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// Copyright 2013 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.
#ifndef V8_ALLOCATION_SITE_SCOPES_H_
#define V8_ALLOCATION_SITE_SCOPES_H_
#include "src/handles.h"
#include "src/objects.h"
namespace v8 {
namespace internal {
// AllocationSiteContext is the base class for walking and copying a nested
// boilerplate with AllocationSite and AllocationMemento support.
class AllocationSiteContext {
public:
explicit AllocationSiteContext(Isolate* isolate) {
isolate_ = isolate;
}
Handle<AllocationSite> top() { return top_; }
Handle<AllocationSite> current() { return current_; }
bool ShouldCreateMemento(Handle<JSObject> object) { return false; }
Isolate* isolate() { return isolate_; }
protected:
void update_current_site(AllocationSite* site) {
*(current_.location()) = site;
}
void InitializeTraversal(Handle<AllocationSite> site) {
top_ = site;
current_ = Handle<AllocationSite>::New(*top_, isolate());
}
private:
Isolate* isolate_;
Handle<AllocationSite> top_;
Handle<AllocationSite> current_;
};
// AllocationSiteCreationContext aids in the creation of AllocationSites to
// accompany object literals.
class AllocationSiteCreationContext : public AllocationSiteContext {
public:
explicit AllocationSiteCreationContext(Isolate* isolate)
: AllocationSiteContext(isolate) { }
Handle<AllocationSite> EnterNewScope();
void ExitScope(Handle<AllocationSite> site, Handle<JSObject> object);
};
// AllocationSiteUsageContext aids in the creation of AllocationMementos placed
// behind some/all components of a copied object literal.
class AllocationSiteUsageContext : public AllocationSiteContext {
public:
AllocationSiteUsageContext(Isolate* isolate, Handle<AllocationSite> site,
bool activated)
: AllocationSiteContext(isolate),
top_site_(site),
activated_(activated) { }
inline Handle<AllocationSite> EnterNewScope() {
if (top().is_null()) {
InitializeTraversal(top_site_);
} else {
// Advance current site
Object* nested_site = current()->nested_site();
// Something is wrong if we advance to the end of the list here.
update_current_site(AllocationSite::cast(nested_site));
}
return Handle<AllocationSite>(*current(), isolate());
}
inline void ExitScope(Handle<AllocationSite> scope_site,
Handle<JSObject> object) {
// This assert ensures that we are pointing at the right sub-object in a
// recursive walk of a nested literal.
DCHECK(object.is_null() || *object == scope_site->transition_info());
}
bool ShouldCreateMemento(Handle<JSObject> object);
private:
Handle<AllocationSite> top_site_;
bool activated_;
};
} // namespace internal
} // namespace v8
#endif // V8_ALLOCATION_SITE_SCOPES_H_
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