1/* Iterate through modules.
2   Copyright (C) 2005, 2008 Red Hat, Inc.
3   This file is part of Red Hat elfutils.
4
5   Red Hat elfutils is free software; you can redistribute it and/or modify
6   it under the terms of the GNU General Public License as published by the
7   Free Software Foundation; version 2 of the License.
8
9   Red Hat elfutils is distributed in the hope that it will be useful, but
10   WITHOUT ANY WARRANTY; without even the implied warranty of
11   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12   General Public License for more details.
13
14   You should have received a copy of the GNU General Public License along
15   with Red Hat elfutils; if not, write to the Free Software Foundation,
16   Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.
17
18   In addition, as a special exception, Red Hat, Inc. gives You the
19   additional right to link the code of Red Hat elfutils with code licensed
20   under any Open Source Initiative certified open source license
21   (http://www.opensource.org/licenses/index.php) which requires the
22   distribution of source code with any binary distribution and to
23   distribute linked combinations of the two.  Non-GPL Code permitted under
24   this exception must only link to the code of Red Hat elfutils through
25   those well defined interfaces identified in the file named EXCEPTION
26   found in the source code files (the "Approved Interfaces").  The files
27   of Non-GPL Code may instantiate templates or use macros or inline
28   functions from the Approved Interfaces without causing the resulting
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30   Inc. may make changes or additions to the list of Approved Interfaces.
31   Red Hat's grant of this exception is conditioned upon your not adding
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33   exception, please contact Red Hat.  You must obey the GNU General Public
34   License in all respects for all of the Red Hat elfutils code and other
35   code used in conjunction with Red Hat elfutils except the Non-GPL Code
36   covered by this exception.  If you modify this file, you may extend this
37   exception to your version of the file, but you are not obligated to do
38   so.  If you do not wish to provide this exception without modification,
39   you must delete this exception statement from your version and license
40   this file solely under the GPL without exception.
41
42   Red Hat elfutils is an included package of the Open Invention Network.
43   An included package of the Open Invention Network is a package for which
44   Open Invention Network licensees cross-license their patents.  No patent
45   license is granted, either expressly or impliedly, by designation as an
46   included package.  Should you wish to participate in the Open Invention
47   Network licensing program, please visit www.openinventionnetwork.com
48   <http://www.openinventionnetwork.com>.  */
49
50#include "libdwflP.h"
51
52ptrdiff_t
53dwfl_getmodules (Dwfl *dwfl,
54		 int (*callback) (Dwfl_Module *, void **,
55				  const char *, Dwarf_Addr, void *),
56		 void *arg,
57		 ptrdiff_t offset)
58{
59  if (dwfl == NULL)
60    return -1;
61
62  /* We iterate through the linked list when it's all we have.
63     But continuing from an offset is slow that way.  So when
64     DWFL->lookup_module is populated, we can instead keep our
65     place by jumping directly into the array.  Since the actions
66     of a callback could cause it to get populated, we must
67     choose the style of place-holder when we return an offset,
68     and we encode the choice in the low bits of that value.  */
69
70  Dwfl_Module *m = dwfl->modulelist;
71
72  if ((offset & 3) == 1)
73    {
74      offset >>= 2;
75      for (ptrdiff_t pos = 0; pos < offset; ++pos)
76	if (m == NULL)
77	  return -1;
78	else
79	  m = m->next;
80    }
81  else if (((offset & 3) == 2) && likely (dwfl->lookup_module != NULL))
82    {
83      offset >>= 2;
84
85      if ((size_t) offset - 1 == dwfl->lookup_elts)
86	return 0;
87
88      if (unlikely ((size_t) offset - 1 > dwfl->lookup_elts))
89	return -1;
90
91      m = dwfl->lookup_module[offset - 1];
92      if (unlikely (m == NULL))
93	return -1;
94    }
95  else if (offset != 0)
96    {
97      __libdwfl_seterrno (DWFL_E_BADSTROFF);
98      return -1;
99    }
100
101  while (m != NULL)
102    {
103      int ok = (*callback) (MODCB_ARGS (m), arg);
104      ++offset;
105      m = m->next;
106      if (ok != DWARF_CB_OK)
107	return ((dwfl->lookup_module == NULL) ? ((offset << 2) | 1)
108		: (((m == NULL ? (ptrdiff_t) dwfl->lookup_elts + 1
109		     : m->segment + 1) << 2) | 2));
110    }
111  return 0;
112}
113INTDEF (dwfl_getmodules)
114