1 //===-- LibStdcppUniquePointer.cpp ----------------------------------------===//
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 "LibStdcpp.h"
10
11 #include "lldb/Core/ValueObject.h"
12 #include "lldb/DataFormatters/FormattersHelpers.h"
13 #include "lldb/DataFormatters/TypeSynthetic.h"
14 #include "lldb/Utility/ConstString.h"
15
16 #include <memory>
17 #include <vector>
18
19 using namespace lldb;
20 using namespace lldb_private;
21 using namespace lldb_private::formatters;
22
23 namespace {
24
25 class LibStdcppUniquePtrSyntheticFrontEnd : public SyntheticChildrenFrontEnd {
26 public:
27 explicit LibStdcppUniquePtrSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
28
29 size_t CalculateNumChildren() override;
30
31 lldb::ValueObjectSP GetChildAtIndex(size_t idx) override;
32
33 bool Update() override;
34
35 bool MightHaveChildren() override;
36
37 size_t GetIndexOfChildWithName(ConstString name) override;
38
39 bool GetSummary(Stream &stream, const TypeSummaryOptions &options);
40
41 private:
42 // The lifetime of a ValueObject and all its derivative ValueObjects
43 // (children, clones, etc.) is managed by a ClusterManager. These
44 // objects are only destroyed when every shared pointer to any of them
45 // is destroyed, so we must not store a shared pointer to any ValueObject
46 // derived from our backend ValueObject (since we're in the same cluster).
47 ValueObject* m_ptr_obj = nullptr;
48 ValueObject* m_obj_obj = nullptr;
49 ValueObject* m_del_obj = nullptr;
50
51 ValueObjectSP GetTuple();
52 };
53
54 } // end of anonymous namespace
55
LibStdcppUniquePtrSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)56 LibStdcppUniquePtrSyntheticFrontEnd::LibStdcppUniquePtrSyntheticFrontEnd(
57 lldb::ValueObjectSP valobj_sp)
58 : SyntheticChildrenFrontEnd(*valobj_sp) {
59 Update();
60 }
61
GetTuple()62 ValueObjectSP LibStdcppUniquePtrSyntheticFrontEnd::GetTuple() {
63 ValueObjectSP valobj_backend_sp = m_backend.GetSP();
64
65 if (!valobj_backend_sp)
66 return nullptr;
67
68 ValueObjectSP valobj_sp = valobj_backend_sp->GetNonSyntheticValue();
69 if (!valobj_sp)
70 return nullptr;
71
72 ValueObjectSP obj_child_sp =
73 valobj_sp->GetChildMemberWithName(ConstString("_M_t"), true);
74 if (!obj_child_sp)
75 return nullptr;
76
77 ValueObjectSP obj_subchild_sp =
78 obj_child_sp->GetChildMemberWithName(ConstString("_M_t"), true);
79
80 // if there is a _M_t subchild, the tuple is found in the obj_subchild_sp
81 // (for libstdc++ 6.0.23).
82 if (obj_subchild_sp) {
83 return obj_subchild_sp;
84 }
85
86 return obj_child_sp;
87 }
88
Update()89 bool LibStdcppUniquePtrSyntheticFrontEnd::Update() {
90 ValueObjectSP tuple_sp = GetTuple();
91
92 if (!tuple_sp)
93 return false;
94
95 std::unique_ptr<SyntheticChildrenFrontEnd> tuple_frontend(
96 LibStdcppTupleSyntheticFrontEndCreator(nullptr, tuple_sp));
97
98 ValueObjectSP ptr_obj = tuple_frontend->GetChildAtIndex(0);
99 if (ptr_obj)
100 m_ptr_obj = ptr_obj->Clone(ConstString("pointer")).get();
101
102 ValueObjectSP del_obj = tuple_frontend->GetChildAtIndex(1);
103 if (del_obj)
104 m_del_obj = del_obj->Clone(ConstString("deleter")).get();
105
106 if (m_ptr_obj) {
107 Status error;
108 ValueObjectSP obj_obj = m_ptr_obj->Dereference(error);
109 if (error.Success()) {
110 m_obj_obj = obj_obj->Clone(ConstString("object")).get();
111 }
112 }
113
114 return false;
115 }
116
MightHaveChildren()117 bool LibStdcppUniquePtrSyntheticFrontEnd::MightHaveChildren() { return true; }
118
119 lldb::ValueObjectSP
GetChildAtIndex(size_t idx)120 LibStdcppUniquePtrSyntheticFrontEnd::GetChildAtIndex(size_t idx) {
121 if (idx == 0 && m_ptr_obj)
122 return m_ptr_obj->GetSP();
123 if (idx == 1 && m_del_obj)
124 return m_del_obj->GetSP();
125 if (idx == 2 && m_obj_obj)
126 return m_obj_obj->GetSP();
127 return lldb::ValueObjectSP();
128 }
129
CalculateNumChildren()130 size_t LibStdcppUniquePtrSyntheticFrontEnd::CalculateNumChildren() {
131 if (m_del_obj)
132 return 2;
133 return 1;
134 }
135
GetIndexOfChildWithName(ConstString name)136 size_t LibStdcppUniquePtrSyntheticFrontEnd::GetIndexOfChildWithName(
137 ConstString name) {
138 if (name == "ptr" || name == "pointer")
139 return 0;
140 if (name == "del" || name == "deleter")
141 return 1;
142 if (name == "obj" || name == "object" || name == "$$dereference$$")
143 return 2;
144 return UINT32_MAX;
145 }
146
GetSummary(Stream & stream,const TypeSummaryOptions & options)147 bool LibStdcppUniquePtrSyntheticFrontEnd::GetSummary(
148 Stream &stream, const TypeSummaryOptions &options) {
149 if (!m_ptr_obj)
150 return false;
151
152 bool success;
153 uint64_t ptr_value = m_ptr_obj->GetValueAsUnsigned(0, &success);
154 if (!success)
155 return false;
156 if (ptr_value == 0)
157 stream.Printf("nullptr");
158 else
159 stream.Printf("0x%" PRIx64, ptr_value);
160 return true;
161 }
162
163 SyntheticChildrenFrontEnd *
LibStdcppUniquePtrSyntheticFrontEndCreator(CXXSyntheticChildren *,lldb::ValueObjectSP valobj_sp)164 lldb_private::formatters::LibStdcppUniquePtrSyntheticFrontEndCreator(
165 CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
166 return (valobj_sp ? new LibStdcppUniquePtrSyntheticFrontEnd(valobj_sp)
167 : nullptr);
168 }
169
LibStdcppUniquePointerSummaryProvider(ValueObject & valobj,Stream & stream,const TypeSummaryOptions & options)170 bool lldb_private::formatters::LibStdcppUniquePointerSummaryProvider(
171 ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) {
172 LibStdcppUniquePtrSyntheticFrontEnd formatter(valobj.GetSP());
173 return formatter.GetSummary(stream, options);
174 }
175