1/* Return reference offset represented by attribute.
2   Copyright (C) 2003 Red Hat, Inc.
3   Written by Ulrich Drepper <drepper@redhat.com>, 2003.
4
5   This program is Open Source software; you can redistribute it and/or
6   modify it under the terms of the Open Software License version 1.0 as
7   published by the Open Source Initiative.
8
9   You should have received a copy of the Open Software License along
10   with this program; if not, you may obtain a copy of the Open Software
11   License version 1.0 from http://www.opensource.org/licenses/osl.php or
12   by writing the Open Source Initiative c/o Lawrence Rosen, Esq.,
13   3001 King Ranch Road, Ukiah, CA 95482.   */
14
15#ifdef HAVE_CONFIG_H
16# include <config.h>
17#endif
18
19#include <dwarf.h>
20#include "libdwP.h"
21
22
23int
24dwarf_formref (attr, return_offset)
25     Dwarf_Attribute *attr;
26     Dwarf_Off *return_offset;
27{
28  if (attr == NULL)
29    return -1;
30
31  unsigned int u128;
32  unsigned char *datap;
33
34  switch (attr->form)
35    {
36    case DW_FORM_ref1:
37      *return_offset = *attr->valp;
38      break;
39
40    case DW_FORM_ref2:
41      *return_offset = read_2ubyte_unaligned (attr->cu->dbg, attr->valp);
42      break;
43
44    case DW_FORM_ref4:
45      *return_offset = read_4ubyte_unaligned (attr->cu->dbg, attr->valp);
46      break;
47
48    case DW_FORM_ref8:
49      *return_offset = read_8ubyte_unaligned (attr->cu->dbg, attr->valp);
50      break;
51
52    case DW_FORM_ref_udata:
53      datap = attr->valp;
54      get_uleb128 (u128, datap);
55      *return_offset = u128;
56      break;
57
58    case DW_FORM_ref_addr:
59      __libdw_seterrno (DWARF_E_INVALID_REFERENCE);
60      return -1;
61
62    default:
63      __libdw_seterrno (DWARF_E_NO_REFERENCE);
64      return -1;
65    }
66
67  return 0;
68}
69