1 /* Look up the DIE in a reference-form attribute.
2 Copyright (C) 2005-2010 Red Hat, Inc.
3 This file is part of elfutils.
5 This file is free software; you can redistribute it and/or modify
6 it under the terms of either
8 * the GNU Lesser General Public License as published by the Free
9 Software Foundation; either version 3 of the License, or (at
10 your option) any later version
14 * the GNU General Public License as published by the Free
15 Software Foundation; either version 2 of the License, or (at
16 your option) any later version
18 or both in parallel, as here.
20 elfutils is distributed in the hope that it will be useful, but
21 WITHOUT ANY WARRANTY; without even the implied warranty of
22 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
23 General Public License for more details.
25 You should have received copies of the GNU General Public License and
26 the GNU Lesser General Public License along with this program. If
27 not, see <http://www.gnu.org/licenses/>. */
39 dwarf_formref_die (attr, result)
40 Dwarf_Attribute *attr;
46 struct Dwarf_CU *cu = attr->cu;
49 if (attr->form == DW_FORM_ref_addr || attr->form == DW_FORM_GNU_ref_alt)
51 /* This has an absolute offset. */
53 uint8_t ref_size = (cu->version == 2 && attr->form == DW_FORM_ref_addr
57 Dwarf *dbg_ret = (attr->form == DW_FORM_GNU_ref_alt
58 ? cu->dbg->alt_dwarf : cu->dbg);
62 __libdw_seterrno (DWARF_E_NO_ALT_DEBUGLINK);
66 if (__libdw_read_offset (cu->dbg, dbg_ret, IDX_debug_info, attr->valp,
67 ref_size, &offset, IDX_debug_info, 0))
70 return INTUSE(dwarf_offdie) (dbg_ret, offset, result);
74 if (attr->form == DW_FORM_ref_sig8)
76 /* This doesn't have an offset, but instead a value we
77 have to match in the .debug_types type unit headers. */
79 uint64_t sig = read_8ubyte_unaligned (cu->dbg, attr->valp);
80 cu = Dwarf_Sig8_Hash_find (&cu->dbg->sig8_hash, sig, NULL);
82 /* Not seen before. We have to scan through the type units. */
85 cu = __libdw_intern_next_unit (attr->cu->dbg, true);
88 __libdw_seterrno (INTUSE(dwarf_errno) ()
89 ?: DWARF_E_INVALID_REFERENCE);
93 while (cu->type_sig8 != sig);
95 data = cu->dbg->sectiondata[IDX_debug_types];
96 offset = cu->type_offset;
100 /* Other forms produce an offset from the CU. */
101 if (unlikely (__libdw_formref (attr, &offset) != 0))
107 if (unlikely (data->d_size - cu->start <= offset))
109 __libdw_seterrno (DWARF_E_INVALID_DWARF);
113 memset (result, '\0', sizeof (Dwarf_Die));
114 result->addr = (char *) data->d_buf + cu->start + offset;
118 INTDEF (dwarf_formref_die)