Branch data     Line data    Source code

       1                 :            : /* Find the split (or skeleton) unit for a given unit.
       2                 :            :    Copyright (C) 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 "libdwP.h"
      34                 :            : #include "libelfP.h"
      35                 :            : 
      36                 :            : #include <limits.h>
      37                 :            : #include <search.h>
      38                 :            : #include <stdlib.h>
      39                 :            : #include <string.h>
      40                 :            : #include <sys/types.h>
      41                 :            : #include <sys/stat.h>
      42                 :            : #include <fcntl.h>
      43                 :            : 
      44                 :            : static void
      45                 :        100 : try_split_file (Dwarf_CU *cu, const char *dwo_path)
      46                 :            : {
      47                 :        100 :   int split_fd = open (dwo_path, O_RDONLY);
      48         [ +  + ]:        100 :   if (split_fd != -1)
      49                 :            :     {
      50                 :         98 :       Dwarf *split_dwarf = dwarf_begin (split_fd, DWARF_C_READ);
      51         [ +  - ]:         98 :       if (split_dwarf != NULL)
      52                 :            :         {
      53                 :         98 :           Dwarf_CU *split = NULL;
      54                 :         98 :           while (dwarf_get_units (split_dwarf, split, &split,
      55         [ +  + ]:        100 :                                   NULL, NULL, NULL, NULL) == 0)
      56                 :            :             {
      57         [ +  - ]:         98 :               if (split->unit_type == DW_UT_split_compile
      58         [ +  + ]:         98 :                   && cu->unit_id8 == split->unit_id8)
      59                 :            :                 {
      60         [ -  + ]:         96 :                   if (tsearch (split->dbg, &cu->dbg->split_tree,
      61                 :            :                                __libdw_finddbg_cb) == NULL)
      62                 :            :                     {
      63                 :            :                       /* Something went wrong.  Don't link.  */
      64                 :          0 :                       __libdw_seterrno (DWARF_E_NOMEM);
      65                 :          0 :                       break;
      66                 :            :                     }
      67                 :            : 
      68                 :            :                   /* Link skeleton and split compile units.  */
      69                 :         96 :                   __libdw_link_skel_split (cu, split);
      70                 :            : 
      71                 :            :                   /* We have everything we need from this ELF
      72                 :            :                      file.  And we are going to close the fd to
      73                 :            :                      not run out of file descriptors.  */
      74                 :         96 :                   elf_cntl (split_dwarf->elf, ELF_C_FDDONE);
      75                 :         96 :                   break;
      76                 :            :                 }
      77                 :            :             }
      78         [ +  + ]:         98 :           if (cu->split == (Dwarf_CU *) -1)
      79                 :          2 :             dwarf_end (split_dwarf);
      80                 :            :         }
      81                 :            :       /* Always close, because we don't want to run out of file
      82                 :            :          descriptors.  See also the elf_fcntl ELF_C_FDDONE call
      83                 :            :          above.  */
      84                 :         98 :       close (split_fd);
      85                 :            :     }
      86                 :        100 : }
      87                 :            : 
      88                 :            : Dwarf_CU *
      89                 :            : internal_function
      90                 :        642 : __libdw_find_split_unit (Dwarf_CU *cu)
      91                 :            : {
      92                 :            :   /* Only try once.  */
      93         [ +  + ]:        642 :   if (cu->split != (Dwarf_CU *) -1)
      94                 :            :     return cu->split;
      95                 :            : 
      96                 :            :   /* We need a skeleton unit with a comp_dir and [GNU_]dwo_name attributes.
      97                 :            :      The split unit will be the first in the dwo file and should have the
      98                 :            :      same id as the skeleton.  */
      99         [ +  - ]:         98 :   if (cu->unit_type == DW_UT_skeleton)
     100                 :            :     {
     101                 :         98 :       Dwarf_Die cudie = CUDIE (cu);
     102                 :         98 :       Dwarf_Attribute dwo_name;
     103                 :            :       /* It is fine if dwo_dir doesn't exists, but then dwo_name needs
     104                 :            :          to be an absolute path.  */
     105         [ +  + ]:         98 :       if (dwarf_attr (&cudie, DW_AT_dwo_name, &dwo_name) != NULL
     106         [ +  - ]:         52 :           || dwarf_attr (&cudie, DW_AT_GNU_dwo_name, &dwo_name) != NULL)
     107                 :            :         {
     108                 :            :           /* First try the dwo file name in the same directory
     109                 :            :              as we found the skeleton file.  */
     110                 :         98 :           const char *dwo_file = dwarf_formstring (&dwo_name);
     111                 :         98 :           const char *debugdir = cu->dbg->debugdir;
     112                 :         98 :           char *dwo_path = __libdw_filepath (debugdir, NULL, dwo_file);
     113         [ +  - ]:         98 :           if (dwo_path != NULL)
     114                 :            :             {
     115                 :         98 :               try_split_file (cu, dwo_path);
     116                 :         98 :               free (dwo_path);
     117                 :            :             }
     118                 :            : 
     119         [ +  + ]:         98 :           if (cu->split == (Dwarf_CU *) -1)
     120                 :            :             {
     121                 :            :               /* Try compdir plus dwo_name.  */
     122                 :          2 :               Dwarf_Attribute compdir;
     123                 :          2 :               dwarf_attr (&cudie, DW_AT_comp_dir, &compdir);
     124                 :          2 :               const char *dwo_dir = dwarf_formstring (&compdir);
     125         [ +  - ]:          2 :               if (dwo_dir != NULL)
     126                 :            :                 {
     127                 :          2 :                   dwo_path = __libdw_filepath (debugdir, dwo_dir, dwo_file);
     128         [ +  - ]:          2 :                   if (dwo_path != NULL)
     129                 :            :                     {
     130                 :          2 :                       try_split_file (cu, dwo_path);
     131                 :          2 :                       free (dwo_path);
     132                 :            :                     }
     133                 :            :                 }
     134                 :            :             }
     135                 :            :           /* XXX If still not found we could try stripping dirs from the
     136                 :            :              comp_dir and adding them from the comp_dir, assuming
     137                 :            :              someone moved a whole build tree around.  */
     138                 :            :         }
     139                 :            :     }
     140                 :            : 
     141                 :            :   /* If we found nothing, make sure we don't try again.  */
     142         [ +  + ]:         98 :   if (cu->split == (Dwarf_CU *) -1)
     143                 :          2 :     cu->split = NULL;
     144                 :            : 
     145                 :         98 :   return cu->split;
     146                 :            : }