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bae7f79e ILT |
1 | // symtab.h -- the gold symbol table -*- C++ -*- |
2 | ||
6d1c4efb | 3 | // Copyright 2006, 2007, 2008, 2009, 2010, 2011 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 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 | |
6d1c4efb ILT |
139 | // Return the symbol's name as name@version (or name@@version). |
140 | std::string | |
141 | versioned_name() const; | |
142 | ||
ead1e424 ILT |
143 | // Return the symbol source. |
144 | Source | |
145 | source() const | |
146 | { return this->source_; } | |
147 | ||
14bfc3f5 ILT |
148 | // Return the object with which this symbol is associated. |
149 | Object* | |
150 | object() const | |
ead1e424 | 151 | { |
a3ad94ed | 152 | gold_assert(this->source_ == FROM_OBJECT); |
ead1e424 ILT |
153 | return this->u_.from_object.object; |
154 | } | |
155 | ||
f6ce93d6 ILT |
156 | // Return the index of the section in the input relocatable or |
157 | // dynamic object file. | |
ead1e424 | 158 | unsigned int |
d491d34e | 159 | shndx(bool* is_ordinary) const |
ead1e424 | 160 | { |
a3ad94ed | 161 | gold_assert(this->source_ == FROM_OBJECT); |
d491d34e | 162 | *is_ordinary = this->is_ordinary_shndx_; |
16649710 | 163 | return this->u_.from_object.shndx; |
ead1e424 ILT |
164 | } |
165 | ||
166 | // Return the output data section with which this symbol is | |
167 | // associated, if the symbol was specially defined with respect to | |
168 | // an output data section. | |
169 | Output_data* | |
170 | output_data() const | |
171 | { | |
a3ad94ed | 172 | gold_assert(this->source_ == IN_OUTPUT_DATA); |
ead1e424 ILT |
173 | return this->u_.in_output_data.output_data; |
174 | } | |
175 | ||
176 | // If this symbol was defined with respect to an output data | |
177 | // section, return whether the value is an offset from end. | |
178 | bool | |
179 | offset_is_from_end() const | |
180 | { | |
a3ad94ed | 181 | gold_assert(this->source_ == IN_OUTPUT_DATA); |
ead1e424 ILT |
182 | return this->u_.in_output_data.offset_is_from_end; |
183 | } | |
184 | ||
185 | // Return the output segment with which this symbol is associated, | |
186 | // if the symbol was specially defined with respect to an output | |
187 | // segment. | |
188 | Output_segment* | |
189 | output_segment() const | |
190 | { | |
a3ad94ed | 191 | gold_assert(this->source_ == IN_OUTPUT_SEGMENT); |
ead1e424 ILT |
192 | return this->u_.in_output_segment.output_segment; |
193 | } | |
194 | ||
195 | // If this symbol was defined with respect to an output segment, | |
196 | // return the offset base. | |
197 | Segment_offset_base | |
198 | offset_base() const | |
199 | { | |
a3ad94ed | 200 | gold_assert(this->source_ == IN_OUTPUT_SEGMENT); |
ead1e424 ILT |
201 | return this->u_.in_output_segment.offset_base; |
202 | } | |
14bfc3f5 ILT |
203 | |
204 | // Return the symbol binding. | |
205 | elfcpp::STB | |
206 | binding() const | |
207 | { return this->binding_; } | |
208 | ||
1564db8d ILT |
209 | // Return the symbol type. |
210 | elfcpp::STT | |
211 | type() const | |
212 | { return this->type_; } | |
213 | ||
53d7974c L |
214 | // Return true for function symbol. |
215 | bool | |
216 | is_func() const | |
217 | { | |
218 | return (this->type_ == elfcpp::STT_FUNC | |
219 | || this->type_ == elfcpp::STT_GNU_IFUNC); | |
220 | } | |
221 | ||
1564db8d ILT |
222 | // Return the symbol visibility. |
223 | elfcpp::STV | |
224 | visibility() const | |
225 | { return this->visibility_; } | |
226 | ||
0602e05a ILT |
227 | // Set the visibility. |
228 | void | |
2ea97941 ILT |
229 | set_visibility(elfcpp::STV visibility) |
230 | { this->visibility_ = visibility; } | |
0602e05a ILT |
231 | |
232 | // Override symbol visibility. | |
233 | void | |
234 | override_visibility(elfcpp::STV); | |
235 | ||
ce279a62 CC |
236 | // Set whether the symbol was originally a weak undef or a regular undef |
237 | // when resolved by a dynamic def. | |
238 | inline void | |
239 | set_undef_binding(elfcpp::STB bind) | |
240 | { | |
241 | if (!this->undef_binding_set_ || this->undef_binding_weak_) | |
242 | { | |
243 | this->undef_binding_weak_ = bind == elfcpp::STB_WEAK; | |
244 | this->undef_binding_set_ = true; | |
245 | } | |
246 | } | |
247 | ||
248 | // Return TRUE if a weak undef was resolved by a dynamic def. | |
249 | inline bool | |
250 | is_undef_binding_weak() const | |
251 | { return this->undef_binding_weak_; } | |
252 | ||
1564db8d ILT |
253 | // Return the non-visibility part of the st_other field. |
254 | unsigned char | |
ead1e424 ILT |
255 | nonvis() const |
256 | { return this->nonvis_; } | |
14bfc3f5 | 257 | |
1564db8d ILT |
258 | // Return whether this symbol is a forwarder. This will never be |
259 | // true of a symbol found in the hash table, but may be true of | |
260 | // symbol pointers attached to object files. | |
261 | bool | |
262 | is_forwarder() const | |
263 | { return this->is_forwarder_; } | |
264 | ||
265 | // Mark this symbol as a forwarder. | |
266 | void | |
267 | set_forwarder() | |
268 | { this->is_forwarder_ = true; } | |
269 | ||
aeddab66 ILT |
270 | // Return whether this symbol has an alias in the weak aliases table |
271 | // in Symbol_table. | |
272 | bool | |
273 | has_alias() const | |
274 | { return this->has_alias_; } | |
275 | ||
276 | // Mark this symbol as having an alias. | |
277 | void | |
278 | set_has_alias() | |
279 | { this->has_alias_ = true; } | |
280 | ||
c06b7b0b ILT |
281 | // Return whether this symbol needs an entry in the dynamic symbol |
282 | // table. | |
283 | bool | |
284 | needs_dynsym_entry() const | |
429c1569 ILT |
285 | { |
286 | return (this->needs_dynsym_entry_ | |
8d6d383d ILT |
287 | || (this->in_reg() |
288 | && this->in_dyn() | |
289 | && this->is_externally_visible())); | |
429c1569 | 290 | } |
c06b7b0b ILT |
291 | |
292 | // Mark this symbol as needing an entry in the dynamic symbol table. | |
293 | void | |
294 | set_needs_dynsym_entry() | |
295 | { this->needs_dynsym_entry_ = true; } | |
296 | ||
436ca963 ILT |
297 | // Return whether this symbol should be added to the dynamic symbol |
298 | // table. | |
299 | bool | |
ce97fa81 | 300 | should_add_dynsym_entry(Symbol_table*) const; |
436ca963 | 301 | |
008db82e ILT |
302 | // Return whether this symbol has been seen in a regular object. |
303 | bool | |
304 | in_reg() const | |
305 | { return this->in_reg_; } | |
306 | ||
307 | // Mark this symbol as having been seen in a regular object. | |
308 | void | |
309 | set_in_reg() | |
310 | { this->in_reg_ = true; } | |
311 | ||
1ebd95fd ILT |
312 | // Return whether this symbol has been seen in a dynamic object. |
313 | bool | |
314 | in_dyn() const | |
315 | { return this->in_dyn_; } | |
316 | ||
f6ce93d6 | 317 | // Mark this symbol as having been seen in a dynamic object. |
1564db8d ILT |
318 | void |
319 | set_in_dyn() | |
320 | { this->in_dyn_ = true; } | |
321 | ||
89fc3421 CC |
322 | // Return whether this symbol has been seen in a real ELF object. |
323 | // (IN_REG will return TRUE if the symbol has been seen in either | |
324 | // a real ELF object or an object claimed by a plugin.) | |
325 | bool | |
326 | in_real_elf() const | |
327 | { return this->in_real_elf_; } | |
328 | ||
329 | // Mark this symbol as having been seen in a real ELF object. | |
330 | void | |
331 | set_in_real_elf() | |
332 | { this->in_real_elf_ = true; } | |
333 | ||
880cd20d ILT |
334 | // Return whether this symbol was defined in a section that was |
335 | // discarded from the link. This is used to control some error | |
336 | // reporting. | |
337 | bool | |
338 | is_defined_in_discarded_section() const | |
339 | { return this->is_defined_in_discarded_section_; } | |
340 | ||
341 | // Mark this symbol as having been defined in a discarded section. | |
342 | void | |
343 | set_is_defined_in_discarded_section() | |
344 | { this->is_defined_in_discarded_section_ = true; } | |
345 | ||
c06b7b0b ILT |
346 | // Return the index of this symbol in the output file symbol table. |
347 | // A value of -1U means that this symbol is not going into the | |
348 | // output file. This starts out as zero, and is set to a non-zero | |
349 | // value by Symbol_table::finalize. It is an error to ask for the | |
350 | // symbol table index before it has been set. | |
351 | unsigned int | |
352 | symtab_index() const | |
353 | { | |
a3ad94ed | 354 | gold_assert(this->symtab_index_ != 0); |
c06b7b0b ILT |
355 | return this->symtab_index_; |
356 | } | |
357 | ||
358 | // Set the index of the symbol in the output file symbol table. | |
359 | void | |
360 | set_symtab_index(unsigned int index) | |
361 | { | |
a3ad94ed | 362 | gold_assert(index != 0); |
c06b7b0b ILT |
363 | this->symtab_index_ = index; |
364 | } | |
365 | ||
a3ad94ed ILT |
366 | // Return whether this symbol already has an index in the output |
367 | // file symbol table. | |
368 | bool | |
369 | has_symtab_index() const | |
370 | { return this->symtab_index_ != 0; } | |
371 | ||
c06b7b0b ILT |
372 | // Return the index of this symbol in the dynamic symbol table. A |
373 | // value of -1U means that this symbol is not going into the dynamic | |
374 | // symbol table. This starts out as zero, and is set to a non-zero | |
375 | // during Layout::finalize. It is an error to ask for the dynamic | |
376 | // symbol table index before it has been set. | |
377 | unsigned int | |
378 | dynsym_index() const | |
379 | { | |
a3ad94ed | 380 | gold_assert(this->dynsym_index_ != 0); |
c06b7b0b ILT |
381 | return this->dynsym_index_; |
382 | } | |
383 | ||
384 | // Set the index of the symbol in the dynamic symbol table. | |
385 | void | |
386 | set_dynsym_index(unsigned int index) | |
387 | { | |
a3ad94ed | 388 | gold_assert(index != 0); |
c06b7b0b ILT |
389 | this->dynsym_index_ = index; |
390 | } | |
391 | ||
16649710 ILT |
392 | // Return whether this symbol already has an index in the dynamic |
393 | // symbol table. | |
394 | bool | |
395 | has_dynsym_index() const | |
396 | { return this->dynsym_index_ != 0; } | |
397 | ||
ead1e424 | 398 | // Return whether this symbol has an entry in the GOT section. |
07f397ab | 399 | // For a TLS symbol, this GOT entry will hold its tp-relative offset. |
92e059d8 | 400 | bool |
0a65a3a7 CC |
401 | has_got_offset(unsigned int got_type) const |
402 | { return this->got_offsets_.get_offset(got_type) != -1U; } | |
ead1e424 ILT |
403 | |
404 | // Return the offset into the GOT section of this symbol. | |
405 | unsigned int | |
0a65a3a7 | 406 | got_offset(unsigned int got_type) const |
ead1e424 | 407 | { |
2ea97941 ILT |
408 | unsigned int got_offset = this->got_offsets_.get_offset(got_type); |
409 | gold_assert(got_offset != -1U); | |
410 | return got_offset; | |
ead1e424 ILT |
411 | } |
412 | ||
413 | // Set the GOT offset of this symbol. | |
414 | void | |
2ea97941 ILT |
415 | set_got_offset(unsigned int got_type, unsigned int got_offset) |
416 | { this->got_offsets_.set_offset(got_type, got_offset); } | |
07f397ab | 417 | |
0e70b911 CC |
418 | // Return the GOT offset list. |
419 | const Got_offset_list* | |
420 | got_offset_list() const | |
421 | { return this->got_offsets_.get_list(); } | |
422 | ||
a3ad94ed | 423 | // Return whether this symbol has an entry in the PLT section. |
ead1e424 | 424 | bool |
a3ad94ed | 425 | has_plt_offset() const |
880cd20d | 426 | { return this->plt_offset_ != -1U; } |
a3ad94ed ILT |
427 | |
428 | // Return the offset into the PLT section of this symbol. | |
429 | unsigned int | |
430 | plt_offset() const | |
431 | { | |
432 | gold_assert(this->has_plt_offset()); | |
433 | return this->plt_offset_; | |
434 | } | |
435 | ||
436 | // Set the PLT offset of this symbol. | |
437 | void | |
2ea97941 | 438 | set_plt_offset(unsigned int plt_offset) |
a3ad94ed | 439 | { |
880cd20d | 440 | gold_assert(plt_offset != -1U); |
2ea97941 | 441 | this->plt_offset_ = plt_offset; |
a3ad94ed ILT |
442 | } |
443 | ||
ab5c9e90 ILT |
444 | // Return whether this dynamic symbol needs a special value in the |
445 | // dynamic symbol table. | |
446 | bool | |
447 | needs_dynsym_value() const | |
448 | { return this->needs_dynsym_value_; } | |
449 | ||
450 | // Set that this dynamic symbol needs a special value in the dynamic | |
451 | // symbol table. | |
452 | void | |
453 | set_needs_dynsym_value() | |
454 | { | |
455 | gold_assert(this->object()->is_dynamic()); | |
456 | this->needs_dynsym_value_ = true; | |
457 | } | |
458 | ||
a3ad94ed ILT |
459 | // Return true if the final value of this symbol is known at link |
460 | // time. | |
461 | bool | |
b3b74ddc | 462 | final_value_is_known() const; |
ead1e424 | 463 | |
8a5e3e08 ILT |
464 | // Return true if SHNDX represents a common symbol. This depends on |
465 | // the target. | |
466 | static bool | |
467 | is_common_shndx(unsigned int shndx); | |
468 | ||
f6ce93d6 ILT |
469 | // Return whether this is a defined symbol (not undefined or |
470 | // common). | |
471 | bool | |
472 | is_defined() const | |
473 | { | |
d491d34e ILT |
474 | bool is_ordinary; |
475 | if (this->source_ != FROM_OBJECT) | |
f3e9c5c5 | 476 | return this->source_ != IS_UNDEFINED; |
2ea97941 | 477 | unsigned int shndx = this->shndx(&is_ordinary); |
d491d34e | 478 | return (is_ordinary |
2ea97941 ILT |
479 | ? shndx != elfcpp::SHN_UNDEF |
480 | : !Symbol::is_common_shndx(shndx)); | |
a3ad94ed ILT |
481 | } |
482 | ||
14b31740 | 483 | // Return true if this symbol is from a dynamic object. |
a3ad94ed | 484 | bool |
14b31740 | 485 | is_from_dynobj() const |
a3ad94ed | 486 | { |
14b31740 | 487 | return this->source_ == FROM_OBJECT && this->object()->is_dynamic(); |
f6ce93d6 ILT |
488 | } |
489 | ||
f3a2388f CC |
490 | // Return whether this is a placeholder symbol from a plugin object. |
491 | bool | |
492 | is_placeholder() const | |
493 | { | |
494 | return this->source_ == FROM_OBJECT && this->object()->pluginobj() != NULL; | |
495 | } | |
496 | ||
ead1e424 ILT |
497 | // Return whether this is an undefined symbol. |
498 | bool | |
499 | is_undefined() const | |
500 | { | |
d491d34e | 501 | bool is_ordinary; |
f3e9c5c5 ILT |
502 | return ((this->source_ == FROM_OBJECT |
503 | && this->shndx(&is_ordinary) == elfcpp::SHN_UNDEF | |
504 | && is_ordinary) | |
505 | || this->source_ == IS_UNDEFINED); | |
ead1e424 ILT |
506 | } |
507 | ||
86925eef CC |
508 | // Return whether this is a weak undefined symbol. |
509 | bool | |
510 | is_weak_undefined() const | |
f3e9c5c5 | 511 | { return this->is_undefined() && this->binding() == elfcpp::STB_WEAK; } |
86925eef | 512 | |
86925eef CC |
513 | // Return whether this is an absolute symbol. |
514 | bool | |
515 | is_absolute() const | |
516 | { | |
d491d34e | 517 | bool is_ordinary; |
f3e9c5c5 ILT |
518 | return ((this->source_ == FROM_OBJECT |
519 | && this->shndx(&is_ordinary) == elfcpp::SHN_ABS | |
520 | && !is_ordinary) | |
521 | || this->source_ == IS_CONSTANT); | |
86925eef CC |
522 | } |
523 | ||
ead1e424 ILT |
524 | // Return whether this is a common symbol. |
525 | bool | |
526 | is_common() const | |
527 | { | |
8a5e3e08 ILT |
528 | if (this->source_ != FROM_OBJECT) |
529 | return false; | |
eda294df ILT |
530 | if (this->type_ == elfcpp::STT_COMMON) |
531 | return true; | |
d491d34e | 532 | bool is_ordinary; |
2ea97941 ILT |
533 | unsigned int shndx = this->shndx(&is_ordinary); |
534 | return !is_ordinary && Symbol::is_common_shndx(shndx); | |
ead1e424 | 535 | } |
92e059d8 | 536 | |
a6badf5a ILT |
537 | // Return whether this symbol can be seen outside this object. |
538 | bool | |
539 | is_externally_visible() const | |
540 | { | |
541 | return (this->visibility_ == elfcpp::STV_DEFAULT | |
542 | || this->visibility_ == elfcpp::STV_PROTECTED); | |
543 | } | |
544 | ||
436ca963 ILT |
545 | // Return true if this symbol can be preempted by a definition in |
546 | // another link unit. | |
547 | bool | |
548 | is_preemptible() const | |
549 | { | |
386c048c ILT |
550 | // It doesn't make sense to ask whether a symbol defined in |
551 | // another object is preemptible. | |
552 | gold_assert(!this->is_from_dynobj()); | |
553 | ||
8fc19601 ILT |
554 | // It doesn't make sense to ask whether an undefined symbol |
555 | // is preemptible. | |
556 | gold_assert(!this->is_undefined()); | |
557 | ||
f1f70eae ILT |
558 | // If a symbol does not have default visibility, it can not be |
559 | // seen outside this link unit and therefore is not preemptible. | |
560 | if (this->visibility_ != elfcpp::STV_DEFAULT) | |
561 | return false; | |
562 | ||
563 | // If this symbol has been forced to be a local symbol by a | |
564 | // version script, then it is not visible outside this link unit | |
565 | // and is not preemptible. | |
566 | if (this->is_forced_local_) | |
567 | return false; | |
568 | ||
569 | // If we are not producing a shared library, then nothing is | |
570 | // preemptible. | |
571 | if (!parameters->options().shared()) | |
572 | return false; | |
573 | ||
574 | // If the user used -Bsymbolic, then nothing is preemptible. | |
575 | if (parameters->options().Bsymbolic()) | |
576 | return false; | |
577 | ||
578 | // If the user used -Bsymbolic-functions, then functions are not | |
579 | // preemptible. We explicitly check for not being STT_OBJECT, | |
580 | // rather than for being STT_FUNC, because that is what the GNU | |
581 | // linker does. | |
582 | if (this->type() != elfcpp::STT_OBJECT | |
583 | && parameters->options().Bsymbolic_functions()) | |
584 | return false; | |
585 | ||
586 | // Otherwise the symbol is preemptible. | |
587 | return true; | |
436ca963 ILT |
588 | } |
589 | ||
d61c6bd4 | 590 | // Return true if this symbol is a function that needs a PLT entry. |
d61c6bd4 ILT |
591 | bool |
592 | needs_plt_entry() const | |
593 | { | |
6d479619 CC |
594 | // An undefined symbol from an executable does not need a PLT entry. |
595 | if (this->is_undefined() && !parameters->options().shared()) | |
596 | return false; | |
597 | ||
7223e9ca ILT |
598 | // An STT_GNU_IFUNC symbol always needs a PLT entry, even when |
599 | // doing a static link. | |
600 | if (this->type() == elfcpp::STT_GNU_IFUNC) | |
601 | return true; | |
602 | ||
603 | // We only need a PLT entry for a function. | |
604 | if (!this->is_func()) | |
605 | return false; | |
606 | ||
607 | // If we're doing a static link or a -pie link, we don't create | |
608 | // PLT entries. | |
609 | if (parameters->doing_static_link() | |
610 | || parameters->options().pie()) | |
611 | return false; | |
612 | ||
613 | // We need a PLT entry if the function is defined in a dynamic | |
614 | // object, or is undefined when building a shared object, or if it | |
615 | // is subject to pre-emption. | |
616 | return (this->is_from_dynobj() | |
617 | || this->is_undefined() | |
618 | || this->is_preemptible()); | |
d61c6bd4 ILT |
619 | } |
620 | ||
0700cf32 ILT |
621 | // When determining whether a reference to a symbol needs a dynamic |
622 | // relocation, we need to know several things about the reference. | |
95a2c8d6 RS |
623 | // These flags may be or'ed together. 0 means that the symbol |
624 | // isn't referenced at all. | |
0700cf32 ILT |
625 | enum Reference_flags |
626 | { | |
95a2c8d6 RS |
627 | // A reference to the symbol's absolute address. This includes |
628 | // references that cause an absolute address to be stored in the GOT. | |
0700cf32 | 629 | ABSOLUTE_REF = 1, |
95a2c8d6 RS |
630 | // A reference that calculates the offset of the symbol from some |
631 | // anchor point, such as the PC or GOT. | |
632 | RELATIVE_REF = 2, | |
633 | // A TLS-related reference. | |
634 | TLS_REF = 4, | |
635 | // A reference that can always be treated as a function call. | |
636 | FUNCTION_CALL = 8 | |
0700cf32 ILT |
637 | }; |
638 | ||
d61c6bd4 ILT |
639 | // Given a direct absolute or pc-relative static relocation against |
640 | // the global symbol, this function returns whether a dynamic relocation | |
641 | // is needed. | |
642 | ||
643 | bool | |
0700cf32 | 644 | needs_dynamic_reloc(int flags) const |
d61c6bd4 | 645 | { |
8fc19601 ILT |
646 | // No dynamic relocations in a static link! |
647 | if (parameters->doing_static_link()) | |
648 | return false; | |
649 | ||
6d479619 | 650 | // A reference to an undefined symbol from an executable should be |
f3c69fca CC |
651 | // statically resolved to 0, and does not need a dynamic relocation. |
652 | // This matches gnu ld behavior. | |
6d479619 | 653 | if (this->is_undefined() && !parameters->options().shared()) |
f3c69fca CC |
654 | return false; |
655 | ||
656 | // A reference to an absolute symbol does not need a dynamic relocation. | |
657 | if (this->is_absolute()) | |
86925eef CC |
658 | return false; |
659 | ||
d61c6bd4 | 660 | // An absolute reference within a position-independent output file |
0700cf32 ILT |
661 | // will need a dynamic relocation. |
662 | if ((flags & ABSOLUTE_REF) | |
8851ecca | 663 | && parameters->options().output_is_position_independent()) |
d61c6bd4 ILT |
664 | return true; |
665 | ||
666 | // A function call that can branch to a local PLT entry does not need | |
95a2c8d6 RS |
667 | // a dynamic relocation. |
668 | if ((flags & FUNCTION_CALL) && this->has_plt_offset()) | |
d61c6bd4 ILT |
669 | return false; |
670 | ||
671 | // A reference to any PLT entry in a non-position-independent executable | |
672 | // does not need a dynamic relocation. | |
8851ecca | 673 | if (!parameters->options().output_is_position_independent() |
d61c6bd4 ILT |
674 | && this->has_plt_offset()) |
675 | return false; | |
676 | ||
677 | // A reference to a symbol defined in a dynamic object or to a | |
678 | // symbol that is preemptible will need a dynamic relocation. | |
8fc19601 ILT |
679 | if (this->is_from_dynobj() |
680 | || this->is_undefined() | |
681 | || this->is_preemptible()) | |
d61c6bd4 ILT |
682 | return true; |
683 | ||
684 | // For all other cases, return FALSE. | |
685 | return false; | |
686 | } | |
687 | ||
de4c45bd | 688 | // Whether we should use the PLT offset associated with a symbol for |
95a2c8d6 | 689 | // a relocation. FLAGS is a set of Reference_flags. |
de4c45bd ILT |
690 | |
691 | bool | |
95a2c8d6 | 692 | use_plt_offset(int flags) const |
de4c45bd ILT |
693 | { |
694 | // If the symbol doesn't have a PLT offset, then naturally we | |
695 | // don't want to use it. | |
696 | if (!this->has_plt_offset()) | |
697 | return false; | |
698 | ||
7223e9ca ILT |
699 | // For a STT_GNU_IFUNC symbol we always have to use the PLT entry. |
700 | if (this->type() == elfcpp::STT_GNU_IFUNC) | |
701 | return true; | |
702 | ||
de4c45bd ILT |
703 | // If we are going to generate a dynamic relocation, then we will |
704 | // wind up using that, so no need to use the PLT entry. | |
95a2c8d6 | 705 | if (this->needs_dynamic_reloc(flags)) |
de4c45bd ILT |
706 | return false; |
707 | ||
708 | // If the symbol is from a dynamic object, we need to use the PLT | |
709 | // entry. | |
710 | if (this->is_from_dynobj()) | |
711 | return true; | |
712 | ||
713 | // If we are generating a shared object, and this symbol is | |
714 | // undefined or preemptible, we need to use the PLT entry. | |
715 | if (parameters->options().shared() | |
716 | && (this->is_undefined() || this->is_preemptible())) | |
717 | return true; | |
718 | ||
95a2c8d6 RS |
719 | // If this is a call to a weak undefined symbol, we need to use |
720 | // the PLT entry; the symbol may be defined by a library loaded | |
721 | // at runtime. | |
722 | if ((flags & FUNCTION_CALL) && this->is_weak_undefined()) | |
de4c45bd ILT |
723 | return true; |
724 | ||
725 | // Otherwise we can use the regular definition. | |
726 | return false; | |
727 | } | |
728 | ||
d61c6bd4 ILT |
729 | // Given a direct absolute static relocation against |
730 | // the global symbol, where a dynamic relocation is needed, this | |
731 | // function returns whether a relative dynamic relocation can be used. | |
732 | // The caller must determine separately whether the static relocation | |
733 | // is compatible with a relative relocation. | |
734 | ||
735 | bool | |
736 | can_use_relative_reloc(bool is_function_call) const | |
737 | { | |
738 | // A function call that can branch to a local PLT entry can | |
739 | // use a RELATIVE relocation. | |
740 | if (is_function_call && this->has_plt_offset()) | |
741 | return true; | |
742 | ||
743 | // A reference to a symbol defined in a dynamic object or to a | |
9b547ce6 | 744 | // symbol that is preemptible can not use a RELATIVE relocation. |
8fc19601 ILT |
745 | if (this->is_from_dynobj() |
746 | || this->is_undefined() | |
747 | || this->is_preemptible()) | |
d61c6bd4 ILT |
748 | return false; |
749 | ||
750 | // For all other cases, return TRUE. | |
751 | return true; | |
752 | } | |
753 | ||
77e65537 ILT |
754 | // Return the output section where this symbol is defined. Return |
755 | // NULL if the symbol has an absolute value. | |
756 | Output_section* | |
757 | output_section() const; | |
758 | ||
759 | // Set the symbol's output section. This is used for symbols | |
760 | // defined in scripts. This should only be called after the symbol | |
761 | // table has been finalized. | |
762 | void | |
763 | set_output_section(Output_section*); | |
a445fddf | 764 | |
f6ce93d6 ILT |
765 | // Return whether there should be a warning for references to this |
766 | // symbol. | |
767 | bool | |
768 | has_warning() const | |
769 | { return this->has_warning_; } | |
770 | ||
771 | // Mark this symbol as having a warning. | |
772 | void | |
773 | set_has_warning() | |
774 | { this->has_warning_ = true; } | |
775 | ||
46fe1623 ILT |
776 | // Return whether this symbol is defined by a COPY reloc from a |
777 | // dynamic object. | |
778 | bool | |
779 | is_copied_from_dynobj() const | |
780 | { return this->is_copied_from_dynobj_; } | |
781 | ||
782 | // Mark this symbol as defined by a COPY reloc. | |
783 | void | |
784 | set_is_copied_from_dynobj() | |
785 | { this->is_copied_from_dynobj_ = true; } | |
786 | ||
55a93433 ILT |
787 | // Return whether this symbol is forced to visibility STB_LOCAL |
788 | // by a "local:" entry in a version script. | |
789 | bool | |
790 | is_forced_local() const | |
791 | { return this->is_forced_local_; } | |
792 | ||
793 | // Mark this symbol as forced to STB_LOCAL visibility. | |
794 | void | |
795 | set_is_forced_local() | |
796 | { this->is_forced_local_ = true; } | |
797 | ||
966d4097 DK |
798 | // Return true if this may need a COPY relocation. |
799 | // References from an executable object to non-function symbols | |
800 | // defined in a dynamic object may need a COPY relocation. | |
801 | bool | |
802 | may_need_copy_reloc() const | |
803 | { | |
d89051bd | 804 | return (!parameters->options().output_is_position_independent() |
966d4097 DK |
805 | && parameters->options().copyreloc() |
806 | && this->is_from_dynobj() | |
53d7974c | 807 | && !this->is_func()); |
966d4097 DK |
808 | } |
809 | ||
5146f448 CC |
810 | // Return true if this symbol was predefined by the linker. |
811 | bool | |
812 | is_predefined() const | |
813 | { return this->is_predefined_; } | |
814 | ||
14bfc3f5 ILT |
815 | protected: |
816 | // Instances of this class should always be created at a specific | |
817 | // size. | |
818 | Symbol() | |
f6ce93d6 | 819 | { memset(this, 0, sizeof *this); } |
14bfc3f5 | 820 | |
ead1e424 ILT |
821 | // Initialize the general fields. |
822 | void | |
823 | init_fields(const char* name, const char* version, | |
824 | elfcpp::STT type, elfcpp::STB binding, | |
825 | elfcpp::STV visibility, unsigned char nonvis); | |
826 | ||
d491d34e ILT |
827 | // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the |
828 | // section index, IS_ORDINARY is whether it is a normal section | |
829 | // index rather than a special code. | |
14bfc3f5 ILT |
830 | template<int size, bool big_endian> |
831 | void | |
ca09d69a | 832 | init_base_object(const char* name, const char* version, Object* object, |
f3e9c5c5 ILT |
833 | const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx, |
834 | bool is_ordinary); | |
bae7f79e | 835 | |
ead1e424 ILT |
836 | // Initialize fields for an Output_data. |
837 | void | |
75517b77 ILT |
838 | init_base_output_data(const char* name, const char* version, Output_data*, |
839 | elfcpp::STT, elfcpp::STB, elfcpp::STV, | |
5146f448 CC |
840 | unsigned char nonvis, bool offset_is_from_end, |
841 | bool is_predefined); | |
ead1e424 ILT |
842 | |
843 | // Initialize fields for an Output_segment. | |
844 | void | |
75517b77 ILT |
845 | init_base_output_segment(const char* name, const char* version, |
846 | Output_segment* os, elfcpp::STT type, | |
847 | elfcpp::STB binding, elfcpp::STV visibility, | |
848 | unsigned char nonvis, | |
5146f448 CC |
849 | Segment_offset_base offset_base, |
850 | bool is_predefined); | |
ead1e424 ILT |
851 | |
852 | // Initialize fields for a constant. | |
853 | void | |
75517b77 ILT |
854 | init_base_constant(const char* name, const char* version, elfcpp::STT type, |
855 | elfcpp::STB binding, elfcpp::STV visibility, | |
5146f448 | 856 | unsigned char nonvis, bool is_predefined); |
f3e9c5c5 ILT |
857 | |
858 | // Initialize fields for an undefined symbol. | |
859 | void | |
75517b77 ILT |
860 | init_base_undefined(const char* name, const char* version, elfcpp::STT type, |
861 | elfcpp::STB binding, elfcpp::STV visibility, | |
862 | unsigned char nonvis); | |
ead1e424 | 863 | |
1564db8d ILT |
864 | // Override existing symbol. |
865 | template<int size, bool big_endian> | |
866 | void | |
d491d34e ILT |
867 | override_base(const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx, |
868 | bool is_ordinary, Object* object, const char* version); | |
1564db8d | 869 | |
86f2e683 ILT |
870 | // Override existing symbol with a special symbol. |
871 | void | |
872 | override_base_with_special(const Symbol* from); | |
873 | ||
75517b77 ILT |
874 | // Override symbol version. |
875 | void | |
876 | override_version(const char* version); | |
877 | ||
c7912668 ILT |
878 | // Allocate a common symbol by giving it a location in the output |
879 | // file. | |
880 | void | |
881 | allocate_base_common(Output_data*); | |
882 | ||
bae7f79e | 883 | private: |
14bfc3f5 ILT |
884 | Symbol(const Symbol&); |
885 | Symbol& operator=(const Symbol&); | |
886 | ||
887 | // Symbol name (expected to point into a Stringpool). | |
888 | const char* name_; | |
889 | // Symbol version (expected to point into a Stringpool). This may | |
890 | // be NULL. | |
bae7f79e | 891 | const char* version_; |
ead1e424 ILT |
892 | |
893 | union | |
894 | { | |
895 | // This struct is used if SOURCE_ == FROM_OBJECT. | |
896 | struct | |
897 | { | |
898 | // Object in which symbol is defined, or in which it was first | |
899 | // seen. | |
900 | Object* object; | |
901 | // Section number in object_ in which symbol is defined. | |
16649710 | 902 | unsigned int shndx; |
ead1e424 ILT |
903 | } from_object; |
904 | ||
905 | // This struct is used if SOURCE_ == IN_OUTPUT_DATA. | |
906 | struct | |
907 | { | |
908 | // Output_data in which symbol is defined. Before | |
909 | // Layout::finalize the symbol's value is an offset within the | |
910 | // Output_data. | |
911 | Output_data* output_data; | |
912 | // True if the offset is from the end, false if the offset is | |
913 | // from the beginning. | |
914 | bool offset_is_from_end; | |
915 | } in_output_data; | |
916 | ||
917 | // This struct is used if SOURCE_ == IN_OUTPUT_SEGMENT. | |
918 | struct | |
919 | { | |
920 | // Output_segment in which the symbol is defined. Before | |
921 | // Layout::finalize the symbol's value is an offset. | |
922 | Output_segment* output_segment; | |
923 | // The base to use for the offset before Layout::finalize. | |
924 | Segment_offset_base offset_base; | |
925 | } in_output_segment; | |
926 | } u_; | |
927 | ||
c06b7b0b ILT |
928 | // The index of this symbol in the output file. If the symbol is |
929 | // not going into the output file, this value is -1U. This field | |
930 | // starts as always holding zero. It is set to a non-zero value by | |
931 | // Symbol_table::finalize. | |
932 | unsigned int symtab_index_; | |
933 | ||
934 | // The index of this symbol in the dynamic symbol table. If the | |
935 | // symbol is not going into the dynamic symbol table, this value is | |
936 | // -1U. This field starts as always holding zero. It is set to a | |
937 | // non-zero value during Layout::finalize. | |
938 | unsigned int dynsym_index_; | |
939 | ||
880cd20d ILT |
940 | // The GOT section entries for this symbol. A symbol may have more |
941 | // than one GOT offset (e.g., when mixing modules compiled with two | |
942 | // different TLS models), but will usually have at most one. | |
0a65a3a7 | 943 | Got_offset_list got_offsets_; |
07f397ab | 944 | |
880cd20d ILT |
945 | // If this symbol has an entry in the PLT section, then this is the |
946 | // offset from the start of the PLT section. This is -1U if there | |
947 | // is no PLT entry. | |
a3ad94ed ILT |
948 | unsigned int plt_offset_; |
949 | ||
d491d34e | 950 | // Symbol type (bits 0 to 3). |
bae7f79e | 951 | elfcpp::STT type_ : 4; |
d491d34e | 952 | // Symbol binding (bits 4 to 7). |
bae7f79e | 953 | elfcpp::STB binding_ : 4; |
d491d34e | 954 | // Symbol visibility (bits 8 to 9). |
14bfc3f5 | 955 | elfcpp::STV visibility_ : 2; |
d491d34e | 956 | // Rest of symbol st_other field (bits 10 to 15). |
ead1e424 | 957 | unsigned int nonvis_ : 6; |
d491d34e | 958 | // The type of symbol (bits 16 to 18). |
f6ce93d6 | 959 | Source source_ : 3; |
880cd20d | 960 | // True if this is the default version of the symbol (bit 19). |
1564db8d | 961 | bool is_def_ : 1; |
14bfc3f5 ILT |
962 | // True if this symbol really forwards to another symbol. This is |
963 | // used when we discover after the fact that two different entries | |
964 | // in the hash table really refer to the same symbol. This will | |
965 | // never be set for a symbol found in the hash table, but may be set | |
966 | // for a symbol found in the list of symbols attached to an Object. | |
967 | // It forwards to the symbol found in the forwarders_ map of | |
880cd20d | 968 | // Symbol_table (bit 20). |
1564db8d | 969 | bool is_forwarder_ : 1; |
aeddab66 | 970 | // True if the symbol has an alias in the weak_aliases table in |
880cd20d | 971 | // Symbol_table (bit 21). |
aeddab66 | 972 | bool has_alias_ : 1; |
d491d34e | 973 | // True if this symbol needs to be in the dynamic symbol table (bit |
880cd20d | 974 | // 22). |
c06b7b0b | 975 | bool needs_dynsym_entry_ : 1; |
880cd20d | 976 | // True if we've seen this symbol in a regular object (bit 23). |
008db82e | 977 | bool in_reg_ : 1; |
880cd20d | 978 | // True if we've seen this symbol in a dynamic object (bit 24). |
1564db8d | 979 | bool in_dyn_ : 1; |
ab5c9e90 | 980 | // True if this is a dynamic symbol which needs a special value in |
880cd20d | 981 | // the dynamic symbol table (bit 25). |
ab5c9e90 | 982 | bool needs_dynsym_value_ : 1; |
880cd20d | 983 | // True if there is a warning for this symbol (bit 26). |
f6ce93d6 | 984 | bool has_warning_ : 1; |
46fe1623 | 985 | // True if we are using a COPY reloc for this symbol, so that the |
880cd20d | 986 | // real definition lives in a dynamic object (bit 27). |
46fe1623 | 987 | bool is_copied_from_dynobj_ : 1; |
55a93433 | 988 | // True if this symbol was forced to local visibility by a version |
880cd20d | 989 | // script (bit 28). |
55a93433 | 990 | bool is_forced_local_ : 1; |
d491d34e ILT |
991 | // True if the field u_.from_object.shndx is an ordinary section |
992 | // index, not one of the special codes from SHN_LORESERVE to | |
880cd20d | 993 | // SHN_HIRESERVE (bit 29). |
d491d34e | 994 | bool is_ordinary_shndx_ : 1; |
880cd20d | 995 | // True if we've seen this symbol in a real ELF object (bit 30). |
89fc3421 | 996 | bool in_real_elf_ : 1; |
880cd20d ILT |
997 | // True if this symbol is defined in a section which was discarded |
998 | // (bit 31). | |
999 | bool is_defined_in_discarded_section_ : 1; | |
ce279a62 CC |
1000 | // True if UNDEF_BINDING_WEAK_ has been set (bit 32). |
1001 | bool undef_binding_set_ : 1; | |
1002 | // True if this symbol was a weak undef resolved by a dynamic def | |
1003 | // (bit 33). | |
1004 | bool undef_binding_weak_ : 1; | |
5146f448 CC |
1005 | // True if this symbol is a predefined linker symbol (bit 34). |
1006 | bool is_predefined_ : 1; | |
bae7f79e ILT |
1007 | }; |
1008 | ||
14bfc3f5 ILT |
1009 | // The parts of a symbol which are size specific. Using a template |
1010 | // derived class like this helps us use less space on a 32-bit system. | |
bae7f79e ILT |
1011 | |
1012 | template<int size> | |
14bfc3f5 ILT |
1013 | class Sized_symbol : public Symbol |
1014 | { | |
1015 | public: | |
1564db8d ILT |
1016 | typedef typename elfcpp::Elf_types<size>::Elf_Addr Value_type; |
1017 | typedef typename elfcpp::Elf_types<size>::Elf_WXword Size_type; | |
1018 | ||
14bfc3f5 ILT |
1019 | Sized_symbol() |
1020 | { } | |
1021 | ||
d491d34e ILT |
1022 | // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the |
1023 | // section index, IS_ORDINARY is whether it is a normal section | |
1024 | // index rather than a special code. | |
14bfc3f5 ILT |
1025 | template<bool big_endian> |
1026 | void | |
ca09d69a | 1027 | init_object(const char* name, const char* version, Object* object, |
f3e9c5c5 ILT |
1028 | const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx, |
1029 | bool is_ordinary); | |
14bfc3f5 | 1030 | |
ead1e424 ILT |
1031 | // Initialize fields for an Output_data. |
1032 | void | |
75517b77 ILT |
1033 | init_output_data(const char* name, const char* version, Output_data*, |
1034 | Value_type value, Size_type symsize, elfcpp::STT, | |
1035 | elfcpp::STB, elfcpp::STV, unsigned char nonvis, | |
5146f448 | 1036 | bool offset_is_from_end, bool is_predefined); |
ead1e424 ILT |
1037 | |
1038 | // Initialize fields for an Output_segment. | |
1039 | void | |
75517b77 ILT |
1040 | init_output_segment(const char* name, const char* version, Output_segment*, |
1041 | Value_type value, Size_type symsize, elfcpp::STT, | |
1042 | elfcpp::STB, elfcpp::STV, unsigned char nonvis, | |
5146f448 | 1043 | Segment_offset_base offset_base, bool is_predefined); |
ead1e424 ILT |
1044 | |
1045 | // Initialize fields for a constant. | |
1046 | void | |
75517b77 ILT |
1047 | init_constant(const char* name, const char* version, Value_type value, |
1048 | Size_type symsize, elfcpp::STT, elfcpp::STB, elfcpp::STV, | |
5146f448 | 1049 | unsigned char nonvis, bool is_predefined); |
f3e9c5c5 ILT |
1050 | |
1051 | // Initialize fields for an undefined symbol. | |
1052 | void | |
75517b77 ILT |
1053 | init_undefined(const char* name, const char* version, elfcpp::STT, |
1054 | elfcpp::STB, elfcpp::STV, unsigned char nonvis); | |
ead1e424 | 1055 | |
1564db8d ILT |
1056 | // Override existing symbol. |
1057 | template<bool big_endian> | |
1058 | void | |
d491d34e ILT |
1059 | override(const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx, |
1060 | bool is_ordinary, Object* object, const char* version); | |
1564db8d | 1061 | |
86f2e683 ILT |
1062 | // Override existing symbol with a special symbol. |
1063 | void | |
1064 | override_with_special(const Sized_symbol<size>*); | |
1065 | ||
1564db8d ILT |
1066 | // Return the symbol's value. |
1067 | Value_type | |
1068 | value() const | |
1069 | { return this->value_; } | |
1070 | ||
1071 | // Return the symbol's size (we can't call this 'size' because that | |
1072 | // is a template parameter). | |
1073 | Size_type | |
1074 | symsize() const | |
ead1e424 ILT |
1075 | { return this->symsize_; } |
1076 | ||
1077 | // Set the symbol size. This is used when resolving common symbols. | |
1078 | void | |
2ea97941 ILT |
1079 | set_symsize(Size_type symsize) |
1080 | { this->symsize_ = symsize; } | |
1564db8d | 1081 | |
75f65a3e ILT |
1082 | // Set the symbol value. This is called when we store the final |
1083 | // values of the symbols into the symbol table. | |
1084 | void | |
2ea97941 ILT |
1085 | set_value(Value_type value) |
1086 | { this->value_ = value; } | |
75f65a3e | 1087 | |
c7912668 ILT |
1088 | // Allocate a common symbol by giving it a location in the output |
1089 | // file. | |
1090 | void | |
1091 | allocate_common(Output_data*, Value_type value); | |
1092 | ||
14bfc3f5 ILT |
1093 | private: |
1094 | Sized_symbol(const Sized_symbol&); | |
1095 | Sized_symbol& operator=(const Sized_symbol&); | |
1096 | ||
ead1e424 ILT |
1097 | // Symbol value. Before Layout::finalize this is the offset in the |
1098 | // input section. This is set to the final value during | |
1099 | // Layout::finalize. | |
1564db8d | 1100 | Value_type value_; |
14bfc3f5 | 1101 | // Symbol size. |
ead1e424 ILT |
1102 | Size_type symsize_; |
1103 | }; | |
1104 | ||
1105 | // A struct describing a symbol defined by the linker, where the value | |
1106 | // of the symbol is defined based on an output section. This is used | |
1107 | // for symbols defined by the linker, like "_init_array_start". | |
1108 | ||
1109 | struct Define_symbol_in_section | |
1110 | { | |
1111 | // The symbol name. | |
1112 | const char* name; | |
1113 | // The name of the output section with which this symbol should be | |
1114 | // associated. If there is no output section with that name, the | |
1115 | // symbol will be defined as zero. | |
1116 | const char* output_section; | |
1117 | // The offset of the symbol within the output section. This is an | |
1118 | // offset from the start of the output section, unless start_at_end | |
1119 | // is true, in which case this is an offset from the end of the | |
1120 | // output section. | |
1121 | uint64_t value; | |
1122 | // The size of the symbol. | |
1123 | uint64_t size; | |
1124 | // The symbol type. | |
1125 | elfcpp::STT type; | |
1126 | // The symbol binding. | |
1127 | elfcpp::STB binding; | |
1128 | // The symbol visibility. | |
1129 | elfcpp::STV visibility; | |
1130 | // The rest of the st_other field. | |
1131 | unsigned char nonvis; | |
1132 | // If true, the value field is an offset from the end of the output | |
1133 | // section. | |
1134 | bool offset_is_from_end; | |
1135 | // If true, this symbol is defined only if we see a reference to it. | |
1136 | bool only_if_ref; | |
1137 | }; | |
1138 | ||
1139 | // A struct describing a symbol defined by the linker, where the value | |
1140 | // of the symbol is defined based on a segment. This is used for | |
1141 | // symbols defined by the linker, like "_end". We describe the | |
1142 | // segment with which the symbol should be associated by its | |
1143 | // characteristics. If no segment meets these characteristics, the | |
1144 | // symbol will be defined as zero. If there is more than one segment | |
1145 | // which meets these characteristics, we will use the first one. | |
1146 | ||
1147 | struct Define_symbol_in_segment | |
1148 | { | |
1149 | // The symbol name. | |
1150 | const char* name; | |
1151 | // The segment type where the symbol should be defined, typically | |
1152 | // PT_LOAD. | |
1153 | elfcpp::PT segment_type; | |
1154 | // Bitmask of segment flags which must be set. | |
1155 | elfcpp::PF segment_flags_set; | |
1156 | // Bitmask of segment flags which must be clear. | |
1157 | elfcpp::PF segment_flags_clear; | |
1158 | // The offset of the symbol within the segment. The offset is | |
1159 | // calculated from the position set by offset_base. | |
1160 | uint64_t value; | |
1161 | // The size of the symbol. | |
1162 | uint64_t size; | |
1163 | // The symbol type. | |
1164 | elfcpp::STT type; | |
1165 | // The symbol binding. | |
1166 | elfcpp::STB binding; | |
1167 | // The symbol visibility. | |
1168 | elfcpp::STV visibility; | |
1169 | // The rest of the st_other field. | |
1170 | unsigned char nonvis; | |
1171 | // The base from which we compute the offset. | |
1172 | Symbol::Segment_offset_base offset_base; | |
1173 | // If true, this symbol is defined only if we see a reference to it. | |
1174 | bool only_if_ref; | |
14bfc3f5 ILT |
1175 | }; |
1176 | ||
f6ce93d6 ILT |
1177 | // This class manages warnings. Warnings are a GNU extension. When |
1178 | // we see a section named .gnu.warning.SYM in an object file, and if | |
1179 | // we wind using the definition of SYM from that object file, then we | |
1180 | // will issue a warning for any relocation against SYM from a | |
1181 | // different object file. The text of the warning is the contents of | |
1182 | // the section. This is not precisely the definition used by the old | |
1183 | // GNU linker; the old GNU linker treated an occurrence of | |
1184 | // .gnu.warning.SYM as defining a warning symbol. A warning symbol | |
1185 | // would trigger a warning on any reference. However, it was | |
1186 | // inconsistent in that a warning in a dynamic object only triggered | |
1187 | // if there was no definition in a regular object. This linker is | |
1188 | // different in that we only issue a warning if we use the symbol | |
1189 | // definition from the same object file as the warning section. | |
1190 | ||
1191 | class Warnings | |
1192 | { | |
1193 | public: | |
1194 | Warnings() | |
1195 | : warnings_() | |
1196 | { } | |
1197 | ||
cb295612 ILT |
1198 | // Add a warning for symbol NAME in object OBJ. WARNING is the text |
1199 | // of the warning. | |
f6ce93d6 ILT |
1200 | void |
1201 | add_warning(Symbol_table* symtab, const char* name, Object* obj, | |
cb295612 | 1202 | const std::string& warning); |
f6ce93d6 ILT |
1203 | |
1204 | // For each symbol for which we should give a warning, make a note | |
1205 | // on the symbol. | |
1206 | void | |
cb295612 | 1207 | note_warnings(Symbol_table* symtab); |
f6ce93d6 | 1208 | |
75f2446e ILT |
1209 | // Issue a warning for a reference to SYM at RELINFO's location. |
1210 | template<int size, bool big_endian> | |
f6ce93d6 | 1211 | void |
75f2446e ILT |
1212 | issue_warning(const Symbol* sym, const Relocate_info<size, big_endian>*, |
1213 | size_t relnum, off_t reloffset) const; | |
f6ce93d6 ILT |
1214 | |
1215 | private: | |
1216 | Warnings(const Warnings&); | |
1217 | Warnings& operator=(const Warnings&); | |
1218 | ||
1219 | // What we need to know to get the warning text. | |
1220 | struct Warning_location | |
1221 | { | |
1222 | // The object the warning is in. | |
1223 | Object* object; | |
cb295612 | 1224 | // The warning text. |
f6ce93d6 ILT |
1225 | std::string text; |
1226 | ||
1227 | Warning_location() | |
cb295612 | 1228 | : object(NULL), text() |
f6ce93d6 ILT |
1229 | { } |
1230 | ||
1231 | void | |
cb295612 | 1232 | set(Object* o, const std::string& t) |
f6ce93d6 ILT |
1233 | { |
1234 | this->object = o; | |
cb295612 | 1235 | this->text = t; |
f6ce93d6 | 1236 | } |
f6ce93d6 ILT |
1237 | }; |
1238 | ||
1239 | // A mapping from warning symbol names (canonicalized in | |
70e654ba | 1240 | // Symbol_table's namepool_ field) to warning information. |
f6ce93d6 ILT |
1241 | typedef Unordered_map<const char*, Warning_location> Warning_table; |
1242 | ||
1243 | Warning_table warnings_; | |
1244 | }; | |
1245 | ||
14bfc3f5 ILT |
1246 | // The main linker symbol table. |
1247 | ||
bae7f79e ILT |
1248 | class Symbol_table |
1249 | { | |
1250 | public: | |
99fff23b ILT |
1251 | // The different places where a symbol definition can come from. |
1252 | enum Defined | |
1253 | { | |
1254 | // Defined in an object file--the normal case. | |
1255 | OBJECT, | |
1256 | // Defined for a COPY reloc. | |
1257 | COPY, | |
1258 | // Defined on the command line using --defsym. | |
1259 | DEFSYM, | |
1260 | // Defined (so to speak) on the command line using -u. | |
1261 | UNDEFINED, | |
1262 | // Defined in a linker script. | |
1263 | SCRIPT, | |
1264 | // Predefined by the linker. | |
1265 | PREDEFINED, | |
5146f448 CC |
1266 | // Defined by the linker during an incremental base link, but not |
1267 | // a predefined symbol (e.g., common, defined in script). | |
1268 | INCREMENTAL_BASE, | |
99fff23b ILT |
1269 | }; |
1270 | ||
fc59c572 ILT |
1271 | // The order in which we sort common symbols. |
1272 | enum Sort_commons_order | |
1273 | { | |
1274 | SORT_COMMONS_BY_SIZE_DESCENDING, | |
1275 | SORT_COMMONS_BY_ALIGNMENT_DESCENDING, | |
1276 | SORT_COMMONS_BY_ALIGNMENT_ASCENDING | |
1277 | }; | |
1278 | ||
9b547ce6 | 1279 | // COUNT is an estimate of how many symbols will be inserted in the |
6d013333 ILT |
1280 | // symbol table. It's ok to put 0 if you don't know; a correct |
1281 | // guess will just save some CPU by reducing hashtable resizes. | |
09124467 | 1282 | Symbol_table(unsigned int count, const Version_script_info& version_script); |
bae7f79e | 1283 | |
1564db8d | 1284 | ~Symbol_table(); |
bae7f79e | 1285 | |
ef15dade | 1286 | void |
2ea97941 ILT |
1287 | set_icf(Icf* icf) |
1288 | { this->icf_ = icf;} | |
ef15dade ST |
1289 | |
1290 | Icf* | |
1291 | icf() const | |
1292 | { return this->icf_; } | |
1293 | ||
1294 | // Returns true if ICF determined that this is a duplicate section. | |
1295 | bool | |
1296 | is_section_folded(Object* obj, unsigned int shndx) const; | |
1297 | ||
6d03d481 | 1298 | void |
2ea97941 ILT |
1299 | set_gc(Garbage_collection* gc) |
1300 | { this->gc_ = gc; } | |
6d03d481 ST |
1301 | |
1302 | Garbage_collection* | |
ef15dade | 1303 | gc() const |
6d03d481 ST |
1304 | { return this->gc_; } |
1305 | ||
1306 | // During garbage collection, this keeps undefined symbols. | |
1307 | void | |
88a4108b | 1308 | gc_mark_undef_symbols(Layout*); |
6d03d481 ST |
1309 | |
1310 | // During garbage collection, this ensures externally visible symbols | |
1311 | // are not treated as garbage while building shared objects. | |
1312 | void | |
1313 | gc_mark_symbol_for_shlib(Symbol* sym); | |
1314 | ||
1315 | // During garbage collection, this keeps sections that correspond to | |
1316 | // symbols seen in dynamic objects. | |
1317 | inline void | |
1318 | gc_mark_dyn_syms(Symbol* sym); | |
1319 | ||
dbe717ef | 1320 | // Add COUNT external symbols from the relocatable object RELOBJ to |
d491d34e ILT |
1321 | // the symbol table. SYMS is the symbols, SYMNDX_OFFSET is the |
1322 | // offset in the symbol table of the first symbol, SYM_NAMES is | |
1323 | // their names, SYM_NAME_SIZE is the size of SYM_NAMES. This sets | |
92de84a6 ILT |
1324 | // SYMPOINTERS to point to the symbols in the symbol table. It sets |
1325 | // *DEFINED to the number of defined symbols. | |
14bfc3f5 ILT |
1326 | template<int size, bool big_endian> |
1327 | void | |
6fa2a40b | 1328 | add_from_relobj(Sized_relobj_file<size, big_endian>* relobj, |
dbe717ef | 1329 | const unsigned char* syms, size_t count, |
d491d34e ILT |
1330 | size_t symndx_offset, const char* sym_names, |
1331 | size_t sym_name_size, | |
6fa2a40b | 1332 | typename Sized_relobj_file<size, big_endian>::Symbols*, |
92de84a6 | 1333 | size_t* defined); |
89fc3421 CC |
1334 | |
1335 | // Add one external symbol from the plugin object OBJ to the symbol table. | |
1336 | // Returns a pointer to the resolved symbol in the symbol table. | |
1337 | template<int size, bool big_endian> | |
1338 | Symbol* | |
1339 | add_from_pluginobj(Sized_pluginobj<size, big_endian>* obj, | |
1340 | const char* name, const char* ver, | |
1341 | elfcpp::Sym<size, big_endian>* sym); | |
14bfc3f5 | 1342 | |
dbe717ef ILT |
1343 | // Add COUNT dynamic symbols from the dynamic object DYNOBJ to the |
1344 | // symbol table. SYMS is the symbols. SYM_NAMES is their names. | |
1345 | // SYM_NAME_SIZE is the size of SYM_NAMES. The other parameters are | |
1346 | // symbol version data. | |
1347 | template<int size, bool big_endian> | |
1348 | void | |
1349 | add_from_dynobj(Sized_dynobj<size, big_endian>* dynobj, | |
1350 | const unsigned char* syms, size_t count, | |
1351 | const char* sym_names, size_t sym_name_size, | |
1352 | const unsigned char* versym, size_t versym_size, | |
92de84a6 | 1353 | const std::vector<const char*>*, |
6fa2a40b | 1354 | typename Sized_relobj_file<size, big_endian>::Symbols*, |
92de84a6 | 1355 | size_t* defined); |
dbe717ef | 1356 | |
cdc29364 CC |
1357 | // Add one external symbol from the incremental object OBJ to the symbol |
1358 | // table. Returns a pointer to the resolved symbol in the symbol table. | |
1359 | template<int size, bool big_endian> | |
26d3c67d | 1360 | Sized_symbol<size>* |
cdc29364 CC |
1361 | add_from_incrobj(Object* obj, const char* name, |
1362 | const char* ver, elfcpp::Sym<size, big_endian>* sym); | |
1363 | ||
ead1e424 ILT |
1364 | // Define a special symbol based on an Output_data. It is a |
1365 | // multiple definition error if this symbol is already defined. | |
14b31740 | 1366 | Symbol* |
99fff23b | 1367 | define_in_output_data(const char* name, const char* version, Defined, |
14b31740 | 1368 | Output_data*, uint64_t value, uint64_t symsize, |
ead1e424 ILT |
1369 | elfcpp::STT type, elfcpp::STB binding, |
1370 | elfcpp::STV visibility, unsigned char nonvis, | |
1371 | bool offset_is_from_end, bool only_if_ref); | |
1372 | ||
1373 | // Define a special symbol based on an Output_segment. It is a | |
1374 | // multiple definition error if this symbol is already defined. | |
14b31740 | 1375 | Symbol* |
99fff23b | 1376 | define_in_output_segment(const char* name, const char* version, Defined, |
9b07f471 | 1377 | Output_segment*, uint64_t value, uint64_t symsize, |
ead1e424 ILT |
1378 | elfcpp::STT type, elfcpp::STB binding, |
1379 | elfcpp::STV visibility, unsigned char nonvis, | |
1380 | Symbol::Segment_offset_base, bool only_if_ref); | |
1381 | ||
1382 | // Define a special symbol with a constant value. It is a multiple | |
1383 | // definition error if this symbol is already defined. | |
14b31740 | 1384 | Symbol* |
99fff23b | 1385 | define_as_constant(const char* name, const char* version, Defined, |
14b31740 ILT |
1386 | uint64_t value, uint64_t symsize, elfcpp::STT type, |
1387 | elfcpp::STB binding, elfcpp::STV visibility, | |
caa9d5d9 ILT |
1388 | unsigned char nonvis, bool only_if_ref, |
1389 | bool force_override); | |
ead1e424 | 1390 | |
a445fddf ILT |
1391 | // Define a set of symbols in output sections. If ONLY_IF_REF is |
1392 | // true, only define them if they are referenced. | |
ead1e424 | 1393 | void |
a445fddf ILT |
1394 | define_symbols(const Layout*, int count, const Define_symbol_in_section*, |
1395 | bool only_if_ref); | |
ead1e424 | 1396 | |
a445fddf ILT |
1397 | // Define a set of symbols in output segments. If ONLY_IF_REF is |
1398 | // true, only defined them if they are referenced. | |
ead1e424 | 1399 | void |
a445fddf ILT |
1400 | define_symbols(const Layout*, int count, const Define_symbol_in_segment*, |
1401 | bool only_if_ref); | |
ead1e424 | 1402 | |
46fe1623 ILT |
1403 | // Define SYM using a COPY reloc. POSD is the Output_data where the |
1404 | // symbol should be defined--typically a .dyn.bss section. VALUE is | |
1405 | // the offset within POSD. | |
1406 | template<int size> | |
1407 | void | |
9b07f471 | 1408 | define_with_copy_reloc(Sized_symbol<size>* sym, Output_data* posd, |
fe8718a4 | 1409 | typename elfcpp::Elf_types<size>::Elf_Addr); |
46fe1623 | 1410 | |
61ba1cf9 ILT |
1411 | // Look up a symbol. |
1412 | Symbol* | |
1413 | lookup(const char*, const char* version = NULL) const; | |
1414 | ||
14bfc3f5 | 1415 | // Return the real symbol associated with the forwarder symbol FROM. |
bae7f79e | 1416 | Symbol* |
c06b7b0b | 1417 | resolve_forwards(const Symbol* from) const; |
bae7f79e | 1418 | |
1564db8d ILT |
1419 | // Return the sized version of a symbol in this table. |
1420 | template<int size> | |
1421 | Sized_symbol<size>* | |
7d1a9ebb | 1422 | get_sized_symbol(Symbol*) const; |
1564db8d ILT |
1423 | |
1424 | template<int size> | |
1425 | const Sized_symbol<size>* | |
7d1a9ebb | 1426 | get_sized_symbol(const Symbol*) const; |
54dc6425 | 1427 | |
ead1e424 | 1428 | // Return the count of undefined symbols seen. |
114dfbe1 | 1429 | size_t |
ead1e424 ILT |
1430 | saw_undefined() const |
1431 | { return this->saw_undefined_; } | |
1432 | ||
1433 | // Allocate the common symbols | |
1434 | void | |
7d9e3d98 | 1435 | allocate_commons(Layout*, Mapfile*); |
ead1e424 | 1436 | |
cb295612 ILT |
1437 | // Add a warning for symbol NAME in object OBJ. WARNING is the text |
1438 | // of the warning. | |
f6ce93d6 | 1439 | void |
cb295612 ILT |
1440 | add_warning(const char* name, Object* obj, const std::string& warning) |
1441 | { this->warnings_.add_warning(this, name, obj, warning); } | |
f6ce93d6 ILT |
1442 | |
1443 | // Canonicalize a symbol name for use in the hash table. | |
1444 | const char* | |
1445 | canonicalize_name(const char* name) | |
cfd73a4e | 1446 | { return this->namepool_.add(name, true, NULL); } |
f6ce93d6 ILT |
1447 | |
1448 | // Possibly issue a warning for a reference to SYM at LOCATION which | |
1449 | // is in OBJ. | |
75f2446e | 1450 | template<int size, bool big_endian> |
f6ce93d6 | 1451 | void |
75f2446e ILT |
1452 | issue_warning(const Symbol* sym, |
1453 | const Relocate_info<size, big_endian>* relinfo, | |
1454 | size_t relnum, off_t reloffset) const | |
1455 | { this->warnings_.issue_warning(sym, relinfo, relnum, reloffset); } | |
f6ce93d6 | 1456 | |
70e654ba ILT |
1457 | // Check candidate_odr_violations_ to find symbols with the same name |
1458 | // but apparently different definitions (different source-file/line-no). | |
1459 | void | |
17a1d0a9 | 1460 | detect_odr_violations(const Task*, const char* output_file_name) const; |
70e654ba | 1461 | |
f3e9c5c5 ILT |
1462 | // Add any undefined symbols named on the command line to the symbol |
1463 | // table. | |
1464 | void | |
88a4108b | 1465 | add_undefined_symbols_from_command_line(Layout*); |
f3e9c5c5 | 1466 | |
46fe1623 ILT |
1467 | // SYM is defined using a COPY reloc. Return the dynamic object |
1468 | // where the original definition was found. | |
1469 | Dynobj* | |
1470 | get_copy_source(const Symbol* sym) const; | |
1471 | ||
a3ad94ed ILT |
1472 | // Set the dynamic symbol indexes. INDEX is the index of the first |
1473 | // global dynamic symbol. Pointers to the symbols are stored into | |
1474 | // the vector. The names are stored into the Stringpool. This | |
1475 | // returns an updated dynamic symbol index. | |
1476 | unsigned int | |
9b07f471 ILT |
1477 | set_dynsym_indexes(unsigned int index, std::vector<Symbol*>*, |
1478 | Stringpool*, Versions*); | |
a3ad94ed | 1479 | |
75f65a3e | 1480 | // Finalize the symbol table after we have set the final addresses |
c06b7b0b | 1481 | // of all the input sections. This sets the final symbol indexes, |
55a93433 ILT |
1482 | // values and adds the names to *POOL. *PLOCAL_SYMCOUNT is the |
1483 | // index of the first global symbol. OFF is the file offset of the | |
1484 | // global symbol table, DYNOFF is the offset of the globals in the | |
1485 | // dynamic symbol table, DYN_GLOBAL_INDEX is the index of the first | |
1486 | // global dynamic symbol, and DYNCOUNT is the number of global | |
1487 | // dynamic symbols. This records the parameters, and returns the | |
1488 | // new file offset. It updates *PLOCAL_SYMCOUNT if it created any | |
1489 | // local symbols. | |
75f65a3e | 1490 | off_t |
55a93433 | 1491 | finalize(off_t off, off_t dynoff, size_t dyn_global_index, size_t dyncount, |
ca09d69a | 1492 | Stringpool* pool, unsigned int* plocal_symcount); |
1564db8d | 1493 | |
cdc29364 CC |
1494 | // Set the final file offset of the symbol table. |
1495 | void | |
1496 | set_file_offset(off_t off) | |
1497 | { this->offset_ = off; } | |
1498 | ||
c0a62865 DK |
1499 | // Status code of Symbol_table::compute_final_value. |
1500 | enum Compute_final_value_status | |
1501 | { | |
1502 | // No error. | |
1503 | CFVS_OK, | |
9b547ce6 | 1504 | // Unsupported symbol section. |
c0a62865 DK |
1505 | CFVS_UNSUPPORTED_SYMBOL_SECTION, |
1506 | // No output section. | |
1507 | CFVS_NO_OUTPUT_SECTION | |
1508 | }; | |
1509 | ||
1510 | // Compute the final value of SYM and store status in location PSTATUS. | |
1511 | // During relaxation, this may be called multiple times for a symbol to | |
1512 | // compute its would-be final value in each relaxation pass. | |
1513 | ||
1514 | template<int size> | |
1515 | typename Sized_symbol<size>::Value_type | |
1516 | compute_final_value(const Sized_symbol<size>* sym, | |
1517 | Compute_final_value_status* pstatus) const; | |
1518 | ||
09ec0418 CC |
1519 | // Return the index of the first global symbol. |
1520 | unsigned int | |
1521 | first_global_index() const | |
1522 | { return this->first_global_index_; } | |
1523 | ||
1524 | // Return the total number of symbols in the symbol table. | |
1525 | unsigned int | |
1526 | output_count() const | |
1527 | { return this->output_count_; } | |
1528 | ||
61ba1cf9 ILT |
1529 | // Write out the global symbols. |
1530 | void | |
fd9d194f | 1531 | write_globals(const Stringpool*, const Stringpool*, |
d491d34e | 1532 | Output_symtab_xindex*, Output_symtab_xindex*, |
16649710 | 1533 | Output_file*) const; |
61ba1cf9 | 1534 | |
a3ad94ed ILT |
1535 | // Write out a section symbol. Return the updated offset. |
1536 | void | |
d491d34e ILT |
1537 | write_section_symbol(const Output_section*, Output_symtab_xindex*, |
1538 | Output_file*, off_t) const; | |
a3ad94ed | 1539 | |
0e70b911 CC |
1540 | // Loop over all symbols, applying the function F to each. |
1541 | template<int size, typename F> | |
1542 | void | |
1543 | for_all_symbols(F f) const | |
1544 | { | |
1545 | for (Symbol_table_type::const_iterator p = this->table_.begin(); | |
1546 | p != this->table_.end(); | |
1547 | ++p) | |
1548 | { | |
1549 | Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second); | |
1550 | f(sym); | |
1551 | } | |
1552 | } | |
1553 | ||
abaa3995 ILT |
1554 | // Dump statistical information to stderr. |
1555 | void | |
1556 | print_stats() const; | |
1557 | ||
09124467 ILT |
1558 | // Return the version script information. |
1559 | const Version_script_info& | |
1560 | version_script() const | |
1561 | { return version_script_; } | |
1562 | ||
bae7f79e ILT |
1563 | private: |
1564 | Symbol_table(const Symbol_table&); | |
1565 | Symbol_table& operator=(const Symbol_table&); | |
1566 | ||
155a0dd7 ILT |
1567 | // The type of the list of common symbols. |
1568 | typedef std::vector<Symbol*> Commons_type; | |
1569 | ||
8c500701 ILT |
1570 | // The type of the symbol hash table. |
1571 | ||
1572 | typedef std::pair<Stringpool::Key, Stringpool::Key> Symbol_table_key; | |
1573 | ||
a9bfd952 | 1574 | // The hash function. The key values are Stringpool keys. |
8c500701 ILT |
1575 | struct Symbol_table_hash |
1576 | { | |
a9bfd952 DK |
1577 | inline size_t |
1578 | operator()(const Symbol_table_key& key) const | |
1579 | { | |
1580 | return key.first ^ key.second; | |
1581 | } | |
8c500701 ILT |
1582 | }; |
1583 | ||
1584 | struct Symbol_table_eq | |
1585 | { | |
1586 | bool | |
1587 | operator()(const Symbol_table_key&, const Symbol_table_key&) const; | |
1588 | }; | |
1589 | ||
1590 | typedef Unordered_map<Symbol_table_key, Symbol*, Symbol_table_hash, | |
1591 | Symbol_table_eq> Symbol_table_type; | |
1592 | ||
71ff8986 ILT |
1593 | // A map from symbol name (as a pointer into the namepool) to all |
1594 | // the locations the symbols is (weakly) defined (and certain other | |
1595 | // conditions are met). This map will be used later to detect | |
1596 | // possible One Definition Rule (ODR) violations. | |
1597 | struct Symbol_location | |
1598 | { | |
1599 | Object* object; // Object where the symbol is defined. | |
1600 | unsigned int shndx; // Section-in-object where the symbol is defined. | |
1601 | off_t offset; // Offset-in-section where the symbol is defined. | |
1602 | bool operator==(const Symbol_location& that) const | |
1603 | { | |
1604 | return (this->object == that.object | |
1605 | && this->shndx == that.shndx | |
1606 | && this->offset == that.offset); | |
1607 | } | |
1608 | }; | |
1609 | ||
1610 | struct Symbol_location_hash | |
1611 | { | |
1612 | size_t operator()(const Symbol_location& loc) const | |
1613 | { return reinterpret_cast<uintptr_t>(loc.object) ^ loc.offset ^ loc.shndx; } | |
1614 | }; | |
1615 | ||
1616 | typedef Unordered_map<const char*, | |
1617 | Unordered_set<Symbol_location, Symbol_location_hash> > | |
1618 | Odr_map; | |
1619 | ||
14bfc3f5 ILT |
1620 | // Make FROM a forwarder symbol to TO. |
1621 | void | |
1622 | make_forwarder(Symbol* from, Symbol* to); | |
1623 | ||
1624 | // Add a symbol. | |
1625 | template<int size, bool big_endian> | |
aeddab66 | 1626 | Sized_symbol<size>* |
ca09d69a NC |
1627 | add_from_object(Object*, const char* name, Stringpool::Key name_key, |
1628 | const char* version, Stringpool::Key version_key, | |
70e654ba | 1629 | bool def, const elfcpp::Sym<size, big_endian>& sym, |
d491d34e ILT |
1630 | unsigned int st_shndx, bool is_ordinary, |
1631 | unsigned int orig_st_shndx); | |
14bfc3f5 | 1632 | |
8c500701 ILT |
1633 | // Define a default symbol. |
1634 | template<int size, bool big_endian> | |
1635 | void | |
1636 | define_default_version(Sized_symbol<size>*, bool, | |
1637 | Symbol_table_type::iterator); | |
1638 | ||
14bfc3f5 ILT |
1639 | // Resolve symbols. |
1640 | template<int size, bool big_endian> | |
aeddab66 | 1641 | void |
1564db8d ILT |
1642 | resolve(Sized_symbol<size>* to, |
1643 | const elfcpp::Sym<size, big_endian>& sym, | |
d491d34e ILT |
1644 | unsigned int st_shndx, bool is_ordinary, |
1645 | unsigned int orig_st_shndx, | |
14b31740 | 1646 | Object*, const char* version); |
14bfc3f5 | 1647 | |
1564db8d | 1648 | template<int size, bool big_endian> |
aeddab66 | 1649 | void |
95d14cd3 | 1650 | resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from); |
14b31740 | 1651 | |
0602e05a ILT |
1652 | // Record that a symbol is forced to be local by a version script or |
1653 | // by visibility. | |
55a93433 ILT |
1654 | void |
1655 | force_local(Symbol*); | |
1656 | ||
0864d551 ILT |
1657 | // Adjust NAME and *NAME_KEY for wrapping. |
1658 | const char* | |
029ba973 | 1659 | wrap_symbol(const char* name, Stringpool::Key* name_key); |
0864d551 | 1660 | |
86f2e683 ILT |
1661 | // Whether we should override a symbol, based on flags in |
1662 | // resolve.cc. | |
1663 | static bool | |
ce279a62 | 1664 | should_override(const Symbol*, unsigned int, Defined, Object*, bool*, bool*); |
86f2e683 | 1665 | |
1ae4d23b ILT |
1666 | // Report a problem in symbol resolution. |
1667 | static void | |
1668 | report_resolve_problem(bool is_error, const char* msg, const Symbol* to, | |
99fff23b | 1669 | Defined, Object* object); |
1ae4d23b | 1670 | |
aeddab66 ILT |
1671 | // Override a symbol. |
1672 | template<int size, bool big_endian> | |
1673 | void | |
1674 | override(Sized_symbol<size>* tosym, | |
1675 | const elfcpp::Sym<size, big_endian>& fromsym, | |
d491d34e | 1676 | unsigned int st_shndx, bool is_ordinary, |
aeddab66 ILT |
1677 | Object* object, const char* version); |
1678 | ||
86f2e683 ILT |
1679 | // Whether we should override a symbol with a special symbol which |
1680 | // is automatically defined by the linker. | |
1681 | static bool | |
99fff23b | 1682 | should_override_with_special(const Symbol*, Defined); |
86f2e683 | 1683 | |
aeddab66 ILT |
1684 | // Override a symbol with a special symbol. |
1685 | template<int size> | |
1686 | void | |
1687 | override_with_special(Sized_symbol<size>* tosym, | |
1688 | const Sized_symbol<size>* fromsym); | |
1689 | ||
1690 | // Record all weak alias sets for a dynamic object. | |
1691 | template<int size> | |
1692 | void | |
1693 | record_weak_aliases(std::vector<Sized_symbol<size>*>*); | |
1694 | ||
14b31740 ILT |
1695 | // Define a special symbol. |
1696 | template<int size, bool big_endian> | |
1697 | Sized_symbol<size>* | |
9b07f471 | 1698 | define_special_symbol(const char** pname, const char** pversion, |
8c500701 ILT |
1699 | bool only_if_ref, Sized_symbol<size>** poldsym, |
1700 | bool* resolve_oldsym); | |
14bfc3f5 | 1701 | |
ead1e424 ILT |
1702 | // Define a symbol in an Output_data, sized version. |
1703 | template<int size> | |
14b31740 | 1704 | Sized_symbol<size>* |
99fff23b ILT |
1705 | do_define_in_output_data(const char* name, const char* version, Defined, |
1706 | Output_data*, | |
ead1e424 ILT |
1707 | typename elfcpp::Elf_types<size>::Elf_Addr value, |
1708 | typename elfcpp::Elf_types<size>::Elf_WXword ssize, | |
1709 | elfcpp::STT type, elfcpp::STB binding, | |
1710 | elfcpp::STV visibility, unsigned char nonvis, | |
1711 | bool offset_is_from_end, bool only_if_ref); | |
1712 | ||
1713 | // Define a symbol in an Output_segment, sized version. | |
1714 | template<int size> | |
14b31740 | 1715 | Sized_symbol<size>* |
ead1e424 | 1716 | do_define_in_output_segment( |
99fff23b | 1717 | const char* name, const char* version, Defined, Output_segment* os, |
ead1e424 ILT |
1718 | typename elfcpp::Elf_types<size>::Elf_Addr value, |
1719 | typename elfcpp::Elf_types<size>::Elf_WXword ssize, | |
1720 | elfcpp::STT type, elfcpp::STB binding, | |
1721 | elfcpp::STV visibility, unsigned char nonvis, | |
1722 | Symbol::Segment_offset_base offset_base, bool only_if_ref); | |
1723 | ||
1724 | // Define a symbol as a constant, sized version. | |
1725 | template<int size> | |
14b31740 | 1726 | Sized_symbol<size>* |
ead1e424 | 1727 | do_define_as_constant( |
99fff23b | 1728 | const char* name, const char* version, Defined, |
ead1e424 ILT |
1729 | typename elfcpp::Elf_types<size>::Elf_Addr value, |
1730 | typename elfcpp::Elf_types<size>::Elf_WXword ssize, | |
1731 | elfcpp::STT type, elfcpp::STB binding, | |
1732 | elfcpp::STV visibility, unsigned char nonvis, | |
caa9d5d9 | 1733 | bool only_if_ref, bool force_override); |
ead1e424 | 1734 | |
f3e9c5c5 ILT |
1735 | // Add any undefined symbols named on the command line to the symbol |
1736 | // table, sized version. | |
1737 | template<int size> | |
1738 | void | |
88a4108b ILT |
1739 | do_add_undefined_symbols_from_command_line(Layout*); |
1740 | ||
1741 | // Add one undefined symbol. | |
1742 | template<int size> | |
1743 | void | |
1744 | add_undefined_symbol_from_command_line(const char* name); | |
f3e9c5c5 | 1745 | |
8a5e3e08 ILT |
1746 | // Types of common symbols. |
1747 | ||
1748 | enum Commons_section_type | |
1749 | { | |
1750 | COMMONS_NORMAL, | |
1751 | COMMONS_TLS, | |
1752 | COMMONS_SMALL, | |
1753 | COMMONS_LARGE | |
1754 | }; | |
1755 | ||
ead1e424 ILT |
1756 | // Allocate the common symbols, sized version. |
1757 | template<int size> | |
1758 | void | |
fc59c572 | 1759 | do_allocate_commons(Layout*, Mapfile*, Sort_commons_order); |
155a0dd7 ILT |
1760 | |
1761 | // Allocate the common symbols from one list. | |
1762 | template<int size> | |
1763 | void | |
8a5e3e08 | 1764 | do_allocate_commons_list(Layout*, Commons_section_type, Commons_type*, |
fc59c572 | 1765 | Mapfile*, Sort_commons_order); |
ead1e424 | 1766 | |
71ff8986 ILT |
1767 | // Returns all of the lines attached to LOC, not just the one the |
1768 | // instruction actually came from. This helps the ODR checker avoid | |
1769 | // false positives. | |
1770 | static std::vector<std::string> | |
1771 | linenos_from_loc(const Task* task, const Symbol_location& loc); | |
1772 | ||
70e654ba ILT |
1773 | // Implement detect_odr_violations. |
1774 | template<int size, bool big_endian> | |
1775 | void | |
1776 | sized_detect_odr_violations() const; | |
1777 | ||
75f65a3e ILT |
1778 | // Finalize symbols specialized for size. |
1779 | template<int size> | |
1780 | off_t | |
55a93433 ILT |
1781 | sized_finalize(off_t, Stringpool*, unsigned int*); |
1782 | ||
1783 | // Finalize a symbol. Return whether it should be added to the | |
1784 | // symbol table. | |
1785 | template<int size> | |
1786 | bool | |
1787 | sized_finalize_symbol(Symbol*); | |
1788 | ||
1789 | // Add a symbol the final symtab by setting its index. | |
1790 | template<int size> | |
1791 | void | |
1792 | add_to_final_symtab(Symbol*, Stringpool*, unsigned int* pindex, off_t* poff); | |
75f65a3e | 1793 | |
61ba1cf9 ILT |
1794 | // Write globals specialized for size and endianness. |
1795 | template<int size, bool big_endian> | |
1796 | void | |
fd9d194f ILT |
1797 | sized_write_globals(const Stringpool*, const Stringpool*, |
1798 | Output_symtab_xindex*, Output_symtab_xindex*, | |
1799 | Output_file*) const; | |
16649710 ILT |
1800 | |
1801 | // Write out a symbol to P. | |
1802 | template<int size, bool big_endian> | |
1803 | void | |
ab5c9e90 ILT |
1804 | sized_write_symbol(Sized_symbol<size>*, |
1805 | typename elfcpp::Elf_types<size>::Elf_Addr value, | |
ce279a62 | 1806 | unsigned int shndx, elfcpp::STB, |
7d1a9ebb | 1807 | const Stringpool*, unsigned char* p) const; |
61ba1cf9 | 1808 | |
9a2d6984 ILT |
1809 | // Possibly warn about an undefined symbol from a dynamic object. |
1810 | void | |
fd9d194f | 1811 | warn_about_undefined_dynobj_symbol(Symbol*) const; |
9a2d6984 | 1812 | |
a3ad94ed ILT |
1813 | // Write out a section symbol, specialized for size and endianness. |
1814 | template<int size, bool big_endian> | |
1815 | void | |
d491d34e ILT |
1816 | sized_write_section_symbol(const Output_section*, Output_symtab_xindex*, |
1817 | Output_file*, off_t) const; | |
a3ad94ed | 1818 | |
55a93433 ILT |
1819 | // The type of the list of symbols which have been forced local. |
1820 | typedef std::vector<Symbol*> Forced_locals; | |
1821 | ||
46fe1623 ILT |
1822 | // A map from symbols with COPY relocs to the dynamic objects where |
1823 | // they are defined. | |
1824 | typedef Unordered_map<const Symbol*, Dynobj*> Copied_symbol_dynobjs; | |
1825 | ||
ead1e424 ILT |
1826 | // We increment this every time we see a new undefined symbol, for |
1827 | // use in archive groups. | |
114dfbe1 | 1828 | size_t saw_undefined_; |
c06b7b0b ILT |
1829 | // The index of the first global symbol in the output file. |
1830 | unsigned int first_global_index_; | |
75f65a3e ILT |
1831 | // The file offset within the output symtab section where we should |
1832 | // write the table. | |
1833 | off_t offset_; | |
61ba1cf9 | 1834 | // The number of global symbols we want to write out. |
55a93433 | 1835 | unsigned int output_count_; |
16649710 ILT |
1836 | // The file offset of the global dynamic symbols, or 0 if none. |
1837 | off_t dynamic_offset_; | |
16649710 ILT |
1838 | // The index of the first global dynamic symbol. |
1839 | unsigned int first_dynamic_global_index_; | |
16649710 | 1840 | // The number of global dynamic symbols, or 0 if none. |
55a93433 | 1841 | unsigned int dynamic_count_; |
54dc6425 | 1842 | // The symbol hash table. |
14bfc3f5 | 1843 | Symbol_table_type table_; |
54dc6425 ILT |
1844 | // A pool of symbol names. This is used for all global symbols. |
1845 | // Entries in the hash table point into this pool. | |
14bfc3f5 | 1846 | Stringpool namepool_; |
14bfc3f5 | 1847 | // Forwarding symbols. |
c06b7b0b | 1848 | Unordered_map<const Symbol*, Symbol*> forwarders_; |
aeddab66 ILT |
1849 | // Weak aliases. A symbol in this list points to the next alias. |
1850 | // The aliases point to each other in a circular list. | |
1851 | Unordered_map<Symbol*, Symbol*> weak_aliases_; | |
ead1e424 ILT |
1852 | // We don't expect there to be very many common symbols, so we keep |
1853 | // a list of them. When we find a common symbol we add it to this | |
1854 | // list. It is possible that by the time we process the list the | |
1855 | // symbol is no longer a common symbol. It may also have become a | |
1856 | // forwarder. | |
1857 | Commons_type commons_; | |
155a0dd7 ILT |
1858 | // This is like the commons_ field, except that it holds TLS common |
1859 | // symbols. | |
1860 | Commons_type tls_commons_; | |
8a5e3e08 ILT |
1861 | // This is for small common symbols. |
1862 | Commons_type small_commons_; | |
1863 | // This is for large common symbols. | |
1864 | Commons_type large_commons_; | |
55a93433 ILT |
1865 | // A list of symbols which have been forced to be local. We don't |
1866 | // expect there to be very many of them, so we keep a list of them | |
1867 | // rather than walking the whole table to find them. | |
1868 | Forced_locals forced_locals_; | |
f6ce93d6 ILT |
1869 | // Manage symbol warnings. |
1870 | Warnings warnings_; | |
70e654ba ILT |
1871 | // Manage potential One Definition Rule (ODR) violations. |
1872 | Odr_map candidate_odr_violations_; | |
1873 | ||
46fe1623 ILT |
1874 | // When we emit a COPY reloc for a symbol, we define it in an |
1875 | // Output_data. When it's time to emit version information for it, | |
1876 | // we need to know the dynamic object in which we found the original | |
1877 | // definition. This maps symbols with COPY relocs to the dynamic | |
1878 | // object where they were defined. | |
1879 | Copied_symbol_dynobjs copied_symbol_dynobjs_; | |
09124467 ILT |
1880 | // Information parsed from the version script, if any. |
1881 | const Version_script_info& version_script_; | |
6d03d481 | 1882 | Garbage_collection* gc_; |
ef15dade | 1883 | Icf* icf_; |
bae7f79e ILT |
1884 | }; |
1885 | ||
1564db8d ILT |
1886 | // We inline get_sized_symbol for efficiency. |
1887 | ||
1888 | template<int size> | |
1889 | Sized_symbol<size>* | |
7d1a9ebb | 1890 | Symbol_table::get_sized_symbol(Symbol* sym) const |
1564db8d | 1891 | { |
8851ecca | 1892 | gold_assert(size == parameters->target().get_size()); |
1564db8d ILT |
1893 | return static_cast<Sized_symbol<size>*>(sym); |
1894 | } | |
1895 | ||
1896 | template<int size> | |
1897 | const Sized_symbol<size>* | |
7d1a9ebb | 1898 | Symbol_table::get_sized_symbol(const Symbol* sym) const |
1564db8d | 1899 | { |
8851ecca | 1900 | gold_assert(size == parameters->target().get_size()); |
1564db8d ILT |
1901 | return static_cast<const Sized_symbol<size>*>(sym); |
1902 | } | |
1903 | ||
bae7f79e ILT |
1904 | } // End namespace gold. |
1905 | ||
1906 | #endif // !defined(GOLD_SYMTAB_H) |