == parameters->target().get_size()); |
1564db8d ILT |
1885 | return static_cast<const Sized_symbol<size>*>(sym); |
1886 | } | |
1887 | ||
bae7f79e ILT |
1888 | } // End namespace gold. |
1889 | ||
1890 | #endif // !defined(GOLD_SYMTAB_H) |