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Commit 35f3e9d0 authored by Marja Hölttä's avatar Marja Hölttä Committed by Commit Bot
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Reland: [objects.h splitting] Move Map and related classes. 

Previous version was https://chromium-review.googlesource.com/502808

BUG=v8:5402

Change-Id: If327f4d7884577b7e5e6159372bf28a80cd21e51
Reviewed-on: https://chromium-review.googlesource.com/506073
Commit-Queue: Marja Hölttä <marja@chromium.org>
Reviewed-by: 's avatarBenedikt Meurer <bmeurer@chromium.org>
Reviewed-by: 's avatarMichael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45369}
parent 51f95dea
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Showing with 961 additions and 886 deletions
BUILD.gn
View file @ 35f3e9d0
......@@ -688,6 +688,8 @@ action("postmortem-metadata") {
sources = [
"src/objects.h",
"src/objects-inl.h",
"src/objects/map.h",
"src/objects/map-inl.h",
]
outputs = [
......@@ -1737,6 +1739,8 @@ v8_source_set("v8_base") {
"src/objects/intl-objects.h",
"src/objects/literal-objects.cc",
"src/objects/literal-objects.h",
"src/objects/map-inl.h",
"src/objects/map.h",
"src/objects/module-info.h",
"src/objects/object-macros-undef.h",
"src/objects/object-macros.h",
......
src/ast/ast.cc
View file @ 35f3e9d0
......@@ -19,6 +19,7 @@
#include "src/elements.h"
#include "src/objects-inl.h"
#include "src/objects/literal-objects.h"
#include "src/objects/map.h"
#include "src/property-details.h"
#include "src/property.h"
#include "src/string-stream.h"
......@@ -1030,6 +1031,24 @@ void Expression::RecordToBooleanTypeFeedback(TypeFeedbackOracle* oracle) {
}
}
void SmallMapList::AddMapIfMissing(Handle<Map> map, Zone* zone) {
if (!Map::TryUpdate(map).ToHandle(&map)) return;
for (int i = 0; i < length(); ++i) {
if (at(i).is_identical_to(map)) return;
}
Add(map, zone);
}
void SmallMapList::FilterForPossibleTransitions(Map* root_map) {
for (int i = list_.length() - 1; i >= 0; i--) {
if (at(i)->FindRootMap() != root_map) {
list_.RemoveElement(list_.at(i));
}
}
}
Handle<Map> SmallMapList::at(int i) const { return Handle<Map>(list_.at(i)); }
SmallMapList* Expression::GetReceiverTypes() {
switch (node_type()) {
#define NODE_LIST(V) \
......
src/ast/ast.h
View file @ 35f3e9d0
......@@ -252,29 +252,15 @@ class SmallMapList final {
bool is_empty() const { return list_.is_empty(); }
int length() const { return list_.length(); }
void AddMapIfMissing(Handle<Map> map, Zone* zone) {
if (!Map::TryUpdate(map).ToHandle(&map)) return;
for (int i = 0; i < length(); ++i) {
if (at(i).is_identical_to(map)) return;
}
Add(map, zone);
}
void AddMapIfMissing(Handle<Map> map, Zone* zone);
void FilterForPossibleTransitions(Map* root_map) {
for (int i = list_.length() - 1; i >= 0; i--) {
if (at(i)->FindRootMap() != root_map) {
list_.RemoveElement(list_.at(i));
}
}
}
void FilterForPossibleTransitions(Map* root_map);
void Add(Handle<Map> handle, Zone* zone) {
list_.Add(handle.location(), zone);
}
Handle<Map> at(int i) const {
return Handle<Map>(list_.at(i));
}
Handle<Map> at(int i) const;
Handle<Map> first() const { return at(0); }
Handle<Map> last() const { return at(length() - 1); }
......
src/compilation-dependencies.h
View file @ 35f3e9d0
......@@ -7,6 +7,7 @@
#include "src/handles.h"
#include "src/objects.h"
#include "src/objects/map.h"
namespace v8 {
namespace internal {
......
src/compiler.cc
View file @ 35f3e9d0
......@@ -29,6 +29,7 @@
#include "src/isolate-inl.h"
#include "src/log-inl.h"
#include "src/messages.h"
#include "src/objects/map.h"
#include "src/parsing/parsing.h"
#include "src/parsing/rewriter.h"
#include "src/parsing/scanner-character-streams.h"
......
src/compiler/access-info.h
View file @ 35f3e9d0
......@@ -10,6 +10,7 @@
#include "src/field-index.h"
#include "src/machine-type.h"
#include "src/objects.h"
#include "src/objects/map.h"
#include "src/zone/zone-containers.h"
namespace v8 {
......
src/compiler/js-native-context-specialization.h
View file @ 35f3e9d0
......@@ -8,7 +8,7 @@
#include "src/base/flags.h"
#include "src/compiler/graph-reducer.h"
#include "src/deoptimize-reason.h"
#include "src/feedback-vector.h"
#include "src/objects/map.h"
namespace v8 {
namespace internal {
......@@ -16,6 +16,7 @@ namespace internal {
// Forward declarations.
class CompilationDependencies;
class Factory;
class FeedbackNexus;
namespace compiler {
......
src/compiler/simplified-operator.cc
View file @ 35f3e9d0
......@@ -8,6 +8,7 @@
#include "src/compiler/opcodes.h"
#include "src/compiler/operator.h"
#include "src/compiler/types.h"
#include "src/objects/map.h"
namespace v8 {
namespace internal {
......
src/contexts-inl.h
View file @ 35f3e9d0
......@@ -9,6 +9,7 @@
#include "src/heap/heap.h"
#include "src/objects-inl.h"
#include "src/objects/dictionary.h"
#include "src/objects/map-inl.h"
#include "src/objects/regexp-match-info.h"
namespace v8 {
......
src/crankshaft/hydrogen.cc
View file @ 35f3e9d0
......@@ -42,6 +42,7 @@
// GetRootConstructor
#include "src/ic/ic-inl.h"
#include "src/isolate-inl.h"
#include "src/objects/map.h"
#include "src/runtime/runtime.h"
#if V8_TARGET_ARCH_IA32
......
src/feedback-vector.h
View file @ 35f3e9d0
......@@ -9,7 +9,7 @@
#include "src/base/logging.h"
#include "src/elements-kind.h"
#include "src/objects.h"
#include "src/objects/map.h"
#include "src/type-hints.h"
#include "src/zone/zone-containers.h"
......
src/field-type.h
View file @ 35f3e9d0
......@@ -7,6 +7,7 @@
#include "src/ast/ast-types.h"
#include "src/objects.h"
#include "src/objects/map.h"
#include "src/ostreams.h"
namespace v8 {
......
src/heap/spaces.h
View file @ 35f3e9d0
......@@ -21,6 +21,7 @@
#include "src/heap/marking.h"
#include "src/list.h"
#include "src/objects.h"
#include "src/objects/map.h"
#include "src/utils.h"
namespace v8 {
......
src/ic/ic.h
View file @ 35f3e9d0
......@@ -10,6 +10,7 @@
#include "src/ic/ic-state.h"
#include "src/macro-assembler.h"
#include "src/messages.h"
#include "src/objects/map.h"
namespace v8 {
namespace internal {
......
src/lookup.h
View file @ 35f3e9d0
......@@ -10,6 +10,7 @@
#include "src/isolate.h"
#include "src/objects.h"
#include "src/objects/descriptor-array.h"
#include "src/objects/map.h"
namespace v8 {
namespace internal {
......
src/map-updater.h
View file @ 35f3e9d0
......@@ -2,13 +2,14 @@
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_MAP_RECONFIGURER_H_
#define V8_MAP_RECONFIGURER_H_
#ifndef V8_MAP_UPDATER_H_
#define V8_MAP_UPDATER_H_
#include "src/elements-kind.h"
#include "src/field-type.h"
#include "src/globals.h"
#include "src/handles.h"
#include "src/objects.h"
#include "src/objects/map.h"
#include "src/property-details.h"
namespace v8 {
......@@ -180,4 +181,4 @@ class MapUpdater {
} // namespace internal
} // namespace v8
#endif // V8_MAP_RECONFIGURER_H_
#endif // V8_MAP_UPDATER_H_
src/objects-inl.h
View file @ 35f3e9d0
......@@ -523,24 +523,6 @@ bool HeapObject::IsNormalizedMapCache() const {
return NormalizedMapCache::IsNormalizedMapCache(this);
}
int NormalizedMapCache::GetIndex(Handle<Map> map) {
return map->Hash() % NormalizedMapCache::kEntries;
}
bool NormalizedMapCache::IsNormalizedMapCache(const HeapObject* obj) {
if (!obj->IsFixedArray()) return false;
if (FixedArray::cast(obj)->length() != NormalizedMapCache::kEntries) {
return false;
}
#ifdef VERIFY_HEAP
if (FLAG_verify_heap) {
reinterpret_cast<NormalizedMapCache*>(const_cast<HeapObject*>(obj))
->NormalizedMapCacheVerify();
}
#endif
return true;
}
bool HeapObject::IsCompilationCacheTable() const { return IsHashTable(); }
bool HeapObject::IsCodeCacheHashTable() const { return IsHashTable(); }
......@@ -679,7 +661,6 @@ CAST_ACCESSOR(JSWeakCollection)
CAST_ACCESSOR(JSWeakMap)
CAST_ACCESSOR(JSWeakSet)
CAST_ACCESSOR(LayoutDescriptor)
CAST_ACCESSOR(Map)
CAST_ACCESSOR(ModuleInfo)
CAST_ACCESSOR(Name)
CAST_ACCESSOR(NameDictionary)
......@@ -1995,18 +1976,6 @@ InterceptorInfo* JSObject::GetNamedInterceptor() {
return map()->GetNamedInterceptor();
}
InterceptorInfo* Map::GetNamedInterceptor() {
DCHECK(has_named_interceptor());
FunctionTemplateInfo* info = GetFunctionTemplateInfo();
return InterceptorInfo::cast(info->named_property_handler());
}
InterceptorInfo* Map::GetIndexedInterceptor() {
DCHECK(has_indexed_interceptor());
FunctionTemplateInfo* info = GetFunctionTemplateInfo();
return InterceptorInfo::cast(info->indexed_property_handler());
}
double Oddball::to_number_raw() const {
return READ_DOUBLE_FIELD(this, kToNumberRawOffset);
}
......
src/objects.cc
View file @ 35f3e9d0
......@@ -58,6 +58,7 @@
#include "src/objects/code-cache-inl.h"
#include "src/objects/compilation-cache-inl.h"
#include "src/objects/frame-array-inl.h"
#include "src/objects/map.h"
#include "src/property-descriptor.h"
#include "src/prototype.h"
#include "src/regexp/jsregexp.h"
......
src/objects.h
View file @ 35f3e9d0
......@@ -3085,35 +3085,6 @@ template <SearchMode search_mode, typename T>
inline int Search(T* array, Name* name, int valid_entries = 0,
int* out_insertion_index = NULL);
// The cache for maps used by normalized (dictionary mode) objects.
// Such maps do not have property descriptors, so a typical program
// needs very limited number of distinct normalized maps.
class NormalizedMapCache: public FixedArray {
public:
static Handle<NormalizedMapCache> New(Isolate* isolate);
MUST_USE_RESULT MaybeHandle<Map> Get(Handle<Map> fast_map,
PropertyNormalizationMode mode);
void Set(Handle<Map> fast_map, Handle<Map> normalized_map);
void Clear();
DECLARE_CAST(NormalizedMapCache)
static inline bool IsNormalizedMapCache(const HeapObject* obj);
DECLARE_VERIFIER(NormalizedMapCache)
private:
static const int kEntries = 64;
static inline int GetIndex(Handle<Map> map);
// The following declarations hide base class methods.
Object* get(int index);
void set(int index, Object* value);
};
// HandlerTable is a fixed array containing entries for exception handlers in
// the code object it is associated with. The tables comes in two flavors:
// 1) Based on ranges: Used for unoptimized code. Contains one entry per
......@@ -4441,787 +4412,8 @@ class DependentCode: public FixedArray {
STATIC_ASSERT(kGroupCount <= GroupField::kMax + 1);
};
class PrototypeInfo;
typedef std::vector<Handle<Map>> MapHandles;
// All heap objects have a Map that describes their structure.
// A Map contains information about:
// - Size information about the object
// - How to iterate over an object (for garbage collection)
class Map: public HeapObject {
public:
// Instance size.
// Size in bytes or kVariableSizeSentinel if instances do not have
// a fixed size.
inline int instance_size();
inline void set_instance_size(int value);
// Only to clear an unused byte, remove once byte is used.
inline void clear_unused();
// [inobject_properties_or_constructor_function_index]: Provides access
// to the inobject properties in case of JSObject maps, or the constructor
// function index in case of primitive maps.
inline int inobject_properties_or_constructor_function_index();
inline void set_inobject_properties_or_constructor_function_index(int value);
// Count of properties allocated in the object (JSObject only).
inline int GetInObjectProperties();
inline void SetInObjectProperties(int value);
// Index of the constructor function in the native context (primitives only),
// or the special sentinel value to indicate that there is no object wrapper
// for the primitive (i.e. in case of null or undefined).
static const int kNoConstructorFunctionIndex = 0;
inline int GetConstructorFunctionIndex();
inline void SetConstructorFunctionIndex(int value);
static MaybeHandle<JSFunction> GetConstructorFunction(
Handle<Map> map, Handle<Context> native_context);
// Retrieve interceptors.
inline InterceptorInfo* GetNamedInterceptor();
inline InterceptorInfo* GetIndexedInterceptor();
// Instance type.
inline InstanceType instance_type();
inline void set_instance_type(InstanceType value);
// Tells how many unused property fields are available in the
// instance (only used for JSObject in fast mode).
inline int unused_property_fields();
inline void set_unused_property_fields(int value);
// Bit field.
inline byte bit_field() const;
inline void set_bit_field(byte value);
// Bit field 2.
inline byte bit_field2() const;
inline void set_bit_field2(byte value);
// Bit field 3.
inline uint32_t bit_field3() const;
inline void set_bit_field3(uint32_t bits);
class EnumLengthBits: public BitField<int,
0, kDescriptorIndexBitCount> {}; // NOLINT
class NumberOfOwnDescriptorsBits: public BitField<int,
kDescriptorIndexBitCount, kDescriptorIndexBitCount> {}; // NOLINT
STATIC_ASSERT(kDescriptorIndexBitCount + kDescriptorIndexBitCount == 20);
class DictionaryMap : public BitField<bool, 20, 1> {};
class OwnsDescriptors : public BitField<bool, 21, 1> {};
class HasHiddenPrototype : public BitField<bool, 22, 1> {};
class Deprecated : public BitField<bool, 23, 1> {};
class IsUnstable : public BitField<bool, 24, 1> {};
class IsMigrationTarget : public BitField<bool, 25, 1> {};
class ImmutablePrototype : public BitField<bool, 26, 1> {};
class NewTargetIsBase : public BitField<bool, 27, 1> {};
// Bit 28 is free.
// Keep this bit field at the very end for better code in
// Builtins::kJSConstructStubGeneric stub.
// This counter is used for in-object slack tracking.
// The in-object slack tracking is considered enabled when the counter is
// non zero. The counter only has a valid count for initial maps. For
// transitioned maps only kNoSlackTracking has a meaning, namely that inobject
// slack tracking already finished for the transition tree. Any other value
// indicates that either inobject slack tracking is still in progress, or that
// the map isn't part of the transition tree anymore.
class ConstructionCounter : public BitField<int, 29, 3> {};
static const int kSlackTrackingCounterStart = 7;
static const int kSlackTrackingCounterEnd = 1;
static const int kNoSlackTracking = 0;
STATIC_ASSERT(kSlackTrackingCounterStart <= ConstructionCounter::kMax);
// Inobject slack tracking is the way to reclaim unused inobject space.
//
// The instance size is initially determined by adding some slack to
// expected_nof_properties (to allow for a few extra properties added
// after the constructor). There is no guarantee that the extra space
// will not be wasted.
//
// Here is the algorithm to reclaim the unused inobject space:
// - Detect the first constructor call for this JSFunction.
// When it happens enter the "in progress" state: initialize construction
// counter in the initial_map.
// - While the tracking is in progress initialize unused properties of a new
// object with one_pointer_filler_map instead of undefined_value (the "used"
// part is initialized with undefined_value as usual). This way they can
// be resized quickly and safely.
// - Once enough objects have been created compute the 'slack'
// (traverse the map transition tree starting from the
// initial_map and find the lowest value of unused_property_fields).
// - Traverse the transition tree again and decrease the instance size
// of every map. Existing objects will resize automatically (they are
// filled with one_pointer_filler_map). All further allocations will
// use the adjusted instance size.
// - SharedFunctionInfo's expected_nof_properties left unmodified since
// allocations made using different closures could actually create different
// kind of objects (see prototype inheritance pattern).
//
// Important: inobject slack tracking is not attempted during the snapshot
// creation.
static const int kGenerousAllocationCount =
kSlackTrackingCounterStart - kSlackTrackingCounterEnd + 1;
// Starts the tracking by initializing object constructions countdown counter.
void StartInobjectSlackTracking();
// True if the object constructions countdown counter is a range
// [kSlackTrackingCounterEnd, kSlackTrackingCounterStart].
inline bool IsInobjectSlackTrackingInProgress();
// Does the tracking step.
inline void InobjectSlackTrackingStep();
// Completes inobject slack tracking for the transition tree starting at this
// initial map.
void CompleteInobjectSlackTracking();
// Tells whether the object in the prototype property will be used
// for instances created from this function. If the prototype
// property is set to a value that is not a JSObject, the prototype
// property will not be used to create instances of the function.
// See ECMA-262, 13.2.2.
inline void set_non_instance_prototype(bool value);
inline bool has_non_instance_prototype();
// Tells whether the instance has a [[Construct]] internal method.
// This property is implemented according to ES6, section 7.2.4.
inline void set_is_constructor(bool value);
inline bool is_constructor() const;
// Tells whether the instance with this map has a hidden prototype.
inline void set_has_hidden_prototype(bool value);
inline bool has_hidden_prototype() const;
// Records and queries whether the instance has a named interceptor.
inline void set_has_named_interceptor();
inline bool has_named_interceptor();
// Records and queries whether the instance has an indexed interceptor.
inline void set_has_indexed_interceptor();
inline bool has_indexed_interceptor();
// Tells whether the instance is undetectable.
// An undetectable object is a special class of JSObject: 'typeof' operator
// returns undefined, ToBoolean returns false. Otherwise it behaves like
// a normal JS object. It is useful for implementing undetectable
// document.all in Firefox & Safari.
// See https://bugzilla.mozilla.org/show_bug.cgi?id=248549.
inline void set_is_undetectable();
inline bool is_undetectable();
// Tells whether the instance has a [[Call]] internal method.
// This property is implemented according to ES6, section 7.2.3.
inline void set_is_callable();
inline bool is_callable() const;
inline void set_new_target_is_base(bool value);
inline bool new_target_is_base();
inline void set_is_extensible(bool value);
inline bool is_extensible();
inline void set_is_prototype_map(bool value);
inline bool is_prototype_map() const;
inline void set_elements_kind(ElementsKind elements_kind);
inline ElementsKind elements_kind();
// Tells whether the instance has fast elements that are only Smis.
inline bool has_fast_smi_elements();
// Tells whether the instance has fast elements.
inline bool has_fast_object_elements();
inline bool has_fast_smi_or_object_elements();
inline bool has_fast_double_elements();
inline bool has_fast_elements();
inline bool has_sloppy_arguments_elements();
inline bool has_fast_sloppy_arguments_elements();
inline bool has_fast_string_wrapper_elements();
inline bool has_fixed_typed_array_elements();
inline bool has_dictionary_elements();
static bool IsValidElementsTransition(ElementsKind from_kind,
ElementsKind to_kind);
// Returns true if the current map doesn't have DICTIONARY_ELEMENTS but if a
// map with DICTIONARY_ELEMENTS was found in the prototype chain.
bool DictionaryElementsInPrototypeChainOnly();
inline Map* ElementsTransitionMap();
inline FixedArrayBase* GetInitialElements();
// [raw_transitions]: Provides access to the transitions storage field.
// Don't call set_raw_transitions() directly to overwrite transitions, use
// the TransitionArray::ReplaceTransitions() wrapper instead!
DECL_ACCESSORS(raw_transitions, Object)
// [prototype_info]: Per-prototype metadata. Aliased with transitions
// (which prototype maps don't have).
DECL_ACCESSORS(prototype_info, Object)
// PrototypeInfo is created lazily using this helper (which installs it on
// the given prototype's map).
static Handle<PrototypeInfo> GetOrCreatePrototypeInfo(
Handle<JSObject> prototype, Isolate* isolate);
static Handle<PrototypeInfo> GetOrCreatePrototypeInfo(
Handle<Map> prototype_map, Isolate* isolate);
inline bool should_be_fast_prototype_map() const;
static void SetShouldBeFastPrototypeMap(Handle<Map> map, bool value,
Isolate* isolate);
// [prototype chain validity cell]: Associated with a prototype object,
// stored in that object's map's PrototypeInfo, indicates that prototype
// chains through this object are currently valid. The cell will be
// invalidated and replaced when the prototype chain changes.
static Handle<Cell> GetOrCreatePrototypeChainValidityCell(Handle<Map> map,
Isolate* isolate);
static const int kPrototypeChainValid = 0;
static const int kPrototypeChainInvalid = 1;
// Return the map of the root of object's prototype chain.
Map* GetPrototypeChainRootMap(Isolate* isolate);
// Returns a WeakCell object containing given prototype. The cell is cached
// in PrototypeInfo which is created lazily.
static Handle<WeakCell> GetOrCreatePrototypeWeakCell(
Handle<JSObject> prototype, Isolate* isolate);
Map* FindRootMap();
Map* FindFieldOwner(int descriptor);
inline int GetInObjectPropertyOffset(int index);
int NumberOfFields();
// Returns true if transition to the given map requires special
// synchronization with the concurrent marker.
bool TransitionRequiresSynchronizationWithGC(Map* target);
// Returns true if transition to the given map removes a tagged in-object
// field.
bool TransitionRemovesTaggedField(Map* target);
// Returns true if transition to the given map replaces a tagged in-object
// field with an untagged in-object field.
bool TransitionChangesTaggedFieldToUntaggedField(Map* target);
// TODO(ishell): candidate with JSObject::MigrateToMap().
bool InstancesNeedRewriting(Map* target);
bool InstancesNeedRewriting(Map* target, int target_number_of_fields,
int target_inobject, int target_unused,
int* old_number_of_fields);
// TODO(ishell): moveit!
static Handle<Map> GeneralizeAllFields(Handle<Map> map);
MUST_USE_RESULT static Handle<FieldType> GeneralizeFieldType(
Representation rep1, Handle<FieldType> type1, Representation rep2,
Handle<FieldType> type2, Isolate* isolate);
static void GeneralizeField(Handle<Map> map, int modify_index,
PropertyConstness new_constness,
Representation new_representation,
Handle<FieldType> new_field_type);
static Handle<Map> ReconfigureProperty(Handle<Map> map, int modify_index,
PropertyKind new_kind,
PropertyAttributes new_attributes,
Representation new_representation,
Handle<FieldType> new_field_type);
static Handle<Map> ReconfigureElementsKind(Handle<Map> map,
ElementsKind new_elements_kind);
static Handle<Map> PrepareForDataProperty(Handle<Map> old_map,
int descriptor_number,
PropertyConstness constness,
Handle<Object> value);
static Handle<Map> Normalize(Handle<Map> map, PropertyNormalizationMode mode,
const char* reason);
// Tells whether the map is used for JSObjects in dictionary mode (ie
// normalized objects, ie objects for which HasFastProperties returns false).
// A map can never be used for both dictionary mode and fast mode JSObjects.
// False by default and for HeapObjects that are not JSObjects.
inline void set_dictionary_map(bool value);
inline bool is_dictionary_map();
// Tells whether the instance needs security checks when accessing its
// properties.
inline void set_is_access_check_needed(bool access_check_needed);
inline bool is_access_check_needed();
// Returns true if map has a non-empty stub code cache.
inline bool has_code_cache();
// [prototype]: implicit prototype object.
DECL_ACCESSORS(prototype, Object)
// TODO(jkummerow): make set_prototype private.
static void SetPrototype(
Handle<Map> map, Handle<Object> prototype,
PrototypeOptimizationMode proto_mode = FAST_PROTOTYPE);
// [constructor]: points back to the function or FunctionTemplateInfo
// responsible for this map.
// The field overlaps with the back pointer. All maps in a transition tree
// have the same constructor, so maps with back pointers can walk the
// back pointer chain until they find the map holding their constructor.
// Returns null_value if there's neither a constructor function nor a
// FunctionTemplateInfo available.
DECL_ACCESSORS(constructor_or_backpointer, Object)
inline Object* GetConstructor() const;
inline FunctionTemplateInfo* GetFunctionTemplateInfo() const;
inline void SetConstructor(Object* constructor,
WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
// [back pointer]: points back to the parent map from which a transition
// leads to this map. The field overlaps with the constructor (see above).
inline Object* GetBackPointer();
inline void SetBackPointer(Object* value,
WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
// [instance descriptors]: describes the object.
DECL_ACCESSORS(instance_descriptors, DescriptorArray)
// [layout descriptor]: describes the object layout.
DECL_ACCESSORS(layout_descriptor, LayoutDescriptor)
// |layout descriptor| accessor which can be used from GC.
inline LayoutDescriptor* layout_descriptor_gc_safe();
inline bool HasFastPointerLayout() const;
// |layout descriptor| accessor that is safe to call even when
// FLAG_unbox_double_fields is disabled (in this case Map does not contain
// |layout_descriptor| field at all).
inline LayoutDescriptor* GetLayoutDescriptor();
inline void UpdateDescriptors(DescriptorArray* descriptors,
LayoutDescriptor* layout_descriptor);
inline void InitializeDescriptors(DescriptorArray* descriptors,
LayoutDescriptor* layout_descriptor);
// [stub cache]: contains stubs compiled for this map.
DECL_ACCESSORS(code_cache, FixedArray)
// [dependent code]: list of optimized codes that weakly embed this map.
DECL_ACCESSORS(dependent_code, DependentCode)
// [weak cell cache]: cache that stores a weak cell pointing to this map.
DECL_ACCESSORS(weak_cell_cache, Object)
inline PropertyDetails GetLastDescriptorDetails();
inline int LastAdded();
inline int NumberOfOwnDescriptors();
inline void SetNumberOfOwnDescriptors(int number);
inline Cell* RetrieveDescriptorsPointer();
// Checks whether all properties are stored either in the map or on the object
// (inobject, properties, or elements backing store), requiring no special
// checks.
bool OnlyHasSimpleProperties();
inline int EnumLength();
inline void SetEnumLength(int length);
inline bool owns_descriptors();
inline void set_owns_descriptors(bool owns_descriptors);
inline void mark_unstable();
inline bool is_stable();
inline void set_migration_target(bool value);
inline bool is_migration_target();
inline void set_immutable_proto(bool value);
inline bool is_immutable_proto();
inline void set_construction_counter(int value);
inline int construction_counter();
inline void deprecate();
inline bool is_deprecated();
inline bool CanBeDeprecated();
// Returns a non-deprecated version of the input. If the input was not
// deprecated, it is directly returned. Otherwise, the non-deprecated version
// is found by re-transitioning from the root of the transition tree using the
// descriptor array of the map. Returns MaybeHandle<Map>() if no updated map
// is found.
static MaybeHandle<Map> TryUpdate(Handle<Map> map) WARN_UNUSED_RESULT;
// Returns a non-deprecated version of the input. This method may deprecate
// existing maps along the way if encodings conflict. Not for use while
// gathering type feedback. Use TryUpdate in those cases instead.
static Handle<Map> Update(Handle<Map> map);
static inline Handle<Map> CopyInitialMap(Handle<Map> map);
static Handle<Map> CopyInitialMap(Handle<Map> map, int instance_size,
int in_object_properties,
int unused_property_fields);
static Handle<Map> CopyInitialMapNormalized(
Handle<Map> map,
PropertyNormalizationMode mode = CLEAR_INOBJECT_PROPERTIES);
static Handle<Map> CopyDropDescriptors(Handle<Map> map);
static Handle<Map> CopyInsertDescriptor(Handle<Map> map,
Descriptor* descriptor,
TransitionFlag flag);
static Handle<Object> WrapFieldType(Handle<FieldType> type);
static FieldType* UnwrapFieldType(Object* wrapped_type);
MUST_USE_RESULT static MaybeHandle<Map> CopyWithField(
Handle<Map> map, Handle<Name> name, Handle<FieldType> type,
PropertyAttributes attributes, PropertyConstness constness,
Representation representation, TransitionFlag flag);
MUST_USE_RESULT static MaybeHandle<Map> CopyWithConstant(
Handle<Map> map,
Handle<Name> name,
Handle<Object> constant,
PropertyAttributes attributes,
TransitionFlag flag);
// Returns a new map with all transitions dropped from the given map and
// the ElementsKind set.
static Handle<Map> TransitionElementsTo(Handle<Map> map,
ElementsKind to_kind);
static Handle<Map> AsElementsKind(Handle<Map> map, ElementsKind kind);
static Handle<Map> CopyAsElementsKind(Handle<Map> map,
ElementsKind kind,
TransitionFlag flag);
static Handle<Map> AsLanguageMode(Handle<Map> initial_map,
LanguageMode language_mode,
FunctionKind kind);
static Handle<Map> CopyForPreventExtensions(Handle<Map> map,
PropertyAttributes attrs_to_add,
Handle<Symbol> transition_marker,
const char* reason);
static Handle<Map> FixProxy(Handle<Map> map, InstanceType type, int size);
// Maximal number of fast properties. Used to restrict the number of map
// transitions to avoid an explosion in the number of maps for objects used as
// dictionaries.
inline bool TooManyFastProperties(StoreFromKeyed store_mode);
static Handle<Map> TransitionToDataProperty(Handle<Map> map,
Handle<Name> name,
Handle<Object> value,
PropertyAttributes attributes,
PropertyConstness constness,
StoreFromKeyed store_mode);
static Handle<Map> TransitionToAccessorProperty(
Isolate* isolate, Handle<Map> map, Handle<Name> name, int descriptor,
Handle<Object> getter, Handle<Object> setter,
PropertyAttributes attributes);
static Handle<Map> ReconfigureExistingProperty(Handle<Map> map,
int descriptor,
PropertyKind kind,
PropertyAttributes attributes);
inline void AppendDescriptor(Descriptor* desc);
// Returns a copy of the map, prepared for inserting into the transition
// tree (if the |map| owns descriptors then the new one will share
// descriptors with |map|).
static Handle<Map> CopyForTransition(Handle<Map> map, const char* reason);
// Returns a copy of the map, with all transitions dropped from the
// instance descriptors.
static Handle<Map> Copy(Handle<Map> map, const char* reason);
static Handle<Map> Create(Isolate* isolate, int inobject_properties);
// Returns the next free property index (only valid for FAST MODE).
int NextFreePropertyIndex();
// Returns the number of properties described in instance_descriptors
// filtering out properties with the specified attributes.
int NumberOfDescribedProperties(DescriptorFlag which = OWN_DESCRIPTORS,
PropertyFilter filter = ALL_PROPERTIES);
DECLARE_CAST(Map)
// Code cache operations.
// Clears the code cache.
inline void ClearCodeCache(Heap* heap);
// Update code cache.
static void UpdateCodeCache(Handle<Map> map,
Handle<Name> name,
Handle<Code> code);
// Extend the descriptor array of the map with the list of descriptors.
// In case of duplicates, the latest descriptor is used.
static void AppendCallbackDescriptors(Handle<Map> map,
Handle<Object> descriptors);
static inline int SlackForArraySize(int old_size, int size_limit);
static void EnsureDescriptorSlack(Handle<Map> map, int slack);
Code* LookupInCodeCache(Name* name, Code::Flags code);
static Handle<Map> GetObjectCreateMap(Handle<HeapObject> prototype);
// Computes a hash value for this map, to be used in HashTables and such.
int Hash();
// Returns the transitioned map for this map with the most generic
// elements_kind that's found in |candidates|, or |nullptr| if no match is
// found at all.
Map* FindElementsKindTransitionedMap(MapHandles const& candidates);
inline bool CanTransition();
inline bool IsBooleanMap();
inline bool IsPrimitiveMap();
inline bool IsJSReceiverMap();
inline bool IsJSObjectMap();
inline bool IsJSArrayMap();
inline bool IsJSFunctionMap();
inline bool IsStringMap();
inline bool IsJSProxyMap();
inline bool IsModuleMap();
inline bool IsJSGlobalProxyMap();
inline bool IsJSGlobalObjectMap();
inline bool IsJSTypedArrayMap();
inline bool IsJSDataViewMap();
inline bool IsSpecialReceiverMap();
inline bool CanOmitMapChecks();
static void AddDependentCode(Handle<Map> map,
DependentCode::DependencyGroup group,
Handle<Code> code);
bool IsMapInArrayPrototypeChain();
static Handle<WeakCell> WeakCellForMap(Handle<Map> map);
// Dispatched behavior.
DECLARE_PRINTER(Map)
DECLARE_VERIFIER(Map)
#ifdef VERIFY_HEAP
void DictionaryMapVerify();
void VerifyOmittedMapChecks();
#endif
inline int visitor_id();
inline void set_visitor_id(int visitor_id);
static Handle<Map> TransitionToPrototype(Handle<Map> map,
Handle<Object> prototype,
PrototypeOptimizationMode mode);
static Handle<Map> TransitionToImmutableProto(Handle<Map> map);
static const int kMaxPreAllocatedPropertyFields = 255;
// Layout description.
static const int kInstanceSizesOffset = HeapObject::kHeaderSize;
static const int kInstanceAttributesOffset = kInstanceSizesOffset + kIntSize;
static const int kBitField3Offset = kInstanceAttributesOffset + kIntSize;
static const int kPrototypeOffset = kBitField3Offset + kPointerSize;
static const int kConstructorOrBackPointerOffset =
kPrototypeOffset + kPointerSize;
// When there is only one transition, it is stored directly in this field;
// otherwise a transition array is used.
// For prototype maps, this slot is used to store this map's PrototypeInfo
// struct.
static const int kTransitionsOrPrototypeInfoOffset =
kConstructorOrBackPointerOffset + kPointerSize;
static const int kDescriptorsOffset =
kTransitionsOrPrototypeInfoOffset + kPointerSize;
#if V8_DOUBLE_FIELDS_UNBOXING
static const int kLayoutDescriptorOffset = kDescriptorsOffset + kPointerSize;
static const int kCodeCacheOffset = kLayoutDescriptorOffset + kPointerSize;
#else
static const int kLayoutDescriptorOffset = 1; // Must not be ever accessed.
static const int kCodeCacheOffset = kDescriptorsOffset + kPointerSize;
#endif
static const int kDependentCodeOffset = kCodeCacheOffset + kPointerSize;
static const int kWeakCellCacheOffset = kDependentCodeOffset + kPointerSize;
static const int kSize = kWeakCellCacheOffset + kPointerSize;
// Layout of pointer fields. Heap iteration code relies on them
// being continuously allocated.
static const int kPointerFieldsBeginOffset = Map::kPrototypeOffset;
static const int kPointerFieldsEndOffset = kSize;
// Byte offsets within kInstanceSizesOffset.
static const int kInstanceSizeOffset = kInstanceSizesOffset + 0;
static const int kInObjectPropertiesOrConstructorFunctionIndexByte = 1;
static const int kInObjectPropertiesOrConstructorFunctionIndexOffset =
kInstanceSizesOffset + kInObjectPropertiesOrConstructorFunctionIndexByte;
// Note there is one byte available for use here.
static const int kUnusedByte = 2;
static const int kUnusedOffset = kInstanceSizesOffset + kUnusedByte;
static const int kVisitorIdByte = 3;
static const int kVisitorIdOffset = kInstanceSizesOffset + kVisitorIdByte;
// Byte offsets within kInstanceAttributesOffset attributes.
#if V8_TARGET_LITTLE_ENDIAN
// Order instance type and bit field together such that they can be loaded
// together as a 16-bit word with instance type in the lower 8 bits regardless
// of endianess. Also provide endian-independent offset to that 16-bit word.
static const int kInstanceTypeOffset = kInstanceAttributesOffset + 0;
static const int kBitFieldOffset = kInstanceAttributesOffset + 1;
#else
static const int kBitFieldOffset = kInstanceAttributesOffset + 0;
static const int kInstanceTypeOffset = kInstanceAttributesOffset + 1;
#endif
static const int kInstanceTypeAndBitFieldOffset =
kInstanceAttributesOffset + 0;
static const int kBitField2Offset = kInstanceAttributesOffset + 2;
static const int kUnusedPropertyFieldsOffset = kInstanceAttributesOffset + 3;
STATIC_ASSERT(kInstanceTypeAndBitFieldOffset ==
Internals::kMapInstanceTypeAndBitFieldOffset);
// Bit positions for bit field.
static const int kHasNonInstancePrototype = 0;
static const int kIsCallable = 1;
static const int kHasNamedInterceptor = 2;
static const int kHasIndexedInterceptor = 3;
static const int kIsUndetectable = 4;
static const int kIsAccessCheckNeeded = 5;
static const int kIsConstructor = 6;
// Bit 7 is free.
// Bit positions for bit field 2
static const int kIsExtensible = 0;
// Bit 1 is free.
class IsPrototypeMapBits : public BitField<bool, 2, 1> {};
class ElementsKindBits: public BitField<ElementsKind, 3, 5> {};
// Derived values from bit field 2
static const int8_t kMaximumBitField2FastElementValue = static_cast<int8_t>(
(FAST_ELEMENTS + 1) << Map::ElementsKindBits::kShift) - 1;
static const int8_t kMaximumBitField2FastSmiElementValue =
static_cast<int8_t>((FAST_SMI_ELEMENTS + 1) <<
Map::ElementsKindBits::kShift) - 1;
static const int8_t kMaximumBitField2FastHoleyElementValue =
static_cast<int8_t>((FAST_HOLEY_ELEMENTS + 1) <<
Map::ElementsKindBits::kShift) - 1;
static const int8_t kMaximumBitField2FastHoleySmiElementValue =
static_cast<int8_t>((FAST_HOLEY_SMI_ELEMENTS + 1) <<
Map::ElementsKindBits::kShift) - 1;
typedef FixedBodyDescriptor<kPointerFieldsBeginOffset,
kPointerFieldsEndOffset,
kSize> BodyDescriptor;
// Compares this map to another to see if they describe equivalent objects.
// If |mode| is set to CLEAR_INOBJECT_PROPERTIES, |other| is treated as if
// it had exactly zero inobject properties.
// The "shared" flags of both this map and |other| are ignored.
bool EquivalentToForNormalization(Map* other, PropertyNormalizationMode mode);
// Returns true if given field is unboxed double.
inline bool IsUnboxedDoubleField(FieldIndex index);
#if V8_TRACE_MAPS
static void TraceTransition(const char* what, Map* from, Map* to, Name* name);
static void TraceAllTransitions(Map* map);
#endif
static inline Handle<Map> AddMissingTransitionsForTesting(
Handle<Map> split_map, Handle<DescriptorArray> descriptors,
Handle<LayoutDescriptor> full_layout_descriptor);
// Fires when the layout of an object with a leaf map changes.
// This includes adding transitions to the leaf map or changing
// the descriptor array.
inline void NotifyLeafMapLayoutChange();
private:
// Returns the map that this (root) map transitions to if its elements_kind
// is changed to |elements_kind|, or |nullptr| if no such map is cached yet.
Map* LookupElementsTransitionMap(ElementsKind elements_kind);
// Tries to replay property transitions starting from this (root) map using
// the descriptor array of the |map|. The |root_map| is expected to have
// proper elements kind and therefore elements kinds transitions are not
// taken by this function. Returns |nullptr| if matching transition map is
// not found.
Map* TryReplayPropertyTransitions(Map* map);
static void ConnectTransition(Handle<Map> parent, Handle<Map> child,
Handle<Name> name, SimpleTransitionFlag flag);
bool EquivalentToForTransition(Map* other);
static Handle<Map> RawCopy(Handle<Map> map, int instance_size);
static Handle<Map> ShareDescriptor(Handle<Map> map,
Handle<DescriptorArray> descriptors,
Descriptor* descriptor);
static Handle<Map> AddMissingTransitions(
Handle<Map> map, Handle<DescriptorArray> descriptors,
Handle<LayoutDescriptor> full_layout_descriptor);
static void InstallDescriptors(
Handle<Map> parent_map, Handle<Map> child_map, int new_descriptor,
Handle<DescriptorArray> descriptors,
Handle<LayoutDescriptor> full_layout_descriptor);
static Handle<Map> CopyAddDescriptor(Handle<Map> map,
Descriptor* descriptor,
TransitionFlag flag);
static Handle<Map> CopyReplaceDescriptors(
Handle<Map> map, Handle<DescriptorArray> descriptors,
Handle<LayoutDescriptor> layout_descriptor, TransitionFlag flag,
MaybeHandle<Name> maybe_name, const char* reason,
SimpleTransitionFlag simple_flag);
static Handle<Map> CopyReplaceDescriptor(Handle<Map> map,
Handle<DescriptorArray> descriptors,
Descriptor* descriptor,
int index,
TransitionFlag flag);
static MUST_USE_RESULT MaybeHandle<Map> TryReconfigureExistingProperty(
Handle<Map> map, int descriptor, PropertyKind kind,
PropertyAttributes attributes, const char** reason);
static Handle<Map> CopyNormalized(Handle<Map> map,
PropertyNormalizationMode mode);
// TODO(ishell): Move to MapUpdater.
static Handle<Map> CopyGeneralizeAllFields(
Handle<Map> map, ElementsKind elements_kind, int modify_index,
PropertyKind kind, PropertyAttributes attributes, const char* reason);
void DeprecateTransitionTree();
void ReplaceDescriptors(DescriptorArray* new_descriptors,
LayoutDescriptor* new_layout_descriptor);
// Update field type of the given descriptor to new representation and new
// type. The type must be prepared for storing in descriptor array:
// it must be either a simple type or a map wrapped in a weak cell.
void UpdateFieldType(int descriptor_number, Handle<Name> name,
PropertyConstness new_constness,
Representation new_representation,
Handle<Object> new_wrapped_type);
// TODO(ishell): Move to MapUpdater.
void PrintReconfiguration(FILE* file, int modify_index, PropertyKind kind,
PropertyAttributes attributes);
// TODO(ishell): Move to MapUpdater.
void PrintGeneralization(FILE* file, const char* reason, int modify_index,
int split, int descriptors, bool constant_to_field,
Representation old_representation,
Representation new_representation,
MaybeHandle<FieldType> old_field_type,
MaybeHandle<Object> old_value,
MaybeHandle<FieldType> new_field_type,
MaybeHandle<Object> new_value);
static const int kFastPropertiesSoftLimit = 12;
static const int kMaxFastProperties = 128;
friend class MapUpdater;
DISALLOW_IMPLICIT_CONSTRUCTORS(Map);
};
// An abstract superclass, a marker class really, for simple structure classes.
// It doesn't carry much functionality but allows struct classes to be
// identified in the type system.
......
src/objects/map-inl.h 0 → 100644
View file @ 35f3e9d0
// Copyright 2017 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_OBJECTS_MAP_INL_H_
#define V8_OBJECTS_MAP_INL_H_
#include "src/objects/map.h"
// Has to be the last include (doesn't have include guards):
#include "src/objects/object-macros.h"
namespace v8 {
namespace internal {
CAST_ACCESSOR(Map)
InterceptorInfo* Map::GetNamedInterceptor() {
DCHECK(has_named_interceptor());
FunctionTemplateInfo* info = GetFunctionTemplateInfo();
return InterceptorInfo::cast(info->named_property_handler());
}
InterceptorInfo* Map::GetIndexedInterceptor() {
DCHECK(has_indexed_interceptor());
FunctionTemplateInfo* info = GetFunctionTemplateInfo();
return InterceptorInfo::cast(info->indexed_property_handler());
}
int NormalizedMapCache::GetIndex(Handle<Map> map) {
return map->Hash() % NormalizedMapCache::kEntries;
}
bool NormalizedMapCache::IsNormalizedMapCache(const HeapObject* obj) {
if (!obj->IsFixedArray()) return false;
if (FixedArray::cast(obj)->length() != NormalizedMapCache::kEntries) {
return false;
}
#ifdef VERIFY_HEAP
if (FLAG_verify_heap) {
reinterpret_cast<NormalizedMapCache*>(const_cast<HeapObject*>(obj))
->NormalizedMapCacheVerify();
}
#endif
return true;
}
} // namespace internal
} // namespace v8
#include "src/objects/object-macros-undef.h"
#endif // V8_OBJECTS_MAP_INL_H_
src/objects/map.h 0 → 100644
View file @ 35f3e9d0
// Copyright 2017 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_OBJECTS_MAP_H_
#define V8_OBJECTS_MAP_H_
#include "src/objects.h"
#include "src/globals.h"
// Has to be the last include (doesn't have include guards):
#include "src/objects/object-macros.h"
namespace v8 {
namespace internal {
typedef std::vector<Handle<Map>> MapHandles;
// All heap objects have a Map that describes their structure.
// A Map contains information about:
// - Size information about the object
// - How to iterate over an object (for garbage collection)
class Map : public HeapObject {
public:
// Instance size.
// Size in bytes or kVariableSizeSentinel if instances do not have
// a fixed size.
inline int instance_size();
inline void set_instance_size(int value);
// Only to clear an unused byte, remove once byte is used.
inline void clear_unused();
// [inobject_properties_or_constructor_function_index]: Provides access
// to the inobject properties in case of JSObject maps, or the constructor
// function index in case of primitive maps.
inline int inobject_properties_or_constructor_function_index();
inline void set_inobject_properties_or_constructor_function_index(int value);
// Count of properties allocated in the object (JSObject only).
inline int GetInObjectProperties();
inline void SetInObjectProperties(int value);
// Index of the constructor function in the native context (primitives only),
// or the special sentinel value to indicate that there is no object wrapper
// for the primitive (i.e. in case of null or undefined).
static const int kNoConstructorFunctionIndex = 0;
inline int GetConstructorFunctionIndex();
inline void SetConstructorFunctionIndex(int value);
static MaybeHandle<JSFunction> GetConstructorFunction(
Handle<Map> map, Handle<Context> native_context);
// Retrieve interceptors.
inline InterceptorInfo* GetNamedInterceptor();
inline InterceptorInfo* GetIndexedInterceptor();
// Instance type.
inline InstanceType instance_type();
inline void set_instance_type(InstanceType value);
// Tells how many unused property fields are available in the
// instance (only used for JSObject in fast mode).
inline int unused_property_fields();
inline void set_unused_property_fields(int value);
// Bit field.
inline byte bit_field() const;
inline void set_bit_field(byte value);
// Bit field 2.
inline byte bit_field2() const;
inline void set_bit_field2(byte value);
// Bit field 3.
inline uint32_t bit_field3() const;
inline void set_bit_field3(uint32_t bits);
class EnumLengthBits : public BitField<int, 0, kDescriptorIndexBitCount> {
}; // NOLINT
class NumberOfOwnDescriptorsBits
: public BitField<int, kDescriptorIndexBitCount,
kDescriptorIndexBitCount> {}; // NOLINT
STATIC_ASSERT(kDescriptorIndexBitCount + kDescriptorIndexBitCount == 20);
class DictionaryMap : public BitField<bool, 20, 1> {};
class OwnsDescriptors : public BitField<bool, 21, 1> {};
class HasHiddenPrototype : public BitField<bool, 22, 1> {};
class Deprecated : public BitField<bool, 23, 1> {};
class IsUnstable : public BitField<bool, 24, 1> {};
class IsMigrationTarget : public BitField<bool, 25, 1> {};
class ImmutablePrototype : public BitField<bool, 26, 1> {};
class NewTargetIsBase : public BitField<bool, 27, 1> {};
// Bit 28 is free.
// Keep this bit field at the very end for better code in
// Builtins::kJSConstructStubGeneric stub.
// This counter is used for in-object slack tracking.
// The in-object slack tracking is considered enabled when the counter is
// non zero. The counter only has a valid count for initial maps. For
// transitioned maps only kNoSlackTracking has a meaning, namely that inobject
// slack tracking already finished for the transition tree. Any other value
// indicates that either inobject slack tracking is still in progress, or that
// the map isn't part of the transition tree anymore.
class ConstructionCounter : public BitField<int, 29, 3> {};
static const int kSlackTrackingCounterStart = 7;
static const int kSlackTrackingCounterEnd = 1;
static const int kNoSlackTracking = 0;
STATIC_ASSERT(kSlackTrackingCounterStart <= ConstructionCounter::kMax);
// Inobject slack tracking is the way to reclaim unused inobject space.
//
// The instance size is initially determined by adding some slack to
// expected_nof_properties (to allow for a few extra properties added
// after the constructor). There is no guarantee that the extra space
// will not be wasted.
//
// Here is the algorithm to reclaim the unused inobject space:
// - Detect the first constructor call for this JSFunction.
// When it happens enter the "in progress" state: initialize construction
// counter in the initial_map.
// - While the tracking is in progress initialize unused properties of a new
// object with one_pointer_filler_map instead of undefined_value (the "used"
// part is initialized with undefined_value as usual). This way they can
// be resized quickly and safely.
// - Once enough objects have been created compute the 'slack'
// (traverse the map transition tree starting from the
// initial_map and find the lowest value of unused_property_fields).
// - Traverse the transition tree again and decrease the instance size
// of every map. Existing objects will resize automatically (they are
// filled with one_pointer_filler_map). All further allocations will
// use the adjusted instance size.
// - SharedFunctionInfo's expected_nof_properties left unmodified since
// allocations made using different closures could actually create different
// kind of objects (see prototype inheritance pattern).
//
// Important: inobject slack tracking is not attempted during the snapshot
// creation.
static const int kGenerousAllocationCount =
kSlackTrackingCounterStart - kSlackTrackingCounterEnd + 1;
// Starts the tracking by initializing object constructions countdown counter.
void StartInobjectSlackTracking();
// True if the object constructions countdown counter is a range
// [kSlackTrackingCounterEnd, kSlackTrackingCounterStart].
inline bool IsInobjectSlackTrackingInProgress();
// Does the tracking step.
inline void InobjectSlackTrackingStep();
// Completes inobject slack tracking for the transition tree starting at this
// initial map.
void CompleteInobjectSlackTracking();
// Tells whether the object in the prototype property will be used
// for instances created from this function. If the prototype
// property is set to a value that is not a JSObject, the prototype
// property will not be used to create instances of the function.
// See ECMA-262, 13.2.2.
inline void set_non_instance_prototype(bool value);
inline bool has_non_instance_prototype();
// Tells whether the instance has a [[Construct]] internal method.
// This property is implemented according to ES6, section 7.2.4.
inline void set_is_constructor(bool value);
inline bool is_constructor() const;
// Tells whether the instance with this map has a hidden prototype.
inline void set_has_hidden_prototype(bool value);
inline bool has_hidden_prototype() const;
// Records and queries whether the instance has a named interceptor.
inline void set_has_named_interceptor();
inline bool has_named_interceptor();
// Records and queries whether the instance has an indexed interceptor.
inline void set_has_indexed_interceptor();
inline bool has_indexed_interceptor();
// Tells whether the instance is undetectable.
// An undetectable object is a special class of JSObject: 'typeof' operator
// returns undefined, ToBoolean returns false. Otherwise it behaves like
// a normal JS object. It is useful for implementing undetectable
// document.all in Firefox & Safari.
// See https://bugzilla.mozilla.org/show_bug.cgi?id=248549.
inline void set_is_undetectable();
inline bool is_undetectable();
// Tells whether the instance has a [[Call]] internal method.
// This property is implemented according to ES6, section 7.2.3.
inline void set_is_callable();
inline bool is_callable() const;
inline void set_new_target_is_base(bool value);
inline bool new_target_is_base();
inline void set_is_extensible(bool value);
inline bool is_extensible();
inline void set_is_prototype_map(bool value);
inline bool is_prototype_map() const;
inline void set_elements_kind(ElementsKind elements_kind);
inline ElementsKind elements_kind();
// Tells whether the instance has fast elements that are only Smis.
inline bool has_fast_smi_elements();
// Tells whether the instance has fast elements.
inline bool has_fast_object_elements();
inline bool has_fast_smi_or_object_elements();
inline bool has_fast_double_elements();
inline bool has_fast_elements();
inline bool has_sloppy_arguments_elements();
inline bool has_fast_sloppy_arguments_elements();
inline bool has_fast_string_wrapper_elements();
inline bool has_fixed_typed_array_elements();
inline bool has_dictionary_elements();
static bool IsValidElementsTransition(ElementsKind from_kind,
ElementsKind to_kind);
// Returns true if the current map doesn't have DICTIONARY_ELEMENTS but if a
// map with DICTIONARY_ELEMENTS was found in the prototype chain.
bool DictionaryElementsInPrototypeChainOnly();
inline Map* ElementsTransitionMap();
inline FixedArrayBase* GetInitialElements();
// [raw_transitions]: Provides access to the transitions storage field.
// Don't call set_raw_transitions() directly to overwrite transitions, use
// the TransitionArray::ReplaceTransitions() wrapper instead!
DECL_ACCESSORS(raw_transitions, Object)
// [prototype_info]: Per-prototype metadata. Aliased with transitions
// (which prototype maps don't have).
DECL_ACCESSORS(prototype_info, Object)
// PrototypeInfo is created lazily using this helper (which installs it on
// the given prototype's map).
static Handle<PrototypeInfo> GetOrCreatePrototypeInfo(
Handle<JSObject> prototype, Isolate* isolate);
static Handle<PrototypeInfo> GetOrCreatePrototypeInfo(
Handle<Map> prototype_map, Isolate* isolate);
inline bool should_be_fast_prototype_map() const;
static void SetShouldBeFastPrototypeMap(Handle<Map> map, bool value,
Isolate* isolate);
// [prototype chain validity cell]: Associated with a prototype object,
// stored in that object's map's PrototypeInfo, indicates that prototype
// chains through this object are currently valid. The cell will be
// invalidated and replaced when the prototype chain changes.
static Handle<Cell> GetOrCreatePrototypeChainValidityCell(Handle<Map> map,
Isolate* isolate);
static const int kPrototypeChainValid = 0;
static const int kPrototypeChainInvalid = 1;
// Return the map of the root of object's prototype chain.
Map* GetPrototypeChainRootMap(Isolate* isolate);
// Returns a WeakCell object containing given prototype. The cell is cached
// in PrototypeInfo which is created lazily.
static Handle<WeakCell> GetOrCreatePrototypeWeakCell(
Handle<JSObject> prototype, Isolate* isolate);
Map* FindRootMap();
Map* FindFieldOwner(int descriptor);
inline int GetInObjectPropertyOffset(int index);
int NumberOfFields();
// Returns true if transition to the given map requires special
// synchronization with the concurrent marker.
bool TransitionRequiresSynchronizationWithGC(Map* target);
// Returns true if transition to the given map removes a tagged in-object
// field.
bool TransitionRemovesTaggedField(Map* target);
// Returns true if transition to the given map replaces a tagged in-object
// field with an untagged in-object field.
bool TransitionChangesTaggedFieldToUntaggedField(Map* target);
// TODO(ishell): candidate with JSObject::MigrateToMap().
bool InstancesNeedRewriting(Map* target);
bool InstancesNeedRewriting(Map* target, int target_number_of_fields,
int target_inobject, int target_unused,
int* old_number_of_fields);
// TODO(ishell): moveit!
static Handle<Map> GeneralizeAllFields(Handle<Map> map);
MUST_USE_RESULT static Handle<FieldType> GeneralizeFieldType(
Representation rep1, Handle<FieldType> type1, Representation rep2,
Handle<FieldType> type2, Isolate* isolate);
static void GeneralizeField(Handle<Map> map, int modify_index,
PropertyConstness new_constness,
Representation new_representation,
Handle<FieldType> new_field_type);
static Handle<Map> ReconfigureProperty(Handle<Map> map, int modify_index,
PropertyKind new_kind,
PropertyAttributes new_attributes,
Representation new_representation,
Handle<FieldType> new_field_type);
static Handle<Map> ReconfigureElementsKind(Handle<Map> map,
ElementsKind new_elements_kind);
static Handle<Map> PrepareForDataProperty(Handle<Map> old_map,
int descriptor_number,
PropertyConstness constness,
Handle<Object> value);
static Handle<Map> Normalize(Handle<Map> map, PropertyNormalizationMode mode,
const char* reason);
// Tells whether the map is used for JSObjects in dictionary mode (ie
// normalized objects, ie objects for which HasFastProperties returns false).
// A map can never be used for both dictionary mode and fast mode JSObjects.
// False by default and for HeapObjects that are not JSObjects.
inline void set_dictionary_map(bool value);
inline bool is_dictionary_map();
// Tells whether the instance needs security checks when accessing its
// properties.
inline void set_is_access_check_needed(bool access_check_needed);
inline bool is_access_check_needed();
// Returns true if map has a non-empty stub code cache.
inline bool has_code_cache();
// [prototype]: implicit prototype object.
DECL_ACCESSORS(prototype, Object)
// TODO(jkummerow): make set_prototype private.
static void SetPrototype(
Handle<Map> map, Handle<Object> prototype,
PrototypeOptimizationMode proto_mode = FAST_PROTOTYPE);
// [constructor]: points back to the function or FunctionTemplateInfo
// responsible for this map.
// The field overlaps with the back pointer. All maps in a transition tree
// have the same constructor, so maps with back pointers can walk the
// back pointer chain until they find the map holding their constructor.
// Returns null_value if there's neither a constructor function nor a
// FunctionTemplateInfo available.
DECL_ACCESSORS(constructor_or_backpointer, Object)
inline Object* GetConstructor() const;
inline FunctionTemplateInfo* GetFunctionTemplateInfo() const;
inline void SetConstructor(Object* constructor,
WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
// [back pointer]: points back to the parent map from which a transition
// leads to this map. The field overlaps with the constructor (see above).
inline Object* GetBackPointer();
inline void SetBackPointer(Object* value,
WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
// [instance descriptors]: describes the object.
DECL_ACCESSORS(instance_descriptors, DescriptorArray)
// [layout descriptor]: describes the object layout.
DECL_ACCESSORS(layout_descriptor, LayoutDescriptor)
// |layout descriptor| accessor which can be used from GC.
inline LayoutDescriptor* layout_descriptor_gc_safe();
inline bool HasFastPointerLayout() const;
// |layout descriptor| accessor that is safe to call even when
// FLAG_unbox_double_fields is disabled (in this case Map does not contain
// |layout_descriptor| field at all).
inline LayoutDescriptor* GetLayoutDescriptor();
inline void UpdateDescriptors(DescriptorArray* descriptors,
LayoutDescriptor* layout_descriptor);
inline void InitializeDescriptors(DescriptorArray* descriptors,
LayoutDescriptor* layout_descriptor);
// [stub cache]: contains stubs compiled for this map.
DECL_ACCESSORS(code_cache, FixedArray)
// [dependent code]: list of optimized codes that weakly embed this map.
DECL_ACCESSORS(dependent_code, DependentCode)
// [weak cell cache]: cache that stores a weak cell pointing to this map.
DECL_ACCESSORS(weak_cell_cache, Object)
inline PropertyDetails GetLastDescriptorDetails();
inline int LastAdded();
inline int NumberOfOwnDescriptors();
inline void SetNumberOfOwnDescriptors(int number);
inline Cell* RetrieveDescriptorsPointer();
// Checks whether all properties are stored either in the map or on the object
// (inobject, properties, or elements backing store), requiring no special
// checks.
bool OnlyHasSimpleProperties();
inline int EnumLength();
inline void SetEnumLength(int length);
inline bool owns_descriptors();
inline void set_owns_descriptors(bool owns_descriptors);
inline void mark_unstable();
inline bool is_stable();
inline void set_migration_target(bool value);
inline bool is_migration_target();
inline void set_immutable_proto(bool value);
inline bool is_immutable_proto();
inline void set_construction_counter(int value);
inline int construction_counter();
inline void deprecate();
inline bool is_deprecated();
inline bool CanBeDeprecated();
// Returns a non-deprecated version of the input. If the input was not
// deprecated, it is directly returned. Otherwise, the non-deprecated version
// is found by re-transitioning from the root of the transition tree using the
// descriptor array of the map. Returns MaybeHandle<Map>() if no updated map
// is found.
static MaybeHandle<Map> TryUpdate(Handle<Map> map) WARN_UNUSED_RESULT;
// Returns a non-deprecated version of the input. This method may deprecate
// existing maps along the way if encodings conflict. Not for use while
// gathering type feedback. Use TryUpdate in those cases instead.
static Handle<Map> Update(Handle<Map> map);
static inline Handle<Map> CopyInitialMap(Handle<Map> map);
static Handle<Map> CopyInitialMap(Handle<Map> map, int instance_size,
int in_object_properties,
int unused_property_fields);
static Handle<Map> CopyInitialMapNormalized(
Handle<Map> map,
PropertyNormalizationMode mode = CLEAR_INOBJECT_PROPERTIES);
static Handle<Map> CopyDropDescriptors(Handle<Map> map);
static Handle<Map> CopyInsertDescriptor(Handle<Map> map,
Descriptor* descriptor,
TransitionFlag flag);
static Handle<Object> WrapFieldType(Handle<FieldType> type);
static FieldType* UnwrapFieldType(Object* wrapped_type);
MUST_USE_RESULT static MaybeHandle<Map> CopyWithField(
Handle<Map> map, Handle<Name> name, Handle<FieldType> type,
PropertyAttributes attributes, PropertyConstness constness,
Representation representation, TransitionFlag flag);
MUST_USE_RESULT static MaybeHandle<Map> CopyWithConstant(
Handle<Map> map, Handle<Name> name, Handle<Object> constant,
PropertyAttributes attributes, TransitionFlag flag);
// Returns a new map with all transitions dropped from the given map and
// the ElementsKind set.
static Handle<Map> TransitionElementsTo(Handle<Map> map,
ElementsKind to_kind);
static Handle<Map> AsElementsKind(Handle<Map> map, ElementsKind kind);
static Handle<Map> CopyAsElementsKind(Handle<Map> map, ElementsKind kind,
TransitionFlag flag);
static Handle<Map> AsLanguageMode(Handle<Map> initial_map,
LanguageMode language_mode,
FunctionKind kind);
static Handle<Map> CopyForPreventExtensions(Handle<Map> map,
PropertyAttributes attrs_to_add,
Handle<Symbol> transition_marker,
const char* reason);
static Handle<Map> FixProxy(Handle<Map> map, InstanceType type, int size);
// Maximal number of fast properties. Used to restrict the number of map
// transitions to avoid an explosion in the number of maps for objects used as
// dictionaries.
inline bool TooManyFastProperties(StoreFromKeyed store_mode);
static Handle<Map> TransitionToDataProperty(Handle<Map> map,
Handle<Name> name,
Handle<Object> value,
PropertyAttributes attributes,
PropertyConstness constness,
StoreFromKeyed store_mode);
static Handle<Map> TransitionToAccessorProperty(
Isolate* isolate, Handle<Map> map, Handle<Name> name, int descriptor,
Handle<Object> getter, Handle<Object> setter,
PropertyAttributes attributes);
static Handle<Map> ReconfigureExistingProperty(Handle<Map> map,
int descriptor,
PropertyKind kind,
PropertyAttributes attributes);
inline void AppendDescriptor(Descriptor* desc);
// Returns a copy of the map, prepared for inserting into the transition
// tree (if the |map| owns descriptors then the new one will share
// descriptors with |map|).
static Handle<Map> CopyForTransition(Handle<Map> map, const char* reason);
// Returns a copy of the map, with all transitions dropped from the
// instance descriptors.
static Handle<Map> Copy(Handle<Map> map, const char* reason);
static Handle<Map> Create(Isolate* isolate, int inobject_properties);
// Returns the next free property index (only valid for FAST MODE).
int NextFreePropertyIndex();
// Returns the number of properties described in instance_descriptors
// filtering out properties with the specified attributes.
int NumberOfDescribedProperties(DescriptorFlag which = OWN_DESCRIPTORS,
PropertyFilter filter = ALL_PROPERTIES);
DECLARE_CAST(Map)
// Code cache operations.
// Clears the code cache.
inline void ClearCodeCache(Heap* heap);
// Update code cache.
static void UpdateCodeCache(Handle<Map> map, Handle<Name> name,
Handle<Code> code);
// Extend the descriptor array of the map with the list of descriptors.
// In case of duplicates, the latest descriptor is used.
static void AppendCallbackDescriptors(Handle<Map> map,
Handle<Object> descriptors);
static inline int SlackForArraySize(int old_size, int size_limit);
static void EnsureDescriptorSlack(Handle<Map> map, int slack);
Code* LookupInCodeCache(Name* name, Code::Flags code);
static Handle<Map> GetObjectCreateMap(Handle<HeapObject> prototype);
// Computes a hash value for this map, to be used in HashTables and such.
int Hash();
// Returns the transitioned map for this map with the most generic
// elements_kind that's found in |candidates|, or |nullptr| if no match is
// found at all.
Map* FindElementsKindTransitionedMap(MapHandles const& candidates);
inline bool CanTransition();
inline bool IsBooleanMap();
inline bool IsPrimitiveMap();
inline bool IsJSReceiverMap();
inline bool IsJSObjectMap();
inline bool IsJSArrayMap();
inline bool IsJSFunctionMap();
inline bool IsStringMap();
inline bool IsJSProxyMap();
inline bool IsModuleMap();
inline bool IsJSGlobalProxyMap();
inline bool IsJSGlobalObjectMap();
inline bool IsJSTypedArrayMap();
inline bool IsJSDataViewMap();
inline bool IsSpecialReceiverMap();
inline bool CanOmitMapChecks();
static void AddDependentCode(Handle<Map> map,
DependentCode::DependencyGroup group,
Handle<Code> code);
bool IsMapInArrayPrototypeChain();
static Handle<WeakCell> WeakCellForMap(Handle<Map> map);
// Dispatched behavior.
DECLARE_PRINTER(Map)
DECLARE_VERIFIER(Map)
#ifdef VERIFY_HEAP
void DictionaryMapVerify();
void VerifyOmittedMapChecks();
#endif
inline int visitor_id();
inline void set_visitor_id(int visitor_id);
static Handle<Map> TransitionToPrototype(Handle<Map> map,
Handle<Object> prototype,
PrototypeOptimizationMode mode);
static Handle<Map> TransitionToImmutableProto(Handle<Map> map);
static const int kMaxPreAllocatedPropertyFields = 255;
// Layout description.
static const int kInstanceSizesOffset = HeapObject::kHeaderSize;
static const int kInstanceAttributesOffset = kInstanceSizesOffset + kIntSize;
static const int kBitField3Offset = kInstanceAttributesOffset + kIntSize;
static const int kPrototypeOffset = kBitField3Offset + kPointerSize;
static const int kConstructorOrBackPointerOffset =
kPrototypeOffset + kPointerSize;
// When there is only one transition, it is stored directly in this field;
// otherwise a transition array is used.
// For prototype maps, this slot is used to store this map's PrototypeInfo
// struct.
static const int kTransitionsOrPrototypeInfoOffset =
kConstructorOrBackPointerOffset + kPointerSize;
static const int kDescriptorsOffset =
kTransitionsOrPrototypeInfoOffset + kPointerSize;
#if V8_DOUBLE_FIELDS_UNBOXING
static const int kLayoutDescriptorOffset = kDescriptorsOffset + kPointerSize;
static const int kCodeCacheOffset = kLayoutDescriptorOffset + kPointerSize;
#else
static const int kLayoutDescriptorOffset = 1; // Must not be ever accessed.
static const int kCodeCacheOffset = kDescriptorsOffset + kPointerSize;
#endif
static const int kDependentCodeOffset = kCodeCacheOffset + kPointerSize;
static const int kWeakCellCacheOffset = kDependentCodeOffset + kPointerSize;
static const int kSize = kWeakCellCacheOffset + kPointerSize;
// Layout of pointer fields. Heap iteration code relies on them
// being continuously allocated.
static const int kPointerFieldsBeginOffset = Map::kPrototypeOffset;
static const int kPointerFieldsEndOffset = kSize;
// Byte offsets within kInstanceSizesOffset.
static const int kInstanceSizeOffset = kInstanceSizesOffset + 0;
static const int kInObjectPropertiesOrConstructorFunctionIndexByte = 1;
static const int kInObjectPropertiesOrConstructorFunctionIndexOffset =
kInstanceSizesOffset + kInObjectPropertiesOrConstructorFunctionIndexByte;
// Note there is one byte available for use here.
static const int kUnusedByte = 2;
static const int kUnusedOffset = kInstanceSizesOffset + kUnusedByte;
static const int kVisitorIdByte = 3;
static const int kVisitorIdOffset = kInstanceSizesOffset + kVisitorIdByte;
// Byte offsets within kInstanceAttributesOffset attributes.
#if V8_TARGET_LITTLE_ENDIAN
// Order instance type and bit field together such that they can be loaded
// together as a 16-bit word with instance type in the lower 8 bits regardless
// of endianess. Also provide endian-independent offset to that 16-bit word.
static const int kInstanceTypeOffset = kInstanceAttributesOffset + 0;
static const int kBitFieldOffset = kInstanceAttributesOffset + 1;
#else
static const int kBitFieldOffset = kInstanceAttributesOffset + 0;
static const int kInstanceTypeOffset = kInstanceAttributesOffset + 1;
#endif
static const int kInstanceTypeAndBitFieldOffset =
kInstanceAttributesOffset + 0;
static const int kBitField2Offset = kInstanceAttributesOffset + 2;
static const int kUnusedPropertyFieldsOffset = kInstanceAttributesOffset + 3;
STATIC_ASSERT(kInstanceTypeAndBitFieldOffset ==
Internals::kMapInstanceTypeAndBitFieldOffset);
// Bit positions for bit field.
static const int kHasNonInstancePrototype = 0;
static const int kIsCallable = 1;
static const int kHasNamedInterceptor = 2;
static const int kHasIndexedInterceptor = 3;
static const int kIsUndetectable = 4;
static const int kIsAccessCheckNeeded = 5;
static const int kIsConstructor = 6;
// Bit 7 is free.
// Bit positions for bit field 2
static const int kIsExtensible = 0;
// Bit 1 is free.
class IsPrototypeMapBits : public BitField<bool, 2, 1> {};
class ElementsKindBits : public BitField<ElementsKind, 3, 5> {};
// Derived values from bit field 2
static const int8_t kMaximumBitField2FastElementValue =
static_cast<int8_t>((FAST_ELEMENTS + 1)
<< Map::ElementsKindBits::kShift) -
1;
static const int8_t kMaximumBitField2FastSmiElementValue =
static_cast<int8_t>((FAST_SMI_ELEMENTS + 1)
<< Map::ElementsKindBits::kShift) -
1;
static const int8_t kMaximumBitField2FastHoleyElementValue =
static_cast<int8_t>((FAST_HOLEY_ELEMENTS + 1)
<< Map::ElementsKindBits::kShift) -
1;
static const int8_t kMaximumBitField2FastHoleySmiElementValue =
static_cast<int8_t>((FAST_HOLEY_SMI_ELEMENTS + 1)
<< Map::ElementsKindBits::kShift) -
1;
typedef FixedBodyDescriptor<kPointerFieldsBeginOffset,
kPointerFieldsEndOffset, kSize>
BodyDescriptor;
// Compares this map to another to see if they describe equivalent objects.
// If |mode| is set to CLEAR_INOBJECT_PROPERTIES, |other| is treated as if
// it had exactly zero inobject properties.
// The "shared" flags of both this map and |other| are ignored.
bool EquivalentToForNormalization(Map* other, PropertyNormalizationMode mode);
// Returns true if given field is unboxed double.
inline bool IsUnboxedDoubleField(FieldIndex index);
#if V8_TRACE_MAPS
static void TraceTransition(const char* what, Map* from, Map* to, Name* name);
static void TraceAllTransitions(Map* map);
#endif
static inline Handle<Map> AddMissingTransitionsForTesting(
Handle<Map> split_map, Handle<DescriptorArray> descriptors,
Handle<LayoutDescriptor> full_layout_descriptor);
// Fires when the layout of an object with a leaf map changes.
// This includes adding transitions to the leaf map or changing
// the descriptor array.
inline void NotifyLeafMapLayoutChange();
private:
// Returns the map that this (root) map transitions to if its elements_kind
// is changed to |elements_kind|, or |nullptr| if no such map is cached yet.
Map* LookupElementsTransitionMap(ElementsKind elements_kind);
// Tries to replay property transitions starting from this (root) map using
// the descriptor array of the |map|. The |root_map| is expected to have
// proper elements kind and therefore elements kinds transitions are not
// taken by this function. Returns |nullptr| if matching transition map is
// not found.
Map* TryReplayPropertyTransitions(Map* map);
static void ConnectTransition(Handle<Map> parent, Handle<Map> child,
Handle<Name> name, SimpleTransitionFlag flag);
bool EquivalentToForTransition(Map* other);
static Handle<Map> RawCopy(Handle<Map> map, int instance_size);
static Handle<Map> ShareDescriptor(Handle<Map> map,
Handle<DescriptorArray> descriptors,
Descriptor* descriptor);
static Handle<Map> AddMissingTransitions(
Handle<Map> map, Handle<DescriptorArray> descriptors,
Handle<LayoutDescriptor> full_layout_descriptor);
static void InstallDescriptors(
Handle<Map> parent_map, Handle<Map> child_map, int new_descriptor,
Handle<DescriptorArray> descriptors,
Handle<LayoutDescriptor> full_layout_descriptor);
static Handle<Map> CopyAddDescriptor(Handle<Map> map, Descriptor* descriptor,
TransitionFlag flag);
static Handle<Map> CopyReplaceDescriptors(
Handle<Map> map, Handle<DescriptorArray> descriptors,
Handle<LayoutDescriptor> layout_descriptor, TransitionFlag flag,
MaybeHandle<Name> maybe_name, const char* reason,
SimpleTransitionFlag simple_flag);
static Handle<Map> CopyReplaceDescriptor(Handle<Map> map,
Handle<DescriptorArray> descriptors,
Descriptor* descriptor, int index,
TransitionFlag flag);
static MUST_USE_RESULT MaybeHandle<Map> TryReconfigureExistingProperty(
Handle<Map> map, int descriptor, PropertyKind kind,
PropertyAttributes attributes, const char** reason);
static Handle<Map> CopyNormalized(Handle<Map> map,
PropertyNormalizationMode mode);
// TODO(ishell): Move to MapUpdater.
static Handle<Map> CopyGeneralizeAllFields(
Handle<Map> map, ElementsKind elements_kind, int modify_index,
PropertyKind kind, PropertyAttributes attributes, const char* reason);
void DeprecateTransitionTree();
void ReplaceDescriptors(DescriptorArray* new_descriptors,
LayoutDescriptor* new_layout_descriptor);
// Update field type of the given descriptor to new representation and new
// type. The type must be prepared for storing in descriptor array:
// it must be either a simple type or a map wrapped in a weak cell.
void UpdateFieldType(int descriptor_number, Handle<Name> name,
PropertyConstness new_constness,
Representation new_representation,
Handle<Object> new_wrapped_type);
// TODO(ishell): Move to MapUpdater.
void PrintReconfiguration(FILE* file, int modify_index, PropertyKind kind,
PropertyAttributes attributes);
// TODO(ishell): Move to MapUpdater.
void PrintGeneralization(FILE* file, const char* reason, int modify_index,
int split, int descriptors, bool constant_to_field,
Representation old_representation,
Representation new_representation,
MaybeHandle<FieldType> old_field_type,
MaybeHandle<Object> old_value,
MaybeHandle<FieldType> new_field_type,
MaybeHandle<Object> new_value);
static const int kFastPropertiesSoftLimit = 12;
static const int kMaxFastProperties = 128;
friend class MapUpdater;
DISALLOW_IMPLICIT_CONSTRUCTORS(Map);
};
// The cache for maps used by normalized (dictionary mode) objects.
// Such maps do not have property descriptors, so a typical program
// needs very limited number of distinct normalized maps.
class NormalizedMapCache : public FixedArray {
public:
static Handle<NormalizedMapCache> New(Isolate* isolate);
MUST_USE_RESULT MaybeHandle<Map> Get(Handle<Map> fast_map,
PropertyNormalizationMode mode);
void Set(Handle<Map> fast_map, Handle<Map> normalized_map);
void Clear();
DECLARE_CAST(NormalizedMapCache)
static inline bool IsNormalizedMapCache(const HeapObject* obj);
DECLARE_VERIFIER(NormalizedMapCache)
private:
static const int kEntries = 64;
static inline int GetIndex(Handle<Map> map);
// The following declarations hide base class methods.
Object* get(int index);
void set(int index, Object* value);
};
} // namespace internal
} // namespace v8
#include "src/objects/object-macros-undef.h"
#endif // V8_OBJECTS_MAP_H_
src/transitions.h
View file @ 35f3e9d0
......@@ -10,6 +10,7 @@
#include "src/isolate.h"
#include "src/objects.h"
#include "src/objects/descriptor-array.h"
#include "src/objects/map.h"
namespace v8 {
namespace internal {
......
src/type-info.cc
View file @ 35f3e9d0
......@@ -10,6 +10,7 @@
#include "src/ic/ic.h"
#include "src/ic/stub-cache.h"
#include "src/objects-inl.h"
#include "src/objects/map.h"
namespace v8 {
namespace internal {
......
src/v8.gyp
View file @ 35f3e9d0
......@@ -1131,6 +1131,8 @@
'objects/intl-objects.h',
'objects/literal-objects.cc',
'objects/literal-objects.h',
'objects/map-inl.h',
'objects/map.h',
'objects/module-info.h',
'objects/object-macros.h',
'objects/object-macros-undef.h',
......@@ -2452,6 +2454,8 @@
'heapobject_files': [
'objects.h',
'objects-inl.h',
'objects/map.h',
'objects/map-inl.h',
],
},
'actions': [
......
tools/gen-postmortem-metadata.py
View file @ 35f3e9d0
......@@ -335,15 +335,9 @@ def get_base_class(klass):
return get_base_class(k['parent']);
#
# Loads class hierarchy and type information from "objects.h".
# Loads class hierarchy and type information from "objects.h" etc.
#
def load_objects():
objfilename = sys.argv[2];
objfile = open(objfilename, 'r');
in_insttype = False;
typestr = '';
#
# Construct a dictionary for the classes we're sure should be present.
#
......@@ -351,11 +345,29 @@ def load_objects():
for klass in expected_classes:
checktypes[klass] = True;
for filename in sys.argv[2:]:
if not filename.endswith("-inl.h"):
load_objects_from_file(filename, checktypes)
if (len(checktypes) > 0):
for klass in checktypes:
print('error: expected class \"%s\" not found' % klass);
sys.exit(1);
def load_objects_from_file(objfilename, checktypes):
objfile = open(objfilename, 'r');
in_insttype = False;
typestr = '';
#
# Iterate objects.h line-by-line to collect type and class information.
# For types, we accumulate a string representing the entire InstanceType
# enum definition and parse it later because it's easier to do so
# without the embedded newlines.
# Iterate the header file line-by-line to collect type and class
# information. For types, we accumulate a string representing the entire
# InstanceType enum definition and parse it later because it's easier to
# do so without the embedded newlines.
#
for line in objfile:
if (line.startswith('enum InstanceType {')):
......@@ -482,13 +494,6 @@ def load_objects():
if (cctype in checktypes):
del checktypes[cctype];
if (len(checktypes) > 0):
for klass in checktypes:
print('error: expected class \"%s\" not found' % klass);
sys.exit(1);
#
# For a given macro call, pick apart the arguments and return an object
# describing the corresponding output constant. See load_fields().
......@@ -528,11 +533,19 @@ def parse_field(call):
});
#
# Load field offset information from objects-inl.h.
# Load field offset information from objects-inl.h etc.
#
def load_fields():
inlfilename = sys.argv[3];
inlfile = open(inlfilename, 'r');
for filename in sys.argv[2:]:
if filename.endswith("-inl.h"):
load_fields_from_file(filename)
for body in extras_accessors:
fields.append(parse_field('ACCESSORS(%s)' % body));
def load_fields_from_file(filename):
inlfile = open(filename, 'r');
#
# Each class's fields and the corresponding offsets are described in the
......@@ -584,9 +597,6 @@ def load_fields():
fields.append(parse_field(current));
current = '';
for body in extras_accessors:
fields.append(parse_field('ACCESSORS(%s)' % body));
#
# Emit a block of constants.
#
......
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