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// Copyright 2015 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/debug/debug-frames.h"
#include "src/frames-inl.h"
namespace v8 {
namespace internal {
FrameInspector::FrameInspector(JavaScriptFrame* frame,
int inlined_jsframe_index, Isolate* isolate)
: frame_(frame), deoptimized_frame_(NULL), isolate_(isolate) {
has_adapted_arguments_ = frame_->has_adapted_arguments();
is_bottommost_ = inlined_jsframe_index == 0;
is_optimized_ = frame_->is_optimized();
// Calculate the deoptimized frame.
if (frame->is_optimized()) {
// TODO(turbofan): Revisit once we support deoptimization.
if (frame->LookupCode()->is_turbofanned() &&
frame->function()->shared()->asm_function() &&
!FLAG_turbo_asm_deoptimization) {
is_optimized_ = false;
return;
}
deoptimized_frame_ = Deoptimizer::DebuggerInspectableFrame(
frame, inlined_jsframe_index, isolate);
}
}
FrameInspector::~FrameInspector() {
// Get rid of the calculated deoptimized frame if any.
if (deoptimized_frame_ != NULL) {
Deoptimizer::DeleteDebuggerInspectableFrame(deoptimized_frame_, isolate_);
}
}
int FrameInspector::GetParametersCount() {
return is_optimized_ ? deoptimized_frame_->parameters_count()
: frame_->ComputeParametersCount();
}
int FrameInspector::expression_count() {
return deoptimized_frame_->expression_count();
}
Object* FrameInspector::GetFunction() {
return is_optimized_ ? deoptimized_frame_->GetFunction() : frame_->function();
}
Object* FrameInspector::GetParameter(int index) {
return is_optimized_ ? deoptimized_frame_->GetParameter(index)
: frame_->GetParameter(index);
}
Object* FrameInspector::GetExpression(int index) {
// TODO(turbofan): Revisit once we support deoptimization.
if (frame_->LookupCode()->is_turbofanned() &&
frame_->function()->shared()->asm_function() &&
!FLAG_turbo_asm_deoptimization) {
return isolate_->heap()->undefined_value();
}
return is_optimized_ ? deoptimized_frame_->GetExpression(index)
: frame_->GetExpression(index);
}
int FrameInspector::GetSourcePosition() {
return is_optimized_ ? deoptimized_frame_->GetSourcePosition()
: frame_->LookupCode()->SourcePosition(frame_->pc());
}
bool FrameInspector::IsConstructor() {
return is_optimized_ && !is_bottommost_
? deoptimized_frame_->HasConstructStub()
: frame_->IsConstructor();
}
Object* FrameInspector::GetContext() {
return is_optimized_ ? deoptimized_frame_->GetContext() : frame_->context();
}
// To inspect all the provided arguments the frame might need to be
// replaced with the arguments frame.
void FrameInspector::SetArgumentsFrame(JavaScriptFrame* frame) {
DCHECK(has_adapted_arguments_);
frame_ = frame;
is_optimized_ = frame_->is_optimized();
DCHECK(!is_optimized_);
}
// Create a plain JSObject which materializes the local scope for the specified
// frame.
void FrameInspector::MaterializeStackLocals(Handle<JSObject> target,
Handle<ScopeInfo> scope_info) {
HandleScope scope(isolate_);
// First fill all parameters.
for (int i = 0; i < scope_info->ParameterCount(); ++i) {
// Do not materialize the parameter if it is shadowed by a context local.
Handle<String> name(scope_info->ParameterName(i));
if (ParameterIsShadowedByContextLocal(scope_info, name)) continue;
Handle<Object> value(i < GetParametersCount()
? GetParameter(i)
: isolate_->heap()->undefined_value(),
isolate_);
DCHECK(!value->IsTheHole());
JSObject::SetOwnPropertyIgnoreAttributes(target, name, value, NONE).Check();
}
// Second fill all stack locals.
for (int i = 0; i < scope_info->StackLocalCount(); ++i) {
if (scope_info->LocalIsSynthetic(i)) continue;
Handle<String> name(scope_info->StackLocalName(i));
Handle<Object> value(GetExpression(scope_info->StackLocalIndex(i)),
isolate_);
if (value->IsTheHole()) value = isolate_->factory()->undefined_value();
JSObject::SetOwnPropertyIgnoreAttributes(target, name, value, NONE).Check();
}
}
void FrameInspector::MaterializeStackLocals(Handle<JSObject> target,
Handle<JSFunction> function) {
Handle<SharedFunctionInfo> shared(function->shared());
Handle<ScopeInfo> scope_info(shared->scope_info());
MaterializeStackLocals(target, scope_info);
}
void FrameInspector::UpdateStackLocalsFromMaterializedObject(
Handle<JSObject> target, Handle<ScopeInfo> scope_info) {
if (is_optimized_) {
// Optimized frames are not supported. Simply give up.
return;
}
HandleScope scope(isolate_);
// Parameters.
for (int i = 0; i < scope_info->ParameterCount(); ++i) {
// Shadowed parameters were not materialized.
Handle<String> name(scope_info->ParameterName(i));
if (ParameterIsShadowedByContextLocal(scope_info, name)) continue;
DCHECK(!frame_->GetParameter(i)->IsTheHole());
Handle<Object> value =
Object::GetPropertyOrElement(target, name).ToHandleChecked();
frame_->SetParameterValue(i, *value);
}
// Stack locals.
for (int i = 0; i < scope_info->StackLocalCount(); ++i) {
if (scope_info->LocalIsSynthetic(i)) continue;
int index = scope_info->StackLocalIndex(i);
if (frame_->GetExpression(index)->IsTheHole()) continue;
Handle<Object> value =
Object::GetPropertyOrElement(
target, handle(scope_info->StackLocalName(i), isolate_))
.ToHandleChecked();
frame_->SetExpression(index, *value);
}
}
bool FrameInspector::ParameterIsShadowedByContextLocal(
Handle<ScopeInfo> info, Handle<String> parameter_name) {
VariableMode mode;
InitializationFlag init_flag;
MaybeAssignedFlag maybe_assigned_flag;
return ScopeInfo::ContextSlotIndex(info, parameter_name, &mode, &init_flag,
&maybe_assigned_flag) != -1;
}
SaveContext* DebugFrameHelper::FindSavedContextForFrame(
Isolate* isolate, JavaScriptFrame* frame) {
SaveContext* save = isolate->save_context();
while (save != NULL && !save->IsBelowFrame(frame)) {
save = save->prev();
}
DCHECK(save != NULL);
return save;
}
int DebugFrameHelper::FindIndexedNonNativeFrame(JavaScriptFrameIterator* it,
int index) {
int count = -1;
for (; !it->done(); it->Advance()) {
List<FrameSummary> frames(FLAG_max_inlining_levels + 1);
it->frame()->Summarize(&frames);
for (int i = frames.length() - 1; i >= 0; i--) {
// Omit functions from native and extension scripts.
if (!frames[i].function()->shared()->IsSubjectToDebugging()) continue;
if (++count == index) return i;
}
}
return -1;
}
} // namespace internal
} // namespace v8
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