Commit | Line | Data |
---|---|---|
bae7f79e ILT |
1 | // symtab.h -- the gold symbol table -*- C++ -*- |
2 | ||
3 | // Symbol_table | |
4 | // The symbol table. | |
5 | ||
bae7f79e ILT |
6 | #include <string> |
7 | #include <utility> | |
ead1e424 | 8 | #include <vector> |
bae7f79e ILT |
9 | |
10 | #include "elfcpp.h" | |
14bfc3f5 | 11 | #include "stringpool.h" |
f6ce93d6 | 12 | #include "object.h" |
bae7f79e ILT |
13 | |
14 | #ifndef GOLD_SYMTAB_H | |
15 | #define GOLD_SYMTAB_H | |
16 | ||
17 | namespace gold | |
18 | { | |
19 | ||
14bfc3f5 | 20 | class Object; |
f6ce93d6 | 21 | class Relobj; |
dbe717ef ILT |
22 | template<int size, bool big_endian> |
23 | class Sized_relobj; | |
f6ce93d6 | 24 | class Dynobj; |
dbe717ef ILT |
25 | template<int size, bool big_endian> |
26 | class Sized_dynobj; | |
14b31740 | 27 | class Versions; |
ead1e424 | 28 | class Output_data; |
a3ad94ed | 29 | class Output_section; |
ead1e424 | 30 | class Output_segment; |
61ba1cf9 ILT |
31 | class Output_file; |
32 | class Target; | |
14bfc3f5 | 33 | |
14bfc3f5 ILT |
34 | // The base class of an entry in the symbol table. The symbol table |
35 | // can have a lot of entries, so we don't want this class to big. | |
36 | // Size dependent fields can be found in the template class | |
37 | // Sized_symbol. Targets may support their own derived classes. | |
bae7f79e | 38 | |
bae7f79e ILT |
39 | class Symbol |
40 | { | |
41 | public: | |
ead1e424 ILT |
42 | // Because we want the class to be small, we don't use any virtual |
43 | // functions. But because symbols can be defined in different | |
44 | // places, we need to classify them. This enum is the different | |
45 | // sources of symbols we support. | |
46 | enum Source | |
47 | { | |
f6ce93d6 ILT |
48 | // Symbol defined in a relocatable or dynamic input file--this is |
49 | // the most common case. | |
ead1e424 ILT |
50 | FROM_OBJECT, |
51 | // Symbol defined in an Output_data, a special section created by | |
52 | // the target. | |
53 | IN_OUTPUT_DATA, | |
54 | // Symbol defined in an Output_segment, with no associated | |
55 | // section. | |
56 | IN_OUTPUT_SEGMENT, | |
57 | // Symbol value is constant. | |
58 | CONSTANT | |
59 | }; | |
60 | ||
61 | // When the source is IN_OUTPUT_SEGMENT, we need to describe what | |
62 | // the offset means. | |
63 | enum Segment_offset_base | |
64 | { | |
65 | // From the start of the segment. | |
66 | SEGMENT_START, | |
67 | // From the end of the segment. | |
68 | SEGMENT_END, | |
69 | // From the filesz of the segment--i.e., after the loaded bytes | |
70 | // but before the bytes which are allocated but zeroed. | |
71 | SEGMENT_BSS | |
72 | }; | |
73 | ||
14bfc3f5 ILT |
74 | // Return the symbol name. |
75 | const char* | |
76 | name() const | |
77 | { return this->name_; } | |
78 | ||
79 | // Return the symbol version. This will return NULL for an | |
80 | // unversioned symbol. | |
81 | const char* | |
82 | version() const | |
83 | { return this->version_; } | |
84 | ||
ead1e424 ILT |
85 | // Return the symbol source. |
86 | Source | |
87 | source() const | |
88 | { return this->source_; } | |
89 | ||
14bfc3f5 ILT |
90 | // Return the object with which this symbol is associated. |
91 | Object* | |
92 | object() const | |
ead1e424 | 93 | { |
a3ad94ed | 94 | gold_assert(this->source_ == FROM_OBJECT); |
ead1e424 ILT |
95 | return this->u_.from_object.object; |
96 | } | |
97 | ||
f6ce93d6 ILT |
98 | // Return the index of the section in the input relocatable or |
99 | // dynamic object file. | |
ead1e424 | 100 | unsigned int |
16649710 | 101 | shndx() const |
ead1e424 | 102 | { |
a3ad94ed | 103 | gold_assert(this->source_ == FROM_OBJECT); |
16649710 | 104 | return this->u_.from_object.shndx; |
ead1e424 ILT |
105 | } |
106 | ||
107 | // Return the output data section with which this symbol is | |
108 | // associated, if the symbol was specially defined with respect to | |
109 | // an output data section. | |
110 | Output_data* | |
111 | output_data() const | |
112 | { | |
a3ad94ed | 113 | gold_assert(this->source_ == IN_OUTPUT_DATA); |
ead1e424 ILT |
114 | return this->u_.in_output_data.output_data; |
115 | } | |
116 | ||
117 | // If this symbol was defined with respect to an output data | |
118 | // section, return whether the value is an offset from end. | |
119 | bool | |
120 | offset_is_from_end() const | |
121 | { | |
a3ad94ed | 122 | gold_assert(this->source_ == IN_OUTPUT_DATA); |
ead1e424 ILT |
123 | return this->u_.in_output_data.offset_is_from_end; |
124 | } | |
125 | ||
126 | // Return the output segment with which this symbol is associated, | |
127 | // if the symbol was specially defined with respect to an output | |
128 | // segment. | |
129 | Output_segment* | |
130 | output_segment() const | |
131 | { | |
a3ad94ed | 132 | gold_assert(this->source_ == IN_OUTPUT_SEGMENT); |
ead1e424 ILT |
133 | return this->u_.in_output_segment.output_segment; |
134 | } | |
135 | ||
136 | // If this symbol was defined with respect to an output segment, | |
137 | // return the offset base. | |
138 | Segment_offset_base | |
139 | offset_base() const | |
140 | { | |
a3ad94ed | 141 | gold_assert(this->source_ == IN_OUTPUT_SEGMENT); |
ead1e424 ILT |
142 | return this->u_.in_output_segment.offset_base; |
143 | } | |
14bfc3f5 ILT |
144 | |
145 | // Return the symbol binding. | |
146 | elfcpp::STB | |
147 | binding() const | |
148 | { return this->binding_; } | |
149 | ||
1564db8d ILT |
150 | // Return the symbol type. |
151 | elfcpp::STT | |
152 | type() const | |
153 | { return this->type_; } | |
154 | ||
155 | // Return the symbol visibility. | |
156 | elfcpp::STV | |
157 | visibility() const | |
158 | { return this->visibility_; } | |
159 | ||
160 | // Return the non-visibility part of the st_other field. | |
161 | unsigned char | |
ead1e424 ILT |
162 | nonvis() const |
163 | { return this->nonvis_; } | |
14bfc3f5 | 164 | |
1564db8d ILT |
165 | // Return whether this symbol is a forwarder. This will never be |
166 | // true of a symbol found in the hash table, but may be true of | |
167 | // symbol pointers attached to object files. | |
168 | bool | |
169 | is_forwarder() const | |
170 | { return this->is_forwarder_; } | |
171 | ||
172 | // Mark this symbol as a forwarder. | |
173 | void | |
174 | set_forwarder() | |
175 | { this->is_forwarder_ = true; } | |
176 | ||
c06b7b0b ILT |
177 | // Return whether this symbol needs an entry in the dynamic symbol |
178 | // table. | |
179 | bool | |
180 | needs_dynsym_entry() const | |
181 | { return this->needs_dynsym_entry_; } | |
182 | ||
183 | // Mark this symbol as needing an entry in the dynamic symbol table. | |
184 | void | |
185 | set_needs_dynsym_entry() | |
186 | { this->needs_dynsym_entry_ = true; } | |
187 | ||
008db82e ILT |
188 | // Return whether this symbol has been seen in a regular object. |
189 | bool | |
190 | in_reg() const | |
191 | { return this->in_reg_; } | |
192 | ||
193 | // Mark this symbol as having been seen in a regular object. | |
194 | void | |
195 | set_in_reg() | |
196 | { this->in_reg_ = true; } | |
197 | ||
1ebd95fd ILT |
198 | // Return whether this symbol has been seen in a dynamic object. |
199 | bool | |
200 | in_dyn() const | |
201 | { return this->in_dyn_; } | |
202 | ||
f6ce93d6 | 203 | // Mark this symbol as having been seen in a dynamic object. |
1564db8d ILT |
204 | void |
205 | set_in_dyn() | |
206 | { this->in_dyn_ = true; } | |
207 | ||
c06b7b0b ILT |
208 | // Return the index of this symbol in the output file symbol table. |
209 | // A value of -1U means that this symbol is not going into the | |
210 | // output file. This starts out as zero, and is set to a non-zero | |
211 | // value by Symbol_table::finalize. It is an error to ask for the | |
212 | // symbol table index before it has been set. | |
213 | unsigned int | |
214 | symtab_index() const | |
215 | { | |
a3ad94ed | 216 | gold_assert(this->symtab_index_ != 0); |
c06b7b0b ILT |
217 | return this->symtab_index_; |
218 | } | |
219 | ||
220 | // Set the index of the symbol in the output file symbol table. | |
221 | void | |
222 | set_symtab_index(unsigned int index) | |
223 | { | |
a3ad94ed | 224 | gold_assert(index != 0); |
c06b7b0b ILT |
225 | this->symtab_index_ = index; |
226 | } | |
227 | ||
a3ad94ed ILT |
228 | // Return whether this symbol already has an index in the output |
229 | // file symbol table. | |
230 | bool | |
231 | has_symtab_index() const | |
232 | { return this->symtab_index_ != 0; } | |
233 | ||
c06b7b0b ILT |
234 | // Return the index of this symbol in the dynamic symbol table. A |
235 | // value of -1U means that this symbol is not going into the dynamic | |
236 | // symbol table. This starts out as zero, and is set to a non-zero | |
237 | // during Layout::finalize. It is an error to ask for the dynamic | |
238 | // symbol table index before it has been set. | |
239 | unsigned int | |
240 | dynsym_index() const | |
241 | { | |
a3ad94ed | 242 | gold_assert(this->dynsym_index_ != 0); |
c06b7b0b ILT |
243 | return this->dynsym_index_; |
244 | } | |
245 | ||
246 | // Set the index of the symbol in the dynamic symbol table. | |
247 | void | |
248 | set_dynsym_index(unsigned int index) | |
249 | { | |
a3ad94ed | 250 | gold_assert(index != 0); |
c06b7b0b ILT |
251 | this->dynsym_index_ = index; |
252 | } | |
253 | ||
16649710 ILT |
254 | // Return whether this symbol already has an index in the dynamic |
255 | // symbol table. | |
256 | bool | |
257 | has_dynsym_index() const | |
258 | { return this->dynsym_index_ != 0; } | |
259 | ||
ead1e424 | 260 | // Return whether this symbol has an entry in the GOT section. |
92e059d8 | 261 | bool |
ead1e424 ILT |
262 | has_got_offset() const |
263 | { return this->has_got_offset_; } | |
264 | ||
265 | // Return the offset into the GOT section of this symbol. | |
266 | unsigned int | |
267 | got_offset() const | |
268 | { | |
a3ad94ed | 269 | gold_assert(this->has_got_offset()); |
ead1e424 ILT |
270 | return this->got_offset_; |
271 | } | |
272 | ||
273 | // Set the GOT offset of this symbol. | |
274 | void | |
275 | set_got_offset(unsigned int got_offset) | |
276 | { | |
277 | this->has_got_offset_ = true; | |
278 | this->got_offset_ = got_offset; | |
279 | } | |
280 | ||
a3ad94ed | 281 | // Return whether this symbol has an entry in the PLT section. |
ead1e424 | 282 | bool |
a3ad94ed ILT |
283 | has_plt_offset() const |
284 | { return this->has_plt_offset_; } | |
285 | ||
286 | // Return the offset into the PLT section of this symbol. | |
287 | unsigned int | |
288 | plt_offset() const | |
289 | { | |
290 | gold_assert(this->has_plt_offset()); | |
291 | return this->plt_offset_; | |
292 | } | |
293 | ||
294 | // Set the PLT offset of this symbol. | |
295 | void | |
296 | set_plt_offset(unsigned int plt_offset) | |
297 | { | |
298 | this->has_plt_offset_ = true; | |
299 | this->plt_offset_ = plt_offset; | |
300 | } | |
301 | ||
302 | // Return true if the final value of this symbol is known at link | |
303 | // time. | |
304 | bool | |
305 | final_value_is_known(const General_options* options) const | |
306 | { | |
307 | if (options->is_shared()) | |
308 | return false; | |
309 | return this->source_ != FROM_OBJECT || !this->object()->is_dynamic(); | |
310 | } | |
ead1e424 | 311 | |
f6ce93d6 ILT |
312 | // Return whether this is a defined symbol (not undefined or |
313 | // common). | |
314 | bool | |
315 | is_defined() const | |
316 | { | |
317 | return (this->source_ != FROM_OBJECT | |
16649710 ILT |
318 | || (this->shndx() != elfcpp::SHN_UNDEF |
319 | && this->shndx() != elfcpp::SHN_COMMON)); | |
a3ad94ed ILT |
320 | } |
321 | ||
14b31740 | 322 | // Return true if this symbol is from a dynamic object. |
a3ad94ed | 323 | bool |
14b31740 | 324 | is_from_dynobj() const |
a3ad94ed | 325 | { |
14b31740 | 326 | return this->source_ == FROM_OBJECT && this->object()->is_dynamic(); |
f6ce93d6 ILT |
327 | } |
328 | ||
ead1e424 ILT |
329 | // Return whether this is an undefined symbol. |
330 | bool | |
331 | is_undefined() const | |
332 | { | |
16649710 | 333 | return this->source_ == FROM_OBJECT && this->shndx() == elfcpp::SHN_UNDEF; |
ead1e424 ILT |
334 | } |
335 | ||
336 | // Return whether this is a common symbol. | |
337 | bool | |
338 | is_common() const | |
339 | { | |
f6ce93d6 | 340 | return (this->source_ == FROM_OBJECT |
16649710 | 341 | && (this->shndx() == elfcpp::SHN_COMMON |
f6ce93d6 | 342 | || this->type_ == elfcpp::STT_COMMON)); |
ead1e424 | 343 | } |
92e059d8 | 344 | |
a6badf5a ILT |
345 | // Return whether this symbol can be seen outside this object. |
346 | bool | |
347 | is_externally_visible() const | |
348 | { | |
349 | return (this->visibility_ == elfcpp::STV_DEFAULT | |
350 | || this->visibility_ == elfcpp::STV_PROTECTED); | |
351 | } | |
352 | ||
f6ce93d6 ILT |
353 | // Return whether there should be a warning for references to this |
354 | // symbol. | |
355 | bool | |
356 | has_warning() const | |
357 | { return this->has_warning_; } | |
358 | ||
359 | // Mark this symbol as having a warning. | |
360 | void | |
361 | set_has_warning() | |
362 | { this->has_warning_ = true; } | |
363 | ||
14bfc3f5 ILT |
364 | protected: |
365 | // Instances of this class should always be created at a specific | |
366 | // size. | |
367 | Symbol() | |
f6ce93d6 | 368 | { memset(this, 0, sizeof *this); } |
14bfc3f5 | 369 | |
ead1e424 ILT |
370 | // Initialize the general fields. |
371 | void | |
372 | init_fields(const char* name, const char* version, | |
373 | elfcpp::STT type, elfcpp::STB binding, | |
374 | elfcpp::STV visibility, unsigned char nonvis); | |
375 | ||
14bfc3f5 ILT |
376 | // Initialize fields from an ELF symbol in OBJECT. |
377 | template<int size, bool big_endian> | |
378 | void | |
379 | init_base(const char *name, const char* version, Object* object, | |
380 | const elfcpp::Sym<size, big_endian>&); | |
bae7f79e | 381 | |
ead1e424 ILT |
382 | // Initialize fields for an Output_data. |
383 | void | |
384 | init_base(const char* name, Output_data*, elfcpp::STT, elfcpp::STB, | |
385 | elfcpp::STV, unsigned char nonvis, bool offset_is_from_end); | |
386 | ||
387 | // Initialize fields for an Output_segment. | |
388 | void | |
389 | init_base(const char* name, Output_segment* os, elfcpp::STT type, | |
390 | elfcpp::STB binding, elfcpp::STV visibility, | |
391 | unsigned char nonvis, Segment_offset_base offset_base); | |
392 | ||
393 | // Initialize fields for a constant. | |
394 | void | |
395 | init_base(const char* name, elfcpp::STT type, elfcpp::STB binding, | |
396 | elfcpp::STV visibility, unsigned char nonvis); | |
397 | ||
1564db8d ILT |
398 | // Override existing symbol. |
399 | template<int size, bool big_endian> | |
400 | void | |
14b31740 ILT |
401 | override_base(const elfcpp::Sym<size, big_endian>&, Object* object, |
402 | const char* version); | |
1564db8d | 403 | |
bae7f79e | 404 | private: |
14bfc3f5 ILT |
405 | Symbol(const Symbol&); |
406 | Symbol& operator=(const Symbol&); | |
407 | ||
408 | // Symbol name (expected to point into a Stringpool). | |
409 | const char* name_; | |
410 | // Symbol version (expected to point into a Stringpool). This may | |
411 | // be NULL. | |
bae7f79e | 412 | const char* version_; |
ead1e424 ILT |
413 | |
414 | union | |
415 | { | |
416 | // This struct is used if SOURCE_ == FROM_OBJECT. | |
417 | struct | |
418 | { | |
419 | // Object in which symbol is defined, or in which it was first | |
420 | // seen. | |
421 | Object* object; | |
422 | // Section number in object_ in which symbol is defined. | |
16649710 | 423 | unsigned int shndx; |
ead1e424 ILT |
424 | } from_object; |
425 | ||
426 | // This struct is used if SOURCE_ == IN_OUTPUT_DATA. | |
427 | struct | |
428 | { | |
429 | // Output_data in which symbol is defined. Before | |
430 | // Layout::finalize the symbol's value is an offset within the | |
431 | // Output_data. | |
432 | Output_data* output_data; | |
433 | // True if the offset is from the end, false if the offset is | |
434 | // from the beginning. | |
435 | bool offset_is_from_end; | |
436 | } in_output_data; | |
437 | ||
438 | // This struct is used if SOURCE_ == IN_OUTPUT_SEGMENT. | |
439 | struct | |
440 | { | |
441 | // Output_segment in which the symbol is defined. Before | |
442 | // Layout::finalize the symbol's value is an offset. | |
443 | Output_segment* output_segment; | |
444 | // The base to use for the offset before Layout::finalize. | |
445 | Segment_offset_base offset_base; | |
446 | } in_output_segment; | |
447 | } u_; | |
448 | ||
c06b7b0b ILT |
449 | // The index of this symbol in the output file. If the symbol is |
450 | // not going into the output file, this value is -1U. This field | |
451 | // starts as always holding zero. It is set to a non-zero value by | |
452 | // Symbol_table::finalize. | |
453 | unsigned int symtab_index_; | |
454 | ||
455 | // The index of this symbol in the dynamic symbol table. If the | |
456 | // symbol is not going into the dynamic symbol table, this value is | |
457 | // -1U. This field starts as always holding zero. It is set to a | |
458 | // non-zero value during Layout::finalize. | |
459 | unsigned int dynsym_index_; | |
460 | ||
ead1e424 | 461 | // If this symbol has an entry in the GOT section (has_got_offset_ |
c06b7b0b | 462 | // is true), this is the offset from the start of the GOT section. |
ead1e424 | 463 | unsigned int got_offset_; |
c06b7b0b | 464 | |
a3ad94ed ILT |
465 | // If this symbol has an entry in the PLT section (has_plt_offset_ |
466 | // is true), then this is the offset from the start of the PLT | |
467 | // section. | |
468 | unsigned int plt_offset_; | |
469 | ||
14bfc3f5 | 470 | // Symbol type. |
bae7f79e | 471 | elfcpp::STT type_ : 4; |
14bfc3f5 | 472 | // Symbol binding. |
bae7f79e | 473 | elfcpp::STB binding_ : 4; |
14bfc3f5 ILT |
474 | // Symbol visibility. |
475 | elfcpp::STV visibility_ : 2; | |
476 | // Rest of symbol st_other field. | |
ead1e424 ILT |
477 | unsigned int nonvis_ : 6; |
478 | // The type of symbol. | |
f6ce93d6 | 479 | Source source_ : 3; |
14bfc3f5 ILT |
480 | // True if this symbol always requires special target-specific |
481 | // handling. | |
ead1e424 | 482 | bool is_target_special_ : 1; |
14bfc3f5 | 483 | // True if this is the default version of the symbol. |
1564db8d | 484 | bool is_def_ : 1; |
14bfc3f5 ILT |
485 | // True if this symbol really forwards to another symbol. This is |
486 | // used when we discover after the fact that two different entries | |
487 | // in the hash table really refer to the same symbol. This will | |
488 | // never be set for a symbol found in the hash table, but may be set | |
489 | // for a symbol found in the list of symbols attached to an Object. | |
490 | // It forwards to the symbol found in the forwarders_ map of | |
491 | // Symbol_table. | |
1564db8d | 492 | bool is_forwarder_ : 1; |
c06b7b0b ILT |
493 | // True if this symbol needs to be in the dynamic symbol table. |
494 | bool needs_dynsym_entry_ : 1; | |
008db82e ILT |
495 | // True if we've seen this symbol in a regular object. |
496 | bool in_reg_ : 1; | |
1564db8d ILT |
497 | // True if we've seen this symbol in a dynamic object. |
498 | bool in_dyn_ : 1; | |
ead1e424 ILT |
499 | // True if the symbol has an entry in the GOT section. |
500 | bool has_got_offset_ : 1; | |
a3ad94ed ILT |
501 | // True if the symbol has an entry in the PLT section. |
502 | bool has_plt_offset_ : 1; | |
f6ce93d6 ILT |
503 | // True if there is a warning for this symbol. |
504 | bool has_warning_ : 1; | |
bae7f79e ILT |
505 | }; |
506 | ||
14bfc3f5 ILT |
507 | // The parts of a symbol which are size specific. Using a template |
508 | // derived class like this helps us use less space on a 32-bit system. | |
bae7f79e ILT |
509 | |
510 | template<int size> | |
14bfc3f5 ILT |
511 | class Sized_symbol : public Symbol |
512 | { | |
513 | public: | |
1564db8d ILT |
514 | typedef typename elfcpp::Elf_types<size>::Elf_Addr Value_type; |
515 | typedef typename elfcpp::Elf_types<size>::Elf_WXword Size_type; | |
516 | ||
14bfc3f5 ILT |
517 | Sized_symbol() |
518 | { } | |
519 | ||
520 | // Initialize fields from an ELF symbol in OBJECT. | |
521 | template<bool big_endian> | |
522 | void | |
523 | init(const char *name, const char* version, Object* object, | |
524 | const elfcpp::Sym<size, big_endian>&); | |
525 | ||
ead1e424 ILT |
526 | // Initialize fields for an Output_data. |
527 | void | |
528 | init(const char* name, Output_data*, Value_type value, Size_type symsize, | |
529 | elfcpp::STT, elfcpp::STB, elfcpp::STV, unsigned char nonvis, | |
530 | bool offset_is_from_end); | |
531 | ||
532 | // Initialize fields for an Output_segment. | |
533 | void | |
534 | init(const char* name, Output_segment*, Value_type value, Size_type symsize, | |
535 | elfcpp::STT, elfcpp::STB, elfcpp::STV, unsigned char nonvis, | |
536 | Segment_offset_base offset_base); | |
537 | ||
538 | // Initialize fields for a constant. | |
539 | void | |
540 | init(const char* name, Value_type value, Size_type symsize, | |
541 | elfcpp::STT, elfcpp::STB, elfcpp::STV, unsigned char nonvis); | |
542 | ||
1564db8d ILT |
543 | // Override existing symbol. |
544 | template<bool big_endian> | |
545 | void | |
14b31740 ILT |
546 | override(const elfcpp::Sym<size, big_endian>&, Object* object, |
547 | const char* version); | |
1564db8d ILT |
548 | |
549 | // Return the symbol's value. | |
550 | Value_type | |
551 | value() const | |
552 | { return this->value_; } | |
553 | ||
554 | // Return the symbol's size (we can't call this 'size' because that | |
555 | // is a template parameter). | |
556 | Size_type | |
557 | symsize() const | |
ead1e424 ILT |
558 | { return this->symsize_; } |
559 | ||
560 | // Set the symbol size. This is used when resolving common symbols. | |
561 | void | |
562 | set_symsize(Size_type symsize) | |
563 | { this->symsize_ = symsize; } | |
1564db8d | 564 | |
75f65a3e ILT |
565 | // Set the symbol value. This is called when we store the final |
566 | // values of the symbols into the symbol table. | |
567 | void | |
568 | set_value(Value_type value) | |
569 | { this->value_ = value; } | |
570 | ||
14bfc3f5 ILT |
571 | private: |
572 | Sized_symbol(const Sized_symbol&); | |
573 | Sized_symbol& operator=(const Sized_symbol&); | |
574 | ||
ead1e424 ILT |
575 | // Symbol value. Before Layout::finalize this is the offset in the |
576 | // input section. This is set to the final value during | |
577 | // Layout::finalize. | |
1564db8d | 578 | Value_type value_; |
14bfc3f5 | 579 | // Symbol size. |
ead1e424 ILT |
580 | Size_type symsize_; |
581 | }; | |
582 | ||
583 | // A struct describing a symbol defined by the linker, where the value | |
584 | // of the symbol is defined based on an output section. This is used | |
585 | // for symbols defined by the linker, like "_init_array_start". | |
586 | ||
587 | struct Define_symbol_in_section | |
588 | { | |
589 | // The symbol name. | |
590 | const char* name; | |
591 | // The name of the output section with which this symbol should be | |
592 | // associated. If there is no output section with that name, the | |
593 | // symbol will be defined as zero. | |
594 | const char* output_section; | |
595 | // The offset of the symbol within the output section. This is an | |
596 | // offset from the start of the output section, unless start_at_end | |
597 | // is true, in which case this is an offset from the end of the | |
598 | // output section. | |
599 | uint64_t value; | |
600 | // The size of the symbol. | |
601 | uint64_t size; | |
602 | // The symbol type. | |
603 | elfcpp::STT type; | |
604 | // The symbol binding. | |
605 | elfcpp::STB binding; | |
606 | // The symbol visibility. | |
607 | elfcpp::STV visibility; | |
608 | // The rest of the st_other field. | |
609 | unsigned char nonvis; | |
610 | // If true, the value field is an offset from the end of the output | |
611 | // section. | |
612 | bool offset_is_from_end; | |
613 | // If true, this symbol is defined only if we see a reference to it. | |
614 | bool only_if_ref; | |
615 | }; | |
616 | ||
617 | // A struct describing a symbol defined by the linker, where the value | |
618 | // of the symbol is defined based on a segment. This is used for | |
619 | // symbols defined by the linker, like "_end". We describe the | |
620 | // segment with which the symbol should be associated by its | |
621 | // characteristics. If no segment meets these characteristics, the | |
622 | // symbol will be defined as zero. If there is more than one segment | |
623 | // which meets these characteristics, we will use the first one. | |
624 | ||
625 | struct Define_symbol_in_segment | |
626 | { | |
627 | // The symbol name. | |
628 | const char* name; | |
629 | // The segment type where the symbol should be defined, typically | |
630 | // PT_LOAD. | |
631 | elfcpp::PT segment_type; | |
632 | // Bitmask of segment flags which must be set. | |
633 | elfcpp::PF segment_flags_set; | |
634 | // Bitmask of segment flags which must be clear. | |
635 | elfcpp::PF segment_flags_clear; | |
636 | // The offset of the symbol within the segment. The offset is | |
637 | // calculated from the position set by offset_base. | |
638 | uint64_t value; | |
639 | // The size of the symbol. | |
640 | uint64_t size; | |
641 | // The symbol type. | |
642 | elfcpp::STT type; | |
643 | // The symbol binding. | |
644 | elfcpp::STB binding; | |
645 | // The symbol visibility. | |
646 | elfcpp::STV visibility; | |
647 | // The rest of the st_other field. | |
648 | unsigned char nonvis; | |
649 | // The base from which we compute the offset. | |
650 | Symbol::Segment_offset_base offset_base; | |
651 | // If true, this symbol is defined only if we see a reference to it. | |
652 | bool only_if_ref; | |
14bfc3f5 ILT |
653 | }; |
654 | ||
f6ce93d6 ILT |
655 | // This class manages warnings. Warnings are a GNU extension. When |
656 | // we see a section named .gnu.warning.SYM in an object file, and if | |
657 | // we wind using the definition of SYM from that object file, then we | |
658 | // will issue a warning for any relocation against SYM from a | |
659 | // different object file. The text of the warning is the contents of | |
660 | // the section. This is not precisely the definition used by the old | |
661 | // GNU linker; the old GNU linker treated an occurrence of | |
662 | // .gnu.warning.SYM as defining a warning symbol. A warning symbol | |
663 | // would trigger a warning on any reference. However, it was | |
664 | // inconsistent in that a warning in a dynamic object only triggered | |
665 | // if there was no definition in a regular object. This linker is | |
666 | // different in that we only issue a warning if we use the symbol | |
667 | // definition from the same object file as the warning section. | |
668 | ||
669 | class Warnings | |
670 | { | |
671 | public: | |
672 | Warnings() | |
673 | : warnings_() | |
674 | { } | |
675 | ||
676 | // Add a warning for symbol NAME in section SHNDX in object OBJ. | |
677 | void | |
678 | add_warning(Symbol_table* symtab, const char* name, Object* obj, | |
679 | unsigned int shndx); | |
680 | ||
681 | // For each symbol for which we should give a warning, make a note | |
682 | // on the symbol. | |
683 | void | |
684 | note_warnings(Symbol_table* symtab); | |
685 | ||
686 | // Issue a warning for a reference to SYM at LOCATION. | |
687 | void | |
c06b7b0b | 688 | issue_warning(const Symbol* sym, const std::string& location) const; |
f6ce93d6 ILT |
689 | |
690 | private: | |
691 | Warnings(const Warnings&); | |
692 | Warnings& operator=(const Warnings&); | |
693 | ||
694 | // What we need to know to get the warning text. | |
695 | struct Warning_location | |
696 | { | |
697 | // The object the warning is in. | |
698 | Object* object; | |
699 | // The index of the warning section. | |
700 | unsigned int shndx; | |
701 | // The warning text if we have already loaded it. | |
702 | std::string text; | |
703 | ||
704 | Warning_location() | |
705 | : object(NULL), shndx(0), text() | |
706 | { } | |
707 | ||
708 | void | |
709 | set(Object* o, unsigned int s) | |
710 | { | |
711 | this->object = o; | |
712 | this->shndx = s; | |
713 | } | |
714 | ||
715 | void | |
716 | set_text(const char* t, off_t l) | |
717 | { this->text.assign(t, l); } | |
718 | }; | |
719 | ||
720 | // A mapping from warning symbol names (canonicalized in | |
721 | // Symbol_table's namepool_ field) to | |
722 | typedef Unordered_map<const char*, Warning_location> Warning_table; | |
723 | ||
724 | Warning_table warnings_; | |
725 | }; | |
726 | ||
14bfc3f5 ILT |
727 | // The main linker symbol table. |
728 | ||
bae7f79e ILT |
729 | class Symbol_table |
730 | { | |
731 | public: | |
732 | Symbol_table(); | |
733 | ||
1564db8d | 734 | ~Symbol_table(); |
bae7f79e | 735 | |
dbe717ef | 736 | // Add COUNT external symbols from the relocatable object RELOBJ to |
f6ce93d6 ILT |
737 | // the symbol table. SYMS is the symbols, SYM_NAMES is their names, |
738 | // SYM_NAME_SIZE is the size of SYM_NAMES. This sets SYMPOINTERS to | |
739 | // point to the symbols in the symbol table. | |
14bfc3f5 ILT |
740 | template<int size, bool big_endian> |
741 | void | |
dbe717ef ILT |
742 | add_from_relobj(Sized_relobj<size, big_endian>* relobj, |
743 | const unsigned char* syms, size_t count, | |
744 | const char* sym_names, size_t sym_name_size, | |
14bfc3f5 ILT |
745 | Symbol** sympointers); |
746 | ||
dbe717ef ILT |
747 | // Add COUNT dynamic symbols from the dynamic object DYNOBJ to the |
748 | // symbol table. SYMS is the symbols. SYM_NAMES is their names. | |
749 | // SYM_NAME_SIZE is the size of SYM_NAMES. The other parameters are | |
750 | // symbol version data. | |
751 | template<int size, bool big_endian> | |
752 | void | |
753 | add_from_dynobj(Sized_dynobj<size, big_endian>* dynobj, | |
754 | const unsigned char* syms, size_t count, | |
755 | const char* sym_names, size_t sym_name_size, | |
756 | const unsigned char* versym, size_t versym_size, | |
757 | const std::vector<const char*>*); | |
758 | ||
ead1e424 ILT |
759 | // Define a special symbol based on an Output_data. It is a |
760 | // multiple definition error if this symbol is already defined. | |
14b31740 ILT |
761 | Symbol* |
762 | define_in_output_data(const Target*, const char* name, const char* version, | |
763 | Output_data*, uint64_t value, uint64_t symsize, | |
ead1e424 ILT |
764 | elfcpp::STT type, elfcpp::STB binding, |
765 | elfcpp::STV visibility, unsigned char nonvis, | |
766 | bool offset_is_from_end, bool only_if_ref); | |
767 | ||
768 | // Define a special symbol based on an Output_segment. It is a | |
769 | // multiple definition error if this symbol is already defined. | |
14b31740 ILT |
770 | Symbol* |
771 | define_in_output_segment(const Target*, const char* name, | |
772 | const char* version, Output_segment*, | |
ead1e424 ILT |
773 | uint64_t value, uint64_t symsize, |
774 | elfcpp::STT type, elfcpp::STB binding, | |
775 | elfcpp::STV visibility, unsigned char nonvis, | |
776 | Symbol::Segment_offset_base, bool only_if_ref); | |
777 | ||
778 | // Define a special symbol with a constant value. It is a multiple | |
779 | // definition error if this symbol is already defined. | |
14b31740 ILT |
780 | Symbol* |
781 | define_as_constant(const Target*, const char* name, const char* version, | |
782 | uint64_t value, uint64_t symsize, elfcpp::STT type, | |
783 | elfcpp::STB binding, elfcpp::STV visibility, | |
784 | unsigned char nonvis, bool only_if_ref); | |
ead1e424 ILT |
785 | |
786 | // Define a set of symbols in output sections. | |
787 | void | |
14b31740 | 788 | define_symbols(const Layout*, const Target*, int count, |
ead1e424 ILT |
789 | const Define_symbol_in_section*); |
790 | ||
791 | // Define a set of symbols in output segments. | |
792 | void | |
14b31740 | 793 | define_symbols(const Layout*, const Target*, int count, |
ead1e424 ILT |
794 | const Define_symbol_in_segment*); |
795 | ||
61ba1cf9 ILT |
796 | // Look up a symbol. |
797 | Symbol* | |
798 | lookup(const char*, const char* version = NULL) const; | |
799 | ||
14bfc3f5 | 800 | // Return the real symbol associated with the forwarder symbol FROM. |
bae7f79e | 801 | Symbol* |
c06b7b0b | 802 | resolve_forwards(const Symbol* from) const; |
bae7f79e | 803 | |
a3ad94ed | 804 | // Return the bitsize (32 or 64) of the symbols in the table. |
14bfc3f5 ILT |
805 | int |
806 | get_size() const | |
807 | { return this->size_; } | |
bae7f79e | 808 | |
1564db8d ILT |
809 | // Return the sized version of a symbol in this table. |
810 | template<int size> | |
811 | Sized_symbol<size>* | |
5482377d | 812 | get_sized_symbol(Symbol* ACCEPT_SIZE) const; |
1564db8d ILT |
813 | |
814 | template<int size> | |
815 | const Sized_symbol<size>* | |
5482377d | 816 | get_sized_symbol(const Symbol* ACCEPT_SIZE) const; |
54dc6425 | 817 | |
ead1e424 ILT |
818 | // Return the count of undefined symbols seen. |
819 | int | |
820 | saw_undefined() const | |
821 | { return this->saw_undefined_; } | |
822 | ||
823 | // Allocate the common symbols | |
824 | void | |
825 | allocate_commons(const General_options&, Layout*); | |
826 | ||
f6ce93d6 ILT |
827 | // Add a warning for symbol NAME in section SHNDX in object OBJ. |
828 | void | |
829 | add_warning(const char* name, Object* obj, unsigned int shndx) | |
830 | { this->warnings_.add_warning(this, name, obj, shndx); } | |
831 | ||
832 | // Canonicalize a symbol name for use in the hash table. | |
833 | const char* | |
834 | canonicalize_name(const char* name) | |
f0641a0b | 835 | { return this->namepool_.add(name, NULL); } |
f6ce93d6 ILT |
836 | |
837 | // Possibly issue a warning for a reference to SYM at LOCATION which | |
838 | // is in OBJ. | |
839 | void | |
c06b7b0b | 840 | issue_warning(const Symbol* sym, const std::string& location) const |
f6ce93d6 ILT |
841 | { this->warnings_.issue_warning(sym, location); } |
842 | ||
a3ad94ed ILT |
843 | // Set the dynamic symbol indexes. INDEX is the index of the first |
844 | // global dynamic symbol. Pointers to the symbols are stored into | |
845 | // the vector. The names are stored into the Stringpool. This | |
846 | // returns an updated dynamic symbol index. | |
847 | unsigned int | |
14b31740 ILT |
848 | set_dynsym_indexes(const General_options*, const Target*, unsigned int index, |
849 | std::vector<Symbol*>*, Stringpool*, Versions*); | |
a3ad94ed | 850 | |
75f65a3e | 851 | // Finalize the symbol table after we have set the final addresses |
c06b7b0b ILT |
852 | // of all the input sections. This sets the final symbol indexes, |
853 | // values and adds the names to *POOL. INDEX is the index of the | |
16649710 ILT |
854 | // first global symbol. OFF is the file offset of the global symbol |
855 | // table, DYNOFF is the offset of the globals in the dynamic symbol | |
856 | // table, DYN_GLOBAL_INDEX is the index of the first global dynamic | |
857 | // symbol, and DYNCOUNT is the number of global dynamic symbols. | |
858 | // This records the parameters, and returns the new file offset. | |
75f65a3e | 859 | off_t |
16649710 ILT |
860 | finalize(unsigned int index, off_t off, off_t dynoff, |
861 | size_t dyn_global_index, size_t dyncount, Stringpool* pool); | |
1564db8d | 862 | |
61ba1cf9 ILT |
863 | // Write out the global symbols. |
864 | void | |
16649710 ILT |
865 | write_globals(const Target*, const Stringpool*, const Stringpool*, |
866 | Output_file*) const; | |
61ba1cf9 | 867 | |
a3ad94ed ILT |
868 | // Write out a section symbol. Return the updated offset. |
869 | void | |
870 | write_section_symbol(const Target*, const Output_section*, Output_file*, | |
871 | off_t) const; | |
872 | ||
bae7f79e ILT |
873 | private: |
874 | Symbol_table(const Symbol_table&); | |
875 | Symbol_table& operator=(const Symbol_table&); | |
876 | ||
a3ad94ed | 877 | // Set the size (32 or 64) of the symbols in the table. |
14bfc3f5 ILT |
878 | void |
879 | set_size(int size) | |
880 | { this->size_ = size; } | |
881 | ||
882 | // Make FROM a forwarder symbol to TO. | |
883 | void | |
884 | make_forwarder(Symbol* from, Symbol* to); | |
885 | ||
886 | // Add a symbol. | |
887 | template<int size, bool big_endian> | |
888 | Symbol* | |
f0641a0b ILT |
889 | add_from_object(Object*, const char *name, Stringpool::Key name_key, |
890 | const char *version, Stringpool::Key version_key, | |
891 | bool def, const elfcpp::Sym<size, big_endian>& sym); | |
14bfc3f5 ILT |
892 | |
893 | // Resolve symbols. | |
894 | template<int size, bool big_endian> | |
895 | static void | |
1564db8d ILT |
896 | resolve(Sized_symbol<size>* to, |
897 | const elfcpp::Sym<size, big_endian>& sym, | |
14b31740 | 898 | Object*, const char* version); |
14bfc3f5 | 899 | |
1564db8d | 900 | template<int size, bool big_endian> |
14bfc3f5 | 901 | static void |
14b31740 ILT |
902 | resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from, |
903 | const char* version ACCEPT_SIZE_ENDIAN); | |
904 | ||
905 | // Define a special symbol. | |
906 | template<int size, bool big_endian> | |
907 | Sized_symbol<size>* | |
908 | define_special_symbol(const Target* target, const char* name, | |
909 | const char* version, bool only_if_ref | |
910 | ACCEPT_SIZE_ENDIAN); | |
14bfc3f5 | 911 | |
ead1e424 ILT |
912 | // Define a symbol in an Output_data, sized version. |
913 | template<int size> | |
14b31740 ILT |
914 | Sized_symbol<size>* |
915 | do_define_in_output_data(const Target*, const char* name, | |
916 | const char* version, Output_data*, | |
ead1e424 ILT |
917 | typename elfcpp::Elf_types<size>::Elf_Addr value, |
918 | typename elfcpp::Elf_types<size>::Elf_WXword ssize, | |
919 | elfcpp::STT type, elfcpp::STB binding, | |
920 | elfcpp::STV visibility, unsigned char nonvis, | |
921 | bool offset_is_from_end, bool only_if_ref); | |
922 | ||
923 | // Define a symbol in an Output_segment, sized version. | |
924 | template<int size> | |
14b31740 | 925 | Sized_symbol<size>* |
ead1e424 | 926 | do_define_in_output_segment( |
14b31740 | 927 | const Target*, const char* name, const char* version, Output_segment* os, |
ead1e424 ILT |
928 | typename elfcpp::Elf_types<size>::Elf_Addr value, |
929 | typename elfcpp::Elf_types<size>::Elf_WXword ssize, | |
930 | elfcpp::STT type, elfcpp::STB binding, | |
931 | elfcpp::STV visibility, unsigned char nonvis, | |
932 | Symbol::Segment_offset_base offset_base, bool only_if_ref); | |
933 | ||
934 | // Define a symbol as a constant, sized version. | |
935 | template<int size> | |
14b31740 | 936 | Sized_symbol<size>* |
ead1e424 | 937 | do_define_as_constant( |
14b31740 | 938 | const Target*, const char* name, const char* version, |
ead1e424 ILT |
939 | typename elfcpp::Elf_types<size>::Elf_Addr value, |
940 | typename elfcpp::Elf_types<size>::Elf_WXword ssize, | |
941 | elfcpp::STT type, elfcpp::STB binding, | |
942 | elfcpp::STV visibility, unsigned char nonvis, | |
943 | bool only_if_ref); | |
944 | ||
945 | // Allocate the common symbols, sized version. | |
946 | template<int size> | |
947 | void | |
948 | do_allocate_commons(const General_options&, Layout*); | |
949 | ||
75f65a3e ILT |
950 | // Finalize symbols specialized for size. |
951 | template<int size> | |
952 | off_t | |
c06b7b0b | 953 | sized_finalize(unsigned int, off_t, Stringpool*); |
75f65a3e | 954 | |
61ba1cf9 ILT |
955 | // Write globals specialized for size and endianness. |
956 | template<int size, bool big_endian> | |
957 | void | |
16649710 ILT |
958 | sized_write_globals(const Target*, const Stringpool*, const Stringpool*, |
959 | Output_file*) const; | |
960 | ||
961 | // Write out a symbol to P. | |
962 | template<int size, bool big_endian> | |
963 | void | |
964 | sized_write_symbol(Sized_symbol<size>*, unsigned int shndx, | |
6a469986 ILT |
965 | const Stringpool*, unsigned char* p |
966 | ACCEPT_SIZE_ENDIAN) const; | |
61ba1cf9 | 967 | |
a3ad94ed ILT |
968 | // Write out a section symbol, specialized for size and endianness. |
969 | template<int size, bool big_endian> | |
970 | void | |
971 | sized_write_section_symbol(const Output_section*, Output_file*, off_t) const; | |
972 | ||
54dc6425 ILT |
973 | // The type of the symbol hash table. |
974 | ||
f0641a0b | 975 | typedef std::pair<Stringpool::Key, Stringpool::Key> Symbol_table_key; |
14bfc3f5 ILT |
976 | |
977 | struct Symbol_table_hash | |
978 | { | |
979 | size_t | |
980 | operator()(const Symbol_table_key&) const; | |
981 | }; | |
982 | ||
983 | struct Symbol_table_eq | |
984 | { | |
985 | bool | |
986 | operator()(const Symbol_table_key&, const Symbol_table_key&) const; | |
987 | }; | |
988 | ||
989 | typedef Unordered_map<Symbol_table_key, Symbol*, Symbol_table_hash, | |
990 | Symbol_table_eq> Symbol_table_type; | |
991 | ||
ead1e424 ILT |
992 | // The type of the list of common symbols. |
993 | ||
994 | typedef std::vector<Symbol*> Commons_type; | |
995 | ||
14bfc3f5 ILT |
996 | // The size of the symbols in the symbol table (32 or 64). |
997 | int size_; | |
998 | ||
ead1e424 ILT |
999 | // We increment this every time we see a new undefined symbol, for |
1000 | // use in archive groups. | |
1001 | int saw_undefined_; | |
1002 | ||
c06b7b0b ILT |
1003 | // The index of the first global symbol in the output file. |
1004 | unsigned int first_global_index_; | |
1005 | ||
75f65a3e ILT |
1006 | // The file offset within the output symtab section where we should |
1007 | // write the table. | |
1008 | off_t offset_; | |
1009 | ||
61ba1cf9 ILT |
1010 | // The number of global symbols we want to write out. |
1011 | size_t output_count_; | |
1012 | ||
16649710 ILT |
1013 | // The file offset of the global dynamic symbols, or 0 if none. |
1014 | off_t dynamic_offset_; | |
1015 | ||
1016 | // The index of the first global dynamic symbol. | |
1017 | unsigned int first_dynamic_global_index_; | |
1018 | ||
1019 | // The number of global dynamic symbols, or 0 if none. | |
1020 | off_t dynamic_count_; | |
1021 | ||
54dc6425 | 1022 | // The symbol hash table. |
14bfc3f5 ILT |
1023 | Symbol_table_type table_; |
1024 | ||
54dc6425 ILT |
1025 | // A pool of symbol names. This is used for all global symbols. |
1026 | // Entries in the hash table point into this pool. | |
14bfc3f5 | 1027 | Stringpool namepool_; |
bae7f79e | 1028 | |
14bfc3f5 | 1029 | // Forwarding symbols. |
c06b7b0b | 1030 | Unordered_map<const Symbol*, Symbol*> forwarders_; |
ead1e424 ILT |
1031 | |
1032 | // We don't expect there to be very many common symbols, so we keep | |
1033 | // a list of them. When we find a common symbol we add it to this | |
1034 | // list. It is possible that by the time we process the list the | |
1035 | // symbol is no longer a common symbol. It may also have become a | |
1036 | // forwarder. | |
1037 | Commons_type commons_; | |
f6ce93d6 ILT |
1038 | |
1039 | // Manage symbol warnings. | |
1040 | Warnings warnings_; | |
bae7f79e ILT |
1041 | }; |
1042 | ||
1564db8d ILT |
1043 | // We inline get_sized_symbol for efficiency. |
1044 | ||
1045 | template<int size> | |
1046 | Sized_symbol<size>* | |
5482377d | 1047 | Symbol_table::get_sized_symbol(Symbol* sym ACCEPT_SIZE) const |
1564db8d | 1048 | { |
a3ad94ed | 1049 | gold_assert(size == this->get_size()); |
1564db8d ILT |
1050 | return static_cast<Sized_symbol<size>*>(sym); |
1051 | } | |
1052 | ||
1053 | template<int size> | |
1054 | const Sized_symbol<size>* | |
5482377d | 1055 | Symbol_table::get_sized_symbol(const Symbol* sym ACCEPT_SIZE) const |
1564db8d | 1056 | { |
a3ad94ed | 1057 | gold_assert(size == this->get_size()); |
1564db8d ILT |
1058 | return static_cast<const Sized_symbol<size>*>(sym); |
1059 | } | |
1060 | ||
bae7f79e ILT |
1061 | } // End namespace gold. |
1062 | ||
1063 | #endif // !defined(GOLD_SYMTAB_H) |