1 //===-- LibCxxQueue.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 #include "lldb/DataFormatters/FormattersHelpers.h" 11 12 using namespace lldb; 13 using namespace lldb_private; 14 15 namespace { 16 17 class QueueFrontEnd : public SyntheticChildrenFrontEnd { 18 public: QueueFrontEnd(ValueObject & valobj)19 QueueFrontEnd(ValueObject &valobj) : SyntheticChildrenFrontEnd(valobj) { 20 Update(); 21 } 22 GetIndexOfChildWithName(ConstString name)23 llvm::Expected<size_t> GetIndexOfChildWithName(ConstString name) override { 24 if (m_container_sp) 25 return m_container_sp->GetIndexOfChildWithName(name); 26 return llvm::createStringError("Type has no child named '%s'", 27 name.AsCString()); 28 } 29 30 lldb::ChildCacheState Update() override; 31 CalculateNumChildren()32 llvm::Expected<uint32_t> CalculateNumChildren() override { 33 return m_container_sp ? m_container_sp->GetNumChildren() : 0; 34 } 35 GetChildAtIndex(uint32_t idx)36 ValueObjectSP GetChildAtIndex(uint32_t idx) override { 37 return m_container_sp ? m_container_sp->GetChildAtIndex(idx) 38 : nullptr; 39 } 40 41 private: 42 // The lifetime of a ValueObject and all its derivative ValueObjects 43 // (children, clones, etc.) is managed by a ClusterManager. These 44 // objects are only destroyed when every shared pointer to any of them 45 // is destroyed, so we must not store a shared pointer to any ValueObject 46 // derived from our backend ValueObject (since we're in the same cluster). 47 ValueObject* m_container_sp = nullptr; 48 }; 49 } // namespace 50 Update()51lldb::ChildCacheState QueueFrontEnd::Update() { 52 m_container_sp = nullptr; 53 ValueObjectSP c_sp = m_backend.GetChildMemberWithName("c"); 54 if (!c_sp) 55 return lldb::ChildCacheState::eRefetch; 56 m_container_sp = c_sp->GetSyntheticValue().get(); 57 return lldb::ChildCacheState::eRefetch; 58 } 59 60 SyntheticChildrenFrontEnd * LibcxxQueueFrontEndCreator(CXXSyntheticChildren *,lldb::ValueObjectSP valobj_sp)61formatters::LibcxxQueueFrontEndCreator(CXXSyntheticChildren *, 62 lldb::ValueObjectSP valobj_sp) { 63 if (valobj_sp) 64 return new QueueFrontEnd(*valobj_sp); 65 return nullptr; 66 } 67