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ValueObjectMemory.cpp
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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
10#include "lldb/Core/Value.h"
11#include "lldb/Symbol/Type.h"
13#include "lldb/Target/Target.h"
15#include "lldb/Utility/Scalar.h"
16#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
25namespace lldb_private {
27}
28
29using namespace lldb;
30using namespace lldb_private;
31
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
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
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),
58 // Do not attempt to construct one of these objects with no variable!
59 assert(m_type_sp.get() != nullptr);
60 SetName(ConstString(name));
62 TargetSP target_sp(GetTargetSP());
63 lldb::addr_t load_address = m_address.GetLoadAddress(target_sp.get());
64 if (load_address != LLDB_INVALID_ADDRESS) {
66 m_value.GetScalar() = load_address;
67 } else {
68 lldb::addr_t file_address = m_address.GetFileAddress();
69 if (file_address != LLDB_INVALID_ADDRESS) {
71 m_value.GetScalar() = file_address;
72 } else {
73 m_value.GetScalar() = m_address.GetOffset();
75 }
76 }
77}
78
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) {
96 m_value.GetScalar() = load_address;
97 } else {
98 lldb::addr_t file_address = m_address.GetFileAddress();
99 if (file_address != LLDB_INVALID_ADDRESS) {
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
110
112 if (m_type_sp)
113 return m_type_sp->GetForwardCompilerType();
114 return m_compiler_type;
115}
116
118 if (m_type_sp)
119 return m_type_sp->GetName();
120 return m_compiler_type.GetTypeName();
121}
122
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(true);
132 if (!child_count)
133 return child_count;
134 return *child_count <= max ? *child_count : max;
135 }
136
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
146llvm::Expected<uint64_t> ValueObjectMemory::GetByteSize() {
148 if (m_type_sp) {
149 if (auto size =
150 m_type_sp->GetByteSize(exe_ctx.GetBestExecutionContextScope()))
151 return *size;
152 return llvm::createStringError("could not get byte size of memory object");
153 }
154 return m_compiler_type.GetByteSize(exe_ctx.GetBestExecutionContextScope());
155}
156
158 // RETHINK: Should this be inherited from somewhere?
160}
161
163 SetValueIsValid(false);
164 m_error.Clear();
165
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) {
180 m_error = Status::FromErrorString("Invalid value");
181 return false;
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, m_data, GetModule().get());
186 break;
187
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) {
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)
220 else {
222 }
223
224 m_error = value.GetValueAsData(&exe_ctx, m_data, GetModule().get());
225 }
226 break;
227 }
228
229 SetValueIsValid(m_error.Success());
230 }
231 return m_error.Success();
232}
233
235 // FIXME: Maybe try to read the memory address, and if that works, then
236 // we are in scope?
237 return true;
238}
239
A section + offset based address class.
Definition Address.h:62
uint32_t GetAddressByteSize() const
Returns the size in bytes of an address of the current architecture.
Definition ArchSpec.cpp:685
lldb::ByteOrder GetByteOrder() const
Returns the byte order for the architecture specification.
Definition ArchSpec.cpp:732
static std::shared_ptr< ClusterManager > Create()
Generic representation of a type in a programming language.
A uniqued constant string class.
Definition ConstString.h:40
"lldb/Target/ExecutionContextScope.h" Inherit from this if your object can reconstruct its execution ...
"lldb/Target/ExecutionContext.h" A class that contains an execution context.
ExecutionContextScope * GetBestExecutionContextScope() const
Target * GetTargetPtr() const
Returns a pointer to the target object.
Process * GetProcessPtr() const
Returns a pointer to the process object.
static Status FromErrorString(const char *str)
Definition Status.h:141
const ArchSpec & GetArchitecture() const
Definition Target.h:1056
llvm::Expected< uint32_t > CalculateNumChildren(uint32_t max) override
Should only be called by ValueObject::GetNumChildren().
static lldb::ValueObjectSP Create(ExecutionContextScope *exe_scope, llvm::StringRef name, const Address &address, lldb::TypeSP &type_sp)
lldb::ValueType GetValueType() const override
llvm::Expected< uint64_t > GetByteSize() override
lldb::ModuleSP GetModule() override
Return the module associated with this value object in case the value is from an executable file and ...
Address m_address
The variable that this value object is based upon.
ValueObjectMemory(ExecutionContextScope *exe_scope, ValueObjectManager &manager, llvm::StringRef name, const Address &address, lldb::TypeSP &type_sp)
CompilerType GetCompilerTypeImpl() override
ConstString GetDisplayTypeName() override
void SetValueIsValid(bool valid)
ClusterManager< ValueObject > ValueObjectManager
ValueObject(ExecutionContextScope *exe_scope, ValueObjectManager &manager, AddressType child_ptr_or_ref_addr_type=eAddressTypeLoad)
Use this constructor to create a "root variable object".
Status m_error
An error object that can describe any errors that occur when updating values.
DataExtractor m_data
A data extractor that can be used to extract the value.
void SetValueDidChange(bool value_changed)
void SetName(ConstString name)
Change the name of the current ValueObject.
lldb::TargetSP GetTargetSP() const
const ExecutionContextRef & GetExecutionContextRef() const
const Scalar & GetScalar() const
See comment on m_scalar to understand what GetScalar returns.
Definition Value.h:113
Status GetValueAsData(ExecutionContext *exe_ctx, DataExtractor &data, Module *module)
Definition Value.cpp:323
ValueType
Type that describes Value::m_value.
Definition Value.h:41
@ HostAddress
A host address value (for memory in the process that < A is using liblldb).
Definition Value.h:52
@ FileAddress
A file address value.
Definition Value.h:47
@ LoadAddress
A load address value.
Definition Value.h:49
@ Scalar
A raw scalar value.
Definition Value.h:45
ValueType GetValueType() const
Definition Value.cpp:111
void SetCompilerType(const CompilerType &compiler_type)
Definition Value.cpp:276
void SetContext(ContextType context_type, void *p)
Definition Value.h:96
@ LLDBType
lldb_private::Type *.
Definition Value.h:63
#define LLDB_INVALID_ADDRESS
A class that represents a running process on the host machine.
std::shared_ptr< lldb_private::ValueObject > ValueObjectSP
std::shared_ptr< lldb_private::Type > TypeSP
uint64_t addr_t
Definition lldb-types.h:80
std::shared_ptr< lldb_private::Target > TargetSP
std::shared_ptr< lldb_private::Module > ModuleSP
@ eValueTypeVariableGlobal
globals variable