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/DataBufferHeap.h"
17 #include "lldb/Core/Error.h"
18 #include "lldb/Core/Stream.h"
19 #include "lldb/Core/ValueObject.h"
20 #include "lldb/Core/ValueObjectConstResult.h"
21 #include "lldb/DataFormatters/FormattersHelpers.h"
22 #include "lldb/Host/Endian.h"
23 #include "lldb/Symbol/ClangASTContext.h"
24 #include "lldb/Target/Target.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 : public SyntheticChildrenFrontEnd
33         {
34         public:
35             LibcxxStdUnorderedMapSyntheticFrontEnd (lldb::ValueObjectSP valobj_sp);
36 
37             ~LibcxxStdUnorderedMapSyntheticFrontEnd() override = default;
38 
39             size_t
40             CalculateNumChildren() override;
41 
42             lldb::ValueObjectSP
43             GetChildAtIndex(size_t idx) override;
44 
45             bool
46             Update() override;
47 
48             bool
49             MightHaveChildren() override;
50 
51             size_t
52             GetIndexOfChildWithName(const ConstString &name) override;
53 
54         private:
55             ValueObject* m_tree;
56             size_t m_num_elements;
57             ValueObject* m_next_element;
58             std::map<size_t,lldb::ValueObjectSP> m_children;
59             std::vector<std::pair<ValueObject*, uint64_t> > m_elements_cache;
60         };
61     } // namespace formatters
62 } // namespace lldb_private
63 
64 lldb_private::formatters::LibcxxStdUnorderedMapSyntheticFrontEnd::LibcxxStdUnorderedMapSyntheticFrontEnd (lldb::ValueObjectSP valobj_sp) :
65     SyntheticChildrenFrontEnd(*valobj_sp),
66     m_tree(nullptr),
67     m_num_elements(0),
68     m_next_element(nullptr),
69     m_children(),
70     m_elements_cache()
71 {
72     if (valobj_sp)
73         Update();
74 }
75 
76 size_t
77 lldb_private::formatters::LibcxxStdUnorderedMapSyntheticFrontEnd::CalculateNumChildren ()
78 {
79     if (m_num_elements != UINT32_MAX)
80         return m_num_elements;
81     return 0;
82 }
83 
84 lldb::ValueObjectSP
85 lldb_private::formatters::LibcxxStdUnorderedMapSyntheticFrontEnd::GetChildAtIndex (size_t idx)
86 {
87     if (idx >= CalculateNumChildren())
88         return lldb::ValueObjectSP();
89     if (m_tree == nullptr)
90         return lldb::ValueObjectSP();
91 
92     auto cached = m_children.find(idx);
93     if (cached != m_children.end())
94         return cached->second;
95 
96     while (idx >= m_elements_cache.size())
97     {
98         if (m_next_element == nullptr)
99             return lldb::ValueObjectSP();
100 
101         Error error;
102         ValueObjectSP node_sp = m_next_element->Dereference(error);
103         if (!node_sp || error.Fail())
104             return lldb::ValueObjectSP();
105 
106         ValueObjectSP value_sp = node_sp->GetChildMemberWithName(ConstString("__value_"), true);
107         ValueObjectSP hash_sp = node_sp->GetChildMemberWithName(ConstString("__hash_"), true);
108         if (!hash_sp || !value_sp)
109             return lldb::ValueObjectSP();
110         m_elements_cache.push_back({value_sp.get(),hash_sp->GetValueAsUnsigned(0)});
111         m_next_element = node_sp->GetChildMemberWithName(ConstString("__next_"),true).get();
112         if (!m_next_element || m_next_element->GetValueAsUnsigned(0) == 0)
113             m_next_element = nullptr;
114     }
115 
116     std::pair<ValueObject*, uint64_t> val_hash = m_elements_cache[idx];
117     if (!val_hash.first)
118         return lldb::ValueObjectSP();
119     StreamString stream;
120     stream.Printf("[%" PRIu64 "]", (uint64_t)idx);
121     DataExtractor data;
122     Error error;
123     val_hash.first->GetData(data, error);
124     if (error.Fail())
125         return lldb::ValueObjectSP();
126     const bool thread_and_frame_only_if_stopped = true;
127     ExecutionContext exe_ctx = val_hash.first->GetExecutionContextRef().Lock(thread_and_frame_only_if_stopped);
128     ValueObjectSP child_sp(val_hash.first->CreateValueObjectFromData(stream.GetData(),
129                                                                      data,
130                                                                      exe_ctx,
131                                                                      val_hash.first->GetCompilerType()));
132     if (child_sp)
133         m_children.emplace(idx, child_sp);
134     return child_sp;
135 }
136 
137 bool
138 lldb_private::formatters::LibcxxStdUnorderedMapSyntheticFrontEnd::Update()
139 {
140     m_num_elements = UINT32_MAX;
141     m_next_element = nullptr;
142     m_elements_cache.clear();
143     m_children.clear();
144     ValueObjectSP table_sp = m_backend.GetChildMemberWithName(ConstString("__table_"), true);
145     if (!table_sp)
146         return false;
147     ValueObjectSP num_elements_sp = table_sp->GetChildAtNamePath({ConstString("__p2_"),ConstString("__first_")});
148     if (!num_elements_sp)
149         return false;
150     m_num_elements = num_elements_sp->GetValueAsUnsigned(0);
151     m_tree = table_sp->GetChildAtNamePath({ConstString("__p1_"),ConstString("__first_"),ConstString("__next_")}).get();
152     if (m_num_elements > 0)
153         m_next_element = table_sp->GetChildAtNamePath({ConstString("__p1_"),ConstString("__first_"),ConstString("__next_")}).get();
154     return false;
155 }
156 
157 bool
158 lldb_private::formatters::LibcxxStdUnorderedMapSyntheticFrontEnd::MightHaveChildren ()
159 {
160     return true;
161 }
162 
163 size_t
164 lldb_private::formatters::LibcxxStdUnorderedMapSyntheticFrontEnd::GetIndexOfChildWithName (const ConstString &name)
165 {
166     return ExtractIndexFromString(name.GetCString());
167 }
168 
169 SyntheticChildrenFrontEnd*
170 lldb_private::formatters::LibcxxStdUnorderedMapSyntheticFrontEndCreator (CXXSyntheticChildren*, lldb::ValueObjectSP valobj_sp)
171 {
172     return (valobj_sp ? new LibcxxStdUnorderedMapSyntheticFrontEnd(valobj_sp) : nullptr);
173 }
174