Initial import of binutils 2.27 on vendor branch

[dragonfly.git] / contrib / binutils-2.27 / gold / i386.cc

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

// Copyright (C) 2006-2016 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 "dwarf.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"
#include "freebsd.h"
#include "nacl.h"
#include "gc.h"

namespace
{

using namespace gold;

// A class to handle the .got.plt section.

class Output_data_got_plt_i386 : public Output_section_data_build
{
 public:
  Output_data_got_plt_i386(Layout* layout)
    : Output_section_data_build(4),
      layout_(layout)
  { }

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

  // Write to a map file.
  void
  do_print_to_mapfile(Mapfile* mapfile) const
  { mapfile->print_output_data(this, "** GOT PLT"); }

 private:
  // A pointer to the Layout class, so that we can find the .dynamic
  // section when we write out the GOT PLT section.
  Layout* layout_;
};

// A class to handle the PLT data.
// This is an abstract base class that handles most of the linker details
// but does not know the actual contents of PLT entries.  The derived
// classes below fill in those details.

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*, uint64_t addralign,
                       Output_data_got_plt_i386*, Output_data_space*);

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

  // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
  unsigned int
  add_local_ifunc_entry(Symbol_table*, Layout*,
                        Sized_relobj_file<32, false>* relobj,
                        unsigned int local_sym_index);

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

  // Return where the TLS_DESC relocations should go.
  Reloc_section*
  rel_tls_desc(Layout*);

  // Return where the IRELATIVE relocations should go.
  Reloc_section*
  rel_irelative(Symbol_table*, Layout*);

  // Return whether we created a section for IRELATIVE relocations.
  bool
  has_irelative_section() const
  { return this->irelative_rel_ != NULL; }

  // Return the number of PLT entries.
  unsigned int
  entry_count() const
  { return this->count_ + this->irelative_count_; }

  // Return the offset of the first non-reserved PLT entry.
  unsigned int
  first_plt_entry_offset()
  { return this->get_plt_entry_size(); }

  // Return the size of a PLT entry.
  unsigned int
  get_plt_entry_size() const
  { return this->do_get_plt_entry_size(); }

  // Return the PLT address to use for a global symbol.
  uint64_t
  address_for_global(const Symbol*);

  // Return the PLT address to use for a local symbol.
  uint64_t
  address_for_local(const Relobj*, unsigned int symndx);

  // Add .eh_frame information for the PLT.
  void
  add_eh_frame(Layout* layout)
  { this->do_add_eh_frame(layout); }

 protected:
  // Fill the first PLT entry, given the pointer to the PLT section data
  // and the runtime address of the GOT.
  void
  fill_first_plt_entry(unsigned char* pov,
                       elfcpp::Elf_types<32>::Elf_Addr got_address)
  { this->do_fill_first_plt_entry(pov, got_address); }

  // Fill a normal PLT entry, given the pointer to the entry's data in the
  // section, the runtime address of the GOT, the offset into the GOT of
  // the corresponding slot, the offset into the relocation section of the
  // corresponding reloc, and the offset of this entry within the whole
  // PLT.  Return the offset from this PLT entry's runtime address that
  // should be used to compute the initial value of the GOT slot.
  unsigned int
  fill_plt_entry(unsigned char* pov,
                 elfcpp::Elf_types<32>::Elf_Addr got_address,
                 unsigned int got_offset,
                 unsigned int plt_offset,
                 unsigned int plt_rel_offset)
  {
    return this->do_fill_plt_entry(pov, got_address, got_offset,
                                   plt_offset, plt_rel_offset);
  }

  virtual unsigned int
  do_get_plt_entry_size() const = 0;

  virtual void
  do_fill_first_plt_entry(unsigned char* pov,
                          elfcpp::Elf_types<32>::Elf_Addr got_address) = 0;

  virtual unsigned int
  do_fill_plt_entry(unsigned char* pov,
                    elfcpp::Elf_types<32>::Elf_Addr got_address,
                    unsigned int got_offset,
                    unsigned int plt_offset,
                    unsigned int plt_rel_offset) = 0;

  virtual void
  do_add_eh_frame(Layout*) = 0;

  void
  do_adjust_output_section(Output_section* os);

  // Write to a map file.
  void
  do_print_to_mapfile(Mapfile* mapfile) const
  { mapfile->print_output_data(this, _("** PLT")); }

  // The .eh_frame unwind information for the PLT.
  // The CIE is common across variants of the PLT format.
  static const int plt_eh_frame_cie_size = 16;
  static const unsigned char plt_eh_frame_cie[plt_eh_frame_cie_size];

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

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

  // We keep a list of global STT_GNU_IFUNC symbols, each with its
  // offset in the GOT.
  struct Global_ifunc
  {
    Symbol* sym;
    unsigned int got_offset;
  };

  // We keep a list of local STT_GNU_IFUNC symbols, each with its
  // offset in the GOT.
  struct Local_ifunc
  {
    Sized_relobj_file<32, false>* object;
    unsigned int local_sym_index;
    unsigned int got_offset;
  };

  // The reloc section.
  Reloc_section* rel_;
  // The TLS_DESC relocations, if necessary.  These must follow the
  // regular PLT relocs.
  Reloc_section* tls_desc_rel_;
  // The IRELATIVE relocations, if necessary.  These must follow the
  // regular relocatoins and the TLS_DESC relocations.
  Reloc_section* irelative_rel_;
  // The .got.plt section.
  Output_data_got_plt_i386* got_plt_;
  // The part of the .got.plt section used for IRELATIVE relocs.
  Output_data_space* got_irelative_;
  // The number of PLT entries.
  unsigned int count_;
  // Number of PLT entries with R_386_IRELATIVE relocs.  These follow
  // the regular PLT entries.
  unsigned int irelative_count_;
  // Global STT_GNU_IFUNC symbols.
  std::vector<Global_ifunc> global_ifuncs_;
  // Local STT_GNU_IFUNC symbols.
  std::vector<Local_ifunc> local_ifuncs_;
};

// This is an abstract class for the standard PLT layout.
// The derived classes below handle the actual PLT contents
// for the executable (non-PIC) and shared-library (PIC) cases.
// The unwind information is uniform across those two, so it's here.

class Output_data_plt_i386_standard : public Output_data_plt_i386
{
 public:
  Output_data_plt_i386_standard(Layout* layout,
                                Output_data_got_plt_i386* got_plt,
                                Output_data_space* got_irelative)
    : Output_data_plt_i386(layout, plt_entry_size, got_plt, got_irelative)
  { }

 protected:
  virtual unsigned int
  do_get_plt_entry_size() const
  { return plt_entry_size; }

  virtual void
  do_add_eh_frame(Layout* layout)
  {
    layout->add_eh_frame_for_plt(this, plt_eh_frame_cie, plt_eh_frame_cie_size,
                                 plt_eh_frame_fde, plt_eh_frame_fde_size);
  }

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

  // The .eh_frame unwind information for the PLT.
  static const int plt_eh_frame_fde_size = 32;
  static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
};

// Actually fill the PLT contents for an executable (non-PIC).

class Output_data_plt_i386_exec : public Output_data_plt_i386_standard
{
public:
  Output_data_plt_i386_exec(Layout* layout,
                            Output_data_got_plt_i386* got_plt,
                            Output_data_space* got_irelative)
    : Output_data_plt_i386_standard(layout, got_plt, got_irelative)
  { }

 protected:
  virtual void
  do_fill_first_plt_entry(unsigned char* pov,
                          elfcpp::Elf_types<32>::Elf_Addr got_address);

  virtual unsigned int
  do_fill_plt_entry(unsigned char* pov,
                    elfcpp::Elf_types<32>::Elf_Addr got_address,
                    unsigned int got_offset,
                    unsigned int plt_offset,
                    unsigned int plt_rel_offset);

 private:
  // The first entry in the PLT for an executable.
  static const unsigned char first_plt_entry[plt_entry_size];

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

// Actually fill the PLT contents for a shared library (PIC).

class Output_data_plt_i386_dyn : public Output_data_plt_i386_standard
{
 public:
  Output_data_plt_i386_dyn(Layout* layout,
                           Output_data_got_plt_i386* got_plt,
                           Output_data_space* got_irelative)
    : Output_data_plt_i386_standard(layout, got_plt, got_irelative)
  { }

 protected:
  virtual void
  do_fill_first_plt_entry(unsigned char* pov, elfcpp::Elf_types<32>::Elf_Addr);

  virtual unsigned int
  do_fill_plt_entry(unsigned char* pov,
                    elfcpp::Elf_types<32>::Elf_Addr,
                    unsigned int got_offset,
                    unsigned int plt_offset,
                    unsigned int plt_rel_offset);

 private:
  // The first entry in the PLT for a shared object.
  static const unsigned char first_plt_entry[plt_entry_size];

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

// 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(const Target::Target_info* info = &i386_info)
    : Sized_target<32, false>(info),
      got_(NULL), plt_(NULL), got_plt_(NULL), got_irelative_(NULL),
      got_tlsdesc_(NULL), global_offset_table_(NULL), rel_dyn_(NULL),
      rel_irelative_(NULL), copy_relocs_(elfcpp::R_386_COPY),
      got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
  { }

  // Process the relocations to determine unreferenced sections for
  // garbage collection.
  void
  gc_process_relocs(Symbol_table* symtab,
                    Layout* layout,
                    Sized_relobj_file<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);

  // Scan the relocations to look for symbol adjustments.
  void
  scan_relocs(Symbol_table* symtab,
              Layout* layout,
              Sized_relobj_file<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*, const Input_objects*, Symbol_table*);

  // 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,
                   const Reloc_symbol_changes*);

  // Scan the relocs during a relocatable link.
  void
  scan_relocatable_relocs(Symbol_table* symtab,
                          Layout* layout,
                          Sized_relobj_file<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*);

  // Scan the relocs for --emit-relocs.
  void
  emit_relocs_scan(Symbol_table* symtab,
                   Layout* layout,
                   Sized_relobj_file<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_syms,
                   Relocatable_relocs* rr);

  // Emit relocations for a section.
  void
  relocate_relocs(const Relocate_info<32, false>*,
                  unsigned int sh_type,
                  const unsigned char* prelocs,
                  size_t reloc_count,
                  Output_section* output_section,
                  elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
                  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(const Symbol* sym) const
  { return strcmp(sym->name(), "___tls_get_addr") == 0; }

  // Return whether a symbol name implies a local label.  The UnixWare
  // 2.1 cc generates temporary symbols that start with .X, so we
  // recognize them here.  FIXME: do other SVR4 compilers also use .X?.
  // If so, we should move the .X recognition into
  // Target::do_is_local_label_name.
  bool
  do_is_local_label_name(const char* name) const
  {
    if (name[0] == '.' && name[1] == 'X')
      return true;
    return Target::do_is_local_label_name(name);
  }

  // Return the PLT address to use for a global symbol.
  uint64_t
  do_plt_address_for_global(const Symbol* gsym) const
  { return this->plt_section()->address_for_global(gsym); }

  uint64_t
  do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const
  { return this->plt_section()->address_for_local(relobj, symndx); }

  // We can tell whether we take the address of a function.
  inline bool
  do_can_check_for_function_pointers() const
  { return true; }

  // Return the base for a DW_EH_PE_datarel encoding.
  uint64_t
  do_ehframe_datarel_base() const;

  // Return whether SYM is call to a non-split function.
  bool
  do_is_call_to_non_split(const Symbol* sym, const unsigned char*,
                          const unsigned char*, section_size_type) const;

  // Adjust -fsplit-stack code which calls non-split-stack code.
  void
  do_calls_non_split(Relobj* object, unsigned int shndx,
                     section_offset_type fnoffset, section_size_type fnsize,
                     const unsigned char* prelocs, size_t reloc_count,
                     unsigned char* view, section_size_type view_size,
                     std::string* from, std::string* to) const;

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

  // Return the number of entries in the GOT.
  unsigned int
  got_entry_count() const
  {
    if (this->got_ == NULL)
      return 0;
    return this->got_size() / 4;
  }

  // Return the number of entries in the PLT.
  unsigned int
  plt_entry_count() const;

  // Return the offset of the first non-reserved PLT entry.
  unsigned int
  first_plt_entry_offset() const;

  // Return the size of each PLT entry.
  unsigned int
  plt_entry_size() const;

 protected:
  // Instantiate the plt_ member.
  // This chooses the right PLT flavor for an executable or a shared object.
  Output_data_plt_i386*
  make_data_plt(Layout* layout,
                Output_data_got_plt_i386* got_plt,
                Output_data_space* got_irelative,
                bool dyn)
  { return this->do_make_data_plt(layout, got_plt, got_irelative, dyn); }

  virtual Output_data_plt_i386*
  do_make_data_plt(Layout* layout,
                   Output_data_got_plt_i386* got_plt,
                   Output_data_space* got_irelative,
                   bool dyn)
  {
    if (dyn)
      return new Output_data_plt_i386_dyn(layout, got_plt, got_irelative);
    else
      return new Output_data_plt_i386_exec(layout, got_plt, got_irelative);
  }

 private:
  // The class which scans relocations.
  struct Scan
  {
    static inline int

    get_reference_flags(unsigned int r_type);

    inline void
    local(Symbol_table* symtab, Layout* layout, Target_i386* target,
          Sized_relobj_file<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,
          bool is_discarded);

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

    inline bool
    local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
                                        Target_i386* target,
                                        Sized_relobj_file<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 bool
    global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
                                         Target_i386* target,
                                         Sized_relobj_file<32, false>* object,
                                         unsigned int data_shndx,
                                         Output_section* output_section,
                                         const elfcpp::Rel<32, false>& reloc,
                                         unsigned int r_type,
                                         Symbol* gsym);

    inline bool
    possible_function_pointer_reloc(unsigned int r_type);

    bool
    reloc_needs_plt_for_ifunc(Sized_relobj_file<32, false>*,
                              unsigned int r_type);

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

    static void
    unsupported_reloc_global(Sized_relobj_file<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,
                              unsigned int r_type,
                              bool is_32bit,
                              Output_section* output_section);

    // Do a relocation.  Return false if the caller should not issue
    // any warnings about this relocation.
    inline bool
    relocate(const Relocate_info<32, false>*, unsigned int,
             Target_i386*, Output_section*, size_t, const unsigned char*,
             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,
                 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,
                      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 for inquiring about properties of a relocation,
  // used while scanning relocs during a relocatable link and
  // garbage collection.
  class Classify_reloc :
      public gold::Default_classify_reloc<elfcpp::SHT_REL, 32, false>
  {
   public:
    typedef Reloc_types<elfcpp::SHT_REL, 32, false>::Reloc Reltype;

    // Return the explicit addend of the relocation (return 0 for SHT_REL).
    static elfcpp::Elf_types<32>::Elf_Swxword
    get_r_addend(const Reltype*)
    { return 0; }

    // Return the size of the addend of the relocation (only used for SHT_REL).
    static 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);

  // Check if relocation against this symbol is a candidate for
  // conversion from
  // mov foo@GOT(%reg), %reg
  // to
  // lea foo@GOTOFF(%reg), %reg.
  static bool
  can_convert_mov_to_lea(const Symbol* gsym)
  {
    gold_assert(gsym != NULL);
    return (gsym->type() != elfcpp::STT_GNU_IFUNC
            && !gsym->is_undefined ()
            && !gsym->is_from_dynobj()
            && !gsym->is_preemptible()
            && (!parameters->options().shared()
                || (gsym->visibility() != elfcpp::STV_DEFAULT
                    && gsym->visibility() != elfcpp::STV_PROTECTED)
                || parameters->options().Bsymbolic())
            && strcmp(gsym->name(), "_DYNAMIC") != 0);
  }

  // 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_got_plt_i386*
  got_plt_section() const
  {
    gold_assert(this->got_plt_ != NULL);
    return this->got_plt_;
  }

  // Get the GOT section for TLSDESC entries.
  Output_data_got<32, false>*
  got_tlsdesc_section() const
  {
    gold_assert(this->got_tlsdesc_ != NULL);
    return this->got_tlsdesc_;
  }

  // Create the PLT section.
  void
  make_plt_section(Symbol_table* symtab, Layout* layout);

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

  // Create a PLT entry for a local STT_GNU_IFUNC symbol.
  void
  make_local_ifunc_plt_entry(Symbol_table*, Layout*,
                             Sized_relobj_file<32, false>* relobj,
                             unsigned int local_sym_index);

  // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
  void
  define_tls_base_symbol(Symbol_table*, Layout*);

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

  // Get the PLT section.
  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*);

  // Get the section to use for TLS_DESC relocations.
  Reloc_section*
  rel_tls_desc_section(Layout*) const;

  // Get the section to use for IRELATIVE relocations.
  Reloc_section*
  rel_irelative_section(Layout*);

  // Add a potential copy relocation.
  void
  copy_reloc(Symbol_table* symtab, Layout* layout,
             Sized_relobj_file<32, false>* object,
             unsigned int shndx, Output_section* output_section,
             Symbol* sym, const elfcpp::Rel<32, false>& reloc)
  {
    unsigned int r_type = elfcpp::elf_r_type<32>(reloc.get_r_info());
    this->copy_relocs_.copy_reloc(symtab, layout,
                                  symtab->get_sized_symbol<32>(sym),
                                  object, shndx, output_section,
                                  r_type, reloc.get_r_offset(), 0,
                                  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.
  // These values are exposed to the ABI in an incremental link.
  // Do not renumber existing values without changing the version
  // number of the .gnu_incremental_inputs section.
  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_got_plt_i386* got_plt_;
  // The GOT section for IRELATIVE relocations.
  Output_data_space* got_irelative_;
  // The GOT section for TLSDESC relocations.
  Output_data_got<32, false>* got_tlsdesc_;
  // The _GLOBAL_OFFSET_TABLE_ symbol.
  Symbol* global_offset_table_;
  // The dynamic reloc section.
  Reloc_section* rel_dyn_;
  // The section to use for IRELATIVE relocs.
  Reloc_section* rel_irelative_;
  // Relocs saved to avoid a COPY reloc.
  Copy_relocs<elfcpp::SHT_REL, 32, false> copy_relocs_;
  // Offset of the GOT entry for the TLS module index.
  unsigned int got_mod_index_offset_;
  // True if the _TLS_MODULE_BASE_ symbol has been defined.
  bool tls_base_symbol_defined_;
};

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
  true,                 // can_icf_inline_merge_sections
  '\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)
  false,                // isolate_execinstr
  0,                    // rosegment_gap
  elfcpp::SHN_UNDEF,    // small_common_shndx
  elfcpp::SHN_UNDEF,    // large_common_shndx
  0,                    // small_common_section_flags
  0,                    // large_common_section_flags
  NULL,                 // attributes_section
  NULL,                 // attributes_vendor
  "_start",             // entry_symbol_name
  32,                   // hash_entry_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>();

      // When using -z now, we can treat .got.plt as a relro section.
      // Without -z now, it is modified after program startup by lazy
      // PLT relocations.
      bool is_got_plt_relro = parameters->options().now();
      Output_section_order got_order = (is_got_plt_relro
                                        ? ORDER_RELRO
                                        : ORDER_RELRO_LAST);
      Output_section_order got_plt_order = (is_got_plt_relro
                                            ? ORDER_RELRO
                                            : ORDER_NON_RELRO_FIRST);

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

      this->got_plt_ = new Output_data_got_plt_i386(layout);
      layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
                                      (elfcpp::SHF_ALLOC
                                       | elfcpp::SHF_WRITE),
                                      this->got_plt_, got_plt_order,
                                      is_got_plt_relro);

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

      if (!is_got_plt_relro)
        {
          // Those bytes can go into the relro segment.
          layout->increase_relro(3 * 4);
        }

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

      // If there are any IRELATIVE relocations, they get GOT entries
      // in .got.plt after the jump slot relocations.
      this->got_irelative_ = new Output_data_space(4, "** GOT IRELATIVE PLT");
      layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
                                      (elfcpp::SHF_ALLOC
                                       | elfcpp::SHF_WRITE),
                                      this->got_irelative_,
                                      got_plt_order, is_got_plt_relro);

      // If there are any TLSDESC relocations, they get GOT entries in
      // .got.plt after the jump slot entries.
      this->got_tlsdesc_ = new Output_data_got<32, false>();
      layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
                                      (elfcpp::SHF_ALLOC
                                       | elfcpp::SHF_WRITE),
                                      this->got_tlsdesc_,
                                      got_plt_order, is_got_plt_relro);
    }

  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(parameters->options().combreloc());
      layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
                                      elfcpp::SHF_ALLOC, this->rel_dyn_,
                                      ORDER_DYNAMIC_RELOCS, false);
    }
  return this->rel_dyn_;
}

// Get the section to use for IRELATIVE relocs, creating it if
// necessary.  These go in .rel.dyn, but only after all other dynamic
// relocations.  They need to follow the other dynamic relocations so
// that they can refer to global variables initialized by those
// relocs.

Target_i386::Reloc_section*
Target_i386::rel_irelative_section(Layout* layout)
{
  if (this->rel_irelative_ == NULL)
    {
      // Make sure we have already create the dynamic reloc section.
      this->rel_dyn_section(layout);
      this->rel_irelative_ = new Reloc_section(false);
      layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
                                      elfcpp::SHF_ALLOC, this->rel_irelative_,
                                      ORDER_DYNAMIC_RELOCS, false);
      gold_assert(this->rel_dyn_->output_section()
                  == this->rel_irelative_->output_section());
    }
  return this->rel_irelative_;
}

// Write the first three reserved words of the .got.plt section.
// The remainder of the section is written while writing the PLT
// in Output_data_plt_i386::do_write.

void
Output_data_got_plt_i386::do_write(Output_file* of)
{
  // The first entry in the GOT is the address of the .dynamic section
  // aka the PT_DYNAMIC segment.  The next two entries are reserved.
  // We saved space for them when we created the section in
  // Target_i386::got_section.
  const off_t got_file_offset = this->offset();
  gold_assert(this->data_size() >= 12);
  unsigned char* const got_view = of->get_output_view(got_file_offset, 12);
  Output_section* dynamic = this->layout_->dynamic_section();
  uint32_t dynamic_addr = dynamic == NULL ? 0 : dynamic->address();
  elfcpp::Swap<32, false>::writeval(got_view, dynamic_addr);
  memset(got_view + 4, 0, 8);
  of->write_output_view(got_file_offset, 12, got_view);
}

// 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,
                                           uint64_t addralign,
                                           Output_data_got_plt_i386* got_plt,
                                           Output_data_space* got_irelative)
  : Output_section_data(addralign),
    tls_desc_rel_(NULL), irelative_rel_(NULL), got_plt_(got_plt),
    got_irelative_(got_irelative), count_(0), irelative_count_(0),
    global_ifuncs_(), local_ifuncs_()
{
  this->rel_ = new Reloc_section(false);
  layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
                                  elfcpp::SHF_ALLOC, this->rel_,
                                  ORDER_DYNAMIC_PLT_RELOCS, false);
}

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_table* symtab, Layout* layout,
                                Symbol* gsym)
{
  gold_assert(!gsym->has_plt_offset());

  // Every PLT entry needs a reloc.
  if (gsym->type() == elfcpp::STT_GNU_IFUNC
      && gsym->can_use_relative_reloc(false))
    {
      gsym->set_plt_offset(this->irelative_count_ * this->get_plt_entry_size());
      ++this->irelative_count_;
      section_offset_type got_offset =
        this->got_irelative_->current_data_size();
      this->got_irelative_->set_current_data_size(got_offset + 4);
      Reloc_section* rel = this->rel_irelative(symtab, layout);
      rel->add_symbolless_global_addend(gsym, elfcpp::R_386_IRELATIVE,
                                        this->got_irelative_, got_offset);
      struct Global_ifunc gi;
      gi.sym = gsym;
      gi.got_offset = got_offset;
      this->global_ifuncs_.push_back(gi);
    }
  else
    {
      // When setting the PLT offset we skip the initial reserved PLT
      // entry.
      gsym->set_plt_offset((this->count_ + 1) * this->get_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);

      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.
}

// Add an entry to the PLT for a local STT_GNU_IFUNC symbol.  Return
// the PLT offset.

unsigned int
Output_data_plt_i386::add_local_ifunc_entry(
    Symbol_table* symtab,
    Layout* layout,
    Sized_relobj_file<32, false>* relobj,
    unsigned int local_sym_index)
{
  unsigned int plt_offset = this->irelative_count_ * this->get_plt_entry_size();
  ++this->irelative_count_;

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

  // Every PLT entry needs a GOT entry which points back to the PLT
  // entry.
  this->got_irelative_->set_current_data_size(got_offset + 4);

  // Every PLT entry needs a reloc.
  Reloc_section* rel = this->rel_irelative(symtab, layout);
  rel->add_symbolless_local_addend(relobj, local_sym_index,
                                   elfcpp::R_386_IRELATIVE,
                                   this->got_irelative_, got_offset);

  struct Local_ifunc li;
  li.object = relobj;
  li.local_sym_index = local_sym_index;
  li.got_offset = got_offset;
  this->local_ifuncs_.push_back(li);

  return plt_offset;
}

// Return where the TLS_DESC relocations should go, creating it if
// necessary. These follow the JUMP_SLOT relocations.

Output_data_plt_i386::Reloc_section*
Output_data_plt_i386::rel_tls_desc(Layout* layout)
{
  if (this->tls_desc_rel_ == NULL)
    {
      this->tls_desc_rel_ = new Reloc_section(false);
      layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
                                      elfcpp::SHF_ALLOC, this->tls_desc_rel_,
                                      ORDER_DYNAMIC_PLT_RELOCS, false);
      gold_assert(this->tls_desc_rel_->output_section()
                  == this->rel_->output_section());
    }
  return this->tls_desc_rel_;
}

// Return where the IRELATIVE relocations should go in the PLT.  These
// follow the JUMP_SLOT and TLS_DESC relocations.

Output_data_plt_i386::Reloc_section*
Output_data_plt_i386::rel_irelative(Symbol_table* symtab, Layout* layout)
{
  if (this->irelative_rel_ == NULL)
    {
      // Make sure we have a place for the TLS_DESC relocations, in
      // case we see any later on.
      this->rel_tls_desc(layout);
      this->irelative_rel_ = new Reloc_section(false);
      layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
                                      elfcpp::SHF_ALLOC, this->irelative_rel_,
                                      ORDER_DYNAMIC_PLT_RELOCS, false);
      gold_assert(this->irelative_rel_->output_section()
                  == this->rel_->output_section());

      if (parameters->doing_static_link())
        {
          // A statically linked executable will only have a .rel.plt
          // section to hold R_386_IRELATIVE relocs for STT_GNU_IFUNC
          // symbols.  The library will use these symbols to locate
          // the IRELATIVE relocs at program startup time.
          symtab->define_in_output_data("__rel_iplt_start", NULL,
                                        Symbol_table::PREDEFINED,
                                        this->irelative_rel_, 0, 0,
                                        elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
                                        elfcpp::STV_HIDDEN, 0, false, true);
          symtab->define_in_output_data("__rel_iplt_end", NULL,
                                        Symbol_table::PREDEFINED,
                                        this->irelative_rel_, 0, 0,
                                        elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
                                        elfcpp::STV_HIDDEN, 0, true, true);
        }
    }
  return this->irelative_rel_;
}

// Return the PLT address to use for a global symbol.

uint64_t
Output_data_plt_i386::address_for_global(const Symbol* gsym)
{
  uint64_t offset = 0;
  if (gsym->type() == elfcpp::STT_GNU_IFUNC
      && gsym->can_use_relative_reloc(false))
    offset = (this->count_ + 1) * this->get_plt_entry_size();
  return this->address() + offset + gsym->plt_offset();
}

// Return the PLT address to use for a local symbol.  These are always
// IRELATIVE relocs.

uint64_t
Output_data_plt_i386::address_for_local(const Relobj* object,
                                        unsigned int r_sym)
{
  return (this->address()
          + (this->count_ + 1) * this->get_plt_entry_size()
          + object->local_plt_offset(r_sym));
}

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

const 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
};

void
Output_data_plt_i386_exec::do_fill_first_plt_entry(
    unsigned char* pov,
    elfcpp::Elf_types<32>::Elf_Addr got_address)
{
  memcpy(pov, 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);
}

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

const 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
};

void
Output_data_plt_i386_dyn::do_fill_first_plt_entry(
    unsigned char* pov,
    elfcpp::Elf_types<32>::Elf_Addr)
{
  memcpy(pov, first_plt_entry, plt_entry_size);
}

// Subsequent entries in the PLT for an executable.

const 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
};

unsigned int
Output_data_plt_i386_exec::do_fill_plt_entry(
    unsigned char* pov,
    elfcpp::Elf_types<32>::Elf_Addr got_address,
    unsigned int got_offset,
    unsigned int plt_offset,
    unsigned int plt_rel_offset)
{
  memcpy(pov, 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 + 12 + 4));
  return 6;
}

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

const 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
};

unsigned int
Output_data_plt_i386_dyn::do_fill_plt_entry(unsigned char* pov,
                                            elfcpp::Elf_types<32>::Elf_Addr,
                                            unsigned int got_offset,
                                            unsigned int plt_offset,
                                            unsigned int plt_rel_offset)
{
  memcpy(pov, plt_entry, plt_entry_size);
  elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
  elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
  elfcpp::Swap<32, false>::writeval(pov + 12, - (plt_offset + 12 + 4));
  return 6;
}

// The .eh_frame unwind information for the PLT.

const unsigned char
Output_data_plt_i386::plt_eh_frame_cie[plt_eh_frame_cie_size] =
{
  1,                            // CIE version.
  'z',                          // Augmentation: augmentation size included.
  'R',                          // Augmentation: FDE encoding included.
  '\0',                         // End of augmentation string.
  1,                            // Code alignment factor.
  0x7c,                         // Data alignment factor.
  8,                            // Return address column.
  1,                            // Augmentation size.
  (elfcpp::DW_EH_PE_pcrel       // FDE encoding.
   | elfcpp::DW_EH_PE_sdata4),
  elfcpp::DW_CFA_def_cfa, 4, 4, // DW_CFA_def_cfa: r4 (esp) ofs 4.
  elfcpp::DW_CFA_offset + 8, 1, // DW_CFA_offset: r8 (eip) at cfa-4.
  elfcpp::DW_CFA_nop,           // Align to 16 bytes.
  elfcpp::DW_CFA_nop
};

const unsigned char
Output_data_plt_i386_standard::plt_eh_frame_fde[plt_eh_frame_fde_size] =
{
  0, 0, 0, 0,                           // Replaced with offset to .plt.
  0, 0, 0, 0,                           // Replaced with size of .plt.
  0,                                    // Augmentation size.
  elfcpp::DW_CFA_def_cfa_offset, 8,     // DW_CFA_def_cfa_offset: 8.
  elfcpp::DW_CFA_advance_loc + 6,       // Advance 6 to __PLT__ + 6.
  elfcpp::DW_CFA_def_cfa_offset, 12,    // DW_CFA_def_cfa_offset: 12.
  elfcpp::DW_CFA_advance_loc + 10,      // Advance 10 to __PLT__ + 16.
  elfcpp::DW_CFA_def_cfa_expression,    // DW_CFA_def_cfa_expression.
  11,                                   // Block length.
  elfcpp::DW_OP_breg4, 4,               // Push %esp + 4.
  elfcpp::DW_OP_breg8, 0,               // Push %eip.
  elfcpp::DW_OP_lit15,                  // Push 0xf.
  elfcpp::DW_OP_and,                    // & (%eip & 0xf).
  elfcpp::DW_OP_lit11,                  // Push 0xb.
  elfcpp::DW_OP_ge,                     // >= ((%eip & 0xf) >= 0xb)
  elfcpp::DW_OP_lit2,                   // Push 2.
  elfcpp::DW_OP_shl,                    // << (((%eip & 0xf) >= 0xb) << 2)
  elfcpp::DW_OP_plus,                   // + ((((%eip&0xf)>=0xb)<<2)+%esp+4
  elfcpp::DW_CFA_nop,                   // Align to 32 bytes.
  elfcpp::DW_CFA_nop,
  elfcpp::DW_CFA_nop,
  elfcpp::DW_CFA_nop
};

// 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();
  gold_assert(parameters->incremental_update()
              || (got_file_offset + this->got_plt_->data_size()
                  == this->got_irelative_->offset()));
  const section_size_type got_size =
    convert_to_section_size_type(this->got_plt_->data_size()
                                 + this->got_irelative_->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();

  this->fill_first_plt_entry(pov, got_address);
  pov += this->get_plt_entry_size();

  // The first three entries in the GOT are reserved, and are written
  // by Output_data_got_plt_i386::do_write.
  unsigned char* got_pov = got_view + 12;

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

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

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

  // If any STT_GNU_IFUNC symbols have PLT entries, we need to change
  // the GOT to point to the actual symbol value, rather than point to
  // the PLT entry.  That will let the dynamic linker call the right
  // function when resolving IRELATIVE relocations.
  unsigned char* got_irelative_view = got_view + this->got_plt_->data_size();
  for (std::vector<Global_ifunc>::const_iterator p =
         this->global_ifuncs_.begin();
       p != this->global_ifuncs_.end();
       ++p)
    {
      const Sized_symbol<32>* ssym =
        static_cast<const Sized_symbol<32>*>(p->sym);
      elfcpp::Swap<32, false>::writeval(got_irelative_view + p->got_offset,
                                        ssym->value());
    }

  for (std::vector<Local_ifunc>::const_iterator p =
         this->local_ifuncs_.begin();
       p != this->local_ifuncs_.end();
       ++p)
    {
      const Symbol_value<32>* psymval =
        p->object->local_symbol(p->local_sym_index);
      elfcpp::Swap<32, false>::writeval(got_irelative_view + p->got_offset,
                                        psymval->value(p->object, 0));
    }

  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 the PLT section.

void
Target_i386::make_plt_section(Symbol_table* symtab, Layout* layout)
{
  if (this->plt_ == NULL)
    {
      // Create the GOT sections first.
      this->got_section(symtab, layout);

      const bool dyn = parameters->options().output_is_position_independent();
      this->plt_ = this->make_data_plt(layout,
                                       this->got_plt_,
                                       this->got_irelative_,
                                       dyn);

      // Add unwind information if requested.
      if (parameters->options().ld_generated_unwind_info())
        this->plt_->add_eh_frame(layout);

      layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
                                      (elfcpp::SHF_ALLOC
                                       | elfcpp::SHF_EXECINSTR),
                                      this->plt_, ORDER_PLT, false);

      // Make the sh_info field of .rel.plt point to .plt.
      Output_section* rel_plt_os = this->plt_->rel_plt()->output_section();
      rel_plt_os->set_info_section(this->plt_->output_section());
    }
}

// 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)
    this->make_plt_section(symtab, layout);
  this->plt_->add_entry(symtab, layout, gsym);
}

// Make a PLT entry for a local STT_GNU_IFUNC symbol.

void
Target_i386::make_local_ifunc_plt_entry(Symbol_table* symtab, Layout* layout,
                                        Sized_relobj_file<32, false>* relobj,
                                        unsigned int local_sym_index)
{
  if (relobj->local_has_plt_offset(local_sym_index))
    return;
  if (this->plt_ == NULL)
    this->make_plt_section(symtab, layout);
  unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
                                                              relobj,
                                                              local_sym_index);
  relobj->set_local_plt_offset(local_sym_index, plt_offset);
}

// Return the number of entries in the PLT.

unsigned int
Target_i386::plt_entry_count() const
{
  if (this->plt_ == NULL)
    return 0;
  return this->plt_->entry_count();
}

// Return the offset of the first non-reserved PLT entry.

unsigned int
Target_i386::first_plt_entry_offset() const
{
  if (this->plt_ == NULL)
    return 0;
  return this->plt_->first_plt_entry_offset();
}

// Return the size of each PLT entry.

unsigned int
Target_i386::plt_entry_size() const
{
  if (this->plt_ == NULL)
    return 0;
  return this->plt_->get_plt_entry_size();
}

// Get the section to use for TLS_DESC relocations.

Target_i386::Reloc_section*
Target_i386::rel_tls_desc_section(Layout* layout) const
{
  return this->plt_section()->rel_tls_desc(layout);
}

// Define the _TLS_MODULE_BASE_ symbol in the TLS segment.

void
Target_i386::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
{
  if (this->tls_base_symbol_defined_)
    return;

  Output_segment* tls_segment = layout->tls_segment();
  if (tls_segment != NULL)
    {
      bool is_exec = parameters->options().output_is_executable();
      symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
                                       Symbol_table::PREDEFINED,
                                       tls_segment, 0, 0,
                                       elfcpp::STT_TLS,
                                       elfcpp::STB_LOCAL,
                                       elfcpp::STV_HIDDEN, 0,
                                       (is_exec
                                        ? Symbol::SEGMENT_END
                                        : Symbol::SEGMENT_START),
                                       true);
    }
  this->tls_base_symbol_defined_ = true;
}

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

unsigned int
Target_i386::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
                                 Sized_relobj_file<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();
    }
}

// Get the Reference_flags for a particular relocation.

int
Target_i386::Scan::get_reference_flags(unsigned int r_type)
{
  switch (r_type)
    {
    case elfcpp::R_386_NONE:
    case elfcpp::R_386_GNU_VTINHERIT:
    case elfcpp::R_386_GNU_VTENTRY:
    case elfcpp::R_386_GOTPC:
      // No symbol reference.
      return 0;

    case elfcpp::R_386_32:
    case elfcpp::R_386_16:
    case elfcpp::R_386_8:
      return Symbol::ABSOLUTE_REF;

    case elfcpp::R_386_PC32:
    case elfcpp::R_386_PC16:
    case elfcpp::R_386_PC8:
    case elfcpp::R_386_GOTOFF:
      return Symbol::RELATIVE_REF;

    case elfcpp::R_386_PLT32:
      return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;

    case elfcpp::R_386_GOT32:
    case elfcpp::R_386_GOT32X:
      // Absolute in GOT.
      return Symbol::ABSOLUTE_REF;

    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 Symbol::TLS_REF;

    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_IRELATIVE:
    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:
    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:
      // Not expected.  We will give an error later.
      return 0;
    }
}

// Report an unsupported relocation against a local symbol.

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

// Return whether we need to make a PLT entry for a relocation of a
// given type against a STT_GNU_IFUNC symbol.

bool
Target_i386::Scan::reloc_needs_plt_for_ifunc(
    Sized_relobj_file<32, false>* object,
    unsigned int r_type)
{
  int flags = Scan::get_reference_flags(r_type);
  if (flags & Symbol::TLS_REF)
    gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
               object->name().c_str(), r_type);
  return flags != 0;
}

// Scan a relocation for a local symbol.

inline void
Target_i386::Scan::local(Symbol_table* symtab,
                         Layout* layout,
                         Target_i386* target,
                         Sized_relobj_file<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,
                         bool is_discarded)
{
  if (is_discarded)
    return;

  // A local STT_GNU_IFUNC symbol may require a PLT entry.
  if (lsym.get_st_type() == elfcpp::STT_GNU_IFUNC
      && this->reloc_needs_plt_for_ifunc(object, r_type))
    {
      unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
      target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
    }

  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);
          unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
          if (lsym.get_st_type() != elfcpp::STT_SECTION)
            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);
              unsigned int shndx = lsym.get_st_shndx();
              bool is_ordinary;
              shndx = object->adjust_sym_shndx(r_sym, shndx,
                                               &is_ordinary);
              if (!is_ordinary)
                object->error(_("section symbol %u has bad shndx %u"),
                              r_sym, shndx);
              else
                rel_dyn->add_local_section(object, 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:
    case elfcpp::R_386_GOT32X:
      {
        // We need GOT section.
        Output_data_got<32, false>* got = target->got_section(symtab, layout);

        // If the relocation symbol isn't IFUNC,
        // and is local, then we will convert
        // mov foo@GOT(%reg), %reg
        // to
        // lea foo@GOTOFF(%reg), %reg
        // in Relocate::relocate.
        if (reloc.get_r_offset() >= 2
            && lsym.get_st_type() != elfcpp::STT_GNU_IFUNC)
          {
            section_size_type stype;
            const unsigned char* view = object->section_contents(data_shndx,
                                                                 &stype, true);
            if (view[reloc.get_r_offset() - 2] == 0x8b)
              break;
          }

        // Otherwise, the symbol requires a GOT entry.
        unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());

        // For a STT_GNU_IFUNC symbol we want the PLT offset.  That
        // lets function pointers compare correctly with shared
        // libraries.  Otherwise we would need an IRELATIVE reloc.
        bool is_new;
        if (lsym.get_st_type() == elfcpp::STT_GNU_IFUNC)
          is_new = got->add_local_plt(object, r_sym, GOT_TYPE_STANDARD);
        else
          is_new = got->add_local(object, r_sym, GOT_TYPE_STANDARD);
        if (is_new)
          {
            // 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 got_offset =
                  object->local_got_offset(r_sym, GOT_TYPE_STANDARD);
                rel_dyn->add_local_relative(object, r_sym,
                                            elfcpp::R_386_RELATIVE,
                                            got, got_offset);
              }
          }
      }
      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_IRELATIVE:
    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());
                unsigned int shndx = lsym.get_st_shndx();
                bool is_ordinary;
                shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
                if (!is_ordinary)
                  object->error(_("local symbol %u has bad shndx %u"),
                              r_sym, shndx);
                else
                  got->add_local_pair_with_rel(object, r_sym, shndx,
                                               GOT_TYPE_TLS_PAIR,
                                               target->rel_dyn_section(layout),
                                               elfcpp::R_386_TLS_DTPMOD32);
              }
            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)
            target->define_tls_base_symbol(symtab, layout);
            if (optimized_type == tls::TLSOPT_NONE)
              {
                // Create a double GOT entry with an R_386_TLS_DESC
                // reloc.  The R_386_TLS_DESC reloc is resolved
                // lazily, so the GOT entry needs to be in an area in
                // .got.plt, not .got.  Call got_section to make sure
                // the section has been created.
                target->got_section(symtab, layout);
                Output_data_got<32, false>* got = target->got_tlsdesc_section();
                unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
                if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
                  {
                    unsigned int got_offset = got->add_constant(0);
                    // The local symbol value is stored in the second
                    // GOT entry.
                    got->add_local(object, r_sym, GOT_TYPE_TLS_DESC);
                    // That set the GOT offset of the local symbol to
                    // point to the second entry, but we want it to
                    // point to the first.
                    object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
                                                 got_offset);
                    Reloc_section* rt = target->rel_tls_desc_section(layout);
                    rt->add_absolute(elfcpp::R_386_TLS_DESC, got, got_offset);
                  }
              }
            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_file<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());
}

inline bool
Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type)
{
  switch (r_type)
    {
    case elfcpp::R_386_32:
    case elfcpp::R_386_16:
    case elfcpp::R_386_8:
    case elfcpp::R_386_GOTOFF:
    case elfcpp::R_386_GOT32:
    case elfcpp::R_386_GOT32X:
      {
        return true;
      }
    default:
      return false;
    }
  return false;
}

inline bool
Target_i386::Scan::local_reloc_may_be_function_pointer(
  Symbol_table* ,
  Layout* ,
  Target_i386* ,
  Sized_relobj_file<32, false>* ,
  unsigned int ,
  Output_section* ,
  const elfcpp::Rel<32, false>& ,
  unsigned int r_type,
  const elfcpp::Sym<32, false>&)
{
  return possible_function_pointer_reloc(r_type);
}

inline bool
Target_i386::Scan::global_reloc_may_be_function_pointer(
  Symbol_table* ,
  Layout* ,
  Target_i386* ,
  Sized_relobj_file<32, false>* ,
  unsigned int ,
  Output_section* ,
  const elfcpp::Rel<32, false>& ,
  unsigned int r_type,
  Symbol*)
{
  return possible_function_pointer_reloc(r_type);
}

// Scan a relocation for a global symbol.

inline void
Target_i386::Scan::global(Symbol_table* symtab,
                                 Layout* layout,
                                 Target_i386* target,
                                 Sized_relobj_file<32, false>* object,
                                 unsigned int data_shndx,
                                 Output_section* output_section,
                                 const elfcpp::Rel<32, false>& reloc,
                                 unsigned int r_type,
                                 Symbol* gsym)
{
  // A STT_GNU_IFUNC symbol may require a PLT entry.
  if (gsym->type() == elfcpp::STT_GNU_IFUNC
      && this->reloc_needs_plt_for_ifunc(object, r_type))
    target->make_plt_entry(symtab, layout, 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(Scan::get_reference_flags(r_type)))
          {
            if (!parameters->options().output_is_position_independent()
                && gsym->may_need_copy_reloc())
              {
                target->copy_reloc(symtab, layout, object,
                                   data_shndx, output_section, gsym, reloc);
              }
            else if (r_type == elfcpp::R_386_32
                     && gsym->type() == elfcpp::STT_GNU_IFUNC
                     && gsym->can_use_relative_reloc(false)
                     && !gsym->is_from_dynobj()
                     && !gsym->is_undefined()
                     && !gsym->is_preemptible())
              {
                // Use an IRELATIVE reloc for a locally defined
                // STT_GNU_IFUNC symbol.  This makes a function
                // address in a PIE executable match the address in a
                // shared library that it links against.
                Reloc_section* rel_dyn = target->rel_irelative_section(layout);
                rel_dyn->add_symbolless_global_addend(gsym,
                                                      elfcpp::R_386_IRELATIVE,
                                                      output_section,
                                                      object, data_shndx,
                                                      reloc.get_r_offset());
              }
            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.
        if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
          {
            if (parameters->options().output_is_executable()
                && gsym->may_need_copy_reloc())
              {
                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:
    case elfcpp::R_386_GOT32X:
      {
        // The symbol requires a GOT section.
        Output_data_got<32, false>* got = target->got_section(symtab, layout);

        // If we convert this from
        // mov foo@GOT(%reg), %reg
        // to
        // lea foo@GOTOFF(%reg), %reg
        // in Relocate::relocate, then there is nothing to do here.
        if (reloc.get_r_offset() >= 2
            && Target_i386::can_convert_mov_to_lea(gsym))
          {
            section_size_type stype;
            const unsigned char* view = object->section_contents(data_shndx,
                                                                 &stype, true);
            if (view[reloc.get_r_offset() - 2] == 0x8b)
              break;
          }

        if (gsym->final_value_is_known())
          {
            // For a STT_GNU_IFUNC symbol we want the PLT address.
            if (gsym->type() == elfcpp::STT_GNU_IFUNC)
              got->add_global_plt(gsym, GOT_TYPE_STANDARD);
            else
              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);

            // Use a GLOB_DAT rather than a RELATIVE reloc if:
            //
            // 1) The symbol may be defined in some other module.
            //
            // 2) We are building a shared library and this is a
            // protected symbol; using GLOB_DAT means that the dynamic
            // linker can use the address of the PLT in the main
            // executable when appropriate so that function address
            // comparisons work.
            //
            // 3) This is a STT_GNU_IFUNC symbol in position dependent
            // code, again so that function address comparisons work.
            if (gsym->is_from_dynobj()
                || gsym->is_undefined()
                || gsym->is_preemptible()
                || (gsym->visibility() == elfcpp::STV_PROTECTED
                    && parameters->options().shared())
                || (gsym->type() == elfcpp::STT_GNU_IFUNC
                    && parameters->options().output_is_position_independent()))
              got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
                                       rel_dyn, elfcpp::R_386_GLOB_DAT);
            else
              {
                // For a STT_GNU_IFUNC symbol we want to write the PLT
                // offset into the GOT, so that function pointer
                // comparisons work correctly.
                bool is_new;
                if (gsym->type() != elfcpp::STT_GNU_IFUNC)
                  is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
                else
                  {
                    is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
                    // Tell the dynamic linker to use the PLT address
                    // when resolving relocations.
                    if (gsym->is_from_dynobj()
                        && !parameters->options().shared())
                      gsym->set_needs_dynsym_value();
                  }
                if (is_new)
                  {
                    unsigned int got_off = gsym->got_offset(GOT_TYPE_STANDARD);
                    rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
                                                 got, got_off);
                  }
              }
          }
      }
      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:
      // A GOT-relative reference must resolve locally.
      if (!gsym->is_defined())
        gold_error(_("%s: relocation R_386_GOTOFF against undefined symbol %s"
                     " cannot be used when making a shared object"),
                   object->name().c_str(), gsym->name());
      else if (gsym->is_from_dynobj())
        gold_error(_("%s: relocation R_386_GOTOFF against external symbol %s"
                     " cannot be used when making a shared object"),
                   object->name().c_str(), gsym->name());
      else if (gsym->is_preemptible())
        gold_error(_("%s: relocation R_386_GOTOFF against preemptible symbol %s"
                     " cannot be used when making a shared object"),
                   object->name().c_str(), gsym->name());
      // We need a GOT section.
      target->got_section(symtab, layout);
      break;

    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_IRELATIVE:
    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)
            target->define_tls_base_symbol(symtab, layout);
            if (optimized_type == tls::TLSOPT_NONE)
              {
                // Create a double GOT entry with an R_386_TLS_DESC
                // reloc.  The R_386_TLS_DESC reloc is resolved
                // lazily, so the GOT entry needs to be in an area in
                // .got.plt, not .got.  Call got_section to make sure
                // the section has been created.
                target->got_section(symtab, layout);
                Output_data_got<32, false>* got = target->got_tlsdesc_section();
                Reloc_section* rt = target->rel_tls_desc_section(layout);
                got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt,
                                             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;
    }
}

// Process relocations for gc.

void
Target_i386::gc_process_relocs(Symbol_table* symtab,
                                      Layout* layout,
                                      Sized_relobj_file<32, false>* object,
                                      unsigned int data_shndx,
                                      unsigned int,
                                      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)
{
  gold::gc_process_relocs<32, false, Target_i386, Scan, Classify_reloc>(
    symtab,
    layout,
    this,
    object,
    data_shndx,
    prelocs,
    reloc_count,
    output_section,
    needs_special_offset_handling,
    local_symbol_count,
    plocal_symbols);
}

// Scan relocations for a section.

void
Target_i386::scan_relocs(Symbol_table* symtab,
                                Layout* layout,
                                Sized_relobj_file<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, Scan, Classify_reloc>(
    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,
    const Input_objects*,
    Symbol_table* symtab)
{
  const Reloc_section* rel_plt = (this->plt_ == NULL
                                  ? NULL
                                  : this->plt_->rel_plt());
  layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
                                  this->rel_dyn_, true, false);

  // 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));

  // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
  // the .got.plt section.
  Symbol* sym = this->global_offset_table_;
  if (sym != NULL)
    {
      uint32_t data_size = this->got_plt_->current_data_size();
      symtab->get_sized_symbol<32>(sym)->set_symsize(data_size);
    }

  if (parameters->doing_static_link()
      && (this->plt_ == NULL || !this->plt_->has_irelative_section()))
    {
      // If linking statically, make sure that the __rel_iplt symbols
      // were defined if necessary, even if we didn't create a PLT.
      static const Define_symbol_in_segment syms[] =
        {
          {
            "__rel_iplt_start",         // name
            elfcpp::PT_LOAD,            // segment_type
            elfcpp::PF_W,               // segment_flags_set
            elfcpp::PF(0),              // segment_flags_clear
            0,                          // value
            0,                          // size
            elfcpp::STT_NOTYPE,         // type
            elfcpp::STB_GLOBAL,         // binding
            elfcpp::STV_HIDDEN,         // visibility
            0,                          // nonvis
            Symbol::SEGMENT_START,      // offset_from_base
            true                        // only_if_ref
          },
          {
            "__rel_iplt_end",           // name
            elfcpp::PT_LOAD,            // segment_type
            elfcpp::PF_W,               // segment_flags_set
            elfcpp::PF(0),              // segment_flags_clear
            0,                          // value
            0,                          // size
            elfcpp::STT_NOTYPE,         // type
            elfcpp::STB_GLOBAL,         // binding
            elfcpp::STV_HIDDEN,         // visibility
            0,                          // nonvis
            Symbol::SEGMENT_START,      // offset_from_base
            true                        // only_if_ref
          }
        };

      symtab->define_symbols(layout, 2, syms,
                             layout->script_options()->saw_sections_clause());
    }
}

// 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,
                                                 unsigned int r_type,
                                                 bool is_32bit,
                                                 Output_section* output_section)
{
  // If the output section is not allocated, then we didn't call
  // scan_relocs, we didn't create a dynamic reloc, and we must apply
  // the reloc here.
  if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
    return true;

  int ref_flags = Scan::get_reference_flags(r_type);

  // 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,
                                unsigned int,
                                Target_i386* target,
                                Output_section* output_section,
                                size_t relnum,
                                const unsigned char* preloc,
                                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)
{
  const elfcpp::Rel<32, false> rel(preloc);
  unsigned int r_type = elfcpp::elf_r_type<32>(rel.get_r_info());

  if (this->skip_call_tls_get_addr_)
    {
      if ((r_type != elfcpp::R_386_PLT32
           && r_type != elfcpp::R_386_GOT32X
           && r_type != elfcpp::R_386_PC32)
          || 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;
        }
    }

  if (view == NULL)
    return true;

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

  // Pick the value to use for symbols defined in shared objects.
  Symbol_value<32> symval;
  if (gsym != NULL
      && gsym->type() == elfcpp::STT_GNU_IFUNC
      && r_type == elfcpp::R_386_32
      && gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type))
      && gsym->can_use_relative_reloc(false)
      && !gsym->is_from_dynobj()
      && !gsym->is_undefined()
      && !gsym->is_preemptible())
    {
      // In this case we are generating a R_386_IRELATIVE reloc.  We
      // want to use the real value of the symbol, not the PLT offset.
    }
  else if (gsym != NULL
           && gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
    {
      symval.set_output_value(target->plt_address_for_global(gsym));
      psymval = &symval;
    }
  else if (gsym == NULL && psymval->is_ifunc_symbol())
    {
      unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
      if (object->local_has_plt_offset(r_sym))
        {
          symval.set_output_value(target->plt_address_for_local(object, r_sym));
          psymval = &symval;
        }
    }

  bool baseless;

  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, r_type, true, output_section))
        Relocate_functions<32, false>::rel32(view, object, psymval);
      break;

    case elfcpp::R_386_PC32:
      if (should_apply_static_reloc(gsym, r_type, true, output_section))
        Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
      break;

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

    case elfcpp::R_386_PC16:
      if (should_apply_static_reloc(gsym, r_type, false, output_section))
        Relocate_functions<32, false>::pcrel16(view, object, psymval, address);
      break;

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

    case elfcpp::R_386_PC8:
      if (should_apply_static_reloc(gsym, r_type, false, output_section))
        Relocate_functions<32, false>::pcrel8(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:
    case elfcpp::R_386_GOT32X:
      baseless = (view[-1] & 0xc7) == 0x5;
      // R_386_GOT32 and R_386_GOT32X don't work without base register
      // when generating a position-independent output file.
      if (baseless
          && parameters->options().output_is_position_independent())
        {
          if(gsym)
            gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
                                   _("unexpected reloc %u against global symbol %s without base register in object file when generating a position-independent output file"),
                                   r_type, gsym->demangled_name().c_str());
          else
            gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
                                   _("unexpected reloc %u against local symbol without base register in object file when generating a position-independent output file"),
                                   r_type);
        }

      // Convert
      // mov foo@GOT(%reg), %reg
      // to
      // lea foo@GOTOFF(%reg), %reg
      // if possible.
      if (rel.get_r_offset() >= 2
          && view[-2] == 0x8b
          && ((gsym == NULL && !psymval->is_ifunc_symbol())
              || (gsym != NULL
                  && Target_i386::can_convert_mov_to_lea(gsym))))
        {
          view[-2] = 0x8d;
          elfcpp::Elf_types<32>::Elf_Addr value;
          value = psymval->value(object, 0);
          // Don't subtract the .got.plt section address for baseless
          // addressing.
          if (!baseless)
            value -= target->got_plt_section()->address();
          Relocate_functions<32, false>::rel32(view, value);
        }
      else
        {
          // 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.
          unsigned int got_offset = 0;
          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());
            }
          // Add the .got.plt section address for baseless addressing.
          if (baseless)
            got_offset += target->got_plt_section()->address();
          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:
    case elfcpp::R_386_IRELATIVE:
      // 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_file<32, false>* object = relinfo->object;

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

  const bool is_final = (gsym == NULL
                         ? !parameters->options().shared()
                         : 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)
        {
          if (tls_segment == NULL)
            {
              gold_assert(parameters->errors()->error_count() > 0
                          || issue_undefined_symbol_error(gsym));
              return;
            }
          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)
            {
              this->tls_gd_to_ie(relinfo, relnum, 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:
      this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
      if (optimized_type == tls::TLSOPT_TO_LE)
        {
          if (tls_segment == NULL)
            {
              gold_assert(parameters->errors()->error_count() > 0
                          || issue_undefined_symbol_error(gsym));
              return;
            }
          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 = 0;
          if (r_type == elfcpp::R_386_TLS_GOTDESC
              && optimized_type == tls::TLSOPT_NONE)
            {
              // We created GOT entries in the .got.tlsdesc portion of
              // the .got.plt section, but the offset stored in the
              // symbol is the offset within .got.tlsdesc.
              got_offset = (target->got_size()
                            + target->got_plt_section()->data_size());
            }
          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)
            {
              this->tls_desc_gd_to_ie(relinfo, relnum, 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)
        {
          if (tls_segment == NULL)
            {
              gold_assert(parameters->errors()->error_count() > 0
                          || issue_undefined_symbol_error(gsym));
              return;
            }
          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
      if (optimized_type == tls::TLSOPT_TO_LE)
        {
          // This reloc can appear in debugging sections, in which
          // case we must not convert to local-exec.  We decide what
          // to do based on whether the section is marked as
          // containing executable code.  That is what the GNU linker
          // does as well.
          elfcpp::Shdr<32, false> shdr(relinfo->data_shdr);
          if ((shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0)
            {
              if (tls_segment == NULL)
                {
                  gold_assert(parameters->errors()->error_count() > 0
                              || issue_undefined_symbol_error(gsym));
                  return;
                }
              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)
        {
          if (tls_segment == NULL)
            {
              gold_assert(parameters->errors()->error_count() > 0
                          || issue_undefined_symbol_error(gsym));
              return;
            }
          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())
        {
          if (tls_segment == NULL)
            {
              gold_assert(parameters->errors()->error_count() > 0
                          || issue_undefined_symbol_error(gsym));
              return;
            }
          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())
        {
          if (tls_segment == NULL)
            {
              gold_assert(parameters->errors()->error_count() > 0
                          || issue_undefined_symbol_error(gsym));
              return;
            }
          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(,%ebx,1),%eax; call ___tls_get_addr@PLT
  //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
  // leal foo(%ebx),%eax; call ___tls_get_addr@PLT
  //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
  // leal foo(%reg),%eax; call *___tls_get_addr@GOT(%reg)
  //  ==> 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];
  unsigned char op3 = view[4];

  tls::check_tls(relinfo, relnum, rel.get_r_offset(),
                 op2 == 0x8d || op2 == 0x04);
  tls::check_tls(relinfo, relnum, rel.get_r_offset(),
                 op3 == 0xe8 || op3 == 0xff);

  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
    {
      unsigned char reg = op1 & 7;
      tls::check_tls(relinfo, relnum, rel.get_r_offset(),
                     ((op1 & 0xf8) == 0x80
                      && reg != 4
                      && reg != 0
                      && (op3 == 0xe8 || (view[5] & 0x7) == reg)));
      if (op3 == 0xff
          || (rel.get_r_offset() + 9 < view_size
              && view[9] == 0x90))
        {
          // There is an indirect call or 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,
                                    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@PLT
  //  ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
  // leal foo(%ebx),%eax; call ___tls_get_addr@PLT; nop
  //  ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
  // leal foo(%reg),%eax; call *___tls_get_addr@GOT(%reg)
  //  ==> movl %gs:0,%eax; addl foo@gotntpoff(%reg),%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];
  unsigned char op3 = view[4];

  tls::check_tls(relinfo, relnum, rel.get_r_offset(),
                 op2 == 0x8d || op2 == 0x04);
  tls::check_tls(relinfo, relnum, rel.get_r_offset(),
                 op3 == 0xe8 || op3 == 0xff);

  int roff;

  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)));
      roff = 5;
    }
  else
    {
      unsigned char reg = op1 & 7;
      tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 10);
      tls::check_tls(relinfo, relnum, rel.get_r_offset(),
                     ((op1 & 0xf8) == 0x80
                      && reg != 4
                      && reg != 0
                      && ((op3 == 0xe8 && view[9] == 0x90)
                           || (view[5] & 0x7) == reg)));
      roff = 6;
    }

  memcpy(view + roff - 8, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
  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,
    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(%ebx), %eax; call ___tls_get_addr@PLT
  // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
  // leal foo(%reg), %eax; call call *___tls_get_addr@GOT(%reg)
  // ==> movl %gs:0,%eax; leal (%esi),%esi

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

  unsigned char op1 = view[-1];
  unsigned char op2 = view[-2];
  unsigned char op3 = view[4];

  tls::check_tls(relinfo, relnum, rel.get_r_offset(),
                 op3 == 0xe8 || op3 == 0xff);
  tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size,
                   op3 == 0xe8 ? 9 : 10);

  // FIXME: Does this test really always pass?
  tls::check_tls(relinfo, relnum, rel.get_r_offset(), op2 == 0x8d);

  unsigned char reg = op1 & 7;
  tls::check_tls(relinfo, relnum, rel.get_r_offset(),
                 ((op1 & 0xf8) == 0x80
                  && reg != 4
                  && reg != 0
                  && (op3 == 0xe8 || (view[5] & 0x7) == reg)));

  if (op3 == 0xe8)
    memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
  else
    memcpy(view - 2, "\x65\xa1\0\0\0\0\x8d\xb6\0\0\0\0", 12);

  // 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,
                              const Reloc_symbol_changes* reloc_symbol_changes)
{
  gold_assert(sh_type == elfcpp::SHT_REL);

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

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

unsigned int
Target_i386::Classify_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_GOT32X:
    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_IRELATIVE:
    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(Symbol_table* symtab,
                                     Layout* layout,
                                     Sized_relobj_file<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)
{
  typedef gold::Default_scan_relocatable_relocs<Classify_reloc>
      Scan_relocatable_relocs;

  gold_assert(sh_type == elfcpp::SHT_REL);

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

// Scan the relocs for --emit-relocs.

void
Target_i386::emit_relocs_scan(Symbol_table* symtab,
                              Layout* layout,
                              Sized_relobj_file<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_syms,
                              Relocatable_relocs* rr)
{
  typedef gold::Default_classify_reloc<elfcpp::SHT_REL, 32, false>
      Classify_reloc;
  typedef gold::Default_emit_relocs_strategy<Classify_reloc>
      Emit_relocs_strategy;

  gold_assert(sh_type == elfcpp::SHT_REL);

  gold::scan_relocatable_relocs<32, false, Emit_relocs_strategy>(
    symtab,
    layout,
    object,
    data_shndx,
    prelocs,
    reloc_count,
    output_section,
    needs_special_offset_handling,
    local_symbol_count,
    plocal_syms,
    rr);
}

// Emit relocations for a section.

void
Target_i386::relocate_relocs(
    const Relocate_info<32, false>* relinfo,
    unsigned int sh_type,
    const unsigned char* prelocs,
    size_t reloc_count,
    Output_section* output_section,
    elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
    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_relocs<32, false, Classify_reloc>(
    relinfo,
    prelocs,
    reloc_count,
    output_section,
    offset_in_output_section,
    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_address_for_global(gsym);
}

// 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, static_cast<char>(0x90)));
    }

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

  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);
}

// Return the value to use for the base of a DW_EH_PE_datarel offset
// in an FDE.  Solaris and SVR4 use DW_EH_PE_datarel because their
// assembler can not write out the difference between two labels in
// different sections, so instead of using a pc-relative value they
// use an offset from the GOT.

uint64_t
Target_i386::do_ehframe_datarel_base() const
{
  gold_assert(this->global_offset_table_ != NULL);
  Symbol* sym = this->global_offset_table_;
  Sized_symbol<32>* ssym = static_cast<Sized_symbol<32>*>(sym);
  return ssym->value();
}

// Return whether SYM should be treated as a call to a non-split
// function.  We don't want that to be true of a call to a
// get_pc_thunk function.

bool
Target_i386::do_is_call_to_non_split(const Symbol* sym,
                                     const unsigned char*,
                                     const unsigned char*,
                                     section_size_type) const
{
  return (sym->type() == elfcpp::STT_FUNC
          && !is_prefix_of("__i686.get_pc_thunk.", sym->name()));
}

// FNOFFSET in section SHNDX in OBJECT is the start of a function
// compiled with -fsplit-stack.  The function calls non-split-stack
// code.  We have to change the function so that it always ensures
// that it has enough stack space to run some random function.

void
Target_i386::do_calls_non_split(Relobj* object, unsigned int shndx,
                                       section_offset_type fnoffset,
                                       section_size_type fnsize,
                                       const unsigned char*,
                                       size_t,
                                       unsigned char* view,
                                       section_size_type view_size,
                                       std::string* from,
                                       std::string* to) const
{
  // The function starts with a comparison of the stack pointer and a
  // field in the TCB.  This is followed by a jump.

  // cmp %gs:NN,%esp
  if (this->match_view(view, view_size, fnoffset, "\x65\x3b\x25", 3)
      && fnsize > 7)
    {
      // We will call __morestack if the carry flag is set after this
      // comparison.  We turn the comparison into an stc instruction
      // and some nops.
      view[fnoffset] = '\xf9';
      this->set_view_to_nop(view, view_size, fnoffset + 1, 6);
    }
  // lea NN(%esp),%ecx
  // lea NN(%esp),%edx
  else if ((this->match_view(view, view_size, fnoffset, "\x8d\x8c\x24", 3)
            || this->match_view(view, view_size, fnoffset, "\x8d\x94\x24", 3))
           && fnsize > 7)
    {
      // This is loading an offset from the stack pointer for a
      // comparison.  The offset is negative, so we decrease the
      // offset by the amount of space we need for the stack.  This
      // means we will avoid calling __morestack if there happens to
      // be plenty of space on the stack already.
      unsigned char* pval = view + fnoffset + 3;
      uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
      val -= parameters->options().split_stack_adjust_size();
      elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
    }
  else
    {
      if (!object->has_no_split_stack())
        object->error(_("failed to match split-stack sequence at "
                        "section %u offset %0zx"),
                      shndx, static_cast<size_t>(fnoffset));
      return;
    }

  // We have to change the function so that it calls
  // __morestack_non_split instead of __morestack.  The former will
  // allocate additional stack space.
  *from = "__morestack";
  *to = "__morestack_non_split";
}

// The selector for i386 object files.  Note this is never instantiated
// directly.  It's only used in Target_selector_i386_nacl, below.

class Target_selector_i386 : public Target_selector_freebsd
{
public:
  Target_selector_i386()
    : Target_selector_freebsd(elfcpp::EM_386, 32, false,
                              "elf32-i386", "elf32-i386-freebsd",
                              "elf_i386")
  { }

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

// NaCl variant.  It uses different PLT contents.

class Output_data_plt_i386_nacl : public Output_data_plt_i386
{
 public:
  Output_data_plt_i386_nacl(Layout* layout,
                            Output_data_got_plt_i386* got_plt,
                            Output_data_space* got_irelative)
    : Output_data_plt_i386(layout, plt_entry_size, got_plt, got_irelative)
  { }

 protected:
  virtual unsigned int
  do_get_plt_entry_size() const
  { return plt_entry_size; }

  virtual void
  do_add_eh_frame(Layout* layout)
  {
    layout->add_eh_frame_for_plt(this, plt_eh_frame_cie, plt_eh_frame_cie_size,
                                 plt_eh_frame_fde, plt_eh_frame_fde_size);
  }

  // The size of an entry in the PLT.
  static const int plt_entry_size = 64;

  // The .eh_frame unwind information for the PLT.
  static const int plt_eh_frame_fde_size = 32;
  static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
};

class Output_data_plt_i386_nacl_exec : public Output_data_plt_i386_nacl
{
public:
  Output_data_plt_i386_nacl_exec(Layout* layout,
                                 Output_data_got_plt_i386* got_plt,
                                 Output_data_space* got_irelative)
    : Output_data_plt_i386_nacl(layout, got_plt, got_irelative)
  { }

 protected:
  virtual void
  do_fill_first_plt_entry(unsigned char* pov,
                          elfcpp::Elf_types<32>::Elf_Addr got_address);

  virtual unsigned int
  do_fill_plt_entry(unsigned char* pov,
                    elfcpp::Elf_types<32>::Elf_Addr got_address,
                    unsigned int got_offset,
                    unsigned int plt_offset,
                    unsigned int plt_rel_offset);

 private:
  // The first entry in the PLT for an executable.
  static const unsigned char first_plt_entry[plt_entry_size];

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

class Output_data_plt_i386_nacl_dyn : public Output_data_plt_i386_nacl
{
 public:
  Output_data_plt_i386_nacl_dyn(Layout* layout,
                                Output_data_got_plt_i386* got_plt,
                                Output_data_space* got_irelative)
    : Output_data_plt_i386_nacl(layout, got_plt, got_irelative)
  { }

 protected:
  virtual void
  do_fill_first_plt_entry(unsigned char* pov, elfcpp::Elf_types<32>::Elf_Addr);

  virtual unsigned int
  do_fill_plt_entry(unsigned char* pov,
                    elfcpp::Elf_types<32>::Elf_Addr,
                    unsigned int got_offset,
                    unsigned int plt_offset,
                    unsigned int plt_rel_offset);

 private:
  // The first entry in the PLT for a shared object.
  static const unsigned char first_plt_entry[plt_entry_size];

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

class Target_i386_nacl : public Target_i386
{
 public:
  Target_i386_nacl()
    : Target_i386(&i386_nacl_info)
  { }

 protected:
  virtual Output_data_plt_i386*
  do_make_data_plt(Layout* layout,
                   Output_data_got_plt_i386* got_plt,
                   Output_data_space* got_irelative,
                   bool dyn)
  {
    if (dyn)
      return new Output_data_plt_i386_nacl_dyn(layout, got_plt, got_irelative);
    else
      return new Output_data_plt_i386_nacl_exec(layout, got_plt, got_irelative);
  }

  virtual std::string
  do_code_fill(section_size_type length) const;

 private:
  static const Target::Target_info i386_nacl_info;
};

const Target::Target_info Target_i386_nacl::i386_nacl_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
  true,                 // can_icf_inline_merge_sections
  '\0',                 // wrap_char
  "/lib/ld-nacl-x86-32.so.1", // dynamic_linker
  0x20000,              // default_text_segment_address
  0x10000,              // abi_pagesize (overridable by -z max-page-size)
  0x10000,              // common_pagesize (overridable by -z common-page-size)
  true,                 // isolate_execinstr
  0x10000000,           // rosegment_gap
  elfcpp::SHN_UNDEF,    // small_common_shndx
  elfcpp::SHN_UNDEF,    // large_common_shndx
  0,                    // small_common_section_flags
  0,                    // large_common_section_flags
  NULL,                 // attributes_section
  NULL,                 // attributes_vendor
  "_start",             // entry_symbol_name
  32,                   // hash_entry_size
};

#define NACLMASK        0xe0            // 32-byte alignment mask

const unsigned char
Output_data_plt_i386_nacl_exec::first_plt_entry[plt_entry_size] =
{
  0xff, 0x35,                          // pushl contents of memory address
  0, 0, 0, 0,                          // replaced with address of .got + 4
  0x8b, 0x0d,                          // movl contents of address, %ecx
  0, 0, 0, 0,                          // replaced with address of .got + 8
  0x83, 0xe1, NACLMASK,                // andl $NACLMASK, %ecx
  0xff, 0xe1,                          // jmp *%ecx
  0x90, 0x90, 0x90, 0x90, 0x90, 0x90,  // nops
  0x90, 0x90, 0x90, 0x90, 0x90, 0x90,  // nops
  0x90, 0x90, 0x90, 0x90, 0x90, 0x90,  // nops
  0x90, 0x90, 0x90, 0x90, 0x90, 0x90,  // nops
  0x90, 0x90, 0x90, 0x90, 0x90, 0x90,  // nops
  0x90, 0x90, 0x90, 0x90, 0x90, 0x90,  // nops
  0x90, 0x90, 0x90, 0x90, 0x90, 0x90,  // nops
  0x90, 0x90, 0x90, 0x90, 0x90
};

void
Output_data_plt_i386_nacl_exec::do_fill_first_plt_entry(
    unsigned char* pov,
    elfcpp::Elf_types<32>::Elf_Addr got_address)
{
  memcpy(pov, 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);
}

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

const unsigned char
Output_data_plt_i386_nacl_dyn::first_plt_entry[plt_entry_size] =
{
  0xff, 0xb3, 4, 0, 0, 0,       // pushl 4(%ebx)
  0x8b, 0x4b, 0x08,             // mov 0x8(%ebx), %ecx
  0x83, 0xe1, NACLMASK,         // andl $NACLMASK, %ecx
  0xff, 0xe1,                   // jmp *%ecx
  0x90, 0x90, 0x90, 0x90, 0x90,  // nops
  0x90, 0x90, 0x90, 0x90, 0x90,  // nops
  0x90, 0x90, 0x90, 0x90, 0x90,  // nops
  0x90, 0x90, 0x90, 0x90, 0x90,  // nops
  0x90, 0x90, 0x90, 0x90, 0x90,  // nops
  0x90, 0x90, 0x90, 0x90, 0x90,  // nops
  0x90, 0x90, 0x90, 0x90, 0x90,  // nops
  0x90, 0x90, 0x90, 0x90, 0x90,  // nops
  0x90, 0x90, 0x90, 0x90, 0x90,  // nops
  0x90, 0x90, 0x90, 0x90, 0x90   // nops
};

void
Output_data_plt_i386_nacl_dyn::do_fill_first_plt_entry(
    unsigned char* pov,
    elfcpp::Elf_types<32>::Elf_Addr)
{
  memcpy(pov, first_plt_entry, plt_entry_size);
}

// Subsequent entries in the PLT for an executable.

const unsigned char
Output_data_plt_i386_nacl_exec::plt_entry[plt_entry_size] =
{
  0x8b, 0x0d,                    // movl contents of address, %ecx */
  0, 0, 0, 0,                    // replaced with address of symbol in .got
  0x83, 0xe1, NACLMASK,          // andl $NACLMASK, %ecx
  0xff, 0xe1,                    // jmp *%ecx

  // Pad to the next 32-byte boundary with nop instructions.
  0x90,
  0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
  0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,

  // Lazy GOT entries point here (32-byte aligned).
  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

  // Pad to the next 32-byte boundary with nop instructions.
  0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
  0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
  0x90, 0x90
};

unsigned int
Output_data_plt_i386_nacl_exec::do_fill_plt_entry(
    unsigned char* pov,
    elfcpp::Elf_types<32>::Elf_Addr got_address,
    unsigned int got_offset,
    unsigned int plt_offset,
    unsigned int plt_rel_offset)
{
  memcpy(pov, plt_entry, plt_entry_size);
  elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
                                              got_address + got_offset);
  elfcpp::Swap_unaligned<32, false>::writeval(pov + 33, plt_rel_offset);
  elfcpp::Swap<32, false>::writeval(pov + 38, - (plt_offset + 38 + 4));
  return 32;
}

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

const unsigned char
Output_data_plt_i386_nacl_dyn::plt_entry[plt_entry_size] =
{
  0x8b, 0x8b,          // movl offset(%ebx), %ecx
  0, 0, 0, 0,          // replaced with offset of symbol in .got
  0x83, 0xe1, 0xe0,    // andl $NACLMASK, %ecx
  0xff, 0xe1,          // jmp *%ecx

  // Pad to the next 32-byte boundary with nop instructions.
  0x90,
  0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
  0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,

  // Lazy GOT entries point here (32-byte aligned).
  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.

  // Pad to the next 32-byte boundary with nop instructions.
  0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
  0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
  0x90, 0x90
};

unsigned int
Output_data_plt_i386_nacl_dyn::do_fill_plt_entry(
    unsigned char* pov,
    elfcpp::Elf_types<32>::Elf_Addr,
    unsigned int got_offset,
    unsigned int plt_offset,
    unsigned int plt_rel_offset)
{
  memcpy(pov, plt_entry, plt_entry_size);
  elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
  elfcpp::Swap_unaligned<32, false>::writeval(pov + 33, plt_rel_offset);
  elfcpp::Swap<32, false>::writeval(pov + 38, - (plt_offset + 38 + 4));
  return 32;
}

const unsigned char
Output_data_plt_i386_nacl::plt_eh_frame_fde[plt_eh_frame_fde_size] =
{
  0, 0, 0, 0,                           // Replaced with offset to .plt.
  0, 0, 0, 0,                           // Replaced with size of .plt.
  0,                                    // Augmentation size.
  elfcpp::DW_CFA_def_cfa_offset, 8,     // DW_CFA_def_cfa_offset: 8.
  elfcpp::DW_CFA_advance_loc + 6,       // Advance 6 to __PLT__ + 6.
  elfcpp::DW_CFA_def_cfa_offset, 12,    // DW_CFA_def_cfa_offset: 12.
  elfcpp::DW_CFA_advance_loc + 58,      // Advance 58 to __PLT__ + 64.
  elfcpp::DW_CFA_def_cfa_expression,    // DW_CFA_def_cfa_expression.
  13,                                   // Block length.
  elfcpp::DW_OP_breg4, 4,               // Push %esp + 4.
  elfcpp::DW_OP_breg8, 0,               // Push %eip.
  elfcpp::DW_OP_const1u, 63,            // Push 0x3f.
  elfcpp::DW_OP_and,                    // & (%eip & 0x3f).
  elfcpp::DW_OP_const1u, 37,            // Push 0x25.
  elfcpp::DW_OP_ge,                     // >= ((%eip & 0x3f) >= 0x25)
  elfcpp::DW_OP_lit2,                   // Push 2.
  elfcpp::DW_OP_shl,                    // << (((%eip & 0x3f) >= 0x25) << 2)
  elfcpp::DW_OP_plus,                   // + ((((%eip&0x3f)>=0x25)<<2)+%esp+4
  elfcpp::DW_CFA_nop,                   // Align to 32 bytes.
  elfcpp::DW_CFA_nop
};

// Return a string used to fill a code section with nops.
// For NaCl, long NOPs are only valid if they do not cross
// bundle alignment boundaries, so keep it simple with one-byte NOPs.
std::string
Target_i386_nacl::do_code_fill(section_size_type length) const
{
  return std::string(length, static_cast<char>(0x90));
}

// The selector for i386-nacl object files.

class Target_selector_i386_nacl
  : public Target_selector_nacl<Target_selector_i386, Target_i386_nacl>
{
 public:
  Target_selector_i386_nacl()
    : Target_selector_nacl<Target_selector_i386,
                           Target_i386_nacl>("x86-32",
                                             "elf32-i386-nacl",
                                             "elf_i386_nacl")
  { }
};

Target_selector_i386_nacl target_selector_i386;

// IAMCU variant.  It uses EM_IAMCU, not EM_386.

class Target_iamcu : public Target_i386
{
 public:
  Target_iamcu()
    : Target_i386(&iamcu_info)
  { }

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

const Target::Target_info Target_iamcu::iamcu_info =
{
  32,                   // size
  false,                // is_big_endian
  elfcpp::EM_IAMCU,     // machine_code
  false,                // has_make_symbol
  false,                // has_resolve
  true,                 // has_code_fill
  true,                 // is_default_stack_executable
  true,                 // can_icf_inline_merge_sections
  '\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)
  false,                // isolate_execinstr
  0,                    // rosegment_gap
  elfcpp::SHN_UNDEF,    // small_common_shndx
  elfcpp::SHN_UNDEF,    // large_common_shndx
  0,                    // small_common_section_flags
  0,                    // large_common_section_flags
  NULL,                 // attributes_section
  NULL,                 // attributes_vendor
  "_start",             // entry_symbol_name
  32,                   // hash_entry_size
};

class Target_selector_iamcu : public Target_selector
{
public:
  Target_selector_iamcu()
    : Target_selector(elfcpp::EM_IAMCU, 32, false, "elf32-iamcu",
                      "elf_iamcu")
  { }

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

Target_selector_iamcu target_selector_iamcu;

} // End anonymous namespace.