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/Core/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/Log.h"
22 #include "lldb/Utility/Scalar.h"
23 #include "lldb/Utility/Status.h"
24 #include "lldb/Utility/Stream.h"
25 
26 #include "llvm/ADT/StringRef.h"
27 
28 #include <assert.h>
29 #include <memory>
30 
31 namespace lldb_private {
32 class ExecutionContextScope;
33 }
34 
35 using namespace lldb;
36 using namespace lldb_private;
37 
38 #pragma mark ValueObjectRegisterSet
39 
40 ValueObjectSP
41 ValueObjectRegisterSet::Create(ExecutionContextScope *exe_scope,
42                                lldb::RegisterContextSP &reg_ctx_sp,
43                                uint32_t set_idx) {
44   auto manager_sp = ValueObjectManager::Create();
45   return (new ValueObjectRegisterSet(exe_scope, *manager_sp, reg_ctx_sp,
46                                      set_idx))
47       ->GetSP();
48 }
49 
50 ValueObjectRegisterSet::ValueObjectRegisterSet(ExecutionContextScope *exe_scope,
51                                                ValueObjectManager &manager,
52                                                lldb::RegisterContextSP &reg_ctx,
53                                                uint32_t reg_set_idx)
54     : ValueObject(exe_scope, manager), m_reg_ctx_sp(reg_ctx),
55       m_reg_set(nullptr), m_reg_set_idx(reg_set_idx) {
56   assert(reg_ctx);
57   m_reg_set = reg_ctx->GetRegisterSet(m_reg_set_idx);
58   if (m_reg_set) {
59     m_name.SetCString(m_reg_set->name);
60   }
61 }
62 
63 ValueObjectRegisterSet::~ValueObjectRegisterSet() {}
64 
65 CompilerType ValueObjectRegisterSet::GetCompilerTypeImpl() {
66   return CompilerType();
67 }
68 
69 ConstString ValueObjectRegisterSet::GetTypeName() { return ConstString(); }
70 
71 ConstString ValueObjectRegisterSet::GetQualifiedTypeName() {
72   return ConstString();
73 }
74 
75 size_t ValueObjectRegisterSet::CalculateNumChildren(uint32_t max) {
76   const RegisterSet *reg_set = m_reg_ctx_sp->GetRegisterSet(m_reg_set_idx);
77   if (reg_set) {
78     auto reg_count = reg_set->num_registers;
79     return reg_count <= max ? reg_count : max;
80   }
81   return 0;
82 }
83 
84 llvm::Optional<uint64_t> ValueObjectRegisterSet::GetByteSize() { return 0; }
85 
86 bool ValueObjectRegisterSet::UpdateValue() {
87   m_error.Clear();
88   SetValueDidChange(false);
89   ExecutionContext exe_ctx(GetExecutionContextRef());
90   StackFrame *frame = exe_ctx.GetFramePtr();
91   if (frame == nullptr)
92     m_reg_ctx_sp.reset();
93   else {
94     m_reg_ctx_sp = frame->GetRegisterContext();
95     if (m_reg_ctx_sp) {
96       const RegisterSet *reg_set = m_reg_ctx_sp->GetRegisterSet(m_reg_set_idx);
97       if (reg_set == nullptr)
98         m_reg_ctx_sp.reset();
99       else if (m_reg_set != reg_set) {
100         SetValueDidChange(true);
101         m_name.SetCString(reg_set->name);
102       }
103     }
104   }
105   if (m_reg_ctx_sp) {
106     SetValueIsValid(true);
107   } else {
108     SetValueIsValid(false);
109     m_error.SetErrorToGenericError();
110     m_children.Clear();
111   }
112   return m_error.Success();
113 }
114 
115 ValueObject *ValueObjectRegisterSet::CreateChildAtIndex(
116     size_t idx, bool synthetic_array_member, int32_t synthetic_index) {
117   ValueObject *valobj = nullptr;
118   if (m_reg_ctx_sp && m_reg_set) {
119     const size_t num_children = GetNumChildren();
120     if (idx < num_children)
121       valobj = new ValueObjectRegister(*this, m_reg_ctx_sp,
122                                        m_reg_set->registers[idx]);
123   }
124   return valobj;
125 }
126 
127 lldb::ValueObjectSP
128 ValueObjectRegisterSet::GetChildMemberWithName(ConstString name,
129                                                bool can_create) {
130   ValueObject *valobj = nullptr;
131   if (m_reg_ctx_sp && m_reg_set) {
132     const RegisterInfo *reg_info =
133         m_reg_ctx_sp->GetRegisterInfoByName(name.GetStringRef());
134     if (reg_info != nullptr)
135       valobj = new ValueObjectRegister(*this, m_reg_ctx_sp,
136                                        reg_info->kinds[eRegisterKindLLDB]);
137   }
138   if (valobj)
139     return valobj->GetSP();
140   else
141     return ValueObjectSP();
142 }
143 
144 size_t
145 ValueObjectRegisterSet::GetIndexOfChildWithName(ConstString name) {
146   if (m_reg_ctx_sp && m_reg_set) {
147     const RegisterInfo *reg_info =
148         m_reg_ctx_sp->GetRegisterInfoByName(name.GetStringRef());
149     if (reg_info != nullptr)
150       return reg_info->kinds[eRegisterKindLLDB];
151   }
152   return UINT32_MAX;
153 }
154 
155 #pragma mark -
156 #pragma mark ValueObjectRegister
157 
158 void ValueObjectRegister::ConstructObject(uint32_t reg_num) {
159   const RegisterInfo *reg_info = m_reg_ctx_sp->GetRegisterInfoAtIndex(reg_num);
160   if (reg_info) {
161     m_reg_info = *reg_info;
162     if (reg_info->name)
163       m_name.SetCString(reg_info->name);
164     else if (reg_info->alt_name)
165       m_name.SetCString(reg_info->alt_name);
166   }
167 }
168 
169 ValueObjectRegister::ValueObjectRegister(ValueObject &parent,
170                                          lldb::RegisterContextSP &reg_ctx_sp,
171                                          uint32_t reg_num)
172     : ValueObject(parent), m_reg_ctx_sp(reg_ctx_sp), m_reg_info(),
173       m_reg_value(), m_type_name(), m_compiler_type() {
174   assert(reg_ctx_sp.get());
175   ConstructObject(reg_num);
176 }
177 
178 ValueObjectSP ValueObjectRegister::Create(ExecutionContextScope *exe_scope,
179                                           lldb::RegisterContextSP &reg_ctx_sp,
180                                           uint32_t reg_num) {
181   auto manager_sp = ValueObjectManager::Create();
182   return (new ValueObjectRegister(exe_scope, *manager_sp, reg_ctx_sp, reg_num))
183       ->GetSP();
184 }
185 
186 ValueObjectRegister::ValueObjectRegister(ExecutionContextScope *exe_scope,
187                                          ValueObjectManager &manager,
188                                          lldb::RegisterContextSP &reg_ctx,
189                                          uint32_t reg_num)
190     : ValueObject(exe_scope, manager), m_reg_ctx_sp(reg_ctx), m_reg_info(),
191       m_reg_value(), m_type_name(), m_compiler_type() {
192   assert(reg_ctx);
193   ConstructObject(reg_num);
194 }
195 
196 ValueObjectRegister::~ValueObjectRegister() {}
197 
198 CompilerType ValueObjectRegister::GetCompilerTypeImpl() {
199   if (!m_compiler_type.IsValid()) {
200     ExecutionContext exe_ctx(GetExecutionContextRef());
201     if (auto *target = exe_ctx.GetTargetPtr()) {
202       if (auto *exe_module = target->GetExecutableModulePointer()) {
203         auto type_system_or_err =
204             exe_module->GetTypeSystemForLanguage(eLanguageTypeC);
205         if (auto err = type_system_or_err.takeError()) {
206           LLDB_LOG_ERROR(
207               lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_TYPES),
208               std::move(err), "Unable to get CompilerType from TypeSystem");
209         } else {
210           m_compiler_type =
211               type_system_or_err->GetBuiltinTypeForEncodingAndBitSize(
212                   m_reg_info.encoding, m_reg_info.byte_size * 8);
213         }
214       }
215     }
216   }
217   return m_compiler_type;
218 }
219 
220 ConstString ValueObjectRegister::GetTypeName() {
221   if (m_type_name.IsEmpty())
222     m_type_name = GetCompilerType().GetTypeName();
223   return m_type_name;
224 }
225 
226 size_t ValueObjectRegister::CalculateNumChildren(uint32_t max) {
227   ExecutionContext exe_ctx(GetExecutionContextRef());
228   auto children_count = GetCompilerType().GetNumChildren(true, &exe_ctx);
229   return children_count <= max ? children_count : max;
230 }
231 
232 llvm::Optional<uint64_t> ValueObjectRegister::GetByteSize() {
233   return m_reg_info.byte_size;
234 }
235 
236 bool ValueObjectRegister::UpdateValue() {
237   m_error.Clear();
238   ExecutionContext exe_ctx(GetExecutionContextRef());
239   StackFrame *frame = exe_ctx.GetFramePtr();
240   if (frame == nullptr) {
241     m_reg_ctx_sp.reset();
242     m_reg_value.Clear();
243   }
244 
245   if (m_reg_ctx_sp) {
246     RegisterValue m_old_reg_value(m_reg_value);
247     if (m_reg_ctx_sp->ReadRegister(&m_reg_info, m_reg_value)) {
248       if (m_reg_value.GetData(m_data)) {
249         Process *process = exe_ctx.GetProcessPtr();
250         if (process)
251           m_data.SetAddressByteSize(process->GetAddressByteSize());
252         m_value.SetContext(Value::eContextTypeRegisterInfo,
253                            (void *)&m_reg_info);
254         m_value.SetValueType(Value::eValueTypeHostAddress);
255         m_value.GetScalar() = (uintptr_t)m_data.GetDataStart();
256         SetValueIsValid(true);
257         SetValueDidChange(!(m_old_reg_value == m_reg_value));
258         return true;
259       }
260     }
261   }
262 
263   SetValueIsValid(false);
264   m_error.SetErrorToGenericError();
265   return false;
266 }
267 
268 bool ValueObjectRegister::SetValueFromCString(const char *value_str,
269                                               Status &error) {
270   // The new value will be in the m_data.  Copy that into our register value.
271   error =
272       m_reg_value.SetValueFromString(&m_reg_info, llvm::StringRef(value_str));
273   if (error.Success()) {
274     if (m_reg_ctx_sp->WriteRegister(&m_reg_info, m_reg_value)) {
275       SetNeedsUpdate();
276       return true;
277     } else
278       return false;
279   } else
280     return false;
281 }
282 
283 bool ValueObjectRegister::SetData(DataExtractor &data, Status &error) {
284   error = m_reg_value.SetValueFromData(&m_reg_info, data, 0, false);
285   if (error.Success()) {
286     if (m_reg_ctx_sp->WriteRegister(&m_reg_info, m_reg_value)) {
287       SetNeedsUpdate();
288       return true;
289     } else
290       return false;
291   } else
292     return false;
293 }
294 
295 bool ValueObjectRegister::ResolveValue(Scalar &scalar) {
296   if (UpdateValueIfNeeded(
297           false)) // make sure that you are up to date before returning anything
298     return m_reg_value.GetScalarValue(scalar);
299   return false;
300 }
301 
302 void ValueObjectRegister::GetExpressionPath(Stream &s,
303                                             GetExpressionPathFormat epformat) {
304   s.Printf("$%s", m_reg_info.name);
305 }
306