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/ValueObject/ValueObjectMemory.h"
10#include "lldb/Core/Value.h"
11#include "lldb/Symbol/Type.h"
12#include "lldb/Target/ExecutionContext.h"
13#include "lldb/Target/Target.h"
14#include "lldb/Utility/DataExtractor.h"
15#include "lldb/Utility/Scalar.h"
16#include "lldb/Utility/Status.h"
17#include "lldb/ValueObject/ValueObject.h"
18#include "lldb/lldb-types.h"
19#include "llvm/Support/ErrorHandling.h"
20
21#include <cassert>
22#include <memory>
23#include <optional>
24
25namespace lldb_private {
26class ExecutionContextScope;
27}
28
29using namespace lldb;
30using namespace lldb_private;
31
32ValueObjectSP 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
41ValueObjectSP 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
51ValueObjectMemory::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(context_type: Value::ContextType::LLDBType, p: m_type_sp.get());
62 TargetSP target_sp(GetTargetSP());
63 lldb::addr_t load_address = m_address.GetLoadAddress(target: 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
79ValueObjectMemory::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: 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
109ValueObjectMemory::~ValueObjectMemory() = default;
110
111CompilerType ValueObjectMemory::GetCompilerTypeImpl() {
112 if (m_type_sp)
113 return m_type_sp->GetForwardCompilerType();
114 return m_compiler_type;
115}
116
117ConstString ValueObjectMemory::GetTypeName() {
118 if (m_type_sp)
119 return m_type_sp->GetName();
120 return m_compiler_type.GetTypeName();
121}
122
123ConstString ValueObjectMemory::GetDisplayTypeName() {
124 if (m_type_sp)
125 return m_type_sp->GetForwardCompilerType().GetDisplayTypeName();
126 return m_compiler_type.GetDisplayTypeName();
127}
128
129llvm::Expected<uint32_t> ValueObjectMemory::CalculateNumChildren(uint32_t max) {
130 if (m_type_sp) {
131 auto child_count = m_type_sp->GetNumChildren(omit_empty_base_classes: 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: &exe_ctx);
141 if (!child_count)
142 return child_count;
143 return *child_count <= max ? *child_count : max;
144}
145
146llvm::Expected<uint64_t> ValueObjectMemory::GetByteSize() {
147 ExecutionContext exe_ctx(GetExecutionContextRef());
148 if (m_type_sp) {
149 if (auto size =
150 m_type_sp->GetByteSize(exe_scope: exe_ctx.GetBestExecutionContextScope()))
151 return *size;
152 return llvm::createStringError(Fmt: "could not get byte size of memory object");
153 }
154 return m_compiler_type.GetByteSize(exe_scope: exe_ctx.GetBestExecutionContextScope());
155}
156
157lldb::ValueType ValueObjectMemory::GetValueType() const {
158 // RETHINK: Should this be inherited from somewhere?
159 return lldb::eValueTypeVariableGlobal;
160}
161
162bool ValueObjectMemory::UpdateValue() {
163 SetValueIsValid(false);
164 m_error.Clear();
165
166 ExecutionContext exe_ctx(GetExecutionContextRef());
167
168 Target *target = exe_ctx.GetTargetPtr();
169 if (target) {
170 m_data.SetByteOrder(target->GetArchitecture().GetByteOrder());
171 m_data.SetAddressByteSize(target->GetArchitecture().GetAddressByteSize());
172 }
173
174 Value old_value(m_value);
175 if (m_address.IsValid()) {
176 Value::ValueType value_type = m_value.GetValueType();
177
178 switch (value_type) {
179 case Value::ValueType::Invalid:
180 m_error = Status::FromErrorString(str: "Invalid value");
181 return false;
182 case Value::ValueType::Scalar:
183 // The variable value is in the Scalar value inside the m_value. We can
184 // point our m_data right to it.
185 m_error = m_value.GetValueAsData(exe_ctx: &exe_ctx, data&: m_data, module: GetModule().get());
186 break;
187
188 case Value::ValueType::FileAddress:
189 case Value::ValueType::LoadAddress:
190 case Value::ValueType::HostAddress:
191 // The DWARF expression result was an address in the inferior process. If
192 // this variable is an aggregate type, we just need the address as the
193 // main value as all child variable objects will rely upon this location
194 // and add an offset and then read their own values as needed. If this
195 // variable is a simple type, we read all data for it into m_data. Make
196 // sure this type has a value before we try and read it
197
198 // If we have a file address, convert it to a load address if we can.
199 if (value_type == Value::ValueType::FileAddress &&
200 exe_ctx.GetProcessPtr()) {
201 lldb::addr_t load_addr = m_address.GetLoadAddress(target);
202 if (load_addr != LLDB_INVALID_ADDRESS) {
203 m_value.SetValueType(Value::ValueType::LoadAddress);
204 m_value.GetScalar() = load_addr;
205 }
206 }
207
208 if (!CanProvideValue()) {
209 // this value object represents an aggregate type whose children have
210 // values, but this object does not. So we say we are changed if our
211 // location has changed.
212 SetValueDidChange(value_type != old_value.GetValueType() ||
213 m_value.GetScalar() != old_value.GetScalar());
214 } else {
215 // Copy the Value and set the context to use our Variable so it can
216 // extract read its value into m_data appropriately
217 Value value(m_value);
218 if (m_type_sp)
219 value.SetContext(context_type: Value::ContextType::LLDBType, p: m_type_sp.get());
220 else {
221 value.SetCompilerType(m_compiler_type);
222 }
223
224 m_error = value.GetValueAsData(exe_ctx: &exe_ctx, data&: m_data, module: GetModule().get());
225 }
226 break;
227 }
228
229 SetValueIsValid(m_error.Success());
230 }
231 return m_error.Success();
232}
233
234bool ValueObjectMemory::IsInScope() {
235 // FIXME: Maybe try to read the memory address, and if that works, then
236 // we are in scope?
237 return true;
238}
239
240lldb::ModuleSP ValueObjectMemory::GetModule() { return m_address.GetModule(); }
241

source code of lldb/source/ValueObject/ValueObjectMemory.cpp