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