100 lines · cpp
1//===-- LibCxxTuple.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-exception6//7//===----------------------------------------------------------------------===//8 9#include "LibCxx.h"10#include "lldb/DataFormatters/FormattersHelpers.h"11 12using namespace lldb;13using namespace lldb_private;14 15namespace {16 17class TupleFrontEnd: public SyntheticChildrenFrontEnd {18public:19 TupleFrontEnd(ValueObject &valobj) : SyntheticChildrenFrontEnd(valobj) {20 Update();21 }22 23 llvm::Expected<size_t> GetIndexOfChildWithName(ConstString name) override {24 auto optional_idx = formatters::ExtractIndexFromString(name.GetCString());25 if (!optional_idx) {26 return llvm::createStringError("Type has no child named '%s'",27 name.AsCString());28 }29 return *optional_idx;30 }31 32 lldb::ChildCacheState Update() override;33 llvm::Expected<uint32_t> CalculateNumChildren() override {34 return m_elements.size();35 }36 ValueObjectSP GetChildAtIndex(uint32_t idx) override;37 38private:39 // The lifetime of a ValueObject and all its derivative ValueObjects40 // (children, clones, etc.) is managed by a ClusterManager. These41 // objects are only destroyed when every shared pointer to any of them42 // is destroyed, so we must not store a shared pointer to any ValueObject43 // derived from our backend ValueObject (since we're in the same cluster).44 std::vector<ValueObject*> m_elements;45 ValueObject* m_base = nullptr;46};47}48 49lldb::ChildCacheState TupleFrontEnd::Update() {50 m_elements.clear();51 m_base = nullptr;52 53 ValueObjectSP base_sp;54 base_sp = m_backend.GetChildMemberWithName("__base_");55 if (!base_sp) {56 // Pre r304382 name of the base element.57 base_sp = m_backend.GetChildMemberWithName("base_");58 }59 if (!base_sp)60 return lldb::ChildCacheState::eRefetch;61 m_base = base_sp.get();62 m_elements.assign(base_sp->GetCompilerType().GetNumDirectBaseClasses(),63 nullptr);64 return lldb::ChildCacheState::eRefetch;65}66 67ValueObjectSP TupleFrontEnd::GetChildAtIndex(uint32_t idx) {68 if (idx >= m_elements.size())69 return ValueObjectSP();70 if (!m_base)71 return ValueObjectSP();72 if (m_elements[idx])73 return m_elements[idx]->GetSP();74 75 CompilerType holder_type =76 m_base->GetCompilerType().GetDirectBaseClassAtIndex(idx, nullptr);77 if (!holder_type)78 return ValueObjectSP();79 ValueObjectSP holder_sp = m_base->GetChildAtIndex(idx);80 if (!holder_sp)81 return ValueObjectSP();82 83 ValueObjectSP elem_sp = holder_sp->GetChildAtIndex(0);84 if (elem_sp)85 m_elements[idx] =86 elem_sp->Clone(ConstString(llvm::formatv("[{0}]", idx).str())).get();87 88 if (m_elements[idx])89 return m_elements[idx]->GetSP();90 return ValueObjectSP();91}92 93SyntheticChildrenFrontEnd *94formatters::LibcxxTupleFrontEndCreator(CXXSyntheticChildren *,95 lldb::ValueObjectSP valobj_sp) {96 if (valobj_sp)97 return new TupleFrontEnd(*valobj_sp);98 return nullptr;99}100