LCOV - code coverage report
Current view: top level - libdw - dwarf_entry_breakpoints.c (source / functions) Hit Total Coverage
Test: elfutils-0.173 Lines: 36 58 62.1 %
Date: 2018-06-29 23:49:12 Functions: 4 4 100.0 %
Legend: Lines: hit not hit

          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             :   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         166 :       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          50 :             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          70 :   Dwarf_Die cudie = CUDIE (die->cu);
     112             :   Dwarf_Lines *lines;
     113             :   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             :   Dwarf_Addr base;
     126             :   Dwarf_Addr begin;
     127             :   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          70 :     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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