1 /* Find CU for given offset.
2 Copyright (C) 2003-2010 Red Hat, Inc.
3 This file is part of Red Hat elfutils.
4 Written by Ulrich Drepper <drepper@redhat.com>, 2003.
5
6 Red Hat elfutils is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by the
8 Free Software Foundation; version 2 of the License.
9
10 Red Hat elfutils is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
14
15 You should have received a copy of the GNU General Public License along
16 with Red Hat elfutils; if not, write to the Free Software Foundation,
17 Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.
18
19 In addition, as a special exception, Red Hat, Inc. gives You the
20 additional right to link the code of Red Hat elfutils with code licensed
21 under any Open Source Initiative certified open source license
22 (http://www.opensource.org/licenses/index.php) which requires the
23 distribution of source code with any binary distribution and to
24 distribute linked combinations of the two. Non-GPL Code permitted under
25 this exception must only link to the code of Red Hat elfutils through
26 those well defined interfaces identified in the file named EXCEPTION
27 found in the source code files (the "Approved Interfaces"). The files
28 of Non-GPL Code may instantiate templates or use macros or inline
29 functions from the Approved Interfaces without causing the resulting
30 work to be covered by the GNU General Public License. Only Red Hat,
31 Inc. may make changes or additions to the list of Approved Interfaces.
32 Red Hat's grant of this exception is conditioned upon your not adding
33 any new exceptions. If you wish to add a new Approved Interface or
34 exception, please contact Red Hat. You must obey the GNU General Public
35 License in all respects for all of the Red Hat elfutils code and other
36 code used in conjunction with Red Hat elfutils except the Non-GPL Code
37 covered by this exception. If you modify this file, you may extend this
38 exception to your version of the file, but you are not obligated to do
39 so. If you do not wish to provide this exception without modification,
40 you must delete this exception statement from your version and license
41 this file solely under the GPL without exception.
42
43 Red Hat elfutils is an included package of the Open Invention Network.
44 An included package of the Open Invention Network is a package for which
45 Open Invention Network licensees cross-license their patents. No patent
46 license is granted, either expressly or impliedly, by designation as an
47 included package. Should you wish to participate in the Open Invention
48 Network licensing program, please visit www.openinventionnetwork.com
49 <http://www.openinventionnetwork.com>. */
50
51 #ifdef HAVE_CONFIG_H
52 # include <config.h>
53 #endif
54
55 #include <assert.h>
56 #include <search.h>
57 #include "libdwP.h"
58
59
60 struct Dwarf_CU *
61 internal_function
__libdw_intern_next_unit(dbg,debug_types)62 __libdw_intern_next_unit (dbg, debug_types)
63 Dwarf *dbg;
64 bool debug_types;
65 {
66 Dwarf_Off *const offsetp
67 = debug_types ? &dbg->next_tu_offset : &dbg->next_cu_offset;
68
69 Dwarf_Off oldoff = *offsetp;
70 uint16_t version;
71 uint8_t address_size;
72 uint8_t offset_size;
73 Dwarf_Off abbrev_offset;
74 uint64_t type_sig8 = 0;
75 Dwarf_Off type_offset = 0;
76
77 if (INTUSE(dwarf_next_unit) (dbg, oldoff, offsetp, NULL,
78 &version, &abbrev_offset,
79 &address_size, &offset_size,
80 debug_types ? &type_sig8 : NULL,
81 debug_types ? &type_offset : NULL) != 0)
82 /* No more entries. */
83 return NULL;
84
85 /* We only know how to handle the DWARF version 2 through 4 formats. */
86 if (unlikely (version < 2) || unlikely (version > 4))
87 {
88 __libdw_seterrno (DWARF_E_INVALID_DWARF);
89 return NULL;
90 }
91
92 /* Create an entry for this CU. */
93 struct Dwarf_CU *newp = libdw_typed_alloc (dbg, struct Dwarf_CU);
94
95 newp->dbg = dbg;
96 newp->start = oldoff;
97 newp->end = *offsetp;
98 newp->address_size = address_size;
99 newp->offset_size = offset_size;
100 newp->version = version;
101 newp->type_sig8 = type_sig8;
102 newp->type_offset = type_offset;
103 Dwarf_Abbrev_Hash_init (&newp->abbrev_hash, 41);
104 newp->orig_abbrev_offset = newp->last_abbrev_offset = abbrev_offset;
105 newp->lines = NULL;
106 newp->locs = NULL;
107
108 return newp;
109 }
110
111
112 static int
findcu_cb(const void * arg1,const void * arg2)113 findcu_cb (const void *arg1, const void *arg2)
114 {
115 struct Dwarf_CU *cu1 = (struct Dwarf_CU *) arg1;
116 struct Dwarf_CU *cu2 = (struct Dwarf_CU *) arg2;
117
118 /* Find out which of the two arguments is the search value. It has
119 end offset 0. */
120 if (cu1->end == 0)
121 {
122 if (cu1->start < cu2->start)
123 return -1;
124 if (cu1->start >= cu2->end)
125 return 1;
126 }
127 else
128 {
129 if (cu2->start < cu1->start)
130 return 1;
131 if (cu2->start >= cu1->end)
132 return -1;
133 }
134
135 return 0;
136 }
137
138 struct Dwarf_CU *
__libdw_findcu(dbg,start,debug_types)139 __libdw_findcu (dbg, start, debug_types)
140 Dwarf *dbg;
141 Dwarf_Off start;
142 bool debug_types;
143 {
144 void **tree = debug_types ? &dbg->tu_tree : &dbg->cu_tree;
145 Dwarf_Off *next_offset
146 = debug_types ? &dbg->next_tu_offset : &dbg->next_cu_offset;
147
148 /* Maybe we already know that CU. */
149 struct Dwarf_CU fake = { .start = start, .end = 0 };
150 struct Dwarf_CU **found = tfind (&fake, tree, findcu_cb);
151 if (found != NULL)
152 return *found;
153
154 if (start < *next_offset)
155 {
156 __libdw_seterrno (DWARF_E_INVALID_DWARF);
157 return NULL;
158 }
159
160 /* No. Then read more CUs. */
161 while (1)
162 {
163 Dwarf_Off oldoff = *next_offset;
164 struct Dwarf_CU *newp = __libdw_intern_next_unit (dbg, debug_types);
165 if (newp == NULL)
166 return NULL;
167
168 /* Add the new entry to the search tree. */
169 if (tsearch (newp, tree, findcu_cb) == NULL)
170 {
171 /* Something went wrong. Undo the operation. */
172 *next_offset = oldoff;
173 __libdw_seterrno (DWARF_E_NOMEM);
174 return NULL;
175 }
176
177 /* Is this the one we are looking for? */
178 if (start < *next_offset)
179 // XXX Match exact offset.
180 return newp;
181 }
182 /* NOTREACHED */
183 }
184