3c74dc9f4d
This patch adds two macros to declare per-type allocators: - JS_DECLARE_ALLOCATOR(TypeName) - JS_DEFINE_ALLOCATOR(TypeName) When used, they add a type-specific CellAllocator that the Heap will delegate allocation requests to. The result of this is that GC objects of the same type always end up within the same HeapBlock, drastically reducing the ability to perform type confusion attacks. It also improves HeapBlock utilization, since each block now has cells sized exactly to the type used within that block. (Previously we only had a handful of block sizes available, and most GC allocations ended up with a large amount of slack in their tails.) There is a small performance hit from this, but I'm sure we can make up for it elsewhere. Note that the old size-based allocators still exist, and we fall back to them for any type that doesn't have its own CellAllocator.
49 lines
1.9 KiB
C++
49 lines
1.9 KiB
C++
/*
|
|
* Copyright (c) 2022, David Tuin <davidot@serenityos.org>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <LibJS/Module.h>
|
|
#include <LibJS/Runtime/DeclarativeEnvironment.h>
|
|
#include <LibJS/Runtime/Environment.h>
|
|
|
|
namespace JS {
|
|
|
|
// 9.1.1.5 Module Environment Records, https://tc39.es/ecma262/#sec-module-environment-records
|
|
class ModuleEnvironment final : public DeclarativeEnvironment {
|
|
JS_ENVIRONMENT(ModuleEnvironment, DeclarativeEnvironment);
|
|
JS_DECLARE_ALLOCATOR(ModuleEnvironment);
|
|
|
|
public:
|
|
// Note: Module Environment Records support all of the declarative Environment Record methods listed
|
|
// in Table 18 and share the same specifications for all of those methods except for
|
|
// GetBindingValue, DeleteBinding, HasThisBinding and GetThisBinding.
|
|
// In addition, module Environment Records support the methods listed in Table 24.
|
|
virtual ThrowCompletionOr<Value> get_binding_value(VM&, DeprecatedFlyString const& name, bool strict) override;
|
|
virtual ThrowCompletionOr<bool> delete_binding(VM&, DeprecatedFlyString const& name) override;
|
|
virtual bool has_this_binding() const final { return true; }
|
|
virtual ThrowCompletionOr<Value> get_this_binding(VM&) const final;
|
|
ThrowCompletionOr<void> create_import_binding(DeprecatedFlyString name, Module* module, DeprecatedFlyString binding_name);
|
|
|
|
private:
|
|
explicit ModuleEnvironment(Environment* outer_environment);
|
|
|
|
virtual void visit_edges(Visitor&) override;
|
|
|
|
struct IndirectBinding {
|
|
DeprecatedFlyString name;
|
|
GCPtr<Module> module;
|
|
DeprecatedFlyString binding_name;
|
|
};
|
|
IndirectBinding const* get_indirect_binding(DeprecatedFlyString const& name) const;
|
|
|
|
virtual Optional<BindingAndIndex> find_binding_and_index(DeprecatedFlyString const& name) const override;
|
|
|
|
// FIXME: Since we always access this via the name this could be a map.
|
|
Vector<IndirectBinding> m_indirect_bindings;
|
|
};
|
|
|
|
}
|