1//===-- ValueObjectRegister.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/ValueObjectRegister.h"
10
11#include "lldb/Core/Module.h"
12#include "lldb/Core/Value.h"
13#include "lldb/Symbol/CompilerType.h"
14#include "lldb/Symbol/TypeSystem.h"
15#include "lldb/Target/ExecutionContext.h"
16#include "lldb/Target/Process.h"
17#include "lldb/Target/RegisterContext.h"
18#include "lldb/Target/StackFrame.h"
19#include "lldb/Target/Target.h"
20#include "lldb/Utility/DataExtractor.h"
21#include "lldb/Utility/LLDBLog.h"
22#include "lldb/Utility/Log.h"
23#include "lldb/Utility/Scalar.h"
24#include "lldb/Utility/Status.h"
25#include "lldb/Utility/Stream.h"
26
27#include "llvm/ADT/StringRef.h"
28
29#include <cassert>
30#include <memory>
31#include <optional>
32
33namespace lldb_private {
34class ExecutionContextScope;
35}
36
37using namespace lldb;
38using namespace lldb_private;
39
40#pragma mark ValueObjectRegisterSet
41
42ValueObjectSP
43ValueObjectRegisterSet::Create(ExecutionContextScope *exe_scope,
44 lldb::RegisterContextSP &reg_ctx_sp,
45 uint32_t set_idx) {
46 auto manager_sp = ValueObjectManager::Create();
47 return (new ValueObjectRegisterSet(exe_scope, *manager_sp, reg_ctx_sp,
48 set_idx))
49 ->GetSP();
50}
51
52ValueObjectRegisterSet::ValueObjectRegisterSet(ExecutionContextScope *exe_scope,
53 ValueObjectManager &manager,
54 lldb::RegisterContextSP &reg_ctx,
55 uint32_t reg_set_idx)
56 : ValueObject(exe_scope, manager), m_reg_ctx_sp(reg_ctx),
57 m_reg_set(nullptr), m_reg_set_idx(reg_set_idx) {
58 assert(reg_ctx);
59 m_reg_set = reg_ctx->GetRegisterSet(reg_set: m_reg_set_idx);
60 if (m_reg_set) {
61 m_name.SetCString(m_reg_set->name);
62 }
63}
64
65ValueObjectRegisterSet::~ValueObjectRegisterSet() = default;
66
67CompilerType ValueObjectRegisterSet::GetCompilerTypeImpl() {
68 return CompilerType();
69}
70
71ConstString ValueObjectRegisterSet::GetTypeName() { return ConstString(); }
72
73ConstString ValueObjectRegisterSet::GetQualifiedTypeName() {
74 return ConstString();
75}
76
77llvm::Expected<uint32_t>
78ValueObjectRegisterSet::CalculateNumChildren(uint32_t max) {
79 const RegisterSet *reg_set = m_reg_ctx_sp->GetRegisterSet(reg_set: m_reg_set_idx);
80 if (reg_set) {
81 auto reg_count = reg_set->num_registers;
82 return reg_count <= max ? reg_count : max;
83 }
84 return 0;
85}
86
87llvm::Expected<uint64_t> ValueObjectRegisterSet::GetByteSize() { return 0; }
88
89bool ValueObjectRegisterSet::UpdateValue() {
90 m_error.Clear();
91 SetValueDidChange(false);
92 ExecutionContext exe_ctx(GetExecutionContextRef());
93 StackFrame *frame = exe_ctx.GetFramePtr();
94 if (frame == nullptr)
95 m_reg_ctx_sp.reset();
96 else {
97 m_reg_ctx_sp = frame->GetRegisterContext();
98 if (m_reg_ctx_sp) {
99 const RegisterSet *reg_set = m_reg_ctx_sp->GetRegisterSet(reg_set: m_reg_set_idx);
100 if (reg_set == nullptr)
101 m_reg_ctx_sp.reset();
102 else if (m_reg_set != reg_set) {
103 SetValueDidChange(true);
104 m_name.SetCString(reg_set->name);
105 }
106 }
107 }
108 if (m_reg_ctx_sp) {
109 SetValueIsValid(true);
110 } else {
111 SetValueIsValid(false);
112 m_error = Status::FromErrorString(str: "no register context");
113 m_children.Clear();
114 }
115 return m_error.Success();
116}
117
118ValueObject *ValueObjectRegisterSet::CreateChildAtIndex(size_t idx) {
119 if (m_reg_ctx_sp && m_reg_set) {
120 return new ValueObjectRegister(
121 *this, m_reg_ctx_sp,
122 m_reg_ctx_sp->GetRegisterInfoAtIndex(reg: m_reg_set->registers[idx]));
123 }
124 return nullptr;
125}
126
127lldb::ValueObjectSP
128ValueObjectRegisterSet::GetChildMemberWithName(llvm::StringRef name,
129 bool can_create) {
130 ValueObject *valobj = nullptr;
131 if (m_reg_ctx_sp && m_reg_set) {
132 const RegisterInfo *reg_info = m_reg_ctx_sp->GetRegisterInfoByName(reg_name: name);
133 if (reg_info != nullptr)
134 valobj = new ValueObjectRegister(*this, m_reg_ctx_sp, reg_info);
135 }
136 if (valobj)
137 return valobj->GetSP();
138 else
139 return ValueObjectSP();
140}
141
142llvm::Expected<size_t>
143ValueObjectRegisterSet::GetIndexOfChildWithName(llvm::StringRef name) {
144 if (m_reg_ctx_sp && m_reg_set) {
145 const RegisterInfo *reg_info = m_reg_ctx_sp->GetRegisterInfoByName(reg_name: name);
146 if (reg_info != nullptr)
147 return reg_info->kinds[eRegisterKindLLDB];
148 }
149 return llvm::createStringError(Fmt: "Type has no child named '%s'",
150 Vals: name.str().c_str());
151}
152
153#pragma mark -
154#pragma mark ValueObjectRegister
155
156void ValueObjectRegister::ConstructObject(const RegisterInfo *reg_info) {
157 if (reg_info) {
158 m_reg_info = *reg_info;
159 if (reg_info->name)
160 m_name.SetCString(reg_info->name);
161 else if (reg_info->alt_name)
162 m_name.SetCString(reg_info->alt_name);
163 }
164}
165
166ValueObjectRegister::ValueObjectRegister(ValueObject &parent,
167 lldb::RegisterContextSP &reg_ctx_sp,
168 const RegisterInfo *reg_info)
169 : ValueObject(parent), m_reg_ctx_sp(reg_ctx_sp), m_reg_info(),
170 m_reg_value(), m_type_name(), m_compiler_type() {
171 assert(reg_ctx_sp.get());
172 ConstructObject(reg_info);
173}
174
175ValueObjectSP ValueObjectRegister::Create(ExecutionContextScope *exe_scope,
176 lldb::RegisterContextSP &reg_ctx_sp,
177 const RegisterInfo *reg_info) {
178 auto manager_sp = ValueObjectManager::Create();
179 return (new ValueObjectRegister(exe_scope, *manager_sp, reg_ctx_sp, reg_info))
180 ->GetSP();
181}
182
183ValueObjectRegister::ValueObjectRegister(ExecutionContextScope *exe_scope,
184 ValueObjectManager &manager,
185 lldb::RegisterContextSP &reg_ctx,
186 const RegisterInfo *reg_info)
187 : ValueObject(exe_scope, manager), m_reg_ctx_sp(reg_ctx), m_reg_info(),
188 m_reg_value(), m_type_name(), m_compiler_type() {
189 assert(reg_ctx);
190 ConstructObject(reg_info);
191}
192
193ValueObjectRegister::~ValueObjectRegister() = default;
194
195CompilerType ValueObjectRegister::GetCompilerTypeImpl() {
196 if (!m_compiler_type.IsValid()) {
197 ExecutionContext exe_ctx(GetExecutionContextRef());
198 if (auto *target = exe_ctx.GetTargetPtr()) {
199 if (auto *exe_module = target->GetExecutableModulePointer()) {
200 auto type_system_or_err =
201 exe_module->GetTypeSystemForLanguage(language: eLanguageTypeC);
202 if (auto err = type_system_or_err.takeError()) {
203 LLDB_LOG_ERROR(GetLog(LLDBLog::Types), std::move(err),
204 "Unable to get CompilerType from TypeSystem: {0}");
205 } else {
206 if (auto ts = *type_system_or_err)
207 m_compiler_type = ts->GetBuiltinTypeForEncodingAndBitSize(
208 encoding: m_reg_info.encoding, bit_size: m_reg_info.byte_size * 8);
209 }
210 }
211 }
212 }
213 return m_compiler_type;
214}
215
216ConstString ValueObjectRegister::GetTypeName() {
217 if (m_type_name.IsEmpty())
218 m_type_name = GetCompilerType().GetTypeName();
219 return m_type_name;
220}
221
222llvm::Expected<uint32_t>
223ValueObjectRegister::CalculateNumChildren(uint32_t max) {
224 ExecutionContext exe_ctx(GetExecutionContextRef());
225 auto children_count = GetCompilerType().GetNumChildren(omit_empty_base_classes: true, exe_ctx: &exe_ctx);
226 if (!children_count)
227 return children_count;
228 return *children_count <= max ? *children_count : max;
229}
230
231llvm::Expected<uint64_t> ValueObjectRegister::GetByteSize() {
232 return m_reg_info.byte_size;
233}
234
235bool ValueObjectRegister::UpdateValue() {
236 m_error.Clear();
237 ExecutionContext exe_ctx(GetExecutionContextRef());
238 StackFrame *frame = exe_ctx.GetFramePtr();
239 if (frame == nullptr) {
240 m_reg_ctx_sp.reset();
241 m_reg_value.Clear();
242 }
243
244 if (m_reg_ctx_sp) {
245 RegisterValue m_old_reg_value(m_reg_value);
246 if (m_reg_ctx_sp->ReadRegister(reg_info: &m_reg_info, reg_value&: m_reg_value)) {
247 if (m_reg_value.GetData(data&: m_data)) {
248 Process *process = exe_ctx.GetProcessPtr();
249 if (process)
250 m_data.SetAddressByteSize(process->GetAddressByteSize());
251 m_value.SetContext(context_type: Value::ContextType::RegisterInfo,
252 p: (void *)&m_reg_info);
253 m_value.SetValueType(Value::ValueType::HostAddress);
254 m_value.GetScalar() = (uintptr_t)m_data.GetDataStart();
255 SetValueIsValid(true);
256 SetValueDidChange(!(m_old_reg_value == m_reg_value));
257 return true;
258 }
259 }
260 }
261
262 SetValueIsValid(false);
263 m_error = Status::FromErrorString(str: "no register context");
264 return false;
265}
266
267bool ValueObjectRegister::SetValueFromCString(const char *value_str,
268 Status &error) {
269 // The new value will be in the m_data. Copy that into our register value.
270 error =
271 m_reg_value.SetValueFromString(reg_info: &m_reg_info, value_str: llvm::StringRef(value_str));
272 if (!error.Success())
273 return false;
274
275 if (!m_reg_ctx_sp->WriteRegister(reg_info: &m_reg_info, reg_value: m_reg_value)) {
276 error = Status::FromErrorString(str: "unable to write back to register");
277 return false;
278 }
279
280 SetNeedsUpdate();
281 return true;
282}
283
284bool ValueObjectRegister::SetData(DataExtractor &data, Status &error) {
285 error = m_reg_value.SetValueFromData(reg_info: m_reg_info, data, offset: 0, partial_data_ok: false);
286 if (!error.Success())
287 return false;
288
289 if (!m_reg_ctx_sp->WriteRegister(reg_info: &m_reg_info, reg_value: m_reg_value)) {
290 error = Status::FromErrorString(str: "unable to write back to register");
291 return false;
292 }
293
294 SetNeedsUpdate();
295 return true;
296}
297
298bool ValueObjectRegister::ResolveValue(Scalar &scalar) {
299 if (UpdateValueIfNeeded(
300 update_format: false)) // make sure that you are up to date before returning anything
301 return m_reg_value.GetScalarValue(scalar);
302 return false;
303}
304
305void ValueObjectRegister::GetExpressionPath(Stream &s,
306 GetExpressionPathFormat epformat) {
307 s.Printf(format: "$%s", m_reg_info.name);
308}
309

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