197 lines · cpp
1//===-- LibCxxProxyArray.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 11#include "lldb/DataFormatters/FormattersHelpers.h"12#include "lldb/ValueObject/ValueObject.h"13#include <optional>14 15using namespace lldb;16using namespace lldb_private;17using namespace lldb_private::formatters;18 19namespace lldb_private {20namespace formatters {21 22/// Data formatter for libc++'s std::"proxy_array".23///24/// A proxy_array's are created by using:25/// std::gslice_array operator[](const std::gslice& gslicearr);26/// std::mask_array operator[](const std::valarray<bool>& boolarr);27/// std::indirect_array operator[](const std::valarray<std::size_t>& indarr);28///29/// These arrays have the following members:30/// - __vp_ points to std::valarray::__begin_31/// - __1d_ an array of offsets of the elements from @a __vp_32class LibcxxStdProxyArraySyntheticFrontEnd : public SyntheticChildrenFrontEnd {33public:34 LibcxxStdProxyArraySyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);35 36 ~LibcxxStdProxyArraySyntheticFrontEnd() override;37 38 llvm::Expected<uint32_t> CalculateNumChildren() override;39 40 lldb::ValueObjectSP GetChildAtIndex(uint32_t idx) override;41 42 lldb::ChildCacheState Update() override;43 44 llvm::Expected<size_t> GetIndexOfChildWithName(ConstString name) override;45 46private:47 /// A non-owning pointer to the array's __vp_.48 ValueObject *m_base = nullptr;49 /// The type of the array's template argument T.50 CompilerType m_element_type;51 /// The sizeof the array's template argument T.52 uint32_t m_element_size = 0;53 54 /// A non-owning pointer to the array's __1d_.__begin_.55 ValueObject *m_start = nullptr;56 /// A non-owning pointer to the array's __1d_.__end_.57 ValueObject *m_finish = nullptr;58 /// The type of the __1d_ array's template argument T (size_t).59 CompilerType m_element_type_size_t;60 /// The sizeof the __1d_ array's template argument T (size_t)61 uint32_t m_element_size_size_t = 0;62};63 64} // namespace formatters65} // namespace lldb_private66 67lldb_private::formatters::LibcxxStdProxyArraySyntheticFrontEnd::68 LibcxxStdProxyArraySyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)69 : SyntheticChildrenFrontEnd(*valobj_sp), m_element_type() {70 if (valobj_sp)71 Update();72}73 74lldb_private::formatters::LibcxxStdProxyArraySyntheticFrontEnd::75 ~LibcxxStdProxyArraySyntheticFrontEnd() {76 // these need to stay around because they are child objects who will follow77 // their parent's life cycle78 // delete m_base;79}80 81llvm::Expected<uint32_t> lldb_private::formatters::82 LibcxxStdProxyArraySyntheticFrontEnd::CalculateNumChildren() {83 84 if (!m_start || !m_finish)85 return 0;86 uint64_t start_val = m_start->GetValueAsUnsigned(0);87 uint64_t finish_val = m_finish->GetValueAsUnsigned(0);88 89 if (start_val == 0 || finish_val == 0)90 return 0;91 92 if (start_val >= finish_val)93 return 0;94 95 size_t num_children = (finish_val - start_val);96 if (num_children % m_element_size_size_t)97 return 0;98 return num_children / m_element_size_size_t;99}100 101lldb::ValueObjectSP102lldb_private::formatters::LibcxxStdProxyArraySyntheticFrontEnd::GetChildAtIndex(103 uint32_t idx) {104 if (!m_base)105 return lldb::ValueObjectSP();106 107 uint64_t offset = idx * m_element_size_size_t;108 offset = offset + m_start->GetValueAsUnsigned(0);109 110 lldb::ValueObjectSP indirect = CreateValueObjectFromAddress(111 "", offset, m_backend.GetExecutionContextRef(), m_element_type_size_t);112 if (!indirect)113 return lldb::ValueObjectSP();114 115 const size_t value = indirect->GetValueAsUnsigned(0);116 if (!value)117 return lldb::ValueObjectSP();118 119 offset = value * m_element_size;120 offset = offset + m_base->GetValueAsUnsigned(0);121 122 StreamString name;123 name.Printf("[%" PRIu64 "] -> [%zu]", (uint64_t)idx, value);124 return CreateValueObjectFromAddress(name.GetString(), offset,125 m_backend.GetExecutionContextRef(),126 m_element_type);127}128 129lldb::ChildCacheState130lldb_private::formatters::LibcxxStdProxyArraySyntheticFrontEnd::Update() {131 m_base = nullptr;132 m_start = nullptr;133 m_finish = nullptr;134 135 CompilerType type = m_backend.GetCompilerType();136 if (type.GetNumTemplateArguments() == 0)137 return ChildCacheState::eRefetch;138 139 m_element_type = type.GetTypeTemplateArgument(0);140 if (std::optional<uint64_t> size =141 llvm::expectedToOptional(m_element_type.GetByteSize(nullptr)))142 m_element_size = *size;143 144 if (m_element_size == 0)145 return ChildCacheState::eRefetch;146 147 ValueObjectSP vector = m_backend.GetChildMemberWithName("__1d_");148 if (!vector)149 return ChildCacheState::eRefetch;150 151 type = vector->GetCompilerType();152 if (type.GetNumTemplateArguments() == 0)153 return ChildCacheState::eRefetch;154 155 m_element_type_size_t = type.GetTypeTemplateArgument(0);156 if (std::optional<uint64_t> size =157 llvm::expectedToOptional(m_element_type_size_t.GetByteSize(nullptr)))158 m_element_size_size_t = *size;159 160 if (m_element_size_size_t == 0)161 return ChildCacheState::eRefetch;162 163 ValueObjectSP base = m_backend.GetChildMemberWithName("__vp_");164 ValueObjectSP start = vector->GetChildMemberWithName("__begin_");165 ValueObjectSP finish = vector->GetChildMemberWithName("__end_");166 if (!base || !start || !finish)167 return ChildCacheState::eRefetch;168 169 m_base = base.get();170 m_start = start.get();171 m_finish = finish.get();172 173 return ChildCacheState::eRefetch;174}175 176llvm::Expected<size_t>177lldb_private::formatters::LibcxxStdProxyArraySyntheticFrontEnd::178 GetIndexOfChildWithName(ConstString name) {179 if (!m_base)180 return llvm::createStringError("Type has no child named '%s'",181 name.AsCString());182 auto optional_idx = formatters::ExtractIndexFromString(name.GetCString());183 if (!optional_idx) {184 return llvm::createStringError("Type has no child named '%s'",185 name.AsCString());186 }187 return *optional_idx;188}189 190lldb_private::SyntheticChildrenFrontEnd *191lldb_private::formatters::LibcxxStdProxyArraySyntheticFrontEndCreator(192 CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {193 if (!valobj_sp)194 return nullptr;195 return new LibcxxStdProxyArraySyntheticFrontEnd(valobj_sp);196}197