1 /* Enumerate the PC ranges covered by a DIE.
2 Copyright (C) 2005, 2007 Red Hat, Inc.
3 This file is part of Red Hat elfutils.
4
5 Red Hat elfutils is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by the
7 Free Software Foundation; version 2 of the License.
8
9 Red Hat elfutils is distributed in the hope that it will be useful, but
10 WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 General Public License for more details.
13
14 You should have received a copy of the GNU General Public License along
15 with Red Hat elfutils; if not, write to the Free Software Foundation,
16 Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.
17
18 In addition, as a special exception, Red Hat, Inc. gives You the
19 additional right to link the code of Red Hat elfutils with code licensed
20 under any Open Source Initiative certified open source license
21 (http://www.opensource.org/licenses/index.php) which requires the
22 distribution of source code with any binary distribution and to
23 distribute linked combinations of the two. Non-GPL Code permitted under
24 this exception must only link to the code of Red Hat elfutils through
25 those well defined interfaces identified in the file named EXCEPTION
26 found in the source code files (the "Approved Interfaces"). The files
27 of Non-GPL Code may instantiate templates or use macros or inline
28 functions from the Approved Interfaces without causing the resulting
29 work to be covered by the GNU General Public License. Only Red Hat,
30 Inc. may make changes or additions to the list of Approved Interfaces.
31 Red Hat's grant of this exception is conditioned upon your not adding
32 any new exceptions. If you wish to add a new Approved Interface or
33 exception, please contact Red Hat. You must obey the GNU General Public
34 License in all respects for all of the Red Hat elfutils code and other
35 code used in conjunction with Red Hat elfutils except the Non-GPL Code
36 covered by this exception. If you modify this file, you may extend this
37 exception to your version of the file, but you are not obligated to do
38 so. If you do not wish to provide this exception without modification,
39 you must delete this exception statement from your version and license
40 this file solely under the GPL without exception.
41
42 Red Hat elfutils is an included package of the Open Invention Network.
43 An included package of the Open Invention Network is a package for which
44 Open Invention Network licensees cross-license their patents. No patent
45 license is granted, either expressly or impliedly, by designation as an
46 included package. Should you wish to participate in the Open Invention
47 Network licensing program, please visit www.openinventionnetwork.com
48 <http://www.openinventionnetwork.com>. */
49
50 #ifdef HAVE_CONFIG_H
51 # include <config.h>
52 #endif
53
54 #include "libdwP.h"
55 #include <dwarf.h>
56 #include <assert.h>
57
58
59 ptrdiff_t
dwarf_ranges(Dwarf_Die * die,ptrdiff_t offset,Dwarf_Addr * basep,Dwarf_Addr * startp,Dwarf_Addr * endp)60 dwarf_ranges (Dwarf_Die *die, ptrdiff_t offset, Dwarf_Addr *basep,
61 Dwarf_Addr *startp, Dwarf_Addr *endp)
62 {
63 if (die == NULL)
64 return -1;
65
66 if (offset == 0
67 /* Usually there is a single contiguous range. */
68 && INTUSE(dwarf_highpc) (die, endp) == 0
69 && INTUSE(dwarf_lowpc) (die, startp) == 0)
70 /* A offset into .debug_ranges will never be 1, it must be at least a
71 multiple of 4. So we can return 1 as a special case value to mark
72 there are no ranges to look for on the next call. */
73 return 1;
74
75 if (offset == 1)
76 return 0;
77
78 /* We have to look for a noncontiguous range. */
79
80 const Elf_Data *d = die->cu->dbg->sectiondata[IDX_debug_ranges];
81 if (d == NULL)
82 {
83 __libdw_seterrno (DWARF_E_NO_DEBUG_RANGES);
84 return -1;
85 }
86
87 if (offset == 0)
88 {
89 Dwarf_Attribute attr_mem;
90 Dwarf_Attribute *attr = INTUSE(dwarf_attr) (die, DW_AT_ranges,
91 &attr_mem);
92 if (attr == NULL)
93 return -1;
94
95 /* Must have the form data4 or data8 which act as an offset. */
96 Dwarf_Word start_offset;
97 if (INTUSE(dwarf_formudata) (attr, &start_offset) != 0)
98 return -1;
99
100 offset = start_offset;
101 assert ((Dwarf_Word) offset == start_offset);
102
103 /* Fetch the CU's base address. */
104 Dwarf_Die cudie = CUDIE (attr->cu);
105
106 /* Find the base address of the compilation unit. It will
107 normally be specified by DW_AT_low_pc. In DWARF-3 draft 4,
108 the base address could be overridden by DW_AT_entry_pc. It's
109 been removed, but GCC emits DW_AT_entry_pc and not DW_AT_lowpc
110 for compilation units with discontinuous ranges. */
111 if (unlikely (INTUSE(dwarf_lowpc) (&cudie, basep) != 0)
112 && INTUSE(dwarf_formaddr) (INTUSE(dwarf_attr) (&cudie,
113 DW_AT_entry_pc,
114 &attr_mem),
115 basep) != 0)
116 {
117 if (INTUSE(dwarf_errno) () == 0)
118 {
119 invalid:
120 __libdw_seterrno (DWARF_E_INVALID_DWARF);
121 }
122 return -1;
123 }
124 }
125 else if (offset < 0 || (size_t) offset >= d->d_size)
126 {
127 __libdw_seterrno (DWARF_E_INVALID_OFFSET);
128 return -1l;
129 }
130
131 unsigned char *readp = d->d_buf + offset;
132
133 next:
134 if ((unsigned char *) d->d_buf + d->d_size - readp
135 < die->cu->address_size * 2)
136 goto invalid;
137
138 Dwarf_Addr begin;
139 Dwarf_Addr end;
140 if (die->cu->address_size == 8)
141 {
142 begin = read_8ubyte_unaligned_inc (die->cu->dbg, readp);
143 end = read_8ubyte_unaligned_inc (die->cu->dbg, readp);
144 if (begin == (uint64_t) -1l) /* Base address entry. */
145 {
146 *basep = end;
147 goto next;
148 }
149 }
150 else
151 {
152 begin = read_4ubyte_unaligned_inc (die->cu->dbg, readp);
153 end = read_4ubyte_unaligned_inc (die->cu->dbg, readp);
154 if (begin == (uint32_t) -1) /* Base address entry. */
155 {
156 *basep = end;
157 goto next;
158 }
159 }
160
161 if (begin == 0 && end == 0) /* End of list entry. */
162 return 0;
163
164 /* We have an address range entry. */
165 *startp = *basep + begin;
166 *endp = *basep + end;
167 return readp - (unsigned char *) d->d_buf;
168 }
169 INTDEF (dwarf_ranges)
170