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

1 files changed, 1647 insertions, 0 deletions

diff --git a/gold/dynobj.cc b/gold/dynobj.cc
new file mode 100644
index 000000000000..1bd5a85e4392
--- /dev/null
+++ b/gold/dynobj.cc
@@ -0,0 +1,1647 @@
+// dynobj.cc -- dynamic object support for gold
+
+#include "gold.h"
+
+#include <vector>
+#include <cstring>
+
+#include "elfcpp.h"
+#include "symtab.h"
+#include "dynobj.h"
+
+namespace gold
+{
+
+// Class Dynobj.
+
+// Return the string to use in a DT_NEEDED entry.
+
+const char*
+Dynobj::soname() const
+{
+  if (!this->soname_.empty())
+    return this->soname_.c_str();
+  return this->name().c_str();
+}
+
+// Class Sized_dynobj.
+
+template<int size, bool big_endian>
+Sized_dynobj<size, big_endian>::Sized_dynobj(
+    const std::string& name,
+    Input_file* input_file,
+    off_t offset,
+    const elfcpp::Ehdr<size, big_endian>& ehdr)
+  : Dynobj(name, input_file, offset),
+    elf_file_(this, ehdr)
+{
+}
+
+// Set up the object.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::setup(
+    const elfcpp::Ehdr<size, big_endian>& ehdr)
+{
+  this->set_target(ehdr.get_e_machine(), size, big_endian,
+		   ehdr.get_e_ident()[elfcpp::EI_OSABI],
+		   ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]);
+
+  const unsigned int shnum = this->elf_file_.shnum();
+  this->set_shnum(shnum);
+}
+
+// Find the SHT_DYNSYM section and the various version sections, and
+// the dynamic section, given the section headers.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::find_dynsym_sections(
+    const unsigned char* pshdrs,
+    unsigned int* pdynsym_shndx,
+    unsigned int* pversym_shndx,
+    unsigned int* pverdef_shndx,
+    unsigned int* pverneed_shndx,
+    unsigned int* pdynamic_shndx)
+{
+  *pdynsym_shndx = -1U;
+  *pversym_shndx = -1U;
+  *pverdef_shndx = -1U;
+  *pverneed_shndx = -1U;
+  *pdynamic_shndx = -1U;
+
+  const unsigned int shnum = this->shnum();
+  const unsigned char* p = pshdrs;
+  for (unsigned int i = 0; i < shnum; ++i, p += This::shdr_size)
+    {
+      typename This::Shdr shdr(p);
+
+      unsigned int* pi;
+      switch (shdr.get_sh_type())
+	{
+	case elfcpp::SHT_DYNSYM:
+	  pi = pdynsym_shndx;
+	  break;
+	case elfcpp::SHT_GNU_versym:
+	  pi = pversym_shndx;
+	  break;
+	case elfcpp::SHT_GNU_verdef:
+	  pi = pverdef_shndx;
+	  break;
+	case elfcpp::SHT_GNU_verneed:
+	  pi = pverneed_shndx;
+	  break;
+	case elfcpp::SHT_DYNAMIC:
+	  pi = pdynamic_shndx;
+	  break;
+	default:
+	  pi = NULL;
+	  break;
+	}
+
+      if (pi == NULL)
+	continue;
+
+      if (*pi != -1U)
+	{
+	  fprintf(stderr,
+		  _("%s: %s: unexpected duplicate type %u section: %u, %u\n"),
+		  program_name, this->name().c_str(), shdr.get_sh_type(),
+		  *pi, i);
+	  gold_exit(false);
+	}
+
+      *pi = i;
+    }
+}
+
+// Read the contents of section SHNDX.  PSHDRS points to the section
+// headers.  TYPE is the expected section type.  LINK is the expected
+// section link.  Store the data in *VIEW and *VIEW_SIZE.  The
+// section's sh_info field is stored in *VIEW_INFO.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::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)
+{
+  if (shndx == -1U)
+    {
+      *view = NULL;
+      *view_size = 0;
+      *view_info = 0;
+      return;
+    }
+
+  typename This::Shdr shdr(pshdrs + shndx * This::shdr_size);
+
+  gold_assert(shdr.get_sh_type() == type);
+
+  if (shdr.get_sh_link() != link)
+    {
+      fprintf(stderr,
+	      _("%s: %s: unexpected link in section %u header: %u != %u\n"),
+	      program_name, this->name().c_str(), shndx,
+	      shdr.get_sh_link(), link);
+      gold_exit(false);
+    }
+
+  *view = this->get_lasting_view(shdr.get_sh_offset(), shdr.get_sh_size());
+  *view_size = shdr.get_sh_size();
+  *view_info = shdr.get_sh_info();
+}
+
+// Set the soname field if this shared object has a DT_SONAME tag.
+// PSHDRS points to the section headers.  DYNAMIC_SHNDX is the section
+// index of the SHT_DYNAMIC section.  STRTAB_SHNDX, STRTAB, and
+// STRTAB_SIZE are the section index and contents of a string table
+// which may be the one associated with the SHT_DYNAMIC section.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::set_soname(const unsigned char* pshdrs,
+					   unsigned int dynamic_shndx,
+					   unsigned int strtab_shndx,
+					   const unsigned char* strtabu,
+					   off_t strtab_size)
+{
+  typename This::Shdr dynamicshdr(pshdrs + dynamic_shndx * This::shdr_size);
+  gold_assert(dynamicshdr.get_sh_type() == elfcpp::SHT_DYNAMIC);
+
+  const off_t dynamic_size = dynamicshdr.get_sh_size();
+  const unsigned char* pdynamic = this->get_view(dynamicshdr.get_sh_offset(),
+						 dynamic_size);
+
+  const unsigned int link = dynamicshdr.get_sh_link();
+  if (link != strtab_shndx)
+    {
+      if (link >= this->shnum())
+	{
+	  fprintf(stderr,
+		  _("%s: %s: DYNAMIC section %u link out of range: %u\n"),
+		  program_name, this->name().c_str(),
+		  dynamic_shndx, link);
+	  gold_exit(false);
+	}
+
+      typename This::Shdr strtabshdr(pshdrs + link * This::shdr_size);
+      if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
+	{
+	  fprintf(stderr,
+		  _("%s: %s: DYNAMIC section %u link %u is not a strtab\n"),
+		  program_name, this->name().c_str(),
+		  dynamic_shndx, link);
+	  gold_exit(false);
+	}
+
+      strtab_size = strtabshdr.get_sh_size();
+      strtabu = this->get_view(strtabshdr.get_sh_offset(), strtab_size);
+    }
+
+  for (const unsigned char* p = pdynamic;
+       p < pdynamic + dynamic_size;
+       p += This::dyn_size)
+    {
+      typename This::Dyn dyn(p);
+
+      if (dyn.get_d_tag() == elfcpp::DT_SONAME)
+	{
+	  off_t val = dyn.get_d_val();
+	  if (val >= strtab_size)
+	    {
+	      fprintf(stderr,
+		      _("%s: %s: DT_SONAME value out of range: "
+			"%lld >= %lld\n"),
+		      program_name, this->name().c_str(),
+		      static_cast<long long>(val),
+		      static_cast<long long>(strtab_size));
+	      gold_exit(false);
+	    }
+
+	  const char* strtab = reinterpret_cast<const char*>(strtabu);
+	  this->set_soname_string(strtab + val);
+	  return;
+	}
+
+      if (dyn.get_d_tag() == elfcpp::DT_NULL)
+	return;
+    }
+
+  fprintf(stderr, _("%s: %s: missing DT_NULL in dynamic segment\n"),
+	  program_name, this->name().c_str());
+  gold_exit(false);
+}
+
+// Read the symbols and sections from a dynamic object.  We read the
+// dynamic symbols, not the normal symbols.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
+{
+  this->read_section_data(&this->elf_file_, sd);
+
+  const unsigned char* const pshdrs = sd->section_headers->data();
+
+  unsigned int dynsym_shndx;
+  unsigned int versym_shndx;
+  unsigned int verdef_shndx;
+  unsigned int verneed_shndx;
+  unsigned int dynamic_shndx;
+  this->find_dynsym_sections(pshdrs, &dynsym_shndx, &versym_shndx,
+			     &verdef_shndx, &verneed_shndx, &dynamic_shndx);
+
+  unsigned int strtab_shndx = -1U;
+
+  if (dynsym_shndx == -1U)
+    {
+      sd->symbols = NULL;
+      sd->symbols_size = 0;
+      sd->symbol_names = NULL;
+      sd->symbol_names_size = 0;
+    }
+  else
+    {
+      // Get the dynamic symbols.
+      typename This::Shdr dynsymshdr(pshdrs + dynsym_shndx * This::shdr_size);
+      gold_assert(dynsymshdr.get_sh_type() == elfcpp::SHT_DYNSYM);
+
+      sd->symbols = this->get_lasting_view(dynsymshdr.get_sh_offset(),
+					   dynsymshdr.get_sh_size());
+      sd->symbols_size = dynsymshdr.get_sh_size();
+
+      // Get the symbol names.
+      strtab_shndx = dynsymshdr.get_sh_link();
+      if (strtab_shndx >= this->shnum())
+	{
+	  fprintf(stderr,
+		  _("%s: %s: invalid dynamic symbol table name index: %u\n"),
+		  program_name, this->name().c_str(), strtab_shndx);
+	  gold_exit(false);
+	}
+      typename This::Shdr strtabshdr(pshdrs + strtab_shndx * This::shdr_size);
+      if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
+	{
+	  fprintf(stderr,
+		  _("%s: %s: dynamic symbol table name section "
+		    "has wrong type: %u\n"),
+		  program_name, this->name().c_str(),
+		  static_cast<unsigned int>(strtabshdr.get_sh_type()));
+	  gold_exit(false);
+	}
+
+      sd->symbol_names = this->get_lasting_view(strtabshdr.get_sh_offset(),
+						strtabshdr.get_sh_size());
+      sd->symbol_names_size = strtabshdr.get_sh_size();
+
+      // Get the version information.
+
+      unsigned int dummy;
+      this->read_dynsym_section(pshdrs, versym_shndx, elfcpp::SHT_GNU_versym,
+				dynsym_shndx, &sd->versym, &sd->versym_size,
+				&dummy);
+
+      // We require that the version definition and need section link
+      // to the same string table as the dynamic symbol table.  This
+      // is not a technical requirement, but it always happens in
+      // practice.  We could change this if necessary.
+
+      this->read_dynsym_section(pshdrs, verdef_shndx, elfcpp::SHT_GNU_verdef,
+				strtab_shndx, &sd->verdef, &sd->verdef_size,
+				&sd->verdef_info);
+
+      this->read_dynsym_section(pshdrs, verneed_shndx, elfcpp::SHT_GNU_verneed,
+				strtab_shndx, &sd->verneed, &sd->verneed_size,
+				&sd->verneed_info);
+    }
+
+  // Read the SHT_DYNAMIC section to find whether this shared object
+  // has a DT_SONAME tag.  This doesn't really have anything to do
+  // with reading the symbols, but this is a convenient place to do
+  // it.
+  if (dynamic_shndx != -1U)
+    this->set_soname(pshdrs, dynamic_shndx, strtab_shndx,
+		     (sd->symbol_names == NULL
+		      ? NULL
+		      : sd->symbol_names->data()),
+		     sd->symbol_names_size);
+}
+
+// Lay out the input sections for a dynamic object.  We don't want to
+// include sections from a dynamic object, so all that we actually do
+// here is check for .gnu.warning sections.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::do_layout(const General_options&,
+					  Symbol_table* symtab,
+					  Layout*,
+					  Read_symbols_data* sd)
+{
+  const unsigned int shnum = this->shnum();
+  if (shnum == 0)
+    return;
+
+  // Get the section headers.
+  const unsigned char* pshdrs = sd->section_headers->data();
+
+  // Get the section names.
+  const unsigned char* pnamesu = sd->section_names->data();
+  const char* pnames = reinterpret_cast<const char*>(pnamesu);
+
+  // Skip the first, dummy, section.
+  pshdrs += This::shdr_size;
+  for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
+    {
+      typename This::Shdr shdr(pshdrs);
+
+      if (shdr.get_sh_name() >= sd->section_names_size)
+	{
+	  fprintf(stderr,
+		  _("%s: %s: bad section name offset for section %u: %lu\n"),
+		  program_name, this->name().c_str(), i,
+		  static_cast<unsigned long>(shdr.get_sh_name()));
+	  gold_exit(false);
+	}
+
+      const char* name = pnames + shdr.get_sh_name();
+
+      this->handle_gnu_warning_section(name, i, symtab);
+    }
+
+  delete sd->section_headers;
+  sd->section_headers = NULL;
+  delete sd->section_names;
+  sd->section_names = NULL;
+}
+
+// Add an entry to the vector mapping version numbers to version
+// strings.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::set_version_map(
+    Version_map* version_map,
+    unsigned int ndx,
+    const char* name) const
+{
+  if (ndx >= version_map->size())
+    version_map->resize(ndx + 1);
+  if ((*version_map)[ndx] != NULL)
+    {
+      fprintf(stderr, _("%s: %s: duplicate definition for version %u\n"),
+	      program_name, this->name().c_str(), ndx);
+      gold_exit(false);
+    }
+  (*version_map)[ndx] = name;
+}
+
+// Add mappings for the version definitions to VERSION_MAP.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::make_verdef_map(
+    Read_symbols_data* sd,
+    Version_map* version_map) const
+{
+  if (sd->verdef == NULL)
+    return;
+
+  const char* names = reinterpret_cast<const char*>(sd->symbol_names->data());
+  off_t names_size = sd->symbol_names_size;
+
+  const unsigned char* pverdef = sd->verdef->data();
+  off_t verdef_size = sd->verdef_size;
+  const unsigned int count = sd->verdef_info;
+
+  const unsigned char* p = pverdef;
+  for (unsigned int i = 0; i < count; ++i)
+    {
+      elfcpp::Verdef<size, big_endian> verdef(p);
+
+      if (verdef.get_vd_version() != elfcpp::VER_DEF_CURRENT)
+	{
+	  fprintf(stderr, _("%s: %s: unexpected verdef version %u\n"),
+		  program_name, this->name().c_str(), verdef.get_vd_version());
+	  gold_exit(false);
+	}
+
+      const unsigned int vd_ndx = verdef.get_vd_ndx();
+
+      // The GNU linker clears the VERSYM_HIDDEN bit.  I'm not
+      // sure why.
+
+      // The first Verdaux holds the name of this version.  Subsequent
+      // ones are versions that this one depends upon, which we don't
+      // care about here.
+      const unsigned int vd_cnt = verdef.get_vd_cnt();
+      if (vd_cnt < 1)
+	{
+	  fprintf(stderr, _("%s: %s: verdef vd_cnt field too small: %u\n"),
+		  program_name, this->name().c_str(), vd_cnt);
+	  gold_exit(false);
+	}
+
+      const unsigned int vd_aux = verdef.get_vd_aux();
+      if ((p - pverdef) + vd_aux >= verdef_size)
+	{
+	  fprintf(stderr,
+		  _("%s: %s: verdef vd_aux field out of range: %u\n"),
+		  program_name, this->name().c_str(), vd_aux);
+	  gold_exit(false);
+	}
+
+      const unsigned char* pvda = p + vd_aux;
+      elfcpp::Verdaux<size, big_endian> verdaux(pvda);
+
+      const unsigned int vda_name = verdaux.get_vda_name();
+      if (vda_name >= names_size)
+	{
+	  fprintf(stderr,
+		  _("%s: %s: verdaux vda_name field out of range: %u\n"),
+		  program_name, this->name().c_str(), vda_name);
+	  gold_exit(false);
+	}
+
+      this->set_version_map(version_map, vd_ndx, names + vda_name);
+
+      const unsigned int vd_next = verdef.get_vd_next();
+      if ((p - pverdef) + vd_next >= verdef_size)
+	{
+	  fprintf(stderr,
+		  _("%s: %s: verdef vd_next field out of range: %u\n"),
+		  program_name, this->name().c_str(), vd_next);
+	  gold_exit(false);
+	}
+
+      p += vd_next;
+    }
+}
+
+// Add mappings for the required versions to VERSION_MAP.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::make_verneed_map(
+    Read_symbols_data* sd,
+    Version_map* version_map) const
+{
+  if (sd->verneed == NULL)
+    return;
+
+  const char* names = reinterpret_cast<const char*>(sd->symbol_names->data());
+  off_t names_size = sd->symbol_names_size;
+
+  const unsigned char* pverneed = sd->verneed->data();
+  const off_t verneed_size = sd->verneed_size;
+  const unsigned int count = sd->verneed_info;
+
+  const unsigned char* p = pverneed;
+  for (unsigned int i = 0; i < count; ++i)
+    {
+      elfcpp::Verneed<size, big_endian> verneed(p);
+
+      if (verneed.get_vn_version() != elfcpp::VER_NEED_CURRENT)
+	{
+	  fprintf(stderr, _("%s: %s: unexpected verneed version %u\n"),
+		  program_name, this->name().c_str(),
+		  verneed.get_vn_version());
+	  gold_exit(false);
+	}
+
+      const unsigned int vn_aux = verneed.get_vn_aux();
+
+      if ((p - pverneed) + vn_aux >= verneed_size)
+	{
+	  fprintf(stderr,
+		  _("%s: %s: verneed vn_aux field out of range: %u\n"),
+		  program_name, this->name().c_str(), vn_aux);
+	  gold_exit(false);
+	}
+
+      const unsigned int vn_cnt = verneed.get_vn_cnt();
+      const unsigned char* pvna = p + vn_aux;
+      for (unsigned int j = 0; j < vn_cnt; ++j)
+	{
+	  elfcpp::Vernaux<size, big_endian> vernaux(pvna);
+
+	  const unsigned int vna_name = vernaux.get_vna_name();
+	  if (vna_name >= names_size)
+	    {
+	      fprintf(stderr,
+		      _("%s: %s: vernaux vna_name field "
+			"out of range: %u\n"),
+		      program_name, this->name().c_str(), vna_name);
+	      gold_exit(false);
+	    }
+
+	  this->set_version_map(version_map, vernaux.get_vna_other(),
+				names + vna_name);
+
+	  const unsigned int vna_next = vernaux.get_vna_next();
+	  if ((pvna - pverneed) + vna_next >= verneed_size)
+	    {
+	      fprintf(stderr,
+		      _("%s: %s: verneed vna_next field "
+			"out of range: %u\n"),
+		      program_name, this->name().c_str(), vna_next);
+	      gold_exit(false);
+	    }
+
+	  pvna += vna_next;
+	}
+
+      const unsigned int vn_next = verneed.get_vn_next();
+      if ((p - pverneed) + vn_next >= verneed_size)
+	{
+	  fprintf(stderr,
+		  _("%s: %s: verneed vn_next field out of range: %u\n"),
+		  program_name, this->name().c_str(), vn_next);
+	  gold_exit(false);
+	}
+
+      p += vn_next;
+    }
+}
+
+// Create a vector mapping version numbers to version strings.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::make_version_map(
+    Read_symbols_data* sd,
+    Version_map* version_map) const
+{
+  if (sd->verdef == NULL && sd->verneed == NULL)
+    return;
+
+  // A guess at the maximum version number we will see.  If this is
+  // wrong we will be less efficient but still correct.
+  version_map->reserve(sd->verdef_info + sd->verneed_info * 10);
+
+  this->make_verdef_map(sd, version_map);
+  this->make_verneed_map(sd, version_map);
+}
+
+// Add the dynamic symbols to the symbol table.
+
+template<int size, bool big_endian>
+void
+Sized_dynobj<size, big_endian>::do_add_symbols(Symbol_table* symtab,
+					       Read_symbols_data* sd)
+{
+  if (sd->symbols == NULL)
+    {
+      gold_assert(sd->symbol_names == NULL);
+      gold_assert(sd->versym == NULL && sd->verdef == NULL
+		  && sd->verneed == NULL);
+      return;
+    }
+
+  const int sym_size = This::sym_size;
+  const size_t symcount = sd->symbols_size / sym_size;
+  if (symcount * sym_size != sd->symbols_size)
+    {
+      fprintf(stderr,
+	      _("%s: %s: size of dynamic symbols is not "
+		"multiple of symbol size\n"),
+	      program_name, this->name().c_str());
+      gold_exit(false);
+    }
+
+  Version_map version_map;
+  this->make_version_map(sd, &version_map);
+
+  const char* sym_names =
+    reinterpret_cast<const char*>(sd->symbol_names->data());
+  symtab->add_from_dynobj(this, sd->symbols->data(), symcount,
+			  sym_names, sd->symbol_names_size,
+			  (sd->versym == NULL
+			   ? NULL
+			   : sd->versym->data()),
+			  sd->versym_size,
+			  &version_map);
+
+  delete sd->symbols;
+  sd->symbols = NULL;
+  delete sd->symbol_names;
+  sd->symbol_names = NULL;
+  if (sd->versym != NULL)
+    {
+      delete sd->versym;
+      sd->versym = NULL;
+    }
+  if (sd->verdef != NULL)
+    {
+      delete sd->verdef;
+      sd->verdef = NULL;
+    }
+  if (sd->verneed != NULL)
+    {
+      delete sd->verneed;
+      sd->verneed = NULL;
+    }
+}
+
+// Given a vector of hash codes, compute the number of hash buckets to
+// use.
+
+unsigned int
+Dynobj::compute_bucket_count(const std::vector<uint32_t>& hashcodes,
+			     bool for_gnu_hash_table)
+{
+  // FIXME: Implement optional hash table optimization.
+
+  // Array used to determine the number of hash table buckets to use
+  // based on the number of symbols there are.  If there are fewer
+  // than 3 symbols we use 1 bucket, fewer than 17 symbols we use 3
+  // buckets, fewer than 37 we use 17 buckets, and so forth.  We never
+  // use more than 32771 buckets.  This is straight from the old GNU
+  // linker.
+  static const unsigned int buckets[] =
+  {
+    1, 3, 17, 37, 67, 97, 131, 197, 263, 521, 1031, 2053, 4099, 8209,
+    16411, 32771
+  };
+  const int buckets_count = sizeof buckets / sizeof buckets[0];
+
+  unsigned int symcount = hashcodes.size();
+  unsigned int ret = 1;
+  for (int i = 0; i < buckets_count; ++i)
+    {
+      if (symcount < buckets[i])
+	break;
+      ret = buckets[i];
+    }
+
+  if (for_gnu_hash_table && ret < 2)
+    ret = 2;
+
+  return ret;
+}
+
+// The standard ELF hash function.  This hash function must not
+// change, as the dynamic linker uses it also.
+
+uint32_t
+Dynobj::elf_hash(const char* name)
+{
+  const unsigned char* nameu = reinterpret_cast<const unsigned char*>(name);
+  uint32_t h = 0;
+  unsigned char c;
+  while ((c = *nameu++) != '\0')
+    {
+      h = (h << 4) + c;
+      uint32_t g = h & 0xf0000000;
+      if (g != 0)
+	{
+	  h ^= g >> 24;
+	  // The ELF ABI says h &= ~g, but using xor is equivalent in
+	  // this case (since g was set from h) and may save one
+	  // instruction.
+	  h ^= g;
+	}
+    }
+  return h;
+}
+
+// Create a standard ELF hash table, setting *PPHASH and *PHASHLEN.
+// DYNSYMS is a vector with all the global dynamic symbols.
+// LOCAL_DYNSYM_COUNT is the number of local symbols in the dynamic
+// symbol table.
+
+void
+Dynobj::create_elf_hash_table(const Target* target,
+			      const std::vector<Symbol*>& dynsyms,
+			      unsigned int local_dynsym_count,
+			      unsigned char** pphash,
+			      unsigned int* phashlen)
+{
+  unsigned int dynsym_count = dynsyms.size();
+
+  // Get the hash values for all the symbols.
+  std::vector<uint32_t> dynsym_hashvals(dynsym_count);
+  for (unsigned int i = 0; i < dynsym_count; ++i)
+    dynsym_hashvals[i] = Dynobj::elf_hash(dynsyms[i]->name());
+
+  const unsigned int bucketcount =
+    Dynobj::compute_bucket_count(dynsym_hashvals, false);
+
+  std::vector<uint32_t> bucket(bucketcount);
+  std::vector<uint32_t> chain(local_dynsym_count + dynsym_count);
+
+  for (unsigned int i = 0; i < dynsym_count; ++i)
+    {
+      unsigned int dynsym_index = dynsyms[i]->dynsym_index();
+      unsigned int bucketpos = dynsym_hashvals[i] % bucketcount;
+      chain[dynsym_index] = bucket[bucketpos];
+      bucket[bucketpos] = dynsym_index;
+    }
+
+  unsigned int hashlen = ((2
+			   + bucketcount
+			   + local_dynsym_count
+			   + dynsym_count)
+			  * 4);
+  unsigned char* phash = new unsigned char[hashlen];
+
+  if (target->is_big_endian())
+    Dynobj::sized_create_elf_hash_table<true>(bucket, chain, phash, hashlen);
+  else
+    Dynobj::sized_create_elf_hash_table<false>(bucket, chain, phash, hashlen);
+
+  *pphash = phash;
+  *phashlen = hashlen;
+}
+
+// Fill in an ELF hash table.
+
+template<bool big_endian>
+void
+Dynobj::sized_create_elf_hash_table(const std::vector<uint32_t>& bucket,
+				    const std::vector<uint32_t>& chain,
+				    unsigned char* phash,
+				    unsigned int hashlen)
+{
+  unsigned char* p = phash;
+
+  const unsigned int bucketcount = bucket.size();
+  const unsigned int chaincount = chain.size();
+
+  elfcpp::Swap<32, big_endian>::writeval(p, bucketcount);
+  p += 4;
+  elfcpp::Swap<32, big_endian>::writeval(p, chaincount);
+  p += 4;
+
+  for (unsigned int i = 0; i < bucketcount; ++i)
+    {
+      elfcpp::Swap<32, big_endian>::writeval(p, bucket[i]);
+      p += 4;
+    }
+
+  for (unsigned int i = 0; i < chaincount; ++i)
+    {
+      elfcpp::Swap<32, big_endian>::writeval(p, chain[i]);
+      p += 4;
+    }
+
+  gold_assert(static_cast<unsigned int>(p - phash) == hashlen);
+}
+
+// The hash function used for the GNU hash table.  This hash function
+// must not change, as the dynamic linker uses it also.
+
+uint32_t
+Dynobj::gnu_hash(const char* name)
+{
+  const unsigned char* nameu = reinterpret_cast<const unsigned char*>(name);
+  uint32_t h = 5381;
+  unsigned char c;
+  while ((c = *nameu++) != '\0')
+    h = (h << 5) + h + c;
+  return h;
+}
+
+// Create a GNU hash table, setting *PPHASH and *PHASHLEN.  GNU hash
+// tables are an extension to ELF which are recognized by the GNU
+// dynamic linker.  They are referenced using dynamic tag DT_GNU_HASH.
+// TARGET is the target.  DYNSYMS is a vector with all the global
+// symbols which will be going into the dynamic symbol table.
+// LOCAL_DYNSYM_COUNT is the number of local symbols in the dynamic
+// symbol table.
+
+void
+Dynobj::create_gnu_hash_table(const Target* target,
+			      const std::vector<Symbol*>& dynsyms,
+			      unsigned int local_dynsym_count,
+			      unsigned char** pphash,
+			      unsigned int* phashlen)
+{
+  const unsigned int count = dynsyms.size();
+
+  // Sort the dynamic symbols into two vectors.  Symbols which we do
+  // not want to put into the hash table we store into
+  // UNHASHED_DYNSYMS.  Symbols which we do want to store we put into
+  // HASHED_DYNSYMS.  DYNSYM_HASHVALS is parallel to HASHED_DYNSYMS,
+  // and records the hash codes.
+
+  std::vector<Symbol*> unhashed_dynsyms;
+  unhashed_dynsyms.reserve(count);
+
+  std::vector<Symbol*> hashed_dynsyms;
+  hashed_dynsyms.reserve(count);
+
+  std::vector<uint32_t> dynsym_hashvals;
+  dynsym_hashvals.reserve(count);
+  
+  for (unsigned int i = 0; i < count; ++i)
+    {
+      Symbol* sym = dynsyms[i];
+
+      // FIXME: Should put on unhashed_dynsyms if the symbol is
+      // hidden.
+      if (sym->is_undefined())
+	unhashed_dynsyms.push_back(sym);
+      else
+	{
+	  hashed_dynsyms.push_back(sym);
+	  dynsym_hashvals.push_back(Dynobj::gnu_hash(sym->name()));
+	}
+    }
+
+  // Put the unhashed symbols at the start of the global portion of
+  // the dynamic symbol table.
+  const unsigned int unhashed_count = unhashed_dynsyms.size();
+  unsigned int unhashed_dynsym_index = local_dynsym_count;
+  for (unsigned int i = 0; i < unhashed_count; ++i)
+    {
+      unhashed_dynsyms[i]->set_dynsym_index(unhashed_dynsym_index);
+      ++unhashed_dynsym_index;
+    }
+
+  // For the actual data generation we call out to a templatized
+  // function.
+  int size = target->get_size();
+  bool big_endian = target->is_big_endian();
+  if (size == 32)
+    {
+      if (big_endian)
+	Dynobj::sized_create_gnu_hash_table<32, true>(hashed_dynsyms,
+						      dynsym_hashvals,
+						      unhashed_dynsym_index,
+						      pphash,
+						      phashlen);
+      else
+	Dynobj::sized_create_gnu_hash_table<32, false>(hashed_dynsyms,
+						       dynsym_hashvals,
+						       unhashed_dynsym_index,
+						       pphash,
+						       phashlen);
+    }
+  else if (size == 64)
+    {
+      if (big_endian)
+	Dynobj::sized_create_gnu_hash_table<64, true>(hashed_dynsyms,
+						      dynsym_hashvals,
+						      unhashed_dynsym_index,
+						      pphash,
+						      phashlen);
+      else
+	Dynobj::sized_create_gnu_hash_table<64, false>(hashed_dynsyms,
+						       dynsym_hashvals,
+						       unhashed_dynsym_index,
+						       pphash,
+						       phashlen);
+    }
+  else
+    gold_unreachable();
+}
+
+// Create the actual data for a GNU hash table.  This is just a copy
+// of the code from the old GNU linker.
+
+template<int size, bool big_endian>
+void
+Dynobj::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)
+{
+  if (hashed_dynsyms.empty())
+    {
+      // Special case for the empty hash table.
+      unsigned int hashlen = 5 * 4 + size / 8;
+      unsigned char* phash = new unsigned char[hashlen];
+      // One empty bucket.
+      elfcpp::Swap<32, big_endian>::writeval(phash, 1);
+      // Symbol index above unhashed symbols.
+      elfcpp::Swap<32, big_endian>::writeval(phash + 4, unhashed_dynsym_count);
+      // One word for bitmask.
+      elfcpp::Swap<32, big_endian>::writeval(phash + 8, 1);
+      // Only bloom filter.
+      elfcpp::Swap<32, big_endian>::writeval(phash + 12, 0);
+      // No valid hashes.
+      elfcpp::Swap<size, big_endian>::writeval(phash + 16, 0);
+      // No hashes in only bucket.
+      elfcpp::Swap<32, big_endian>::writeval(phash + 16 + size / 8, 0);
+
+      *phashlen = hashlen;
+      *pphash = phash;
+
+      return;
+    }
+
+  const unsigned int bucketcount =
+    Dynobj::compute_bucket_count(dynsym_hashvals, true);
+
+  const unsigned int nsyms = hashed_dynsyms.size();
+
+  uint32_t maskbitslog2 = 1;
+  uint32_t x = nsyms >> 1;
+  while (x != 0)
+    {
+      ++maskbitslog2;
+      x >>= 1;
+    }
+  if (maskbitslog2 < 3)
+    maskbitslog2 = 5;
+  else if (((1U << (maskbitslog2 - 2)) & nsyms) != 0)
+    maskbitslog2 += 3;
+  else
+    maskbitslog2 += 2;
+
+  uint32_t shift1;
+  if (size == 32)
+    shift1 = 5;
+  else
+    {
+      if (maskbitslog2 == 5)
+	maskbitslog2 = 6;
+      shift1 = 6;
+    }
+  uint32_t mask = (1U << shift1) - 1U;
+  uint32_t shift2 = maskbitslog2;
+  uint32_t maskbits = 1U << maskbitslog2;
+  uint32_t maskwords = 1U << (maskbitslog2 - shift1);
+
+  typedef typename elfcpp::Elf_types<size>::Elf_WXword Word;
+  std::vector<Word> bitmask(maskwords);
+  std::vector<uint32_t> counts(bucketcount);
+  std::vector<uint32_t> indx(bucketcount);
+  uint32_t symindx = unhashed_dynsym_count;
+
+  // Count the number of times each hash bucket is used.
+  for (unsigned int i = 0; i < nsyms; ++i)
+    ++counts[dynsym_hashvals[i] % bucketcount];
+
+  unsigned int cnt = symindx;
+  for (unsigned int i = 0; i < bucketcount; ++i)
+    {
+      indx[i] = cnt;
+      cnt += counts[i];
+    }
+
+  unsigned int hashlen = (4 + bucketcount + nsyms) * 4;
+  hashlen += maskbits / 8;
+  unsigned char* phash = new unsigned char[hashlen];
+
+  elfcpp::Swap<32, big_endian>::writeval(phash, bucketcount);
+  elfcpp::Swap<32, big_endian>::writeval(phash + 4, symindx);
+  elfcpp::Swap<32, big_endian>::writeval(phash + 8, maskwords);
+  elfcpp::Swap<32, big_endian>::writeval(phash + 12, shift2);
+
+  unsigned char* p = phash + 16 + maskbits / 8;
+  for (unsigned int i = 0; i < bucketcount; ++i)
+    {
+      if (counts[i] == 0)
+	elfcpp::Swap<32, big_endian>::writeval(p, 0);
+      else
+	elfcpp::Swap<32, big_endian>::writeval(p, indx[i]);
+      p += 4;
+    }
+
+  for (unsigned int i = 0; i < nsyms; ++i)
+    {
+      Symbol* sym = hashed_dynsyms[i];
+      uint32_t hashval = dynsym_hashvals[i];
+
+      unsigned int bucket = hashval % bucketcount;
+      unsigned int val = ((hashval >> shift1)
+			  & ((maskbits >> shift1) - 1));
+      bitmask[val] |= (static_cast<Word>(1U)) << (hashval & mask);
+      bitmask[val] |= (static_cast<Word>(1U)) << ((hashval >> shift2) & mask);
+      val = hashval & ~ 1U;
+      if (counts[bucket] == 1)
+	{
+	  // Last element terminates the chain.
+	  val |= 1;
+	}
+      elfcpp::Swap<32, big_endian>::writeval(p + (indx[bucket] - symindx) * 4,
+					     val);
+      --counts[bucket];
+
+      sym->set_dynsym_index(indx[bucket]);
+      ++indx[bucket];
+    }
+
+  p = phash + 16;
+  for (unsigned int i = 0; i < maskwords; ++i)
+    {
+      elfcpp::Swap<size, big_endian>::writeval(p, bitmask[i]);
+      p += size / 8;
+    }
+
+  *phashlen = hashlen;
+  *pphash = phash;
+}
+
+// Verdef methods.
+
+// Write this definition to a buffer for the output section.
+
+template<int size, bool big_endian>
+unsigned char*
+Verdef::write(const Stringpool* dynpool, bool is_last, unsigned char* pb
+              ACCEPT_SIZE_ENDIAN) const
+{
+  const int verdef_size = elfcpp::Elf_sizes<size>::verdef_size;
+  const int verdaux_size = elfcpp::Elf_sizes<size>::verdaux_size;
+
+  elfcpp::Verdef_write<size, big_endian> vd(pb);
+  vd.set_vd_version(elfcpp::VER_DEF_CURRENT);
+  vd.set_vd_flags((this->is_base_ ? elfcpp::VER_FLG_BASE : 0)
+		  | (this->is_weak_ ? elfcpp::VER_FLG_WEAK : 0));
+  vd.set_vd_ndx(this->index());
+  vd.set_vd_cnt(1 + this->deps_.size());
+  vd.set_vd_hash(Dynobj::elf_hash(this->name()));
+  vd.set_vd_aux(verdef_size);
+  vd.set_vd_next(is_last
+		 ? 0
+		 : verdef_size + (1 + this->deps_.size()) * verdaux_size);
+  pb += verdef_size;
+
+  elfcpp::Verdaux_write<size, big_endian> vda(pb);
+  vda.set_vda_name(dynpool->get_offset(this->name()));
+  vda.set_vda_next(this->deps_.empty() ? 0 : verdaux_size);
+  pb += verdaux_size;
+
+  Deps::const_iterator p;
+  unsigned int i;
+  for (p = this->deps_.begin(), i = 0;
+       p != this->deps_.end();
+       ++p, ++i)
+    {
+      elfcpp::Verdaux_write<size, big_endian> vda(pb);
+      vda.set_vda_name(dynpool->get_offset(*p));
+      vda.set_vda_next(i + 1 >= this->deps_.size() ? 0 : verdaux_size);
+      pb += verdaux_size;
+    }
+
+  return pb;
+}
+
+// Verneed methods.
+
+Verneed::~Verneed()
+{
+  for (Need_versions::iterator p = this->need_versions_.begin();
+       p != this->need_versions_.end();
+       ++p)
+    delete *p;
+}
+
+// Add a new version to this file reference.
+
+Verneed_version*
+Verneed::add_name(const char* name)
+{
+  Verneed_version* vv = new Verneed_version(name);
+  this->need_versions_.push_back(vv);
+  return vv;
+}
+
+// Set the version indexes starting at INDEX.
+
+unsigned int
+Verneed::finalize(unsigned int index)
+{
+  for (Need_versions::iterator p = this->need_versions_.begin();
+       p != this->need_versions_.end();
+       ++p)
+    {
+      (*p)->set_index(index);
+      ++index;
+    }
+  return index;
+}
+
+// Write this list of referenced versions to a buffer for the output
+// section.
+
+template<int size, bool big_endian>
+unsigned char*
+Verneed::write(const Stringpool* dynpool, bool is_last,
+	       unsigned char* pb ACCEPT_SIZE_ENDIAN) const
+{
+  const int verneed_size = elfcpp::Elf_sizes<size>::verneed_size;
+  const int vernaux_size = elfcpp::Elf_sizes<size>::vernaux_size;
+
+  elfcpp::Verneed_write<size, big_endian> vn(pb);
+  vn.set_vn_version(elfcpp::VER_NEED_CURRENT);
+  vn.set_vn_cnt(this->need_versions_.size());
+  vn.set_vn_file(dynpool->get_offset(this->filename()));
+  vn.set_vn_aux(verneed_size);
+  vn.set_vn_next(is_last
+		 ? 0
+		 : verneed_size + this->need_versions_.size() * vernaux_size);
+  pb += verneed_size;
+
+  Need_versions::const_iterator p;
+  unsigned int i;
+  for (p = this->need_versions_.begin(), i = 0;
+       p != this->need_versions_.end();
+       ++p, ++i)
+    {
+      elfcpp::Vernaux_write<size, big_endian> vna(pb);
+      vna.set_vna_hash(Dynobj::elf_hash((*p)->version()));
+      // FIXME: We need to sometimes set VER_FLG_WEAK here.
+      vna.set_vna_flags(0);
+      vna.set_vna_other((*p)->index());
+      vna.set_vna_name(dynpool->get_offset((*p)->version()));
+      vna.set_vna_next(i + 1 >= this->need_versions_.size()
+		       ? 0
+		       : vernaux_size);
+      pb += vernaux_size;
+    }
+
+  return pb;
+}
+
+// Versions methods.
+
+Versions::~Versions()
+{
+  for (Defs::iterator p = this->defs_.begin();
+       p != this->defs_.end();
+       ++p)
+    delete *p;
+
+  for (Needs::iterator p = this->needs_.begin();
+       p != this->needs_.end();
+       ++p)
+    delete *p;
+}
+
+// Record version information for a symbol going into the dynamic
+// symbol table.
+
+void
+Versions::record_version(const General_options* options,
+			 Stringpool* dynpool, const Symbol* sym)
+{
+  gold_assert(!this->is_finalized_);
+  gold_assert(sym->version() != NULL);
+
+  Stringpool::Key version_key;
+  const char* version = dynpool->add(sym->version(), &version_key);
+
+  if (!sym->is_from_dynobj())
+    this->add_def(options, sym, version, version_key);
+  else
+    {
+      // This is a version reference.
+
+      Object* object = sym->object();
+      gold_assert(object->is_dynamic());
+      Dynobj* dynobj = static_cast<Dynobj*>(object);
+
+      this->add_need(dynpool, dynobj->soname(), version, version_key);
+    }
+}
+
+// We've found a symbol SYM defined in version VERSION.
+
+void
+Versions::add_def(const General_options* options, const Symbol* sym,
+		  const char* version, Stringpool::Key version_key)
+{
+  Key k(version_key, 0);
+  Version_base* const vbnull = NULL;
+  std::pair<Version_table::iterator, bool> ins =
+    this->version_table_.insert(std::make_pair(k, vbnull));
+
+  if (!ins.second)
+    {
+      // We already have an entry for this version.
+      Version_base* vb = ins.first->second;
+
+      // We have now seen a symbol in this version, so it is not
+      // weak.
+      vb->clear_weak();
+
+      // FIXME: When we support version scripts, we will need to
+      // check whether this symbol should be forced local.
+    }
+  else
+    {
+      // If we are creating a shared object, it is an error to
+      // find a definition of a symbol with a version which is not
+      // in the version script.
+      if (options->is_shared())
+	{
+	  fprintf(stderr, _("%s: symbol %s has undefined version %s\n"),
+		  program_name, sym->name(), version);
+	  gold_exit(false);
+	}
+
+      // If this is the first version we are defining, first define
+      // the base version.  FIXME: Should use soname here when
+      // creating a shared object.
+      Verdef* vdbase = new Verdef(options->output_file_name(), true, false,
+				  true);
+      this->defs_.push_back(vdbase);
+
+      // When creating a regular executable, automatically define
+      // a new version.
+      Verdef* vd = new Verdef(version, false, false, false);
+      this->defs_.push_back(vd);
+      ins.first->second = vd;
+    }
+}
+
+// Add a reference to version NAME in file FILENAME.
+
+void
+Versions::add_need(Stringpool* dynpool, const char* filename, const char* name,
+		   Stringpool::Key name_key)
+{
+  Stringpool::Key filename_key;
+  filename = dynpool->add(filename, &filename_key);
+
+  Key k(name_key, filename_key);
+  Version_base* const vbnull = NULL;
+  std::pair<Version_table::iterator, bool> ins =
+    this->version_table_.insert(std::make_pair(k, vbnull));
+
+  if (!ins.second)
+    {
+      // We already have an entry for this filename/version.
+      return;
+    }
+
+  // See whether we already have this filename.  We don't expect many
+  // version references, so we just do a linear search.  This could be
+  // replaced by a hash table.
+  Verneed* vn = NULL;
+  for (Needs::iterator p = this->needs_.begin();
+       p != this->needs_.end();
+       ++p)
+    {
+      if ((*p)->filename() == filename)
+	{
+	  vn = *p;
+	  break;
+	}
+    }
+
+  if (vn == NULL)
+    {
+      // We have a new filename.
+      vn = new Verneed(filename);
+      this->needs_.push_back(vn);
+    }
+
+  ins.first->second = vn->add_name(name);
+}
+
+// Set the version indexes.  Create a new dynamic version symbol for
+// each new version definition.
+
+unsigned int
+Versions::finalize(const Target* target, Symbol_table* symtab,
+		   unsigned int dynsym_index, std::vector<Symbol*>* syms)
+{
+  gold_assert(!this->is_finalized_);
+
+  unsigned int vi = 1;
+
+  for (Defs::iterator p = this->defs_.begin();
+       p != this->defs_.end();
+       ++p)
+    {
+      (*p)->set_index(vi);
+      ++vi;
+
+      // Create a version symbol if necessary.
+      if (!(*p)->is_symbol_created())
+	{
+	  Symbol* vsym = symtab->define_as_constant(target, (*p)->name(),
+						    (*p)->name(), 0, 0,
+						    elfcpp::STT_OBJECT,
+						    elfcpp::STB_GLOBAL,
+						    elfcpp::STV_DEFAULT, 0,
+						    false);
+	  vsym->set_needs_dynsym_entry();
+	  ++dynsym_index;
+	  syms->push_back(vsym);
+	  // The name is already in the dynamic pool.
+	}
+    }
+
+  // Index 1 is used for global symbols.
+  if (vi == 1)
+    {
+      gold_assert(this->defs_.empty());
+      vi = 2;
+    }
+
+  for (Needs::iterator p = this->needs_.begin();
+       p != this->needs_.end();
+       ++p)
+    vi = (*p)->finalize(vi);
+
+  this->is_finalized_ = true;
+
+  return dynsym_index;
+}
+
+// Return the version index to use for a symbol.  This does two hash
+// table lookups: one in DYNPOOL and one in this->version_table_.
+// Another approach alternative would be store a pointer in SYM, which
+// would increase the size of the symbol table.  Or perhaps we could
+// use a hash table from dynamic symbol pointer values to Version_base
+// pointers.
+
+unsigned int
+Versions::version_index(const Stringpool* dynpool, const Symbol* sym) const
+{
+  Stringpool::Key version_key;
+  const char* version = dynpool->find(sym->version(), &version_key);
+  gold_assert(version != NULL);
+
+  Key k;
+  if (!sym->is_from_dynobj())
+    k = Key(version_key, 0);
+  else
+    {
+      Object* object = sym->object();
+      gold_assert(object->is_dynamic());
+      Dynobj* dynobj = static_cast<Dynobj*>(object);
+
+      Stringpool::Key filename_key;
+      const char* filename = dynpool->find(dynobj->soname(), &filename_key);
+      gold_assert(filename != NULL);
+
+      k = Key(version_key, filename_key);
+    }
+
+  Version_table::const_iterator p = this->version_table_.find(k);
+  gold_assert(p != this->version_table_.end());
+
+  return p->second->index();
+}
+
+// Return an allocated buffer holding the contents of the symbol
+// version section.
+
+template<int size, bool big_endian>
+void
+Versions::symbol_section_contents(const Stringpool* dynpool,
+				  unsigned int local_symcount,
+				  const std::vector<Symbol*>& syms,
+				  unsigned char** pp,
+				  unsigned int* psize
+                                  ACCEPT_SIZE_ENDIAN) const
+{
+  gold_assert(this->is_finalized_);
+
+  unsigned int sz = (local_symcount + syms.size()) * 2;
+  unsigned char* pbuf = new unsigned char[sz];
+
+  for (unsigned int i = 0; i < local_symcount; ++i)
+    elfcpp::Swap<16, big_endian>::writeval(pbuf + i * 2,
+					   elfcpp::VER_NDX_LOCAL);
+
+  for (std::vector<Symbol*>::const_iterator p = syms.begin();
+       p != syms.end();
+       ++p)
+    {
+      unsigned int version_index;
+      const char* version = (*p)->version();
+      if (version == NULL)
+	version_index = elfcpp::VER_NDX_GLOBAL;
+      else
+	version_index = this->version_index(dynpool, *p);
+      elfcpp::Swap<16, big_endian>::writeval(pbuf + (*p)->dynsym_index() * 2,
+					     version_index);
+    }
+
+  *pp = pbuf;
+  *psize = sz;
+}
+
+// Return an allocated buffer holding the contents of the version
+// definition section.
+
+template<int size, bool big_endian>
+void
+Versions::def_section_contents(const Stringpool* dynpool,
+			       unsigned char** pp, unsigned int* psize,
+			       unsigned int* pentries
+                               ACCEPT_SIZE_ENDIAN) const
+{
+  gold_assert(this->is_finalized_);
+  gold_assert(!this->defs_.empty());
+
+  const int verdef_size = elfcpp::Elf_sizes<size>::verdef_size;
+  const int verdaux_size = elfcpp::Elf_sizes<size>::verdaux_size;
+
+  unsigned int sz = 0;
+  for (Defs::const_iterator p = this->defs_.begin();
+       p != this->defs_.end();
+       ++p)
+    {
+      sz += verdef_size + verdaux_size;
+      sz += (*p)->count_dependencies() * verdaux_size;
+    }
+
+  unsigned char* pbuf = new unsigned char[sz];
+
+  unsigned char* pb = pbuf;
+  Defs::const_iterator p;
+  unsigned int i;
+  for (p = this->defs_.begin(), i = 0;
+       p != this->defs_.end();
+       ++p, ++i)
+    pb = (*p)->write SELECT_SIZE_ENDIAN_NAME(size, big_endian)(
+            dynpool, i + 1 >= this->defs_.size(), pb
+            SELECT_SIZE_ENDIAN(size, big_endian));
+
+  gold_assert(static_cast<unsigned int>(pb - pbuf) == sz);
+
+  *pp = pbuf;
+  *psize = sz;
+  *pentries = this->defs_.size();
+}
+
+// Return an allocated buffer holding the contents of the version
+// reference section.
+
+template<int size, bool big_endian>
+void
+Versions::need_section_contents(const Stringpool* dynpool,
+				unsigned char** pp, unsigned int *psize,
+				unsigned int *pentries
+                                ACCEPT_SIZE_ENDIAN) const
+{
+  gold_assert(this->is_finalized_);
+  gold_assert(!this->needs_.empty());
+
+  const int verneed_size = elfcpp::Elf_sizes<size>::verneed_size;
+  const int vernaux_size = elfcpp::Elf_sizes<size>::vernaux_size;
+
+  unsigned int sz = 0;
+  for (Needs::const_iterator p = this->needs_.begin();
+       p != this->needs_.end();
+       ++p)
+    {
+      sz += verneed_size;
+      sz += (*p)->count_versions() * vernaux_size;
+    }
+
+  unsigned char* pbuf = new unsigned char[sz];
+
+  unsigned char* pb = pbuf;
+  Needs::const_iterator p;
+  unsigned int i;
+  for (p = this->needs_.begin(), i = 0;
+       p != this->needs_.end();
+       ++p, ++i)
+    pb = (*p)->write SELECT_SIZE_ENDIAN_NAME(size, big_endian)(
+	    dynpool, i + 1 >= this->needs_.size(), pb
+            SELECT_SIZE_ENDIAN(size, big_endian));
+
+  gold_assert(static_cast<unsigned int>(pb - pbuf) == sz);
+
+  *pp = pbuf;
+  *psize = sz;
+  *pentries = this->needs_.size();
+}
+
+// Instantiate the templates we need.  We could use the configure
+// script to restrict this to only the ones for implemented targets.
+
+template
+class Sized_dynobj<32, false>;
+
+template
+class Sized_dynobj<32, true>;
+
+template
+class Sized_dynobj<64, false>;
+
+template
+class Sized_dynobj<64, true>;
+
+template
+void
+Versions::symbol_section_contents<32, false>(
+    const Stringpool*,
+    unsigned int,
+    const std::vector<Symbol*>&,
+    unsigned char**,
+    unsigned int*
+    ACCEPT_SIZE_ENDIAN_EXPLICIT(32, false)) const;
+
+template
+void
+Versions::symbol_section_contents<32, true>(
+    const Stringpool*,
+    unsigned int,
+    const std::vector<Symbol*>&,
+    unsigned char**,
+    unsigned int*
+    ACCEPT_SIZE_ENDIAN_EXPLICIT(32, true)) const;
+
+template
+void
+Versions::symbol_section_contents<64, false>(
+    const Stringpool*,
+    unsigned int,
+    const std::vector<Symbol*>&,
+    unsigned char**,
+    unsigned int*
+    ACCEPT_SIZE_ENDIAN_EXPLICIT(64, false)) const;
+
+template
+void
+Versions::symbol_section_contents<64, true>(
+    const Stringpool*,
+    unsigned int,
+    const std::vector<Symbol*>&,
+    unsigned char**,
+    unsigned int*
+    ACCEPT_SIZE_ENDIAN_EXPLICIT(64, true)) const;
+
+template
+void
+Versions::def_section_contents<32, false>(
+    const Stringpool*,
+    unsigned char**,
+    unsigned int*,
+    unsigned int*
+    ACCEPT_SIZE_ENDIAN_EXPLICIT(32, false)) const;
+
+template
+void
+Versions::def_section_contents<32, true>(
+    const Stringpool*,
+    unsigned char**,
+    unsigned int*,
+    unsigned int*
+    ACCEPT_SIZE_ENDIAN_EXPLICIT(32, true)) const;
+
+template
+void
+Versions::def_section_contents<64, false>(
+    const Stringpool*,
+    unsigned char**,
+    unsigned int*,
+    unsigned int*
+    ACCEPT_SIZE_ENDIAN_EXPLICIT(64, false)) const;
+
+template
+void
+Versions::def_section_contents<64, true>(
+    const Stringpool*,
+    unsigned char**,
+    unsigned int*,
+    unsigned int*
+    ACCEPT_SIZE_ENDIAN_EXPLICIT(64, true)) const;
+
+template
+void
+Versions::need_section_contents<32, false>(
+    const Stringpool*,
+    unsigned char**,
+    unsigned int*,
+    unsigned int*
+    ACCEPT_SIZE_ENDIAN_EXPLICIT(32, false)) const;
+
+template
+void
+Versions::need_section_contents<32, true>(
+    const Stringpool*,
+    unsigned char**,
+    unsigned int*,
+    unsigned int*
+    ACCEPT_SIZE_ENDIAN_EXPLICIT(32, true)) const;
+
+template
+void
+Versions::need_section_contents<64, false>(
+    const Stringpool*,
+    unsigned char**,
+    unsigned int*,
+    unsigned int*
+    ACCEPT_SIZE_ENDIAN_EXPLICIT(64, false)) const;
+
+template
+void
+Versions::need_section_contents<64, true>(
+    const Stringpool*,
+    unsigned char**,
+    unsigned int*,
+    unsigned int*
+    ACCEPT_SIZE_ENDIAN_EXPLICIT(64, true)) const;
+
+} // End namespace gold.