227 lines · cpp
1//===-- ValueObjectChild.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 "lldb/ValueObject/ValueObjectChild.h"10 11#include "lldb/Core/Value.h"12#include "lldb/Symbol/CompilerType.h"13#include "lldb/Target/ExecutionContext.h"14#include "lldb/Target/Process.h"15#include "lldb/Utility/Flags.h"16#include "lldb/Utility/Scalar.h"17#include "lldb/Utility/Status.h"18#include "lldb/lldb-forward.h"19 20#include <functional>21#include <memory>22#include <vector>23 24#include <cstdio>25#include <cstring>26 27using namespace lldb_private;28 29ValueObjectChild::ValueObjectChild(30 ValueObject &parent, const CompilerType &compiler_type, ConstString name,31 uint64_t byte_size, int32_t byte_offset, uint32_t bitfield_bit_size,32 uint32_t bitfield_bit_offset, bool is_base_class, bool is_deref_of_parent,33 AddressType child_ptr_or_ref_addr_type, uint64_t language_flags)34 : ValueObject(parent), m_compiler_type(compiler_type),35 m_byte_size(byte_size), m_byte_offset(byte_offset),36 m_bitfield_bit_size(bitfield_bit_size),37 m_bitfield_bit_offset(bitfield_bit_offset),38 m_is_base_class(is_base_class), m_is_deref_of_parent(is_deref_of_parent),39 m_can_update_with_invalid_exe_ctx() {40 m_name = name;41 SetAddressTypeOfChildren(child_ptr_or_ref_addr_type);42 SetLanguageFlags(language_flags);43}44 45ValueObjectChild::~ValueObjectChild() = default;46 47lldb::ValueType ValueObjectChild::GetValueType() const {48 return m_parent->GetValueType();49}50 51llvm::Expected<uint32_t> ValueObjectChild::CalculateNumChildren(uint32_t max) {52 ExecutionContext exe_ctx(GetExecutionContextRef());53 auto children_count = GetCompilerType().GetNumChildren(true, &exe_ctx);54 if (!children_count)55 return children_count;56 return *children_count <= max ? *children_count : max;57}58 59static void AdjustForBitfieldness(ConstString &name,60 uint8_t bitfield_bit_size) {61 if (name && bitfield_bit_size)62 name.SetString(llvm::formatv("{0}:{1}", name, bitfield_bit_size).str());63}64 65ConstString ValueObjectChild::GetTypeName() {66 if (m_type_name.IsEmpty()) {67 m_type_name = GetCompilerType().GetTypeName();68 AdjustForBitfieldness(m_type_name, m_bitfield_bit_size);69 }70 return m_type_name;71}72 73ConstString ValueObjectChild::GetQualifiedTypeName() {74 ConstString qualified_name = GetCompilerType().GetTypeName();75 AdjustForBitfieldness(qualified_name, m_bitfield_bit_size);76 return qualified_name;77}78 79ConstString ValueObjectChild::GetDisplayTypeName() {80 ConstString display_name = GetCompilerType().GetDisplayTypeName();81 AdjustForBitfieldness(display_name, m_bitfield_bit_size);82 return display_name;83}84 85LazyBool ValueObjectChild::CanUpdateWithInvalidExecutionContext() {86 if (m_can_update_with_invalid_exe_ctx)87 return *m_can_update_with_invalid_exe_ctx;88 if (m_parent) {89 ValueObject *opinionated_parent =90 m_parent->FollowParentChain([](ValueObject *valobj) -> bool {91 return (valobj->CanUpdateWithInvalidExecutionContext() ==92 eLazyBoolCalculate);93 });94 if (opinionated_parent)95 return *(m_can_update_with_invalid_exe_ctx =96 opinionated_parent->CanUpdateWithInvalidExecutionContext());97 }98 return *(m_can_update_with_invalid_exe_ctx =99 this->ValueObject::CanUpdateWithInvalidExecutionContext());100}101 102bool ValueObjectChild::UpdateValue() {103 m_error.Clear();104 SetValueIsValid(false);105 ValueObject *parent = m_parent;106 if (parent) {107 if (parent->UpdateValueIfNeeded(false)) {108 m_value.SetCompilerType(GetCompilerType());109 110 CompilerType parent_type(parent->GetCompilerType());111 // Copy the parent scalar value and the scalar value type112 m_value.GetScalar() = parent->GetValue().GetScalar();113 m_value.SetValueType(parent->GetValue().GetValueType());114 115 Flags parent_type_flags(parent_type.GetTypeInfo());116 const bool is_instance_ptr_base =117 ((m_is_base_class) &&118 (parent_type_flags.AnySet(lldb::eTypeInstanceIsPointer)));119 120 if (parent->GetCompilerType().ShouldTreatScalarValueAsAddress()) {121 m_value.GetScalar() = parent->GetPointerValue().address;122 123 switch (parent->GetAddressTypeOfChildren()) {124 case eAddressTypeFile: {125 lldb::ProcessSP process_sp(GetProcessSP());126 if (process_sp && process_sp->IsAlive())127 m_value.SetValueType(Value::ValueType::LoadAddress);128 else129 m_value.SetValueType(Value::ValueType::FileAddress);130 } break;131 case eAddressTypeLoad:132 m_value.SetValueType(is_instance_ptr_base133 ? Value::ValueType::Scalar134 : Value::ValueType::LoadAddress);135 break;136 case eAddressTypeHost:137 m_value.SetValueType(Value::ValueType::HostAddress);138 break;139 case eAddressTypeInvalid:140 // TODO: does this make sense?141 m_value.SetValueType(Value::ValueType::Scalar);142 break;143 }144 }145 switch (m_value.GetValueType()) {146 case Value::ValueType::Invalid:147 break;148 case Value::ValueType::LoadAddress:149 case Value::ValueType::FileAddress:150 case Value::ValueType::HostAddress: {151 lldb::addr_t addr = m_value.GetScalar().ULongLong(LLDB_INVALID_ADDRESS);152 if (addr == LLDB_INVALID_ADDRESS) {153 m_error = Status::FromErrorString("parent address is invalid.");154 } else if (addr == 0) {155 m_error = Status::FromErrorString("parent is NULL");156 } else {157 // If a bitfield doesn't fit into the child_byte_size'd window at158 // child_byte_offset, move the window forward until it fits. The159 // problem here is that Value has no notion of bitfields and thus the160 // Value's DataExtractor is sized like the bitfields CompilerType; a161 // sequence of bitfields, however, can be larger than their underlying162 // type.163 if (m_bitfield_bit_offset) {164 const bool thread_and_frame_only_if_stopped = true;165 ExecutionContext exe_ctx(GetExecutionContextRef().Lock(166 thread_and_frame_only_if_stopped));167 if (auto type_bit_size =168 llvm::expectedToOptional(GetCompilerType().GetBitSize(169 exe_ctx.GetBestExecutionContextScope()))) {170 uint64_t bitfield_end =171 m_bitfield_bit_size + m_bitfield_bit_offset;172 if (bitfield_end > *type_bit_size) {173 uint64_t overhang_bytes =174 (bitfield_end - *type_bit_size + 7) / 8;175 m_byte_offset += overhang_bytes;176 m_bitfield_bit_offset -= overhang_bytes * 8;177 }178 }179 }180 181 // Set this object's scalar value to the address of its value by182 // adding its byte offset to the parent address183 m_value.GetScalar() += m_byte_offset;184 }185 } break;186 187 case Value::ValueType::Scalar:188 // try to extract the child value from the parent's scalar value189 {190 Scalar scalar(m_value.GetScalar());191 scalar.ExtractBitfield(8 * m_byte_size, 8 * m_byte_offset);192 m_value.GetScalar() = scalar;193 }194 break;195 }196 197 if (m_error.Success()) {198 const bool thread_and_frame_only_if_stopped = true;199 ExecutionContext exe_ctx(200 GetExecutionContextRef().Lock(thread_and_frame_only_if_stopped));201 if (GetCompilerType().GetTypeInfo() & lldb::eTypeHasValue) {202 Value &value = is_instance_ptr_base ? m_parent->GetValue() : m_value;203 m_error = value.GetValueAsData(&exe_ctx, m_data, GetModule().get());204 } else {205 m_error.Clear(); // No value so nothing to read...206 }207 }208 209 } else {210 m_error = Status::FromErrorStringWithFormat(211 "parent failed to evaluate: %s", parent->GetError().AsCString());212 }213 } else {214 m_error = Status::FromErrorString(215 "ValueObjectChild has a NULL parent ValueObject.");216 }217 218 return m_error.Success();219}220 221bool ValueObjectChild::IsInScope() {222 ValueObject *root(GetRoot());223 if (root)224 return root->IsInScope();225 return false;226}227