1 //===-- LibCxxInitializerList.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/ValueObject.h"
17 #include "lldb/DataFormatters/FormattersHelpers.h"
18 #include "lldb/Utility/ConstString.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 LibcxxInitializerListSyntheticFrontEnd
27     : public SyntheticChildrenFrontEnd {
28 public:
29   LibcxxInitializerListSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
30 
31   ~LibcxxInitializerListSyntheticFrontEnd() override;
32 
33   size_t CalculateNumChildren() override;
34 
35   lldb::ValueObjectSP GetChildAtIndex(size_t idx) override;
36 
37   bool Update() override;
38 
39   bool MightHaveChildren() override;
40 
41   size_t GetIndexOfChildWithName(const ConstString &name) override;
42 
43 private:
44   ValueObject *m_start;
45   CompilerType m_element_type;
46   uint32_t m_element_size;
47   size_t m_num_elements;
48 };
49 } // namespace formatters
50 } // namespace lldb_private
51 
52 lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::
53     LibcxxInitializerListSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
54     : SyntheticChildrenFrontEnd(*valobj_sp), m_start(nullptr), m_element_type(),
55       m_element_size(0), m_num_elements(0) {
56   if (valobj_sp)
57     Update();
58 }
59 
60 lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::
61     ~LibcxxInitializerListSyntheticFrontEnd() {
62   // this needs to stay around because it's a child object who will follow its
63   // parent's life cycle
64   // delete m_start;
65 }
66 
67 size_t lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::
68     CalculateNumChildren() {
69   static ConstString g___size_("__size_");
70   m_num_elements = 0;
71   ValueObjectSP size_sp(m_backend.GetChildMemberWithName(g___size_, true));
72   if (size_sp)
73     m_num_elements = size_sp->GetValueAsUnsigned(0);
74   return m_num_elements;
75 }
76 
77 lldb::ValueObjectSP lldb_private::formatters::
78     LibcxxInitializerListSyntheticFrontEnd::GetChildAtIndex(size_t idx) {
79   if (!m_start)
80     return lldb::ValueObjectSP();
81 
82   uint64_t offset = idx * m_element_size;
83   offset = offset + m_start->GetValueAsUnsigned(0);
84   StreamString name;
85   name.Printf("[%" PRIu64 "]", (uint64_t)idx);
86   return CreateValueObjectFromAddress(name.GetString(), offset,
87                                       m_backend.GetExecutionContextRef(),
88                                       m_element_type);
89 }
90 
91 bool lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::
92     Update() {
93   static ConstString g___begin_("__begin_");
94 
95   m_start = nullptr;
96   m_num_elements = 0;
97   m_element_type = m_backend.GetCompilerType().GetTypeTemplateArgument(0);
98   if (!m_element_type.IsValid())
99     return false;
100 
101   m_element_size = m_element_type.GetByteSize(nullptr);
102 
103   if (m_element_size > 0)
104     m_start =
105         m_backend.GetChildMemberWithName(g___begin_, true)
106             .get(); // store raw pointers or end up with a circular dependency
107 
108   return false;
109 }
110 
111 bool lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::
112     MightHaveChildren() {
113   return true;
114 }
115 
116 size_t lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::
117     GetIndexOfChildWithName(const ConstString &name) {
118   if (!m_start)
119     return UINT32_MAX;
120   return ExtractIndexFromString(name.GetCString());
121 }
122 
123 lldb_private::SyntheticChildrenFrontEnd *
124 lldb_private::formatters::LibcxxInitializerListSyntheticFrontEndCreator(
125     CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
126   return (valobj_sp ? new LibcxxInitializerListSyntheticFrontEnd(valobj_sp)
127                     : nullptr);
128 }
129