1 //===-- LibStdcppUniquePointer.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 #include "LibStdcpp.h"
11 
12 #include "lldb/Core/ValueObject.h"
13 #include "lldb/DataFormatters/FormattersHelpers.h"
14 #include "lldb/DataFormatters/TypeSynthetic.h"
15 #include "lldb/Utility/ConstString.h"
16 
17 #include <memory>
18 #include <vector>
19 
20 using namespace lldb;
21 using namespace lldb_private;
22 using namespace lldb_private::formatters;
23 
24 namespace {
25 
26 class LibStdcppUniquePtrSyntheticFrontEnd : public SyntheticChildrenFrontEnd {
27 public:
28   explicit LibStdcppUniquePtrSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
29 
30   size_t CalculateNumChildren() override;
31 
32   lldb::ValueObjectSP GetChildAtIndex(size_t idx) override;
33 
34   bool Update() override;
35 
36   bool MightHaveChildren() override;
37 
38   size_t GetIndexOfChildWithName(const ConstString &name) override;
39 
40   bool GetSummary(Stream &stream, const TypeSummaryOptions &options);
41 
42 private:
43   ValueObjectSP m_ptr_obj;
44   ValueObjectSP m_obj_obj;
45   ValueObjectSP m_del_obj;
46 
47   ValueObjectSP GetTuple();
48 };
49 
50 } // end of anonymous namespace
51 
52 LibStdcppUniquePtrSyntheticFrontEnd::LibStdcppUniquePtrSyntheticFrontEnd(
53     lldb::ValueObjectSP valobj_sp)
54     : SyntheticChildrenFrontEnd(*valobj_sp) {
55   Update();
56 }
57 
58 ValueObjectSP LibStdcppUniquePtrSyntheticFrontEnd::GetTuple() {
59   ValueObjectSP valobj_backend_sp = m_backend.GetSP();
60 
61   if (!valobj_backend_sp)
62     return nullptr;
63 
64   ValueObjectSP valobj_sp = valobj_backend_sp->GetNonSyntheticValue();
65   if (!valobj_sp)
66     return nullptr;
67 
68   ValueObjectSP obj_child_sp =
69       valobj_sp->GetChildMemberWithName(ConstString("_M_t"), true);
70   if (!obj_child_sp)
71       return nullptr;
72 
73   ValueObjectSP obj_subchild_sp =
74       obj_child_sp->GetChildMemberWithName(ConstString("_M_t"), true);
75 
76   // if there is a _M_t subchild, the tuple is found in the obj_subchild_sp
77   // (for libstdc++ 6.0.23).
78   if (obj_subchild_sp) {
79     return obj_subchild_sp;
80   }
81 
82   return obj_child_sp;
83 }
84 
85 bool LibStdcppUniquePtrSyntheticFrontEnd::Update() {
86   ValueObjectSP tuple_sp = GetTuple();
87 
88   if (!tuple_sp)
89     return false;
90 
91   std::unique_ptr<SyntheticChildrenFrontEnd> tuple_frontend(
92       LibStdcppTupleSyntheticFrontEndCreator(nullptr, tuple_sp));
93 
94   ValueObjectSP ptr_obj = tuple_frontend->GetChildAtIndex(0);
95   if (ptr_obj)
96     m_ptr_obj = ptr_obj->Clone(ConstString("pointer"));
97 
98   ValueObjectSP del_obj = tuple_frontend->GetChildAtIndex(1);
99   if (del_obj)
100     m_del_obj = del_obj->Clone(ConstString("deleter"));
101 
102   if (m_ptr_obj) {
103     Status error;
104     ValueObjectSP obj_obj = m_ptr_obj->Dereference(error);
105     if (error.Success()) {
106       m_obj_obj = obj_obj->Clone(ConstString("object"));
107     }
108   }
109 
110   return false;
111 }
112 
113 bool LibStdcppUniquePtrSyntheticFrontEnd::MightHaveChildren() { return true; }
114 
115 lldb::ValueObjectSP
116 LibStdcppUniquePtrSyntheticFrontEnd::GetChildAtIndex(size_t idx) {
117   if (idx == 0)
118     return m_ptr_obj;
119   if (idx == 1)
120     return m_del_obj;
121   if (idx == 2)
122     return m_obj_obj;
123   return lldb::ValueObjectSP();
124 }
125 
126 size_t LibStdcppUniquePtrSyntheticFrontEnd::CalculateNumChildren() {
127   if (m_del_obj)
128     return 2;
129   return 1;
130 }
131 
132 size_t LibStdcppUniquePtrSyntheticFrontEnd::GetIndexOfChildWithName(
133     const ConstString &name) {
134   if (name == ConstString("ptr") || name == ConstString("pointer"))
135     return 0;
136   if (name == ConstString("del") || name == ConstString("deleter"))
137     return 1;
138   if (name == ConstString("obj") || name == ConstString("object") ||
139       name == ConstString("$$dereference$$"))
140     return 2;
141   return UINT32_MAX;
142 }
143 
144 bool LibStdcppUniquePtrSyntheticFrontEnd::GetSummary(
145     Stream &stream, const TypeSummaryOptions &options) {
146   if (!m_ptr_obj)
147     return false;
148 
149   bool success;
150   uint64_t ptr_value = m_ptr_obj->GetValueAsUnsigned(0, &success);
151   if (!success)
152     return false;
153   if (ptr_value == 0)
154     stream.Printf("nullptr");
155   else
156     stream.Printf("0x%" PRIx64, ptr_value);
157   return true;
158 }
159 
160 SyntheticChildrenFrontEnd *
161 lldb_private::formatters::LibStdcppUniquePtrSyntheticFrontEndCreator(
162     CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
163   return (valobj_sp ? new LibStdcppUniquePtrSyntheticFrontEnd(valobj_sp)
164                     : nullptr);
165 }
166 
167 bool lldb_private::formatters::LibStdcppUniquePointerSummaryProvider(
168     ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) {
169   LibStdcppUniquePtrSyntheticFrontEnd formatter(valobj.GetSP());
170   return formatter.GetSummary(stream, options);
171 }
172