Branch data Line data Source code
1 : : /* Look up the DIE in a reference-form attribute.
2 : : Copyright (C) 2005-2010, 2018 Red Hat, Inc.
3 : : This file is part of elfutils.
4 : :
5 : : This file is free software; you can redistribute it and/or modify
6 : : it under the terms of either
7 : :
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
11 : :
12 : : or
13 : :
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
17 : :
18 : : or both in parallel, as here.
19 : :
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.
24 : :
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/>. */
28 : :
29 : : #ifdef HAVE_CONFIG_H
30 : : # include <config.h>
31 : : #endif
32 : :
33 : : #include <string.h>
34 : : #include "libdwP.h"
35 : : #include <dwarf.h>
36 : :
37 : :
38 : : Dwarf_Die *
39 : 2502078 : dwarf_formref_die (Dwarf_Attribute *attr, Dwarf_Die *result)
40 : : {
41 [ + + ]: 2502078 : if (attr == NULL)
42 : : return NULL;
43 : :
44 : 2142802 : struct Dwarf_CU *cu = attr->cu;
45 : :
46 : 2142802 : Dwarf_Off offset;
47 [ + + ]: 2142802 : if (attr->form == DW_FORM_ref_addr || attr->form == DW_FORM_GNU_ref_alt
48 [ + - - + ]: 2142652 : || attr->form == DW_FORM_ref_sup4 || attr->form == DW_FORM_ref_sup8)
49 : : {
50 : : /* This has an absolute offset. */
51 : :
52 : 150 : uint8_t ref_size;
53 [ - + - - ]: 150 : if (cu->version == 2 && attr->form == DW_FORM_ref_addr)
54 : 0 : ref_size = cu->address_size;
55 [ + - ]: 150 : else if (attr->form == DW_FORM_ref_sup4)
56 : : ref_size = 4;
57 [ + - ]: 150 : else if (attr->form == DW_FORM_ref_sup8)
58 : : ref_size = 8;
59 : : else
60 : 150 : ref_size = cu->offset_size;
61 : :
62 : 300 : Dwarf *dbg_ret = (attr->form == DW_FORM_GNU_ref_alt
63 [ + + ]: 150 : ? INTUSE(dwarf_getalt) (cu->dbg) : cu->dbg);
64 : :
65 [ - + ]: 150 : if (dbg_ret == NULL)
66 : : {
67 : 0 : __libdw_seterrno (DWARF_E_NO_ALT_DEBUGLINK);
68 : 0 : return NULL;
69 : : }
70 : :
71 [ - + ]: 150 : if (__libdw_read_offset (cu->dbg, dbg_ret, IDX_debug_info, attr->valp,
72 : : ref_size, &offset, IDX_debug_info, 0))
73 : : return NULL;
74 : :
75 : 150 : return INTUSE(dwarf_offdie) (dbg_ret, offset, result);
76 : : }
77 : :
78 : 2142652 : const unsigned char *datap;
79 : 2142652 : size_t size;
80 [ + + ]: 2142652 : if (attr->form == DW_FORM_ref_sig8)
81 : : {
82 : : /* This doesn't have an offset, but instead a value we
83 : : have to match in the type unit headers. */
84 : :
85 [ - + ]: 12 : uint64_t sig = read_8ubyte_unaligned (cu->dbg, attr->valp);
86 : 12 : cu = Dwarf_Sig8_Hash_find (&cu->dbg->sig8_hash, sig);
87 [ + + ]: 12 : if (cu == NULL)
88 : : {
89 : : /* Not seen before. We have to scan through the type units.
90 : : Since DWARFv5 these can (also) be found in .debug_info,
91 : : so scan that first. */
92 : : bool scan_debug_types = false;
93 : 4 : do
94 : : {
95 : 4 : mutex_lock (attr->cu->dbg->dwarf_lock);
96 : 4 : cu = __libdw_intern_next_unit (attr->cu->dbg, scan_debug_types);
97 : 4 : mutex_unlock (attr->cu->dbg->dwarf_lock);
98 : :
99 [ + + ]: 4 : if (cu == NULL)
100 : : {
101 [ + - ]: 2 : if (scan_debug_types == false)
102 : : scan_debug_types = true;
103 : : else
104 : : {
105 [ # # ]: 0 : __libdw_seterrno (INTUSE(dwarf_errno) ()
106 : : ?: DWARF_E_INVALID_REFERENCE);
107 : 0 : return NULL;
108 : : }
109 : : }
110 : : }
111 [ - + ]: 2 : while (cu == NULL || cu->unit_id8 != sig);
112 : : }
113 : :
114 : 12 : int secid = cu_sec_idx (cu);
115 : 12 : datap = cu->dbg->sectiondata[secid]->d_buf;
116 : 12 : size = cu->dbg->sectiondata[secid]->d_size;
117 : 12 : offset = cu->start + cu->subdie_offset;
118 : : }
119 : : else
120 : : {
121 : : /* Other forms produce an offset from the CU. */
122 [ - + ]: 2142640 : if (unlikely (__libdw_formref (attr, &offset) != 0))
123 : : return NULL;
124 : :
125 : 2142640 : datap = cu->startp;
126 : 2142640 : size = cu->endp - cu->startp;
127 : : }
128 : :
129 [ - + ]: 2142652 : if (unlikely (offset >= size))
130 : : {
131 : 0 : __libdw_seterrno (DWARF_E_INVALID_DWARF);
132 : 0 : return NULL;
133 : : }
134 : :
135 : 2142652 : memset (result, '\0', sizeof (Dwarf_Die));
136 : 2142652 : result->addr = (char *) datap + offset;
137 : 2142652 : result->cu = cu;
138 : 2142652 : return result;
139 : : }
140 : : INTDEF (dwarf_formref_die)
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