1//===-- LibStdcppTuple.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 "LibStdcpp.h"
10
11#include "lldb/Core/ValueObject.h"
12#include "lldb/DataFormatters/FormattersHelpers.h"
13#include "lldb/DataFormatters/TypeSynthetic.h"
14#include "lldb/Utility/ConstString.h"
15
16#include <memory>
17#include <vector>
18
19using namespace lldb;
20using namespace lldb_private;
21using namespace lldb_private::formatters;
22
23namespace {
24
25class LibStdcppTupleSyntheticFrontEnd : public SyntheticChildrenFrontEnd {
26public:
27 explicit LibStdcppTupleSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
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 bool MightHaveChildren() override;
36
37 size_t GetIndexOfChildWithName(ConstString name) override;
38
39private:
40 // The lifetime of a ValueObject and all its derivative ValueObjects
41 // (children, clones, etc.) is managed by a ClusterManager. These
42 // objects are only destroyed when every shared pointer to any of them
43 // is destroyed, so we must not store a shared pointer to any ValueObject
44 // derived from our backend ValueObject (since we're in the same cluster).
45 std::vector<ValueObject*> m_members;
46};
47
48} // end of anonymous namespace
49
50LibStdcppTupleSyntheticFrontEnd::LibStdcppTupleSyntheticFrontEnd(
51 lldb::ValueObjectSP valobj_sp)
52 : SyntheticChildrenFrontEnd(*valobj_sp) {
53 Update();
54}
55
56lldb::ChildCacheState LibStdcppTupleSyntheticFrontEnd::Update() {
57 m_members.clear();
58
59 ValueObjectSP valobj_backend_sp = m_backend.GetSP();
60 if (!valobj_backend_sp)
61 return lldb::ChildCacheState::eRefetch;
62
63 ValueObjectSP next_child_sp = valobj_backend_sp->GetNonSyntheticValue();
64 while (next_child_sp != nullptr) {
65 ValueObjectSP current_child = next_child_sp;
66 next_child_sp = nullptr;
67
68 size_t child_count = current_child->GetNumChildrenIgnoringErrors();
69 for (size_t i = 0; i < child_count; ++i) {
70 ValueObjectSP child_sp = current_child->GetChildAtIndex(idx: i);
71 llvm::StringRef name_str = child_sp->GetName().GetStringRef();
72 if (name_str.starts_with(Prefix: "std::_Tuple_impl<")) {
73 next_child_sp = child_sp;
74 } else if (name_str.starts_with(Prefix: "std::_Head_base<")) {
75 ValueObjectSP value_sp =
76 child_sp->GetChildMemberWithName(name: "_M_head_impl");
77 if (value_sp) {
78 StreamString name;
79 name.Printf(format: "[%zd]", m_members.size());
80 m_members.push_back(x: value_sp->Clone(new_name: ConstString(name.GetString())).get());
81 }
82 }
83 }
84 }
85
86 return lldb::ChildCacheState::eRefetch;
87}
88
89bool LibStdcppTupleSyntheticFrontEnd::MightHaveChildren() { return true; }
90
91lldb::ValueObjectSP
92LibStdcppTupleSyntheticFrontEnd::GetChildAtIndex(uint32_t idx) {
93 if (idx < m_members.size() && m_members[idx])
94 return m_members[idx]->GetSP();
95 return lldb::ValueObjectSP();
96}
97
98llvm::Expected<uint32_t>
99LibStdcppTupleSyntheticFrontEnd::CalculateNumChildren() {
100 return m_members.size();
101}
102
103size_t LibStdcppTupleSyntheticFrontEnd::GetIndexOfChildWithName(
104 ConstString name) {
105 return ExtractIndexFromString(item_name: name.GetCString());
106}
107
108SyntheticChildrenFrontEnd *
109lldb_private::formatters::LibStdcppTupleSyntheticFrontEndCreator(
110 CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
111 return (valobj_sp ? new LibStdcppTupleSyntheticFrontEnd(valobj_sp) : nullptr);
112}
113

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