xref: /llvm-project/lldb/source/Plugins/Language/CPlusPlus/LibCxxTuple.cpp (revision 333739d0e22acfbc354588cf49e783063aabe96a)
1 //===-- LibCxxTuple.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 #include "LibCxx.h"
11 #include "lldb/DataFormatters/FormattersHelpers.h"
12 
13 using namespace lldb;
14 using namespace lldb_private;
15 
16 namespace {
17 
18 class TupleFrontEnd: public SyntheticChildrenFrontEnd {
19 public:
20   TupleFrontEnd(ValueObject &valobj) : SyntheticChildrenFrontEnd(valobj) {
21     Update();
22   }
23 
24   size_t GetIndexOfChildWithName(const ConstString &name) override {
25     return formatters::ExtractIndexFromString(name.GetCString());
26   }
27 
28   bool MightHaveChildren() override { return true; }
29   bool Update() override;
30   size_t CalculateNumChildren() override { return m_elements.size(); }
31   ValueObjectSP GetChildAtIndex(size_t idx) override;
32 
33 private:
34   std::vector<ValueObjectSP> m_elements;
35   ValueObjectSP m_base_sp;
36 };
37 }
38 
39 bool TupleFrontEnd::Update() {
40   m_elements.clear();
41   m_base_sp = m_backend.GetChildMemberWithName(ConstString("base_"), true);
42   if (! m_base_sp)
43     return false;
44   m_elements.assign(m_base_sp->GetCompilerType().GetNumDirectBaseClasses(),
45                     ValueObjectSP());
46   return false;
47 }
48 
49 ValueObjectSP TupleFrontEnd::GetChildAtIndex(size_t idx) {
50   if (idx >= m_elements.size())
51     return ValueObjectSP();
52   if (!m_base_sp)
53     return ValueObjectSP();
54   if (m_elements[idx])
55     return m_elements[idx];
56 
57   CompilerType holder_type =
58       m_base_sp->GetCompilerType().GetDirectBaseClassAtIndex(idx, nullptr);
59   if (!holder_type)
60     return ValueObjectSP();
61   ValueObjectSP holder_sp = m_base_sp->GetChildAtIndex(idx, true);
62   if (!holder_sp)
63     return ValueObjectSP();
64 
65   ValueObjectSP elem_sp = holder_sp->GetChildAtIndex(0, true);
66   if (elem_sp)
67     m_elements[idx] =
68         elem_sp->Clone(ConstString(llvm::formatv("[{0}]", idx).str()));
69 
70   return m_elements[idx];
71 }
72 
73 SyntheticChildrenFrontEnd *
74 formatters::LibcxxTupleFrontEndCreator(CXXSyntheticChildren *,
75                                        lldb::ValueObjectSP valobj_sp) {
76   if (valobj_sp)
77     return new TupleFrontEnd(*valobj_sp);
78   return nullptr;
79 }
80