Branch data     Line data    Source code

       1                 :            : /* Return DWARF attribute associated with a location expression op.
       2                 :            :    Copyright (C) 2013, 2014, 2017, 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 <dwarf.h>
      34                 :            : #include <libdwP.h>
      35                 :            : 
      36                 :            : static Dwarf_CU *
      37                 :      41390 : attr_form_cu (Dwarf_Attribute *attr)
      38                 :            : {
      39                 :            :   /* If the attribute has block/expr form the data comes from the
      40                 :            :      .debug_info from the same cu as the attr.  Otherwise it comes from
      41                 :            :      the .debug_loc or .debug_loclists data section.  */
      42         [ +  + ]:      41390 :   switch (attr->form)
      43                 :            :     {
      44                 :       2051 :     case DW_FORM_block1:
      45                 :            :     case DW_FORM_block2:
      46                 :            :     case DW_FORM_block4:
      47                 :            :     case DW_FORM_block:
      48                 :            :     case DW_FORM_exprloc:
      49                 :       2051 :       return attr->cu;
      50                 :      39339 :     default:
      51                 :      39339 :       return (attr->cu->version < 5
      52                 :         16 :               ? attr->cu->dbg->fake_loc_cu
      53         [ +  + ]:      39339 :               : attr->cu->dbg->fake_loclists_cu);
      54                 :            :     }
      55                 :            : }
      56                 :            : 
      57                 :            : static unsigned char *
      58                 :         41 : addr_valp (Dwarf_CU *cu, Dwarf_Word index)
      59                 :            : {
      60                 :         41 :   Elf_Data *debug_addr = cu->dbg->sectiondata[IDX_debug_addr];
      61         [ -  + ]:         41 :   if (debug_addr == NULL)
      62                 :            :     {
      63                 :          0 :       __libdw_seterrno (DWARF_E_NO_DEBUG_ADDR);
      64                 :          0 :       return NULL;
      65                 :            :     }
      66                 :            : 
      67                 :         41 :   Dwarf_Word offset = __libdw_cu_addr_base (cu) + (index * cu->address_size);
      68                 :         41 :   return (unsigned char *) debug_addr->d_buf + offset;
      69                 :            : }
      70                 :            : 
      71                 :            : int
      72                 :      45057 : dwarf_getlocation_attr (Dwarf_Attribute *attr, const Dwarf_Op *op, Dwarf_Attribute *result)
      73                 :            : {
      74         [ -  + ]:      45057 :   if (attr == NULL)
      75                 :            :     return -1;
      76                 :            : 
      77   [ +  +  +  +  :      45057 :   switch (op->atom)
             +  -  +  - ]
      78                 :            :     {
      79                 :        749 :       case DW_OP_implicit_value:
      80                 :        749 :         result->code = DW_AT_const_value;
      81                 :        749 :         result->form = DW_FORM_block;
      82                 :        749 :         result->valp = (unsigned char *) (uintptr_t) op->number2;
      83                 :        749 :         result->cu = attr_form_cu (attr);
      84                 :        749 :         break;
      85                 :            : 
      86                 :      40640 :       case DW_OP_entry_value:
      87                 :            :       case DW_OP_GNU_entry_value:
      88                 :      40640 :         result->code = DW_AT_location;
      89                 :      40640 :         result->form = DW_FORM_exprloc;
      90                 :      40640 :         result->valp = (unsigned char *) (uintptr_t) op->number2;
      91                 :      40640 :         result->cu = attr_form_cu (attr);
      92                 :      40640 :         break;
      93                 :            : 
      94                 :          1 :       case DW_OP_const_type:
      95                 :            :       case DW_OP_GNU_const_type:
      96                 :          1 :         result->code = DW_AT_const_value;
      97                 :          1 :         result->form = DW_FORM_block1;
      98                 :          1 :         result->valp = (unsigned char *) (uintptr_t) op->number2;
      99                 :          1 :         result->cu = attr_form_cu (attr);
     100                 :          1 :         break;
     101                 :            : 
     102                 :         18 :       case DW_OP_GNU_const_index:
     103                 :            :       case DW_OP_constx:
     104                 :         18 :         result->code = DW_AT_const_value;
     105         [ -  + ]:         18 :         if (attr->cu->address_size == 4)
     106                 :          0 :           result->form = DW_FORM_data4;
     107                 :            :         else
     108                 :         18 :           result->form = DW_FORM_data8;
     109                 :         18 :         result->valp = addr_valp (attr->cu, op->number);
     110         [ -  + ]:         18 :         if (result->valp == NULL)
     111                 :            :           return -1;
     112                 :         18 :         result->cu = attr->cu->dbg->fake_addr_cu;
     113                 :         18 :         break;
     114                 :            : 
     115                 :         23 :       case DW_OP_GNU_addr_index:
     116                 :            :       case DW_OP_addrx:
     117                 :         23 :         result->code = DW_AT_low_pc;
     118                 :         23 :         result->form = DW_FORM_addr;
     119                 :         23 :         result->valp = addr_valp (attr->cu, op->number);
     120         [ -  + ]:         23 :         if (result->valp == NULL)
     121                 :            :           return -1;
     122                 :         23 :         result->cu = attr->cu->dbg->fake_addr_cu;
     123                 :         23 :         break;
     124                 :            : 
     125                 :          0 :       case DW_OP_call2:
     126                 :            :       case DW_OP_call4:
     127                 :            :       case DW_OP_call_ref:
     128                 :            :         {
     129                 :          0 :           Dwarf_Die die;
     130         [ #  # ]:          0 :           if (INTUSE(dwarf_getlocation_die) (attr, op, &die) != 0)
     131                 :          0 :             return -1;
     132         [ #  # ]:          0 :           if (INTUSE(dwarf_attr) (&die, DW_AT_location, result) == NULL)
     133                 :            :             {
     134                 :          0 :               __libdw_empty_loc_attr (result);
     135                 :          0 :               return 0;
     136                 :            :             }
     137                 :            :         }
     138                 :          0 :         break;
     139                 :            : 
     140                 :       3626 :       case DW_OP_implicit_pointer:
     141                 :            :       case DW_OP_GNU_implicit_pointer:
     142                 :            :       case DW_OP_GNU_variable_value:
     143                 :            :         {
     144                 :       3626 :           Dwarf_Die die;
     145         [ +  - ]:       3626 :           if (INTUSE(dwarf_getlocation_die) (attr, op, &die) != 0)
     146                 :         19 :             return -1;
     147         [ +  + ]:       3626 :           if (INTUSE(dwarf_attr) (&die, DW_AT_location, result) == NULL
     148         [ +  - ]:         19 :               && INTUSE(dwarf_attr) (&die, DW_AT_const_value, result) == NULL)
     149                 :            :             {
     150                 :         19 :               __libdw_empty_loc_attr (result);
     151                 :         19 :               return 0;
     152                 :            :             }
     153                 :            :         }
     154                 :       3607 :         break;
     155                 :            : 
     156                 :          0 :       default:
     157                 :          0 :         __libdw_seterrno (DWARF_E_INVALID_ACCESS);
     158                 :          0 :         return -1;
     159                 :            :     }
     160                 :            : 
     161                 :            :   return 0;
     162                 :            : }