1/* Return signed constant represented by attribute.
2   Copyright (C) 2003, 2005, 2014, 2017 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
38int
39dwarf_formsdata (Dwarf_Attribute *attr, Dwarf_Sword *return_sval)
40{
41  if (attr == NULL)
42    return -1;
43
44  const unsigned char *datap = attr->valp;
45  const unsigned char *endp = attr->cu->endp;
46
47  switch (attr->form)
48    {
49    case DW_FORM_data1:
50      if (datap + 1 > endp)
51	{
52	invalid:
53	  __libdw_seterrno (DWARF_E_INVALID_DWARF);
54	  return -1;
55	}
56      *return_sval = (signed char) *attr->valp;
57      break;
58
59    case DW_FORM_data2:
60      if (datap + 2 > endp)
61	goto invalid;
62      *return_sval = read_2sbyte_unaligned (attr->cu->dbg, attr->valp);
63      break;
64
65    case DW_FORM_data4:
66      if (datap + 4 > endp)
67	goto invalid;
68      *return_sval = read_4sbyte_unaligned (attr->cu->dbg, attr->valp);
69      break;
70
71    case DW_FORM_data8:
72      if (datap + 8 > endp)
73	goto invalid;
74      *return_sval = read_8sbyte_unaligned (attr->cu->dbg, attr->valp);
75      break;
76
77    case DW_FORM_sdata:
78      if (datap + 1 > endp)
79	goto invalid;
80      get_sleb128 (*return_sval, datap, endp);
81      break;
82
83    case DW_FORM_udata:
84      if (datap + 1 > endp)
85	goto invalid;
86      get_uleb128 (*return_sval, datap, endp);
87      break;
88
89    case DW_FORM_implicit_const:
90      // The data comes from the abbrev, which has been bounds checked.
91      get_sleb128_unchecked (*return_sval, datap);
92      break;
93
94    default:
95      __libdw_seterrno (DWARF_E_NO_CONSTANT);
96      return -1;
97    }
98
99  return 0;
100}
101INTDEF(dwarf_formsdata)
102