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 llvm::Expected<uint32_t> CalculateNumChildren() override;
29
30 lldb::ValueObjectSP GetChildAtIndex(uint32_t idx) override;
31
32 lldb::ChildCacheState 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 llvm::Expected<uint32_t> CalculateNumChildren() override;
50
51 lldb::ValueObjectSP GetChildAtIndex(uint32_t idx) override;
52
53 lldb::ChildCacheState 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 llvm::Expected<uint32_t> lldb_private::formatters::
CalculateNumChildren()86 LibcxxStdVectorSyntheticFrontEnd::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(uint32_t idx)105 lldb_private::formatters::LibcxxStdVectorSyntheticFrontEnd::GetChildAtIndex(
106 uint32_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
119 lldb::ChildCacheState
Update()120 lldb_private::formatters::LibcxxStdVectorSyntheticFrontEnd::Update() {
121 m_start = m_finish = nullptr;
122 ValueObjectSP data_type_finder_sp(
123 m_backend.GetChildMemberWithName("__end_cap_"));
124 if (!data_type_finder_sp)
125 return lldb::ChildCacheState::eRefetch;
126
127 data_type_finder_sp =
128 GetFirstValueOfLibCXXCompressedPair(*data_type_finder_sp);
129 if (!data_type_finder_sp)
130 return lldb::ChildCacheState::eRefetch;
131
132 m_element_type = data_type_finder_sp->GetCompilerType().GetPointeeType();
133 if (std::optional<uint64_t> size = m_element_type.GetByteSize(nullptr)) {
134 m_element_size = *size;
135
136 if (m_element_size > 0) {
137 // store raw pointers or end up with a circular dependency
138 m_start = m_backend.GetChildMemberWithName("__begin_").get();
139 m_finish = m_backend.GetChildMemberWithName("__end_").get();
140 }
141 }
142 return lldb::ChildCacheState::eRefetch;
143 }
144
145 bool lldb_private::formatters::LibcxxStdVectorSyntheticFrontEnd::
MightHaveChildren()146 MightHaveChildren() {
147 return true;
148 }
149
150 size_t lldb_private::formatters::LibcxxStdVectorSyntheticFrontEnd::
GetIndexOfChildWithName(ConstString name)151 GetIndexOfChildWithName(ConstString name) {
152 if (!m_start || !m_finish)
153 return UINT32_MAX;
154 return ExtractIndexFromString(name.GetCString());
155 }
156
157 lldb_private::formatters::LibcxxVectorBoolSyntheticFrontEnd::
LibcxxVectorBoolSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)158 LibcxxVectorBoolSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
159 : SyntheticChildrenFrontEnd(*valobj_sp), m_bool_type(), m_exe_ctx_ref(),
160 m_children() {
161 if (valobj_sp) {
162 Update();
163 m_bool_type =
164 valobj_sp->GetCompilerType().GetBasicTypeFromAST(lldb::eBasicTypeBool);
165 }
166 }
167
168 llvm::Expected<uint32_t> lldb_private::formatters::
CalculateNumChildren()169 LibcxxVectorBoolSyntheticFrontEnd::CalculateNumChildren() {
170 return m_count;
171 }
172
173 lldb::ValueObjectSP
GetChildAtIndex(uint32_t idx)174 lldb_private::formatters::LibcxxVectorBoolSyntheticFrontEnd::GetChildAtIndex(
175 uint32_t idx) {
176 auto iter = m_children.find(idx), end = m_children.end();
177 if (iter != end)
178 return iter->second;
179 if (idx >= m_count)
180 return {};
181 if (m_base_data_address == 0 || m_count == 0)
182 return {};
183 if (!m_bool_type)
184 return {};
185 size_t byte_idx = (idx >> 3); // divide by 8 to get byte index
186 size_t bit_index = (idx & 7); // efficient idx % 8 for bit index
187 lldb::addr_t byte_location = m_base_data_address + byte_idx;
188 ProcessSP process_sp(m_exe_ctx_ref.GetProcessSP());
189 if (!process_sp)
190 return {};
191 uint8_t byte = 0;
192 uint8_t mask = 0;
193 Status err;
194 size_t bytes_read = process_sp->ReadMemory(byte_location, &byte, 1, err);
195 if (err.Fail() || bytes_read == 0)
196 return {};
197 mask = 1 << bit_index;
198 bool bit_set = ((byte & mask) != 0);
199 std::optional<uint64_t> size = m_bool_type.GetByteSize(nullptr);
200 if (!size)
201 return {};
202 WritableDataBufferSP buffer_sp(new DataBufferHeap(*size, 0));
203 if (bit_set && buffer_sp && buffer_sp->GetBytes()) {
204 // regardless of endianness, anything non-zero is true
205 *(buffer_sp->GetBytes()) = 1;
206 }
207 StreamString name;
208 name.Printf("[%" PRIu64 "]", (uint64_t)idx);
209 ValueObjectSP retval_sp(CreateValueObjectFromData(
210 name.GetString(),
211 DataExtractor(buffer_sp, process_sp->GetByteOrder(),
212 process_sp->GetAddressByteSize()),
213 m_exe_ctx_ref, m_bool_type));
214 if (retval_sp)
215 m_children[idx] = retval_sp;
216 return retval_sp;
217 }
218
219 /*(std::__1::vector<std::__1::allocator<bool> >) vBool = {
220 __begin_ = 0x00000001001000e0
221 __size_ = 56
222 __cap_alloc_ = {
223 std::__1::__libcpp_compressed_pair_imp<unsigned long,
224 std::__1::allocator<unsigned long> > = {
225 __first_ = 1
226 }
227 }
228 }*/
229
230 lldb::ChildCacheState
Update()231 lldb_private::formatters::LibcxxVectorBoolSyntheticFrontEnd::Update() {
232 m_children.clear();
233 ValueObjectSP valobj_sp = m_backend.GetSP();
234 if (!valobj_sp)
235 return lldb::ChildCacheState::eRefetch;
236 m_exe_ctx_ref = valobj_sp->GetExecutionContextRef();
237 ValueObjectSP size_sp(valobj_sp->GetChildMemberWithName("__size_"));
238 if (!size_sp)
239 return lldb::ChildCacheState::eRefetch;
240 m_count = size_sp->GetValueAsUnsigned(0);
241 if (!m_count)
242 return lldb::ChildCacheState::eReuse;
243 ValueObjectSP begin_sp(valobj_sp->GetChildMemberWithName("__begin_"));
244 if (!begin_sp) {
245 m_count = 0;
246 return lldb::ChildCacheState::eRefetch;
247 }
248 m_base_data_address = begin_sp->GetValueAsUnsigned(0);
249 if (!m_base_data_address) {
250 m_count = 0;
251 return lldb::ChildCacheState::eRefetch;
252 }
253 return lldb::ChildCacheState::eRefetch;
254 }
255
256 size_t lldb_private::formatters::LibcxxVectorBoolSyntheticFrontEnd::
GetIndexOfChildWithName(ConstString name)257 GetIndexOfChildWithName(ConstString name) {
258 if (!m_count || !m_base_data_address)
259 return UINT32_MAX;
260 const char *item_name = name.GetCString();
261 uint32_t idx = ExtractIndexFromString(item_name);
262 if (idx < UINT32_MAX && idx >= CalculateNumChildrenIgnoringErrors())
263 return UINT32_MAX;
264 return idx;
265 }
266
267 lldb_private::SyntheticChildrenFrontEnd *
LibcxxStdVectorSyntheticFrontEndCreator(CXXSyntheticChildren *,lldb::ValueObjectSP valobj_sp)268 lldb_private::formatters::LibcxxStdVectorSyntheticFrontEndCreator(
269 CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
270 if (!valobj_sp)
271 return nullptr;
272 CompilerType type = valobj_sp->GetCompilerType();
273 if (!type.IsValid() || type.GetNumTemplateArguments() == 0)
274 return nullptr;
275 CompilerType arg_type = type.GetTypeTemplateArgument(0);
276 if (arg_type.GetTypeName() == "bool")
277 return new LibcxxVectorBoolSyntheticFrontEnd(valobj_sp);
278 return new LibcxxStdVectorSyntheticFrontEnd(valobj_sp);
279 }
280