Add s390 backend.

[deliverable/binutils-gdb.git] / gold / s390.cc

// s390.cc -- s390 target support for gold.

// Copyright (C) 2015 Free Software Foundation, Inc.
// Written by Marcin Kościelnicki <koriakin@0x04.net>.

// 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 "s390.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 "gc.h"
#include "icf.h"

namespace
{

using namespace gold;

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

template<int size>
class Output_data_got_plt_s390 : public Output_section_data_build
{
 public:
  Output_data_got_plt_s390(Layout* layout)
    : Output_section_data_build(size/8),
      layout_(layout)
  { }

  Output_data_got_plt_s390(Layout* layout, off_t data_size)
    : Output_section_data_build(data_size, size/8),
      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.

template<int size>
class Output_data_plt_s390 : public Output_section_data
{
 public:
  typedef Output_data_reloc<elfcpp::SHT_RELA, true, size, true>
    Reloc_section;

  Output_data_plt_s390(Layout* layout,
                         Output_data_got<size, true>* got,
                         Output_data_got_plt_s390<size>* got_plt,
                         Output_data_space* got_irelative)
    : Output_section_data(4), layout_(layout),
      irelative_rel_(NULL), got_(got), got_plt_(got_plt),
      got_irelative_(got_irelative), count_(0),
      irelative_count_(0), free_list_()
  { this->init(layout); }

  Output_data_plt_s390(Layout* layout,
                         Output_data_got<size, true>* got,
                         Output_data_got_plt_s390<size>* got_plt,
                         Output_data_space* got_irelative,
                         unsigned int plt_count)
    : Output_section_data((plt_count + 1) * plt_entry_size,
                          4, false),
      layout_(layout), irelative_rel_(NULL), got_(got),
      got_plt_(got_plt), got_irelative_(got_irelative), count_(plt_count),
      irelative_count_(0), free_list_()
  {
    this->init(layout);

    // Initialize the free list and reserve the first entry.
    this->free_list_.init((plt_count + 1) * plt_entry_size, false);
    this->free_list_.remove(0, plt_entry_size);
  }

  // Initialize the PLT section.
  void
  init(Layout* layout);

  // 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<size, true>*, unsigned int);

  // Add the relocation for a PLT entry.
  void
  add_relocation(Symbol_table*, Layout*, Symbol*, unsigned int);

  // Return the .rela.plt section data.
  Reloc_section*
  rela_plt()
  { return this->rel_; }

  // Return where the IRELATIVE relocations should go in the PLT
  // relocations.
  Reloc_section*
  rela_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 plt_entry_size; }

  // Return the size of a PLT entry.
  unsigned int
  get_plt_entry_size() const
  { return plt_entry_size; }

  // Reserve a slot in the PLT for an existing symbol in an incremental update.
  void
  reserve_slot(unsigned int plt_index)
  {
    this->free_list_.remove((plt_index + 1) * plt_entry_size,
                            (plt_index + 2) * 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)
  {
          (void)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);
  }

 protected:
  // Fill in the first PLT entry.
  void
  fill_first_plt_entry(unsigned char* pov,
                       typename elfcpp::Elf_types<size>::Elf_Addr got_address,
                       typename elfcpp::Elf_types<size>::Elf_Addr plt_address);

  // Fill in a normal PLT entry.  Returns the offset into the entry that
  // should be the initial GOT slot value.
  unsigned int
  fill_plt_entry(unsigned char* pov,
                 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
                 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
                 unsigned int got_offset,
                 unsigned int plt_offset,
                 unsigned int plt_rel_offset);

  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")); }

 private:
  // Set the final size.
  void
  set_final_data_size();

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

  // A pointer to the Layout class, so that we can find the .dynamic
  // section when we write out the GOT PLT section.
  Layout* layout_;
  // The reloc section.
  Reloc_section* rel_;
  // The IRELATIVE relocs, if necessary.  These must follow the
  // regular PLT relocations.
  Reloc_section* irelative_rel_;
  // The .got section.
  Output_data_got<size, true>* got_;
  // The .got.plt section.
  Output_data_got_plt_s390<size>* 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_TILEGX_IRELATIVE relocs.  These
  // follow the regular PLT entries.
  unsigned int irelative_count_;
  // List of available regions within the section, for incremental
  // update links.
  Free_list free_list_;

  // The size of an entry in the PLT.
  static const int plt_entry_size = 0x20;
  // The first entry in the PLT.
  static const unsigned char first_plt_entry_32_abs[plt_entry_size];
  static const unsigned char first_plt_entry_32_pic[plt_entry_size];
  static const unsigned char first_plt_entry_64[plt_entry_size];
  // Other entries in the PLT for an executable.
  static const unsigned char plt_entry_32_abs[plt_entry_size];
  static const unsigned char plt_entry_32_pic12[plt_entry_size];
  static const unsigned char plt_entry_32_pic16[plt_entry_size];
  static const unsigned char plt_entry_32_pic[plt_entry_size];
  static const unsigned char plt_entry_64[plt_entry_size];

  // The .eh_frame unwind information for the PLT.
  static const int plt_eh_frame_cie_size = 12;
  static const unsigned char plt_eh_frame_cie[plt_eh_frame_cie_size];
  static const int plt_eh_frame_fde_size = 12;
  static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
};


template<int size>
class Target_s390 : public Sized_target<size, true>
{
 public:
  typedef Output_data_reloc<elfcpp::SHT_RELA, true, size, true> Reloc_section;

  Target_s390()
    : Sized_target<size, true>(&s390_info),
      got_(NULL), plt_(NULL), got_plt_(NULL), got_irelative_(NULL),
      global_offset_table_(NULL), rela_dyn_(NULL),
      rela_irelative_(NULL), copy_relocs_(elfcpp::R_390_COPY),
      got_mod_index_offset_(-1U), tls_base_symbol_defined_(false),
      layout_(NULL)
  { }

  // Scan the relocations to look for symbol adjustments.
  void
  gc_process_relocs(Symbol_table* symtab,
                    Layout* layout,
                    Sized_relobj_file<size, true>* 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<size, true>* 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<size, true>*,
                   unsigned int sh_type,
                   const unsigned char* prelocs,
                   size_t reloc_count,
                   Output_section* output_section,
                   bool needs_special_offset_handling,
                   unsigned char* view,
                   typename elfcpp::Elf_types<size>::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<size, true>* 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*);

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

  // Emit relocations for a section.
  void
  relocate_relocs(
      const Relocate_info<size, true>*,
      unsigned int sh_type,
      const unsigned char* prelocs,
      size_t reloc_count,
      Output_section* output_section,
      typename elfcpp::Elf_types<size>::Elf_Off offset_in_output_section,
      const Relocatable_relocs*,
      unsigned char* view,
      typename elfcpp::Elf_types<size>::Elf_Addr view_address,
      section_size_type view_size,
      unsigned char* reloc_view,
      section_size_type reloc_view_size);

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

  // 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); }

  // Return the offset to use for the GOT_INDX'th got entry which is
  // for a local tls symbol specified by OBJECT, SYMNDX.
  int64_t
  do_tls_offset_for_local(const Relobj* object,
                          unsigned int symndx,
                          unsigned int got_indx) const;

  // Return the offset to use for the GOT_INDX'th got entry which is
  // for global tls symbol GSYM.
  int64_t
  do_tls_offset_for_global(Symbol* gsym, unsigned int got_indx) const;

  // This function should be defined in targets that can use relocation
  // types to determine (implemented in local_reloc_may_be_function_pointer
  // and global_reloc_may_be_function_pointer)
  // if a function's pointer is taken.  ICF uses this in safe mode to only
  // fold those functions whose pointer is defintely not taken.
  bool
  do_can_check_for_function_pointers() const
  { return true; }

  // 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() / (size / 8);
  }

  // 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;

  // Create the GOT section for an incremental update.
  Output_data_got_base*
  init_got_plt_for_update(Symbol_table* symtab,
                          Layout* layout,
                          unsigned int got_count,
                          unsigned int plt_count);

  // Reserve a GOT entry for a local symbol, and regenerate any
  // necessary dynamic relocations.
  void
  reserve_local_got_entry(unsigned int got_index,
                          Sized_relobj<size, true>* obj,
                          unsigned int r_sym,
                          unsigned int got_type);

  // Reserve a GOT entry for a global symbol, and regenerate any
  // necessary dynamic relocations.
  void
  reserve_global_got_entry(unsigned int got_index, Symbol* gsym,
                           unsigned int got_type);

  // Register an existing PLT entry for a global symbol.
  void
  register_global_plt_entry(Symbol_table*, Layout*, unsigned int plt_index,
                            Symbol* gsym);

  // Force a COPY relocation for a given symbol.
  void
  emit_copy_reloc(Symbol_table*, Symbol*, Output_section*, off_t);

  // Apply an incremental relocation.
  void
  apply_relocation(const Relocate_info<size, true>* relinfo,
                   typename elfcpp::Elf_types<size>::Elf_Addr r_offset,
                   unsigned int r_type,
                   typename elfcpp::Elf_types<size>::Elf_Swxword r_addend,
                   const Symbol* gsym,
                   unsigned char* view,
                   typename elfcpp::Elf_types<size>::Elf_Addr address,
                   section_size_type view_size);

 private:

  // The class which scans relocations.
  class Scan
  {
  public:
    Scan()
      : issued_non_pic_error_(false)
    { }

    static inline int
    get_reference_flags(unsigned int r_type);

    inline void
    local(Symbol_table* symtab, Layout* layout, Target_s390* target,
          Sized_relobj_file<size, true>* object,
          unsigned int data_shndx,
          Output_section* output_section,
          const elfcpp::Rela<size, true>& reloc, unsigned int r_type,
          const elfcpp::Sym<size, true>& lsym,
          bool is_discarded);

    inline void
    global(Symbol_table* symtab, Layout* layout, Target_s390* target,
           Sized_relobj_file<size, true>* object,
           unsigned int data_shndx,
           Output_section* output_section,
           const elfcpp::Rela<size, true>& reloc, unsigned int r_type,
           Symbol* gsym);

    inline bool
    local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
                                        Target_s390* target,
                                        Sized_relobj_file<size, true>* object,
                                        unsigned int data_shndx,
                                        Output_section* output_section,
                                        const elfcpp::Rela<size, true>& reloc,
                                        unsigned int r_type,
                                        const elfcpp::Sym<size, true>& lsym);

    inline bool
    global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
                                         Target_s390* target,
                                         Sized_relobj_file<size, true>* object,
                                         unsigned int data_shndx,
                                         Output_section* output_section,
                                         const elfcpp::Rela<size, true>& reloc,
                                         unsigned int r_type,
                                         Symbol* gsym);

  private:
    static void
    unsupported_reloc_local(Sized_relobj_file<size, true>*,
                            unsigned int r_type);

    static void
    unsupported_reloc_global(Sized_relobj_file<size, true>*,
                             unsigned int r_type, Symbol*);

    void
    check_non_pic(Relobj*, unsigned int r_type);

    inline bool
    possible_function_pointer_reloc(unsigned int r_type);

    bool
    reloc_needs_plt_for_ifunc(Sized_relobj_file<size, true>*,
                              unsigned int r_type);

    // Whether we have issued an error about a non-PIC compilation.
    bool issued_non_pic_error_;
  };

  // The class which implements relocation.
  class Relocate
  {
   public:
    // Do a relocation.  Return false if the caller should not issue
    // any warnings about this relocation.
    inline bool
    relocate(const Relocate_info<size, true>*, Target_s390*,
             Output_section*,
             size_t relnum, const elfcpp::Rela<size, true>&,
             unsigned int r_type, const Sized_symbol<size>*,
             const Symbol_value<size>*,
             unsigned char*, typename elfcpp::Elf_types<size>::Elf_Addr,
             section_size_type);

   private:
    // Do a TLS relocation.
    inline typename elfcpp::Elf_types<size>::Elf_Addr
    relocate_tls(const Relocate_info<size, true>*, Target_s390*,
                 size_t relnum, const elfcpp::Rela<size, true>&,
                 unsigned int r_type, const Sized_symbol<size>*,
                 const Symbol_value<size>*,
                 unsigned char*, section_size_type);

    // Do a TLS General-Dynamic to Initial-Exec transition.
    inline void
    tls_gd_to_ie(const Relocate_info<size, true>*, size_t relnum,
                 const elfcpp::Rela<size, true>&,
                 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<size, true>*, size_t relnum,
                 const elfcpp::Rela<size, true>&,
                 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<size, true>*, size_t relnum,
                 const elfcpp::Rela<size, true>&,
                 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<size, true>*, size_t relnum,
                 const elfcpp::Rela<size, true>&,
                 unsigned char* view,
                 section_size_type view_size);
  };

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

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

  // Get the GOT section.
  const Output_data_got<size, true>*
  got_section() const
  {
    gold_assert(this->got_ != NULL);
    return this->got_;
  }

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

  typename elfcpp::Elf_types<size>::Elf_Addr
  got_address() const
  {
    gold_assert(this->got_ != NULL);
    return this->got_plt_->address();
  }

  typename elfcpp::Elf_types<size>::Elf_Addr
  got_main_offset() const
  {
    gold_assert(this->got_ != NULL);
    return this->got_->address() - this->got_address();
  }

  // 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<size, true>* relobj,
                             unsigned int local_sym_index);

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

  // Get the PLT section.
  Output_data_plt_s390<size>*
  plt_section() const
  {
    gold_assert(this->plt_ != NULL);
    return this->plt_;
  }

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

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

  // Add a potential copy relocation.
  void
  copy_reloc(Symbol_table* symtab, Layout* layout,
             Sized_relobj_file<size, true>* object,
             unsigned int shndx, Output_section* output_section,
             Symbol* sym, const elfcpp::Rela<size, true>& reloc)
  {
    this->copy_relocs_.copy_reloc(symtab, layout,
                                  symtab->get_sized_symbol<size>(sym),
                                  object, shndx, output_section,
                                  reloc, this->rela_dyn_section(layout));
  }

  // Information about this specific target which we pass to the
  // general Target structure.
  static Target::Target_info s390_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_OFFSET = 1,    // GOT entry for TLS offset
    GOT_TYPE_TLS_PAIR = 2,      // GOT entry for TLS module/offset pair
  };

  // The GOT section.
  Output_data_got<size, true>* got_;
  // The PLT section.
  Output_data_plt_s390<size>* plt_;
  // The GOT PLT section.
  Output_data_got_plt_s390<size>* got_plt_;
  // The GOT section for IRELATIVE relocations.
  Output_data_space* got_irelative_;
  // The _GLOBAL_OFFSET_TABLE_ symbol.
  Symbol* global_offset_table_;
  // The dynamic reloc section.
  Reloc_section* rela_dyn_;
  // The section to use for IRELATIVE relocs.
  Reloc_section* rela_irelative_;
  // Relocs saved to avoid a COPY reloc.
  Copy_relocs<elfcpp::SHT_RELA, size, true> 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_;
  // For use in do_tls_offset_for_*
  Layout *layout_;
};

template<>
Target::Target_info Target_s390<32>::s390_info =
{
  32,                   // size
  true,                 // is_big_endian
  elfcpp::EM_S390,      // 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.so.1",       // dynamic_linker
  0x00400000,           // default_text_segment_address
  4 * 1024,             // abi_pagesize (overridable by -z max-page-size)
  4 * 1024,             // 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
};

template<>
Target::Target_info Target_s390<64>::s390_info =
{
  64,                   // size
  true,                 // is_big_endian
  elfcpp::EM_S390,      // 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/ld64.so.1",     // dynamic_linker
  0x80000000ll,         // default_text_segment_address
  4 * 1024,             // abi_pagesize (overridable by -z max-page-size)
  4 * 1024,             // 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
  64,                   // hash_entry_size
};

template<int size>
class S390_relocate_functions
{
public:
  enum Overflow_check
  {
    CHECK_NONE,
    CHECK_SIGNED,
    CHECK_UNSIGNED,
    CHECK_BITFIELD,
    CHECK_LOW_INSN,
    CHECK_HIGH_INSN
  };

  enum Status
  {
    STATUS_OK,
    STATUS_OVERFLOW
  };

private:
  typedef S390_relocate_functions<size> This;
  typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;

  template<int valsize>
  static inline bool
  has_overflow_signed(Address value)
  {
    // limit = 1 << (valsize - 1) without shift count exceeding size of type
    Address limit = static_cast<Address>(1) << ((valsize - 1) >> 1);
    limit <<= ((valsize - 1) >> 1);
    limit <<= ((valsize - 1) - 2 * ((valsize - 1) >> 1));
    return value + limit > (limit << 1) - 1;
  }

  template<int valsize>
  static inline bool
  has_overflow_unsigned(Address value)
  {
    Address limit = static_cast<Address>(1) << ((valsize - 1) >> 1);
    limit <<= ((valsize - 1) >> 1);
    limit <<= ((valsize - 1) - 2 * ((valsize - 1) >> 1));
    return value > (limit << 1) - 1;
  }

  template<int fieldsize>
  static inline void
  rela(unsigned char* view, Address mask, Address value)
  {
    typedef typename elfcpp::Swap<fieldsize, true>::Valtype Valtype;
    Valtype* wv = reinterpret_cast<Valtype*>(view);
    Valtype val = elfcpp::Swap<fieldsize, true>::readval(view);
    val &= ~mask;
    value &= mask;
    elfcpp::Swap<fieldsize, true>::writeval(wv, val | value);
  }

public:
  // R_390_12, R_390_GOT12, R_390_GOTPLT12, R_390_GOTIE12
  static inline Status
  rela12(unsigned char* view, Address value)
  {
    if (This::template has_overflow_unsigned<12>(value))
      return STATUS_OVERFLOW;
    This::template rela<16>(view, 0x0fff, value);
    return STATUS_OK;
  }

  // R_390_16, R_390_GOT16, R_390_GOTPLT16, R_390_GOTOFF16, R_390_PLTOFF16
  static inline Status
  rela16(unsigned char* view, Address value)
  {
    if (This::template has_overflow_signed<16>(value))
      return STATUS_OVERFLOW;
    This::template rela<16>(view, 0xffff, value);
    return STATUS_OK;
  }

  // R_390_20, R_390_GOT20, R_390_GOTPLT20, R_390_GOTIE20
  static inline Status
  rela20(unsigned char* view, Address value)
  {
    if (This::template has_overflow_signed<20>(value))
      return STATUS_OVERFLOW;
    This::template rela<16>(view, 0x0fff, value);
    This::template rela<16>(view + 2, 0xff00, value >> (12 - 8));
    return STATUS_OK;
  }

  // R_390_PC12DBL, R_390_PLT12DBL
  static inline Status
  pcrela12dbl(unsigned char* view, Address value, Address address)
  {
    value -= address;
    if ((value & 1) != 0)
      return STATUS_OVERFLOW;
    if (This::template has_overflow_signed<13>(value))
      return STATUS_OVERFLOW;
    value >>= 1;
    This::template rela<16>(view, 0x0fff, value);
    return STATUS_OK;
  }

  // R_390_PC16DBL, R_390_PLT16DBL
  static inline Status
  pcrela16dbl(unsigned char* view, Address value, Address address)
  {
    value -= address;
    if ((value & 1) != 0)
      return STATUS_OVERFLOW;
    if (This::template has_overflow_signed<17>(value))
      return STATUS_OVERFLOW;
    value >>= 1;
    This::template rela<16>(view, 0xffff, value);
    return STATUS_OK;
  }

  // R_390_PC24DBL, R_390_PLT24DBL
  static inline Status
  pcrela24dbl(unsigned char* view, Address value, Address address)
  {
    value -= address;
    if ((value & 1) != 0)
      return STATUS_OVERFLOW;
    if (This::template has_overflow_signed<25>(value))
      return STATUS_OVERFLOW;
    value >>= 1;
    // Swap doesn't take 24-bit fields well...
    This::template rela<8>(view, 0xff, value >> 16);
    This::template rela<16>(view + 1, 0xffff, value);
    return STATUS_OK;
  }

  // R_390_PC32DBL, R_390_PLT32DBL, R_390_GOTPCDBL, R_390_GOTENT, R_390_GOTPLTENT
  static inline Status
  pcrela32dbl(unsigned char* view, Address value, Address address)
  {
    Address reloc = value - address;
    if ((reloc & 1) != 0)
      {
        gold_warning(_("R_390_PC32DBL target misaligned at %llx"), (long long)address);
        // Wait for a fix for https://sourceware.org/bugzilla/show_bug.cgi?id=18960
        // return STATUS_OVERFLOW;
      }
    if (This::template has_overflow_signed<33>(reloc))
      return STATUS_OVERFLOW;
    reloc >>= 1;
    if (value < address && size == 32)
      reloc |= 0x80000000;
    This::template rela<32>(view, 0xffffffff, reloc);
    return STATUS_OK;
  }

};

// Initialize the PLT section.

template<int size>
void
Output_data_plt_s390<size>::init(Layout* layout)
{
  this->rel_ = new Reloc_section(false);
  layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
                                  elfcpp::SHF_ALLOC, this->rel_,
                                  ORDER_DYNAMIC_PLT_RELOCS, false);
}

template<int size>
void
Output_data_plt_s390<size>::do_adjust_output_section(Output_section* os)
{
  os->set_entsize(plt_entry_size);
}

// Add an entry to the PLT.

template<int size>
void
Output_data_plt_s390<size>::add_entry(Symbol_table* symtab, Layout* layout,
                                        Symbol* gsym)
{
  gold_assert(!gsym->has_plt_offset());

  unsigned int plt_index;
  off_t plt_offset;
  section_offset_type got_offset;

  unsigned int* pcount;
  unsigned int offset;
  unsigned int reserved;
  Output_section_data_build* got;
  if (gsym->type() == elfcpp::STT_GNU_IFUNC
      && gsym->can_use_relative_reloc(false))
    {
      pcount = &this->irelative_count_;
      offset = 0;
      reserved = 0;
      got = this->got_irelative_;
    }
  else
    {
      pcount = &this->count_;
      offset = 1;
      reserved = 3;
      got = this->got_plt_;
    }

  if (!this->is_data_size_valid())
    {
      // Note that when setting the PLT offset for a non-IRELATIVE
      // entry we skip the initial reserved PLT entry.
      plt_index = *pcount + offset;
      plt_offset = plt_index * plt_entry_size;

      ++*pcount;

      got_offset = (plt_index - offset + reserved) * size / 8;
      gold_assert(got_offset == got->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).
      got->set_current_data_size(got_offset + size / 8);
    }
  else
    {
      // FIXME: This is probably not correct for IRELATIVE relocs.

      // For incremental updates, find an available slot.
      plt_offset = this->free_list_.allocate(plt_entry_size,
                                             plt_entry_size, 0);
      if (plt_offset == -1)
        gold_fallback(_("out of patch space (PLT);"
                        " relink with --incremental-full"));

      // The GOT and PLT entries have a 1-1 correspondance, so the GOT offset
      // can be calculated from the PLT index, adjusting for the three
      // reserved entries at the beginning of the GOT.
      plt_index = plt_offset / plt_entry_size - 1;
      got_offset = (plt_index - offset + reserved) * size / 8;
    }

  gsym->set_plt_offset(plt_offset);

  // Every PLT entry needs a reloc.
  this->add_relocation(symtab, layout, gsym, 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.

template<int size>
unsigned int
Output_data_plt_s390<size>::add_local_ifunc_entry(
    Symbol_table* symtab,
    Layout* layout,
    Sized_relobj_file<size, true>* relobj,
    unsigned int local_sym_index)
{
  unsigned int plt_offset = this->irelative_count_ * 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 + size / 8);

  // Every PLT entry needs a reloc.
  Reloc_section* rela = this->rela_irelative(symtab, layout);
  rela->add_symbolless_local_addend(relobj, local_sym_index,
                                    elfcpp::R_390_IRELATIVE,
                                    this->got_irelative_, got_offset, 0);

  return plt_offset;
}

// Add the relocation for a PLT entry.

template<int size>
void
Output_data_plt_s390<size>::add_relocation(Symbol_table* symtab,
                                             Layout* layout,
                                             Symbol* gsym,
                                             unsigned int got_offset)
{
  if (gsym->type() == elfcpp::STT_GNU_IFUNC
      && gsym->can_use_relative_reloc(false))
    {
      Reloc_section* rela = this->rela_irelative(symtab, layout);
      rela->add_symbolless_global_addend(gsym, elfcpp::R_390_IRELATIVE,
                                         this->got_irelative_, got_offset, 0);
    }
  else
    {
      gsym->set_needs_dynsym_entry();
      this->rel_->add_global(gsym, elfcpp::R_390_JMP_SLOT, this->got_plt_,
                             got_offset, 0);
    }
}

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

template<int size>
typename Output_data_plt_s390<size>::Reloc_section*
Output_data_plt_s390<size>::rela_irelative(Symbol_table* symtab,
                                             Layout* layout)
{
  if (this->irelative_rel_ == NULL)
    {
      this->irelative_rel_ = new Reloc_section(false);
      layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
                                      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 .rela.plt
          // section to hold R_390_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("__rela_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("__rela_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.

template<int size>
uint64_t
Output_data_plt_s390<size>::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) * 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.

template<int size>
uint64_t
Output_data_plt_s390<size>::address_for_local(const Relobj* object,
                                                unsigned int r_sym)
{
  return (this->address()
          + (this->count_ + 1) * plt_entry_size
          + object->local_plt_offset(r_sym));
}

// Set the final size.
template<int size>
void
Output_data_plt_s390<size>::set_final_data_size()
{
  unsigned int count = this->count_ + this->irelative_count_;
  this->set_data_size((count + 1) * plt_entry_size);
}

template<int size>
const unsigned char
Output_data_plt_s390<size>::first_plt_entry_32_abs[plt_entry_size] =
{
  0x50, 0x10, 0xf0, 0x1c, // st %r1, 28(%r15)
  0x0d, 0x10, // basr %r1, %r0
  0x58, 0x10, 0x10, 0x12, // l %r1, 18(%r1)
  0xd2, 0x03, 0xf0, 0x18, 0x10, 0x04, // mvc 24(4,%r15), 4(%r1)
  0x58, 0x10, 0x10, 0x08, // l %r1, 8(%r1)
  0x07, 0xf1, // br %r1
  0x00, 0x00, // padding
  0x00, 0x00, 0x00, 0x00, // _GLOBAL_OFFSET_TABLE_ (to fill)
  0x00, 0x00, 0x00, 0x00, // padding
};

template<int size>
const unsigned char
Output_data_plt_s390<size>::first_plt_entry_32_pic[plt_entry_size] =
{
  0x50, 0x10, 0xf0, 0x1c, // st %r1, 28(%r15)
  0x58, 0x10, 0xc0, 0x04, // l %r1, 4(%r12)
  0x50, 0x10, 0xf0, 0x18, // st %r1, 24(%r15)
  0x58, 0x10, 0xc0, 0x08, // l %r1, 8(%r12)
  0x07, 0xf1, // br %r1
  0x00, 0x00, // padding
  0x00, 0x00, 0x00, 0x00, // padding
  0x00, 0x00, 0x00, 0x00, // padding
  0x00, 0x00, 0x00, 0x00, // padding
};

template<int size>
const unsigned char
Output_data_plt_s390<size>::first_plt_entry_64[plt_entry_size] =
{
  0xe3, 0x10, 0xf0, 0x38, 0x00, 0x24, // stg %r1, 56(%r15)
  0xc0, 0x10, 0x00, 0x00, 0x00, 0x00, // larl %r1, _GLOBAL_OFFSET_TABLE_ (to fill)
  0xd2, 0x07, 0xf0, 0x30, 0x10, 0x08, // mvc 48(8,%r15), 8(%r1)
  0xe3, 0x10, 0x10, 0x10, 0x00, 0x04, // lg %r1, 16(%r1)
  0x07, 0xf1, // br %r1
  0x07, 0x00, // nopr
  0x07, 0x00, // nopr
  0x07, 0x00, // nopr
};

template<int size>
void
Output_data_plt_s390<size>::fill_first_plt_entry(
    unsigned char* pov,
    typename elfcpp::Elf_types<size>::Elf_Addr got_address,
    typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
{
  if (size == 64)
    {
      memcpy(pov, first_plt_entry_64, plt_entry_size);
      S390_relocate_functions<size>::pcrela32dbl(pov + 8, got_address, (plt_address + 6));
    }
  else if (!parameters->options().output_is_position_independent())
    {
      memcpy(pov, first_plt_entry_32_abs, plt_entry_size);
      elfcpp::Swap<32, true>::writeval(pov + 24, got_address);
    }
  else
    {
      memcpy(pov, first_plt_entry_32_pic, plt_entry_size);
    }
}

template<int size>
const unsigned char
Output_data_plt_s390<size>::plt_entry_32_abs[plt_entry_size] =
{
  // first part
  0x0d, 0x10, // basr %r1, %r0
  0x58, 0x10, 0x10, 0x16, // l %r1, 22(%r1)
  0x58, 0x10, 0x10, 0x00, // l %r1, 0(%r1)
  0x07, 0xf1, // br %r1
  // second part
  0x0d, 0x10, // basr %r1, %r0
  0x58, 0x10, 0x10, 0x0e, // l %r1, 14(%r1)
  0xa7, 0xf4, 0x00, 0x00, // j first_plt_entry (to fill)
  0x00, 0x00, // padding
  0x00, 0x00, 0x00, 0x00, // _GLOBAL_OFFSET_TABLE_+sym@gotplt (to fill)
  0x00, 0x00, 0x00, 0x00, // offset of relocation in .rela.plt (to fill)
};

template<int size>
const unsigned char
Output_data_plt_s390<size>::plt_entry_32_pic12[plt_entry_size] =
{
  // first part
  0x58, 0x10, 0xc0, 0x00, // l %r1, sym@gotplt(%r12) (to fill)
  0x07, 0xf1, // br %r1
  0x00, 0x00, // padding
  0x00, 0x00, 0x00, 0x00, // padding
  // second part
  0x0d, 0x10, // basr %r1, %r0
  0x58, 0x10, 0x10, 0x0e, // l %r1, 14(%r1)
  0xa7, 0xf4, 0x00, 0x00, // j first_plt_entry (to fill)
  0x00, 0x00, // padding
  0x00, 0x00, 0x00, 0x00, // padding
  0x00, 0x00, 0x00, 0x00, // offset of relocation in .rela.plt (to fill)
};

template<int size>
const unsigned char
Output_data_plt_s390<size>::plt_entry_32_pic16[plt_entry_size] =
{
  // first part
  0xa7, 0x18, 0x00, 0x00, // lhi %r1, sym@gotplt (to fill)
  0x58, 0x11, 0xc0, 0x00, // l %r1, 0(%r1, %r12)
  0x07, 0xf1, // br %r1
  0x00, 0x00, // padding
  // second part
  0x0d, 0x10, // basr %r1, %r0
  0x58, 0x10, 0x10, 0x0e, // l %r1, 14(%r1)
  0xa7, 0xf4, 0x00, 0x00, // j first_plt_entry (to fill)
  0x00, 0x00, // padding
  0x00, 0x00, 0x00, 0x00, // padding
  0x00, 0x00, 0x00, 0x00, // offset of relocation in .rela.plt (to fill)
};

template<int size>
const unsigned char
Output_data_plt_s390<size>::plt_entry_32_pic[plt_entry_size] =
{
  // first part
  0x0d, 0x10, // basr %r1, %r0
  0x58, 0x10, 0x10, 0x16, // l %r1, 22(%r1)
  0x58, 0x11, 0xc0, 0x00, // l %r1, 0(%r1, %r12)
  0x07, 0xf1, // br %r1
  // second part
  0x0d, 0x10, // basr %r1, %r0
  0x58, 0x10, 0x10, 0x0e, // l %r1, 14(%r1)
  0xa7, 0xf4, 0x00, 0x00, // j first_plt_entry (to fill)
  0x00, 0x00, // padding
  0x00, 0x00, 0x00, 0x00, // sym@gotplt (to fill)
  0x00, 0x00, 0x00, 0x00, // offset of relocation in .rela.plt (to fill)
};

template<int size>
const unsigned char
Output_data_plt_s390<size>::plt_entry_64[plt_entry_size] =
{
  // first part
  0xc0, 0x10, 0x00, 0x00, 0x00, 0x00, // larl %r1, _GLOBAL_OFFSET_TABLE_+off (to fill)
  0xe3, 0x10, 0x10, 0x00, 0x00, 0x04, // lg %r1, 0(%r1)
  0x07, 0xf1, // br %r1
  // second part
  0x0d, 0x10, // basr %r1, %r0
  0xe3, 0x10, 0x10, 0x0c, 0x00, 0x14, // lgf %r1, 12(%r1)
  0xc0, 0xf4, 0x00, 0x00, 0x00, 0x00, // jg first_plt_entry (to fill)
  0x00, 0x00, 0x00, 0x00, // offset of relocation in .rela.plt (to fill)
};

template<int size>
unsigned int
Output_data_plt_s390<size>::fill_plt_entry(
    unsigned char* pov,
    typename elfcpp::Elf_types<size>::Elf_Addr got_address,
    typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
    unsigned int got_offset,
    unsigned int plt_offset,
    unsigned int plt_rel_offset)
{
  if (size == 64)
  {
    memcpy(pov, plt_entry_64, plt_entry_size);
    S390_relocate_functions<size>::pcrela32dbl(pov + 2, got_address + got_offset, plt_address + plt_offset);
    S390_relocate_functions<size>::pcrela32dbl(pov + 24, plt_address, plt_address + plt_offset + 22);
  }
  else
  {
    if (!parameters->options().output_is_position_independent())
      {
        memcpy(pov, plt_entry_32_abs, plt_entry_size);
        elfcpp::Swap<32, true>::writeval(pov + 24, got_address + got_offset);
      }
    else
      {
        if (got_offset < 0x1000)
          {
            memcpy(pov, plt_entry_32_pic12, plt_entry_size);
            S390_relocate_functions<size>::rela12(pov + 2, got_offset);
          }
        else if (got_offset < 0x8000)
          {
            memcpy(pov, plt_entry_32_pic16, plt_entry_size);
            S390_relocate_functions<size>::rela16(pov + 2, got_offset);
          }
        else
          {
            memcpy(pov, plt_entry_32_pic, plt_entry_size);
            elfcpp::Swap<32, true>::writeval(pov + 24, got_offset);
          }
      }
    typename elfcpp::Elf_types<size>::Elf_Addr target = plt_address;
    if (plt_offset >= 0x10000)
      {
        // Would overflow pcrela16dbl - aim at the farthest previous jump
        // we can reach.
        if (plt_offset > 0x10000)
          {
            // Use the full range of pcrel16dbl.
            target = plt_address + plt_offset - 0x10000 + 18;
          }
        else
          {
            // if plt_offset is exactly 0x10000, the above would aim at 18th byte
            // of first_plt_entry, which doesn't have the jump back like the others.
            // Aim at the next entry instead.
            target = plt_address + plt_offset - 0xffe0 + 18;
          }
      }
    S390_relocate_functions<size>::pcrela16dbl(pov + 20, target, plt_address + plt_offset + 18);
  }
  elfcpp::Swap<32, true>::writeval(pov + 28, plt_rel_offset);
  if (size == 64)
    return 14;
  else
    return 12;
}

// The .eh_frame unwind information for the PLT.

template<>
const unsigned char
Output_data_plt_s390<32>::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.
  14,                           // Return address column.
  1,                            // Augmentation size.
  (elfcpp::DW_EH_PE_pcrel       // FDE encoding.
   | elfcpp::DW_EH_PE_sdata4),
  elfcpp::DW_CFA_def_cfa, 15, 0x60,     // DW_CFA_def_cfa: r15 ofs 0x60.
};

template<>
const unsigned char
Output_data_plt_s390<64>::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.
  0x78,                         // Data alignment factor.
  14,                           // Return address column.
  1,                            // Augmentation size.
  (elfcpp::DW_EH_PE_pcrel       // FDE encoding.
   | elfcpp::DW_EH_PE_sdata4),
  elfcpp::DW_CFA_def_cfa, 15, 0xa0,     // DW_CFA_def_cfa: r15 ofs 0xa0.
};

template<int size>
const unsigned char
Output_data_plt_s390<size>::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_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.

template<int size>
void
Output_data_plt_s390<size>::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;

  // The base address of the .plt section.
  typename elfcpp::Elf_types<size>::Elf_Addr plt_address = this->address();
  // The base address of the PLT portion of the .got section,
  // which is where the GOT pointer will point, and where the
  // three reserved GOT entries are located.
  typename elfcpp::Elf_types<size>::Elf_Addr got_address
    = this->got_plt_->address();

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

  unsigned char* got_pov = got_view;

  const int rel_size = elfcpp::Elf_sizes<size>::rela_size;

  unsigned int plt_offset = this->get_plt_entry_size();
  unsigned int plt_rel_offset = 0;
  unsigned int got_offset = 3 * size / 8;
  const unsigned int count = this->count_ + this->irelative_count_;
  // The first three entries in the GOT are reserved, and are written
  // by Output_data_got_plt_s390::do_write.
  got_pov += 3 * size / 8;

  for (unsigned int plt_index = 0;
       plt_index < count;
       ++plt_index,
         pov += plt_entry_size,
         got_pov += size / 8,
         plt_offset += plt_entry_size,
         plt_rel_offset += rel_size,
         got_offset += size / 8)
    {
      // Set and adjust the PLT entry itself.
      unsigned int lazy_offset = this->fill_plt_entry(pov,
                                                      got_address, plt_address,
                                                      got_offset, plt_offset,
                                                      plt_rel_offset);

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

  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);
}

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

template<int size>
Output_data_got<size, true>*
Target_s390<size>::got_section(Symbol_table* symtab, Layout* layout)
{
  if (this->got_ == NULL)
    {
      gold_assert(symtab != NULL && layout != NULL);

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

      // The old GNU linker creates a .got.plt section.  We just
      // create another set of data in the .got section.  Note that we
      // always create a PLT if we create a GOT, although the PLT
      // might be empty.
      this->got_plt_ = new Output_data_got_plt_s390<size>(layout);
      layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
                                      (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
                                      this->got_plt_, got_order, is_got_relro);

      // The first three entries are reserved.
      this->got_plt_->set_current_data_size(3 * size / 8);

      // If there are any IRELATIVE relocations, they get GOT entries
      // in .got.plt after the jump slot entries.
      this->got_irelative_ = new Output_data_space(size / 8, "** GOT IRELATIVE PLT");
      layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
                                      (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
                                      this->got_irelative_,
                                      got_order, is_got_relro);

      // Unlike some targets (.e.g x86), S/390 does not use separate .got and
      // .got.plt sections in output.  The output .got section contains both
      // PLT and non-PLT GOT entries.
      this->got_ = new Output_data_got<size, true>();

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

      // Define _GLOBAL_OFFSET_TABLE_ at the start of the GOT.
      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);

    }
  return this->got_;
}

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

template<int size>
typename Target_s390<size>::Reloc_section*
Target_s390<size>::rela_dyn_section(Layout* layout)
{
  if (this->rela_dyn_ == NULL)
    {
      gold_assert(layout != NULL);
      this->rela_dyn_ = new Reloc_section(parameters->options().combreloc());
      layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
                                      elfcpp::SHF_ALLOC, this->rela_dyn_,
                                      ORDER_DYNAMIC_RELOCS, false);
    }
  return this->rela_dyn_;
}

// Get the section to use for IRELATIVE relocs, creating it if
// necessary.  These go in .rela.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.

template<int size>
typename Target_s390<size>::Reloc_section*
Target_s390<size>::rela_irelative_section(Layout* layout)
{
  if (this->rela_irelative_ == NULL)
    {
      // Make sure we have already created the dynamic reloc section.
      this->rela_dyn_section(layout);
      this->rela_irelative_ = new Reloc_section(false);
      layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
                                      elfcpp::SHF_ALLOC, this->rela_irelative_,
                                      ORDER_DYNAMIC_RELOCS, false);
      gold_assert(this->rela_dyn_->output_section()
                  == this->rela_irelative_->output_section());
    }
  return this->rela_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_s390::do_write.

template<int size>
void
Output_data_got_plt_s390<size>::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_x86_64::got_section.
  const off_t got_file_offset = this->offset();
  gold_assert(this->data_size() >= 3 * size / 8);
  unsigned char* const got_view =
      of->get_output_view(got_file_offset, 3 * size / 8);
  Output_section* dynamic = this->layout_->dynamic_section();
  uint64_t dynamic_addr = dynamic == NULL ? 0 : dynamic->address();
  elfcpp::Swap<size, true>::writeval(got_view, dynamic_addr);
  memset(got_view + size / 8, 0, 2 * size / 8);
  of->write_output_view(got_file_offset, 3 * size / 8, got_view);
}

// Create the PLT section.

template<int size>
void
Target_s390<size>::make_plt_section(Symbol_table* symtab, Layout* layout)
{
  if (this->plt_ == NULL)
    {
      // Create the GOT sections first.
      this->got_section(symtab, layout);

      // Ensure that .rela.dyn always appears before .rela.plt  This is
      // necessary due to how, on 32-bit S/390 and some other targets,
      // .rela.dyn needs to include .rela.plt in it's range.
      this->rela_dyn_section(layout);

      this->plt_ = new Output_data_plt_s390<size>(layout,
                      this->got_, this->got_plt_, this->got_irelative_);

      // 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 .rela.plt point to .plt.
      Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
      rela_plt_os->set_info_section(this->plt_->output_section());
    }
}

// Create a PLT entry for a global symbol.

template<int size>
void
Target_s390<size>::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.

template<int size>
void
Target_s390<size>::make_local_ifunc_plt_entry(
    Symbol_table* symtab, Layout* layout,
    Sized_relobj_file<size, true>* 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.

template<int size>
unsigned int
Target_s390<size>::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.

template<int size>
unsigned int
Target_s390<size>::first_plt_entry_offset() const
{
  return this->plt_->first_plt_entry_offset();
}

// Return the size of each PLT entry.

template<int size>
unsigned int
Target_s390<size>::plt_entry_size() const
{
  return this->plt_->get_plt_entry_size();
}

// Create the GOT and PLT sections for an incremental update.

template<int size>
Output_data_got_base*
Target_s390<size>::init_got_plt_for_update(Symbol_table* symtab,
                                       Layout* layout,
                                       unsigned int got_count,
                                       unsigned int plt_count)
{
  gold_assert(this->got_ == NULL);

  // Add the three reserved entries.
  this->got_plt_ = new Output_data_got_plt_s390<size>(layout, (plt_count + 3) * size / 8);
  layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
                                  (elfcpp::SHF_ALLOC
                                   | elfcpp::SHF_WRITE),
                                  this->got_plt_, ORDER_NON_RELRO_FIRST,
                                  false);

  // If there are any IRELATIVE relocations, they get GOT entries in
  // .got.plt after the jump slot entries.
  this->got_irelative_ = new Output_data_space(0, size / 8, "** GOT IRELATIVE PLT");
  layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
                                  elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
                                  this->got_irelative_,
                                  ORDER_NON_RELRO_FIRST, false);

  this->got_ = new Output_data_got<size, true>(got_count * size / 8);
  layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
                                  (elfcpp::SHF_ALLOC
                                   | elfcpp::SHF_WRITE),
                                  this->got_, ORDER_RELRO_LAST,
                                  true);

  // 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);

  // Create the PLT section.
  this->plt_ = new Output_data_plt_s390<size>(layout,
                  this->got_, this->got_plt_, this->got_irelative_, plt_count);

  // 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 .rela.plt point to .plt.
  Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
  rela_plt_os->set_info_section(this->plt_->output_section());

  // Create the rela_dyn section.
  this->rela_dyn_section(layout);

  return this->got_;
}

// Reserve a GOT entry for a local symbol, and regenerate any
// necessary dynamic relocations.

template<int size>
void
Target_s390<size>::reserve_local_got_entry(
    unsigned int got_index,
    Sized_relobj<size, true>* obj,
    unsigned int r_sym,
    unsigned int got_type)
{
  unsigned int got_offset = got_index * size / 8;
  Reloc_section* rela_dyn = this->rela_dyn_section(NULL);

  this->got_->reserve_local(got_index, obj, r_sym, got_type);
  switch (got_type)
    {
    case GOT_TYPE_STANDARD:
      if (parameters->options().output_is_position_independent())
        rela_dyn->add_local_relative(obj, r_sym, elfcpp::R_390_RELATIVE,
                                     this->got_, got_offset, 0, false);
      break;
    case GOT_TYPE_TLS_OFFSET:
      rela_dyn->add_local(obj, r_sym, elfcpp::R_390_TLS_TPOFF,
                          this->got_, got_offset, 0);
      break;
    case GOT_TYPE_TLS_PAIR:
      this->got_->reserve_slot(got_index + 1);
      rela_dyn->add_local(obj, r_sym, elfcpp::R_390_TLS_DTPMOD,
                          this->got_, got_offset, 0);
      break;
    default:
      gold_unreachable();
    }
}

// Reserve a GOT entry for a global symbol, and regenerate any
// necessary dynamic relocations.

template<int size>
void
Target_s390<size>::reserve_global_got_entry(unsigned int got_index,
                                              Symbol* gsym,
                                              unsigned int got_type)
{
  unsigned int got_offset = got_index * size / 8;
  Reloc_section* rela_dyn = this->rela_dyn_section(NULL);

  this->got_->reserve_global(got_index, gsym, got_type);
  switch (got_type)
    {
    case GOT_TYPE_STANDARD:
      if (!gsym->final_value_is_known())
        {
          if (gsym->is_from_dynobj()
              || gsym->is_undefined()
              || gsym->is_preemptible()
              || gsym->type() == elfcpp::STT_GNU_IFUNC)
            rela_dyn->add_global(gsym, elfcpp::R_390_GLOB_DAT,
                                 this->got_, got_offset, 0);
          else
            rela_dyn->add_global_relative(gsym, elfcpp::R_390_RELATIVE,
                                          this->got_, got_offset, 0, false);
        }
      break;
    case GOT_TYPE_TLS_OFFSET:
      rela_dyn->add_global_relative(gsym, elfcpp::R_390_TLS_TPOFF,
                                    this->got_, got_offset, 0, false);
      break;
    case GOT_TYPE_TLS_PAIR:
      this->got_->reserve_slot(got_index + 1);
      rela_dyn->add_global_relative(gsym, elfcpp::R_390_TLS_DTPMOD,
                                    this->got_, got_offset, 0, false);
      rela_dyn->add_global_relative(gsym, elfcpp::R_390_TLS_DTPOFF,
                                    this->got_, got_offset + size / 8, 0, false);
      break;
    default:
      gold_unreachable();
    }
}

// Register an existing PLT entry for a global symbol.

template<int size>
void
Target_s390<size>::register_global_plt_entry(Symbol_table* symtab,
                                               Layout* layout,
                                               unsigned int plt_index,
                                               Symbol* gsym)
{
  gold_assert(this->plt_ != NULL);
  gold_assert(!gsym->has_plt_offset());

  this->plt_->reserve_slot(plt_index);

  gsym->set_plt_offset((plt_index + 1) * this->plt_entry_size());

  unsigned int got_offset = (plt_index + 3) * size / 8;
  this->plt_->add_relocation(symtab, layout, gsym, got_offset);
}

// Force a COPY relocation for a given symbol.

template<int size>
void
Target_s390<size>::emit_copy_reloc(
    Symbol_table* symtab, Symbol* sym, Output_section* os, off_t offset)
{
  this->copy_relocs_.emit_copy_reloc(symtab,
                                     symtab->get_sized_symbol<size>(sym),
                                     os,
                                     offset,
                                     this->rela_dyn_section(NULL));
}

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

template<int size>
unsigned int
Target_s390<size>::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
                                         Sized_relobj_file<size, true>* object)
{
  if (this->got_mod_index_offset_ == -1U)
    {
      gold_assert(symtab != NULL && layout != NULL && object != NULL);
      Reloc_section* rela_dyn = this->rela_dyn_section(layout);
      Output_data_got<size, true>* got = this->got_section(symtab, layout);
      unsigned int got_offset = got->add_constant(0);
      rela_dyn->add_local(object, 0, elfcpp::R_390_TLS_DTPMOD, got,
                          got_offset, 0);
      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.

template<int size>
tls::Tls_optimization
Target_s390<size>::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_390_TLS_GD32:
    case elfcpp::R_390_TLS_GD64:
    case elfcpp::R_390_TLS_GDCALL:
      // 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_390_TLS_LDM32:
    case elfcpp::R_390_TLS_LDM64:
    case elfcpp::R_390_TLS_LDO32:
    case elfcpp::R_390_TLS_LDO64:
    case elfcpp::R_390_TLS_LDCALL:
      // 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_390_TLS_IE32:
    case elfcpp::R_390_TLS_IE64:
    case elfcpp::R_390_TLS_GOTIE32:
    case elfcpp::R_390_TLS_GOTIE64:
    case elfcpp::R_390_TLS_LOAD:
      // 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_390_TLS_GOTIE12:
    case elfcpp::R_390_TLS_IEENT:
    case elfcpp::R_390_TLS_GOTIE20:
      // These are Initial-Exec, but cannot be optimized.
      return tls::TLSOPT_NONE;

    case elfcpp::R_390_TLS_LE32:
    case elfcpp::R_390_TLS_LE64:
      // 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.

template<int size>
int
Target_s390<size>::Scan::get_reference_flags(unsigned int r_type)
{
  switch (r_type)
    {
    case elfcpp::R_390_NONE:
    case elfcpp::R_390_GNU_VTINHERIT:
    case elfcpp::R_390_GNU_VTENTRY:
    case elfcpp::R_390_GOTPC:
    case elfcpp::R_390_GOTPCDBL:
      // No symbol reference.
      return 0;

    case elfcpp::R_390_64:
    case elfcpp::R_390_32:
    case elfcpp::R_390_20:
    case elfcpp::R_390_16:
    case elfcpp::R_390_12:
    case elfcpp::R_390_8:
      return Symbol::ABSOLUTE_REF;

    case elfcpp::R_390_PC12DBL:
    case elfcpp::R_390_PC16:
    case elfcpp::R_390_PC16DBL:
    case elfcpp::R_390_PC24DBL:
    case elfcpp::R_390_PC32:
    case elfcpp::R_390_PC32DBL:
    case elfcpp::R_390_PC64:
    case elfcpp::R_390_GOTOFF16:
    case elfcpp::R_390_GOTOFF32:
    case elfcpp::R_390_GOTOFF64:
      return Symbol::RELATIVE_REF;

    case elfcpp::R_390_PLT12DBL:
    case elfcpp::R_390_PLT16DBL:
    case elfcpp::R_390_PLT24DBL:
    case elfcpp::R_390_PLT32:
    case elfcpp::R_390_PLT32DBL:
    case elfcpp::R_390_PLT64:
    case elfcpp::R_390_PLTOFF16:
    case elfcpp::R_390_PLTOFF32:
    case elfcpp::R_390_PLTOFF64:
      return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;

    case elfcpp::R_390_GOT12:
    case elfcpp::R_390_GOT16:
    case elfcpp::R_390_GOT20:
    case elfcpp::R_390_GOT32:
    case elfcpp::R_390_GOT64:
    case elfcpp::R_390_GOTENT:
    case elfcpp::R_390_GOTPLT12:
    case elfcpp::R_390_GOTPLT16:
    case elfcpp::R_390_GOTPLT20:
    case elfcpp::R_390_GOTPLT32:
    case elfcpp::R_390_GOTPLT64:
    case elfcpp::R_390_GOTPLTENT:
      // Absolute in GOT.
      return Symbol::ABSOLUTE_REF;

    case elfcpp::R_390_TLS_GD32:          // Global-dynamic
    case elfcpp::R_390_TLS_GD64:
    case elfcpp::R_390_TLS_GDCALL:
    case elfcpp::R_390_TLS_LDM32:         // Local-dynamic
    case elfcpp::R_390_TLS_LDM64:
    case elfcpp::R_390_TLS_LDO32:
    case elfcpp::R_390_TLS_LDO64:
    case elfcpp::R_390_TLS_LDCALL:
    case elfcpp::R_390_TLS_IE32:          // Initial-exec
    case elfcpp::R_390_TLS_IE64:
    case elfcpp::R_390_TLS_IEENT:
    case elfcpp::R_390_TLS_GOTIE12:
    case elfcpp::R_390_TLS_GOTIE20:
    case elfcpp::R_390_TLS_GOTIE32:
    case elfcpp::R_390_TLS_GOTIE64:
    case elfcpp::R_390_TLS_LOAD:
    case elfcpp::R_390_TLS_LE32:          // Local-exec
    case elfcpp::R_390_TLS_LE64:
      return Symbol::TLS_REF;

    case elfcpp::R_390_COPY:
    case elfcpp::R_390_GLOB_DAT:
    case elfcpp::R_390_JMP_SLOT:
    case elfcpp::R_390_RELATIVE:
    case elfcpp::R_390_IRELATIVE:
    case elfcpp::R_390_TLS_TPOFF:
    case elfcpp::R_390_TLS_DTPOFF:
    case elfcpp::R_390_TLS_DTPMOD:
    default:
      // Not expected.  We will give an error later.
      return 0;
    }
}

// Report an unsupported relocation against a local symbol.

template<int size>
void
Target_s390<size>::Scan::unsupported_reloc_local(
     Sized_relobj_file<size, true>* object,
     unsigned int r_type)
{
  gold_error(_("%s: unsupported reloc %u against local symbol"),
             object->name().c_str(), r_type);
}

// We are about to emit a dynamic relocation of type R_TYPE.  If the
// dynamic linker does not support it, issue an error.

template<int size>
void
Target_s390<size>::Scan::check_non_pic(Relobj* object, unsigned int r_type)
{
  gold_assert(r_type != elfcpp::R_390_NONE);

  if (size == 64)
    {
      switch (r_type)
        {
          // These are the relocation types supported by glibc for s390 64-bit.
        case elfcpp::R_390_RELATIVE:
        case elfcpp::R_390_IRELATIVE:
        case elfcpp::R_390_COPY:
        case elfcpp::R_390_GLOB_DAT:
        case elfcpp::R_390_JMP_SLOT:
        case elfcpp::R_390_TLS_DTPMOD:
        case elfcpp::R_390_TLS_DTPOFF:
        case elfcpp::R_390_TLS_TPOFF:
        case elfcpp::R_390_8:
        case elfcpp::R_390_16:
        case elfcpp::R_390_32:
        case elfcpp::R_390_64:
        case elfcpp::R_390_PC16:
        case elfcpp::R_390_PC16DBL:
        case elfcpp::R_390_PC32:
        case elfcpp::R_390_PC32DBL:
        case elfcpp::R_390_PC64:
          return;

        default:
          break;
        }
    }
  else
    {
      switch (r_type)
        {
          // These are the relocation types supported by glibc for s390 32-bit.
        case elfcpp::R_390_RELATIVE:
        case elfcpp::R_390_IRELATIVE:
        case elfcpp::R_390_COPY:
        case elfcpp::R_390_GLOB_DAT:
        case elfcpp::R_390_JMP_SLOT:
        case elfcpp::R_390_TLS_DTPMOD:
        case elfcpp::R_390_TLS_DTPOFF:
        case elfcpp::R_390_TLS_TPOFF:
        case elfcpp::R_390_8:
        case elfcpp::R_390_16:
        case elfcpp::R_390_32:
        case elfcpp::R_390_PC16:
        case elfcpp::R_390_PC16DBL:
        case elfcpp::R_390_PC32:
        case elfcpp::R_390_PC32DBL:
          return;

        default:
          break;
        }
    }

  // This prevents us from issuing more than one error per reloc
  // section.  But we can still wind up issuing more than one
  // error per object file.
  if (this->issued_non_pic_error_)
    return;
  gold_assert(parameters->options().output_is_position_independent());
  object->error(_("requires unsupported dynamic reloc; "
                  "recompile with -fPIC"));
  this->issued_non_pic_error_ = true;
  return;
}

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

template<int size>
bool
Target_s390<size>::Scan::reloc_needs_plt_for_ifunc(
     Sized_relobj_file<size, true>* 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.

template<int size>
inline void
Target_s390<size>::Scan::local(Symbol_table* symtab,
                                 Layout* layout,
                                 Target_s390<size>* target,
                                 Sized_relobj_file<size, true>* object,
                                 unsigned int data_shndx,
                                 Output_section* output_section,
                                 const elfcpp::Rela<size, true>& reloc,
                                 unsigned int r_type,
                                 const elfcpp::Sym<size, true>& lsym,
                                 bool is_discarded)
{
  if (is_discarded)
    return;

  // A local STT_GNU_IFUNC symbol may require a PLT entry.
  bool is_ifunc = lsym.get_st_type() == elfcpp::STT_GNU_IFUNC;

  if (is_ifunc && this->reloc_needs_plt_for_ifunc(object, r_type))
    {
      unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
      target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
    }

  switch (r_type)
    {
    case elfcpp::R_390_NONE:
    case elfcpp::R_390_GNU_VTINHERIT:
    case elfcpp::R_390_GNU_VTENTRY:
      break;

    case elfcpp::R_390_64:
      // 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_390_RELATIVE relocation so the dynamic loader can
      // relocate it easily.
      if (parameters->options().output_is_position_independent() && size == 64)
        {
          unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
          Reloc_section* rela_dyn = target->rela_dyn_section(layout);
          rela_dyn->add_local_relative(object, r_sym,
                                       elfcpp::R_390_RELATIVE,
                                       output_section, data_shndx,
                                       reloc.get_r_offset(),
                                       reloc.get_r_addend(), is_ifunc);
        }
      break;

    case elfcpp::R_390_32:
    case elfcpp::R_390_20:
    case elfcpp::R_390_16:
    case elfcpp::R_390_12:
    case elfcpp::R_390_8:
      if (parameters->options().output_is_position_independent())
        {
          if (size == 32 && r_type == elfcpp::R_390_32)
            {
              unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
              Reloc_section* rela_dyn = target->rela_dyn_section(layout);
              rela_dyn->add_local_relative(object, r_sym,
                                           elfcpp::R_390_RELATIVE,
                                           output_section, data_shndx,
                                           reloc.get_r_offset(),
                                           reloc.get_r_addend(), is_ifunc);
              break;
            }

          check_non_pic(object, r_type);

          Reloc_section* rela_dyn = target->rela_dyn_section(layout);
          unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
          if (lsym.get_st_type() != elfcpp::STT_SECTION)
            rela_dyn->add_local(object, r_sym, r_type, output_section,
                                data_shndx, reloc.get_r_offset(),
                                reloc.get_r_addend());
          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
                rela_dyn->add_local_section(object, shndx,
                                            r_type, output_section,
                                            data_shndx, reloc.get_r_offset(),
                                            reloc.get_r_addend());
            }
        }
      break;

    case elfcpp::R_390_PC12DBL:
    case elfcpp::R_390_PC16:
    case elfcpp::R_390_PC16DBL:
    case elfcpp::R_390_PC24DBL:
    case elfcpp::R_390_PC32:
    case elfcpp::R_390_PC32DBL:
    case elfcpp::R_390_PC64:
      break;

    case elfcpp::R_390_PLT12DBL:
    case elfcpp::R_390_PLT16DBL:
    case elfcpp::R_390_PLT24DBL:
    case elfcpp::R_390_PLT32:
    case elfcpp::R_390_PLT32DBL:
    case elfcpp::R_390_PLT64:
      // Since we know this is a local symbol, we can handle this as a
      // PC32 reloc.
      break;

    case elfcpp::R_390_GOTPC:
    case elfcpp::R_390_GOTPCDBL:
    case elfcpp::R_390_GOTOFF16:
    case elfcpp::R_390_GOTOFF32:
    case elfcpp::R_390_GOTOFF64:
    case elfcpp::R_390_PLTOFF16:
    case elfcpp::R_390_PLTOFF32:
    case elfcpp::R_390_PLTOFF64:
      // We need a GOT section.
      target->got_section(symtab, layout);
      // For PLTOFF*, we'd normally want a PLT section, but since we
      // know this is a local symbol, no PLT is needed.
      break;

    case elfcpp::R_390_GOT12:
    case elfcpp::R_390_GOT16:
    case elfcpp::R_390_GOT20:
    case elfcpp::R_390_GOT32:
    case elfcpp::R_390_GOT64:
    case elfcpp::R_390_GOTENT:
    case elfcpp::R_390_GOTPLT12:
    case elfcpp::R_390_GOTPLT16:
    case elfcpp::R_390_GOTPLT20:
    case elfcpp::R_390_GOTPLT32:
    case elfcpp::R_390_GOTPLT64:
    case elfcpp::R_390_GOTPLTENT:
      {
        // The symbol requires a GOT section.
        Output_data_got<size, true>* got = target->got_section(symtab, layout);

        // The symbol requires a GOT entry.
        unsigned int r_sym = elfcpp::elf_r_sym<size>(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 (is_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 relocation for this symbol's GOT entry.
            if (parameters->options().output_is_position_independent())
              {
                Reloc_section* rela_dyn = target->rela_dyn_section(layout);
                unsigned int got_offset =
                  object->local_got_offset(r_sym, GOT_TYPE_STANDARD);
                rela_dyn->add_local_relative(object, r_sym,
                                             elfcpp::R_390_RELATIVE,
                                             got, got_offset, 0, is_ifunc);
              }
          }
        // For GOTPLT*, we'd normally want a PLT section, but since
        // we know this is a local symbol, no PLT is needed.
      }
      break;

    case elfcpp::R_390_COPY:
    case elfcpp::R_390_GLOB_DAT:
    case elfcpp::R_390_JMP_SLOT:
    case elfcpp::R_390_RELATIVE:
    case elfcpp::R_390_IRELATIVE:
      // These are outstanding tls relocs, which are unexpected when linking
    case elfcpp::R_390_TLS_TPOFF:
    case elfcpp::R_390_TLS_DTPOFF:
    case elfcpp::R_390_TLS_DTPMOD:
      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_390_TLS_GD32:          // Global-dynamic
    case elfcpp::R_390_TLS_GD64:
    case elfcpp::R_390_TLS_GDCALL:
    case elfcpp::R_390_TLS_LDM32:         // Local-dynamic
    case elfcpp::R_390_TLS_LDM64:
    case elfcpp::R_390_TLS_LDO32:
    case elfcpp::R_390_TLS_LDO64:
    case elfcpp::R_390_TLS_LDCALL:
    case elfcpp::R_390_TLS_IE32:          // Initial-exec
    case elfcpp::R_390_TLS_IE64:
    case elfcpp::R_390_TLS_IEENT:
    case elfcpp::R_390_TLS_GOTIE12:
    case elfcpp::R_390_TLS_GOTIE20:
    case elfcpp::R_390_TLS_GOTIE32:
    case elfcpp::R_390_TLS_GOTIE64:
    case elfcpp::R_390_TLS_LOAD:
    case elfcpp::R_390_TLS_LE32:          // Local-exec
    case elfcpp::R_390_TLS_LE64:
      {
        bool output_is_shared = parameters->options().shared();
        const tls::Tls_optimization optimized_type
            = Target_s390<size>::optimize_tls_reloc(!output_is_shared,
                                                      r_type);
        switch (r_type)
          {
          case elfcpp::R_390_TLS_GD32:       // General-dynamic
          case elfcpp::R_390_TLS_GD64:
          case elfcpp::R_390_TLS_GDCALL:
            if (optimized_type == tls::TLSOPT_NONE)
              {
                // Create a pair of GOT entries for the module index and
                // dtv-relative offset.
                Output_data_got<size, true>* got
                    = target->got_section(symtab, layout);
                unsigned int r_sym = elfcpp::elf_r_sym<size>(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->rela_dyn_section(layout),
                                               elfcpp::R_390_TLS_DTPMOD);
              }
            else if (optimized_type != tls::TLSOPT_TO_LE)
              unsupported_reloc_local(object, r_type);
            break;

          case elfcpp::R_390_TLS_LDM32:       // Local-dynamic
          case elfcpp::R_390_TLS_LDM64:
          case elfcpp::R_390_TLS_LDCALL:
            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_390_TLS_LDO32:
          case elfcpp::R_390_TLS_LDO64:
            break;

          case elfcpp::R_390_TLS_IE32:    // Initial-exec
          case elfcpp::R_390_TLS_IE64:
            // These two involve an absolute address
            if (parameters->options().shared()
                && optimized_type == tls::TLSOPT_NONE)
              {
                if ((size == 32 && r_type == elfcpp::R_390_TLS_IE32) ||
                    (size == 64 && r_type == elfcpp::R_390_TLS_IE64))
                  {
                    // We need to create a dynamic relocation.
                    Reloc_section* rela_dyn = target->rela_dyn_section(layout);
                    unsigned int r_sym =
                        elfcpp::elf_r_sym<size>(reloc.get_r_info());
                    rela_dyn->add_local_relative(object, r_sym,
                                                elfcpp::R_390_RELATIVE,
                                                output_section, data_shndx,
                                                reloc.get_r_offset(),
                                                reloc.get_r_addend(), false);
                  }
                else
                  {
                    unsupported_reloc_local(object, r_type);
                  }
              }
            // fall through
          case elfcpp::R_390_TLS_IEENT:
          case elfcpp::R_390_TLS_GOTIE12:
          case elfcpp::R_390_TLS_GOTIE20:
          case elfcpp::R_390_TLS_GOTIE32:
          case elfcpp::R_390_TLS_GOTIE64:
          case elfcpp::R_390_TLS_LOAD:
            layout->set_has_static_tls();
            if (optimized_type == tls::TLSOPT_NONE)
              {
                if (!output_is_shared)
                  {
                    // We're making an executable, and the symbol is local, but
                    // we cannot optimize to LE.  Make a const GOT entry instead.
                    Output_data_got<size, true>* got
                        = target->got_section(symtab, layout);
                    unsigned int r_sym
                        = elfcpp::elf_r_sym<size>(reloc.get_r_info());
                    got->add_local_plt(object, r_sym, GOT_TYPE_TLS_OFFSET);
                  }
                else
                {
                  // Create a GOT entry for the tp-relative offset.
                  Output_data_got<size, true>* got
                      = target->got_section(symtab, layout);
                  unsigned int r_sym
                      = elfcpp::elf_r_sym<size>(reloc.get_r_info());
                  got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
                                          target->rela_dyn_section(layout),
                                          elfcpp::R_390_TLS_TPOFF);
                }
              }
            else if (optimized_type != tls::TLSOPT_TO_LE)
              unsupported_reloc_local(object, r_type);
            break;

          case elfcpp::R_390_TLS_LE32:     // Local-exec
          case elfcpp::R_390_TLS_LE64:
            layout->set_has_static_tls();
            if (output_is_shared)
            {
              // We need to create a dynamic relocation.
              if ((size == 32 && r_type == elfcpp::R_390_TLS_LE32) ||
                  (size == 64 && r_type == elfcpp::R_390_TLS_LE64))
                {
                  Reloc_section* rela_dyn = target->rela_dyn_section(layout);
                  unsigned int r_sym
                      = elfcpp::elf_r_sym<size>(reloc.get_r_info());
                  gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
                  rela_dyn->add_local(object, r_sym, elfcpp::R_390_TLS_TPOFF,
                                      output_section, data_shndx,
                                      reloc.get_r_offset(),
                                      reloc.get_r_addend());
                }
              else
                {
                  unsupported_reloc_local(object, r_type);
                }
            }
            break;

          default:
            gold_unreachable();
          }
      }
      break;

    default:
      gold_error(_("%s: unsupported reloc %u against local symbol"),
                 object->name().c_str(), r_type);
      break;
    }
}

// Scan a relocation for a global symbol.

template<int size>
inline void
Target_s390<size>::Scan::global(Symbol_table* symtab,
                            Layout* layout,
                            Target_s390<size>* target,
                            Sized_relobj_file<size, true>* object,
                            unsigned int data_shndx,
                            Output_section* output_section,
                            const elfcpp::Rela<size, true>& 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_390_NONE:
    case elfcpp::R_390_GNU_VTINHERIT:
    case elfcpp::R_390_GNU_VTENTRY:
      break;

    case elfcpp::R_390_64:
    case elfcpp::R_390_32:
    case elfcpp::R_390_20:
    case elfcpp::R_390_16:
    case elfcpp::R_390_12:
    case elfcpp::R_390_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 (((size == 64 && r_type == elfcpp::R_390_64)
                      || (size == 32 && r_type == elfcpp::R_390_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* rela_dyn =
                  target->rela_irelative_section(layout);
                unsigned int r_type = elfcpp::R_390_IRELATIVE;
                rela_dyn->add_symbolless_global_addend(gsym, r_type,
                                                       output_section, object,
                                                       data_shndx,
                                                       reloc.get_r_offset(),
                                                       reloc.get_r_addend());
              }
            else if (((size == 64 && r_type == elfcpp::R_390_64)
                      || (size == 32 && r_type == elfcpp::R_390_32))
                     && gsym->can_use_relative_reloc(false))
              {
                Reloc_section* rela_dyn = target->rela_dyn_section(layout);
                rela_dyn->add_global_relative(gsym, elfcpp::R_390_RELATIVE,
                                              output_section, object,
                                              data_shndx,
                                              reloc.get_r_offset(),
                                              reloc.get_r_addend(), false);
              }
            else
              {
                check_non_pic(object, r_type);
                Reloc_section* rela_dyn = target->rela_dyn_section(layout);
                rela_dyn->add_global(gsym, r_type, output_section, object,
                                     data_shndx, reloc.get_r_offset(),
                                     reloc.get_r_addend());
              }
          }
      }
      break;

    case elfcpp::R_390_PC12DBL:
    case elfcpp::R_390_PC16:
    case elfcpp::R_390_PC16DBL:
    case elfcpp::R_390_PC24DBL:
    case elfcpp::R_390_PC32:
    case elfcpp::R_390_PC32DBL:
    case elfcpp::R_390_PC64:
      {
        // Make a PLT entry if necessary.
        if (gsym->needs_plt_entry())
          {
            target->make_plt_entry(symtab, layout, gsym);
            // larl is often used to take address of a function.  Aim the
            // symbol at 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_executable()
                && gsym->may_need_copy_reloc())
              {
                target->copy_reloc(symtab, layout, object,
                                   data_shndx, output_section, gsym, reloc);
              }
            else
              {
                check_non_pic(object, r_type);
                Reloc_section* rela_dyn = target->rela_dyn_section(layout);
                rela_dyn->add_global(gsym, r_type, output_section, object,
                                     data_shndx, reloc.get_r_offset(),
                                     reloc.get_r_addend());
              }
          }
      }
      break;

    case elfcpp::R_390_PLT12DBL:
    case elfcpp::R_390_PLT16DBL:
    case elfcpp::R_390_PLT24DBL:
    case elfcpp::R_390_PLT32:
    case elfcpp::R_390_PLT32DBL:
    case elfcpp::R_390_PLT64:
      // 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_390_GOTPC:
    case elfcpp::R_390_GOTPCDBL:
    case elfcpp::R_390_GOTOFF16:
    case elfcpp::R_390_GOTOFF32:
    case elfcpp::R_390_GOTOFF64:
    case elfcpp::R_390_PLTOFF16:
    case elfcpp::R_390_PLTOFF32:
    case elfcpp::R_390_PLTOFF64:
      // We need a GOT section.
      target->got_section(symtab, layout);
      // For PLTOFF*, we also need a PLT entry (but only if the
      // symbol is not fully resolved).
      if ((r_type == elfcpp::R_390_PLTOFF16
           || r_type == elfcpp::R_390_PLTOFF32
           || r_type == elfcpp::R_390_PLTOFF64)
          && !gsym->final_value_is_known())
        target->make_plt_entry(symtab, layout, gsym);
      break;

    case elfcpp::R_390_GOT12:
    case elfcpp::R_390_GOT16:
    case elfcpp::R_390_GOT20:
    case elfcpp::R_390_GOT32:
    case elfcpp::R_390_GOT64:
    case elfcpp::R_390_GOTENT:
    case elfcpp::R_390_GOTPLT12:
    case elfcpp::R_390_GOTPLT16:
    case elfcpp::R_390_GOTPLT20:
    case elfcpp::R_390_GOTPLT32:
    case elfcpp::R_390_GOTPLT64:
    case elfcpp::R_390_GOTPLTENT:
      {
        // The symbol requires a GOT entry.
        Output_data_got<size, true>* got = target->got_section(symtab, layout);

        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
            // dynamic relocation for it.
            Reloc_section* rela_dyn = target->rela_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, rela_dyn,
                                       elfcpp::R_390_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);
                    rela_dyn->add_global_relative(gsym,
                                                  elfcpp::R_390_RELATIVE,
                                                  got, got_off, 0, false);
                  }
              }
          }
      }
      break;

    case elfcpp::R_390_COPY:
    case elfcpp::R_390_GLOB_DAT:
    case elfcpp::R_390_JMP_SLOT:
    case elfcpp::R_390_RELATIVE:
    case elfcpp::R_390_IRELATIVE:
      // These are outstanding tls relocs, which are unexpected when linking
    case elfcpp::R_390_TLS_TPOFF:
    case elfcpp::R_390_TLS_DTPOFF:
    case elfcpp::R_390_TLS_DTPMOD:
      gold_error(_("%s: unexpected reloc %u in object file"),
                 object->name().c_str(), r_type);
      break;

      // These are initial tls relocs, which are expected for global()
    case elfcpp::R_390_TLS_GD32:          // Global-dynamic
    case elfcpp::R_390_TLS_GD64:
    case elfcpp::R_390_TLS_GDCALL:
    case elfcpp::R_390_TLS_LDM32:         // Local-dynamic
    case elfcpp::R_390_TLS_LDM64:
    case elfcpp::R_390_TLS_LDO32:
    case elfcpp::R_390_TLS_LDO64:
    case elfcpp::R_390_TLS_LDCALL:
    case elfcpp::R_390_TLS_IE32:          // Initial-exec
    case elfcpp::R_390_TLS_IE64:
    case elfcpp::R_390_TLS_IEENT:
    case elfcpp::R_390_TLS_GOTIE12:
    case elfcpp::R_390_TLS_GOTIE20:
    case elfcpp::R_390_TLS_GOTIE32:
    case elfcpp::R_390_TLS_GOTIE64:
    case elfcpp::R_390_TLS_LOAD:
    case elfcpp::R_390_TLS_LE32:          // Local-exec
    case elfcpp::R_390_TLS_LE64:
      {
        // For the optimizable Initial-Exec model, we can treat undef symbols
        // as final when building an executable.
        const bool is_final = (gsym->final_value_is_known() ||
                               ((r_type == elfcpp::R_390_TLS_IE32 ||
                                 r_type == elfcpp::R_390_TLS_IE64 ||
                                 r_type == elfcpp::R_390_TLS_GOTIE32 ||
                                 r_type == elfcpp::R_390_TLS_GOTIE64) &&
                                gsym->is_undefined() &&
                                parameters->options().output_is_executable()));
        const tls::Tls_optimization optimized_type
            = Target_s390<size>::optimize_tls_reloc(is_final, r_type);
        switch (r_type)
          {
          case elfcpp::R_390_TLS_GD32:       // General-dynamic
          case elfcpp::R_390_TLS_GD64:
          case elfcpp::R_390_TLS_GDCALL:
            if (optimized_type == tls::TLSOPT_NONE)
              {
                // Create a pair of GOT entries for the module index and
                // dtv-relative offset.
                Output_data_got<size, true>* got
                    = target->got_section(symtab, layout);
                got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
                                              target->rela_dyn_section(layout),
                                              elfcpp::R_390_TLS_DTPMOD,
                                              elfcpp::R_390_TLS_DTPOFF);
              }
            else if (optimized_type == tls::TLSOPT_TO_IE)
              {
                // Create a GOT entry for the tp-relative offset.
                Output_data_got<size, true>* got
                    = target->got_section(symtab, layout);
                got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
                                         target->rela_dyn_section(layout),
                                         elfcpp::R_390_TLS_TPOFF);
              }
            else if (optimized_type != tls::TLSOPT_TO_LE)
              unsupported_reloc_global(object, r_type, gsym);
            break;

          case elfcpp::R_390_TLS_LDM32:       // Local-dynamic
          case elfcpp::R_390_TLS_LDM64:
          case elfcpp::R_390_TLS_LDCALL:
            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_390_TLS_LDO32:
          case elfcpp::R_390_TLS_LDO64:
            break;

          case elfcpp::R_390_TLS_IE32:    // Initial-exec
          case elfcpp::R_390_TLS_IE64:
            // These two involve an absolute address
            if (parameters->options().shared())
              {
                if ((size == 32 && r_type == elfcpp::R_390_TLS_IE32) ||
                    (size == 64 && r_type == elfcpp::R_390_TLS_IE64))
                  {
                    // We need to create a dynamic relocation.
                    Reloc_section* rela_dyn = target->rela_dyn_section(layout);
                    rela_dyn->add_global_relative(gsym, elfcpp::R_390_RELATIVE,
                                                  output_section, object,
                                                  data_shndx,
                                                  reloc.get_r_offset(),
                                                  reloc.get_r_addend(), false);
                  }
                else
                  {
                    unsupported_reloc_global(object, r_type, gsym);
                  }
              }
            // fall through
          case elfcpp::R_390_TLS_IEENT:
          case elfcpp::R_390_TLS_GOTIE12:
          case elfcpp::R_390_TLS_GOTIE20:
          case elfcpp::R_390_TLS_GOTIE32:
          case elfcpp::R_390_TLS_GOTIE64:
          case elfcpp::R_390_TLS_LOAD:
            layout->set_has_static_tls();
            if (optimized_type == tls::TLSOPT_NONE)
              {
                if (is_final && !parameters->options().shared())
                  {
                    // We're making an executable, and the symbol is local, but
                    // we cannot optimize to LE.  Make a const GOT entry instead.
                    Output_data_got<size, true>* got
                        = target->got_section(symtab, layout);
                    got->add_global_plt(gsym, GOT_TYPE_TLS_OFFSET);
                  }
                else
                  {
                    // Create a GOT entry for the tp-relative offset.
                    Output_data_got<size, true>* got
                        = target->got_section(symtab, layout);
                    got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
                                             target->rela_dyn_section(layout),
                                             elfcpp::R_390_TLS_TPOFF);
                  }
              }
            else if (optimized_type != tls::TLSOPT_TO_LE)
              unsupported_reloc_global(object, r_type, gsym);
            break;

          case elfcpp::R_390_TLS_LE32:     // Local-exec
          case elfcpp::R_390_TLS_LE64:
            layout->set_has_static_tls();
            if (parameters->options().shared())
              {
                // We need to create a dynamic relocation.
                if ((size == 32 && r_type == elfcpp::R_390_TLS_LE32) ||
                    (size == 64 && r_type == elfcpp::R_390_TLS_LE64))
                  {
                    Reloc_section* rela_dyn = target->rela_dyn_section(layout);
                    rela_dyn->add_global(gsym, elfcpp::R_390_TLS_TPOFF,
                                         output_section, object,
                                         data_shndx, reloc.get_r_offset(),
                                         reloc.get_r_addend());
                  }
                else
                  {
                    unsupported_reloc_global(object, r_type, gsym);
                  }
              }
            break;

          default:
            gold_unreachable();
          }
      }
      break;

    default:
      gold_error(_("%s: unsupported reloc %u against global symbol %s"),
                 object->name().c_str(), r_type,
                 gsym->demangled_name().c_str());
      break;
    }
}


// Report an unsupported relocation against a global symbol.

template<int size>
void
Target_s390<size>::Scan::unsupported_reloc_global(
    Sized_relobj_file<size, true>* 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());
}

// Returns true if this relocation type could be that of a function pointer.
template<int size>
inline bool
Target_s390<size>::Scan::possible_function_pointer_reloc(unsigned int r_type)
{
  switch (r_type)
    {
    case elfcpp::R_390_32:
    case elfcpp::R_390_64:
    case elfcpp::R_390_PC32DBL: // could be used by larl insn
    case elfcpp::R_390_GOT12:
    case elfcpp::R_390_GOT16:
    case elfcpp::R_390_GOT20:
    case elfcpp::R_390_GOT32:
    case elfcpp::R_390_GOT64:
    case elfcpp::R_390_GOTENT:
    case elfcpp::R_390_GOTOFF16:
    case elfcpp::R_390_GOTOFF32:
    case elfcpp::R_390_GOTOFF64:
      return true;
    }
  return false;
}

// For safe ICF, scan a relocation for a local symbol to check if it
// corresponds to a function pointer being taken.  In that case mark
// the function whose pointer was taken as not foldable.

template<int size>
inline bool
Target_s390<size>::Scan::local_reloc_may_be_function_pointer(
  Symbol_table* ,
  Layout* ,
  Target_s390<size>* ,
  Sized_relobj_file<size, true>* ,
  unsigned int ,
  Output_section* ,
  const elfcpp::Rela<size, true>& ,
  unsigned int r_type,
  const elfcpp::Sym<size, true>&)
{
  // When building a shared library, do not fold any local symbols.
  return (parameters->options().shared()
          || possible_function_pointer_reloc(r_type));
}

// For safe ICF, scan a relocation for a global symbol to check if it
// corresponds to a function pointer being taken.  In that case mark
// the function whose pointer was taken as not foldable.

template<int size>
inline bool
Target_s390<size>::Scan::global_reloc_may_be_function_pointer(
  Symbol_table*,
  Layout* ,
  Target_s390<size>* ,
  Sized_relobj_file<size, true>* ,
  unsigned int ,
  Output_section* ,
  const elfcpp::Rela<size, true>& ,
  unsigned int r_type,
  Symbol* gsym)
{
  // When building a shared library, do not fold symbols whose visibility
  // is hidden, internal or protected.
  return ((parameters->options().shared()
           && (gsym->visibility() == elfcpp::STV_INTERNAL
               || gsym->visibility() == elfcpp::STV_PROTECTED
               || gsym->visibility() == elfcpp::STV_HIDDEN))
          || possible_function_pointer_reloc(r_type));
}

template<int size>
void
Target_s390<size>::gc_process_relocs(Symbol_table* symtab,
                                       Layout* layout,
                                       Sized_relobj_file<size, true>* 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_REL)
    return;

  gold::gc_process_relocs<size, true, Target_s390<size>, elfcpp::SHT_RELA,
                          typename Target_s390<size>::Scan,
                          typename Target_s390<size>::Relocatable_size_for_reloc>(
    symtab,
    layout,
    this,
    object,
    data_shndx,
    prelocs,
    reloc_count,
    output_section,
    needs_special_offset_handling,
    local_symbol_count,
    plocal_symbols);
}

// Perform a relocation.

template<int size>
inline bool
Target_s390<size>::Relocate::relocate(
    const Relocate_info<size, true>* relinfo,
    Target_s390<size>* target,
    Output_section*,
    size_t relnum,
    const elfcpp::Rela<size, true>& rela,
    unsigned int r_type,
    const Sized_symbol<size>* gsym,
    const Symbol_value<size>* psymval,
    unsigned char* view,
    typename elfcpp::Elf_types<size>::Elf_Addr address,
    section_size_type view_size)
{
  if (view == NULL)
    return true;

  const Sized_relobj_file<size, true>* object = relinfo->object;

  // Pick the value to use for symbols defined in the PLT.
  Symbol_value<size> symval;
  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<size>(rela.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;
        }
    }

  const elfcpp::Elf_Xword addend = rela.get_r_addend();

  typename elfcpp::Elf_types<size>::Elf_Addr value = 0;

  switch (r_type)
    {
    case elfcpp::R_390_PLT64:
    case elfcpp::R_390_PLT32:
    case elfcpp::R_390_PLT32DBL:
    case elfcpp::R_390_PLT24DBL:
    case elfcpp::R_390_PLT16DBL:
    case elfcpp::R_390_PLT12DBL:
      gold_assert(gsym == NULL
                  || gsym->has_plt_offset()
                  || gsym->final_value_is_known()
                  || (gsym->is_defined()
                      && !gsym->is_from_dynobj()
                      && !gsym->is_preemptible()));
      // fallthru
    case elfcpp::R_390_8:
    case elfcpp::R_390_12:
    case elfcpp::R_390_16:
    case elfcpp::R_390_20:
    case elfcpp::R_390_32:
    case elfcpp::R_390_64:
    case elfcpp::R_390_PC16:
    case elfcpp::R_390_PC32:
    case elfcpp::R_390_PC64:
    case elfcpp::R_390_PC32DBL:
    case elfcpp::R_390_PC24DBL:
    case elfcpp::R_390_PC16DBL:
    case elfcpp::R_390_PC12DBL:
      value = psymval->value(object, addend);
      break;

    case elfcpp::R_390_GOTPC:
    case elfcpp::R_390_GOTPCDBL:
      gold_assert(gsym != NULL);
      value = target->got_address() + addend;
      break;

    case elfcpp::R_390_PLTOFF64:
    case elfcpp::R_390_PLTOFF32:
    case elfcpp::R_390_PLTOFF16:
      gold_assert(gsym == NULL
                  || gsym->has_plt_offset()
                  || gsym->final_value_is_known());
      // fallthru
    case elfcpp::R_390_GOTOFF64:
    case elfcpp::R_390_GOTOFF32:
    case elfcpp::R_390_GOTOFF16:
      value = (psymval->value(object, addend)
               - target->got_address());
      break;

    case elfcpp::R_390_GOT12:
    case elfcpp::R_390_GOT16:
    case elfcpp::R_390_GOT20:
    case elfcpp::R_390_GOT32:
    case elfcpp::R_390_GOT64:
    case elfcpp::R_390_GOTENT:
    case elfcpp::R_390_GOTPLT12:
    case elfcpp::R_390_GOTPLT16:
    case elfcpp::R_390_GOTPLT20:
    case elfcpp::R_390_GOTPLT32:
    case elfcpp::R_390_GOTPLT64:
    case elfcpp::R_390_GOTPLTENT:
      {
        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);
          }
        else
          {
            unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.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);
          }
        value = got_offset + target->got_main_offset() + addend;
      }
      break;

      // These are initial tls relocs, which are expected when linking
    case elfcpp::R_390_TLS_LOAD:
    case elfcpp::R_390_TLS_GDCALL:          // Global-dynamic
    case elfcpp::R_390_TLS_GD32:
    case elfcpp::R_390_TLS_GD64:
    case elfcpp::R_390_TLS_LDCALL:          // Local-dynamic
    case elfcpp::R_390_TLS_LDM32:
    case elfcpp::R_390_TLS_LDM64:
    case elfcpp::R_390_TLS_LDO32:
    case elfcpp::R_390_TLS_LDO64:
    case elfcpp::R_390_TLS_GOTIE12:         // Initial-exec
    case elfcpp::R_390_TLS_GOTIE20:
    case elfcpp::R_390_TLS_GOTIE32:
    case elfcpp::R_390_TLS_GOTIE64:
    case elfcpp::R_390_TLS_IE32:
    case elfcpp::R_390_TLS_IE64:
    case elfcpp::R_390_TLS_IEENT:
    case elfcpp::R_390_TLS_LE32:            // Local-exec
    case elfcpp::R_390_TLS_LE64:
      value = this->relocate_tls(relinfo, target, relnum, rela, r_type, gsym, psymval,
                         view, view_size);
      break;

    default:
      break;
    }

  typename S390_relocate_functions<size>::Status status
      = S390_relocate_functions<size>::STATUS_OK;

  switch (r_type)
    {
    case elfcpp::R_390_NONE:
    case elfcpp::R_390_GNU_VTINHERIT:
    case elfcpp::R_390_GNU_VTENTRY:
    case elfcpp::R_390_TLS_GDCALL:
    case elfcpp::R_390_TLS_LDCALL:
    case elfcpp::R_390_TLS_LOAD:
      break;

    case elfcpp::R_390_64:
    case elfcpp::R_390_GOT64:
    case elfcpp::R_390_GOTPLT64:
    case elfcpp::R_390_PLTOFF64:
    case elfcpp::R_390_GOTOFF64:
    case elfcpp::R_390_TLS_GD64:
    case elfcpp::R_390_TLS_LDM64:
    case elfcpp::R_390_TLS_LDO64:
    case elfcpp::R_390_TLS_GOTIE64:
    case elfcpp::R_390_TLS_IE64:
    case elfcpp::R_390_TLS_LE64:
      Relocate_functions<size, true>::rela64(view, value, 0);
      break;

    case elfcpp::R_390_32:
    case elfcpp::R_390_GOT32:
    case elfcpp::R_390_GOTPLT32:
    case elfcpp::R_390_PLTOFF32:
    case elfcpp::R_390_GOTOFF32:
    case elfcpp::R_390_TLS_GD32:
    case elfcpp::R_390_TLS_LDM32:
    case elfcpp::R_390_TLS_LDO32:
    case elfcpp::R_390_TLS_GOTIE32:
    case elfcpp::R_390_TLS_IE32:
    case elfcpp::R_390_TLS_LE32:
      Relocate_functions<size, true>::rela32(view, value, 0);
      break;

    case elfcpp::R_390_20:
    case elfcpp::R_390_GOT20:
    case elfcpp::R_390_GOTPLT20:
    case elfcpp::R_390_TLS_GOTIE20:
      status = S390_relocate_functions<size>::rela20(view, value);
      break;

    case elfcpp::R_390_16:
    case elfcpp::R_390_GOT16:
    case elfcpp::R_390_GOTPLT16:
    case elfcpp::R_390_PLTOFF16:
    case elfcpp::R_390_GOTOFF16:
      status = S390_relocate_functions<size>::rela16(view, value);
      break;

    case elfcpp::R_390_12:
    case elfcpp::R_390_GOT12:
    case elfcpp::R_390_GOTPLT12:
    case elfcpp::R_390_TLS_GOTIE12:
      status = S390_relocate_functions<size>::rela12(view, value);
      break;

    case elfcpp::R_390_8:
      Relocate_functions<size, true>::rela8(view, value, 0);
      break;

    case elfcpp::R_390_PC16:
      Relocate_functions<size, true>::pcrela16(view, value, 0,
                                               address);
      break;

    case elfcpp::R_390_PLT64:
    case elfcpp::R_390_PC64:
      Relocate_functions<size, true>::pcrela64(view, value, 0, address);
      break;

    case elfcpp::R_390_PLT32:
    case elfcpp::R_390_PC32:
    case elfcpp::R_390_GOTPC:
      Relocate_functions<size, true>::pcrela32(view, value, 0, address);
      break;

    case elfcpp::R_390_PLT32DBL:
    case elfcpp::R_390_PC32DBL:
    case elfcpp::R_390_GOTPCDBL:
      status = S390_relocate_functions<size>::pcrela32dbl(view, value, address);
      break;

    case elfcpp::R_390_PLT24DBL:
    case elfcpp::R_390_PC24DBL:
      status = S390_relocate_functions<size>::pcrela24dbl(view, value, address);
      break;

    case elfcpp::R_390_PLT16DBL:
    case elfcpp::R_390_PC16DBL:
      status = S390_relocate_functions<size>::pcrela16dbl(view, value, address);
      break;

    case elfcpp::R_390_PLT12DBL:
    case elfcpp::R_390_PC12DBL:
      status = S390_relocate_functions<size>::pcrela12dbl(view, value, address);
      break;

    case elfcpp::R_390_GOTENT:
    case elfcpp::R_390_GOTPLTENT:
    case elfcpp::R_390_TLS_IEENT:
      value += target->got_address();
      status = S390_relocate_functions<size>::pcrela32dbl(view, value, address);
      break;

    case elfcpp::R_390_COPY:
    case elfcpp::R_390_GLOB_DAT:
    case elfcpp::R_390_JMP_SLOT:
    case elfcpp::R_390_RELATIVE:
    case elfcpp::R_390_IRELATIVE:
      // These are outstanding tls relocs, which are unexpected when linking
    case elfcpp::R_390_TLS_TPOFF:
    case elfcpp::R_390_TLS_DTPMOD:
    case elfcpp::R_390_TLS_DTPOFF:
      gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
                             _("unexpected reloc %u in object file"),
                             r_type);
      break;

    default:
      gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
                             _("unsupported reloc %u"),
                             r_type);
      break;
    }

  if (status != S390_relocate_functions<size>::STATUS_OK)
    {
      gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
                             _("relocation overflow"));
    }

  return true;
}

// Perform a TLS relocation.

template<int size>
inline typename elfcpp::Elf_types<size>::Elf_Addr
Target_s390<size>::Relocate::relocate_tls(
    const Relocate_info<size, true>* relinfo,
    Target_s390<size>* target,
    size_t relnum,
    const elfcpp::Rela<size, true>& rela,
    unsigned int r_type,
    const Sized_symbol<size>* gsym,
    const Symbol_value<size>* psymval,
    unsigned char* view,
    section_size_type view_size)
{
  Output_segment* tls_segment = relinfo->layout->tls_segment();

  const Sized_relobj_file<size, true>* object = relinfo->object;
  const elfcpp::Elf_Xword addend = rela.get_r_addend();
  elfcpp::Shdr<size, true> data_shdr(relinfo->data_shdr);
  bool is_allocatable = (data_shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0;

  typename elfcpp::Elf_types<size>::Elf_Addr value
      = psymval->value(relinfo->object, addend);

  const bool is_final = (gsym == NULL
                         ? !parameters->options().shared()
                         : gsym->final_value_is_known());
  tls::Tls_optimization optimized_type
      = Target_s390<size>::optimize_tls_reloc(is_final, r_type);
  switch (r_type)
    {
    case elfcpp::R_390_TLS_GDCALL:            // Global-dynamic marker
      if (optimized_type == tls::TLSOPT_TO_LE)
        {
          if (tls_segment == NULL)
            {
              gold_assert(parameters->errors()->error_count() > 0
                          || issue_undefined_symbol_error(gsym));
              return 0;
            }
          this->tls_gd_to_le(relinfo, relnum, rela, view, view_size);
          break;
        }
      else
        {
          if (optimized_type == tls::TLSOPT_TO_IE)
            {
              this->tls_gd_to_ie(relinfo, relnum, rela, view, view_size);
              break;
            }
          else if (optimized_type == tls::TLSOPT_NONE)
            {
              break;
            }
        }
      gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
                             _("unsupported reloc %u"), r_type);
      break;

    case elfcpp::R_390_TLS_GD32:            // Global-dynamic
    case elfcpp::R_390_TLS_GD64:
      if (optimized_type == tls::TLSOPT_TO_LE)
        {
          if (tls_segment == NULL)
            {
              gold_assert(parameters->errors()->error_count() > 0
                          || issue_undefined_symbol_error(gsym));
              return 0;
            }
          return value - tls_segment->memsz();
        }
      else
        {
          unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
                                   ? GOT_TYPE_TLS_OFFSET
                                   : GOT_TYPE_TLS_PAIR);
          if (gsym != NULL)
            {
              gold_assert(gsym->has_got_offset(got_type));
              return (gsym->got_offset(got_type)
                      + target->got_main_offset()
                      + addend);
            }
          else
            {
              unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
              gold_assert(object->local_has_got_offset(r_sym, got_type));
              return (object->local_got_offset(r_sym, got_type)
                      + target->got_main_offset()
                      + addend);
            }
        }
      gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
                             _("unsupported reloc %u"), r_type);
      break;

    case elfcpp::R_390_TLS_LDCALL:            // Local-dynamic marker
      // This is a marker relocation. If the sequence is being turned to LE,
      // we modify the instruction, otherwise the instruction is untouched.
      if (optimized_type == tls::TLSOPT_TO_LE)
        {
          if (tls_segment == NULL)
            {
              gold_assert(parameters->errors()->error_count() > 0
                          || issue_undefined_symbol_error(gsym));
              return 0;
            }
          this->tls_ld_to_le(relinfo, relnum, rela, view, view_size);
          break;
        }
      else if (optimized_type == tls::TLSOPT_NONE)
        {
          break;
        }
      gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
                             _("unsupported reloc %u"), r_type);
      break;

    case elfcpp::R_390_TLS_LDM32:            // Local-dynamic module
    case elfcpp::R_390_TLS_LDM64:
      if (optimized_type == tls::TLSOPT_TO_LE)
        {
          if (tls_segment == NULL)
            {
              gold_assert(parameters->errors()->error_count() > 0
                          || issue_undefined_symbol_error(gsym));
              return 0;
            }
          // Doesn't matter what we fill it with - it's going to be unused.
          return 0;
        }
      else if (optimized_type == tls::TLSOPT_NONE)
        {
          // Relocate the field with the offset of the GOT entry for
          // the module index.
          return (target->got_mod_index_entry(NULL, NULL, NULL)
                  + addend
                  + target->got_main_offset());
        }
      gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
                             _("unsupported reloc %u"), r_type);
      break;

    case elfcpp::R_390_TLS_LDO32:         // Local-dynamic offset
    case elfcpp::R_390_TLS_LDO64:
      // This relocation type is used in debugging information.
      // In that case we need to not optimize the value.  If the
      // section is not allocatable, then we assume we should not
      // optimize this reloc.
      if (optimized_type == tls::TLSOPT_TO_LE && is_allocatable)
        {
          if (tls_segment == NULL)
            {
              gold_assert(parameters->errors()->error_count() > 0
                          || issue_undefined_symbol_error(gsym));
              return 0;
            }
          value -= tls_segment->memsz();
        }
      return value;

    case elfcpp::R_390_TLS_LOAD:         // Initial-exec marker
      // This is a marker relocation. If the sequence is being turned to LE,
      // we modify the instruction, otherwise the instruction is untouched.
      if (gsym != NULL
          && gsym->is_undefined()
          && parameters->options().output_is_executable())
        {
          Target_s390<size>::Relocate::tls_ie_to_le(relinfo, relnum,
                                                      rela, view,
                                                      view_size);
          break;
        }
      else if (optimized_type == tls::TLSOPT_TO_LE)
        {
          if (tls_segment == NULL)
            {
              gold_assert(parameters->errors()->error_count() > 0
                          || issue_undefined_symbol_error(gsym));
              return 0;
            }
          Target_s390<size>::Relocate::tls_ie_to_le(relinfo, relnum,
                                                      rela, view,
                                                      view_size);
          break;
        }
      else if (optimized_type == tls::TLSOPT_NONE)
        {
          break;
        }
      gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
                             _("unsupported reloc type %u"),
                             r_type);
      break;

    case elfcpp::R_390_TLS_GOTIE12:       // Initial-exec, not optimizable
    case elfcpp::R_390_TLS_GOTIE20:
    case elfcpp::R_390_TLS_IEENT:
    case elfcpp::R_390_TLS_GOTIE32:       // Initial-exec, optimizable
    case elfcpp::R_390_TLS_GOTIE64:
    case elfcpp::R_390_TLS_IE32:
    case elfcpp::R_390_TLS_IE64:
      if (gsym != NULL
          && gsym->is_undefined()
          && parameters->options().output_is_executable()
          // These three cannot be optimized to LE, no matter what
          && r_type != elfcpp::R_390_TLS_GOTIE12
          && r_type != elfcpp::R_390_TLS_GOTIE20
          && r_type != elfcpp::R_390_TLS_IEENT)
        {
          return value;
        }
      else if (optimized_type == tls::TLSOPT_TO_LE)
        {
          if (tls_segment == NULL)
            {
              gold_assert(parameters->errors()->error_count() > 0
                          || issue_undefined_symbol_error(gsym));
              return 0;
            }
          return value - tls_segment->memsz();
        }
      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_offset;
          if (gsym != NULL)
            {
              gold_assert(gsym->has_got_offset(GOT_TYPE_TLS_OFFSET));
              got_offset = gsym->got_offset(GOT_TYPE_TLS_OFFSET);
            }
          else
            {
              unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
              gold_assert(object->local_has_got_offset(r_sym,
                                                       GOT_TYPE_TLS_OFFSET));
              got_offset = object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET);
            }
          got_offset += target->got_main_offset();
          if (r_type == elfcpp::R_390_TLS_IE32
              || r_type == elfcpp::R_390_TLS_IE64)
            return target->got_address() + got_offset + addend;
          else
            return got_offset + addend;
        }
      gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
                             _("unsupported reloc type %u"),
                             r_type);
      break;

    case elfcpp::R_390_TLS_LE32:          // Local-exec
    case elfcpp::R_390_TLS_LE64:
      if (tls_segment == NULL)
        {
          gold_assert(parameters->errors()->error_count() > 0
                      || issue_undefined_symbol_error(gsym));
          return 0;
        }
      return value - tls_segment->memsz();
    }
  return 0;
}

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

template<int size>
inline void
Target_s390<size>::Relocate::tls_gd_to_ie(
    const Relocate_info<size, true>* relinfo,
    size_t relnum,
    const elfcpp::Rela<size, true>& rela,
    unsigned char* view,
    section_size_type view_size)
{
  tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
  if (view[0] == 0x4d)
    {
      // bas, don't care about details
      // Change to l %r2, 0(%r2, %r12)
      view[0] = 0x58;
      view[1] = 0x22;
      view[2] = 0xc0;
      view[3] = 0x00;
      return;
    }
  else if (view[0] == 0xc0)
    {
      tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 6);
      // brasl %r14, __tls_get_offset@plt
      if (view[1] == 0xe5)
        {
          // Change to l/lg %r2, 0(%r2, %r12)
          // There was a PLT32DBL reloc at the last 4 bytes, overwrite its result.
          if (size == 32)
            {
              // l
              view[0] = 0x58;
              view[1] = 0x22;
              view[2] = 0xc0;
              view[3] = 0x00;
              // nop
              view[4] = 0x07;
              view[5] = 0x07;
            }
          else
            {
              // lg
              view[0] = 0xe3;
              view[1] = 0x22;
              view[2] = 0xc0;
              view[3] = 0;
              view[4] = 0;
              view[5] = 0x04;
            }
          return;
        }
    }
  gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
                         _("unsupported op for GD to IE"));
}

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

template<int size>
inline void
Target_s390<size>::Relocate::tls_gd_to_le(
    const Relocate_info<size, true>* relinfo,
    size_t relnum,
    const elfcpp::Rela<size, true>& rela,
    unsigned char* view,
    section_size_type view_size)
{
  tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
  if (view[0] == 0x0d)
    {
      // basr, change to nop
      view[0] = 0x07;
      view[1] = 0x07;
    }
  else if (view[0] == 0x4d)
    {
      tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
      // bas, don't care about details, change to nop
      view[0] = 0x47;
      view[1] = 0;
      view[2] = 0;
      view[3] = 0;
      return;
    }
  else if (view[0] == 0xc0)
    {
      tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 6);
      // brasl %r14, __tls_get_offset@plt
      if (view[1] == 0xe5)
        {
          // Change to nop jump. There was a PLT32DBL reloc at the last
          // 4 bytes, overwrite its result.
          view[1] = 0x04;
          view[2] = 0;
          view[3] = 0;
          view[4] = 0;
          view[5] = 0;
          return;
        }
    }
  gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
                         _("unsupported op for GD to LE"));
}

template<int size>
inline void
Target_s390<size>::Relocate::tls_ld_to_le(
    const Relocate_info<size, true>* relinfo,
    size_t relnum,
    const elfcpp::Rela<size, true>& rela,
    unsigned char* view,
    section_size_type view_size)
{
  tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);

  if (view[0] == 0x0d)
    {
      // basr, change to nop
      view[0] = 0x07;
      view[1] = 0x07;
    }
  else if (view[0] == 0x4d)
    {
      // bas, don't care about details, change to nop
      view[0] = 0x47;
      view[1] = 0;
      view[2] = 0;
      view[3] = 0;
      return;
    }
  else if (view[0] == 0xc0)
    {
      tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 6);
      // brasl %r14, __tls_get_offset@plt
      if (view[1] == 0xe5)
        {
          // Change to nop jump. There was a PLT32DBL reloc at the last
          // 4 bytes, overwrite its result.
          view[1] = 0x04;
          view[2] = 0;
          view[3] = 0;
          view[4] = 0;
          view[5] = 0;
          return;
        }
    }
  gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
                         _("unsupported op for LD to LE"));
}

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

template<int size>
inline void
Target_s390<size>::Relocate::tls_ie_to_le(
    const Relocate_info<size, true>* relinfo,
    size_t relnum,
    const elfcpp::Rela<size, true>& rela,
    unsigned char* view,
    section_size_type view_size)
{
  tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);

  if (view[0] == 0x58)
    {
      // l %rX, 0(%rY) or l %rX, 0(%rY, %r12)
      if ((view[2] & 0x0f) != 0 || view[3] != 0)
        goto err;
      int rx = view[1] >> 4 & 0xf;
      int ry = view[1] & 0xf;
      int rz = view[2] >> 4 & 0xf;
      if (rz == 0)
        {
        }
      else if (ry == 0)
        {
          ry = rz;
        }
      else if (rz == 12)
        {
        }
      else if (ry == 12)
        {
          ry = rz;
        }
      else
        goto err;
      // to lr %rX, $rY
      view[0] = 0x18;
      view[1] = rx << 4 | ry;
      // and insert a nop
      view[2] = 0x07;
      view[3] = 0x00;
    }
  else if (view[0] == 0xe3)
    {
      tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 6);
      // lg %rX, 0(%rY) or lg %rX, 0(%rY, %r12)
      if ((view[2] & 0x0f) != 0 ||
          view[3] != 0 ||
          view[4] != 0 ||
          view[5] != 0x04)
        goto err;
      int rx = view[1] >> 4 & 0xf;
      int ry = view[1] & 0xf;
      int rz = view[2] >> 4 & 0xf;
      if (rz == 0)
        {
        }
      else if (ry == 0)
        {
          ry = rz;
        }
      else if (rz == 12)
        {
        }
      else if (ry == 12)
        {
          ry = rz;
        }
      else
        goto err;
      // to sllg %rX, $rY, 0
      view[0] = 0xeb;
      view[1] = rx << 4 | ry;
      view[2] = 0x00;
      view[3] = 0x00;
      view[4] = 0x00;
      view[5] = 0x0d;
    }
  else
    {
err:
      gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
                             _("unsupported op for IE to LE"));
    }
}

// Scan relocations for a section.

template<int size>
void
Target_s390<size>::scan_relocs(Symbol_table* symtab,
                                 Layout* layout,
                                 Sized_relobj_file<size, true>* 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_REL)
    {
      gold_error(_("%s: unsupported REL reloc section"),
                 object->name().c_str());
      return;
    }

  gold::scan_relocs<size, true, Target_s390<size>, elfcpp::SHT_RELA,
      typename Target_s390<size>::Scan>(
    symtab,
    layout,
    this,
    object,
    data_shndx,
    prelocs,
    reloc_count,
    output_section,
    needs_special_offset_handling,
    local_symbol_count,
    plocal_symbols);
}

// Finalize the sections.

template<int size>
void
Target_s390<size>::do_finalize_sections(
    Layout* layout,
    const Input_objects*,
    Symbol_table* symtab)
{
  const Reloc_section* rel_plt = (this->plt_ == NULL
                                  ? NULL
                                  : this->plt_->rela_plt());
  layout->add_target_dynamic_tags(false, this->got_plt_, rel_plt,
                                  this->rela_dyn_, true, size == 32);

  this->layout_ = layout;

  // 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->rela_dyn_section(layout));

  // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
  // the .got section.
  Symbol* sym = this->global_offset_table_;
  if (sym != NULL)
    {
      uint64_t data_size = this->got_->current_data_size();
      symtab->get_sized_symbol<size>(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 __rela_iplt symbols
      // were defined if necessary, even if we didn't create a PLT.
      static const Define_symbol_in_segment syms[] =
        {
          {
            "__rela_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
          },
          {
            "__rela_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 the size of a relocation while scanning during a relocatable
// link.

template<int size>
unsigned int
Target_s390<size>::Relocatable_size_for_reloc::get_size_for_reloc(
    unsigned int r_type,
    Relobj* object)
{
  switch (r_type)
    {
    case elfcpp::R_390_NONE:
    case elfcpp::R_390_GNU_VTINHERIT:
    case elfcpp::R_390_GNU_VTENTRY:
    case elfcpp::R_390_TLS_GD32:          // Global-dynamic
    case elfcpp::R_390_TLS_GD64:
    case elfcpp::R_390_TLS_GDCALL:
    case elfcpp::R_390_TLS_LDM32:         // Local-dynamic
    case elfcpp::R_390_TLS_LDM64:
    case elfcpp::R_390_TLS_LDO32:
    case elfcpp::R_390_TLS_LDO64:
    case elfcpp::R_390_TLS_LDCALL:
    case elfcpp::R_390_TLS_IE32:          // Initial-exec
    case elfcpp::R_390_TLS_IE64:
    case elfcpp::R_390_TLS_IEENT:
    case elfcpp::R_390_TLS_GOTIE12:
    case elfcpp::R_390_TLS_GOTIE20:
    case elfcpp::R_390_TLS_GOTIE32:
    case elfcpp::R_390_TLS_GOTIE64:
    case elfcpp::R_390_TLS_LOAD:
    case elfcpp::R_390_TLS_LE32:          // Local-exec
    case elfcpp::R_390_TLS_LE64:
      return 0;

    case elfcpp::R_390_64:
    case elfcpp::R_390_PC64:
    case elfcpp::R_390_GOT64:
    case elfcpp::R_390_PLT64:
    case elfcpp::R_390_GOTOFF64:
    case elfcpp::R_390_GOTPLT64:
    case elfcpp::R_390_PLTOFF64:
      return 8;

    case elfcpp::R_390_32:
    case elfcpp::R_390_PC32:
    case elfcpp::R_390_GOT32:
    case elfcpp::R_390_PLT32:
    case elfcpp::R_390_GOTOFF32:
    case elfcpp::R_390_GOTPC:
    case elfcpp::R_390_PC32DBL:
    case elfcpp::R_390_PLT32DBL:
    case elfcpp::R_390_GOTPCDBL:
    case elfcpp::R_390_GOTENT:
    case elfcpp::R_390_GOTPLT32:
    case elfcpp::R_390_GOTPLTENT:
    case elfcpp::R_390_PLTOFF32:
    case elfcpp::R_390_20:
    case elfcpp::R_390_GOT20:
    case elfcpp::R_390_GOTPLT20:
      return 4;

    case elfcpp::R_390_PC24DBL:
    case elfcpp::R_390_PLT24DBL:
      return 3;

    case elfcpp::R_390_12:
    case elfcpp::R_390_GOT12:
    case elfcpp::R_390_GOTPLT12:
    case elfcpp::R_390_PC12DBL:
    case elfcpp::R_390_PLT12DBL:
    case elfcpp::R_390_16:
    case elfcpp::R_390_GOT16:
    case elfcpp::R_390_PC16:
    case elfcpp::R_390_PC16DBL:
    case elfcpp::R_390_PLT16DBL:
    case elfcpp::R_390_GOTOFF16:
    case elfcpp::R_390_GOTPLT16:
    case elfcpp::R_390_PLTOFF16:
      return 2;

    case elfcpp::R_390_8:
      return 1;

      // These are relocations which should only be seen by the
      // dynamic linker, and should never be seen here.
    case elfcpp::R_390_COPY:
    case elfcpp::R_390_GLOB_DAT:
    case elfcpp::R_390_JMP_SLOT:
    case elfcpp::R_390_RELATIVE:
    case elfcpp::R_390_IRELATIVE:
    case elfcpp::R_390_TLS_DTPMOD:
    case elfcpp::R_390_TLS_DTPOFF:
    case elfcpp::R_390_TLS_TPOFF:
      object->error(_("unexpected reloc %u in object file"), r_type);
      return 0;

    default:
      object->error(_("unsupported reloc %u in object file"), r_type);
      return 0;
    }
}

// Scan the relocs during a relocatable link.

template<int size>
void
Target_s390<size>::scan_relocatable_relocs(
    Symbol_table* symtab,
    Layout* layout,
    Sized_relobj_file<size, true>* object,
    unsigned int data_shndx,
    unsigned int sh_type,
    const unsigned char* prelocs,
    size_t reloc_count,
    Output_section* output_section,
    bool needs_special_offset_handling,
    size_t local_symbol_count,
    const unsigned char* plocal_symbols,
    Relocatable_relocs* rr)
{
  gold_assert(sh_type == elfcpp::SHT_RELA);

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

  gold::scan_relocatable_relocs<size, true, elfcpp::SHT_RELA,
      Scan_relocatable_relocs>(
    symtab,
    layout,
    object,
    data_shndx,
    prelocs,
    reloc_count,
    output_section,
    needs_special_offset_handling,
    local_symbol_count,
    plocal_symbols,
    rr);
}

// Relocate a section during a relocatable link.

template<int size>
void
Target_s390<size>::relocate_relocs(
    const Relocate_info<size, true>* relinfo,
    unsigned int sh_type,
    const unsigned char* prelocs,
    size_t reloc_count,
    Output_section* output_section,
    typename elfcpp::Elf_types<size>::Elf_Off offset_in_output_section,
    const Relocatable_relocs* rr,
    unsigned char* view,
    typename elfcpp::Elf_types<size>::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_RELA);

  gold::relocate_relocs<size, true, elfcpp::SHT_RELA>(
    relinfo,
    prelocs,
    reloc_count,
    output_section,
    offset_in_output_section,
    rr,
    view,
    view_address,
    view_size,
    reloc_view,
    reloc_view_size);
}

// Return the offset to use for the GOT_INDX'th got entry which is
// for a local tls symbol specified by OBJECT, SYMNDX.
template<int size>
int64_t
Target_s390<size>::do_tls_offset_for_local(
    const Relobj*,
    unsigned int,
    unsigned int) const
{
  // The only way we can get called is when IEENT/GOTIE12/GOTIE20
  // couldn't be optimised to LE.
  Output_segment* tls_segment = layout_->tls_segment();
  return -tls_segment->memsz();
}

// Return the offset to use for the GOT_INDX'th got entry which is
// for global tls symbol GSYM.
template<int size>
int64_t
Target_s390<size>::do_tls_offset_for_global(
    Symbol*,
    unsigned int) const
{
  Output_segment* tls_segment = layout_->tls_segment();
  return -tls_segment->memsz();
}

// 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.

template<int size>
uint64_t
Target_s390<size>::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.

template<int size>
std::string
Target_s390<size>::do_code_fill(section_size_type length) const
{
  if (length & 1)
    gold_warning(_("S/390 code fill of odd length requested"));
  return std::string(length, static_cast<char>(0x07));
}

// Relocate section data.

template<int size>
void
Target_s390<size>::relocate_section(
    const Relocate_info<size, true>* 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,
    typename elfcpp::Elf_types<size>::Elf_Addr address,
    section_size_type view_size,
    const Reloc_symbol_changes* reloc_symbol_changes)
{
  gold_assert(sh_type == elfcpp::SHT_RELA);

  gold::relocate_section<size, true, Target_s390<size>, elfcpp::SHT_RELA,
                         typename Target_s390<size>::Relocate,
                         gold::Default_comdat_behavior>(
    relinfo,
    this,
    prelocs,
    reloc_count,
    output_section,
    needs_special_offset_handling,
    view,
    address,
    view_size,
    reloc_symbol_changes);
}

// Apply an incremental relocation.  Incremental relocations always refer
// to global symbols.

template<int size>
void
Target_s390<size>::apply_relocation(
    const Relocate_info<size, true>* relinfo,
    typename elfcpp::Elf_types<size>::Elf_Addr r_offset,
    unsigned int r_type,
    typename elfcpp::Elf_types<size>::Elf_Swxword r_addend,
    const Symbol* gsym,
    unsigned char* view,
    typename elfcpp::Elf_types<size>::Elf_Addr address,
    section_size_type view_size)
{
  gold::apply_relocation<size, true, Target_s390<size>,
                         typename Target_s390<size>::Relocate>(
    relinfo,
    this,
    r_offset,
    r_type,
    r_addend,
    gsym,
    view,
    address,
    view_size);
}

// The selector for s390 object files.

template<int size>
class Target_selector_s390 : public Target_selector
{
public:
  Target_selector_s390()
    : Target_selector(elfcpp::EM_S390, size, true,
                      (size == 64 ? "elf64-s390" : "elf32-s390"),
                      (size == 64 ? "elf64_s390" : "elf32_s390"))
  { }

  virtual Target*
  do_instantiate_target()
  { return new Target_s390<size>(); }
};

Target_selector_s390<32> target_selector_s390;
Target_selector_s390<64> target_selector_s390x;

} // End anonymous namespace.