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,
55                                       bool can_create = true) override;
56 
57   lldb::ValueObjectSP GetChildMemberWithName(llvm::StringRef name,
58                                              bool can_create = true) override;
59 
60   size_t GetIndexOfChildWithName(llvm::StringRef name) override;
61 
62   lldb::ValueObjectSP
63   GetDynamicValue(lldb::DynamicValueType valueType) override;
64 
65   bool IsInScope() override;
66 
67   bool HasSyntheticValue() override { return false; }
68 
69   bool IsSynthetic() override { return true; }
70 
71   void CalculateSyntheticValue() override {}
72 
73   bool IsDynamic() override {
74     return ((m_parent != nullptr) ? m_parent->IsDynamic() : false);
75   }
76 
77   lldb::ValueObjectSP GetStaticValue() override {
78     return ((m_parent != nullptr) ? m_parent->GetStaticValue() : GetSP());
79   }
80 
81   virtual lldb::DynamicValueType GetDynamicValueType() {
82     return ((m_parent != nullptr) ? m_parent->GetDynamicValueType()
83                                   : lldb::eNoDynamicValues);
84   }
85 
86   lldb::VariableSP GetVariable() override {
87     return m_parent != nullptr ? m_parent->GetVariable() : nullptr;
88   }
89 
90   ValueObject *GetParent() override {
91     return ((m_parent != nullptr) ? m_parent->GetParent() : nullptr);
92   }
93 
94   const ValueObject *GetParent() const override {
95     return ((m_parent != nullptr) ? m_parent->GetParent() : nullptr);
96   }
97 
98   lldb::ValueObjectSP GetNonSyntheticValue() override;
99 
100   bool CanProvideValue() override;
101 
102   bool DoesProvideSyntheticValue() override {
103     return (UpdateValueIfNeeded(), m_provides_value == eLazyBoolYes);
104   }
105 
106   bool GetIsConstant() const override { return false; }
107 
108   bool SetValueFromCString(const char *value_str, Status &error) override;
109 
110   void SetFormat(lldb::Format format) override;
111 
112   lldb::LanguageType GetPreferredDisplayLanguage() override;
113 
114   void SetPreferredDisplayLanguage(lldb::LanguageType);
115 
116   bool IsSyntheticChildrenGenerated() override;
117 
118   void SetSyntheticChildrenGenerated(bool b) override;
119 
120   bool GetDeclaration(Declaration &decl) override;
121 
122   uint64_t GetLanguageFlags() override;
123 
124   void SetLanguageFlags(uint64_t flags) override;
125 
126 protected:
127   bool UpdateValue() override;
128 
129   LazyBool CanUpdateWithInvalidExecutionContext() override {
130     return eLazyBoolYes;
131   }
132 
133   CompilerType GetCompilerTypeImpl() override;
134 
135   virtual void CreateSynthFilter();
136 
137   // we need to hold on to the SyntheticChildren because someone might delete
138   // the type binding while we are alive
139   lldb::SyntheticChildrenSP m_synth_sp;
140   std::unique_ptr<SyntheticChildrenFrontEnd> m_synth_filter_up;
141 
142   typedef std::map<uint32_t, ValueObject *> ByIndexMap;
143   typedef std::map<const char *, uint32_t> NameToIndexMap;
144   typedef std::vector<lldb::ValueObjectSP> SyntheticChildrenCache;
145 
146   typedef ByIndexMap::iterator ByIndexIterator;
147   typedef NameToIndexMap::iterator NameToIndexIterator;
148 
149   std::mutex m_child_mutex;
150   /// Guarded by m_child_mutex;
151   ByIndexMap m_children_byindex;
152   /// Guarded by m_child_mutex;
153   NameToIndexMap m_name_toindex;
154   /// Guarded by m_child_mutex;
155   SyntheticChildrenCache m_synthetic_children_cache;
156 
157   // FIXME: use the ValueObject's  ChildrenManager instead of a special purpose
158   // solution.
159   uint32_t m_synthetic_children_count;
160 
161   ConstString m_parent_type_name;
162 
163   LazyBool m_might_have_children;
164 
165   LazyBool m_provides_value;
166 
167 private:
168   friend class ValueObject;
169   ValueObjectSynthetic(ValueObject &parent, lldb::SyntheticChildrenSP filter);
170 
171   void CopyValueData(ValueObject *source);
172 
173   ValueObjectSynthetic(const ValueObjectSynthetic &) = delete;
174   const ValueObjectSynthetic &operator=(const ValueObjectSynthetic &) = delete;
175 };
176 
177 } // namespace lldb_private
178 
179 #endif // LLDB_CORE_VALUEOBJECTSYNTHETICFILTER_H
180