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LibCxxMap.cpp
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1 //===-- LibCxxMap.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"
15 #include "lldb/Target/Target.h"
17 #include "lldb/Utility/Endian.h"
18 #include "lldb/Utility/Status.h"
19 #include "lldb/Utility/Stream.h"
20 
21 using namespace lldb;
22 using namespace lldb_private;
23 using namespace lldb_private::formatters;
24 
25 class MapEntry {
26 public:
27  MapEntry() = default;
28  explicit MapEntry(ValueObjectSP entry_sp) : m_entry_sp(entry_sp) {}
29  MapEntry(const MapEntry &rhs) = default;
30  explicit MapEntry(ValueObject *entry)
31  : m_entry_sp(entry ? entry->GetSP() : ValueObjectSP()) {}
32 
33  ValueObjectSP left() const {
34  static ConstString g_left("__left_");
35  if (!m_entry_sp)
36  return m_entry_sp;
37  return m_entry_sp->GetSyntheticChildAtOffset(
38  0, m_entry_sp->GetCompilerType(), true);
39  }
40 
41  ValueObjectSP right() const {
42  static ConstString g_right("__right_");
43  if (!m_entry_sp)
44  return m_entry_sp;
45  return m_entry_sp->GetSyntheticChildAtOffset(
46  m_entry_sp->GetProcessSP()->GetAddressByteSize(),
47  m_entry_sp->GetCompilerType(), true);
48  }
49 
50  ValueObjectSP parent() const {
51  static ConstString g_parent("__parent_");
52  if (!m_entry_sp)
53  return m_entry_sp;
54  return m_entry_sp->GetSyntheticChildAtOffset(
55  2 * m_entry_sp->GetProcessSP()->GetAddressByteSize(),
56  m_entry_sp->GetCompilerType(), true);
57  }
58 
59  uint64_t value() const {
60  if (!m_entry_sp)
61  return 0;
62  return m_entry_sp->GetValueAsUnsigned(0);
63  }
64 
65  bool error() const {
66  if (!m_entry_sp)
67  return true;
68  return m_entry_sp->GetError().Fail();
69  }
70 
71  bool null() const { return (value() == 0); }
72 
73  ValueObjectSP GetEntry() const { return m_entry_sp; }
74 
75  void SetEntry(ValueObjectSP entry) { m_entry_sp = entry; }
76 
77  bool operator==(const MapEntry &rhs) const {
78  return (rhs.m_entry_sp.get() == m_entry_sp.get());
79  }
80 
81 private:
82  ValueObjectSP m_entry_sp;
83 };
84 
85 class MapIterator {
86 public:
87  MapIterator() = default;
88  MapIterator(MapEntry entry, size_t depth = 0)
89  : m_entry(entry), m_max_depth(depth), m_error(false) {}
90  MapIterator(ValueObjectSP entry, size_t depth = 0)
91  : m_entry(entry), m_max_depth(depth), m_error(false) {}
93  : m_entry(rhs.m_entry), m_max_depth(rhs.m_max_depth), m_error(false) {}
94  MapIterator(ValueObject *entry, size_t depth = 0)
95  : m_entry(entry), m_max_depth(depth), m_error(false) {}
96 
97  ValueObjectSP value() { return m_entry.GetEntry(); }
98 
99  ValueObjectSP advance(size_t count) {
100  ValueObjectSP fail;
101  if (m_error)
102  return fail;
103  size_t steps = 0;
104  while (count > 0) {
105  next();
106  count--, steps++;
107  if (m_error || m_entry.null() || (steps > m_max_depth))
108  return fail;
109  }
110  return m_entry.GetEntry();
111  }
112 
113 protected:
114  void next() {
115  if (m_entry.null())
116  return;
117  MapEntry right(m_entry.right());
118  if (!right.null()) {
119  m_entry = tree_min(std::move(right));
120  return;
121  }
122  size_t steps = 0;
123  while (!is_left_child(m_entry)) {
124  if (m_entry.error()) {
125  m_error = true;
126  return;
127  }
128  m_entry.SetEntry(m_entry.parent());
129  steps++;
130  if (steps > m_max_depth) {
131  m_entry = MapEntry();
132  return;
133  }
134  }
135  m_entry = MapEntry(m_entry.parent());
136  }
137 
138 private:
139  MapEntry tree_min(MapEntry &&x) {
140  if (x.null())
141  return MapEntry();
142  MapEntry left(x.left());
143  size_t steps = 0;
144  while (!left.null()) {
145  if (left.error()) {
146  m_error = true;
147  return MapEntry();
148  }
149  x = left;
150  left.SetEntry(x.left());
151  steps++;
152  if (steps > m_max_depth)
153  return MapEntry();
154  }
155  return x;
156  }
157 
158  bool is_left_child(const MapEntry &x) {
159  if (x.null())
160  return false;
161  MapEntry rhs(x.parent());
162  rhs.SetEntry(rhs.left());
163  return x.value() == rhs.value();
164  }
165 
166  MapEntry m_entry;
167  size_t m_max_depth;
168  bool m_error;
169 };
170 
171 namespace lldb_private {
172 namespace formatters {
174 public:
175  LibcxxStdMapSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
176 
177  ~LibcxxStdMapSyntheticFrontEnd() override = default;
178 
179  size_t CalculateNumChildren() override;
180 
181  lldb::ValueObjectSP GetChildAtIndex(size_t idx) override;
182 
183  bool Update() override;
184 
185  bool MightHaveChildren() override;
186 
187  size_t GetIndexOfChildWithName(ConstString name) override;
188 
189 private:
190  bool GetDataType();
191 
192  void GetValueOffset(const lldb::ValueObjectSP &node);
193 
194  ValueObject *m_tree;
195  ValueObject *m_root_node;
196  CompilerType m_element_type;
197  uint32_t m_skip_size;
198  size_t m_count;
199  std::map<size_t, MapIterator> m_iterators;
200 };
201 } // namespace formatters
202 } // namespace lldb_private
203 
205  LibcxxStdMapSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
206  : SyntheticChildrenFrontEnd(*valobj_sp), m_tree(nullptr),
207  m_root_node(nullptr), m_element_type(), m_skip_size(UINT32_MAX),
208  m_count(UINT32_MAX), m_iterators() {
209  if (valobj_sp)
210  Update();
211 }
212 
215  static ConstString g___pair3_("__pair3_");
216  static ConstString g___first_("__first_");
217  static ConstString g___value_("__value_");
218 
219  if (m_count != UINT32_MAX)
220  return m_count;
221  if (m_tree == nullptr)
222  return 0;
223  ValueObjectSP m_item(m_tree->GetChildMemberWithName(g___pair3_, true));
224  if (!m_item)
225  return 0;
226 
227  switch (m_item->GetCompilerType().GetNumDirectBaseClasses()) {
228  case 1:
229  // Assume a pre llvm r300140 __compressed_pair implementation:
230  m_item = m_item->GetChildMemberWithName(g___first_, true);
231  break;
232  case 2: {
233  // Assume a post llvm r300140 __compressed_pair implementation:
234  ValueObjectSP first_elem_parent = m_item->GetChildAtIndex(0, true);
235  m_item = first_elem_parent->GetChildMemberWithName(g___value_, true);
236  break;
237  }
238  default:
239  return false;
240  }
241 
242  if (!m_item)
243  return 0;
244  m_count = m_item->GetValueAsUnsigned(0);
245  return m_count;
246 }
247 
248 bool lldb_private::formatters::LibcxxStdMapSyntheticFrontEnd::GetDataType() {
249  static ConstString g___value_("__value_");
250  static ConstString g_tree_("__tree_");
251  static ConstString g_pair3("__pair3_");
252 
253  if (m_element_type.GetOpaqueQualType() && m_element_type.GetTypeSystem())
254  return true;
255  m_element_type.Clear();
256  ValueObjectSP deref;
257  Status error;
258  deref = m_root_node->Dereference(error);
259  if (!deref || error.Fail())
260  return false;
261  deref = deref->GetChildMemberWithName(g___value_, true);
262  if (deref) {
263  m_element_type = deref->GetCompilerType();
264  return true;
265  }
266  deref = m_backend.GetChildAtNamePath({g_tree_, g_pair3});
267  if (!deref)
268  return false;
269  m_element_type = deref->GetCompilerType()
272  if (m_element_type) {
273  std::string name;
274  uint64_t bit_offset_ptr;
275  uint32_t bitfield_bit_size_ptr;
276  bool is_bitfield_ptr;
277  m_element_type = m_element_type.GetFieldAtIndex(
278  0, name, &bit_offset_ptr, &bitfield_bit_size_ptr, &is_bitfield_ptr);
279  m_element_type = m_element_type.GetTypedefedType();
280  return m_element_type.IsValid();
281  } else {
282  m_element_type = m_backend.GetCompilerType().GetTypeTemplateArgument(0);
283  return m_element_type.IsValid();
284  }
285 }
286 
287 void lldb_private::formatters::LibcxxStdMapSyntheticFrontEnd::GetValueOffset(
288  const lldb::ValueObjectSP &node) {
289  if (m_skip_size != UINT32_MAX)
290  return;
291  if (!node)
292  return;
293  CompilerType node_type(node->GetCompilerType());
294  uint64_t bit_offset;
295  if (node_type.GetIndexOfFieldWithName("__value_", nullptr, &bit_offset) !=
296  UINT32_MAX) {
297  m_skip_size = bit_offset / 8u;
298  } else {
299  ClangASTContext *ast_ctx =
300  llvm::dyn_cast_or_null<ClangASTContext>(node_type.GetTypeSystem());
301  if (!ast_ctx)
302  return;
303  CompilerType tree_node_type = ast_ctx->CreateStructForIdentifier(
304  ConstString(),
305  {{"ptr0", ast_ctx->GetBasicType(lldb::eBasicTypeVoid).GetPointerType()},
306  {"ptr1", ast_ctx->GetBasicType(lldb::eBasicTypeVoid).GetPointerType()},
307  {"ptr2", ast_ctx->GetBasicType(lldb::eBasicTypeVoid).GetPointerType()},
308  {"cw", ast_ctx->GetBasicType(lldb::eBasicTypeBool)},
309  {"payload", (m_element_type.GetCompleteType(), m_element_type)}});
310  std::string child_name;
311  uint32_t child_byte_size;
312  int32_t child_byte_offset = 0;
313  uint32_t child_bitfield_bit_size;
314  uint32_t child_bitfield_bit_offset;
315  bool child_is_base_class;
316  bool child_is_deref_of_parent;
317  uint64_t language_flags;
318  if (tree_node_type
319  .GetChildCompilerTypeAtIndex(
320  nullptr, 4, true, true, true, child_name, child_byte_size,
321  child_byte_offset, child_bitfield_bit_size,
322  child_bitfield_bit_offset, child_is_base_class,
323  child_is_deref_of_parent, nullptr, language_flags)
324  .IsValid())
325  m_skip_size = (uint32_t)child_byte_offset;
326  }
327 }
328 
329 lldb::ValueObjectSP
331  size_t idx) {
332  static ConstString g___cc("__cc");
333  static ConstString g___nc("__nc");
334  static ConstString g___value_("__value_");
335 
336  if (idx >= CalculateNumChildren())
337  return lldb::ValueObjectSP();
338  if (m_tree == nullptr || m_root_node == nullptr)
339  return lldb::ValueObjectSP();
340 
341  MapIterator iterator(m_root_node, CalculateNumChildren());
342 
343  const bool need_to_skip = (idx > 0);
344  size_t actual_advancde = idx;
345  if (need_to_skip) {
346  auto cached_iterator = m_iterators.find(idx - 1);
347  if (cached_iterator != m_iterators.end()) {
348  iterator = cached_iterator->second;
349  actual_advancde = 1;
350  }
351  }
352 
353  ValueObjectSP iterated_sp(iterator.advance(actual_advancde));
354  if (!iterated_sp) {
355  // this tree is garbage - stop
356  m_tree =
357  nullptr; // this will stop all future searches until an Update() happens
358  return iterated_sp;
359  }
360  if (GetDataType()) {
361  if (!need_to_skip) {
362  Status error;
363  iterated_sp = iterated_sp->Dereference(error);
364  if (!iterated_sp || error.Fail()) {
365  m_tree = nullptr;
366  return lldb::ValueObjectSP();
367  }
368  GetValueOffset(iterated_sp);
369  auto child_sp = iterated_sp->GetChildMemberWithName(g___value_, true);
370  if (child_sp)
371  iterated_sp = child_sp;
372  else
373  iterated_sp = iterated_sp->GetSyntheticChildAtOffset(
374  m_skip_size, m_element_type, true);
375  if (!iterated_sp) {
376  m_tree = nullptr;
377  return lldb::ValueObjectSP();
378  }
379  } else {
380  // because of the way our debug info is made, we need to read item 0
381  // first so that we can cache information used to generate other elements
382  if (m_skip_size == UINT32_MAX)
383  GetChildAtIndex(0);
384  if (m_skip_size == UINT32_MAX) {
385  m_tree = nullptr;
386  return lldb::ValueObjectSP();
387  }
388  iterated_sp = iterated_sp->GetSyntheticChildAtOffset(
389  m_skip_size, m_element_type, true);
390  if (!iterated_sp) {
391  m_tree = nullptr;
392  return lldb::ValueObjectSP();
393  }
394  }
395  } else {
396  m_tree = nullptr;
397  return lldb::ValueObjectSP();
398  }
399  // at this point we have a valid
400  // we need to copy current_sp into a new object otherwise we will end up with
401  // all items named __value_
402  DataExtractor data;
403  Status error;
404  iterated_sp->GetData(data, error);
405  if (error.Fail()) {
406  m_tree = nullptr;
407  return lldb::ValueObjectSP();
408  }
409  StreamString name;
410  name.Printf("[%" PRIu64 "]", (uint64_t)idx);
411  auto potential_child_sp = CreateValueObjectFromData(
413  m_element_type);
414  if (potential_child_sp) {
415  switch (potential_child_sp->GetNumChildren()) {
416  case 1: {
417  auto child0_sp = potential_child_sp->GetChildAtIndex(0, true);
418  if (child0_sp && child0_sp->GetName() == g___cc)
419  potential_child_sp = child0_sp->Clone(ConstString(name.GetString()));
420  break;
421  }
422  case 2: {
423  auto child0_sp = potential_child_sp->GetChildAtIndex(0, true);
424  auto child1_sp = potential_child_sp->GetChildAtIndex(1, true);
425  if (child0_sp && child0_sp->GetName() == g___cc && child1_sp &&
426  child1_sp->GetName() == g___nc)
427  potential_child_sp = child0_sp->Clone(ConstString(name.GetString()));
428  break;
429  }
430  }
431  }
432  m_iterators[idx] = iterator;
433  return potential_child_sp;
434 }
435 
437  static ConstString g___tree_("__tree_");
438  static ConstString g___begin_node_("__begin_node_");
439  m_count = UINT32_MAX;
440  m_tree = m_root_node = nullptr;
441  m_iterators.clear();
442  m_tree = m_backend.GetChildMemberWithName(g___tree_, true).get();
443  if (!m_tree)
444  return false;
445  m_root_node = m_tree->GetChildMemberWithName(g___begin_node_, true).get();
446  return false;
447 }
448 
451  return true;
452 }
453 
456  return ExtractIndexFromString(name.GetCString());
457 }
458 
461  CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
462  return (valobj_sp ? new LibcxxStdMapSyntheticFrontEnd(valobj_sp) : nullptr);
463 }
ValueObjectSP right() const
Definition: LibCxxMap.cpp:41
An data extractor class.
Definition: DataExtractor.h:47
MapIterator(ValueObject *entry, size_t depth=0)
Definition: LibCxxMap.cpp:94
bool operator==(const MapEntry &rhs) const
Definition: LibCxxMap.cpp:77
CompilerType GetCompilerType()
Enumerations for broadcasting.
Definition: SBLaunchInfo.h:14
void next()
Definition: LibCxxMap.cpp:114
virtual lldb::ValueObjectSP Dereference(Status &error)
virtual lldb::ValueObjectSP GetChildMemberWithName(ConstString name, bool can_create)
lldb::ValueObjectSP GetChildAtNamePath(llvm::ArrayRef< ConstString > names, ConstString *name_of_error=nullptr)
MapIterator(const MapIterator &rhs)
Definition: LibCxxMap.cpp:92
ValueObjectSP value()
Definition: LibCxxMap.cpp:97
uint64_t value() const
Definition: LibCxxMap.cpp:59
ValueObjectSP left() const
Definition: LibCxxMap.cpp:33
MapIterator(ValueObjectSP entry, size_t depth=0)
Definition: LibCxxMap.cpp:90
void SetEntry(ValueObjectSP entry)
Definition: LibCxxMap.cpp:75
bool error() const
Definition: LibCxxMap.cpp:65
MapEntry(ValueObject *entry)
Definition: LibCxxMap.cpp:30
CompilerType CreateStructForIdentifier(ConstString type_name, const std::initializer_list< std::pair< const char *, CompilerType >> &type_fields, bool packed=false)
size_t ExtractIndexFromString(const char *item_name)
lldb::opaque_compiler_type_t GetOpaqueQualType() const
Definition: CompilerType.h:165
#define UINT32_MAX
Definition: lldb-defines.h:31
ValueObjectSP GetEntry() const
Definition: LibCxxMap.cpp:73
lldb::ValueObjectSP CreateValueObjectFromData(llvm::StringRef name, const DataExtractor &data, const ExecutionContext &exe_ctx, CompilerType type)
TypeSystem * GetTypeSystem() const
Definition: CompilerType.h:150
MapEntry(ValueObjectSP entry_sp)
Definition: LibCxxMap.cpp:28
bool null() const
Definition: LibCxxMap.cpp:71
llvm::StringRef GetString() const
lldb::ValueObjectSP GetChildAtIndex(size_t idx) override
Definition: LibCxxMap.cpp:330
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
MapIterator(MapEntry entry, size_t depth=0)
Definition: LibCxxMap.cpp:88
SyntheticChildrenFrontEnd * LibcxxStdMapSyntheticFrontEndCreator(CXXSyntheticChildren *, lldb::ValueObjectSP)
Definition: LibCxxMap.cpp:460
CompilerType GetPointerType() const
static size_t CalculateNumChildren(CompilerType container_type, CompilerType element_type, lldb_private::ExecutionContextScope *exe_scope=nullptr)
Definition: VectorType.cpp:168
ValueObjectSP parent() const
Definition: LibCxxMap.cpp:50
A uniqued constant string class.
Definition: ConstString.h:38
bool Fail() const
Test for error condition.
Definition: Status.cpp:181
const char * GetCString() const
Get the string value as a C string.
Definition: ConstString.h:247
ValueObjectSP advance(size_t count)
Definition: LibCxxMap.cpp:99
Definition: SBAddress.h:15
LibcxxStdMapSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
Definition: LibCxxMap.cpp:205
CompilerType GetTypedefedType() const
CompilerType GetTypeTemplateArgument(size_t idx) const
CompilerType GetFieldAtIndex(size_t idx, std::string &name, uint64_t *bit_offset_ptr, uint32_t *bitfield_bit_size_ptr, bool *is_bitfield_ptr) const
size_t GetIndexOfChildWithName(ConstString name) override
Definition: LibCxxMap.cpp:455
CompilerType GetBasicType(lldb::BasicType type)
An error handling class.
Definition: Status.h:44