/* Return tag of given DIE.
   Copyright (C) 2003-2011, 2014 Red Hat, Inc.
   This file is part of elfutils.
   Written by Ulrich Drepper <drepper@redhat.com>, 2003.

   This file is free software; you can redistribute it and/or modify
   it under the terms of either

     * the GNU Lesser General Public License as published by the Free
       Software Foundation; either version 3 of the License, or (at
       your option) any later version

   or

     * 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

   or both in parallel, as here.

   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 copies of the GNU General Public License and
   the GNU Lesser General Public License along with this program.  If
   not, see <http://www.gnu.org/licenses/>.  */

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

#include "libdwP.h"


Dwarf_Abbrev *
internal_function
__libdw_findabbrev (struct Dwarf_CU *cu, unsigned int code)
{
  Dwarf_Abbrev *abb;

  /* Abbreviation code can never have a value of 0.  */
  if (unlikely (code == 0))
    return DWARF_END_ABBREV;

  /* See whether the entry is already in the hash table.  */
  abb = Dwarf_Abbrev_Hash_find (&cu->abbrev_hash, code);
  if (abb == NULL)
    {
      mutex_lock (cu->abbrev_lock);

      /* Check once more in case entry was added before abbrev_lock
	 was acquired.  */
      abb = Dwarf_Abbrev_Hash_find (&cu->abbrev_hash, code);

      if (abb == NULL)
	while (cu->last_abbrev_offset != (size_t) -1l)
	  {
	    size_t length;

	    /* Find the next entry.  It gets automatically added to the
	       hash table.  */
	    abb = __libdw_getabbrev (cu->dbg, cu, cu->last_abbrev_offset,
				     &length);

	    if (abb == NULL || abb == DWARF_END_ABBREV)
	      {
		/* Make sure we do not try to search for it again.  */
		cu->last_abbrev_offset = (size_t) -1l;
		mutex_unlock (cu->abbrev_lock);
		return DWARF_END_ABBREV;
	      }

	    cu->last_abbrev_offset += length;

	    /* Is this the code we are looking for?  */
	    if (abb->code == code)
	      break;
	  }

      mutex_unlock (cu->abbrev_lock);
    }

  /* This is our second (or third, etc.) call to __libdw_findabbrev
     and the code is invalid.  */
  if (unlikely (abb == NULL))
    abb = DWARF_END_ABBREV;

  return abb;
}


int
dwarf_tag (Dwarf_Die *die)
{
  /* Find the abbreviation entry.  */
  Dwarf_Abbrev *abbrevp = __libdw_dieabbrev (die, NULL);
  if (unlikely (abbrevp == DWARF_END_ABBREV))
    {
      __libdw_seterrno (DWARF_E_INVALID_DWARF);
      return DW_TAG_invalid;
    }

  return abbrevp->tag;
}
INTDEF(dwarf_tag)
