1 // dynobj.h -- dynamic object support for gold -*- C++ -*-
3 // Copyright 2006, 2007 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
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.
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.
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.
28 #include "stringpool.h"
34 class General_options;
36 // A dynamic object (ET_DYN). This is an abstract base class itself.
37 // The implementations is the template class Sized_dynobj.
39 class Dynobj : public Object
42 Dynobj(const std::string& name, Input_file* input_file, off_t offset = 0);
44 // Return the name to use in a DT_NEEDED entry for this object.
48 // Compute the ELF hash code for a string.
50 elf_hash(const char*);
52 // Create a standard ELF hash table, setting *PPHASH and *PHASHLEN.
53 // DYNSYMS is the global dynamic symbols. LOCAL_DYNSYM_COUNT is the
54 // number of local dynamic symbols, which is the index of the first
55 // dynamic gobal symbol.
57 create_elf_hash_table(const std::vector<Symbol*>& dynsyms,
58 unsigned int local_dynsym_count,
59 unsigned char** pphash,
60 unsigned int* phashlen);
62 // Create a GNU hash table, setting *PPHASH and *PHASHLEN. DYNSYMS
63 // is the global dynamic symbols. LOCAL_DYNSYM_COUNT is the number
64 // of local dynamic symbols, which is the index of the first dynamic
67 create_gnu_hash_table(const std::vector<Symbol*>& dynsyms,
68 unsigned int local_dynsym_count,
69 unsigned char** pphash, unsigned int* phashlen);
72 // Set the DT_SONAME string.
74 set_soname_string(const char* s)
75 { this->soname_.assign(s); }
78 // Compute the GNU hash code for a string.
80 gnu_hash(const char*);
82 // Compute the number of hash buckets to use.
84 compute_bucket_count(const std::vector<uint32_t>& hashcodes,
85 bool for_gnu_hash_table);
87 // Sized version of create_elf_hash_table.
88 template<bool big_endian>
90 sized_create_elf_hash_table(const std::vector<uint32_t>& bucket,
91 const std::vector<uint32_t>& chain,
93 unsigned int hashlen);
95 // Sized version of create_gnu_hash_table.
96 template<int size, bool big_endian>
98 sized_create_gnu_hash_table(const std::vector<Symbol*>& hashed_dynsyms,
99 const std::vector<uint32_t>& dynsym_hashvals,
100 unsigned int unhashed_dynsym_count,
101 unsigned char** pphash,
102 unsigned int* phashlen);
104 // The DT_SONAME name, if any.
108 // A dynamic object, size and endian specific version.
110 template<int size, bool big_endian>
111 class Sized_dynobj : public Dynobj
114 Sized_dynobj(const std::string& name, Input_file* input_file, off_t offset,
115 const typename elfcpp::Ehdr<size, big_endian>&);
117 // Set up the object file based on the ELF header.
119 setup(const typename elfcpp::Ehdr<size, big_endian>&);
123 do_read_symbols(Read_symbols_data*);
125 // Lay out the input sections.
127 do_layout(Symbol_table*, Layout*, Read_symbols_data*);
129 // Add the symbols to the symbol table.
131 do_add_symbols(Symbol_table*, Read_symbols_data*);
133 // Get the name of a section.
135 do_section_name(unsigned int shndx)
136 { return this->elf_file_.section_name(shndx); }
138 // Return a view of the contents of a section. Set *PLEN to the
141 do_section_contents(unsigned int shndx)
142 { return this->elf_file_.section_contents(shndx); }
144 // Return section flags.
146 do_section_flags(unsigned int shndx)
147 { return this->elf_file_.section_flags(shndx); }
149 // Return section type.
151 do_section_type(unsigned int shndx)
152 { return this->elf_file_.section_type(shndx); }
154 // Return the section link field.
156 do_section_link(unsigned int shndx)
157 { return this->elf_file_.section_link(shndx); }
159 // Return the section link field.
161 do_section_info(unsigned int shndx)
162 { return this->elf_file_.section_info(shndx); }
166 typedef Sized_dynobj<size, big_endian> This;
167 static const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
168 static const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
169 static const int dyn_size = elfcpp::Elf_sizes<size>::dyn_size;
170 typedef elfcpp::Shdr<size, big_endian> Shdr;
171 typedef elfcpp::Dyn<size, big_endian> Dyn;
173 // Find the dynamic symbol table and the version sections, given the
176 find_dynsym_sections(const unsigned char* pshdrs,
177 unsigned int* pdynshm_shndx,
178 unsigned int* pversym_shndx,
179 unsigned int* pverdef_shndx,
180 unsigned int* pverneed_shndx,
181 unsigned int* pdynamic_shndx);
183 // Read the dynamic symbol section SHNDX.
185 read_dynsym_section(const unsigned char* pshdrs, unsigned int shndx,
186 elfcpp::SHT type, unsigned int link,
187 File_view** view, off_t* view_size,
188 unsigned int* view_info);
190 // Set the SONAME from the SHT_DYNAMIC section at DYNAMIC_SHNDX.
191 // The STRTAB parameters may have the relevant string table.
193 set_soname(const unsigned char* pshdrs, unsigned int dynamic_shndx,
194 unsigned int strtab_shndx, const unsigned char* strtabu,
197 // Mapping from version number to version name.
198 typedef std::vector<const char*> Version_map;
200 // Create the version map.
202 make_version_map(Read_symbols_data* sd, Version_map*) const;
204 // Add version definitions to the version map.
206 make_verdef_map(Read_symbols_data* sd, Version_map*) const;
208 // Add version references to the version map.
210 make_verneed_map(Read_symbols_data* sd, Version_map*) const;
212 // Add an entry to the version map.
214 set_version_map(Version_map*, unsigned int ndx, const char* name) const;
216 // General access to the ELF file.
217 elfcpp::Elf_file<size, big_endian, Object> elf_file_;
220 // A base class for Verdef and Verneed_version which just handles the
221 // version index which will be stored in the SHT_GNU_versym section.
234 // Return the version index.
238 gold_assert(this->index_ != -1U);
242 // Set the version index.
244 set_index(unsigned int index)
246 gold_assert(this->index_ == -1U);
247 this->index_ = index;
250 // Clear the weak flag in a version definition.
255 Version_base(const Version_base&);
256 Version_base& operator=(const Version_base&);
258 // The index of the version definition or reference.
262 // This class handles a version being defined in the file we are
265 class Verdef : public Version_base
268 Verdef(const char* name, bool is_base, bool is_weak, bool is_symbol_created)
269 : name_(name), deps_(), is_base_(is_base), is_weak_(is_weak),
270 is_symbol_created_(is_symbol_created)
273 // Return the version name.
276 { return this->name_; }
278 // Return the number of dependencies.
280 count_dependencies() const
281 { return this->deps_.size(); }
283 // Add a dependency to this version. The NAME should be
284 // canonicalized in the dynamic Stringpool.
286 add_dependency(const char* name)
287 { this->deps_.push_back(name); }
289 // Return whether this definition is weak.
292 { return this->is_weak_; }
294 // Clear the weak flag.
297 { this->is_weak_ = false; }
299 // Return whether a version symbol has been created for this
302 is_symbol_created() const
303 { return this->is_symbol_created_; }
305 // Write contents to buffer.
306 template<int size, bool big_endian>
308 write(const Stringpool*, bool is_last, unsigned char*
309 ACCEPT_SIZE_ENDIAN) const;
312 Verdef(const Verdef&);
313 Verdef& operator=(const Verdef&);
315 // The type of the list of version dependencies. Each dependency
316 // should be canonicalized in the dynamic Stringpool.
317 typedef std::vector<const char*> Deps;
319 // The name of this version. This should be canonicalized in the
320 // dynamic Stringpool.
322 // A list of other versions which this version depends upon.
324 // Whether this is the base version.
326 // Whether this version is weak.
328 // Whether a version symbol has been created.
329 bool is_symbol_created_;
332 // A referened version. This will be associated with a filename by
335 class Verneed_version : public Version_base
338 Verneed_version(const char* version)
342 // Return the version name.
345 { return this->version_; }
347 // Clear the weak flag. This is invalid for a reference.
350 { gold_unreachable(); }
353 Verneed_version(const Verneed_version&);
354 Verneed_version& operator=(const Verneed_version&);
356 const char* version_;
359 // Version references in a single dynamic object.
364 Verneed(const char* filename)
365 : filename_(filename), need_versions_()
370 // Return the file name.
373 { return this->filename_; }
375 // Return the number of versions.
377 count_versions() const
378 { return this->need_versions_.size(); }
380 // Add a version name. The name should be canonicalized in the
381 // dynamic Stringpool. If the name is already present, this does
384 add_name(const char* name);
386 // Set the version indexes, starting at INDEX. Return the updated
389 finalize(unsigned int index);
391 // Write contents to buffer.
392 template<int size, bool big_endian>
394 write(const Stringpool*, bool is_last, unsigned char*
395 ACCEPT_SIZE_ENDIAN) const;
398 Verneed(const Verneed&);
399 Verneed& operator=(const Verneed&);
401 // The type of the list of version names. Each name should be
402 // canonicalized in the dynamic Stringpool.
403 typedef std::vector<Verneed_version*> Need_versions;
405 // The filename of the dynamic object. This should be
406 // canonicalized in the dynamic Stringpool.
407 const char* filename_;
408 // The list of version names.
409 Need_versions need_versions_;
412 // This class handles version definitions and references which go into
419 : defs_(), needs_(), version_table_(), is_finalized_(false)
424 // SYM is going into the dynamic symbol table and has a version.
425 // Record the appropriate version information.
427 record_version(const Symbol_table* symtab, Stringpool*, const Symbol* sym);
429 // Set the version indexes. DYNSYM_INDEX is the index we should use
430 // for the next dynamic symbol. We add new dynamic symbols to SYMS
431 // and return an updated DYNSYM_INDEX.
433 finalize(const Target*, Symbol_table* symtab, unsigned int dynsym_index,
434 std::vector<Symbol*>* syms);
436 // Return whether there are any version definitions.
439 { return !this->defs_.empty(); }
441 // Return whether there are any version references.
444 { return !this->needs_.empty(); }
446 // Build an allocated buffer holding the contents of the symbol
447 // version section (.gnu.version).
448 template<int size, bool big_endian>
450 symbol_section_contents(const Symbol_table*, const Stringpool*,
451 unsigned int local_symcount,
452 const std::vector<Symbol*>& syms,
453 unsigned char**, unsigned int*
454 ACCEPT_SIZE_ENDIAN) const;
456 // Build an allocated buffer holding the contents of the version
457 // definition section (.gnu.version_d).
458 template<int size, bool big_endian>
460 def_section_contents(const Stringpool*, unsigned char**,
461 unsigned int* psize, unsigned int* pentries
462 ACCEPT_SIZE_ENDIAN) const;
464 // Build an allocated buffer holding the contents of the version
465 // reference section (.gnu.version_r).
466 template<int size, bool big_endian>
468 need_section_contents(const Stringpool*, unsigned char**,
469 unsigned int* psize, unsigned int* pentries
470 ACCEPT_SIZE_ENDIAN) const;
473 // The type of the list of version definitions.
474 typedef std::vector<Verdef*> Defs;
476 // The type of the list of version references.
477 typedef std::vector<Verneed*> Needs;
479 // Handle a symbol SYM defined with version VERSION.
481 add_def(const Symbol* sym, const char* version, Stringpool::Key);
483 // Add a reference to version NAME in file FILENAME.
485 add_need(Stringpool*, const char* filename, const char* name,
488 // Get the dynamic object to use for SYM.
490 get_dynobj_for_sym(const Symbol_table*, const Symbol* sym) const;
492 // Return the version index to use for SYM.
494 version_index(const Symbol_table*, const Stringpool*,
495 const Symbol* sym) const;
497 // We keep a hash table mapping canonicalized name/version pairs to
499 typedef std::pair<Stringpool::Key, Stringpool::Key> Key;
501 struct Version_table_hash
504 operator()(const Key& k) const
505 { return k.first + k.second; }
508 struct Version_table_eq
511 operator()(const Key& k1, const Key& k2) const
512 { return k1.first == k2.first && k1.second == k2.second; }
515 typedef Unordered_map<Key, Version_base*, Version_table_hash,
516 Version_table_eq> Version_table;
518 // The version definitions.
520 // The version references.
522 // The mapping from a canonicalized version/filename pair to a
523 // version index. The filename may be NULL.
524 Version_table version_table_;
525 // Whether the version indexes have been set.
529 } // End namespace gold.
531 #endif // !defined(GOLD_DYNOBJ_H)