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// 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_ROOTS_INL_H_
#define V8_ROOTS_ROOTS_INL_H_
#include "src/common/ptr-compr-inl.h"
#include "src/execution/isolate.h"
#include "src/execution/local-isolate.h"
#include "src/handles/handles.h"
#include "src/heap/read-only-heap.h"
#include "src/objects/api-callbacks.h"
#include "src/objects/cell.h"
#include "src/objects/descriptor-array.h"
#include "src/objects/feedback-vector.h"
#include "src/objects/heap-number.h"
#include "src/objects/hole.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"
#include "src/objects/swiss-name-dictionary.h"
#include "src/objects/tagged.h"
#include "src/roots/roots.h"
#include "src/roots/static-roots.h"
#if V8_ENABLE_WEBASSEMBLY
#include "src/wasm/wasm-objects.h"
#endif
namespace v8 {
namespace internal {
V8_INLINE constexpr bool operator<(RootIndex lhs, RootIndex rhs) {
using type = typename std::underlying_type<RootIndex>::type;
return static_cast<type>(lhs) < static_cast<type>(rhs);
}
V8_INLINE RootIndex operator++(RootIndex& index) {
using type = typename std::underlying_type<RootIndex>::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(const Isolate* isolate)
: read_only_roots_(reinterpret_cast<Address*>(
isolate->roots_table().read_only_roots_begin().address())) {}
ReadOnlyRoots::ReadOnlyRoots(LocalIsolate* isolate)
: ReadOnlyRoots(isolate->factory()->read_only_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) \
Tagged<Type> ReadOnlyRoots::name() const { \
DCHECK(CheckType_##name()); \
return unchecked_##name(); \
} \
Tagged<Type> ReadOnlyRoots::unchecked_##name() const { \
return Tagged<Type>::unchecked_cast(object_at(RootIndex::k##CamelName)); \
} \
Handle<Type> ReadOnlyRoots::name##_handle() const { \
DCHECK(CheckType_##name()); \
Address* location = GetLocation(RootIndex::k##CamelName); \
return Handle<Type>(location); \
}
READ_ONLY_ROOT_LIST(ROOT_ACCESSOR)
#undef ROOT_ACCESSOR
Tagged<Boolean> ReadOnlyRoots::boolean_value(bool value) const {
return value ? Tagged<Boolean>(true_value()) : Tagged<Boolean>(false_value());
}
Handle<Boolean> ReadOnlyRoots::boolean_value_handle(bool value) const {
return value ? Handle<Boolean>(true_value_handle())
: Handle<Boolean>(false_value_handle());
}
Address* ReadOnlyRoots::GetLocation(RootIndex root_index) const {
size_t index = static_cast<size_t>(root_index);
DCHECK_LT(index, kEntriesCount);
Address* location = &read_only_roots_[index];
// Filler objects must be created before the free space map is initialized.
// Bootstrapping is able to handle kNullAddress being returned here.
DCHECK_IMPLIES(*location == kNullAddress,
root_index == RootIndex::kFreeSpaceMap);
return location;
}
Address ReadOnlyRoots::first_name_for_protector() const {
return address_at(RootIndex::kFirstNameForProtector);
}
Address ReadOnlyRoots::last_name_for_protector() const {
return address_at(RootIndex::kLastNameForProtector);
}
bool ReadOnlyRoots::IsNameForProtector(Tagged<HeapObject> object) const {
return base::IsInRange(object.ptr(), first_name_for_protector(),
last_name_for_protector());
}
void ReadOnlyRoots::VerifyNameForProtectorsPages() const {
// The symbols and strings that can cause protector invalidation should
// reside on the same page so we can do a fast range check.
CHECK_EQ(Page::FromAddress(first_name_for_protector()),
Page::FromAddress(last_name_for_protector()));
}
Handle<Object> ReadOnlyRoots::handle_at(RootIndex root_index) const {
return Handle<Object>(GetLocation(root_index));
}
Tagged<Object> ReadOnlyRoots::object_at(RootIndex root_index) const {
return Tagged<Object>(address_at(root_index));
}
Address ReadOnlyRoots::address_at(RootIndex root_index) const {
#if V8_STATIC_ROOTS_BOOL
return V8HeapCompressionScheme::DecompressTagged(
V8HeapCompressionScheme::base(),
StaticReadOnlyRootsPointerTable[static_cast<int>(root_index)]);
#else
return *GetLocation(root_index);
#endif
}
bool ReadOnlyRoots::is_initialized(RootIndex root_index) const {
size_t index = static_cast<size_t>(root_index);
DCHECK_LT(index, kEntriesCount);
return read_only_roots_[index] != kNullAddress;
}
} // namespace internal
} // namespace v8
#endif // V8_ROOTS_ROOTS_INL_H_
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