1 //===-- LibCxxInitializerList.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 "LibCxx.h"
10
11 #include "lldb/Core/ValueObject.h"
12 #include "lldb/DataFormatters/FormattersHelpers.h"
13 #include "lldb/Utility/ConstString.h"
14 #include <optional>
15
16 using namespace lldb;
17 using namespace lldb_private;
18 using namespace lldb_private::formatters;
19
20 namespace lldb_private {
21 namespace formatters {
22 class LibcxxInitializerListSyntheticFrontEnd
23 : public SyntheticChildrenFrontEnd {
24 public:
25 LibcxxInitializerListSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
26
27 ~LibcxxInitializerListSyntheticFrontEnd() override;
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 private:
40 ValueObject *m_start = nullptr;
41 CompilerType m_element_type;
42 uint32_t m_element_size = 0;
43 size_t m_num_elements = 0;
44 };
45 } // namespace formatters
46 } // namespace lldb_private
47
48 lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::
LibcxxInitializerListSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)49 LibcxxInitializerListSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
50 : SyntheticChildrenFrontEnd(*valobj_sp), m_element_type() {
51 if (valobj_sp)
52 Update();
53 }
54
55 lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::
~LibcxxInitializerListSyntheticFrontEnd()56 ~LibcxxInitializerListSyntheticFrontEnd() {
57 // this needs to stay around because it's a child object who will follow its
58 // parent's life cycle
59 // delete m_start;
60 }
61
62 size_t lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::
CalculateNumChildren()63 CalculateNumChildren() {
64 static ConstString g_size_("__size_");
65 m_num_elements = 0;
66 ValueObjectSP size_sp(m_backend.GetChildMemberWithName(g_size_, true));
67 if (size_sp)
68 m_num_elements = size_sp->GetValueAsUnsigned(0);
69 return m_num_elements;
70 }
71
72 lldb::ValueObjectSP lldb_private::formatters::
GetChildAtIndex(size_t idx)73 LibcxxInitializerListSyntheticFrontEnd::GetChildAtIndex(size_t idx) {
74 if (!m_start)
75 return lldb::ValueObjectSP();
76
77 uint64_t offset = idx * m_element_size;
78 offset = offset + m_start->GetValueAsUnsigned(0);
79 StreamString name;
80 name.Printf("[%" PRIu64 "]", (uint64_t)idx);
81 return CreateValueObjectFromAddress(name.GetString(), offset,
82 m_backend.GetExecutionContextRef(),
83 m_element_type);
84 }
85
86 bool lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::
Update()87 Update() {
88 static ConstString g_begin_("__begin_");
89
90 m_start = nullptr;
91 m_num_elements = 0;
92 m_element_type = m_backend.GetCompilerType().GetTypeTemplateArgument(0);
93 if (!m_element_type.IsValid())
94 return false;
95
96 if (std::optional<uint64_t> size = m_element_type.GetByteSize(nullptr)) {
97 m_element_size = *size;
98 // Store raw pointers or end up with a circular dependency.
99 m_start = m_backend.GetChildMemberWithName(g_begin_, true).get();
100 }
101
102 return false;
103 }
104
105 bool lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::
MightHaveChildren()106 MightHaveChildren() {
107 return true;
108 }
109
110 size_t lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::
GetIndexOfChildWithName(ConstString name)111 GetIndexOfChildWithName(ConstString name) {
112 if (!m_start)
113 return UINT32_MAX;
114 return ExtractIndexFromString(name.GetCString());
115 }
116
117 lldb_private::SyntheticChildrenFrontEnd *
LibcxxInitializerListSyntheticFrontEndCreator(CXXSyntheticChildren *,lldb::ValueObjectSP valobj_sp)118 lldb_private::formatters::LibcxxInitializerListSyntheticFrontEndCreator(
119 CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
120 return (valobj_sp ? new LibcxxInitializerListSyntheticFrontEnd(valobj_sp)
121 : nullptr);
122 }
123