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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 | 64 | // The base class of an entry in the symbol table. The symbol table |
c9269dff | 65 | // can have a lot of entries, so we don't want this class too big. |
14bfc3f5 ILT |
66 | // Size dependent fields can be found in the template class |
67 | // Sized_symbol. Targets may support their own derived classes. | |
bae7f79e | 68 | |
bae7f79e ILT |
69 | class Symbol |
70 | { | |
71 | public: | |
ead1e424 ILT |
72 | // Because we want the class to be small, we don't use any virtual |
73 | // functions. But because symbols can be defined in different | |
74 | // places, we need to classify them. This enum is the different | |
75 | // sources of symbols we support. | |
76 | enum Source | |
77 | { | |
f6ce93d6 ILT |
78 | // Symbol defined in a relocatable or dynamic input file--this is |
79 | // the most common case. | |
ead1e424 ILT |
80 | FROM_OBJECT, |
81 | // Symbol defined in an Output_data, a special section created by | |
82 | // the target. | |
83 | IN_OUTPUT_DATA, | |
84 | // Symbol defined in an Output_segment, with no associated | |
85 | // section. | |
86 | IN_OUTPUT_SEGMENT, | |
87 | // Symbol value is constant. | |
f3e9c5c5 ILT |
88 | IS_CONSTANT, |
89 | // Symbol is undefined. | |
90 | IS_UNDEFINED | |
ead1e424 ILT |
91 | }; |
92 | ||
93 | // When the source is IN_OUTPUT_SEGMENT, we need to describe what | |
94 | // the offset means. | |
95 | enum Segment_offset_base | |
96 | { | |
97 | // From the start of the segment. | |
98 | SEGMENT_START, | |
99 | // From the end of the segment. | |
100 | SEGMENT_END, | |
101 | // From the filesz of the segment--i.e., after the loaded bytes | |
102 | // but before the bytes which are allocated but zeroed. | |
103 | SEGMENT_BSS | |
104 | }; | |
105 | ||
14bfc3f5 ILT |
106 | // Return the symbol name. |
107 | const char* | |
108 | name() const | |
109 | { return this->name_; } | |
110 | ||
a2b1aa12 ILT |
111 | // Return the (ANSI) demangled version of the name, if |
112 | // parameters.demangle() is true. Otherwise, return the name. This | |
113 | // is intended to be used only for logging errors, so it's not | |
114 | // super-efficient. | |
115 | std::string | |
116 | demangled_name() const; | |
117 | ||
14bfc3f5 ILT |
118 | // Return the symbol version. This will return NULL for an |
119 | // unversioned symbol. | |
120 | const char* | |
121 | version() const | |
122 | { return this->version_; } | |
123 | ||
32e2b61d AM |
124 | void |
125 | clear_version() | |
126 | { this->version_ = NULL; } | |
127 | ||
09124467 ILT |
128 | // Return whether this version is the default for this symbol name |
129 | // (eg, "foo@@V2" is a default version; "foo@V1" is not). Only | |
130 | // meaningful for versioned symbols. | |
131 | bool | |
132 | is_default() const | |
133 | { | |
134 | gold_assert(this->version_ != NULL); | |
135 | return this->is_def_; | |
136 | } | |
137 | ||
be3e6201 | 138 | // Set that this version is the default for this symbol name. |
09124467 | 139 | void |
be3e6201 ILT |
140 | set_is_default() |
141 | { this->is_def_ = true; } | |
09124467 | 142 | |
6d1c4efb ILT |
143 | // Return the symbol's name as name@version (or name@@version). |
144 | std::string | |
145 | versioned_name() const; | |
146 | ||
ead1e424 ILT |
147 | // Return the symbol source. |
148 | Source | |
149 | source() const | |
150 | { return this->source_; } | |
151 | ||
14bfc3f5 ILT |
152 | // Return the object with which this symbol is associated. |
153 | Object* | |
154 | object() const | |
ead1e424 | 155 | { |
a3ad94ed | 156 | gold_assert(this->source_ == FROM_OBJECT); |
ead1e424 ILT |
157 | return this->u_.from_object.object; |
158 | } | |
159 | ||
f6ce93d6 ILT |
160 | // Return the index of the section in the input relocatable or |
161 | // dynamic object file. | |
ead1e424 | 162 | unsigned int |
d491d34e | 163 | shndx(bool* is_ordinary) const |
ead1e424 | 164 | { |
a3ad94ed | 165 | gold_assert(this->source_ == FROM_OBJECT); |
d491d34e | 166 | *is_ordinary = this->is_ordinary_shndx_; |
16649710 | 167 | return this->u_.from_object.shndx; |
ead1e424 ILT |
168 | } |
169 | ||
170 | // Return the output data section with which this symbol is | |
171 | // associated, if the symbol was specially defined with respect to | |
172 | // an output data section. | |
173 | Output_data* | |
174 | output_data() const | |
175 | { | |
a3ad94ed | 176 | gold_assert(this->source_ == IN_OUTPUT_DATA); |
ead1e424 ILT |
177 | return this->u_.in_output_data.output_data; |
178 | } | |
179 | ||
180 | // If this symbol was defined with respect to an output data | |
181 | // section, return whether the value is an offset from end. | |
182 | bool | |
183 | offset_is_from_end() const | |
184 | { | |
a3ad94ed | 185 | gold_assert(this->source_ == IN_OUTPUT_DATA); |
ead1e424 ILT |
186 | return this->u_.in_output_data.offset_is_from_end; |
187 | } | |
188 | ||
189 | // Return the output segment with which this symbol is associated, | |
190 | // if the symbol was specially defined with respect to an output | |
191 | // segment. | |
192 | Output_segment* | |
193 | output_segment() const | |
194 | { | |
a3ad94ed | 195 | gold_assert(this->source_ == IN_OUTPUT_SEGMENT); |
ead1e424 ILT |
196 | return this->u_.in_output_segment.output_segment; |
197 | } | |
198 | ||
199 | // If this symbol was defined with respect to an output segment, | |
200 | // return the offset base. | |
201 | Segment_offset_base | |
202 | offset_base() const | |
203 | { | |
a3ad94ed | 204 | gold_assert(this->source_ == IN_OUTPUT_SEGMENT); |
ead1e424 ILT |
205 | return this->u_.in_output_segment.offset_base; |
206 | } | |
14bfc3f5 ILT |
207 | |
208 | // Return the symbol binding. | |
209 | elfcpp::STB | |
210 | binding() const | |
211 | { return this->binding_; } | |
212 | ||
1564db8d ILT |
213 | // Return the symbol type. |
214 | elfcpp::STT | |
215 | type() const | |
216 | { return this->type_; } | |
217 | ||
53d7974c L |
218 | // Return true for function symbol. |
219 | bool | |
220 | is_func() const | |
221 | { | |
222 | return (this->type_ == elfcpp::STT_FUNC | |
223 | || this->type_ == elfcpp::STT_GNU_IFUNC); | |
224 | } | |
225 | ||
1564db8d ILT |
226 | // Return the symbol visibility. |
227 | elfcpp::STV | |
228 | visibility() const | |
229 | { return this->visibility_; } | |
230 | ||
0602e05a ILT |
231 | // Set the visibility. |
232 | void | |
2ea97941 ILT |
233 | set_visibility(elfcpp::STV visibility) |
234 | { this->visibility_ = visibility; } | |
0602e05a ILT |
235 | |
236 | // Override symbol visibility. | |
237 | void | |
238 | override_visibility(elfcpp::STV); | |
239 | ||
ce279a62 CC |
240 | // Set whether the symbol was originally a weak undef or a regular undef |
241 | // when resolved by a dynamic def. | |
242 | inline void | |
243 | set_undef_binding(elfcpp::STB bind) | |
244 | { | |
245 | if (!this->undef_binding_set_ || this->undef_binding_weak_) | |
246 | { | |
247 | this->undef_binding_weak_ = bind == elfcpp::STB_WEAK; | |
248 | this->undef_binding_set_ = true; | |
249 | } | |
250 | } | |
251 | ||
252 | // Return TRUE if a weak undef was resolved by a dynamic def. | |
253 | inline bool | |
254 | is_undef_binding_weak() const | |
255 | { return this->undef_binding_weak_; } | |
256 | ||
1564db8d ILT |
257 | // Return the non-visibility part of the st_other field. |
258 | unsigned char | |
ead1e424 ILT |
259 | nonvis() const |
260 | { return this->nonvis_; } | |
14bfc3f5 | 261 | |
1564db8d ILT |
262 | // Return whether this symbol is a forwarder. This will never be |
263 | // true of a symbol found in the hash table, but may be true of | |
264 | // symbol pointers attached to object files. | |
265 | bool | |
266 | is_forwarder() const | |
267 | { return this->is_forwarder_; } | |
268 | ||
269 | // Mark this symbol as a forwarder. | |
270 | void | |
271 | set_forwarder() | |
272 | { this->is_forwarder_ = true; } | |
273 | ||
aeddab66 ILT |
274 | // Return whether this symbol has an alias in the weak aliases table |
275 | // in Symbol_table. | |
276 | bool | |
277 | has_alias() const | |
278 | { return this->has_alias_; } | |
279 | ||
280 | // Mark this symbol as having an alias. | |
281 | void | |
282 | set_has_alias() | |
283 | { this->has_alias_ = true; } | |
284 | ||
c06b7b0b ILT |
285 | // Return whether this symbol needs an entry in the dynamic symbol |
286 | // table. | |
287 | bool | |
288 | needs_dynsym_entry() const | |
429c1569 ILT |
289 | { |
290 | return (this->needs_dynsym_entry_ | |
8d6d383d ILT |
291 | || (this->in_reg() |
292 | && this->in_dyn() | |
293 | && this->is_externally_visible())); | |
429c1569 | 294 | } |
c06b7b0b ILT |
295 | |
296 | // Mark this symbol as needing an entry in the dynamic symbol table. | |
297 | void | |
298 | set_needs_dynsym_entry() | |
299 | { this->needs_dynsym_entry_ = true; } | |
300 | ||
436ca963 ILT |
301 | // Return whether this symbol should be added to the dynamic symbol |
302 | // table. | |
303 | bool | |
ce97fa81 | 304 | should_add_dynsym_entry(Symbol_table*) const; |
436ca963 | 305 | |
008db82e ILT |
306 | // Return whether this symbol has been seen in a regular object. |
307 | bool | |
308 | in_reg() const | |
309 | { return this->in_reg_; } | |
310 | ||
311 | // Mark this symbol as having been seen in a regular object. | |
312 | void | |
313 | set_in_reg() | |
314 | { this->in_reg_ = true; } | |
315 | ||
1ebd95fd ILT |
316 | // Return whether this symbol has been seen in a dynamic object. |
317 | bool | |
318 | in_dyn() const | |
319 | { return this->in_dyn_; } | |
320 | ||
f6ce93d6 | 321 | // Mark this symbol as having been seen in a dynamic object. |
1564db8d ILT |
322 | void |
323 | set_in_dyn() | |
324 | { this->in_dyn_ = true; } | |
325 | ||
89fc3421 CC |
326 | // Return whether this symbol has been seen in a real ELF object. |
327 | // (IN_REG will return TRUE if the symbol has been seen in either | |
328 | // a real ELF object or an object claimed by a plugin.) | |
329 | bool | |
330 | in_real_elf() const | |
331 | { return this->in_real_elf_; } | |
332 | ||
333 | // Mark this symbol as having been seen in a real ELF object. | |
334 | void | |
335 | set_in_real_elf() | |
336 | { this->in_real_elf_ = true; } | |
337 | ||
880cd20d ILT |
338 | // Return whether this symbol was defined in a section that was |
339 | // discarded from the link. This is used to control some error | |
340 | // reporting. | |
341 | bool | |
342 | is_defined_in_discarded_section() const | |
343 | { return this->is_defined_in_discarded_section_; } | |
344 | ||
345 | // Mark this symbol as having been defined in a discarded section. | |
346 | void | |
347 | set_is_defined_in_discarded_section() | |
348 | { this->is_defined_in_discarded_section_ = true; } | |
349 | ||
c06b7b0b ILT |
350 | // Return the index of this symbol in the output file symbol table. |
351 | // A value of -1U means that this symbol is not going into the | |
352 | // output file. This starts out as zero, and is set to a non-zero | |
353 | // value by Symbol_table::finalize. It is an error to ask for the | |
354 | // symbol table index before it has been set. | |
355 | unsigned int | |
356 | symtab_index() const | |
357 | { | |
a3ad94ed | 358 | gold_assert(this->symtab_index_ != 0); |
c06b7b0b ILT |
359 | return this->symtab_index_; |
360 | } | |
361 | ||
362 | // Set the index of the symbol in the output file symbol table. | |
363 | void | |
364 | set_symtab_index(unsigned int index) | |
365 | { | |
a3ad94ed | 366 | gold_assert(index != 0); |
c06b7b0b ILT |
367 | this->symtab_index_ = index; |
368 | } | |
369 | ||
a3ad94ed ILT |
370 | // Return whether this symbol already has an index in the output |
371 | // file symbol table. | |
372 | bool | |
373 | has_symtab_index() const | |
374 | { return this->symtab_index_ != 0; } | |
375 | ||
c06b7b0b ILT |
376 | // Return the index of this symbol in the dynamic symbol table. A |
377 | // value of -1U means that this symbol is not going into the dynamic | |
378 | // symbol table. This starts out as zero, and is set to a non-zero | |
379 | // during Layout::finalize. It is an error to ask for the dynamic | |
380 | // symbol table index before it has been set. | |
381 | unsigned int | |
382 | dynsym_index() const | |
383 | { | |
a3ad94ed | 384 | gold_assert(this->dynsym_index_ != 0); |
c06b7b0b ILT |
385 | return this->dynsym_index_; |
386 | } | |
387 | ||
388 | // Set the index of the symbol in the dynamic symbol table. | |
389 | void | |
390 | set_dynsym_index(unsigned int index) | |
391 | { | |
a3ad94ed | 392 | gold_assert(index != 0); |
c06b7b0b ILT |
393 | this->dynsym_index_ = index; |
394 | } | |
395 | ||
16649710 ILT |
396 | // Return whether this symbol already has an index in the dynamic |
397 | // symbol table. | |
398 | bool | |
399 | has_dynsym_index() const | |
400 | { return this->dynsym_index_ != 0; } | |
401 | ||
ead1e424 | 402 | // Return whether this symbol has an entry in the GOT section. |
07f397ab | 403 | // For a TLS symbol, this GOT entry will hold its tp-relative offset. |
92e059d8 | 404 | bool |
0a65a3a7 CC |
405 | has_got_offset(unsigned int got_type) const |
406 | { return this->got_offsets_.get_offset(got_type) != -1U; } | |
ead1e424 ILT |
407 | |
408 | // Return the offset into the GOT section of this symbol. | |
409 | unsigned int | |
0a65a3a7 | 410 | got_offset(unsigned int got_type) const |
ead1e424 | 411 | { |
2ea97941 ILT |
412 | unsigned int got_offset = this->got_offsets_.get_offset(got_type); |
413 | gold_assert(got_offset != -1U); | |
414 | return got_offset; | |
ead1e424 ILT |
415 | } |
416 | ||
417 | // Set the GOT offset of this symbol. | |
418 | void | |
2ea97941 ILT |
419 | set_got_offset(unsigned int got_type, unsigned int got_offset) |
420 | { this->got_offsets_.set_offset(got_type, got_offset); } | |
07f397ab | 421 | |
0e70b911 CC |
422 | // Return the GOT offset list. |
423 | const Got_offset_list* | |
424 | got_offset_list() const | |
425 | { return this->got_offsets_.get_list(); } | |
426 | ||
a3ad94ed | 427 | // Return whether this symbol has an entry in the PLT section. |
ead1e424 | 428 | bool |
a3ad94ed | 429 | has_plt_offset() const |
880cd20d | 430 | { return this->plt_offset_ != -1U; } |
a3ad94ed ILT |
431 | |
432 | // Return the offset into the PLT section of this symbol. | |
433 | unsigned int | |
434 | plt_offset() const | |
435 | { | |
436 | gold_assert(this->has_plt_offset()); | |
437 | return this->plt_offset_; | |
438 | } | |
439 | ||
440 | // Set the PLT offset of this symbol. | |
441 | void | |
2ea97941 | 442 | set_plt_offset(unsigned int plt_offset) |
a3ad94ed | 443 | { |
880cd20d | 444 | gold_assert(plt_offset != -1U); |
2ea97941 | 445 | this->plt_offset_ = plt_offset; |
a3ad94ed ILT |
446 | } |
447 | ||
ab5c9e90 ILT |
448 | // Return whether this dynamic symbol needs a special value in the |
449 | // dynamic symbol table. | |
450 | bool | |
451 | needs_dynsym_value() const | |
452 | { return this->needs_dynsym_value_; } | |
453 | ||
454 | // Set that this dynamic symbol needs a special value in the dynamic | |
455 | // symbol table. | |
456 | void | |
457 | set_needs_dynsym_value() | |
458 | { | |
459 | gold_assert(this->object()->is_dynamic()); | |
460 | this->needs_dynsym_value_ = true; | |
461 | } | |
462 | ||
a3ad94ed ILT |
463 | // Return true if the final value of this symbol is known at link |
464 | // time. | |
465 | bool | |
b3b74ddc | 466 | final_value_is_known() const; |
ead1e424 | 467 | |
8a5e3e08 ILT |
468 | // Return true if SHNDX represents a common symbol. This depends on |
469 | // the target. | |
470 | static bool | |
471 | is_common_shndx(unsigned int shndx); | |
472 | ||
f6ce93d6 ILT |
473 | // Return whether this is a defined symbol (not undefined or |
474 | // common). | |
475 | bool | |
476 | is_defined() const | |
477 | { | |
d491d34e ILT |
478 | bool is_ordinary; |
479 | if (this->source_ != FROM_OBJECT) | |
f3e9c5c5 | 480 | return this->source_ != IS_UNDEFINED; |
2ea97941 | 481 | unsigned int shndx = this->shndx(&is_ordinary); |
d491d34e | 482 | return (is_ordinary |
2ea97941 ILT |
483 | ? shndx != elfcpp::SHN_UNDEF |
484 | : !Symbol::is_common_shndx(shndx)); | |
a3ad94ed ILT |
485 | } |
486 | ||
14b31740 | 487 | // Return true if this symbol is from a dynamic object. |
a3ad94ed | 488 | bool |
14b31740 | 489 | is_from_dynobj() const |
a3ad94ed | 490 | { |
14b31740 | 491 | return this->source_ == FROM_OBJECT && this->object()->is_dynamic(); |
f6ce93d6 ILT |
492 | } |
493 | ||
f3a2388f CC |
494 | // Return whether this is a placeholder symbol from a plugin object. |
495 | bool | |
496 | is_placeholder() const | |
497 | { | |
498 | return this->source_ == FROM_OBJECT && this->object()->pluginobj() != NULL; | |
499 | } | |
500 | ||
ead1e424 ILT |
501 | // Return whether this is an undefined symbol. |
502 | bool | |
503 | is_undefined() const | |
504 | { | |
d491d34e | 505 | bool is_ordinary; |
f3e9c5c5 ILT |
506 | return ((this->source_ == FROM_OBJECT |
507 | && this->shndx(&is_ordinary) == elfcpp::SHN_UNDEF | |
508 | && is_ordinary) | |
509 | || this->source_ == IS_UNDEFINED); | |
ead1e424 ILT |
510 | } |
511 | ||
86925eef CC |
512 | // Return whether this is a weak undefined symbol. |
513 | bool | |
514 | is_weak_undefined() const | |
f3e9c5c5 | 515 | { return this->is_undefined() && this->binding() == elfcpp::STB_WEAK; } |
86925eef | 516 | |
86925eef CC |
517 | // Return whether this is an absolute symbol. |
518 | bool | |
519 | is_absolute() const | |
520 | { | |
d491d34e | 521 | bool is_ordinary; |
f3e9c5c5 ILT |
522 | return ((this->source_ == FROM_OBJECT |
523 | && this->shndx(&is_ordinary) == elfcpp::SHN_ABS | |
524 | && !is_ordinary) | |
525 | || this->source_ == IS_CONSTANT); | |
86925eef CC |
526 | } |
527 | ||
ead1e424 ILT |
528 | // Return whether this is a common symbol. |
529 | bool | |
530 | is_common() const | |
531 | { | |
8a5e3e08 ILT |
532 | if (this->source_ != FROM_OBJECT) |
533 | return false; | |
eda294df ILT |
534 | if (this->type_ == elfcpp::STT_COMMON) |
535 | return true; | |
d491d34e | 536 | bool is_ordinary; |
2ea97941 ILT |
537 | unsigned int shndx = this->shndx(&is_ordinary); |
538 | return !is_ordinary && Symbol::is_common_shndx(shndx); | |
ead1e424 | 539 | } |
92e059d8 | 540 | |
a6badf5a ILT |
541 | // Return whether this symbol can be seen outside this object. |
542 | bool | |
543 | is_externally_visible() const | |
544 | { | |
804eb480 ST |
545 | return ((this->visibility_ == elfcpp::STV_DEFAULT |
546 | || this->visibility_ == elfcpp::STV_PROTECTED) | |
547 | && !this->is_forced_local_); | |
a6badf5a ILT |
548 | } |
549 | ||
436ca963 ILT |
550 | // Return true if this symbol can be preempted by a definition in |
551 | // another link unit. | |
552 | bool | |
553 | is_preemptible() const | |
554 | { | |
386c048c ILT |
555 | // It doesn't make sense to ask whether a symbol defined in |
556 | // another object is preemptible. | |
557 | gold_assert(!this->is_from_dynobj()); | |
558 | ||
8fc19601 ILT |
559 | // It doesn't make sense to ask whether an undefined symbol |
560 | // is preemptible. | |
561 | gold_assert(!this->is_undefined()); | |
562 | ||
f1f70eae ILT |
563 | // If a symbol does not have default visibility, it can not be |
564 | // seen outside this link unit and therefore is not preemptible. | |
565 | if (this->visibility_ != elfcpp::STV_DEFAULT) | |
566 | return false; | |
567 | ||
568 | // If this symbol has been forced to be a local symbol by a | |
569 | // version script, then it is not visible outside this link unit | |
570 | // and is not preemptible. | |
571 | if (this->is_forced_local_) | |
572 | return false; | |
573 | ||
574 | // If we are not producing a shared library, then nothing is | |
575 | // preemptible. | |
576 | if (!parameters->options().shared()) | |
577 | return false; | |
578 | ||
579 | // If the user used -Bsymbolic, then nothing is preemptible. | |
580 | if (parameters->options().Bsymbolic()) | |
581 | return false; | |
582 | ||
583 | // If the user used -Bsymbolic-functions, then functions are not | |
584 | // preemptible. We explicitly check for not being STT_OBJECT, | |
585 | // rather than for being STT_FUNC, because that is what the GNU | |
586 | // linker does. | |
587 | if (this->type() != elfcpp::STT_OBJECT | |
588 | && parameters->options().Bsymbolic_functions()) | |
589 | return false; | |
590 | ||
591 | // Otherwise the symbol is preemptible. | |
592 | return true; | |
436ca963 ILT |
593 | } |
594 | ||
d61c6bd4 | 595 | // Return true if this symbol is a function that needs a PLT entry. |
d61c6bd4 ILT |
596 | bool |
597 | needs_plt_entry() const | |
598 | { | |
6d479619 CC |
599 | // An undefined symbol from an executable does not need a PLT entry. |
600 | if (this->is_undefined() && !parameters->options().shared()) | |
601 | return false; | |
602 | ||
7223e9ca ILT |
603 | // An STT_GNU_IFUNC symbol always needs a PLT entry, even when |
604 | // doing a static link. | |
605 | if (this->type() == elfcpp::STT_GNU_IFUNC) | |
606 | return true; | |
607 | ||
608 | // We only need a PLT entry for a function. | |
609 | if (!this->is_func()) | |
610 | return false; | |
611 | ||
612 | // If we're doing a static link or a -pie link, we don't create | |
613 | // PLT entries. | |
614 | if (parameters->doing_static_link() | |
615 | || parameters->options().pie()) | |
616 | return false; | |
617 | ||
618 | // We need a PLT entry if the function is defined in a dynamic | |
619 | // object, or is undefined when building a shared object, or if it | |
620 | // is subject to pre-emption. | |
621 | return (this->is_from_dynobj() | |
622 | || this->is_undefined() | |
623 | || this->is_preemptible()); | |
d61c6bd4 ILT |
624 | } |
625 | ||
0700cf32 ILT |
626 | // When determining whether a reference to a symbol needs a dynamic |
627 | // relocation, we need to know several things about the reference. | |
95a2c8d6 RS |
628 | // These flags may be or'ed together. 0 means that the symbol |
629 | // isn't referenced at all. | |
0700cf32 ILT |
630 | enum Reference_flags |
631 | { | |
95a2c8d6 RS |
632 | // A reference to the symbol's absolute address. This includes |
633 | // references that cause an absolute address to be stored in the GOT. | |
0700cf32 | 634 | ABSOLUTE_REF = 1, |
95a2c8d6 RS |
635 | // A reference that calculates the offset of the symbol from some |
636 | // anchor point, such as the PC or GOT. | |
637 | RELATIVE_REF = 2, | |
638 | // A TLS-related reference. | |
639 | TLS_REF = 4, | |
640 | // A reference that can always be treated as a function call. | |
641 | FUNCTION_CALL = 8 | |
0700cf32 ILT |
642 | }; |
643 | ||
d61c6bd4 ILT |
644 | // Given a direct absolute or pc-relative static relocation against |
645 | // the global symbol, this function returns whether a dynamic relocation | |
646 | // is needed. | |
647 | ||
648 | bool | |
0700cf32 | 649 | needs_dynamic_reloc(int flags) const |
d61c6bd4 | 650 | { |
8fc19601 ILT |
651 | // No dynamic relocations in a static link! |
652 | if (parameters->doing_static_link()) | |
653 | return false; | |
654 | ||
6d479619 | 655 | // A reference to an undefined symbol from an executable should be |
f3c69fca CC |
656 | // statically resolved to 0, and does not need a dynamic relocation. |
657 | // This matches gnu ld behavior. | |
6d479619 | 658 | if (this->is_undefined() && !parameters->options().shared()) |
f3c69fca CC |
659 | return false; |
660 | ||
661 | // A reference to an absolute symbol does not need a dynamic relocation. | |
662 | if (this->is_absolute()) | |
86925eef CC |
663 | return false; |
664 | ||
d61c6bd4 | 665 | // An absolute reference within a position-independent output file |
0700cf32 ILT |
666 | // will need a dynamic relocation. |
667 | if ((flags & ABSOLUTE_REF) | |
8851ecca | 668 | && parameters->options().output_is_position_independent()) |
d61c6bd4 ILT |
669 | return true; |
670 | ||
671 | // A function call that can branch to a local PLT entry does not need | |
95a2c8d6 RS |
672 | // a dynamic relocation. |
673 | if ((flags & FUNCTION_CALL) && this->has_plt_offset()) | |
d61c6bd4 ILT |
674 | return false; |
675 | ||
676 | // A reference to any PLT entry in a non-position-independent executable | |
677 | // does not need a dynamic relocation. | |
8851ecca | 678 | if (!parameters->options().output_is_position_independent() |
d61c6bd4 ILT |
679 | && this->has_plt_offset()) |
680 | return false; | |
681 | ||
682 | // A reference to a symbol defined in a dynamic object or to a | |
683 | // symbol that is preemptible will need a dynamic relocation. | |
8fc19601 ILT |
684 | if (this->is_from_dynobj() |
685 | || this->is_undefined() | |
686 | || this->is_preemptible()) | |
d61c6bd4 ILT |
687 | return true; |
688 | ||
689 | // For all other cases, return FALSE. | |
690 | return false; | |
691 | } | |
692 | ||
de4c45bd | 693 | // Whether we should use the PLT offset associated with a symbol for |
95a2c8d6 | 694 | // a relocation. FLAGS is a set of Reference_flags. |
de4c45bd ILT |
695 | |
696 | bool | |
95a2c8d6 | 697 | use_plt_offset(int flags) const |
de4c45bd ILT |
698 | { |
699 | // If the symbol doesn't have a PLT offset, then naturally we | |
700 | // don't want to use it. | |
701 | if (!this->has_plt_offset()) | |
702 | return false; | |
703 | ||
7223e9ca ILT |
704 | // For a STT_GNU_IFUNC symbol we always have to use the PLT entry. |
705 | if (this->type() == elfcpp::STT_GNU_IFUNC) | |
706 | return true; | |
707 | ||
de4c45bd ILT |
708 | // If we are going to generate a dynamic relocation, then we will |
709 | // wind up using that, so no need to use the PLT entry. | |
95a2c8d6 | 710 | if (this->needs_dynamic_reloc(flags)) |
de4c45bd ILT |
711 | return false; |
712 | ||
713 | // If the symbol is from a dynamic object, we need to use the PLT | |
714 | // entry. | |
715 | if (this->is_from_dynobj()) | |
716 | return true; | |
717 | ||
718 | // If we are generating a shared object, and this symbol is | |
719 | // undefined or preemptible, we need to use the PLT entry. | |
720 | if (parameters->options().shared() | |
721 | && (this->is_undefined() || this->is_preemptible())) | |
722 | return true; | |
723 | ||
95a2c8d6 RS |
724 | // If this is a call to a weak undefined symbol, we need to use |
725 | // the PLT entry; the symbol may be defined by a library loaded | |
726 | // at runtime. | |
727 | if ((flags & FUNCTION_CALL) && this->is_weak_undefined()) | |
de4c45bd ILT |
728 | return true; |
729 | ||
730 | // Otherwise we can use the regular definition. | |
731 | return false; | |
732 | } | |
733 | ||
d61c6bd4 ILT |
734 | // Given a direct absolute static relocation against |
735 | // the global symbol, where a dynamic relocation is needed, this | |
736 | // function returns whether a relative dynamic relocation can be used. | |
737 | // The caller must determine separately whether the static relocation | |
738 | // is compatible with a relative relocation. | |
739 | ||
740 | bool | |
741 | can_use_relative_reloc(bool is_function_call) const | |
742 | { | |
743 | // A function call that can branch to a local PLT entry can | |
744 | // use a RELATIVE relocation. | |
745 | if (is_function_call && this->has_plt_offset()) | |
746 | return true; | |
747 | ||
748 | // A reference to a symbol defined in a dynamic object or to a | |
9b547ce6 | 749 | // symbol that is preemptible can not use a RELATIVE relocation. |
8fc19601 ILT |
750 | if (this->is_from_dynobj() |
751 | || this->is_undefined() | |
752 | || this->is_preemptible()) | |
d61c6bd4 ILT |
753 | return false; |
754 | ||
755 | // For all other cases, return TRUE. | |
756 | return true; | |
757 | } | |
758 | ||
77e65537 ILT |
759 | // Return the output section where this symbol is defined. Return |
760 | // NULL if the symbol has an absolute value. | |
761 | Output_section* | |
762 | output_section() const; | |
763 | ||
764 | // Set the symbol's output section. This is used for symbols | |
765 | // defined in scripts. This should only be called after the symbol | |
766 | // table has been finalized. | |
767 | void | |
768 | set_output_section(Output_section*); | |
a445fddf | 769 | |
f6ce93d6 ILT |
770 | // Return whether there should be a warning for references to this |
771 | // symbol. | |
772 | bool | |
773 | has_warning() const | |
774 | { return this->has_warning_; } | |
775 | ||
776 | // Mark this symbol as having a warning. | |
777 | void | |
778 | set_has_warning() | |
779 | { this->has_warning_ = true; } | |
780 | ||
46fe1623 ILT |
781 | // Return whether this symbol is defined by a COPY reloc from a |
782 | // dynamic object. | |
783 | bool | |
784 | is_copied_from_dynobj() const | |
785 | { return this->is_copied_from_dynobj_; } | |
786 | ||
787 | // Mark this symbol as defined by a COPY reloc. | |
788 | void | |
789 | set_is_copied_from_dynobj() | |
790 | { this->is_copied_from_dynobj_ = true; } | |
791 | ||
55a93433 ILT |
792 | // Return whether this symbol is forced to visibility STB_LOCAL |
793 | // by a "local:" entry in a version script. | |
794 | bool | |
795 | is_forced_local() const | |
796 | { return this->is_forced_local_; } | |
797 | ||
798 | // Mark this symbol as forced to STB_LOCAL visibility. | |
799 | void | |
800 | set_is_forced_local() | |
801 | { this->is_forced_local_ = true; } | |
802 | ||
966d4097 DK |
803 | // Return true if this may need a COPY relocation. |
804 | // References from an executable object to non-function symbols | |
805 | // defined in a dynamic object may need a COPY relocation. | |
806 | bool | |
807 | may_need_copy_reloc() const | |
808 | { | |
d89051bd | 809 | return (!parameters->options().output_is_position_independent() |
966d4097 DK |
810 | && parameters->options().copyreloc() |
811 | && this->is_from_dynobj() | |
53d7974c | 812 | && !this->is_func()); |
966d4097 DK |
813 | } |
814 | ||
5146f448 CC |
815 | // Return true if this symbol was predefined by the linker. |
816 | bool | |
817 | is_predefined() const | |
818 | { return this->is_predefined_; } | |
819 | ||
14bfc3f5 ILT |
820 | protected: |
821 | // Instances of this class should always be created at a specific | |
822 | // size. | |
823 | Symbol() | |
f6ce93d6 | 824 | { memset(this, 0, sizeof *this); } |
14bfc3f5 | 825 | |
ead1e424 ILT |
826 | // Initialize the general fields. |
827 | void | |
828 | init_fields(const char* name, const char* version, | |
829 | elfcpp::STT type, elfcpp::STB binding, | |
830 | elfcpp::STV visibility, unsigned char nonvis); | |
831 | ||
d491d34e ILT |
832 | // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the |
833 | // section index, IS_ORDINARY is whether it is a normal section | |
834 | // index rather than a special code. | |
14bfc3f5 ILT |
835 | template<int size, bool big_endian> |
836 | void | |
ca09d69a | 837 | init_base_object(const char* name, const char* version, Object* object, |
f3e9c5c5 ILT |
838 | const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx, |
839 | bool is_ordinary); | |
bae7f79e | 840 | |
ead1e424 ILT |
841 | // Initialize fields for an Output_data. |
842 | void | |
75517b77 ILT |
843 | init_base_output_data(const char* name, const char* version, Output_data*, |
844 | elfcpp::STT, elfcpp::STB, elfcpp::STV, | |
5146f448 CC |
845 | unsigned char nonvis, bool offset_is_from_end, |
846 | bool is_predefined); | |
ead1e424 ILT |
847 | |
848 | // Initialize fields for an Output_segment. | |
849 | void | |
75517b77 ILT |
850 | init_base_output_segment(const char* name, const char* version, |
851 | Output_segment* os, elfcpp::STT type, | |
852 | elfcpp::STB binding, elfcpp::STV visibility, | |
853 | unsigned char nonvis, | |
5146f448 CC |
854 | Segment_offset_base offset_base, |
855 | bool is_predefined); | |
ead1e424 ILT |
856 | |
857 | // Initialize fields for a constant. | |
858 | void | |
75517b77 ILT |
859 | init_base_constant(const char* name, const char* version, elfcpp::STT type, |
860 | elfcpp::STB binding, elfcpp::STV visibility, | |
5146f448 | 861 | unsigned char nonvis, bool is_predefined); |
f3e9c5c5 ILT |
862 | |
863 | // Initialize fields for an undefined symbol. | |
864 | void | |
75517b77 ILT |
865 | init_base_undefined(const char* name, const char* version, elfcpp::STT type, |
866 | elfcpp::STB binding, elfcpp::STV visibility, | |
867 | unsigned char nonvis); | |
ead1e424 | 868 | |
1564db8d ILT |
869 | // Override existing symbol. |
870 | template<int size, bool big_endian> | |
871 | void | |
d491d34e ILT |
872 | override_base(const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx, |
873 | bool is_ordinary, Object* object, const char* version); | |
1564db8d | 874 | |
86f2e683 ILT |
875 | // Override existing symbol with a special symbol. |
876 | void | |
877 | override_base_with_special(const Symbol* from); | |
878 | ||
75517b77 ILT |
879 | // Override symbol version. |
880 | void | |
881 | override_version(const char* version); | |
882 | ||
c7912668 ILT |
883 | // Allocate a common symbol by giving it a location in the output |
884 | // file. | |
885 | void | |
886 | allocate_base_common(Output_data*); | |
887 | ||
bae7f79e | 888 | private: |
14bfc3f5 ILT |
889 | Symbol(const Symbol&); |
890 | Symbol& operator=(const Symbol&); | |
891 | ||
892 | // Symbol name (expected to point into a Stringpool). | |
893 | const char* name_; | |
894 | // Symbol version (expected to point into a Stringpool). This may | |
895 | // be NULL. | |
bae7f79e | 896 | const char* version_; |
ead1e424 ILT |
897 | |
898 | union | |
899 | { | |
900 | // This struct is used if SOURCE_ == FROM_OBJECT. | |
901 | struct | |
902 | { | |
903 | // Object in which symbol is defined, or in which it was first | |
904 | // seen. | |
905 | Object* object; | |
906 | // Section number in object_ in which symbol is defined. | |
16649710 | 907 | unsigned int shndx; |
ead1e424 ILT |
908 | } from_object; |
909 | ||
910 | // This struct is used if SOURCE_ == IN_OUTPUT_DATA. | |
911 | struct | |
912 | { | |
913 | // Output_data in which symbol is defined. Before | |
914 | // Layout::finalize the symbol's value is an offset within the | |
915 | // Output_data. | |
916 | Output_data* output_data; | |
917 | // True if the offset is from the end, false if the offset is | |
918 | // from the beginning. | |
919 | bool offset_is_from_end; | |
920 | } in_output_data; | |
921 | ||
922 | // This struct is used if SOURCE_ == IN_OUTPUT_SEGMENT. | |
923 | struct | |
924 | { | |
925 | // Output_segment in which the symbol is defined. Before | |
926 | // Layout::finalize the symbol's value is an offset. | |
927 | Output_segment* output_segment; | |
928 | // The base to use for the offset before Layout::finalize. | |
929 | Segment_offset_base offset_base; | |
930 | } in_output_segment; | |
931 | } u_; | |
932 | ||
c06b7b0b ILT |
933 | // The index of this symbol in the output file. If the symbol is |
934 | // not going into the output file, this value is -1U. This field | |
935 | // starts as always holding zero. It is set to a non-zero value by | |
936 | // Symbol_table::finalize. | |
937 | unsigned int symtab_index_; | |
938 | ||
939 | // The index of this symbol in the dynamic symbol table. If the | |
940 | // symbol is not going into the dynamic symbol table, this value is | |
941 | // -1U. This field starts as always holding zero. It is set to a | |
942 | // non-zero value during Layout::finalize. | |
943 | unsigned int dynsym_index_; | |
944 | ||
880cd20d ILT |
945 | // The GOT section entries for this symbol. A symbol may have more |
946 | // than one GOT offset (e.g., when mixing modules compiled with two | |
947 | // different TLS models), but will usually have at most one. | |
0a65a3a7 | 948 | Got_offset_list got_offsets_; |
07f397ab | 949 | |
880cd20d ILT |
950 | // If this symbol has an entry in the PLT section, then this is the |
951 | // offset from the start of the PLT section. This is -1U if there | |
952 | // is no PLT entry. | |
a3ad94ed ILT |
953 | unsigned int plt_offset_; |
954 | ||
d491d34e | 955 | // Symbol type (bits 0 to 3). |
bae7f79e | 956 | elfcpp::STT type_ : 4; |
d491d34e | 957 | // Symbol binding (bits 4 to 7). |
bae7f79e | 958 | elfcpp::STB binding_ : 4; |
d491d34e | 959 | // Symbol visibility (bits 8 to 9). |
14bfc3f5 | 960 | elfcpp::STV visibility_ : 2; |
d491d34e | 961 | // Rest of symbol st_other field (bits 10 to 15). |
ead1e424 | 962 | unsigned int nonvis_ : 6; |
d491d34e | 963 | // The type of symbol (bits 16 to 18). |
f6ce93d6 | 964 | Source source_ : 3; |
880cd20d | 965 | // True if this is the default version of the symbol (bit 19). |
1564db8d | 966 | bool is_def_ : 1; |
14bfc3f5 ILT |
967 | // True if this symbol really forwards to another symbol. This is |
968 | // used when we discover after the fact that two different entries | |
969 | // in the hash table really refer to the same symbol. This will | |
970 | // never be set for a symbol found in the hash table, but may be set | |
971 | // for a symbol found in the list of symbols attached to an Object. | |
972 | // It forwards to the symbol found in the forwarders_ map of | |
880cd20d | 973 | // Symbol_table (bit 20). |
1564db8d | 974 | bool is_forwarder_ : 1; |
aeddab66 | 975 | // True if the symbol has an alias in the weak_aliases table in |
880cd20d | 976 | // Symbol_table (bit 21). |
aeddab66 | 977 | bool has_alias_ : 1; |
d491d34e | 978 | // True if this symbol needs to be in the dynamic symbol table (bit |
880cd20d | 979 | // 22). |
c06b7b0b | 980 | bool needs_dynsym_entry_ : 1; |
880cd20d | 981 | // True if we've seen this symbol in a regular object (bit 23). |
008db82e | 982 | bool in_reg_ : 1; |
880cd20d | 983 | // True if we've seen this symbol in a dynamic object (bit 24). |
1564db8d | 984 | bool in_dyn_ : 1; |
ab5c9e90 | 985 | // True if this is a dynamic symbol which needs a special value in |
880cd20d | 986 | // the dynamic symbol table (bit 25). |
ab5c9e90 | 987 | bool needs_dynsym_value_ : 1; |
880cd20d | 988 | // True if there is a warning for this symbol (bit 26). |
f6ce93d6 | 989 | bool has_warning_ : 1; |
46fe1623 | 990 | // True if we are using a COPY reloc for this symbol, so that the |
880cd20d | 991 | // real definition lives in a dynamic object (bit 27). |
46fe1623 | 992 | bool is_copied_from_dynobj_ : 1; |
55a93433 | 993 | // True if this symbol was forced to local visibility by a version |
880cd20d | 994 | // script (bit 28). |
55a93433 | 995 | bool is_forced_local_ : 1; |
d491d34e ILT |
996 | // True if the field u_.from_object.shndx is an ordinary section |
997 | // index, not one of the special codes from SHN_LORESERVE to | |
880cd20d | 998 | // SHN_HIRESERVE (bit 29). |
d491d34e | 999 | bool is_ordinary_shndx_ : 1; |
f7c5b166 CC |
1000 | // True if we've seen this symbol in a "real" ELF object (bit 30). |
1001 | // If the symbol has been seen in a relocatable, non-IR, object file, | |
1002 | // it's known to be referenced from outside the IR. A reference from | |
1003 | // a dynamic object doesn't count as a "real" ELF, and we'll simply | |
1004 | // mark the symbol as "visible" from outside the IR. The compiler | |
1005 | // can use this distinction to guide its handling of COMDAT symbols. | |
89fc3421 | 1006 | bool in_real_elf_ : 1; |
880cd20d ILT |
1007 | // True if this symbol is defined in a section which was discarded |
1008 | // (bit 31). | |
1009 | bool is_defined_in_discarded_section_ : 1; | |
ce279a62 CC |
1010 | // True if UNDEF_BINDING_WEAK_ has been set (bit 32). |
1011 | bool undef_binding_set_ : 1; | |
1012 | // True if this symbol was a weak undef resolved by a dynamic def | |
1013 | // (bit 33). | |
1014 | bool undef_binding_weak_ : 1; | |
5146f448 CC |
1015 | // True if this symbol is a predefined linker symbol (bit 34). |
1016 | bool is_predefined_ : 1; | |
bae7f79e ILT |
1017 | }; |
1018 | ||
14bfc3f5 ILT |
1019 | // The parts of a symbol which are size specific. Using a template |
1020 | // derived class like this helps us use less space on a 32-bit system. | |
bae7f79e ILT |
1021 | |
1022 | template<int size> | |
14bfc3f5 ILT |
1023 | class Sized_symbol : public Symbol |
1024 | { | |
1025 | public: | |
1564db8d ILT |
1026 | typedef typename elfcpp::Elf_types<size>::Elf_Addr Value_type; |
1027 | typedef typename elfcpp::Elf_types<size>::Elf_WXword Size_type; | |
1028 | ||
14bfc3f5 ILT |
1029 | Sized_symbol() |
1030 | { } | |
1031 | ||
d491d34e ILT |
1032 | // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the |
1033 | // section index, IS_ORDINARY is whether it is a normal section | |
1034 | // index rather than a special code. | |
14bfc3f5 ILT |
1035 | template<bool big_endian> |
1036 | void | |
ca09d69a | 1037 | init_object(const char* name, const char* version, Object* object, |
f3e9c5c5 ILT |
1038 | const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx, |
1039 | bool is_ordinary); | |
14bfc3f5 | 1040 | |
ead1e424 ILT |
1041 | // Initialize fields for an Output_data. |
1042 | void | |
75517b77 ILT |
1043 | init_output_data(const char* name, const char* version, Output_data*, |
1044 | Value_type value, Size_type symsize, elfcpp::STT, | |
1045 | elfcpp::STB, elfcpp::STV, unsigned char nonvis, | |
5146f448 | 1046 | bool offset_is_from_end, bool is_predefined); |
ead1e424 ILT |
1047 | |
1048 | // Initialize fields for an Output_segment. | |
1049 | void | |
75517b77 ILT |
1050 | init_output_segment(const char* name, const char* version, Output_segment*, |
1051 | Value_type value, Size_type symsize, elfcpp::STT, | |
1052 | elfcpp::STB, elfcpp::STV, unsigned char nonvis, | |
5146f448 | 1053 | Segment_offset_base offset_base, bool is_predefined); |
ead1e424 ILT |
1054 | |
1055 | // Initialize fields for a constant. | |
1056 | void | |
75517b77 ILT |
1057 | init_constant(const char* name, const char* version, Value_type value, |
1058 | Size_type symsize, elfcpp::STT, elfcpp::STB, elfcpp::STV, | |
5146f448 | 1059 | unsigned char nonvis, bool is_predefined); |
f3e9c5c5 ILT |
1060 | |
1061 | // Initialize fields for an undefined symbol. | |
1062 | void | |
75517b77 ILT |
1063 | init_undefined(const char* name, const char* version, elfcpp::STT, |
1064 | elfcpp::STB, elfcpp::STV, unsigned char nonvis); | |
ead1e424 | 1065 | |
1564db8d ILT |
1066 | // Override existing symbol. |
1067 | template<bool big_endian> | |
1068 | void | |
d491d34e ILT |
1069 | override(const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx, |
1070 | bool is_ordinary, Object* object, const char* version); | |
1564db8d | 1071 | |
86f2e683 ILT |
1072 | // Override existing symbol with a special symbol. |
1073 | void | |
1074 | override_with_special(const Sized_symbol<size>*); | |
1075 | ||
1564db8d ILT |
1076 | // Return the symbol's value. |
1077 | Value_type | |
1078 | value() const | |
1079 | { return this->value_; } | |
1080 | ||
1081 | // Return the symbol's size (we can't call this 'size' because that | |
1082 | // is a template parameter). | |
1083 | Size_type | |
1084 | symsize() const | |
ead1e424 ILT |
1085 | { return this->symsize_; } |
1086 | ||
1087 | // Set the symbol size. This is used when resolving common symbols. | |
1088 | void | |
2ea97941 ILT |
1089 | set_symsize(Size_type symsize) |
1090 | { this->symsize_ = symsize; } | |
1564db8d | 1091 | |
75f65a3e ILT |
1092 | // Set the symbol value. This is called when we store the final |
1093 | // values of the symbols into the symbol table. | |
1094 | void | |
2ea97941 ILT |
1095 | set_value(Value_type value) |
1096 | { this->value_ = value; } | |
75f65a3e | 1097 | |
c7912668 ILT |
1098 | // Allocate a common symbol by giving it a location in the output |
1099 | // file. | |
1100 | void | |
1101 | allocate_common(Output_data*, Value_type value); | |
1102 | ||
14bfc3f5 ILT |
1103 | private: |
1104 | Sized_symbol(const Sized_symbol&); | |
1105 | Sized_symbol& operator=(const Sized_symbol&); | |
1106 | ||
ead1e424 ILT |
1107 | // Symbol value. Before Layout::finalize this is the offset in the |
1108 | // input section. This is set to the final value during | |
1109 | // Layout::finalize. | |
1564db8d | 1110 | Value_type value_; |
14bfc3f5 | 1111 | // Symbol size. |
ead1e424 ILT |
1112 | Size_type symsize_; |
1113 | }; | |
1114 | ||
1115 | // A struct describing a symbol defined by the linker, where the value | |
1116 | // of the symbol is defined based on an output section. This is used | |
1117 | // for symbols defined by the linker, like "_init_array_start". | |
1118 | ||
1119 | struct Define_symbol_in_section | |
1120 | { | |
1121 | // The symbol name. | |
1122 | const char* name; | |
1123 | // The name of the output section with which this symbol should be | |
1124 | // associated. If there is no output section with that name, the | |
1125 | // symbol will be defined as zero. | |
1126 | const char* output_section; | |
1127 | // The offset of the symbol within the output section. This is an | |
1128 | // offset from the start of the output section, unless start_at_end | |
1129 | // is true, in which case this is an offset from the end of the | |
1130 | // output section. | |
1131 | uint64_t value; | |
1132 | // The size of the symbol. | |
1133 | uint64_t size; | |
1134 | // The symbol type. | |
1135 | elfcpp::STT type; | |
1136 | // The symbol binding. | |
1137 | elfcpp::STB binding; | |
1138 | // The symbol visibility. | |
1139 | elfcpp::STV visibility; | |
1140 | // The rest of the st_other field. | |
1141 | unsigned char nonvis; | |
1142 | // If true, the value field is an offset from the end of the output | |
1143 | // section. | |
1144 | bool offset_is_from_end; | |
1145 | // If true, this symbol is defined only if we see a reference to it. | |
1146 | bool only_if_ref; | |
1147 | }; | |
1148 | ||
1149 | // A struct describing a symbol defined by the linker, where the value | |
1150 | // of the symbol is defined based on a segment. This is used for | |
1151 | // symbols defined by the linker, like "_end". We describe the | |
1152 | // segment with which the symbol should be associated by its | |
1153 | // characteristics. If no segment meets these characteristics, the | |
1154 | // symbol will be defined as zero. If there is more than one segment | |
1155 | // which meets these characteristics, we will use the first one. | |
1156 | ||
1157 | struct Define_symbol_in_segment | |
1158 | { | |
1159 | // The symbol name. | |
1160 | const char* name; | |
1161 | // The segment type where the symbol should be defined, typically | |
1162 | // PT_LOAD. | |
1163 | elfcpp::PT segment_type; | |
1164 | // Bitmask of segment flags which must be set. | |
1165 | elfcpp::PF segment_flags_set; | |
1166 | // Bitmask of segment flags which must be clear. | |
1167 | elfcpp::PF segment_flags_clear; | |
1168 | // The offset of the symbol within the segment. The offset is | |
1169 | // calculated from the position set by offset_base. | |
1170 | uint64_t value; | |
1171 | // The size of the symbol. | |
1172 | uint64_t size; | |
1173 | // The symbol type. | |
1174 | elfcpp::STT type; | |
1175 | // The symbol binding. | |
1176 | elfcpp::STB binding; | |
1177 | // The symbol visibility. | |
1178 | elfcpp::STV visibility; | |
1179 | // The rest of the st_other field. | |
1180 | unsigned char nonvis; | |
1181 | // The base from which we compute the offset. | |
1182 | Symbol::Segment_offset_base offset_base; | |
1183 | // If true, this symbol is defined only if we see a reference to it. | |
1184 | bool only_if_ref; | |
14bfc3f5 ILT |
1185 | }; |
1186 | ||
dc3714f3 AM |
1187 | // Specify an object/section/offset location. Used by ODR code. |
1188 | ||
1189 | struct Symbol_location | |
1190 | { | |
1191 | // Object where the symbol is defined. | |
1192 | Object* object; | |
1193 | // Section-in-object where the symbol is defined. | |
1194 | unsigned int shndx; | |
1195 | // For relocatable objects, offset-in-section where the symbol is defined. | |
1196 | // For dynamic objects, address where the symbol is defined. | |
1197 | off_t offset; | |
1198 | bool operator==(const Symbol_location& that) const | |
1199 | { | |
1200 | return (this->object == that.object | |
1201 | && this->shndx == that.shndx | |
1202 | && this->offset == that.offset); | |
1203 | } | |
1204 | }; | |
1205 | ||
f6ce93d6 ILT |
1206 | // This class manages warnings. Warnings are a GNU extension. When |
1207 | // we see a section named .gnu.warning.SYM in an object file, and if | |
1208 | // we wind using the definition of SYM from that object file, then we | |
1209 | // will issue a warning for any relocation against SYM from a | |
1210 | // different object file. The text of the warning is the contents of | |
1211 | // the section. This is not precisely the definition used by the old | |
1212 | // GNU linker; the old GNU linker treated an occurrence of | |
1213 | // .gnu.warning.SYM as defining a warning symbol. A warning symbol | |
1214 | // would trigger a warning on any reference. However, it was | |
1215 | // inconsistent in that a warning in a dynamic object only triggered | |
1216 | // if there was no definition in a regular object. This linker is | |
1217 | // different in that we only issue a warning if we use the symbol | |
1218 | // definition from the same object file as the warning section. | |
1219 | ||
1220 | class Warnings | |
1221 | { | |
1222 | public: | |
1223 | Warnings() | |
1224 | : warnings_() | |
1225 | { } | |
1226 | ||
cb295612 ILT |
1227 | // Add a warning for symbol NAME in object OBJ. WARNING is the text |
1228 | // of the warning. | |
f6ce93d6 ILT |
1229 | void |
1230 | add_warning(Symbol_table* symtab, const char* name, Object* obj, | |
cb295612 | 1231 | const std::string& warning); |
f6ce93d6 ILT |
1232 | |
1233 | // For each symbol for which we should give a warning, make a note | |
1234 | // on the symbol. | |
1235 | void | |
cb295612 | 1236 | note_warnings(Symbol_table* symtab); |
f6ce93d6 | 1237 | |
75f2446e ILT |
1238 | // Issue a warning for a reference to SYM at RELINFO's location. |
1239 | template<int size, bool big_endian> | |
f6ce93d6 | 1240 | void |
75f2446e ILT |
1241 | issue_warning(const Symbol* sym, const Relocate_info<size, big_endian>*, |
1242 | size_t relnum, off_t reloffset) const; | |
f6ce93d6 ILT |
1243 | |
1244 | private: | |
1245 | Warnings(const Warnings&); | |
1246 | Warnings& operator=(const Warnings&); | |
1247 | ||
1248 | // What we need to know to get the warning text. | |
1249 | struct Warning_location | |
1250 | { | |
1251 | // The object the warning is in. | |
1252 | Object* object; | |
cb295612 | 1253 | // The warning text. |
f6ce93d6 ILT |
1254 | std::string text; |
1255 | ||
1256 | Warning_location() | |
cb295612 | 1257 | : object(NULL), text() |
f6ce93d6 ILT |
1258 | { } |
1259 | ||
1260 | void | |
cb295612 | 1261 | set(Object* o, const std::string& t) |
f6ce93d6 ILT |
1262 | { |
1263 | this->object = o; | |
cb295612 | 1264 | this->text = t; |
f6ce93d6 | 1265 | } |
f6ce93d6 ILT |
1266 | }; |
1267 | ||
1268 | // A mapping from warning symbol names (canonicalized in | |
70e654ba | 1269 | // Symbol_table's namepool_ field) to warning information. |
f6ce93d6 ILT |
1270 | typedef Unordered_map<const char*, Warning_location> Warning_table; |
1271 | ||
1272 | Warning_table warnings_; | |
1273 | }; | |
1274 | ||
14bfc3f5 ILT |
1275 | // The main linker symbol table. |
1276 | ||
bae7f79e ILT |
1277 | class Symbol_table |
1278 | { | |
1279 | public: | |
99fff23b ILT |
1280 | // The different places where a symbol definition can come from. |
1281 | enum Defined | |
1282 | { | |
1283 | // Defined in an object file--the normal case. | |
1284 | OBJECT, | |
1285 | // Defined for a COPY reloc. | |
1286 | COPY, | |
1287 | // Defined on the command line using --defsym. | |
1288 | DEFSYM, | |
1289 | // Defined (so to speak) on the command line using -u. | |
1290 | UNDEFINED, | |
1291 | // Defined in a linker script. | |
1292 | SCRIPT, | |
1293 | // Predefined by the linker. | |
1294 | PREDEFINED, | |
5146f448 CC |
1295 | // Defined by the linker during an incremental base link, but not |
1296 | // a predefined symbol (e.g., common, defined in script). | |
1297 | INCREMENTAL_BASE, | |
99fff23b ILT |
1298 | }; |
1299 | ||
fc59c572 ILT |
1300 | // The order in which we sort common symbols. |
1301 | enum Sort_commons_order | |
1302 | { | |
1303 | SORT_COMMONS_BY_SIZE_DESCENDING, | |
1304 | SORT_COMMONS_BY_ALIGNMENT_DESCENDING, | |
1305 | SORT_COMMONS_BY_ALIGNMENT_ASCENDING | |
1306 | }; | |
1307 | ||
9b547ce6 | 1308 | // COUNT is an estimate of how many symbols will be inserted in the |
6d013333 ILT |
1309 | // symbol table. It's ok to put 0 if you don't know; a correct |
1310 | // guess will just save some CPU by reducing hashtable resizes. | |
09124467 | 1311 | Symbol_table(unsigned int count, const Version_script_info& version_script); |
bae7f79e | 1312 | |
1564db8d | 1313 | ~Symbol_table(); |
bae7f79e | 1314 | |
ef15dade | 1315 | void |
2ea97941 ILT |
1316 | set_icf(Icf* icf) |
1317 | { this->icf_ = icf;} | |
ef15dade ST |
1318 | |
1319 | Icf* | |
1320 | icf() const | |
1321 | { return this->icf_; } | |
1322 | ||
1323 | // Returns true if ICF determined that this is a duplicate section. | |
1324 | bool | |
1325 | is_section_folded(Object* obj, unsigned int shndx) const; | |
1326 | ||
6d03d481 | 1327 | void |
2ea97941 ILT |
1328 | set_gc(Garbage_collection* gc) |
1329 | { this->gc_ = gc; } | |
6d03d481 ST |
1330 | |
1331 | Garbage_collection* | |
ef15dade | 1332 | gc() const |
6d03d481 ST |
1333 | { return this->gc_; } |
1334 | ||
1335 | // During garbage collection, this keeps undefined symbols. | |
1336 | void | |
88a4108b | 1337 | gc_mark_undef_symbols(Layout*); |
6d03d481 | 1338 | |
7257cc92 | 1339 | // This tells garbage collection that this symbol is referenced. |
6d03d481 | 1340 | void |
7257cc92 | 1341 | gc_mark_symbol(Symbol* sym); |
6d03d481 ST |
1342 | |
1343 | // During garbage collection, this keeps sections that correspond to | |
1344 | // symbols seen in dynamic objects. | |
1345 | inline void | |
1346 | gc_mark_dyn_syms(Symbol* sym); | |
1347 | ||
dbe717ef | 1348 | // Add COUNT external symbols from the relocatable object RELOBJ to |
d491d34e ILT |
1349 | // the symbol table. SYMS is the symbols, SYMNDX_OFFSET is the |
1350 | // offset in the symbol table of the first symbol, SYM_NAMES is | |
1351 | // their names, SYM_NAME_SIZE is the size of SYM_NAMES. This sets | |
92de84a6 ILT |
1352 | // SYMPOINTERS to point to the symbols in the symbol table. It sets |
1353 | // *DEFINED to the number of defined symbols. | |
14bfc3f5 ILT |
1354 | template<int size, bool big_endian> |
1355 | void | |
6fa2a40b | 1356 | add_from_relobj(Sized_relobj_file<size, big_endian>* relobj, |
dbe717ef | 1357 | const unsigned char* syms, size_t count, |
d491d34e ILT |
1358 | size_t symndx_offset, const char* sym_names, |
1359 | size_t sym_name_size, | |
6fa2a40b | 1360 | typename Sized_relobj_file<size, big_endian>::Symbols*, |
92de84a6 | 1361 | size_t* defined); |
89fc3421 CC |
1362 | |
1363 | // Add one external symbol from the plugin object OBJ to the symbol table. | |
1364 | // Returns a pointer to the resolved symbol in the symbol table. | |
1365 | template<int size, bool big_endian> | |
1366 | Symbol* | |
1367 | add_from_pluginobj(Sized_pluginobj<size, big_endian>* obj, | |
1368 | const char* name, const char* ver, | |
1369 | elfcpp::Sym<size, big_endian>* sym); | |
14bfc3f5 | 1370 | |
dbe717ef ILT |
1371 | // Add COUNT dynamic symbols from the dynamic object DYNOBJ to the |
1372 | // symbol table. SYMS is the symbols. SYM_NAMES is their names. | |
1373 | // SYM_NAME_SIZE is the size of SYM_NAMES. The other parameters are | |
1374 | // symbol version data. | |
1375 | template<int size, bool big_endian> | |
1376 | void | |
1377 | add_from_dynobj(Sized_dynobj<size, big_endian>* dynobj, | |
1378 | const unsigned char* syms, size_t count, | |
1379 | const char* sym_names, size_t sym_name_size, | |
1380 | const unsigned char* versym, size_t versym_size, | |
92de84a6 | 1381 | const std::vector<const char*>*, |
6fa2a40b | 1382 | typename Sized_relobj_file<size, big_endian>::Symbols*, |
92de84a6 | 1383 | size_t* defined); |
dbe717ef | 1384 | |
cdc29364 CC |
1385 | // Add one external symbol from the incremental object OBJ to the symbol |
1386 | // table. Returns a pointer to the resolved symbol in the symbol table. | |
1387 | template<int size, bool big_endian> | |
26d3c67d | 1388 | Sized_symbol<size>* |
cdc29364 CC |
1389 | add_from_incrobj(Object* obj, const char* name, |
1390 | const char* ver, elfcpp::Sym<size, big_endian>* sym); | |
1391 | ||
ead1e424 ILT |
1392 | // Define a special symbol based on an Output_data. It is a |
1393 | // multiple definition error if this symbol is already defined. | |
14b31740 | 1394 | Symbol* |
99fff23b | 1395 | define_in_output_data(const char* name, const char* version, Defined, |
14b31740 | 1396 | Output_data*, uint64_t value, uint64_t symsize, |
ead1e424 ILT |
1397 | elfcpp::STT type, elfcpp::STB binding, |
1398 | elfcpp::STV visibility, unsigned char nonvis, | |
1399 | bool offset_is_from_end, bool only_if_ref); | |
1400 | ||
1401 | // Define a special symbol based on an Output_segment. It is a | |
1402 | // multiple definition error if this symbol is already defined. | |
14b31740 | 1403 | Symbol* |
99fff23b | 1404 | define_in_output_segment(const char* name, const char* version, Defined, |
9b07f471 | 1405 | Output_segment*, uint64_t value, uint64_t symsize, |
ead1e424 ILT |
1406 | elfcpp::STT type, elfcpp::STB binding, |
1407 | elfcpp::STV visibility, unsigned char nonvis, | |
1408 | Symbol::Segment_offset_base, bool only_if_ref); | |
1409 | ||
1410 | // Define a special symbol with a constant value. It is a multiple | |
1411 | // definition error if this symbol is already defined. | |
14b31740 | 1412 | Symbol* |
99fff23b | 1413 | define_as_constant(const char* name, const char* version, Defined, |
14b31740 ILT |
1414 | uint64_t value, uint64_t symsize, elfcpp::STT type, |
1415 | elfcpp::STB binding, elfcpp::STV visibility, | |
caa9d5d9 ILT |
1416 | unsigned char nonvis, bool only_if_ref, |
1417 | bool force_override); | |
ead1e424 | 1418 | |
a445fddf ILT |
1419 | // Define a set of symbols in output sections. If ONLY_IF_REF is |
1420 | // true, only define them if they are referenced. | |
ead1e424 | 1421 | void |
a445fddf ILT |
1422 | define_symbols(const Layout*, int count, const Define_symbol_in_section*, |
1423 | bool only_if_ref); | |
ead1e424 | 1424 | |
a445fddf ILT |
1425 | // Define a set of symbols in output segments. If ONLY_IF_REF is |
1426 | // true, only defined them if they are referenced. | |
ead1e424 | 1427 | void |
a445fddf ILT |
1428 | define_symbols(const Layout*, int count, const Define_symbol_in_segment*, |
1429 | bool only_if_ref); | |
ead1e424 | 1430 | |
46fe1623 ILT |
1431 | // Define SYM using a COPY reloc. POSD is the Output_data where the |
1432 | // symbol should be defined--typically a .dyn.bss section. VALUE is | |
1433 | // the offset within POSD. | |
1434 | template<int size> | |
1435 | void | |
9b07f471 | 1436 | define_with_copy_reloc(Sized_symbol<size>* sym, Output_data* posd, |
fe8718a4 | 1437 | typename elfcpp::Elf_types<size>::Elf_Addr); |
46fe1623 | 1438 | |
61ba1cf9 ILT |
1439 | // Look up a symbol. |
1440 | Symbol* | |
1441 | lookup(const char*, const char* version = NULL) const; | |
1442 | ||
14bfc3f5 | 1443 | // Return the real symbol associated with the forwarder symbol FROM. |
bae7f79e | 1444 | Symbol* |
c06b7b0b | 1445 | resolve_forwards(const Symbol* from) const; |
bae7f79e | 1446 | |
1564db8d ILT |
1447 | // Return the sized version of a symbol in this table. |
1448 | template<int size> | |
1449 | Sized_symbol<size>* | |
7d1a9ebb | 1450 | get_sized_symbol(Symbol*) const; |
1564db8d ILT |
1451 | |
1452 | template<int size> | |
1453 | const Sized_symbol<size>* | |
7d1a9ebb | 1454 | get_sized_symbol(const Symbol*) const; |
54dc6425 | 1455 | |
ead1e424 | 1456 | // Return the count of undefined symbols seen. |
114dfbe1 | 1457 | size_t |
ead1e424 ILT |
1458 | saw_undefined() const |
1459 | { return this->saw_undefined_; } | |
1460 | ||
1461 | // Allocate the common symbols | |
1462 | void | |
7d9e3d98 | 1463 | allocate_commons(Layout*, Mapfile*); |
ead1e424 | 1464 | |
cb295612 ILT |
1465 | // Add a warning for symbol NAME in object OBJ. WARNING is the text |
1466 | // of the warning. | |
f6ce93d6 | 1467 | void |
cb295612 ILT |
1468 | add_warning(const char* name, Object* obj, const std::string& warning) |
1469 | { this->warnings_.add_warning(this, name, obj, warning); } | |
f6ce93d6 ILT |
1470 | |
1471 | // Canonicalize a symbol name for use in the hash table. | |
1472 | const char* | |
1473 | canonicalize_name(const char* name) | |
cfd73a4e | 1474 | { return this->namepool_.add(name, true, NULL); } |
f6ce93d6 ILT |
1475 | |
1476 | // Possibly issue a warning for a reference to SYM at LOCATION which | |
1477 | // is in OBJ. | |
75f2446e | 1478 | template<int size, bool big_endian> |
f6ce93d6 | 1479 | void |
75f2446e ILT |
1480 | issue_warning(const Symbol* sym, |
1481 | const Relocate_info<size, big_endian>* relinfo, | |
1482 | size_t relnum, off_t reloffset) const | |
1483 | { this->warnings_.issue_warning(sym, relinfo, relnum, reloffset); } | |
f6ce93d6 | 1484 | |
70e654ba ILT |
1485 | // Check candidate_odr_violations_ to find symbols with the same name |
1486 | // but apparently different definitions (different source-file/line-no). | |
1487 | void | |
17a1d0a9 | 1488 | detect_odr_violations(const Task*, const char* output_file_name) const; |
70e654ba | 1489 | |
f3e9c5c5 ILT |
1490 | // Add any undefined symbols named on the command line to the symbol |
1491 | // table. | |
1492 | void | |
88a4108b | 1493 | add_undefined_symbols_from_command_line(Layout*); |
f3e9c5c5 | 1494 | |
46fe1623 ILT |
1495 | // SYM is defined using a COPY reloc. Return the dynamic object |
1496 | // where the original definition was found. | |
1497 | Dynobj* | |
1498 | get_copy_source(const Symbol* sym) const; | |
1499 | ||
a3ad94ed ILT |
1500 | // Set the dynamic symbol indexes. INDEX is the index of the first |
1501 | // global dynamic symbol. Pointers to the symbols are stored into | |
1502 | // the vector. The names are stored into the Stringpool. This | |
1503 | // returns an updated dynamic symbol index. | |
1504 | unsigned int | |
9b07f471 ILT |
1505 | set_dynsym_indexes(unsigned int index, std::vector<Symbol*>*, |
1506 | Stringpool*, Versions*); | |
a3ad94ed | 1507 | |
75f65a3e | 1508 | // Finalize the symbol table after we have set the final addresses |
c06b7b0b | 1509 | // of all the input sections. This sets the final symbol indexes, |
55a93433 ILT |
1510 | // values and adds the names to *POOL. *PLOCAL_SYMCOUNT is the |
1511 | // index of the first global symbol. OFF is the file offset of the | |
1512 | // global symbol table, DYNOFF is the offset of the globals in the | |
1513 | // dynamic symbol table, DYN_GLOBAL_INDEX is the index of the first | |
1514 | // global dynamic symbol, and DYNCOUNT is the number of global | |
1515 | // dynamic symbols. This records the parameters, and returns the | |
1516 | // new file offset. It updates *PLOCAL_SYMCOUNT if it created any | |
1517 | // local symbols. | |
75f65a3e | 1518 | off_t |
55a93433 | 1519 | finalize(off_t off, off_t dynoff, size_t dyn_global_index, size_t dyncount, |
ca09d69a | 1520 | Stringpool* pool, unsigned int* plocal_symcount); |
1564db8d | 1521 | |
cdc29364 CC |
1522 | // Set the final file offset of the symbol table. |
1523 | void | |
1524 | set_file_offset(off_t off) | |
1525 | { this->offset_ = off; } | |
1526 | ||
c0a62865 DK |
1527 | // Status code of Symbol_table::compute_final_value. |
1528 | enum Compute_final_value_status | |
1529 | { | |
1530 | // No error. | |
1531 | CFVS_OK, | |
9b547ce6 | 1532 | // Unsupported symbol section. |
c0a62865 DK |
1533 | CFVS_UNSUPPORTED_SYMBOL_SECTION, |
1534 | // No output section. | |
1535 | CFVS_NO_OUTPUT_SECTION | |
1536 | }; | |
1537 | ||
1538 | // Compute the final value of SYM and store status in location PSTATUS. | |
1539 | // During relaxation, this may be called multiple times for a symbol to | |
1540 | // compute its would-be final value in each relaxation pass. | |
1541 | ||
1542 | template<int size> | |
1543 | typename Sized_symbol<size>::Value_type | |
1544 | compute_final_value(const Sized_symbol<size>* sym, | |
1545 | Compute_final_value_status* pstatus) const; | |
1546 | ||
09ec0418 CC |
1547 | // Return the index of the first global symbol. |
1548 | unsigned int | |
1549 | first_global_index() const | |
1550 | { return this->first_global_index_; } | |
1551 | ||
1552 | // Return the total number of symbols in the symbol table. | |
1553 | unsigned int | |
1554 | output_count() const | |
1555 | { return this->output_count_; } | |
1556 | ||
61ba1cf9 ILT |
1557 | // Write out the global symbols. |
1558 | void | |
fd9d194f | 1559 | write_globals(const Stringpool*, const Stringpool*, |
d491d34e | 1560 | Output_symtab_xindex*, Output_symtab_xindex*, |
16649710 | 1561 | Output_file*) const; |
61ba1cf9 | 1562 | |
a3ad94ed ILT |
1563 | // Write out a section symbol. Return the updated offset. |
1564 | void | |
d491d34e ILT |
1565 | write_section_symbol(const Output_section*, Output_symtab_xindex*, |
1566 | Output_file*, off_t) const; | |
a3ad94ed | 1567 | |
0e70b911 CC |
1568 | // Loop over all symbols, applying the function F to each. |
1569 | template<int size, typename F> | |
1570 | void | |
1571 | for_all_symbols(F f) const | |
1572 | { | |
1573 | for (Symbol_table_type::const_iterator p = this->table_.begin(); | |
1574 | p != this->table_.end(); | |
1575 | ++p) | |
1576 | { | |
1577 | Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second); | |
1578 | f(sym); | |
1579 | } | |
1580 | } | |
1581 | ||
abaa3995 ILT |
1582 | // Dump statistical information to stderr. |
1583 | void | |
1584 | print_stats() const; | |
1585 | ||
09124467 ILT |
1586 | // Return the version script information. |
1587 | const Version_script_info& | |
1588 | version_script() const | |
1589 | { return version_script_; } | |
1590 | ||
bae7f79e ILT |
1591 | private: |
1592 | Symbol_table(const Symbol_table&); | |
1593 | Symbol_table& operator=(const Symbol_table&); | |
1594 | ||
155a0dd7 ILT |
1595 | // The type of the list of common symbols. |
1596 | typedef std::vector<Symbol*> Commons_type; | |
1597 | ||
8c500701 ILT |
1598 | // The type of the symbol hash table. |
1599 | ||
1600 | typedef std::pair<Stringpool::Key, Stringpool::Key> Symbol_table_key; | |
1601 | ||
a9bfd952 | 1602 | // The hash function. The key values are Stringpool keys. |
8c500701 ILT |
1603 | struct Symbol_table_hash |
1604 | { | |
a9bfd952 DK |
1605 | inline size_t |
1606 | operator()(const Symbol_table_key& key) const | |
1607 | { | |
1608 | return key.first ^ key.second; | |
1609 | } | |
8c500701 ILT |
1610 | }; |
1611 | ||
1612 | struct Symbol_table_eq | |
1613 | { | |
1614 | bool | |
1615 | operator()(const Symbol_table_key&, const Symbol_table_key&) const; | |
1616 | }; | |
1617 | ||
1618 | typedef Unordered_map<Symbol_table_key, Symbol*, Symbol_table_hash, | |
1619 | Symbol_table_eq> Symbol_table_type; | |
1620 | ||
71ff8986 ILT |
1621 | // A map from symbol name (as a pointer into the namepool) to all |
1622 | // the locations the symbols is (weakly) defined (and certain other | |
1623 | // conditions are met). This map will be used later to detect | |
1624 | // possible One Definition Rule (ODR) violations. | |
71ff8986 ILT |
1625 | struct Symbol_location_hash |
1626 | { | |
1627 | size_t operator()(const Symbol_location& loc) const | |
1628 | { return reinterpret_cast<uintptr_t>(loc.object) ^ loc.offset ^ loc.shndx; } | |
1629 | }; | |
1630 | ||
1631 | typedef Unordered_map<const char*, | |
1632 | Unordered_set<Symbol_location, Symbol_location_hash> > | |
1633 | Odr_map; | |
1634 | ||
14bfc3f5 ILT |
1635 | // Make FROM a forwarder symbol to TO. |
1636 | void | |
1637 | make_forwarder(Symbol* from, Symbol* to); | |
1638 | ||
1639 | // Add a symbol. | |
1640 | template<int size, bool big_endian> | |
aeddab66 | 1641 | Sized_symbol<size>* |
ca09d69a NC |
1642 | add_from_object(Object*, const char* name, Stringpool::Key name_key, |
1643 | const char* version, Stringpool::Key version_key, | |
70e654ba | 1644 | bool def, const elfcpp::Sym<size, big_endian>& sym, |
d491d34e ILT |
1645 | unsigned int st_shndx, bool is_ordinary, |
1646 | unsigned int orig_st_shndx); | |
14bfc3f5 | 1647 | |
8c500701 ILT |
1648 | // Define a default symbol. |
1649 | template<int size, bool big_endian> | |
1650 | void | |
1651 | define_default_version(Sized_symbol<size>*, bool, | |
1652 | Symbol_table_type::iterator); | |
1653 | ||
14bfc3f5 ILT |
1654 | // Resolve symbols. |
1655 | template<int size, bool big_endian> | |
aeddab66 | 1656 | void |
1564db8d ILT |
1657 | resolve(Sized_symbol<size>* to, |
1658 | const elfcpp::Sym<size, big_endian>& sym, | |
d491d34e ILT |
1659 | unsigned int st_shndx, bool is_ordinary, |
1660 | unsigned int orig_st_shndx, | |
14b31740 | 1661 | Object*, const char* version); |
14bfc3f5 | 1662 | |
1564db8d | 1663 | template<int size, bool big_endian> |
aeddab66 | 1664 | void |
95d14cd3 | 1665 | resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from); |
14b31740 | 1666 | |
0602e05a ILT |
1667 | // Record that a symbol is forced to be local by a version script or |
1668 | // by visibility. | |
55a93433 ILT |
1669 | void |
1670 | force_local(Symbol*); | |
1671 | ||
0864d551 ILT |
1672 | // Adjust NAME and *NAME_KEY for wrapping. |
1673 | const char* | |
029ba973 | 1674 | wrap_symbol(const char* name, Stringpool::Key* name_key); |
0864d551 | 1675 | |
86f2e683 ILT |
1676 | // Whether we should override a symbol, based on flags in |
1677 | // resolve.cc. | |
1678 | static bool | |
62855347 ILT |
1679 | should_override(const Symbol*, unsigned int, elfcpp::STT, Defined, |
1680 | Object*, bool*, bool*); | |
86f2e683 | 1681 | |
1ae4d23b ILT |
1682 | // Report a problem in symbol resolution. |
1683 | static void | |
1684 | report_resolve_problem(bool is_error, const char* msg, const Symbol* to, | |
99fff23b | 1685 | Defined, Object* object); |
1ae4d23b | 1686 | |
aeddab66 ILT |
1687 | // Override a symbol. |
1688 | template<int size, bool big_endian> | |
1689 | void | |
1690 | override(Sized_symbol<size>* tosym, | |
1691 | const elfcpp::Sym<size, big_endian>& fromsym, | |
d491d34e | 1692 | unsigned int st_shndx, bool is_ordinary, |
aeddab66 ILT |
1693 | Object* object, const char* version); |
1694 | ||
86f2e683 ILT |
1695 | // Whether we should override a symbol with a special symbol which |
1696 | // is automatically defined by the linker. | |
1697 | static bool | |
62855347 | 1698 | should_override_with_special(const Symbol*, elfcpp::STT, Defined); |
86f2e683 | 1699 | |
aeddab66 ILT |
1700 | // Override a symbol with a special symbol. |
1701 | template<int size> | |
1702 | void | |
1703 | override_with_special(Sized_symbol<size>* tosym, | |
1704 | const Sized_symbol<size>* fromsym); | |
1705 | ||
1706 | // Record all weak alias sets for a dynamic object. | |
1707 | template<int size> | |
1708 | void | |
1709 | record_weak_aliases(std::vector<Sized_symbol<size>*>*); | |
1710 | ||
14b31740 ILT |
1711 | // Define a special symbol. |
1712 | template<int size, bool big_endian> | |
1713 | Sized_symbol<size>* | |
9b07f471 | 1714 | define_special_symbol(const char** pname, const char** pversion, |
8c500701 ILT |
1715 | bool only_if_ref, Sized_symbol<size>** poldsym, |
1716 | bool* resolve_oldsym); | |
14bfc3f5 | 1717 | |
ead1e424 ILT |
1718 | // Define a symbol in an Output_data, sized version. |
1719 | template<int size> | |
14b31740 | 1720 | Sized_symbol<size>* |
99fff23b ILT |
1721 | do_define_in_output_data(const char* name, const char* version, Defined, |
1722 | Output_data*, | |
ead1e424 ILT |
1723 | typename elfcpp::Elf_types<size>::Elf_Addr value, |
1724 | typename elfcpp::Elf_types<size>::Elf_WXword ssize, | |
1725 | elfcpp::STT type, elfcpp::STB binding, | |
1726 | elfcpp::STV visibility, unsigned char nonvis, | |
1727 | bool offset_is_from_end, bool only_if_ref); | |
1728 | ||
1729 | // Define a symbol in an Output_segment, sized version. | |
1730 | template<int size> | |
14b31740 | 1731 | Sized_symbol<size>* |
ead1e424 | 1732 | do_define_in_output_segment( |
99fff23b | 1733 | const char* name, const char* version, Defined, Output_segment* os, |
ead1e424 ILT |
1734 | typename elfcpp::Elf_types<size>::Elf_Addr value, |
1735 | typename elfcpp::Elf_types<size>::Elf_WXword ssize, | |
1736 | elfcpp::STT type, elfcpp::STB binding, | |
1737 | elfcpp::STV visibility, unsigned char nonvis, | |
1738 | Symbol::Segment_offset_base offset_base, bool only_if_ref); | |
1739 | ||
1740 | // Define a symbol as a constant, sized version. | |
1741 | template<int size> | |
14b31740 | 1742 | Sized_symbol<size>* |
ead1e424 | 1743 | do_define_as_constant( |
99fff23b | 1744 | const char* name, const char* version, Defined, |
ead1e424 ILT |
1745 | typename elfcpp::Elf_types<size>::Elf_Addr value, |
1746 | typename elfcpp::Elf_types<size>::Elf_WXword ssize, | |
1747 | elfcpp::STT type, elfcpp::STB binding, | |
1748 | elfcpp::STV visibility, unsigned char nonvis, | |
caa9d5d9 | 1749 | bool only_if_ref, bool force_override); |
ead1e424 | 1750 | |
f3e9c5c5 ILT |
1751 | // Add any undefined symbols named on the command line to the symbol |
1752 | // table, sized version. | |
1753 | template<int size> | |
1754 | void | |
88a4108b ILT |
1755 | do_add_undefined_symbols_from_command_line(Layout*); |
1756 | ||
1757 | // Add one undefined symbol. | |
1758 | template<int size> | |
1759 | void | |
1760 | add_undefined_symbol_from_command_line(const char* name); | |
f3e9c5c5 | 1761 | |
8a5e3e08 ILT |
1762 | // Types of common symbols. |
1763 | ||
1764 | enum Commons_section_type | |
1765 | { | |
1766 | COMMONS_NORMAL, | |
1767 | COMMONS_TLS, | |
1768 | COMMONS_SMALL, | |
1769 | COMMONS_LARGE | |
1770 | }; | |
1771 | ||
ead1e424 ILT |
1772 | // Allocate the common symbols, sized version. |
1773 | template<int size> | |
1774 | void | |
fc59c572 | 1775 | do_allocate_commons(Layout*, Mapfile*, Sort_commons_order); |
155a0dd7 ILT |
1776 | |
1777 | // Allocate the common symbols from one list. | |
1778 | template<int size> | |
1779 | void | |
8a5e3e08 | 1780 | do_allocate_commons_list(Layout*, Commons_section_type, Commons_type*, |
fc59c572 | 1781 | Mapfile*, Sort_commons_order); |
ead1e424 | 1782 | |
71ff8986 ILT |
1783 | // Returns all of the lines attached to LOC, not just the one the |
1784 | // instruction actually came from. This helps the ODR checker avoid | |
1785 | // false positives. | |
1786 | static std::vector<std::string> | |
1787 | linenos_from_loc(const Task* task, const Symbol_location& loc); | |
1788 | ||
70e654ba ILT |
1789 | // Implement detect_odr_violations. |
1790 | template<int size, bool big_endian> | |
1791 | void | |
1792 | sized_detect_odr_violations() const; | |
1793 | ||
75f65a3e ILT |
1794 | // Finalize symbols specialized for size. |
1795 | template<int size> | |
1796 | off_t | |
55a93433 ILT |
1797 | sized_finalize(off_t, Stringpool*, unsigned int*); |
1798 | ||
1799 | // Finalize a symbol. Return whether it should be added to the | |
1800 | // symbol table. | |
1801 | template<int size> | |
1802 | bool | |
1803 | sized_finalize_symbol(Symbol*); | |
1804 | ||
1805 | // Add a symbol the final symtab by setting its index. | |
1806 | template<int size> | |
1807 | void | |
1808 | add_to_final_symtab(Symbol*, Stringpool*, unsigned int* pindex, off_t* poff); | |
75f65a3e | 1809 | |
61ba1cf9 ILT |
1810 | // Write globals specialized for size and endianness. |
1811 | template<int size, bool big_endian> | |
1812 | void | |
fd9d194f ILT |
1813 | sized_write_globals(const Stringpool*, const Stringpool*, |
1814 | Output_symtab_xindex*, Output_symtab_xindex*, | |
1815 | Output_file*) const; | |
16649710 ILT |
1816 | |
1817 | // Write out a symbol to P. | |
1818 | template<int size, bool big_endian> | |
1819 | void | |
ab5c9e90 ILT |
1820 | sized_write_symbol(Sized_symbol<size>*, |
1821 | typename elfcpp::Elf_types<size>::Elf_Addr value, | |
ce279a62 | 1822 | unsigned int shndx, elfcpp::STB, |
7d1a9ebb | 1823 | const Stringpool*, unsigned char* p) const; |
61ba1cf9 | 1824 | |
9a2d6984 ILT |
1825 | // Possibly warn about an undefined symbol from a dynamic object. |
1826 | void | |
fd9d194f | 1827 | warn_about_undefined_dynobj_symbol(Symbol*) const; |
9a2d6984 | 1828 | |
a3ad94ed ILT |
1829 | // Write out a section symbol, specialized for size and endianness. |
1830 | template<int size, bool big_endian> | |
1831 | void | |
d491d34e ILT |
1832 | sized_write_section_symbol(const Output_section*, Output_symtab_xindex*, |
1833 | Output_file*, off_t) const; | |
a3ad94ed | 1834 | |
55a93433 ILT |
1835 | // The type of the list of symbols which have been forced local. |
1836 | typedef std::vector<Symbol*> Forced_locals; | |
1837 | ||
46fe1623 ILT |
1838 | // A map from symbols with COPY relocs to the dynamic objects where |
1839 | // they are defined. | |
1840 | typedef Unordered_map<const Symbol*, Dynobj*> Copied_symbol_dynobjs; | |
1841 | ||
ead1e424 ILT |
1842 | // We increment this every time we see a new undefined symbol, for |
1843 | // use in archive groups. | |
114dfbe1 | 1844 | size_t saw_undefined_; |
c06b7b0b ILT |
1845 | // The index of the first global symbol in the output file. |
1846 | unsigned int first_global_index_; | |
75f65a3e ILT |
1847 | // The file offset within the output symtab section where we should |
1848 | // write the table. | |
1849 | off_t offset_; | |
61ba1cf9 | 1850 | // The number of global symbols we want to write out. |
55a93433 | 1851 | unsigned int output_count_; |
16649710 ILT |
1852 | // The file offset of the global dynamic symbols, or 0 if none. |
1853 | off_t dynamic_offset_; | |
16649710 ILT |
1854 | // The index of the first global dynamic symbol. |
1855 | unsigned int first_dynamic_global_index_; | |
16649710 | 1856 | // The number of global dynamic symbols, or 0 if none. |
55a93433 | 1857 | unsigned int dynamic_count_; |
54dc6425 | 1858 | // The symbol hash table. |
14bfc3f5 | 1859 | Symbol_table_type table_; |
54dc6425 ILT |
1860 | // A pool of symbol names. This is used for all global symbols. |
1861 | // Entries in the hash table point into this pool. | |
14bfc3f5 | 1862 | Stringpool namepool_; |
14bfc3f5 | 1863 | // Forwarding symbols. |
c06b7b0b | 1864 | Unordered_map<const Symbol*, Symbol*> forwarders_; |
aeddab66 ILT |
1865 | // Weak aliases. A symbol in this list points to the next alias. |
1866 | // The aliases point to each other in a circular list. | |
1867 | Unordered_map<Symbol*, Symbol*> weak_aliases_; | |
ead1e424 ILT |
1868 | // We don't expect there to be very many common symbols, so we keep |
1869 | // a list of them. When we find a common symbol we add it to this | |
1870 | // list. It is possible that by the time we process the list the | |
1871 | // symbol is no longer a common symbol. It may also have become a | |
1872 | // forwarder. | |
1873 | Commons_type commons_; | |
155a0dd7 ILT |
1874 | // This is like the commons_ field, except that it holds TLS common |
1875 | // symbols. | |
1876 | Commons_type tls_commons_; | |
8a5e3e08 ILT |
1877 | // This is for small common symbols. |
1878 | Commons_type small_commons_; | |
1879 | // This is for large common symbols. | |
1880 | Commons_type large_commons_; | |
55a93433 ILT |
1881 | // A list of symbols which have been forced to be local. We don't |
1882 | // expect there to be very many of them, so we keep a list of them | |
1883 | // rather than walking the whole table to find them. | |
1884 | Forced_locals forced_locals_; | |
f6ce93d6 ILT |
1885 | // Manage symbol warnings. |
1886 | Warnings warnings_; | |
70e654ba ILT |
1887 | // Manage potential One Definition Rule (ODR) violations. |
1888 | Odr_map candidate_odr_violations_; | |
1889 | ||
46fe1623 ILT |
1890 | // When we emit a COPY reloc for a symbol, we define it in an |
1891 | // Output_data. When it's time to emit version information for it, | |
1892 | // we need to know the dynamic object in which we found the original | |
1893 | // definition. This maps symbols with COPY relocs to the dynamic | |
1894 | // object where they were defined. | |
1895 | Copied_symbol_dynobjs copied_symbol_dynobjs_; | |
09124467 ILT |
1896 | // Information parsed from the version script, if any. |
1897 | const Version_script_info& version_script_; | |
6d03d481 | 1898 | Garbage_collection* gc_; |
ef15dade | 1899 | Icf* icf_; |
bae7f79e ILT |
1900 | }; |
1901 | ||
1564db8d ILT |
1902 | // We inline get_sized_symbol for efficiency. |
1903 | ||
1904 | template<int size> | |
1905 | Sized_symbol<size>* | |
7d1a9ebb | 1906 | Symbol_table::get_sized_symbol(Symbol* sym) const |
1564db8d | 1907 | { |
8851ecca | 1908 | gold_assert(size == parameters->target().get_size()); |
1564db8d ILT |
1909 | return static_cast<Sized_symbol<size>*>(sym); |
1910 | } | |
1911 | ||
1912 | template<int size> | |
1913 | const Sized_symbol<size>* | |
7d1a9ebb | 1914 | Symbol_table::get_sized_symbol(const Symbol* sym) const |
1564db8d | 1915 | { |
8851ecca | 1916 | gold_assert(size == parameters->target().get_size()); |
1564db8d ILT |
1917 | return static_cast<const Sized_symbol<size>*>(sym); |
1918 | } | |
1919 | ||
bae7f79e ILT |
1920 | } // End namespace gold. |
1921 | ||
1922 | #endif // !defined(GOLD_SYMTAB_H) |