1 //===-- LibCxxVector.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 // C Includes
11 // C++ Includes
12 // Other libraries and framework includes
13 // Project includes
14 #include "LibCxx.h"
15 
16 #include "lldb/Core/ConstString.h"
17 #include "lldb/Core/ValueObject.h"
18 #include "lldb/DataFormatters/FormattersHelpers.h"
19 
20 using namespace lldb;
21 using namespace lldb_private;
22 using namespace lldb_private::formatters;
23 
24 namespace lldb_private {
25     namespace formatters {
26         class LibcxxStdVectorSyntheticFrontEnd : public SyntheticChildrenFrontEnd
27         {
28         public:
29             LibcxxStdVectorSyntheticFrontEnd (lldb::ValueObjectSP valobj_sp);
30 
31             ~LibcxxStdVectorSyntheticFrontEnd() override;
32 
33             size_t
34             CalculateNumChildren() override;
35 
36             lldb::ValueObjectSP
37             GetChildAtIndex(size_t idx) override;
38 
39             bool
40             Update() override;
41 
42             bool
43             MightHaveChildren() override;
44 
45             size_t
46             GetIndexOfChildWithName(const ConstString &name) override;
47 
48         private:
49             ValueObject* m_start;
50             ValueObject* m_finish;
51             CompilerType m_element_type;
52             uint32_t m_element_size;
53         };
54     } // namespace formatters
55 } // namespace lldb_private
56 
57 lldb_private::formatters::LibcxxStdVectorSyntheticFrontEnd::LibcxxStdVectorSyntheticFrontEnd (lldb::ValueObjectSP valobj_sp) :
58     SyntheticChildrenFrontEnd(*valobj_sp),
59     m_start(nullptr),
60     m_finish(nullptr),
61     m_element_type(),
62     m_element_size(0)
63 {
64     if (valobj_sp)
65         Update();
66 }
67 
68 lldb_private::formatters::LibcxxStdVectorSyntheticFrontEnd::~LibcxxStdVectorSyntheticFrontEnd()
69 {
70     // these need to stay around because they are child objects who will follow their parent's life cycle
71     // delete m_start;
72     // delete m_finish;
73 }
74 
75 size_t
76 lldb_private::formatters::LibcxxStdVectorSyntheticFrontEnd::CalculateNumChildren ()
77 {
78     if (!m_start || !m_finish)
79         return 0;
80     uint64_t start_val = m_start->GetValueAsUnsigned(0);
81     uint64_t finish_val = m_finish->GetValueAsUnsigned(0);
82 
83     if (start_val == 0 || finish_val == 0)
84         return 0;
85 
86     if (start_val >= finish_val)
87         return 0;
88 
89     size_t num_children = (finish_val - start_val);
90     if (num_children % m_element_size)
91         return 0;
92     return num_children/m_element_size;
93 }
94 
95 lldb::ValueObjectSP
96 lldb_private::formatters::LibcxxStdVectorSyntheticFrontEnd::GetChildAtIndex (size_t idx)
97 {
98     if (!m_start || !m_finish)
99         return lldb::ValueObjectSP();
100 
101     uint64_t offset = idx * m_element_size;
102     offset = offset + m_start->GetValueAsUnsigned(0);
103     StreamString name;
104     name.Printf("[%" PRIu64 "]", (uint64_t)idx);
105     return CreateValueObjectFromAddress(name.GetData(),
106                                         offset,
107                                         m_backend.GetExecutionContextRef(),
108                                         m_element_type);
109 }
110 
111 bool
112 lldb_private::formatters::LibcxxStdVectorSyntheticFrontEnd::Update()
113 {
114     m_start = m_finish = nullptr;
115     ValueObjectSP data_type_finder_sp(m_backend.GetChildMemberWithName(ConstString("__end_cap_"),true));
116     if (!data_type_finder_sp)
117         return false;
118     data_type_finder_sp = data_type_finder_sp->GetChildMemberWithName(ConstString("__first_"),true);
119     if (!data_type_finder_sp)
120         return false;
121     m_element_type = data_type_finder_sp->GetCompilerType().GetPointeeType();
122     m_element_size = m_element_type.GetByteSize(nullptr);
123 
124     if (m_element_size > 0)
125     {
126         // store raw pointers or end up with a circular dependency
127         m_start = m_backend.GetChildMemberWithName(ConstString("__begin_"),true).get();
128         m_finish = m_backend.GetChildMemberWithName(ConstString("__end_"),true).get();
129     }
130     return false;
131 }
132 
133 bool
134 lldb_private::formatters::LibcxxStdVectorSyntheticFrontEnd::MightHaveChildren ()
135 {
136     return true;
137 }
138 
139 size_t
140 lldb_private::formatters::LibcxxStdVectorSyntheticFrontEnd::GetIndexOfChildWithName (const ConstString &name)
141 {
142     if (!m_start || !m_finish)
143         return UINT32_MAX;
144     return ExtractIndexFromString(name.GetCString());
145 }
146 
147 lldb_private::SyntheticChildrenFrontEnd*
148 lldb_private::formatters::LibcxxStdVectorSyntheticFrontEndCreator (CXXSyntheticChildren*, lldb::ValueObjectSP valobj_sp)
149 {
150     return (valobj_sp ? new LibcxxStdVectorSyntheticFrontEnd(valobj_sp) : nullptr);
151 }
152