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