xref: /freebsd-src/contrib/llvm-project/lldb/source/Plugins/Language/CPlusPlus/LibStdcppUniquePointer.cpp (revision 0b57cec536236d46e3dba9bd041533462f33dbb7)
1 //===-- LibStdcppUniquePointer.cpp ------------------------------*- 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 #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   ValueObjectSP m_ptr_obj;
43   ValueObjectSP m_obj_obj;
44   ValueObjectSP m_del_obj;
45 
46   ValueObjectSP GetTuple();
47 };
48 
49 } // end of anonymous namespace
50 
51 LibStdcppUniquePtrSyntheticFrontEnd::LibStdcppUniquePtrSyntheticFrontEnd(
52     lldb::ValueObjectSP valobj_sp)
53     : SyntheticChildrenFrontEnd(*valobj_sp) {
54   Update();
55 }
56 
57 ValueObjectSP LibStdcppUniquePtrSyntheticFrontEnd::GetTuple() {
58   ValueObjectSP valobj_backend_sp = m_backend.GetSP();
59 
60   if (!valobj_backend_sp)
61     return nullptr;
62 
63   ValueObjectSP valobj_sp = valobj_backend_sp->GetNonSyntheticValue();
64   if (!valobj_sp)
65     return nullptr;
66 
67   ValueObjectSP obj_child_sp =
68       valobj_sp->GetChildMemberWithName(ConstString("_M_t"), true);
69   if (!obj_child_sp)
70       return nullptr;
71 
72   ValueObjectSP obj_subchild_sp =
73       obj_child_sp->GetChildMemberWithName(ConstString("_M_t"), true);
74 
75   // if there is a _M_t subchild, the tuple is found in the obj_subchild_sp
76   // (for libstdc++ 6.0.23).
77   if (obj_subchild_sp) {
78     return obj_subchild_sp;
79   }
80 
81   return obj_child_sp;
82 }
83 
84 bool LibStdcppUniquePtrSyntheticFrontEnd::Update() {
85   ValueObjectSP tuple_sp = GetTuple();
86 
87   if (!tuple_sp)
88     return false;
89 
90   std::unique_ptr<SyntheticChildrenFrontEnd> tuple_frontend(
91       LibStdcppTupleSyntheticFrontEndCreator(nullptr, tuple_sp));
92 
93   ValueObjectSP ptr_obj = tuple_frontend->GetChildAtIndex(0);
94   if (ptr_obj)
95     m_ptr_obj = ptr_obj->Clone(ConstString("pointer"));
96 
97   ValueObjectSP del_obj = tuple_frontend->GetChildAtIndex(1);
98   if (del_obj)
99     m_del_obj = del_obj->Clone(ConstString("deleter"));
100 
101   if (m_ptr_obj) {
102     Status error;
103     ValueObjectSP obj_obj = m_ptr_obj->Dereference(error);
104     if (error.Success()) {
105       m_obj_obj = obj_obj->Clone(ConstString("object"));
106     }
107   }
108 
109   return false;
110 }
111 
112 bool LibStdcppUniquePtrSyntheticFrontEnd::MightHaveChildren() { return true; }
113 
114 lldb::ValueObjectSP
115 LibStdcppUniquePtrSyntheticFrontEnd::GetChildAtIndex(size_t idx) {
116   if (idx == 0)
117     return m_ptr_obj;
118   if (idx == 1)
119     return m_del_obj;
120   if (idx == 2)
121     return m_obj_obj;
122   return lldb::ValueObjectSP();
123 }
124 
125 size_t LibStdcppUniquePtrSyntheticFrontEnd::CalculateNumChildren() {
126   if (m_del_obj)
127     return 2;
128   return 1;
129 }
130 
131 size_t LibStdcppUniquePtrSyntheticFrontEnd::GetIndexOfChildWithName(
132     ConstString name) {
133   if (name == "ptr" || name == "pointer")
134     return 0;
135   if (name == "del" || name == "deleter")
136     return 1;
137   if (name == "obj" || name == "object" || name == "$$dereference$$")
138     return 2;
139   return UINT32_MAX;
140 }
141 
142 bool LibStdcppUniquePtrSyntheticFrontEnd::GetSummary(
143     Stream &stream, const TypeSummaryOptions &options) {
144   if (!m_ptr_obj)
145     return false;
146 
147   bool success;
148   uint64_t ptr_value = m_ptr_obj->GetValueAsUnsigned(0, &success);
149   if (!success)
150     return false;
151   if (ptr_value == 0)
152     stream.Printf("nullptr");
153   else
154     stream.Printf("0x%" PRIx64, ptr_value);
155   return true;
156 }
157 
158 SyntheticChildrenFrontEnd *
159 lldb_private::formatters::LibStdcppUniquePtrSyntheticFrontEndCreator(
160     CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
161   return (valobj_sp ? new LibStdcppUniquePtrSyntheticFrontEnd(valobj_sp)
162                     : nullptr);
163 }
164 
165 bool lldb_private::formatters::LibStdcppUniquePointerSummaryProvider(
166     ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) {
167   LibStdcppUniquePtrSyntheticFrontEnd formatter(valobj.GetSP());
168   return formatter.GetSummary(stream, options);
169 }
170