1 // Copyright 2015 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "src/debug/debug-frames.h"
6
7 #include "src/frames-inl.h"
8
9 namespace v8 {
10 namespace internal {
11
FrameInspector(StandardFrame * frame,int inlined_jsframe_index,Isolate * isolate)12 FrameInspector::FrameInspector(StandardFrame* frame, int inlined_jsframe_index,
13 Isolate* isolate)
14 : frame_(frame), deoptimized_frame_(NULL), isolate_(isolate) {
15 JavaScriptFrame* js_frame =
16 frame->is_java_script() ? javascript_frame() : nullptr;
17 DCHECK(js_frame || frame->is_wasm());
18 has_adapted_arguments_ = js_frame && js_frame->has_adapted_arguments();
19 is_bottommost_ = inlined_jsframe_index == 0;
20 is_optimized_ = frame_->is_optimized();
21 is_interpreted_ = frame_->is_interpreted();
22 // Calculate the deoptimized frame.
23 if (frame->is_optimized()) {
24 DCHECK(js_frame != nullptr);
25 // TODO(turbofan): Revisit once we support deoptimization.
26 if (js_frame->LookupCode()->is_turbofanned() &&
27 js_frame->function()->shared()->asm_function() &&
28 !FLAG_turbo_asm_deoptimization) {
29 is_optimized_ = false;
30 return;
31 }
32
33 deoptimized_frame_ = Deoptimizer::DebuggerInspectableFrame(
34 js_frame, inlined_jsframe_index, isolate);
35 }
36 }
37
~FrameInspector()38 FrameInspector::~FrameInspector() {
39 // Get rid of the calculated deoptimized frame if any.
40 if (deoptimized_frame_ != nullptr) {
41 delete deoptimized_frame_;
42 }
43 }
44
GetParametersCount()45 int FrameInspector::GetParametersCount() {
46 return is_optimized_ ? deoptimized_frame_->parameters_count()
47 : frame_->ComputeParametersCount();
48 }
49
GetScript()50 Handle<Script> FrameInspector::GetScript() {
51 Object* script = is_optimized_
52 ? deoptimized_frame_->GetFunction()->shared()->script()
53 : frame_->script();
54 return handle(Script::cast(script), isolate_);
55 }
56
GetFunction()57 Handle<JSFunction> FrameInspector::GetFunction() {
58 DCHECK(!frame_->is_wasm());
59 return is_optimized_ ? deoptimized_frame_->GetFunction()
60 : handle(javascript_frame()->function(), isolate_);
61 }
62
GetParameter(int index)63 Handle<Object> FrameInspector::GetParameter(int index) {
64 return is_optimized_ ? deoptimized_frame_->GetParameter(index)
65 : handle(frame_->GetParameter(index), isolate_);
66 }
67
GetExpression(int index)68 Handle<Object> FrameInspector::GetExpression(int index) {
69 // TODO(turbofan): Revisit once we support deoptimization.
70 if (frame_->is_java_script() &&
71 javascript_frame()->LookupCode()->is_turbofanned() &&
72 javascript_frame()->function()->shared()->asm_function() &&
73 !FLAG_turbo_asm_deoptimization) {
74 return isolate_->factory()->undefined_value();
75 }
76 return is_optimized_ ? deoptimized_frame_->GetExpression(index)
77 : handle(frame_->GetExpression(index), isolate_);
78 }
79
GetSourcePosition()80 int FrameInspector::GetSourcePosition() {
81 return is_optimized_ ? deoptimized_frame_->GetSourcePosition()
82 : frame_->position();
83 }
84
IsConstructor()85 bool FrameInspector::IsConstructor() {
86 return is_optimized_ && !is_bottommost_
87 ? deoptimized_frame_->HasConstructStub()
88 : frame_->IsConstructor();
89 }
90
GetContext()91 Handle<Object> FrameInspector::GetContext() {
92 return is_optimized_ ? deoptimized_frame_->GetContext()
93 : handle(frame_->context(), isolate_);
94 }
95
96
97 // To inspect all the provided arguments the frame might need to be
98 // replaced with the arguments frame.
SetArgumentsFrame(StandardFrame * frame)99 void FrameInspector::SetArgumentsFrame(StandardFrame* frame) {
100 DCHECK(has_adapted_arguments_);
101 DCHECK(frame->is_arguments_adaptor());
102 frame_ = frame;
103 is_optimized_ = frame_->is_optimized();
104 is_interpreted_ = frame_->is_interpreted();
105 DCHECK(!is_optimized_);
106 }
107
108
109 // Create a plain JSObject which materializes the local scope for the specified
110 // frame.
MaterializeStackLocals(Handle<JSObject> target,Handle<ScopeInfo> scope_info)111 void FrameInspector::MaterializeStackLocals(Handle<JSObject> target,
112 Handle<ScopeInfo> scope_info) {
113 HandleScope scope(isolate_);
114 // First fill all parameters.
115 for (int i = 0; i < scope_info->ParameterCount(); ++i) {
116 // Do not materialize the parameter if it is shadowed by a context local.
117 // TODO(yangguo): check whether this is necessary, now that we materialize
118 // context locals as well.
119 Handle<String> name(scope_info->ParameterName(i));
120 if (ScopeInfo::VariableIsSynthetic(*name)) continue;
121 if (ParameterIsShadowedByContextLocal(scope_info, name)) continue;
122
123 Handle<Object> value =
124 i < GetParametersCount()
125 ? GetParameter(i)
126 : Handle<Object>::cast(isolate_->factory()->undefined_value());
127 DCHECK(!value->IsTheHole(isolate_));
128
129 JSObject::SetOwnPropertyIgnoreAttributes(target, name, value, NONE).Check();
130 }
131
132 // Second fill all stack locals.
133 for (int i = 0; i < scope_info->StackLocalCount(); ++i) {
134 Handle<String> name(scope_info->StackLocalName(i));
135 if (ScopeInfo::VariableIsSynthetic(*name)) continue;
136 Handle<Object> value = GetExpression(scope_info->StackLocalIndex(i));
137 // TODO(yangguo): We convert optimized out values to {undefined} when they
138 // are passed to the debugger. Eventually we should handle them somehow.
139 if (value->IsTheHole(isolate_)) {
140 value = isolate_->factory()->undefined_value();
141 }
142 if (value->IsOptimizedOut(isolate_)) {
143 value = isolate_->factory()->undefined_value();
144 }
145 JSObject::SetOwnPropertyIgnoreAttributes(target, name, value, NONE).Check();
146 }
147 }
148
149
MaterializeStackLocals(Handle<JSObject> target,Handle<JSFunction> function)150 void FrameInspector::MaterializeStackLocals(Handle<JSObject> target,
151 Handle<JSFunction> function) {
152 Handle<SharedFunctionInfo> shared(function->shared());
153 Handle<ScopeInfo> scope_info(shared->scope_info());
154 MaterializeStackLocals(target, scope_info);
155 }
156
157
UpdateStackLocalsFromMaterializedObject(Handle<JSObject> target,Handle<ScopeInfo> scope_info)158 void FrameInspector::UpdateStackLocalsFromMaterializedObject(
159 Handle<JSObject> target, Handle<ScopeInfo> scope_info) {
160 // Optimized frames and wasm frames are not supported. Simply give up.
161 if (is_optimized_ || frame_->is_wasm()) return;
162
163 HandleScope scope(isolate_);
164
165 // Parameters.
166 for (int i = 0; i < scope_info->ParameterCount(); ++i) {
167 // Shadowed parameters were not materialized.
168 Handle<String> name(scope_info->ParameterName(i));
169 if (ScopeInfo::VariableIsSynthetic(*name)) continue;
170 if (ParameterIsShadowedByContextLocal(scope_info, name)) continue;
171
172 DCHECK(!javascript_frame()->GetParameter(i)->IsTheHole(isolate_));
173 Handle<Object> value =
174 Object::GetPropertyOrElement(target, name).ToHandleChecked();
175 javascript_frame()->SetParameterValue(i, *value);
176 }
177
178 // Stack locals.
179 for (int i = 0; i < scope_info->StackLocalCount(); ++i) {
180 Handle<String> name(scope_info->StackLocalName(i));
181 if (ScopeInfo::VariableIsSynthetic(*name)) continue;
182 int index = scope_info->StackLocalIndex(i);
183 if (frame_->GetExpression(index)->IsTheHole(isolate_)) continue;
184 Handle<Object> value =
185 Object::GetPropertyOrElement(target, name).ToHandleChecked();
186 frame_->SetExpression(index, *value);
187 }
188 }
189
190
ParameterIsShadowedByContextLocal(Handle<ScopeInfo> info,Handle<String> parameter_name)191 bool FrameInspector::ParameterIsShadowedByContextLocal(
192 Handle<ScopeInfo> info, Handle<String> parameter_name) {
193 VariableMode mode;
194 InitializationFlag init_flag;
195 MaybeAssignedFlag maybe_assigned_flag;
196 return ScopeInfo::ContextSlotIndex(info, parameter_name, &mode, &init_flag,
197 &maybe_assigned_flag) != -1;
198 }
199
FindSavedContextForFrame(Isolate * isolate,StandardFrame * frame)200 SaveContext* DebugFrameHelper::FindSavedContextForFrame(Isolate* isolate,
201 StandardFrame* frame) {
202 SaveContext* save = isolate->save_context();
203 while (save != NULL && !save->IsBelowFrame(frame)) {
204 save = save->prev();
205 }
206 DCHECK(save != NULL);
207 return save;
208 }
209
FindIndexedNonNativeFrame(StackTraceFrameIterator * it,int index)210 int DebugFrameHelper::FindIndexedNonNativeFrame(StackTraceFrameIterator* it,
211 int index) {
212 int count = -1;
213 for (; !it->done(); it->Advance()) {
214 if (it->is_wasm()) {
215 if (++count == index) return 0;
216 continue;
217 }
218 List<FrameSummary> frames(FLAG_max_inlining_levels + 1);
219 it->javascript_frame()->Summarize(&frames);
220 for (int i = frames.length() - 1; i >= 0; i--) {
221 // Omit functions from native and extension scripts.
222 if (!frames[i].function()->shared()->IsSubjectToDebugging()) continue;
223 if (++count == index) return i;
224 }
225 }
226 return -1;
227 }
228
229
230 } // namespace internal
231 } // namespace v8
232