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/DataFormatters/FormattersHelpers.h"
12#include "lldb/Utility/ConstString.h"
13#include "lldb/ValueObject/ValueObject.h"
14#include <optional>
15
16using namespace lldb;
17using namespace lldb_private;
18using namespace lldb_private::formatters;
19
20namespace lldb_private {
21namespace formatters {
22class LibcxxInitializerListSyntheticFrontEnd
23 : public SyntheticChildrenFrontEnd {
24public:
25 LibcxxInitializerListSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
26
27 ~LibcxxInitializerListSyntheticFrontEnd() override;
28
29 llvm::Expected<uint32_t> CalculateNumChildren() override;
30
31 lldb::ValueObjectSP GetChildAtIndex(uint32_t idx) override;
32
33 lldb::ChildCacheState Update() override;
34
35 llvm::Expected<size_t> GetIndexOfChildWithName(ConstString name) override;
36
37private:
38 ValueObject *m_start = nullptr;
39 CompilerType m_element_type;
40 uint32_t m_element_size = 0;
41 size_t m_num_elements = 0;
42};
43} // namespace formatters
44} // namespace lldb_private
45
46lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::
47 LibcxxInitializerListSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
48 : SyntheticChildrenFrontEnd(*valobj_sp), m_element_type() {
49 if (valobj_sp)
50 Update();
51}
52
53lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::
54 ~LibcxxInitializerListSyntheticFrontEnd() {
55 // this needs to stay around because it's a child object who will follow its
56 // parent's life cycle
57 // delete m_start;
58}
59
60llvm::Expected<uint32_t> lldb_private::formatters::
61 LibcxxInitializerListSyntheticFrontEnd::CalculateNumChildren() {
62 m_num_elements = 0;
63 ValueObjectSP size_sp(m_backend.GetChildMemberWithName(name: "__size_"));
64 if (size_sp)
65 m_num_elements = size_sp->GetValueAsUnsigned(fail_value: 0);
66 return m_num_elements;
67}
68
69lldb::ValueObjectSP lldb_private::formatters::
70 LibcxxInitializerListSyntheticFrontEnd::GetChildAtIndex(uint32_t idx) {
71 if (!m_start)
72 return lldb::ValueObjectSP();
73
74 uint64_t offset = idx * m_element_size;
75 offset = offset + m_start->GetValueAsUnsigned(fail_value: 0);
76 StreamString name;
77 name.Printf(format: "[%" PRIu64 "]", (uint64_t)idx);
78 return CreateValueObjectFromAddress(name: name.GetString(), address: offset,
79 exe_ctx: m_backend.GetExecutionContextRef(),
80 type: m_element_type);
81}
82
83lldb::ChildCacheState
84lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::Update() {
85 m_start = nullptr;
86 m_num_elements = 0;
87 m_element_type = m_backend.GetCompilerType().GetTypeTemplateArgument(idx: 0);
88 if (!m_element_type.IsValid())
89 return lldb::ChildCacheState::eRefetch;
90
91 llvm::Expected<uint64_t> size_or_err = m_element_type.GetByteSize(exe_scope: nullptr);
92 if (!size_or_err)
93 LLDB_LOG_ERRORV(GetLog(LLDBLog::DataFormatters), size_or_err.takeError(),
94 "{0}");
95 else {
96 m_element_size = *size_or_err;
97 // Store raw pointers or end up with a circular dependency.
98 m_start = m_backend.GetChildMemberWithName(name: "__begin_").get();
99 }
100
101 return lldb::ChildCacheState::eRefetch;
102}
103
104llvm::Expected<size_t>
105lldb_private::formatters::LibcxxInitializerListSyntheticFrontEnd::
106 GetIndexOfChildWithName(ConstString name) {
107 if (!m_start) {
108 return llvm::createStringError(Fmt: "Type has no child named '%s'",
109 Vals: name.AsCString());
110 }
111 auto optional_idx = formatters::ExtractIndexFromString(item_name: name.GetCString());
112 if (!optional_idx) {
113 return llvm::createStringError(Fmt: "Type has no child named '%s'",
114 Vals: name.AsCString());
115 }
116 return *optional_idx;
117}
118
119lldb_private::SyntheticChildrenFrontEnd *
120lldb_private::formatters::LibcxxInitializerListSyntheticFrontEndCreator(
121 CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
122 return (valobj_sp ? new LibcxxInitializerListSyntheticFrontEnd(valobj_sp)
123 : nullptr);
124}
125

source code of lldb/source/Plugins/Language/CPlusPlus/LibCxxInitializerList.cpp