1 /* Find line information for address.
2    Copyright (C) 2004, 2005, 2014 Red Hat, Inc.
3    This file is part of elfutils.
4    Written by Ulrich Drepper <drepper@redhat.com>, 2004.
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 <assert.h>
36 
37 
38 Dwarf_Line *
39 dwarf_getsrc_die (Dwarf_Die *cudie, Dwarf_Addr addr)
40 {
41   Dwarf_Lines *lines;
42   size_t nlines;
43 
44   if (INTUSE(dwarf_getsrclines) (cudie, &lines, &nlines) != 0)
45     return NULL;
46 
47   /* The lines are sorted by address, so we can use binary search.  */
48   if (nlines > 0)
49     {
50       size_t l = 0, u = nlines - 1;
51       while (l < u)
52 	{
53 	  size_t idx = u - (u - l) / 2;
54 	  Dwarf_Line *line = &lines->info[idx];
55 	  if (addr < line->addr)
56 	    u = idx - 1;
57 	  else
58 	    l = idx;
59 	}
60 
61       /* This is guaranteed for us by libdw read_srclines.  */
62       assert (lines->info[nlines - 1].end_sequence);
63 
64       /* The last line which is less than or equal to addr is what we
65 	 want, unless it is the end_sequence which is after the
66 	 current line sequence.  */
67       Dwarf_Line *line = &lines->info[l];
68       if (! line->end_sequence && line->addr <= addr)
69 	return &lines->info[l];
70     }
71 
72   __libdw_seterrno (DWARF_E_ADDR_OUTOFRANGE);
73   return NULL;
74 }
75