Branch data     Line data    Source code

       1                 :            : /* Look up the DIE in a reference-form attribute.
       2                 :            :    Copyright (C) 2005-2010, 2018 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                 :    2434850 : dwarf_formref_die (Dwarf_Attribute *attr, Dwarf_Die *result)
      40                 :            : {
      41         [ +  + ]:    2434850 :   if (attr == NULL)
      42                 :            :     return NULL;
      43                 :            : 
      44                 :    2083122 :   struct Dwarf_CU *cu = attr->cu;
      45                 :            : 
      46                 :    2083122 :   Dwarf_Off offset;
      47         [ +  + ]:    2083122 :   if (attr->form == DW_FORM_ref_addr || attr->form == DW_FORM_GNU_ref_alt
      48   [ +  -  -  + ]:    2082972 :       || attr->form == DW_FORM_ref_sup4 || attr->form == DW_FORM_ref_sup8)
      49                 :            :     {
      50                 :            :       /* This has an absolute offset.  */
      51                 :            : 
      52                 :        150 :       uint8_t ref_size;
      53   [ -  +  -  - ]:        150 :       if (cu->version == 2 && attr->form == DW_FORM_ref_addr)
      54                 :          0 :         ref_size = cu->address_size;
      55         [ +  - ]:        150 :       else if (attr->form == DW_FORM_ref_sup4)
      56                 :            :         ref_size = 4;
      57         [ +  - ]:        150 :       else if (attr->form == DW_FORM_ref_sup8)
      58                 :            :         ref_size = 8;
      59                 :            :       else
      60                 :        150 :         ref_size = cu->offset_size;
      61                 :            : 
      62                 :        300 :       Dwarf *dbg_ret = (attr->form == DW_FORM_GNU_ref_alt
      63         [ +  + ]:        150 :                         ? INTUSE(dwarf_getalt) (cu->dbg) : cu->dbg);
      64                 :            : 
      65         [ -  + ]:        150 :       if (dbg_ret == NULL)
      66                 :            :         {
      67                 :          0 :           __libdw_seterrno (DWARF_E_NO_ALT_DEBUGLINK);
      68                 :          0 :           return NULL;
      69                 :            :         }
      70                 :            : 
      71         [ -  + ]:        150 :       if (__libdw_read_offset (cu->dbg, dbg_ret, IDX_debug_info, attr->valp,
      72                 :            :                                ref_size, &offset, IDX_debug_info, 0))
      73                 :            :         return NULL;
      74                 :            : 
      75                 :        150 :       return INTUSE(dwarf_offdie) (dbg_ret, offset, result);
      76                 :            :     }
      77                 :            : 
      78                 :    2082972 :   const unsigned char *datap;
      79                 :    2082972 :   size_t size;
      80         [ +  + ]:    2082972 :   if (attr->form == DW_FORM_ref_sig8)
      81                 :            :     {
      82                 :            :       /* This doesn't have an offset, but instead a value we
      83                 :            :          have to match in the type unit headers.  */
      84                 :            : 
      85         [ -  + ]:         12 :       uint64_t sig = read_8ubyte_unaligned (cu->dbg, attr->valp);
      86                 :         12 :       cu = Dwarf_Sig8_Hash_find (&cu->dbg->sig8_hash, sig);
      87         [ +  + ]:         12 :       if (cu == NULL)
      88                 :            :         {
      89                 :            :           /* Not seen before.  We have to scan through the type units.
      90                 :            :              Since DWARFv5 these can (also) be found in .debug_info,
      91                 :            :              so scan that first.  */
      92                 :            :           bool scan_debug_types = false;
      93                 :          4 :           do
      94                 :            :             {
      95                 :          4 :               rwlock_wrlock(attr->cu->dbg->dwarf_lock);
      96                 :          4 :               cu = __libdw_intern_next_unit (attr->cu->dbg, scan_debug_types);
      97                 :          4 :               rwlock_unlock(attr->cu->dbg->dwarf_lock);
      98                 :            : 
      99         [ +  + ]:          4 :               if (cu == NULL)
     100                 :            :                 {
     101         [ +  - ]:          2 :                   if (scan_debug_types == false)
     102                 :            :                     scan_debug_types = true;
     103                 :            :                   else
     104                 :            :                     {
     105         [ #  # ]:          0 :                       __libdw_seterrno (INTUSE(dwarf_errno) ()
     106                 :            :                                         ?: DWARF_E_INVALID_REFERENCE);
     107                 :          0 :                       return NULL;
     108                 :            :                     }
     109                 :            :                 }
     110                 :            :             }
     111         [ -  + ]:          2 :           while (cu == NULL || cu->unit_id8 != sig);
     112                 :            :         }
     113                 :            : 
     114                 :         12 :       int secid = cu_sec_idx (cu);
     115                 :         12 :       datap = cu->dbg->sectiondata[secid]->d_buf;
     116                 :         12 :       size = cu->dbg->sectiondata[secid]->d_size;
     117                 :         12 :       offset = cu->start + cu->subdie_offset;
     118                 :            :     }
     119                 :            :   else
     120                 :            :     {
     121                 :            :       /* Other forms produce an offset from the CU.  */
     122         [ -  + ]:    2082960 :       if (unlikely (__libdw_formref (attr, &offset) != 0))
     123                 :            :         return NULL;
     124                 :            : 
     125                 :    2082960 :       datap = cu->startp;
     126                 :    2082960 :       size = cu->endp - cu->startp;
     127                 :            :     }
     128                 :            : 
     129         [ -  + ]:    2082972 :   if (unlikely (offset >= size))
     130                 :            :     {
     131                 :          0 :       __libdw_seterrno (DWARF_E_INVALID_DWARF);
     132                 :          0 :       return NULL;
     133                 :            :     }
     134                 :            : 
     135                 :    2082972 :   memset (result, '\0', sizeof (Dwarf_Die));
     136                 :    2082972 :   result->addr = (char *) datap + offset;
     137                 :    2082972 :   result->cu = cu;
     138                 :    2082972 :   return result;
     139                 :            : }
     140                 :            : INTDEF (dwarf_formref_die)