libdwarf/dwarf_get_aranges.c

/* Return list address ranges.
   Copyright (C) 2000, 2001, 2002 Red Hat, Inc.
   This file is part of Red Hat elfutils.
   Written by Ulrich Drepper <drepper@redhat.com>, 2000.

   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.

   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 <stdlib.h>

#include <libdwarfP.h>


struct arangelist
{
  Dwarf_Arange arange;
  struct arangelist *next;
};


int
dwarf_get_aranges (dbg, aranges, return_count, error)
     Dwarf_Debug dbg;
     Dwarf_Arange **aranges;
     Dwarf_Signed *return_count;
     Dwarf_Error *error;
{
  Dwarf_Small *readp;
  Dwarf_Small *readendp;
  struct arangelist *arangelist = NULL;
  unsigned int narangelist = 0;

  if (dbg->sections[IDX_debug_aranges].addr == NULL)
    return DW_DLV_NO_ENTRY;

  readp = (Dwarf_Small *) dbg->sections[IDX_debug_aranges].addr;
  readendp = readp + dbg->sections[IDX_debug_aranges].size;

  while (readp < readendp)
    {
      Dwarf_Small *hdrstart = readp;
      Dwarf_Unsigned length;
      unsigned int length_bytes;
      unsigned int version;
      Dwarf_Unsigned offset;
      unsigned int address_size;
      unsigned int segment_size;
      Dwarf_Arange_Info arange_info;

      /* Each entry starts with a header:

	 1. A 4-byte or 12-byte length containing the length of the
	 set of entries for this compilation unit, not including the
	 length field itself. [...]

	 2. A 2-byte version identifier containing the value 2 for
	 DWARF Version 2.1.

	 3. A 4-byte or 8-byte offset into the .debug_info section. [...]

	 4. A 1-byte unsigned integer containing the size in bytes of
	 an address (or the offset portion of an address for segmented
	 addressing) on the target system.

	 5. A 1-byte unsigned integer containing the size in bytes of
	 a segment descriptor on the target system.  */
      length = read_4ubyte_unaligned (dbg, readp);
      readp += 4;
      length_bytes = 4;
      if (length == 0xffffffff)
	{
	  length = read_8ubyte_unaligned (dbg, readp);
	  readp += 8;
	  length_bytes = 8;
	}

      version = read_2ubyte_unaligned (dbg, readp);
      readp += 2;
      if (version != 2)
	{
	  __libdwarf_error (dbg, error, DW_E_INVALID_DWARF);
	  return DW_DLV_ERROR;
	}

      if (length_bytes == 4)
	offset = read_4ubyte_unaligned (dbg, readp);
      else
	offset = read_8ubyte_unaligned (dbg, readp);
      readp += length_bytes;

      address_size = *readp++;
      segment_size = *readp++;

      /* Round the address to the next multiple of 2*address_size.  */
      readp += ((2 * address_size - ((readp - hdrstart) % (2 * address_size)))
		% (2 * address_size));

      arange_info =
	(Dwarf_Arange_Info) malloc (sizeof (struct Dwarf_Arange_s));
      if (arange_info == NULL)
	{
	  __libdwarf_error (dbg, error, DW_E_NOMEM);
	  return DW_DLV_ERROR;
	}

      arange_info->dbg = dbg;
      arange_info->offset = offset;

      while (1)
	{
	  Dwarf_Unsigned range_address;
	  Dwarf_Unsigned range_length;
	  struct arangelist *new_arange;

	  if (address_size == 4)
	    {
	      range_address = read_4ubyte_unaligned (dbg, readp);
	      readp += 4;
	      range_length = read_4ubyte_unaligned (dbg, readp);
	      readp += 4;
	    }
	  else if (likely (address_size == 8))
	    {
	      range_address = read_8ubyte_unaligned (dbg, readp);
	      readp += 8;
	      range_length = read_8ubyte_unaligned (dbg, readp);
	      readp += 8;
	    }
	  else
	    abort ();

	  /* Two zero values mark the end.  */
	  if (range_address == 0 && range_length == 0)
	    break;

	  new_arange =
	    (struct arangelist *) alloca (sizeof (struct arangelist));
	  new_arange->arange =
	    (Dwarf_Arange) malloc (sizeof (struct Dwarf_Arange_s));
	  if (new_arange->arange == NULL)
	    {
	      __libdwarf_error (dbg, error, DW_E_NOMEM);
	      return DW_DLV_ERROR;
	    }

	  new_arange->arange->address = range_address;
	  new_arange->arange->length = range_length;
	  new_arange->arange->info = arange_info;

	  new_arange->next = arangelist;
	  arangelist = new_arange;
	  ++narangelist;
	}
    }

  if (narangelist == 0)
    return DW_DLV_NO_ENTRY;

  /* Allocate the array for the result.  */
  *return_count = narangelist;
  *aranges = (Dwarf_Arange *) malloc (narangelist
				      * sizeof (struct Dwarf_Arange_s));
  if (*aranges == NULL)
    {
      __libdwarf_error (dbg, error, DW_E_NOMEM);
      return DW_DLV_ERROR;
    }

  while (narangelist-- > 0)
    {
      (*aranges)[narangelist] = arangelist->arange;
      arangelist = arangelist->next;
    }

  return DW_DLV_OK;
}