2001-05-25 H.J. Lu <hjl@gnu.org>

[binutils.git] / bfd / elf32-i370.c

/* i370-specific support for 32-bit ELF
   Copyright 1994, 1995, 1996, 1997, 1998, 2000, 2001
   Free Software Foundation, Inc.
   Written by Ian Lance Taylor, Cygnus Support.
   Hacked by Linas Vepstas for i370 linas@linas.org

This file is part of BFD, the Binary File Descriptor library.

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 2 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

/* This file is based on a preliminary PowerPC ELF ABI.
   But its been hacked on for the IBM 360/370 architectures.
   Basically, the 31bit relocation works, and just about everything
   else is a wild card.  In particular, don't expect shared libs or
   dynamic loading to work ...  its never been tested ...
*/

#include "bfd.h"
#include "sysdep.h"
#include "bfdlink.h"
#include "libbfd.h"
#include "elf-bfd.h"
#include "elf/i370.h"

#define USE_RELA                /* we want RELA relocations, not REL */

/* i370 relocations */
/* Note that there is really just one relocation that we currently
 * support (and only one that we seem to need, at the moment), and
 * that is the 31-bit address relocation.  Note that the 370/390
 * only supports a 31-bit (2GB) address space.
 */
enum i370_reloc_type
{
  R_I370_NONE           =   0,
  R_I370_ADDR31         =   1,
  R_I370_ADDR32         =   2,
  R_I370_ADDR16         =   3,
  R_I370_REL31          =   4,
  R_I370_REL32          =   5,
  R_I370_ADDR12         =   6,
  R_I370_REL12          =   7,
  R_I370_ADDR8          =   8,
  R_I370_REL8           =   9,
  R_I370_COPY           =  10,
  R_I370_RELATIVE       =  11,

  R_I370_max
};
\f
static reloc_howto_type *i370_elf_howto_table[ (int)R_I370_max ];

static reloc_howto_type i370_elf_howto_raw[] =
{
  /* This reloc does nothing.  */
  HOWTO (R_I370_NONE,           /* type */
         0,                     /* rightshift */
         2,                     /* size (0 = byte, 1 = short, 2 = long) */
         32,                    /* bitsize */
         false,                 /* pc_relative */
         0,                     /* bitpos */
         complain_overflow_bitfield, /* complain_on_overflow */
         bfd_elf_generic_reloc, /* special_function */
         "R_I370_NONE",         /* name */
         false,                 /* partial_inplace */
         0,                     /* src_mask */
         0,                     /* dst_mask */
         false),                /* pcrel_offset */

  /* A standard 31 bit relocation.  */
  HOWTO (R_I370_ADDR31,         /* type */
         0,                     /* rightshift */
         2,                     /* size (0 = byte, 1 = short, 2 = long) */
         31,                    /* bitsize */
         false,                 /* pc_relative */
         0,                     /* bitpos */
         complain_overflow_bitfield, /* complain_on_overflow */
         bfd_elf_generic_reloc, /* special_function */
         "R_I370_ADDR31",       /* name */
         false,                 /* partial_inplace */
         0,                     /* src_mask */
         0x7fffffff,            /* dst_mask */
         false),                /* pcrel_offset */

  /* A standard 32 bit relocation.  */
  HOWTO (R_I370_ADDR32,         /* type */
         0,                     /* rightshift */
         2,                     /* size (0 = byte, 1 = short, 2 = long) */
         32,                    /* bitsize */
         false,                 /* pc_relative */
         0,                     /* bitpos */
         complain_overflow_bitfield, /* complain_on_overflow */
         bfd_elf_generic_reloc, /* special_function */
         "R_I370_ADDR32",       /* name */
         false,                 /* partial_inplace */
         0,                     /* src_mask */
         0xffffffff,            /* dst_mask */
         false),                /* pcrel_offset */

  /* A standard 16 bit relocation.  */
  HOWTO (R_I370_ADDR16,         /* type */
         0,                     /* rightshift */
         1,                     /* size (0 = byte, 1 = short, 2 = long) */
         16,                    /* bitsize */
         false,                 /* pc_relative */
         0,                     /* bitpos */
         complain_overflow_bitfield, /* complain_on_overflow */
         bfd_elf_generic_reloc, /* special_function */
         "R_I370_ADDR16",       /* name */
         false,                 /* partial_inplace */
         0,                     /* src_mask */
         0xffff,                /* dst_mask */
         false),                /* pcrel_offset */

  /* 31-bit PC relative */
  HOWTO (R_I370_REL31,          /* type */
         0,                     /* rightshift */
         2,                     /* size (0 = byte, 1 = short, 2 = long) */
         31,                    /* bitsize */
         true,                  /* pc_relative */
         0,                     /* bitpos */
         complain_overflow_bitfield, /* complain_on_overflow */
         bfd_elf_generic_reloc, /* special_function */
         "R_I370_REL31",        /* name */
         false,                 /* partial_inplace */
         0,                     /* src_mask */
         0x7fffffff,            /* dst_mask */
         true),                 /* pcrel_offset */

  /* 32-bit PC relative */
  HOWTO (R_I370_REL32,          /* type */
         0,                     /* rightshift */
         2,                     /* size (0 = byte, 1 = short, 2 = long) */
         32,                    /* bitsize */
         true,                  /* pc_relative */
         0,                     /* bitpos */
         complain_overflow_bitfield, /* complain_on_overflow */
         bfd_elf_generic_reloc, /* special_function */
         "R_I370_REL32",        /* name */
         false,                 /* partial_inplace */
         0,                     /* src_mask */
         0xffffffff,            /* dst_mask */
         true),                 /* pcrel_offset */

  /* A standard 12 bit relocation.  */
  HOWTO (R_I370_ADDR12,         /* type */
         0,                     /* rightshift */
         1,                     /* size (0 = byte, 1 = short, 2 = long) */
         12,                    /* bitsize */
         false,                 /* pc_relative */
         0,                     /* bitpos */
         complain_overflow_bitfield, /* complain_on_overflow */
         bfd_elf_generic_reloc, /* special_function */
         "R_I370_ADDR12",       /* name */
         false,                 /* partial_inplace */
         0,                     /* src_mask */
         0xfff,                 /* dst_mask */
         false),                /* pcrel_offset */

  /* 12-bit PC relative */
  HOWTO (R_I370_REL12,          /* type */
         0,                     /* rightshift */
         1,                     /* size (0 = byte, 1 = short, 2 = long) */
         12,                    /* bitsize */
         true,                  /* pc_relative */
         0,                     /* bitpos */
         complain_overflow_bitfield, /* complain_on_overflow */
         bfd_elf_generic_reloc, /* special_function */
         "R_I370_REL12",        /* name */
         false,                 /* partial_inplace */
         0,                     /* src_mask */
         0xfff,                 /* dst_mask */
         true),                 /* pcrel_offset */

  /* A standard 8 bit relocation.  */
  HOWTO (R_I370_ADDR8,          /* type */
         0,                     /* rightshift */
         0,                     /* size (0 = byte, 1 = short, 2 = long) */
         8,                     /* bitsize */
         false,                 /* pc_relative */
         0,                     /* bitpos */
         complain_overflow_bitfield, /* complain_on_overflow */
         bfd_elf_generic_reloc, /* special_function */
         "R_I370_ADDR8",        /* name */
         false,                 /* partial_inplace */
         0,                     /* src_mask */
         0xff,                  /* dst_mask */
         false),                /* pcrel_offset */

  /* 8-bit PC relative */
  HOWTO (R_I370_REL8,           /* type */
         0,                     /* rightshift */
         0,                     /* size (0 = byte, 1 = short, 2 = long) */
         8,                     /* bitsize */
         true,                  /* pc_relative */
         0,                     /* bitpos */
         complain_overflow_bitfield, /* complain_on_overflow */
         bfd_elf_generic_reloc, /* special_function */
         "R_I370_REL8",         /* name */
         false,                 /* partial_inplace */
         0,                     /* src_mask */
         0xff,                  /* dst_mask */
         true),                 /* pcrel_offset */

  /* This is used only by the dynamic linker.  The symbol should exist
     both in the object being run and in some shared library.  The
     dynamic linker copies the data addressed by the symbol from the
     shared library into the object, because the object being
     run has to have the data at some particular address.  */
  HOWTO (R_I370_COPY,           /* type */
         0,                     /* rightshift */
         2,                     /* size (0 = byte, 1 = short, 2 = long) */
         32,                    /* bitsize */
         false,                 /* pc_relative */
         0,                     /* bitpos */
         complain_overflow_bitfield, /* complain_on_overflow */
         bfd_elf_generic_reloc,  /* special_function */
         "R_I370_COPY",         /* name */
         false,                 /* partial_inplace */
         0,                     /* src_mask */
         0,                     /* dst_mask */
         false),                /* pcrel_offset */

  /* Used only by the dynamic linker.  When the object is run, this
     longword is set to the load address of the object, plus the
     addend.  */
  HOWTO (R_I370_RELATIVE,       /* type */
         0,                     /* rightshift */
         2,                     /* size (0 = byte, 1 = short, 2 = long) */
         32,                    /* bitsize */
         false,                 /* pc_relative */
         0,                     /* bitpos */
         complain_overflow_bitfield, /* complain_on_overflow */
         bfd_elf_generic_reloc,  /* special_function */
         "R_I370_RELATIVE",     /* name */
         false,                 /* partial_inplace */
         0,                     /* src_mask */
         0xffffffff,            /* dst_mask */
         false),                /* pcrel_offset */

};
\f
static void i370_elf_howto_init PARAMS ((void));
static void i370_elf_info_to_howto PARAMS ((bfd *abfd, arelent *cache_ptr,
                                            Elf32_Internal_Rela *dst));
static boolean i370_elf_set_private_flags PARAMS ((bfd *, flagword));
\f
/* Initialize the i370_elf_howto_table, so that linear accesses can be done.  */

static void
i370_elf_howto_init ()
{
  unsigned int i, type;

  for (i = 0; i < sizeof (i370_elf_howto_raw) / sizeof (i370_elf_howto_raw[0]); i++)
    {
      type = i370_elf_howto_raw[i].type;
      BFD_ASSERT (type < sizeof (i370_elf_howto_table) / sizeof (i370_elf_howto_table[0]));
      i370_elf_howto_table[type] = &i370_elf_howto_raw[i];
    }
}
\f
static reloc_howto_type *
i370_elf_reloc_type_lookup (abfd, code)
     bfd *abfd ATTRIBUTE_UNUSED;
     bfd_reloc_code_real_type code;
{
  enum i370_reloc_type i370_reloc = R_I370_NONE;

  if (!i370_elf_howto_table[ R_I370_ADDR31 ])   /* Initialize howto table if needed */
    i370_elf_howto_init ();

  switch ((int)code)
    {
    default:
      return (reloc_howto_type *)NULL;

    case BFD_RELOC_NONE:        i370_reloc = R_I370_NONE;       break;
    case BFD_RELOC_32:          i370_reloc = R_I370_ADDR31;     break;
    case BFD_RELOC_16:          i370_reloc = R_I370_ADDR16;     break;
    case BFD_RELOC_32_PCREL:    i370_reloc = R_I370_REL31;      break;
    case BFD_RELOC_CTOR:        i370_reloc = R_I370_ADDR31;     break;
    case BFD_RELOC_I370_D12:    i370_reloc = R_I370_ADDR12;     break;
    }

  return i370_elf_howto_table[ (int)i370_reloc ];
};

static boolean i370_elf_copy_private_bfd_data PARAMS ((bfd *, bfd *));
static boolean i370_elf_merge_private_bfd_data PARAMS ((bfd *, bfd *));

static boolean i370_elf_relocate_section PARAMS ((bfd *,
                                                  struct bfd_link_info *info,
                                                  bfd *,
                                                  asection *,
                                                  bfd_byte *,
                                                  Elf_Internal_Rela *relocs,
                                                  Elf_Internal_Sym *local_syms,
                                                  asection **));

static boolean i370_elf_create_dynamic_sections PARAMS ((bfd *,
                                                         struct bfd_link_info *));

static boolean i370_elf_section_from_shdr PARAMS ((bfd *,
                                                   Elf32_Internal_Shdr *,
                                                   char *));
static boolean i370_elf_fake_sections PARAMS ((bfd *,
                                               Elf32_Internal_Shdr *,
                                               asection *));
#if 0
static elf_linker_section_t *i370_elf_create_linker_section
  PARAMS ((bfd *abfd,
           struct bfd_link_info *info,
           enum elf_linker_section_enum));
#endif
static boolean i370_elf_check_relocs PARAMS ((bfd *,
                                             struct bfd_link_info *,
                                             asection *,
                                             const Elf_Internal_Rela *));

static boolean i370_elf_adjust_dynamic_symbol PARAMS ((struct bfd_link_info *,
                                                      struct elf_link_hash_entry *));

static boolean i370_elf_adjust_dynindx PARAMS ((struct elf_link_hash_entry *, PTR));

static boolean i370_elf_size_dynamic_sections PARAMS ((bfd *, struct bfd_link_info *));

static boolean i370_elf_finish_dynamic_sections PARAMS ((bfd *, struct bfd_link_info *));

/* The name of the dynamic interpreter.  This is put in the .interp
    section.  */

#define ELF_DYNAMIC_INTERPRETER "/lib/ld.so"

/* Set the howto pointer for an i370 ELF reloc.  */

static void
i370_elf_info_to_howto (abfd, cache_ptr, dst)
     bfd *abfd ATTRIBUTE_UNUSED;
     arelent *cache_ptr;
     Elf32_Internal_Rela *dst;
{
  if (!i370_elf_howto_table[ R_I370_ADDR31 ])   /* Initialize howto table */
    i370_elf_howto_init ();

  BFD_ASSERT (ELF32_R_TYPE (dst->r_info) < (unsigned int) R_I370_max);
  cache_ptr->howto = i370_elf_howto_table[ELF32_R_TYPE (dst->r_info)];
}

/* hack alert --  the following several routines look generic to me ...
 * why are we bothering with them ???
 */
/* Function to set whether a module needs the -mrelocatable bit set.  */
static boolean
i370_elf_set_private_flags (abfd, flags)
     bfd *abfd;
     flagword flags;
{
  BFD_ASSERT (!elf_flags_init (abfd)
              || elf_elfheader (abfd)->e_flags == flags);

  elf_elfheader (abfd)->e_flags = flags;
  elf_flags_init (abfd) = true;
  return true;
}

/* Copy backend specific data from one object module to another */
static boolean
i370_elf_copy_private_bfd_data (ibfd, obfd)
     bfd *ibfd;
     bfd *obfd;
{
  if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour
      || bfd_get_flavour (obfd) != bfd_target_elf_flavour)
    return true;

  BFD_ASSERT (!elf_flags_init (obfd)
              || elf_elfheader (obfd)->e_flags == elf_elfheader (ibfd)->e_flags);

  elf_elfheader (obfd)->e_flags = elf_elfheader (ibfd)->e_flags;
  elf_flags_init (obfd) = true;
  return true;
}

/* Merge backend specific data from an object file to the output
   object file when linking */
static boolean
i370_elf_merge_private_bfd_data (ibfd, obfd)
     bfd *ibfd;
     bfd *obfd;
{
  flagword old_flags;
  flagword new_flags;

  if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour
      || bfd_get_flavour (obfd) != bfd_target_elf_flavour)
    return true;

  new_flags = elf_elfheader (ibfd)->e_flags;
  old_flags = elf_elfheader (obfd)->e_flags;
  if (!elf_flags_init (obfd))   /* First call, no flags set */
    {
      elf_flags_init (obfd) = true;
      elf_elfheader (obfd)->e_flags = new_flags;
    }

  else if (new_flags == old_flags)      /* Compatible flags are ok */
    ;

  else                                  /* Incompatible flags */
    {
      (*_bfd_error_handler)
        ("%s: uses different e_flags (0x%lx) fields than previous modules (0x%lx)",
         bfd_get_filename (ibfd), (long)new_flags, (long)old_flags);

      bfd_set_error (bfd_error_bad_value);
      return false;
    }

  return true;
}
\f
/* Handle an i370 specific section when reading an object file.  This
   is called when elfcode.h finds a section with an unknown type.  */
/* XXX hack alert bogus This routine is mostly all junk and almost
 * certainly does the wrong thing.  Its here simply because it does
 * just enough to allow glibc-2.1 ld.so to compile & link.
 */

static boolean
i370_elf_section_from_shdr (abfd, hdr, name)
     bfd *abfd;
     Elf32_Internal_Shdr *hdr;
     char *name;
{
  asection *newsect;
  flagword flags;

  if (! _bfd_elf_make_section_from_shdr (abfd, hdr, name))
    return false;

  newsect = hdr->bfd_section;
  flags = bfd_get_section_flags (abfd, newsect);
  if (hdr->sh_flags & SHF_EXCLUDE)
    flags |= SEC_EXCLUDE;

  if (hdr->sh_type == SHT_ORDERED)
    flags |= SEC_SORT_ENTRIES;

  bfd_set_section_flags (abfd, newsect, flags);
  return true;
}
\f
/* Set up any other section flags and such that may be necessary.  */
/* XXX hack alert bogus This routine is mostly all junk and almost
 * certainly does the wrong thing.  Its here simply because it does
 * just enough to allow glibc-2.1 ld.so to compile & link.
 */

static boolean
i370_elf_fake_sections (abfd, shdr, asect)
     bfd *abfd ATTRIBUTE_UNUSED;
     Elf32_Internal_Shdr *shdr;
     asection *asect;
{
  if ((asect->flags & SEC_EXCLUDE) != 0)
    shdr->sh_flags |= SHF_EXCLUDE;

  if ((asect->flags & SEC_SORT_ENTRIES) != 0)
    shdr->sh_type = SHT_ORDERED;

  return true;
}
\f
#if 0
/* Create a special linker section */
/* XXX hack alert bogus This routine is mostly all junk and almost
 * certainly does the wrong thing.  Its here simply because it does
 * just enough to allow glibc-2.1 ld.so to compile & link.
 */

static elf_linker_section_t *
i370_elf_create_linker_section (abfd, info, which)
     bfd *abfd;
     struct bfd_link_info *info;
     enum elf_linker_section_enum which;
{
  bfd *dynobj = elf_hash_table (info)->dynobj;
  elf_linker_section_t *lsect;

  /* Record the first bfd section that needs the special section */
  if (!dynobj)
    dynobj = elf_hash_table (info)->dynobj = abfd;

  /* If this is the first time, create the section */
  lsect = elf_linker_section (dynobj, which);
  if (!lsect)
    {
      elf_linker_section_t defaults;
      static elf_linker_section_t zero_section;

      defaults = zero_section;
      defaults.which = which;
      defaults.hole_written_p = false;
      defaults.alignment = 2;

      /* Both of these sections are (technically) created by the user
         putting data in them, so they shouldn't be marked
         SEC_LINKER_CREATED.

         The linker creates them so it has somewhere to attach their
         respective symbols. In fact, if they were empty it would
         be OK to leave the symbol set to 0 (or any random number), because
         the appropriate register should never be used.  */
      defaults.flags = (SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS
                        | SEC_IN_MEMORY);

      switch (which)
        {
        default:
          (*_bfd_error_handler) ("%s: Unknown special linker type %d",
                                 bfd_get_filename (abfd),
                                 (int)which);

          bfd_set_error (bfd_error_bad_value);
          return (elf_linker_section_t *)0;

        case LINKER_SECTION_SDATA:      /* .sdata/.sbss section */
          defaults.name           = ".sdata";
          defaults.rel_name       = ".rela.sdata";
          defaults.bss_name       = ".sbss";
          defaults.sym_name       = "_SDA_BASE_";
          defaults.sym_offset     = 32768;
          break;

        case LINKER_SECTION_SDATA2:     /* .sdata2/.sbss2 section */
          defaults.name           = ".sdata2";
          defaults.rel_name       = ".rela.sdata2";
          defaults.bss_name       = ".sbss2";
          defaults.sym_name       = "_SDA2_BASE_";
          defaults.sym_offset     = 32768;
          defaults.flags         |= SEC_READONLY;
          break;
        }

      lsect = _bfd_elf_create_linker_section (abfd, info, which, &defaults);
    }

  return lsect;
}
#endif
\f
/* We have to create .dynsbss and .rela.sbss here so that they get mapped
   to output sections (just like _bfd_elf_create_dynamic_sections has
   to create .dynbss and .rela.bss).  */
/* XXX hack alert bogus This routine is mostly all junk and almost
 * certainly does the wrong thing.  Its here simply because it does
 * just enough to allow glibc-2.1 ld.so to compile & link.
 */

static boolean
i370_elf_create_dynamic_sections (abfd, info)
     bfd *abfd;
     struct bfd_link_info *info;
{
  register asection *s;
  flagword flags;

  if (!_bfd_elf_create_dynamic_sections(abfd, info))
    return false;

  flags = (SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS | SEC_IN_MEMORY
           | SEC_LINKER_CREATED);

  s = bfd_make_section (abfd, ".dynsbss");
  if (s == NULL
      || ! bfd_set_section_flags (abfd, s, SEC_ALLOC))
    return false;

  if (! info->shared)
    {
      s = bfd_make_section (abfd, ".rela.sbss");
      if (s == NULL
          || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
          || ! bfd_set_section_alignment (abfd, s, 2))
        return false;
    }

   /* xxx beats me, seem to need a rela.text ...  */
   s = bfd_make_section (abfd, ".rela.text");
   if (s == NULL
      || ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
      || ! bfd_set_section_alignment (abfd, s, 2))
    return false;
  return true;
}

/* Adjust a symbol defined by a dynamic object and referenced by a
   regular object.  The current definition is in some section of the
   dynamic object, but we're not including those sections.  We have to
   change the definition to something the rest of the link can
   understand.  */
/* XXX hack alert bogus This routine is mostly all junk and almost
 * certainly does the wrong thing.  Its here simply because it does
 * just enough to allow glibc-2.1 ld.so to compile & link.
 */

static boolean
i370_elf_adjust_dynamic_symbol (info, h)
     struct bfd_link_info *info;
     struct elf_link_hash_entry *h;
{
  bfd *dynobj = elf_hash_table (info)->dynobj;
  asection *s;
  unsigned int power_of_two;

#ifdef DEBUG
  fprintf (stderr, "i370_elf_adjust_dynamic_symbol called for %s\n",
           h->root.root.string);
#endif

  /* Make sure we know what is going on here.  */
  BFD_ASSERT (dynobj != NULL
              && ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT)
                  || h->weakdef != NULL
                  || ((h->elf_link_hash_flags
                       & ELF_LINK_HASH_DEF_DYNAMIC) != 0
                      && (h->elf_link_hash_flags
                          & ELF_LINK_HASH_REF_REGULAR) != 0
                      && (h->elf_link_hash_flags
                          & ELF_LINK_HASH_DEF_REGULAR) == 0)));

  s = bfd_get_section_by_name (dynobj, ".rela.text");
  BFD_ASSERT (s != NULL);
  s->_raw_size += sizeof (Elf32_External_Rela);

  /* If this is a weak symbol, and there is a real definition, the
     processor independent code will have arranged for us to see the
     real definition first, and we can just use the same value.  */
  if (h->weakdef != NULL)
    {
      BFD_ASSERT (h->weakdef->root.type == bfd_link_hash_defined
                  || h->weakdef->root.type == bfd_link_hash_defweak);
      h->root.u.def.section = h->weakdef->root.u.def.section;
      h->root.u.def.value = h->weakdef->root.u.def.value;
      return true;
    }

  /* This is a reference to a symbol defined by a dynamic object which
     is not a function.  */

  /* If we are creating a shared library, we must presume that the
     only references to the symbol are via the global offset table.
     For such cases we need not do anything here; the relocations will
     be handled correctly by relocate_section.  */
  if (info->shared)
    return true;

  /* We must allocate the symbol in our .dynbss section, which will
     become part of the .bss section of the executable.  There will be
     an entry for this symbol in the .dynsym section.  The dynamic
     object will contain position independent code, so all references
     from the dynamic object to this symbol will go through the global
     offset table.  The dynamic linker will use the .dynsym entry to
     determine the address it must put in the global offset table, so
     both the dynamic object and the regular object will refer to the
     same memory location for the variable.

     Of course, if the symbol is sufficiently small, we must instead
     allocate it in .sbss.  FIXME: It would be better to do this if and
     only if there were actually SDAREL relocs for that symbol.  */

  if (h->size <= elf_gp_size (dynobj))
    s = bfd_get_section_by_name (dynobj, ".dynsbss");
  else
    s = bfd_get_section_by_name (dynobj, ".dynbss");
  BFD_ASSERT (s != NULL);

  /* We must generate a R_I370_COPY reloc to tell the dynamic linker to
     copy the initial value out of the dynamic object and into the
     runtime process image.  We need to remember the offset into the
     .rela.bss section we are going to use.  */
  if ((h->root.u.def.section->flags & SEC_ALLOC) != 0)
    {
      asection *srel;

      if (h->size <= elf_gp_size (dynobj))
        srel = bfd_get_section_by_name (dynobj, ".rela.sbss");
      else
        srel = bfd_get_section_by_name (dynobj, ".rela.bss");
      BFD_ASSERT (srel != NULL);
      srel->_raw_size += sizeof (Elf32_External_Rela);
      h->elf_link_hash_flags |= ELF_LINK_HASH_NEEDS_COPY;
    }

  /* We need to figure out the alignment required for this symbol.  I
     have no idea how ELF linkers handle this.  */
  power_of_two = bfd_log2 (h->size);
  if (power_of_two > 4)
    power_of_two = 4;

  /* Apply the required alignment.  */
  s->_raw_size = BFD_ALIGN (s->_raw_size,
                            (bfd_size_type) (1 << power_of_two));
  if (power_of_two > bfd_get_section_alignment (dynobj, s))
    {
      if (! bfd_set_section_alignment (dynobj, s, power_of_two))
        return false;
    }

  /* Define the symbol as being at this point in the section.  */
  h->root.u.def.section = s;
  h->root.u.def.value = s->_raw_size;

  /* Increment the section size to make room for the symbol.  */
  s->_raw_size += h->size;

  return true;
}
\f
/* Increment the index of a dynamic symbol by a given amount.  Called
   via elf_link_hash_traverse.  */
/* XXX hack alert bogus This routine is mostly all junk and almost
 * certainly does the wrong thing.  Its here simply because it does
 * just enough to allow glibc-2.1 ld.so to compile & link.
 */

static boolean
i370_elf_adjust_dynindx (h, cparg)
     struct elf_link_hash_entry *h;
     PTR cparg;
{
  int *cp = (int *) cparg;

#ifdef DEBUG
  fprintf (stderr,
           "i370_elf_adjust_dynindx called, h->dynindx = %d, *cp = %d\n",
           h->dynindx, *cp);
#endif

  if (h->dynindx != -1)
    h->dynindx += *cp;

  return true;
}
\f
/* Set the sizes of the dynamic sections.  */
/* XXX hack alert bogus This routine is mostly all junk and almost
 * certainly does the wrong thing.  Its here simply because it does
 * just enough to allow glibc-2.1 ld.so to compile & link.
 */

static boolean
i370_elf_size_dynamic_sections (output_bfd, info)
     bfd *output_bfd;
     struct bfd_link_info *info;
{
  bfd *dynobj;
  asection *s;
  boolean plt;
  boolean relocs;
  boolean reltext;

#ifdef DEBUG
  fprintf (stderr, "i370_elf_size_dynamic_sections called\n");
#endif

  dynobj = elf_hash_table (info)->dynobj;
  BFD_ASSERT (dynobj != NULL);

  if (elf_hash_table (info)->dynamic_sections_created)
    {
      /* Set the contents of the .interp section to the interpreter.  */
      if (! info->shared)
        {
          s = bfd_get_section_by_name (dynobj, ".interp");
          BFD_ASSERT (s != NULL);
          s->_raw_size = sizeof ELF_DYNAMIC_INTERPRETER;
          s->contents = (unsigned char *) ELF_DYNAMIC_INTERPRETER;
        }
    }
  else
    {
      /* We may have created entries in the .rela.got, .rela.sdata, and
         .rela.sdata2 sections.  However, if we are not creating the
         dynamic sections, we will not actually use these entries.  Reset
         the size of .rela.got, et al, which will cause it to get
         stripped from the output file below.  */
      static char *rela_sections[] = { ".rela.got", ".rela.sdata",
                                       ".rela.sdata2", ".rela.sbss",
                                       (char *)0 };
      char **p;

      for (p = rela_sections; *p != (char *)0; p++)
        {
          s = bfd_get_section_by_name (dynobj, *p);
          if (s != NULL)
            s->_raw_size = 0;
        }
    }

  /* The check_relocs and adjust_dynamic_symbol entry points have
     determined the sizes of the various dynamic sections.  Allocate
     memory for them.  */
  plt = false;
  relocs = false;
  reltext = false;
  for (s = dynobj->sections; s != NULL; s = s->next)
    {
      const char *name;
      boolean strip;

      if ((s->flags & SEC_LINKER_CREATED) == 0)
        continue;

      /* It's OK to base decisions on the section name, because none
         of the dynobj section names depend upon the input files.  */
      name = bfd_get_section_name (dynobj, s);
      strip = false;

      if (strcmp (name, ".plt") == 0)
        {
          if (s->_raw_size == 0)
            {
              /* Strip this section if we don't need it; see the
                 comment below.  */
              strip = true;
            }
          else
            {
              /* Remember whether there is a PLT.  */
              plt = true;
            }
        }
      else if (strncmp (name, ".rela", 5) == 0)
        {
          if (s->_raw_size == 0)
            {
              /* If we don't need this section, strip it from the
                 output file.  This is mostly to handle .rela.bss and
                 .rela.plt.  We must create both sections in
                 create_dynamic_sections, because they must be created
                 before the linker maps input sections to output
                 sections.  The linker does that before
                 adjust_dynamic_symbol is called, and it is that
                 function which decides whether anything needs to go
                 into these sections.  */
              strip = true;
            }
          else
            {
              asection *target;
              const char *outname;

              /* Remember whether there are any relocation sections.  */
              relocs = true;

              /* If this relocation section applies to a read only
                 section, then we probably need a DT_TEXTREL entry.  */
              outname = bfd_get_section_name (output_bfd,
                                              s->output_section);
              target = bfd_get_section_by_name (output_bfd, outname + 5);
              if (target != NULL
                  && (target->flags & SEC_READONLY) != 0
                  && (target->flags & SEC_ALLOC) != 0)
                reltext = true;

              /* We use the reloc_count field as a counter if we need
                 to copy relocs into the output file.  */
              s->reloc_count = 0;
            }
        }
      else if (strcmp (name, ".got") != 0
               && strcmp (name, ".sdata") != 0
               && strcmp (name, ".sdata2") != 0)
        {
          /* It's not one of our sections, so don't allocate space.  */
          continue;
        }

      if (strip)
        {
          asection **spp;

          for (spp = &s->output_section->owner->sections;
               *spp != s->output_section;
               spp = &(*spp)->next)
            ;
          *spp = s->output_section->next;
          --s->output_section->owner->section_count;

          continue;
        }
      /* Allocate memory for the section contents.  */
      s->contents = (bfd_byte *) bfd_zalloc (dynobj, s->_raw_size);
      if (s->contents == NULL && s->_raw_size != 0)
        return false;
    }

  if (elf_hash_table (info)->dynamic_sections_created)
    {
      /* Add some entries to the .dynamic section.  We fill in the
         values later, in i370_elf_finish_dynamic_sections, but we
         must add the entries now so that we get the correct size for
         the .dynamic section.  The DT_DEBUG entry is filled in by the
         dynamic linker and used by the debugger.  */
      if (! info->shared)
        {
          if (! bfd_elf32_add_dynamic_entry (info, DT_DEBUG, 0))
            return false;
        }

      if (plt)
        {
          if (! bfd_elf32_add_dynamic_entry (info, DT_PLTGOT, 0)
              || ! bfd_elf32_add_dynamic_entry (info, DT_PLTRELSZ, 0)
              || ! bfd_elf32_add_dynamic_entry (info, DT_PLTREL, DT_RELA)
              || ! bfd_elf32_add_dynamic_entry (info, DT_JMPREL, 0))
            return false;
        }

      if (relocs)
        {
          if (! bfd_elf32_add_dynamic_entry (info, DT_RELA, 0)
              || ! bfd_elf32_add_dynamic_entry (info, DT_RELASZ, 0)
              || ! bfd_elf32_add_dynamic_entry (info, DT_RELAENT,
                                                sizeof (Elf32_External_Rela)))
            return false;
        }

      if (reltext)
        {
          if (! bfd_elf32_add_dynamic_entry (info, DT_TEXTREL, 0))
            return false;
          info->flags |= DF_TEXTREL;
        }
    }

  /* If we are generating a shared library, we generate a section
     symbol for each output section.  These are local symbols, which
     means that they must come first in the dynamic symbol table.
     That means we must increment the dynamic symbol index of every
     other dynamic symbol.

     FIXME: We assume that there will never be relocations to
     locations in linker-created sections that do not have
     externally-visible names. Instead, we should work out precisely
     which sections relocations are targetted at.  */
  if (info->shared)
    {
      int c;

      for (c = 0, s = output_bfd->sections; s != NULL; s = s->next)
        {
          if ((s->flags & SEC_LINKER_CREATED) != 0
              || (s->flags & SEC_ALLOC) == 0)
            {
              elf_section_data (s)->dynindx = -1;
              continue;
            }

          /* These symbols will have no names, so we don't need to
             fiddle with dynstr_index.  */

          elf_section_data (s)->dynindx = c + 1;

          c++;
        }

      elf_link_hash_traverse (elf_hash_table (info),
                              i370_elf_adjust_dynindx,
                              (PTR) &c);
      elf_hash_table (info)->dynsymcount += c;
    }

  return true;
}
\f
/* Look through the relocs for a section during the first phase, and
   allocate space in the global offset table or procedure linkage
   table.  */
/* XXX hack alert bogus This routine is mostly all junk and almost
 * certainly does the wrong thing.  Its here simply because it does
 * just enough to allow glibc-2.1 ld.so to compile & link.
 */

static boolean
i370_elf_check_relocs (abfd, info, sec, relocs)
     bfd *abfd;
     struct bfd_link_info *info;
     asection *sec;
     const Elf_Internal_Rela *relocs;
{
  bfd *dynobj;
  Elf_Internal_Shdr *symtab_hdr;
  struct elf_link_hash_entry **sym_hashes;
  const Elf_Internal_Rela *rel;
  const Elf_Internal_Rela *rel_end;
  bfd_vma *local_got_offsets;
  asection *sreloc;

  if (info->relocateable)
    return true;

#ifdef DEBUG
  fprintf (stderr, "i370_elf_check_relocs called for section %s in %s\n",
           bfd_get_section_name (abfd, sec),
           bfd_get_filename (abfd));
#endif

  dynobj = elf_hash_table (info)->dynobj;
  symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
  sym_hashes = elf_sym_hashes (abfd);
  local_got_offsets = elf_local_got_offsets (abfd);

  sreloc = NULL;

  rel_end = relocs + sec->reloc_count;
  for (rel = relocs; rel < rel_end; rel++)
    {
      unsigned long r_symndx;
      struct elf_link_hash_entry *h;

      r_symndx = ELF32_R_SYM (rel->r_info);
      if (r_symndx < symtab_hdr->sh_info)
        h = NULL;
      else
        h = sym_hashes[r_symndx - symtab_hdr->sh_info];

      if (info->shared)
        {
#ifdef DEBUG
          fprintf (stderr,
                   "i370_elf_check_relocs needs to create relocation for %s\n",
                   (h && h->root.root.string)
                   ? h->root.root.string : "<unknown>");
#endif
          if (sreloc == NULL)
            {
              const char *name;

              name = (bfd_elf_string_from_elf_section
                      (abfd,
                       elf_elfheader (abfd)->e_shstrndx,
                       elf_section_data (sec)->rel_hdr.sh_name));
              if (name == NULL)
                return false;

              BFD_ASSERT (strncmp (name, ".rela", 5) == 0
                          && strcmp (bfd_get_section_name (abfd, sec), name + 5) == 0);

              sreloc = bfd_get_section_by_name (dynobj, name);
              if (sreloc == NULL)
                {
                  flagword flags;

                  sreloc = bfd_make_section (dynobj, name);
                  flags = (SEC_HAS_CONTENTS | SEC_READONLY
                           | SEC_IN_MEMORY | SEC_LINKER_CREATED);
                  if ((sec->flags & SEC_ALLOC) != 0)
                    flags |= SEC_ALLOC | SEC_LOAD;
                  if (sreloc == NULL
                      || ! bfd_set_section_flags (dynobj, sreloc, flags)
                      || ! bfd_set_section_alignment (dynobj, sreloc, 2))
                    return false;
                }
            }

          sreloc->_raw_size += sizeof (Elf32_External_Rela);

          /* FIXME: We should here do what the m68k and i386
             backends do: if the reloc is pc-relative, record it
             in case it turns out that the reloc is unnecessary
             because the symbol is forced local by versioning or
             we are linking with -Bdynamic.  Fortunately this
             case is not frequent.  */
        }
    }

  return true;
}
\f
/* Finish up the dynamic sections.  */
/* XXX hack alert bogus This routine is mostly all junk and almost
 * certainly does the wrong thing.  Its here simply because it does
 * just enough to allow glibc-2.1 ld.so to compile & link.
 */

static boolean
i370_elf_finish_dynamic_sections (output_bfd, info)
     bfd *output_bfd;
     struct bfd_link_info *info;
{
  asection *sdyn;
  bfd *dynobj = elf_hash_table (info)->dynobj;
  asection *sgot = bfd_get_section_by_name (dynobj, ".got");

#ifdef DEBUG
  fprintf (stderr, "i370_elf_finish_dynamic_sections called\n");
#endif

  sdyn = bfd_get_section_by_name (dynobj, ".dynamic");

  if (elf_hash_table (info)->dynamic_sections_created)
    {
      asection *splt;
      Elf32_External_Dyn *dyncon, *dynconend;

      splt = bfd_get_section_by_name (dynobj, ".plt");
      BFD_ASSERT (splt != NULL && sdyn != NULL);

      dyncon = (Elf32_External_Dyn *) sdyn->contents;
      dynconend = (Elf32_External_Dyn *) (sdyn->contents + sdyn->_raw_size);
      for (; dyncon < dynconend; dyncon++)
        {
          Elf_Internal_Dyn dyn;
          const char *name;
          boolean size;

          bfd_elf32_swap_dyn_in (dynobj, dyncon, &dyn);

          switch (dyn.d_tag)
            {
            case DT_PLTGOT:   name = ".plt";      size = false; break;
            case DT_PLTRELSZ: name = ".rela.plt"; size = true;  break;
            case DT_JMPREL:   name = ".rela.plt"; size = false; break;
            default:          name = NULL;        size = false; break;
            }

          if (name != NULL)
            {
              asection *s;

              s = bfd_get_section_by_name (output_bfd, name);
              if (s == NULL)
                dyn.d_un.d_val = 0;
              else
                {
                  if (! size)
                    dyn.d_un.d_ptr = s->vma;
                  else
                    {
                      if (s->_cooked_size != 0)
                        dyn.d_un.d_val = s->_cooked_size;
                      else
                        dyn.d_un.d_val = s->_raw_size;
                    }
                }
              bfd_elf32_swap_dyn_out (output_bfd, &dyn, dyncon);
            }
        }
    }

  /* Add a blrl instruction at _GLOBAL_OFFSET_TABLE_-4 so that a function can
     easily find the address of the _GLOBAL_OFFSET_TABLE_.  */
/* XXX this is clearly very wrong for the 370 arch */
  if (sgot)
    {
      unsigned char *contents = sgot->contents;
      bfd_put_32 (output_bfd, 0x4e800021 /* blrl */, contents);

      if (sdyn == NULL)
        bfd_put_32 (output_bfd, (bfd_vma) 0, contents+4);
      else
        bfd_put_32 (output_bfd,
                    sdyn->output_section->vma + sdyn->output_offset,
                    contents+4);

      elf_section_data (sgot->output_section)->this_hdr.sh_entsize = 4;
    }

  if (info->shared)
    {
      asection *sdynsym;
      asection *s;
      Elf_Internal_Sym sym;
      int maxdindx = 0;

      /* Set up the section symbols for the output sections.  */

      sdynsym = bfd_get_section_by_name (dynobj, ".dynsym");
      BFD_ASSERT (sdynsym != NULL);

      sym.st_size = 0;
      sym.st_name = 0;
      sym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION);
      sym.st_other = 0;

      for (s = output_bfd->sections; s != NULL; s = s->next)
        {
          int indx, dindx;

          sym.st_value = s->vma;

          indx = elf_section_data (s)->this_idx;
          dindx = elf_section_data (s)->dynindx;
          if (dindx != -1)
            {
              BFD_ASSERT(indx > 0);
              BFD_ASSERT(dindx > 0);

              if (dindx > maxdindx)
                maxdindx = dindx;

              sym.st_shndx = indx;

              bfd_elf32_swap_symbol_out (output_bfd, &sym,
                                         (PTR) (((Elf32_External_Sym *)
                                                 sdynsym->contents)
                                                + dindx));
            }
        }

      /* Set the sh_info field of the output .dynsym section to the
         index of the first global symbol.  */
      elf_section_data (sdynsym->output_section)->this_hdr.sh_info =
        maxdindx + 1;
    }

  return true;
}
\f
/* The RELOCATE_SECTION function is called by the ELF backend linker
   to handle the relocations for a section.

   The relocs are always passed as Rela structures; if the section
   actually uses Rel structures, the r_addend field will always be
   zero.

   This function is responsible for adjust the section contents as
   necessary, and (if using Rela relocs and generating a
   relocateable output file) adjusting the reloc addend as
   necessary.

   This function does not have to worry about setting the reloc
   address or the reloc symbol index.

   LOCAL_SYMS is a pointer to the swapped in local symbols.

   LOCAL_SECTIONS is an array giving the section in the input file
   corresponding to the st_shndx field of each local symbol.

   The global hash table entry for the global symbols can be found
   via elf_sym_hashes (input_bfd).

   When generating relocateable output, this function must handle
   STB_LOCAL/STT_SECTION symbols specially.  The output symbol is
   going to be the section symbol corresponding to the output
   section, which means that the addend must be adjusted
   accordingly.  */

static boolean
i370_elf_relocate_section (output_bfd, info, input_bfd, input_section,
                          contents, relocs, local_syms, local_sections)
     bfd *output_bfd;
     struct bfd_link_info *info;
     bfd *input_bfd;
     asection *input_section;
     bfd_byte *contents;
     Elf_Internal_Rela *relocs;
     Elf_Internal_Sym *local_syms;
     asection **local_sections;
{
  Elf_Internal_Shdr *symtab_hdr           = &elf_tdata (input_bfd)->symtab_hdr;
  struct elf_link_hash_entry **sym_hashes = elf_sym_hashes (input_bfd);
  bfd *dynobj                             = elf_hash_table (info)->dynobj;
  Elf_Internal_Rela *rel                  = relocs;
  Elf_Internal_Rela *relend               = relocs + input_section->reloc_count;
  asection *sreloc                        = NULL;
  bfd_vma *local_got_offsets;
  boolean ret                             = true;

#ifdef DEBUG
  fprintf (stderr, "i370_elf_relocate_section called for %s section %s, %ld relocations%s\n",
           bfd_get_filename (input_bfd),
           bfd_section_name(input_bfd, input_section),
           (long)input_section->reloc_count,
           (info->relocateable) ? " (relocatable)" : "");
#endif

  if (!i370_elf_howto_table[ R_I370_ADDR31 ])   /* Initialize howto table if needed */
    i370_elf_howto_init ();

  local_got_offsets = elf_local_got_offsets (input_bfd);

  for (; rel < relend; rel++)
    {
      enum i370_reloc_type r_type       = (enum i370_reloc_type)ELF32_R_TYPE (rel->r_info);
      bfd_vma offset                    = rel->r_offset;
      bfd_vma addend                    = rel->r_addend;
      bfd_reloc_status_type r           = bfd_reloc_other;
      Elf_Internal_Sym *sym             = (Elf_Internal_Sym *)0;
      asection *sec                     = (asection *)0;
      struct elf_link_hash_entry *h     = (struct elf_link_hash_entry *)0;
      const char *sym_name              = (const char *)0;
      reloc_howto_type *howto;
      unsigned long r_symndx;
      bfd_vma relocation;

      /* Unknown relocation handling */
      if ((unsigned)r_type >= (unsigned)R_I370_max
          || !i370_elf_howto_table[(int)r_type])
        {
          (*_bfd_error_handler) ("%s: unknown relocation type %d",
                                 bfd_get_filename (input_bfd),
                                 (int)r_type);

          bfd_set_error (bfd_error_bad_value);
          ret = false;
          continue;
        }

      howto = i370_elf_howto_table[(int)r_type];
      r_symndx = ELF32_R_SYM (rel->r_info);

      if (info->relocateable)
        {
          /* This is a relocateable link.  We don't have to change
             anything, unless the reloc is against a section symbol,
             in which case we have to adjust according to where the
             section symbol winds up in the output section.  */
          if (r_symndx < symtab_hdr->sh_info)
            {
              sym = local_syms + r_symndx;
              if ((unsigned)ELF_ST_TYPE (sym->st_info) == STT_SECTION)
                {
                  sec = local_sections[r_symndx];
                  addend = rel->r_addend += sec->output_offset + sym->st_value;
                }
            }

#ifdef DEBUG
          fprintf (stderr, "\ttype = %s (%d), symbol index = %ld, offset = %ld, addend = %ld\n",
                   howto->name,
                   (int)r_type,
                   r_symndx,
                   (long)offset,
                   (long)addend);
#endif
          continue;
        }

      /* This is a final link.  */
      if (r_symndx < symtab_hdr->sh_info)
        {
          sym = local_syms + r_symndx;
          sec = local_sections[r_symndx];
          sym_name = "<local symbol>";

          relocation = (sec->output_section->vma
                        + sec->output_offset
                        + sym->st_value);
        }
      else
        {
          h = sym_hashes[r_symndx - symtab_hdr->sh_info];
          while (h->root.type == bfd_link_hash_indirect
                 || h->root.type == bfd_link_hash_warning)
            h = (struct elf_link_hash_entry *) h->root.u.i.link;
          sym_name = h->root.root.string;
          if (h->root.type == bfd_link_hash_defined
              || h->root.type == bfd_link_hash_defweak)
            {
              sec = h->root.u.def.section;
              if (info->shared
                  && ((! info->symbolic && h->dynindx != -1)
                      || (h->elf_link_hash_flags
                          & ELF_LINK_HASH_DEF_REGULAR) == 0)
                  && (input_section->flags & SEC_ALLOC) != 0
                  && (r_type == R_I370_ADDR31
                      || r_type == R_I370_COPY
                      || r_type == R_I370_ADDR16
                      || r_type == R_I370_RELATIVE))
                {
                  /* In these cases, we don't need the relocation
                     value.  We check specially because in some
                     obscure cases sec->output_section will be NULL.  */
                  relocation = 0;
                }
              else
                relocation = (h->root.u.def.value
                              + sec->output_section->vma
                              + sec->output_offset);
            }
          else if (h->root.type == bfd_link_hash_undefweak)
            relocation = 0;
          else if (info->shared
                   && ELF_ST_VISIBILITY (h->other) == STV_DEFAULT)
            relocation = 0;
          else
            {
              (*info->callbacks->undefined_symbol) (info,
                                                    h->root.root.string,
                                                    input_bfd,
                                                    input_section,
                                                    rel->r_offset,
                                                    true);
              ret = false;
              continue;
            }
        }

      switch ((int)r_type)
        {
        default:
          (*_bfd_error_handler) ("%s: unknown relocation type %d for symbol %s",
                                 bfd_get_filename (input_bfd),
                                 (int)r_type, sym_name);

          bfd_set_error (bfd_error_bad_value);
          ret = false;
          continue;

        /* Relocations that may need to be propagated if this is a shared
           object.  */
        case (int)R_I370_REL31:
          /* If these relocations are not to a named symbol, they can be
             handled right here, no need to bother the dynamic linker.  */
          if (h == NULL
              || strcmp (h->root.root.string, "_GLOBAL_OFFSET_TABLE_") == 0)
            break;
        /* fall through */

        /* Relocations that always need to be propagated if this is a shared
           object.  */
        case (int)R_I370_NONE:
        case (int)R_I370_ADDR31:
        case (int)R_I370_ADDR16:
          if (info->shared)
            {
              Elf_Internal_Rela outrel;
              boolean skip;

#ifdef DEBUG
              fprintf (stderr,
                       "i370_elf_relocate_section needs to create relocation for %s\n",
                       (h && h->root.root.string) ? h->root.root.string : "<unknown>");
#endif

              /* When generating a shared object, these relocations
                 are copied into the output file to be resolved at run
                 time.  */

              if (sreloc == NULL)
                {
                  const char *name;

                  name = (bfd_elf_string_from_elf_section
                          (input_bfd,
                           elf_elfheader (input_bfd)->e_shstrndx,
                           elf_section_data (input_section)->rel_hdr.sh_name));
                  if (name == NULL)
                    return false;

                  BFD_ASSERT (strncmp (name, ".rela", 5) == 0
                              && strcmp (bfd_get_section_name (input_bfd,
                                                               input_section),
                                         name + 5) == 0);

                  sreloc = bfd_get_section_by_name (dynobj, name);
                  BFD_ASSERT (sreloc != NULL);
                }

              skip = false;

              if (elf_section_data (input_section)->stab_info == NULL)
                outrel.r_offset = rel->r_offset;
              else
                {
                  bfd_vma off;

                  off = (_bfd_stab_section_offset
                         (output_bfd, &elf_hash_table (info)->stab_info,
                          input_section,
                          &elf_section_data (input_section)->stab_info,
                          rel->r_offset));
                  if (off == (bfd_vma) -1)
                    skip = true;
                  outrel.r_offset = off;
                }

              outrel.r_offset += (input_section->output_section->vma
                                  + input_section->output_offset);

              if (skip)
                memset (&outrel, 0, sizeof outrel);
              /* h->dynindx may be -1 if this symbol was marked to
                 become local.  */
              else if (h != NULL
                       && ((! info->symbolic && h->dynindx != -1)
                           || (h->elf_link_hash_flags
                               & ELF_LINK_HASH_DEF_REGULAR) == 0))
                {
                  BFD_ASSERT (h->dynindx != -1);
                  outrel.r_info = ELF32_R_INFO (h->dynindx, r_type);
                  outrel.r_addend = rel->r_addend;
                }
              else
                {
                  if (r_type == R_I370_ADDR31)
                    {
                      outrel.r_info = ELF32_R_INFO (0, R_I370_RELATIVE);
                      outrel.r_addend = relocation + rel->r_addend;
                    }
                  else
                    {
                      long indx;

                      if (h == NULL)
                        sec = local_sections[r_symndx];
                      else
                        {
                          BFD_ASSERT (h->root.type == bfd_link_hash_defined
                                      || (h->root.type
                                          == bfd_link_hash_defweak));
                          sec = h->root.u.def.section;
                        }
                      if (sec != NULL && bfd_is_abs_section (sec))
                        indx = 0;
                      else if (sec == NULL || sec->owner == NULL)
                        {
                          bfd_set_error (bfd_error_bad_value);
                          return false;
                        }
                      else
                        {
                          asection *osec;

                          osec = sec->output_section;
                          indx = elf_section_data (osec)->dynindx;
                          BFD_ASSERT(indx > 0);
#ifdef DEBUG
                          if (indx <= 0)
                            {
                              printf ("indx=%d section=%s flags=%08x name=%s\n",
                                      indx, osec->name, osec->flags,
                                      h->root.root.string);
                            }
#endif
                        }

                      outrel.r_info = ELF32_R_INFO (indx, r_type);
                      outrel.r_addend = relocation + rel->r_addend;
                    }
                }

              bfd_elf32_swap_reloca_out (output_bfd, &outrel,
                                         (((Elf32_External_Rela *)
                                           sreloc->contents)
                                          + sreloc->reloc_count));
              ++sreloc->reloc_count;

              /* This reloc will be computed at runtime, so there's no
                 need to do anything now, unless this is a RELATIVE
                 reloc in an unallocated section.  */
              if (skip
                  || (input_section->flags & SEC_ALLOC) != 0
                  || ELF32_R_TYPE (outrel.r_info) != R_I370_RELATIVE)
                continue;
            }
          break;

        case (int)R_I370_COPY:
        case (int)R_I370_RELATIVE:
          (*_bfd_error_handler) ("%s: Relocation %s is not yet supported for symbol %s.",
                                 bfd_get_filename (input_bfd),
                                 i370_elf_howto_table[ (int)r_type ]->name,
                                 sym_name);

          bfd_set_error (bfd_error_invalid_operation);
          ret = false;
          continue;
        }

#ifdef DEBUG
      fprintf (stderr, "\ttype = %s (%d), name = %s, symbol index = %ld, offset = %ld, addend = %ld\n",
               howto->name,
               (int)r_type,
               sym_name,
               r_symndx,
               (long)offset,
               (long)addend);
#endif

      r = _bfd_final_link_relocate (howto,
                                    input_bfd,
                                    input_section,
                                    contents,
                                    offset,
                                    relocation,
                                    addend);

      if (r != bfd_reloc_ok)
        {
          ret = false;
          switch (r)
            {
            default:
              break;

            case bfd_reloc_overflow:
              {
                const char *name;

                if (h != NULL)
                  name = h->root.root.string;
                else
                  {
                    name = bfd_elf_string_from_elf_section (input_bfd,
                                                            symtab_hdr->sh_link,
                                                            sym->st_name);
                    if (name == NULL)
                      break;

                    if (*name == '\0')
                      name = bfd_section_name (input_bfd, sec);
                  }

                (*info->callbacks->reloc_overflow) (info,
                                                    name,
                                                    howto->name,
                                                    (bfd_vma) 0,
                                                    input_bfd,
                                                    input_section,
                                                    offset);
              }
              break;

            }
        }
    }

#ifdef DEBUG
  fprintf (stderr, "\n");
#endif

  return ret;
}

static void
i370_elf_post_process_headers (abfd, link_info)
    bfd * abfd;
    struct bfd_link_info * link_info ATTRIBUTE_UNUSED;
{
  Elf_Internal_Ehdr * i_ehdrp;  /* Elf file header, internal form */

  i_ehdrp = elf_elfheader (abfd);
  i_ehdrp->e_ident[EI_OSABI] = ELFOSABI_LINUX;
}
\f
#define TARGET_BIG_SYM          bfd_elf32_i370_vec
#define TARGET_BIG_NAME         "elf32-i370"
#define ELF_ARCH                bfd_arch_i370
#define ELF_MACHINE_CODE        EM_S370
#ifdef EM_I370_OLD
#define ELF_MACHINE_ALT1        EM_I370_OLD
#endif
#define ELF_MAXPAGESIZE         0x1000
#define elf_info_to_howto       i370_elf_info_to_howto

#define elf_backend_plt_not_loaded 1
#define elf_backend_got_symbol_offset 4

#define bfd_elf32_bfd_reloc_type_lookup         i370_elf_reloc_type_lookup
#define bfd_elf32_bfd_set_private_flags         i370_elf_set_private_flags
#define bfd_elf32_bfd_copy_private_bfd_data     i370_elf_copy_private_bfd_data
#define bfd_elf32_bfd_merge_private_bfd_data    i370_elf_merge_private_bfd_data
#define elf_backend_relocate_section            i370_elf_relocate_section

/* dynamic loader support is mostly broken; just enough here to be able to
 * link glibc's ld.so without errors.
 */
#define elf_backend_create_dynamic_sections     i370_elf_create_dynamic_sections
#define elf_backend_size_dynamic_sections       i370_elf_size_dynamic_sections
#define elf_backend_finish_dynamic_sections     i370_elf_finish_dynamic_sections
#define elf_backend_fake_sections               i370_elf_fake_sections
#define elf_backend_section_from_shdr           i370_elf_section_from_shdr
#define elf_backend_adjust_dynamic_symbol       i370_elf_adjust_dynamic_symbol
#define elf_backend_check_relocs                i370_elf_check_relocs

/*
#define elf_backend_add_symbol_hook             i370_elf_add_symbol_hook
#define elf_backend_finish_dynamic_symbol       i370_elf_finish_dynamic_symbol
#define elf_backend_additional_program_headers  i370_elf_additional_program_headers
#define elf_backend_modify_segment_map          i370_elf_modify_segment_map
*/

#define elf_backend_post_process_headers        i370_elf_post_process_headers

int i370_noop()
{
  return 1;
}

/* we need to define these at least as no-ops to link glibc ld.so */

#define elf_backend_add_symbol_hook \
  (boolean (*) PARAMS ((bfd *, struct bfd_link_info *, \
                        const Elf_Internal_Sym *, const char **, flagword *, \
                        asection **, bfd_vma *)))               i370_noop
#define elf_backend_finish_dynamic_symbol \
  (boolean (*) PARAMS ((bfd *, struct bfd_link_info *, \
                        struct elf_link_hash_entry *, \
                        Elf_Internal_Sym *)))                   i370_noop
#define elf_backend_additional_program_headers \
  (int (*) PARAMS ((bfd *)))                                    i370_noop
#define elf_backend_modify_segment_map \
  (boolean (*) PARAMS ((bfd *)))                                i370_noop

#include "elf32-target.h"