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 the section link field.
151 do_section_link(unsigned int shndx
)
152 { return this->elf_file_
.section_link(shndx
); }
156 typedef Sized_dynobj
<size
, big_endian
> This
;
157 static const int shdr_size
= elfcpp::Elf_sizes
<size
>::shdr_size
;
158 static const int sym_size
= elfcpp::Elf_sizes
<size
>::sym_size
;
159 static const int dyn_size
= elfcpp::Elf_sizes
<size
>::dyn_size
;
160 typedef elfcpp::Shdr
<size
, big_endian
> Shdr
;
161 typedef elfcpp::Dyn
<size
, big_endian
> Dyn
;
163 // Find the dynamic symbol table and the version sections, given the
166 find_dynsym_sections(const unsigned char* pshdrs
,
167 unsigned int* pdynshm_shndx
,
168 unsigned int* pversym_shndx
,
169 unsigned int* pverdef_shndx
,
170 unsigned int* pverneed_shndx
,
171 unsigned int* pdynamic_shndx
);
173 // Read the dynamic symbol section SHNDX.
175 read_dynsym_section(const unsigned char* pshdrs
, unsigned int shndx
,
176 elfcpp::SHT type
, unsigned int link
,
177 File_view
** view
, off_t
* view_size
,
178 unsigned int* view_info
);
180 // Set the SONAME from the SHT_DYNAMIC section at DYNAMIC_SHNDX.
181 // The STRTAB parameters may have the relevant string table.
183 set_soname(const unsigned char* pshdrs
, unsigned int dynamic_shndx
,
184 unsigned int strtab_shndx
, const unsigned char* strtabu
,
187 // Mapping from version number to version name.
188 typedef std::vector
<const char*> Version_map
;
190 // Create the version map.
192 make_version_map(Read_symbols_data
* sd
, Version_map
*) const;
194 // Add version definitions to the version map.
196 make_verdef_map(Read_symbols_data
* sd
, Version_map
*) const;
198 // Add version references to the version map.
200 make_verneed_map(Read_symbols_data
* sd
, Version_map
*) const;
202 // Add an entry to the version map.
204 set_version_map(Version_map
*, unsigned int ndx
, const char* name
) const;
206 // General access to the ELF file.
207 elfcpp::Elf_file
<size
, big_endian
, Object
> elf_file_
;
210 // A base class for Verdef and Verneed_version which just handles the
211 // version index which will be stored in the SHT_GNU_versym section.
224 // Return the version index.
228 gold_assert(this->index_
!= -1U);
232 // Set the version index.
234 set_index(unsigned int index
)
236 gold_assert(this->index_
== -1U);
237 this->index_
= index
;
240 // Clear the weak flag in a version definition.
245 Version_base(const Version_base
&);
246 Version_base
& operator=(const Version_base
&);
248 // The index of the version definition or reference.
252 // This class handles a version being defined in the file we are
255 class Verdef
: public Version_base
258 Verdef(const char* name
, bool is_base
, bool is_weak
, bool is_symbol_created
)
259 : name_(name
), deps_(), is_base_(is_base
), is_weak_(is_weak
),
260 is_symbol_created_(is_symbol_created
)
263 // Return the version name.
266 { return this->name_
; }
268 // Return the number of dependencies.
270 count_dependencies() const
271 { return this->deps_
.size(); }
273 // Add a dependency to this version. The NAME should be
274 // canonicalized in the dynamic Stringpool.
276 add_dependency(const char* name
)
277 { this->deps_
.push_back(name
); }
279 // Return whether this definition is weak.
282 { return this->is_weak_
; }
284 // Clear the weak flag.
287 { this->is_weak_
= false; }
289 // Return whether a version symbol has been created for this
292 is_symbol_created() const
293 { return this->is_symbol_created_
; }
295 // Write contents to buffer.
296 template<int size
, bool big_endian
>
298 write(const Stringpool
*, bool is_last
, unsigned char*
299 ACCEPT_SIZE_ENDIAN
) const;
302 Verdef(const Verdef
&);
303 Verdef
& operator=(const Verdef
&);
305 // The type of the list of version dependencies. Each dependency
306 // should be canonicalized in the dynamic Stringpool.
307 typedef std::vector
<const char*> Deps
;
309 // The name of this version. This should be canonicalized in the
310 // dynamic Stringpool.
312 // A list of other versions which this version depends upon.
314 // Whether this is the base version.
316 // Whether this version is weak.
318 // Whether a version symbol has been created.
319 bool is_symbol_created_
;
322 // A referened version. This will be associated with a filename by
325 class Verneed_version
: public Version_base
328 Verneed_version(const char* version
)
332 // Return the version name.
335 { return this->version_
; }
337 // Clear the weak flag. This is invalid for a reference.
340 { gold_unreachable(); }
343 Verneed_version(const Verneed_version
&);
344 Verneed_version
& operator=(const Verneed_version
&);
346 const char* version_
;
349 // Version references in a single dynamic object.
354 Verneed(const char* filename
)
355 : filename_(filename
), need_versions_()
360 // Return the file name.
363 { return this->filename_
; }
365 // Return the number of versions.
367 count_versions() const
368 { return this->need_versions_
.size(); }
370 // Add a version name. The name should be canonicalized in the
371 // dynamic Stringpool. If the name is already present, this does
374 add_name(const char* name
);
376 // Set the version indexes, starting at INDEX. Return the updated
379 finalize(unsigned int index
);
381 // Write contents to buffer.
382 template<int size
, bool big_endian
>
384 write(const Stringpool
*, bool is_last
, unsigned char*
385 ACCEPT_SIZE_ENDIAN
) const;
388 Verneed(const Verneed
&);
389 Verneed
& operator=(const Verneed
&);
391 // The type of the list of version names. Each name should be
392 // canonicalized in the dynamic Stringpool.
393 typedef std::vector
<Verneed_version
*> Need_versions
;
395 // The filename of the dynamic object. This should be
396 // canonicalized in the dynamic Stringpool.
397 const char* filename_
;
398 // The list of version names.
399 Need_versions need_versions_
;
402 // This class handles version definitions and references which go into
409 : defs_(), needs_(), version_table_(), is_finalized_(false)
414 // SYM is going into the dynamic symbol table and has a version.
415 // Record the appropriate version information.
417 record_version(const Symbol_table
* symtab
, Stringpool
*, const Symbol
* sym
);
419 // Set the version indexes. DYNSYM_INDEX is the index we should use
420 // for the next dynamic symbol. We add new dynamic symbols to SYMS
421 // and return an updated DYNSYM_INDEX.
423 finalize(const Target
*, Symbol_table
* symtab
, unsigned int dynsym_index
,
424 std::vector
<Symbol
*>* syms
);
426 // Return whether there are any version definitions.
429 { return !this->defs_
.empty(); }
431 // Return whether there are any version references.
434 { return !this->needs_
.empty(); }
436 // Build an allocated buffer holding the contents of the symbol
437 // version section (.gnu.version).
438 template<int size
, bool big_endian
>
440 symbol_section_contents(const Symbol_table
*, const Stringpool
*,
441 unsigned int local_symcount
,
442 const std::vector
<Symbol
*>& syms
,
443 unsigned char**, unsigned int*
444 ACCEPT_SIZE_ENDIAN
) const;
446 // Build an allocated buffer holding the contents of the version
447 // definition section (.gnu.version_d).
448 template<int size
, bool big_endian
>
450 def_section_contents(const Stringpool
*, unsigned char**,
451 unsigned int* psize
, unsigned int* pentries
452 ACCEPT_SIZE_ENDIAN
) const;
454 // Build an allocated buffer holding the contents of the version
455 // reference section (.gnu.version_r).
456 template<int size
, bool big_endian
>
458 need_section_contents(const Stringpool
*, unsigned char**,
459 unsigned int* psize
, unsigned int* pentries
460 ACCEPT_SIZE_ENDIAN
) const;
463 // The type of the list of version definitions.
464 typedef std::vector
<Verdef
*> Defs
;
466 // The type of the list of version references.
467 typedef std::vector
<Verneed
*> Needs
;
469 // Handle a symbol SYM defined with version VERSION.
471 add_def(const Symbol
* sym
, const char* version
, Stringpool::Key
);
473 // Add a reference to version NAME in file FILENAME.
475 add_need(Stringpool
*, const char* filename
, const char* name
,
478 // Get the dynamic object to use for SYM.
480 get_dynobj_for_sym(const Symbol_table
*, const Symbol
* sym
) const;
482 // Return the version index to use for SYM.
484 version_index(const Symbol_table
*, const Stringpool
*,
485 const Symbol
* sym
) const;
487 // We keep a hash table mapping canonicalized name/version pairs to
489 typedef std::pair
<Stringpool::Key
, Stringpool::Key
> Key
;
491 struct Version_table_hash
494 operator()(const Key
& k
) const
495 { return k
.first
+ k
.second
; }
498 struct Version_table_eq
501 operator()(const Key
& k1
, const Key
& k2
) const
502 { return k1
.first
== k2
.first
&& k1
.second
== k2
.second
; }
505 typedef Unordered_map
<Key
, Version_base
*, Version_table_hash
,
506 Version_table_eq
> Version_table
;
508 // The version definitions.
510 // The version references.
512 // The mapping from a canonicalized version/filename pair to a
513 // version index. The filename may be NULL.
514 Version_table version_table_
;
515 // Whether the version indexes have been set.
519 } // End namespace gold.
521 #endif // !defined(GOLD_DYNOBJ_H)