1 //===-- ValueObjectSyntheticFilter.h ----------------------------*- 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 #ifndef LLDB_CORE_VALUEOBJECTSYNTHETICFILTER_H
10 #define LLDB_CORE_VALUEOBJECTSYNTHETICFILTER_H
11 
12 #include "lldb/Core/ValueObject.h"
13 #include "lldb/Symbol/CompilerType.h"
14 #include "lldb/Utility/ConstString.h"
15 #include "lldb/lldb-defines.h"
16 #include "lldb/lldb-enumerations.h"
17 #include "lldb/lldb-forward.h"
18 #include "lldb/lldb-private-enumerations.h"
19 
20 #include <cstdint>
21 #include <memory>
22 #include <optional>
23 
24 #include <cstddef>
25 
26 namespace lldb_private {
27 class Declaration;
28 class Status;
29 class SyntheticChildrenFrontEnd;
30 
31 /// A ValueObject that obtains its children from some source other than
32 /// real information.
33 /// This is currently used to implement Python-based children and filters but
34 /// you can bind it to any source of synthetic information and have it behave
35 /// accordingly.
36 class ValueObjectSynthetic : public ValueObject {
37 public:
38   ~ValueObjectSynthetic() override;
39 
40   std::optional<uint64_t> GetByteSize() override;
41 
42   ConstString GetTypeName() override;
43 
44   ConstString GetQualifiedTypeName() override;
45 
46   ConstString GetDisplayTypeName() override;
47 
48   bool MightHaveChildren() override;
49 
50   size_t CalculateNumChildren(uint32_t max) override;
51 
52   lldb::ValueType GetValueType() const override;
53 
54   lldb::ValueObjectSP GetChildAtIndex(size_t idx, bool can_create) override;
55 
56   lldb::ValueObjectSP GetChildMemberWithName(ConstString name,
57                                              bool can_create) override;
58 
59   size_t GetIndexOfChildWithName(ConstString name) override;
60 
61   lldb::ValueObjectSP
62   GetDynamicValue(lldb::DynamicValueType valueType) override;
63 
64   bool IsInScope() override;
65 
66   bool HasSyntheticValue() override { return false; }
67 
68   bool IsSynthetic() override { return true; }
69 
70   void CalculateSyntheticValue() override {}
71 
72   bool IsDynamic() override {
73     return ((m_parent != nullptr) ? m_parent->IsDynamic() : false);
74   }
75 
76   lldb::ValueObjectSP GetStaticValue() override {
77     return ((m_parent != nullptr) ? m_parent->GetStaticValue() : GetSP());
78   }
79 
80   virtual lldb::DynamicValueType GetDynamicValueType() {
81     return ((m_parent != nullptr) ? m_parent->GetDynamicValueType()
82                                   : lldb::eNoDynamicValues);
83   }
84 
85   ValueObject *GetParent() override {
86     return ((m_parent != nullptr) ? m_parent->GetParent() : nullptr);
87   }
88 
89   const ValueObject *GetParent() const override {
90     return ((m_parent != nullptr) ? m_parent->GetParent() : nullptr);
91   }
92 
93   lldb::ValueObjectSP GetNonSyntheticValue() override;
94 
95   bool CanProvideValue() override;
96 
97   bool DoesProvideSyntheticValue() override {
98     return (UpdateValueIfNeeded(), m_provides_value == eLazyBoolYes);
99   }
100 
101   bool GetIsConstant() const override { return false; }
102 
103   bool SetValueFromCString(const char *value_str, Status &error) override;
104 
105   void SetFormat(lldb::Format format) override;
106 
107   lldb::LanguageType GetPreferredDisplayLanguage() override;
108 
109   void SetPreferredDisplayLanguage(lldb::LanguageType);
110 
111   bool IsSyntheticChildrenGenerated() override;
112 
113   void SetSyntheticChildrenGenerated(bool b) override;
114 
115   bool GetDeclaration(Declaration &decl) override;
116 
117   uint64_t GetLanguageFlags() override;
118 
119   void SetLanguageFlags(uint64_t flags) override;
120 
121 protected:
122   bool UpdateValue() override;
123 
124   LazyBool CanUpdateWithInvalidExecutionContext() override {
125     return eLazyBoolYes;
126   }
127 
128   CompilerType GetCompilerTypeImpl() override;
129 
130   virtual void CreateSynthFilter();
131 
132   // we need to hold on to the SyntheticChildren because someone might delete
133   // the type binding while we are alive
134   lldb::SyntheticChildrenSP m_synth_sp;
135   std::unique_ptr<SyntheticChildrenFrontEnd> m_synth_filter_up;
136 
137   typedef std::map<uint32_t, ValueObject *> ByIndexMap;
138   typedef std::map<const char *, uint32_t> NameToIndexMap;
139   typedef std::vector<lldb::ValueObjectSP> SyntheticChildrenCache;
140 
141   typedef ByIndexMap::iterator ByIndexIterator;
142   typedef NameToIndexMap::iterator NameToIndexIterator;
143 
144   std::mutex m_child_mutex;
145   /// Guarded by m_child_mutex;
146   ByIndexMap m_children_byindex;
147   /// Guarded by m_child_mutex;
148   NameToIndexMap m_name_toindex;
149   /// Guarded by m_child_mutex;
150   SyntheticChildrenCache m_synthetic_children_cache;
151 
152   // FIXME: use the ValueObject's  ChildrenManager instead of a special purpose
153   // solution.
154   uint32_t m_synthetic_children_count;
155 
156   ConstString m_parent_type_name;
157 
158   LazyBool m_might_have_children;
159 
160   LazyBool m_provides_value;
161 
162 private:
163   friend class ValueObject;
164   ValueObjectSynthetic(ValueObject &parent, lldb::SyntheticChildrenSP filter);
165 
166   void CopyValueData(ValueObject *source);
167 
168   ValueObjectSynthetic(const ValueObjectSynthetic &) = delete;
169   const ValueObjectSynthetic &operator=(const ValueObjectSynthetic &) = delete;
170 };
171 
172 } // namespace lldb_private
173 
174 #endif // LLDB_CORE_VALUEOBJECTSYNTHETICFILTER_H
175