[deliverable/binutils-gdb.git] / gold / i386.cc

// i386.cc -- i386 target support for gold.

// Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.

// This file is part of gold.

// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
// MA 02110-1301, USA.

#include "gold.h"

#include <cstring>

#include "elfcpp.h"
#include "parameters.h"
#include "reloc.h"
#include "i386.h"
#include "object.h"
#include "symtab.h"
#include "layout.h"
#include "output.h"
#include "copy-relocs.h"
#include "target.h"
#include "target-reloc.h"
#include "target-select.h"
#include "tls.h"

namespace
{

using namespace gold;

class Output_data_plt_i386;

// The i386 target class.
// TLS info comes from
//   http://people.redhat.com/drepper/tls.pdf
//   http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt

class Target_i386 : public Sized_target<32, false>
{
 public:
  typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;

  Target_i386()
    : Sized_target<32, false>(&i386_info),
      got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
      copy_relocs_(elfcpp::R_386_COPY), dynbss_(NULL),
      got_mod_index_offset_(-1U)
  { }

  // Scan the relocations to look for symbol adjustments.
  void
  scan_relocs(const General_options& options,
	      Symbol_table* symtab,
	      Layout* layout,
	      Sized_relobj<32, false>* object,
	      unsigned int data_shndx,
	      unsigned int sh_type,
	      const unsigned char* prelocs,
	      size_t reloc_count,
	      Output_section* output_section,
	      bool needs_special_offset_handling,
	      size_t local_symbol_count,
	      const unsigned char* plocal_symbols);

  // Finalize the sections.
  void
  do_finalize_sections(Layout*);

  // Return the value to use for a dynamic which requires special
  // treatment.
  uint64_t
  do_dynsym_value(const Symbol*) const;

  // Relocate a section.
  void
  relocate_section(const Relocate_info<32, false>*,
		   unsigned int sh_type,
		   const unsigned char* prelocs,
		   size_t reloc_count,
		   Output_section* output_section,
		   bool needs_special_offset_handling,
		   unsigned char* view,
		   elfcpp::Elf_types<32>::Elf_Addr view_address,
		   section_size_type view_size);

  // Scan the relocs during a relocatable link.
  void
  scan_relocatable_relocs(const General_options& options,
			  Symbol_table* symtab,
			  Layout* layout,
			  Sized_relobj<32, false>* object,
			  unsigned int data_shndx,
			  unsigned int sh_type,
			  const unsigned char* prelocs,
			  size_t reloc_count,
			  Output_section* output_section,
			  bool needs_special_offset_handling,
			  size_t local_symbol_count,
			  const unsigned char* plocal_symbols,
			  Relocatable_relocs*);

  // Relocate a section during a relocatable link.
  void
  relocate_for_relocatable(const Relocate_info<32, false>*,
			   unsigned int sh_type,
			   const unsigned char* prelocs,
			   size_t reloc_count,
			   Output_section* output_section,
			   off_t offset_in_output_section,
			   const Relocatable_relocs*,
			   unsigned char* view,
			   elfcpp::Elf_types<32>::Elf_Addr view_address,
			   section_size_type view_size,
			   unsigned char* reloc_view,
			   section_size_type reloc_view_size);

  // Return a string used to fill a code section with nops.
  std::string
  do_code_fill(section_size_type length) const;

  // Return whether SYM is defined by the ABI.
  bool
  do_is_defined_by_abi(Symbol* sym) const
  { return strcmp(sym->name(), "___tls_get_addr") == 0; }

  // Return the size of the GOT section.
  section_size_type
  got_size()
  {
    gold_assert(this->got_ != NULL);
    return this->got_->data_size();
  }

 private:
  // The class which scans relocations.
  struct Scan
  {
    inline void
    local(const General_options& options, Symbol_table* symtab,
	  Layout* layout, Target_i386* target,
	  Sized_relobj<32, false>* object,
	  unsigned int data_shndx,
	  Output_section* output_section,
	  const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
	  const elfcpp::Sym<32, false>& lsym);

    inline void
    global(const General_options& options, Symbol_table* symtab,
	   Layout* layout, Target_i386* target,
	   Sized_relobj<32, false>* object,
	   unsigned int data_shndx,
	   Output_section* output_section,
	   const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
	   Symbol* gsym);

    static void
    unsupported_reloc_local(Sized_relobj<32, false>*, unsigned int r_type);

    static void
    unsupported_reloc_global(Sized_relobj<32, false>*, unsigned int r_type,
			     Symbol*);
  };

  // The class which implements relocation.
  class Relocate
  {
   public:
    Relocate()
      : skip_call_tls_get_addr_(false),
	local_dynamic_type_(LOCAL_DYNAMIC_NONE)
    { }

    ~Relocate()
    {
      if (this->skip_call_tls_get_addr_)
	{
	  // FIXME: This needs to specify the location somehow.
	  gold_error(_("missing expected TLS relocation"));
	}
    }

    // Return whether the static relocation needs to be applied.
    inline bool
    should_apply_static_reloc(const Sized_symbol<32>* gsym,
                              int ref_flags,
                              bool is_32bit);

    // Do a relocation.  Return false if the caller should not issue
    // any warnings about this relocation.
    inline bool
    relocate(const Relocate_info<32, false>*, Target_i386*, size_t relnum,
	     const elfcpp::Rel<32, false>&,
	     unsigned int r_type, const Sized_symbol<32>*,
	     const Symbol_value<32>*,
	     unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
	     section_size_type);

   private:
    // Do a TLS relocation.
    inline void
    relocate_tls(const Relocate_info<32, false>*, Target_i386* target,
                 size_t relnum, const elfcpp::Rel<32, false>&,
		 unsigned int r_type, const Sized_symbol<32>*,
		 const Symbol_value<32>*,
		 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
		 section_size_type);

    // Do a TLS General-Dynamic to Initial-Exec transition.
    inline void
    tls_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
		 Output_segment* tls_segment,
		 const elfcpp::Rel<32, false>&, unsigned int r_type,
		 elfcpp::Elf_types<32>::Elf_Addr value,
		 unsigned char* view,
		 section_size_type view_size);

    // Do a TLS General-Dynamic to Local-Exec transition.
    inline void
    tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
		 Output_segment* tls_segment,
		 const elfcpp::Rel<32, false>&, unsigned int r_type,
		 elfcpp::Elf_types<32>::Elf_Addr value,
		 unsigned char* view,
		 section_size_type view_size);

    // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
    // transition.
    inline void
    tls_desc_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
		      Output_segment* tls_segment,
		      const elfcpp::Rel<32, false>&, unsigned int r_type,
		      elfcpp::Elf_types<32>::Elf_Addr value,
		      unsigned char* view,
		      section_size_type view_size);

    // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
    // transition.
    inline void
    tls_desc_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
		      Output_segment* tls_segment,
		      const elfcpp::Rel<32, false>&, unsigned int r_type,
		      elfcpp::Elf_types<32>::Elf_Addr value,
		      unsigned char* view,
		      section_size_type view_size);

    // Do a TLS Local-Dynamic to Local-Exec transition.
    inline void
    tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum,
		 Output_segment* tls_segment,
		 const elfcpp::Rel<32, false>&, unsigned int r_type,
		 elfcpp::Elf_types<32>::Elf_Addr value,
		 unsigned char* view,
		 section_size_type view_size);

    // Do a TLS Initial-Exec to Local-Exec transition.
    static inline void
    tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
		 Output_segment* tls_segment,
		 const elfcpp::Rel<32, false>&, unsigned int r_type,
		 elfcpp::Elf_types<32>::Elf_Addr value,
		 unsigned char* view,
		 section_size_type view_size);

    // We need to keep track of which type of local dynamic relocation
    // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
    enum Local_dynamic_type
    {
      LOCAL_DYNAMIC_NONE,
      LOCAL_DYNAMIC_SUN,
      LOCAL_DYNAMIC_GNU
    };

    // This is set if we should skip the next reloc, which should be a
    // PLT32 reloc against ___tls_get_addr.
    bool skip_call_tls_get_addr_;
    // The type of local dynamic relocation we have seen in the section
    // being relocated, if any.
    Local_dynamic_type local_dynamic_type_;
  };

  // A class which returns the size required for a relocation type,
  // used while scanning relocs during a relocatable link.
  class Relocatable_size_for_reloc
  {
   public:
    unsigned int
    get_size_for_reloc(unsigned int, Relobj*);
  };

  // Adjust TLS relocation type based on the options and whether this
  // is a local symbol.
  static tls::Tls_optimization
  optimize_tls_reloc(bool is_final, int r_type);

  // Get the GOT section, creating it if necessary.
  Output_data_got<32, false>*
  got_section(Symbol_table*, Layout*);

  // Get the GOT PLT section.
  Output_data_space*
  got_plt_section() const
  {
    gold_assert(this->got_plt_ != NULL);
    return this->got_plt_;
  }

  // Create a PLT entry for a global symbol.
  void
  make_plt_entry(Symbol_table*, Layout*, Symbol*);

  // Create a GOT entry for the TLS module index.
  unsigned int
  got_mod_index_entry(Symbol_table* symtab, Layout* layout,
		      Sized_relobj<32, false>* object);

  // Get the PLT section.
  const Output_data_plt_i386*
  plt_section() const
  {
    gold_assert(this->plt_ != NULL);
    return this->plt_;
  }

  // Get the dynamic reloc section, creating it if necessary.
  Reloc_section*
  rel_dyn_section(Layout*);

  // Return true if the symbol may need a COPY relocation.
  // References from an executable object to non-function symbols
  // defined in a dynamic object may need a COPY relocation.
  bool
  may_need_copy_reloc(Symbol* gsym)
  {
    return (!parameters->options().shared()
            && gsym->is_from_dynobj()
            && gsym->type() != elfcpp::STT_FUNC);
  }

  // Add a potential copy relocation.
  void
  copy_reloc(Symbol_table* symtab, Layout* layout, Relobj* object,
	     unsigned int shndx, Output_section* output_section,
	     Symbol* sym, const elfcpp::Rel<32, false>& reloc)
  {
    this->copy_relocs_.copy_reloc(symtab, layout,
				  symtab->get_sized_symbol<32>(sym),
				  object, shndx, output_section, reloc,
				  this->rel_dyn_section(layout));
  }

  // Information about this specific target which we pass to the
  // general Target structure.
  static const Target::Target_info i386_info;

  // The types of GOT entries needed for this platform.
  enum Got_type
  {
    GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
    GOT_TYPE_TLS_NOFFSET = 1,   // GOT entry for negative TLS offset
    GOT_TYPE_TLS_OFFSET = 2,    // GOT entry for positive TLS offset
    GOT_TYPE_TLS_PAIR = 3,      // GOT entry for TLS module/offset pair
    GOT_TYPE_TLS_DESC = 4       // GOT entry for TLS_DESC pair
  };

  // The GOT section.
  Output_data_got<32, false>* got_;
  // The PLT section.
  Output_data_plt_i386* plt_;
  // The GOT PLT section.
  Output_data_space* got_plt_;
  // The dynamic reloc section.
  Reloc_section* rel_dyn_;
  // Relocs saved to avoid a COPY reloc.
  Copy_relocs<elfcpp::SHT_REL, 32, false> copy_relocs_;
  // Space for variables copied with a COPY reloc.
  Output_data_space* dynbss_;
  // Offset of the GOT entry for the TLS module index.
  unsigned int got_mod_index_offset_;
};

const Target::Target_info Target_i386::i386_info =
{
  32,			// size
  false,		// is_big_endian
  elfcpp::EM_386,	// machine_code
  false,		// has_make_symbol
  false,		// has_resolve
  true,			// has_code_fill
  true,			// is_default_stack_executable
  '\0',			// wrap_char
  "/usr/lib/libc.so.1",	// dynamic_linker
  0x08048000,		// default_text_segment_address
  0x1000,		// abi_pagesize (overridable by -z max-page-size)
  0x1000		// common_pagesize (overridable by -z common-page-size)
};

// Get the GOT section, creating it if necessary.

Output_data_got<32, false>*
Target_i386::got_section(Symbol_table* symtab, Layout* layout)
{
  if (this->got_ == NULL)
    {
      gold_assert(symtab != NULL && layout != NULL);

      this->got_ = new Output_data_got<32, false>();

      layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
				      elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
				      this->got_);

      // The old GNU linker creates a .got.plt section.  We just
      // create another set of data in the .got section.  Note that we
      // always create a PLT if we create a GOT, although the PLT
      // might be empty.
      this->got_plt_ = new Output_data_space(4);
      layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
				      elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
				      this->got_plt_);

      // The first three entries are reserved.
      this->got_plt_->set_current_data_size(3 * 4);

      // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
      symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
				    this->got_plt_,
				    0, 0, elfcpp::STT_OBJECT,
				    elfcpp::STB_LOCAL,
				    elfcpp::STV_HIDDEN, 0,
				    false, false);
    }

  return this->got_;
}

// Get the dynamic reloc section, creating it if necessary.

Target_i386::Reloc_section*
Target_i386::rel_dyn_section(Layout* layout)
{
  if (this->rel_dyn_ == NULL)
    {
      gold_assert(layout != NULL);
      this->rel_dyn_ = new Reloc_section();
      layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
				      elfcpp::SHF_ALLOC, this->rel_dyn_);
    }
  return this->rel_dyn_;
}

// A class to handle the PLT data.

class Output_data_plt_i386 : public Output_section_data
{
 public:
  typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;

  Output_data_plt_i386(Layout*, Output_data_space*);

  // Add an entry to the PLT.
  void
  add_entry(Symbol* gsym);

  // Return the .rel.plt section data.
  const Reloc_section*
  rel_plt() const
  { return this->rel_; }

 protected:
  void
  do_adjust_output_section(Output_section* os);

 private:
  // The size of an entry in the PLT.
  static const int plt_entry_size = 16;

  // The first entry in the PLT for an executable.
  static unsigned char exec_first_plt_entry[plt_entry_size];

  // The first entry in the PLT for a shared object.
  static unsigned char dyn_first_plt_entry[plt_entry_size];

  // Other entries in the PLT for an executable.
  static unsigned char exec_plt_entry[plt_entry_size];

  // Other entries in the PLT for a shared object.
  static unsigned char dyn_plt_entry[plt_entry_size];

  // Set the final size.
  void
  set_final_data_size()
  { this->set_data_size((this->count_ + 1) * plt_entry_size); }

  // Write out the PLT data.
  void
  do_write(Output_file*);

  // The reloc section.
  Reloc_section* rel_;
  // The .got.plt section.
  Output_data_space* got_plt_;
  // The number of PLT entries.
  unsigned int count_;
};

// Create the PLT section.  The ordinary .got section is an argument,
// since we need to refer to the start.  We also create our own .got
// section just for PLT entries.

Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
					   Output_data_space* got_plt)
  : Output_section_data(4), got_plt_(got_plt), count_(0)
{
  this->rel_ = new Reloc_section();
  layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
				  elfcpp::SHF_ALLOC, this->rel_);
}

void
Output_data_plt_i386::do_adjust_output_section(Output_section* os)
{
  // UnixWare sets the entsize of .plt to 4, and so does the old GNU
  // linker, and so do we.
  os->set_entsize(4);
}

// Add an entry to the PLT.

void
Output_data_plt_i386::add_entry(Symbol* gsym)
{
  gold_assert(!gsym->has_plt_offset());

  // Note that when setting the PLT offset we skip the initial
  // reserved PLT entry.
  gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);

  ++this->count_;

  section_offset_type got_offset = this->got_plt_->current_data_size();

  // Every PLT entry needs a GOT entry which points back to the PLT
  // entry (this will be changed by the dynamic linker, normally
  // lazily when the function is called).
  this->got_plt_->set_current_data_size(got_offset + 4);

  // Every PLT entry needs a reloc.
  gsym->set_needs_dynsym_entry();
  this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
			 got_offset);

  // Note that we don't need to save the symbol.  The contents of the
  // PLT are independent of which symbols are used.  The symbols only
  // appear in the relocations.
}

// The first entry in the PLT for an executable.

unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] =
{
  0xff, 0x35,	// pushl contents of memory address
  0, 0, 0, 0,	// replaced with address of .got + 4
  0xff, 0x25,	// jmp indirect
  0, 0, 0, 0,	// replaced with address of .got + 8
  0, 0, 0, 0	// unused
};

// The first entry in the PLT for a shared object.

unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] =
{
  0xff, 0xb3, 4, 0, 0, 0,	// pushl 4(%ebx)
  0xff, 0xa3, 8, 0, 0, 0,	// jmp *8(%ebx)
  0, 0, 0, 0			// unused
};

// Subsequent entries in the PLT for an executable.

unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] =
{
  0xff, 0x25,	// jmp indirect
  0, 0, 0, 0,	// replaced with address of symbol in .got
  0x68,		// pushl immediate
  0, 0, 0, 0,	// replaced with offset into relocation table
  0xe9,		// jmp relative
  0, 0, 0, 0	// replaced with offset to start of .plt
};

// Subsequent entries in the PLT for a shared object.

unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] =
{
  0xff, 0xa3,	// jmp *offset(%ebx)
  0, 0, 0, 0,	// replaced with offset of symbol in .got
  0x68,		// pushl immediate
  0, 0, 0, 0,	// replaced with offset into relocation table
  0xe9,		// jmp relative
  0, 0, 0, 0	// replaced with offset to start of .plt
};

// Write out the PLT.  This uses the hand-coded instructions above,
// and adjusts them as needed.  This is all specified by the i386 ELF
// Processor Supplement.

void
Output_data_plt_i386::do_write(Output_file* of)
{
  const off_t offset = this->offset();
  const section_size_type oview_size =
    convert_to_section_size_type(this->data_size());
  unsigned char* const oview = of->get_output_view(offset, oview_size);

  const off_t got_file_offset = this->got_plt_->offset();
  const section_size_type got_size =
    convert_to_section_size_type(this->got_plt_->data_size());
  unsigned char* const got_view = of->get_output_view(got_file_offset,
						      got_size);

  unsigned char* pov = oview;

  elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
  elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();

  if (parameters->options().shared())
    memcpy(pov, dyn_first_plt_entry, plt_entry_size);
  else
    {
      memcpy(pov, exec_first_plt_entry, plt_entry_size);
      elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
      elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
    }
  pov += plt_entry_size;

  unsigned char* got_pov = got_view;

  memset(got_pov, 0, 12);
  got_pov += 12;

  const int rel_size = elfcpp::Elf_sizes<32>::rel_size;

  unsigned int plt_offset = plt_entry_size;
  unsigned int plt_rel_offset = 0;
  unsigned int got_offset = 12;
  const unsigned int count = this->count_;
  for (unsigned int i = 0;
       i < count;
       ++i,
	 pov += plt_entry_size,
	 got_pov += 4,
	 plt_offset += plt_entry_size,
	 plt_rel_offset += rel_size,
	 got_offset += 4)
    {
      // Set and adjust the PLT entry itself.

      if (parameters->options().shared())
	{
	  memcpy(pov, dyn_plt_entry, plt_entry_size);
	  elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
	}
      else
	{
	  memcpy(pov, exec_plt_entry, plt_entry_size);
	  elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
						      (got_address
						       + got_offset));
	}

      elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
      elfcpp::Swap<32, false>::writeval(pov + 12,
					- (plt_offset + plt_entry_size));

      // Set the entry in the GOT.
      elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6);
    }

  gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
  gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);

  of->write_output_view(offset, oview_size, oview);
  of->write_output_view(got_file_offset, got_size, got_view);
}

// Create a PLT entry for a global symbol.

void
Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
{
  if (gsym->has_plt_offset())
    return;

  if (this->plt_ == NULL)
    {
      // Create the GOT sections first.
      this->got_section(symtab, layout);

      this->plt_ = new Output_data_plt_i386(layout, this->got_plt_);
      layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
				      (elfcpp::SHF_ALLOC
				       | elfcpp::SHF_EXECINSTR),
				      this->plt_);
    }

  this->plt_->add_entry(gsym);
}

// Create a GOT entry for the TLS module index.

unsigned int
Target_i386::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
			         Sized_relobj<32, false>* object)
{
  if (this->got_mod_index_offset_ == -1U)
    {
      gold_assert(symtab != NULL && layout != NULL && object != NULL);
      Reloc_section* rel_dyn = this->rel_dyn_section(layout);
      Output_data_got<32, false>* got = this->got_section(symtab, layout);
      unsigned int got_offset = got->add_constant(0);
      rel_dyn->add_local(object, 0, elfcpp::R_386_TLS_DTPMOD32, got,
                         got_offset);
      got->add_constant(0);
      this->got_mod_index_offset_ = got_offset;
    }
  return this->got_mod_index_offset_;
}

// Optimize the TLS relocation type based on what we know about the
// symbol.  IS_FINAL is true if the final address of this symbol is
// known at link time.

tls::Tls_optimization
Target_i386::optimize_tls_reloc(bool is_final, int r_type)
{
  // If we are generating a shared library, then we can't do anything
  // in the linker.
  if (parameters->options().shared())
    return tls::TLSOPT_NONE;

  switch (r_type)
    {
    case elfcpp::R_386_TLS_GD:
    case elfcpp::R_386_TLS_GOTDESC:
    case elfcpp::R_386_TLS_DESC_CALL:
      // These are General-Dynamic which permits fully general TLS
      // access.  Since we know that we are generating an executable,
      // we can convert this to Initial-Exec.  If we also know that
      // this is a local symbol, we can further switch to Local-Exec.
      if (is_final)
	return tls::TLSOPT_TO_LE;
      return tls::TLSOPT_TO_IE;

    case elfcpp::R_386_TLS_LDM:
      // This is Local-Dynamic, which refers to a local symbol in the
      // dynamic TLS block.  Since we know that we generating an
      // executable, we can switch to Local-Exec.
      return tls::TLSOPT_TO_LE;

    case elfcpp::R_386_TLS_LDO_32:
      // Another type of Local-Dynamic relocation.
      return tls::TLSOPT_TO_LE;

    case elfcpp::R_386_TLS_IE:
    case elfcpp::R_386_TLS_GOTIE:
    case elfcpp::R_386_TLS_IE_32:
      // These are Initial-Exec relocs which get the thread offset
      // from the GOT.  If we know that we are linking against the
      // local symbol, we can switch to Local-Exec, which links the
      // thread offset into the instruction.
      if (is_final)
	return tls::TLSOPT_TO_LE;
      return tls::TLSOPT_NONE;

    case elfcpp::R_386_TLS_LE:
    case elfcpp::R_386_TLS_LE_32:
      // When we already have Local-Exec, there is nothing further we
      // can do.
      return tls::TLSOPT_NONE;

    default:
      gold_unreachable();
    }
}

// Report an unsupported relocation against a local symbol.

void
Target_i386::Scan::unsupported_reloc_local(Sized_relobj<32, false>* object,
					   unsigned int r_type)
{
  gold_error(_("%s: unsupported reloc %u against local symbol"),
	     object->name().c_str(), r_type);
}

// Scan a relocation for a local symbol.

inline void
Target_i386::Scan::local(const General_options&,
			 Symbol_table* symtab,
			 Layout* layout,
			 Target_i386* target,
			 Sized_relobj<32, false>* object,
			 unsigned int data_shndx,
			 Output_section* output_section,
			 const elfcpp::Rel<32, false>& reloc,
			 unsigned int r_type,
			 const elfcpp::Sym<32, false>& lsym)
{
  switch (r_type)
    {
    case elfcpp::R_386_NONE:
    case elfcpp::R_386_GNU_VTINHERIT:
    case elfcpp::R_386_GNU_VTENTRY:
      break;

    case elfcpp::R_386_32:
      // If building a shared library (or a position-independent
      // executable), we need to create a dynamic relocation for
      // this location. The relocation applied at link time will
      // apply the link-time value, so we flag the location with
      // an R_386_RELATIVE relocation so the dynamic loader can
      // relocate it easily.
      if (parameters->options().output_is_position_independent())
        {
          Reloc_section* rel_dyn = target->rel_dyn_section(layout);
          unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
          rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE,
                                      output_section, data_shndx,
                                      reloc.get_r_offset());
        }
      break;

    case elfcpp::R_386_16:
    case elfcpp::R_386_8:
      // If building a shared library (or a position-independent
      // executable), we need to create a dynamic relocation for
      // this location. Because the addend needs to remain in the
      // data section, we need to be careful not to apply this
      // relocation statically.
      if (parameters->options().output_is_position_independent())
        {
          Reloc_section* rel_dyn = target->rel_dyn_section(layout);
          if (lsym.get_st_type() != elfcpp::STT_SECTION)
            {
              unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
              rel_dyn->add_local(object, r_sym, r_type, output_section,
                                 data_shndx, reloc.get_r_offset());
            }
          else
            {
              gold_assert(lsym.get_st_value() == 0);
              rel_dyn->add_local_section(object, lsym.get_st_shndx(),
                                         r_type, output_section,
                                         data_shndx, reloc.get_r_offset());
            }
        }
      break;

    case elfcpp::R_386_PC32:
    case elfcpp::R_386_PC16:
    case elfcpp::R_386_PC8:
      break;

    case elfcpp::R_386_PLT32:
      // Since we know this is a local symbol, we can handle this as a
      // PC32 reloc.
      break;

    case elfcpp::R_386_GOTOFF:
    case elfcpp::R_386_GOTPC:
      // We need a GOT section.
      target->got_section(symtab, layout);
      break;

    case elfcpp::R_386_GOT32:
      {
        // The symbol requires a GOT entry.
        Output_data_got<32, false>* got = target->got_section(symtab, layout);
        unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
        if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
          {
            // If we are generating a shared object, we need to add a
            // dynamic RELATIVE relocation for this symbol's GOT entry.
            if (parameters->options().output_is_position_independent())
              {
                Reloc_section* rel_dyn = target->rel_dyn_section(layout);
                unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
                rel_dyn->add_local_relative(
                    object, r_sym, elfcpp::R_386_RELATIVE, got,
                    object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
              }
          }
      }
      break;

      // These are relocations which should only be seen by the
      // dynamic linker, and should never be seen here.
    case elfcpp::R_386_COPY:
    case elfcpp::R_386_GLOB_DAT:
    case elfcpp::R_386_JUMP_SLOT:
    case elfcpp::R_386_RELATIVE:
    case elfcpp::R_386_TLS_TPOFF:
    case elfcpp::R_386_TLS_DTPMOD32:
    case elfcpp::R_386_TLS_DTPOFF32:
    case elfcpp::R_386_TLS_TPOFF32:
    case elfcpp::R_386_TLS_DESC:
      gold_error(_("%s: unexpected reloc %u in object file"),
		 object->name().c_str(), r_type);
      break;

      // These are initial TLS relocs, which are expected when
      // linking.
    case elfcpp::R_386_TLS_GD:            // Global-dynamic
    case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
    case elfcpp::R_386_TLS_DESC_CALL:
    case elfcpp::R_386_TLS_LDM:           // Local-dynamic
    case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
    case elfcpp::R_386_TLS_IE:            // Initial-exec
    case elfcpp::R_386_TLS_IE_32:
    case elfcpp::R_386_TLS_GOTIE:
    case elfcpp::R_386_TLS_LE:            // Local-exec
    case elfcpp::R_386_TLS_LE_32:
      {
	bool output_is_shared = parameters->options().shared();
	const tls::Tls_optimization optimized_type
            = Target_i386::optimize_tls_reloc(!output_is_shared, r_type);
	switch (r_type)
	  {
	  case elfcpp::R_386_TLS_GD:          // Global-dynamic
	    if (optimized_type == tls::TLSOPT_NONE)
	      {
	        // Create a pair of GOT entries for the module index and
	        // dtv-relative offset.
                Output_data_got<32, false>* got
                    = target->got_section(symtab, layout);
                unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
                got->add_local_pair_with_rel(object, r_sym, 
                                             lsym.get_st_shndx(),
                                             GOT_TYPE_TLS_PAIR,
                                             target->rel_dyn_section(layout),
                                             elfcpp::R_386_TLS_DTPMOD32, 0);
	      }
	    else if (optimized_type != tls::TLSOPT_TO_LE)
	      unsupported_reloc_local(object, r_type);
	    break;

	  case elfcpp::R_386_TLS_GOTDESC:     // Global-dynamic (from ~oliva)
            if (optimized_type == tls::TLSOPT_NONE)
              {
                // Create a double GOT entry with an R_386_TLS_DESC reloc.
                Output_data_got<32, false>* got
                    = target->got_section(symtab, layout);
                unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
                got->add_local_pair_with_rel(object, r_sym, 
                                             lsym.get_st_shndx(),
                                             GOT_TYPE_TLS_DESC,
                                             target->rel_dyn_section(layout),
                                             elfcpp::R_386_TLS_DESC, 0);
              }
            else if (optimized_type != tls::TLSOPT_TO_LE)
              unsupported_reloc_local(object, r_type);
	    break;

	  case elfcpp::R_386_TLS_DESC_CALL:
	    break;

	  case elfcpp::R_386_TLS_LDM:         // Local-dynamic
	    if (optimized_type == tls::TLSOPT_NONE)
	      {
	        // Create a GOT entry for the module index.
	        target->got_mod_index_entry(symtab, layout, object);
	      }
	    else if (optimized_type != tls::TLSOPT_TO_LE)
	      unsupported_reloc_local(object, r_type);
	    break;

	  case elfcpp::R_386_TLS_LDO_32:      // Alternate local-dynamic
	    break;

	  case elfcpp::R_386_TLS_IE:          // Initial-exec
	  case elfcpp::R_386_TLS_IE_32:
	  case elfcpp::R_386_TLS_GOTIE:
	    layout->set_has_static_tls();
	    if (optimized_type == tls::TLSOPT_NONE)
	      {
	        // For the R_386_TLS_IE relocation, we need to create a
	        // dynamic relocation when building a shared library.
	        if (r_type == elfcpp::R_386_TLS_IE
	            && parameters->options().shared())
	          {
                    Reloc_section* rel_dyn = target->rel_dyn_section(layout);
                    unsigned int r_sym
                        = elfcpp::elf_r_sym<32>(reloc.get_r_info());
                    rel_dyn->add_local_relative(object, r_sym,
                                                elfcpp::R_386_RELATIVE,
                                                output_section, data_shndx,
                                                reloc.get_r_offset());
	          }
	        // Create a GOT entry for the tp-relative offset.
                Output_data_got<32, false>* got
                    = target->got_section(symtab, layout);
                unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
	        unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
		                           ? elfcpp::R_386_TLS_TPOFF32
		                           : elfcpp::R_386_TLS_TPOFF);
	        unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
		                         ? GOT_TYPE_TLS_OFFSET
		                         : GOT_TYPE_TLS_NOFFSET);
                got->add_local_with_rel(object, r_sym, got_type,
                                        target->rel_dyn_section(layout),
                                        dyn_r_type);
	      }
	    else if (optimized_type != tls::TLSOPT_TO_LE)
	      unsupported_reloc_local(object, r_type);
	    break;

	  case elfcpp::R_386_TLS_LE:          // Local-exec
	  case elfcpp::R_386_TLS_LE_32:
	    layout->set_has_static_tls();
	    if (output_is_shared)
	      {
	        // We need to create a dynamic relocation.
                gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
                unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
                unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
                                           ? elfcpp::R_386_TLS_TPOFF32
                                           : elfcpp::R_386_TLS_TPOFF);
                Reloc_section* rel_dyn = target->rel_dyn_section(layout);
                rel_dyn->add_local(object, r_sym, dyn_r_type, output_section,
                                   data_shndx, reloc.get_r_offset());
	      }
	    break;

	  default:
	    gold_unreachable();
	  }
      }
      break;

    case elfcpp::R_386_32PLT:
    case elfcpp::R_386_TLS_GD_32:
    case elfcpp::R_386_TLS_GD_PUSH:
    case elfcpp::R_386_TLS_GD_CALL:
    case elfcpp::R_386_TLS_GD_POP:
    case elfcpp::R_386_TLS_LDM_32:
    case elfcpp::R_386_TLS_LDM_PUSH:
    case elfcpp::R_386_TLS_LDM_CALL:
    case elfcpp::R_386_TLS_LDM_POP:
    case elfcpp::R_386_USED_BY_INTEL_200:
    default:
      unsupported_reloc_local(object, r_type);
      break;
    }
}

// Report an unsupported relocation against a global symbol.

void
Target_i386::Scan::unsupported_reloc_global(Sized_relobj<32, false>* object,
					    unsigned int r_type,
					    Symbol* gsym)
{
  gold_error(_("%s: unsupported reloc %u against global symbol %s"),
	     object->name().c_str(), r_type, gsym->demangled_name().c_str());
}

// Scan a relocation for a global symbol.

inline void
Target_i386::Scan::global(const General_options&,
			  Symbol_table* symtab,
			  Layout* layout,
			  Target_i386* target,
			  Sized_relobj<32, false>* object,
			  unsigned int data_shndx,
                          Output_section* output_section,
			  const elfcpp::Rel<32, false>& reloc,
			  unsigned int r_type,
			  Symbol* gsym)
{
  switch (r_type)
    {
    case elfcpp::R_386_NONE:
    case elfcpp::R_386_GNU_VTINHERIT:
    case elfcpp::R_386_GNU_VTENTRY:
      break;

    case elfcpp::R_386_32:
    case elfcpp::R_386_16:
    case elfcpp::R_386_8:
      {
        // Make a PLT entry if necessary.
        if (gsym->needs_plt_entry())
          {
            target->make_plt_entry(symtab, layout, gsym);
            // Since this is not a PC-relative relocation, we may be
            // taking the address of a function. In that case we need to
            // set the entry in the dynamic symbol table to the address of
            // the PLT entry.
            if (gsym->is_from_dynobj() && !parameters->options().shared())
              gsym->set_needs_dynsym_value();
          }
        // Make a dynamic relocation if necessary.
        if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
          {
            if (target->may_need_copy_reloc(gsym))
              {
	        target->copy_reloc(symtab, layout, object,
	                           data_shndx, output_section, gsym, reloc);
              }
            else if (r_type == elfcpp::R_386_32
                     && gsym->can_use_relative_reloc(false))
              {
                Reloc_section* rel_dyn = target->rel_dyn_section(layout);
                rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
                                             output_section, object,
                                             data_shndx, reloc.get_r_offset());
              }
            else
              {
                Reloc_section* rel_dyn = target->rel_dyn_section(layout);
                rel_dyn->add_global(gsym, r_type, output_section, object,
                                    data_shndx, reloc.get_r_offset());
              }
          }
      }
      break;

    case elfcpp::R_386_PC32:
    case elfcpp::R_386_PC16:
    case elfcpp::R_386_PC8:
      {
        // Make a PLT entry if necessary.
        if (gsym->needs_plt_entry())
          {
            // These relocations are used for function calls only in
            // non-PIC code.  For a 32-bit relocation in a shared library,
            // we'll need a text relocation anyway, so we can skip the
            // PLT entry and let the dynamic linker bind the call directly
            // to the target.  For smaller relocations, we should use a
            // PLT entry to ensure that the call can reach.
            if (!parameters->options().shared()
                || r_type != elfcpp::R_386_PC32)
              target->make_plt_entry(symtab, layout, gsym);
          }
        // Make a dynamic relocation if necessary.
        int flags = Symbol::NON_PIC_REF;
        if (gsym->type() == elfcpp::STT_FUNC)
          flags |= Symbol::FUNCTION_CALL;
        if (gsym->needs_dynamic_reloc(flags))
          {
            if (target->may_need_copy_reloc(gsym))
              {
	        target->copy_reloc(symtab, layout, object,
	                           data_shndx, output_section, gsym, reloc);
              }
            else
              {
                Reloc_section* rel_dyn = target->rel_dyn_section(layout);
                rel_dyn->add_global(gsym, r_type, output_section, object,
                                    data_shndx, reloc.get_r_offset());
              }
          }
      }
      break;

    case elfcpp::R_386_GOT32:
      {
        // The symbol requires a GOT entry.
        Output_data_got<32, false>* got = target->got_section(symtab, layout);
        if (gsym->final_value_is_known())
          got->add_global(gsym, GOT_TYPE_STANDARD);
        else
          {
            // If this symbol is not fully resolved, we need to add a
            // GOT entry with a dynamic relocation.
            Reloc_section* rel_dyn = target->rel_dyn_section(layout);
            if (gsym->is_from_dynobj()
                || gsym->is_undefined()
                || gsym->is_preemptible())
              got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
                                       rel_dyn, elfcpp::R_386_GLOB_DAT);
            else
              {
                if (got->add_global(gsym, GOT_TYPE_STANDARD))
                  rel_dyn->add_global_relative(
                      gsym, elfcpp::R_386_RELATIVE, got,
                      gsym->got_offset(GOT_TYPE_STANDARD));
              }
          }
      }
      break;

    case elfcpp::R_386_PLT32:
      // If the symbol is fully resolved, this is just a PC32 reloc.
      // Otherwise we need a PLT entry.
      if (gsym->final_value_is_known())
	break;
      // If building a shared library, we can also skip the PLT entry
      // if the symbol is defined in the output file and is protected
      // or hidden.
      if (gsym->is_defined()
          && !gsym->is_from_dynobj()
          && !gsym->is_preemptible())
	break;
      target->make_plt_entry(symtab, layout, gsym);
      break;

    case elfcpp::R_386_GOTOFF:
    case elfcpp::R_386_GOTPC:
      // We need a GOT section.
      target->got_section(symtab, layout);
      break;

      // These are relocations which should only be seen by the
      // dynamic linker, and should never be seen here.
    case elfcpp::R_386_COPY:
    case elfcpp::R_386_GLOB_DAT:
    case elfcpp::R_386_JUMP_SLOT:
    case elfcpp::R_386_RELATIVE:
    case elfcpp::R_386_TLS_TPOFF:
    case elfcpp::R_386_TLS_DTPMOD32:
    case elfcpp::R_386_TLS_DTPOFF32:
    case elfcpp::R_386_TLS_TPOFF32:
    case elfcpp::R_386_TLS_DESC:
      gold_error(_("%s: unexpected reloc %u in object file"),
		 object->name().c_str(), r_type);
      break;

      // These are initial tls relocs, which are expected when
      // linking.
    case elfcpp::R_386_TLS_GD:            // Global-dynamic
    case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
    case elfcpp::R_386_TLS_DESC_CALL:
    case elfcpp::R_386_TLS_LDM:           // Local-dynamic
    case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
    case elfcpp::R_386_TLS_IE:            // Initial-exec
    case elfcpp::R_386_TLS_IE_32:
    case elfcpp::R_386_TLS_GOTIE:
    case elfcpp::R_386_TLS_LE:            // Local-exec
    case elfcpp::R_386_TLS_LE_32:
      {
	const bool is_final = gsym->final_value_is_known();
	const tls::Tls_optimization optimized_type
            = Target_i386::optimize_tls_reloc(is_final, r_type);
	switch (r_type)
	  {
	  case elfcpp::R_386_TLS_GD:          // Global-dynamic
	    if (optimized_type == tls::TLSOPT_NONE)
	      {
	        // Create a pair of GOT entries for the module index and
	        // dtv-relative offset.
                Output_data_got<32, false>* got
                    = target->got_section(symtab, layout);
                got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
                                             target->rel_dyn_section(layout),
                                             elfcpp::R_386_TLS_DTPMOD32,
                                             elfcpp::R_386_TLS_DTPOFF32);
	      }
	    else if (optimized_type == tls::TLSOPT_TO_IE)
	      {
	        // Create a GOT entry for the tp-relative offset.
                Output_data_got<32, false>* got
                    = target->got_section(symtab, layout);
                got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
                                         target->rel_dyn_section(layout),
                                         elfcpp::R_386_TLS_TPOFF);
	      }
	    else if (optimized_type != tls::TLSOPT_TO_LE)
	      unsupported_reloc_global(object, r_type, gsym);
	    break;

	  case elfcpp::R_386_TLS_GOTDESC:     // Global-dynamic (~oliva url)
            if (optimized_type == tls::TLSOPT_NONE)
              {
                // Create a double GOT entry with an R_386_TLS_DESC reloc.
                Output_data_got<32, false>* got
                    = target->got_section(symtab, layout);
                got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC,
                                             target->rel_dyn_section(layout),
                                             elfcpp::R_386_TLS_DESC, 0);
              }
            else if (optimized_type == tls::TLSOPT_TO_IE)
              {
	        // Create a GOT entry for the tp-relative offset.
                Output_data_got<32, false>* got
                    = target->got_section(symtab, layout);
                got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
                                         target->rel_dyn_section(layout),
                                         elfcpp::R_386_TLS_TPOFF);
              }
            else if (optimized_type != tls::TLSOPT_TO_LE)
              unsupported_reloc_global(object, r_type, gsym);
	    break;

	  case elfcpp::R_386_TLS_DESC_CALL:
	    break;

	  case elfcpp::R_386_TLS_LDM:         // Local-dynamic
	    if (optimized_type == tls::TLSOPT_NONE)
	      {
	        // Create a GOT entry for the module index.
	        target->got_mod_index_entry(symtab, layout, object);
	      }
	    else if (optimized_type != tls::TLSOPT_TO_LE)
	      unsupported_reloc_global(object, r_type, gsym);
	    break;

	  case elfcpp::R_386_TLS_LDO_32:      // Alternate local-dynamic
	    break;

	  case elfcpp::R_386_TLS_IE:          // Initial-exec
	  case elfcpp::R_386_TLS_IE_32:
	  case elfcpp::R_386_TLS_GOTIE:
	    layout->set_has_static_tls();
	    if (optimized_type == tls::TLSOPT_NONE)
	      {
	        // For the R_386_TLS_IE relocation, we need to create a
	        // dynamic relocation when building a shared library.
	        if (r_type == elfcpp::R_386_TLS_IE
	            && parameters->options().shared())
	          {
                    Reloc_section* rel_dyn = target->rel_dyn_section(layout);
                    rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
                                                 output_section, object,
                                                 data_shndx,
                                                 reloc.get_r_offset());
	          }
	        // Create a GOT entry for the tp-relative offset.
                Output_data_got<32, false>* got
                    = target->got_section(symtab, layout);
	        unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
		                           ? elfcpp::R_386_TLS_TPOFF32
		                           : elfcpp::R_386_TLS_TPOFF);
	        unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
		                         ? GOT_TYPE_TLS_OFFSET
		                         : GOT_TYPE_TLS_NOFFSET);
                got->add_global_with_rel(gsym, got_type,
                                         target->rel_dyn_section(layout),
                                         dyn_r_type);
	      }
	    else if (optimized_type != tls::TLSOPT_TO_LE)
	      unsupported_reloc_global(object, r_type, gsym);
	    break;

	  case elfcpp::R_386_TLS_LE:          // Local-exec
	  case elfcpp::R_386_TLS_LE_32:
	    layout->set_has_static_tls();
	    if (parameters->options().shared())
	      {
	        // We need to create a dynamic relocation.
                unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
                                           ? elfcpp::R_386_TLS_TPOFF32
                                           : elfcpp::R_386_TLS_TPOFF);
                Reloc_section* rel_dyn = target->rel_dyn_section(layout);
                rel_dyn->add_global(gsym, dyn_r_type, output_section, object,
                                    data_shndx, reloc.get_r_offset());
	      }
	    break;

	  default:
	    gold_unreachable();
	  }
      }
      break;

    case elfcpp::R_386_32PLT:
    case elfcpp::R_386_TLS_GD_32:
    case elfcpp::R_386_TLS_GD_PUSH:
    case elfcpp::R_386_TLS_GD_CALL:
    case elfcpp::R_386_TLS_GD_POP:
    case elfcpp::R_386_TLS_LDM_32:
    case elfcpp::R_386_TLS_LDM_PUSH:
    case elfcpp::R_386_TLS_LDM_CALL:
    case elfcpp::R_386_TLS_LDM_POP:
    case elfcpp::R_386_USED_BY_INTEL_200:
    default:
      unsupported_reloc_global(object, r_type, gsym);
      break;
    }
}

// Scan relocations for a section.

void
Target_i386::scan_relocs(const General_options& options,
			 Symbol_table* symtab,
			 Layout* layout,
			 Sized_relobj<32, false>* object,
			 unsigned int data_shndx,
			 unsigned int sh_type,
			 const unsigned char* prelocs,
			 size_t reloc_count,
			 Output_section* output_section,
			 bool needs_special_offset_handling,
			 size_t local_symbol_count,
			 const unsigned char* plocal_symbols)
{
  if (sh_type == elfcpp::SHT_RELA)
    {
      gold_error(_("%s: unsupported RELA reloc section"),
		 object->name().c_str());
      return;
    }

  gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL,
		    Target_i386::Scan>(
    options,
    symtab,
    layout,
    this,
    object,
    data_shndx,
    prelocs,
    reloc_count,
    output_section,
    needs_special_offset_handling,
    local_symbol_count,
    plocal_symbols);
}

// Finalize the sections.

void
Target_i386::do_finalize_sections(Layout* layout)
{
  // Fill in some more dynamic tags.
  Output_data_dynamic* const odyn = layout->dynamic_data();
  if (odyn != NULL)
    {
      if (this->got_plt_ != NULL)
	odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_);

      if (this->plt_ != NULL)
	{
	  const Output_data* od = this->plt_->rel_plt();
	  odyn->add_section_size(elfcpp::DT_PLTRELSZ, od);
	  odyn->add_section_address(elfcpp::DT_JMPREL, od);
	  odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_REL);
	}

      if (this->rel_dyn_ != NULL)
	{
	  const Output_data* od = this->rel_dyn_;
	  odyn->add_section_address(elfcpp::DT_REL, od);
	  odyn->add_section_size(elfcpp::DT_RELSZ, od);
	  odyn->add_constant(elfcpp::DT_RELENT,
			     elfcpp::Elf_sizes<32>::rel_size);
	}

      if (!parameters->options().shared())
	{
	  // The value of the DT_DEBUG tag is filled in by the dynamic
	  // linker at run time, and used by the debugger.
	  odyn->add_constant(elfcpp::DT_DEBUG, 0);
	}
    }

  // Emit any relocs we saved in an attempt to avoid generating COPY
  // relocs.
  if (this->copy_relocs_.any_saved_relocs())
    this->copy_relocs_.emit(this->rel_dyn_section(layout));
}

// Return whether a direct absolute static relocation needs to be applied.
// In cases where Scan::local() or Scan::global() has created
// a dynamic relocation other than R_386_RELATIVE, the addend
// of the relocation is carried in the data, and we must not
// apply the static relocation.

inline bool
Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym,
                                                 int ref_flags,
                                                 bool is_32bit)
{
  // For local symbols, we will have created a non-RELATIVE dynamic
  // relocation only if (a) the output is position independent,
  // (b) the relocation is absolute (not pc- or segment-relative), and
  // (c) the relocation is not 32 bits wide.
  if (gsym == NULL)
    return !(parameters->options().output_is_position_independent()
             && (ref_flags & Symbol::ABSOLUTE_REF)
             && !is_32bit);

  // For global symbols, we use the same helper routines used in the
  // scan pass.  If we did not create a dynamic relocation, or if we
  // created a RELATIVE dynamic relocation, we should apply the static
  // relocation.
  bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
  bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
                && gsym->can_use_relative_reloc(ref_flags
                                                & Symbol::FUNCTION_CALL);
  return !has_dyn || is_rel;
}

// Perform a relocation.

inline bool
Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
				Target_i386* target,
				size_t relnum,
				const elfcpp::Rel<32, false>& rel,
				unsigned int r_type,
				const Sized_symbol<32>* gsym,
				const Symbol_value<32>* psymval,
				unsigned char* view,
				elfcpp::Elf_types<32>::Elf_Addr address,
				section_size_type view_size)
{
  if (this->skip_call_tls_get_addr_)
    {
      if (r_type != elfcpp::R_386_PLT32
	  || gsym == NULL
	  || strcmp(gsym->name(), "___tls_get_addr") != 0)
	gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
			       _("missing expected TLS relocation"));
      else
	{
	  this->skip_call_tls_get_addr_ = false;
	  return false;
	}
    }

  // Pick the value to use for symbols defined in shared objects.
  Symbol_value<32> symval;
  bool is_nonpic = (r_type == elfcpp::R_386_PC8
                    || r_type == elfcpp::R_386_PC16
                    || r_type == elfcpp::R_386_PC32);
  if (gsym != NULL
      && (gsym->is_from_dynobj()
          || (parameters->options().shared()
              && (gsym->is_undefined() || gsym->is_preemptible())))
      && gsym->has_plt_offset()
      && (!is_nonpic || !parameters->options().shared()))
    {
      symval.set_output_value(target->plt_section()->address()
			      + gsym->plt_offset());
      psymval = &symval;
    }

  const Sized_relobj<32, false>* object = relinfo->object;

  // Get the GOT offset if needed.
  // The GOT pointer points to the end of the GOT section.
  // We need to subtract the size of the GOT section to get
  // the actual offset to use in the relocation.
  bool have_got_offset = false;
  unsigned int got_offset = 0;
  switch (r_type)
    {
    case elfcpp::R_386_GOT32:
      if (gsym != NULL)
        {
          gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
          got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
                        - target->got_size());
        }
      else
        {
          unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
          gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
          got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
                        - target->got_size());
        }
      have_got_offset = true;
      break;

    default:
      break;
    }

  switch (r_type)
    {
    case elfcpp::R_386_NONE:
    case elfcpp::R_386_GNU_VTINHERIT:
    case elfcpp::R_386_GNU_VTENTRY:
      break;

    case elfcpp::R_386_32:
      if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true))
        Relocate_functions<32, false>::rel32(view, object, psymval);
      break;

    case elfcpp::R_386_PC32:
      {
        int ref_flags = Symbol::NON_PIC_REF;
        if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC)
          ref_flags |= Symbol::FUNCTION_CALL;
        if (should_apply_static_reloc(gsym, ref_flags, true))
          Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
      }
      break;

    case elfcpp::R_386_16:
      if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false))
        Relocate_functions<32, false>::rel16(view, object, psymval);
      break;

    case elfcpp::R_386_PC16:
      {
        int ref_flags = Symbol::NON_PIC_REF;
        if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC)
          ref_flags |= Symbol::FUNCTION_CALL;
        if (should_apply_static_reloc(gsym, ref_flags, false))
          Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
      }
      break;

    case elfcpp::R_386_8:
      if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false))
        Relocate_functions<32, false>::rel8(view, object, psymval);
      break;

    case elfcpp::R_386_PC8:
      {
        int ref_flags = Symbol::NON_PIC_REF;
        if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC)
          ref_flags |= Symbol::FUNCTION_CALL;
        if (should_apply_static_reloc(gsym, ref_flags, false))
          Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
      }
      break;

    case elfcpp::R_386_PLT32:
      gold_assert(gsym == NULL
		  || gsym->has_plt_offset()
		  || gsym->final_value_is_known()
		  || (gsym->is_defined()
		      && !gsym->is_from_dynobj()
		      && !gsym->is_preemptible()));
      Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
      break;

    case elfcpp::R_386_GOT32:
      gold_assert(have_got_offset);
      Relocate_functions<32, false>::rel32(view, got_offset);
      break;

    case elfcpp::R_386_GOTOFF:
      {
	elfcpp::Elf_types<32>::Elf_Addr value;
	value = (psymval->value(object, 0)
		 - target->got_plt_section()->address());
	Relocate_functions<32, false>::rel32(view, value);
      }
      break;

    case elfcpp::R_386_GOTPC:
      {
	elfcpp::Elf_types<32>::Elf_Addr value;
	value = target->got_plt_section()->address();
	Relocate_functions<32, false>::pcrel32(view, value, address);
      }
      break;

    case elfcpp::R_386_COPY:
    case elfcpp::R_386_GLOB_DAT:
    case elfcpp::R_386_JUMP_SLOT:
    case elfcpp::R_386_RELATIVE:
      // These are outstanding tls relocs, which are unexpected when
      // linking.
    case elfcpp::R_386_TLS_TPOFF:
    case elfcpp::R_386_TLS_DTPMOD32:
    case elfcpp::R_386_TLS_DTPOFF32:
    case elfcpp::R_386_TLS_TPOFF32:
    case elfcpp::R_386_TLS_DESC:
      gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
			     _("unexpected reloc %u in object file"),
			     r_type);
      break;

      // These are initial tls relocs, which are expected when
      // linking.
    case elfcpp::R_386_TLS_GD:             // Global-dynamic
    case elfcpp::R_386_TLS_GOTDESC:        // Global-dynamic (from ~oliva url)
    case elfcpp::R_386_TLS_DESC_CALL:
    case elfcpp::R_386_TLS_LDM:            // Local-dynamic
    case elfcpp::R_386_TLS_LDO_32:         // Alternate local-dynamic
    case elfcpp::R_386_TLS_IE:             // Initial-exec
    case elfcpp::R_386_TLS_IE_32:
    case elfcpp::R_386_TLS_GOTIE:
    case elfcpp::R_386_TLS_LE:             // Local-exec
    case elfcpp::R_386_TLS_LE_32:
      this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
                         view, address, view_size);
      break;

    case elfcpp::R_386_32PLT:
    case elfcpp::R_386_TLS_GD_32:
    case elfcpp::R_386_TLS_GD_PUSH:
    case elfcpp::R_386_TLS_GD_CALL:
    case elfcpp::R_386_TLS_GD_POP:
    case elfcpp::R_386_TLS_LDM_32:
    case elfcpp::R_386_TLS_LDM_PUSH:
    case elfcpp::R_386_TLS_LDM_CALL:
    case elfcpp::R_386_TLS_LDM_POP:
    case elfcpp::R_386_USED_BY_INTEL_200:
    default:
      gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
			     _("unsupported reloc %u"),
			     r_type);
      break;
    }

  return true;
}

// Perform a TLS relocation.

inline void
Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
                                    Target_i386* target,
				    size_t relnum,
				    const elfcpp::Rel<32, false>& rel,
				    unsigned int r_type,
				    const Sized_symbol<32>* gsym,
				    const Symbol_value<32>* psymval,
				    unsigned char* view,
				    elfcpp::Elf_types<32>::Elf_Addr,
				    section_size_type view_size)
{
  Output_segment* tls_segment = relinfo->layout->tls_segment();

  const Sized_relobj<32, false>* object = relinfo->object;

  elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);

  const bool is_final =
    (gsym == NULL
     ? !parameters->options().output_is_position_independent()
     : gsym->final_value_is_known());
  const tls::Tls_optimization optimized_type
      = Target_i386::optimize_tls_reloc(is_final, r_type);
  switch (r_type)
    {
    case elfcpp::R_386_TLS_GD:           // Global-dynamic
      if (optimized_type == tls::TLSOPT_TO_LE)
	{
	  gold_assert(tls_segment != NULL);
	  this->tls_gd_to_le(relinfo, relnum, tls_segment,
			     rel, r_type, value, view,
			     view_size);
	  break;
	}
      else
        {
          unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
                                   ? GOT_TYPE_TLS_NOFFSET
                                   : GOT_TYPE_TLS_PAIR);
          unsigned int got_offset;
          if (gsym != NULL)
            {
              gold_assert(gsym->has_got_offset(got_type));
              got_offset = gsym->got_offset(got_type) - target->got_size();
            }
          else
            {
              unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
              gold_assert(object->local_has_got_offset(r_sym, got_type));
              got_offset = (object->local_got_offset(r_sym, got_type)
			    - target->got_size());
            }
          if (optimized_type == tls::TLSOPT_TO_IE)
	    {
              gold_assert(tls_segment != NULL);
	      this->tls_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
                                 got_offset, view, view_size);
              break;
	    }
          else if (optimized_type == tls::TLSOPT_NONE)
            {
              // Relocate the field with the offset of the pair of GOT
              // entries.
              Relocate_functions<32, false>::rel32(view, got_offset);
              break;
            }
        }
      gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
			     _("unsupported reloc %u"),
			     r_type);
      break;

    case elfcpp::R_386_TLS_GOTDESC:      // Global-dynamic (from ~oliva url)
    case elfcpp::R_386_TLS_DESC_CALL:
      if (optimized_type == tls::TLSOPT_TO_LE)
        {
	  gold_assert(tls_segment != NULL);
	  this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
			          rel, r_type, value, view,
			          view_size);
	  break;
        }
      else
        {
          unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
                                   ? GOT_TYPE_TLS_NOFFSET
                                   : GOT_TYPE_TLS_DESC);
          unsigned int got_offset;
          if (gsym != NULL)
            {
              gold_assert(gsym->has_got_offset(got_type));
              got_offset = gsym->got_offset(got_type) - target->got_size();
            }
          else
            {
              unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
              gold_assert(object->local_has_got_offset(r_sym, got_type));
              got_offset = (object->local_got_offset(r_sym, got_type)
			    - target->got_size());
            }
          if (optimized_type == tls::TLSOPT_TO_IE)
	    {
              gold_assert(tls_segment != NULL);
	      this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
                                      got_offset, view, view_size);
              break;
	    }
          else if (optimized_type == tls::TLSOPT_NONE)
            {
              if (r_type == elfcpp::R_386_TLS_GOTDESC)
                {
                  // Relocate the field with the offset of the pair of GOT
                  // entries.
                  Relocate_functions<32, false>::rel32(view, got_offset);
                }
              break;
            }
        }
      gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
			     _("unsupported reloc %u"),
			     r_type);
      break;

    case elfcpp::R_386_TLS_LDM:          // Local-dynamic
      if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN)
	{
	  gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
				 _("both SUN and GNU model "
				   "TLS relocations"));
	  break;
	}
      this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
      if (optimized_type == tls::TLSOPT_TO_LE)
	{
          gold_assert(tls_segment != NULL);
	  this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type,
			     value, view, view_size);
	  break;
	}
      else if (optimized_type == tls::TLSOPT_NONE)
        {
          // Relocate the field with the offset of the GOT entry for
          // the module index.
          unsigned int got_offset;
          got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
			- target->got_size());
          Relocate_functions<32, false>::rel32(view, got_offset);
          break;
        }
      gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
			     _("unsupported reloc %u"),
			     r_type);
      break;

    case elfcpp::R_386_TLS_LDO_32:       // Alternate local-dynamic
      // This reloc can appear in debugging sections, in which case we
      // won't see the TLS_LDM reloc.  The local_dynamic_type field
      // tells us this.
      if (optimized_type == tls::TLSOPT_TO_LE)
	{
          gold_assert(tls_segment != NULL);
          value -= tls_segment->memsz();
	}
      Relocate_functions<32, false>::rel32(view, value);
      break;

    case elfcpp::R_386_TLS_IE:           // Initial-exec
    case elfcpp::R_386_TLS_GOTIE:
    case elfcpp::R_386_TLS_IE_32:
      if (optimized_type == tls::TLSOPT_TO_LE)
	{
          gold_assert(tls_segment != NULL);
	  Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
					      rel, r_type, value, view,
					      view_size);
	  break;
	}
      else if (optimized_type == tls::TLSOPT_NONE)
        {
          // Relocate the field with the offset of the GOT entry for
          // the tp-relative offset of the symbol.
	  unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
		                   ? GOT_TYPE_TLS_OFFSET
		                   : GOT_TYPE_TLS_NOFFSET);
          unsigned int got_offset;
          if (gsym != NULL)
            {
              gold_assert(gsym->has_got_offset(got_type));
              got_offset = gsym->got_offset(got_type);
            }
          else
            {
              unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
              gold_assert(object->local_has_got_offset(r_sym, got_type));
              got_offset = object->local_got_offset(r_sym, got_type);
            }
          // For the R_386_TLS_IE relocation, we need to apply the
          // absolute address of the GOT entry.
          if (r_type == elfcpp::R_386_TLS_IE)
            got_offset += target->got_plt_section()->address();
          // All GOT offsets are relative to the end of the GOT.
          got_offset -= target->got_size();
          Relocate_functions<32, false>::rel32(view, got_offset);
          break;
        }
      gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
			     _("unsupported reloc %u"),
			     r_type);
      break;

    case elfcpp::R_386_TLS_LE:           // Local-exec
      // If we're creating a shared library, a dynamic relocation will
      // have been created for this location, so do not apply it now.
      if (!parameters->options().shared())
        {
          gold_assert(tls_segment != NULL);
          value -= tls_segment->memsz();
          Relocate_functions<32, false>::rel32(view, value);
        }
      break;

    case elfcpp::R_386_TLS_LE_32:
      // If we're creating a shared library, a dynamic relocation will
      // have been created for this location, so do not apply it now.
      if (!parameters->options().shared())
        {
          gold_assert(tls_segment != NULL);
          value = tls_segment->memsz() - value;
          Relocate_functions<32, false>::rel32(view, value);
        }
      break;
    }
}

// Do a relocation in which we convert a TLS General-Dynamic to a
// Local-Exec.

inline void
Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
				    size_t relnum,
				    Output_segment* tls_segment,
				    const elfcpp::Rel<32, false>& rel,
				    unsigned int,
				    elfcpp::Elf_types<32>::Elf_Addr value,
				    unsigned char* view,
				    section_size_type view_size)
{
  // leal foo(,%reg,1),%eax; call ___tls_get_addr
  //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
  // leal foo(%reg),%eax; call ___tls_get_addr
  //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax

  tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
  tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);

  unsigned char op1 = view[-1];
  unsigned char op2 = view[-2];

  tls::check_tls(relinfo, relnum, rel.get_r_offset(),
                 op2 == 0x8d || op2 == 0x04);
  tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);

  int roff = 5;

  if (op2 == 0x04)
    {
      tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
      tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
      tls::check_tls(relinfo, relnum, rel.get_r_offset(),
                     ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
      memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
    }
  else
    {
      tls::check_tls(relinfo, relnum, rel.get_r_offset(),
                     (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
      if (rel.get_r_offset() + 9 < view_size
          && view[9] == 0x90)
	{
	  // There is a trailing nop.  Use the size byte subl.
	  memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
	  roff = 6;
	}
      else
	{
	  // Use the five byte subl.
	  memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
	}
    }

  value = tls_segment->memsz() - value;
  Relocate_functions<32, false>::rel32(view + roff, value);

  // The next reloc should be a PLT32 reloc against __tls_get_addr.
  // We can skip it.
  this->skip_call_tls_get_addr_ = true;
}

// Do a relocation in which we convert a TLS General-Dynamic to an
// Initial-Exec.

inline void
Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo,
				    size_t relnum,
				    Output_segment*,
				    const elfcpp::Rel<32, false>& rel,
				    unsigned int,
				    elfcpp::Elf_types<32>::Elf_Addr value,
				    unsigned char* view,
				    section_size_type view_size)
{
  // leal foo(,%ebx,1),%eax; call ___tls_get_addr
  //  ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax

  tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
  tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);

  unsigned char op1 = view[-1];
  unsigned char op2 = view[-2];

  tls::check_tls(relinfo, relnum, rel.get_r_offset(),
                 op2 == 0x8d || op2 == 0x04);
  tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);

  int roff = 5;

  // FIXME: For now, support only the first (SIB) form.
  tls::check_tls(relinfo, relnum, rel.get_r_offset(), op2 == 0x04);

  if (op2 == 0x04)
    {
      tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
      tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
      tls::check_tls(relinfo, relnum, rel.get_r_offset(),
                     ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
      memcpy(view - 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
    }
  else
    {
      tls::check_tls(relinfo, relnum, rel.get_r_offset(),
                     (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
      if (rel.get_r_offset() + 9 < view_size
          && view[9] == 0x90)
	{
          // FIXME: This is not the right instruction sequence.
	  // There is a trailing nop.  Use the size byte subl.
	  memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
	  roff = 6;
	}
      else
	{
          // FIXME: This is not the right instruction sequence.
	  // Use the five byte subl.
	  memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
	}
    }

  Relocate_functions<32, false>::rel32(view + roff, value);

  // The next reloc should be a PLT32 reloc against __tls_get_addr.
  // We can skip it.
  this->skip_call_tls_get_addr_ = true;
}

// Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
// General-Dynamic to a Local-Exec.

inline void
Target_i386::Relocate::tls_desc_gd_to_le(
    const Relocate_info<32, false>* relinfo,
    size_t relnum,
    Output_segment* tls_segment,
    const elfcpp::Rel<32, false>& rel,
    unsigned int r_type,
    elfcpp::Elf_types<32>::Elf_Addr value,
    unsigned char* view,
    section_size_type view_size)
{
  if (r_type == elfcpp::R_386_TLS_GOTDESC)
    {
      // leal foo@TLSDESC(%ebx), %eax
      // ==> leal foo@NTPOFF, %eax
      tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
      tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
      tls::check_tls(relinfo, relnum, rel.get_r_offset(),
                     view[-2] == 0x8d && view[-1] == 0x83);
      view[-1] = 0x05;
      value -= tls_segment->memsz();
      Relocate_functions<32, false>::rel32(view, value);
    }
  else
    {
      // call *foo@TLSCALL(%eax)
      // ==> nop; nop
      gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
      tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
      tls::check_tls(relinfo, relnum, rel.get_r_offset(),
                     view[0] == 0xff && view[1] == 0x10);
      view[0] = 0x66;
      view[1] = 0x90;
    }
}

// Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
// General-Dynamic to an Initial-Exec.

inline void
Target_i386::Relocate::tls_desc_gd_to_ie(
    const Relocate_info<32, false>* relinfo,
    size_t relnum,
    Output_segment*,
    const elfcpp::Rel<32, false>& rel,
    unsigned int r_type,
    elfcpp::Elf_types<32>::Elf_Addr value,
    unsigned char* view,
    section_size_type view_size)
{
  if (r_type == elfcpp::R_386_TLS_GOTDESC)
    {
      // leal foo@TLSDESC(%ebx), %eax
      // ==> movl foo@GOTNTPOFF(%ebx), %eax
      tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
      tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
      tls::check_tls(relinfo, relnum, rel.get_r_offset(),
                     view[-2] == 0x8d && view[-1] == 0x83);
      view[-2] = 0x8b;
      Relocate_functions<32, false>::rel32(view, value);
    }
  else
    {
      // call *foo@TLSCALL(%eax)
      // ==> nop; nop
      gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
      tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
      tls::check_tls(relinfo, relnum, rel.get_r_offset(),
                     view[0] == 0xff && view[1] == 0x10);
      view[0] = 0x66;
      view[1] = 0x90;
    }
}

// Do a relocation in which we convert a TLS Local-Dynamic to a
// Local-Exec.

inline void
Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo,
				    size_t relnum,
				    Output_segment*,
				    const elfcpp::Rel<32, false>& rel,
				    unsigned int,
				    elfcpp::Elf_types<32>::Elf_Addr,
				    unsigned char* view,
				    section_size_type view_size)
{
  // leal foo(%reg), %eax; call ___tls_get_addr
  // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi

  tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
  tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);

  // FIXME: Does this test really always pass?
  tls::check_tls(relinfo, relnum, rel.get_r_offset(),
                 view[-2] == 0x8d && view[-1] == 0x83);

  tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);

  memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);

  // The next reloc should be a PLT32 reloc against __tls_get_addr.
  // We can skip it.
  this->skip_call_tls_get_addr_ = true;
}

// Do a relocation in which we convert a TLS Initial-Exec to a
// Local-Exec.

inline void
Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
				    size_t relnum,
				    Output_segment* tls_segment,
				    const elfcpp::Rel<32, false>& rel,
				    unsigned int r_type,
				    elfcpp::Elf_types<32>::Elf_Addr value,
				    unsigned char* view,
				    section_size_type view_size)
{
  // We have to actually change the instructions, which means that we
  // need to examine the opcodes to figure out which instruction we
  // are looking at.
  if (r_type == elfcpp::R_386_TLS_IE)
    {
      // movl %gs:XX,%eax  ==>  movl $YY,%eax
      // movl %gs:XX,%reg  ==>  movl $YY,%reg
      // addl %gs:XX,%reg  ==>  addl $YY,%reg
      tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1);
      tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);

      unsigned char op1 = view[-1];
      if (op1 == 0xa1)
	{
	  // movl XX,%eax  ==>  movl $YY,%eax
	  view[-1] = 0xb8;
	}
      else
	{
	  tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);

	  unsigned char op2 = view[-2];
	  if (op2 == 0x8b)
	    {
	      // movl XX,%reg  ==>  movl $YY,%reg
	      tls::check_tls(relinfo, relnum, rel.get_r_offset(),
                             (op1 & 0xc7) == 0x05);
	      view[-2] = 0xc7;
	      view[-1] = 0xc0 | ((op1 >> 3) & 7);
	    }
	  else if (op2 == 0x03)
	    {
	      // addl XX,%reg  ==>  addl $YY,%reg
	      tls::check_tls(relinfo, relnum, rel.get_r_offset(),
                             (op1 & 0xc7) == 0x05);
	      view[-2] = 0x81;
	      view[-1] = 0xc0 | ((op1 >> 3) & 7);
	    }
	  else
	    tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
	}
    }
  else
    {
      // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
      // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
      // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
      tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
      tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);

      unsigned char op1 = view[-1];
      unsigned char op2 = view[-2];
      tls::check_tls(relinfo, relnum, rel.get_r_offset(),
                     (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
      if (op2 == 0x8b)
	{
	  // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
	  view[-2] = 0xc7;
	  view[-1] = 0xc0 | ((op1 >> 3) & 7);
	}
      else if (op2 == 0x2b)
	{
	  // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
	  view[-2] = 0x81;
	  view[-1] = 0xe8 | ((op1 >> 3) & 7);
	}
      else if (op2 == 0x03)
	{
	  // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
	  view[-2] = 0x81;
	  view[-1] = 0xc0 | ((op1 >> 3) & 7);
	}
      else
	tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
    }

  value = tls_segment->memsz() - value;
  if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
    value = - value;

  Relocate_functions<32, false>::rel32(view, value);
}

// Relocate section data.

void
Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
			      unsigned int sh_type,
			      const unsigned char* prelocs,
			      size_t reloc_count,
			      Output_section* output_section,
			      bool needs_special_offset_handling,
			      unsigned char* view,
			      elfcpp::Elf_types<32>::Elf_Addr address,
			      section_size_type view_size)
{
  gold_assert(sh_type == elfcpp::SHT_REL);

  gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL,
			 Target_i386::Relocate>(
    relinfo,
    this,
    prelocs,
    reloc_count,
    output_section,
    needs_special_offset_handling,
    view,
    address,
    view_size);
}

// Return the size of a relocation while scanning during a relocatable
// link.

unsigned int
Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
    unsigned int r_type,
    Relobj* object)
{
  switch (r_type)
    {
    case elfcpp::R_386_NONE:
    case elfcpp::R_386_GNU_VTINHERIT:
    case elfcpp::R_386_GNU_VTENTRY:
    case elfcpp::R_386_TLS_GD:            // Global-dynamic
    case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
    case elfcpp::R_386_TLS_DESC_CALL:
    case elfcpp::R_386_TLS_LDM:           // Local-dynamic
    case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
    case elfcpp::R_386_TLS_IE:            // Initial-exec
    case elfcpp::R_386_TLS_IE_32:
    case elfcpp::R_386_TLS_GOTIE:
    case elfcpp::R_386_TLS_LE:            // Local-exec
    case elfcpp::R_386_TLS_LE_32:
      return 0;

    case elfcpp::R_386_32:
    case elfcpp::R_386_PC32:
    case elfcpp::R_386_GOT32:
    case elfcpp::R_386_PLT32:
    case elfcpp::R_386_GOTOFF:
    case elfcpp::R_386_GOTPC:
     return 4;

    case elfcpp::R_386_16:
    case elfcpp::R_386_PC16:
      return 2;

    case elfcpp::R_386_8:
    case elfcpp::R_386_PC8:
      return 1;

      // These are relocations which should only be seen by the
      // dynamic linker, and should never be seen here.
    case elfcpp::R_386_COPY:
    case elfcpp::R_386_GLOB_DAT:
    case elfcpp::R_386_JUMP_SLOT:
    case elfcpp::R_386_RELATIVE:
    case elfcpp::R_386_TLS_TPOFF:
    case elfcpp::R_386_TLS_DTPMOD32:
    case elfcpp::R_386_TLS_DTPOFF32:
    case elfcpp::R_386_TLS_TPOFF32:
    case elfcpp::R_386_TLS_DESC:
      object->error(_("unexpected reloc %u in object file"), r_type);
      return 0;

    case elfcpp::R_386_32PLT:
    case elfcpp::R_386_TLS_GD_32:
    case elfcpp::R_386_TLS_GD_PUSH:
    case elfcpp::R_386_TLS_GD_CALL:
    case elfcpp::R_386_TLS_GD_POP:
    case elfcpp::R_386_TLS_LDM_32:
    case elfcpp::R_386_TLS_LDM_PUSH:
    case elfcpp::R_386_TLS_LDM_CALL:
    case elfcpp::R_386_TLS_LDM_POP:
    case elfcpp::R_386_USED_BY_INTEL_200:
    default:
      object->error(_("unsupported reloc %u in object file"), r_type);
      return 0;
    }
}

// Scan the relocs during a relocatable link.

void
Target_i386::scan_relocatable_relocs(const General_options& options,
				     Symbol_table* symtab,
				     Layout* layout,
				     Sized_relobj<32, false>* object,
				     unsigned int data_shndx,
				     unsigned int sh_type,
				     const unsigned char* prelocs,
				     size_t reloc_count,
				     Output_section* output_section,
				     bool needs_special_offset_handling,
				     size_t local_symbol_count,
				     const unsigned char* plocal_symbols,
				     Relocatable_relocs* rr)
{
  gold_assert(sh_type == elfcpp::SHT_REL);

  typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL,
    Relocatable_size_for_reloc> Scan_relocatable_relocs;

  gold::scan_relocatable_relocs<32, false, elfcpp::SHT_REL,
      Scan_relocatable_relocs>(
    options,
    symtab,
    layout,
    object,
    data_shndx,
    prelocs,
    reloc_count,
    output_section,
    needs_special_offset_handling,
    local_symbol_count,
    plocal_symbols,
    rr);
}

// Relocate a section during a relocatable link.

void
Target_i386::relocate_for_relocatable(
    const Relocate_info<32, false>* relinfo,
    unsigned int sh_type,
    const unsigned char* prelocs,
    size_t reloc_count,
    Output_section* output_section,
    off_t offset_in_output_section,
    const Relocatable_relocs* rr,
    unsigned char* view,
    elfcpp::Elf_types<32>::Elf_Addr view_address,
    section_size_type view_size,
    unsigned char* reloc_view,
    section_size_type reloc_view_size)
{
  gold_assert(sh_type == elfcpp::SHT_REL);

  gold::relocate_for_relocatable<32, false, elfcpp::SHT_REL>(
    relinfo,
    prelocs,
    reloc_count,
    output_section,
    offset_in_output_section,
    rr,
    view,
    view_address,
    view_size,
    reloc_view,
    reloc_view_size);
}

// Return the value to use for a dynamic which requires special
// treatment.  This is how we support equality comparisons of function
// pointers across shared library boundaries, as described in the
// processor specific ABI supplement.

uint64_t
Target_i386::do_dynsym_value(const Symbol* gsym) const
{
  gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
  return this->plt_section()->address() + gsym->plt_offset();
}

// Return a string used to fill a code section with nops to take up
// the specified length.

std::string
Target_i386::do_code_fill(section_size_type length) const
{
  if (length >= 16)
    {
      // Build a jmp instruction to skip over the bytes.
      unsigned char jmp[5];
      jmp[0] = 0xe9;
      elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
      return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
              + std::string(length - 5, '\0'));
    }

  // Nop sequences of various lengths.
  const char nop1[1] = { 0x90 };                   // nop
  const char nop2[2] = { 0x66, 0x90 };             // xchg %ax %ax
  const char nop3[3] = { 0x8d, 0x76, 0x00 };       // leal 0(%esi),%esi
  const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00};  // leal 0(%esi,1),%esi
  const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26,   // nop
                         0x00 };                   // leal 0(%esi,1),%esi
  const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00,   // leal 0L(%esi),%esi
                         0x00, 0x00 };
  const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00,   // leal 0L(%esi,1),%esi
                         0x00, 0x00, 0x00 };
  const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26,   // nop
                         0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
  const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc,   // movl %esi,%esi
                         0x27, 0x00, 0x00, 0x00,   // leal 0L(%edi,1),%edi
                         0x00 };
  const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
                           0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
                           0x00, 0x00 };
  const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
                           0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
                           0x00, 0x00, 0x00 };
  const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
                           0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
                           0x00, 0x00, 0x00, 0x00 };
  const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
                           0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
                           0x27, 0x00, 0x00, 0x00,
                           0x00 };
  const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
                           0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
                           0xbc, 0x27, 0x00, 0x00,
                           0x00, 0x00 };
  const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
                           0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
                           0x90, 0x90, 0x90, 0x90,
                           0x90, 0x90, 0x90 };

  const char* nops[16] = {
    NULL,
    nop1, nop2, nop3, nop4, nop5, nop6, nop7,
    nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
  };

  return std::string(nops[length], length);
}

// The selector for i386 object files.

class Target_selector_i386 : public Target_selector
{
public:
  Target_selector_i386()
    : Target_selector(elfcpp::EM_386, 32, false, "elf32-i386")
  { }

  Target*
  do_instantiate_target()
  { return new Target_i386(); }
};

Target_selector_i386 target_selector_i386;

} // End anonymous namespace.