dwarf_getsrc_die.c revision 07d4f2fc1cb53f170a71bc13617bbdd9cb1c3c60 
1/* Find line information for address.
2   Copyright (C) 2004, 2005 Red Hat, Inc.
3   Written by Ulrich Drepper <drepper@redhat.com>, 2004.
4
5   This program is Open Source software; you can redistribute it and/or
6   modify it under the terms of the Open Software License version 1.0 as
7   published by the Open Source Initiative.
8
9   You should have received a copy of the Open Software License along
10   with this program; if not, you may obtain a copy of the Open Software
11   License version 1.0 from http://www.opensource.org/licenses/osl.php or
12   by writing the Open Source Initiative c/o Lawrence Rosen, Esq.,
13   3001 King Ranch Road, Ukiah, CA 95482.   */
14
15#ifdef HAVE_CONFIG_H
16# include <config.h>
17#endif
18
19#include "libdwP.h"
20#include <assert.h>
21
22
23Dwarf_Line *
24dwarf_getsrc_die (Dwarf_Die *cudie, Dwarf_Addr addr)
25{
26  Dwarf_Lines *lines;
27  size_t nlines;
28
29  if (INTUSE(dwarf_getsrclines) (cudie, &lines, &nlines) != 0)
30    return NULL;
31
32  /* The lines are sorted by address, so we can use binary search.  */
33  size_t l = 0, u = nlines;
34  while (l < u)
35    {
36      size_t idx = (l + u) / 2;
37      if (addr < lines->info[idx].addr)
38	u = idx;
39      else if (addr > lines->info[idx].addr || lines->info[idx].end_sequence)
40	l = idx + 1;
41      else
42	return &lines->info[idx];
43    }
44
45  if (nlines > 0)
46    assert (lines->info[nlines - 1].end_sequence);
47
48  /* If none were equal, the closest one below is what we want.  We
49     never want the last one, because it's the end-sequence marker
50     with an address at the high bound of the CU's code.  If the debug
51     information is faulty and no end-sequence marker is present, we
52     still ignore it.  */
53  if (u > 0 && u < nlines && addr > lines->info[u - 1].addr)
54    {
55      while (lines->info[u - 1].end_sequence && u > 0)
56	--u;
57      if (u > 0)
58	return &lines->info[u - 1];
59    }
60
61  __libdw_seterrno (DWARF_E_ADDR_OUTOFRANGE);
62  return NULL;
63}
64