contrib/llvm-project/lldb/source/Plugins/Language/CPlusPlus/LibStdcppTuple.cpp

   1 //===-- LibStdcppTuple.cpp --------------------------------------*- C++ -*-===//
   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
  19 using namespace lldb;
  20 using namespace lldb_private;
  21 using namespace lldb_private::formatters;
  22
  23 namespace {
  24
  25 class LibStdcppTupleSyntheticFrontEnd : public SyntheticChildrenFrontEnd {
  26 public:
  27   explicit LibStdcppTupleSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
  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   std::vector<ValueObjectSP> m_members;
  41 };
  42
  43 } // end of anonymous namespace
  44
  45 LibStdcppTupleSyntheticFrontEnd::LibStdcppTupleSyntheticFrontEnd(
  46     lldb::ValueObjectSP valobj_sp)
  47     : SyntheticChildrenFrontEnd(*valobj_sp) {
  48   Update();
  49 }
  50
  51 bool LibStdcppTupleSyntheticFrontEnd::Update() {
  52   m_members.clear();
  53
  54   ValueObjectSP valobj_backend_sp = m_backend.GetSP();
  55   if (!valobj_backend_sp)
  56     return false;
  57
  58   ValueObjectSP next_child_sp = valobj_backend_sp->GetNonSyntheticValue();
  59   while (next_child_sp != nullptr) {
  60     ValueObjectSP current_child = next_child_sp;
  61     next_child_sp = nullptr;
  62
  63     size_t child_count = current_child->GetNumChildren();
  64     for (size_t i = 0; i < child_count; ++i) {
  65       ValueObjectSP child_sp = current_child->GetChildAtIndex(i, true);
  66       llvm::StringRef name_str = child_sp->GetName().GetStringRef();
  67       if (name_str.startswith("std::_Tuple_impl<")) {
  68         next_child_sp = child_sp;
  69       } else if (name_str.startswith("std::_Head_base<")) {
  70         ValueObjectSP value_sp =
  71             child_sp->GetChildMemberWithName(ConstString("_M_head_impl"), true);
  72         if (value_sp) {
  73           StreamString name;
  74           name.Printf("[%zd]", m_members.size());
  75           m_members.push_back(value_sp->Clone(ConstString(name.GetString())));
  76         }
  77       }
  78     }
  79   }
  80
  81   return false;
  82 }
  83
  84 bool LibStdcppTupleSyntheticFrontEnd::MightHaveChildren() { return true; }
  85
  86 lldb::ValueObjectSP
  87 LibStdcppTupleSyntheticFrontEnd::GetChildAtIndex(size_t idx) {
  88   if (idx < m_members.size())
  89     return m_members[idx];
  90   return lldb::ValueObjectSP();
  91 }
  92
  93 size_t LibStdcppTupleSyntheticFrontEnd::CalculateNumChildren() {
  94   return m_members.size();
  95 }
  96
  97 size_t LibStdcppTupleSyntheticFrontEnd::GetIndexOfChildWithName(
  98     ConstString name) {
  99   return ExtractIndexFromString(name.GetCString());
 100 }
 101
 102 SyntheticChildrenFrontEnd *
 103 lldb_private::formatters::LibStdcppTupleSyntheticFrontEndCreator(
 104     CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
 105   return (valobj_sp ? new LibStdcppTupleSyntheticFrontEnd(valobj_sp) : nullptr);
 106 }