Line data    Source code

       1             : /* Return sibling of given DIE.
       2             :    Copyright (C) 2003-2010, 2014, 2015 Red Hat, Inc.
       3             :    This file is part of elfutils.
       4             :    Written by Ulrich Drepper <drepper@redhat.com>, 2003.
       5             : 
       6             :    This file is free software; you can redistribute it and/or modify
       7             :    it under the terms of either
       8             : 
       9             :      * the GNU Lesser General Public License as published by the Free
      10             :        Software Foundation; either version 3 of the License, or (at
      11             :        your option) any later version
      12             : 
      13             :    or
      14             : 
      15             :      * the GNU General Public License as published by the Free
      16             :        Software Foundation; either version 2 of the License, or (at
      17             :        your option) any later version
      18             : 
      19             :    or both in parallel, as here.
      20             : 
      21             :    elfutils is distributed in the hope that it will be useful, but
      22             :    WITHOUT ANY WARRANTY; without even the implied warranty of
      23             :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      24             :    General Public License for more details.
      25             : 
      26             :    You should have received copies of the GNU General Public License and
      27             :    the GNU Lesser General Public License along with this program.  If
      28             :    not, see <http://www.gnu.org/licenses/>.  */
      29             : 
      30             : #ifdef HAVE_CONFIG_H
      31             : # include <config.h>
      32             : #endif
      33             : 
      34             : #include "libdwP.h"
      35             : #include <dwarf.h>
      36             : #include <string.h>
      37             : 
      38             : 
      39             : int
      40     2536791 : dwarf_siblingof (Dwarf_Die *die, Dwarf_Die *result)
      41             : {
      42             :   /* Ignore previous errors.  */
      43     2536791 :   if (die == NULL)
      44             :     return -1;
      45             : 
      46             :   /* result is declared NN */
      47             : 
      48     2536791 :   if (result != die)
      49       12069 :     result->addr = NULL;
      50             : 
      51     2536791 :   unsigned int level = 0;
      52             : 
      53             :   /* Copy of the current DIE.  */
      54     2536791 :   Dwarf_Die this_die = *die;
      55             :   /* Temporary attributes we create.  */
      56             :   Dwarf_Attribute sibattr;
      57             :   /* Copy of the CU in the request.  */
      58     2536791 :   sibattr.cu = this_die.cu;
      59             :   /* That's the address we start looking.  */
      60     2536791 :   unsigned char *addr = this_die.addr;
      61             :   /* End of the buffer.  */
      62     2536791 :   unsigned char *endp = sibattr.cu->endp;
      63             : 
      64             :   /* Search for the beginning of the next die on this level.  We
      65             :      must not return the dies for children of the given die.  */
      66             :   do
      67             :     {
      68             :       /* Find the end of the DIE or the sibling attribute.  */
      69     2963233 :       addr = __libdw_find_attr (&this_die, DW_AT_sibling, &sibattr.code,
      70             :                                 &sibattr.form);
      71     2963233 :       if (addr != NULL && sibattr.code == DW_AT_sibling)
      72      655821 :         {
      73             :           Dwarf_Off offset;
      74      655821 :           sibattr.valp = addr;
      75      655821 :           if (unlikely (__libdw_formref (&sibattr, &offset) != 0))
      76             :             /* Something went wrong.  */
      77           0 :             return -1;
      78             : 
      79             :           /* The sibling attribute should point after this DIE in the CU.
      80             :              But not after the end of the CU.  */
      81      655821 :           size_t size = sibattr.cu->endp - sibattr.cu->startp;
      82      655821 :           size_t die_off = this_die.addr - this_die.cu->startp;
      83      655821 :           if (unlikely (offset >= size || offset <= die_off))
      84             :             {
      85           0 :               __libdw_seterrno (DWARF_E_INVALID_DWARF);
      86           0 :               return -1;
      87             :             }
      88             : 
      89             :           /* Compute the next address.  */
      90      655821 :           addr = sibattr.cu->startp + offset;
      91             :         }
      92     2307412 :       else if (unlikely (addr == NULL)
      93     2307412 :                || unlikely (this_die.abbrev == DWARF_END_ABBREV))
      94             :         return -1;
      95     2307412 :       else if (this_die.abbrev->has_children)
      96             :         /* This abbreviation has children.  */
      97       76749 :         ++level;
      98             : 
      99             : 
     100             :       while (1)
     101             :         {
     102             :           /* Make sure we are still in range.  Some producers might skip
     103             :              the trailing NUL bytes.  */
     104     3116731 :           if (addr >= endp)
     105             :             return 1;
     106             : 
     107     3038691 :           if (*addr != '\0')
     108             :             break;
     109             : 
     110      259282 :           if (level-- == 0)
     111             :             {
     112      182533 :               if (result != die)
     113        3411 :                 result->addr = addr;
     114             :               /* No more sibling at all.  */
     115             :               return 1;
     116             :             }
     117             : 
     118       76749 :           ++addr;
     119             :         }
     120             : 
     121             :       /* Initialize the 'current DIE'.  */
     122     2779409 :       this_die.addr = addr;
     123     2779409 :       this_die.abbrev = NULL;
     124             :     }
     125     2779409 :   while (level > 0);
     126             : 
     127             :   /* Maybe we reached the end of the CU.  */
     128             :   if (addr >= endp)
     129             :     return 1;
     130             : 
     131             :   /* Clear the entire DIE structure.  This signals we have not yet
     132             :      determined any of the information.  */
     133     2352967 :   memset (result, '\0', sizeof (Dwarf_Die));
     134             : 
     135             :   /* We have the address.  */
     136     2352967 :   result->addr = addr;
     137             : 
     138             :   /* Same CU as the parent.  */
     139     2352967 :   result->cu = sibattr.cu;
     140             : 
     141     2352967 :   return 0;
     142             : }
     143             : INTDEF(dwarf_siblingof)