1 /* Return reference offset represented by attribute.
2 Copyright (C) 2003-2010, 2014 Red Hat, Inc.
3 This file is part of elfutils.
4 Written by Ulrich Drepper <drepper@redhat.com>, 2003.
5
6 This file is free software; you can redistribute it and/or modify
7 it under the terms of either
8
9 * the GNU Lesser General Public License as published by the Free
10 Software Foundation; either version 3 of the License, or (at
11 your option) any later version
12
13 or
14
15 * the GNU General Public License as published by the Free
16 Software Foundation; either version 2 of the License, or (at
17 your option) any later version
18
19 or both in parallel, as here.
20
21 elfutils is distributed in the hope that it will be useful, but
22 WITHOUT ANY WARRANTY; without even the implied warranty of
23 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
24 General Public License for more details.
25
26 You should have received copies of the GNU General Public License and
27 the GNU Lesser General Public License along with this program. If
28 not, see <http://www.gnu.org/licenses/>. */
29
30 #ifdef HAVE_CONFIG_H
31 # include <config.h>
32 #endif
33
34 #include <dwarf.h>
35 #include "libdwP.h"
36
37 int
38 internal_function
__libdw_formref(Dwarf_Attribute * attr,Dwarf_Off * return_offset)39 __libdw_formref (Dwarf_Attribute *attr, Dwarf_Off *return_offset)
40 {
41 const unsigned char *datap = attr->valp;
42 const unsigned char *endp = attr->cu->endp;
43
44 if (attr->valp == NULL)
45 {
46 __libdw_seterrno (DWARF_E_INVALID_REFERENCE);
47 return -1;
48 }
49
50 switch (attr->form)
51 {
52 case DW_FORM_ref1:
53 if (datap + 1 > endp)
54 {
55 invalid:
56 __libdw_seterrno (DWARF_E_INVALID_DWARF);
57 return -1;
58 }
59 *return_offset = *attr->valp;
60 break;
61
62 case DW_FORM_ref2:
63 if (datap + 2 > endp)
64 goto invalid;
65 *return_offset = read_2ubyte_unaligned (attr->cu->dbg, attr->valp);
66 break;
67
68 case DW_FORM_ref4:
69 if (datap + 4 > endp)
70 goto invalid;
71 *return_offset = read_4ubyte_unaligned (attr->cu->dbg, attr->valp);
72 break;
73
74 case DW_FORM_ref8:
75 if (datap + 8 > endp)
76 goto invalid;
77 *return_offset = read_8ubyte_unaligned (attr->cu->dbg, attr->valp);
78 break;
79
80 case DW_FORM_ref_udata:
81 if (datap + 1 > endp)
82 goto invalid;
83 get_uleb128 (*return_offset, datap, endp);
84 break;
85
86 case DW_FORM_ref_addr:
87 case DW_FORM_ref_sig8:
88 case DW_FORM_GNU_ref_alt:
89 case DW_FORM_ref_sup4:
90 case DW_FORM_ref_sup8:
91 /* These aren't handled by dwarf_formref, only by dwarf_formref_die. */
92 __libdw_seterrno (DWARF_E_INVALID_REFERENCE);
93 return -1;
94
95 default:
96 __libdw_seterrno (DWARF_E_NO_REFERENCE);
97 return -1;
98 }
99
100 return 0;
101 }
102
103 /* This is the old public entry point.
104 It is now deprecated in favor of dwarf_formref_die. */
105 int
dwarf_formref(Dwarf_Attribute * attr,Dwarf_Off * return_offset)106 dwarf_formref (Dwarf_Attribute *attr, Dwarf_Off *return_offset)
107 {
108 if (attr == NULL)
109 return -1;
110
111 return __libdw_formref (attr, return_offset);
112 }
113