LCOV - code coverage report
Current view: top level - libdw - dwarf_entry_breakpoints.c (source / functions) Hit Total Coverage
Test: elfutils-0.189 Lines: 42 64 65.6 %
Date: 2023-08-02 17:40:45 Functions: 4 4 100.0 %
Legend: Lines: hit not hit | Branches: + taken - not taken # not executed Branches: 28 56 50.0 %

           Branch data     Line data    Source code
       1                 :            : /* Find entry breakpoint locations for a function.
       2                 :            :    Copyright (C) 2005-2009 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                 :            : #include "libdwP.h"
      33                 :            : #include <dwarf.h>
      34                 :            : #include <stdlib.h>
      35                 :            : 
      36                 :            : 
      37                 :            : /* Add one breakpoint location to the result vector.  */
      38                 :            : static inline int
      39                 :         35 : add_bkpt (Dwarf_Addr pc, Dwarf_Addr **bkpts, int *pnbkpts)
      40                 :            : {
      41                 :         35 :   Dwarf_Addr *newlist = realloc (*bkpts, ++(*pnbkpts) * sizeof newlist[0]);
      42         [ -  + ]:         35 :   if (newlist == NULL)
      43                 :            :     {
      44                 :          0 :       free (*bkpts);
      45                 :          0 :       *bkpts = NULL;
      46                 :          0 :       __libdw_seterrno (DWARF_E_NOMEM);
      47                 :          0 :       return -1;
      48                 :            :     }
      49                 :         35 :   newlist[*pnbkpts - 1] = pc;
      50                 :         35 :   *bkpts = newlist;
      51                 :         35 :   return *pnbkpts;
      52                 :            : }
      53                 :            : 
      54                 :            : /* Fallback result, break at the entrypc/lowpc value.  */
      55                 :            : static inline int
      56                 :          2 : entrypc_bkpt (Dwarf_Die *die, Dwarf_Addr **bkpts, int *pnbkpts)
      57                 :            : {
      58                 :          2 :   Dwarf_Addr pc;
      59         [ +  - ]:          2 :   return INTUSE(dwarf_entrypc) (die, &pc) < 0 ? -1 : add_bkpt (pc, bkpts, pnbkpts);
      60                 :            : }
      61                 :            : 
      62                 :            : /* Search a contiguous PC range for prologue-end markers.
      63                 :            :    If DWARF, look for proper markers.
      64                 :            :    Failing that, if ADHOC, look for the ad hoc convention.  */
      65                 :            : static inline int
      66                 :         35 : search_range (Dwarf_Addr low, Dwarf_Addr high,
      67                 :            :               bool dwarf, bool adhoc,
      68                 :            :               Dwarf_Lines *lines, size_t nlines,
      69                 :            :               Dwarf_Addr **bkpts, int *pnbkpts)
      70                 :            : {
      71                 :         35 :       size_t l = 0, u = nlines;
      72         [ +  - ]:        131 :       while (l < u)
      73                 :            :         {
      74                 :        131 :           size_t idx = (l + u) / 2;
      75         [ +  + ]:        131 :           if (lines->info[idx].addr < low)
      76                 :         34 :             l = idx + 1;
      77         [ +  + ]:         97 :           else if (lines->info[idx].addr > low)
      78                 :            :             u = idx;
      79         [ +  + ]:         39 :           else if (lines->info[idx].end_sequence)
      80                 :          4 :             l = idx + 1;
      81                 :            :           else
      82                 :            :             {
      83                 :            :               l = idx;
      84                 :            :               break;
      85                 :            :             }
      86                 :            :         }
      87         [ +  - ]:         35 :       if (l < u)
      88                 :            :         {
      89         [ +  - ]:         35 :           if (dwarf)
      90   [ +  +  +  + ]:         85 :             for (size_t i = l; i < u && lines->info[i].addr < high; ++i)
      91         [ -  + ]:         50 :               if (lines->info[i].prologue_end
      92         [ #  # ]:          0 :                   && add_bkpt (lines->info[i].addr, bkpts, pnbkpts) < 0)
      93                 :            :                 return -1;
      94   [ +  -  +  - ]:         35 :           if (adhoc && *pnbkpts == 0)
      95   [ +  -  +  + ]:         37 :             while (++l < nlines && lines->info[l].addr < high)
      96         [ +  + ]:         35 :               if (!lines->info[l].end_sequence)
      97                 :         33 :                 return add_bkpt (lines->info[l].addr, bkpts, pnbkpts);
      98                 :          2 :           return *pnbkpts;
      99                 :            :         }
     100                 :          0 :       __libdw_seterrno (DWARF_E_INVALID_DWARF);
     101                 :          0 :       return -1;
     102                 :            : }
     103                 :            : 
     104                 :            : int
     105                 :         35 : dwarf_entry_breakpoints (Dwarf_Die *die, Dwarf_Addr **bkpts)
     106                 :            : {
     107                 :         35 :   int nbkpts = 0;
     108                 :         35 :   *bkpts = NULL;
     109                 :            : 
     110                 :            :   /* Fetch the CU's line records to look for this DIE's addresses.  */
     111                 :         35 :   Dwarf_Die cudie = CUDIE (die->cu);
     112                 :         35 :   Dwarf_Lines *lines;
     113                 :         35 :   size_t nlines;
     114         [ -  + ]:         35 :   if (INTUSE(dwarf_getsrclines) (&cudie, &lines, &nlines) < 0)
     115                 :            :     {
     116                 :          0 :       int error = INTUSE (dwarf_errno) ();
     117         [ #  # ]:          0 :       if (error == 0)           /* CU has no DW_AT_stmt_list.  */
     118                 :          0 :         return entrypc_bkpt (die, bkpts, &nbkpts);
     119                 :          0 :       __libdw_seterrno (error);
     120                 :          0 :       return -1;
     121                 :            :     }
     122                 :            : 
     123                 :            :   /* Search each contiguous address range for DWARF prologue_end markers.  */
     124                 :            : 
     125                 :         35 :   Dwarf_Addr base;
     126                 :         35 :   Dwarf_Addr begin;
     127                 :         35 :   Dwarf_Addr end;
     128                 :         35 :   ptrdiff_t offset = INTUSE(dwarf_ranges) (die, 0, &base, &begin, &end);
     129         [ -  + ]:         35 :   if (offset < 0)
     130                 :            :     return -1;
     131                 :            : 
     132                 :            :   /* Most often there is a single contiguous PC range for the DIE.  */
     133         [ +  - ]:         35 :   if (offset == 1)
     134                 :         35 :     return search_range (begin, end, true, true, lines, nlines, bkpts, &nbkpts)
     135         [ +  + ]:         35 :         ?: entrypc_bkpt (die, bkpts, &nbkpts);
     136                 :            : 
     137                 :            :   Dwarf_Addr lowpc = (Dwarf_Addr) -1l;
     138                 :            :   Dwarf_Addr highpc = (Dwarf_Addr) -1l;
     139         [ #  # ]:          0 :   while (offset > 0)
     140                 :            :     {
     141                 :            :       /* We have an address range entry.  */
     142         [ #  # ]:          0 :       if (search_range (begin, end, true, false,
     143                 :            :                         lines, nlines, bkpts, &nbkpts) < 0)
     144                 :            :         return -1;
     145                 :            : 
     146         [ #  # ]:          0 :       if (begin < lowpc)
     147                 :            :         {
     148                 :          0 :           lowpc = begin;
     149                 :          0 :           highpc = end;
     150                 :            :         }
     151                 :            : 
     152                 :          0 :       offset = INTUSE(dwarf_ranges) (die, offset, &base, &begin, &end);
     153                 :            :     }
     154                 :            : 
     155                 :            :   /* If we didn't find any proper DWARF markers, then look in the
     156                 :            :      lowest-addressed range for an ad hoc marker.  Failing that,
     157                 :            :      fall back to just using the entrypc value.  */
     158                 :          0 :   return (nbkpts
     159         [ #  # ]:          0 :           ?: (lowpc == (Dwarf_Addr) -1l ? 0
     160         [ #  # ]:          0 :               : search_range (lowpc, highpc, false, true,
     161                 :            :                               lines, nlines, bkpts, &nbkpts))
     162         [ #  # ]:          0 :           ?: entrypc_bkpt (die, bkpts, &nbkpts));
     163                 :            : }

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