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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 | |
429c1569 ILT |
181 | { |
182 | return (this->needs_dynsym_entry_ | |
183 | || (this->in_reg() && this->in_dyn())); | |
184 | } | |
c06b7b0b ILT |
185 | |
186 | // Mark this symbol as needing an entry in the dynamic symbol table. | |
187 | void | |
188 | set_needs_dynsym_entry() | |
189 | { this->needs_dynsym_entry_ = true; } | |
190 | ||
008db82e ILT |
191 | // Return whether this symbol has been seen in a regular object. |
192 | bool | |
193 | in_reg() const | |
194 | { return this->in_reg_; } | |
195 | ||
196 | // Mark this symbol as having been seen in a regular object. | |
197 | void | |
198 | set_in_reg() | |
199 | { this->in_reg_ = true; } | |
200 | ||
1ebd95fd ILT |
201 | // Return whether this symbol has been seen in a dynamic object. |
202 | bool | |
203 | in_dyn() const | |
204 | { return this->in_dyn_; } | |
205 | ||
f6ce93d6 | 206 | // Mark this symbol as having been seen in a dynamic object. |
1564db8d ILT |
207 | void |
208 | set_in_dyn() | |
209 | { this->in_dyn_ = true; } | |
210 | ||
c06b7b0b ILT |
211 | // Return the index of this symbol in the output file symbol table. |
212 | // A value of -1U means that this symbol is not going into the | |
213 | // output file. This starts out as zero, and is set to a non-zero | |
214 | // value by Symbol_table::finalize. It is an error to ask for the | |
215 | // symbol table index before it has been set. | |
216 | unsigned int | |
217 | symtab_index() const | |
218 | { | |
a3ad94ed | 219 | gold_assert(this->symtab_index_ != 0); |
c06b7b0b ILT |
220 | return this->symtab_index_; |
221 | } | |
222 | ||
223 | // Set the index of the symbol in the output file symbol table. | |
224 | void | |
225 | set_symtab_index(unsigned int index) | |
226 | { | |
a3ad94ed | 227 | gold_assert(index != 0); |
c06b7b0b ILT |
228 | this->symtab_index_ = index; |
229 | } | |
230 | ||
a3ad94ed ILT |
231 | // Return whether this symbol already has an index in the output |
232 | // file symbol table. | |
233 | bool | |
234 | has_symtab_index() const | |
235 | { return this->symtab_index_ != 0; } | |
236 | ||
c06b7b0b ILT |
237 | // Return the index of this symbol in the dynamic symbol table. A |
238 | // value of -1U means that this symbol is not going into the dynamic | |
239 | // symbol table. This starts out as zero, and is set to a non-zero | |
240 | // during Layout::finalize. It is an error to ask for the dynamic | |
241 | // symbol table index before it has been set. | |
242 | unsigned int | |
243 | dynsym_index() const | |
244 | { | |
a3ad94ed | 245 | gold_assert(this->dynsym_index_ != 0); |
c06b7b0b ILT |
246 | return this->dynsym_index_; |
247 | } | |
248 | ||
249 | // Set the index of the symbol in the dynamic symbol table. | |
250 | void | |
251 | set_dynsym_index(unsigned int index) | |
252 | { | |
a3ad94ed | 253 | gold_assert(index != 0); |
c06b7b0b ILT |
254 | this->dynsym_index_ = index; |
255 | } | |
256 | ||
16649710 ILT |
257 | // Return whether this symbol already has an index in the dynamic |
258 | // symbol table. | |
259 | bool | |
260 | has_dynsym_index() const | |
261 | { return this->dynsym_index_ != 0; } | |
262 | ||
ead1e424 | 263 | // Return whether this symbol has an entry in the GOT section. |
92e059d8 | 264 | bool |
ead1e424 ILT |
265 | has_got_offset() const |
266 | { return this->has_got_offset_; } | |
267 | ||
268 | // Return the offset into the GOT section of this symbol. | |
269 | unsigned int | |
270 | got_offset() const | |
271 | { | |
a3ad94ed | 272 | gold_assert(this->has_got_offset()); |
ead1e424 ILT |
273 | return this->got_offset_; |
274 | } | |
275 | ||
276 | // Set the GOT offset of this symbol. | |
277 | void | |
278 | set_got_offset(unsigned int got_offset) | |
279 | { | |
280 | this->has_got_offset_ = true; | |
281 | this->got_offset_ = got_offset; | |
282 | } | |
283 | ||
a3ad94ed | 284 | // Return whether this symbol has an entry in the PLT section. |
ead1e424 | 285 | bool |
a3ad94ed ILT |
286 | has_plt_offset() const |
287 | { return this->has_plt_offset_; } | |
288 | ||
289 | // Return the offset into the PLT section of this symbol. | |
290 | unsigned int | |
291 | plt_offset() const | |
292 | { | |
293 | gold_assert(this->has_plt_offset()); | |
294 | return this->plt_offset_; | |
295 | } | |
296 | ||
297 | // Set the PLT offset of this symbol. | |
298 | void | |
299 | set_plt_offset(unsigned int plt_offset) | |
300 | { | |
301 | this->has_plt_offset_ = true; | |
302 | this->plt_offset_ = plt_offset; | |
303 | } | |
304 | ||
305 | // Return true if the final value of this symbol is known at link | |
306 | // time. | |
307 | bool | |
308 | final_value_is_known(const General_options* options) const | |
309 | { | |
310 | if (options->is_shared()) | |
311 | return false; | |
312 | return this->source_ != FROM_OBJECT || !this->object()->is_dynamic(); | |
313 | } | |
ead1e424 | 314 | |
f6ce93d6 ILT |
315 | // Return whether this is a defined symbol (not undefined or |
316 | // common). | |
317 | bool | |
318 | is_defined() const | |
319 | { | |
320 | return (this->source_ != FROM_OBJECT | |
16649710 ILT |
321 | || (this->shndx() != elfcpp::SHN_UNDEF |
322 | && this->shndx() != elfcpp::SHN_COMMON)); | |
a3ad94ed ILT |
323 | } |
324 | ||
14b31740 | 325 | // Return true if this symbol is from a dynamic object. |
a3ad94ed | 326 | bool |
14b31740 | 327 | is_from_dynobj() const |
a3ad94ed | 328 | { |
14b31740 | 329 | return this->source_ == FROM_OBJECT && this->object()->is_dynamic(); |
f6ce93d6 ILT |
330 | } |
331 | ||
ead1e424 ILT |
332 | // Return whether this is an undefined symbol. |
333 | bool | |
334 | is_undefined() const | |
335 | { | |
16649710 | 336 | return this->source_ == FROM_OBJECT && this->shndx() == elfcpp::SHN_UNDEF; |
ead1e424 ILT |
337 | } |
338 | ||
339 | // Return whether this is a common symbol. | |
340 | bool | |
341 | is_common() const | |
342 | { | |
f6ce93d6 | 343 | return (this->source_ == FROM_OBJECT |
16649710 | 344 | && (this->shndx() == elfcpp::SHN_COMMON |
f6ce93d6 | 345 | || this->type_ == elfcpp::STT_COMMON)); |
ead1e424 | 346 | } |
92e059d8 | 347 | |
a6badf5a ILT |
348 | // Return whether this symbol can be seen outside this object. |
349 | bool | |
350 | is_externally_visible() const | |
351 | { | |
352 | return (this->visibility_ == elfcpp::STV_DEFAULT | |
353 | || this->visibility_ == elfcpp::STV_PROTECTED); | |
354 | } | |
355 | ||
f6ce93d6 ILT |
356 | // Return whether there should be a warning for references to this |
357 | // symbol. | |
358 | bool | |
359 | has_warning() const | |
360 | { return this->has_warning_; } | |
361 | ||
362 | // Mark this symbol as having a warning. | |
363 | void | |
364 | set_has_warning() | |
365 | { this->has_warning_ = true; } | |
366 | ||
14bfc3f5 ILT |
367 | protected: |
368 | // Instances of this class should always be created at a specific | |
369 | // size. | |
370 | Symbol() | |
f6ce93d6 | 371 | { memset(this, 0, sizeof *this); } |
14bfc3f5 | 372 | |
ead1e424 ILT |
373 | // Initialize the general fields. |
374 | void | |
375 | init_fields(const char* name, const char* version, | |
376 | elfcpp::STT type, elfcpp::STB binding, | |
377 | elfcpp::STV visibility, unsigned char nonvis); | |
378 | ||
14bfc3f5 ILT |
379 | // Initialize fields from an ELF symbol in OBJECT. |
380 | template<int size, bool big_endian> | |
381 | void | |
382 | init_base(const char *name, const char* version, Object* object, | |
383 | const elfcpp::Sym<size, big_endian>&); | |
bae7f79e | 384 | |
ead1e424 ILT |
385 | // Initialize fields for an Output_data. |
386 | void | |
387 | init_base(const char* name, Output_data*, elfcpp::STT, elfcpp::STB, | |
388 | elfcpp::STV, unsigned char nonvis, bool offset_is_from_end); | |
389 | ||
390 | // Initialize fields for an Output_segment. | |
391 | void | |
392 | init_base(const char* name, Output_segment* os, elfcpp::STT type, | |
393 | elfcpp::STB binding, elfcpp::STV visibility, | |
394 | unsigned char nonvis, Segment_offset_base offset_base); | |
395 | ||
396 | // Initialize fields for a constant. | |
397 | void | |
398 | init_base(const char* name, elfcpp::STT type, elfcpp::STB binding, | |
399 | elfcpp::STV visibility, unsigned char nonvis); | |
400 | ||
1564db8d ILT |
401 | // Override existing symbol. |
402 | template<int size, bool big_endian> | |
403 | void | |
14b31740 ILT |
404 | override_base(const elfcpp::Sym<size, big_endian>&, Object* object, |
405 | const char* version); | |
1564db8d | 406 | |
bae7f79e | 407 | private: |
14bfc3f5 ILT |
408 | Symbol(const Symbol&); |
409 | Symbol& operator=(const Symbol&); | |
410 | ||
411 | // Symbol name (expected to point into a Stringpool). | |
412 | const char* name_; | |
413 | // Symbol version (expected to point into a Stringpool). This may | |
414 | // be NULL. | |
bae7f79e | 415 | const char* version_; |
ead1e424 ILT |
416 | |
417 | union | |
418 | { | |
419 | // This struct is used if SOURCE_ == FROM_OBJECT. | |
420 | struct | |
421 | { | |
422 | // Object in which symbol is defined, or in which it was first | |
423 | // seen. | |
424 | Object* object; | |
425 | // Section number in object_ in which symbol is defined. | |
16649710 | 426 | unsigned int shndx; |
ead1e424 ILT |
427 | } from_object; |
428 | ||
429 | // This struct is used if SOURCE_ == IN_OUTPUT_DATA. | |
430 | struct | |
431 | { | |
432 | // Output_data in which symbol is defined. Before | |
433 | // Layout::finalize the symbol's value is an offset within the | |
434 | // Output_data. | |
435 | Output_data* output_data; | |
436 | // True if the offset is from the end, false if the offset is | |
437 | // from the beginning. | |
438 | bool offset_is_from_end; | |
439 | } in_output_data; | |
440 | ||
441 | // This struct is used if SOURCE_ == IN_OUTPUT_SEGMENT. | |
442 | struct | |
443 | { | |
444 | // Output_segment in which the symbol is defined. Before | |
445 | // Layout::finalize the symbol's value is an offset. | |
446 | Output_segment* output_segment; | |
447 | // The base to use for the offset before Layout::finalize. | |
448 | Segment_offset_base offset_base; | |
449 | } in_output_segment; | |
450 | } u_; | |
451 | ||
c06b7b0b ILT |
452 | // The index of this symbol in the output file. If the symbol is |
453 | // not going into the output file, this value is -1U. This field | |
454 | // starts as always holding zero. It is set to a non-zero value by | |
455 | // Symbol_table::finalize. | |
456 | unsigned int symtab_index_; | |
457 | ||
458 | // The index of this symbol in the dynamic symbol table. If the | |
459 | // symbol is not going into the dynamic symbol table, this value is | |
460 | // -1U. This field starts as always holding zero. It is set to a | |
461 | // non-zero value during Layout::finalize. | |
462 | unsigned int dynsym_index_; | |
463 | ||
ead1e424 | 464 | // If this symbol has an entry in the GOT section (has_got_offset_ |
c06b7b0b | 465 | // is true), this is the offset from the start of the GOT section. |
ead1e424 | 466 | unsigned int got_offset_; |
c06b7b0b | 467 | |
a3ad94ed ILT |
468 | // If this symbol has an entry in the PLT section (has_plt_offset_ |
469 | // is true), then this is the offset from the start of the PLT | |
470 | // section. | |
471 | unsigned int plt_offset_; | |
472 | ||
14bfc3f5 | 473 | // Symbol type. |
bae7f79e | 474 | elfcpp::STT type_ : 4; |
14bfc3f5 | 475 | // Symbol binding. |
bae7f79e | 476 | elfcpp::STB binding_ : 4; |
14bfc3f5 ILT |
477 | // Symbol visibility. |
478 | elfcpp::STV visibility_ : 2; | |
479 | // Rest of symbol st_other field. | |
ead1e424 ILT |
480 | unsigned int nonvis_ : 6; |
481 | // The type of symbol. | |
f6ce93d6 | 482 | Source source_ : 3; |
14bfc3f5 ILT |
483 | // True if this symbol always requires special target-specific |
484 | // handling. | |
ead1e424 | 485 | bool is_target_special_ : 1; |
14bfc3f5 | 486 | // True if this is the default version of the symbol. |
1564db8d | 487 | bool is_def_ : 1; |
14bfc3f5 ILT |
488 | // True if this symbol really forwards to another symbol. This is |
489 | // used when we discover after the fact that two different entries | |
490 | // in the hash table really refer to the same symbol. This will | |
491 | // never be set for a symbol found in the hash table, but may be set | |
492 | // for a symbol found in the list of symbols attached to an Object. | |
493 | // It forwards to the symbol found in the forwarders_ map of | |
494 | // Symbol_table. | |
1564db8d | 495 | bool is_forwarder_ : 1; |
c06b7b0b ILT |
496 | // True if this symbol needs to be in the dynamic symbol table. |
497 | bool needs_dynsym_entry_ : 1; | |
008db82e ILT |
498 | // True if we've seen this symbol in a regular object. |
499 | bool in_reg_ : 1; | |
1564db8d ILT |
500 | // True if we've seen this symbol in a dynamic object. |
501 | bool in_dyn_ : 1; | |
ead1e424 ILT |
502 | // True if the symbol has an entry in the GOT section. |
503 | bool has_got_offset_ : 1; | |
a3ad94ed ILT |
504 | // True if the symbol has an entry in the PLT section. |
505 | bool has_plt_offset_ : 1; | |
f6ce93d6 ILT |
506 | // True if there is a warning for this symbol. |
507 | bool has_warning_ : 1; | |
bae7f79e ILT |
508 | }; |
509 | ||
14bfc3f5 ILT |
510 | // The parts of a symbol which are size specific. Using a template |
511 | // derived class like this helps us use less space on a 32-bit system. | |
bae7f79e ILT |
512 | |
513 | template<int size> | |
14bfc3f5 ILT |
514 | class Sized_symbol : public Symbol |
515 | { | |
516 | public: | |
1564db8d ILT |
517 | typedef typename elfcpp::Elf_types<size>::Elf_Addr Value_type; |
518 | typedef typename elfcpp::Elf_types<size>::Elf_WXword Size_type; | |
519 | ||
14bfc3f5 ILT |
520 | Sized_symbol() |
521 | { } | |
522 | ||
523 | // Initialize fields from an ELF symbol in OBJECT. | |
524 | template<bool big_endian> | |
525 | void | |
526 | init(const char *name, const char* version, Object* object, | |
527 | const elfcpp::Sym<size, big_endian>&); | |
528 | ||
ead1e424 ILT |
529 | // Initialize fields for an Output_data. |
530 | void | |
531 | init(const char* name, Output_data*, Value_type value, Size_type symsize, | |
532 | elfcpp::STT, elfcpp::STB, elfcpp::STV, unsigned char nonvis, | |
533 | bool offset_is_from_end); | |
534 | ||
535 | // Initialize fields for an Output_segment. | |
536 | void | |
537 | init(const char* name, Output_segment*, Value_type value, Size_type symsize, | |
538 | elfcpp::STT, elfcpp::STB, elfcpp::STV, unsigned char nonvis, | |
539 | Segment_offset_base offset_base); | |
540 | ||
541 | // Initialize fields for a constant. | |
542 | void | |
543 | init(const char* name, Value_type value, Size_type symsize, | |
544 | elfcpp::STT, elfcpp::STB, elfcpp::STV, unsigned char nonvis); | |
545 | ||
1564db8d ILT |
546 | // Override existing symbol. |
547 | template<bool big_endian> | |
548 | void | |
14b31740 ILT |
549 | override(const elfcpp::Sym<size, big_endian>&, Object* object, |
550 | const char* version); | |
1564db8d ILT |
551 | |
552 | // Return the symbol's value. | |
553 | Value_type | |
554 | value() const | |
555 | { return this->value_; } | |
556 | ||
557 | // Return the symbol's size (we can't call this 'size' because that | |
558 | // is a template parameter). | |
559 | Size_type | |
560 | symsize() const | |
ead1e424 ILT |
561 | { return this->symsize_; } |
562 | ||
563 | // Set the symbol size. This is used when resolving common symbols. | |
564 | void | |
565 | set_symsize(Size_type symsize) | |
566 | { this->symsize_ = symsize; } | |
1564db8d | 567 | |
75f65a3e ILT |
568 | // Set the symbol value. This is called when we store the final |
569 | // values of the symbols into the symbol table. | |
570 | void | |
571 | set_value(Value_type value) | |
572 | { this->value_ = value; } | |
573 | ||
14bfc3f5 ILT |
574 | private: |
575 | Sized_symbol(const Sized_symbol&); | |
576 | Sized_symbol& operator=(const Sized_symbol&); | |
577 | ||
ead1e424 ILT |
578 | // Symbol value. Before Layout::finalize this is the offset in the |
579 | // input section. This is set to the final value during | |
580 | // Layout::finalize. | |
1564db8d | 581 | Value_type value_; |
14bfc3f5 | 582 | // Symbol size. |
ead1e424 ILT |
583 | Size_type symsize_; |
584 | }; | |
585 | ||
586 | // A struct describing a symbol defined by the linker, where the value | |
587 | // of the symbol is defined based on an output section. This is used | |
588 | // for symbols defined by the linker, like "_init_array_start". | |
589 | ||
590 | struct Define_symbol_in_section | |
591 | { | |
592 | // The symbol name. | |
593 | const char* name; | |
594 | // The name of the output section with which this symbol should be | |
595 | // associated. If there is no output section with that name, the | |
596 | // symbol will be defined as zero. | |
597 | const char* output_section; | |
598 | // The offset of the symbol within the output section. This is an | |
599 | // offset from the start of the output section, unless start_at_end | |
600 | // is true, in which case this is an offset from the end of the | |
601 | // output section. | |
602 | uint64_t value; | |
603 | // The size of the symbol. | |
604 | uint64_t size; | |
605 | // The symbol type. | |
606 | elfcpp::STT type; | |
607 | // The symbol binding. | |
608 | elfcpp::STB binding; | |
609 | // The symbol visibility. | |
610 | elfcpp::STV visibility; | |
611 | // The rest of the st_other field. | |
612 | unsigned char nonvis; | |
613 | // If true, the value field is an offset from the end of the output | |
614 | // section. | |
615 | bool offset_is_from_end; | |
616 | // If true, this symbol is defined only if we see a reference to it. | |
617 | bool only_if_ref; | |
618 | }; | |
619 | ||
620 | // A struct describing a symbol defined by the linker, where the value | |
621 | // of the symbol is defined based on a segment. This is used for | |
622 | // symbols defined by the linker, like "_end". We describe the | |
623 | // segment with which the symbol should be associated by its | |
624 | // characteristics. If no segment meets these characteristics, the | |
625 | // symbol will be defined as zero. If there is more than one segment | |
626 | // which meets these characteristics, we will use the first one. | |
627 | ||
628 | struct Define_symbol_in_segment | |
629 | { | |
630 | // The symbol name. | |
631 | const char* name; | |
632 | // The segment type where the symbol should be defined, typically | |
633 | // PT_LOAD. | |
634 | elfcpp::PT segment_type; | |
635 | // Bitmask of segment flags which must be set. | |
636 | elfcpp::PF segment_flags_set; | |
637 | // Bitmask of segment flags which must be clear. | |
638 | elfcpp::PF segment_flags_clear; | |
639 | // The offset of the symbol within the segment. The offset is | |
640 | // calculated from the position set by offset_base. | |
641 | uint64_t value; | |
642 | // The size of the symbol. | |
643 | uint64_t size; | |
644 | // The symbol type. | |
645 | elfcpp::STT type; | |
646 | // The symbol binding. | |
647 | elfcpp::STB binding; | |
648 | // The symbol visibility. | |
649 | elfcpp::STV visibility; | |
650 | // The rest of the st_other field. | |
651 | unsigned char nonvis; | |
652 | // The base from which we compute the offset. | |
653 | Symbol::Segment_offset_base offset_base; | |
654 | // If true, this symbol is defined only if we see a reference to it. | |
655 | bool only_if_ref; | |
14bfc3f5 ILT |
656 | }; |
657 | ||
f6ce93d6 ILT |
658 | // This class manages warnings. Warnings are a GNU extension. When |
659 | // we see a section named .gnu.warning.SYM in an object file, and if | |
660 | // we wind using the definition of SYM from that object file, then we | |
661 | // will issue a warning for any relocation against SYM from a | |
662 | // different object file. The text of the warning is the contents of | |
663 | // the section. This is not precisely the definition used by the old | |
664 | // GNU linker; the old GNU linker treated an occurrence of | |
665 | // .gnu.warning.SYM as defining a warning symbol. A warning symbol | |
666 | // would trigger a warning on any reference. However, it was | |
667 | // inconsistent in that a warning in a dynamic object only triggered | |
668 | // if there was no definition in a regular object. This linker is | |
669 | // different in that we only issue a warning if we use the symbol | |
670 | // definition from the same object file as the warning section. | |
671 | ||
672 | class Warnings | |
673 | { | |
674 | public: | |
675 | Warnings() | |
676 | : warnings_() | |
677 | { } | |
678 | ||
679 | // Add a warning for symbol NAME in section SHNDX in object OBJ. | |
680 | void | |
681 | add_warning(Symbol_table* symtab, const char* name, Object* obj, | |
682 | unsigned int shndx); | |
683 | ||
684 | // For each symbol for which we should give a warning, make a note | |
685 | // on the symbol. | |
686 | void | |
687 | note_warnings(Symbol_table* symtab); | |
688 | ||
689 | // Issue a warning for a reference to SYM at LOCATION. | |
690 | void | |
c06b7b0b | 691 | issue_warning(const Symbol* sym, const std::string& location) const; |
f6ce93d6 ILT |
692 | |
693 | private: | |
694 | Warnings(const Warnings&); | |
695 | Warnings& operator=(const Warnings&); | |
696 | ||
697 | // What we need to know to get the warning text. | |
698 | struct Warning_location | |
699 | { | |
700 | // The object the warning is in. | |
701 | Object* object; | |
702 | // The index of the warning section. | |
703 | unsigned int shndx; | |
704 | // The warning text if we have already loaded it. | |
705 | std::string text; | |
706 | ||
707 | Warning_location() | |
708 | : object(NULL), shndx(0), text() | |
709 | { } | |
710 | ||
711 | void | |
712 | set(Object* o, unsigned int s) | |
713 | { | |
714 | this->object = o; | |
715 | this->shndx = s; | |
716 | } | |
717 | ||
718 | void | |
719 | set_text(const char* t, off_t l) | |
720 | { this->text.assign(t, l); } | |
721 | }; | |
722 | ||
723 | // A mapping from warning symbol names (canonicalized in | |
724 | // Symbol_table's namepool_ field) to | |
725 | typedef Unordered_map<const char*, Warning_location> Warning_table; | |
726 | ||
727 | Warning_table warnings_; | |
728 | }; | |
729 | ||
14bfc3f5 ILT |
730 | // The main linker symbol table. |
731 | ||
bae7f79e ILT |
732 | class Symbol_table |
733 | { | |
734 | public: | |
735 | Symbol_table(); | |
736 | ||
1564db8d | 737 | ~Symbol_table(); |
bae7f79e | 738 | |
dbe717ef | 739 | // Add COUNT external symbols from the relocatable object RELOBJ to |
f6ce93d6 ILT |
740 | // the symbol table. SYMS is the symbols, SYM_NAMES is their names, |
741 | // SYM_NAME_SIZE is the size of SYM_NAMES. This sets SYMPOINTERS to | |
742 | // point to the symbols in the symbol table. | |
14bfc3f5 ILT |
743 | template<int size, bool big_endian> |
744 | void | |
dbe717ef ILT |
745 | add_from_relobj(Sized_relobj<size, big_endian>* relobj, |
746 | const unsigned char* syms, size_t count, | |
747 | const char* sym_names, size_t sym_name_size, | |
14bfc3f5 ILT |
748 | Symbol** sympointers); |
749 | ||
dbe717ef ILT |
750 | // Add COUNT dynamic symbols from the dynamic object DYNOBJ to the |
751 | // symbol table. SYMS is the symbols. SYM_NAMES is their names. | |
752 | // SYM_NAME_SIZE is the size of SYM_NAMES. The other parameters are | |
753 | // symbol version data. | |
754 | template<int size, bool big_endian> | |
755 | void | |
756 | add_from_dynobj(Sized_dynobj<size, big_endian>* dynobj, | |
757 | const unsigned char* syms, size_t count, | |
758 | const char* sym_names, size_t sym_name_size, | |
759 | const unsigned char* versym, size_t versym_size, | |
760 | const std::vector<const char*>*); | |
761 | ||
ead1e424 ILT |
762 | // Define a special symbol based on an Output_data. It is a |
763 | // multiple definition error if this symbol is already defined. | |
14b31740 ILT |
764 | Symbol* |
765 | define_in_output_data(const Target*, const char* name, const char* version, | |
766 | Output_data*, uint64_t value, uint64_t symsize, | |
ead1e424 ILT |
767 | elfcpp::STT type, elfcpp::STB binding, |
768 | elfcpp::STV visibility, unsigned char nonvis, | |
769 | bool offset_is_from_end, bool only_if_ref); | |
770 | ||
771 | // Define a special symbol based on an Output_segment. It is a | |
772 | // multiple definition error if this symbol is already defined. | |
14b31740 ILT |
773 | Symbol* |
774 | define_in_output_segment(const Target*, const char* name, | |
775 | const char* version, Output_segment*, | |
ead1e424 ILT |
776 | uint64_t value, uint64_t symsize, |
777 | elfcpp::STT type, elfcpp::STB binding, | |
778 | elfcpp::STV visibility, unsigned char nonvis, | |
779 | Symbol::Segment_offset_base, bool only_if_ref); | |
780 | ||
781 | // Define a special symbol with a constant value. It is a multiple | |
782 | // definition error if this symbol is already defined. | |
14b31740 ILT |
783 | Symbol* |
784 | define_as_constant(const Target*, const char* name, const char* version, | |
785 | uint64_t value, uint64_t symsize, elfcpp::STT type, | |
786 | elfcpp::STB binding, elfcpp::STV visibility, | |
787 | unsigned char nonvis, bool only_if_ref); | |
ead1e424 ILT |
788 | |
789 | // Define a set of symbols in output sections. | |
790 | void | |
14b31740 | 791 | define_symbols(const Layout*, const Target*, int count, |
ead1e424 ILT |
792 | const Define_symbol_in_section*); |
793 | ||
794 | // Define a set of symbols in output segments. | |
795 | void | |
14b31740 | 796 | define_symbols(const Layout*, const Target*, int count, |
ead1e424 ILT |
797 | const Define_symbol_in_segment*); |
798 | ||
61ba1cf9 ILT |
799 | // Look up a symbol. |
800 | Symbol* | |
801 | lookup(const char*, const char* version = NULL) const; | |
802 | ||
14bfc3f5 | 803 | // Return the real symbol associated with the forwarder symbol FROM. |
bae7f79e | 804 | Symbol* |
c06b7b0b | 805 | resolve_forwards(const Symbol* from) const; |
bae7f79e | 806 | |
a3ad94ed | 807 | // Return the bitsize (32 or 64) of the symbols in the table. |
14bfc3f5 ILT |
808 | int |
809 | get_size() const | |
810 | { return this->size_; } | |
bae7f79e | 811 | |
1564db8d ILT |
812 | // Return the sized version of a symbol in this table. |
813 | template<int size> | |
814 | Sized_symbol<size>* | |
5482377d | 815 | get_sized_symbol(Symbol* ACCEPT_SIZE) const; |
1564db8d ILT |
816 | |
817 | template<int size> | |
818 | const Sized_symbol<size>* | |
5482377d | 819 | get_sized_symbol(const Symbol* ACCEPT_SIZE) const; |
54dc6425 | 820 | |
ead1e424 ILT |
821 | // Return the count of undefined symbols seen. |
822 | int | |
823 | saw_undefined() const | |
824 | { return this->saw_undefined_; } | |
825 | ||
826 | // Allocate the common symbols | |
827 | void | |
828 | allocate_commons(const General_options&, Layout*); | |
829 | ||
f6ce93d6 ILT |
830 | // Add a warning for symbol NAME in section SHNDX in object OBJ. |
831 | void | |
832 | add_warning(const char* name, Object* obj, unsigned int shndx) | |
833 | { this->warnings_.add_warning(this, name, obj, shndx); } | |
834 | ||
835 | // Canonicalize a symbol name for use in the hash table. | |
836 | const char* | |
837 | canonicalize_name(const char* name) | |
f0641a0b | 838 | { return this->namepool_.add(name, NULL); } |
f6ce93d6 ILT |
839 | |
840 | // Possibly issue a warning for a reference to SYM at LOCATION which | |
841 | // is in OBJ. | |
842 | void | |
c06b7b0b | 843 | issue_warning(const Symbol* sym, const std::string& location) const |
f6ce93d6 ILT |
844 | { this->warnings_.issue_warning(sym, location); } |
845 | ||
a3ad94ed ILT |
846 | // Set the dynamic symbol indexes. INDEX is the index of the first |
847 | // global dynamic symbol. Pointers to the symbols are stored into | |
848 | // the vector. The names are stored into the Stringpool. This | |
849 | // returns an updated dynamic symbol index. | |
850 | unsigned int | |
14b31740 ILT |
851 | set_dynsym_indexes(const General_options*, const Target*, unsigned int index, |
852 | std::vector<Symbol*>*, Stringpool*, Versions*); | |
a3ad94ed | 853 | |
75f65a3e | 854 | // Finalize the symbol table after we have set the final addresses |
c06b7b0b ILT |
855 | // of all the input sections. This sets the final symbol indexes, |
856 | // values and adds the names to *POOL. INDEX is the index of the | |
16649710 ILT |
857 | // first global symbol. OFF is the file offset of the global symbol |
858 | // table, DYNOFF is the offset of the globals in the dynamic symbol | |
859 | // table, DYN_GLOBAL_INDEX is the index of the first global dynamic | |
860 | // symbol, and DYNCOUNT is the number of global dynamic symbols. | |
861 | // This records the parameters, and returns the new file offset. | |
75f65a3e | 862 | off_t |
16649710 ILT |
863 | finalize(unsigned int index, off_t off, off_t dynoff, |
864 | size_t dyn_global_index, size_t dyncount, Stringpool* pool); | |
1564db8d | 865 | |
61ba1cf9 ILT |
866 | // Write out the global symbols. |
867 | void | |
16649710 ILT |
868 | write_globals(const Target*, const Stringpool*, const Stringpool*, |
869 | Output_file*) const; | |
61ba1cf9 | 870 | |
a3ad94ed ILT |
871 | // Write out a section symbol. Return the updated offset. |
872 | void | |
873 | write_section_symbol(const Target*, const Output_section*, Output_file*, | |
874 | off_t) const; | |
875 | ||
bae7f79e ILT |
876 | private: |
877 | Symbol_table(const Symbol_table&); | |
878 | Symbol_table& operator=(const Symbol_table&); | |
879 | ||
a3ad94ed | 880 | // Set the size (32 or 64) of the symbols in the table. |
14bfc3f5 ILT |
881 | void |
882 | set_size(int size) | |
883 | { this->size_ = size; } | |
884 | ||
885 | // Make FROM a forwarder symbol to TO. | |
886 | void | |
887 | make_forwarder(Symbol* from, Symbol* to); | |
888 | ||
889 | // Add a symbol. | |
890 | template<int size, bool big_endian> | |
891 | Symbol* | |
f0641a0b ILT |
892 | add_from_object(Object*, const char *name, Stringpool::Key name_key, |
893 | const char *version, Stringpool::Key version_key, | |
894 | bool def, const elfcpp::Sym<size, big_endian>& sym); | |
14bfc3f5 ILT |
895 | |
896 | // Resolve symbols. | |
897 | template<int size, bool big_endian> | |
898 | static void | |
1564db8d ILT |
899 | resolve(Sized_symbol<size>* to, |
900 | const elfcpp::Sym<size, big_endian>& sym, | |
14b31740 | 901 | Object*, const char* version); |
14bfc3f5 | 902 | |
1564db8d | 903 | template<int size, bool big_endian> |
14bfc3f5 | 904 | static void |
14b31740 ILT |
905 | resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from, |
906 | const char* version ACCEPT_SIZE_ENDIAN); | |
907 | ||
908 | // Define a special symbol. | |
909 | template<int size, bool big_endian> | |
910 | Sized_symbol<size>* | |
911 | define_special_symbol(const Target* target, const char* name, | |
912 | const char* version, bool only_if_ref | |
913 | ACCEPT_SIZE_ENDIAN); | |
14bfc3f5 | 914 | |
ead1e424 ILT |
915 | // Define a symbol in an Output_data, sized version. |
916 | template<int size> | |
14b31740 ILT |
917 | Sized_symbol<size>* |
918 | do_define_in_output_data(const Target*, const char* name, | |
919 | const char* version, Output_data*, | |
ead1e424 ILT |
920 | typename elfcpp::Elf_types<size>::Elf_Addr value, |
921 | typename elfcpp::Elf_types<size>::Elf_WXword ssize, | |
922 | elfcpp::STT type, elfcpp::STB binding, | |
923 | elfcpp::STV visibility, unsigned char nonvis, | |
924 | bool offset_is_from_end, bool only_if_ref); | |
925 | ||
926 | // Define a symbol in an Output_segment, sized version. | |
927 | template<int size> | |
14b31740 | 928 | Sized_symbol<size>* |
ead1e424 | 929 | do_define_in_output_segment( |
14b31740 | 930 | const Target*, const char* name, const char* version, Output_segment* os, |
ead1e424 ILT |
931 | typename elfcpp::Elf_types<size>::Elf_Addr value, |
932 | typename elfcpp::Elf_types<size>::Elf_WXword ssize, | |
933 | elfcpp::STT type, elfcpp::STB binding, | |
934 | elfcpp::STV visibility, unsigned char nonvis, | |
935 | Symbol::Segment_offset_base offset_base, bool only_if_ref); | |
936 | ||
937 | // Define a symbol as a constant, sized version. | |
938 | template<int size> | |
14b31740 | 939 | Sized_symbol<size>* |
ead1e424 | 940 | do_define_as_constant( |
14b31740 | 941 | const Target*, const char* name, const char* version, |
ead1e424 ILT |
942 | typename elfcpp::Elf_types<size>::Elf_Addr value, |
943 | typename elfcpp::Elf_types<size>::Elf_WXword ssize, | |
944 | elfcpp::STT type, elfcpp::STB binding, | |
945 | elfcpp::STV visibility, unsigned char nonvis, | |
946 | bool only_if_ref); | |
947 | ||
948 | // Allocate the common symbols, sized version. | |
949 | template<int size> | |
950 | void | |
951 | do_allocate_commons(const General_options&, Layout*); | |
952 | ||
75f65a3e ILT |
953 | // Finalize symbols specialized for size. |
954 | template<int size> | |
955 | off_t | |
c06b7b0b | 956 | sized_finalize(unsigned int, off_t, Stringpool*); |
75f65a3e | 957 | |
61ba1cf9 ILT |
958 | // Write globals specialized for size and endianness. |
959 | template<int size, bool big_endian> | |
960 | void | |
16649710 ILT |
961 | sized_write_globals(const Target*, const Stringpool*, const Stringpool*, |
962 | Output_file*) const; | |
963 | ||
964 | // Write out a symbol to P. | |
965 | template<int size, bool big_endian> | |
966 | void | |
967 | sized_write_symbol(Sized_symbol<size>*, unsigned int shndx, | |
6a469986 ILT |
968 | const Stringpool*, unsigned char* p |
969 | ACCEPT_SIZE_ENDIAN) const; | |
61ba1cf9 | 970 | |
a3ad94ed ILT |
971 | // Write out a section symbol, specialized for size and endianness. |
972 | template<int size, bool big_endian> | |
973 | void | |
974 | sized_write_section_symbol(const Output_section*, Output_file*, off_t) const; | |
975 | ||
54dc6425 ILT |
976 | // The type of the symbol hash table. |
977 | ||
f0641a0b | 978 | typedef std::pair<Stringpool::Key, Stringpool::Key> Symbol_table_key; |
14bfc3f5 ILT |
979 | |
980 | struct Symbol_table_hash | |
981 | { | |
982 | size_t | |
983 | operator()(const Symbol_table_key&) const; | |
984 | }; | |
985 | ||
986 | struct Symbol_table_eq | |
987 | { | |
988 | bool | |
989 | operator()(const Symbol_table_key&, const Symbol_table_key&) const; | |
990 | }; | |
991 | ||
992 | typedef Unordered_map<Symbol_table_key, Symbol*, Symbol_table_hash, | |
993 | Symbol_table_eq> Symbol_table_type; | |
994 | ||
ead1e424 ILT |
995 | // The type of the list of common symbols. |
996 | ||
997 | typedef std::vector<Symbol*> Commons_type; | |
998 | ||
14bfc3f5 ILT |
999 | // The size of the symbols in the symbol table (32 or 64). |
1000 | int size_; | |
1001 | ||
ead1e424 ILT |
1002 | // We increment this every time we see a new undefined symbol, for |
1003 | // use in archive groups. | |
1004 | int saw_undefined_; | |
1005 | ||
c06b7b0b ILT |
1006 | // The index of the first global symbol in the output file. |
1007 | unsigned int first_global_index_; | |
1008 | ||
75f65a3e ILT |
1009 | // The file offset within the output symtab section where we should |
1010 | // write the table. | |
1011 | off_t offset_; | |
1012 | ||
61ba1cf9 ILT |
1013 | // The number of global symbols we want to write out. |
1014 | size_t output_count_; | |
1015 | ||
16649710 ILT |
1016 | // The file offset of the global dynamic symbols, or 0 if none. |
1017 | off_t dynamic_offset_; | |
1018 | ||
1019 | // The index of the first global dynamic symbol. | |
1020 | unsigned int first_dynamic_global_index_; | |
1021 | ||
1022 | // The number of global dynamic symbols, or 0 if none. | |
1023 | off_t dynamic_count_; | |
1024 | ||
54dc6425 | 1025 | // The symbol hash table. |
14bfc3f5 ILT |
1026 | Symbol_table_type table_; |
1027 | ||
54dc6425 ILT |
1028 | // A pool of symbol names. This is used for all global symbols. |
1029 | // Entries in the hash table point into this pool. | |
14bfc3f5 | 1030 | Stringpool namepool_; |
bae7f79e | 1031 | |
14bfc3f5 | 1032 | // Forwarding symbols. |
c06b7b0b | 1033 | Unordered_map<const Symbol*, Symbol*> forwarders_; |
ead1e424 ILT |
1034 | |
1035 | // We don't expect there to be very many common symbols, so we keep | |
1036 | // a list of them. When we find a common symbol we add it to this | |
1037 | // list. It is possible that by the time we process the list the | |
1038 | // symbol is no longer a common symbol. It may also have become a | |
1039 | // forwarder. | |
1040 | Commons_type commons_; | |
f6ce93d6 ILT |
1041 | |
1042 | // Manage symbol warnings. | |
1043 | Warnings warnings_; | |
bae7f79e ILT |
1044 | }; |
1045 | ||
1564db8d ILT |
1046 | // We inline get_sized_symbol for efficiency. |
1047 | ||
1048 | template<int size> | |
1049 | Sized_symbol<size>* | |
5482377d | 1050 | Symbol_table::get_sized_symbol(Symbol* sym ACCEPT_SIZE) const |
1564db8d | 1051 | { |
a3ad94ed | 1052 | gold_assert(size == this->get_size()); |
1564db8d ILT |
1053 | return static_cast<Sized_symbol<size>*>(sym); |
1054 | } | |
1055 | ||
1056 | template<int size> | |
1057 | const Sized_symbol<size>* | |
5482377d | 1058 | Symbol_table::get_sized_symbol(const Symbol* sym ACCEPT_SIZE) const |
1564db8d | 1059 | { |
a3ad94ed | 1060 | gold_assert(size == this->get_size()); |
1564db8d ILT |
1061 | return static_cast<const Sized_symbol<size>*>(sym); |
1062 | } | |
1063 | ||
bae7f79e ILT |
1064 | } // End namespace gold. |
1065 | ||
1066 | #endif // !defined(GOLD_SYMTAB_H) |