1 /* Get attributes of the DIE.
2 Copyright (C) 2004, 2005, 2008 Red Hat, Inc.
3 This file is part of Red Hat elfutils.
4 Written by Ulrich Drepper <drepper@redhat.com>, 2004.
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 "libdwP.h"
56
57
58 ptrdiff_t
dwarf_getattrs(Dwarf_Die * die,int (* callback)(Dwarf_Attribute *,void *),void * arg,ptrdiff_t offset)59 dwarf_getattrs (Dwarf_Die *die, int (*callback) (Dwarf_Attribute *, void *),
60 void *arg, ptrdiff_t offset)
61 {
62 if (die == NULL)
63 return -1l;
64
65 const unsigned char *die_addr = die->addr;
66
67 /* Get the abbreviation code. */
68 unsigned int u128;
69 get_uleb128 (u128, die_addr);
70
71 if (die->abbrev == NULL)
72 /* Find the abbreviation. */
73 die->abbrev = __libdw_findabbrev (die->cu, u128);
74
75 if (unlikely (die->abbrev == DWARF_END_ABBREV))
76 {
77 invalid_dwarf:
78 __libdw_seterrno (DWARF_E_INVALID_DWARF);
79 return -1l;
80 }
81
82 /* This is where the attributes start. */
83 const unsigned char *attrp = die->abbrev->attrp + offset;
84
85 /* Go over the list of attributes. */
86 Dwarf *dbg = die->cu->dbg;
87 while (1)
88 {
89 /* Are we still in bounds? */
90 if (unlikely (attrp
91 >= ((unsigned char *) dbg->sectiondata[IDX_debug_abbrev]->d_buf
92 + dbg->sectiondata[IDX_debug_abbrev]->d_size)))
93 goto invalid_dwarf;
94
95 /* Get attribute name and form. */
96 Dwarf_Attribute attr;
97 const unsigned char *remembered_attrp = attrp;
98
99 // XXX Fix bound checks
100 get_uleb128 (attr.code, attrp);
101 get_uleb128 (attr.form, attrp);
102
103 /* We can stop if we found the attribute with value zero. */
104 if (attr.code == 0 && attr.form == 0)
105 /* Do not return 0 here - there would be no way to
106 distinguish this value from the attribute at offset 0.
107 Instead we return +1 which would never be a valid
108 offset of an attribute. */
109 return 1l;
110
111 /* Fill in the rest. */
112 attr.valp = (unsigned char *) die_addr;
113 attr.cu = die->cu;
114
115 /* Now call the callback function. */
116 if (callback (&attr, arg) != DWARF_CB_OK)
117 /* Return the offset of the start of the attribute, so that
118 dwarf_getattrs() can be restarted from this point if the
119 caller so desires. */
120 return remembered_attrp - die->abbrev->attrp;
121
122 /* Skip over the rest of this attribute (if there is any). */
123 if (attr.form != 0)
124 {
125 size_t len = __libdw_form_val_len (dbg, die->cu, attr.form,
126 die_addr);
127
128 if (unlikely (len == (size_t) -1l))
129 /* Something wrong with the file. */
130 return -1l;
131
132 // XXX We need better boundary checks.
133 die_addr += len;
134 }
135 }
136 /* NOTREACHED */
137 }
138