LCOV - code coverage report
Current view: top level - elfutils/libdw - dwarf_child.c (source / functions) Hit Total Coverage
Test: lcov.out Lines: 53 58 91.4 %
Date: 2013-03-08 Functions: 2 2 100.0 %
Legend: Lines: hit not hit | Branches: + taken - not taken # not executed Branches: 37 50 74.0 %

           Branch data     Line data    Source code
       1                 :            : /* Return child of current DIE.
       2                 :            :    Copyright (C) 2003-2011 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 <string.h>
      36                 :            : 
      37                 :            : /* Some arbitrary value not conflicting with any existing code.  */
      38                 :            : #define INVALID 0xffffe444
      39                 :            : 
      40                 :            : 
      41                 :            : unsigned char *
      42                 :            : internal_function
      43                 :   15755283 : __libdw_find_attr (Dwarf_Die *die, unsigned int search_name,
      44                 :            :                    unsigned int *codep, unsigned int *formp)
      45                 :            : {
      46                 :   15755283 :   Dwarf *dbg = die->cu->dbg;
      47                 :   15755283 :   const unsigned char *readp = (unsigned char *) die->addr;
      48                 :            : 
      49                 :            :   /* First we have to get the abbreviation code so that we can decode
      50                 :            :      the data in the DIE.  */
      51                 :            :   unsigned int abbrev_code;
      52         [ +  + ]:   15755283 :   get_uleb128 (abbrev_code, readp);
      53                 :            : 
      54                 :            :   /* Find the abbreviation entry.  */
      55                 :   15755283 :   Dwarf_Abbrev *abbrevp = die->abbrev;
      56         [ +  + ]:   15755283 :   if (abbrevp == NULL)
      57                 :            :     {
      58                 :     333727 :       abbrevp = __libdw_findabbrev (die->cu, abbrev_code);
      59         [ +  - ]:     333727 :       die->abbrev = abbrevp ?: DWARF_END_ABBREV;
      60                 :            :     }
      61         [ -  + ]:   15755283 :   if (unlikely (die->abbrev == DWARF_END_ABBREV))
      62                 :            :     {
      63                 :            :     invalid_dwarf:
      64                 :          0 :       __libdw_seterrno (DWARF_E_INVALID_DWARF);
      65                 :            :       return NULL;
      66                 :            :     }
      67                 :            : 
      68                 :            :   /* Search the name attribute.  */
      69                 :   15755283 :   unsigned char *const endp
      70                 :   15755283 :     = ((unsigned char *) dbg->sectiondata[IDX_debug_abbrev]->d_buf
      71                 :   15755283 :        + dbg->sectiondata[IDX_debug_abbrev]->d_size);
      72                 :            : 
      73                 :   75046663 :   const unsigned char *attrp = die->abbrev->attrp;
      74                 :            :   while (1)
      75                 :            :     {
      76                 :            :       /* Are we still in bounds?  This test needs to be refined.  */
      77         [ -  + ]:   75046663 :       if (unlikely (attrp + 1 >= endp))
      78                 :            :         goto invalid_dwarf;
      79                 :            : 
      80                 :            :       /* Get attribute name and form.
      81                 :            : 
      82                 :            :          XXX We don't check whether this reads beyond the end of the
      83                 :            :          section.  */
      84                 :            :       unsigned int attr_name;
      85         [ +  + ]:   75046663 :       get_uleb128 (attr_name, attrp);
      86                 :            :       unsigned int attr_form;
      87         [ +  + ]:   75046663 :       get_uleb128 (attr_form, attrp);
      88                 :            : 
      89                 :            :       /* We can stop if we found the attribute with value zero.  */
      90         [ +  + ]:   75046663 :       if (attr_name == 0 && attr_form == 0)
      91                 :            :         break;
      92                 :            : 
      93                 :            :       /* Is this the name attribute?  */
      94         [ +  + ]:   60895386 :       if (attr_name == search_name && search_name != INVALID)
      95                 :            :         {
      96         [ +  - ]:    1604006 :           if (codep != NULL)
      97                 :    1604006 :             *codep = attr_name;
      98         [ +  + ]:    1604006 :           if (formp != NULL)
      99                 :    1600991 :             *formp = attr_form;
     100                 :            : 
     101                 :    1604006 :           return (unsigned char *) readp;
     102                 :            :         }
     103                 :            : 
     104                 :            :       /* Skip over the rest of this attribute (if there is any).  */
     105         [ -  + ]:   59291380 :       if (attr_form != 0)
     106                 :            :         {
     107                 :   59291380 :           size_t len = __libdw_form_val_len (dbg, die->cu, attr_form, readp);
     108                 :            : 
     109         [ -  + ]:   59291380 :           if (unlikely (len == (size_t) -1l))
     110                 :            :             {
     111                 :          0 :               readp = NULL;
     112                 :          0 :               break;
     113                 :            :             }
     114                 :            : 
     115                 :            :           // XXX We need better boundary checks.
     116                 :   59291380 :           readp += len;
     117                 :            :         }
     118                 :            :     }
     119                 :            : 
     120                 :            :   // XXX Do we need other values?
     121         [ +  + ]:   14151277 :   if (codep != NULL)
     122                 :   14030228 :     *codep = INVALID;
     123         [ +  + ]:   14151277 :   if (formp != NULL)
     124                 :    2489157 :     *formp = INVALID;
     125                 :            : 
     126                 :   15755283 :   return (unsigned char *) readp;
     127                 :            : }
     128                 :            : 
     129                 :            : 
     130                 :            : int
     131                 :     739505 : dwarf_child (die, result)
     132                 :            :      Dwarf_Die *die;
     133                 :            :      Dwarf_Die *result;
     134                 :            : {
     135                 :            :   /* Ignore previous errors.  */
     136         [ +  - ]:     739505 :   if (die == NULL)
     137                 :            :     return -1;
     138                 :            : 
     139                 :            :   /* Skip past the last attribute.  */
     140                 :     739505 :   void *addr = NULL;
     141                 :            : 
     142                 :            :   /* If we already know there are no children do not search.  */
     143         [ +  - ]:     739505 :   if (die->abbrev != DWARF_END_ABBREV
     144 [ +  + ][ +  + ]:     739505 :       && (die->abbrev == NULL || die->abbrev->has_children))
     145                 :     121049 :     addr = __libdw_find_attr (die, INVALID, NULL, NULL);
     146         [ +  - ]:     739505 :   if (unlikely (die->abbrev == (Dwarf_Abbrev *) -1l))
     147                 :            :     return -1;
     148                 :            : 
     149                 :            :   /* Make sure the DIE really has children.  */
     150         [ +  + ]:     739505 :   if (! die->abbrev->has_children)
     151                 :            :     /* There cannot be any children.  */
     152                 :            :     return 1;
     153                 :            : 
     154         [ +  - ]:     121049 :   if (addr == NULL)
     155                 :            :     return -1;
     156                 :            : 
     157                 :            :   /* RESULT can be the same as DIE.  So preserve what we need.  */
     158                 :     121049 :   struct Dwarf_CU *cu = die->cu;
     159                 :     121049 :   Elf_Data *cu_sec = cu_data (cu);
     160                 :            : 
     161                 :            :   /* It's kosher (just suboptimal) to have a null entry first thing (7.5.3).
     162                 :            :      So if this starts with ULEB128 of 0 (even with silly encoding of 0),
     163                 :            :      it is a kosher null entry and we do not really have any children.  */
     164                 :     121049 :   const unsigned char *code = addr;
     165                 :     121049 :   const unsigned char *endp = (cu_sec->d_buf + cu_sec->d_size);
     166                 :            :   while (1)
     167                 :            :     {
     168         [ +  - ]:     121049 :       if (unlikely (code >= endp)) /* Truncated section.  */
     169                 :            :         return 1;
     170         [ -  + ]:     121049 :       if (unlikely (*code == 0x80))
     171                 :          0 :         ++code;
     172                 :            :       else
     173                 :            :         break;
     174                 :          0 :     }
     175         [ +  - ]:     121049 :   if (unlikely (*code == '\0'))
     176                 :            :     return 1;
     177                 :            : 
     178                 :            :   /* Clear the entire DIE structure.  This signals we have not yet
     179                 :            :      determined any of the information.  */
     180                 :     121049 :   memset (result, '\0', sizeof (Dwarf_Die));
     181                 :            : 
     182                 :            :   /* We have the address.  */
     183                 :     121049 :   result->addr = addr;
     184                 :            : 
     185                 :            :   /* Same CU as the parent.  */
     186                 :     121049 :   result->cu = cu;
     187                 :            : 
     188                 :     739505 :   return 0;
     189                 :            : }
     190                 :     121049 : INTDEF(dwarf_child)

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