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LibCxxVector.cpp
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1 //===-- LibCxxVector.cpp ----------------------------------------*- C++ -*-===//
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"
14 
15 using namespace lldb;
16 using namespace lldb_private;
17 using namespace lldb_private::formatters;
18 
19 namespace lldb_private {
20 namespace formatters {
22 public:
23  LibcxxStdVectorSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
24 
26 
27  size_t CalculateNumChildren() override;
28 
29  lldb::ValueObjectSP GetChildAtIndex(size_t idx) override;
30 
31  bool Update() override;
32 
33  bool MightHaveChildren() override;
34 
35  size_t GetIndexOfChildWithName(ConstString name) override;
36 
37 private:
38  ValueObject *m_start;
39  ValueObject *m_finish;
40  CompilerType m_element_type;
41  uint32_t m_element_size;
42 };
43 
45 public:
46  LibcxxVectorBoolSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
47 
48  size_t CalculateNumChildren() override;
49 
50  lldb::ValueObjectSP GetChildAtIndex(size_t idx) override;
51 
52  bool Update() override;
53 
54  bool MightHaveChildren() override { return true; }
55 
56  size_t GetIndexOfChildWithName(ConstString name) override;
57 
58 private:
59  CompilerType m_bool_type;
60  ExecutionContextRef m_exe_ctx_ref;
61  uint64_t m_count;
62  lldb::addr_t m_base_data_address;
63  std::map<size_t, lldb::ValueObjectSP> m_children;
64 };
65 
66 } // namespace formatters
67 } // namespace lldb_private
68 
70  LibcxxStdVectorSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
71  : SyntheticChildrenFrontEnd(*valobj_sp), m_start(nullptr),
72  m_finish(nullptr), m_element_type(), m_element_size(0) {
73  if (valobj_sp)
74  Update();
75 }
76 
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 
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
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,
116  m_element_type);
117 }
118 
120  m_start = m_finish = nullptr;
121  ValueObjectSP data_type_finder_sp(
122  m_backend.GetChildMemberWithName(ConstString("__end_cap_"), true));
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 = data_type_finder_sp->GetChildMemberWithName(
130  ConstString("__first_"), true);
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, true);
136  data_type_finder_sp = first_elem_parent_sp->GetChildMemberWithName(
137  ConstString("__value_"), true);
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 (llvm::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 =
153  m_backend.GetChildMemberWithName(ConstString("__begin_"), true).get();
154  m_finish =
155  m_backend.GetChildMemberWithName(ConstString("__end_"), true).get();
156  }
157  }
158  return false;
159 }
160 
163  return true;
164 }
165 
168  if (!m_start || !m_finish)
169  return UINT32_MAX;
170  return ExtractIndexFromString(name.GetCString());
171 }
172 
174  LibcxxVectorBoolSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
175  : SyntheticChildrenFrontEnd(*valobj_sp), m_bool_type(), m_exe_ctx_ref(),
176  m_count(0), m_base_data_address(0), m_children() {
177  if (valobj_sp) {
178  Update();
179  m_bool_type =
180  valobj_sp->GetCompilerType().GetBasicTypeFromAST(lldb::eBasicTypeBool);
181  }
182 }
183 
186  return m_count;
187 }
188 
189 lldb::ValueObjectSP
191  size_t idx) {
192  auto iter = m_children.find(idx), end = m_children.end();
193  if (iter != end)
194  return iter->second;
195  if (idx >= m_count)
196  return {};
197  if (m_base_data_address == 0 || m_count == 0)
198  return {};
199  if (!m_bool_type)
200  return {};
201  size_t byte_idx = (idx >> 3); // divide by 8 to get byte index
202  size_t bit_index = (idx & 7); // efficient idx % 8 for bit index
203  lldb::addr_t byte_location = m_base_data_address + byte_idx;
204  ProcessSP process_sp(m_exe_ctx_ref.GetProcessSP());
205  if (!process_sp)
206  return {};
207  uint8_t byte = 0;
208  uint8_t mask = 0;
209  Status err;
210  size_t bytes_read = process_sp->ReadMemory(byte_location, &byte, 1, err);
211  if (err.Fail() || bytes_read == 0)
212  return {};
213  mask = 1 << bit_index;
214  bool bit_set = ((byte & mask) != 0);
215  llvm::Optional<uint64_t> size = m_bool_type.GetByteSize(nullptr);
216  if (!size)
217  return {};
218  DataBufferSP buffer_sp(new DataBufferHeap(*size, 0));
219  if (bit_set && buffer_sp && buffer_sp->GetBytes()) {
220  // regardless of endianness, anything non-zero is true
221  *(buffer_sp->GetBytes()) = 1;
222  }
223  StreamString name;
224  name.Printf("[%" PRIu64 "]", (uint64_t)idx);
225  ValueObjectSP retval_sp(CreateValueObjectFromData(
226  name.GetString(),
227  DataExtractor(buffer_sp, process_sp->GetByteOrder(),
228  process_sp->GetAddressByteSize()),
229  m_exe_ctx_ref, m_bool_type));
230  if (retval_sp)
231  m_children[idx] = retval_sp;
232  return retval_sp;
233 }
234 
235 /*(std::__1::vector<std::__1::allocator<bool> >) vBool = {
236  __begin_ = 0x00000001001000e0
237  __size_ = 56
238  __cap_alloc_ = {
239  std::__1::__libcpp_compressed_pair_imp<unsigned long,
240  std::__1::allocator<unsigned long> > = {
241  __first_ = 1
242  }
243  }
244  }*/
245 
247  m_children.clear();
248  ValueObjectSP valobj_sp = m_backend.GetSP();
249  if (!valobj_sp)
250  return false;
251  m_exe_ctx_ref = valobj_sp->GetExecutionContextRef();
252  ValueObjectSP size_sp(
253  valobj_sp->GetChildMemberWithName(ConstString("__size_"), true));
254  if (!size_sp)
255  return false;
256  m_count = size_sp->GetValueAsUnsigned(0);
257  if (!m_count)
258  return true;
259  ValueObjectSP begin_sp(
260  valobj_sp->GetChildMemberWithName(ConstString("__begin_"), true));
261  if (!begin_sp) {
262  m_count = 0;
263  return false;
264  }
265  m_base_data_address = begin_sp->GetValueAsUnsigned(0);
266  if (!m_base_data_address) {
267  m_count = 0;
268  return false;
269  }
270  return false;
271 }
272 
275  if (!m_count || !m_base_data_address)
276  return UINT32_MAX;
277  const char *item_name = name.GetCString();
278  uint32_t idx = ExtractIndexFromString(item_name);
279  if (idx < UINT32_MAX && idx >= CalculateNumChildren())
280  return UINT32_MAX;
281  return idx;
282 }
283 
286  CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
287  if (!valobj_sp)
288  return nullptr;
289  CompilerType type = valobj_sp->GetCompilerType();
290  if (!type.IsValid() || type.GetNumTemplateArguments() == 0)
291  return nullptr;
292  CompilerType arg_type = type.GetTypeTemplateArgument(0);
293  if (arg_type.GetTypeName() == "bool")
294  return new LibcxxVectorBoolSyntheticFrontEnd(valobj_sp);
295  return new LibcxxStdVectorSyntheticFrontEnd(valobj_sp);
296 }
LibcxxStdVectorSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
An data extractor class.
Definition: DataExtractor.h:47
Enumerations for broadcasting.
Definition: SBLaunchInfo.h:14
virtual lldb::ValueObjectSP GetChildMemberWithName(ConstString name, bool can_create)
lldb::ValueObjectSP GetChildAtIndex(size_t idx) override
lldb::ProcessSP GetProcessSP() const
Get accessor that creates a strong reference from the weak process reference contained in this object...
LibcxxVectorBoolSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
llvm::Optional< uint64_t > GetByteSize(ExecutionContextScope *exe_scope) const
Return the size of the type in bytes.
CompilerType GetBasicTypeFromAST(lldb::BasicType basic_type) const
CompilerType GetPointeeType() const
A subclass of DataBuffer that stores a data buffer on the heap.
size_t ExtractIndexFromString(const char *item_name)
#define UINT32_MAX
Definition: lldb-defines.h:31
SyntheticChildrenFrontEnd * LibcxxStdVectorSyntheticFrontEndCreator(CXXSyntheticChildren *, lldb::ValueObjectSP)
size_t GetIndexOfChildWithName(ConstString name) override
lldb::ValueObjectSP CreateValueObjectFromData(llvm::StringRef name, const DataExtractor &data, const ExecutionContext &exe_ctx, CompilerType type)
llvm::StringRef GetString() const
const ExecutionContextRef & GetExecutionContextRef() const
Definition: ValueObject.h:353
size_t Printf(const char *format,...) __attribute__((format(printf
Output printf formatted output to the stream.
Definition: Stream.cpp:106
Execution context objects refer to objects in the execution of the program that is being debugged...
static size_t CalculateNumChildren(CompilerType container_type, CompilerType element_type, lldb_private::ExecutionContextScope *exe_scope=nullptr)
Definition: VectorType.cpp:168
size_t GetNumTemplateArguments() const
uint64_t addr_t
Definition: lldb-types.h:83
lldb::ValueObjectSP CreateValueObjectFromAddress(llvm::StringRef name, uint64_t address, const ExecutionContext &exe_ctx, CompilerType type)
A uniqued constant string class.
Definition: ConstString.h:38
bool Fail() const
Test for error condition.
Definition: Status.cpp:181
lldb::ValueObjectSP GetChildAtIndex(size_t idx) override
const char * GetCString() const
Get the string value as a C string.
Definition: ConstString.h:247
virtual uint64_t GetValueAsUnsigned(uint64_t fail_value, bool *success=nullptr)
Definition: SBAddress.h:15
lldb::ValueObjectSP GetSP()
Definition: ValueObject.h:565
CompilerType GetTypeTemplateArgument(size_t idx) const
ConstString GetTypeName() const
An error handling class.
Definition: Status.h:44