/* TXVU-specific support for 32-bit ELF.
   Copyright (C) 1997 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/txvu.h"

static reloc_howto_type *bfd_elf32_bfd_reloc_type_lookup
  PARAMS ((bfd *abfd, bfd_reloc_code_real_type code));
static void txvu_info_to_howto_rel
  PARAMS ((bfd *, arelent *, Elf32_Internal_Rela *));
static boolean txvu_elf_relocate_section
  PARAMS ((bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *,
	   Elf_Internal_Rela *, Elf_Internal_Sym *, asection **));

/* Use RELA, not REL.  REL incurs complications one would rather not
   deal with.  */
/*#define USE_REL*/

static reloc_howto_type txvu_elf_howto_table[] =
{
  /* This reloc does nothing.  */
  HOWTO (R_TXVU_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_TXVU_NONE",		/* name */
	 false,			/* partial_inplace */
	 0,			/* src_mask */
	 0,			/* dst_mask */
	 false),		/* pcrel_offset */

  /* insert reloc entries here */
};

/* Map BFD reloc types to TXVU ELF reloc types.  */

struct txvu_reloc_map
{
  unsigned char bfd_reloc_val;
  unsigned char elf_reloc_val;
};

static const struct txvu_reloc_map txvu_reloc_map[] =
{
  { BFD_RELOC_NONE, R_TXVU_NONE },
  /* insert reloc entries here */
};

static reloc_howto_type *
bfd_elf32_bfd_reloc_type_lookup (abfd, code)
     bfd *abfd;
     bfd_reloc_code_real_type code;
{
  unsigned int i;

  for (i = 0;
       i < sizeof (txvu_reloc_map) / sizeof (struct txvu_reloc_map);
       i++)
    {
      if (txvu_reloc_map[i].bfd_reloc_val == code)
	return &txvu_elf_howto_table[txvu_reloc_map[i].elf_reloc_val];
    }

  return NULL;
}

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

static void
txvu_info_to_howto_rel (abfd, cache_ptr, dst)
     bfd *abfd;
     arelent *cache_ptr;
     Elf32_Internal_Rela *dst;
{
  unsigned int r_type = ELF32_R_TYPE (dst->r_info);
  BFD_ASSERT (r_type < (unsigned int) R_TXVU_max);
  cache_ptr->howto = &txvu_elf_howto_table[r_type];
}

/* Relocate a TXVU 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 adjust the section contents as
   necessary, and (if using Rela relocs and generating a
   relocateable output file) adjusting the reloc addend as
   necessary.

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

   LOCAL_SYMS is a pointer to the swapped in local symbols.

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

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

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

static boolean
txvu_elf_relocate_section (output_bfd, info, input_bfd, input_section,
			   contents, relocs, local_syms, local_sections)
     bfd *output_bfd;
     struct bfd_link_info *info;
     bfd *input_bfd;
     asection *input_section;
     bfd_byte *contents;
     Elf_Internal_Rela *relocs;
     Elf_Internal_Sym *local_syms;
     asection **local_sections;
{
  Elf_Internal_Shdr *symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
  struct elf_link_hash_entry **sym_hashes = elf_sym_hashes (input_bfd);
  Elf_Internal_Rela *rel, *relend;
  bfd *dynobj = elf_hash_table (info)->dynobj;
  /* Assume success.  */
  boolean ret = true;

  rel = relocs;
  relend = relocs + input_section->reloc_count;
  for (; rel < relend; rel++)
    {
      int r_type;
      reloc_howto_type *howto;
      unsigned long r_symndx;
      /* We can't modify r_addend here as elf_link_input_bfd has an assert to
	 ensure it's zero (we use REL relocs, not RELA).  Therefore this
	 should be assigning zero to `addend', but for clarity we use
	 `r_addend'.  */
      /* ??? The previous comment is old, revisit and delete.  */
      bfd_vma addend = rel->r_addend;
      bfd_vma offset = rel->r_offset;
      struct elf_link_hash_entry *h;
      Elf_Internal_Sym *sym;
      asection *sec;
      const char *sym_name;
      bfd_reloc_status_type r;
      const char *errmsg = NULL;

      r_type = ELF32_R_TYPE (rel->r_info);
      if (r_type < 0 || r_type >= (int) R_TXVU_max)
	{
	  (*_bfd_error_handler) ("%s: unknown relocation type %d",
				 bfd_get_filename (input_bfd),
				 (int) r_type);
	  bfd_set_error (bfd_error_bad_value);
	  ret = false;
	  continue;
	}

      howto = txvu_elf_howto_table + r_type;
      r_symndx = ELF32_R_SYM (rel->r_info);

      if (info->relocateable)
	{
	  /* This is a relocateable link.  We don't have to change
	     anything, unless the reloc is against a section symbol,
	     in which case we have to adjust according to where the
	     section symbol winds up in the output section.  */
	  sec = NULL;
	  if (r_symndx >= symtab_hdr->sh_info)
	    {
	      /* External symbol.  */
	      continue;
	    }

	  /* Local symbol.  */
	  sym = local_syms + r_symndx;
	  sym_name = "<local symbol>";
	  /* STT_SECTION: symbol is associated with a section.  */
	  if (ELF_ST_TYPE (sym->st_info) != STT_SECTION)
	    {
	      /* Symbol isn't associated with a section.  Nothing to do.  */
	      continue;
	    }

	  sec = local_sections[r_symndx];
	  addend += sec->output_offset + sym->st_value;
	  rel->r_addend = addend;

	  /* Addends are stored with relocs.  We're done.  */
	  continue;
	}
      else
	{
	  bfd_vma relocation;

	  /* This is a final link.  */
	  h = NULL;
	  sym = NULL;
	  sec = NULL;

	  if (r_symndx < symtab_hdr->sh_info)
	    {
	      /* Local symbol.  */
	      sym = local_syms + r_symndx;
	      sec = local_sections[r_symndx];
	      sym_name = "<local symbol>";
	      relocation = (sec->output_section->vma
			    + sec->output_offset
			    + sym->st_value);
	    }
	  else
	    {
	      /* External symbol.  */
	      h = sym_hashes[r_symndx - symtab_hdr->sh_info];
	      while (h->root.type == bfd_link_hash_indirect
		     || h->root.type == bfd_link_hash_warning)
		h = (struct elf_link_hash_entry *) h->root.u.i.link;
	      sym_name = h->root.root.string;

	      if (h->root.type == bfd_link_hash_defined
		  || h->root.type == bfd_link_hash_defweak)
		{
		  sec = h->root.u.def.section;
		  if (sec->output_section == NULL)
		    relocation = 0;
		  else
		    relocation = (h->root.u.def.value
				  + sec->output_section->vma
				  + sec->output_offset);
		}
	      else if (h->root.type == bfd_link_hash_undefweak)
		relocation = 0;
	      else
		{
		  if (! ((*info->callbacks->undefined_symbol)
			 (info, h->root.root.string, input_bfd,
			  input_section, offset)))
		    return false;
		  relocation = 0;
		}
	    }

	  /* Sanity check the address.  */
	  if (offset > input_section->_raw_size)
	    {
	      r = bfd_reloc_outofrange;
	      goto check_reloc;
	    }

	  switch ((int) r_type)
	    {
	      /* insert reloc handling code here */
	    default :
	      r = _bfd_final_link_relocate (howto, input_bfd, input_section,
					    contents, offset,
					    relocation, addend);
	      break;
	    }
	}

    check_reloc:

      if (r != bfd_reloc_ok)
	{
	  /* FIXME: This should be generic enough to go in a utility.  */
	  const char *name;

	  if (h != NULL)
	    name = h->root.root.string;
	  else
	    {
	      name = (bfd_elf_string_from_elf_section
		      (input_bfd, symtab_hdr->sh_link, sym->st_name));
	      if (name == NULL || *name == '\0')
		name = bfd_section_name (input_bfd, sec);
	    }

	  if (errmsg != NULL)
	    goto common_error;

	  switch (r)
	    {
	    case bfd_reloc_overflow:
	      if (! ((*info->callbacks->reloc_overflow)
		     (info, name, howto->name, (bfd_vma) 0,
		      input_bfd, input_section, offset)))
		return false;
	      break;

	    case bfd_reloc_undefined:
	      if (! ((*info->callbacks->undefined_symbol)
		     (info, name, input_bfd, input_section,
		      offset)))
		return false;
	      break;

	    case bfd_reloc_outofrange:
	      errmsg = "internal error: out of range error";
	      goto common_error;

	    case bfd_reloc_notsupported:
	      errmsg = "internal error: unsupported relocation error";
	      goto common_error;

	    case bfd_reloc_dangerous:
	      errmsg = "internal error: dangerous error";
	      goto common_error;

	    default:
	      errmsg = "internal error: unknown error";
	      /* fall through */

	    common_error:
	      if (!((*info->callbacks->warning)
		    (info, errmsg, name, input_bfd, input_section,
		     offset)))
		return false;
	      break;
	    }
	}
    }

  return ret;
}

#define ELF_ARCH		bfd_arch_txvu
#define ELF_MACHINE_CODE	EM_CYGNUS_TXVU
#define ELF_MAXPAGESIZE		0x1000

#define TARGET_BIG_SYM          bfd_elf32_txvu_vec
#define TARGET_BIG_NAME		"elf32-txvu"

#define elf_info_to_howto			txvu_info_to_howto_rel
#define elf_backend_relocate_section		txvu_elf_relocate_section
					
#include "elf32-target.h"