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f6ce93d6 ILT |
1 | // dynobj.h -- dynamic object support for gold -*- C++ -*- |
2 | ||
6cb15b7f ILT |
3 | // Copyright 2006, 2007 Free Software Foundation, Inc. |
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 | ||
f6ce93d6 ILT |
23 | #ifndef GOLD_DYNOBJ_H |
24 | #define GOLD_DYNOBJ_H | |
25 | ||
dbe717ef ILT |
26 | #include <vector> |
27 | ||
14b31740 | 28 | #include "stringpool.h" |
f6ce93d6 ILT |
29 | #include "object.h" |
30 | ||
31 | namespace gold | |
32 | { | |
33 | ||
14b31740 | 34 | class General_options; |
14b31740 | 35 | |
f6ce93d6 ILT |
36 | // A dynamic object (ET_DYN). This is an abstract base class itself. |
37 | // The implementations is the template class Sized_dynobj. | |
38 | ||
39 | class Dynobj : public Object | |
40 | { | |
41 | public: | |
e2827e5f ILT |
42 | // We keep a list of all the DT_NEEDED entries we find. |
43 | typedef std::vector<std::string> Needed; | |
44 | ||
a7a81c1d | 45 | Dynobj(const std::string& name, Input_file* input_file, off_t offset = 0); |
a3ad94ed ILT |
46 | |
47 | // Return the name to use in a DT_NEEDED entry for this object. | |
48 | const char* | |
e2827e5f ILT |
49 | soname() const |
50 | { return this->soname_.c_str(); } | |
51 | ||
52 | // Return the list of DT_NEEDED strings. | |
53 | const Needed& | |
54 | needed() const | |
55 | { return this->needed_; } | |
56 | ||
57 | // Return whether this dynamic object has any DT_NEEDED entries | |
58 | // which were not seen during the link. | |
59 | bool | |
60 | has_unknown_needed_entries() const | |
61 | { | |
62 | gold_assert(this->unknown_needed_ != UNKNOWN_NEEDED_UNSET); | |
63 | return this->unknown_needed_ == UNKNOWN_NEEDED_TRUE; | |
64 | } | |
65 | ||
66 | // Set whether this dynamic object has any DT_NEEDED entries which | |
67 | // were not seen during the link. | |
68 | void | |
69 | set_has_unknown_needed_entries(bool set) | |
70 | { | |
71 | gold_assert(this->unknown_needed_ == UNKNOWN_NEEDED_UNSET); | |
72 | this->unknown_needed_ = set ? UNKNOWN_NEEDED_TRUE : UNKNOWN_NEEDED_FALSE; | |
73 | } | |
a3ad94ed | 74 | |
14b31740 ILT |
75 | // Compute the ELF hash code for a string. |
76 | static uint32_t | |
77 | elf_hash(const char*); | |
78 | ||
a3ad94ed ILT |
79 | // Create a standard ELF hash table, setting *PPHASH and *PHASHLEN. |
80 | // DYNSYMS is the global dynamic symbols. LOCAL_DYNSYM_COUNT is the | |
81 | // number of local dynamic symbols, which is the index of the first | |
82 | // dynamic gobal symbol. | |
83 | static void | |
9025d29d | 84 | create_elf_hash_table(const std::vector<Symbol*>& dynsyms, |
a3ad94ed ILT |
85 | unsigned int local_dynsym_count, |
86 | unsigned char** pphash, | |
87 | unsigned int* phashlen); | |
88 | ||
89 | // Create a GNU hash table, setting *PPHASH and *PHASHLEN. DYNSYMS | |
90 | // is the global dynamic symbols. LOCAL_DYNSYM_COUNT is the number | |
91 | // of local dynamic symbols, which is the index of the first dynamic | |
92 | // gobal symbol. | |
93 | static void | |
9025d29d | 94 | create_gnu_hash_table(const std::vector<Symbol*>& dynsyms, |
a3ad94ed ILT |
95 | unsigned int local_dynsym_count, |
96 | unsigned char** pphash, unsigned int* phashlen); | |
97 | ||
98 | protected: | |
99 | // Set the DT_SONAME string. | |
100 | void | |
101 | set_soname_string(const char* s) | |
102 | { this->soname_.assign(s); } | |
103 | ||
e2827e5f ILT |
104 | // Add an entry to the list of DT_NEEDED strings. |
105 | void | |
106 | add_needed(const char* s) | |
107 | { this->needed_.push_back(std::string(s)); } | |
108 | ||
a3ad94ed | 109 | private: |
a3ad94ed ILT |
110 | // Compute the GNU hash code for a string. |
111 | static uint32_t | |
112 | gnu_hash(const char*); | |
113 | ||
114 | // Compute the number of hash buckets to use. | |
115 | static unsigned int | |
116 | compute_bucket_count(const std::vector<uint32_t>& hashcodes, | |
117 | bool for_gnu_hash_table); | |
118 | ||
119 | // Sized version of create_elf_hash_table. | |
120 | template<bool big_endian> | |
121 | static void | |
122 | sized_create_elf_hash_table(const std::vector<uint32_t>& bucket, | |
123 | const std::vector<uint32_t>& chain, | |
124 | unsigned char* phash, | |
125 | unsigned int hashlen); | |
126 | ||
127 | // Sized version of create_gnu_hash_table. | |
128 | template<int size, bool big_endian> | |
129 | static void | |
130 | sized_create_gnu_hash_table(const std::vector<Symbol*>& hashed_dynsyms, | |
131 | const std::vector<uint32_t>& dynsym_hashvals, | |
132 | unsigned int unhashed_dynsym_count, | |
133 | unsigned char** pphash, | |
134 | unsigned int* phashlen); | |
135 | ||
e2827e5f ILT |
136 | // Values for the has_unknown_needed_entries_ field. |
137 | enum Unknown_needed | |
138 | { | |
139 | UNKNOWN_NEEDED_UNSET, | |
140 | UNKNOWN_NEEDED_TRUE, | |
141 | UNKNOWN_NEEDED_FALSE | |
142 | }; | |
143 | ||
a3ad94ed ILT |
144 | // The DT_SONAME name, if any. |
145 | std::string soname_; | |
e2827e5f ILT |
146 | // The list of DT_NEEDED entries. |
147 | Needed needed_; | |
148 | // Whether this dynamic object has any DT_NEEDED entries not seen | |
149 | // during the link. | |
150 | Unknown_needed unknown_needed_; | |
f6ce93d6 ILT |
151 | }; |
152 | ||
153 | // A dynamic object, size and endian specific version. | |
154 | ||
155 | template<int size, bool big_endian> | |
156 | class Sized_dynobj : public Dynobj | |
157 | { | |
158 | public: | |
159 | Sized_dynobj(const std::string& name, Input_file* input_file, off_t offset, | |
160 | const typename elfcpp::Ehdr<size, big_endian>&); | |
161 | ||
dbe717ef ILT |
162 | // Set up the object file based on the ELF header. |
163 | void | |
164 | setup(const typename elfcpp::Ehdr<size, big_endian>&); | |
165 | ||
f6ce93d6 ILT |
166 | // Read the symbols. |
167 | void | |
168 | do_read_symbols(Read_symbols_data*); | |
169 | ||
170 | // Lay out the input sections. | |
171 | void | |
7e1edb90 | 172 | do_layout(Symbol_table*, Layout*, Read_symbols_data*); |
f6ce93d6 ILT |
173 | |
174 | // Add the symbols to the symbol table. | |
175 | void | |
176 | do_add_symbols(Symbol_table*, Read_symbols_data*); | |
177 | ||
dbe717ef ILT |
178 | // Get the name of a section. |
179 | std::string | |
180 | do_section_name(unsigned int shndx) | |
181 | { return this->elf_file_.section_name(shndx); } | |
182 | ||
f6ce93d6 ILT |
183 | // Return a view of the contents of a section. Set *PLEN to the |
184 | // size. | |
dbe717ef ILT |
185 | Object::Location |
186 | do_section_contents(unsigned int shndx) | |
187 | { return this->elf_file_.section_contents(shndx); } | |
f6ce93d6 | 188 | |
a3ad94ed ILT |
189 | // Return section flags. |
190 | uint64_t | |
191 | do_section_flags(unsigned int shndx) | |
192 | { return this->elf_file_.section_flags(shndx); } | |
193 | ||
730cdc88 ILT |
194 | // Return section type. |
195 | unsigned int | |
196 | do_section_type(unsigned int shndx) | |
197 | { return this->elf_file_.section_type(shndx); } | |
198 | ||
f7e2ee48 ILT |
199 | // Return the section link field. |
200 | unsigned int | |
201 | do_section_link(unsigned int shndx) | |
202 | { return this->elf_file_.section_link(shndx); } | |
203 | ||
4c50553d ILT |
204 | // Return the section link field. |
205 | unsigned int | |
206 | do_section_info(unsigned int shndx) | |
207 | { return this->elf_file_.section_info(shndx); } | |
208 | ||
dbe717ef ILT |
209 | private: |
210 | // For convenience. | |
211 | typedef Sized_dynobj<size, big_endian> This; | |
212 | static const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size; | |
213 | static const int sym_size = elfcpp::Elf_sizes<size>::sym_size; | |
214 | static const int dyn_size = elfcpp::Elf_sizes<size>::dyn_size; | |
215 | typedef elfcpp::Shdr<size, big_endian> Shdr; | |
216 | typedef elfcpp::Dyn<size, big_endian> Dyn; | |
217 | ||
218 | // Find the dynamic symbol table and the version sections, given the | |
219 | // section headers. | |
220 | void | |
221 | find_dynsym_sections(const unsigned char* pshdrs, | |
222 | unsigned int* pdynshm_shndx, | |
223 | unsigned int* pversym_shndx, | |
224 | unsigned int* pverdef_shndx, | |
225 | unsigned int* pverneed_shndx, | |
226 | unsigned int* pdynamic_shndx); | |
227 | ||
228 | // Read the dynamic symbol section SHNDX. | |
229 | void | |
230 | read_dynsym_section(const unsigned char* pshdrs, unsigned int shndx, | |
231 | elfcpp::SHT type, unsigned int link, | |
8383303e | 232 | File_view** view, section_size_type* view_size, |
dbe717ef ILT |
233 | unsigned int* view_info); |
234 | ||
e2827e5f | 235 | // Read the dynamic tags. |
dbe717ef | 236 | void |
e2827e5f ILT |
237 | read_dynamic(const unsigned char* pshdrs, unsigned int dynamic_shndx, |
238 | unsigned int strtab_shndx, const unsigned char* strtabu, | |
239 | off_t strtab_size); | |
dbe717ef ILT |
240 | |
241 | // Mapping from version number to version name. | |
242 | typedef std::vector<const char*> Version_map; | |
243 | ||
244 | // Create the version map. | |
245 | void | |
246 | make_version_map(Read_symbols_data* sd, Version_map*) const; | |
247 | ||
14b31740 ILT |
248 | // Add version definitions to the version map. |
249 | void | |
250 | make_verdef_map(Read_symbols_data* sd, Version_map*) const; | |
251 | ||
252 | // Add version references to the version map. | |
253 | void | |
254 | make_verneed_map(Read_symbols_data* sd, Version_map*) const; | |
255 | ||
dbe717ef ILT |
256 | // Add an entry to the version map. |
257 | void | |
258 | set_version_map(Version_map*, unsigned int ndx, const char* name) const; | |
259 | ||
260 | // General access to the ELF file. | |
261 | elfcpp::Elf_file<size, big_endian, Object> elf_file_; | |
f6ce93d6 ILT |
262 | }; |
263 | ||
14b31740 ILT |
264 | // A base class for Verdef and Verneed_version which just handles the |
265 | // version index which will be stored in the SHT_GNU_versym section. | |
266 | ||
267 | class Version_base | |
268 | { | |
269 | public: | |
270 | Version_base() | |
271 | : index_(-1U) | |
272 | { } | |
273 | ||
274 | virtual | |
275 | ~Version_base() | |
276 | { } | |
277 | ||
278 | // Return the version index. | |
279 | unsigned int | |
280 | index() const | |
281 | { | |
282 | gold_assert(this->index_ != -1U); | |
283 | return this->index_; | |
284 | } | |
285 | ||
286 | // Set the version index. | |
287 | void | |
288 | set_index(unsigned int index) | |
289 | { | |
290 | gold_assert(this->index_ == -1U); | |
291 | this->index_ = index; | |
292 | } | |
293 | ||
294 | // Clear the weak flag in a version definition. | |
295 | virtual void | |
296 | clear_weak() = 0; | |
297 | ||
298 | private: | |
299 | Version_base(const Version_base&); | |
300 | Version_base& operator=(const Version_base&); | |
301 | ||
302 | // The index of the version definition or reference. | |
303 | unsigned int index_; | |
304 | }; | |
305 | ||
306 | // This class handles a version being defined in the file we are | |
307 | // generating. | |
308 | ||
309 | class Verdef : public Version_base | |
310 | { | |
311 | public: | |
312 | Verdef(const char* name, bool is_base, bool is_weak, bool is_symbol_created) | |
313 | : name_(name), deps_(), is_base_(is_base), is_weak_(is_weak), | |
314 | is_symbol_created_(is_symbol_created) | |
315 | { } | |
316 | ||
317 | // Return the version name. | |
318 | const char* | |
319 | name() const | |
320 | { return this->name_; } | |
321 | ||
322 | // Return the number of dependencies. | |
323 | unsigned int | |
324 | count_dependencies() const | |
325 | { return this->deps_.size(); } | |
326 | ||
327 | // Add a dependency to this version. The NAME should be | |
328 | // canonicalized in the dynamic Stringpool. | |
329 | void | |
330 | add_dependency(const char* name) | |
331 | { this->deps_.push_back(name); } | |
332 | ||
333 | // Return whether this definition is weak. | |
334 | bool | |
335 | is_weak() const | |
336 | { return this->is_weak_; } | |
337 | ||
338 | // Clear the weak flag. | |
339 | void | |
340 | clear_weak() | |
341 | { this->is_weak_ = false; } | |
342 | ||
343 | // Return whether a version symbol has been created for this | |
344 | // definition. | |
345 | bool | |
346 | is_symbol_created() const | |
347 | { return this->is_symbol_created_; } | |
348 | ||
349 | // Write contents to buffer. | |
350 | template<int size, bool big_endian> | |
351 | unsigned char* | |
91da9340 ILT |
352 | write(const Stringpool*, bool is_last, unsigned char* |
353 | ACCEPT_SIZE_ENDIAN) const; | |
14b31740 ILT |
354 | |
355 | private: | |
356 | Verdef(const Verdef&); | |
357 | Verdef& operator=(const Verdef&); | |
358 | ||
359 | // The type of the list of version dependencies. Each dependency | |
360 | // should be canonicalized in the dynamic Stringpool. | |
361 | typedef std::vector<const char*> Deps; | |
362 | ||
363 | // The name of this version. This should be canonicalized in the | |
364 | // dynamic Stringpool. | |
365 | const char* name_; | |
366 | // A list of other versions which this version depends upon. | |
367 | Deps deps_; | |
368 | // Whether this is the base version. | |
369 | bool is_base_; | |
370 | // Whether this version is weak. | |
371 | bool is_weak_; | |
372 | // Whether a version symbol has been created. | |
373 | bool is_symbol_created_; | |
374 | }; | |
375 | ||
376 | // A referened version. This will be associated with a filename by | |
377 | // Verneed. | |
378 | ||
379 | class Verneed_version : public Version_base | |
380 | { | |
381 | public: | |
382 | Verneed_version(const char* version) | |
383 | : version_(version) | |
384 | { } | |
385 | ||
386 | // Return the version name. | |
387 | const char* | |
388 | version() const | |
389 | { return this->version_; } | |
390 | ||
391 | // Clear the weak flag. This is invalid for a reference. | |
392 | void | |
393 | clear_weak() | |
394 | { gold_unreachable(); } | |
395 | ||
396 | private: | |
397 | Verneed_version(const Verneed_version&); | |
398 | Verneed_version& operator=(const Verneed_version&); | |
399 | ||
400 | const char* version_; | |
401 | }; | |
402 | ||
403 | // Version references in a single dynamic object. | |
404 | ||
405 | class Verneed | |
406 | { | |
407 | public: | |
408 | Verneed(const char* filename) | |
409 | : filename_(filename), need_versions_() | |
410 | { } | |
411 | ||
412 | ~Verneed(); | |
413 | ||
414 | // Return the file name. | |
415 | const char* | |
416 | filename() const | |
417 | { return this->filename_; } | |
418 | ||
419 | // Return the number of versions. | |
420 | unsigned int | |
421 | count_versions() const | |
422 | { return this->need_versions_.size(); } | |
423 | ||
424 | // Add a version name. The name should be canonicalized in the | |
425 | // dynamic Stringpool. If the name is already present, this does | |
426 | // nothing. | |
427 | Verneed_version* | |
428 | add_name(const char* name); | |
429 | ||
430 | // Set the version indexes, starting at INDEX. Return the updated | |
431 | // INDEX. | |
432 | unsigned int | |
433 | finalize(unsigned int index); | |
434 | ||
435 | // Write contents to buffer. | |
436 | template<int size, bool big_endian> | |
437 | unsigned char* | |
91da9340 ILT |
438 | write(const Stringpool*, bool is_last, unsigned char* |
439 | ACCEPT_SIZE_ENDIAN) const; | |
14b31740 ILT |
440 | |
441 | private: | |
442 | Verneed(const Verneed&); | |
443 | Verneed& operator=(const Verneed&); | |
444 | ||
445 | // The type of the list of version names. Each name should be | |
446 | // canonicalized in the dynamic Stringpool. | |
447 | typedef std::vector<Verneed_version*> Need_versions; | |
448 | ||
449 | // The filename of the dynamic object. This should be | |
450 | // canonicalized in the dynamic Stringpool. | |
451 | const char* filename_; | |
452 | // The list of version names. | |
453 | Need_versions need_versions_; | |
454 | }; | |
455 | ||
456 | // This class handles version definitions and references which go into | |
457 | // the output file. | |
458 | ||
459 | class Versions | |
460 | { | |
461 | public: | |
462 | Versions() | |
463 | : defs_(), needs_(), version_table_(), is_finalized_(false) | |
464 | { } | |
465 | ||
466 | ~Versions(); | |
467 | ||
468 | // SYM is going into the dynamic symbol table and has a version. | |
469 | // Record the appropriate version information. | |
470 | void | |
35cdfc9a | 471 | record_version(const Symbol_table* symtab, Stringpool*, const Symbol* sym); |
14b31740 ILT |
472 | |
473 | // Set the version indexes. DYNSYM_INDEX is the index we should use | |
474 | // for the next dynamic symbol. We add new dynamic symbols to SYMS | |
475 | // and return an updated DYNSYM_INDEX. | |
476 | unsigned int | |
477 | finalize(const Target*, Symbol_table* symtab, unsigned int dynsym_index, | |
478 | std::vector<Symbol*>* syms); | |
479 | ||
480 | // Return whether there are any version definitions. | |
481 | bool | |
482 | any_defs() const | |
483 | { return !this->defs_.empty(); } | |
484 | ||
485 | // Return whether there are any version references. | |
486 | bool | |
487 | any_needs() const | |
488 | { return !this->needs_.empty(); } | |
489 | ||
490 | // Build an allocated buffer holding the contents of the symbol | |
491 | // version section (.gnu.version). | |
492 | template<int size, bool big_endian> | |
493 | void | |
46fe1623 ILT |
494 | symbol_section_contents(const Symbol_table*, const Stringpool*, |
495 | unsigned int local_symcount, | |
14b31740 | 496 | const std::vector<Symbol*>& syms, |
91da9340 ILT |
497 | unsigned char**, unsigned int* |
498 | ACCEPT_SIZE_ENDIAN) const; | |
14b31740 ILT |
499 | |
500 | // Build an allocated buffer holding the contents of the version | |
501 | // definition section (.gnu.version_d). | |
502 | template<int size, bool big_endian> | |
503 | void | |
504 | def_section_contents(const Stringpool*, unsigned char**, | |
91da9340 ILT |
505 | unsigned int* psize, unsigned int* pentries |
506 | ACCEPT_SIZE_ENDIAN) const; | |
14b31740 ILT |
507 | |
508 | // Build an allocated buffer holding the contents of the version | |
509 | // reference section (.gnu.version_r). | |
510 | template<int size, bool big_endian> | |
511 | void | |
512 | need_section_contents(const Stringpool*, unsigned char**, | |
91da9340 ILT |
513 | unsigned int* psize, unsigned int* pentries |
514 | ACCEPT_SIZE_ENDIAN) const; | |
14b31740 ILT |
515 | |
516 | private: | |
517 | // The type of the list of version definitions. | |
518 | typedef std::vector<Verdef*> Defs; | |
519 | ||
520 | // The type of the list of version references. | |
521 | typedef std::vector<Verneed*> Needs; | |
522 | ||
523 | // Handle a symbol SYM defined with version VERSION. | |
524 | void | |
35cdfc9a | 525 | add_def(const Symbol* sym, const char* version, Stringpool::Key); |
14b31740 ILT |
526 | |
527 | // Add a reference to version NAME in file FILENAME. | |
528 | void | |
529 | add_need(Stringpool*, const char* filename, const char* name, | |
530 | Stringpool::Key); | |
531 | ||
46fe1623 ILT |
532 | // Get the dynamic object to use for SYM. |
533 | Dynobj* | |
534 | get_dynobj_for_sym(const Symbol_table*, const Symbol* sym) const; | |
535 | ||
14b31740 ILT |
536 | // Return the version index to use for SYM. |
537 | unsigned int | |
46fe1623 ILT |
538 | version_index(const Symbol_table*, const Stringpool*, |
539 | const Symbol* sym) const; | |
14b31740 ILT |
540 | |
541 | // We keep a hash table mapping canonicalized name/version pairs to | |
542 | // a version base. | |
543 | typedef std::pair<Stringpool::Key, Stringpool::Key> Key; | |
544 | ||
545 | struct Version_table_hash | |
546 | { | |
547 | size_t | |
548 | operator()(const Key& k) const | |
549 | { return k.first + k.second; } | |
550 | }; | |
551 | ||
552 | struct Version_table_eq | |
553 | { | |
554 | bool | |
555 | operator()(const Key& k1, const Key& k2) const | |
556 | { return k1.first == k2.first && k1.second == k2.second; } | |
557 | }; | |
558 | ||
559 | typedef Unordered_map<Key, Version_base*, Version_table_hash, | |
560 | Version_table_eq> Version_table; | |
561 | ||
562 | // The version definitions. | |
563 | Defs defs_; | |
564 | // The version references. | |
565 | Needs needs_; | |
566 | // The mapping from a canonicalized version/filename pair to a | |
567 | // version index. The filename may be NULL. | |
568 | Version_table version_table_; | |
569 | // Whether the version indexes have been set. | |
570 | bool is_finalized_; | |
571 | }; | |
572 | ||
f6ce93d6 ILT |
573 | } // End namespace gold. |
574 | ||
575 | #endif // !defined(GOLD_DYNOBJ_H) |