Branch data     Line data    Source code

       1                 :            : /* Look up the DIE in a reference-form attribute.
       2                 :            :    Copyright (C) 2005-2010 Red Hat, Inc.
       3                 :            :    This file is part of elfutils.
       4                 :            : 
       5                 :            :    This file is free software; you can redistribute it and/or modify
       6                 :            :    it under the terms of either
       7                 :            : 
       8                 :            :      * the GNU Lesser General Public License as published by the Free
       9                 :            :        Software Foundation; either version 3 of the License, or (at
      10                 :            :        your option) any later version
      11                 :            : 
      12                 :            :    or
      13                 :            : 
      14                 :            :      * the GNU General Public License as published by the Free
      15                 :            :        Software Foundation; either version 2 of the License, or (at
      16                 :            :        your option) any later version
      17                 :            : 
      18                 :            :    or both in parallel, as here.
      19                 :            : 
      20                 :            :    elfutils is distributed in the hope that it will be useful, but
      21                 :            :    WITHOUT ANY WARRANTY; without even the implied warranty of
      22                 :            :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      23                 :            :    General Public License for more details.
      24                 :            : 
      25                 :            :    You should have received copies of the GNU General Public License and
      26                 :            :    the GNU Lesser General Public License along with this program.  If
      27                 :            :    not, see <http://www.gnu.org/licenses/>.  */
      28                 :            : 
      29                 :            : #ifdef HAVE_CONFIG_H
      30                 :            : # include <config.h>
      31                 :            : #endif
      32                 :            : 
      33                 :            : #include <string.h>
      34                 :            : #include "libdwP.h"
      35                 :            : #include <dwarf.h>
      36                 :            : 
      37                 :            : 
      38                 :            : Dwarf_Die *
      39                 :     593376 : dwarf_formref_die (attr, result)
      40                 :            :      Dwarf_Attribute *attr;
      41                 :            :      Dwarf_Die *result;
      42                 :            : {
      43         [ +  - ]:     593376 :   if (attr == NULL)
      44                 :            :     return NULL;
      45                 :            : 
      46                 :     593376 :   struct Dwarf_CU *cu = attr->cu;
      47                 :            : 
      48                 :            :   Dwarf_Off offset;
      49         [ +  + ]:     593376 :   if (attr->form == DW_FORM_ref_addr || attr->form == DW_FORM_GNU_ref_alt)
      50                 :            :     {
      51                 :            :       /* This has an absolute offset.  */
      52                 :            : 
      53         [ -  + ]:          8 :       uint8_t ref_size = (cu->version == 2
      54                 :            :                           ? cu->address_size
      55                 :            :                           : cu->offset_size);
      56                 :            : 
      57                 :          8 :       Dwarf *dbg_ret = (attr->form == DW_FORM_GNU_ref_alt
      58         [ +  - ]:          8 :                         ? cu->dbg->alt_dwarf : cu->dbg);
      59                 :            : 
      60         [ -  + ]:          8 :       if (dbg_ret == NULL)
      61                 :            :         {
      62                 :          0 :           __libdw_seterrno (DWARF_E_NO_ALT_DEBUGLINK);
      63                 :            :           return NULL;
      64                 :            :         }
      65                 :            : 
      66         [ +  - ]:          8 :       if (__libdw_read_offset (cu->dbg, dbg_ret, IDX_debug_info, attr->valp,
      67                 :            :                                ref_size, &offset, IDX_debug_info, 0))
      68                 :            :         return NULL;
      69                 :            : 
      70                 :          8 :       return INTUSE(dwarf_offdie) (dbg_ret, offset, result);
      71                 :            :     }
      72                 :            : 
      73                 :            :   Elf_Data *data;
      74         [ +  + ]:     593368 :   if (attr->form == DW_FORM_ref_sig8)
      75                 :            :     {
      76                 :            :       /* This doesn't have an offset, but instead a value we
      77                 :            :          have to match in the .debug_types type unit headers.  */
      78                 :            : 
      79 [ -  + ][ #  # ]:          1 :       uint64_t sig = read_8ubyte_unaligned (cu->dbg, attr->valp);
      80                 :          1 :       cu = Dwarf_Sig8_Hash_find (&cu->dbg->sig8_hash, sig, NULL);
      81         [ +  - ]:          1 :       if (cu == NULL)
      82                 :            :         /* Not seen before.  We have to scan through the type units.  */
      83                 :            :         do
      84                 :            :           {
      85                 :          1 :             cu = __libdw_intern_next_unit (attr->cu->dbg, true);
      86         [ -  + ]:          1 :             if (cu == NULL)
      87                 :            :               {
      88         [ #  # ]:          0 :                 __libdw_seterrno (INTUSE(dwarf_errno) ()
      89                 :            :                                   ?: DWARF_E_INVALID_REFERENCE);
      90                 :            :                 return NULL;
      91                 :            :               }
      92                 :          1 :             Dwarf_Sig8_Hash_insert (&cu->dbg->sig8_hash, cu->type_sig8, cu);
      93                 :            :           }
      94         [ -  + ]:          1 :         while (cu->type_sig8 != sig);
      95                 :            : 
      96                 :          1 :       data = cu->dbg->sectiondata[IDX_debug_types];
      97                 :          1 :       offset = cu->type_offset;
      98                 :            :     }
      99                 :            :   else
     100                 :            :     {
     101                 :            :       /* Other forms produce an offset from the CU.  */
     102         [ +  - ]:     593367 :       if (unlikely (__libdw_formref (attr, &offset) != 0))
     103                 :            :         return NULL;
     104                 :            : 
     105                 :     593367 :       data = cu_data (cu);
     106                 :            :     }
     107                 :            : 
     108         [ -  + ]:     593368 :   if (unlikely (data->d_size - cu->start <= offset))
     109                 :            :     {
     110                 :          0 :       __libdw_seterrno (DWARF_E_INVALID_DWARF);
     111                 :            :       return NULL;
     112                 :            :     }
     113                 :            : 
     114                 :     593368 :   memset (result, '\0', sizeof (Dwarf_Die));
     115                 :     593368 :   result->addr = (char *) data->d_buf + cu->start + offset;
     116                 :     593376 :   result->cu = cu;
     117                 :            :   return result;
     118                 :            : }
     119                 :     593367 : INTDEF (dwarf_formref_die)