/* Error handling in libelf.
   Copyright (C) 1998, 1999, 2000, 2002, 2003, 2004, 2005, 2006 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 <assert.h>
#include <libintl.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>

#include "libelfP.h"


#ifdef USE_TLS
/* The error number.  */
static __thread int global_error;
#else
/* This is the key for the thread specific memory.  */
static tls_key_t key;

/* The error number.  Used in non-threaded programs.  */
static int global_error;
static bool threaded;
/* We need to initialize the thread-specific data.  */
once_define (static, once);

/* The initialization and destruction functions.  */
static void init (void);
static void free_key_mem (void *mem);
#endif	/* TLS */


int
elf_errno (void)
{
  int result;

#ifndef USE_TLS
  /* If we have not yet initialized the buffer do it now.  */
  once_execute (once, init);

  if (threaded)
    {
    /* We do not allocate memory for the data.  It is only a word.
       We can store it in place of the pointer.  */
      result = (intptr_t) getspecific (key);

      setspecific (key, (void *) (intptr_t) ELF_E_NOERROR);
      return result;
    }
#endif	/* TLS */

  result = global_error;
  global_error = ELF_E_NOERROR;
  return result;
}


/* Return the appropriate message for the error.  */
static const char msgstr[] =
{
#define ELF_E_NOERROR_IDX 0
  N_("no error")
  "\0"
#define ELF_E_UNKNOWN_ERROR_IDX (ELF_E_NOERROR_IDX + sizeof "no error")
  N_("unknown error")
  "\0"
#define ELF_E_UNKNOWN_VERSION_IDX \
  (ELF_E_UNKNOWN_ERROR_IDX + sizeof "unknown error")
  N_("unknown version")
  "\0"
#define ELF_E_UNKNOWN_TYPE_IDX \
  (ELF_E_UNKNOWN_VERSION_IDX + sizeof "unknown version")
  N_("unknown type")
  "\0"
#define ELF_E_INVALID_HANDLE_IDX \
  (ELF_E_UNKNOWN_TYPE_IDX + sizeof "unknown type")
  N_("invalid `Elf' handle")
  "\0"
#define ELF_E_SOURCE_SIZE_IDX \
  (ELF_E_INVALID_HANDLE_IDX + sizeof "invalid `Elf' handle")
  N_("invalid size of source operand")
  "\0"
#define ELF_E_DEST_SIZE_IDX \
  (ELF_E_SOURCE_SIZE_IDX + sizeof "invalid size of source operand")
  N_("invalid size of destination operand")
  "\0"
#define ELF_E_INVALID_ENCODING_IDX \
  (ELF_E_DEST_SIZE_IDX + sizeof "invalid size of destination operand")
  N_("invalid encoding")
  "\0"
#define ELF_E_NOMEM_IDX \
  (ELF_E_INVALID_ENCODING_IDX + sizeof "invalid encoding")
  N_("out of memory")
  "\0"
#define ELF_E_INVALID_FILE_IDX \
  (ELF_E_NOMEM_IDX + sizeof "out of memory")
  N_("invalid file descriptor")
  "\0"
#define ELF_E_INVALID_OP_IDX \
  (ELF_E_INVALID_FILE_IDX + sizeof "invalid file descriptor")
  N_("invalid operation")
  "\0"
#define ELF_E_NO_VERSION_IDX \
  (ELF_E_INVALID_OP_IDX + sizeof "invalid operation")
  N_("ELF version not set")
  "\0"
#define ELF_E_INVALID_CMD_IDX \
  (ELF_E_NO_VERSION_IDX + sizeof "ELF version not set")
  N_("invalid command")
  "\0"
#define ELF_E_RANGE_IDX \
  (ELF_E_INVALID_CMD_IDX + sizeof "invalid command")
  N_("offset out of range")
  "\0"
#define ELF_E_ARCHIVE_FMAG_IDX \
  (ELF_E_RANGE_IDX + sizeof "offset out of range")
  N_("invalid fmag field in archive header")
  "\0"
#define ELF_E_INVALID_ARCHIVE_IDX \
  (ELF_E_ARCHIVE_FMAG_IDX + sizeof "invalid fmag field in archive header")
  N_("invalid archive file")
  "\0"
#define ELF_E_NO_ARCHIVE_IDX \
  (ELF_E_INVALID_ARCHIVE_IDX + sizeof "invalid archive file")
  N_("descriptor is not for an archive")
  "\0"
#define ELF_E_NO_INDEX_IDX \
  (ELF_E_NO_ARCHIVE_IDX + sizeof "descriptor is not for an archive")
  N_("no index available")
  "\0"
#define ELF_E_READ_ERROR_IDX \
  (ELF_E_NO_INDEX_IDX + sizeof "no index available")
  N_("cannot read data from file")
  "\0"
#define ELF_E_WRITE_ERROR_IDX \
  (ELF_E_READ_ERROR_IDX + sizeof "cannot read data from file")
  N_("cannot write data to file")
  "\0"
#define ELF_E_INVALID_CLASS_IDX \
  (ELF_E_WRITE_ERROR_IDX + sizeof "cannot write data to file")
  N_("invalid binary class")
  "\0"
#define ELF_E_INVALID_INDEX_IDX \
  (ELF_E_INVALID_CLASS_IDX + sizeof "invalid binary class")
  N_("invalid section index")
  "\0"
#define ELF_E_INVALID_OPERAND_IDX \
  (ELF_E_INVALID_INDEX_IDX + sizeof "invalid section index")
  N_("invalid operand")
  "\0"
#define ELF_E_INVALID_SECTION_IDX \
  (ELF_E_INVALID_OPERAND_IDX + sizeof "invalid operand")
  N_("invalid section")
  "\0"
#define ELF_E_INVALID_COMMAND_IDX \
  (ELF_E_INVALID_SECTION_IDX + sizeof "invalid section")
  N_("invalid command")
  "\0"
#define ELF_E_WRONG_ORDER_EHDR_IDX \
  (ELF_E_INVALID_COMMAND_IDX + sizeof "invalid command")
  N_("executable header not created first")
  "\0"
#define ELF_E_FD_DISABLED_IDX \
  (ELF_E_WRONG_ORDER_EHDR_IDX + sizeof "executable header not created first")
  N_("file descriptor disabled")
  "\0"
#define ELF_E_FD_MISMATCH_IDX \
  (ELF_E_FD_DISABLED_IDX + sizeof "file descriptor disabled")
  N_("archive/member fildes mismatch")
  "\0"
#define ELF_E_OFFSET_RANGE_IDX \
  (ELF_E_FD_MISMATCH_IDX + sizeof "archive/member fildes mismatch")
  N_("offset out of range")
  "\0"
#define ELF_E_NOT_NUL_SECTION_IDX \
  (ELF_E_OFFSET_RANGE_IDX + sizeof "offset out of range")
  N_("cannot manipulate null section")
  "\0"
#define ELF_E_DATA_MISMATCH_IDX \
  (ELF_E_NOT_NUL_SECTION_IDX + sizeof "cannot manipulate null section")
  N_("data/scn mismatch")
  "\0"
#define ELF_E_INVALID_SECTION_HEADER_IDX \
  (ELF_E_DATA_MISMATCH_IDX + sizeof "data/scn mismatch")
  N_("invalid section header")
  "\0"
#define ELF_E_INVALID_DATA_IDX \
  (ELF_E_INVALID_SECTION_HEADER_IDX + sizeof "invalid section header")
  N_("invalid data")
  "\0"
#define ELF_E_DATA_ENCODING_IDX \
  (ELF_E_INVALID_DATA_IDX + sizeof "invalid data")
  N_("unknown data encoding")
  "\0"
#define ELF_E_SECTION_TOO_SMALL_IDX \
  (ELF_E_DATA_ENCODING_IDX + sizeof "unknown data encoding")
  N_("section `sh_size' too small for data")
  "\0"
#define ELF_E_INVALID_ALIGN_IDX \
  (ELF_E_SECTION_TOO_SMALL_IDX + sizeof "section `sh_size' too small for data")
  N_("invalid section alignment")
  "\0"
#define ELF_E_INVALID_SHENTSIZE_IDX \
  (ELF_E_INVALID_ALIGN_IDX + sizeof "invalid section alignment")
  N_("invalid section entry size")
  "\0"
#define ELF_E_UPDATE_RO_IDX \
  (ELF_E_INVALID_SHENTSIZE_IDX + sizeof "invalid section entry size")
  N_("update() for write on read-only file")
  "\0"
#define ELF_E_NOFILE_IDX \
  (ELF_E_UPDATE_RO_IDX + sizeof "update() for write on read-only file")
  N_("no such file")
  "\0"
#define ELF_E_GROUP_NOT_REL_IDX \
  (ELF_E_NOFILE_IDX + sizeof "no such file")
  N_("only relocatable files can contain section groups")
  "\0"
#define ELF_E_INVALID_PHDR_IDX \
  (ELF_E_GROUP_NOT_REL_IDX \
   + sizeof "only relocatable files can contain section groups")
  N_("program header only allowed in executables, shared objects, and \
core files")
  "\0"
#define ELF_E_NO_PHDR_IDX \
  (ELF_E_INVALID_PHDR_IDX \
   + sizeof "program header only allowed in executables, shared objects, and \
core files")
  N_("file has no program header")
  "\0"
#define ELF_E_INVALID_OFFSET_IDX \
  (ELF_E_NO_PHDR_IDX \
   + sizeof "file has no program header")
  N_("invalid offset")
};


static const uint_fast16_t msgidx[ELF_E_NUM] =
{
  [ELF_E_NOERROR] = ELF_E_NOERROR_IDX,
  [ELF_E_UNKNOWN_ERROR] = ELF_E_UNKNOWN_ERROR_IDX,
  [ELF_E_UNKNOWN_VERSION] = ELF_E_UNKNOWN_VERSION_IDX,
  [ELF_E_UNKNOWN_TYPE] = ELF_E_UNKNOWN_TYPE_IDX,
  [ELF_E_INVALID_HANDLE] = ELF_E_INVALID_HANDLE_IDX,
  [ELF_E_SOURCE_SIZE] = ELF_E_SOURCE_SIZE_IDX,
  [ELF_E_DEST_SIZE] = ELF_E_DEST_SIZE_IDX,
  [ELF_E_INVALID_ENCODING] = ELF_E_INVALID_ENCODING_IDX,
  [ELF_E_NOMEM] = ELF_E_NOMEM_IDX,
  [ELF_E_INVALID_FILE] = ELF_E_INVALID_FILE_IDX,
  [ELF_E_INVALID_OP] = ELF_E_INVALID_OP_IDX,
  [ELF_E_NO_VERSION] = ELF_E_NO_VERSION_IDX,
  [ELF_E_INVALID_CMD] = ELF_E_INVALID_CMD_IDX,
  [ELF_E_RANGE] = ELF_E_RANGE_IDX,
  [ELF_E_ARCHIVE_FMAG] = ELF_E_ARCHIVE_FMAG_IDX,
  [ELF_E_INVALID_ARCHIVE] = ELF_E_INVALID_ARCHIVE_IDX,
  [ELF_E_NO_ARCHIVE] = ELF_E_NO_ARCHIVE_IDX,
  [ELF_E_NO_INDEX] = ELF_E_NO_INDEX_IDX,
  [ELF_E_READ_ERROR] = ELF_E_READ_ERROR_IDX,
  [ELF_E_WRITE_ERROR] = ELF_E_WRITE_ERROR_IDX,
  [ELF_E_INVALID_CLASS] = ELF_E_INVALID_CLASS_IDX,
  [ELF_E_INVALID_INDEX] = ELF_E_INVALID_INDEX_IDX,
  [ELF_E_INVALID_OPERAND] = ELF_E_INVALID_OPERAND_IDX,
  [ELF_E_INVALID_SECTION] = ELF_E_INVALID_SECTION_IDX,
  [ELF_E_INVALID_COMMAND] = ELF_E_INVALID_COMMAND_IDX,
  [ELF_E_WRONG_ORDER_EHDR] = ELF_E_WRONG_ORDER_EHDR_IDX,
  [ELF_E_FD_DISABLED] = ELF_E_FD_DISABLED_IDX,
  [ELF_E_FD_MISMATCH] = ELF_E_FD_MISMATCH_IDX,
  [ELF_E_OFFSET_RANGE] = ELF_E_OFFSET_RANGE_IDX,
  [ELF_E_NOT_NUL_SECTION] = ELF_E_NOT_NUL_SECTION_IDX,
  [ELF_E_DATA_MISMATCH] = ELF_E_DATA_MISMATCH_IDX,
  [ELF_E_INVALID_SECTION_HEADER] = ELF_E_INVALID_SECTION_HEADER_IDX,
  [ELF_E_INVALID_DATA] = ELF_E_INVALID_DATA_IDX,
  [ELF_E_DATA_ENCODING] = ELF_E_DATA_ENCODING_IDX,
  [ELF_E_SECTION_TOO_SMALL] = ELF_E_SECTION_TOO_SMALL_IDX,
  [ELF_E_INVALID_ALIGN] = ELF_E_INVALID_ALIGN_IDX,
  [ELF_E_INVALID_SHENTSIZE] = ELF_E_INVALID_SHENTSIZE_IDX,
  [ELF_E_UPDATE_RO] = ELF_E_UPDATE_RO_IDX,
  [ELF_E_NOFILE] = ELF_E_NOFILE_IDX,
  [ELF_E_GROUP_NOT_REL] = ELF_E_GROUP_NOT_REL_IDX,
  [ELF_E_INVALID_PHDR] = ELF_E_INVALID_PHDR_IDX,
  [ELF_E_NO_PHDR] = ELF_E_NO_PHDR_IDX,
  [ELF_E_INVALID_OFFSET] = ELF_E_INVALID_OFFSET_IDX
};
#define nmsgidx ((int) (sizeof (msgidx) / sizeof (msgidx[0])))


void
__libelf_seterrno (value)
     int value;
{
#ifndef USE_TLS
  /* If we have not yet initialized the buffer do it now.  */
  once_execute (once, init);

  if (threaded)
    /* We do not allocate memory for the data.  It is only a word.
       We can store it in place of the pointer.  */
    setspecific (key, (void *) (intptr_t) value);
#endif	/* TLS */

  global_error = value >= 0 && value < nmsgidx ? value : ELF_E_UNKNOWN_ERROR;
}


const char *
elf_errmsg (error)
     int error;
{
  int last_error;

#ifndef USE_TLS
  /* If we have not yet initialized the buffer do it now.  */
  once_execute (once, init);

  if ((error == 0 || error == -1) && threaded)
    /* We do not allocate memory for the data.  It is only a word.
       We can store it in place of the pointer.  */
    last_error = (intptr_t) getspecific (key);
  else
#endif	/* TLS */
    last_error = global_error;

  if (error == 0)
    {
      assert (msgidx[last_error] < sizeof (msgstr));
      return last_error != 0 ? _(msgstr + msgidx[last_error]) : NULL;
    }
  else if (error < -1 || error >= nmsgidx)
    return _(msgstr + ELF_E_UNKNOWN_ERROR_IDX);

  assert (msgidx[error == -1 ? last_error : error] < sizeof (msgstr));
  return _(msgstr + msgidx[error == -1 ? last_error : error]);
}


#ifndef USE_TLS
/* Free the thread specific data, this is done if a thread terminates.  */
static void
free_key_mem (void *mem __attribute__ ((unused)))
{
  setspecific (key, NULL);
}


/* Initialize the key for the global variable.  */
static void
init (void)
{
  // XXX Screw you, gcc4, the unused function attribute does not work.
  __asm ("" :: "r" (free_key_mem));

  if (key_create (&key, free_key_mem) == 0)
    /* Creating the key succeeded.  */
    threaded = true;
}
#endif	/* TLS */