libelf/gelf_xlate.c

/* Transformation functions for ELF data types.
   Copyright (C) 1998,1999,2000,2002,2004,2005,2006,2007 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.

   Red Hat elfutils 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 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
   distribution of source code with any binary distribution and to
   distribute linked combinations of the two.  Non-GPL Code permitted under
   this exception must only link to the code of Red Hat elfutils through
   those well defined interfaces identified in the file named EXCEPTION
   found in the source code files (the "Approved Interfaces").  The files
   of Non-GPL Code may instantiate templates or use macros or inline
   functions from the Approved Interfaces without causing the resulting
   work to be covered by the GNU General Public License.  Only Red Hat,
   Inc. may make changes or additions to the list of Approved Interfaces.
   Red Hat's grant of this exception is conditioned upon your not adding
   any new exceptions.  If you wish to add a new Approved Interface or
   exception, please contact Red Hat.  You must obey the GNU General Public
   License in all respects for all of the Red Hat elfutils code and other
   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
   so.  If you do not wish to provide this exception without modification,
   you must delete this exception statement from your version and license
   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
   included package.  Should you wish to participate in the Open Invention
   Network licensing program, please visit www.openinventionnetwork.com
   <http://www.openinventionnetwork.com>.  */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include <byteswap.h>
#include <stdint.h>
#include <string.h>
#include <stdlib.h>

#include "libelfP.h"

#ifndef LIBELFBITS
# define LIBELFBITS	32
#endif


/* Well, what shall I say.  Nothing to do here.  */
#define elf_cvt_Byte(dest, src, n) \
  (__builtin_constant_p (n) && (n) == 1					      \
   ? (void) (*((char *) (dest)) = *((char *) (src)))			      \
   : Elf32_cvt_Byte (dest, src, n))
static void
(elf_cvt_Byte) (void *dest, const void *src, size_t n,
		int encode __attribute__ ((unused)))
{
  memmove (dest, src, n);
}


/* We'll optimize the definition of the conversion functions here a
   bit.  We need only functions for 16, 32, and 64 bits.  The
   functions referenced in the table will be aliases for one of these
   functions.  Which one is decided by the ELFxx_FSZ_type.  */

#if ALLOW_UNALIGNED

#define FETCH(Bits, ptr)	(*(const uint##Bits##_t *) ptr)
#define STORE(Bits, ptr, val)	(*(uint##Bits##_t *) ptr = val)

#else

union unaligned
  {
    uint16_t u16;
    uint32_t u32;
    uint64_t u64;
  } __attribute__ ((packed));

#define FETCH(Bits, ptr)	(((const union unaligned *) ptr)->u##Bits)
#define STORE(Bits, ptr, val)	(((union unaligned *) ptr)->u##Bits = val)

#endif

/* Now define the conversion functions for the basic types.  We use here
   the fact that file and memory types are the same and that we have the
   ELFxx_FSZ_* macros.

   At the same time we define inline functions which we will use to
   convert the complex types.  */
#define FUNDAMENTAL(NAME, Name, Bits) \
  INLINE2 (ELFW2(Bits,FSZ_##NAME), ElfW2(Bits,cvt_##Name), ElfW2(Bits,Name))
#define INLINE2(Bytes, FName, TName) \
  INLINE3 (Bytes, FName, TName)
#define INLINE3(Bytes, FName, TName)					      \
  static inline void FName##1 (void *dest, const void *ptr)		      \
  {									      \
    switch (Bytes)							      \
      {									      \
      case 2: STORE (16, dest, bswap_16 (FETCH (16, ptr))); break;	      \
      case 4: STORE (32, dest, bswap_32 (FETCH (32, ptr))); break;	      \
      case 8: STORE (64, dest, bswap_64 (FETCH (64, ptr))); break;	      \
      default:								      \
	abort ();							      \
      }									      \
  }									      \
									      \
  static void FName (void *dest, const void *ptr, size_t len,		      \
		     int encode __attribute__ ((unused)))		      \
  {									      \
    size_t n = len / sizeof (TName);					      \
    if (dest < ptr)							      \
      while (n-- > 0)							      \
	{								      \
	  FName##1 (dest, ptr);						      \
	  dest += Bytes;						      \
	  ptr += Bytes;							      \
	}								      \
    else								      \
      {									      \
	dest += len;							      \
	ptr += len;							      \
	while (n-- > 0)							      \
	  {								      \
	    ptr -= Bytes;						      \
	    dest -= Bytes;						      \
	    FName##1 (dest, ptr);					      \
	  }								      \
      }									      \
  }


/* Now the tricky part: define the transformation functions for the
   complex types.  We will use the definitions of the types in
   abstract.h.  */
#define START(Bits, Name, EName) \
  static void								      \
  ElfW2 (Bits, cvt_##Name) (void *dest, const void *src, size_t len,	      \
			    int encode __attribute__ ((unused)))	      \
  { ElfW2(Bits, Name) *tdest = (ElfW2(Bits, Name) *) dest;		      \
    ElfW2(Bits, Name) *tsrc = (ElfW2(Bits, Name) *) src;		      \
    size_t n;								      \
    for (n = len / sizeof (ElfW2(Bits, Name)); n > 0; ++tdest, ++tsrc, --n) {
#define END(Bits, Name) } }
#define TYPE_EXTRA(Code)
#define TYPE_XLATE(Code) Code
#define TYPE_NAME(Type, Name) TYPE_NAME2 (Type, Name)
#define TYPE_NAME2(Type, Name) Type##1 (&tdest->Name, &tsrc->Name);
#define TYPE(Name, Bits) TYPE2 (Name, Bits)
#define TYPE2(Name, Bits) TYPE3 (Name##Bits)
#define TYPE3(Name) Name (cvt_)

/* Signal that we are generating conversion functions.  */
#define GENERATE_CONVERSION

/* First generate the 32-bit conversion functions.  */
#define LIBELFBITS 32
#include "gelf_xlate.h"

/* Now generate the 64-bit conversion functions.  */
#define LIBELFBITS 64
#include "gelf_xlate.h"


/* We have a few functions which we must create by hand since the sections
   do not contain records of only one type.  */
#include "version_xlate.h"
#include "gnuhash_xlate.h"
#include "note_xlate.h"


/* Now the externally visible table with the function pointers.  */
const xfct_t __elf_xfctstom[EV_NUM - 1][EV_NUM - 1][ELFCLASSNUM - 1][ELF_T_NUM] =
{
  [EV_CURRENT - 1] = {
    [EV_CURRENT - 1] = {
      [ELFCLASS32 - 1] = {
#define define_xfcts(Bits) \
	[ELF_T_BYTE]	= elf_cvt_Byte,					      \
	[ELF_T_ADDR]	= ElfW2(Bits, cvt_Addr),			      \
	[ELF_T_DYN]	= ElfW2(Bits, cvt_Dyn),				      \
	[ELF_T_EHDR]	= ElfW2(Bits, cvt_Ehdr),			      \
	[ELF_T_HALF]	= ElfW2(Bits, cvt_Half),			      \
	[ELF_T_OFF]	= ElfW2(Bits, cvt_Off),				      \
	[ELF_T_PHDR]	= ElfW2(Bits, cvt_Phdr),			      \
	[ELF_T_RELA]	= ElfW2(Bits, cvt_Rela),			      \
	[ELF_T_REL]	= ElfW2(Bits, cvt_Rel),				      \
	[ELF_T_SHDR]	= ElfW2(Bits, cvt_Shdr),			      \
	[ELF_T_SWORD]	= ElfW2(Bits, cvt_Sword),			      \
	[ELF_T_SYM]	= ElfW2(Bits, cvt_Sym),				      \
	[ELF_T_WORD]	= ElfW2(Bits, cvt_Word),			      \
	[ELF_T_XWORD]	= ElfW2(Bits, cvt_Xword),			      \
	[ELF_T_SXWORD]	= ElfW2(Bits, cvt_Sxword),			      \
	[ELF_T_VDEF]	= elf_cvt_Verdef,				      \
	[ELF_T_VDAUX]	= elf_cvt_Verdef,				      \
	[ELF_T_VNEED]	= elf_cvt_Verneed,				      \
	[ELF_T_VNAUX]	= elf_cvt_Verneed,				      \
	[ELF_T_NHDR]	= elf_cvt_note,					      \
	[ELF_T_SYMINFO] = ElfW2(Bits, cvt_Syminfo),			      \
	[ELF_T_MOVE]	= ElfW2(Bits, cvt_Move),			      \
	[ELF_T_LIB]	= ElfW2(Bits, cvt_Lib),				      \
	[ELF_T_AUXV]	= ElfW2(Bits, cvt_auxv_t)
        define_xfcts (32),
	[ELF_T_GNUHASH] = Elf32_cvt_Word
      },
      [ELFCLASS64 - 1] = {
	define_xfcts (64),
	[ELF_T_GNUHASH] = elf_cvt_gnuhash
      }
    }
  }
};
/* For now we only handle the case where the memory representation is the
   same as the file representation.  Should this change we have to define
   separate functions.  For now reuse them.  */
strong_alias (__elf_xfctstom, __elf_xfctstof)