osprey/cygnus/bfd/elf32-openrisc.c

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

/* OpenRISC-specific support for 32-bit ELF.
   Copyright 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
   Contributed by Johan Rydberg, jrydberg@opencores.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.  */

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

/* Forward declarations.  */

static reloc_howto_type *openrisc_reloc_type_lookup
  PARAMS ((bfd * , bfd_reloc_code_real_type));
static void openrisc_info_to_howto_rela
  PARAMS ((bfd *, arelent *, Elf_Internal_Rela *));
static bfd_boolean openrisc_elf_relocate_section
  PARAMS ((bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *,
     Elf_Internal_Rela *, Elf_Internal_Sym *, asection **));
static bfd_reloc_status_type openrisc_final_link_relocate
  PARAMS ((reloc_howto_type *, bfd *, asection *, bfd_byte *,
           Elf_Internal_Rela *, bfd_vma));
static bfd_boolean openrisc_elf_gc_sweep_hook
  PARAMS ((bfd *, struct bfd_link_info *, asection *,
           const Elf_Internal_Rela *));
static asection * openrisc_elf_gc_mark_hook
  PARAMS ((asection *, struct bfd_link_info *, Elf_Internal_Rela *,
     struct elf_link_hash_entry *, Elf_Internal_Sym *));
static bfd_boolean openrisc_elf_check_relocs
  PARAMS ((bfd *, struct bfd_link_info *, asection *,
     const Elf_Internal_Rela *));
static bfd_boolean openrisc_elf_object_p
  PARAMS ((bfd *));
static void openrisc_elf_final_write_processing
  PARAMS ((bfd *, bfd_boolean));


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

  /* A PC relative 26 bit relocation, right shifted by 2.  */
  HOWTO (R_OPENRISC_INSN_REL_26, /* type */
   2,     /* rightshift */
   2,     /* size (0 = byte, 1 = short, 2 = long) */
   26,      /* bitsize */
   TRUE,      /* pc_relative */
   0,     /* bitpos */
   complain_overflow_signed, /* complain_on_overflow */
   bfd_elf_generic_reloc, /* special_function */
   "R_OPENRISC_INSN_REL_26", /* name */
   FALSE,     /* partial_inplace */
   0x00000000,    /* src_mask */
   0x03ffffff,    /* dst_mask */
   FALSE),    /* pcrel_offset */

  /* A absolute 26 bit relocation, right shifted by 2.  */
  HOWTO (R_OPENRISC_INSN_ABS_26, /* type */
   2,     /* rightshift */
   2,     /* size (0 = byte, 1 = short, 2 = long) */
   26,      /* bitsize */
   FALSE,     /* pc_relative */
   0,     /* bitpos */
   complain_overflow_signed, /* complain_on_overflow */
   bfd_elf_generic_reloc, /* special_function */
   "R_OPENRISC_INSN_ABS_26", /* name */
   FALSE,     /* partial_inplace */
   0x00000000,    /* src_mask */
   0x03ffffff,    /* dst_mask */
   FALSE),    /* pcrel_offset */

  HOWTO (R_OPENRISC_LO_16_IN_INSN, /* 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_OPENRISC_LO_16_IN_INSN", /* name */
   FALSE,     /* partial_inplace */
   0,     /* src_mask */
   0x0000ffff,    /* dst_mask */
   FALSE),    /* pcrel_offset */

  HOWTO (R_OPENRISC_HI_16_IN_INSN, /* 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_OPENRISC_HI_16_IN_INSN",  /* name */
   FALSE,     /* partial_inplace */
   0,     /* src_mask */
   0x0000ffff,    /* dst_mask */
   FALSE),    /* pcrel_offset */

  /* An 8 bit absolute relocation.  */
  HOWTO (R_OPENRISC_8,    /* 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_OPENRISC_8",  /* name */
   TRUE,      /* partial_inplace */
   0x0000,    /* src_mask */
   0x00ff,    /* dst_mask */
   FALSE),    /* pcrel_offset */

  /* A 16 bit absolute relocation.  */
  HOWTO (R_OPENRISC_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_OPENRISC_16", /* name */
   TRUE,      /* partial_inplace */
   0x00000000,    /* src_mask */
   0x0000ffff,    /* dst_mask */
   FALSE),    /* pcrel_offset */

  /* A 32 bit absolute relocation.  */
  HOWTO (R_OPENRISC_32,   /* 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_OPENRISC_32", /* name */
   TRUE,      /* partial_inplace */
   0x00000000,    /* src_mask */
   0xffffffff,    /* dst_mask */
   FALSE),    /* pcrel_offset */

  /* GNU extension to record C++ vtable hierarchy */
  HOWTO (R_OPENRISC_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_OPENRISC_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_OPENRISC_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_OPENRISC_GNU_VTENTRY", /* name */
   FALSE,     /* partial_inplace */
   0,     /* src_mask */
   0,     /* dst_mask */
   FALSE),    /* pcrel_offset */
};

/* Map BFD reloc types to OpenRISC ELF reloc types.  */

struct openrisc_reloc_map
  {
    bfd_reloc_code_real_type bfd_reloc_val;
    unsigned int openrisc_reloc_val;
  };

static const struct openrisc_reloc_map openrisc_reloc_map[] =
  {
    { BFD_RELOC_NONE,     R_OPENRISC_NONE },
    { BFD_RELOC_32,     R_OPENRISC_32 },
    { BFD_RELOC_16,     R_OPENRISC_16 },
    { BFD_RELOC_8,    R_OPENRISC_8 },
    { BFD_RELOC_OPENRISC_REL_26,R_OPENRISC_INSN_REL_26 },
    { BFD_RELOC_OPENRISC_ABS_26,R_OPENRISC_INSN_ABS_26 },
    { BFD_RELOC_HI16,     R_OPENRISC_HI_16_IN_INSN },
    { BFD_RELOC_LO16,     R_OPENRISC_LO_16_IN_INSN },
    { BFD_RELOC_VTABLE_INHERIT, R_OPENRISC_GNU_VTINHERIT },
    { BFD_RELOC_VTABLE_ENTRY,   R_OPENRISC_GNU_VTENTRY }
  };

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

  for (i = ARRAY_SIZE (openrisc_reloc_map); --i;)
    if (openrisc_reloc_map[i].bfd_reloc_val == code)
      return & openrisc_elf_howto_table[openrisc_reloc_map[i].
               openrisc_reloc_val];

  return NULL;
}

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

static void
openrisc_info_to_howto_rela (abfd, cache_ptr, dst)
     bfd * abfd ATTRIBUTE_UNUSED;
     arelent * cache_ptr;
     Elf_Internal_Rela * dst;
{
  unsigned int r_type;

  r_type = ELF32_R_TYPE (dst->r_info);
  BFD_ASSERT (r_type < (unsigned int) R_OPENRISC_max);
  cache_ptr->howto = & openrisc_elf_howto_table[r_type];
}

/* Perform a single relocation.  By default we use the standard BFD
   routines, but a few relocs, we have to do them ourselves.  */

static bfd_reloc_status_type
openrisc_final_link_relocate (howto, input_bfd, input_section, contents, rel,
            relocation)
     reloc_howto_type *howto;
     bfd *input_bfd;
     asection *input_section;
     bfd_byte *contents;
     Elf_Internal_Rela *rel;
     bfd_vma relocation;
{
  bfd_reloc_status_type r = bfd_reloc_ok;

  switch (howto->type)
    {
    case R_OPENRISC_LO_16_IN_INSN:
      relocation &= 0xffff;
      r = _bfd_final_link_relocate (howto, input_bfd, input_section,
            contents, rel->r_offset,
            relocation, rel->r_addend);
      break;

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

  return r;
}

/* Relocate an OpenRISC 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
openrisc_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;
  struct elf_link_hash_entry **sym_hashes;
  Elf_Internal_Rela *rel;
  Elf_Internal_Rela *relend;

  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;

  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);

      if (r_type == R_OPENRISC_GNU_VTINHERIT
    || r_type == R_OPENRISC_GNU_VTENTRY)
  continue;

      if ((unsigned int) r_type >
    (sizeof openrisc_elf_howto_table / sizeof (reloc_howto_type)))
  abort ();

      /* This is a final link.  */
      howto = openrisc_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 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);
  }

      r = openrisc_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;
  }
    }

  return TRUE;
}

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

static asection *
openrisc_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_OPENRISC_GNU_VTINHERIT:
  case R_OPENRISC_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
openrisc_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;
}

/* 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
openrisc_elf_check_relocs (abfd, info, sec, 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, **sym_hashes_end;
  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);
  sym_hashes_end =
    sym_hashes + symtab_hdr->sh_size / sizeof (Elf32_External_Sym);
  if (!elf_bad_symtab (abfd))
    sym_hashes_end -= symtab_hdr->sh_info;

  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];

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

  return TRUE;
}

/* Set the right machine number.  */

static bfd_boolean
openrisc_elf_object_p (abfd)
     bfd *abfd;
{
  switch (elf_elfheader (abfd)->e_flags & 0xf)
    {
    default:
      (void) bfd_default_set_arch_mach (abfd, bfd_arch_openrisc, 0);
      break;
    }
  return TRUE;
}

/* Store the machine number in the flags field.  */

static void
openrisc_elf_final_write_processing (abfd, linker)
     bfd *abfd;
     bfd_boolean linker ATTRIBUTE_UNUSED;
{
  unsigned long val;

  switch (bfd_get_mach (abfd))
    {
    default:
      val = 0;
      break;
    }

  elf_elfheader (abfd)->e_flags &= ~0xf;
  elf_elfheader (abfd)->e_flags |= val;
}


#define ELF_ARCH      bfd_arch_openrisc
#define ELF_MACHINE_CODE    EM_OPENRISC
#define ELF_MACHINE_ALT1    EM_OPENRISC_OLD
#define ELF_MAXPAGESIZE     0x1000

#define TARGET_BIG_SYM      bfd_elf32_openrisc_vec
#define TARGET_BIG_NAME     "elf32-openrisc"

#define elf_info_to_howto_rel   NULL
#define elf_info_to_howto   openrisc_info_to_howto_rela
#define elf_backend_relocate_section  openrisc_elf_relocate_section
#define elf_backend_gc_mark_hook  openrisc_elf_gc_mark_hook
#define elf_backend_gc_sweep_hook openrisc_elf_gc_sweep_hook
#define elf_backend_check_relocs  openrisc_elf_check_relocs

#define elf_backend_can_gc_sections 1
#define elf_backend_rela_normal   1

#define bfd_elf32_bfd_reloc_type_lookup openrisc_reloc_type_lookup

#define elf_backend_object_p                openrisc_elf_object_p
#define elf_backend_final_write_processing  openrisc_elf_final_write_processing

#include "elf32-target.h"

---