1/* Find line information for given file/line/column triple.
2   Copyright (C) 2005 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
62int
63dwarf_getsrc_file (Dwarf *dbg, const char *fname, int lineno, int column,
64		   Dwarf_Line ***srcsp, size_t *nsrcs)
65{
66  if (dbg == NULL)
67    return -1;
68
69  bool is_basename = strchr (fname, '/') == NULL;
70
71  size_t max_match = *nsrcs ?: ~0u;
72  size_t act_match = *nsrcs;
73  size_t cur_match = 0;
74  Dwarf_Line **match = *nsrcs == 0 ? NULL : *srcsp;
75
76  Dwarf_Off off = 0;
77  size_t cuhl;
78  Dwarf_Off noff;
79
80  while (INTUSE(dwarf_nextcu) (dbg, off, &noff, &cuhl, NULL, NULL, NULL) == 0)
81    {
82      Dwarf_Die cudie_mem;
83      Dwarf_Die *cudie = INTUSE(dwarf_offdie) (dbg, off + cuhl, &cudie_mem);
84      if (cudie == NULL)
85	continue;
86
87      /* Get the line number information for this file.  */
88      Dwarf_Lines *lines;
89      size_t nlines;
90      if (INTUSE(dwarf_getsrclines) (cudie, &lines, &nlines) != 0)
91	return -1;
92
93      /* Search through all the line number records for a matching
94	 file and line/column number.  If any of the numbers is zero,
95	 no match is performed.  */
96      unsigned int lastfile = UINT_MAX;
97      bool lastmatch = false;
98      for (size_t cnt = 0; cnt < nlines; ++cnt)
99	{
100	  Dwarf_Line *line = &lines->info[cnt];
101
102	  if (lastfile != line->file)
103	    {
104	      lastfile = line->file;
105	      if (lastfile >= line->files->nfiles)
106		{
107		  __libdw_seterrno (DWARF_E_INVALID_DWARF);
108		  return -1;
109		}
110
111	      /* Match the name with the name the user provided.  */
112	      const char *fname2 = line->files->info[lastfile].name;
113	      if (is_basename)
114		lastmatch = strcmp (basename (fname2), fname) == 0;
115	      else
116		lastmatch = strcmp (fname2, fname) == 0;
117	    }
118	  if (!lastmatch)
119	    continue;
120
121	  /* See whether line and possibly column match.  */
122	  if (lineno != 0
123	      && (lineno > line->line
124		  || (column != 0 && column > line->column)))
125	    /* Cannot match.  */
126	    continue;
127
128	  /* Determine whether this is the best match so far.  */
129	  size_t inner;
130	  for (inner = 0; inner < cur_match; ++inner)
131	    if (match[inner]->files == line->files
132		&& match[inner]->file == line->file)
133	      break;
134	  if (inner < cur_match
135	      && (match[inner]->line != line->line
136		  || match[inner]->line != lineno
137		  || (column != 0
138		      && (match[inner]->column != line->column
139			  || match[inner]->column != column))))
140	    {
141	      /* We know about this file already.  If this is a better
142		 match for the line number, use it.  */
143	      if (match[inner]->line >= line->line
144		  && (match[inner]->line != line->line
145		      || match[inner]->column >= line->column))
146		/*  Use the new line.  Otherwise the old one.  */
147		match[inner] = line;
148	      continue;
149	    }
150
151	  if (cur_match < max_match)
152	    {
153	      if (cur_match == act_match)
154		{
155		  /* Enlarge the array for the results.  */
156		  act_match += 10;
157		  Dwarf_Line **newp = realloc (match,
158					       act_match
159					       * sizeof (Dwarf_Line *));
160		  if (newp == NULL)
161		    {
162		      free (match);
163		      __libdw_seterrno (DWARF_E_NOMEM);
164		      return -1;
165		    }
166		  match = newp;
167		}
168
169	      match[cur_match++] = line;
170	    }
171	}
172
173      /* If we managed to find as many matches as the user requested
174	 already, there is no need to go on to the next CU.  */
175      if (cur_match == max_match)
176	break;
177
178      off = noff;
179    }
180
181  if (cur_match > 0)
182    {
183      assert (*nsrcs == 0 || *srcsp == match);
184
185      *nsrcs = cur_match;
186      *srcsp = match;
187
188      return 0;
189    }
190
191  __libdw_seterrno (DWARF_E_NO_MATCH);
192  return -1;
193}
194