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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/compilation-dependencies.h"
#include "src/factory.h"
#include "src/handles-inl.h"
#include "src/isolate.h"
#include "src/objects-inl.h"
#include "src/zone.h"
namespace v8 {
namespace internal {
DependentCode* CompilationDependencies::Get(Handle<Object> object) {
if (object->IsMap()) {
return Handle<Map>::cast(object)->dependent_code();
} else if (object->IsPropertyCell()) {
return Handle<PropertyCell>::cast(object)->dependent_code();
} else if (object->IsAllocationSite()) {
return Handle<AllocationSite>::cast(object)->dependent_code();
}
UNREACHABLE();
return nullptr;
}
void CompilationDependencies::Set(Handle<Object> object,
Handle<DependentCode> dep) {
if (object->IsMap()) {
Handle<Map>::cast(object)->set_dependent_code(*dep);
} else if (object->IsPropertyCell()) {
Handle<PropertyCell>::cast(object)->set_dependent_code(*dep);
} else if (object->IsAllocationSite()) {
Handle<AllocationSite>::cast(object)->set_dependent_code(*dep);
} else {
UNREACHABLE();
}
}
void CompilationDependencies::Insert(DependentCode::DependencyGroup group,
Handle<HeapObject> object) {
if (groups_[group] == nullptr) {
groups_[group] = new (zone_) ZoneList<Handle<HeapObject>>(2, zone_);
}
groups_[group]->Add(object, zone_);
if (object_wrapper_.is_null()) {
// Allocate the wrapper if necessary.
object_wrapper_ =
isolate_->factory()->NewForeign(reinterpret_cast<Address>(this));
}
// Get the old dependent code list.
Handle<DependentCode> old_dependent_code =
Handle<DependentCode>(Get(object), isolate_);
Handle<DependentCode> new_dependent_code =
DependentCode::InsertCompilationDependencies(old_dependent_code, group,
object_wrapper_);
// Set the new dependent code list if the head of the list changed.
if (!new_dependent_code.is_identical_to(old_dependent_code)) {
Set(object, new_dependent_code);
}
}
void CompilationDependencies::Commit(Handle<Code> code) {
if (IsEmpty()) return;
DCHECK(!object_wrapper_.is_null());
Handle<WeakCell> cell = Code::WeakCellFor(code);
AllowDeferredHandleDereference get_wrapper;
for (int i = 0; i < DependentCode::kGroupCount; i++) {
ZoneList<Handle<HeapObject>>* group_objects = groups_[i];
if (group_objects == nullptr) continue;
DependentCode::DependencyGroup group =
static_cast<DependentCode::DependencyGroup>(i);
for (int j = 0; j < group_objects->length(); j++) {
DependentCode* dependent_code = Get(group_objects->at(j));
dependent_code->UpdateToFinishedCode(group, *object_wrapper_, *cell);
}
groups_[i] = nullptr; // Zone-allocated, no need to delete.
}
}
void CompilationDependencies::Rollback() {
if (IsEmpty()) return;
AllowDeferredHandleDereference get_wrapper;
// Unregister from all dependent maps if not yet committed.
for (int i = 0; i < DependentCode::kGroupCount; i++) {
ZoneList<Handle<HeapObject>>* group_objects = groups_[i];
if (group_objects == nullptr) continue;
DependentCode::DependencyGroup group =
static_cast<DependentCode::DependencyGroup>(i);
for (int j = 0; j < group_objects->length(); j++) {
DependentCode* dependent_code = Get(group_objects->at(j));
dependent_code->RemoveCompilationDependencies(group, *object_wrapper_);
}
groups_[i] = nullptr; // Zone-allocated, no need to delete.
}
}
void CompilationDependencies::AssumeMapNotDeprecated(Handle<Map> map) {
DCHECK(!map->is_deprecated());
// Do nothing if the map cannot be deprecated.
if (map->CanBeDeprecated()) {
Insert(DependentCode::kTransitionGroup, map);
}
}
void CompilationDependencies::AssumeMapStable(Handle<Map> map) {
DCHECK(map->is_stable());
// Do nothing if the map cannot transition.
if (map->CanTransition()) {
Insert(DependentCode::kPrototypeCheckGroup, map);
}
}
void CompilationDependencies::AssumePrototypeMapsStable(
Handle<Map> map, MaybeHandle<JSReceiver> prototype) {
for (PrototypeIterator i(map); !i.IsAtEnd(); i.Advance()) {
Handle<JSReceiver> const current =
PrototypeIterator::GetCurrent<JSReceiver>(i);
AssumeMapStable(handle(current->map()));
Handle<JSReceiver> last;
if (prototype.ToHandle(&last) && last.is_identical_to(current)) {
break;
}
}
}
void CompilationDependencies::AssumeTransitionStable(
Handle<AllocationSite> site) {
// Do nothing if the object doesn't have any useful element transitions left.
ElementsKind kind =
site->SitePointsToLiteral()
? JSObject::cast(site->transition_info())->GetElementsKind()
: site->GetElementsKind();
if (AllocationSite::GetMode(kind) == TRACK_ALLOCATION_SITE) {
Insert(DependentCode::kAllocationSiteTransitionChangedGroup, site);
}
}
} // namespace internal
} // namespace v8
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