1 /* Find CU for given offset.
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 <assert.h>
35 #include <search.h>
36 #include "libdwP.h"
37
38 static int
findcu_cb(const void * arg1,const void * arg2)39 findcu_cb (const void *arg1, const void *arg2)
40 {
41 struct Dwarf_CU *cu1 = (struct Dwarf_CU *) arg1;
42 struct Dwarf_CU *cu2 = (struct Dwarf_CU *) arg2;
43
44 /* Find out which of the two arguments is the search value. It has
45 end offset 0. */
46 if (cu1->end == 0)
47 {
48 if (cu1->start < cu2->start)
49 return -1;
50 if (cu1->start >= cu2->end)
51 return 1;
52 }
53 else
54 {
55 if (cu2->start < cu1->start)
56 return 1;
57 if (cu2->start >= cu1->end)
58 return -1;
59 }
60
61 return 0;
62 }
63
64 struct Dwarf_CU *
65 internal_function
__libdw_intern_next_unit(dbg,debug_types)66 __libdw_intern_next_unit (dbg, debug_types)
67 Dwarf *dbg;
68 bool debug_types;
69 {
70 Dwarf_Off *const offsetp
71 = debug_types ? &dbg->next_tu_offset : &dbg->next_cu_offset;
72 void **tree = debug_types ? &dbg->tu_tree : &dbg->cu_tree;
73
74 Dwarf_Off oldoff = *offsetp;
75 uint16_t version;
76 uint8_t address_size;
77 uint8_t offset_size;
78 Dwarf_Off abbrev_offset;
79 uint64_t type_sig8 = 0;
80 Dwarf_Off type_offset = 0;
81
82 if (INTUSE(dwarf_next_unit) (dbg, oldoff, offsetp, NULL,
83 &version, &abbrev_offset,
84 &address_size, &offset_size,
85 debug_types ? &type_sig8 : NULL,
86 debug_types ? &type_offset : NULL) != 0)
87 /* No more entries. */
88 return NULL;
89
90 /* We only know how to handle the DWARF version 2 through 4 formats. */
91 if (unlikely (version < 2) || unlikely (version > 4))
92 {
93 __libdw_seterrno (DWARF_E_INVALID_DWARF);
94 return NULL;
95 }
96
97 /* Invalid or truncated debug section data? */
98 Elf_Data *data = dbg->sectiondata[debug_types
99 ? IDX_debug_types : IDX_debug_info];
100 if (unlikely (*offsetp > data->d_size))
101 *offsetp = data->d_size;
102
103 /* Create an entry for this CU. */
104 struct Dwarf_CU *newp = libdw_typed_alloc (dbg, struct Dwarf_CU);
105
106 newp->dbg = dbg;
107 newp->start = oldoff;
108 newp->end = *offsetp;
109 newp->address_size = address_size;
110 newp->offset_size = offset_size;
111 newp->version = version;
112 newp->type_sig8 = type_sig8;
113 newp->type_offset = type_offset;
114 Dwarf_Abbrev_Hash_init (&newp->abbrev_hash, 41);
115 newp->orig_abbrev_offset = newp->last_abbrev_offset = abbrev_offset;
116 newp->lines = NULL;
117 newp->locs = NULL;
118
119 if (debug_types)
120 Dwarf_Sig8_Hash_insert (&dbg->sig8_hash, type_sig8, newp);
121
122 newp->startp = data->d_buf + newp->start;
123 newp->endp = data->d_buf + newp->end;
124
125 /* Add the new entry to the search tree. */
126 if (tsearch (newp, tree, findcu_cb) == NULL)
127 {
128 /* Something went wrong. Undo the operation. */
129 *offsetp = oldoff;
130 __libdw_seterrno (DWARF_E_NOMEM);
131 return NULL;
132 }
133
134 return newp;
135 }
136
137 struct Dwarf_CU *
__libdw_findcu(dbg,start,debug_types)138 __libdw_findcu (dbg, start, debug_types)
139 Dwarf *dbg;
140 Dwarf_Off start;
141 bool debug_types;
142 {
143 void **tree = debug_types ? &dbg->tu_tree : &dbg->cu_tree;
144 Dwarf_Off *next_offset
145 = debug_types ? &dbg->next_tu_offset : &dbg->next_cu_offset;
146
147 /* Maybe we already know that CU. */
148 struct Dwarf_CU fake = { .start = start, .end = 0 };
149 struct Dwarf_CU **found = tfind (&fake, tree, findcu_cb);
150 if (found != NULL)
151 return *found;
152
153 if (start < *next_offset)
154 {
155 __libdw_seterrno (DWARF_E_INVALID_DWARF);
156 return NULL;
157 }
158
159 /* No. Then read more CUs. */
160 while (1)
161 {
162 struct Dwarf_CU *newp = __libdw_intern_next_unit (dbg, debug_types);
163 if (newp == NULL)
164 return NULL;
165
166 /* Is this the one we are looking for? */
167 if (start < *next_offset)
168 // XXX Match exact offset.
169 return newp;
170 }
171 /* NOTREACHED */
172 }
173