LCOV - code coverage report
Current view: top level - libdw - dwarf_getlocation_attr.c (source / functions) Hit Total Coverage
Test: elfutils-0.172 Lines: 53 66 80.3 %
Date: 2018-06-11 22:52:14 Functions: 2 2 100.0 %
Legend: Lines: hit not hit

          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             : 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             :   switch (attr->form)
      43             :     {
      44             :     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             :       return attr->cu;
      50       30860 :     default:
      51       30860 :       return (attr->cu->version < 5
      52       30842 :               ? attr->cu->dbg->fake_loc_cu
      53       61702 :               : attr->cu->dbg->fake_loclists_cu);
      54             :     }
      55             : }
      56             : 
      57             : static unsigned char *
      58          37 : addr_valp (Dwarf_CU *cu, Dwarf_Word index)
      59             : {
      60          37 :   Elf_Data *debug_addr = cu->dbg->sectiondata[IDX_debug_addr];
      61          37 :   if (debug_addr == NULL)
      62             :     {
      63           0 :       __libdw_seterrno (DWARF_E_NO_DEBUG_ADDR);
      64           0 :       return NULL;
      65             :     }
      66             : 
      67          37 :   Dwarf_Word offset = __libdw_cu_addr_base (cu) + (index * cu->address_size);
      68          37 :   return (unsigned char *) debug_addr->d_buf + offset;
      69             : }
      70             : 
      71             : int
      72       39015 : dwarf_getlocation_attr (Dwarf_Attribute *attr, const Dwarf_Op *op, Dwarf_Attribute *result)
      73             : {
      74       39015 :   if (attr == NULL)
      75             :     return -1;
      76             : 
      77       39015 :   switch (op->atom)
      78             :     {
      79         516 :       case DW_OP_implicit_value:
      80         516 :         result->code = DW_AT_const_value;
      81         516 :         result->form = DW_FORM_block;
      82         516 :         result->valp = (unsigned char *) (uintptr_t) op->number2;
      83        1032 :         result->cu = attr_form_cu (attr);
      84         516 :         break;
      85             : 
      86       31627 :       case DW_OP_entry_value:
      87             :       case DW_OP_GNU_entry_value:
      88       31627 :         result->code = DW_AT_location;
      89       31627 :         result->form = DW_FORM_exprloc;
      90       31627 :         result->valp = (unsigned char *) (uintptr_t) op->number2;
      91       63254 :         result->cu = attr_form_cu (attr);
      92       31627 :         break;
      93             : 
      94           2 :       case DW_OP_const_type:
      95             :       case DW_OP_GNU_const_type:
      96           2 :         result->code = DW_AT_const_value;
      97           2 :         result->form = DW_FORM_block1;
      98           2 :         result->valp = (unsigned char *) (uintptr_t) op->number2;
      99           4 :         result->cu = attr_form_cu (attr);
     100           2 :         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          19 :       case DW_OP_GNU_addr_index:
     116             :       case DW_OP_addrx:
     117          19 :         result->code = DW_AT_low_pc;
     118          19 :         result->form = DW_FORM_addr;
     119          19 :         result->valp = addr_valp (attr->cu, op->number);
     120          19 :         if (result->valp == NULL)
     121             :           return -1;
     122          19 :         result->cu = attr->cu->dbg->fake_addr_cu;
     123          19 :         break;
     124             : 
     125           0 :       case DW_OP_call2:
     126             :       case DW_OP_call4:
     127             :       case DW_OP_call_ref:
     128           0 :         {
     129             :           Dwarf_Die die;
     130           0 :           if (INTUSE(dwarf_getlocation_die) (attr, op, &die) != 0)
     131             :             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        6833 :       case DW_OP_implicit_pointer:
     141             :       case DW_OP_GNU_implicit_pointer:
     142             :       case DW_OP_GNU_variable_value:
     143        6833 :         {
     144             :           Dwarf_Die die;
     145        6833 :           if (INTUSE(dwarf_getlocation_die) (attr, op, &die) != 0)
     146             :             return -1;
     147        6833 :           if (INTUSE(dwarf_attr) (&die, DW_AT_location, result) == NULL
     148           8 :               && INTUSE(dwarf_attr) (&die, DW_AT_const_value, result) == NULL)
     149             :             {
     150           8 :               __libdw_empty_loc_attr (result);
     151           8 :               return 0;
     152             :             }
     153             :         }
     154        6825 :         break;
     155             : 
     156           0 :       default:
     157           0 :         __libdw_seterrno (DWARF_E_INVALID_ACCESS);
     158           0 :         return -1;
     159             :     }
     160             : 
     161             :   return 0;
     162             : }

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