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1 | // dynobj.h -- dynamic object support for gold -*- C++ -*- |
2 | ||
3 | #ifndef GOLD_DYNOBJ_H | |
4 | #define GOLD_DYNOBJ_H | |
5 | ||
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6 | #include <vector> |
7 | ||
14b31740 | 8 | #include "stringpool.h" |
f6ce93d6 ILT |
9 | #include "object.h" |
10 | ||
11 | namespace gold | |
12 | { | |
13 | ||
14b31740 | 14 | class General_options; |
14b31740 | 15 | |
f6ce93d6 ILT |
16 | // A dynamic object (ET_DYN). This is an abstract base class itself. |
17 | // The implementations is the template class Sized_dynobj. | |
18 | ||
19 | class Dynobj : public Object | |
20 | { | |
21 | public: | |
22 | Dynobj(const std::string& name, Input_file* input_file, off_t offset = 0) | |
a3ad94ed | 23 | : Object(name, input_file, true, offset), soname_() |
f6ce93d6 | 24 | { } |
a3ad94ed ILT |
25 | |
26 | // Return the name to use in a DT_NEEDED entry for this object. | |
27 | const char* | |
28 | soname() const; | |
29 | ||
14b31740 ILT |
30 | // Compute the ELF hash code for a string. |
31 | static uint32_t | |
32 | elf_hash(const char*); | |
33 | ||
a3ad94ed ILT |
34 | // Create a standard ELF hash table, setting *PPHASH and *PHASHLEN. |
35 | // DYNSYMS is the global dynamic symbols. LOCAL_DYNSYM_COUNT is the | |
36 | // number of local dynamic symbols, which is the index of the first | |
37 | // dynamic gobal symbol. | |
38 | static void | |
39 | create_elf_hash_table(const Target*, const std::vector<Symbol*>& dynsyms, | |
40 | unsigned int local_dynsym_count, | |
41 | unsigned char** pphash, | |
42 | unsigned int* phashlen); | |
43 | ||
44 | // Create a GNU hash table, setting *PPHASH and *PHASHLEN. DYNSYMS | |
45 | // is the global dynamic symbols. LOCAL_DYNSYM_COUNT is the number | |
46 | // of local dynamic symbols, which is the index of the first dynamic | |
47 | // gobal symbol. | |
48 | static void | |
49 | create_gnu_hash_table(const Target*, const std::vector<Symbol*>& dynsyms, | |
50 | unsigned int local_dynsym_count, | |
51 | unsigned char** pphash, unsigned int* phashlen); | |
52 | ||
53 | protected: | |
54 | // Set the DT_SONAME string. | |
55 | void | |
56 | set_soname_string(const char* s) | |
57 | { this->soname_.assign(s); } | |
58 | ||
59 | private: | |
a3ad94ed ILT |
60 | // Compute the GNU hash code for a string. |
61 | static uint32_t | |
62 | gnu_hash(const char*); | |
63 | ||
64 | // Compute the number of hash buckets to use. | |
65 | static unsigned int | |
66 | compute_bucket_count(const std::vector<uint32_t>& hashcodes, | |
67 | bool for_gnu_hash_table); | |
68 | ||
69 | // Sized version of create_elf_hash_table. | |
70 | template<bool big_endian> | |
71 | static void | |
72 | sized_create_elf_hash_table(const std::vector<uint32_t>& bucket, | |
73 | const std::vector<uint32_t>& chain, | |
74 | unsigned char* phash, | |
75 | unsigned int hashlen); | |
76 | ||
77 | // Sized version of create_gnu_hash_table. | |
78 | template<int size, bool big_endian> | |
79 | static void | |
80 | sized_create_gnu_hash_table(const std::vector<Symbol*>& hashed_dynsyms, | |
81 | const std::vector<uint32_t>& dynsym_hashvals, | |
82 | unsigned int unhashed_dynsym_count, | |
83 | unsigned char** pphash, | |
84 | unsigned int* phashlen); | |
85 | ||
86 | // The DT_SONAME name, if any. | |
87 | std::string soname_; | |
f6ce93d6 ILT |
88 | }; |
89 | ||
90 | // A dynamic object, size and endian specific version. | |
91 | ||
92 | template<int size, bool big_endian> | |
93 | class Sized_dynobj : public Dynobj | |
94 | { | |
95 | public: | |
96 | Sized_dynobj(const std::string& name, Input_file* input_file, off_t offset, | |
97 | const typename elfcpp::Ehdr<size, big_endian>&); | |
98 | ||
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99 | // Set up the object file based on the ELF header. |
100 | void | |
101 | setup(const typename elfcpp::Ehdr<size, big_endian>&); | |
102 | ||
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103 | // Read the symbols. |
104 | void | |
105 | do_read_symbols(Read_symbols_data*); | |
106 | ||
107 | // Lay out the input sections. | |
108 | void | |
109 | do_layout(const General_options&, Symbol_table*, Layout*, | |
110 | Read_symbols_data*); | |
111 | ||
112 | // Add the symbols to the symbol table. | |
113 | void | |
114 | do_add_symbols(Symbol_table*, Read_symbols_data*); | |
115 | ||
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116 | // Get the name of a section. |
117 | std::string | |
118 | do_section_name(unsigned int shndx) | |
119 | { return this->elf_file_.section_name(shndx); } | |
120 | ||
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121 | // Return a view of the contents of a section. Set *PLEN to the |
122 | // size. | |
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123 | Object::Location |
124 | do_section_contents(unsigned int shndx) | |
125 | { return this->elf_file_.section_contents(shndx); } | |
f6ce93d6 | 126 | |
a3ad94ed ILT |
127 | // Return section flags. |
128 | uint64_t | |
129 | do_section_flags(unsigned int shndx) | |
130 | { return this->elf_file_.section_flags(shndx); } | |
131 | ||
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132 | private: |
133 | // For convenience. | |
134 | typedef Sized_dynobj<size, big_endian> This; | |
135 | static const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size; | |
136 | static const int sym_size = elfcpp::Elf_sizes<size>::sym_size; | |
137 | static const int dyn_size = elfcpp::Elf_sizes<size>::dyn_size; | |
138 | typedef elfcpp::Shdr<size, big_endian> Shdr; | |
139 | typedef elfcpp::Dyn<size, big_endian> Dyn; | |
140 | ||
141 | // Find the dynamic symbol table and the version sections, given the | |
142 | // section headers. | |
143 | void | |
144 | find_dynsym_sections(const unsigned char* pshdrs, | |
145 | unsigned int* pdynshm_shndx, | |
146 | unsigned int* pversym_shndx, | |
147 | unsigned int* pverdef_shndx, | |
148 | unsigned int* pverneed_shndx, | |
149 | unsigned int* pdynamic_shndx); | |
150 | ||
151 | // Read the dynamic symbol section SHNDX. | |
152 | void | |
153 | read_dynsym_section(const unsigned char* pshdrs, unsigned int shndx, | |
154 | elfcpp::SHT type, unsigned int link, | |
155 | File_view** view, off_t* view_size, | |
156 | unsigned int* view_info); | |
157 | ||
158 | // Set the SONAME from the SHT_DYNAMIC section at DYNAMIC_SHNDX. | |
159 | // The STRTAB parameters may have the relevant string table. | |
160 | void | |
161 | set_soname(const unsigned char* pshdrs, unsigned int dynamic_shndx, | |
162 | unsigned int strtab_shndx, const unsigned char* strtabu, | |
163 | off_t strtab_size); | |
164 | ||
165 | // Mapping from version number to version name. | |
166 | typedef std::vector<const char*> Version_map; | |
167 | ||
168 | // Create the version map. | |
169 | void | |
170 | make_version_map(Read_symbols_data* sd, Version_map*) const; | |
171 | ||
14b31740 ILT |
172 | // Add version definitions to the version map. |
173 | void | |
174 | make_verdef_map(Read_symbols_data* sd, Version_map*) const; | |
175 | ||
176 | // Add version references to the version map. | |
177 | void | |
178 | make_verneed_map(Read_symbols_data* sd, Version_map*) const; | |
179 | ||
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180 | // Add an entry to the version map. |
181 | void | |
182 | set_version_map(Version_map*, unsigned int ndx, const char* name) const; | |
183 | ||
184 | // General access to the ELF file. | |
185 | elfcpp::Elf_file<size, big_endian, Object> elf_file_; | |
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186 | }; |
187 | ||
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188 | // A base class for Verdef and Verneed_version which just handles the |
189 | // version index which will be stored in the SHT_GNU_versym section. | |
190 | ||
191 | class Version_base | |
192 | { | |
193 | public: | |
194 | Version_base() | |
195 | : index_(-1U) | |
196 | { } | |
197 | ||
198 | virtual | |
199 | ~Version_base() | |
200 | { } | |
201 | ||
202 | // Return the version index. | |
203 | unsigned int | |
204 | index() const | |
205 | { | |
206 | gold_assert(this->index_ != -1U); | |
207 | return this->index_; | |
208 | } | |
209 | ||
210 | // Set the version index. | |
211 | void | |
212 | set_index(unsigned int index) | |
213 | { | |
214 | gold_assert(this->index_ == -1U); | |
215 | this->index_ = index; | |
216 | } | |
217 | ||
218 | // Clear the weak flag in a version definition. | |
219 | virtual void | |
220 | clear_weak() = 0; | |
221 | ||
222 | private: | |
223 | Version_base(const Version_base&); | |
224 | Version_base& operator=(const Version_base&); | |
225 | ||
226 | // The index of the version definition or reference. | |
227 | unsigned int index_; | |
228 | }; | |
229 | ||
230 | // This class handles a version being defined in the file we are | |
231 | // generating. | |
232 | ||
233 | class Verdef : public Version_base | |
234 | { | |
235 | public: | |
236 | Verdef(const char* name, bool is_base, bool is_weak, bool is_symbol_created) | |
237 | : name_(name), deps_(), is_base_(is_base), is_weak_(is_weak), | |
238 | is_symbol_created_(is_symbol_created) | |
239 | { } | |
240 | ||
241 | // Return the version name. | |
242 | const char* | |
243 | name() const | |
244 | { return this->name_; } | |
245 | ||
246 | // Return the number of dependencies. | |
247 | unsigned int | |
248 | count_dependencies() const | |
249 | { return this->deps_.size(); } | |
250 | ||
251 | // Add a dependency to this version. The NAME should be | |
252 | // canonicalized in the dynamic Stringpool. | |
253 | void | |
254 | add_dependency(const char* name) | |
255 | { this->deps_.push_back(name); } | |
256 | ||
257 | // Return whether this definition is weak. | |
258 | bool | |
259 | is_weak() const | |
260 | { return this->is_weak_; } | |
261 | ||
262 | // Clear the weak flag. | |
263 | void | |
264 | clear_weak() | |
265 | { this->is_weak_ = false; } | |
266 | ||
267 | // Return whether a version symbol has been created for this | |
268 | // definition. | |
269 | bool | |
270 | is_symbol_created() const | |
271 | { return this->is_symbol_created_; } | |
272 | ||
273 | // Write contents to buffer. | |
274 | template<int size, bool big_endian> | |
275 | unsigned char* | |
91da9340 ILT |
276 | write(const Stringpool*, bool is_last, unsigned char* |
277 | ACCEPT_SIZE_ENDIAN) const; | |
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278 | |
279 | private: | |
280 | Verdef(const Verdef&); | |
281 | Verdef& operator=(const Verdef&); | |
282 | ||
283 | // The type of the list of version dependencies. Each dependency | |
284 | // should be canonicalized in the dynamic Stringpool. | |
285 | typedef std::vector<const char*> Deps; | |
286 | ||
287 | // The name of this version. This should be canonicalized in the | |
288 | // dynamic Stringpool. | |
289 | const char* name_; | |
290 | // A list of other versions which this version depends upon. | |
291 | Deps deps_; | |
292 | // Whether this is the base version. | |
293 | bool is_base_; | |
294 | // Whether this version is weak. | |
295 | bool is_weak_; | |
296 | // Whether a version symbol has been created. | |
297 | bool is_symbol_created_; | |
298 | }; | |
299 | ||
300 | // A referened version. This will be associated with a filename by | |
301 | // Verneed. | |
302 | ||
303 | class Verneed_version : public Version_base | |
304 | { | |
305 | public: | |
306 | Verneed_version(const char* version) | |
307 | : version_(version) | |
308 | { } | |
309 | ||
310 | // Return the version name. | |
311 | const char* | |
312 | version() const | |
313 | { return this->version_; } | |
314 | ||
315 | // Clear the weak flag. This is invalid for a reference. | |
316 | void | |
317 | clear_weak() | |
318 | { gold_unreachable(); } | |
319 | ||
320 | private: | |
321 | Verneed_version(const Verneed_version&); | |
322 | Verneed_version& operator=(const Verneed_version&); | |
323 | ||
324 | const char* version_; | |
325 | }; | |
326 | ||
327 | // Version references in a single dynamic object. | |
328 | ||
329 | class Verneed | |
330 | { | |
331 | public: | |
332 | Verneed(const char* filename) | |
333 | : filename_(filename), need_versions_() | |
334 | { } | |
335 | ||
336 | ~Verneed(); | |
337 | ||
338 | // Return the file name. | |
339 | const char* | |
340 | filename() const | |
341 | { return this->filename_; } | |
342 | ||
343 | // Return the number of versions. | |
344 | unsigned int | |
345 | count_versions() const | |
346 | { return this->need_versions_.size(); } | |
347 | ||
348 | // Add a version name. The name should be canonicalized in the | |
349 | // dynamic Stringpool. If the name is already present, this does | |
350 | // nothing. | |
351 | Verneed_version* | |
352 | add_name(const char* name); | |
353 | ||
354 | // Set the version indexes, starting at INDEX. Return the updated | |
355 | // INDEX. | |
356 | unsigned int | |
357 | finalize(unsigned int index); | |
358 | ||
359 | // Write contents to buffer. | |
360 | template<int size, bool big_endian> | |
361 | unsigned char* | |
91da9340 ILT |
362 | write(const Stringpool*, bool is_last, unsigned char* |
363 | ACCEPT_SIZE_ENDIAN) const; | |
14b31740 ILT |
364 | |
365 | private: | |
366 | Verneed(const Verneed&); | |
367 | Verneed& operator=(const Verneed&); | |
368 | ||
369 | // The type of the list of version names. Each name should be | |
370 | // canonicalized in the dynamic Stringpool. | |
371 | typedef std::vector<Verneed_version*> Need_versions; | |
372 | ||
373 | // The filename of the dynamic object. This should be | |
374 | // canonicalized in the dynamic Stringpool. | |
375 | const char* filename_; | |
376 | // The list of version names. | |
377 | Need_versions need_versions_; | |
378 | }; | |
379 | ||
380 | // This class handles version definitions and references which go into | |
381 | // the output file. | |
382 | ||
383 | class Versions | |
384 | { | |
385 | public: | |
386 | Versions() | |
387 | : defs_(), needs_(), version_table_(), is_finalized_(false) | |
388 | { } | |
389 | ||
390 | ~Versions(); | |
391 | ||
392 | // SYM is going into the dynamic symbol table and has a version. | |
393 | // Record the appropriate version information. | |
394 | void | |
395 | record_version(const General_options*, Stringpool*, const Symbol* sym); | |
396 | ||
397 | // Set the version indexes. DYNSYM_INDEX is the index we should use | |
398 | // for the next dynamic symbol. We add new dynamic symbols to SYMS | |
399 | // and return an updated DYNSYM_INDEX. | |
400 | unsigned int | |
401 | finalize(const Target*, Symbol_table* symtab, unsigned int dynsym_index, | |
402 | std::vector<Symbol*>* syms); | |
403 | ||
404 | // Return whether there are any version definitions. | |
405 | bool | |
406 | any_defs() const | |
407 | { return !this->defs_.empty(); } | |
408 | ||
409 | // Return whether there are any version references. | |
410 | bool | |
411 | any_needs() const | |
412 | { return !this->needs_.empty(); } | |
413 | ||
414 | // Build an allocated buffer holding the contents of the symbol | |
415 | // version section (.gnu.version). | |
416 | template<int size, bool big_endian> | |
417 | void | |
31365f57 ILT |
418 | symbol_section_contents(const General_options*, const Stringpool*, |
419 | unsigned int local_symcount, | |
14b31740 | 420 | const std::vector<Symbol*>& syms, |
91da9340 ILT |
421 | unsigned char**, unsigned int* |
422 | ACCEPT_SIZE_ENDIAN) const; | |
14b31740 ILT |
423 | |
424 | // Build an allocated buffer holding the contents of the version | |
425 | // definition section (.gnu.version_d). | |
426 | template<int size, bool big_endian> | |
427 | void | |
428 | def_section_contents(const Stringpool*, unsigned char**, | |
91da9340 ILT |
429 | unsigned int* psize, unsigned int* pentries |
430 | ACCEPT_SIZE_ENDIAN) const; | |
14b31740 ILT |
431 | |
432 | // Build an allocated buffer holding the contents of the version | |
433 | // reference section (.gnu.version_r). | |
434 | template<int size, bool big_endian> | |
435 | void | |
436 | need_section_contents(const Stringpool*, unsigned char**, | |
91da9340 ILT |
437 | unsigned int* psize, unsigned int* pentries |
438 | ACCEPT_SIZE_ENDIAN) const; | |
14b31740 ILT |
439 | |
440 | private: | |
441 | // The type of the list of version definitions. | |
442 | typedef std::vector<Verdef*> Defs; | |
443 | ||
444 | // The type of the list of version references. | |
445 | typedef std::vector<Verneed*> Needs; | |
446 | ||
447 | // Handle a symbol SYM defined with version VERSION. | |
448 | void | |
449 | add_def(const General_options*, const Symbol* sym, const char* version, | |
450 | Stringpool::Key); | |
451 | ||
452 | // Add a reference to version NAME in file FILENAME. | |
453 | void | |
454 | add_need(Stringpool*, const char* filename, const char* name, | |
455 | Stringpool::Key); | |
456 | ||
457 | // Return the version index to use for SYM. | |
458 | unsigned int | |
31365f57 ILT |
459 | version_index(const General_options*, const Stringpool*, |
460 | const Symbol* sym) const; | |
14b31740 ILT |
461 | |
462 | // We keep a hash table mapping canonicalized name/version pairs to | |
463 | // a version base. | |
464 | typedef std::pair<Stringpool::Key, Stringpool::Key> Key; | |
465 | ||
466 | struct Version_table_hash | |
467 | { | |
468 | size_t | |
469 | operator()(const Key& k) const | |
470 | { return k.first + k.second; } | |
471 | }; | |
472 | ||
473 | struct Version_table_eq | |
474 | { | |
475 | bool | |
476 | operator()(const Key& k1, const Key& k2) const | |
477 | { return k1.first == k2.first && k1.second == k2.second; } | |
478 | }; | |
479 | ||
480 | typedef Unordered_map<Key, Version_base*, Version_table_hash, | |
481 | Version_table_eq> Version_table; | |
482 | ||
483 | // The version definitions. | |
484 | Defs defs_; | |
485 | // The version references. | |
486 | Needs needs_; | |
487 | // The mapping from a canonicalized version/filename pair to a | |
488 | // version index. The filename may be NULL. | |
489 | Version_table version_table_; | |
490 | // Whether the version indexes have been set. | |
491 | bool is_finalized_; | |
492 | }; | |
493 | ||
f6ce93d6 ILT |
494 | } // End namespace gold. |
495 | ||
496 | #endif // !defined(GOLD_DYNOBJ_H) |