1 /* Find source location for PC address in module.
2    Copyright (C) 2005, 2008, 2014 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 "libdwflP.h"
34 #include "../libdw/libdwP.h"
35 
36 Dwfl_Line *
dwfl_module_getsrc(Dwfl_Module * mod,Dwarf_Addr addr)37 dwfl_module_getsrc (Dwfl_Module *mod, Dwarf_Addr addr)
38 {
39   Dwarf_Addr bias;
40   if (INTUSE(dwfl_module_getdwarf) (mod, &bias) == NULL)
41     return NULL;
42 
43   struct dwfl_cu *cu;
44   Dwfl_Error error = __libdwfl_addrcu (mod, addr, &cu);
45   if (likely (error == DWFL_E_NOERROR))
46     error = __libdwfl_cu_getsrclines (cu);
47   if (likely (error == DWFL_E_NOERROR))
48     {
49       Dwarf_Lines *lines = cu->die.cu->lines;
50       size_t nlines = lines->nlines;
51       if (nlines > 0)
52 	{
53 	  /* This is guaranteed for us by libdw read_srclines.  */
54 	  assert(lines->info[nlines - 1].end_sequence);
55 
56 	  /* Now we look at the module-relative address.  */
57 	  addr -= bias;
58 
59 	  /* The lines are sorted by address, so we can use binary search.  */
60 	  size_t l = 0, u = nlines - 1;
61 	  while (l < u)
62 	    {
63 	      size_t idx = u - (u - l) / 2;
64 	      Dwarf_Line *line = &lines->info[idx];
65 	      if (addr < line->addr)
66 		u = idx - 1;
67 	      else
68 		l = idx;
69 	    }
70 
71 	  /* The last line which is less than or equal to addr is what
72 	     we want, unless it is the end_sequence which is after the
73 	     current line sequence.  */
74 	  Dwarf_Line *line = &lines->info[l];
75 	  if (! line->end_sequence && line->addr <= addr)
76 	    return &cu->lines->idx[l];
77 	}
78 
79       error = DWFL_E_ADDR_OUTOFRANGE;
80     }
81 
82   __libdwfl_seterrno (error);
83   return NULL;
84 }
85 INTDEF (dwfl_module_getsrc)
86