Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame^] | 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 | |
| 12 | FrameInspector::FrameInspector(JavaScriptFrame* frame, |
| 13 | int inlined_jsframe_index, Isolate* isolate) |
| 14 | : frame_(frame), deoptimized_frame_(NULL), isolate_(isolate) { |
| 15 | has_adapted_arguments_ = frame_->has_adapted_arguments(); |
| 16 | is_bottommost_ = inlined_jsframe_index == 0; |
| 17 | is_optimized_ = frame_->is_optimized(); |
| 18 | // Calculate the deoptimized frame. |
| 19 | if (frame->is_optimized()) { |
| 20 | // TODO(turbofan): Revisit once we support deoptimization. |
| 21 | if (frame->LookupCode()->is_turbofanned() && |
| 22 | frame->function()->shared()->asm_function() && |
| 23 | !FLAG_turbo_asm_deoptimization) { |
| 24 | is_optimized_ = false; |
| 25 | return; |
| 26 | } |
| 27 | |
| 28 | deoptimized_frame_ = Deoptimizer::DebuggerInspectableFrame( |
| 29 | frame, inlined_jsframe_index, isolate); |
| 30 | } |
| 31 | } |
| 32 | |
| 33 | |
| 34 | FrameInspector::~FrameInspector() { |
| 35 | // Get rid of the calculated deoptimized frame if any. |
| 36 | if (deoptimized_frame_ != NULL) { |
| 37 | Deoptimizer::DeleteDebuggerInspectableFrame(deoptimized_frame_, isolate_); |
| 38 | } |
| 39 | } |
| 40 | |
| 41 | |
| 42 | int FrameInspector::GetParametersCount() { |
| 43 | return is_optimized_ ? deoptimized_frame_->parameters_count() |
| 44 | : frame_->ComputeParametersCount(); |
| 45 | } |
| 46 | |
| 47 | |
| 48 | Object* FrameInspector::GetFunction() { |
| 49 | return is_optimized_ ? deoptimized_frame_->GetFunction() : frame_->function(); |
| 50 | } |
| 51 | |
| 52 | |
| 53 | Object* FrameInspector::GetParameter(int index) { |
| 54 | return is_optimized_ ? deoptimized_frame_->GetParameter(index) |
| 55 | : frame_->GetParameter(index); |
| 56 | } |
| 57 | |
| 58 | |
| 59 | Object* FrameInspector::GetExpression(int index) { |
| 60 | // TODO(turbofan): Revisit once we support deoptimization. |
| 61 | if (frame_->LookupCode()->is_turbofanned() && |
| 62 | frame_->function()->shared()->asm_function() && |
| 63 | !FLAG_turbo_asm_deoptimization) { |
| 64 | return isolate_->heap()->undefined_value(); |
| 65 | } |
| 66 | return is_optimized_ ? deoptimized_frame_->GetExpression(index) |
| 67 | : frame_->GetExpression(index); |
| 68 | } |
| 69 | |
| 70 | |
| 71 | int FrameInspector::GetSourcePosition() { |
| 72 | return is_optimized_ ? deoptimized_frame_->GetSourcePosition() |
| 73 | : frame_->LookupCode()->SourcePosition(frame_->pc()); |
| 74 | } |
| 75 | |
| 76 | |
| 77 | bool FrameInspector::IsConstructor() { |
| 78 | return is_optimized_ && !is_bottommost_ |
| 79 | ? deoptimized_frame_->HasConstructStub() |
| 80 | : frame_->IsConstructor(); |
| 81 | } |
| 82 | |
| 83 | |
| 84 | Object* FrameInspector::GetContext() { |
| 85 | return is_optimized_ ? deoptimized_frame_->GetContext() : frame_->context(); |
| 86 | } |
| 87 | |
| 88 | |
| 89 | // To inspect all the provided arguments the frame might need to be |
| 90 | // replaced with the arguments frame. |
| 91 | void FrameInspector::SetArgumentsFrame(JavaScriptFrame* frame) { |
| 92 | DCHECK(has_adapted_arguments_); |
| 93 | frame_ = frame; |
| 94 | is_optimized_ = frame_->is_optimized(); |
| 95 | DCHECK(!is_optimized_); |
| 96 | } |
| 97 | |
| 98 | |
| 99 | // Create a plain JSObject which materializes the local scope for the specified |
| 100 | // frame. |
| 101 | void FrameInspector::MaterializeStackLocals(Handle<JSObject> target, |
| 102 | Handle<ScopeInfo> scope_info) { |
| 103 | HandleScope scope(isolate_); |
| 104 | // First fill all parameters. |
| 105 | for (int i = 0; i < scope_info->ParameterCount(); ++i) { |
| 106 | // Do not materialize the parameter if it is shadowed by a context local. |
| 107 | // TODO(yangguo): check whether this is necessary, now that we materialize |
| 108 | // context locals as well. |
| 109 | Handle<String> name(scope_info->ParameterName(i)); |
| 110 | if (ParameterIsShadowedByContextLocal(scope_info, name)) continue; |
| 111 | |
| 112 | Handle<Object> value(i < GetParametersCount() |
| 113 | ? GetParameter(i) |
| 114 | : isolate_->heap()->undefined_value(), |
| 115 | isolate_); |
| 116 | DCHECK(!value->IsTheHole()); |
| 117 | |
| 118 | JSObject::SetOwnPropertyIgnoreAttributes(target, name, value, NONE).Check(); |
| 119 | } |
| 120 | |
| 121 | // Second fill all stack locals. |
| 122 | for (int i = 0; i < scope_info->StackLocalCount(); ++i) { |
| 123 | if (scope_info->LocalIsSynthetic(i)) continue; |
| 124 | Handle<String> name(scope_info->StackLocalName(i)); |
| 125 | Handle<Object> value(GetExpression(scope_info->StackLocalIndex(i)), |
| 126 | isolate_); |
| 127 | if (value->IsTheHole()) value = isolate_->factory()->undefined_value(); |
| 128 | |
| 129 | JSObject::SetOwnPropertyIgnoreAttributes(target, name, value, NONE).Check(); |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | |
| 134 | void FrameInspector::MaterializeStackLocals(Handle<JSObject> target, |
| 135 | Handle<JSFunction> function) { |
| 136 | Handle<SharedFunctionInfo> shared(function->shared()); |
| 137 | Handle<ScopeInfo> scope_info(shared->scope_info()); |
| 138 | MaterializeStackLocals(target, scope_info); |
| 139 | } |
| 140 | |
| 141 | |
| 142 | void FrameInspector::UpdateStackLocalsFromMaterializedObject( |
| 143 | Handle<JSObject> target, Handle<ScopeInfo> scope_info) { |
| 144 | if (is_optimized_) { |
| 145 | // Optimized frames are not supported. Simply give up. |
| 146 | return; |
| 147 | } |
| 148 | |
| 149 | HandleScope scope(isolate_); |
| 150 | |
| 151 | // Parameters. |
| 152 | for (int i = 0; i < scope_info->ParameterCount(); ++i) { |
| 153 | // Shadowed parameters were not materialized. |
| 154 | Handle<String> name(scope_info->ParameterName(i)); |
| 155 | if (ParameterIsShadowedByContextLocal(scope_info, name)) continue; |
| 156 | |
| 157 | DCHECK(!frame_->GetParameter(i)->IsTheHole()); |
| 158 | Handle<Object> value = |
| 159 | Object::GetPropertyOrElement(target, name).ToHandleChecked(); |
| 160 | frame_->SetParameterValue(i, *value); |
| 161 | } |
| 162 | |
| 163 | // Stack locals. |
| 164 | for (int i = 0; i < scope_info->StackLocalCount(); ++i) { |
| 165 | if (scope_info->LocalIsSynthetic(i)) continue; |
| 166 | int index = scope_info->StackLocalIndex(i); |
| 167 | if (frame_->GetExpression(index)->IsTheHole()) continue; |
| 168 | Handle<Object> value = |
| 169 | Object::GetPropertyOrElement( |
| 170 | target, handle(scope_info->StackLocalName(i), isolate_)) |
| 171 | .ToHandleChecked(); |
| 172 | frame_->SetExpression(index, *value); |
| 173 | } |
| 174 | } |
| 175 | |
| 176 | |
| 177 | bool FrameInspector::ParameterIsShadowedByContextLocal( |
| 178 | Handle<ScopeInfo> info, Handle<String> parameter_name) { |
| 179 | VariableMode mode; |
| 180 | InitializationFlag init_flag; |
| 181 | MaybeAssignedFlag maybe_assigned_flag; |
| 182 | return ScopeInfo::ContextSlotIndex(info, parameter_name, &mode, &init_flag, |
| 183 | &maybe_assigned_flag) != -1; |
| 184 | } |
| 185 | |
| 186 | |
| 187 | SaveContext* DebugFrameHelper::FindSavedContextForFrame( |
| 188 | Isolate* isolate, JavaScriptFrame* frame) { |
| 189 | SaveContext* save = isolate->save_context(); |
| 190 | while (save != NULL && !save->IsBelowFrame(frame)) { |
| 191 | save = save->prev(); |
| 192 | } |
| 193 | DCHECK(save != NULL); |
| 194 | return save; |
| 195 | } |
| 196 | |
| 197 | |
| 198 | int DebugFrameHelper::FindIndexedNonNativeFrame(JavaScriptFrameIterator* it, |
| 199 | int index) { |
| 200 | int count = -1; |
| 201 | for (; !it->done(); it->Advance()) { |
| 202 | List<FrameSummary> frames(FLAG_max_inlining_levels + 1); |
| 203 | it->frame()->Summarize(&frames); |
| 204 | for (int i = frames.length() - 1; i >= 0; i--) { |
| 205 | // Omit functions from native and extension scripts. |
| 206 | if (!frames[i].function()->shared()->IsSubjectToDebugging()) continue; |
| 207 | if (++count == index) return i; |
| 208 | } |
| 209 | } |
| 210 | return -1; |
| 211 | } |
| 212 | |
| 213 | |
| 214 | } // namespace internal |
| 215 | } // namespace v8 |