vendor/binutils/binutils-master-20070703-075419vendor/binutils

1 files changed, 494 insertions, 0 deletions

diff --git a/gold/dynobj.h b/gold/dynobj.h
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+// dynobj.h -- dynamic object support for gold   -*- C++ -*-
+
+#ifndef GOLD_DYNOBJ_H
+#define GOLD_DYNOBJ_H
+
+#include <vector>
+
+#include "stringpool.h"
+#include "object.h"
+
+namespace gold
+{
+
+class General_options;
+
+// 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:
+  Dynobj(const std::string& name, Input_file* input_file, off_t offset = 0)
+    : Object(name, input_file, true, offset), soname_()
+  { }
+
+  // Return the name to use in a DT_NEEDED entry for this object.
+  const char*
+  soname() const;
+
+  // 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 Target*, 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 Target*, 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); }
+
+ 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);
+
+  // The DT_SONAME name, if any.
+  std::string soname_;
+};
+
+// A dynamic object, size and endian specific version.
+
+template<int size, bool big_endian>
+class Sized_dynobj : public Dynobj
+{
+ public:
+  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 the ELF header.
+  void
+  setup(const typename elfcpp::Ehdr<size, big_endian>&);
+
+  // Read the symbols.
+  void
+  do_read_symbols(Read_symbols_data*);
+
+  // Lay out the input sections.
+  void
+  do_layout(const General_options&, Symbol_table*, Layout*,
+	    Read_symbols_data*);
+
+  // Add the symbols to the symbol table.
+  void
+  do_add_symbols(Symbol_table*, Read_symbols_data*);
+
+  // 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); }
+
+ 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;
+
+  // Find the dynamic symbol table and the version sections, given the
+  // section headers.
+  void
+  find_dynsym_sections(const unsigned char* pshdrs,
+		       unsigned int* pdynshm_shndx,
+		       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, off_t* view_size,
+		      unsigned int* view_info);
+
+  // Set the SONAME from the SHT_DYNAMIC section at DYNAMIC_SHNDX.
+  // The STRTAB parameters may have the relevant string table.
+  void
+  set_soname(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_;
+};
+
+// 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, bool is_base, bool is_weak, bool is_symbol_created)
+    : name_(name), 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*
+        ACCEPT_SIZE_ENDIAN) 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<const char*> 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*
+        ACCEPT_SIZE_ENDIAN) 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()
+    : defs_(), needs_(), version_table_(), is_finalized_(false)
+  { }
+
+  ~Versions();
+
+  // SYM is going into the dynamic symbol table and has a version.
+  // Record the appropriate version information.
+  void
+  record_version(const General_options*, 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(const Target*, 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 Stringpool*, unsigned int local_symcount,
+			  const std::vector<Symbol*>& syms,
+			  unsigned char**, unsigned int*
+                          ACCEPT_SIZE_ENDIAN) 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
+                       ACCEPT_SIZE_ENDIAN) 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
+                        ACCEPT_SIZE_ENDIAN) const;
+
+ private:
+  // 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 General_options*, 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);
+
+  // Return the version index to use for SYM.
+  unsigned int
+  version_index(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_;
+};
+
+} // End namespace gold.
+
+#endif // !defined(GOLD_DYNOBJ_H)