--- /dev/null
+// dynobj.h -- dynamic object support for gold -*- C++ -*-
+
+// Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
+// Written by Ian Lance Taylor <iant@google.com>.
+
+// This file is part of gold.
+
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+// MA 02110-1301, USA.
+
+#ifndef GOLD_DYNOBJ_H
+#define GOLD_DYNOBJ_H
+
+#include <vector>
+
+#include "stringpool.h"
+#include "object.h"
+
+namespace gold
+{
+
+class Version_script_info;
+
+// A dynamic object (ET_DYN). This is an abstract base class itself.
+// The implementations is the template class Sized_dynobj.
+
+class Dynobj : public Object
+{
+ public:
+ // We keep a list of all the DT_NEEDED entries we find.
+ typedef std::vector<std::string> Needed;
+
+ Dynobj(const std::string& name, Input_file* input_file, off_t offset = 0);
+
+ // Return the name to use in a DT_NEEDED entry for this object.
+ const char*
+ soname() const
+ { return this->soname_.c_str(); }
+
+ // Return the list of DT_NEEDED strings.
+ const Needed&
+ needed() const
+ { return this->needed_; }
+
+ // Return whether this dynamic object has any DT_NEEDED entries
+ // which were not seen during the link.
+ bool
+ has_unknown_needed_entries() const
+ {
+ gold_assert(this->unknown_needed_ != UNKNOWN_NEEDED_UNSET);
+ return this->unknown_needed_ == UNKNOWN_NEEDED_TRUE;
+ }
+
+ // Set whether this dynamic object has any DT_NEEDED entries which
+ // were not seen during the link.
+ void
+ set_has_unknown_needed_entries(bool set)
+ {
+ gold_assert(this->unknown_needed_ == UNKNOWN_NEEDED_UNSET);
+ this->unknown_needed_ = set ? UNKNOWN_NEEDED_TRUE : UNKNOWN_NEEDED_FALSE;
+ }
+
+ // Compute the ELF hash code for a string.
+ static uint32_t
+ elf_hash(const char*);
+
+ // Create a standard ELF hash table, setting *PPHASH and *PHASHLEN.
+ // DYNSYMS is the global dynamic symbols. LOCAL_DYNSYM_COUNT is the
+ // number of local dynamic symbols, which is the index of the first
+ // dynamic gobal symbol.
+ static void
+ create_elf_hash_table(const std::vector<Symbol*>& dynsyms,
+ unsigned int local_dynsym_count,
+ unsigned char** pphash,
+ unsigned int* phashlen);
+
+ // Create a GNU hash table, setting *PPHASH and *PHASHLEN. DYNSYMS
+ // is the global dynamic symbols. LOCAL_DYNSYM_COUNT is the number
+ // of local dynamic symbols, which is the index of the first dynamic
+ // gobal symbol.
+ static void
+ create_gnu_hash_table(const std::vector<Symbol*>& dynsyms,
+ unsigned int local_dynsym_count,
+ unsigned char** pphash, unsigned int* phashlen);
+
+ protected:
+ // Set the DT_SONAME string.
+ void
+ set_soname_string(const char* s)
+ { this->soname_.assign(s); }
+
+ // Add an entry to the list of DT_NEEDED strings.
+ void
+ add_needed(const char* s)
+ { this->needed_.push_back(std::string(s)); }
+
+ private:
+ // Compute the GNU hash code for a string.
+ static uint32_t
+ gnu_hash(const char*);
+
+ // Compute the number of hash buckets to use.
+ static unsigned int
+ compute_bucket_count(const std::vector<uint32_t>& hashcodes,
+ bool for_gnu_hash_table);
+
+ // Sized version of create_elf_hash_table.
+ template<bool big_endian>
+ static void
+ sized_create_elf_hash_table(const std::vector<uint32_t>& bucket,
+ const std::vector<uint32_t>& chain,
+ unsigned char* phash,
+ unsigned int hashlen);
+
+ // Sized version of create_gnu_hash_table.
+ template<int size, bool big_endian>
+ static void
+ sized_create_gnu_hash_table(const std::vector<Symbol*>& hashed_dynsyms,
+ const std::vector<uint32_t>& dynsym_hashvals,
+ unsigned int unhashed_dynsym_count,
+ unsigned char** pphash,
+ unsigned int* phashlen);
+
+ // Values for the has_unknown_needed_entries_ field.
+ enum Unknown_needed
+ {
+ UNKNOWN_NEEDED_UNSET,
+ UNKNOWN_NEEDED_TRUE,
+ UNKNOWN_NEEDED_FALSE
+ };
+
+ // The DT_SONAME name, if any.
+ std::string soname_;
+ // The list of DT_NEEDED entries.
+ Needed needed_;
+ // Whether this dynamic object has any DT_NEEDED entries not seen
+ // during the link.
+ Unknown_needed unknown_needed_;
+};
+
+// A dynamic object, size and endian specific version.
+
+template<int size, bool big_endian>
+class Sized_dynobj : public Dynobj
+{
+ public:
+ typedef typename Sized_relobj<size, big_endian>::Symbols Symbols;
+
+ Sized_dynobj(const std::string& name, Input_file* input_file, off_t offset,
+ const typename elfcpp::Ehdr<size, big_endian>&);
+
+ // Set up the object file based on TARGET.
+ void
+ setup();
+
+ // Read the symbols.
+ void
+ do_read_symbols(Read_symbols_data*);
+
+ // Lay out the input sections.
+ void
+ do_layout(Symbol_table*, Layout*, Read_symbols_data*);
+
+ // Add the symbols to the symbol table.
+ void
+ do_add_symbols(Symbol_table*, Read_symbols_data*, Layout*);
+
+ // Get the size of a section.
+ uint64_t
+ do_section_size(unsigned int shndx)
+ { return this->elf_file_.section_size(shndx); }
+
+ // Get the name of a section.
+ std::string
+ do_section_name(unsigned int shndx)
+ { return this->elf_file_.section_name(shndx); }
+
+ // Return a view of the contents of a section. Set *PLEN to the
+ // size.
+ Object::Location
+ do_section_contents(unsigned int shndx)
+ { return this->elf_file_.section_contents(shndx); }
+
+ // Return section flags.
+ uint64_t
+ do_section_flags(unsigned int shndx)
+ { return this->elf_file_.section_flags(shndx); }
+
+ // Not used for dynobj.
+ uint64_t
+ do_section_entsize(unsigned int )
+ { gold_unreachable(); }
+
+ // Return section address.
+ uint64_t
+ do_section_address(unsigned int shndx)
+ { return this->elf_file_.section_addr(shndx); }
+
+ // Return section type.
+ unsigned int
+ do_section_type(unsigned int shndx)
+ { return this->elf_file_.section_type(shndx); }
+
+ // Return the section link field.
+ unsigned int
+ do_section_link(unsigned int shndx)
+ { return this->elf_file_.section_link(shndx); }
+
+ // Return the section link field.
+ unsigned int
+ do_section_info(unsigned int shndx)
+ { return this->elf_file_.section_info(shndx); }
+
+ // Return the section alignment.
+ uint64_t
+ do_section_addralign(unsigned int shndx)
+ { return this->elf_file_.section_addralign(shndx); }
+
+ // Return the Xindex structure to use.
+ Xindex*
+ do_initialize_xindex();
+
+ // Get symbol counts.
+ void
+ do_get_global_symbol_counts(const Symbol_table*, size_t*, size_t*) const;
+
+ private:
+ // For convenience.
+ typedef Sized_dynobj<size, big_endian> This;
+ static const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
+ static const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
+ static const int dyn_size = elfcpp::Elf_sizes<size>::dyn_size;
+ typedef elfcpp::Shdr<size, big_endian> Shdr;
+ typedef elfcpp::Dyn<size, big_endian> Dyn;
+
+ // Adjust a section index if necessary.
+ unsigned int
+ adjust_shndx(unsigned int shndx)
+ {
+ if (shndx >= elfcpp::SHN_LORESERVE)
+ shndx += this->elf_file_.large_shndx_offset();
+ return shndx;
+ }
+
+ // Find the dynamic symbol table and the version sections, given the
+ // section headers.
+ void
+ find_dynsym_sections(const unsigned char* pshdrs,
+ unsigned int* pversym_shndx,
+ unsigned int* pverdef_shndx,
+ unsigned int* pverneed_shndx,
+ unsigned int* pdynamic_shndx);
+
+ // Read the dynamic symbol section SHNDX.
+ void
+ read_dynsym_section(const unsigned char* pshdrs, unsigned int shndx,
+ elfcpp::SHT type, unsigned int link,
+ File_view** view, section_size_type* view_size,
+ unsigned int* view_info);
+
+ // Read the dynamic tags.
+ void
+ read_dynamic(const unsigned char* pshdrs, unsigned int dynamic_shndx,
+ unsigned int strtab_shndx, const unsigned char* strtabu,
+ off_t strtab_size);
+
+ // Mapping from version number to version name.
+ typedef std::vector<const char*> Version_map;
+
+ // Create the version map.
+ void
+ make_version_map(Read_symbols_data* sd, Version_map*) const;
+
+ // Add version definitions to the version map.
+ void
+ make_verdef_map(Read_symbols_data* sd, Version_map*) const;
+
+ // Add version references to the version map.
+ void
+ make_verneed_map(Read_symbols_data* sd, Version_map*) const;
+
+ // Add an entry to the version map.
+ void
+ set_version_map(Version_map*, unsigned int ndx, const char* name) const;
+
+ // General access to the ELF file.
+ elfcpp::Elf_file<size, big_endian, Object> elf_file_;
+ // The section index of the dynamic symbol table.
+ unsigned int dynsym_shndx_;
+ // The entries in the symbol table for the symbols. We only keep
+ // this if we need it to print symbol information.
+ Symbols* symbols_;
+ // Number of defined symbols.
+ size_t defined_count_;
+};
+
+// A base class for Verdef and Verneed_version which just handles the
+// version index which will be stored in the SHT_GNU_versym section.
+
+class Version_base
+{
+ public:
+ Version_base()
+ : index_(-1U)
+ { }
+
+ virtual
+ ~Version_base()
+ { }
+
+ // Return the version index.
+ unsigned int
+ index() const
+ {
+ gold_assert(this->index_ != -1U);
+ return this->index_;
+ }
+
+ // Set the version index.
+ void
+ set_index(unsigned int index)
+ {
+ gold_assert(this->index_ == -1U);
+ this->index_ = index;
+ }
+
+ // Clear the weak flag in a version definition.
+ virtual void
+ clear_weak() = 0;
+
+ private:
+ Version_base(const Version_base&);
+ Version_base& operator=(const Version_base&);
+
+ // The index of the version definition or reference.
+ unsigned int index_;
+};
+
+// This class handles a version being defined in the file we are
+// generating.
+
+class Verdef : public Version_base
+{
+ public:
+ Verdef(const char* name, const std::vector<std::string>& deps,
+ bool is_base, bool is_weak, bool is_symbol_created)
+ : name_(name), deps_(deps), is_base_(is_base), is_weak_(is_weak),
+ is_symbol_created_(is_symbol_created)
+ { }
+
+ // Return the version name.
+ const char*
+ name() const
+ { return this->name_; }
+
+ // Return the number of dependencies.
+ unsigned int
+ count_dependencies() const
+ { return this->deps_.size(); }
+
+ // Add a dependency to this version. The NAME should be
+ // canonicalized in the dynamic Stringpool.
+ void
+ add_dependency(const char* name)
+ { this->deps_.push_back(name); }
+
+ // Return whether this definition is weak.
+ bool
+ is_weak() const
+ { return this->is_weak_; }
+
+ // Clear the weak flag.
+ void
+ clear_weak()
+ { this->is_weak_ = false; }
+
+ // Return whether a version symbol has been created for this
+ // definition.
+ bool
+ is_symbol_created() const
+ { return this->is_symbol_created_; }
+
+ // Write contents to buffer.
+ template<int size, bool big_endian>
+ unsigned char*
+ write(const Stringpool*, bool is_last, unsigned char*) const;
+
+ private:
+ Verdef(const Verdef&);
+ Verdef& operator=(const Verdef&);
+
+ // The type of the list of version dependencies. Each dependency
+ // should be canonicalized in the dynamic Stringpool.
+ typedef std::vector<std::string> Deps;
+
+ // The name of this version. This should be canonicalized in the
+ // dynamic Stringpool.
+ const char* name_;
+ // A list of other versions which this version depends upon.
+ Deps deps_;
+ // Whether this is the base version.
+ bool is_base_;
+ // Whether this version is weak.
+ bool is_weak_;
+ // Whether a version symbol has been created.
+ bool is_symbol_created_;
+};
+
+// A referened version. This will be associated with a filename by
+// Verneed.
+
+class Verneed_version : public Version_base
+{
+ public:
+ Verneed_version(const char* version)
+ : version_(version)
+ { }
+
+ // Return the version name.
+ const char*
+ version() const
+ { return this->version_; }
+
+ // Clear the weak flag. This is invalid for a reference.
+ void
+ clear_weak()
+ { gold_unreachable(); }
+
+ private:
+ Verneed_version(const Verneed_version&);
+ Verneed_version& operator=(const Verneed_version&);
+
+ const char* version_;
+};
+
+// Version references in a single dynamic object.
+
+class Verneed
+{
+ public:
+ Verneed(const char* filename)
+ : filename_(filename), need_versions_()
+ { }
+
+ ~Verneed();
+
+ // Return the file name.
+ const char*
+ filename() const
+ { return this->filename_; }
+
+ // Return the number of versions.
+ unsigned int
+ count_versions() const
+ { return this->need_versions_.size(); }
+
+ // Add a version name. The name should be canonicalized in the
+ // dynamic Stringpool. If the name is already present, this does
+ // nothing.
+ Verneed_version*
+ add_name(const char* name);
+
+ // Set the version indexes, starting at INDEX. Return the updated
+ // INDEX.
+ unsigned int
+ finalize(unsigned int index);
+
+ // Write contents to buffer.
+ template<int size, bool big_endian>
+ unsigned char*
+ write(const Stringpool*, bool is_last, unsigned char*) const;
+
+ private:
+ Verneed(const Verneed&);
+ Verneed& operator=(const Verneed&);
+
+ // The type of the list of version names. Each name should be
+ // canonicalized in the dynamic Stringpool.
+ typedef std::vector<Verneed_version*> Need_versions;
+
+ // The filename of the dynamic object. This should be
+ // canonicalized in the dynamic Stringpool.
+ const char* filename_;
+ // The list of version names.
+ Need_versions need_versions_;
+};
+
+// This class handles version definitions and references which go into
+// the output file.
+
+class Versions
+{
+ public:
+ Versions(const Version_script_info&, Stringpool*);
+
+ ~Versions();
+
+ // SYM is going into the dynamic symbol table and has a version.
+ // Record the appropriate version information.
+ void
+ record_version(const Symbol_table* symtab, Stringpool*, const Symbol* sym);
+
+ // Set the version indexes. DYNSYM_INDEX is the index we should use
+ // for the next dynamic symbol. We add new dynamic symbols to SYMS
+ // and return an updated DYNSYM_INDEX.
+ unsigned int
+ finalize(Symbol_table* symtab, unsigned int dynsym_index,
+ std::vector<Symbol*>* syms);
+
+ // Return whether there are any version definitions.
+ bool
+ any_defs() const
+ { return !this->defs_.empty(); }
+
+ // Return whether there are any version references.
+ bool
+ any_needs() const
+ { return !this->needs_.empty(); }
+
+ // Build an allocated buffer holding the contents of the symbol
+ // version section (.gnu.version).
+ template<int size, bool big_endian>
+ void
+ symbol_section_contents(const Symbol_table*, const Stringpool*,
+ unsigned int local_symcount,
+ const std::vector<Symbol*>& syms,
+ unsigned char**, unsigned int*) const;
+
+ // Build an allocated buffer holding the contents of the version
+ // definition section (.gnu.version_d).
+ template<int size, bool big_endian>
+ void
+ def_section_contents(const Stringpool*, unsigned char**,
+ unsigned int* psize, unsigned int* pentries) const;
+
+ // Build an allocated buffer holding the contents of the version
+ // reference section (.gnu.version_r).
+ template<int size, bool big_endian>
+ void
+ need_section_contents(const Stringpool*, unsigned char**,
+ unsigned int* psize, unsigned int* pentries) const;
+
+ const Version_script_info&
+ version_script() const
+ { return this->version_script_; }
+
+ private:
+ Versions(const Versions&);
+ Versions& operator=(const Versions&);
+
+ // The type of the list of version definitions.
+ typedef std::vector<Verdef*> Defs;
+
+ // The type of the list of version references.
+ typedef std::vector<Verneed*> Needs;
+
+ // Handle a symbol SYM defined with version VERSION.
+ void
+ add_def(const Symbol* sym, const char* version, Stringpool::Key);
+
+ // Add a reference to version NAME in file FILENAME.
+ void
+ add_need(Stringpool*, const char* filename, const char* name,
+ Stringpool::Key);
+
+ // Get the dynamic object to use for SYM.
+ Dynobj*
+ get_dynobj_for_sym(const Symbol_table*, const Symbol* sym) const;
+
+ // Return the version index to use for SYM.
+ unsigned int
+ version_index(const Symbol_table*, const Stringpool*,
+ const Symbol* sym) const;
+
+ // We keep a hash table mapping canonicalized name/version pairs to
+ // a version base.
+ typedef std::pair<Stringpool::Key, Stringpool::Key> Key;
+
+ struct Version_table_hash
+ {
+ size_t
+ operator()(const Key& k) const
+ { return k.first + k.second; }
+ };
+
+ struct Version_table_eq
+ {
+ bool
+ operator()(const Key& k1, const Key& k2) const
+ { return k1.first == k2.first && k1.second == k2.second; }
+ };
+
+ typedef Unordered_map<Key, Version_base*, Version_table_hash,
+ Version_table_eq> Version_table;
+
+ // The version definitions.
+ Defs defs_;
+ // The version references.
+ Needs needs_;
+ // The mapping from a canonicalized version/filename pair to a
+ // version index. The filename may be NULL.
+ Version_table version_table_;
+ // Whether the version indexes have been set.
+ bool is_finalized_;
+ // Contents of --version-script, if passed, or NULL.
+ const Version_script_info& version_script_;
+};
+
+} // End namespace gold.
+
+#endif // !defined(GOLD_DYNOBJ_H)
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