1 //===-- LibCxxUnorderedMap.cpp ----------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 // C Includes
11 // C++ Includes
12 // Other libraries and framework includes
13 // Project includes
14 #include "LibCxx.h"
15 
16 #include "lldb/Core/ValueObject.h"
17 #include "lldb/Core/ValueObjectConstResult.h"
18 #include "lldb/DataFormatters/FormattersHelpers.h"
19 #include "lldb/Symbol/ClangASTContext.h"
20 #include "lldb/Target/Target.h"
21 #include "lldb/Utility/DataBufferHeap.h"
22 #include "lldb/Utility/Endian.h"
23 #include "lldb/Utility/Status.h"
24 #include "lldb/Utility/Stream.h"
25 
26 using namespace lldb;
27 using namespace lldb_private;
28 using namespace lldb_private::formatters;
29 
30 namespace lldb_private {
31 namespace formatters {
32 class LibcxxStdUnorderedMapSyntheticFrontEnd
33     : public SyntheticChildrenFrontEnd {
34 public:
35   LibcxxStdUnorderedMapSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
36 
37   ~LibcxxStdUnorderedMapSyntheticFrontEnd() override = default;
38 
39   size_t CalculateNumChildren() override;
40 
41   lldb::ValueObjectSP GetChildAtIndex(size_t idx) override;
42 
43   bool Update() override;
44 
45   bool MightHaveChildren() override;
46 
47   size_t GetIndexOfChildWithName(const ConstString &name) override;
48 
49 private:
50   CompilerType m_element_type;
51   CompilerType m_node_type;
52   ValueObject *m_tree;
53   size_t m_num_elements;
54   ValueObject *m_next_element;
55   std::vector<std::pair<ValueObject *, uint64_t>> m_elements_cache;
56 };
57 } // namespace formatters
58 } // namespace lldb_private
59 
60 lldb_private::formatters::LibcxxStdUnorderedMapSyntheticFrontEnd::
61     LibcxxStdUnorderedMapSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
62     : SyntheticChildrenFrontEnd(*valobj_sp), m_element_type(), m_tree(nullptr),
63       m_num_elements(0), m_next_element(nullptr), m_elements_cache() {
64   if (valobj_sp)
65     Update();
66 }
67 
68 size_t lldb_private::formatters::LibcxxStdUnorderedMapSyntheticFrontEnd::
69     CalculateNumChildren() {
70   if (m_num_elements != UINT32_MAX)
71     return m_num_elements;
72   return 0;
73 }
74 
75 lldb::ValueObjectSP lldb_private::formatters::
76     LibcxxStdUnorderedMapSyntheticFrontEnd::GetChildAtIndex(size_t idx) {
77   if (idx >= CalculateNumChildren())
78     return lldb::ValueObjectSP();
79   if (m_tree == nullptr)
80     return lldb::ValueObjectSP();
81 
82   while (idx >= m_elements_cache.size()) {
83     if (m_next_element == nullptr)
84       return lldb::ValueObjectSP();
85 
86     Status error;
87     ValueObjectSP node_sp = m_next_element->Dereference(error);
88     if (!node_sp || error.Fail())
89       return lldb::ValueObjectSP();
90 
91     ValueObjectSP value_sp =
92         node_sp->GetChildMemberWithName(ConstString("__value_"), true);
93     ValueObjectSP hash_sp =
94         node_sp->GetChildMemberWithName(ConstString("__hash_"), true);
95     if (!hash_sp || !value_sp) {
96       if (!m_element_type) {
97         auto p1_sp = m_backend.GetChildAtNamePath({ConstString("__table_"),
98                                                    ConstString("__p1_")});
99         if (!p1_sp)
100           return nullptr;
101 
102         ValueObjectSP first_sp = nullptr;
103         switch (p1_sp->GetCompilerType().GetNumDirectBaseClasses()) {
104         case 1:
105           // Assume a pre llvm r300140 __compressed_pair implementation:
106           first_sp = p1_sp->GetChildMemberWithName(ConstString("__first_"),
107                                                    true);
108           break;
109         case 2: {
110           // Assume a post llvm r300140 __compressed_pair implementation:
111           ValueObjectSP first_elem_parent_sp =
112             p1_sp->GetChildAtIndex(0, true);
113           first_sp = p1_sp->GetChildMemberWithName(ConstString("__value_"),
114                                                    true);
115           break;
116         }
117         default:
118           return nullptr;
119         }
120 
121         if (!first_sp)
122           return nullptr;
123         m_element_type = first_sp->GetCompilerType();
124         m_element_type = m_element_type.GetTypeTemplateArgument(0);
125         m_element_type = m_element_type.GetPointeeType();
126         m_node_type = m_element_type;
127         m_element_type = m_element_type.GetTypeTemplateArgument(0);
128         std::string name;
129         m_element_type =
130             m_element_type.GetFieldAtIndex(0, name, nullptr, nullptr, nullptr);
131         m_element_type = m_element_type.GetTypedefedType();
132       }
133       if (!m_node_type)
134         return nullptr;
135       node_sp = node_sp->Cast(m_node_type);
136       value_sp = node_sp->GetChildMemberWithName(ConstString("__value_"), true);
137       hash_sp = node_sp->GetChildMemberWithName(ConstString("__hash_"), true);
138       if (!value_sp || !hash_sp)
139         return nullptr;
140     }
141     m_elements_cache.push_back(
142         {value_sp.get(), hash_sp->GetValueAsUnsigned(0)});
143     m_next_element =
144         node_sp->GetChildMemberWithName(ConstString("__next_"), true).get();
145     if (!m_next_element || m_next_element->GetValueAsUnsigned(0) == 0)
146       m_next_element = nullptr;
147   }
148 
149   std::pair<ValueObject *, uint64_t> val_hash = m_elements_cache[idx];
150   if (!val_hash.first)
151     return lldb::ValueObjectSP();
152   StreamString stream;
153   stream.Printf("[%" PRIu64 "]", (uint64_t)idx);
154   DataExtractor data;
155   Status error;
156   val_hash.first->GetData(data, error);
157   if (error.Fail())
158     return lldb::ValueObjectSP();
159   const bool thread_and_frame_only_if_stopped = true;
160   ExecutionContext exe_ctx = val_hash.first->GetExecutionContextRef().Lock(
161       thread_and_frame_only_if_stopped);
162   return CreateValueObjectFromData(stream.GetString(), data, exe_ctx,
163                                    val_hash.first->GetCompilerType());
164 }
165 
166 bool lldb_private::formatters::LibcxxStdUnorderedMapSyntheticFrontEnd::
167     Update() {
168   m_num_elements = UINT32_MAX;
169   m_next_element = nullptr;
170   m_elements_cache.clear();
171   ValueObjectSP table_sp =
172       m_backend.GetChildMemberWithName(ConstString("__table_"), true);
173   if (!table_sp)
174     return false;
175 
176   ValueObjectSP p2_sp = table_sp->GetChildMemberWithName(
177     ConstString("__p2_"), true);
178   ValueObjectSP num_elements_sp = nullptr;
179   llvm::SmallVector<ConstString, 3> next_path;
180   switch (p2_sp->GetCompilerType().GetNumDirectBaseClasses()) {
181   case 1:
182     // Assume a pre llvm r300140 __compressed_pair implementation:
183     num_elements_sp = p2_sp->GetChildMemberWithName(
184       ConstString("__first_"), true);
185     next_path.append({ConstString("__p1_"), ConstString("__first_"),
186                       ConstString("__next_")});
187     break;
188   case 2: {
189     // Assume a post llvm r300140 __compressed_pair implementation:
190     ValueObjectSP first_elem_parent = p2_sp->GetChildAtIndex(0, true);
191     num_elements_sp = first_elem_parent->GetChildMemberWithName(
192       ConstString("__value_"), true);
193     next_path.append({ConstString("__p1_"), ConstString("__value_"),
194                       ConstString("__next_")});
195     break;
196   }
197   default:
198     return false;
199   }
200 
201   if (!num_elements_sp)
202     return false;
203   m_num_elements = num_elements_sp->GetValueAsUnsigned(0);
204   m_tree = table_sp->GetChildAtNamePath(next_path).get();
205   if (m_num_elements > 0)
206     m_next_element =
207         table_sp->GetChildAtNamePath(next_path).get();
208   return false;
209 }
210 
211 bool lldb_private::formatters::LibcxxStdUnorderedMapSyntheticFrontEnd::
212     MightHaveChildren() {
213   return true;
214 }
215 
216 size_t lldb_private::formatters::LibcxxStdUnorderedMapSyntheticFrontEnd::
217     GetIndexOfChildWithName(const ConstString &name) {
218   return ExtractIndexFromString(name.GetCString());
219 }
220 
221 SyntheticChildrenFrontEnd *
222 lldb_private::formatters::LibcxxStdUnorderedMapSyntheticFrontEndCreator(
223     CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
224   return (valobj_sp ? new LibcxxStdUnorderedMapSyntheticFrontEnd(valobj_sp)
225                     : nullptr);
226 }
227