libelf/elf32_xlatetof.c

/* Convert from memory to file representation.
   Copyright (C) 1998, 1999, 2000, 2002 Red Hat, Inc.
   This file is part of Red Hat elfutils.
   Written by Ulrich Drepper <drepper@redhat.com>, 1998.

   Red Hat elfutils 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; version 2 of the License.

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   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 Red Hat elfutils; if not, write to the Free Software Foundation,
   Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.

   In addition, as a special exception, Red Hat, Inc. gives You the
   additional right to link the code of Red Hat elfutils with code licensed
   under any Open Source Initiative certified open source license
   (http://www.opensource.org/licenses/index.php) which requires the
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   code used in conjunction with Red Hat elfutils except the Non-GPL Code
   covered by this exception.  If you modify this file, you may extend this
   exception to your version of the file, but you are not obligated to do
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   this file solely under the GPL without exception.

   Red Hat elfutils is an included package of the Open Invention Network.
   An included package of the Open Invention Network is a package for which
   Open Invention Network licensees cross-license their patents.  No patent
   license is granted, either expressly or impliedly, by designation as an
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#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include <assert.h>
#include <endian.h>
#include <string.h>

#include "libelfP.h"

#ifndef LIBELFBITS
# define LIBELFBITS	32
#endif


Elf_Data *
elfw2(LIBELFBITS, xlatetof) (dest, src, encode)
     Elf_Data *dest;
     const Elf_Data *src;
     unsigned int encode;
{
  /* First test whether the input data is really suitable for this
     type.  This means, whether there is an integer number of records.
     Note that for this implementation the memory and file size of the
     data types are identical.  */
#if EV_NUM != 2
  size_t recsize = __libelf_type_sizes[src->d_version - 1][ELFW(ELFCLASS,LIBELFBITS) - 1][src->d_type];
#else
  size_t recsize = __libelf_type_sizes[0][ELFW(ELFCLASS,LIBELFBITS) - 1][src->d_type];
#endif

  if (src->d_size % recsize != 0)
    {
      __libelf_seterrno (ELF_E_INVALID_DATA);
      return NULL;
    }

  /* Next see whether the converted data fits in the output buffer.  */
  if (src->d_size > dest->d_size)
    {
      __libelf_seterrno (ELF_E_DEST_SIZE);
      return NULL;
    }

  /* Test the encode parameter.  */
  if (encode != ELFDATA2LSB && encode != ELFDATA2MSB)
    {
      __libelf_seterrno (ELF_E_INVALID_ENCODING);
      return NULL;
    }

  /* Determine the translation function to use.

     At this point we make an assumption which is valid for all
     existing implementations so far: the memory and file sizes are
     the same.  This has very important consequences:
     a) The requirement that the source and destination buffer can
	overlap can easily be fulfilled.
     b) We need only one function to convert from and memory to file
	and vice versa since the function only has to copy and/or
	change the byte order.
  */
  if ((__BYTE_ORDER == __LITTLE_ENDIAN && encode == ELFDATA2LSB)
      || (__BYTE_ORDER == __BIG_ENDIAN && encode == ELFDATA2MSB))
    {
      /* We simply have to copy since the byte order is the same.  */
      if (src->d_buf != dest->d_buf)
	memmove (dest->d_buf, src->d_buf, src->d_size);
    }
  else
    {
      xfct_t fctp;

      /* Get a pointer to the transformation functions.  The `#ifdef' is
	 a small optimization since we don't anticipate another ELF
	 version and so would waste "precious" code.  */
#if EV_NUM != 2
      fctp = __elf_xfctstom[dest->d_version - 1][src->d_version - 1][ELFW(ELFCLASS, LIBELFBITS) - 1][src->d_type];
#else
      fctp = __elf_xfctstom[0][0][ELFW(ELFCLASS, LIBELFBITS) - 1][src->d_type];
#endif

      /* Do the real work.  */
      (*fctp) (dest->d_buf, src->d_buf, src->d_size, 1);
    }

  /* Now set the real destination type and length since the operation was
     successful.  */
  dest->d_type = src->d_type;
  dest->d_size = src->d_size;

  return dest;
}
INTDEF(elfw2(LIBELFBITS, xlatetof))