PR 6716
[binutils-gdb.git] / gold / object.cc
index c1ddae4c4b214c755b26d74a1725793983a138d9..d8f5ec8027492d2178404413e4f352d7b8dd05fc 100644 (file)
@@ -33,6 +33,7 @@
 #include "layout.h"
 #include "output.h"
 #include "symtab.h"
+#include "cref.h"
 #include "reloc.h"
 #include "object.h"
 #include "dynobj.h"
 namespace gold
 {
 
+// Class Xindex.
+
+// Initialize the symtab_xindex_ array.  Find the SHT_SYMTAB_SHNDX
+// section and read it in.  SYMTAB_SHNDX is the index of the symbol
+// table we care about.
+
+template<int size, bool big_endian>
+void
+Xindex::initialize_symtab_xindex(Object* object, unsigned int symtab_shndx)
+{
+  if (!this->symtab_xindex_.empty())
+    return;
+
+  gold_assert(symtab_shndx != 0);
+
+  // Look through the sections in reverse order, on the theory that it
+  // is more likely to be near the end than the beginning.
+  unsigned int i = object->shnum();
+  while (i > 0)
+    {
+      --i;
+      if (object->section_type(i) == elfcpp::SHT_SYMTAB_SHNDX
+         && this->adjust_shndx(object->section_link(i)) == symtab_shndx)
+       {
+         this->read_symtab_xindex<size, big_endian>(object, i, NULL);
+         return;
+       }
+    }
+
+  object->error(_("missing SHT_SYMTAB_SHNDX section"));
+}
+
+// Read in the symtab_xindex_ array, given the section index of the
+// SHT_SYMTAB_SHNDX section.  If PSHDRS is not NULL, it points at the
+// section headers.
+
+template<int size, bool big_endian>
+void
+Xindex::read_symtab_xindex(Object* object, unsigned int xindex_shndx,
+                          const unsigned char* pshdrs)
+{
+  section_size_type bytecount;
+  const unsigned char* contents;
+  if (pshdrs == NULL)
+    contents = object->section_contents(xindex_shndx, &bytecount, false);
+  else
+    {
+      const unsigned char* p = (pshdrs
+                               + (xindex_shndx
+                                  * elfcpp::Elf_sizes<size>::shdr_size));
+      typename elfcpp::Shdr<size, big_endian> shdr(p);
+      bytecount = convert_to_section_size_type(shdr.get_sh_size());
+      contents = object->get_view(shdr.get_sh_offset(), bytecount, true, false);
+    }
+
+  gold_assert(this->symtab_xindex_.empty());
+  this->symtab_xindex_.reserve(bytecount / 4);
+  for (section_size_type i = 0; i < bytecount; i += 4)
+    {
+      unsigned int shndx = elfcpp::Swap<32, big_endian>::readval(contents + i);
+      // We preadjust the section indexes we save.
+      this->symtab_xindex_.push_back(this->adjust_shndx(shndx));
+    }
+}
+
+// Symbol symndx has a section of SHN_XINDEX; return the real section
+// index.
+
+unsigned int
+Xindex::sym_xindex_to_shndx(Object* object, unsigned int symndx)
+{
+  if (symndx >= this->symtab_xindex_.size())
+    {
+      object->error(_("symbol %u out of range for SHT_SYMTAB_SHNDX section"),
+                   symndx);
+      return elfcpp::SHN_UNDEF;
+    }
+  unsigned int shndx = this->symtab_xindex_[symndx];
+  if (shndx < elfcpp::SHN_LORESERVE || shndx >= object->shnum())
+    {
+      object->error(_("extended index for symbol %u out of range: %u"),
+                   symndx, shndx);
+      return elfcpp::SHN_UNDEF;
+    }
+  return shndx;
+}
+
 // Class Object.
 
 // Set the target based on fields in the ELF file header.
@@ -158,10 +246,13 @@ Sized_relobj<size, big_endian>::Sized_relobj(
     output_local_symbol_count_(0),
     output_local_dynsym_count_(0),
     symbols_(),
+    defined_count_(0),
     local_symbol_offset_(0),
     local_dynsym_offset_(0),
     local_values_(),
     local_got_offsets_(),
+    kept_comdat_sections_(),
+    comdat_groups_(),
     has_eh_frame_(false)
 {
 }
@@ -204,6 +295,8 @@ Sized_relobj<size, big_endian>::find_symtab(const unsigned char* pshdrs)
       // to put the symbol table at the end.
       const unsigned char* p = pshdrs + shnum * This::shdr_size;
       unsigned int i = shnum;
+      unsigned int xindex_shndx = 0;
+      unsigned int xindex_link = 0;
       while (i > 0)
        {
          --i;
@@ -212,12 +305,43 @@ Sized_relobj<size, big_endian>::find_symtab(const unsigned char* pshdrs)
          if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
            {
              this->symtab_shndx_ = i;
+             if (xindex_shndx > 0 && xindex_link == i)
+               {
+                 Xindex* xindex =
+                   new Xindex(this->elf_file_.large_shndx_offset());
+                 xindex->read_symtab_xindex<size, big_endian>(this,
+                                                              xindex_shndx,
+                                                              pshdrs);
+                 this->set_xindex(xindex);
+               }
              break;
            }
+
+         // Try to pick up the SHT_SYMTAB_SHNDX section, if there is
+         // one.  This will work if it follows the SHT_SYMTAB
+         // section.
+         if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB_SHNDX)
+           {
+             xindex_shndx = i;
+             xindex_link = this->adjust_shndx(shdr.get_sh_link());
+           }
        }
     }
 }
 
+// Return the Xindex structure to use for object with lots of
+// sections.
+
+template<int size, bool big_endian>
+Xindex*
+Sized_relobj<size, big_endian>::do_initialize_xindex()
+{
+  gold_assert(this->symtab_shndx_ != -1U);
+  Xindex* xindex = new Xindex(this->elf_file_.large_shndx_offset());
+  xindex->initialize_symtab_xindex<size, big_endian>(this, this->symtab_shndx_);
+  return xindex;
+}
+
 // Return whether SHDR has the right type and flags to be a GNU
 // .eh_frame section.
 
@@ -226,8 +350,7 @@ bool
 Sized_relobj<size, big_endian>::check_eh_frame_flags(
     const elfcpp::Shdr<size, big_endian>* shdr) const
 {
-  return (shdr->get_sh_size() > 0
-         && shdr->get_sh_type() == elfcpp::SHT_PROGBITS
+  return (shdr->get_sh_type() == elfcpp::SHT_PROGBITS
          && (shdr->get_sh_flags() & elfcpp::SHF_ALLOC) != 0);
 }
 
@@ -321,10 +444,16 @@ Sized_relobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
   off_t readoff = this->has_eh_frame_ ? dataoff : extoff;
   section_size_type readsize = this->has_eh_frame_ ? datasize : extsize;
 
+  if (readsize == 0)
+    {
+      // No external symbols.  Also weird but also legal.
+      return;
+    }
+
   File_view* fvsymtab = this->get_lasting_view(readoff, readsize, true, false);
 
   // Read the section header for the symbol names.
-  unsigned int strtab_shndx = symtabshdr.get_sh_link();
+  unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
   if (strtab_shndx >= this->shnum())
     {
       this->error(_("invalid symbol table name index: %u"), strtab_shndx);
@@ -352,14 +481,17 @@ Sized_relobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
 }
 
 // Return the section index of symbol SYM.  Set *VALUE to its value in
-// the object file.  Note that for a symbol which is not defined in
-// this object file, this will set *VALUE to 0 and return SHN_UNDEF;
-// it will not return the final value of the symbol in the link.
+// the object file.  Set *IS_ORDINARY if this is an ordinary section
+// index.  not a special cod between SHN_LORESERVE and SHN_HIRESERVE.
+// Note that for a symbol which is not defined in this object file,
+// this will set *VALUE to 0 and return SHN_UNDEF; it will not return
+// the final value of the symbol in the link.
 
 template<int size, bool big_endian>
 unsigned int
 Sized_relobj<size, big_endian>::symbol_section_and_value(unsigned int sym,
-                                                        Address* value)
+                                                        Address* value,
+                                                        bool* is_ordinary)
 {
   section_size_type symbols_size;
   const unsigned char* symbols = this->section_contents(this->symtab_shndx_,
@@ -371,8 +503,8 @@ Sized_relobj<size, big_endian>::symbol_section_and_value(unsigned int sym,
 
   elfcpp::Sym<size, big_endian> elfsym(symbols + sym * This::sym_size);
   *value = elfsym.get_st_value();
-  // FIXME: Handle SHN_XINDEX.
-  return elfsym.get_st_shndx();
+
+  return this->adjust_sym_shndx(sym, elfsym.get_st_shndx(), is_ordinary);
 }
 
 // Return whether to include a section group in the link.  LAYOUT is
@@ -388,10 +520,13 @@ Sized_relobj<size, big_endian>::include_section_group(
     Layout* layout,
     unsigned int index,
     const char* name,
-    const elfcpp::Shdr<size, big_endian>& shdr,
+    const unsigned char* shdrs,
+    const char* section_names,
+    section_size_type section_names_size,
     std::vector<bool>* omit)
 {
   // Read the section contents.
+  typename This::Shdr shdr(shdrs + index * This::shdr_size);
   const unsigned char* pcon = this->get_view(shdr.get_sh_offset(),
                                             shdr.get_sh_size(), true, false);
   const elfcpp::Elf_Word* pword =
@@ -409,17 +544,18 @@ Sized_relobj<size, big_endian>::include_section_group(
 
   // Get the appropriate symbol table header (this will normally be
   // the single SHT_SYMTAB section, but in principle it need not be).
-  const unsigned int link = shdr.get_sh_link();
+  const unsigned int link = this->adjust_shndx(shdr.get_sh_link());
   typename This::Shdr symshdr(this, this->elf_file_.section_header(link));
 
   // Read the symbol table entry.
-  if (shdr.get_sh_info() >= symshdr.get_sh_size() / This::sym_size)
+  unsigned int symndx = shdr.get_sh_info();
+  if (symndx >= symshdr.get_sh_size() / This::sym_size)
     {
       this->error(_("section group %u info %u out of range"),
-                 index, shdr.get_sh_info());
+                 index, symndx);
       return false;
     }
-  off_t symoff = symshdr.get_sh_offset() + shdr.get_sh_info() * This::sym_size;
+  off_t symoff = symshdr.get_sh_offset() + symndx * This::sym_size;
   const unsigned char* psym = this->get_view(symoff, This::sym_size, true,
                                             false);
   elfcpp::Sym<size, big_endian> sym(psym);
@@ -427,60 +563,135 @@ Sized_relobj<size, big_endian>::include_section_group(
   // Read the symbol table names.
   section_size_type symnamelen;
   const unsigned char* psymnamesu;
-  psymnamesu = this->section_contents(symshdr.get_sh_link(), &symnamelen,
-                                     true);
+  psymnamesu = this->section_contents(this->adjust_shndx(symshdr.get_sh_link()),
+                                     &symnamelen, true);
   const char* psymnames = reinterpret_cast<const char*>(psymnamesu);
 
   // Get the section group signature.
   if (sym.get_st_name() >= symnamelen)
     {
       this->error(_("symbol %u name offset %u out of range"),
-                 shdr.get_sh_info(), sym.get_st_name());
+                 symndx, sym.get_st_name());
       return false;
     }
 
-  const char* signature = psymnames + sym.get_st_name();
+  std::string signature(psymnames + sym.get_st_name());
 
   // It seems that some versions of gas will create a section group
   // associated with a section symbol, and then fail to give a name to
   // the section symbol.  In such a case, use the name of the section.
-  // FIXME.
-  std::string secname;
   if (signature[0] == '\0' && sym.get_st_type() == elfcpp::STT_SECTION)
     {
-      secname = this->section_name(sym.get_st_shndx());
-      signature = secname.c_str();
+      bool is_ordinary;
+      unsigned int sym_shndx = this->adjust_sym_shndx(symndx,
+                                                     sym.get_st_shndx(),
+                                                     &is_ordinary);
+      if (!is_ordinary || sym_shndx >= this->shnum())
+       {
+         this->error(_("symbol %u invalid section index %u"),
+                     symndx, sym_shndx);
+         return false;
+       }
+      typename This::Shdr member_shdr(shdrs + sym_shndx * This::shdr_size);
+      if (member_shdr.get_sh_name() < section_names_size)
+        signature = section_names + member_shdr.get_sh_name();
     }
 
-  // Record this section group, and see whether we've already seen one
-  // with the same signature.
+  // Record this section group in the layout, and see whether we've already
+  // seen one with the same signature.
+  bool include_group = ((flags & elfcpp::GRP_COMDAT) == 0
+                        || layout->add_comdat(this, index, signature, true));
+
+  Sized_relobj<size, big_endian>* kept_object = NULL;
+  Comdat_group* kept_group = NULL;
 
-  if ((flags & elfcpp::GRP_COMDAT) == 0
-      || layout->add_comdat(signature, true))
+  if (!include_group)
     {
-      if (parameters->options().relocatable())
-       layout->layout_group(symtab, this, index, name, signature, shdr,
-                            pword);
-      return true;
+      // This group is being discarded.  Find the object and group
+      // that was kept in its place.
+      unsigned int kept_group_index = 0;
+      Relobj* kept_relobj = layout->find_kept_object(signature,
+                                                     &kept_group_index);
+      kept_object = static_cast<Sized_relobj<size, big_endian>*>(kept_relobj);
+      if (kept_object != NULL)
+        kept_group = kept_object->find_comdat_group(kept_group_index);
+    }
+  else if (flags & elfcpp::GRP_COMDAT)
+    {
+      // This group is being kept.  Create the table to map section names
+      // to section indexes and add it to the table of groups.
+      kept_group = new Comdat_group();
+      this->add_comdat_group(index, kept_group);
     }
 
-  // This is a duplicate.  We want to discard the sections in this
-  // group.
   size_t count = shdr.get_sh_size() / sizeof(elfcpp::Elf_Word);
+
+  std::vector<unsigned int> shndxes;
+  bool relocate_group = include_group && parameters->options().relocatable();
+  if (relocate_group)
+    shndxes.reserve(count - 1);
+
   for (size_t i = 1; i < count; ++i)
     {
       elfcpp::Elf_Word secnum =
-       elfcpp::Swap<32, big_endian>::readval(pword + i);
+       this->adjust_shndx(elfcpp::Swap<32, big_endian>::readval(pword + i));
+
+      if (relocate_group)
+       shndxes.push_back(secnum);
+
       if (secnum >= this->shnum())
        {
          this->error(_("section %u in section group %u out of range"),
                      secnum, index);
          continue;
        }
-      (*omit)[secnum] = true;
+
+      // Check for an earlier section number, since we're going to get
+      // it wrong--we may have already decided to include the section.
+      if (secnum < index)
+        this->error(_("invalid section group %u refers to earlier section %u"),
+                    index, secnum);
+
+      // Get the name of the member section.
+      typename This::Shdr member_shdr(shdrs + secnum * This::shdr_size);
+      if (member_shdr.get_sh_name() >= section_names_size)
+        {
+          // This is an error, but it will be diagnosed eventually
+          // in do_layout, so we don't need to do anything here but
+          // ignore it.
+          continue;
+        }
+      std::string mname(section_names + member_shdr.get_sh_name());
+
+      if (!include_group)
+        {
+          (*omit)[secnum] = true;
+          if (kept_group != NULL)
+            {
+              // Find the corresponding kept section, and store that info
+              // in the discarded section table.
+              Comdat_group::const_iterator p = kept_group->find(mname);
+              if (p != kept_group->end())
+                {
+                  Kept_comdat_section* kept =
+                    new Kept_comdat_section(kept_object, p->second);
+                  this->set_kept_comdat_section(secnum, kept);
+                }
+            }
+        }
+      else if (flags & elfcpp::GRP_COMDAT)
+        {
+          // Add the section to the kept group table.
+          gold_assert(kept_group != NULL);
+          kept_group->insert(std::make_pair(mname, secnum));
+        }
     }
 
-  return false;
+  if (relocate_group)
+    layout->layout_group(symtab, this, index, name, signature.c_str(),
+                        shdr, flags, &shndxes);
+
+  return include_group;
 }
 
 // Whether to include a linkonce section in the link.  NAME is the
@@ -502,6 +713,7 @@ template<int size, bool big_endian>
 bool
 Sized_relobj<size, big_endian>::include_linkonce_section(
     Layout* layout,
+    unsigned int index,
     const char* name,
     const elfcpp::Shdr<size, big_endian>&)
 {
@@ -519,8 +731,56 @@ Sized_relobj<size, big_endian>::include_linkonce_section(
     symname = name + strlen(linkonce_t);
   else
     symname = strrchr(name, '.') + 1;
-  bool include1 = layout->add_comdat(symname, false);
-  bool include2 = layout->add_comdat(name, true);
+  std::string sig1(symname);
+  std::string sig2(name);
+  bool include1 = layout->add_comdat(this, index, sig1, false);
+  bool include2 = layout->add_comdat(this, index, sig2, true);
+
+  if (!include2)
+    {
+      // The section is being discarded on the basis of its section
+      // name (i.e., the kept section was also a linkonce section).
+      // In this case, the section index stored with the layout object
+      // is the linkonce section that was kept.
+      unsigned int kept_group_index = 0;
+      Relobj* kept_relobj = layout->find_kept_object(sig2, &kept_group_index);
+      if (kept_relobj != NULL)
+        {
+          Sized_relobj<size, big_endian>* kept_object
+              = static_cast<Sized_relobj<size, big_endian>*>(kept_relobj);
+          Kept_comdat_section* kept =
+            new Kept_comdat_section(kept_object, kept_group_index);
+          this->set_kept_comdat_section(index, kept);
+        }
+    }
+  else if (!include1)
+    {
+      // The section is being discarded on the basis of its symbol
+      // name.  This means that the corresponding kept section was
+      // part of a comdat group, and it will be difficult to identify
+      // the specific section within that group that corresponds to
+      // this linkonce section.  We'll handle the simple case where
+      // the group has only one member section.  Otherwise, it's not
+      // worth the effort.
+      unsigned int kept_group_index = 0;
+      Relobj* kept_relobj = layout->find_kept_object(sig1, &kept_group_index);
+      if (kept_relobj != NULL)
+        {
+          Sized_relobj<size, big_endian>* kept_object =
+              static_cast<Sized_relobj<size, big_endian>*>(kept_relobj);
+          Comdat_group* kept_group =
+            kept_object->find_comdat_group(kept_group_index);
+          if (kept_group != NULL && kept_group->size() == 1)
+            {
+              Comdat_group::const_iterator p = kept_group->begin();
+              gold_assert(p != kept_group->end());
+              Kept_comdat_section* kept =
+                new Kept_comdat_section(kept_object, p->second);
+              this->set_kept_comdat_section(index, kept);
+            }
+        }
+    }
+
   return include1 && include2;
 }
 
@@ -540,7 +800,8 @@ Sized_relobj<size, big_endian>::do_layout(Symbol_table* symtab,
     return;
 
   // Get the section headers.
-  const unsigned char* pshdrs = sd->section_headers->data();
+  const unsigned char* shdrs = sd->section_headers->data();
+  const unsigned char* pshdrs;
 
   // Get the section names.
   const unsigned char* pnamesu = sd->section_names->data();
@@ -552,7 +813,7 @@ Sized_relobj<size, big_endian>::do_layout(Symbol_table* symtab,
   std::vector<unsigned int> reloc_shndx(shnum, 0);
   std::vector<unsigned int> reloc_type(shnum, elfcpp::SHT_NULL);
   // Skip the first, dummy, section.
-  pshdrs += This::shdr_size;
+  pshdrs = shdrs + This::shdr_size;
   for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
     {
       typename This::Shdr shdr(pshdrs);
@@ -560,7 +821,7 @@ Sized_relobj<size, big_endian>::do_layout(Symbol_table* symtab,
       unsigned int sh_type = shdr.get_sh_type();
       if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
        {
-         unsigned int target_shndx = shdr.get_sh_info();
+         unsigned int target_shndx = this->adjust_shndx(shdr.get_sh_info());
          if (target_shndx == 0 || target_shndx >= shnum)
            {
              this->error(_("relocation section %u has bad info %u"),
@@ -578,8 +839,11 @@ Sized_relobj<size, big_endian>::do_layout(Symbol_table* symtab,
        }
     }
 
-  std::vector<Map_to_output>& map_sections(this->map_to_output());
-  map_sections.resize(shnum);
+  Output_sections& out_sections(this->output_sections());
+  std::vector<Address>& out_section_offsets(this->section_offsets_);
+
+  out_sections.resize(shnum);
+  out_section_offsets.resize(shnum);
 
   // If we are only linking for symbols, then there is nothing else to
   // do here.
@@ -610,7 +874,7 @@ Sized_relobj<size, big_endian>::do_layout(Symbol_table* symtab,
   std::vector<unsigned int> eh_frame_sections;
 
   // Skip the first, dummy, section.
-  pshdrs = sd->section_headers->data() + This::shdr_size;
+  pshdrs = shdrs + This::shdr_size;
   for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size)
     {
       typename This::Shdr shdr(pshdrs);
@@ -645,14 +909,15 @@ Sized_relobj<size, big_endian>::do_layout(Symbol_table* symtab,
        {
          if (shdr.get_sh_type() == elfcpp::SHT_GROUP)
            {
-             if (!this->include_section_group(symtab, layout, i, name, shdr,
+             if (!this->include_section_group(symtab, layout, i, name, shdrs,
+                                              pnames, sd->section_names_size,
                                               &omit))
                discard = true;
            }
           else if ((shdr.get_sh_flags() & elfcpp::SHF_GROUP) == 0
                    && Layout::is_linkonce(name))
            {
-             if (!this->include_linkonce_section(layout, name, shdr))
+             if (!this->include_linkonce_section(layout, i, name, shdr))
                discard = true;
            }
        }
@@ -660,7 +925,8 @@ Sized_relobj<size, big_endian>::do_layout(Symbol_table* symtab,
       if (discard)
        {
          // Do not include this section in the link.
-         map_sections[i].output_section = NULL;
+         out_sections[i] = NULL;
+          out_section_offsets[i] = -1U;
          continue;
        }
 
@@ -699,8 +965,11 @@ Sized_relobj<size, big_endian>::do_layout(Symbol_table* symtab,
                                          reloc_shndx[i], reloc_type[i],
                                          &offset);
 
-      map_sections[i].output_section = os;
-      map_sections[i].offset = offset;
+      out_sections[i] = os;
+      if (offset == -1)
+        out_section_offsets[i] = -1U;
+      else
+        out_section_offsets[i] = convert_types<Address, off_t>(offset);
 
       // If this section requires special handling, and if there are
       // relocs that apply to it, then we must do the special handling
@@ -724,17 +993,18 @@ Sized_relobj<size, big_endian>::do_layout(Symbol_table* symtab,
       pshdr = sd->section_headers->data() + i * This::shdr_size;
       typename This::Shdr shdr(pshdr);
 
-      unsigned int data_shndx = shdr.get_sh_info();
+      unsigned int data_shndx = this->adjust_shndx(shdr.get_sh_info());
       if (data_shndx >= shnum)
        {
          // We already warned about this above.
          continue;
        }
 
-      Output_section* data_section = map_sections[data_shndx].output_section;
+      Output_section* data_section = out_sections[data_shndx];
       if (data_section == NULL)
        {
-         map_sections[i].output_section = NULL;
+         out_sections[i] = NULL;
+          out_section_offsets[i] = -1U;
          continue;
        }
 
@@ -743,8 +1013,8 @@ Sized_relobj<size, big_endian>::do_layout(Symbol_table* symtab,
 
       Output_section* os = layout->layout_reloc(this, i, shdr, data_section,
                                                rr);
-      map_sections[i].output_section = os;
-      map_sections[i].offset = -1;
+      out_sections[i] = os;
+      out_section_offsets[i] = -1U;
     }
 
   // Handle the .eh_frame sections at the end.
@@ -770,8 +1040,11 @@ Sized_relobj<size, big_endian>::do_layout(Symbol_table* symtab,
                                                   reloc_shndx[i],
                                                   reloc_type[i],
                                                   &offset);
-      map_sections[i].output_section = os;
-      map_sections[i].offset = offset;
+      out_sections[i] = os;
+      if (offset == -1)
+        out_section_offsets[i] = -1U;
+      else
+        out_section_offsets[i] = convert_types<Address, off_t>(offset);
 
       // If this section requires special handling, and if there are
       // relocs that apply to it, then we must do the special handling
@@ -814,8 +1087,10 @@ Sized_relobj<size, big_endian>::do_add_symbols(Symbol_table* symtab,
     reinterpret_cast<const char*>(sd->symbol_names->data());
   symtab->add_from_relobj(this,
                          sd->symbols->data() + sd->external_symbols_offset,
-                         symcount, sym_names, sd->symbol_names_size,
-                         &this->symbols_);
+                         symcount, this->local_symbol_count_,
+                         sym_names, sd->symbol_names_size,
+                         &this->symbols_,
+                         &this->defined_count_);
 
   delete sd->symbols;
   sd->symbols = NULL;
@@ -856,7 +1131,8 @@ Sized_relobj<size, big_endian>::do_count_local_symbols(Stringpool* pool,
                                              locsize, true, true);
 
   // Read the symbol names.
-  const unsigned int strtab_shndx = symtabshdr.get_sh_link();
+  const unsigned int strtab_shndx =
+    this->adjust_shndx(symtabshdr.get_sh_link());
   section_size_type strtab_size;
   const unsigned char* pnamesu = this->section_contents(strtab_shndx,
                                                        &strtab_size,
@@ -865,7 +1141,7 @@ Sized_relobj<size, big_endian>::do_count_local_symbols(Stringpool* pool,
 
   // Loop over the local symbols.
 
-  const std::vector<Map_to_output>& mo(this->map_to_output());
+  const Output_sections& out_sections(this->output_sections());
   unsigned int shnum = this->shnum();
   unsigned int count = 0;
   unsigned int dyncount = 0;
@@ -877,8 +1153,10 @@ Sized_relobj<size, big_endian>::do_count_local_symbols(Stringpool* pool,
 
       Symbol_value<size>& lv(this->local_values_[i]);
 
-      unsigned int shndx = sym.get_st_shndx();
-      lv.set_input_shndx(shndx);
+      bool is_ordinary;
+      unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
+                                                 &is_ordinary);
+      lv.set_input_shndx(shndx, is_ordinary);
 
       if (sym.get_st_type() == elfcpp::STT_SECTION)
        lv.set_is_section_symbol();
@@ -890,7 +1168,7 @@ Sized_relobj<size, big_endian>::do_count_local_symbols(Stringpool* pool,
 
       // Decide whether this symbol should go into the output file.
 
-      if (shndx < shnum && mo[shndx].output_section == NULL)
+      if (shndx < shnum && out_sections[shndx] == NULL)
         {
          lv.set_no_output_symtab_entry();
           gold_assert(!lv.needs_output_dynsym_entry());
@@ -938,31 +1216,32 @@ Sized_relobj<size, big_endian>::do_count_local_symbols(Stringpool* pool,
 template<int size, bool big_endian>
 unsigned int
 Sized_relobj<size, big_endian>::do_finalize_local_symbols(unsigned int index,
-                                                          off_t off)
+                                                         off_t off)
 {
   gold_assert(off == static_cast<off_t>(align_address(off, size >> 3)));
 
   const unsigned int loccount = this->local_symbol_count_;
   this->local_symbol_offset_ = off;
 
-  const std::vector<Map_to_output>& mo(this->map_to_output());
+  const Output_sections& out_sections(this->output_sections());
+  const std::vector<Address>& out_offsets(this->section_offsets_);
   unsigned int shnum = this->shnum();
 
   for (unsigned int i = 1; i < loccount; ++i)
     {
       Symbol_value<size>& lv(this->local_values_[i]);
 
-      unsigned int shndx = lv.input_shndx();
+      bool is_ordinary;
+      unsigned int shndx = lv.input_shndx(&is_ordinary);
 
       // Set the output symbol value.
-      
-      if (shndx >= elfcpp::SHN_LORESERVE)
+
+      if (!is_ordinary)
        {
          if (shndx == elfcpp::SHN_ABS || shndx == elfcpp::SHN_COMMON)
            lv.set_output_value(lv.input_value());
          else
            {
-             // FIXME: Handle SHN_XINDEX.
              this->error(_("unknown section index %u for local symbol %u"),
                          shndx, i);
              lv.set_output_value(0);
@@ -977,14 +1256,17 @@ Sized_relobj<size, big_endian>::do_finalize_local_symbols(unsigned int index,
              shndx = 0;
            }
 
-         Output_section* os = mo[shndx].output_section;
+         Output_section* os = out_sections[shndx];
 
          if (os == NULL)
            {
-             lv.set_output_value(0);
+              // This local symbol belongs to a section we are discarding.
+              // In some cases when applying relocations later, we will
+              // attempt to match it to the corresponding kept section,
+              // so we leave the input value unchanged here.
              continue;
            }
-         else if (mo[shndx].offset == -1)
+         else if (out_offsets[shndx] == -1U)
            {
              // This is a SHF_MERGE section or one which otherwise
              // requires special handling.  We get the output address
@@ -1007,11 +1289,11 @@ Sized_relobj<size, big_endian>::do_finalize_local_symbols(unsigned int index,
            }
           else if (lv.is_tls_symbol())
            lv.set_output_value(os->tls_offset()
-                               + mo[shndx].offset
+                               + out_offsets[shndx]
                                + lv.input_value());
          else
            lv.set_output_value(os->address()
-                               + mo[shndx].offset
+                               + out_offsets[shndx]
                                + lv.input_value());
        }
 
@@ -1063,7 +1345,9 @@ void
 Sized_relobj<size, big_endian>::write_local_symbols(
     Output_file* of,
     const Stringpool* sympool,
-    const Stringpool* dynpool)
+    const Stringpool* dynpool,
+    Output_symtab_xindex* symtab_xindex,
+    Output_symtab_xindex* dynsym_xindex)
 {
   if (parameters->options().strip_all()
       && this->output_local_dynsym_count_ == 0)
@@ -1091,7 +1375,8 @@ Sized_relobj<size, big_endian>::write_local_symbols(
                                              locsize, true, false);
 
   // Read the symbol names.
-  const unsigned int strtab_shndx = symtabshdr.get_sh_link();
+  const unsigned int strtab_shndx =
+    this->adjust_shndx(symtabshdr.get_sh_link());
   section_size_type strtab_size;
   const unsigned char* pnamesu = this->section_contents(strtab_shndx,
                                                        &strtab_size,
@@ -1111,7 +1396,7 @@ Sized_relobj<size, big_endian>::write_local_symbols(
     dyn_oview = of->get_output_view(this->local_dynsym_offset_,
                                     dyn_output_size);
 
-  const std::vector<Map_to_output>& mo(this->map_to_output());
+  const Output_sections out_sections(this->output_sections());
 
   gold_assert(this->local_values_.size() == loccount);
 
@@ -1122,18 +1407,30 @@ Sized_relobj<size, big_endian>::write_local_symbols(
     {
       elfcpp::Sym<size, big_endian> isym(psyms);
 
-      unsigned int st_shndx = isym.get_st_shndx();
-      if (st_shndx < elfcpp::SHN_LORESERVE)
+      Symbol_value<size>& lv(this->local_values_[i]);
+
+      bool is_ordinary;
+      unsigned int st_shndx = this->adjust_sym_shndx(i, isym.get_st_shndx(),
+                                                    &is_ordinary);
+      if (is_ordinary)
        {
-         gold_assert(st_shndx < mo.size());
-         if (mo[st_shndx].output_section == NULL)
+         gold_assert(st_shndx < out_sections.size());
+         if (out_sections[st_shndx] == NULL)
            continue;
-         st_shndx = mo[st_shndx].output_section->out_shndx();
+         st_shndx = out_sections[st_shndx]->out_shndx();
+         if (st_shndx >= elfcpp::SHN_LORESERVE)
+           {
+             if (lv.needs_output_symtab_entry())
+               symtab_xindex->add(lv.output_symtab_index(), st_shndx);
+             if (lv.needs_output_dynsym_entry())
+               dynsym_xindex->add(lv.output_dynsym_index(), st_shndx);
+             st_shndx = elfcpp::SHN_XINDEX;
+           }
        }
 
       // Write the symbol to the output symbol table.
       if (!parameters->options().strip_all()
-         && this->local_values_[i].needs_output_symtab_entry())
+         && lv.needs_output_symtab_entry())
         {
           elfcpp::Sym_write<size, big_endian> osym(ov);
 
@@ -1150,7 +1447,7 @@ Sized_relobj<size, big_endian>::write_local_symbols(
         }
 
       // Write the symbol to the output dynamic symbol table.
-      if (this->local_values_[i].needs_output_dynsym_entry())
+      if (lv.needs_output_dynsym_entry())
         {
           gold_assert(dyn_ov < dyn_oview + dyn_output_size);
           elfcpp::Sym_write<size, big_endian> osym(dyn_ov);
@@ -1202,7 +1499,8 @@ Sized_relobj<size, big_endian>::get_symbol_location_info(
                                                        &symbols_size,
                                                        false);
 
-  unsigned int symbol_names_shndx = this->section_link(this->symtab_shndx_);
+  unsigned int symbol_names_shndx =
+    this->adjust_shndx(this->section_link(this->symtab_shndx_));
   section_size_type names_size;
   const unsigned char* symbol_names_u =
     this->section_contents(symbol_names_shndx, &names_size, false);
@@ -1222,11 +1520,17 @@ Sized_relobj<size, big_endian>::get_symbol_location_info(
            info->source_file = "(invalid)";
          else
            info->source_file = symbol_names + sym.get_st_name();
+         continue;
        }
-      else if (sym.get_st_shndx() == shndx
-               && static_cast<off_t>(sym.get_st_value()) <= offset
-               && (static_cast<off_t>(sym.get_st_value() + sym.get_st_size())
-                   > offset))
+
+      bool is_ordinary;
+      unsigned int st_shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
+                                                    &is_ordinary);
+      if (is_ordinary
+         && st_shndx == shndx
+         && static_cast<off_t>(sym.get_st_value()) <= offset
+         && (static_cast<off_t>(sym.get_st_value() + sym.get_st_size())
+             > offset))
         {
           if (sym.get_st_name() > names_size)
            info->enclosing_symbol_name = "(invalid)";
@@ -1252,6 +1556,52 @@ Sized_relobj<size, big_endian>::get_symbol_location_info(
   return false;
 }
 
+// Look for a kept section corresponding to the given discarded section,
+// and return its output address.  This is used only for relocations in
+// debugging sections.  If we can't find the kept section, return 0.
+
+template<int size, bool big_endian>
+typename Sized_relobj<size, big_endian>::Address
+Sized_relobj<size, big_endian>::map_to_kept_section(
+    unsigned int shndx,
+    bool* found) const
+{
+  Kept_comdat_section *kept = this->get_kept_comdat_section(shndx);
+  if (kept != NULL)
+    {
+      gold_assert(kept->object_ != NULL);
+      *found = true;
+      Output_section* os = kept->object_->output_section(kept->shndx_);
+      Address offset = kept->object_->get_output_section_offset(kept->shndx_);
+      gold_assert(os != NULL && offset != -1U);
+      return os->address() + offset;
+    }
+  *found = false;
+  return 0;
+}
+
+// Get symbol counts.
+
+template<int size, bool big_endian>
+void
+Sized_relobj<size, big_endian>::do_get_global_symbol_counts(
+    const Symbol_table*,
+    size_t* defined,
+    size_t* used) const
+{
+  *defined = this->defined_count_;
+  size_t count = 0;
+  for (Symbols::const_iterator p = this->symbols_.begin();
+       p != this->symbols_.end();
+       ++p)
+    if (*p != NULL
+       && (*p)->source() == Symbol::FROM_OBJECT
+       && (*p)->object() == this
+       && (*p)->is_defined())
+      ++count;
+  *used = count;
+}
+
 // Input_objects methods.
 
 // Add a regular relocatable object to the list.  Return false if this
@@ -1270,6 +1620,10 @@ Input_objects::add_object(Object* obj)
       return false;
     }
 
+  // Print the filename if the -t/--trace option is selected.
+  if (parameters->options().trace())
+    gold_info("%s", obj->name().c_str());
+
   if (!obj->is_dynamic())
     this->relobj_list_.push_back(static_cast<Relobj*>(obj));
   else
@@ -1302,6 +1656,14 @@ Input_objects::add_object(Object* obj)
        }
     }
 
+  // Add this object to the cross-referencer if requested.
+  if (parameters->options().user_set_print_symbol_counts())
+    {
+      if (this->cref_ == NULL)
+       this->cref_ = new Cref();
+      this->cref_->add_object(obj);
+    }
+
   return true;
 }
 
@@ -1342,6 +1704,38 @@ Input_objects::check_dynamic_dependencies() const
     }
 }
 
+// Start processing an archive.
+
+void
+Input_objects::archive_start(Archive* archive)
+{
+  if (parameters->options().user_set_print_symbol_counts())
+    {
+      if (this->cref_ == NULL)
+       this->cref_ = new Cref();
+      this->cref_->add_archive_start(archive);
+    }
+}
+
+// Stop processing an archive.
+
+void
+Input_objects::archive_stop(Archive* archive)
+{
+  if (parameters->options().user_set_print_symbol_counts())
+    this->cref_->add_archive_stop(archive);
+}
+
+// Print symbol counts
+
+void
+Input_objects::print_symbol_counts(const Symbol_table* symtab) const
+{
+  if (parameters->options().user_set_print_symbol_counts()
+      && this->cref_ != NULL)
+    this->cref_->print_symbol_counts(symtab);
+}
+
 // Relocate_info methods.
 
 // Return a string describing the location of a relocation.  This is
@@ -1516,7 +1910,7 @@ make_elf_object(const std::string& name, Input_file* input_file, off_t offset,
     }
   else
     {
-      if (bytes < elfcpp::Elf_sizes<32>::ehdr_size)
+      if (bytes < elfcpp::Elf_sizes<64>::ehdr_size)
        {
          gold_error(_("%s: ELF file too short"), name.c_str());
          return NULL;