1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
|
/*
* Copyright (c) 2020, Itamar S. <itamar8910@gmail.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "DIE.h"
#include "CompilationUnit.h"
#include "DwarfInfo.h"
#include <AK/ByteBuffer.h>
#include <AK/MemoryStream.h>
namespace Debug::Dwarf {
DIE::DIE(const CompilationUnit& unit, u32 offset)
: m_compilation_unit(unit)
, m_offset(offset)
{
InputMemoryStream stream(m_compilation_unit.dwarf_info().debug_info_data());
stream.discard_or_error(m_offset);
stream.read_LEB128_unsigned(m_abbreviation_code);
m_data_offset = stream.offset();
if (m_abbreviation_code == 0) {
// An abbreviation code of 0 ( = null DIE entry) means the end of a chain of siblings
m_tag = EntryTag::None;
} else {
auto abbreviation_info = m_compilation_unit.abbreviations_map().get(m_abbreviation_code);
ASSERT(abbreviation_info.has_value());
m_tag = abbreviation_info.value().tag;
m_has_children = abbreviation_info.value().has_children;
// We iterate the attributes data only to calculate this DIE's size
for (auto& attribute_spec : abbreviation_info.value().attribute_specifications) {
get_attribute_value(attribute_spec.form, stream);
}
}
m_size = stream.offset() - m_offset;
}
DIE::AttributeValue DIE::get_attribute_value(AttributeDataForm form,
InputMemoryStream& debug_info_stream) const
{
AttributeValue value;
auto assign_raw_bytes_value = [&](size_t length) {
value.data.as_raw_bytes.length = length;
value.data.as_raw_bytes.bytes = reinterpret_cast<const u8*>(m_compilation_unit.dwarf_info().debug_info_data().data()
+ debug_info_stream.offset());
debug_info_stream.discard_or_error(length);
};
switch (form) {
case AttributeDataForm::StringPointer: {
u32 offset;
debug_info_stream >> offset;
value.type = AttributeValue::Type::String;
auto strings_data = m_compilation_unit.dwarf_info().debug_strings_data();
value.data.as_string = reinterpret_cast<const char*>(strings_data.data() + offset);
break;
}
case AttributeDataForm::Data1: {
u8 data;
debug_info_stream >> data;
value.type = AttributeValue::Type::UnsignedNumber;
value.data.as_u32 = data;
break;
}
case AttributeDataForm::Data2: {
u16 data;
debug_info_stream >> data;
value.type = AttributeValue::Type::UnsignedNumber;
value.data.as_u32 = data;
break;
}
case AttributeDataForm::Addr: {
u32 address;
debug_info_stream >> address;
value.type = AttributeValue::Type::UnsignedNumber;
value.data.as_u32 = address;
break;
}
case AttributeDataForm::SData: {
ssize_t data;
debug_info_stream.read_LEB128_signed(data);
value.type = AttributeValue::Type::SignedNumber;
value.data.as_i32 = data;
break;
}
case AttributeDataForm::SecOffset: {
u32 data;
debug_info_stream >> data;
value.type = AttributeValue::Type::SecOffset;
value.data.as_u32 = data;
break;
}
case AttributeDataForm::Data4: {
u32 data;
debug_info_stream >> data;
value.type = AttributeValue::Type::UnsignedNumber;
value.data.as_u32 = data;
break;
}
case AttributeDataForm::Ref4: {
u32 data;
debug_info_stream >> data;
value.type = AttributeValue::Type::DieReference;
value.data.as_u32 = data + m_compilation_unit.offset();
break;
}
case AttributeDataForm::FlagPresent: {
value.type = AttributeValue::Type::Boolean;
value.data.as_bool = true;
break;
}
case AttributeDataForm::ExprLoc: {
size_t length;
debug_info_stream.read_LEB128_unsigned(length);
value.type = AttributeValue::Type::DwarfExpression;
assign_raw_bytes_value(length);
break;
}
case AttributeDataForm::String: {
String str;
u32 str_offset = debug_info_stream.offset();
debug_info_stream >> str;
value.type = AttributeValue::Type::String;
value.data.as_string = reinterpret_cast<const char*>(str_offset + m_compilation_unit.dwarf_info().debug_info_data().data());
break;
}
case AttributeDataForm::Block1: {
value.type = AttributeValue::Type::RawBytes;
u8 length;
debug_info_stream >> length;
assign_raw_bytes_value(length);
break;
}
case AttributeDataForm::Block2: {
value.type = AttributeValue::Type::RawBytes;
u16 length;
debug_info_stream >> length;
assign_raw_bytes_value(length);
break;
}
case AttributeDataForm::Block4: {
value.type = AttributeValue::Type::RawBytes;
u32 length;
debug_info_stream >> length;
assign_raw_bytes_value(length);
break;
}
case AttributeDataForm::Block: {
value.type = AttributeValue::Type::RawBytes;
size_t length;
debug_info_stream.read_LEB128_unsigned(length);
assign_raw_bytes_value(length);
break;
}
default:
dbgln("Unimplemented AttributeDataForm: {}", (u32)form);
ASSERT_NOT_REACHED();
}
return value;
}
Optional<DIE::AttributeValue> DIE::get_attribute(const Attribute& attribute) const
{
InputMemoryStream stream { m_compilation_unit.dwarf_info().debug_info_data() };
stream.discard_or_error(m_data_offset);
auto abbreviation_info = m_compilation_unit.abbreviations_map().get(m_abbreviation_code);
ASSERT(abbreviation_info.has_value());
for (const auto& attribute_spec : abbreviation_info.value().attribute_specifications) {
auto value = get_attribute_value(attribute_spec.form, stream);
if (attribute_spec.attribute == attribute) {
return value;
}
}
return {};
}
void DIE::for_each_child(Function<void(const DIE& child)> callback) const
{
if (!m_has_children)
return;
NonnullOwnPtr<DIE> current_child = make<DIE>(m_compilation_unit, m_offset + m_size);
while (true) {
callback(*current_child);
if (current_child->is_null())
break;
if (!current_child->has_children()) {
current_child = make<DIE>(m_compilation_unit, current_child->offset() + current_child->size());
continue;
}
auto sibling = current_child->get_attribute(Attribute::Sibling);
u32 sibling_offset = 0;
if (sibling.has_value()) {
sibling_offset = sibling.value().data.as_u32;
}
if (!sibling.has_value()) {
// NOTE: According to the spec, the compiler doesn't have to supply the sibling information.
// When it doesn't, we have to recursively iterate the current child's children to find where they end
current_child->for_each_child([&](const DIE& sub_child) {
sibling_offset = sub_child.offset() + sub_child.size();
});
}
current_child = make<DIE>(m_compilation_unit, sibling_offset);
}
}
DIE DIE::get_die_at_offset(u32 offset) const
{
ASSERT(offset >= m_compilation_unit.offset() && offset < m_compilation_unit.offset() + m_compilation_unit.size());
return DIE(m_compilation_unit, offset);
}
}
|
