1 //===-- LibCxxVector.cpp --------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8
9 #include "LibCxx.h"
10
11 #include "lldb/Core/ValueObject.h"
12 #include "lldb/DataFormatters/FormattersHelpers.h"
13 #include "lldb/Utility/ConstString.h"
14 #include <optional>
15
16 using namespace lldb;
17 using namespace lldb_private;
18 using namespace lldb_private::formatters;
19
20 namespace lldb_private {
21 namespace formatters {
22 class LibcxxStdVectorSyntheticFrontEnd : public SyntheticChildrenFrontEnd {
23 public:
24 LibcxxStdVectorSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
25
26 ~LibcxxStdVectorSyntheticFrontEnd() override;
27
28 size_t CalculateNumChildren() override;
29
30 lldb::ValueObjectSP GetChildAtIndex(size_t idx) override;
31
32 bool Update() override;
33
34 bool MightHaveChildren() override;
35
36 size_t GetIndexOfChildWithName(ConstString name) override;
37
38 private:
39 ValueObject *m_start = nullptr;
40 ValueObject *m_finish = nullptr;
41 CompilerType m_element_type;
42 uint32_t m_element_size = 0;
43 };
44
45 class LibcxxVectorBoolSyntheticFrontEnd : public SyntheticChildrenFrontEnd {
46 public:
47 LibcxxVectorBoolSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
48
49 size_t CalculateNumChildren() override;
50
51 lldb::ValueObjectSP GetChildAtIndex(size_t idx) override;
52
53 bool Update() override;
54
MightHaveChildren()55 bool MightHaveChildren() override { return true; }
56
57 size_t GetIndexOfChildWithName(ConstString name) override;
58
59 private:
60 CompilerType m_bool_type;
61 ExecutionContextRef m_exe_ctx_ref;
62 uint64_t m_count = 0;
63 lldb::addr_t m_base_data_address = 0;
64 std::map<size_t, lldb::ValueObjectSP> m_children;
65 };
66
67 } // namespace formatters
68 } // namespace lldb_private
69
70 lldb_private::formatters::LibcxxStdVectorSyntheticFrontEnd::
LibcxxStdVectorSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)71 LibcxxStdVectorSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
72 : SyntheticChildrenFrontEnd(*valobj_sp), m_element_type() {
73 if (valobj_sp)
74 Update();
75 }
76
77 lldb_private::formatters::LibcxxStdVectorSyntheticFrontEnd::
~LibcxxStdVectorSyntheticFrontEnd()78 ~LibcxxStdVectorSyntheticFrontEnd() {
79 // these need to stay around because they are child objects who will follow
80 // their parent's life cycle
81 // delete m_start;
82 // delete m_finish;
83 }
84
85 size_t lldb_private::formatters::LibcxxStdVectorSyntheticFrontEnd::
CalculateNumChildren()86 CalculateNumChildren() {
87 if (!m_start || !m_finish)
88 return 0;
89 uint64_t start_val = m_start->GetValueAsUnsigned(0);
90 uint64_t finish_val = m_finish->GetValueAsUnsigned(0);
91
92 if (start_val == 0 || finish_val == 0)
93 return 0;
94
95 if (start_val >= finish_val)
96 return 0;
97
98 size_t num_children = (finish_val - start_val);
99 if (num_children % m_element_size)
100 return 0;
101 return num_children / m_element_size;
102 }
103
104 lldb::ValueObjectSP
GetChildAtIndex(size_t idx)105 lldb_private::formatters::LibcxxStdVectorSyntheticFrontEnd::GetChildAtIndex(
106 size_t idx) {
107 if (!m_start || !m_finish)
108 return lldb::ValueObjectSP();
109
110 uint64_t offset = idx * m_element_size;
111 offset = offset + m_start->GetValueAsUnsigned(0);
112 StreamString name;
113 name.Printf("[%" PRIu64 "]", (uint64_t)idx);
114 return CreateValueObjectFromAddress(name.GetString(), offset,
115 m_backend.GetExecutionContextRef(),
116 m_element_type);
117 }
118
Update()119 bool lldb_private::formatters::LibcxxStdVectorSyntheticFrontEnd::Update() {
120 m_start = m_finish = nullptr;
121 ValueObjectSP data_type_finder_sp(
122 m_backend.GetChildMemberWithName("__end_cap_"));
123 if (!data_type_finder_sp)
124 return false;
125
126 switch (data_type_finder_sp->GetCompilerType().GetNumDirectBaseClasses()) {
127 case 1:
128 // Assume a pre llvm r300140 __compressed_pair implementation:
129 data_type_finder_sp =
130 data_type_finder_sp->GetChildMemberWithName("__first_");
131 break;
132 case 2: {
133 // Assume a post llvm r300140 __compressed_pair implementation:
134 ValueObjectSP first_elem_parent_sp =
135 data_type_finder_sp->GetChildAtIndex(0);
136 data_type_finder_sp =
137 first_elem_parent_sp->GetChildMemberWithName("__value_");
138 break;
139 }
140 default:
141 return false;
142 }
143
144 if (!data_type_finder_sp)
145 return false;
146 m_element_type = data_type_finder_sp->GetCompilerType().GetPointeeType();
147 if (std::optional<uint64_t> size = m_element_type.GetByteSize(nullptr)) {
148 m_element_size = *size;
149
150 if (m_element_size > 0) {
151 // store raw pointers or end up with a circular dependency
152 m_start = m_backend.GetChildMemberWithName("__begin_").get();
153 m_finish = m_backend.GetChildMemberWithName("__end_").get();
154 }
155 }
156 return false;
157 }
158
159 bool lldb_private::formatters::LibcxxStdVectorSyntheticFrontEnd::
MightHaveChildren()160 MightHaveChildren() {
161 return true;
162 }
163
164 size_t lldb_private::formatters::LibcxxStdVectorSyntheticFrontEnd::
GetIndexOfChildWithName(ConstString name)165 GetIndexOfChildWithName(ConstString name) {
166 if (!m_start || !m_finish)
167 return UINT32_MAX;
168 return ExtractIndexFromString(name.GetCString());
169 }
170
171 lldb_private::formatters::LibcxxVectorBoolSyntheticFrontEnd::
LibcxxVectorBoolSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)172 LibcxxVectorBoolSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
173 : SyntheticChildrenFrontEnd(*valobj_sp), m_bool_type(), m_exe_ctx_ref(),
174 m_children() {
175 if (valobj_sp) {
176 Update();
177 m_bool_type =
178 valobj_sp->GetCompilerType().GetBasicTypeFromAST(lldb::eBasicTypeBool);
179 }
180 }
181
182 size_t lldb_private::formatters::LibcxxVectorBoolSyntheticFrontEnd::
CalculateNumChildren()183 CalculateNumChildren() {
184 return m_count;
185 }
186
187 lldb::ValueObjectSP
GetChildAtIndex(size_t idx)188 lldb_private::formatters::LibcxxVectorBoolSyntheticFrontEnd::GetChildAtIndex(
189 size_t idx) {
190 auto iter = m_children.find(idx), end = m_children.end();
191 if (iter != end)
192 return iter->second;
193 if (idx >= m_count)
194 return {};
195 if (m_base_data_address == 0 || m_count == 0)
196 return {};
197 if (!m_bool_type)
198 return {};
199 size_t byte_idx = (idx >> 3); // divide by 8 to get byte index
200 size_t bit_index = (idx & 7); // efficient idx % 8 for bit index
201 lldb::addr_t byte_location = m_base_data_address + byte_idx;
202 ProcessSP process_sp(m_exe_ctx_ref.GetProcessSP());
203 if (!process_sp)
204 return {};
205 uint8_t byte = 0;
206 uint8_t mask = 0;
207 Status err;
208 size_t bytes_read = process_sp->ReadMemory(byte_location, &byte, 1, err);
209 if (err.Fail() || bytes_read == 0)
210 return {};
211 mask = 1 << bit_index;
212 bool bit_set = ((byte & mask) != 0);
213 std::optional<uint64_t> size = m_bool_type.GetByteSize(nullptr);
214 if (!size)
215 return {};
216 WritableDataBufferSP buffer_sp(new DataBufferHeap(*size, 0));
217 if (bit_set && buffer_sp && buffer_sp->GetBytes()) {
218 // regardless of endianness, anything non-zero is true
219 *(buffer_sp->GetBytes()) = 1;
220 }
221 StreamString name;
222 name.Printf("[%" PRIu64 "]", (uint64_t)idx);
223 ValueObjectSP retval_sp(CreateValueObjectFromData(
224 name.GetString(),
225 DataExtractor(buffer_sp, process_sp->GetByteOrder(),
226 process_sp->GetAddressByteSize()),
227 m_exe_ctx_ref, m_bool_type));
228 if (retval_sp)
229 m_children[idx] = retval_sp;
230 return retval_sp;
231 }
232
233 /*(std::__1::vector<std::__1::allocator<bool> >) vBool = {
234 __begin_ = 0x00000001001000e0
235 __size_ = 56
236 __cap_alloc_ = {
237 std::__1::__libcpp_compressed_pair_imp<unsigned long,
238 std::__1::allocator<unsigned long> > = {
239 __first_ = 1
240 }
241 }
242 }*/
243
Update()244 bool lldb_private::formatters::LibcxxVectorBoolSyntheticFrontEnd::Update() {
245 m_children.clear();
246 ValueObjectSP valobj_sp = m_backend.GetSP();
247 if (!valobj_sp)
248 return false;
249 m_exe_ctx_ref = valobj_sp->GetExecutionContextRef();
250 ValueObjectSP size_sp(valobj_sp->GetChildMemberWithName("__size_"));
251 if (!size_sp)
252 return false;
253 m_count = size_sp->GetValueAsUnsigned(0);
254 if (!m_count)
255 return true;
256 ValueObjectSP begin_sp(valobj_sp->GetChildMemberWithName("__begin_"));
257 if (!begin_sp) {
258 m_count = 0;
259 return false;
260 }
261 m_base_data_address = begin_sp->GetValueAsUnsigned(0);
262 if (!m_base_data_address) {
263 m_count = 0;
264 return false;
265 }
266 return false;
267 }
268
269 size_t lldb_private::formatters::LibcxxVectorBoolSyntheticFrontEnd::
GetIndexOfChildWithName(ConstString name)270 GetIndexOfChildWithName(ConstString name) {
271 if (!m_count || !m_base_data_address)
272 return UINT32_MAX;
273 const char *item_name = name.GetCString();
274 uint32_t idx = ExtractIndexFromString(item_name);
275 if (idx < UINT32_MAX && idx >= CalculateNumChildren())
276 return UINT32_MAX;
277 return idx;
278 }
279
280 lldb_private::SyntheticChildrenFrontEnd *
LibcxxStdVectorSyntheticFrontEndCreator(CXXSyntheticChildren *,lldb::ValueObjectSP valobj_sp)281 lldb_private::formatters::LibcxxStdVectorSyntheticFrontEndCreator(
282 CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
283 if (!valobj_sp)
284 return nullptr;
285 CompilerType type = valobj_sp->GetCompilerType();
286 if (!type.IsValid() || type.GetNumTemplateArguments() == 0)
287 return nullptr;
288 CompilerType arg_type = type.GetTypeTemplateArgument(0);
289 if (arg_type.GetTypeName() == "bool")
290 return new LibcxxVectorBoolSyntheticFrontEnd(valobj_sp);
291 return new LibcxxStdVectorSyntheticFrontEnd(valobj_sp);
292 }
293