1//===-- ValueObjectMemory.cpp ---------------------------------*- C++ -*-===//
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 <assert.h>
22#include <memory>
23
24namespace lldb_private {
25class ExecutionContextScope;
26}
27
28using namespace lldb;
29using namespace lldb_private;
30
31ValueObjectSP ValueObjectMemory::Create(ExecutionContextScope *exe_scope,
32                                        llvm::StringRef name,
33                                        const Address &address,
34                                        lldb::TypeSP &type_sp) {
35  return (new ValueObjectMemory(exe_scope, name, address, type_sp))->GetSP();
36}
37
38ValueObjectSP ValueObjectMemory::Create(ExecutionContextScope *exe_scope,
39                                        llvm::StringRef name,
40                                        const Address &address,
41                                        const CompilerType &ast_type) {
42  return (new ValueObjectMemory(exe_scope, name, address, ast_type))->GetSP();
43}
44
45ValueObjectMemory::ValueObjectMemory(ExecutionContextScope *exe_scope,
46                                     llvm::StringRef name,
47                                     const Address &address,
48                                     lldb::TypeSP &type_sp)
49    : ValueObject(exe_scope), m_address(address), m_type_sp(type_sp),
50      m_compiler_type() {
51  // Do not attempt to construct one of these objects with no variable!
52  assert(m_type_sp.get() != nullptr);
53  SetName(ConstString(name));
54  m_value.SetContext(Value::eContextTypeLLDBType, m_type_sp.get());
55  TargetSP target_sp(GetTargetSP());
56  lldb::addr_t load_address = m_address.GetLoadAddress(target_sp.get());
57  if (load_address != LLDB_INVALID_ADDRESS) {
58    m_value.SetValueType(Value::eValueTypeLoadAddress);
59    m_value.GetScalar() = load_address;
60  } else {
61    lldb::addr_t file_address = m_address.GetFileAddress();
62    if (file_address != LLDB_INVALID_ADDRESS) {
63      m_value.SetValueType(Value::eValueTypeFileAddress);
64      m_value.GetScalar() = file_address;
65    } else {
66      m_value.GetScalar() = m_address.GetOffset();
67      m_value.SetValueType(Value::eValueTypeScalar);
68    }
69  }
70}
71
72ValueObjectMemory::ValueObjectMemory(ExecutionContextScope *exe_scope,
73                                     llvm::StringRef name,
74                                     const Address &address,
75                                     const CompilerType &ast_type)
76    : ValueObject(exe_scope), m_address(address), m_type_sp(),
77      m_compiler_type(ast_type) {
78  // Do not attempt to construct one of these objects with no variable!
79  assert(m_compiler_type.GetTypeSystem());
80  assert(m_compiler_type.GetOpaqueQualType());
81
82  TargetSP target_sp(GetTargetSP());
83
84  SetName(ConstString(name));
85  //    m_value.SetContext(Value::eContextTypeClangType,
86  //    m_compiler_type.GetOpaqueQualType());
87  m_value.SetCompilerType(m_compiler_type);
88  lldb::addr_t load_address = m_address.GetLoadAddress(target_sp.get());
89  if (load_address != LLDB_INVALID_ADDRESS) {
90    m_value.SetValueType(Value::eValueTypeLoadAddress);
91    m_value.GetScalar() = load_address;
92  } else {
93    lldb::addr_t file_address = m_address.GetFileAddress();
94    if (file_address != LLDB_INVALID_ADDRESS) {
95      m_value.SetValueType(Value::eValueTypeFileAddress);
96      m_value.GetScalar() = file_address;
97    } else {
98      m_value.GetScalar() = m_address.GetOffset();
99      m_value.SetValueType(Value::eValueTypeScalar);
100    }
101  }
102}
103
104ValueObjectMemory::~ValueObjectMemory() {}
105
106CompilerType ValueObjectMemory::GetCompilerTypeImpl() {
107  if (m_type_sp)
108    return m_type_sp->GetForwardCompilerType();
109  return m_compiler_type;
110}
111
112ConstString ValueObjectMemory::GetTypeName() {
113  if (m_type_sp)
114    return m_type_sp->GetName();
115  return m_compiler_type.GetConstTypeName();
116}
117
118ConstString ValueObjectMemory::GetDisplayTypeName() {
119  if (m_type_sp)
120    return m_type_sp->GetForwardCompilerType().GetDisplayTypeName();
121  return m_compiler_type.GetDisplayTypeName();
122}
123
124size_t ValueObjectMemory::CalculateNumChildren(uint32_t max) {
125  if (m_type_sp) {
126    auto child_count = m_type_sp->GetNumChildren(true);
127    return child_count <= max ? child_count : max;
128  }
129
130  ExecutionContext exe_ctx(GetExecutionContextRef());
131  const bool omit_empty_base_classes = true;
132  auto child_count =
133      m_compiler_type.GetNumChildren(omit_empty_base_classes, &exe_ctx);
134  return child_count <= max ? child_count : max;
135}
136
137uint64_t ValueObjectMemory::GetByteSize() {
138  if (m_type_sp)
139    return m_type_sp->GetByteSize().getValueOr(0);
140  return m_compiler_type.GetByteSize(nullptr).getValueOr(0);
141}
142
143lldb::ValueType ValueObjectMemory::GetValueType() const {
144  // RETHINK: Should this be inherited from somewhere?
145  return lldb::eValueTypeVariableGlobal;
146}
147
148bool ValueObjectMemory::UpdateValue() {
149  SetValueIsValid(false);
150  m_error.Clear();
151
152  ExecutionContext exe_ctx(GetExecutionContextRef());
153
154  Target *target = exe_ctx.GetTargetPtr();
155  if (target) {
156    m_data.SetByteOrder(target->GetArchitecture().GetByteOrder());
157    m_data.SetAddressByteSize(target->GetArchitecture().GetAddressByteSize());
158  }
159
160  Value old_value(m_value);
161  if (m_address.IsValid()) {
162    Value::ValueType value_type = m_value.GetValueType();
163
164    switch (value_type) {
165    default:
166      llvm_unreachable("Unhandled expression result value kind...");
167
168    case Value::eValueTypeScalar:
169      // The variable value is in the Scalar value inside the m_value. We can
170      // point our m_data right to it.
171      m_error = m_value.GetValueAsData(&exe_ctx, m_data, GetModule().get());
172      break;
173
174    case Value::eValueTypeFileAddress:
175    case Value::eValueTypeLoadAddress:
176    case Value::eValueTypeHostAddress:
177      // The DWARF expression result was an address in the inferior process. If
178      // this variable is an aggregate type, we just need the address as the
179      // main value as all child variable objects will rely upon this location
180      // and add an offset and then read their own values as needed. If this
181      // variable is a simple type, we read all data for it into m_data. Make
182      // sure this type has a value before we try and read it
183
184      // If we have a file address, convert it to a load address if we can.
185      if (value_type == Value::eValueTypeFileAddress &&
186          exe_ctx.GetProcessPtr()) {
187        lldb::addr_t load_addr = m_address.GetLoadAddress(target);
188        if (load_addr != LLDB_INVALID_ADDRESS) {
189          m_value.SetValueType(Value::eValueTypeLoadAddress);
190          m_value.GetScalar() = load_addr;
191        }
192      }
193
194      if (!CanProvideValue()) {
195        // this value object represents an aggregate type whose children have
196        // values, but this object does not. So we say we are changed if our
197        // location has changed.
198        SetValueDidChange(value_type != old_value.GetValueType() ||
199                          m_value.GetScalar() != old_value.GetScalar());
200      } else {
201        // Copy the Value and set the context to use our Variable so it can
202        // extract read its value into m_data appropriately
203        Value value(m_value);
204        if (m_type_sp)
205          value.SetContext(Value::eContextTypeLLDBType, m_type_sp.get());
206        else {
207          // value.SetContext(Value::eContextTypeClangType,
208          // m_compiler_type.GetOpaqueQualType());
209          value.SetCompilerType(m_compiler_type);
210        }
211
212        m_error = value.GetValueAsData(&exe_ctx, m_data, GetModule().get());
213      }
214      break;
215    }
216
217    SetValueIsValid(m_error.Success());
218  }
219  return m_error.Success();
220}
221
222bool ValueObjectMemory::IsInScope() {
223  // FIXME: Maybe try to read the memory address, and if that works, then
224  // we are in scope?
225  return true;
226}
227
228lldb::ModuleSP ValueObjectMemory::GetModule() { return m_address.GetModule(); }
229