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/* MeP-specific support for 32-bit ELF.

   Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009

   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.  */

#include "sysdep.h"

#include "bfd.h"

#include "libbfd.h"

#include "elf-bfd.h"

#include "elf/mep.h"

#include "libiberty.h"

/* Forward declarations.  */

/* Private relocation functions.  */

#define MEPREL(type, size, bits, right, left, pcrel, overflow, mask) \

  {(unsigned)type, right, size, bits, pcrel, left, overflow, mep_reloc, #type, FALSE, 0, mask, 0 }

#define N complain_overflow_dont

#define S complain_overflow_signed

#define U complain_overflow_unsigned

static bfd_reloc_status_type mep_reloc (bfd *, arelent *, struct bfd_symbol *,

                                        void *, asection *, bfd *, char **);

static reloc_howto_type mep_elf_howto_table [] =

{

  /* type, size, bits, leftshift, rightshift, pcrel, OD/OS/OU, mask.  */

  MEPREL (R_MEP_NONE,     0,  0, 0, 0, 0, N, 0),

  MEPREL (R_RELC,         0,  0, 0, 0, 0, N, 0),

  /* MEPRELOC:HOWTO */

    /* This section generated from bfd/mep-relocs.pl from include/elf/mep.h.  */

  MEPREL (R_MEP_8,        0,  8, 0, 0, 0, U, 0xff),

  MEPREL (R_MEP_16,       1, 16, 0, 0, 0, U, 0xffff),

  MEPREL (R_MEP_32,       2, 32, 0, 0, 0, U, 0xffffffff),

  MEPREL (R_MEP_PCREL8A2, 1,  8, 1, 1, 1, S, 0x00fe),

  MEPREL (R_MEP_PCREL12A2,1, 12, 1, 1, 1, S, 0x0ffe),

  MEPREL (R_MEP_PCREL17A2,2, 17, 0, 1, 1, S, 0x0000ffff),

  MEPREL (R_MEP_PCREL24A2,2, 24, 0, 1, 1, S, 0x07f0ffff),

  MEPREL (R_MEP_PCABS24A2,2, 24, 0, 1, 0, U, 0x07f0ffff),

  MEPREL (R_MEP_LOW16,    2, 16, 0, 0, 0, N, 0x0000ffff),

  MEPREL (R_MEP_HI16U,    2, 32, 0,16, 0, N, 0x0000ffff),

  MEPREL (R_MEP_HI16S,    2, 32, 0,16, 0, N, 0x0000ffff),

  MEPREL (R_MEP_GPREL,    2, 16, 0, 0, 0, S, 0x0000ffff),

  MEPREL (R_MEP_TPREL,    2, 16, 0, 0, 0, S, 0x0000ffff),

  MEPREL (R_MEP_TPREL7,   1,  7, 0, 0, 0, U, 0x007f),

  MEPREL (R_MEP_TPREL7A2, 1,  7, 1, 1, 0, U, 0x007e),

  MEPREL (R_MEP_TPREL7A4, 1,  7, 2, 2, 0, U, 0x007c),

  MEPREL (R_MEP_UIMM24,   2, 24, 0, 0, 0, U, 0x00ffffff),

  MEPREL (R_MEP_ADDR24A4, 2, 24, 0, 2, 0, U, 0x00fcffff),

  MEPREL (R_MEP_GNU_VTINHERIT,1,  0,16,32, 0, N, 0x0000),

  MEPREL (R_MEP_GNU_VTENTRY,1,  0,16,32, 0, N, 0x0000),

  /* MEPRELOC:END */

};

#define VALID_MEP_RELOC(N) ((N) >= 0 \

  && (N) < ARRAY_SIZE (mep_elf_howto_table)

#undef N

#undef S

#undef U

static bfd_reloc_status_type

mep_reloc

    (bfd *               abfd ATTRIBUTE_UNUSED,

     arelent *           reloc_entry ATTRIBUTE_UNUSED,

     struct bfd_symbol * symbol ATTRIBUTE_UNUSED,

     void *              data ATTRIBUTE_UNUSED,

     asection *          input_section ATTRIBUTE_UNUSED,

     bfd *               output_bfd ATTRIBUTE_UNUSED,

     char **             error_message ATTRIBUTE_UNUSED)

{

  return bfd_reloc_ok;

}

#define BFD_RELOC_MEP_NONE BFD_RELOC_NONE

#if defined (__STDC__) || defined (ALMOST_STDC) || defined (HAVE_STRINGIZE)

#define MAP(n) case BFD_RELOC_MEP_##n: type = R_MEP_##n; break

#else

#define MAP(n) case BFD_RELOC_MEP_/**/n: type = R_MEP_/**/n; break

#endif

static reloc_howto_type *

mep_reloc_type_lookup

    (bfd * abfd ATTRIBUTE_UNUSED,

     bfd_reloc_code_real_type code)

{

  unsigned int type = 0;

  switch (code)

    {

    MAP(NONE);

    case BFD_RELOC_8:

      type = R_MEP_8;

      break;

    case BFD_RELOC_16:

      type = R_MEP_16;

      break;

    case BFD_RELOC_32:

      type = R_MEP_32;

      break;

    case BFD_RELOC_VTABLE_ENTRY:

      type = R_MEP_GNU_VTENTRY;

      break;

    case BFD_RELOC_VTABLE_INHERIT:

      type = R_MEP_GNU_VTINHERIT;

      break;

    case BFD_RELOC_RELC:

      type = R_RELC;

      break;

    /* MEPRELOC:MAP */

    /* This section generated from bfd/mep-relocs.pl from include/elf/mep.h.  */

    MAP(8);

    MAP(16);

    MAP(32);

    MAP(PCREL8A2);

    MAP(PCREL12A2);

    MAP(PCREL17A2);

    MAP(PCREL24A2);

    MAP(PCABS24A2);

    MAP(LOW16);

    MAP(HI16U);

    MAP(HI16S);

    MAP(GPREL);

    MAP(TPREL);

    MAP(TPREL7);

    MAP(TPREL7A2);

    MAP(TPREL7A4);

    MAP(UIMM24);

    MAP(ADDR24A4);

    MAP(GNU_VTINHERIT);

    MAP(GNU_VTENTRY);

    /* MEPRELOC:END */

    default:

      /* Pacify gcc -Wall.  */

      fprintf (stderr, "mep: no reloc for code %d\n", code);

      return NULL;

    }

  if (mep_elf_howto_table[type].type != type)

    {

      fprintf (stderr, "MeP: howto %d has type %d\n", type, mep_elf_howto_table[type].type);

      abort ();

    }

  return mep_elf_howto_table + type;

}

#undef MAP

static reloc_howto_type *

mep_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED, const char *r_name)

{

  unsigned int i;

  for (i = 0;

       i < sizeof (mep_elf_howto_table) / sizeof (mep_elf_howto_table[0]);

       i++)

    if (mep_elf_howto_table[i].name != NULL

        && strcasecmp (mep_elf_howto_table[i].name, r_name) == 0)

      return &mep_elf_howto_table[i];

  return NULL;

}

/* Perform a single relocation.  */

static struct bfd_link_info *mep_info;

static int warn_tp = 0, warn_sda = 0;

static bfd_vma

mep_lookup_global

    (char *    name,

     bfd_vma   ofs,

     bfd_vma * cache,

     int *     warn)

{

  struct bfd_link_hash_entry *h;

  if (*cache || *warn)

    return *cache;

  h = bfd_link_hash_lookup (mep_info->hash, name, FALSE, FALSE, TRUE);

  if (h == 0 || h->type != bfd_link_hash_defined)

    {

      *warn = ofs + 1;

      return 0;

    }

  *cache = (h->u.def.value

          + h->u.def.section->output_section->vma

          + h->u.def.section->output_offset);

  return *cache;

}

static bfd_vma

mep_tpoff_base (bfd_vma ofs)

{

  static bfd_vma cache = 0;

  return mep_lookup_global ("__tpbase", ofs, &cache, &warn_tp);

}

static bfd_vma

mep_sdaoff_base (bfd_vma ofs)

{

  static bfd_vma cache = 0;

  return mep_lookup_global ("__sdabase", ofs, &cache, &warn_sda);

}

static bfd_reloc_status_type

mep_final_link_relocate

    (reloc_howto_type *  howto,

     bfd *               input_bfd,

     asection *          input_section,

     bfd_byte *          contents,

     Elf_Internal_Rela * rel,

     bfd_vma             relocation)

{

  unsigned long u;

  long s;

  unsigned char *byte;

  bfd_vma pc;

  bfd_reloc_status_type r = bfd_reloc_ok;

  int e2, e4;

  if (bfd_big_endian (input_bfd))

    {

      e2 = 0;

      e4 = 0;

    }

  else

    {

      e2 = 1;

      e4 = 3;

    }

  pc = (input_section->output_section->vma

        + input_section->output_offset

        + rel->r_offset);

  s = relocation + rel->r_addend;

  byte = (unsigned char *)contents + rel->r_offset;

  if (howto->type == R_MEP_PCREL24A2

      && s == 0

      && pc >= 0x800000)

    {

      /* This is an unreachable branch to an undefined weak function.

         Silently ignore it, since the opcode can't do that but should

         never be executed anyway.  */

      return bfd_reloc_ok;

    }

  if (howto->pc_relative)

    s -= pc;

  u = (unsigned long) s;

  switch (howto->type)

    {

    /* MEPRELOC:APPLY */

    /* This section generated from bfd/mep-relocs.pl from include/elf/mep.h.  */

    case R_MEP_8: /* 76543210 */

      if (u > 255) r = bfd_reloc_overflow;

      byte[0] = (u & 0xff);

      break;

    case R_MEP_16: /* fedcba9876543210 */

      if (u > 65535) r = bfd_reloc_overflow;

      byte[0^e2] = ((u >> 8) & 0xff);

      byte[1^e2] = (u & 0xff);

      break;

    case R_MEP_32: /* vutsrqponmlkjihgfedcba9876543210 */

      byte[0^e4] = ((u >> 24) & 0xff);

      byte[1^e4] = ((u >> 16) & 0xff);

      byte[2^e4] = ((u >> 8) & 0xff);

      byte[3^e4] = (u & 0xff);

      break;

    case R_MEP_PCREL8A2: /* --------7654321- */

      if (-128 > s || s > 127) r = bfd_reloc_overflow;

      byte[1^e2] = (byte[1^e2] & 0x01) | (s & 0xfe);

      break;

    case R_MEP_PCREL12A2: /* ----ba987654321- */

      if (-2048 > s || s > 2047) r = bfd_reloc_overflow;

      byte[0^e2] = (byte[0^e2] & 0xf0) | ((s >> 8) & 0x0f);

      byte[1^e2] = (byte[1^e2] & 0x01) | (s & 0xfe);

      break;

    case R_MEP_PCREL17A2: /* ----------------gfedcba987654321 */

      if (-65536 > s || s > 65535) r = bfd_reloc_overflow;

      byte[2^e2] = ((s >> 9) & 0xff);

      byte[3^e2] = ((s >> 1) & 0xff);

      break;

    case R_MEP_PCREL24A2: /* -----7654321----nmlkjihgfedcba98 */

      if (-8388608 > s || s > 8388607) r = bfd_reloc_overflow;

      byte[0^e2] = (byte[0^e2] & 0xf8) | ((s >> 5) & 0x07);

      byte[1^e2] = (byte[1^e2] & 0x0f) | ((s << 3) & 0xf0);

      byte[2^e2] = ((s >> 16) & 0xff);

      byte[3^e2] = ((s >> 8) & 0xff);

      break;

    case R_MEP_PCABS24A2: /* -----7654321----nmlkjihgfedcba98 */

      if (u > 16777215) r = bfd_reloc_overflow;

      byte[0^e2] = (byte[0^e2] & 0xf8) | ((u >> 5) & 0x07);

      byte[1^e2] = (byte[1^e2] & 0x0f) | ((u << 3) & 0xf0);

      byte[2^e2] = ((u >> 16) & 0xff);

      byte[3^e2] = ((u >> 8) & 0xff);

      break;

    case R_MEP_LOW16: /* ----------------fedcba9876543210 */

      byte[2^e2] = ((u >> 8) & 0xff);

      byte[3^e2] = (u & 0xff);

      break;

    case R_MEP_HI16U: /* ----------------vutsrqponmlkjihg */

      byte[2^e2] = ((u >> 24) & 0xff);

      byte[3^e2] = ((u >> 16) & 0xff);

      break;

    case R_MEP_HI16S: /* ----------------vutsrqponmlkjihg */

      if (s & 0x8000)

        s += 0x10000;

      byte[2^e2] = ((s >> 24) & 0xff);

      byte[3^e2] = ((s >> 16) & 0xff);

      break;

    case R_MEP_GPREL: /* ----------------fedcba9876543210 */

      s -= mep_sdaoff_base(rel->r_offset);

      if (-32768 > s || s > 32767) r = bfd_reloc_overflow;

      byte[2^e2] = ((s >> 8) & 0xff);

      byte[3^e2] = (s & 0xff);

      break;

    case R_MEP_TPREL: /* ----------------fedcba9876543210 */

      s -= mep_tpoff_base(rel->r_offset);

      if (-32768 > s || s > 32767) r = bfd_reloc_overflow;

      byte[2^e2] = ((s >> 8) & 0xff);

      byte[3^e2] = (s & 0xff);

      break;

    case R_MEP_TPREL7: /* ---------6543210 */

      u -= mep_tpoff_base(rel->r_offset);

      if (u > 127) r = bfd_reloc_overflow;

      byte[1^e2] = (byte[1^e2] & 0x80) | (u & 0x7f);

      break;

    case R_MEP_TPREL7A2: /* ---------654321- */

      u -= mep_tpoff_base(rel->r_offset);

      if (u > 127) r = bfd_reloc_overflow;

      byte[1^e2] = (byte[1^e2] & 0x81) | (u & 0x7e);

      break;

    case R_MEP_TPREL7A4: /* ---------65432-- */

      u -= mep_tpoff_base(rel->r_offset);

      if (u > 127) r = bfd_reloc_overflow;

      byte[1^e2] = (byte[1^e2] & 0x83) | (u & 0x7c);

      break;

    case R_MEP_UIMM24: /* --------76543210nmlkjihgfedcba98 */

      if (u > 16777215) r = bfd_reloc_overflow;

      byte[1^e2] = (u & 0xff);

      byte[2^e2] = ((u >> 16) & 0xff);

      byte[3^e2] = ((u >> 8) & 0xff);

      break;

    case R_MEP_ADDR24A4: /* --------765432--nmlkjihgfedcba98 */

      if (u > 16777215) r = bfd_reloc_overflow;

      byte[1^e2] = (byte[1^e2] & 0x03) | (u & 0xfc);

      byte[2^e2] = ((u >> 16) & 0xff);

      byte[3^e2] = ((u >> 8) & 0xff);

      break;

    case R_MEP_GNU_VTINHERIT: /* ---------------- */

      break;

    case R_MEP_GNU_VTENTRY: /* ---------------- */

      break;

    /* MEPRELOC:END */

    default:

      abort ();

    }

  return r;

}

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

static void

mep_info_to_howto_rela

    (bfd *               abfd ATTRIBUTE_UNUSED,

     arelent *           cache_ptr,

     Elf_Internal_Rela * dst)

{

  unsigned int r_type;

  r_type = ELF32_R_TYPE (dst->r_info);

  cache_ptr->howto = & mep_elf_howto_table [r_type];

}

/* Relocate a MEP ELF section.

   There is some attempt to make this function usable for many architectures,

   both USE_REL and USE_RELA ['twould be nice if such a critter existed],

   if only to serve as a learning tool.

   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

mep_elf_relocate_section

    (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;

  symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr;

  sym_hashes = elf_sym_hashes (input_bfd);

  relend     = relocs + input_section->reloc_count;

  mep_info = info;

  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);

      r_symndx = ELF32_R_SYM (rel->r_info);

      howto  = mep_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);

          name = bfd_elf_string_from_elf_section

            (input_bfd, symtab_hdr->sh_link, sym->st_name);

          name = (name == NULL) ? bfd_section_name (input_bfd, sec) : name;

        }

      else

        {

          bfd_boolean warned, unresolved_reloc;

          RELOC_FOR_GLOBAL_SYMBOL(info, input_bfd, input_section, rel,

                                  r_symndx, symtab_hdr, sym_hashes,

                                  h, sec, relocation,

                                  unresolved_reloc, warned);

          name = h->root.root.string;

        }

      if (sec != NULL && elf_discarded_section (sec))

        {

          /* For relocs against symbols from removed linkonce sections,

             or sections discarded by a linker script, we just want the

             section contents zeroed.  Avoid any special processing.  */

          _bfd_clear_contents (howto, input_bfd, contents + rel->r_offset);

          rel->r_info = 0;

          rel->r_addend = 0;

          continue;

        }

      if (info->relocatable)

        continue;

      if (r_type == R_RELC)

        r = bfd_elf_perform_complex_relocation (input_bfd, input_section,

                                                contents, rel, relocation);

      else

        r = mep_final_link_relocate (howto, input_bfd, input_section,

                                     contents, rel, relocation);

      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;

        }

    }

  if (warn_tp)

    info->callbacks->undefined_symbol

      (info, "__tpbase", input_bfd, input_section, warn_tp-1, TRUE);

  if (warn_sda)

    info->callbacks->undefined_symbol

      (info, "__sdabase", input_bfd, input_section, warn_sda-1, TRUE);

  if (warn_sda || warn_tp)

    return FALSE;

  return TRUE;

}

/* Function to set the ELF flag bits.  */

static bfd_boolean

mep_elf_set_private_flags (bfd *    abfd,

                           flagword flags)

{

  elf_elfheader (abfd)->e_flags = flags;

  elf_flags_init (abfd) = TRUE;

  return TRUE;

}

static bfd_boolean

mep_elf_copy_private_bfd_data (bfd * ibfd, bfd * obfd)

{

  if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour

      || bfd_get_flavour (obfd) != bfd_target_elf_flavour)

    return TRUE;

  elf_elfheader (obfd)->e_flags = elf_elfheader (ibfd)->e_flags;

  elf_flags_init (obfd) = TRUE;

  /* Copy object attributes.  */

  _bfd_elf_copy_obj_attributes (ibfd, obfd);

  return TRUE;

}

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

   object file when linking.  */

static bfd_boolean

mep_elf_merge_private_bfd_data (bfd * ibfd, bfd * obfd)

{

  static bfd *last_ibfd = 0;

  flagword old_flags, new_flags;

  flagword old_partial, new_partial;

  /* Check if we have the same endianess.  */

  if (_bfd_generic_verify_endian_match (ibfd, obfd) == FALSE)