osprey/cygnus/bfd/elf32-xstormy16.c

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/*
 * Copyright 2003, 2004, 2005, 2006 PathScale, Inc.  All Rights Reserved.
 */

/* XSTORMY16-specific support for 32-bit ELF.
   Copyright 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.

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.  */

#include "bfd.h"
#include "sysdep.h"
#include "libbfd.h"
#include "elf-bfd.h"
#include "elf/xstormy16.h"
#include "libiberty.h"

/* Forward declarations.  */
static reloc_howto_type * xstormy16_reloc_type_lookup
  PARAMS ((bfd *abfd, bfd_reloc_code_real_type code));
static void xstormy16_info_to_howto_rela
  PARAMS ((bfd *, arelent *, Elf_Internal_Rela *));
static bfd_reloc_status_type xstormy16_elf_24_reloc
  PARAMS ((bfd *abfd, arelent *reloc_entry, asymbol *symbol,
     PTR data, asection *input_section, bfd *output_bfd,
     char **error_message));
static bfd_boolean xstormy16_elf_check_relocs
  PARAMS ((bfd *, struct bfd_link_info *, asection *,
     const Elf_Internal_Rela *));
static bfd_boolean xstormy16_relax_plt_check
  PARAMS ((struct elf_link_hash_entry *, PTR));
static bfd_boolean xstormy16_relax_plt_realloc
  PARAMS ((struct elf_link_hash_entry *, PTR));
static bfd_boolean xstormy16_elf_relax_section
  PARAMS ((bfd *abfd, asection *sec, struct bfd_link_info *link_info,
     bfd_boolean *again));
static bfd_boolean xstormy16_elf_always_size_sections
  PARAMS ((bfd *, struct bfd_link_info *));
static bfd_boolean xstormy16_elf_relocate_section
  PARAMS ((bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *,
     Elf_Internal_Rela *, Elf_Internal_Sym *, asection **));
static bfd_boolean xstormy16_elf_finish_dynamic_sections
  PARAMS((bfd *, struct bfd_link_info *));
static bfd_boolean xstormy16_elf_gc_sweep_hook
  PARAMS ((bfd *, struct bfd_link_info *, asection *,
     const Elf_Internal_Rela *));
static asection * xstormy16_elf_gc_mark_hook
  PARAMS ((asection *, struct bfd_link_info *, Elf_Internal_Rela *,
     struct elf_link_hash_entry *, Elf_Internal_Sym *));

static reloc_howto_type xstormy16_elf_howto_table [] =
{
  /* This reloc does nothing.  */
  HOWTO (R_XSTORMY16_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_XSTORMY16_NONE",  /* name */
   FALSE,     /* partial_inplace */
   0,     /* src_mask */
   0,     /* dst_mask */
   FALSE),    /* pcrel_offset */

  /* A 32 bit absolute relocation.  */
  HOWTO (R_XSTORMY16_32,  /* type */
   0,     /* rightshift */
   2,     /* size (0 = byte, 1 = short, 2 = long) */
   32,      /* bitsize */
   FALSE,     /* pc_relative */
   0,     /* bitpos */
   complain_overflow_dont, /* complain_on_overflow */
   bfd_elf_generic_reloc, /* special_function */
   "R_XSTORMY16_32",  /* name */
   FALSE,     /* partial_inplace */
   0,     /* src_mask */
   0xffffffff,    /* dst_mask */
   FALSE),    /* pcrel_offset */

  /* A 16 bit absolute relocation.  */
  HOWTO (R_XSTORMY16_16,  /* 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_XSTORMY16_16",  /* name */
   FALSE,     /* partial_inplace */
   0,     /* src_mask */
   0xffff,    /* dst_mask */
   FALSE),    /* pcrel_offset */

  /* An 8 bit absolute relocation.  */
  HOWTO (R_XSTORMY16_8,   /* type */
   0,     /* rightshift */
   0,     /* size (0 = byte, 1 = short, 2 = long) */
   8,     /* bitsize */
   FALSE,     /* pc_relative */
   0,     /* bitpos */
   complain_overflow_unsigned, /* complain_on_overflow */
   bfd_elf_generic_reloc, /* special_function */
   "R_XSTORMY16_8", /* name */
   FALSE,     /* partial_inplace */
   0,     /* src_mask */
   0xff,      /* dst_mask */
   FALSE),    /* pcrel_offset */

  /* A 32 bit pc-relative relocation.  */
  HOWTO (R_XSTORMY16_PC32,  /* type */
   0,     /* rightshift */
   2,     /* size (0 = byte, 1 = short, 2 = long) */
   32,      /* bitsize */
   TRUE,      /* pc_relative */
   0,     /* bitpos */
   complain_overflow_dont, /* complain_on_overflow */
   bfd_elf_generic_reloc, /* special_function */
   "R_XSTORMY16_PC32",  /* name */
   FALSE,     /* partial_inplace */
   0,     /* src_mask */
   0xffffffff,    /* dst_mask */
   TRUE),     /* pcrel_offset */

  /* A 16 bit pc-relative relocation.  */
  HOWTO (R_XSTORMY16_PC16,  /* type */
   0,     /* rightshift */
   1,     /* size (0 = byte, 1 = short, 2 = long) */
   16,      /* bitsize */
   TRUE,      /* pc_relative */
   0,     /* bitpos */
   complain_overflow_signed, /* complain_on_overflow */
   bfd_elf_generic_reloc, /* special_function */
   "R_XSTORMY16_PC16",  /* name */
   FALSE,     /* partial_inplace */
   0,     /* src_mask */
   0xffffffff,    /* dst_mask */
   TRUE),     /* pcrel_offset */

  /* An 8 bit pc-relative relocation.  */
  HOWTO (R_XSTORMY16_PC8, /* type */
   0,     /* rightshift */
   0,     /* size (0 = byte, 1 = short, 2 = long) */
   8,     /* bitsize */
   TRUE,      /* pc_relative */
   0,     /* bitpos */
   complain_overflow_signed, /* complain_on_overflow */
   bfd_elf_generic_reloc, /* special_function */
   "R_XSTORMY16_PC8", /* name */
   FALSE,     /* partial_inplace */
   0,     /* src_mask */
   0xffffffff,    /* dst_mask */
   TRUE),     /* pcrel_offset */

  /* A 12-bit pc-relative relocation suitable for the branch instructions.  */
  HOWTO (R_XSTORMY16_REL_12,  /* type */
   1,     /* rightshift */
   1,     /* size (0 = byte, 1 = short, 2 = long) */
   11,      /* bitsize */
   TRUE,      /* pc_relative */
   1,     /* bitpos */
   complain_overflow_signed, /* complain_on_overflow */
   bfd_elf_generic_reloc, /* special_function */
   "R_XSTORMY16_REL_12",  /* name */
   FALSE,     /* partial_inplace */
   0,     /* src_mask */
   0x0ffe,    /* dst_mask */
   TRUE),     /* pcrel_offset */

  /* A 24-bit absolute relocation suitable for the jump instructions.  */
  HOWTO (R_XSTORMY16_24,  /* type */
   0,     /* rightshift */
   2,     /* size (0 = byte, 1 = short, 2 = long) */
   24,      /* bitsize */
   FALSE,     /* pc_relative */
   0,     /* bitpos */
   complain_overflow_unsigned, /* complain_on_overflow */
   xstormy16_elf_24_reloc,  /* special_function */
   "R_XSTORMY16_24",  /* name */
   TRUE,      /* partial_inplace */
   0,     /* src_mask */
   0xffff00ff,    /* dst_mask */
   TRUE),     /* pcrel_offset */

  /* A 16 bit absolute relocation to a function pointer.  */
  HOWTO (R_XSTORMY16_FPTR16,  /* 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_XSTORMY16_FPTR16",  /* name */
   FALSE,     /* partial_inplace */
   0,     /* src_mask */
   0xffffffff,    /* dst_mask */
   FALSE),    /* pcrel_offset */

  /* Low order 16 bit value of a high memory address.  */
  HOWTO (R_XSTORMY16_LO16,  /* type */
   0,     /* rightshift */
   1,     /* size (0 = byte, 1 = short, 2 = long) */
   16,      /* bitsize */
   FALSE,     /* pc_relative */
   0,     /* bitpos */
   complain_overflow_dont, /* complain_on_overflow */
   bfd_elf_generic_reloc, /* special_function */
   "R_XSTORMY16_LO16",  /* name */
   FALSE,     /* partial_inplace */
   0,     /* src_mask */
   0xffff,    /* dst_mask */
   FALSE),    /* pcrel_offset */

  /* High order 16 bit value of a high memory address.  */
  HOWTO (R_XSTORMY16_HI16,  /* type */
   16,      /* rightshift */
   1,     /* size (0 = byte, 1 = short, 2 = long) */
   16,      /* bitsize */
   FALSE,     /* pc_relative */
   0,     /* bitpos */
   complain_overflow_dont, /* complain_on_overflow */
   bfd_elf_generic_reloc, /* special_function */
   "R_XSTORMY16_HI16",  /* name */
   FALSE,     /* partial_inplace */
   0,     /* src_mask */
   0xffff,    /* dst_mask */
   FALSE),    /* pcrel_offset */
 
  /* A 12 bit absolute relocation.  */
  HOWTO (R_XSTORMY16_12,  /* type */
   0,     /* rightshift */
   1,     /* size (0 = byte, 1 = short, 2 = long) */
   12,      /* bitsize */
   FALSE,     /* pc_relative */
   0,     /* bitpos */
   complain_overflow_signed, /* complain_on_overflow */
   bfd_elf_generic_reloc, /* special_function */
   "R_XSTORMY16_12",  /* name */
   FALSE,     /* partial_inplace */
   0x0000,    /* src_mask */
   0x0fff,    /* dst_mask */
   FALSE),    /* pcrel_offset */
};

static reloc_howto_type xstormy16_elf_howto_table2 [] =
{
  /* GNU extension to record C++ vtable hierarchy */
  HOWTO (R_XSTORMY16_GNU_VTINHERIT, /* type */
         0,                     /* rightshift */
         2,                     /* size (0 = byte, 1 = short, 2 = long) */
         0,                     /* bitsize */
         FALSE,                 /* pc_relative */
         0,                     /* bitpos */
         complain_overflow_dont, /* complain_on_overflow */
         NULL,                  /* special_function */
         "R_XSTORMY16_GNU_VTINHERIT", /* name */
         FALSE,                 /* partial_inplace */
         0,                     /* src_mask */
         0,                     /* dst_mask */
         FALSE),                /* pcrel_offset */

  /* GNU extension to record C++ vtable member usage */
  HOWTO (R_XSTORMY16_GNU_VTENTRY,     /* type */
         0,                     /* rightshift */
         2,                     /* size (0 = byte, 1 = short, 2 = long) */
         0,                     /* bitsize */
         FALSE,                 /* pc_relative */
         0,                     /* bitpos */
         complain_overflow_dont, /* complain_on_overflow */
         _bfd_elf_rel_vtable_reloc_fn,  /* special_function */
         "R_XSTORMY16_GNU_VTENTRY",   /* name */
         FALSE,                 /* partial_inplace */
         0,                     /* src_mask */
         0,                     /* dst_mask */
         FALSE),                /* pcrel_offset */

};

/* Map BFD reloc types to XSTORMY16 ELF reloc types.  */

typedef struct xstormy16_reloc_map
{
  bfd_reloc_code_real_type  bfd_reloc_val;
  unsigned int              xstormy16_reloc_val;
  reloc_howto_type *        table;
} reloc_map;

static const reloc_map xstormy16_reloc_map [] =
{
  { BFD_RELOC_NONE,                 R_XSTORMY16_NONE,          xstormy16_elf_howto_table },
  { BFD_RELOC_32,                   R_XSTORMY16_32,            xstormy16_elf_howto_table },
  { BFD_RELOC_16,                   R_XSTORMY16_16,            xstormy16_elf_howto_table },
  { BFD_RELOC_8,                    R_XSTORMY16_8,             xstormy16_elf_howto_table },
  { BFD_RELOC_32_PCREL,             R_XSTORMY16_PC32,          xstormy16_elf_howto_table },
  { BFD_RELOC_16_PCREL,             R_XSTORMY16_PC16,          xstormy16_elf_howto_table },
  { BFD_RELOC_8_PCREL,              R_XSTORMY16_PC8,           xstormy16_elf_howto_table },
  { BFD_RELOC_XSTORMY16_REL_12,     R_XSTORMY16_REL_12,        xstormy16_elf_howto_table },
  { BFD_RELOC_XSTORMY16_24,     R_XSTORMY16_24,            xstormy16_elf_howto_table },
  { BFD_RELOC_XSTORMY16_FPTR16,     R_XSTORMY16_FPTR16,        xstormy16_elf_howto_table },
  { BFD_RELOC_LO16,                 R_XSTORMY16_LO16,          xstormy16_elf_howto_table },
  { BFD_RELOC_HI16,                 R_XSTORMY16_HI16,          xstormy16_elf_howto_table },
  { BFD_RELOC_XSTORMY16_12,         R_XSTORMY16_12,            xstormy16_elf_howto_table },
  { BFD_RELOC_VTABLE_INHERIT,       R_XSTORMY16_GNU_VTINHERIT, xstormy16_elf_howto_table2 },
  { BFD_RELOC_VTABLE_ENTRY,         R_XSTORMY16_GNU_VTENTRY,   xstormy16_elf_howto_table2 },
};

static reloc_howto_type *
xstormy16_reloc_type_lookup (abfd, code)
     bfd * abfd ATTRIBUTE_UNUSED;
     bfd_reloc_code_real_type code;
{
  unsigned int i;

  for (i = ARRAY_SIZE (xstormy16_reloc_map); --i;)
    {
      const reloc_map * entry;

      entry = xstormy16_reloc_map + i;

      if (entry->bfd_reloc_val == code)
  return entry->table + (entry->xstormy16_reloc_val
             - entry->table[0].type);
    }

  return NULL;
}

/* Set the howto pointer for an XSTORMY16 ELF reloc.  */

static void
xstormy16_info_to_howto_rela (abfd, cache_ptr, dst)
     bfd * abfd ATTRIBUTE_UNUSED;
     arelent * cache_ptr;
     Elf_Internal_Rela * dst;
{
  unsigned int r_type = ELF32_R_TYPE (dst->r_info);

  if (r_type <= (unsigned int) R_XSTORMY16_12)
    cache_ptr->howto = &xstormy16_elf_howto_table [r_type];
  else if (r_type - R_XSTORMY16_GNU_VTINHERIT
     <= (unsigned int) R_XSTORMY16_GNU_VTENTRY)
    cache_ptr->howto
      = &xstormy16_elf_howto_table2 [r_type - R_XSTORMY16_GNU_VTINHERIT];
  else
    abort ();
}

/* Handle the R_XSTORMY16_24 reloc, which has an odd bit arrangement.  */

static bfd_reloc_status_type
xstormy16_elf_24_reloc (abfd, reloc_entry, symbol, data, input_section,
       output_bfd, error_message)
     bfd *abfd;
     arelent *reloc_entry;
     asymbol *symbol;
     PTR data;
     asection *input_section;
     bfd *output_bfd;
     char **error_message ATTRIBUTE_UNUSED;
{
  bfd_vma relocation, x;

  if (output_bfd != NULL)
    {
      reloc_entry->address += input_section->output_offset;
      return bfd_reloc_ok;
    }

  if (reloc_entry->address > bfd_get_section_limit (abfd, input_section))
    return bfd_reloc_outofrange;

  if (bfd_is_com_section (symbol->section))
    relocation = 0;
  else
    relocation = symbol->value;

  relocation += symbol->section->output_section->vma;
  relocation += symbol->section->output_offset;
  relocation += reloc_entry->addend;

  x = bfd_get_32 (abfd, (bfd_byte *) data + reloc_entry->address);
  x &= 0x0000ff00;
  x |= relocation & 0xff;
  x |= (relocation << 8) & 0xffff0000;
  bfd_put_32 (abfd, x, (bfd_byte *) data + reloc_entry->address);

  if (relocation & ~ (bfd_vma) 0xffffff)
    return bfd_reloc_overflow;

  return bfd_reloc_ok;
}

/* We support 16-bit pointers to code above 64k by generating a thunk
   below 64k containing a JMPF instruction to the final address.  We
   cannot, unfortunately, minimize the number of thunks unless the
   -relax switch is given, as otherwise we have no idea where the
   sections will fall in the address space.  */

static bfd_boolean
xstormy16_elf_check_relocs (abfd, info, sec, relocs)
     bfd *abfd;
     struct bfd_link_info *info;
     asection *sec;
     const Elf_Internal_Rela *relocs;
{
  const Elf_Internal_Rela *rel, *relend;
  struct elf_link_hash_entry **sym_hashes;
  Elf_Internal_Shdr *symtab_hdr;
  bfd_vma *local_plt_offsets;
  asection *splt;
  bfd *dynobj;

  if (info->relocatable)
    return TRUE;

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

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

      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];
    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;
  }

      switch (ELF32_R_TYPE (rel->r_info))
        {
    /* This relocation describes a 16-bit pointer to a function.
       We may need to allocate a thunk in low memory; reserve memory
       for it now.  */
  case R_XSTORMY16_FPTR16:
    if (rel->r_addend != 0)
      {
        (*info->callbacks->warning)
    (info, _("non-zero addend in @fptr reloc"), 0,
     abfd, 0, 0);
      }

    if (dynobj == NULL)
      elf_hash_table (info)->dynobj = dynobj = abfd;
    if (splt == NULL)
      {
        splt = bfd_get_section_by_name (dynobj, ".plt");
        if (splt == NULL)
    {
      splt = bfd_make_section (dynobj, ".plt");
      if (splt == NULL
          || ! bfd_set_section_flags (dynobj, splt,
              (SEC_ALLOC
               | SEC_LOAD
               | SEC_HAS_CONTENTS
               | SEC_IN_MEMORY
               | SEC_LINKER_CREATED
               | SEC_READONLY
               | SEC_CODE))
          || ! bfd_set_section_alignment (dynobj, splt, 1))
        return FALSE;
    }
      }

    if (h != NULL)
      offset = &h->plt.offset;
    else
      {
        if (local_plt_offsets == NULL)
    {
      size_t size;
      unsigned int i;

      size = symtab_hdr->sh_info * sizeof (bfd_vma);
      local_plt_offsets = (bfd_vma *) bfd_alloc (abfd, size);
      if (local_plt_offsets == NULL)
        return FALSE;
      elf_local_got_offsets (abfd) = local_plt_offsets;

      for (i = 0; i < symtab_hdr->sh_info; i++)
        local_plt_offsets[i] = (bfd_vma) -1;
    }
        offset = &local_plt_offsets[r_symndx];
      }

    if (*offset == (bfd_vma) -1)
      {
        *offset = splt->size;
        splt->size += 4;
      }
    break;

    /* This relocation describes the C++ object vtable hierarchy.
       Reconstruct it for later use during GC.  */
        case R_XSTORMY16_GNU_VTINHERIT:
          if (!bfd_elf_gc_record_vtinherit (abfd, sec, h, rel->r_offset))
            return FALSE;
          break;

    /* This relocation describes which C++ vtable entries are actually
       used.  Record for later use during GC.  */
        case R_XSTORMY16_GNU_VTENTRY:
          if (!bfd_elf_gc_record_vtentry (abfd, sec, h, rel->r_addend))
            return FALSE;
          break;
  }
    }

  return TRUE;
}

/* A subroutine of xstormy16_elf_relax_section.  If the global symbol H
   is within the low 64k, remove any entry for it in the plt.  */

struct relax_plt_data
{
  asection *splt;
  bfd_boolean *again;
};

static bfd_boolean
xstormy16_relax_plt_check (h, xdata)
     struct elf_link_hash_entry *h;
     PTR xdata;
{
  struct relax_plt_data *data = (struct relax_plt_data *) xdata;

  if (h->root.type == bfd_link_hash_warning)
    h = (struct elf_link_hash_entry *) h->root.u.i.link;

  if (h->plt.offset != (bfd_vma) -1)
    {
      bfd_vma address;

      if (h->root.type == bfd_link_hash_undefined
    || h->root.type == bfd_link_hash_undefweak)
  address = 0;
      else
  address = (h->root.u.def.section->output_section->vma
       + h->root.u.def.section->output_offset
       + h->root.u.def.value);

      if (address <= 0xffff)
  {
    h->plt.offset = -1;
    data->splt->size -= 4;
    *data->again = TRUE;
  }
    }

  return TRUE;
}

/* A subroutine of xstormy16_elf_relax_section.  If the global symbol H
   previously had a plt entry, give it a new entry offset.  */

static bfd_boolean
xstormy16_relax_plt_realloc (h, xdata)
     struct elf_link_hash_entry *h;
     PTR xdata;
{
  bfd_vma *entry = (bfd_vma *) xdata;

  if (h->root.type == bfd_link_hash_warning)
    h = (struct elf_link_hash_entry *) h->root.u.i.link;

  if (h->plt.offset != (bfd_vma) -1)
    {
      h->plt.offset = *entry;
      *entry += 4;
    }

  return TRUE;
}

static bfd_boolean
xstormy16_elf_relax_section (dynobj, splt, info, again)
     bfd *dynobj;
     asection *splt;
     struct bfd_link_info *info;
     bfd_boolean *again;
{
  struct relax_plt_data relax_plt_data;
  bfd *ibfd;

  /* Assume nothing changes.  */
  *again = FALSE;

  if (info->relocatable)
    return TRUE;

  /* We only relax the .plt section at the moment.  */
  if (dynobj != elf_hash_table (info)->dynobj
      || strcmp (splt->name, ".plt") != 0)
    return TRUE;

  /* Quick check for an empty plt.  */
  if (splt->size == 0)
    return TRUE;

  /* Map across all global symbols; see which ones happen to
     fall in the low 64k.  */
  relax_plt_data.splt = splt;
  relax_plt_data.again = again;
  elf_link_hash_traverse (elf_hash_table (info), xstormy16_relax_plt_check,
        &relax_plt_data);

  /* Likewise for local symbols, though that's somewhat less convenient
     as we have to walk the list of input bfds and swap in symbol data.  */
  for (ibfd = info->input_bfds; ibfd ; ibfd = ibfd->link_next)
    {
      bfd_vma *local_plt_offsets = elf_local_got_offsets (ibfd);
      Elf_Internal_Shdr *symtab_hdr;
      Elf_Internal_Sym *isymbuf = NULL;
      unsigned int idx;

      if (! local_plt_offsets)
  continue;

      symtab_hdr = &elf_tdata (ibfd)->symtab_hdr;
      if (symtab_hdr->sh_info != 0)
  {
    isymbuf = (Elf_Internal_Sym *) symtab_hdr->contents;
    if (isymbuf == NULL)
      isymbuf = bfd_elf_get_elf_syms (ibfd, symtab_hdr,
              symtab_hdr->sh_info, 0,
              NULL, NULL, NULL);
    if (isymbuf == NULL)
      return FALSE;
  }

      for (idx = 0; idx < symtab_hdr->sh_info; ++idx)
  {
    Elf_Internal_Sym *isym;
    asection *tsec;
    bfd_vma address;

    if (local_plt_offsets[idx] == (bfd_vma) -1)
      continue;

    isym = &isymbuf[idx];
    if (isym->st_shndx == SHN_UNDEF)
      continue;
    else if (isym->st_shndx == SHN_ABS)
      tsec = bfd_abs_section_ptr;
    else if (isym->st_shndx == SHN_COMMON)
      tsec = bfd_com_section_ptr;
    else
      tsec = bfd_section_from_elf_index (ibfd, isym->st_shndx);

    address = (tsec->output_section->vma
         + tsec->output_offset
         + isym->st_value);
    if (address <= 0xffff)
      {
        local_plt_offsets[idx] = -1;
        splt->size -= 4;
        *again = TRUE;
      }
  }

      if (isymbuf != NULL
    && symtab_hdr->contents != (unsigned char *) isymbuf)
  {
    if (! info->keep_memory)
      free (isymbuf);
    else
      {
        /* Cache the symbols for elf_link_input_bfd.  */
        symtab_hdr->contents = (unsigned char *) isymbuf;
      }
  }
    }

  /* If we changed anything, walk the symbols again to reallocate
     .plt entry addresses.  */
  if (*again && splt->size > 0)
    {
      bfd_vma entry = 0;

      elf_link_hash_traverse (elf_hash_table (info),
            xstormy16_relax_plt_realloc, &entry);

      for (ibfd = info->input_bfds; ibfd ; ibfd = ibfd->link_next)
  {
    bfd_vma *local_plt_offsets = elf_local_got_offsets (ibfd);
    unsigned int nlocals = elf_tdata (ibfd)->symtab_hdr.sh_info;
    unsigned int idx;

    if (! local_plt_offsets)
      continue;

    for (idx = 0; idx < nlocals; ++idx)
      if (local_plt_offsets[idx] != (bfd_vma) -1)
        {
          local_plt_offsets[idx] = entry;
    entry += 4;
        }
  }
    }

  return TRUE;
}

static bfd_boolean
xstormy16_elf_always_size_sections (output_bfd, info)
     bfd *output_bfd ATTRIBUTE_UNUSED;
     struct bfd_link_info *info;
{
  bfd *dynobj;
  asection *splt;

  if (info->relocatable)
    return TRUE;

  dynobj = elf_hash_table (info)->dynobj;
  if (dynobj == NULL)
    return TRUE;

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

  splt->contents = (bfd_byte *) bfd_zalloc (dynobj, splt->size);
  if (splt->contents == NULL)
    return FALSE;

  return TRUE;
}

/* Relocate an XSTORMY16 ELF section.

   The RELOCATE_SECTION function is called by the new 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 adjusting the section contents as
   necessary, and (if using Rela relocs and generating a relocatable
   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 relocatable 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 bfd_boolean
xstormy16_elf_relocate_section (output_bfd, info, input_bfd, input_section,
         contents, relocs, local_syms, local_sections)
     bfd *                   output_bfd ATTRIBUTE_UNUSED;
     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;
  struct elf_link_hash_entry ** sym_hashes;
  Elf_Internal_Rela *           rel;
  Elf_Internal_Rela *           relend;
  bfd *dynobj;
  asection *splt;

  if (info->relocatable)
    return TRUE;

  symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr;
  sym_hashes = elf_sym_hashes (input_bfd);
  relend     = relocs + input_section->reloc_count;

  dynobj = elf_hash_table (info)->dynobj;
  splt = NULL;
  if (dynobj != NULL)
    splt = bfd_get_section_by_name (dynobj, ".plt");

  for (rel = relocs; rel < relend; rel ++)
    {
      reloc_howto_type *           howto;
      unsigned long                r_symndx;
      Elf_Internal_Sym *           sym;
      asection *                   sec;
      struct elf_link_hash_entry * h;
      bfd_vma                      relocation;
      bfd_reloc_status_type        r;
      const char *                 name = NULL;
      int                          r_type;

      r_type = ELF32_R_TYPE (rel->r_info);

      if (   r_type == R_XSTORMY16_GNU_VTINHERIT
    || r_type == R_XSTORMY16_GNU_VTENTRY)
  continue;

      r_symndx = ELF32_R_SYM (rel->r_info);
      howto  = xstormy16_elf_howto_table + ELF32_R_TYPE (rel->r_info);
      h      = NULL;
      sym    = NULL;
      sec    = NULL;

      if (r_symndx < symtab_hdr->sh_info)
  {
    sym = local_syms + r_symndx;
    sec = local_sections [r_symndx];
    relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel);
  }
      else
  {
    bfd_boolean unresolved_reloc, warned;

    RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel,
           r_symndx, symtab_hdr, sym_hashes,
           h, sec, relocation,
           unresolved_reloc, warned);
  }

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

      switch (ELF32_R_TYPE (rel->r_info))
  {
  case R_XSTORMY16_24:
    {
      bfd_vma reloc = relocation + rel->r_addend;
      unsigned int x;

      x = bfd_get_32 (input_bfd, contents + rel->r_offset);
      x &= 0x0000ff00;
      x |= reloc & 0xff;
      x |= (reloc << 8) & 0xffff0000;
      bfd_put_32 (input_bfd, x, contents + rel->r_offset);

      if (reloc & ~0xffffff)
        r = bfd_reloc_overflow;
      else
        r = bfd_reloc_ok;
      break;
    }

  case R_XSTORMY16_FPTR16:
    {
      bfd_vma *plt_offset;

      if (h != NULL)
        plt_offset = &h->plt.offset;
      else
        plt_offset = elf_local_got_offsets (input_bfd) + r_symndx;

      if (relocation <= 0xffff)
        {
          /* If the symbol is in range for a 16-bit address, we should
       have deallocated the plt entry in relax_section.  */
          BFD_ASSERT (*plt_offset == (bfd_vma) -1);
        }
      else
        {
    /* If the symbol is out of range for a 16-bit address,
       we must have allocated a plt entry.  */
    BFD_ASSERT (*plt_offset != (bfd_vma) -1);

    /* If this is the first time we've processed this symbol,
       fill in the plt entry with the correct symbol address.  */
    if ((*plt_offset & 1) == 0)
      {
        unsigned int x;

        x = 0x00000200;  /* jmpf */
        x |= relocation & 0xff;
        x |= (relocation << 8) & 0xffff0000;
        bfd_put_32 (input_bfd, x, splt->contents + *plt_offset);
        *plt_offset |= 1;
      }

    relocation = (splt->output_section->vma
            + splt->output_offset
            + (*plt_offset & -2));
        }
      r = _bfd_final_link_relocate (howto, input_bfd, input_section,
            contents, rel->r_offset,
            relocation, 0);
      break;
    }

  default:
    r = _bfd_final_link_relocate (howto, input_bfd, input_section,
          contents, rel->r_offset,
          relocation, rel->r_addend);
    break;
  }

      if (r != bfd_reloc_ok)
  {
    const char * msg = (const char *) NULL;

    switch (r)
      {
      case bfd_reloc_overflow:
        r = info->callbacks->reloc_overflow
    (info, (h ? &h->root : NULL), name, howto->name,
     (bfd_vma) 0, input_bfd, input_section, rel->r_offset);
        break;

      case bfd_reloc_undefined:
        r = info->callbacks->undefined_symbol
    (info, name, input_bfd, input_section, rel->r_offset,
     TRUE);
        break;

      case bfd_reloc_outofrange:
        msg = _("internal error: out of range error");
        break;

      case bfd_reloc_notsupported:
        msg = _("internal error: unsupported relocation error");
        break;

      case bfd_reloc_dangerous:
        msg = _("internal error: dangerous relocation");
        break;

      default:
        msg = _("internal error: unknown error");
        break;
      }

    if (msg)
      r = info->callbacks->warning
        (info, msg, name, input_bfd, input_section, rel->r_offset);

    if (! r)
      return FALSE;
  }
    }

  return TRUE;
}

/* This must exist if dynobj is ever set.  */

static bfd_boolean
xstormy16_elf_finish_dynamic_sections (abfd, info)
     bfd *abfd ATTRIBUTE_UNUSED;
     struct bfd_link_info *info;
{
  bfd *dynobj;
  asection *splt;

  /* As an extra sanity check, verify that all plt entries have
     been filled in.  */

  if ((dynobj = elf_hash_table (info)->dynobj) != NULL
      && (splt = bfd_get_section_by_name (dynobj, ".plt")) != NULL)
    {
      bfd_byte *contents = splt->contents;
      unsigned int i, size = splt->size;
      for (i = 0; i < size; i += 4)
  {
    unsigned int x = bfd_get_32 (dynobj, contents + i);
    BFD_ASSERT (x != 0);
  }
    }

  return TRUE;
}

/* Return the section that should be marked against GC for a given
   relocation.  */

static asection *
xstormy16_elf_gc_mark_hook (sec, info, rel, h, sym)
     asection *                   sec;
     struct bfd_link_info *       info ATTRIBUTE_UNUSED;
     Elf_Internal_Rela *          rel;
     struct elf_link_hash_entry * h;
     Elf_Internal_Sym *           sym;
{
  if (h != NULL)
    {
      switch (ELF32_R_TYPE (rel->r_info))
  {
  case R_XSTORMY16_GNU_VTINHERIT:
  case R_XSTORMY16_GNU_VTENTRY:
    break;

  default:
    switch (h->root.type)
      {
      case bfd_link_hash_defined:
      case bfd_link_hash_defweak:
        return h->root.u.def.section;

      case bfd_link_hash_common:
        return h->root.u.c.p->section;

      default:
        break;
      }
  }
    }
  else
    return bfd_section_from_elf_index (sec->owner, sym->st_shndx);

  return NULL;
}

/* Update the got entry reference counts for the section being removed.  */

static bfd_boolean
xstormy16_elf_gc_sweep_hook (abfd, info, sec, relocs)
     bfd *                     abfd ATTRIBUTE_UNUSED;
     struct bfd_link_info *    info ATTRIBUTE_UNUSED;
     asection *                sec ATTRIBUTE_UNUSED;
     const Elf_Internal_Rela * relocs ATTRIBUTE_UNUSED;
{
  return TRUE;
}

#define ELF_ARCH    bfd_arch_xstormy16
#define ELF_MACHINE_CODE  EM_XSTORMY16
#define ELF_MAXPAGESIZE   0x100

#define TARGET_LITTLE_SYM       bfd_elf32_xstormy16_vec
#define TARGET_LITTLE_NAME  "elf32-xstormy16"

#define elf_info_to_howto_rel     NULL
#define elf_info_to_howto     xstormy16_info_to_howto_rela
#define elf_backend_relocate_section    xstormy16_elf_relocate_section
#define elf_backend_gc_mark_hook    xstormy16_elf_gc_mark_hook
#define elf_backend_gc_sweep_hook   xstormy16_elf_gc_sweep_hook
#define elf_backend_check_relocs                xstormy16_elf_check_relocs
#define elf_backend_always_size_sections \
  xstormy16_elf_always_size_sections
#define elf_backend_finish_dynamic_sections \
  xstormy16_elf_finish_dynamic_sections

#define elf_backend_can_gc_sections   1
#define elf_backend_rela_normal     1

#define bfd_elf32_bfd_reloc_type_lookup   xstormy16_reloc_type_lookup
#define bfd_elf32_bfd_relax_section   xstormy16_elf_relax_section

#include "elf32-target.h"

---