* object.cc (Sized_relobj_file::do_layout): Remove unused local
[deliverable/binutils-gdb.git] / gold / object.cc
index 795fa8bf1b0b96410084adb01bed77ede6f27892..99c2ca7a7bee5bcac7312280ecdcd349a878385a 100644 (file)
@@ -1,6 +1,6 @@
 // object.cc -- support for an object file for linking in gold
 
-// Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
+// Copyright 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
 // Written by Ian Lance Taylor <iant@google.com>.
 
 // This file is part of gold.
 #include "demangle.h"
 #include "libiberty.h"
 
+#include "gc.h"
 #include "target-select.h"
 #include "dwarf_reader.h"
 #include "layout.h"
 #include "output.h"
 #include "symtab.h"
+#include "cref.h"
 #include "reloc.h"
 #include "object.h"
 #include "dynobj.h"
+#include "plugin.h"
+#include "compressed_output.h"
+#include "incremental.h"
 
 namespace gold
 {
 
-// Class Object.
+// Struct Read_symbols_data.
+
+// Destroy any remaining File_view objects.
+
+Read_symbols_data::~Read_symbols_data()
+{
+  if (this->section_headers != NULL)
+    delete this->section_headers;
+  if (this->section_names != NULL)
+    delete this->section_names;
+  if (this->symbols != NULL)
+    delete this->symbols;
+  if (this->symbol_names != NULL)
+    delete this->symbol_names;
+  if (this->versym != NULL)
+    delete this->versym;
+  if (this->verdef != NULL)
+    delete this->verdef;
+  if (this->verneed != NULL)
+    delete this->verneed;
+}
+
+// Class Xindex.
 
-// Set the target based on fields in the ELF file header.
+// 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
-Object::set_target(int machine, int size, bool big_endian, int osabi,
-                  int abiversion)
+Xindex::initialize_symtab_xindex(Object* object, unsigned int symtab_shndx)
 {
-  Target* target = select_target(machine, size, big_endian, osabi, abiversion);
-  if (target == NULL)
-    gold_fatal(_("%s: unsupported ELF machine number %d"),
-              this->name().c_str(), machine);
-  this->target_ = target;
+  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.
+
 // Report an error for this object file.  This is used by the
 // elfcpp::Elf_file interface, and also called by the Object code
 // itself.
@@ -80,10 +181,15 @@ Object::section_contents(unsigned int shndx, section_size_type* plen,
 {
   Location loc(this->do_section_contents(shndx));
   *plen = convert_to_section_size_type(loc.data_size);
-  return this->get_view(loc.file_offset, *plen, cache);
+  if (*plen == 0)
+    {
+      static const unsigned char empty[1] = { '\0' };
+      return empty;
+    }
+  return this->get_view(loc.file_offset, *plen, true, cache);
 }
 
-// Read the section data into SD.  This is code common to Sized_relobj
+// Read the section data into SD.  This is code common to Sized_relobj_file
 // and Sized_dynobj, so we put it into Object.
 
 template<int size, bool big_endian>
@@ -96,7 +202,8 @@ Object::read_section_data(elfcpp::Elf_file<size, big_endian, Object>* elf_file,
   // Read the section headers.
   const off_t shoff = elf_file->shoff();
   const unsigned int shnum = this->shnum();
-  sd->section_headers = this->get_lasting_view(shoff, shnum * shdr_size, true);
+  sd->section_headers = this->get_lasting_view(shoff, shnum * shdr_size,
+                                              true, true);
 
   // Read the section names.
   const unsigned char* pshdrs = sd->section_headers->data();
@@ -110,7 +217,8 @@ Object::read_section_data(elfcpp::Elf_file<size, big_endian, Object>* elf_file,
   sd->section_names_size =
     convert_to_section_size_type(shdrnames.get_sh_size());
   sd->section_names = this->get_lasting_view(shdrnames.get_sh_offset(),
-                                            sd->section_names_size, false);
+                                            sd->section_names_size, false,
+                                            false);
 }
 
 // If NAME is the name of a special .gnu.warning section, arrange for
@@ -134,6 +242,12 @@ Object::handle_gnu_warning_section(const char* name, unsigned int shndx,
       section_size_type len;
       const unsigned char* contents = this->section_contents(shndx, &len,
                                                             false);
+      if (len == 0)
+       {
+         const char* warning = name + warn_prefix_len;
+         contents = reinterpret_cast<const unsigned char*>(warning);
+         len = strlen(warning);
+       }
       std::string warning(reinterpret_cast<const char*>(contents), len);
       symtab->add_warning(name + warn_prefix_len, this, warning);
       return true;
@@ -141,46 +255,187 @@ Object::handle_gnu_warning_section(const char* name, unsigned int shndx,
   return false;
 }
 
+// If NAME is the name of the special section which indicates that
+// this object was compiled with -fsplit-stack, mark it accordingly.
+
+bool
+Object::handle_split_stack_section(const char* name)
+{
+  if (strcmp(name, ".note.GNU-split-stack") == 0)
+    {
+      this->uses_split_stack_ = true;
+      return true;
+    }
+  if (strcmp(name, ".note.GNU-no-split-stack") == 0)
+    {
+      this->has_no_split_stack_ = true;
+      return true;
+    }
+  return false;
+}
+
+// Class Relobj
+
+// To copy the symbols data read from the file to a local data structure.
+// This function is called from do_layout only while doing garbage 
+// collection.
+
+void
+Relobj::copy_symbols_data(Symbols_data* gc_sd, Read_symbols_data* sd, 
+                          unsigned int section_header_size)
+{
+  gc_sd->section_headers_data = 
+         new unsigned char[(section_header_size)];
+  memcpy(gc_sd->section_headers_data, sd->section_headers->data(),
+         section_header_size);
+  gc_sd->section_names_data = 
+         new unsigned char[sd->section_names_size];
+  memcpy(gc_sd->section_names_data, sd->section_names->data(),
+         sd->section_names_size);
+  gc_sd->section_names_size = sd->section_names_size;
+  if (sd->symbols != NULL)
+    {
+      gc_sd->symbols_data = 
+             new unsigned char[sd->symbols_size];
+      memcpy(gc_sd->symbols_data, sd->symbols->data(),
+            sd->symbols_size);
+    }
+  else
+    {
+      gc_sd->symbols_data = NULL;
+    }
+  gc_sd->symbols_size = sd->symbols_size;
+  gc_sd->external_symbols_offset = sd->external_symbols_offset;
+  if (sd->symbol_names != NULL)
+    {
+      gc_sd->symbol_names_data =
+             new unsigned char[sd->symbol_names_size];
+      memcpy(gc_sd->symbol_names_data, sd->symbol_names->data(),
+            sd->symbol_names_size);
+    }
+  else
+    {
+      gc_sd->symbol_names_data = NULL;
+    }
+  gc_sd->symbol_names_size = sd->symbol_names_size;
+}
+
+// This function determines if a particular section name must be included
+// in the link.  This is used during garbage collection to determine the
+// roots of the worklist.
+
+bool
+Relobj::is_section_name_included(const char* name)
+{
+  if (is_prefix_of(".ctors", name) 
+      || is_prefix_of(".dtors", name) 
+      || is_prefix_of(".note", name) 
+      || is_prefix_of(".init", name) 
+      || is_prefix_of(".fini", name) 
+      || is_prefix_of(".gcc_except_table", name) 
+      || is_prefix_of(".jcr", name) 
+      || is_prefix_of(".preinit_array", name) 
+      || (is_prefix_of(".text", name) 
+          && strstr(name, "personality")) 
+      || (is_prefix_of(".data", name) 
+          &&  strstr(name, "personality")) 
+      || (is_prefix_of(".gnu.linkonce.d", name)
+         && strstr(name, "personality")))
+    {
+      return true; 
+    }
+  return false;
+}
+
+// Finalize the incremental relocation information.  Allocates a block
+// of relocation entries for each symbol, and sets the reloc_bases_
+// array to point to the first entry in each block.  If CLEAR_COUNTS
+// is TRUE, also clear the per-symbol relocation counters.
+
+void
+Relobj::finalize_incremental_relocs(Layout* layout, bool clear_counts)
+{
+  unsigned int nsyms = this->get_global_symbols()->size();
+  this->reloc_bases_ = new unsigned int[nsyms];
+
+  gold_assert(this->reloc_bases_ != NULL);
+  gold_assert(layout->incremental_inputs() != NULL);
+
+  unsigned int rindex = layout->incremental_inputs()->get_reloc_count();
+  for (unsigned int i = 0; i < nsyms; ++i)
+    {
+      this->reloc_bases_[i] = rindex;
+      rindex += this->reloc_counts_[i];
+      if (clear_counts)
+       this->reloc_counts_[i] = 0;
+    }
+  layout->incremental_inputs()->set_reloc_count(rindex);
+}
+
 // Class Sized_relobj.
 
+// Iterate over local symbols, calling a visitor class V for each GOT offset
+// associated with a local symbol.
+
+template<int size, bool big_endian>
+void
+Sized_relobj<size, big_endian>::do_for_all_local_got_entries(
+    Got_offset_list::Visitor* v) const
+{
+  unsigned int nsyms = this->local_symbol_count();
+  for (unsigned int i = 0; i < nsyms; i++)
+    {
+      Local_got_offsets::const_iterator p = this->local_got_offsets_.find(i);
+      if (p != this->local_got_offsets_.end())
+       {
+         const Got_offset_list* got_offsets = p->second;
+         got_offsets->for_all_got_offsets(v);
+       }
+    }
+}
+
+// Class Sized_relobj_file.
+
 template<int size, bool big_endian>
-Sized_relobj<size, big_endian>::Sized_relobj(
+Sized_relobj_file<size, big_endian>::Sized_relobj_file(
     const std::string& name,
     Input_file* input_file,
     off_t offset,
     const elfcpp::Ehdr<size, big_endian>& ehdr)
-  : Relobj(name, input_file, offset),
+  : Sized_relobj<size, big_endian>(name, input_file, offset),
     elf_file_(this, ehdr),
     symtab_shndx_(-1U),
     local_symbol_count_(0),
     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_(),
-    has_eh_frame_(false)
+    local_plt_offsets_(),
+    kept_comdat_sections_(),
+    has_eh_frame_(false),
+    discarded_eh_frame_shndx_(-1U),
+    deferred_layout_(),
+    deferred_layout_relocs_(),
+    compressed_sections_()
 {
+  this->e_type_ = ehdr.get_e_type();
 }
 
 template<int size, bool big_endian>
-Sized_relobj<size, big_endian>::~Sized_relobj()
+Sized_relobj_file<size, big_endian>::~Sized_relobj_file()
 {
 }
 
 // Set up an object file based on the file header.  This sets up the
-// target and reads the section information.
+// section information.
 
 template<int size, bool big_endian>
 void
-Sized_relobj<size, big_endian>::setup(
-    const elfcpp::Ehdr<size, big_endian>& ehdr)
+Sized_relobj_file<size, big_endian>::do_setup()
 {
-  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);
 }
@@ -192,7 +447,7 @@ Sized_relobj<size, big_endian>::setup(
 
 template<int size, bool big_endian>
 void
-Sized_relobj<size, big_endian>::find_symtab(const unsigned char* pshdrs)
+Sized_relobj_file<size, big_endian>::find_symtab(const unsigned char* pshdrs)
 {
   const unsigned int shnum = this->shnum();
   this->symtab_shndx_ = 0;
@@ -202,6 +457,8 @@ 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;
@@ -210,22 +467,54 @@ 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_file<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.
 
 template<int size, bool big_endian>
 bool
-Sized_relobj<size, big_endian>::check_eh_frame_flags(
+Sized_relobj_file<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
+  elfcpp::Elf_Word sh_type = shdr->get_sh_type();
+  return ((sh_type == elfcpp::SHT_PROGBITS
+          || sh_type == elfcpp::SHT_X86_64_UNWIND)
          && (shdr->get_sh_flags() & elfcpp::SHF_ALLOC) != 0);
 }
 
@@ -234,7 +523,7 @@ Sized_relobj<size, big_endian>::check_eh_frame_flags(
 
 template<int size, bool big_endian>
 bool
-Sized_relobj<size, big_endian>::find_eh_frame(
+Sized_relobj_file<size, big_endian>::find_eh_frame(
     const unsigned char* pshdrs,
     const char* names,
     section_size_type names_size) const
@@ -261,11 +550,55 @@ Sized_relobj<size, big_endian>::find_eh_frame(
   return false;
 }
 
+// Build a table for any compressed debug sections, mapping each section index
+// to the uncompressed size.
+
+template<int size, bool big_endian>
+Compressed_section_map*
+build_compressed_section_map(
+    const unsigned char* pshdrs,
+    unsigned int shnum,
+    const char* names,
+    section_size_type names_size,
+    Sized_relobj_file<size, big_endian>* obj)
+{
+  Compressed_section_map* uncompressed_sizes = new Compressed_section_map();
+  const unsigned int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
+  const unsigned char* p = pshdrs + shdr_size;
+  for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
+    {
+      typename elfcpp::Shdr<size, big_endian> shdr(p);
+      if (shdr.get_sh_type() == elfcpp::SHT_PROGBITS
+         && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
+       {
+         if (shdr.get_sh_name() >= names_size)
+           {
+             obj->error(_("bad section name offset for section %u: %lu"),
+                        i, static_cast<unsigned long>(shdr.get_sh_name()));
+             continue;
+           }
+
+         const char* name = names + shdr.get_sh_name();
+         if (is_compressed_debug_section(name))
+           {
+             section_size_type len;
+             const unsigned char* contents =
+                 obj->section_contents(i, &len, false);
+             uint64_t uncompressed_size = get_uncompressed_size(contents, len);
+             if (uncompressed_size != -1ULL)
+               (*uncompressed_sizes)[i] =
+                   convert_to_section_size_type(uncompressed_size);
+           }
+       }
+    }
+  return uncompressed_sizes;
+}
+
 // Read the sections and symbols from an object file.
 
 template<int size, bool big_endian>
 void
-Sized_relobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
+Sized_relobj_file<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
 {
   this->read_section_data(&this->elf_file_, sd);
 
@@ -280,6 +613,10 @@ Sized_relobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
       if (this->find_eh_frame(pshdrs, names, sd->section_names_size))
         this->has_eh_frame_ = true;
     }
+  if (memmem(names, sd->section_names_size, ".zdebug_", 8) != NULL)
+    this->compressed_sections_ =
+        build_compressed_section_map(pshdrs, this->shnum(), names,
+                                    sd->section_names_size, this);
 
   sd->symbols = NULL;
   sd->symbols_size = 0;
@@ -319,10 +656,16 @@ 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;
 
-  File_view* fvsymtab = this->get_lasting_view(readoff, readsize, false);
+  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);
@@ -338,7 +681,8 @@ Sized_relobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
 
   // Read the symbol names.
   File_view* fvstrtab = this->get_lasting_view(strtabshdr.get_sh_offset(),
-                                              strtabshdr.get_sh_size(), true);
+                                              strtabshdr.get_sh_size(),
+                                              false, true);
 
   sd->symbols = fvsymtab;
   sd->symbols_size = readsize;
@@ -349,14 +693,17 @@ 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 code 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)
+Sized_relobj_file<size, big_endian>::symbol_section_and_value(unsigned int sym,
+                                                             Address* value,
+                                                             bool* is_ordinary)
 {
   section_size_type symbols_size;
   const unsigned char* symbols = this->section_contents(this->symtab_shndx_,
@@ -368,8 +715,8 @@ 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
@@ -380,17 +727,20 @@ Sized_relobj<size, big_endian>::symbol_section_and_value(unsigned int sym,
 
 template<int size, bool big_endian>
 bool
-Sized_relobj<size, big_endian>::include_section_group(
+Sized_relobj_file<size, big_endian>::include_section_group(
     Symbol_table* symtab,
     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(), false);
+                                            shdr.get_sh_size(), true, false);
   const elfcpp::Elf_Word* pword =
     reinterpret_cast<const elfcpp::Elf_Word*>(pcon);
 
@@ -399,84 +749,186 @@ Sized_relobj<size, big_endian>::include_section_group(
   // just like ordinary sections.
   elfcpp::Elf_Word flags = elfcpp::Swap<32, big_endian>::readval(pword);
 
-  // Look up the group signature, which is the name of a symbol.  This
-  // is a lot of effort to go to to read a string.  Why didn't they
-  // just have the group signature point into the string table, rather
-  // than indirect through a symbol?
+  // Look up the group signature, which is the name of a symbol.  ELF
+  // uses a symbol name because some group signatures are long, and
+  // the name is generally already in the symbol table, so it makes
+  // sense to put the long string just once in .strtab rather than in
+  // both .strtab and .shstrtab.
 
   // 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;
-  const unsigned char* psym = this->get_view(symoff, This::sym_size, false);
+  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);
 
   // 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;
+  bool is_comdat;
+  Kept_section* kept_section = NULL;
 
-  if ((flags & elfcpp::GRP_COMDAT) == 0
-      || layout->add_comdat(signature, true))
+  if ((flags & elfcpp::GRP_COMDAT) == 0)
     {
-      if (parameters->options().relocatable())
-       layout->layout_group(symtab, this, index, name, signature, shdr,
-                            pword);
-      return true;
+      include_group = true;
+      is_comdat = false;
+    }
+  else
+    {
+      include_group = layout->find_or_add_kept_section(signature,
+                                                      this, index, true,
+                                                      true, &kept_section);
+      is_comdat = true;
+    }
+
+  if (is_comdat && include_group)
+    {
+      Incremental_inputs* incremental_inputs = layout->incremental_inputs();
+      if (incremental_inputs != NULL)
+       incremental_inputs->report_comdat_group(this, signature.c_str());
     }
 
-  // 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);
-      if (secnum >= this->shnum())
+      elfcpp::Elf_Word shndx =
+       this->adjust_shndx(elfcpp::Swap<32, big_endian>::readval(pword + i));
+
+      if (relocate_group)
+       shndxes.push_back(shndx);
+
+      if (shndx >= this->shnum())
        {
          this->error(_("section %u in section group %u out of range"),
-                     secnum, index);
+                     shndx, 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 (shndx < index)
+        this->error(_("invalid section group %u refers to earlier section %u"),
+                    index, shndx);
+
+      // Get the name of the member section.
+      typename This::Shdr member_shdr(shdrs + shndx * 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)
+       {
+         if (is_comdat)
+           kept_section->add_comdat_section(mname, shndx,
+                                            member_shdr.get_sh_size());
+       }
+      else
+        {
+          (*omit)[shndx] = true;
+
+         if (is_comdat)
+            {
+             Relobj* kept_object = kept_section->object();
+             if (kept_section->is_comdat())
+               {
+                 // Find the corresponding kept section, and store
+                 // that info in the discarded section table.
+                 unsigned int kept_shndx;
+                 uint64_t kept_size;
+                 if (kept_section->find_comdat_section(mname, &kept_shndx,
+                                                       &kept_size))
+                   {
+                     // We don't keep a mapping for this section if
+                     // it has a different size.  The mapping is only
+                     // used for relocation processing, and we don't
+                     // want to treat the sections as similar if the
+                     // sizes are different.  Checking the section
+                     // size is the approach used by the GNU linker.
+                     if (kept_size == member_shdr.get_sh_size())
+                       this->set_kept_comdat_section(shndx, kept_object,
+                                                     kept_shndx);
+                   }
+               }
+             else
+               {
+                 // The existing section is a linkonce section.  Add
+                 // a mapping if there is exactly one section in the
+                 // group (which is true when COUNT == 2) and if it
+                 // is the same size.
+                 if (count == 2
+                     && (kept_section->linkonce_size()
+                         == member_shdr.get_sh_size()))
+                   this->set_kept_comdat_section(shndx, kept_object,
+                                                 kept_section->shndx());
+               }
+            }
+        }
     }
 
-  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
@@ -496,11 +948,13 @@ Sized_relobj<size, big_endian>::include_section_group(
 
 template<int size, bool big_endian>
 bool
-Sized_relobj<size, big_endian>::include_linkonce_section(
+Sized_relobj_file<size, big_endian>::include_linkonce_section(
     Layout* layout,
+    unsigned int index,
     const char* name,
-    const elfcpp::Shdr<size, big_endian>&)
+    const elfcpp::Shdr<size, big_endian>& shdr)
 {
+  typename elfcpp::Elf_types<size>::Elf_WXword sh_size = shdr.get_sh_size();
   // In general the symbol name we want will be the string following
   // the last '.'.  However, we have to handle the case of
   // .gnu.linkonce.t.__i686.get_pc_thunk.bx, which was generated by
@@ -515,48 +969,247 @@ 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);
+  Kept_section* kept1;
+  Kept_section* kept2;
+  bool include1 = layout->find_or_add_kept_section(sig1, this, index, false,
+                                                  false, &kept1);
+  bool include2 = layout->find_or_add_kept_section(sig2, this, index, false,
+                                                  true, &kept2);
+
+  if (!include2)
+    {
+      // We are not including this section because we already saw the
+      // name of the section as a signature.  This normally implies
+      // that the kept section is another linkonce section.  If it is
+      // the same size, record it as the section which corresponds to
+      // this one.
+      if (kept2->object() != NULL
+         && !kept2->is_comdat()
+         && kept2->linkonce_size() == sh_size)
+       this->set_kept_comdat_section(index, kept2->object(), kept2->shndx());
+    }
+  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_shndx;
+      uint64_t kept_size;
+      if (kept1->object() != NULL
+         && kept1->is_comdat()
+         && kept1->find_single_comdat_section(&kept_shndx, &kept_size)
+         && kept_size == sh_size)
+       this->set_kept_comdat_section(index, kept1->object(), kept_shndx);
+    }
+  else
+    {
+      kept1->set_linkonce_size(sh_size);
+      kept2->set_linkonce_size(sh_size);
+    }
+
   return include1 && include2;
 }
 
+// Layout an input section.
+
+template<int size, bool big_endian>
+inline void
+Sized_relobj_file<size, big_endian>::layout_section(
+    Layout* layout,
+    unsigned int shndx,
+    const char* name,
+    const typename This::Shdr& shdr,
+    unsigned int reloc_shndx,
+    unsigned int reloc_type)
+{
+  off_t offset;
+  Output_section* os = layout->layout(this, shndx, name, shdr,
+                                         reloc_shndx, reloc_type, &offset);
+
+  this->output_sections()[shndx] = os;
+  if (offset == -1)
+    this->section_offsets()[shndx] = invalid_address;
+  else
+    this->section_offsets()[shndx] = 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
+  // before we apply the relocs.
+  if (offset == -1 && reloc_shndx != 0)
+    this->set_relocs_must_follow_section_writes();
+}
+
+// Layout an input .eh_frame section.
+
+template<int size, bool big_endian>
+void
+Sized_relobj_file<size, big_endian>::layout_eh_frame_section(
+    Layout* layout,
+    const unsigned char* symbols_data,
+    section_size_type symbols_size,
+    const unsigned char* symbol_names_data,
+    section_size_type symbol_names_size,
+    unsigned int shndx,
+    const typename This::Shdr& shdr,
+    unsigned int reloc_shndx,
+    unsigned int reloc_type)
+{
+  gold_assert(this->has_eh_frame_);
+
+  off_t offset;
+  Output_section* os = layout->layout_eh_frame(this,
+                                              symbols_data,
+                                              symbols_size,
+                                              symbol_names_data,
+                                              symbol_names_size,
+                                              shndx,
+                                              shdr,
+                                              reloc_shndx,
+                                              reloc_type,
+                                              &offset);
+  this->output_sections()[shndx] = os;
+  if (os == NULL || offset == -1)
+    {
+      // An object can contain at most one section holding exception
+      // frame information.
+      gold_assert(this->discarded_eh_frame_shndx_ == -1U);
+      this->discarded_eh_frame_shndx_ = shndx;
+      this->section_offsets()[shndx] = invalid_address;
+    }
+  else
+    this->section_offsets()[shndx] = convert_types<Address, off_t>(offset);
+
+  // If this section requires special handling, and if there are
+  // relocs that aply to it, then we must do the special handling
+  // before we apply the relocs.
+  if (os != NULL && offset == -1 && reloc_shndx != 0)
+    this->set_relocs_must_follow_section_writes();
+}
+
 // Lay out the input sections.  We walk through the sections and check
 // whether they should be included in the link.  If they should, we
 // pass them to the Layout object, which will return an output section
-// and an offset.
+// and an offset.  
+// During garbage collection (--gc-sections) and identical code folding 
+// (--icf), this function is called twice.  When it is called the first 
+// time, it is for setting up some sections as roots to a work-list for
+// --gc-sections and to do comdat processing.  Actual layout happens the 
+// second time around after all the relevant sections have been determined.  
+// The first time, is_worklist_ready or is_icf_ready is false. It is then 
+// set to true after the garbage collection worklist or identical code 
+// folding is processed and the relevant sections to be kept are 
+// determined.  Then, this function is called again to layout the sections.
 
 template<int size, bool big_endian>
 void
-Sized_relobj<size, big_endian>::do_layout(Symbol_table* symtab,
-                                         Layout* layout,
-                                         Read_symbols_data* sd)
+Sized_relobj_file<size, big_endian>::do_layout(Symbol_table* symtab,
+                                              Layout* layout,
+                                              Read_symbols_data* sd)
 {
   const unsigned int shnum = this->shnum();
+  bool is_gc_pass_one = ((parameters->options().gc_sections() 
+                          && !symtab->gc()->is_worklist_ready())
+                         || (parameters->options().icf_enabled()
+                             && !symtab->icf()->is_icf_ready()));
+  bool is_gc_pass_two = ((parameters->options().gc_sections() 
+                          && symtab->gc()->is_worklist_ready())
+                         || (parameters->options().icf_enabled()
+                             && symtab->icf()->is_icf_ready()));
+
+  bool is_gc_or_icf = (parameters->options().gc_sections()
+                       || parameters->options().icf_enabled()); 
+
+  // Both is_gc_pass_one and is_gc_pass_two should not be true.
+  gold_assert(!(is_gc_pass_one  && is_gc_pass_two));
+
   if (shnum == 0)
     return;
+  Symbols_data* gc_sd = NULL;
+  if (is_gc_pass_one)
+    {
+      // During garbage collection save the symbols data to use it when 
+      // re-entering this function.   
+      gc_sd = new Symbols_data;
+      this->copy_symbols_data(gc_sd, sd, This::shdr_size * shnum);
+      this->set_symbols_data(gc_sd);
+    }
+  else if (is_gc_pass_two)
+    {
+      gc_sd = this->get_symbols_data();
+    }
+
+  const unsigned char* section_headers_data = NULL;
+  section_size_type section_names_size;
+  const unsigned char* symbols_data = NULL;
+  section_size_type symbols_size;
+  const unsigned char* symbol_names_data = NULL;
+  section_size_type symbol_names_size;
+  if (is_gc_or_icf)
+    {
+      section_headers_data = gc_sd->section_headers_data;
+      section_names_size = gc_sd->section_names_size;
+      symbols_data = gc_sd->symbols_data;
+      symbols_size = gc_sd->symbols_size;
+      symbol_names_data = gc_sd->symbol_names_data;
+      symbol_names_size = gc_sd->symbol_names_size;
+    }
+  else
+    {
+      section_headers_data = sd->section_headers->data();
+      section_names_size = sd->section_names_size;
+      if (sd->symbols != NULL)
+        symbols_data = sd->symbols->data();
+      symbols_size = sd->symbols_size;
+      if (sd->symbol_names != NULL)
+        symbol_names_data = sd->symbol_names->data();
+      symbol_names_size = sd->symbol_names_size;
+    }
 
   // Get the section headers.
-  const unsigned char* pshdrs = sd->section_headers->data();
+  const unsigned char* shdrs = section_headers_data;
+  const unsigned char* pshdrs;
 
   // Get the section names.
-  const unsigned char* pnamesu = sd->section_names->data();
+  const unsigned char* pnamesu = (is_gc_or_icf) 
+                                 ? gc_sd->section_names_data
+                                 : sd->section_names->data();
+
   const char* pnames = reinterpret_cast<const char*>(pnamesu);
 
+  // If any input files have been claimed by plugins, we need to defer
+  // actual layout until the replacement files have arrived.
+  const bool should_defer_layout =
+      (parameters->options().has_plugins()
+       && parameters->options().plugins()->should_defer_layout());
+  unsigned int num_sections_to_defer = 0;
+
   // For each section, record the index of the reloc section if any.
   // Use 0 to mean that there is no reloc section, -1U to mean that
   // there is more than one.
   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);
 
+      // Count the number of sections whose layout will be deferred.
+      if (should_defer_layout && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC))
+        ++num_sections_to_defer;
+
       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"),
@@ -574,20 +1227,35 @@ 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());
+
+  if (!is_gc_pass_two)
+    {
+      out_sections.resize(shnum);
+      out_section_offsets.resize(shnum);
+    }
 
   // If we are only linking for symbols, then there is nothing else to
   // do here.
   if (this->input_file()->just_symbols())
     {
-      delete sd->section_headers;
-      sd->section_headers = NULL;
-      delete sd->section_names;
-      sd->section_names = NULL;
+      if (!is_gc_pass_two)
+        {
+          delete sd->section_headers;
+          sd->section_headers = NULL;
+          delete sd->section_names;
+          sd->section_names = NULL;
+        }
       return;
     }
 
+  if (num_sections_to_defer > 0)
+    {
+      parameters->options().plugins()->add_deferred_layout_object(this);
+      this->deferred_layout_.reserve(num_sections_to_defer);
+    }
+
   // Whether we've seen a .note.GNU-stack section.
   bool seen_gnu_stack = false;
   // The flags of a .note.GNU-stack section.
@@ -606,12 +1274,12 @@ 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);
 
-      if (shdr.get_sh_name() >= sd->section_names_size)
+      if (shdr.get_sh_name() >= section_names_size)
        {
          this->error(_("bad section name offset for section %u: %lu"),
                      i, static_cast<unsigned long>(shdr.get_sh_name()));
@@ -620,54 +1288,109 @@ Sized_relobj<size, big_endian>::do_layout(Symbol_table* symtab,
 
       const char* name = pnames + shdr.get_sh_name();
 
-      if (this->handle_gnu_warning_section(name, i, symtab))
-       {
-         if (!relocatable)
-           omit[i] = true;
-       }
+      if (!is_gc_pass_two)
+        { 
+          if (this->handle_gnu_warning_section(name, i, symtab))
+            { 
+             if (!relocatable && !parameters->options().shared())
+               omit[i] = true;
+           }
 
-      // The .note.GNU-stack section is special.  It gives the
-      // protection flags that this object file requires for the stack
-      // in memory.
-      if (strcmp(name, ".note.GNU-stack") == 0)
-       {
-         seen_gnu_stack = true;
-         gnu_stack_flags |= shdr.get_sh_flags();
-         omit[i] = true;
-       }
+          // The .note.GNU-stack section is special.  It gives the
+          // protection flags that this object file requires for the stack
+          // in memory.
+          if (strcmp(name, ".note.GNU-stack") == 0)
+            {
+             seen_gnu_stack = true;
+             gnu_stack_flags |= shdr.get_sh_flags();
+             omit[i] = true;
+            }
 
-      bool discard = omit[i];
-      if (!discard)
-       {
-         if (shdr.get_sh_type() == elfcpp::SHT_GROUP)
+         // The .note.GNU-split-stack section is also special.  It
+         // indicates that the object was compiled with
+         // -fsplit-stack.
+         if (this->handle_split_stack_section(name))
            {
-             if (!this->include_section_group(symtab, layout, i, name, shdr,
-                                              &omit))
-               discard = true;
+             if (!relocatable && !parameters->options().shared())
+               omit[i] = true;
            }
-          else if ((shdr.get_sh_flags() & elfcpp::SHF_GROUP) == 0
-                   && Layout::is_linkonce(name))
+
+         // Skip attributes section.
+         if (parameters->target().is_attributes_section(name))
            {
-             if (!this->include_linkonce_section(layout, name, shdr))
-               discard = true;
+             omit[i] = true;
            }
-       }
 
-      if (discard)
-       {
-         // Do not include this section in the link.
-         map_sections[i].output_section = NULL;
-         continue;
-       }
+          bool discard = omit[i];
+          if (!discard)
+            {
+             if (shdr.get_sh_type() == elfcpp::SHT_GROUP)
+               {
+                 if (!this->include_section_group(symtab, layout, i, name, 
+                                                   shdrs, pnames, 
+                                                   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, i, name, shdr))
+                   discard = true;
+               }
+           }
 
-      // When doing a relocatable link we are going to copy input
-      // reloc sections into the output.  We only want to copy the
-      // ones associated with sections which are not being discarded.
-      // However, we don't know that yet for all sections.  So save
-      // reloc sections and process them later.
-      if (emit_relocs
-         && (shdr.get_sh_type() == elfcpp::SHT_REL
-             || shdr.get_sh_type() == elfcpp::SHT_RELA))
+         // Add the section to the incremental inputs layout.
+         Incremental_inputs* incremental_inputs = layout->incremental_inputs();
+         if (incremental_inputs != NULL
+             && !discard
+             && (shdr.get_sh_type() == elfcpp::SHT_PROGBITS
+                 || shdr.get_sh_type() == elfcpp::SHT_NOBITS
+                 || shdr.get_sh_type() == elfcpp::SHT_NOTE))
+           {
+             off_t sh_size = shdr.get_sh_size();
+             section_size_type uncompressed_size;
+             if (this->section_is_compressed(i, &uncompressed_size))
+               sh_size = uncompressed_size;
+             incremental_inputs->report_input_section(this, i, name, sh_size);
+           }
+
+          if (discard)
+            {
+             // Do not include this section in the link.
+             out_sections[i] = NULL;
+              out_section_offsets[i] = invalid_address;
+             continue;
+            }
+        }
+      if (is_gc_pass_one && parameters->options().gc_sections())
+        {
+          if (this->is_section_name_included(name)
+              || shdr.get_sh_type() == elfcpp::SHT_INIT_ARRAY 
+              || shdr.get_sh_type() == elfcpp::SHT_FINI_ARRAY)
+            {
+              symtab->gc()->worklist().push(Section_id(this, i)); 
+            }
+          // If the section name XXX can be represented as a C identifier
+          // it cannot be discarded if there are references to
+          // __start_XXX and __stop_XXX symbols.  These need to be
+          // specially handled.
+          if (is_cident(name))
+            {
+              symtab->gc()->add_cident_section(name, Section_id(this, i));
+            }
+        }
+
+      // When doing a relocatable link we are going to copy input
+      // reloc sections into the output.  We only want to copy the
+      // ones associated with sections which are not being discarded.
+      // However, we don't know that yet for all sections.  So save
+      // reloc sections and process them later. Garbage collection is
+      // not triggered when relocatable code is desired.
+      if (emit_relocs
+         && (shdr.get_sh_type() == elfcpp::SHT_REL
+             || shdr.get_sh_type() == elfcpp::SHT_RELA))
        {
          reloc_sections.push_back(i);
          continue;
@@ -683,54 +1406,161 @@ Sized_relobj<size, big_endian>::do_layout(Symbol_table* symtab,
       // determine which sections are being discarded, and discard the
       // corresponding information.
       if (!relocatable
-         && strcmp(name, ".eh_frame") == 0
-         && this->check_eh_frame_flags(&shdr))
-       {
-         eh_frame_sections.push_back(i);
-         continue;
-       }
+          && strcmp(name, ".eh_frame") == 0
+          && this->check_eh_frame_flags(&shdr))
+        {
+          if (is_gc_pass_one)
+            {
+              out_sections[i] = reinterpret_cast<Output_section*>(1);
+              out_section_offsets[i] = invalid_address;
+            }
+          else if (should_defer_layout)
+           this->deferred_layout_.push_back(Deferred_layout(i, name,
+                                                            pshdrs,
+                                                            reloc_shndx[i],
+                                                            reloc_type[i]));
+         else
+            eh_frame_sections.push_back(i);
+          continue;
+        }
+
+      if (is_gc_pass_two && parameters->options().gc_sections())
+        {
+          // This is executed during the second pass of garbage 
+          // collection. do_layout has been called before and some 
+          // sections have been already discarded. Simply ignore 
+          // such sections this time around.
+          if (out_sections[i] == NULL)
+            {
+              gold_assert(out_section_offsets[i] == invalid_address);
+              continue; 
+            }
+          if (((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0)
+              && symtab->gc()->is_section_garbage(this, i))
+              {
+                if (parameters->options().print_gc_sections())
+                  gold_info(_("%s: removing unused section from '%s'" 
+                              " in file '%s'"),
+                            program_name, this->section_name(i).c_str(), 
+                            this->name().c_str());
+                out_sections[i] = NULL;
+                out_section_offsets[i] = invalid_address;
+                continue;
+              }
+        }
+
+      if (is_gc_pass_two && parameters->options().icf_enabled())
+        {
+          if (out_sections[i] == NULL)
+            {
+              gold_assert(out_section_offsets[i] == invalid_address);
+              continue;
+            }
+          if (((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0)
+              && symtab->icf()->is_section_folded(this, i))
+              {
+                if (parameters->options().print_icf_sections())
+                  {
+                    Section_id folded =
+                                symtab->icf()->get_folded_section(this, i);
+                    Relobj* folded_obj =
+                                reinterpret_cast<Relobj*>(folded.first);
+                    gold_info(_("%s: ICF folding section '%s' in file '%s'"
+                                "into '%s' in file '%s'"),
+                              program_name, this->section_name(i).c_str(),
+                              this->name().c_str(),
+                              folded_obj->section_name(folded.second).c_str(),
+                              folded_obj->name().c_str());
+                  }
+                out_sections[i] = NULL;
+                out_section_offsets[i] = invalid_address;
+                continue;
+              }
+        }
 
-      off_t offset;
-      Output_section* os = layout->layout(this, i, name, shdr,
-                                         reloc_shndx[i], reloc_type[i],
-                                         &offset);
+      // Defer layout here if input files are claimed by plugins.  When gc
+      // is turned on this function is called twice.  For the second call
+      // should_defer_layout should be false.
+      if (should_defer_layout && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC))
+        {
+          gold_assert(!is_gc_pass_two);
+          this->deferred_layout_.push_back(Deferred_layout(i, name, 
+                                                           pshdrs,
+                                                           reloc_shndx[i],
+                                                           reloc_type[i]));
+          // Put dummy values here; real values will be supplied by
+          // do_layout_deferred_sections.
+          out_sections[i] = reinterpret_cast<Output_section*>(2);
+          out_section_offsets[i] = invalid_address;
+          continue;
+        }
 
-      map_sections[i].output_section = os;
-      map_sections[i].offset = offset;
+      // During gc_pass_two if a section that was previously deferred is
+      // found, do not layout the section as layout_deferred_sections will
+      // do it later from gold.cc.
+      if (is_gc_pass_two 
+          && (out_sections[i] == reinterpret_cast<Output_section*>(2)))
+        continue;
 
-      // If this section requires special handling, and if there are
-      // relocs that apply to it, then we must do the special handling
-      // before we apply the relocs.
-      if (offset == -1 && reloc_shndx[i] != 0)
-       this->set_relocs_must_follow_section_writes();
+      if (is_gc_pass_one)
+        {
+          // This is during garbage collection. The out_sections are 
+          // assigned in the second call to this function. 
+          out_sections[i] = reinterpret_cast<Output_section*>(1);
+          out_section_offsets[i] = invalid_address;
+        }
+      else
+        {
+          // When garbage collection is switched on the actual layout
+          // only happens in the second call.
+          this->layout_section(layout, i, name, shdr, reloc_shndx[i],
+                               reloc_type[i]);
+        }
     }
 
-  layout->layout_gnu_stack(seen_gnu_stack, gnu_stack_flags);
+  if (!is_gc_pass_two)
+    layout->layout_gnu_stack(seen_gnu_stack, gnu_stack_flags, this);
 
   // When doing a relocatable link handle the reloc sections at the
-  // end.
+  // end.  Garbage collection  and Identical Code Folding is not 
+  // turned on for relocatable code. 
   if (emit_relocs)
     this->size_relocatable_relocs();
+
+  gold_assert(!(is_gc_or_icf) || reloc_sections.empty());
+
   for (std::vector<unsigned int>::const_iterator p = reloc_sections.begin();
        p != reloc_sections.end();
        ++p)
     {
       unsigned int i = *p;
       const unsigned char* pshdr;
-      pshdr = sd->section_headers->data() + i * This::shdr_size;
+      pshdr = 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 == reinterpret_cast<Output_section*>(2))
+        {
+          // The layout for the data section was deferred, so we need
+          // to defer the relocation section, too.
+         const char* name = pnames + shdr.get_sh_name();
+          this->deferred_layout_relocs_.push_back(
+              Deferred_layout(i, name, pshdr, 0, elfcpp::SHT_NULL));
+         out_sections[i] = reinterpret_cast<Output_section*>(2);
+          out_section_offsets[i] = invalid_address;
+          continue;
+        }
       if (data_section == NULL)
        {
-         map_sections[i].output_section = NULL;
+         out_sections[i] = NULL;
+          out_section_offsets[i] = invalid_address;
          continue;
        }
 
@@ -739,55 +1569,131 @@ 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] = invalid_address;
     }
 
   // Handle the .eh_frame sections at the end.
+  gold_assert(!is_gc_pass_one || eh_frame_sections.empty());
   for (std::vector<unsigned int>::const_iterator p = eh_frame_sections.begin();
        p != eh_frame_sections.end();
        ++p)
     {
-      gold_assert(this->has_eh_frame_);
-      gold_assert(sd->external_symbols_offset != 0);
-
       unsigned int i = *p;
-      const unsigned char *pshdr;
-      pshdr = sd->section_headers->data() + i * This::shdr_size;
+      const unsigned charpshdr;
+      pshdr = section_headers_data + i * This::shdr_size;
       typename This::Shdr shdr(pshdr);
 
-      off_t offset;
-      Output_section* os = layout->layout_eh_frame(this,
-                                                  sd->symbols->data(),
-                                                  sd->symbols_size,
-                                                  sd->symbol_names->data(),
-                                                  sd->symbol_names_size,
-                                                  i, shdr,
-                                                  reloc_shndx[i],
-                                                  reloc_type[i],
-                                                  &offset);
-      map_sections[i].output_section = os;
-      map_sections[i].offset = offset;
-
-      // If this section requires special handling, and if there are
-      // relocs that apply to it, then we must do the special handling
-      // before we apply the relocs.
-      if (offset == -1 && reloc_shndx[i] != 0)
-       this->set_relocs_must_follow_section_writes();
-    }
-
-  delete sd->section_headers;
-  sd->section_headers = NULL;
-  delete sd->section_names;
-  sd->section_names = NULL;
+      this->layout_eh_frame_section(layout,
+                                   symbols_data,
+                                   symbols_size,
+                                   symbol_names_data,
+                                   symbol_names_size,
+                                   i,
+                                   shdr,
+                                   reloc_shndx[i],
+                                   reloc_type[i]);
+    }
+
+  if (is_gc_pass_two)
+    {
+      delete[] gc_sd->section_headers_data;
+      delete[] gc_sd->section_names_data;
+      delete[] gc_sd->symbols_data;
+      delete[] gc_sd->symbol_names_data;
+      this->set_symbols_data(NULL);
+    }
+  else
+    {
+      delete sd->section_headers;
+      sd->section_headers = NULL;
+      delete sd->section_names;
+      sd->section_names = NULL;
+    }
+}
+
+// Layout sections whose layout was deferred while waiting for
+// input files from a plugin.
+
+template<int size, bool big_endian>
+void
+Sized_relobj_file<size, big_endian>::do_layout_deferred_sections(Layout* layout)
+{
+  typename std::vector<Deferred_layout>::iterator deferred;
+
+  for (deferred = this->deferred_layout_.begin();
+       deferred != this->deferred_layout_.end();
+       ++deferred)
+    {
+      typename This::Shdr shdr(deferred->shdr_data_);
+      // If the section is not included, it is because the garbage collector
+      // decided it is not needed.  Avoid reverting that decision.
+      if (!this->is_section_included(deferred->shndx_))
+        continue;
+
+      if (parameters->options().relocatable()
+         || deferred->name_ != ".eh_frame"
+         || !this->check_eh_frame_flags(&shdr))
+       this->layout_section(layout, deferred->shndx_, deferred->name_.c_str(),
+                            shdr, deferred->reloc_shndx_,
+                            deferred->reloc_type_);
+      else
+       {
+         // Reading the symbols again here may be slow.
+         Read_symbols_data sd;
+         this->read_symbols(&sd);
+         this->layout_eh_frame_section(layout,
+                                       sd.symbols->data(),
+                                       sd.symbols_size,
+                                       sd.symbol_names->data(),
+                                       sd.symbol_names_size,
+                                       deferred->shndx_,
+                                       shdr,
+                                       deferred->reloc_shndx_,
+                                       deferred->reloc_type_);
+       }
+    }
+
+  this->deferred_layout_.clear();
+
+  // Now handle the deferred relocation sections.
+
+  Output_sections& out_sections(this->output_sections());
+  std::vector<Address>& out_section_offsets(this->section_offsets());
+
+  for (deferred = this->deferred_layout_relocs_.begin();
+       deferred != this->deferred_layout_relocs_.end();
+       ++deferred)
+    {
+      unsigned int shndx = deferred->shndx_;
+      typename This::Shdr shdr(deferred->shdr_data_);
+      unsigned int data_shndx = this->adjust_shndx(shdr.get_sh_info());
+
+      Output_section* data_section = out_sections[data_shndx];
+      if (data_section == NULL)
+       {
+         out_sections[shndx] = NULL;
+          out_section_offsets[shndx] = invalid_address;
+         continue;
+       }
+
+      Relocatable_relocs* rr = new Relocatable_relocs();
+      this->set_relocatable_relocs(shndx, rr);
+
+      Output_section* os = layout->layout_reloc(this, shndx, shdr,
+                                               data_section, rr);
+      out_sections[shndx] = os;
+      out_section_offsets[shndx] = invalid_address;
+    }
 }
 
 // Add the symbols to the symbol table.
 
 template<int size, bool big_endian>
 void
-Sized_relobj<size, big_endian>::do_add_symbols(Symbol_table* symtab,
-                                              Read_symbols_data* sd)
+Sized_relobj_file<size, big_endian>::do_add_symbols(Symbol_table* symtab,
+                                                   Read_symbols_data* sd,
+                                                   Layout*)
 {
   if (sd->symbols == NULL)
     {
@@ -810,8 +1716,10 @@ 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;
@@ -819,6 +1727,120 @@ Sized_relobj<size, big_endian>::do_add_symbols(Symbol_table* symtab,
   sd->symbol_names = NULL;
 }
 
+// Find out if this object, that is a member of a lib group, should be included
+// in the link. We check every symbol defined by this object. If the symbol
+// table has a strong undefined reference to that symbol, we have to include
+// the object.
+
+template<int size, bool big_endian>
+Archive::Should_include
+Sized_relobj_file<size, big_endian>::do_should_include_member(
+    Symbol_table* symtab,
+    Layout* layout,
+    Read_symbols_data* sd,
+    std::string* why)
+{
+  char* tmpbuf = NULL;
+  size_t tmpbuflen = 0;
+  const char* sym_names =
+      reinterpret_cast<const char*>(sd->symbol_names->data());
+  const unsigned char* syms =
+      sd->symbols->data() + sd->external_symbols_offset;
+  const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
+  size_t symcount = ((sd->symbols_size - sd->external_symbols_offset)
+                         / sym_size);
+
+  const unsigned char* p = syms;
+
+  for (size_t i = 0; i < symcount; ++i, p += sym_size)
+    {
+      elfcpp::Sym<size, big_endian> sym(p);
+      unsigned int st_shndx = sym.get_st_shndx();
+      if (st_shndx == elfcpp::SHN_UNDEF)
+       continue;
+
+      unsigned int st_name = sym.get_st_name();
+      const char* name = sym_names + st_name;
+      Symbol* symbol;
+      Archive::Should_include t = Archive::should_include_member(symtab,
+                                                                layout,
+                                                                name,
+                                                                &symbol, why,
+                                                                &tmpbuf,
+                                                                &tmpbuflen);
+      if (t == Archive::SHOULD_INCLUDE_YES)
+       {
+         if (tmpbuf != NULL)
+           free(tmpbuf);
+         return t;
+       }
+    }
+  if (tmpbuf != NULL)
+    free(tmpbuf);
+  return Archive::SHOULD_INCLUDE_UNKNOWN;
+}
+
+// Iterate over global defined symbols, calling a visitor class V for each.
+
+template<int size, bool big_endian>
+void
+Sized_relobj_file<size, big_endian>::do_for_all_global_symbols(
+    Read_symbols_data* sd,
+    Library_base::Symbol_visitor_base* v)
+{
+  const char* sym_names =
+      reinterpret_cast<const char*>(sd->symbol_names->data());
+  const unsigned char* syms =
+      sd->symbols->data() + sd->external_symbols_offset;
+  const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
+  size_t symcount = ((sd->symbols_size - sd->external_symbols_offset)
+                     / sym_size);
+  const unsigned char* p = syms;
+
+  for (size_t i = 0; i < symcount; ++i, p += sym_size)
+    {
+      elfcpp::Sym<size, big_endian> sym(p);
+      if (sym.get_st_shndx() != elfcpp::SHN_UNDEF)
+       v->visit(sym_names + sym.get_st_name());
+    }
+}
+
+// Return whether the local symbol SYMNDX has a PLT offset.
+
+template<int size, bool big_endian>
+bool
+Sized_relobj_file<size, big_endian>::local_has_plt_offset(
+    unsigned int symndx) const
+{
+  typename Local_plt_offsets::const_iterator p =
+    this->local_plt_offsets_.find(symndx);
+  return p != this->local_plt_offsets_.end();
+}
+
+// Get the PLT offset of a local symbol.
+
+template<int size, bool big_endian>
+unsigned int
+Sized_relobj_file<size, big_endian>::local_plt_offset(unsigned int symndx) const
+{
+  typename Local_plt_offsets::const_iterator p =
+    this->local_plt_offsets_.find(symndx);
+  gold_assert(p != this->local_plt_offsets_.end());
+  return p->second;
+}
+
+// Set the PLT offset of a local symbol.
+
+template<int size, bool big_endian>
+void
+Sized_relobj_file<size, big_endian>::set_local_plt_offset(
+    unsigned int symndx, unsigned int plt_offset)
+{
+  std::pair<typename Local_plt_offsets::iterator, bool> ins =
+    this->local_plt_offsets_.insert(std::make_pair(symndx, plt_offset));
+  gold_assert(ins.second);
+}
+
 // First pass over the local symbols.  Here we add their names to
 // *POOL and *DYNPOOL, and we store the symbol value in
 // THIS->LOCAL_VALUES_.  This function is always called from a
@@ -827,8 +1849,8 @@ Sized_relobj<size, big_endian>::do_add_symbols(Symbol_table* symtab,
 
 template<int size, bool big_endian>
 void
-Sized_relobj<size, big_endian>::do_count_local_symbols(Stringpool* pool,
-                                                      Stringpool* dynpool)
+Sized_relobj_file<size, big_endian>::do_count_local_symbols(Stringpool* pool,
+                                                           Stringpool* dynpool)
 {
   gold_assert(this->symtab_shndx_ != -1U);
   if (this->symtab_shndx_ == 0)
@@ -849,10 +1871,11 @@ Sized_relobj<size, big_endian>::do_count_local_symbols(Stringpool* pool,
   gold_assert(loccount == symtabshdr.get_sh_info());
   off_t locsize = loccount * sym_size;
   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
-                                             locsize, true);
+                                             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,
@@ -861,32 +1884,40 @@ 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;
   // Skip the first, dummy, symbol.
   psyms += sym_size;
+  bool strip_all = parameters->options().strip_all();
+  bool discard_all = parameters->options().discard_all();
+  bool discard_locals = parameters->options().discard_locals();
   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
     {
       elfcpp::Sym<size, big_endian> sym(psyms);
 
       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();
       else if (sym.get_st_type() == elfcpp::STT_TLS)
        lv.set_is_tls_symbol();
+      else if (sym.get_st_type() == elfcpp::STT_GNU_IFUNC)
+       lv.set_is_ifunc_symbol();
 
       // Save the input symbol value for use in do_finalize_local_symbols().
       lv.set_input_value(sym.get_st_value());
 
       // 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)
+         || shndx == this->discarded_eh_frame_shndx_)
         {
          lv.set_no_output_symtab_entry();
           gold_assert(!lv.needs_output_dynsym_entry());
@@ -909,10 +1940,7 @@ Sized_relobj<size, big_endian>::do_count_local_symbols(Stringpool* pool,
          continue;
        }
 
-      // Add the symbol to the symbol table string pool.
       const char* name = pnames + sym.get_st_name();
-      pool->add(name, true, NULL);
-      ++count;
 
       // If needed, add the symbol to the dynamic symbol table string pool.
       if (lv.needs_output_dynsym_entry())
@@ -920,102 +1948,270 @@ Sized_relobj<size, big_endian>::do_count_local_symbols(Stringpool* pool,
           dynpool->add(name, true, NULL);
           ++dyncount;
         }
+
+      if (strip_all
+         || (discard_all && lv.may_be_discarded_from_output_symtab()))
+       {
+         lv.set_no_output_symtab_entry();
+         continue;
+       }
+
+      // If --discard-locals option is used, discard all temporary local
+      // symbols.  These symbols start with system-specific local label
+      // prefixes, typically .L for ELF system.  We want to be compatible
+      // with GNU ld so here we essentially use the same check in
+      // bfd_is_local_label().  The code is different because we already
+      // know that:
+      //
+      //   - the symbol is local and thus cannot have global or weak binding.
+      //   - the symbol is not a section symbol.
+      //   - the symbol has a name.
+      //
+      // We do not discard a symbol if it needs a dynamic symbol entry.
+      if (discard_locals
+         && sym.get_st_type() != elfcpp::STT_FILE
+         && !lv.needs_output_dynsym_entry()
+         && lv.may_be_discarded_from_output_symtab()
+         && parameters->target().is_local_label_name(name))
+       {
+         lv.set_no_output_symtab_entry();
+         continue;
+       }
+
+      // Discard the local symbol if -retain_symbols_file is specified
+      // and the local symbol is not in that file.
+      if (!parameters->options().should_retain_symbol(name))
+        {
+          lv.set_no_output_symtab_entry();
+          continue;
+        }
+
+      // Add the symbol to the symbol table string pool.
+      pool->add(name, true, NULL);
+      ++count;
     }
 
   this->output_local_symbol_count_ = count;
   this->output_local_dynsym_count_ = dyncount;
 }
 
-// Finalize the local symbols.  Here we set the final value in
-// THIS->LOCAL_VALUES_ and set their output symbol table indexes.
-// This function is always called from a singleton thread.  The actual
-// output of the local symbols will occur in a separate task.
+// Compute the final value of a local symbol.
 
 template<int size, bool big_endian>
-unsigned int
-Sized_relobj<size, big_endian>::do_finalize_local_symbols(unsigned int index,
-                                                          off_t off)
+typename Sized_relobj_file<size, big_endian>::Compute_final_local_value_status
+Sized_relobj_file<size, big_endian>::compute_final_local_value_internal(
+    unsigned int r_sym,
+    const Symbol_value<size>* lv_in,
+    Symbol_value<size>* lv_out,
+    bool relocatable,
+    const Output_sections& out_sections,
+    const std::vector<Address>& out_offsets,
+    const Symbol_table* symtab)
 {
-  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());
-  unsigned int shnum = this->shnum();
-
-  for (unsigned int i = 1; i < loccount; ++i)
+  // We are going to overwrite *LV_OUT, if it has a merged symbol value,
+  // we may have a memory leak.
+  gold_assert(lv_out->has_output_value());
+
+  bool is_ordinary;
+  unsigned int shndx = lv_in->input_shndx(&is_ordinary);
+  
+  // Set the output symbol value.
+  
+  if (!is_ordinary)
     {
-      Symbol_value<size>& lv(this->local_values_[i]);
-
-      unsigned int shndx = lv.input_shndx();
-
-      // Set the output symbol value.
+      if (shndx == elfcpp::SHN_ABS || Symbol::is_common_shndx(shndx))
+       lv_out->set_output_value(lv_in->input_value());
+      else
+       {
+         this->error(_("unknown section index %u for local symbol %u"),
+                     shndx, r_sym);
+         lv_out->set_output_value(0);
+         return This::CFLV_ERROR;
+       }
+    }
+  else
+    {
+      if (shndx >= this->shnum())
+       {
+         this->error(_("local symbol %u section index %u out of range"),
+                     r_sym, shndx);
+         lv_out->set_output_value(0);
+         return This::CFLV_ERROR;
+       }
       
-      if (shndx >= elfcpp::SHN_LORESERVE)
+      Output_section* os = out_sections[shndx];
+      Address secoffset = out_offsets[shndx];
+      if (symtab->is_section_folded(this, shndx))
        {
-         if (shndx == elfcpp::SHN_ABS || shndx == elfcpp::SHN_COMMON)
-           lv.set_output_value(lv.input_value());
-         else
+         gold_assert(os == NULL && secoffset == invalid_address);
+         // Get the os of the section it is folded onto.
+         Section_id folded = symtab->icf()->get_folded_section(this,
+                                                               shndx);
+         gold_assert(folded.first != NULL);
+         Sized_relobj_file<size, big_endian>* folded_obj = reinterpret_cast
+           <Sized_relobj_file<size, big_endian>*>(folded.first);
+         os = folded_obj->output_section(folded.second);
+         gold_assert(os != NULL);
+         secoffset = folded_obj->get_output_section_offset(folded.second);
+         
+         // This could be a relaxed input section.
+         if (secoffset == invalid_address)
            {
-             // FIXME: Handle SHN_XINDEX.
-             this->error(_("unknown section index %u for local symbol %u"),
-                         shndx, i);
-             lv.set_output_value(0);
+             const Output_relaxed_input_section* relaxed_section =
+               os->find_relaxed_input_section(folded_obj, folded.second);
+             gold_assert(relaxed_section != NULL);
+             secoffset = relaxed_section->address() - os->address();
            }
        }
-      else
+      
+      if (os == NULL)
        {
-         if (shndx >= shnum)
+         // 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.
+         return This::CFLV_DISCARDED;
+       }
+      else if (secoffset == invalid_address)
+       {
+         uint64_t start;
+         
+         // This is a SHF_MERGE section or one which otherwise
+         // requires special handling.
+         if (shndx == this->discarded_eh_frame_shndx_)
            {
-             this->error(_("local symbol %u section index %u out of range"),
-                         i, shndx);
-             shndx = 0;
+             // This local symbol belongs to a discarded .eh_frame
+             // section.  Just treat it like the case in which
+             // os == NULL above.
+             gold_assert(this->has_eh_frame_);
+             return This::CFLV_DISCARDED;
            }
-
-         Output_section* os = mo[shndx].output_section;
-
-         if (os == NULL)
+         else if (!lv_in->is_section_symbol())
            {
-             lv.set_output_value(0);
-             continue;
+             // This is not a section symbol.  We can determine
+             // the final value now.
+             lv_out->set_output_value(
+                 os->output_address(this, shndx, lv_in->input_value()));
            }
-         else if (mo[shndx].offset == -1)
+         else if (!os->find_starting_output_address(this, shndx, &start))
            {
-             // This is a SHF_MERGE section or one which otherwise
-             // requires special handling.  We get the output address
-             // of the start of the merged section.  If this is not a
-             // section symbol, we can then determine the final
-             // value.  If it is a section symbol, we can not, as in
-             // that case we have to consider the addend to determine
-             // the value to use in a relocation.
-             if (!lv.is_section_symbol())
-               lv.set_output_value(os->output_address(this, shndx,
-                                                       lv.input_value()));
-             else
+             // This is a section symbol, but apparently not one in a
+             // merged section.  First check to see if this is a relaxed
+             // input section.  If so, use its address.  Otherwise just
+             // use the start of the output section.  This happens with
+             // relocatable links when the input object has section
+             // symbols for arbitrary non-merge sections.
+             const Output_section_data* posd =
+               os->find_relaxed_input_section(this, shndx);
+             if (posd != NULL)
                {
-                  section_offset_type start =
-                    os->starting_output_address(this, shndx);
-                 Merged_symbol_value<size>* msv =
-                   new Merged_symbol_value<size>(lv.input_value(), start);
-                 lv.set_merged_symbol_value(msv);
+                 Address relocatable_link_adjustment =
+                   relocatable ? os->address() : 0;
+                 lv_out->set_output_value(posd->address()
+                                          - relocatable_link_adjustment);
                }
+             else
+               lv_out->set_output_value(os->address());
            }
-          else if (lv.is_tls_symbol())
-           lv.set_output_value(os->tls_offset()
-                               + mo[shndx].offset
-                               + lv.input_value());
          else
-           lv.set_output_value(os->address()
-                               + mo[shndx].offset
-                               + lv.input_value());
+           {
+             // We have to consider the addend to determine the
+             // value to use in a relocation.  START is the start
+             // of this input section.  If we are doing a relocatable
+             // link, use offset from start output section instead of
+             // address.
+             Address adjusted_start =
+               relocatable ? start - os->address() : start;
+             Merged_symbol_value<size>* msv =
+               new Merged_symbol_value<size>(lv_in->input_value(),
+                                             adjusted_start);
+             lv_out->set_merged_symbol_value(msv);
+           }
        }
+      else if (lv_in->is_tls_symbol())
+       lv_out->set_output_value(os->tls_offset()
+                                + secoffset
+                                + lv_in->input_value());
+      else
+       lv_out->set_output_value((relocatable ? 0 : os->address())
+                                + secoffset
+                                + lv_in->input_value());
+    }
+  return This::CFLV_OK;
+}
 
-      if (lv.needs_output_symtab_entry())
-        {
-          lv.set_output_symtab_index(index);
-          ++index;
-        }
+// Compute final local symbol value.  R_SYM is the index of a local
+// symbol in symbol table.  LV points to a symbol value, which is
+// expected to hold the input value and to be over-written by the
+// final value.  SYMTAB points to a symbol table.  Some targets may want
+// to know would-be-finalized local symbol values in relaxation.
+// Hence we provide this method.  Since this method updates *LV, a
+// callee should make a copy of the original local symbol value and
+// use the copy instead of modifying an object's local symbols before
+// everything is finalized.  The caller should also free up any allocated
+// memory in the return value in *LV.
+template<int size, bool big_endian>
+typename Sized_relobj_file<size, big_endian>::Compute_final_local_value_status
+Sized_relobj_file<size, big_endian>::compute_final_local_value(
+    unsigned int r_sym,
+    const Symbol_value<size>* lv_in,
+    Symbol_value<size>* lv_out,
+    const Symbol_table* symtab)
+{
+  // This is just a wrapper of compute_final_local_value_internal.
+  const bool relocatable = parameters->options().relocatable();
+  const Output_sections& out_sections(this->output_sections());
+  const std::vector<Address>& out_offsets(this->section_offsets());
+  return this->compute_final_local_value_internal(r_sym, lv_in, lv_out,
+                                                 relocatable, out_sections,
+                                                 out_offsets, symtab);
+}
+
+// Finalize the local symbols.  Here we set the final value in
+// THIS->LOCAL_VALUES_ and set their output symbol table indexes.
+// This function is always called from a singleton thread.  The actual
+// output of the local symbols will occur in a separate task.
+
+template<int size, bool big_endian>
+unsigned int
+Sized_relobj_file<size, big_endian>::do_finalize_local_symbols(
+    unsigned int index,
+    off_t off,
+    Symbol_table* symtab)
+{
+  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 bool relocatable = parameters->options().relocatable();
+  const Output_sections& out_sections(this->output_sections());
+  const std::vector<Address>& out_offsets(this->section_offsets());
+
+  for (unsigned int i = 1; i < loccount; ++i)
+    {
+      Symbol_value<size>* lv = &this->local_values_[i];
+
+      Compute_final_local_value_status cflv_status =
+       this->compute_final_local_value_internal(i, lv, lv, relocatable,
+                                                out_sections, out_offsets,
+                                                symtab);
+      switch (cflv_status)
+       {
+       case CFLV_OK:
+         if (!lv->is_output_symtab_index_set())
+           {
+             lv->set_output_symtab_index(index);
+             ++index;
+           }
+         break;
+       case CFLV_DISCARDED:
+       case CFLV_ERROR:
+         // Do nothing.
+         break;
+       default:
+         gold_unreachable();
+       }
     }
   return index;
 }
@@ -1024,7 +2220,8 @@ Sized_relobj<size, big_endian>::do_finalize_local_symbols(unsigned int index,
 
 template<int size, bool big_endian>
 unsigned int
-Sized_relobj<size, big_endian>::do_set_local_dynsym_indexes(unsigned int index)
+Sized_relobj_file<size, big_endian>::do_set_local_dynsym_indexes(
+    unsigned int index)
 {
   const unsigned int loccount = this->local_symbol_count_;
   for (unsigned int i = 1; i < loccount; ++i)
@@ -1045,36 +2242,67 @@ Sized_relobj<size, big_endian>::do_set_local_dynsym_indexes(unsigned int index)
 
 template<int size, bool big_endian>
 unsigned int
-Sized_relobj<size, big_endian>::do_set_local_dynsym_offset(off_t off)
+Sized_relobj_file<size, big_endian>::do_set_local_dynsym_offset(off_t off)
 {
   gold_assert(off == static_cast<off_t>(align_address(off, size >> 3)));
   this->local_dynsym_offset_ = off;
   return this->output_local_dynsym_count_;
 }
 
-// Return the value of the local symbol symndx.
+// If Symbols_data is not NULL get the section flags from here otherwise
+// get it from the file.
+
 template<int size, bool big_endian>
-typename elfcpp::Elf_types<size>::Elf_Addr
-Sized_relobj<size, big_endian>::local_symbol_value(unsigned int symndx) const
+uint64_t
+Sized_relobj_file<size, big_endian>::do_section_flags(unsigned int shndx)
 {
-  gold_assert(symndx < this->local_symbol_count_);
-  gold_assert(symndx < this->local_values_.size());
-  const Symbol_value<size>& lv(this->local_values_[symndx]);
-  return lv.value(this, 0);
+  Symbols_data* sd = this->get_symbols_data();
+  if (sd != NULL)
+    {
+      const unsigned char* pshdrs = sd->section_headers_data
+                                    + This::shdr_size * shndx;
+      typename This::Shdr shdr(pshdrs);
+      return shdr.get_sh_flags(); 
+    }
+  // If sd is NULL, read the section header from the file.
+  return this->elf_file_.section_flags(shndx); 
+}
+
+// Get the section's ent size from Symbols_data.  Called by get_section_contents
+// in icf.cc
+
+template<int size, bool big_endian>
+uint64_t
+Sized_relobj_file<size, big_endian>::do_section_entsize(unsigned int shndx)
+{
+  Symbols_data* sd = this->get_symbols_data();
+  gold_assert(sd != NULL);
+
+  const unsigned char* pshdrs = sd->section_headers_data
+                                + This::shdr_size * shndx;
+  typename This::Shdr shdr(pshdrs);
+  return shdr.get_sh_entsize(); 
 }
 
 // Write out the local symbols.
 
 template<int size, bool big_endian>
 void
-Sized_relobj<size, big_endian>::write_local_symbols(
+Sized_relobj_file<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,
+    off_t symtab_off)
 {
-  if (parameters->options().strip_all()
-      && this->output_local_dynsym_count_ == 0)
-    return;
+  const bool strip_all = parameters->options().strip_all();
+  if (strip_all)
+    {
+      if (this->output_local_dynsym_count_ == 0)
+       return;
+      this->output_local_symbol_count_ = 0;
+    }
 
   gold_assert(this->symtab_shndx_ != -1U);
   if (this->symtab_shndx_ == 0)
@@ -1095,10 +2323,11 @@ Sized_relobj<size, big_endian>::write_local_symbols(
   const int sym_size = This::sym_size;
   off_t locsize = loccount * sym_size;
   const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
-                                             locsize, false);
+                                             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,
@@ -1110,7 +2339,8 @@ Sized_relobj<size, big_endian>::write_local_symbols(
   off_t output_size = this->output_local_symbol_count_ * sym_size;
   unsigned char* oview = NULL;
   if (output_size > 0)
-    oview = of->get_output_view(this->local_symbol_offset_, output_size);
+    oview = of->get_output_view(symtab_off + this->local_symbol_offset_,
+                               output_size);
 
   off_t dyn_output_size = this->output_local_dynsym_count_ * sym_size;
   unsigned char* dyn_oview = NULL;
@@ -1118,7 +2348,7 @@ 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);
 
@@ -1129,18 +2359,29 @@ 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.has_output_symtab_entry())
+               symtab_xindex->add(lv.output_symtab_index(), st_shndx);
+             if (lv.has_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())
+      if (lv.has_output_symtab_entry())
         {
           elfcpp::Sym_write<size, big_endian> osym(ov);
 
@@ -1157,7 +2398,7 @@ 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.has_output_dynsym_entry())
         {
           gold_assert(dyn_ov < dyn_oview + dyn_output_size);
           elfcpp::Sym_write<size, big_endian> osym(dyn_ov);
@@ -1179,7 +2420,8 @@ Sized_relobj<size, big_endian>::write_local_symbols(
   if (output_size > 0)
     {
       gold_assert(ov - oview == output_size);
-      of->write_output_view(this->local_symbol_offset_, output_size, oview);
+      of->write_output_view(symtab_off + this->local_symbol_offset_,
+                           output_size, oview);
     }
 
   if (dyn_output_size > 0)
@@ -1196,7 +2438,7 @@ Sized_relobj<size, big_endian>::write_local_symbols(
 
 template<int size, bool big_endian>
 bool
-Sized_relobj<size, big_endian>::get_symbol_location_info(
+Sized_relobj_file<size, big_endian>::get_symbol_location_info(
     unsigned int shndx,
     off_t offset,
     Symbol_location_info* info)
@@ -1209,7 +2451,8 @@ 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);
@@ -1229,18 +2472,24 @@ 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)";
          else
             {
               info->enclosing_symbol_name = symbol_names + sym.get_st_name();
-              if (parameters->options().demangle())
+              if (parameters->options().do_demangle())
                 {
                   char* demangled_name = cplus_demangle(
                       info->enclosing_symbol_name.c_str(),
@@ -1259,6 +2508,56 @@ 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_file<size, big_endian>::Address
+Sized_relobj_file<size, big_endian>::map_to_kept_section(
+    unsigned int shndx,
+    bool* found) const
+{
+  Relobj* kept_object;
+  unsigned int kept_shndx;
+  if (this->get_kept_comdat_section(shndx, &kept_object, &kept_shndx))
+    {
+      Sized_relobj_file<size, big_endian>* kept_relobj =
+       static_cast<Sized_relobj_file<size, big_endian>*>(kept_object);
+      Output_section* os = kept_relobj->output_section(kept_shndx);
+      Address offset = kept_relobj->get_output_section_offset(kept_shndx);
+      if (os != NULL && offset != invalid_address)
+       {
+         *found = true;
+         return os->address() + offset;
+       }
+    }
+  *found = false;
+  return 0;
+}
+
+// Get symbol counts.
+
+template<int size, bool big_endian>
+void
+Sized_relobj_file<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 (typename 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
@@ -1267,15 +2566,9 @@ Sized_relobj<size, big_endian>::get_symbol_location_info(
 bool
 Input_objects::add_object(Object* obj)
 {
-  // Set the global target from the first object file we recognize.
-  Target* target = obj->target();
-  if (!parameters->target_valid())
-    set_parameters_target(target);
-  else if (target != &parameters->target())
-    {
-      obj->error(_("incompatible target"));
-      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));
@@ -1294,50 +2587,35 @@ Input_objects::add_object(Object* obj)
        }
 
       this->dynobj_list_.push_back(dynobj);
+    }
 
-      // If this is -lc, remember the directory in which we found it.
-      // We use this when issuing warnings about undefined symbols: as
-      // a heuristic, we don't warn about system libraries found in
-      // the same directory as -lc.
-      if (strncmp(soname, "libc.so", 7) == 0)
-       {
-         const char* object_name = dynobj->name().c_str();
-         const char* base = lbasename(object_name);
-         if (base != object_name)
-           this->system_library_directory_.assign(object_name,
-                                                  base - 1 - object_name);
-       }
+  // Add this object to the cross-referencer if requested.
+  if (parameters->options().user_set_print_symbol_counts()
+      || parameters->options().cref())
+    {
+      if (this->cref_ == NULL)
+       this->cref_ = new Cref();
+      this->cref_->add_object(obj);
     }
 
   return true;
 }
 
-// Return whether an object was found in the system library directory.
-
-bool
-Input_objects::found_in_system_library_directory(const Object* object) const
-{
-  return (!this->system_library_directory_.empty()
-         && object->name().compare(0,
-                                   this->system_library_directory_.size(),
-                                   this->system_library_directory_) == 0);
-}
-
 // For each dynamic object, record whether we've seen all of its
 // explicit dependencies.
 
 void
 Input_objects::check_dynamic_dependencies() const
 {
+  bool issued_copy_dt_needed_error = false;
   for (Dynobj_list::const_iterator p = this->dynobj_list_.begin();
        p != this->dynobj_list_.end();
        ++p)
     {
       const Dynobj::Needed& needed((*p)->needed());
       bool found_all = true;
-      for (Dynobj::Needed::const_iterator pneeded = needed.begin();
-          pneeded != needed.end();
-          ++pneeded)
+      Dynobj::Needed::const_iterator pneeded;
+      for (pneeded = needed.begin(); pneeded != needed.end(); ++pneeded)
        {
          if (this->sonames_.find(*pneeded) == this->sonames_.end())
            {
@@ -1346,51 +2624,110 @@ Input_objects::check_dynamic_dependencies() const
            }
        }
       (*p)->set_has_unknown_needed_entries(!found_all);
+
+      // --copy-dt-needed-entries aka --add-needed is a GNU ld option
+      // that gold does not support.  However, they cause no trouble
+      // unless there is a DT_NEEDED entry that we don't know about;
+      // warn only in that case.
+      if (!found_all
+         && !issued_copy_dt_needed_error
+         && (parameters->options().copy_dt_needed_entries()
+             || parameters->options().add_needed()))
+       {
+         const char* optname;
+         if (parameters->options().copy_dt_needed_entries())
+           optname = "--copy-dt-needed-entries";
+         else
+           optname = "--add-needed";
+         gold_error(_("%s is not supported but is required for %s in %s"),
+                    optname, (*pneeded).c_str(), (*p)->name().c_str());
+         issued_copy_dt_needed_error = true;
+       }
     }
 }
 
+// Start processing an archive.
+
+void
+Input_objects::archive_start(Archive* archive)
+{
+  if (parameters->options().user_set_print_symbol_counts()
+      || parameters->options().cref())
+    {
+      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()
+      || parameters->options().cref())
+    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);
+}
+
+// Print a cross reference table.
+
+void
+Input_objects::print_cref(const Symbol_table* symtab, FILE* f) const
+{
+  if (parameters->options().cref() && this->cref_ != NULL)
+    this->cref_->print_cref(symtab, f);
+}
+
 // Relocate_info methods.
 
-// Return a string describing the location of a relocation.  This is
-// only used in error messages.
+// Return a string describing the location of a relocation when file
+// and lineno information is not available.  This is only used in
+// error messages.
 
 template<int size, bool big_endian>
 std::string
 Relocate_info<size, big_endian>::location(size_t, off_t offset) const
 {
-  // See if we can get line-number information from debugging sections.
-  std::string filename;
-  std::string file_and_lineno;   // Better than filename-only, if available.
-
   Sized_dwarf_line_info<size, big_endian> line_info(this->object);
-  // This will be "" if we failed to parse the debug info for any reason.
-  file_and_lineno = line_info.addr2line(this->data_shndx, offset);
+  std::string ret = line_info.addr2line(this->data_shndx, offset, NULL);
+  if (!ret.empty())
+    return ret;
+
+  ret = this->object->name();
 
-  std::string ret(this->object->name());
-  ret += ':';
   Symbol_location_info info;
   if (this->object->get_symbol_location_info(this->data_shndx, offset, &info))
     {
-      ret += " in function ";
-      ret += info.enclosing_symbol_name;
-      ret += ":";
-      filename = info.source_file;
-    }
-
-  if (!file_and_lineno.empty())
-    ret += file_and_lineno;
-  else
-    {
-      if (!filename.empty())
-        ret += filename;
-      ret += "(";
-      ret += this->object->section_name(this->data_shndx);
-      char buf[100];
-      // Offsets into sections have to be positive.
-      snprintf(buf, sizeof(buf), "+0x%lx", static_cast<long>(offset));
+      if (!info.source_file.empty())
+       {
+         ret += ":";
+         ret += info.source_file;
+       }
+      size_t len = info.enclosing_symbol_name.length() + 100;
+      char* buf = new char[len];
+      snprintf(buf, len, _(":function %s"),
+              info.enclosing_symbol_name.c_str());
       ret += buf;
-      ret += ")";
+      delete[] buf;
+      return ret;
     }
+
+  ret += "(";
+  ret += this->object->section_name(this->data_shndx);
+  char buf[100];
+  snprintf(buf, sizeof buf, "+0x%lx)", static_cast<long>(offset));
+  ret += buf;
   return ret;
 }
 
@@ -1407,29 +2744,29 @@ using namespace gold;
 template<int size, bool big_endian>
 Object*
 make_elf_sized_object(const std::string& name, Input_file* input_file,
-                     off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr)
+                     off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr,
+                     bool* punconfigured)
 {
-  int et = ehdr.get_e_type();
-  if (et == elfcpp::ET_REL)
-    {
-      Sized_relobj<size, big_endian>* obj =
-       new Sized_relobj<size, big_endian>(name, input_file, offset, ehdr);
-      obj->setup(ehdr);
-      return obj;
-    }
-  else if (et == elfcpp::ET_DYN)
-    {
-      Sized_dynobj<size, big_endian>* obj =
-       new Sized_dynobj<size, big_endian>(name, input_file, offset, ehdr);
-      obj->setup(ehdr);
-      return obj;
-    }
-  else
+  Target* target = select_target(ehdr.get_e_machine(), size, big_endian,
+                                ehdr.get_e_ident()[elfcpp::EI_OSABI],
+                                ehdr.get_e_ident()[elfcpp::EI_ABIVERSION]);
+  if (target == NULL)
+    gold_fatal(_("%s: unsupported ELF machine number %d"),
+              name.c_str(), ehdr.get_e_machine());
+
+  if (!parameters->target_valid())
+    set_parameters_target(target);
+  else if (target != &parameters->target())
     {
-      gold_error(_("%s: unsupported ELF file type %d"),
-                name.c_str(), et);
+      if (punconfigured != NULL)
+       *punconfigured = true;
+      else
+       gold_error(_("%s: incompatible target"), name.c_str());
       return NULL;
     }
+
+  return target->make_elf_object<size, big_endian>(name, input_file, offset,
+                                                  ehdr);
 }
 
 } // End anonymous namespace.
@@ -1437,73 +2774,60 @@ make_elf_sized_object(const std::string& name, Input_file* input_file,
 namespace gold
 {
 
-// Read an ELF file and return the appropriate instance of Object.
+// Return whether INPUT_FILE is an ELF object.
 
-Object*
-make_elf_object(const std::string& name, Input_file* input_file, off_t offset,
-               const unsigned char* p, section_offset_type bytes)
+bool
+is_elf_object(Input_file* input_file, off_t offset,
+             const unsigned char** start, int* read_size)
 {
-  if (bytes < elfcpp::EI_NIDENT)
-    {
-      gold_error(_("%s: ELF file too short"), name.c_str());
-      return NULL;
-    }
+  off_t filesize = input_file->file().filesize();
+  int want = elfcpp::Elf_recognizer::max_header_size;
+  if (filesize - offset < want)
+    want = filesize - offset;
 
-  int v = p[elfcpp::EI_VERSION];
-  if (v != elfcpp::EV_CURRENT)
-    {
-      if (v == elfcpp::EV_NONE)
-       gold_error(_("%s: invalid ELF version 0"), name.c_str());
-      else
-       gold_error(_("%s: unsupported ELF version %d"), name.c_str(), v);
-      return NULL;
-    }
+  const unsigned char* p = input_file->file().get_view(offset, 0, want,
+                                                      true, false);
+  *start = p;
+  *read_size = want;
 
-  int c = p[elfcpp::EI_CLASS];
-  if (c == elfcpp::ELFCLASSNONE)
-    {
-      gold_error(_("%s: invalid ELF class 0"), name.c_str());
-      return NULL;
-    }
-  else if (c != elfcpp::ELFCLASS32
-          && c != elfcpp::ELFCLASS64)
-    {
-      gold_error(_("%s: unsupported ELF class %d"), name.c_str(), c);
-      return NULL;
-    }
+  return elfcpp::Elf_recognizer::is_elf_file(p, want);
+}
 
-  int d = p[elfcpp::EI_DATA];
-  if (d == elfcpp::ELFDATANONE)
-    {
-      gold_error(_("%s: invalid ELF data encoding"), name.c_str());
-      return NULL;
-    }
-  else if (d != elfcpp::ELFDATA2LSB
-          && d != elfcpp::ELFDATA2MSB)
+// Read an ELF file and return the appropriate instance of Object.
+
+Object*
+make_elf_object(const std::string& name, Input_file* input_file, off_t offset,
+               const unsigned char* p, section_offset_type bytes,
+               bool* punconfigured)
+{
+  if (punconfigured != NULL)
+    *punconfigured = false;
+
+  std::string error;
+  bool big_endian = false;
+  int size = 0;
+  if (!elfcpp::Elf_recognizer::is_valid_header(p, bytes, &size,
+                                               &big_endian, &error))
     {
-      gold_error(_("%s: unsupported ELF data encoding %d"), name.c_str(), d);
+      gold_error(_("%s: %s"), name.c_str(), error.c_str());
       return NULL;
     }
 
-  bool big_endian = d == elfcpp::ELFDATA2MSB;
-
-  if (c == elfcpp::ELFCLASS32)
+  if (size == 32)
     {
-      if (bytes < elfcpp::Elf_sizes<32>::ehdr_size)
-       {
-         gold_error(_("%s: ELF file too short"), name.c_str());
-         return NULL;
-       }
       if (big_endian)
        {
 #ifdef HAVE_TARGET_32_BIG
          elfcpp::Ehdr<32, true> ehdr(p);
          return make_elf_sized_object<32, true>(name, input_file,
-                                                offset, ehdr);
+                                                offset, ehdr, punconfigured);
 #else
-          gold_error(_("%s: not configured to support "
-                      "32-bit big-endian object"),
-                    name.c_str());
+         if (punconfigured != NULL)
+           *punconfigured = true;
+         else
+           gold_error(_("%s: not configured to support "
+                        "32-bit big-endian object"),
+                      name.c_str());
          return NULL;
 #endif
        }
@@ -1512,32 +2836,33 @@ make_elf_object(const std::string& name, Input_file* input_file, off_t offset,
 #ifdef HAVE_TARGET_32_LITTLE
          elfcpp::Ehdr<32, false> ehdr(p);
          return make_elf_sized_object<32, false>(name, input_file,
-                                                 offset, ehdr);
+                                                 offset, ehdr, punconfigured);
 #else
-          gold_error(_("%s: not configured to support "
-                      "32-bit little-endian object"),
-                    name.c_str());
+         if (punconfigured != NULL)
+           *punconfigured = true;
+         else
+           gold_error(_("%s: not configured to support "
+                        "32-bit little-endian object"),
+                      name.c_str());
          return NULL;
 #endif
        }
     }
-  else
+  else if (size == 64)
     {
-      if (bytes < elfcpp::Elf_sizes<32>::ehdr_size)
-       {
-         gold_error(_("%s: ELF file too short"), name.c_str());
-         return NULL;
-       }
       if (big_endian)
        {
 #ifdef HAVE_TARGET_64_BIG
          elfcpp::Ehdr<64, true> ehdr(p);
          return make_elf_sized_object<64, true>(name, input_file,
-                                                offset, ehdr);
+                                                offset, ehdr, punconfigured);
 #else
-          gold_error(_("%s: not configured to support "
-                      "64-bit big-endian object"),
-                    name.c_str());
+         if (punconfigured != NULL)
+           *punconfigured = true;
+         else
+           gold_error(_("%s: not configured to support "
+                        "64-bit big-endian object"),
+                      name.c_str());
          return NULL;
 #endif
        }
@@ -1546,38 +2871,70 @@ make_elf_object(const std::string& name, Input_file* input_file, off_t offset,
 #ifdef HAVE_TARGET_64_LITTLE
          elfcpp::Ehdr<64, false> ehdr(p);
          return make_elf_sized_object<64, false>(name, input_file,
-                                                 offset, ehdr);
+                                                 offset, ehdr, punconfigured);
 #else
-          gold_error(_("%s: not configured to support "
-                      "64-bit little-endian object"),
-                    name.c_str());
+         if (punconfigured != NULL)
+           *punconfigured = true;
+         else
+           gold_error(_("%s: not configured to support "
+                        "64-bit little-endian object"),
+                      name.c_str());
          return NULL;
 #endif
        }
     }
+  else
+    gold_unreachable();
 }
 
-// Instantiate the templates we need.  We could use the configure
-// script to restrict this to only the ones for implemented targets.
+// Instantiate the templates we need.
 
 #ifdef HAVE_TARGET_32_LITTLE
 template
-class Sized_relobj<32, false>;
+void
+Object::read_section_data<32, false>(elfcpp::Elf_file<32, false, Object>*,
+                                    Read_symbols_data*);
+#endif
+
+#ifdef HAVE_TARGET_32_BIG
+template
+void
+Object::read_section_data<32, true>(elfcpp::Elf_file<32, true, Object>*,
+                                   Read_symbols_data*);
+#endif
+
+#ifdef HAVE_TARGET_64_LITTLE
+template
+void
+Object::read_section_data<64, false>(elfcpp::Elf_file<64, false, Object>*,
+                                    Read_symbols_data*);
+#endif
+
+#ifdef HAVE_TARGET_64_BIG
+template
+void
+Object::read_section_data<64, true>(elfcpp::Elf_file<64, true, Object>*,
+                                   Read_symbols_data*);
+#endif
+
+#ifdef HAVE_TARGET_32_LITTLE
+template
+class Sized_relobj_file<32, false>;
 #endif
 
 #ifdef HAVE_TARGET_32_BIG
 template
-class Sized_relobj<32, true>;
+class Sized_relobj_file<32, true>;
 #endif
 
 #ifdef HAVE_TARGET_64_LITTLE
 template
-class Sized_relobj<64, false>;
+class Sized_relobj_file<64, false>;
 #endif
 
 #ifdef HAVE_TARGET_64_BIG
 template
-class Sized_relobj<64, true>;
+class Sized_relobj_file<64, true>;
 #endif
 
 #ifdef HAVE_TARGET_32_LITTLE
@@ -1600,4 +2957,48 @@ template
 struct Relocate_info<64, true>;
 #endif
 
+#ifdef HAVE_TARGET_32_LITTLE
+template
+void
+Xindex::initialize_symtab_xindex<32, false>(Object*, unsigned int);
+
+template
+void
+Xindex::read_symtab_xindex<32, false>(Object*, unsigned int,
+                                     const unsigned char*);
+#endif
+
+#ifdef HAVE_TARGET_32_BIG
+template
+void
+Xindex::initialize_symtab_xindex<32, true>(Object*, unsigned int);
+
+template
+void
+Xindex::read_symtab_xindex<32, true>(Object*, unsigned int,
+                                    const unsigned char*);
+#endif
+
+#ifdef HAVE_TARGET_64_LITTLE
+template
+void
+Xindex::initialize_symtab_xindex<64, false>(Object*, unsigned int);
+
+template
+void
+Xindex::read_symtab_xindex<64, false>(Object*, unsigned int,
+                                     const unsigned char*);
+#endif
+
+#ifdef HAVE_TARGET_64_BIG
+template
+void
+Xindex::initialize_symtab_xindex<64, true>(Object*, unsigned int);
+
+template
+void
+Xindex::read_symtab_xindex<64, true>(Object*, unsigned int,
+                                    const unsigned char*);
+#endif
+
 } // End namespace gold.
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