1 // dynobj.h -- dynamic object support for gold -*- C++ -*-
8 #include "stringpool.h"
14 class General_options
;
16 // A dynamic object (ET_DYN). This is an abstract base class itself.
17 // The implementations is the template class Sized_dynobj.
19 class Dynobj
: public Object
22 Dynobj(const std::string
& name
, Input_file
* input_file
, off_t offset
= 0)
23 : Object(name
, input_file
, true, offset
), soname_()
26 // Return the name to use in a DT_NEEDED entry for this object.
30 // Compute the ELF hash code for a string.
32 elf_hash(const char*);
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.
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
);
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
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
);
54 // Set the DT_SONAME string.
56 set_soname_string(const char* s
)
57 { this->soname_
.assign(s
); }
60 // Compute the GNU hash code for a string.
62 gnu_hash(const char*);
64 // Compute the number of hash buckets to use.
66 compute_bucket_count(const std::vector
<uint32_t>& hashcodes
,
67 bool for_gnu_hash_table
);
69 // Sized version of create_elf_hash_table.
70 template<bool big_endian
>
72 sized_create_elf_hash_table(const std::vector
<uint32_t>& bucket
,
73 const std::vector
<uint32_t>& chain
,
75 unsigned int hashlen
);
77 // Sized version of create_gnu_hash_table.
78 template<int size
, bool big_endian
>
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
);
86 // The DT_SONAME name, if any.
90 // A dynamic object, size and endian specific version.
92 template<int size
, bool big_endian
>
93 class Sized_dynobj
: public Dynobj
96 Sized_dynobj(const std::string
& name
, Input_file
* input_file
, off_t offset
,
97 const typename
elfcpp::Ehdr
<size
, big_endian
>&);
99 // Set up the object file based on the ELF header.
101 setup(const typename
elfcpp::Ehdr
<size
, big_endian
>&);
105 do_read_symbols(Read_symbols_data
*);
107 // Lay out the input sections.
109 do_layout(Symbol_table
*, Layout
*, Read_symbols_data
*);
111 // Add the symbols to the symbol table.
113 do_add_symbols(Symbol_table
*, Read_symbols_data
*);
115 // Get the name of a section.
117 do_section_name(unsigned int shndx
)
118 { return this->elf_file_
.section_name(shndx
); }
120 // Return a view of the contents of a section. Set *PLEN to the
123 do_section_contents(unsigned int shndx
)
124 { return this->elf_file_
.section_contents(shndx
); }
126 // Return section flags.
128 do_section_flags(unsigned int shndx
)
129 { return this->elf_file_
.section_flags(shndx
); }
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
;
140 // Find the dynamic symbol table and the version sections, given the
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
);
150 // Read the dynamic symbol section SHNDX.
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
);
157 // Set the SONAME from the SHT_DYNAMIC section at DYNAMIC_SHNDX.
158 // The STRTAB parameters may have the relevant string table.
160 set_soname(const unsigned char* pshdrs
, unsigned int dynamic_shndx
,
161 unsigned int strtab_shndx
, const unsigned char* strtabu
,
164 // Mapping from version number to version name.
165 typedef std::vector
<const char*> Version_map
;
167 // Create the version map.
169 make_version_map(Read_symbols_data
* sd
, Version_map
*) const;
171 // Add version definitions to the version map.
173 make_verdef_map(Read_symbols_data
* sd
, Version_map
*) const;
175 // Add version references to the version map.
177 make_verneed_map(Read_symbols_data
* sd
, Version_map
*) const;
179 // Add an entry to the version map.
181 set_version_map(Version_map
*, unsigned int ndx
, const char* name
) const;
183 // General access to the ELF file.
184 elfcpp::Elf_file
<size
, big_endian
, Object
> elf_file_
;
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.
201 // Return the version index.
205 gold_assert(this->index_
!= -1U);
209 // Set the version index.
211 set_index(unsigned int index
)
213 gold_assert(this->index_
== -1U);
214 this->index_
= index
;
217 // Clear the weak flag in a version definition.
222 Version_base(const Version_base
&);
223 Version_base
& operator=(const Version_base
&);
225 // The index of the version definition or reference.
229 // This class handles a version being defined in the file we are
232 class Verdef
: public Version_base
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
)
240 // Return the version name.
243 { return this->name_
; }
245 // Return the number of dependencies.
247 count_dependencies() const
248 { return this->deps_
.size(); }
250 // Add a dependency to this version. The NAME should be
251 // canonicalized in the dynamic Stringpool.
253 add_dependency(const char* name
)
254 { this->deps_
.push_back(name
); }
256 // Return whether this definition is weak.
259 { return this->is_weak_
; }
261 // Clear the weak flag.
264 { this->is_weak_
= false; }
266 // Return whether a version symbol has been created for this
269 is_symbol_created() const
270 { return this->is_symbol_created_
; }
272 // Write contents to buffer.
273 template<int size
, bool big_endian
>
275 write(const Stringpool
*, bool is_last
, unsigned char*
276 ACCEPT_SIZE_ENDIAN
) const;
279 Verdef(const Verdef
&);
280 Verdef
& operator=(const Verdef
&);
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
;
286 // The name of this version. This should be canonicalized in the
287 // dynamic Stringpool.
289 // A list of other versions which this version depends upon.
291 // Whether this is the base version.
293 // Whether this version is weak.
295 // Whether a version symbol has been created.
296 bool is_symbol_created_
;
299 // A referened version. This will be associated with a filename by
302 class Verneed_version
: public Version_base
305 Verneed_version(const char* version
)
309 // Return the version name.
312 { return this->version_
; }
314 // Clear the weak flag. This is invalid for a reference.
317 { gold_unreachable(); }
320 Verneed_version(const Verneed_version
&);
321 Verneed_version
& operator=(const Verneed_version
&);
323 const char* version_
;
326 // Version references in a single dynamic object.
331 Verneed(const char* filename
)
332 : filename_(filename
), need_versions_()
337 // Return the file name.
340 { return this->filename_
; }
342 // Return the number of versions.
344 count_versions() const
345 { return this->need_versions_
.size(); }
347 // Add a version name. The name should be canonicalized in the
348 // dynamic Stringpool. If the name is already present, this does
351 add_name(const char* name
);
353 // Set the version indexes, starting at INDEX. Return the updated
356 finalize(unsigned int index
);
358 // Write contents to buffer.
359 template<int size
, bool big_endian
>
361 write(const Stringpool
*, bool is_last
, unsigned char*
362 ACCEPT_SIZE_ENDIAN
) const;
365 Verneed(const Verneed
&);
366 Verneed
& operator=(const Verneed
&);
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
;
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_
;
379 // This class handles version definitions and references which go into
386 : defs_(), needs_(), version_table_(), is_finalized_(false)
391 // SYM is going into the dynamic symbol table and has a version.
392 // Record the appropriate version information.
394 record_version(const General_options
*, Stringpool
*, const Symbol
* sym
);
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.
400 finalize(const Target
*, Symbol_table
* symtab
, unsigned int dynsym_index
,
401 std::vector
<Symbol
*>* syms
);
403 // Return whether there are any version definitions.
406 { return !this->defs_
.empty(); }
408 // Return whether there are any version references.
411 { return !this->needs_
.empty(); }
413 // Build an allocated buffer holding the contents of the symbol
414 // version section (.gnu.version).
415 template<int size
, bool big_endian
>
417 symbol_section_contents(const Stringpool
*, unsigned int local_symcount
,
418 const std::vector
<Symbol
*>& syms
,
419 unsigned char**, unsigned int*
420 ACCEPT_SIZE_ENDIAN
) const;
422 // Build an allocated buffer holding the contents of the version
423 // definition section (.gnu.version_d).
424 template<int size
, bool big_endian
>
426 def_section_contents(const Stringpool
*, unsigned char**,
427 unsigned int* psize
, unsigned int* pentries
428 ACCEPT_SIZE_ENDIAN
) const;
430 // Build an allocated buffer holding the contents of the version
431 // reference section (.gnu.version_r).
432 template<int size
, bool big_endian
>
434 need_section_contents(const Stringpool
*, unsigned char**,
435 unsigned int* psize
, unsigned int* pentries
436 ACCEPT_SIZE_ENDIAN
) const;
439 // The type of the list of version definitions.
440 typedef std::vector
<Verdef
*> Defs
;
442 // The type of the list of version references.
443 typedef std::vector
<Verneed
*> Needs
;
445 // Handle a symbol SYM defined with version VERSION.
447 add_def(const General_options
*, const Symbol
* sym
, const char* version
,
450 // Add a reference to version NAME in file FILENAME.
452 add_need(Stringpool
*, const char* filename
, const char* name
,
455 // Return the version index to use for SYM.
457 version_index(const Stringpool
*, const Symbol
* sym
) const;
459 // We keep a hash table mapping canonicalized name/version pairs to
461 typedef std::pair
<Stringpool::Key
, Stringpool::Key
> Key
;
463 struct Version_table_hash
466 operator()(const Key
& k
) const
467 { return k
.first
+ k
.second
; }
470 struct Version_table_eq
473 operator()(const Key
& k1
, const Key
& k2
) const
474 { return k1
.first
== k2
.first
&& k1
.second
== k2
.second
; }
477 typedef Unordered_map
<Key
, Version_base
*, Version_table_hash
,
478 Version_table_eq
> Version_table
;
480 // The version definitions.
482 // The version references.
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.
491 } // End namespace gold.
493 #endif // !defined(GOLD_DYNOBJ_H)