1//===-- LibCxxValarray.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/ValueObject/ValueObject.h"
13#include <optional>
14
15using namespace lldb;
16using namespace lldb_private;
17using namespace lldb_private::formatters;
18
19namespace lldb_private {
20namespace formatters {
21class LibcxxStdValarraySyntheticFrontEnd : public SyntheticChildrenFrontEnd {
22public:
23 LibcxxStdValarraySyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
24
25 ~LibcxxStdValarraySyntheticFrontEnd() override;
26
27 llvm::Expected<uint32_t> CalculateNumChildren() override;
28
29 lldb::ValueObjectSP GetChildAtIndex(uint32_t idx) override;
30
31 lldb::ChildCacheState Update() override;
32
33 llvm::Expected<size_t> GetIndexOfChildWithName(ConstString name) override;
34
35private:
36 /// A non-owning pointer to valarray's __begin_ member.
37 ValueObject *m_start = nullptr;
38 /// A non-owning pointer to valarray's __end_ member.
39 ValueObject *m_finish = nullptr;
40 /// The type of valarray's template argument T.
41 CompilerType m_element_type;
42 /// The sizeof valarray's template argument T.
43 uint32_t m_element_size = 0;
44};
45
46} // namespace formatters
47} // namespace lldb_private
48
49lldb_private::formatters::LibcxxStdValarraySyntheticFrontEnd::
50 LibcxxStdValarraySyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
51 : SyntheticChildrenFrontEnd(*valobj_sp), m_element_type() {
52 if (valobj_sp)
53 Update();
54}
55
56lldb_private::formatters::LibcxxStdValarraySyntheticFrontEnd::
57 ~LibcxxStdValarraySyntheticFrontEnd() {
58 // these need to stay around because they are child objects who will follow
59 // their parent's life cycle
60 // delete m_start;
61 // delete m_finish;
62}
63
64llvm::Expected<uint32_t> lldb_private::formatters::
65 LibcxxStdValarraySyntheticFrontEnd::CalculateNumChildren() {
66 if (!m_start || !m_finish)
67 return 0;
68 uint64_t start_val = m_start->GetValueAsUnsigned(fail_value: 0);
69 uint64_t finish_val = m_finish->GetValueAsUnsigned(fail_value: 0);
70
71 if (start_val == 0 || finish_val == 0)
72 return 0;
73
74 if (start_val >= finish_val)
75 return 0;
76
77 size_t num_children = (finish_val - start_val);
78 if (num_children % m_element_size)
79 return 0;
80 return num_children / m_element_size;
81}
82
83lldb::ValueObjectSP
84lldb_private::formatters::LibcxxStdValarraySyntheticFrontEnd::GetChildAtIndex(
85 uint32_t idx) {
86 if (!m_start || !m_finish)
87 return lldb::ValueObjectSP();
88
89 uint64_t offset = idx * m_element_size;
90 offset = offset + m_start->GetValueAsUnsigned(fail_value: 0);
91 StreamString name;
92 name.Printf(format: "[%" PRIu64 "]", (uint64_t)idx);
93 return CreateValueObjectFromAddress(name: name.GetString(), address: offset,
94 exe_ctx: m_backend.GetExecutionContextRef(),
95 type: m_element_type);
96}
97
98lldb::ChildCacheState
99lldb_private::formatters::LibcxxStdValarraySyntheticFrontEnd::Update() {
100 m_start = m_finish = nullptr;
101
102 CompilerType type = m_backend.GetCompilerType();
103 if (type.GetNumTemplateArguments() == 0)
104 return ChildCacheState::eRefetch;
105
106 m_element_type = type.GetTypeTemplateArgument(idx: 0);
107 if (std::optional<uint64_t> size =
108 llvm::expectedToOptional(E: m_element_type.GetByteSize(exe_scope: nullptr)))
109 m_element_size = *size;
110
111 if (m_element_size == 0)
112 return ChildCacheState::eRefetch;
113
114 ValueObjectSP start = m_backend.GetChildMemberWithName(name: "__begin_");
115 ValueObjectSP finish = m_backend.GetChildMemberWithName(name: "__end_");
116
117 if (!start || !finish)
118 return ChildCacheState::eRefetch;
119
120 m_start = start.get();
121 m_finish = finish.get();
122
123 return ChildCacheState::eRefetch;
124}
125
126llvm::Expected<size_t>
127lldb_private::formatters::LibcxxStdValarraySyntheticFrontEnd::
128 GetIndexOfChildWithName(ConstString name) {
129 if (!m_start || !m_finish)
130 return llvm::createStringError(Fmt: "Type has no child named '%s'",
131 Vals: name.AsCString());
132 auto optional_idx = formatters::ExtractIndexFromString(item_name: name.GetCString());
133 if (!optional_idx) {
134 return llvm::createStringError(Fmt: "Type has no child named '%s'",
135 Vals: name.AsCString());
136 }
137 return *optional_idx;
138}
139
140lldb_private::SyntheticChildrenFrontEnd *
141lldb_private::formatters::LibcxxStdValarraySyntheticFrontEndCreator(
142 CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
143 if (!valobj_sp)
144 return nullptr;
145 return new LibcxxStdValarraySyntheticFrontEnd(valobj_sp);
146}
147

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