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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 | ||
dbe717ef ILT |
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 | |
7e1edb90 | 109 | do_layout(Symbol_table*, Layout*, Read_symbols_data*); |
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110 | |
111 | // Add the symbols to the symbol table. | |
112 | void | |
113 | do_add_symbols(Symbol_table*, Read_symbols_data*); | |
114 | ||
dbe717ef ILT |
115 | // Get the name of a section. |
116 | std::string | |
117 | do_section_name(unsigned int shndx) | |
118 | { return this->elf_file_.section_name(shndx); } | |
119 | ||
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120 | // Return a view of the contents of a section. Set *PLEN to the |
121 | // size. | |
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122 | Object::Location |
123 | do_section_contents(unsigned int shndx) | |
124 | { return this->elf_file_.section_contents(shndx); } | |
f6ce93d6 | 125 | |
a3ad94ed ILT |
126 | // Return section flags. |
127 | uint64_t | |
128 | do_section_flags(unsigned int shndx) | |
129 | { return this->elf_file_.section_flags(shndx); } | |
130 | ||
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131 | private: |
132 | // For convenience. | |
133 | typedef Sized_dynobj<size, big_endian> This; | |
134 | static const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size; | |
135 | static const int sym_size = elfcpp::Elf_sizes<size>::sym_size; | |
136 | static const int dyn_size = elfcpp::Elf_sizes<size>::dyn_size; | |
137 | typedef elfcpp::Shdr<size, big_endian> Shdr; | |
138 | typedef elfcpp::Dyn<size, big_endian> Dyn; | |
139 | ||
140 | // Find the dynamic symbol table and the version sections, given the | |
141 | // section headers. | |
142 | void | |
143 | find_dynsym_sections(const unsigned char* pshdrs, | |
144 | unsigned int* pdynshm_shndx, | |
145 | unsigned int* pversym_shndx, | |
146 | unsigned int* pverdef_shndx, | |
147 | unsigned int* pverneed_shndx, | |
148 | unsigned int* pdynamic_shndx); | |
149 | ||
150 | // Read the dynamic symbol section SHNDX. | |
151 | void | |
152 | read_dynsym_section(const unsigned char* pshdrs, unsigned int shndx, | |
153 | elfcpp::SHT type, unsigned int link, | |
154 | File_view** view, off_t* view_size, | |
155 | unsigned int* view_info); | |
156 | ||
157 | // Set the SONAME from the SHT_DYNAMIC section at DYNAMIC_SHNDX. | |
158 | // The STRTAB parameters may have the relevant string table. | |
159 | void | |
160 | set_soname(const unsigned char* pshdrs, unsigned int dynamic_shndx, | |
161 | unsigned int strtab_shndx, const unsigned char* strtabu, | |
162 | off_t strtab_size); | |
163 | ||
164 | // Mapping from version number to version name. | |
165 | typedef std::vector<const char*> Version_map; | |
166 | ||
167 | // Create the version map. | |
168 | void | |
169 | make_version_map(Read_symbols_data* sd, Version_map*) const; | |
170 | ||
14b31740 ILT |
171 | // Add version definitions to the version map. |
172 | void | |
173 | make_verdef_map(Read_symbols_data* sd, Version_map*) const; | |
174 | ||
175 | // Add version references to the version map. | |
176 | void | |
177 | make_verneed_map(Read_symbols_data* sd, Version_map*) const; | |
178 | ||
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179 | // Add an entry to the version map. |
180 | void | |
181 | set_version_map(Version_map*, unsigned int ndx, const char* name) const; | |
182 | ||
183 | // General access to the ELF file. | |
184 | elfcpp::Elf_file<size, big_endian, Object> elf_file_; | |
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185 | }; |
186 | ||
14b31740 ILT |
187 | // A base class for Verdef and Verneed_version which just handles the |
188 | // version index which will be stored in the SHT_GNU_versym section. | |
189 | ||
190 | class Version_base | |
191 | { | |
192 | public: | |
193 | Version_base() | |
194 | : index_(-1U) | |
195 | { } | |
196 | ||
197 | virtual | |
198 | ~Version_base() | |
199 | { } | |
200 | ||
201 | // Return the version index. | |
202 | unsigned int | |
203 | index() const | |
204 | { | |
205 | gold_assert(this->index_ != -1U); | |
206 | return this->index_; | |
207 | } | |
208 | ||
209 | // Set the version index. | |
210 | void | |
211 | set_index(unsigned int index) | |
212 | { | |
213 | gold_assert(this->index_ == -1U); | |
214 | this->index_ = index; | |
215 | } | |
216 | ||
217 | // Clear the weak flag in a version definition. | |
218 | virtual void | |
219 | clear_weak() = 0; | |
220 | ||
221 | private: | |
222 | Version_base(const Version_base&); | |
223 | Version_base& operator=(const Version_base&); | |
224 | ||
225 | // The index of the version definition or reference. | |
226 | unsigned int index_; | |
227 | }; | |
228 | ||
229 | // This class handles a version being defined in the file we are | |
230 | // generating. | |
231 | ||
232 | class Verdef : public Version_base | |
233 | { | |
234 | public: | |
235 | Verdef(const char* name, bool is_base, bool is_weak, bool is_symbol_created) | |
236 | : name_(name), deps_(), is_base_(is_base), is_weak_(is_weak), | |
237 | is_symbol_created_(is_symbol_created) | |
238 | { } | |
239 | ||
240 | // Return the version name. | |
241 | const char* | |
242 | name() const | |
243 | { return this->name_; } | |
244 | ||
245 | // Return the number of dependencies. | |
246 | unsigned int | |
247 | count_dependencies() const | |
248 | { return this->deps_.size(); } | |
249 | ||
250 | // Add a dependency to this version. The NAME should be | |
251 | // canonicalized in the dynamic Stringpool. | |
252 | void | |
253 | add_dependency(const char* name) | |
254 | { this->deps_.push_back(name); } | |
255 | ||
256 | // Return whether this definition is weak. | |
257 | bool | |
258 | is_weak() const | |
259 | { return this->is_weak_; } | |
260 | ||
261 | // Clear the weak flag. | |
262 | void | |
263 | clear_weak() | |
264 | { this->is_weak_ = false; } | |
265 | ||
266 | // Return whether a version symbol has been created for this | |
267 | // definition. | |
268 | bool | |
269 | is_symbol_created() const | |
270 | { return this->is_symbol_created_; } | |
271 | ||
272 | // Write contents to buffer. | |
273 | template<int size, bool big_endian> | |
274 | unsigned char* | |
91da9340 ILT |
275 | write(const Stringpool*, bool is_last, unsigned char* |
276 | ACCEPT_SIZE_ENDIAN) const; | |
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277 | |
278 | private: | |
279 | Verdef(const Verdef&); | |
280 | Verdef& operator=(const Verdef&); | |
281 | ||
282 | // The type of the list of version dependencies. Each dependency | |
283 | // should be canonicalized in the dynamic Stringpool. | |
284 | typedef std::vector<const char*> Deps; | |
285 | ||
286 | // The name of this version. This should be canonicalized in the | |
287 | // dynamic Stringpool. | |
288 | const char* name_; | |
289 | // A list of other versions which this version depends upon. | |
290 | Deps deps_; | |
291 | // Whether this is the base version. | |
292 | bool is_base_; | |
293 | // Whether this version is weak. | |
294 | bool is_weak_; | |
295 | // Whether a version symbol has been created. | |
296 | bool is_symbol_created_; | |
297 | }; | |
298 | ||
299 | // A referened version. This will be associated with a filename by | |
300 | // Verneed. | |
301 | ||
302 | class Verneed_version : public Version_base | |
303 | { | |
304 | public: | |
305 | Verneed_version(const char* version) | |
306 | : version_(version) | |
307 | { } | |
308 | ||
309 | // Return the version name. | |
310 | const char* | |
311 | version() const | |
312 | { return this->version_; } | |
313 | ||
314 | // Clear the weak flag. This is invalid for a reference. | |
315 | void | |
316 | clear_weak() | |
317 | { gold_unreachable(); } | |
318 | ||
319 | private: | |
320 | Verneed_version(const Verneed_version&); | |
321 | Verneed_version& operator=(const Verneed_version&); | |
322 | ||
323 | const char* version_; | |
324 | }; | |
325 | ||
326 | // Version references in a single dynamic object. | |
327 | ||
328 | class Verneed | |
329 | { | |
330 | public: | |
331 | Verneed(const char* filename) | |
332 | : filename_(filename), need_versions_() | |
333 | { } | |
334 | ||
335 | ~Verneed(); | |
336 | ||
337 | // Return the file name. | |
338 | const char* | |
339 | filename() const | |
340 | { return this->filename_; } | |
341 | ||
342 | // Return the number of versions. | |
343 | unsigned int | |
344 | count_versions() const | |
345 | { return this->need_versions_.size(); } | |
346 | ||
347 | // Add a version name. The name should be canonicalized in the | |
348 | // dynamic Stringpool. If the name is already present, this does | |
349 | // nothing. | |
350 | Verneed_version* | |
351 | add_name(const char* name); | |
352 | ||
353 | // Set the version indexes, starting at INDEX. Return the updated | |
354 | // INDEX. | |
355 | unsigned int | |
356 | finalize(unsigned int index); | |
357 | ||
358 | // Write contents to buffer. | |
359 | template<int size, bool big_endian> | |
360 | unsigned char* | |
91da9340 ILT |
361 | write(const Stringpool*, bool is_last, unsigned char* |
362 | ACCEPT_SIZE_ENDIAN) const; | |
14b31740 ILT |
363 | |
364 | private: | |
365 | Verneed(const Verneed&); | |
366 | Verneed& operator=(const Verneed&); | |
367 | ||
368 | // The type of the list of version names. Each name should be | |
369 | // canonicalized in the dynamic Stringpool. | |
370 | typedef std::vector<Verneed_version*> Need_versions; | |
371 | ||
372 | // The filename of the dynamic object. This should be | |
373 | // canonicalized in the dynamic Stringpool. | |
374 | const char* filename_; | |
375 | // The list of version names. | |
376 | Need_versions need_versions_; | |
377 | }; | |
378 | ||
379 | // This class handles version definitions and references which go into | |
380 | // the output file. | |
381 | ||
382 | class Versions | |
383 | { | |
384 | public: | |
385 | Versions() | |
386 | : defs_(), needs_(), version_table_(), is_finalized_(false) | |
387 | { } | |
388 | ||
389 | ~Versions(); | |
390 | ||
391 | // SYM is going into the dynamic symbol table and has a version. | |
392 | // Record the appropriate version information. | |
393 | void | |
394 | record_version(const General_options*, Stringpool*, const Symbol* sym); | |
395 | ||
396 | // Set the version indexes. DYNSYM_INDEX is the index we should use | |
397 | // for the next dynamic symbol. We add new dynamic symbols to SYMS | |
398 | // and return an updated DYNSYM_INDEX. | |
399 | unsigned int | |
400 | finalize(const Target*, Symbol_table* symtab, unsigned int dynsym_index, | |
401 | std::vector<Symbol*>* syms); | |
402 | ||
403 | // Return whether there are any version definitions. | |
404 | bool | |
405 | any_defs() const | |
406 | { return !this->defs_.empty(); } | |
407 | ||
408 | // Return whether there are any version references. | |
409 | bool | |
410 | any_needs() const | |
411 | { return !this->needs_.empty(); } | |
412 | ||
413 | // Build an allocated buffer holding the contents of the symbol | |
414 | // version section (.gnu.version). | |
415 | template<int size, bool big_endian> | |
416 | void | |
7e1edb90 | 417 | symbol_section_contents(const Stringpool*, unsigned int local_symcount, |
14b31740 | 418 | const std::vector<Symbol*>& syms, |
91da9340 ILT |
419 | unsigned char**, unsigned int* |
420 | ACCEPT_SIZE_ENDIAN) const; | |
14b31740 ILT |
421 | |
422 | // Build an allocated buffer holding the contents of the version | |
423 | // definition section (.gnu.version_d). | |
424 | template<int size, bool big_endian> | |
425 | void | |
426 | def_section_contents(const Stringpool*, unsigned char**, | |
91da9340 ILT |
427 | unsigned int* psize, unsigned int* pentries |
428 | ACCEPT_SIZE_ENDIAN) const; | |
14b31740 ILT |
429 | |
430 | // Build an allocated buffer holding the contents of the version | |
431 | // reference section (.gnu.version_r). | |
432 | template<int size, bool big_endian> | |
433 | void | |
434 | need_section_contents(const Stringpool*, unsigned char**, | |
91da9340 ILT |
435 | unsigned int* psize, unsigned int* pentries |
436 | ACCEPT_SIZE_ENDIAN) const; | |
14b31740 ILT |
437 | |
438 | private: | |
439 | // The type of the list of version definitions. | |
440 | typedef std::vector<Verdef*> Defs; | |
441 | ||
442 | // The type of the list of version references. | |
443 | typedef std::vector<Verneed*> Needs; | |
444 | ||
445 | // Handle a symbol SYM defined with version VERSION. | |
446 | void | |
447 | add_def(const General_options*, const Symbol* sym, const char* version, | |
448 | Stringpool::Key); | |
449 | ||
450 | // Add a reference to version NAME in file FILENAME. | |
451 | void | |
452 | add_need(Stringpool*, const char* filename, const char* name, | |
453 | Stringpool::Key); | |
454 | ||
455 | // Return the version index to use for SYM. | |
456 | unsigned int | |
7e1edb90 | 457 | version_index(const Stringpool*, const Symbol* sym) const; |
14b31740 ILT |
458 | |
459 | // We keep a hash table mapping canonicalized name/version pairs to | |
460 | // a version base. | |
461 | typedef std::pair<Stringpool::Key, Stringpool::Key> Key; | |
462 | ||
463 | struct Version_table_hash | |
464 | { | |
465 | size_t | |
466 | operator()(const Key& k) const | |
467 | { return k.first + k.second; } | |
468 | }; | |
469 | ||
470 | struct Version_table_eq | |
471 | { | |
472 | bool | |
473 | operator()(const Key& k1, const Key& k2) const | |
474 | { return k1.first == k2.first && k1.second == k2.second; } | |
475 | }; | |
476 | ||
477 | typedef Unordered_map<Key, Version_base*, Version_table_hash, | |
478 | Version_table_eq> Version_table; | |
479 | ||
480 | // The version definitions. | |
481 | Defs defs_; | |
482 | // The version references. | |
483 | Needs needs_; | |
484 | // The mapping from a canonicalized version/filename pair to a | |
485 | // version index. The filename may be NULL. | |
486 | Version_table version_table_; | |
487 | // Whether the version indexes have been set. | |
488 | bool is_finalized_; | |
489 | }; | |
490 | ||
f6ce93d6 ILT |
491 | } // End namespace gold. |
492 | ||
493 | #endif // !defined(GOLD_DYNOBJ_H) |