1/* Find line information for given file/line/column triple.
2   Copyright (C) 2005-2009 Red Hat, Inc.
3   This file is part of Red Hat elfutils.
4   Written by Ulrich Drepper <drepper@redhat.com>, 2005.
5
6   Red Hat elfutils is free software; you can redistribute it and/or modify
7   it under the terms of the GNU General Public License as published by the
8   Free Software Foundation; version 2 of the License.
9
10   Red Hat elfutils is distributed in the hope that it will be useful, but
11   WITHOUT ANY WARRANTY; without even the implied warranty of
12   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13   General Public License for more details.
14
15   You should have received a copy of the GNU General Public License along
16   with Red Hat elfutils; if not, write to the Free Software Foundation,
17   Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.
18
19   In addition, as a special exception, Red Hat, Inc. gives You the
20   additional right to link the code of Red Hat elfutils with code licensed
21   under any Open Source Initiative certified open source license
22   (http://www.opensource.org/licenses/index.php) which requires the
23   distribution of source code with any binary distribution and to
24   distribute linked combinations of the two.  Non-GPL Code permitted under
25   this exception must only link to the code of Red Hat elfutils through
26   those well defined interfaces identified in the file named EXCEPTION
27   found in the source code files (the "Approved Interfaces").  The files
28   of Non-GPL Code may instantiate templates or use macros or inline
29   functions from the Approved Interfaces without causing the resulting
30   work to be covered by the GNU General Public License.  Only Red Hat,
31   Inc. may make changes or additions to the list of Approved Interfaces.
32   Red Hat's grant of this exception is conditioned upon your not adding
33   any new exceptions.  If you wish to add a new Approved Interface or
34   exception, please contact Red Hat.  You must obey the GNU General Public
35   License in all respects for all of the Red Hat elfutils code and other
36   code used in conjunction with Red Hat elfutils except the Non-GPL Code
37   covered by this exception.  If you modify this file, you may extend this
38   exception to your version of the file, but you are not obligated to do
39   so.  If you do not wish to provide this exception without modification,
40   you must delete this exception statement from your version and license
41   this file solely under the GPL without exception.
42
43   Red Hat elfutils is an included package of the Open Invention Network.
44   An included package of the Open Invention Network is a package for which
45   Open Invention Network licensees cross-license their patents.  No patent
46   license is granted, either expressly or impliedly, by designation as an
47   included package.  Should you wish to participate in the Open Invention
48   Network licensing program, please visit www.openinventionnetwork.com
49   <http://www.openinventionnetwork.com>.  */
50
51#ifdef HAVE_CONFIG_H
52# include <config.h>
53#endif
54
55#include <assert.h>
56#include <limits.h>
57#include <stdlib.h>
58#include <string.h>
59
60#include "libdwP.h"
61
62
63int
64dwarf_getsrc_file (Dwarf *dbg, const char *fname, int lineno, int column,
65		   Dwarf_Line ***srcsp, size_t *nsrcs)
66{
67  if (dbg == NULL)
68    return -1;
69
70  bool is_basename = strchr (fname, '/') == NULL;
71
72  size_t max_match = *nsrcs ?: ~0u;
73  size_t act_match = *nsrcs;
74  size_t cur_match = 0;
75  Dwarf_Line **match = *nsrcs == 0 ? NULL : *srcsp;
76
77  size_t cuhl;
78  Dwarf_Off noff;
79  for (Dwarf_Off off = 0;
80       INTUSE(dwarf_nextcu) (dbg, off, &noff, &cuhl, NULL, NULL, NULL) == 0;
81       off = noff)
82    {
83      Dwarf_Die cudie_mem;
84      Dwarf_Die *cudie = INTUSE(dwarf_offdie) (dbg, off + cuhl, &cudie_mem);
85      if (cudie == NULL)
86	continue;
87
88      /* Get the line number information for this file.  */
89      Dwarf_Lines *lines;
90      size_t nlines;
91      if (INTUSE(dwarf_getsrclines) (cudie, &lines, &nlines) != 0)
92	{
93	  /* Ignore a CU that just has no DW_AT_stmt_list at all.  */
94	  int error = INTUSE(dwarf_errno) ();
95	  if (error == 0)
96	    continue;
97	  __libdw_seterrno (error);
98	  return -1;
99	}
100
101      /* Search through all the line number records for a matching
102	 file and line/column number.  If any of the numbers is zero,
103	 no match is performed.  */
104      unsigned int lastfile = UINT_MAX;
105      bool lastmatch = false;
106      for (size_t cnt = 0; cnt < nlines; ++cnt)
107	{
108	  Dwarf_Line *line = &lines->info[cnt];
109
110	  if (lastfile != line->file)
111	    {
112	      lastfile = line->file;
113	      if (lastfile >= line->files->nfiles)
114		{
115		  __libdw_seterrno (DWARF_E_INVALID_DWARF);
116		  return -1;
117		}
118
119	      /* Match the name with the name the user provided.  */
120	      const char *fname2 = line->files->info[lastfile].name;
121	      if (is_basename)
122		lastmatch = strcmp (basename (fname2), fname) == 0;
123	      else
124		lastmatch = strcmp (fname2, fname) == 0;
125	    }
126	  if (!lastmatch)
127	    continue;
128
129	  /* See whether line and possibly column match.  */
130	  if (lineno != 0
131	      && (lineno > line->line
132		  || (column != 0 && column > line->column)))
133	    /* Cannot match.  */
134	    continue;
135
136	  /* Determine whether this is the best match so far.  */
137	  size_t inner;
138	  for (inner = 0; inner < cur_match; ++inner)
139	    if (match[inner]->files == line->files
140		&& match[inner]->file == line->file)
141	      break;
142	  if (inner < cur_match
143	      && (match[inner]->line != line->line
144		  || match[inner]->line != lineno
145		  || (column != 0
146		      && (match[inner]->column != line->column
147			  || match[inner]->column != column))))
148	    {
149	      /* We know about this file already.  If this is a better
150		 match for the line number, use it.  */
151	      if (match[inner]->line >= line->line
152		  && (match[inner]->line != line->line
153		      || match[inner]->column >= line->column))
154		/*  Use the new line.  Otherwise the old one.  */
155		match[inner] = line;
156	      continue;
157	    }
158
159	  if (cur_match < max_match)
160	    {
161	      if (cur_match == act_match)
162		{
163		  /* Enlarge the array for the results.  */
164		  act_match += 10;
165		  Dwarf_Line **newp = realloc (match,
166					       act_match
167					       * sizeof (Dwarf_Line *));
168		  if (newp == NULL)
169		    {
170		      free (match);
171		      __libdw_seterrno (DWARF_E_NOMEM);
172		      return -1;
173		    }
174		  match = newp;
175		}
176
177	      match[cur_match++] = line;
178	    }
179	}
180
181      /* If we managed to find as many matches as the user requested
182	 already, there is no need to go on to the next CU.  */
183      if (cur_match == max_match)
184	break;
185    }
186
187  if (cur_match > 0)
188    {
189      assert (*nsrcs == 0 || *srcsp == match);
190
191      *nsrcs = cur_match;
192      *srcsp = match;
193
194      return 0;
195    }
196
197  __libdw_seterrno (DWARF_E_NO_MATCH);
198  return -1;
199}
200