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bae7f79e ILT |
1 | // symtab.h -- the gold symbol table -*- C++ -*- |
2 | ||
880cd20d | 3 | // Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. |
6cb15b7f ILT |
4 | // Written by Ian Lance Taylor <iant@google.com>. |
5 | ||
6 | // This file is part of gold. | |
7 | ||
8 | // This program is free software; you can redistribute it and/or modify | |
9 | // it under the terms of the GNU General Public License as published by | |
10 | // the Free Software Foundation; either version 3 of the License, or | |
11 | // (at your option) any later version. | |
12 | ||
13 | // This program is distributed in the hope that it will be useful, | |
14 | // but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | // GNU General Public License for more details. | |
17 | ||
18 | // You should have received a copy of the GNU General Public License | |
19 | // along with this program; if not, write to the Free Software | |
20 | // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, | |
21 | // MA 02110-1301, USA. | |
22 | ||
bae7f79e ILT |
23 | // Symbol_table |
24 | // The symbol table. | |
25 | ||
f345227a ST |
26 | #ifndef GOLD_SYMTAB_H |
27 | #define GOLD_SYMTAB_H | |
28 | ||
bae7f79e ILT |
29 | #include <string> |
30 | #include <utility> | |
ead1e424 | 31 | #include <vector> |
bae7f79e ILT |
32 | |
33 | #include "elfcpp.h" | |
7e1edb90 | 34 | #include "parameters.h" |
14bfc3f5 | 35 | #include "stringpool.h" |
f6ce93d6 | 36 | #include "object.h" |
bae7f79e | 37 | |
bae7f79e ILT |
38 | namespace gold |
39 | { | |
40 | ||
7d9e3d98 | 41 | class Mapfile; |
14bfc3f5 | 42 | class Object; |
f6ce93d6 | 43 | class Relobj; |
dbe717ef ILT |
44 | template<int size, bool big_endian> |
45 | class Sized_relobj; | |
89fc3421 CC |
46 | template<int size, bool big_endian> |
47 | class Sized_pluginobj; | |
f6ce93d6 | 48 | class Dynobj; |
dbe717ef ILT |
49 | template<int size, bool big_endian> |
50 | class Sized_dynobj; | |
14b31740 | 51 | class Versions; |
09124467 | 52 | class Version_script_info; |
9a2d6984 | 53 | class Input_objects; |
ead1e424 | 54 | class Output_data; |
a3ad94ed | 55 | class Output_section; |
ead1e424 | 56 | class Output_segment; |
61ba1cf9 | 57 | class Output_file; |
d491d34e | 58 | class Output_symtab_xindex; |
6d03d481 | 59 | class Garbage_collection; |
ef15dade | 60 | class Icf; |
14bfc3f5 | 61 | |
14bfc3f5 ILT |
62 | // The base class of an entry in the symbol table. The symbol table |
63 | // can have a lot of entries, so we don't want this class to big. | |
64 | // Size dependent fields can be found in the template class | |
65 | // Sized_symbol. Targets may support their own derived classes. | |
bae7f79e | 66 | |
bae7f79e ILT |
67 | class Symbol |
68 | { | |
69 | public: | |
ead1e424 ILT |
70 | // Because we want the class to be small, we don't use any virtual |
71 | // functions. But because symbols can be defined in different | |
72 | // places, we need to classify them. This enum is the different | |
73 | // sources of symbols we support. | |
74 | enum Source | |
75 | { | |
f6ce93d6 ILT |
76 | // Symbol defined in a relocatable or dynamic input file--this is |
77 | // the most common case. | |
ead1e424 ILT |
78 | FROM_OBJECT, |
79 | // Symbol defined in an Output_data, a special section created by | |
80 | // the target. | |
81 | IN_OUTPUT_DATA, | |
82 | // Symbol defined in an Output_segment, with no associated | |
83 | // section. | |
84 | IN_OUTPUT_SEGMENT, | |
85 | // Symbol value is constant. | |
f3e9c5c5 ILT |
86 | IS_CONSTANT, |
87 | // Symbol is undefined. | |
88 | IS_UNDEFINED | |
ead1e424 ILT |
89 | }; |
90 | ||
91 | // When the source is IN_OUTPUT_SEGMENT, we need to describe what | |
92 | // the offset means. | |
93 | enum Segment_offset_base | |
94 | { | |
95 | // From the start of the segment. | |
96 | SEGMENT_START, | |
97 | // From the end of the segment. | |
98 | SEGMENT_END, | |
99 | // From the filesz of the segment--i.e., after the loaded bytes | |
100 | // but before the bytes which are allocated but zeroed. | |
101 | SEGMENT_BSS | |
102 | }; | |
103 | ||
14bfc3f5 ILT |
104 | // Return the symbol name. |
105 | const char* | |
106 | name() const | |
107 | { return this->name_; } | |
108 | ||
a2b1aa12 ILT |
109 | // Return the (ANSI) demangled version of the name, if |
110 | // parameters.demangle() is true. Otherwise, return the name. This | |
111 | // is intended to be used only for logging errors, so it's not | |
112 | // super-efficient. | |
113 | std::string | |
114 | demangled_name() const; | |
115 | ||
14bfc3f5 ILT |
116 | // Return the symbol version. This will return NULL for an |
117 | // unversioned symbol. | |
118 | const char* | |
119 | version() const | |
120 | { return this->version_; } | |
121 | ||
09124467 ILT |
122 | // Return whether this version is the default for this symbol name |
123 | // (eg, "foo@@V2" is a default version; "foo@V1" is not). Only | |
124 | // meaningful for versioned symbols. | |
125 | bool | |
126 | is_default() const | |
127 | { | |
128 | gold_assert(this->version_ != NULL); | |
129 | return this->is_def_; | |
130 | } | |
131 | ||
be3e6201 | 132 | // Set that this version is the default for this symbol name. |
09124467 | 133 | void |
be3e6201 ILT |
134 | set_is_default() |
135 | { this->is_def_ = true; } | |
09124467 | 136 | |
ead1e424 ILT |
137 | // Return the symbol source. |
138 | Source | |
139 | source() const | |
140 | { return this->source_; } | |
141 | ||
14bfc3f5 ILT |
142 | // Return the object with which this symbol is associated. |
143 | Object* | |
144 | object() const | |
ead1e424 | 145 | { |
a3ad94ed | 146 | gold_assert(this->source_ == FROM_OBJECT); |
ead1e424 ILT |
147 | return this->u_.from_object.object; |
148 | } | |
149 | ||
f6ce93d6 ILT |
150 | // Return the index of the section in the input relocatable or |
151 | // dynamic object file. | |
ead1e424 | 152 | unsigned int |
d491d34e | 153 | shndx(bool* is_ordinary) const |
ead1e424 | 154 | { |
a3ad94ed | 155 | gold_assert(this->source_ == FROM_OBJECT); |
d491d34e | 156 | *is_ordinary = this->is_ordinary_shndx_; |
16649710 | 157 | return this->u_.from_object.shndx; |
ead1e424 ILT |
158 | } |
159 | ||
160 | // Return the output data section with which this symbol is | |
161 | // associated, if the symbol was specially defined with respect to | |
162 | // an output data section. | |
163 | Output_data* | |
164 | output_data() const | |
165 | { | |
a3ad94ed | 166 | gold_assert(this->source_ == IN_OUTPUT_DATA); |
ead1e424 ILT |
167 | return this->u_.in_output_data.output_data; |
168 | } | |
169 | ||
170 | // If this symbol was defined with respect to an output data | |
171 | // section, return whether the value is an offset from end. | |
172 | bool | |
173 | offset_is_from_end() const | |
174 | { | |
a3ad94ed | 175 | gold_assert(this->source_ == IN_OUTPUT_DATA); |
ead1e424 ILT |
176 | return this->u_.in_output_data.offset_is_from_end; |
177 | } | |
178 | ||
179 | // Return the output segment with which this symbol is associated, | |
180 | // if the symbol was specially defined with respect to an output | |
181 | // segment. | |
182 | Output_segment* | |
183 | output_segment() const | |
184 | { | |
a3ad94ed | 185 | gold_assert(this->source_ == IN_OUTPUT_SEGMENT); |
ead1e424 ILT |
186 | return this->u_.in_output_segment.output_segment; |
187 | } | |
188 | ||
189 | // If this symbol was defined with respect to an output segment, | |
190 | // return the offset base. | |
191 | Segment_offset_base | |
192 | offset_base() const | |
193 | { | |
a3ad94ed | 194 | gold_assert(this->source_ == IN_OUTPUT_SEGMENT); |
ead1e424 ILT |
195 | return this->u_.in_output_segment.offset_base; |
196 | } | |
14bfc3f5 ILT |
197 | |
198 | // Return the symbol binding. | |
199 | elfcpp::STB | |
200 | binding() const | |
201 | { return this->binding_; } | |
202 | ||
1564db8d ILT |
203 | // Return the symbol type. |
204 | elfcpp::STT | |
205 | type() const | |
206 | { return this->type_; } | |
207 | ||
53d7974c L |
208 | // Return true for function symbol. |
209 | bool | |
210 | is_func() const | |
211 | { | |
212 | return (this->type_ == elfcpp::STT_FUNC | |
213 | || this->type_ == elfcpp::STT_GNU_IFUNC); | |
214 | } | |
215 | ||
1564db8d ILT |
216 | // Return the symbol visibility. |
217 | elfcpp::STV | |
218 | visibility() const | |
219 | { return this->visibility_; } | |
220 | ||
0602e05a ILT |
221 | // Set the visibility. |
222 | void | |
2ea97941 ILT |
223 | set_visibility(elfcpp::STV visibility) |
224 | { this->visibility_ = visibility; } | |
0602e05a ILT |
225 | |
226 | // Override symbol visibility. | |
227 | void | |
228 | override_visibility(elfcpp::STV); | |
229 | ||
1564db8d ILT |
230 | // Return the non-visibility part of the st_other field. |
231 | unsigned char | |
ead1e424 ILT |
232 | nonvis() const |
233 | { return this->nonvis_; } | |
14bfc3f5 | 234 | |
1564db8d ILT |
235 | // Return whether this symbol is a forwarder. This will never be |
236 | // true of a symbol found in the hash table, but may be true of | |
237 | // symbol pointers attached to object files. | |
238 | bool | |
239 | is_forwarder() const | |
240 | { return this->is_forwarder_; } | |
241 | ||
242 | // Mark this symbol as a forwarder. | |
243 | void | |
244 | set_forwarder() | |
245 | { this->is_forwarder_ = true; } | |
246 | ||
aeddab66 ILT |
247 | // Return whether this symbol has an alias in the weak aliases table |
248 | // in Symbol_table. | |
249 | bool | |
250 | has_alias() const | |
251 | { return this->has_alias_; } | |
252 | ||
253 | // Mark this symbol as having an alias. | |
254 | void | |
255 | set_has_alias() | |
256 | { this->has_alias_ = true; } | |
257 | ||
c06b7b0b ILT |
258 | // Return whether this symbol needs an entry in the dynamic symbol |
259 | // table. | |
260 | bool | |
261 | needs_dynsym_entry() const | |
429c1569 ILT |
262 | { |
263 | return (this->needs_dynsym_entry_ | |
8d6d383d ILT |
264 | || (this->in_reg() |
265 | && this->in_dyn() | |
266 | && this->is_externally_visible())); | |
429c1569 | 267 | } |
c06b7b0b ILT |
268 | |
269 | // Mark this symbol as needing an entry in the dynamic symbol table. | |
270 | void | |
271 | set_needs_dynsym_entry() | |
272 | { this->needs_dynsym_entry_ = true; } | |
273 | ||
436ca963 ILT |
274 | // Return whether this symbol should be added to the dynamic symbol |
275 | // table. | |
276 | bool | |
ce97fa81 | 277 | should_add_dynsym_entry(Symbol_table*) const; |
436ca963 | 278 | |
008db82e ILT |
279 | // Return whether this symbol has been seen in a regular object. |
280 | bool | |
281 | in_reg() const | |
282 | { return this->in_reg_; } | |
283 | ||
284 | // Mark this symbol as having been seen in a regular object. | |
285 | void | |
286 | set_in_reg() | |
287 | { this->in_reg_ = true; } | |
288 | ||
1ebd95fd ILT |
289 | // Return whether this symbol has been seen in a dynamic object. |
290 | bool | |
291 | in_dyn() const | |
292 | { return this->in_dyn_; } | |
293 | ||
f6ce93d6 | 294 | // Mark this symbol as having been seen in a dynamic object. |
1564db8d ILT |
295 | void |
296 | set_in_dyn() | |
297 | { this->in_dyn_ = true; } | |
298 | ||
89fc3421 CC |
299 | // Return whether this symbol has been seen in a real ELF object. |
300 | // (IN_REG will return TRUE if the symbol has been seen in either | |
301 | // a real ELF object or an object claimed by a plugin.) | |
302 | bool | |
303 | in_real_elf() const | |
304 | { return this->in_real_elf_; } | |
305 | ||
306 | // Mark this symbol as having been seen in a real ELF object. | |
307 | void | |
308 | set_in_real_elf() | |
309 | { this->in_real_elf_ = true; } | |
310 | ||
880cd20d ILT |
311 | // Return whether this symbol was defined in a section that was |
312 | // discarded from the link. This is used to control some error | |
313 | // reporting. | |
314 | bool | |
315 | is_defined_in_discarded_section() const | |
316 | { return this->is_defined_in_discarded_section_; } | |
317 | ||
318 | // Mark this symbol as having been defined in a discarded section. | |
319 | void | |
320 | set_is_defined_in_discarded_section() | |
321 | { this->is_defined_in_discarded_section_ = true; } | |
322 | ||
c06b7b0b ILT |
323 | // Return the index of this symbol in the output file symbol table. |
324 | // A value of -1U means that this symbol is not going into the | |
325 | // output file. This starts out as zero, and is set to a non-zero | |
326 | // value by Symbol_table::finalize. It is an error to ask for the | |
327 | // symbol table index before it has been set. | |
328 | unsigned int | |
329 | symtab_index() const | |
330 | { | |
a3ad94ed | 331 | gold_assert(this->symtab_index_ != 0); |
c06b7b0b ILT |
332 | return this->symtab_index_; |
333 | } | |
334 | ||
335 | // Set the index of the symbol in the output file symbol table. | |
336 | void | |
337 | set_symtab_index(unsigned int index) | |
338 | { | |
a3ad94ed | 339 | gold_assert(index != 0); |
c06b7b0b ILT |
340 | this->symtab_index_ = index; |
341 | } | |
342 | ||
a3ad94ed ILT |
343 | // Return whether this symbol already has an index in the output |
344 | // file symbol table. | |
345 | bool | |
346 | has_symtab_index() const | |
347 | { return this->symtab_index_ != 0; } | |
348 | ||
c06b7b0b ILT |
349 | // Return the index of this symbol in the dynamic symbol table. A |
350 | // value of -1U means that this symbol is not going into the dynamic | |
351 | // symbol table. This starts out as zero, and is set to a non-zero | |
352 | // during Layout::finalize. It is an error to ask for the dynamic | |
353 | // symbol table index before it has been set. | |
354 | unsigned int | |
355 | dynsym_index() const | |
356 | { | |
a3ad94ed | 357 | gold_assert(this->dynsym_index_ != 0); |
c06b7b0b ILT |
358 | return this->dynsym_index_; |
359 | } | |
360 | ||
361 | // Set the index of the symbol in the dynamic symbol table. | |
362 | void | |
363 | set_dynsym_index(unsigned int index) | |
364 | { | |
a3ad94ed | 365 | gold_assert(index != 0); |
c06b7b0b ILT |
366 | this->dynsym_index_ = index; |
367 | } | |
368 | ||
16649710 ILT |
369 | // Return whether this symbol already has an index in the dynamic |
370 | // symbol table. | |
371 | bool | |
372 | has_dynsym_index() const | |
373 | { return this->dynsym_index_ != 0; } | |
374 | ||
ead1e424 | 375 | // Return whether this symbol has an entry in the GOT section. |
07f397ab | 376 | // For a TLS symbol, this GOT entry will hold its tp-relative offset. |
92e059d8 | 377 | bool |
0a65a3a7 CC |
378 | has_got_offset(unsigned int got_type) const |
379 | { return this->got_offsets_.get_offset(got_type) != -1U; } | |
ead1e424 ILT |
380 | |
381 | // Return the offset into the GOT section of this symbol. | |
382 | unsigned int | |
0a65a3a7 | 383 | got_offset(unsigned int got_type) const |
ead1e424 | 384 | { |
2ea97941 ILT |
385 | unsigned int got_offset = this->got_offsets_.get_offset(got_type); |
386 | gold_assert(got_offset != -1U); | |
387 | return got_offset; | |
ead1e424 ILT |
388 | } |
389 | ||
390 | // Set the GOT offset of this symbol. | |
391 | void | |
2ea97941 ILT |
392 | set_got_offset(unsigned int got_type, unsigned int got_offset) |
393 | { this->got_offsets_.set_offset(got_type, got_offset); } | |
07f397ab | 394 | |
a3ad94ed | 395 | // Return whether this symbol has an entry in the PLT section. |
ead1e424 | 396 | bool |
a3ad94ed | 397 | has_plt_offset() const |
880cd20d | 398 | { return this->plt_offset_ != -1U; } |
a3ad94ed ILT |
399 | |
400 | // Return the offset into the PLT section of this symbol. | |
401 | unsigned int | |
402 | plt_offset() const | |
403 | { | |
404 | gold_assert(this->has_plt_offset()); | |
405 | return this->plt_offset_; | |
406 | } | |
407 | ||
408 | // Set the PLT offset of this symbol. | |
409 | void | |
2ea97941 | 410 | set_plt_offset(unsigned int plt_offset) |
a3ad94ed | 411 | { |
880cd20d | 412 | gold_assert(plt_offset != -1U); |
2ea97941 | 413 | this->plt_offset_ = plt_offset; |
a3ad94ed ILT |
414 | } |
415 | ||
ab5c9e90 ILT |
416 | // Return whether this dynamic symbol needs a special value in the |
417 | // dynamic symbol table. | |
418 | bool | |
419 | needs_dynsym_value() const | |
420 | { return this->needs_dynsym_value_; } | |
421 | ||
422 | // Set that this dynamic symbol needs a special value in the dynamic | |
423 | // symbol table. | |
424 | void | |
425 | set_needs_dynsym_value() | |
426 | { | |
427 | gold_assert(this->object()->is_dynamic()); | |
428 | this->needs_dynsym_value_ = true; | |
429 | } | |
430 | ||
a3ad94ed ILT |
431 | // Return true if the final value of this symbol is known at link |
432 | // time. | |
433 | bool | |
b3b74ddc | 434 | final_value_is_known() const; |
ead1e424 | 435 | |
8a5e3e08 ILT |
436 | // Return true if SHNDX represents a common symbol. This depends on |
437 | // the target. | |
438 | static bool | |
439 | is_common_shndx(unsigned int shndx); | |
440 | ||
f6ce93d6 ILT |
441 | // Return whether this is a defined symbol (not undefined or |
442 | // common). | |
443 | bool | |
444 | is_defined() const | |
445 | { | |
d491d34e ILT |
446 | bool is_ordinary; |
447 | if (this->source_ != FROM_OBJECT) | |
f3e9c5c5 | 448 | return this->source_ != IS_UNDEFINED; |
2ea97941 | 449 | unsigned int shndx = this->shndx(&is_ordinary); |
d491d34e | 450 | return (is_ordinary |
2ea97941 ILT |
451 | ? shndx != elfcpp::SHN_UNDEF |
452 | : !Symbol::is_common_shndx(shndx)); | |
a3ad94ed ILT |
453 | } |
454 | ||
14b31740 | 455 | // Return true if this symbol is from a dynamic object. |
a3ad94ed | 456 | bool |
14b31740 | 457 | is_from_dynobj() const |
a3ad94ed | 458 | { |
14b31740 | 459 | return this->source_ == FROM_OBJECT && this->object()->is_dynamic(); |
f6ce93d6 ILT |
460 | } |
461 | ||
f3a2388f CC |
462 | // Return whether this is a placeholder symbol from a plugin object. |
463 | bool | |
464 | is_placeholder() const | |
465 | { | |
466 | return this->source_ == FROM_OBJECT && this->object()->pluginobj() != NULL; | |
467 | } | |
468 | ||
ead1e424 ILT |
469 | // Return whether this is an undefined symbol. |
470 | bool | |
471 | is_undefined() const | |
472 | { | |
d491d34e | 473 | bool is_ordinary; |
f3e9c5c5 ILT |
474 | return ((this->source_ == FROM_OBJECT |
475 | && this->shndx(&is_ordinary) == elfcpp::SHN_UNDEF | |
476 | && is_ordinary) | |
477 | || this->source_ == IS_UNDEFINED); | |
ead1e424 ILT |
478 | } |
479 | ||
86925eef CC |
480 | // Return whether this is a weak undefined symbol. |
481 | bool | |
482 | is_weak_undefined() const | |
f3e9c5c5 | 483 | { return this->is_undefined() && this->binding() == elfcpp::STB_WEAK; } |
86925eef | 484 | |
86925eef CC |
485 | // Return whether this is an absolute symbol. |
486 | bool | |
487 | is_absolute() const | |
488 | { | |
d491d34e | 489 | bool is_ordinary; |
f3e9c5c5 ILT |
490 | return ((this->source_ == FROM_OBJECT |
491 | && this->shndx(&is_ordinary) == elfcpp::SHN_ABS | |
492 | && !is_ordinary) | |
493 | || this->source_ == IS_CONSTANT); | |
86925eef CC |
494 | } |
495 | ||
ead1e424 ILT |
496 | // Return whether this is a common symbol. |
497 | bool | |
498 | is_common() const | |
499 | { | |
8a5e3e08 ILT |
500 | if (this->source_ != FROM_OBJECT) |
501 | return false; | |
eda294df ILT |
502 | if (this->type_ == elfcpp::STT_COMMON) |
503 | return true; | |
d491d34e | 504 | bool is_ordinary; |
2ea97941 ILT |
505 | unsigned int shndx = this->shndx(&is_ordinary); |
506 | return !is_ordinary && Symbol::is_common_shndx(shndx); | |
ead1e424 | 507 | } |
92e059d8 | 508 | |
a6badf5a ILT |
509 | // Return whether this symbol can be seen outside this object. |
510 | bool | |
511 | is_externally_visible() const | |
512 | { | |
513 | return (this->visibility_ == elfcpp::STV_DEFAULT | |
514 | || this->visibility_ == elfcpp::STV_PROTECTED); | |
515 | } | |
516 | ||
436ca963 ILT |
517 | // Return true if this symbol can be preempted by a definition in |
518 | // another link unit. | |
519 | bool | |
520 | is_preemptible() const | |
521 | { | |
386c048c ILT |
522 | // It doesn't make sense to ask whether a symbol defined in |
523 | // another object is preemptible. | |
524 | gold_assert(!this->is_from_dynobj()); | |
525 | ||
8fc19601 ILT |
526 | // It doesn't make sense to ask whether an undefined symbol |
527 | // is preemptible. | |
528 | gold_assert(!this->is_undefined()); | |
529 | ||
f1f70eae ILT |
530 | // If a symbol does not have default visibility, it can not be |
531 | // seen outside this link unit and therefore is not preemptible. | |
532 | if (this->visibility_ != elfcpp::STV_DEFAULT) | |
533 | return false; | |
534 | ||
535 | // If this symbol has been forced to be a local symbol by a | |
536 | // version script, then it is not visible outside this link unit | |
537 | // and is not preemptible. | |
538 | if (this->is_forced_local_) | |
539 | return false; | |
540 | ||
541 | // If we are not producing a shared library, then nothing is | |
542 | // preemptible. | |
543 | if (!parameters->options().shared()) | |
544 | return false; | |
545 | ||
546 | // If the user used -Bsymbolic, then nothing is preemptible. | |
547 | if (parameters->options().Bsymbolic()) | |
548 | return false; | |
549 | ||
550 | // If the user used -Bsymbolic-functions, then functions are not | |
551 | // preemptible. We explicitly check for not being STT_OBJECT, | |
552 | // rather than for being STT_FUNC, because that is what the GNU | |
553 | // linker does. | |
554 | if (this->type() != elfcpp::STT_OBJECT | |
555 | && parameters->options().Bsymbolic_functions()) | |
556 | return false; | |
557 | ||
558 | // Otherwise the symbol is preemptible. | |
559 | return true; | |
436ca963 ILT |
560 | } |
561 | ||
d61c6bd4 ILT |
562 | // Return true if this symbol is a function that needs a PLT entry. |
563 | // If the symbol is defined in a dynamic object or if it is subject | |
8fc19601 | 564 | // to pre-emption, we need to make a PLT entry. If we're doing a |
374ad285 | 565 | // static link or a -pie link, we don't create PLT entries. |
d61c6bd4 ILT |
566 | bool |
567 | needs_plt_entry() const | |
568 | { | |
6d479619 CC |
569 | // An undefined symbol from an executable does not need a PLT entry. |
570 | if (this->is_undefined() && !parameters->options().shared()) | |
571 | return false; | |
572 | ||
8fc19601 | 573 | return (!parameters->doing_static_link() |
374ad285 | 574 | && !parameters->options().pie() |
53d7974c | 575 | && this->is_func() |
8fc19601 | 576 | && (this->is_from_dynobj() |
f3c69fca | 577 | || this->is_undefined() |
8fc19601 | 578 | || this->is_preemptible())); |
d61c6bd4 ILT |
579 | } |
580 | ||
0700cf32 ILT |
581 | // When determining whether a reference to a symbol needs a dynamic |
582 | // relocation, we need to know several things about the reference. | |
583 | // These flags may be or'ed together. | |
584 | enum Reference_flags | |
585 | { | |
586 | // Reference to the symbol's absolute address. | |
587 | ABSOLUTE_REF = 1, | |
588 | // A non-PIC reference. | |
589 | NON_PIC_REF = 2, | |
590 | // A function call. | |
591 | FUNCTION_CALL = 4 | |
592 | }; | |
593 | ||
d61c6bd4 ILT |
594 | // Given a direct absolute or pc-relative static relocation against |
595 | // the global symbol, this function returns whether a dynamic relocation | |
596 | // is needed. | |
597 | ||
598 | bool | |
0700cf32 | 599 | needs_dynamic_reloc(int flags) const |
d61c6bd4 | 600 | { |
8fc19601 ILT |
601 | // No dynamic relocations in a static link! |
602 | if (parameters->doing_static_link()) | |
603 | return false; | |
604 | ||
6d479619 | 605 | // A reference to an undefined symbol from an executable should be |
f3c69fca CC |
606 | // statically resolved to 0, and does not need a dynamic relocation. |
607 | // This matches gnu ld behavior. | |
6d479619 | 608 | if (this->is_undefined() && !parameters->options().shared()) |
f3c69fca CC |
609 | return false; |
610 | ||
611 | // A reference to an absolute symbol does not need a dynamic relocation. | |
612 | if (this->is_absolute()) | |
86925eef CC |
613 | return false; |
614 | ||
d61c6bd4 | 615 | // An absolute reference within a position-independent output file |
0700cf32 ILT |
616 | // will need a dynamic relocation. |
617 | if ((flags & ABSOLUTE_REF) | |
8851ecca | 618 | && parameters->options().output_is_position_independent()) |
d61c6bd4 ILT |
619 | return true; |
620 | ||
621 | // A function call that can branch to a local PLT entry does not need | |
5240d12a ILT |
622 | // a dynamic relocation. A non-pic pc-relative function call in a |
623 | // shared library cannot use a PLT entry. | |
0700cf32 | 624 | if ((flags & FUNCTION_CALL) |
5240d12a | 625 | && this->has_plt_offset() |
8851ecca | 626 | && !((flags & NON_PIC_REF) && parameters->options().shared())) |
d61c6bd4 ILT |
627 | return false; |
628 | ||
629 | // A reference to any PLT entry in a non-position-independent executable | |
630 | // does not need a dynamic relocation. | |
8851ecca | 631 | if (!parameters->options().output_is_position_independent() |
d61c6bd4 ILT |
632 | && this->has_plt_offset()) |
633 | return false; | |
634 | ||
635 | // A reference to a symbol defined in a dynamic object or to a | |
636 | // symbol that is preemptible will need a dynamic relocation. | |
8fc19601 ILT |
637 | if (this->is_from_dynobj() |
638 | || this->is_undefined() | |
639 | || this->is_preemptible()) | |
d61c6bd4 ILT |
640 | return true; |
641 | ||
642 | // For all other cases, return FALSE. | |
643 | return false; | |
644 | } | |
645 | ||
de4c45bd ILT |
646 | // Whether we should use the PLT offset associated with a symbol for |
647 | // a relocation. IS_NON_PIC_REFERENCE is true if this is a non-PIC | |
648 | // reloc--the same set of relocs for which we would pass NON_PIC_REF | |
649 | // to the needs_dynamic_reloc function. | |
650 | ||
651 | bool | |
652 | use_plt_offset(bool is_non_pic_reference) const | |
653 | { | |
654 | // If the symbol doesn't have a PLT offset, then naturally we | |
655 | // don't want to use it. | |
656 | if (!this->has_plt_offset()) | |
657 | return false; | |
658 | ||
659 | // If we are going to generate a dynamic relocation, then we will | |
660 | // wind up using that, so no need to use the PLT entry. | |
661 | if (this->needs_dynamic_reloc(FUNCTION_CALL | |
662 | | (is_non_pic_reference | |
663 | ? NON_PIC_REF | |
664 | : 0))) | |
665 | return false; | |
666 | ||
667 | // If the symbol is from a dynamic object, we need to use the PLT | |
668 | // entry. | |
669 | if (this->is_from_dynobj()) | |
670 | return true; | |
671 | ||
672 | // If we are generating a shared object, and this symbol is | |
673 | // undefined or preemptible, we need to use the PLT entry. | |
674 | if (parameters->options().shared() | |
675 | && (this->is_undefined() || this->is_preemptible())) | |
676 | return true; | |
677 | ||
678 | // If this is a weak undefined symbol, we need to use the PLT | |
679 | // entry; the symbol may be defined by a library loaded at | |
680 | // runtime. | |
681 | if (this->is_weak_undefined()) | |
682 | return true; | |
683 | ||
684 | // Otherwise we can use the regular definition. | |
685 | return false; | |
686 | } | |
687 | ||
d61c6bd4 ILT |
688 | // Given a direct absolute static relocation against |
689 | // the global symbol, where a dynamic relocation is needed, this | |
690 | // function returns whether a relative dynamic relocation can be used. | |
691 | // The caller must determine separately whether the static relocation | |
692 | // is compatible with a relative relocation. | |
693 | ||
694 | bool | |
695 | can_use_relative_reloc(bool is_function_call) const | |
696 | { | |
697 | // A function call that can branch to a local PLT entry can | |
698 | // use a RELATIVE relocation. | |
699 | if (is_function_call && this->has_plt_offset()) | |
700 | return true; | |
701 | ||
702 | // A reference to a symbol defined in a dynamic object or to a | |
703 | // symbol that is preemptible can not use a RELATIVE relocaiton. | |
8fc19601 ILT |
704 | if (this->is_from_dynobj() |
705 | || this->is_undefined() | |
706 | || this->is_preemptible()) | |
d61c6bd4 ILT |
707 | return false; |
708 | ||
709 | // For all other cases, return TRUE. | |
710 | return true; | |
711 | } | |
712 | ||
77e65537 ILT |
713 | // Return the output section where this symbol is defined. Return |
714 | // NULL if the symbol has an absolute value. | |
715 | Output_section* | |
716 | output_section() const; | |
717 | ||
718 | // Set the symbol's output section. This is used for symbols | |
719 | // defined in scripts. This should only be called after the symbol | |
720 | // table has been finalized. | |
721 | void | |
722 | set_output_section(Output_section*); | |
a445fddf | 723 | |
f6ce93d6 ILT |
724 | // Return whether there should be a warning for references to this |
725 | // symbol. | |
726 | bool | |
727 | has_warning() const | |
728 | { return this->has_warning_; } | |
729 | ||
730 | // Mark this symbol as having a warning. | |
731 | void | |
732 | set_has_warning() | |
733 | { this->has_warning_ = true; } | |
734 | ||
46fe1623 ILT |
735 | // Return whether this symbol is defined by a COPY reloc from a |
736 | // dynamic object. | |
737 | bool | |
738 | is_copied_from_dynobj() const | |
739 | { return this->is_copied_from_dynobj_; } | |
740 | ||
741 | // Mark this symbol as defined by a COPY reloc. | |
742 | void | |
743 | set_is_copied_from_dynobj() | |
744 | { this->is_copied_from_dynobj_ = true; } | |
745 | ||
55a93433 ILT |
746 | // Return whether this symbol is forced to visibility STB_LOCAL |
747 | // by a "local:" entry in a version script. | |
748 | bool | |
749 | is_forced_local() const | |
750 | { return this->is_forced_local_; } | |
751 | ||
752 | // Mark this symbol as forced to STB_LOCAL visibility. | |
753 | void | |
754 | set_is_forced_local() | |
755 | { this->is_forced_local_ = true; } | |
756 | ||
966d4097 DK |
757 | // Return true if this may need a COPY relocation. |
758 | // References from an executable object to non-function symbols | |
759 | // defined in a dynamic object may need a COPY relocation. | |
760 | bool | |
761 | may_need_copy_reloc() const | |
762 | { | |
763 | return (!parameters->options().shared() | |
764 | && parameters->options().copyreloc() | |
765 | && this->is_from_dynobj() | |
53d7974c | 766 | && !this->is_func()); |
966d4097 DK |
767 | } |
768 | ||
14bfc3f5 ILT |
769 | protected: |
770 | // Instances of this class should always be created at a specific | |
771 | // size. | |
772 | Symbol() | |
f6ce93d6 | 773 | { memset(this, 0, sizeof *this); } |
14bfc3f5 | 774 | |
ead1e424 ILT |
775 | // Initialize the general fields. |
776 | void | |
777 | init_fields(const char* name, const char* version, | |
778 | elfcpp::STT type, elfcpp::STB binding, | |
779 | elfcpp::STV visibility, unsigned char nonvis); | |
780 | ||
d491d34e ILT |
781 | // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the |
782 | // section index, IS_ORDINARY is whether it is a normal section | |
783 | // index rather than a special code. | |
14bfc3f5 ILT |
784 | template<int size, bool big_endian> |
785 | void | |
f3e9c5c5 ILT |
786 | init_base_object(const char *name, const char* version, Object* object, |
787 | const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx, | |
788 | bool is_ordinary); | |
bae7f79e | 789 | |
ead1e424 ILT |
790 | // Initialize fields for an Output_data. |
791 | void | |
75517b77 ILT |
792 | init_base_output_data(const char* name, const char* version, Output_data*, |
793 | elfcpp::STT, elfcpp::STB, elfcpp::STV, | |
794 | unsigned char nonvis, bool offset_is_from_end); | |
ead1e424 ILT |
795 | |
796 | // Initialize fields for an Output_segment. | |
797 | void | |
75517b77 ILT |
798 | init_base_output_segment(const char* name, const char* version, |
799 | Output_segment* os, elfcpp::STT type, | |
800 | elfcpp::STB binding, elfcpp::STV visibility, | |
801 | unsigned char nonvis, | |
f3e9c5c5 | 802 | Segment_offset_base offset_base); |
ead1e424 ILT |
803 | |
804 | // Initialize fields for a constant. | |
805 | void | |
75517b77 ILT |
806 | init_base_constant(const char* name, const char* version, elfcpp::STT type, |
807 | elfcpp::STB binding, elfcpp::STV visibility, | |
808 | unsigned char nonvis); | |
f3e9c5c5 ILT |
809 | |
810 | // Initialize fields for an undefined symbol. | |
811 | void | |
75517b77 ILT |
812 | init_base_undefined(const char* name, const char* version, elfcpp::STT type, |
813 | elfcpp::STB binding, elfcpp::STV visibility, | |
814 | unsigned char nonvis); | |
ead1e424 | 815 | |
1564db8d ILT |
816 | // Override existing symbol. |
817 | template<int size, bool big_endian> | |
818 | void | |
d491d34e ILT |
819 | override_base(const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx, |
820 | bool is_ordinary, Object* object, const char* version); | |
1564db8d | 821 | |
86f2e683 ILT |
822 | // Override existing symbol with a special symbol. |
823 | void | |
824 | override_base_with_special(const Symbol* from); | |
825 | ||
75517b77 ILT |
826 | // Override symbol version. |
827 | void | |
828 | override_version(const char* version); | |
829 | ||
c7912668 ILT |
830 | // Allocate a common symbol by giving it a location in the output |
831 | // file. | |
832 | void | |
833 | allocate_base_common(Output_data*); | |
834 | ||
bae7f79e | 835 | private: |
14bfc3f5 ILT |
836 | Symbol(const Symbol&); |
837 | Symbol& operator=(const Symbol&); | |
838 | ||
839 | // Symbol name (expected to point into a Stringpool). | |
840 | const char* name_; | |
841 | // Symbol version (expected to point into a Stringpool). This may | |
842 | // be NULL. | |
bae7f79e | 843 | const char* version_; |
ead1e424 ILT |
844 | |
845 | union | |
846 | { | |
847 | // This struct is used if SOURCE_ == FROM_OBJECT. | |
848 | struct | |
849 | { | |
850 | // Object in which symbol is defined, or in which it was first | |
851 | // seen. | |
852 | Object* object; | |
853 | // Section number in object_ in which symbol is defined. | |
16649710 | 854 | unsigned int shndx; |
ead1e424 ILT |
855 | } from_object; |
856 | ||
857 | // This struct is used if SOURCE_ == IN_OUTPUT_DATA. | |
858 | struct | |
859 | { | |
860 | // Output_data in which symbol is defined. Before | |
861 | // Layout::finalize the symbol's value is an offset within the | |
862 | // Output_data. | |
863 | Output_data* output_data; | |
864 | // True if the offset is from the end, false if the offset is | |
865 | // from the beginning. | |
866 | bool offset_is_from_end; | |
867 | } in_output_data; | |
868 | ||
869 | // This struct is used if SOURCE_ == IN_OUTPUT_SEGMENT. | |
870 | struct | |
871 | { | |
872 | // Output_segment in which the symbol is defined. Before | |
873 | // Layout::finalize the symbol's value is an offset. | |
874 | Output_segment* output_segment; | |
875 | // The base to use for the offset before Layout::finalize. | |
876 | Segment_offset_base offset_base; | |
877 | } in_output_segment; | |
878 | } u_; | |
879 | ||
c06b7b0b ILT |
880 | // The index of this symbol in the output file. If the symbol is |
881 | // not going into the output file, this value is -1U. This field | |
882 | // starts as always holding zero. It is set to a non-zero value by | |
883 | // Symbol_table::finalize. | |
884 | unsigned int symtab_index_; | |
885 | ||
886 | // The index of this symbol in the dynamic symbol table. If the | |
887 | // symbol is not going into the dynamic symbol table, this value is | |
888 | // -1U. This field starts as always holding zero. It is set to a | |
889 | // non-zero value during Layout::finalize. | |
890 | unsigned int dynsym_index_; | |
891 | ||
880cd20d ILT |
892 | // The GOT section entries for this symbol. A symbol may have more |
893 | // than one GOT offset (e.g., when mixing modules compiled with two | |
894 | // different TLS models), but will usually have at most one. | |
0a65a3a7 | 895 | Got_offset_list got_offsets_; |
07f397ab | 896 | |
880cd20d ILT |
897 | // If this symbol has an entry in the PLT section, then this is the |
898 | // offset from the start of the PLT section. This is -1U if there | |
899 | // is no PLT entry. | |
a3ad94ed ILT |
900 | unsigned int plt_offset_; |
901 | ||
d491d34e | 902 | // Symbol type (bits 0 to 3). |
bae7f79e | 903 | elfcpp::STT type_ : 4; |
d491d34e | 904 | // Symbol binding (bits 4 to 7). |
bae7f79e | 905 | elfcpp::STB binding_ : 4; |
d491d34e | 906 | // Symbol visibility (bits 8 to 9). |
14bfc3f5 | 907 | elfcpp::STV visibility_ : 2; |
d491d34e | 908 | // Rest of symbol st_other field (bits 10 to 15). |
ead1e424 | 909 | unsigned int nonvis_ : 6; |
d491d34e | 910 | // The type of symbol (bits 16 to 18). |
f6ce93d6 | 911 | Source source_ : 3; |
880cd20d | 912 | // True if this is the default version of the symbol (bit 19). |
1564db8d | 913 | bool is_def_ : 1; |
14bfc3f5 ILT |
914 | // True if this symbol really forwards to another symbol. This is |
915 | // used when we discover after the fact that two different entries | |
916 | // in the hash table really refer to the same symbol. This will | |
917 | // never be set for a symbol found in the hash table, but may be set | |
918 | // for a symbol found in the list of symbols attached to an Object. | |
919 | // It forwards to the symbol found in the forwarders_ map of | |
880cd20d | 920 | // Symbol_table (bit 20). |
1564db8d | 921 | bool is_forwarder_ : 1; |
aeddab66 | 922 | // True if the symbol has an alias in the weak_aliases table in |
880cd20d | 923 | // Symbol_table (bit 21). |
aeddab66 | 924 | bool has_alias_ : 1; |
d491d34e | 925 | // True if this symbol needs to be in the dynamic symbol table (bit |
880cd20d | 926 | // 22). |
c06b7b0b | 927 | bool needs_dynsym_entry_ : 1; |
880cd20d | 928 | // True if we've seen this symbol in a regular object (bit 23). |
008db82e | 929 | bool in_reg_ : 1; |
880cd20d | 930 | // True if we've seen this symbol in a dynamic object (bit 24). |
1564db8d | 931 | bool in_dyn_ : 1; |
ab5c9e90 | 932 | // True if this is a dynamic symbol which needs a special value in |
880cd20d | 933 | // the dynamic symbol table (bit 25). |
ab5c9e90 | 934 | bool needs_dynsym_value_ : 1; |
880cd20d | 935 | // True if there is a warning for this symbol (bit 26). |
f6ce93d6 | 936 | bool has_warning_ : 1; |
46fe1623 | 937 | // True if we are using a COPY reloc for this symbol, so that the |
880cd20d | 938 | // real definition lives in a dynamic object (bit 27). |
46fe1623 | 939 | bool is_copied_from_dynobj_ : 1; |
55a93433 | 940 | // True if this symbol was forced to local visibility by a version |
880cd20d | 941 | // script (bit 28). |
55a93433 | 942 | bool is_forced_local_ : 1; |
d491d34e ILT |
943 | // True if the field u_.from_object.shndx is an ordinary section |
944 | // index, not one of the special codes from SHN_LORESERVE to | |
880cd20d | 945 | // SHN_HIRESERVE (bit 29). |
d491d34e | 946 | bool is_ordinary_shndx_ : 1; |
880cd20d | 947 | // True if we've seen this symbol in a real ELF object (bit 30). |
89fc3421 | 948 | bool in_real_elf_ : 1; |
880cd20d ILT |
949 | // True if this symbol is defined in a section which was discarded |
950 | // (bit 31). | |
951 | bool is_defined_in_discarded_section_ : 1; | |
bae7f79e ILT |
952 | }; |
953 | ||
14bfc3f5 ILT |
954 | // The parts of a symbol which are size specific. Using a template |
955 | // derived class like this helps us use less space on a 32-bit system. | |
bae7f79e ILT |
956 | |
957 | template<int size> | |
14bfc3f5 ILT |
958 | class Sized_symbol : public Symbol |
959 | { | |
960 | public: | |
1564db8d ILT |
961 | typedef typename elfcpp::Elf_types<size>::Elf_Addr Value_type; |
962 | typedef typename elfcpp::Elf_types<size>::Elf_WXword Size_type; | |
963 | ||
14bfc3f5 ILT |
964 | Sized_symbol() |
965 | { } | |
966 | ||
d491d34e ILT |
967 | // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the |
968 | // section index, IS_ORDINARY is whether it is a normal section | |
969 | // index rather than a special code. | |
14bfc3f5 ILT |
970 | template<bool big_endian> |
971 | void | |
f3e9c5c5 ILT |
972 | init_object(const char *name, const char* version, Object* object, |
973 | const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx, | |
974 | bool is_ordinary); | |
14bfc3f5 | 975 | |
ead1e424 ILT |
976 | // Initialize fields for an Output_data. |
977 | void | |
75517b77 ILT |
978 | init_output_data(const char* name, const char* version, Output_data*, |
979 | Value_type value, Size_type symsize, elfcpp::STT, | |
980 | elfcpp::STB, elfcpp::STV, unsigned char nonvis, | |
981 | bool offset_is_from_end); | |
ead1e424 ILT |
982 | |
983 | // Initialize fields for an Output_segment. | |
984 | void | |
75517b77 ILT |
985 | init_output_segment(const char* name, const char* version, Output_segment*, |
986 | Value_type value, Size_type symsize, elfcpp::STT, | |
987 | elfcpp::STB, elfcpp::STV, unsigned char nonvis, | |
988 | Segment_offset_base offset_base); | |
ead1e424 ILT |
989 | |
990 | // Initialize fields for a constant. | |
991 | void | |
75517b77 ILT |
992 | init_constant(const char* name, const char* version, Value_type value, |
993 | Size_type symsize, elfcpp::STT, elfcpp::STB, elfcpp::STV, | |
994 | unsigned char nonvis); | |
f3e9c5c5 ILT |
995 | |
996 | // Initialize fields for an undefined symbol. | |
997 | void | |
75517b77 ILT |
998 | init_undefined(const char* name, const char* version, elfcpp::STT, |
999 | elfcpp::STB, elfcpp::STV, unsigned char nonvis); | |
ead1e424 | 1000 | |
1564db8d ILT |
1001 | // Override existing symbol. |
1002 | template<bool big_endian> | |
1003 | void | |
d491d34e ILT |
1004 | override(const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx, |
1005 | bool is_ordinary, Object* object, const char* version); | |
1564db8d | 1006 | |
86f2e683 ILT |
1007 | // Override existing symbol with a special symbol. |
1008 | void | |
1009 | override_with_special(const Sized_symbol<size>*); | |
1010 | ||
1564db8d ILT |
1011 | // Return the symbol's value. |
1012 | Value_type | |
1013 | value() const | |
1014 | { return this->value_; } | |
1015 | ||
1016 | // Return the symbol's size (we can't call this 'size' because that | |
1017 | // is a template parameter). | |
1018 | Size_type | |
1019 | symsize() const | |
ead1e424 ILT |
1020 | { return this->symsize_; } |
1021 | ||
1022 | // Set the symbol size. This is used when resolving common symbols. | |
1023 | void | |
2ea97941 ILT |
1024 | set_symsize(Size_type symsize) |
1025 | { this->symsize_ = symsize; } | |
1564db8d | 1026 | |
75f65a3e ILT |
1027 | // Set the symbol value. This is called when we store the final |
1028 | // values of the symbols into the symbol table. | |
1029 | void | |
2ea97941 ILT |
1030 | set_value(Value_type value) |
1031 | { this->value_ = value; } | |
75f65a3e | 1032 | |
c7912668 ILT |
1033 | // Allocate a common symbol by giving it a location in the output |
1034 | // file. | |
1035 | void | |
1036 | allocate_common(Output_data*, Value_type value); | |
1037 | ||
14bfc3f5 ILT |
1038 | private: |
1039 | Sized_symbol(const Sized_symbol&); | |
1040 | Sized_symbol& operator=(const Sized_symbol&); | |
1041 | ||
ead1e424 ILT |
1042 | // Symbol value. Before Layout::finalize this is the offset in the |
1043 | // input section. This is set to the final value during | |
1044 | // Layout::finalize. | |
1564db8d | 1045 | Value_type value_; |
14bfc3f5 | 1046 | // Symbol size. |
ead1e424 ILT |
1047 | Size_type symsize_; |
1048 | }; | |
1049 | ||
1050 | // A struct describing a symbol defined by the linker, where the value | |
1051 | // of the symbol is defined based on an output section. This is used | |
1052 | // for symbols defined by the linker, like "_init_array_start". | |
1053 | ||
1054 | struct Define_symbol_in_section | |
1055 | { | |
1056 | // The symbol name. | |
1057 | const char* name; | |
1058 | // The name of the output section with which this symbol should be | |
1059 | // associated. If there is no output section with that name, the | |
1060 | // symbol will be defined as zero. | |
1061 | const char* output_section; | |
1062 | // The offset of the symbol within the output section. This is an | |
1063 | // offset from the start of the output section, unless start_at_end | |
1064 | // is true, in which case this is an offset from the end of the | |
1065 | // output section. | |
1066 | uint64_t value; | |
1067 | // The size of the symbol. | |
1068 | uint64_t size; | |
1069 | // The symbol type. | |
1070 | elfcpp::STT type; | |
1071 | // The symbol binding. | |
1072 | elfcpp::STB binding; | |
1073 | // The symbol visibility. | |
1074 | elfcpp::STV visibility; | |
1075 | // The rest of the st_other field. | |
1076 | unsigned char nonvis; | |
1077 | // If true, the value field is an offset from the end of the output | |
1078 | // section. | |
1079 | bool offset_is_from_end; | |
1080 | // If true, this symbol is defined only if we see a reference to it. | |
1081 | bool only_if_ref; | |
1082 | }; | |
1083 | ||
1084 | // A struct describing a symbol defined by the linker, where the value | |
1085 | // of the symbol is defined based on a segment. This is used for | |
1086 | // symbols defined by the linker, like "_end". We describe the | |
1087 | // segment with which the symbol should be associated by its | |
1088 | // characteristics. If no segment meets these characteristics, the | |
1089 | // symbol will be defined as zero. If there is more than one segment | |
1090 | // which meets these characteristics, we will use the first one. | |
1091 | ||
1092 | struct Define_symbol_in_segment | |
1093 | { | |
1094 | // The symbol name. | |
1095 | const char* name; | |
1096 | // The segment type where the symbol should be defined, typically | |
1097 | // PT_LOAD. | |
1098 | elfcpp::PT segment_type; | |
1099 | // Bitmask of segment flags which must be set. | |
1100 | elfcpp::PF segment_flags_set; | |
1101 | // Bitmask of segment flags which must be clear. | |
1102 | elfcpp::PF segment_flags_clear; | |
1103 | // The offset of the symbol within the segment. The offset is | |
1104 | // calculated from the position set by offset_base. | |
1105 | uint64_t value; | |
1106 | // The size of the symbol. | |
1107 | uint64_t size; | |
1108 | // The symbol type. | |
1109 | elfcpp::STT type; | |
1110 | // The symbol binding. | |
1111 | elfcpp::STB binding; | |
1112 | // The symbol visibility. | |
1113 | elfcpp::STV visibility; | |
1114 | // The rest of the st_other field. | |
1115 | unsigned char nonvis; | |
1116 | // The base from which we compute the offset. | |
1117 | Symbol::Segment_offset_base offset_base; | |
1118 | // If true, this symbol is defined only if we see a reference to it. | |
1119 | bool only_if_ref; | |
14bfc3f5 ILT |
1120 | }; |
1121 | ||
f6ce93d6 ILT |
1122 | // This class manages warnings. Warnings are a GNU extension. When |
1123 | // we see a section named .gnu.warning.SYM in an object file, and if | |
1124 | // we wind using the definition of SYM from that object file, then we | |
1125 | // will issue a warning for any relocation against SYM from a | |
1126 | // different object file. The text of the warning is the contents of | |
1127 | // the section. This is not precisely the definition used by the old | |
1128 | // GNU linker; the old GNU linker treated an occurrence of | |
1129 | // .gnu.warning.SYM as defining a warning symbol. A warning symbol | |
1130 | // would trigger a warning on any reference. However, it was | |
1131 | // inconsistent in that a warning in a dynamic object only triggered | |
1132 | // if there was no definition in a regular object. This linker is | |
1133 | // different in that we only issue a warning if we use the symbol | |
1134 | // definition from the same object file as the warning section. | |
1135 | ||
1136 | class Warnings | |
1137 | { | |
1138 | public: | |
1139 | Warnings() | |
1140 | : warnings_() | |
1141 | { } | |
1142 | ||
cb295612 ILT |
1143 | // Add a warning for symbol NAME in object OBJ. WARNING is the text |
1144 | // of the warning. | |
f6ce93d6 ILT |
1145 | void |
1146 | add_warning(Symbol_table* symtab, const char* name, Object* obj, | |
cb295612 | 1147 | const std::string& warning); |
f6ce93d6 ILT |
1148 | |
1149 | // For each symbol for which we should give a warning, make a note | |
1150 | // on the symbol. | |
1151 | void | |
cb295612 | 1152 | note_warnings(Symbol_table* symtab); |
f6ce93d6 | 1153 | |
75f2446e ILT |
1154 | // Issue a warning for a reference to SYM at RELINFO's location. |
1155 | template<int size, bool big_endian> | |
f6ce93d6 | 1156 | void |
75f2446e ILT |
1157 | issue_warning(const Symbol* sym, const Relocate_info<size, big_endian>*, |
1158 | size_t relnum, off_t reloffset) const; | |
f6ce93d6 ILT |
1159 | |
1160 | private: | |
1161 | Warnings(const Warnings&); | |
1162 | Warnings& operator=(const Warnings&); | |
1163 | ||
1164 | // What we need to know to get the warning text. | |
1165 | struct Warning_location | |
1166 | { | |
1167 | // The object the warning is in. | |
1168 | Object* object; | |
cb295612 | 1169 | // The warning text. |
f6ce93d6 ILT |
1170 | std::string text; |
1171 | ||
1172 | Warning_location() | |
cb295612 | 1173 | : object(NULL), text() |
f6ce93d6 ILT |
1174 | { } |
1175 | ||
1176 | void | |
cb295612 | 1177 | set(Object* o, const std::string& t) |
f6ce93d6 ILT |
1178 | { |
1179 | this->object = o; | |
cb295612 | 1180 | this->text = t; |
f6ce93d6 | 1181 | } |
f6ce93d6 ILT |
1182 | }; |
1183 | ||
1184 | // A mapping from warning symbol names (canonicalized in | |
70e654ba | 1185 | // Symbol_table's namepool_ field) to warning information. |
f6ce93d6 ILT |
1186 | typedef Unordered_map<const char*, Warning_location> Warning_table; |
1187 | ||
1188 | Warning_table warnings_; | |
1189 | }; | |
1190 | ||
14bfc3f5 ILT |
1191 | // The main linker symbol table. |
1192 | ||
bae7f79e ILT |
1193 | class Symbol_table |
1194 | { | |
1195 | public: | |
99fff23b ILT |
1196 | // The different places where a symbol definition can come from. |
1197 | enum Defined | |
1198 | { | |
1199 | // Defined in an object file--the normal case. | |
1200 | OBJECT, | |
1201 | // Defined for a COPY reloc. | |
1202 | COPY, | |
1203 | // Defined on the command line using --defsym. | |
1204 | DEFSYM, | |
1205 | // Defined (so to speak) on the command line using -u. | |
1206 | UNDEFINED, | |
1207 | // Defined in a linker script. | |
1208 | SCRIPT, | |
1209 | // Predefined by the linker. | |
1210 | PREDEFINED, | |
1211 | }; | |
1212 | ||
fc59c572 ILT |
1213 | // The order in which we sort common symbols. |
1214 | enum Sort_commons_order | |
1215 | { | |
1216 | SORT_COMMONS_BY_SIZE_DESCENDING, | |
1217 | SORT_COMMONS_BY_ALIGNMENT_DESCENDING, | |
1218 | SORT_COMMONS_BY_ALIGNMENT_ASCENDING | |
1219 | }; | |
1220 | ||
6d013333 ILT |
1221 | // COUNT is an estimate of how many symbosl will be inserted in the |
1222 | // symbol table. It's ok to put 0 if you don't know; a correct | |
1223 | // guess will just save some CPU by reducing hashtable resizes. | |
09124467 | 1224 | Symbol_table(unsigned int count, const Version_script_info& version_script); |
bae7f79e | 1225 | |
1564db8d | 1226 | ~Symbol_table(); |
bae7f79e | 1227 | |
ef15dade | 1228 | void |
2ea97941 ILT |
1229 | set_icf(Icf* icf) |
1230 | { this->icf_ = icf;} | |
ef15dade ST |
1231 | |
1232 | Icf* | |
1233 | icf() const | |
1234 | { return this->icf_; } | |
1235 | ||
1236 | // Returns true if ICF determined that this is a duplicate section. | |
1237 | bool | |
1238 | is_section_folded(Object* obj, unsigned int shndx) const; | |
1239 | ||
6d03d481 | 1240 | void |
2ea97941 ILT |
1241 | set_gc(Garbage_collection* gc) |
1242 | { this->gc_ = gc; } | |
6d03d481 ST |
1243 | |
1244 | Garbage_collection* | |
ef15dade | 1245 | gc() const |
6d03d481 ST |
1246 | { return this->gc_; } |
1247 | ||
1248 | // During garbage collection, this keeps undefined symbols. | |
1249 | void | |
1250 | gc_mark_undef_symbols(); | |
1251 | ||
1252 | // During garbage collection, this ensures externally visible symbols | |
1253 | // are not treated as garbage while building shared objects. | |
1254 | void | |
1255 | gc_mark_symbol_for_shlib(Symbol* sym); | |
1256 | ||
1257 | // During garbage collection, this keeps sections that correspond to | |
1258 | // symbols seen in dynamic objects. | |
1259 | inline void | |
1260 | gc_mark_dyn_syms(Symbol* sym); | |
1261 | ||
dbe717ef | 1262 | // Add COUNT external symbols from the relocatable object RELOBJ to |
d491d34e ILT |
1263 | // the symbol table. SYMS is the symbols, SYMNDX_OFFSET is the |
1264 | // offset in the symbol table of the first symbol, SYM_NAMES is | |
1265 | // their names, SYM_NAME_SIZE is the size of SYM_NAMES. This sets | |
92de84a6 ILT |
1266 | // SYMPOINTERS to point to the symbols in the symbol table. It sets |
1267 | // *DEFINED to the number of defined symbols. | |
14bfc3f5 ILT |
1268 | template<int size, bool big_endian> |
1269 | void | |
dbe717ef ILT |
1270 | add_from_relobj(Sized_relobj<size, big_endian>* relobj, |
1271 | const unsigned char* syms, size_t count, | |
d491d34e ILT |
1272 | size_t symndx_offset, const char* sym_names, |
1273 | size_t sym_name_size, | |
92de84a6 ILT |
1274 | typename Sized_relobj<size, big_endian>::Symbols*, |
1275 | size_t* defined); | |
89fc3421 CC |
1276 | |
1277 | // Add one external symbol from the plugin object OBJ to the symbol table. | |
1278 | // Returns a pointer to the resolved symbol in the symbol table. | |
1279 | template<int size, bool big_endian> | |
1280 | Symbol* | |
1281 | add_from_pluginobj(Sized_pluginobj<size, big_endian>* obj, | |
1282 | const char* name, const char* ver, | |
1283 | elfcpp::Sym<size, big_endian>* sym); | |
14bfc3f5 | 1284 | |
dbe717ef ILT |
1285 | // Add COUNT dynamic symbols from the dynamic object DYNOBJ to the |
1286 | // symbol table. SYMS is the symbols. SYM_NAMES is their names. | |
1287 | // SYM_NAME_SIZE is the size of SYM_NAMES. The other parameters are | |
1288 | // symbol version data. | |
1289 | template<int size, bool big_endian> | |
1290 | void | |
1291 | add_from_dynobj(Sized_dynobj<size, big_endian>* dynobj, | |
1292 | const unsigned char* syms, size_t count, | |
1293 | const char* sym_names, size_t sym_name_size, | |
1294 | const unsigned char* versym, size_t versym_size, | |
92de84a6 ILT |
1295 | const std::vector<const char*>*, |
1296 | typename Sized_relobj<size, big_endian>::Symbols*, | |
1297 | size_t* defined); | |
dbe717ef | 1298 | |
ead1e424 ILT |
1299 | // Define a special symbol based on an Output_data. It is a |
1300 | // multiple definition error if this symbol is already defined. | |
14b31740 | 1301 | Symbol* |
99fff23b | 1302 | define_in_output_data(const char* name, const char* version, Defined, |
14b31740 | 1303 | Output_data*, uint64_t value, uint64_t symsize, |
ead1e424 ILT |
1304 | elfcpp::STT type, elfcpp::STB binding, |
1305 | elfcpp::STV visibility, unsigned char nonvis, | |
1306 | bool offset_is_from_end, bool only_if_ref); | |
1307 | ||
1308 | // Define a special symbol based on an Output_segment. It is a | |
1309 | // multiple definition error if this symbol is already defined. | |
14b31740 | 1310 | Symbol* |
99fff23b | 1311 | define_in_output_segment(const char* name, const char* version, Defined, |
9b07f471 | 1312 | Output_segment*, uint64_t value, uint64_t symsize, |
ead1e424 ILT |
1313 | elfcpp::STT type, elfcpp::STB binding, |
1314 | elfcpp::STV visibility, unsigned char nonvis, | |
1315 | Symbol::Segment_offset_base, bool only_if_ref); | |
1316 | ||
1317 | // Define a special symbol with a constant value. It is a multiple | |
1318 | // definition error if this symbol is already defined. | |
14b31740 | 1319 | Symbol* |
99fff23b | 1320 | define_as_constant(const char* name, const char* version, Defined, |
14b31740 ILT |
1321 | uint64_t value, uint64_t symsize, elfcpp::STT type, |
1322 | elfcpp::STB binding, elfcpp::STV visibility, | |
caa9d5d9 ILT |
1323 | unsigned char nonvis, bool only_if_ref, |
1324 | bool force_override); | |
ead1e424 | 1325 | |
a445fddf ILT |
1326 | // Define a set of symbols in output sections. If ONLY_IF_REF is |
1327 | // true, only define them if they are referenced. | |
ead1e424 | 1328 | void |
a445fddf ILT |
1329 | define_symbols(const Layout*, int count, const Define_symbol_in_section*, |
1330 | bool only_if_ref); | |
ead1e424 | 1331 | |
a445fddf ILT |
1332 | // Define a set of symbols in output segments. If ONLY_IF_REF is |
1333 | // true, only defined them if they are referenced. | |
ead1e424 | 1334 | void |
a445fddf ILT |
1335 | define_symbols(const Layout*, int count, const Define_symbol_in_segment*, |
1336 | bool only_if_ref); | |
ead1e424 | 1337 | |
46fe1623 ILT |
1338 | // Define SYM using a COPY reloc. POSD is the Output_data where the |
1339 | // symbol should be defined--typically a .dyn.bss section. VALUE is | |
1340 | // the offset within POSD. | |
1341 | template<int size> | |
1342 | void | |
9b07f471 | 1343 | define_with_copy_reloc(Sized_symbol<size>* sym, Output_data* posd, |
fe8718a4 | 1344 | typename elfcpp::Elf_types<size>::Elf_Addr); |
46fe1623 | 1345 | |
61ba1cf9 ILT |
1346 | // Look up a symbol. |
1347 | Symbol* | |
1348 | lookup(const char*, const char* version = NULL) const; | |
1349 | ||
14bfc3f5 | 1350 | // Return the real symbol associated with the forwarder symbol FROM. |
bae7f79e | 1351 | Symbol* |
c06b7b0b | 1352 | resolve_forwards(const Symbol* from) const; |
bae7f79e | 1353 | |
1564db8d ILT |
1354 | // Return the sized version of a symbol in this table. |
1355 | template<int size> | |
1356 | Sized_symbol<size>* | |
7d1a9ebb | 1357 | get_sized_symbol(Symbol*) const; |
1564db8d ILT |
1358 | |
1359 | template<int size> | |
1360 | const Sized_symbol<size>* | |
7d1a9ebb | 1361 | get_sized_symbol(const Symbol*) const; |
54dc6425 | 1362 | |
ead1e424 | 1363 | // Return the count of undefined symbols seen. |
114dfbe1 | 1364 | size_t |
ead1e424 ILT |
1365 | saw_undefined() const |
1366 | { return this->saw_undefined_; } | |
1367 | ||
1368 | // Allocate the common symbols | |
1369 | void | |
7d9e3d98 | 1370 | allocate_commons(Layout*, Mapfile*); |
ead1e424 | 1371 | |
cb295612 ILT |
1372 | // Add a warning for symbol NAME in object OBJ. WARNING is the text |
1373 | // of the warning. | |
f6ce93d6 | 1374 | void |
cb295612 ILT |
1375 | add_warning(const char* name, Object* obj, const std::string& warning) |
1376 | { this->warnings_.add_warning(this, name, obj, warning); } | |
f6ce93d6 ILT |
1377 | |
1378 | // Canonicalize a symbol name for use in the hash table. | |
1379 | const char* | |
1380 | canonicalize_name(const char* name) | |
cfd73a4e | 1381 | { return this->namepool_.add(name, true, NULL); } |
f6ce93d6 ILT |
1382 | |
1383 | // Possibly issue a warning for a reference to SYM at LOCATION which | |
1384 | // is in OBJ. | |
75f2446e | 1385 | template<int size, bool big_endian> |
f6ce93d6 | 1386 | void |
75f2446e ILT |
1387 | issue_warning(const Symbol* sym, |
1388 | const Relocate_info<size, big_endian>* relinfo, | |
1389 | size_t relnum, off_t reloffset) const | |
1390 | { this->warnings_.issue_warning(sym, relinfo, relnum, reloffset); } | |
f6ce93d6 | 1391 | |
70e654ba ILT |
1392 | // Check candidate_odr_violations_ to find symbols with the same name |
1393 | // but apparently different definitions (different source-file/line-no). | |
1394 | void | |
17a1d0a9 | 1395 | detect_odr_violations(const Task*, const char* output_file_name) const; |
70e654ba | 1396 | |
f3e9c5c5 ILT |
1397 | // Add any undefined symbols named on the command line to the symbol |
1398 | // table. | |
1399 | void | |
1400 | add_undefined_symbols_from_command_line(); | |
1401 | ||
46fe1623 ILT |
1402 | // SYM is defined using a COPY reloc. Return the dynamic object |
1403 | // where the original definition was found. | |
1404 | Dynobj* | |
1405 | get_copy_source(const Symbol* sym) const; | |
1406 | ||
a3ad94ed ILT |
1407 | // Set the dynamic symbol indexes. INDEX is the index of the first |
1408 | // global dynamic symbol. Pointers to the symbols are stored into | |
1409 | // the vector. The names are stored into the Stringpool. This | |
1410 | // returns an updated dynamic symbol index. | |
1411 | unsigned int | |
9b07f471 ILT |
1412 | set_dynsym_indexes(unsigned int index, std::vector<Symbol*>*, |
1413 | Stringpool*, Versions*); | |
a3ad94ed | 1414 | |
75f65a3e | 1415 | // Finalize the symbol table after we have set the final addresses |
c06b7b0b | 1416 | // of all the input sections. This sets the final symbol indexes, |
55a93433 ILT |
1417 | // values and adds the names to *POOL. *PLOCAL_SYMCOUNT is the |
1418 | // index of the first global symbol. OFF is the file offset of the | |
1419 | // global symbol table, DYNOFF is the offset of the globals in the | |
1420 | // dynamic symbol table, DYN_GLOBAL_INDEX is the index of the first | |
1421 | // global dynamic symbol, and DYNCOUNT is the number of global | |
1422 | // dynamic symbols. This records the parameters, and returns the | |
1423 | // new file offset. It updates *PLOCAL_SYMCOUNT if it created any | |
1424 | // local symbols. | |
75f65a3e | 1425 | off_t |
55a93433 ILT |
1426 | finalize(off_t off, off_t dynoff, size_t dyn_global_index, size_t dyncount, |
1427 | Stringpool* pool, unsigned int *plocal_symcount); | |
1564db8d | 1428 | |
c0a62865 DK |
1429 | // Status code of Symbol_table::compute_final_value. |
1430 | enum Compute_final_value_status | |
1431 | { | |
1432 | // No error. | |
1433 | CFVS_OK, | |
1434 | // Unspported symbol section. | |
1435 | CFVS_UNSUPPORTED_SYMBOL_SECTION, | |
1436 | // No output section. | |
1437 | CFVS_NO_OUTPUT_SECTION | |
1438 | }; | |
1439 | ||
1440 | // Compute the final value of SYM and store status in location PSTATUS. | |
1441 | // During relaxation, this may be called multiple times for a symbol to | |
1442 | // compute its would-be final value in each relaxation pass. | |
1443 | ||
1444 | template<int size> | |
1445 | typename Sized_symbol<size>::Value_type | |
1446 | compute_final_value(const Sized_symbol<size>* sym, | |
1447 | Compute_final_value_status* pstatus) const; | |
1448 | ||
61ba1cf9 ILT |
1449 | // Write out the global symbols. |
1450 | void | |
fd9d194f | 1451 | write_globals(const Stringpool*, const Stringpool*, |
d491d34e | 1452 | Output_symtab_xindex*, Output_symtab_xindex*, |
16649710 | 1453 | Output_file*) const; |
61ba1cf9 | 1454 | |
a3ad94ed ILT |
1455 | // Write out a section symbol. Return the updated offset. |
1456 | void | |
d491d34e ILT |
1457 | write_section_symbol(const Output_section*, Output_symtab_xindex*, |
1458 | Output_file*, off_t) const; | |
a3ad94ed | 1459 | |
abaa3995 ILT |
1460 | // Dump statistical information to stderr. |
1461 | void | |
1462 | print_stats() const; | |
1463 | ||
09124467 ILT |
1464 | // Return the version script information. |
1465 | const Version_script_info& | |
1466 | version_script() const | |
1467 | { return version_script_; } | |
1468 | ||
bae7f79e ILT |
1469 | private: |
1470 | Symbol_table(const Symbol_table&); | |
1471 | Symbol_table& operator=(const Symbol_table&); | |
1472 | ||
155a0dd7 ILT |
1473 | // The type of the list of common symbols. |
1474 | typedef std::vector<Symbol*> Commons_type; | |
1475 | ||
8c500701 ILT |
1476 | // The type of the symbol hash table. |
1477 | ||
1478 | typedef std::pair<Stringpool::Key, Stringpool::Key> Symbol_table_key; | |
1479 | ||
1480 | struct Symbol_table_hash | |
1481 | { | |
1482 | size_t | |
1483 | operator()(const Symbol_table_key&) const; | |
1484 | }; | |
1485 | ||
1486 | struct Symbol_table_eq | |
1487 | { | |
1488 | bool | |
1489 | operator()(const Symbol_table_key&, const Symbol_table_key&) const; | |
1490 | }; | |
1491 | ||
1492 | typedef Unordered_map<Symbol_table_key, Symbol*, Symbol_table_hash, | |
1493 | Symbol_table_eq> Symbol_table_type; | |
1494 | ||
14bfc3f5 ILT |
1495 | // Make FROM a forwarder symbol to TO. |
1496 | void | |
1497 | make_forwarder(Symbol* from, Symbol* to); | |
1498 | ||
1499 | // Add a symbol. | |
1500 | template<int size, bool big_endian> | |
aeddab66 | 1501 | Sized_symbol<size>* |
f0641a0b ILT |
1502 | add_from_object(Object*, const char *name, Stringpool::Key name_key, |
1503 | const char *version, Stringpool::Key version_key, | |
70e654ba | 1504 | bool def, const elfcpp::Sym<size, big_endian>& sym, |
d491d34e ILT |
1505 | unsigned int st_shndx, bool is_ordinary, |
1506 | unsigned int orig_st_shndx); | |
14bfc3f5 | 1507 | |
8c500701 ILT |
1508 | // Define a default symbol. |
1509 | template<int size, bool big_endian> | |
1510 | void | |
1511 | define_default_version(Sized_symbol<size>*, bool, | |
1512 | Symbol_table_type::iterator); | |
1513 | ||
14bfc3f5 ILT |
1514 | // Resolve symbols. |
1515 | template<int size, bool big_endian> | |
aeddab66 | 1516 | void |
1564db8d ILT |
1517 | resolve(Sized_symbol<size>* to, |
1518 | const elfcpp::Sym<size, big_endian>& sym, | |
d491d34e ILT |
1519 | unsigned int st_shndx, bool is_ordinary, |
1520 | unsigned int orig_st_shndx, | |
14b31740 | 1521 | Object*, const char* version); |
14bfc3f5 | 1522 | |
1564db8d | 1523 | template<int size, bool big_endian> |
aeddab66 | 1524 | void |
95d14cd3 | 1525 | resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from); |
14b31740 | 1526 | |
0602e05a ILT |
1527 | // Record that a symbol is forced to be local by a version script or |
1528 | // by visibility. | |
55a93433 ILT |
1529 | void |
1530 | force_local(Symbol*); | |
1531 | ||
0864d551 ILT |
1532 | // Adjust NAME and *NAME_KEY for wrapping. |
1533 | const char* | |
029ba973 | 1534 | wrap_symbol(const char* name, Stringpool::Key* name_key); |
0864d551 | 1535 | |
86f2e683 ILT |
1536 | // Whether we should override a symbol, based on flags in |
1537 | // resolve.cc. | |
1538 | static bool | |
99fff23b | 1539 | should_override(const Symbol*, unsigned int, Defined, Object*, bool*); |
86f2e683 | 1540 | |
1ae4d23b ILT |
1541 | // Report a problem in symbol resolution. |
1542 | static void | |
1543 | report_resolve_problem(bool is_error, const char* msg, const Symbol* to, | |
99fff23b | 1544 | Defined, Object* object); |
1ae4d23b | 1545 | |
aeddab66 ILT |
1546 | // Override a symbol. |
1547 | template<int size, bool big_endian> | |
1548 | void | |
1549 | override(Sized_symbol<size>* tosym, | |
1550 | const elfcpp::Sym<size, big_endian>& fromsym, | |
d491d34e | 1551 | unsigned int st_shndx, bool is_ordinary, |
aeddab66 ILT |
1552 | Object* object, const char* version); |
1553 | ||
86f2e683 ILT |
1554 | // Whether we should override a symbol with a special symbol which |
1555 | // is automatically defined by the linker. | |
1556 | static bool | |
99fff23b | 1557 | should_override_with_special(const Symbol*, Defined); |
86f2e683 | 1558 | |
aeddab66 ILT |
1559 | // Override a symbol with a special symbol. |
1560 | template<int size> | |
1561 | void | |
1562 | override_with_special(Sized_symbol<size>* tosym, | |
1563 | const Sized_symbol<size>* fromsym); | |
1564 | ||
1565 | // Record all weak alias sets for a dynamic object. | |
1566 | template<int size> | |
1567 | void | |
1568 | record_weak_aliases(std::vector<Sized_symbol<size>*>*); | |
1569 | ||
14b31740 ILT |
1570 | // Define a special symbol. |
1571 | template<int size, bool big_endian> | |
1572 | Sized_symbol<size>* | |
9b07f471 | 1573 | define_special_symbol(const char** pname, const char** pversion, |
8c500701 ILT |
1574 | bool only_if_ref, Sized_symbol<size>** poldsym, |
1575 | bool* resolve_oldsym); | |
14bfc3f5 | 1576 | |
ead1e424 ILT |
1577 | // Define a symbol in an Output_data, sized version. |
1578 | template<int size> | |
14b31740 | 1579 | Sized_symbol<size>* |
99fff23b ILT |
1580 | do_define_in_output_data(const char* name, const char* version, Defined, |
1581 | Output_data*, | |
ead1e424 ILT |
1582 | typename elfcpp::Elf_types<size>::Elf_Addr value, |
1583 | typename elfcpp::Elf_types<size>::Elf_WXword ssize, | |
1584 | elfcpp::STT type, elfcpp::STB binding, | |
1585 | elfcpp::STV visibility, unsigned char nonvis, | |
1586 | bool offset_is_from_end, bool only_if_ref); | |
1587 | ||
1588 | // Define a symbol in an Output_segment, sized version. | |
1589 | template<int size> | |
14b31740 | 1590 | Sized_symbol<size>* |
ead1e424 | 1591 | do_define_in_output_segment( |
99fff23b | 1592 | const char* name, const char* version, Defined, Output_segment* os, |
ead1e424 ILT |
1593 | typename elfcpp::Elf_types<size>::Elf_Addr value, |
1594 | typename elfcpp::Elf_types<size>::Elf_WXword ssize, | |
1595 | elfcpp::STT type, elfcpp::STB binding, | |
1596 | elfcpp::STV visibility, unsigned char nonvis, | |
1597 | Symbol::Segment_offset_base offset_base, bool only_if_ref); | |
1598 | ||
1599 | // Define a symbol as a constant, sized version. | |
1600 | template<int size> | |
14b31740 | 1601 | Sized_symbol<size>* |
ead1e424 | 1602 | do_define_as_constant( |
99fff23b | 1603 | const char* name, const char* version, Defined, |
ead1e424 ILT |
1604 | typename elfcpp::Elf_types<size>::Elf_Addr value, |
1605 | typename elfcpp::Elf_types<size>::Elf_WXword ssize, | |
1606 | elfcpp::STT type, elfcpp::STB binding, | |
1607 | elfcpp::STV visibility, unsigned char nonvis, | |
caa9d5d9 | 1608 | bool only_if_ref, bool force_override); |
ead1e424 | 1609 | |
f3e9c5c5 ILT |
1610 | // Add any undefined symbols named on the command line to the symbol |
1611 | // table, sized version. | |
1612 | template<int size> | |
1613 | void | |
1614 | do_add_undefined_symbols_from_command_line(); | |
1615 | ||
8a5e3e08 ILT |
1616 | // Types of common symbols. |
1617 | ||
1618 | enum Commons_section_type | |
1619 | { | |
1620 | COMMONS_NORMAL, | |
1621 | COMMONS_TLS, | |
1622 | COMMONS_SMALL, | |
1623 | COMMONS_LARGE | |
1624 | }; | |
1625 | ||
ead1e424 ILT |
1626 | // Allocate the common symbols, sized version. |
1627 | template<int size> | |
1628 | void | |
fc59c572 | 1629 | do_allocate_commons(Layout*, Mapfile*, Sort_commons_order); |
155a0dd7 ILT |
1630 | |
1631 | // Allocate the common symbols from one list. | |
1632 | template<int size> | |
1633 | void | |
8a5e3e08 | 1634 | do_allocate_commons_list(Layout*, Commons_section_type, Commons_type*, |
fc59c572 | 1635 | Mapfile*, Sort_commons_order); |
ead1e424 | 1636 | |
70e654ba ILT |
1637 | // Implement detect_odr_violations. |
1638 | template<int size, bool big_endian> | |
1639 | void | |
1640 | sized_detect_odr_violations() const; | |
1641 | ||
75f65a3e ILT |
1642 | // Finalize symbols specialized for size. |
1643 | template<int size> | |
1644 | off_t | |
55a93433 ILT |
1645 | sized_finalize(off_t, Stringpool*, unsigned int*); |
1646 | ||
1647 | // Finalize a symbol. Return whether it should be added to the | |
1648 | // symbol table. | |
1649 | template<int size> | |
1650 | bool | |
1651 | sized_finalize_symbol(Symbol*); | |
1652 | ||
1653 | // Add a symbol the final symtab by setting its index. | |
1654 | template<int size> | |
1655 | void | |
1656 | add_to_final_symtab(Symbol*, Stringpool*, unsigned int* pindex, off_t* poff); | |
75f65a3e | 1657 | |
61ba1cf9 ILT |
1658 | // Write globals specialized for size and endianness. |
1659 | template<int size, bool big_endian> | |
1660 | void | |
fd9d194f ILT |
1661 | sized_write_globals(const Stringpool*, const Stringpool*, |
1662 | Output_symtab_xindex*, Output_symtab_xindex*, | |
1663 | Output_file*) const; | |
16649710 ILT |
1664 | |
1665 | // Write out a symbol to P. | |
1666 | template<int size, bool big_endian> | |
1667 | void | |
ab5c9e90 ILT |
1668 | sized_write_symbol(Sized_symbol<size>*, |
1669 | typename elfcpp::Elf_types<size>::Elf_Addr value, | |
1670 | unsigned int shndx, | |
7d1a9ebb | 1671 | const Stringpool*, unsigned char* p) const; |
61ba1cf9 | 1672 | |
9a2d6984 ILT |
1673 | // Possibly warn about an undefined symbol from a dynamic object. |
1674 | void | |
fd9d194f | 1675 | warn_about_undefined_dynobj_symbol(Symbol*) const; |
9a2d6984 | 1676 | |
a3ad94ed ILT |
1677 | // Write out a section symbol, specialized for size and endianness. |
1678 | template<int size, bool big_endian> | |
1679 | void | |
d491d34e ILT |
1680 | sized_write_section_symbol(const Output_section*, Output_symtab_xindex*, |
1681 | Output_file*, off_t) const; | |
a3ad94ed | 1682 | |
55a93433 ILT |
1683 | // The type of the list of symbols which have been forced local. |
1684 | typedef std::vector<Symbol*> Forced_locals; | |
1685 | ||
46fe1623 ILT |
1686 | // A map from symbols with COPY relocs to the dynamic objects where |
1687 | // they are defined. | |
1688 | typedef Unordered_map<const Symbol*, Dynobj*> Copied_symbol_dynobjs; | |
1689 | ||
70e654ba ILT |
1690 | // A map from symbol name (as a pointer into the namepool) to all |
1691 | // the locations the symbols is (weakly) defined (and certain other | |
1692 | // conditions are met). This map will be used later to detect | |
1693 | // possible One Definition Rule (ODR) violations. | |
1694 | struct Symbol_location | |
1695 | { | |
1696 | Object* object; // Object where the symbol is defined. | |
1697 | unsigned int shndx; // Section-in-object where the symbol is defined. | |
1698 | off_t offset; // Offset-in-section where the symbol is defined. | |
1699 | bool operator==(const Symbol_location& that) const | |
1700 | { | |
1701 | return (this->object == that.object | |
1702 | && this->shndx == that.shndx | |
1703 | && this->offset == that.offset); | |
1704 | } | |
1705 | }; | |
1706 | ||
1707 | struct Symbol_location_hash | |
1708 | { | |
1709 | size_t operator()(const Symbol_location& loc) const | |
1710 | { return reinterpret_cast<uintptr_t>(loc.object) ^ loc.offset ^ loc.shndx; } | |
1711 | }; | |
1712 | ||
1713 | typedef Unordered_map<const char*, | |
1714 | Unordered_set<Symbol_location, Symbol_location_hash> > | |
1715 | Odr_map; | |
1716 | ||
ead1e424 ILT |
1717 | // We increment this every time we see a new undefined symbol, for |
1718 | // use in archive groups. | |
114dfbe1 | 1719 | size_t saw_undefined_; |
c06b7b0b ILT |
1720 | // The index of the first global symbol in the output file. |
1721 | unsigned int first_global_index_; | |
75f65a3e ILT |
1722 | // The file offset within the output symtab section where we should |
1723 | // write the table. | |
1724 | off_t offset_; | |
61ba1cf9 | 1725 | // The number of global symbols we want to write out. |
55a93433 | 1726 | unsigned int output_count_; |
16649710 ILT |
1727 | // The file offset of the global dynamic symbols, or 0 if none. |
1728 | off_t dynamic_offset_; | |
16649710 ILT |
1729 | // The index of the first global dynamic symbol. |
1730 | unsigned int first_dynamic_global_index_; | |
16649710 | 1731 | // The number of global dynamic symbols, or 0 if none. |
55a93433 | 1732 | unsigned int dynamic_count_; |
54dc6425 | 1733 | // The symbol hash table. |
14bfc3f5 | 1734 | Symbol_table_type table_; |
54dc6425 ILT |
1735 | // A pool of symbol names. This is used for all global symbols. |
1736 | // Entries in the hash table point into this pool. | |
14bfc3f5 | 1737 | Stringpool namepool_; |
14bfc3f5 | 1738 | // Forwarding symbols. |
c06b7b0b | 1739 | Unordered_map<const Symbol*, Symbol*> forwarders_; |
aeddab66 ILT |
1740 | // Weak aliases. A symbol in this list points to the next alias. |
1741 | // The aliases point to each other in a circular list. | |
1742 | Unordered_map<Symbol*, Symbol*> weak_aliases_; | |
ead1e424 ILT |
1743 | // We don't expect there to be very many common symbols, so we keep |
1744 | // a list of them. When we find a common symbol we add it to this | |
1745 | // list. It is possible that by the time we process the list the | |
1746 | // symbol is no longer a common symbol. It may also have become a | |
1747 | // forwarder. | |
1748 | Commons_type commons_; | |
155a0dd7 ILT |
1749 | // This is like the commons_ field, except that it holds TLS common |
1750 | // symbols. | |
1751 | Commons_type tls_commons_; | |
8a5e3e08 ILT |
1752 | // This is for small common symbols. |
1753 | Commons_type small_commons_; | |
1754 | // This is for large common symbols. | |
1755 | Commons_type large_commons_; | |
55a93433 ILT |
1756 | // A list of symbols which have been forced to be local. We don't |
1757 | // expect there to be very many of them, so we keep a list of them | |
1758 | // rather than walking the whole table to find them. | |
1759 | Forced_locals forced_locals_; | |
f6ce93d6 ILT |
1760 | // Manage symbol warnings. |
1761 | Warnings warnings_; | |
70e654ba ILT |
1762 | // Manage potential One Definition Rule (ODR) violations. |
1763 | Odr_map candidate_odr_violations_; | |
1764 | ||
46fe1623 ILT |
1765 | // When we emit a COPY reloc for a symbol, we define it in an |
1766 | // Output_data. When it's time to emit version information for it, | |
1767 | // we need to know the dynamic object in which we found the original | |
1768 | // definition. This maps symbols with COPY relocs to the dynamic | |
1769 | // object where they were defined. | |
1770 | Copied_symbol_dynobjs copied_symbol_dynobjs_; | |
09124467 ILT |
1771 | // Information parsed from the version script, if any. |
1772 | const Version_script_info& version_script_; | |
6d03d481 | 1773 | Garbage_collection* gc_; |
ef15dade | 1774 | Icf* icf_; |
bae7f79e ILT |
1775 | }; |
1776 | ||
1564db8d ILT |
1777 | // We inline get_sized_symbol for efficiency. |
1778 | ||
1779 | template<int size> | |
1780 | Sized_symbol<size>* | |
7d1a9ebb | 1781 | Symbol_table::get_sized_symbol(Symbol* sym) const |
1564db8d | 1782 | { |
8851ecca | 1783 | gold_assert(size == parameters->target().get_size()); |
1564db8d ILT |
1784 | return static_cast<Sized_symbol<size>*>(sym); |
1785 | } | |
1786 | ||
1787 | template<int size> | |
1788 | const Sized_symbol<size>* | |
7d1a9ebb | 1789 | Symbol_table::get_sized_symbol(const Symbol* sym) const |
1564db8d | 1790 | { |
8851ecca | 1791 | gold_assert(size == parameters->target().get_size()); |
1564db8d ILT |
1792 | return static_cast<const Sized_symbol<size>*>(sym); |
1793 | } | |
1794 | ||
bae7f79e ILT |
1795 | } // End namespace gold. |
1796 | ||
1797 | #endif // !defined(GOLD_SYMTAB_H) |