1 //===-- ValueObjectMemory.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 "lldb/Core/ValueObjectMemory.h" 10 #include "lldb/Core/Value.h" 11 #include "lldb/Core/ValueObject.h" 12 #include "lldb/Symbol/Type.h" 13 #include "lldb/Target/ExecutionContext.h" 14 #include "lldb/Target/Target.h" 15 #include "lldb/Utility/DataExtractor.h" 16 #include "lldb/Utility/Scalar.h" 17 #include "lldb/Utility/Status.h" 18 #include "lldb/lldb-types.h" 19 #include "llvm/Support/ErrorHandling.h" 20 21 #include <cassert> 22 #include <memory> 23 #include <optional> 24 25 namespace lldb_private { 26 class ExecutionContextScope; 27 } 28 29 using namespace lldb; 30 using namespace lldb_private; 31 32 ValueObjectSP ValueObjectMemory::Create(ExecutionContextScope *exe_scope, 33 llvm::StringRef name, 34 const Address &address, 35 lldb::TypeSP &type_sp) { 36 auto manager_sp = ValueObjectManager::Create(); 37 return (new ValueObjectMemory(exe_scope, *manager_sp, name, address, type_sp)) 38 ->GetSP(); 39 } 40 41 ValueObjectSP ValueObjectMemory::Create(ExecutionContextScope *exe_scope, 42 llvm::StringRef name, 43 const Address &address, 44 const CompilerType &ast_type) { 45 auto manager_sp = ValueObjectManager::Create(); 46 return (new ValueObjectMemory(exe_scope, *manager_sp, name, address, 47 ast_type)) 48 ->GetSP(); 49 } 50 51 ValueObjectMemory::ValueObjectMemory(ExecutionContextScope *exe_scope, 52 ValueObjectManager &manager, 53 llvm::StringRef name, 54 const Address &address, 55 lldb::TypeSP &type_sp) 56 : ValueObject(exe_scope, manager), m_address(address), m_type_sp(type_sp), 57 m_compiler_type() { 58 // Do not attempt to construct one of these objects with no variable! 59 assert(m_type_sp.get() != nullptr); 60 SetName(ConstString(name)); 61 m_value.SetContext(Value::ContextType::LLDBType, m_type_sp.get()); 62 TargetSP target_sp(GetTargetSP()); 63 lldb::addr_t load_address = m_address.GetLoadAddress(target_sp.get()); 64 if (load_address != LLDB_INVALID_ADDRESS) { 65 m_value.SetValueType(Value::ValueType::LoadAddress); 66 m_value.GetScalar() = load_address; 67 } else { 68 lldb::addr_t file_address = m_address.GetFileAddress(); 69 if (file_address != LLDB_INVALID_ADDRESS) { 70 m_value.SetValueType(Value::ValueType::FileAddress); 71 m_value.GetScalar() = file_address; 72 } else { 73 m_value.GetScalar() = m_address.GetOffset(); 74 m_value.SetValueType(Value::ValueType::Scalar); 75 } 76 } 77 } 78 79 ValueObjectMemory::ValueObjectMemory(ExecutionContextScope *exe_scope, 80 ValueObjectManager &manager, 81 llvm::StringRef name, 82 const Address &address, 83 const CompilerType &ast_type) 84 : ValueObject(exe_scope, manager), m_address(address), m_type_sp(), 85 m_compiler_type(ast_type) { 86 // Do not attempt to construct one of these objects with no variable! 87 assert(m_compiler_type.IsValid()); 88 89 TargetSP target_sp(GetTargetSP()); 90 91 SetName(ConstString(name)); 92 m_value.SetCompilerType(m_compiler_type); 93 lldb::addr_t load_address = m_address.GetLoadAddress(target_sp.get()); 94 if (load_address != LLDB_INVALID_ADDRESS) { 95 m_value.SetValueType(Value::ValueType::LoadAddress); 96 m_value.GetScalar() = load_address; 97 } else { 98 lldb::addr_t file_address = m_address.GetFileAddress(); 99 if (file_address != LLDB_INVALID_ADDRESS) { 100 m_value.SetValueType(Value::ValueType::FileAddress); 101 m_value.GetScalar() = file_address; 102 } else { 103 m_value.GetScalar() = m_address.GetOffset(); 104 m_value.SetValueType(Value::ValueType::Scalar); 105 } 106 } 107 } 108 109 ValueObjectMemory::~ValueObjectMemory() = default; 110 111 CompilerType ValueObjectMemory::GetCompilerTypeImpl() { 112 if (m_type_sp) 113 return m_type_sp->GetForwardCompilerType(); 114 return m_compiler_type; 115 } 116 117 ConstString ValueObjectMemory::GetTypeName() { 118 if (m_type_sp) 119 return m_type_sp->GetName(); 120 return m_compiler_type.GetTypeName(); 121 } 122 123 ConstString ValueObjectMemory::GetDisplayTypeName() { 124 if (m_type_sp) 125 return m_type_sp->GetForwardCompilerType().GetDisplayTypeName(); 126 return m_compiler_type.GetDisplayTypeName(); 127 } 128 129 llvm::Expected<uint32_t> ValueObjectMemory::CalculateNumChildren(uint32_t max) { 130 if (m_type_sp) { 131 auto child_count = m_type_sp->GetNumChildren(true); 132 if (!child_count) 133 return child_count; 134 return *child_count <= max ? *child_count : max; 135 } 136 137 ExecutionContext exe_ctx(GetExecutionContextRef()); 138 const bool omit_empty_base_classes = true; 139 auto child_count = 140 m_compiler_type.GetNumChildren(omit_empty_base_classes, &exe_ctx); 141 if (!child_count) 142 return child_count; 143 return *child_count <= max ? *child_count : max; 144 } 145 146 std::optional<uint64_t> ValueObjectMemory::GetByteSize() { 147 ExecutionContext exe_ctx(GetExecutionContextRef()); 148 if (m_type_sp) 149 return m_type_sp->GetByteSize(exe_ctx.GetBestExecutionContextScope()); 150 return m_compiler_type.GetByteSize(exe_ctx.GetBestExecutionContextScope()); 151 } 152 153 lldb::ValueType ValueObjectMemory::GetValueType() const { 154 // RETHINK: Should this be inherited from somewhere? 155 return lldb::eValueTypeVariableGlobal; 156 } 157 158 bool ValueObjectMemory::UpdateValue() { 159 SetValueIsValid(false); 160 m_error.Clear(); 161 162 ExecutionContext exe_ctx(GetExecutionContextRef()); 163 164 Target *target = exe_ctx.GetTargetPtr(); 165 if (target) { 166 m_data.SetByteOrder(target->GetArchitecture().GetByteOrder()); 167 m_data.SetAddressByteSize(target->GetArchitecture().GetAddressByteSize()); 168 } 169 170 Value old_value(m_value); 171 if (m_address.IsValid()) { 172 Value::ValueType value_type = m_value.GetValueType(); 173 174 switch (value_type) { 175 case Value::ValueType::Invalid: 176 m_error.SetErrorString("Invalid value"); 177 return false; 178 case Value::ValueType::Scalar: 179 // The variable value is in the Scalar value inside the m_value. We can 180 // point our m_data right to it. 181 m_error = m_value.GetValueAsData(&exe_ctx, m_data, GetModule().get()); 182 break; 183 184 case Value::ValueType::FileAddress: 185 case Value::ValueType::LoadAddress: 186 case Value::ValueType::HostAddress: 187 // The DWARF expression result was an address in the inferior process. If 188 // this variable is an aggregate type, we just need the address as the 189 // main value as all child variable objects will rely upon this location 190 // and add an offset and then read their own values as needed. If this 191 // variable is a simple type, we read all data for it into m_data. Make 192 // sure this type has a value before we try and read it 193 194 // If we have a file address, convert it to a load address if we can. 195 if (value_type == Value::ValueType::FileAddress && 196 exe_ctx.GetProcessPtr()) { 197 lldb::addr_t load_addr = m_address.GetLoadAddress(target); 198 if (load_addr != LLDB_INVALID_ADDRESS) { 199 m_value.SetValueType(Value::ValueType::LoadAddress); 200 m_value.GetScalar() = load_addr; 201 } 202 } 203 204 if (!CanProvideValue()) { 205 // this value object represents an aggregate type whose children have 206 // values, but this object does not. So we say we are changed if our 207 // location has changed. 208 SetValueDidChange(value_type != old_value.GetValueType() || 209 m_value.GetScalar() != old_value.GetScalar()); 210 } else { 211 // Copy the Value and set the context to use our Variable so it can 212 // extract read its value into m_data appropriately 213 Value value(m_value); 214 if (m_type_sp) 215 value.SetContext(Value::ContextType::LLDBType, m_type_sp.get()); 216 else { 217 value.SetCompilerType(m_compiler_type); 218 } 219 220 m_error = value.GetValueAsData(&exe_ctx, m_data, GetModule().get()); 221 } 222 break; 223 } 224 225 SetValueIsValid(m_error.Success()); 226 } 227 return m_error.Success(); 228 } 229 230 bool ValueObjectMemory::IsInScope() { 231 // FIXME: Maybe try to read the memory address, and if that works, then 232 // we are in scope? 233 return true; 234 } 235 236 lldb::ModuleSP ValueObjectMemory::GetModule() { return m_address.GetModule(); } 237