libdwarf/dwarf_get_globals.c

/* Return list of global definitions.
   Copyright (C) 2000, 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 <string.h>

#include <libdwarfP.h>


struct globallist
{
  Dwarf_Global global;
  struct globallist *next;
};


/* Read the whole given section.  */
int
dwarf_get_globals (dbg, globals, return_count, error)
     Dwarf_Debug dbg;
     Dwarf_Global **globals;
     Dwarf_Signed *return_count;
     Dwarf_Error *error;
{
  Dwarf_Small *readp;
  Dwarf_Small *readendp;
  struct globallist *globallist = NULL;
  unsigned int ngloballist = 0;

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

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

  while (readp < readendp)
    {
      Dwarf_Unsigned length;
      Dwarf_Unsigned info_length;
      unsigned int length_bytes;
      unsigned int version;
      Dwarf_Unsigned offset;
      Dwarf_Global_Info global_info;

      /* Each entry starts with a header:

 	 1. A 4-byte or 12-byte 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 4-byte or 8-byte length containing the size in bytes of
	 the contents of the .debug_info section generated to
	 represent this compilation unit. [...]  */
      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 (unlikely (version != 2))
	{
	  __libdwarf_error (dbg, error, DW_E_INVALID_DWARF);
	  return DW_DLV_ERROR;
	}

      if (length_bytes == 4)
	{
	  offset = read_4ubyte_unaligned (dbg, readp);
	  readp += 4;
	  info_length = read_4ubyte_unaligned (dbg, readp);
	  readp += 4;
	}
      else
	{
	  offset = read_8ubyte_unaligned (dbg, readp);
	  readp += 8;
	  info_length = read_8ubyte_unaligned (dbg, readp);
	  readp += 8;
	}

      global_info =
	(Dwarf_Global_Info) malloc (sizeof (struct Dwarf_Global_s));
      if (global_info == NULL)
	{
	  __libdwarf_error (dbg, error, DW_E_NOMEM);
	  return DW_DLV_ERROR;
	}

      global_info->dbg = dbg;
      global_info->offset = offset;

      /* Following the section contains tuples of offsets and
         nul-terminated strings.  */
      while (1)
	{
	  Dwarf_Unsigned die_offset;
	  struct globallist *new_global;

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

	  if (die_offset == 0)
	    /* This closes this entry.  */
	    break;

	  new_global =
	    (struct globallist *) alloca (sizeof (struct globallist));
	  new_global->global =
	    (Dwarf_Global) malloc (sizeof (struct Dwarf_Global_s));
	  if (new_global->global == NULL)
	    {
	      __libdwarf_error (dbg, error, DW_E_NOMEM);
	      return DW_DLV_ERROR;
	    }

	  new_global->global->offset = die_offset;
	  new_global->global->name = (char *) readp;
	  new_global->global->info = global_info;

	  new_global->next = globallist;
	  globallist = new_global;
	  ++ngloballist;

	  readp = (Dwarf_Small *) rawmemchr (readp, '\0') + 1;
	}
    }

  if (ngloballist == 0)
    return DW_DLV_NO_ENTRY;

  /* Allocate the array for the result.  */
  *return_count = ngloballist;
  *globals = (Dwarf_Global *) malloc (ngloballist
				      * sizeof (struct Dwarf_Global_s));
  if (*globals == NULL)
    {
      __libdwarf_error (dbg, error, DW_E_NOMEM);
      return DW_DLV_ERROR;
    }

  while (ngloballist-- > 0)
    {
      (*globals)[ngloballist] = globallist->global;
      globallist = globallist->next;
    }

  return DW_DLV_OK;
}