bfd target vector rationalisation

[deliverable/binutils-gdb.git] / bfd / elf32-mcore.c

/* Motorola MCore specific support for 32-bit ELF
   Copyright (C) 1994-2014 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 3 of the License, or
   (at your option) any later version.

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

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


/* This file is based on a preliminary RCE ELF ABI.  The
   information may not match the final RCE ELF ABI.   */

#include "sysdep.h"
#include "bfd.h"
#include "bfdlink.h"
#include "libbfd.h"
#include "elf-bfd.h"
#include "elf/mcore.h"
#include <assert.h>

/* RELA relocs are used here...  */

/* Function to set whether a module needs the -mrelocatable bit set.  */

static bfd_boolean
mcore_elf_set_private_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;
}

/* Merge backend specific data from an object file to the output
   object file when linking.  */

static bfd_boolean
mcore_elf_merge_private_bfd_data (bfd * ibfd, bfd * obfd)
{
  flagword old_flags;
  flagword new_flags;

  /* Check if we have the same endianness.  */
  if (! _bfd_generic_verify_endian_match (ibfd, obfd))
    return FALSE;

  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
    {
      /* FIXME */
    }

  return TRUE;
}
\f
/* Don't pretend we can deal with unsupported relocs.  */

static bfd_reloc_status_type
mcore_elf_unsupported_reloc (bfd * abfd,
                             arelent * reloc_entry,
                             asymbol * symbol ATTRIBUTE_UNUSED,
                             void * data ATTRIBUTE_UNUSED,
                             asection * input_section ATTRIBUTE_UNUSED,
                             bfd * output_bfd ATTRIBUTE_UNUSED,
                             char ** error_message ATTRIBUTE_UNUSED)
{
  BFD_ASSERT (reloc_entry->howto != (reloc_howto_type *)0);

  _bfd_error_handler (_("%B: Relocation %s (%d) is not currently supported.\n"),
                      abfd,
                      reloc_entry->howto->name,
                      reloc_entry->howto->type);

  return bfd_reloc_notsupported;
}

static reloc_howto_type * mcore_elf_howto_table [(int) R_MCORE_max];

static reloc_howto_type mcore_elf_howto_raw[] =
{
  /* This reloc does nothing.  */
  HOWTO (R_MCORE_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 */
         NULL,                  /* special_function */
         "R_MCORE_NONE",        /* name */
         FALSE,                 /* partial_inplace */
         0,                     /* src_mask */
         0,                     /* dst_mask */
         FALSE),                /* pcrel_offset */

  /* A standard 32 bit relocation.  */
  HOWTO (R_MCORE_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 */
         "ADDR32",              /* name *//* For compatibility with coff/pe port.  */
         FALSE,                 /* partial_inplace */
         0x0,                   /* src_mask */
         0xffffffff,            /* dst_mask */
         FALSE),                /* pcrel_offset */

  /* 8 bits + 2 zero bits; jmpi/jsri/lrw instructions.
     Should not appear in object files.  */
  HOWTO (R_MCORE_PCRELIMM8BY4,  /* type */
         2,                     /* rightshift */
         1,                     /* size (0 = byte, 1 = short, 2 = long) */
         8,                     /* bitsize */
         TRUE,                  /* pc_relative */
         0,                     /* bitpos */
         complain_overflow_bitfield, /* complain_on_overflow */
         mcore_elf_unsupported_reloc,   /* special_function */
         "R_MCORE_PCRELIMM8BY4",/* name */
         FALSE,                 /* partial_inplace */
         0,                     /* src_mask */
         0,                     /* dst_mask */
         TRUE),                 /* pcrel_offset */

  /* bsr/bt/bf/br instructions; 11 bits + 1 zero bit
     Span 2k instructions == 4k bytes.
     Only useful pieces at the relocated address are the opcode (5 bits) */
  HOWTO (R_MCORE_PCRELIMM11BY2,/* type */
         1,                     /* rightshift */
         1,                     /* size (0 = byte, 1 = short, 2 = long) */
         11,                    /* bitsize */
         TRUE,                  /* pc_relative */
         0,                     /* bitpos */
         complain_overflow_signed, /* complain_on_overflow */
         bfd_elf_generic_reloc, /* special_function */
         "R_MCORE_PCRELIMM11BY2",/* name */
         FALSE,                 /* partial_inplace */
         0x0,                   /* src_mask */
         0x7ff,                 /* dst_mask */
         TRUE),                 /* pcrel_offset */

  /* 4 bits + 1 zero bit; 'loopt' instruction only; unsupported.  */
  HOWTO (R_MCORE_PCRELIMM4BY2,  /* type */
         1,                     /* rightshift */
         1,                     /* size (0 = byte, 1 = short, 2 = long) */
         4,                     /* bitsize */
         TRUE,                  /* pc_relative */
         0,                     /* bitpos */
         complain_overflow_bitfield, /* complain_on_overflow */
         mcore_elf_unsupported_reloc,/* special_function */
         "R_MCORE_PCRELIMM4BY2",/* name */
         FALSE,                 /* partial_inplace */
         0,                     /* src_mask */
         0,                     /* dst_mask */
         TRUE),                 /* pcrel_offset */

  /* 32-bit pc-relative. Eventually this will help support PIC code.  */
  HOWTO (R_MCORE_PCREL32,       /* 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_MCORE_PCREL32",     /* name */
         FALSE,                 /* partial_inplace */
         0x0,                   /* src_mask */
         0xffffffff,            /* dst_mask */
         TRUE),                 /* pcrel_offset */

  /* Like PCRELIMM11BY2, this relocation indicates that there is a
     'jsri' at the specified address. There is a separate relocation
     entry for the literal pool entry that it references, but we
     might be able to change the jsri to a bsr if the target turns out
     to be close enough [even though we won't reclaim the literal pool
     entry, we'll get some runtime efficiency back]. Note that this
     is a relocation that we are allowed to safely ignore.  */
  HOWTO (R_MCORE_PCRELJSR_IMM11BY2,/* type */
         1,                     /* rightshift */
         1,                     /* size (0 = byte, 1 = short, 2 = long) */
         11,                    /* bitsize */
         TRUE,                  /* pc_relative */
         0,                     /* bitpos */
         complain_overflow_signed, /* complain_on_overflow */
         bfd_elf_generic_reloc, /* special_function */
         "R_MCORE_PCRELJSR_IMM11BY2", /* name */
         FALSE,                 /* partial_inplace */
         0x0,                   /* src_mask */
         0x7ff,                 /* dst_mask */
         TRUE),                 /* pcrel_offset */

  /* GNU extension to record C++ vtable hierarchy.  */
  HOWTO (R_MCORE_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_MCORE_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_MCORE_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_MCORE_GNU_VTENTRY", /* name */
         FALSE,                 /* partial_inplace */
         0,                     /* src_mask */
         0,                     /* dst_mask */
         FALSE),                /* pcrel_offset */

  HOWTO (R_MCORE_RELATIVE,      /* type */
         0,                     /* rightshift */
         2,                     /* size (0 = byte, 1 = short, 2 = long) */
         32,                    /* bitsize */
         FALSE,                 /* pc_relative */
         0,                     /* bitpos */
         complain_overflow_signed, /* complain_on_overflow */
         NULL,                  /* special_function */
         "R_MCORE_RELATIVE",    /* name */
         TRUE,                  /* partial_inplace */
         0xffffffff,            /* src_mask */
         0xffffffff,            /* dst_mask */
         FALSE)                 /* pcrel_offset */
};

#ifndef NUM_ELEM
#define NUM_ELEM(a) (sizeof (a) / sizeof (a)[0])
#endif
\f
/* Initialize the mcore_elf_howto_table, so that linear accesses can be done.  */
static void
mcore_elf_howto_init (void)
{
  unsigned int i;

  for (i = NUM_ELEM (mcore_elf_howto_raw); i--;)
    {
      unsigned int type;

      type = mcore_elf_howto_raw[i].type;

      BFD_ASSERT (type < NUM_ELEM (mcore_elf_howto_table));

      mcore_elf_howto_table [type] = & mcore_elf_howto_raw [i];
    }
}
\f
static reloc_howto_type *
mcore_elf_reloc_type_lookup (bfd * abfd ATTRIBUTE_UNUSED,
                             bfd_reloc_code_real_type code)
{
  enum elf_mcore_reloc_type mcore_reloc = R_MCORE_NONE;

  switch (code)
    {
    case BFD_RELOC_NONE:                     mcore_reloc = R_MCORE_NONE; break;
    case BFD_RELOC_32:                       mcore_reloc = R_MCORE_ADDR32; break;
    case BFD_RELOC_MCORE_PCREL_IMM8BY4:      mcore_reloc = R_MCORE_PCRELIMM8BY4; break;
    case BFD_RELOC_MCORE_PCREL_IMM11BY2:     mcore_reloc = R_MCORE_PCRELIMM11BY2; break;
    case BFD_RELOC_MCORE_PCREL_IMM4BY2:      mcore_reloc = R_MCORE_PCRELIMM4BY2; break;
    case BFD_RELOC_32_PCREL:                 mcore_reloc = R_MCORE_PCREL32; break;
    case BFD_RELOC_MCORE_PCREL_JSR_IMM11BY2: mcore_reloc = R_MCORE_PCRELJSR_IMM11BY2; break;
    case BFD_RELOC_VTABLE_INHERIT:           mcore_reloc = R_MCORE_GNU_VTINHERIT; break;
    case BFD_RELOC_VTABLE_ENTRY:             mcore_reloc = R_MCORE_GNU_VTENTRY; break;
    case BFD_RELOC_RVA:                      mcore_reloc = R_MCORE_RELATIVE; break;
    default:
      return NULL;
    }

  if (! mcore_elf_howto_table [R_MCORE_PCRELIMM8BY4])
    /* Initialize howto table if needed.  */
    mcore_elf_howto_init ();

  return mcore_elf_howto_table [(int) mcore_reloc];
};

static reloc_howto_type *
mcore_elf_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED,
                             const char *r_name)
{
  unsigned int i;

  for (i = 0;
       i < sizeof (mcore_elf_howto_raw) / sizeof (mcore_elf_howto_raw[0]);
       i++)
    if (mcore_elf_howto_raw[i].name != NULL
        && strcasecmp (mcore_elf_howto_raw[i].name, r_name) == 0)
      return &mcore_elf_howto_raw[i];

  return NULL;
}

/* Set the howto pointer for a RCE ELF reloc.  */

static void
mcore_elf_info_to_howto (bfd * abfd ATTRIBUTE_UNUSED,
                         arelent * cache_ptr,
                         Elf_Internal_Rela * dst)
{
  if (! mcore_elf_howto_table [R_MCORE_PCRELIMM8BY4])
    /* Initialize howto table if needed.  */
    mcore_elf_howto_init ();

  BFD_ASSERT (ELF32_R_TYPE (dst->r_info) < (unsigned int) R_MCORE_max);

  cache_ptr->howto = mcore_elf_howto_table [ELF32_R_TYPE (dst->r_info)];
}
\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
   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
mcore_elf_relocate_section (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);
  Elf_Internal_Rela * rel = relocs;
  Elf_Internal_Rela * relend = relocs + input_section->reloc_count;
  bfd_boolean ret = TRUE;

#ifdef DEBUG
  _bfd_error_handler
    ("mcore_elf_relocate_section called for %B section %A, %ld relocations%s",
     input_bfd,
     input_section,
     (long) input_section->reloc_count,
     (info->relocatable) ? " (relocatable)" : "");
#endif

  if (! mcore_elf_howto_table [R_MCORE_PCRELIMM8BY4])   /* Initialize howto table if needed */
    mcore_elf_howto_init ();

  for (; rel < relend; rel++)
    {
      enum elf_mcore_reloc_type    r_type = (enum elf_mcore_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;
      asection *                   sec = NULL;
      reloc_howto_type *           howto;
      bfd_vma                      relocation;
      Elf_Internal_Sym *           sym = NULL;
      unsigned long                r_symndx;
      struct elf_link_hash_entry * h = NULL;
      unsigned short               oldinst = 0;

      /* Unknown relocation handling.  */
      if ((unsigned) r_type >= (unsigned) R_MCORE_max
          || ! mcore_elf_howto_table [(int)r_type])
        {
          _bfd_error_handler (_("%B: Unknown relocation type %d\n"),
                              input_bfd, (int) r_type);

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

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

      /* Complain about known relocation that are not yet supported.  */
      if (howto->special_function == mcore_elf_unsupported_reloc)
        {
          _bfd_error_handler (_("%B: Relocation %s (%d) is not currently supported.\n"),
                              input_bfd,
                              howto->name,
                              (int)r_type);

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

      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);
          addend = rel->r_addend;
        }
      else
        {
          bfd_boolean unresolved_reloc, warned, ignored;

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

      if (sec != NULL && discarded_section (sec))
        RELOC_AGAINST_DISCARDED_SECTION (info, input_bfd, input_section,
                                         rel, 1, relend, howto, 0, contents);

      if (info->relocatable)
        continue;

      switch (r_type)
        {
        default:
          break;

        case R_MCORE_PCRELJSR_IMM11BY2:
          oldinst = bfd_get_16 (input_bfd, contents + offset);
#define MCORE_INST_BSR  0xF800
          bfd_put_16 (input_bfd, (bfd_vma) MCORE_INST_BSR, contents + offset);
          break;
        }

#ifdef DEBUG
      fprintf (stderr, "\ttype = %s (%d), symbol index = %ld, offset = %ld, addend = %ld\n",
               howto->name, r_type, 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 && r_type == R_MCORE_PCRELJSR_IMM11BY2)
        {
          /* Wasn't ok, back it out and give up.  */
          bfd_put_16 (input_bfd, (bfd_vma) oldinst, contents + offset);
          r = bfd_reloc_ok;
        }

      if (r != bfd_reloc_ok)
        {
          ret = FALSE;

          switch (r)
            {
            default:
              break;

            case bfd_reloc_overflow:
              {
                const char * name;

                if (h != NULL)
                  name = NULL;
                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, (h ? &h->root : NULL), name, howto->name,
                   (bfd_vma) 0, input_bfd, input_section, offset);
              }
              break;
            }
        }
    }

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

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

static asection *
mcore_elf_gc_mark_hook (asection *sec,
                        struct bfd_link_info *info,
                        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_MCORE_GNU_VTINHERIT:
      case R_MCORE_GNU_VTENTRY:
        return NULL;
      }

  return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym);
}

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

static bfd_boolean
mcore_elf_gc_sweep_hook (bfd * abfd ATTRIBUTE_UNUSED,
                         struct bfd_link_info * info ATTRIBUTE_UNUSED,
                         asection * sec ATTRIBUTE_UNUSED,
                         const Elf_Internal_Rela * relocs ATTRIBUTE_UNUSED)
{
  return TRUE;
}

/* Look through the relocs for a section during the first phase.
   Since we don't do .gots or .plts, we just need to consider the
   virtual table relocs for gc.  */

static bfd_boolean
mcore_elf_check_relocs (bfd * abfd,
                        struct bfd_link_info * info,
                        asection * sec,
                        const Elf_Internal_Rela * relocs)
{
  Elf_Internal_Shdr * symtab_hdr;
  struct elf_link_hash_entry ** sym_hashes;
  const Elf_Internal_Rela * rel;
  const Elf_Internal_Rela * rel_end;

  if (info->relocatable)
    return TRUE;

  symtab_hdr = & elf_tdata (abfd)->symtab_hdr;
  sym_hashes = elf_sym_hashes (abfd);

  rel_end = relocs + sec->reloc_count;

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

      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;

          /* PR15323, ref flags aren't set for references in the same
             object.  */
          h->root.non_ir_ref = 1;
        }

      switch (ELF32_R_TYPE (rel->r_info))
        {
        /* This relocation describes the C++ object vtable hierarchy.
           Reconstruct it for later use during GC.  */
        case R_MCORE_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_MCORE_GNU_VTENTRY:
          BFD_ASSERT (h != NULL);
          if (h != NULL
              && !bfd_elf_gc_record_vtentry (abfd, sec, h, rel->r_addend))
            return FALSE;
          break;
        }
    }

  return TRUE;
}

static const struct bfd_elf_special_section mcore_elf_special_sections[]=
{
  { STRING_COMMA_LEN (".ctors"), -2, SHT_PROGBITS, SHF_ALLOC + SHF_WRITE },
  { STRING_COMMA_LEN (".dtors"), -2, SHT_PROGBITS, SHF_ALLOC + SHF_WRITE },
  { NULL,                     0,  0, 0,            0 }
};

#define TARGET_BIG_SYM          mcore_elf32_be_vec
#define TARGET_BIG_NAME         "elf32-mcore-big"
#define TARGET_LITTLE_SYM       mcore_elf32_le_vec
#define TARGET_LITTLE_NAME      "elf32-mcore-little"

#define ELF_ARCH                bfd_arch_mcore
#define ELF_MACHINE_CODE        EM_MCORE
#define ELF_MAXPAGESIZE         0x1000          /* 4k, if we ever have 'em */
#define elf_info_to_howto       mcore_elf_info_to_howto
#define elf_info_to_howto_rel   NULL

#define bfd_elf32_bfd_merge_private_bfd_data    mcore_elf_merge_private_bfd_data
#define bfd_elf32_bfd_set_private_flags         mcore_elf_set_private_flags
#define bfd_elf32_bfd_reloc_type_lookup         mcore_elf_reloc_type_lookup
#define bfd_elf32_bfd_reloc_name_lookup mcore_elf_reloc_name_lookup
#define elf_backend_relocate_section            mcore_elf_relocate_section
#define elf_backend_gc_mark_hook                mcore_elf_gc_mark_hook
#define elf_backend_gc_sweep_hook               mcore_elf_gc_sweep_hook
#define elf_backend_check_relocs                mcore_elf_check_relocs
#define elf_backend_special_sections            mcore_elf_special_sections

#define elf_backend_can_gc_sections             1
#define elf_backend_rela_normal                 1

#include "elf32-target.h"