v8/src/roots-inl.h
Maciej Goszczycki b672d08990 Reland "[heap] Set read-only space's and its pages' heap_ to null."
Seems like the CodeBuilder CL actually caused this.

This is a reland of 964edc251f

Original change's description:
> [heap] Set read-only space's and its pages' heap_ to null.
>
> Various small changes are required to enable this.
>
> HeapObject::GetReadOnlyRoots no longer uses the Space's heap when
> possible (see comment in ReadOnlyHeap::GetReadOnlyRoots definition).
> This requires that ReadOnlyRoots be construct-able using a raw pointer
> to the read-only space's roots array.
>
> Global read-only heap state is now cleared by tests where appropriate
> and extra DCHECKs in ReadOnlyHeap::SetUp should make catching future
> issues easier.
>
> String padding is now always cleared just before read-only space is
> sealed when not deserializing.
>
> Change-Id: I7d1db1c11567be5df06ff7066f3a699125f8b372
> Bug: v8:7464
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1535830
> Commit-Queue: Maciej Goszczycki <goszczycki@google.com>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Dan Elphick <delphick@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#61188}

Bug: v8:7464
Change-Id: If75bbd16c2e2af5b80cd60811dfd7866f8be8309
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1599186
Commit-Queue: Maciej Goszczycki <goszczycki@google.com>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61323}
2019-05-08 11:24:43 +00:00

116 lines
4.1 KiB
C++

// Copyright 2018 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_ROOTS_INL_H_
#define V8_ROOTS_INL_H_
#include "src/roots.h"
#include "src/feedback-vector.h"
#include "src/handles.h"
#include "src/heap/read-only-heap.h"
#include "src/isolate.h"
#include "src/objects/api-callbacks.h"
#include "src/objects/descriptor-array.h"
#include "src/objects/heap-number.h"
#include "src/objects/literal-objects.h"
#include "src/objects/map.h"
#include "src/objects/oddball.h"
#include "src/objects/property-array.h"
#include "src/objects/property-cell.h"
#include "src/objects/scope-info.h"
#include "src/objects/slots.h"
#include "src/objects/string.h"
namespace v8 {
namespace internal {
V8_INLINE constexpr bool operator<(RootIndex lhs, RootIndex rhs) {
typedef typename std::underlying_type<RootIndex>::type type;
return static_cast<type>(lhs) < static_cast<type>(rhs);
}
V8_INLINE RootIndex operator++(RootIndex& index) {
typedef typename std::underlying_type<RootIndex>::type type;
index = static_cast<RootIndex>(static_cast<type>(index) + 1);
return index;
}
bool RootsTable::IsRootHandleLocation(Address* handle_location,
RootIndex* index) const {
FullObjectSlot location(handle_location);
FullObjectSlot first_root(&roots_[0]);
FullObjectSlot last_root(&roots_[kEntriesCount]);
if (location >= last_root) return false;
if (location < first_root) return false;
*index = static_cast<RootIndex>(location - first_root);
return true;
}
template <typename T>
bool RootsTable::IsRootHandle(Handle<T> handle, RootIndex* index) const {
// This can't use handle.location() because it is called from places
// where handle dereferencing is disallowed. Comparing the handle's
// location against the root handle list is safe though.
Address* handle_location = reinterpret_cast<Address*>(handle.address());
return IsRootHandleLocation(handle_location, index);
}
ReadOnlyRoots::ReadOnlyRoots(Heap* heap)
: ReadOnlyRoots(Isolate::FromHeap(heap)) {}
ReadOnlyRoots::ReadOnlyRoots(Isolate* isolate)
: read_only_roots_(reinterpret_cast<Address*>(
isolate->roots_table().read_only_roots_begin().address())) {}
ReadOnlyRoots::ReadOnlyRoots(Address* ro_roots) : read_only_roots_(ro_roots) {}
// We use unchecked_cast below because we trust our read-only roots to
// have the right type, and to avoid the heavy #includes that would be
// required for checked casts.
#define ROOT_ACCESSOR(Type, name, CamelName) \
Type ReadOnlyRoots::name() const { \
DCHECK(CheckType(RootIndex::k##CamelName)); \
return Type::unchecked_cast(Object(at(RootIndex::k##CamelName))); \
} \
Handle<Type> ReadOnlyRoots::name##_handle() const { \
DCHECK(CheckType(RootIndex::k##CamelName)); \
return Handle<Type>(&at(RootIndex::k##CamelName)); \
}
READ_ONLY_ROOT_LIST(ROOT_ACCESSOR)
#undef ROOT_ACCESSOR
Map ReadOnlyRoots::MapForFixedTypedArray(ExternalArrayType array_type) {
RootIndex root_index = RootsTable::RootIndexForFixedTypedArray(array_type);
DCHECK(CheckType(root_index));
return Map::unchecked_cast(Object(at(root_index)));
}
Map ReadOnlyRoots::MapForFixedTypedArray(ElementsKind elements_kind) {
RootIndex root_index = RootsTable::RootIndexForFixedTypedArray(elements_kind);
DCHECK(CheckType(root_index));
return Map::unchecked_cast(Object(at(root_index)));
}
FixedTypedArrayBase ReadOnlyRoots::EmptyFixedTypedArrayForTypedArray(
ElementsKind elements_kind) {
RootIndex root_index =
RootsTable::RootIndexForEmptyFixedTypedArray(elements_kind);
DCHECK(CheckType(root_index));
return FixedTypedArrayBase::unchecked_cast(Object(at(root_index)));
}
Address& ReadOnlyRoots::at(RootIndex root_index) const {
size_t index = static_cast<size_t>(root_index);
DCHECK_LT(index, kEntriesCount);
return read_only_roots_[index];
}
} // namespace internal
} // namespace v8
#endif // V8_ROOTS_INL_H_