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authorwolfbeast <mcwerewolf@wolfbeast.com>2020-02-22 21:09:32 +0100
committerwolfbeast <mcwerewolf@wolfbeast.com>2020-04-14 12:56:40 +0200
commitc22a493144e39d76bfa42c46f9d6d17a5143ac35 (patch)
tree83ec59e07c9948eebd529ba56771a622c605a13b /js/src/vm
parentd20ca24a070d547be3bce4d513ef151b6be5f955 (diff)
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Revert #1142 - Remove unboxed objects
- accounting for removal of watch()/unwatch()
Diffstat (limited to 'js/src/vm')
-rw-r--r--js/src/vm/Interpreter.cpp5
-rw-r--r--js/src/vm/NativeObject.cpp27
-rw-r--r--js/src/vm/NativeObject.h5
-rw-r--r--js/src/vm/ObjectGroup-inl.h14
-rw-r--r--js/src/vm/ObjectGroup.cpp55
-rw-r--r--js/src/vm/ObjectGroup.h62
-rw-r--r--js/src/vm/ReceiverGuard.cpp14
-rw-r--r--js/src/vm/TypeInference-inl.h5
-rw-r--r--js/src/vm/TypeInference.cpp156
-rw-r--r--js/src/vm/UnboxedObject-inl.h177
-rw-r--r--js/src/vm/UnboxedObject.cpp946
-rw-r--r--js/src/vm/UnboxedObject.h319
12 files changed, 1765 insertions, 20 deletions
diff --git a/js/src/vm/Interpreter.cpp b/js/src/vm/Interpreter.cpp
index 3cf9b57f6..b87d12924 100644
--- a/js/src/vm/Interpreter.cpp
+++ b/js/src/vm/Interpreter.cpp
@@ -5016,6 +5016,11 @@ js::NewObjectOperationWithTemplate(JSContext* cx, HandleObject templateObject)
NewObjectKind newKind = templateObject->group()->shouldPreTenure() ? TenuredObject : GenericObject;
+ if (templateObject->group()->maybeUnboxedLayout()) {
+ RootedObjectGroup group(cx, templateObject->group());
+ return UnboxedPlainObject::create(cx, group, newKind);
+ }
+
JSObject* obj = CopyInitializerObject(cx, templateObject.as<PlainObject>(), newKind);
if (!obj)
return nullptr;
diff --git a/js/src/vm/NativeObject.cpp b/js/src/vm/NativeObject.cpp
index d801fad06..bd7484e07 100644
--- a/js/src/vm/NativeObject.cpp
+++ b/js/src/vm/NativeObject.cpp
@@ -388,6 +388,33 @@ NativeObject::setLastPropertyMakeNonNative(Shape* shape)
shape_ = shape;
}
+void
+NativeObject::setLastPropertyMakeNative(ExclusiveContext* cx, Shape* shape)
+{
+ MOZ_ASSERT(getClass()->isNative());
+ MOZ_ASSERT(shape->getObjectClass()->isNative());
+ MOZ_ASSERT(!shape->inDictionary());
+
+ // This method is used to convert unboxed objects into native objects. In
+ // this case, the shape_ field was previously used to store other data and
+ // this should be treated as an initialization.
+ shape_.init(shape);
+
+ slots_ = nullptr;
+ elements_ = emptyObjectElements;
+
+ size_t oldSpan = shape->numFixedSlots();
+ size_t newSpan = shape->slotSpan();
+
+ initializeSlotRange(0, oldSpan);
+
+ // A failure at this point will leave the object as a mutant, and we
+ // can't recover.
+ AutoEnterOOMUnsafeRegion oomUnsafe;
+ if (oldSpan != newSpan && !updateSlotsForSpan(cx, oldSpan, newSpan))
+ oomUnsafe.crash("NativeObject::setLastPropertyMakeNative");
+}
+
bool
NativeObject::setSlotSpan(ExclusiveContext* cx, uint32_t span)
{
diff --git a/js/src/vm/NativeObject.h b/js/src/vm/NativeObject.h
index 9cc6d5436..6595703dc 100644
--- a/js/src/vm/NativeObject.h
+++ b/js/src/vm/NativeObject.h
@@ -470,6 +470,11 @@ class NativeObject : public ShapedObject
// that are (temporarily) inconsistent.
void setLastPropertyMakeNonNative(Shape* shape);
+ // As for setLastProperty(), but changes the class associated with the
+ // object to a native one. The object's type has already been changed, and
+ // this brings the shape into sync with it.
+ void setLastPropertyMakeNative(ExclusiveContext* cx, Shape* shape);
+
// Newly-created TypedArrays that map a SharedArrayBuffer are
// marked as shared by giving them an ObjectElements that has the
// ObjectElements::SHARED_MEMORY flag set.
diff --git a/js/src/vm/ObjectGroup-inl.h b/js/src/vm/ObjectGroup-inl.h
index d41343be6..9074f4d97 100644
--- a/js/src/vm/ObjectGroup-inl.h
+++ b/js/src/vm/ObjectGroup-inl.h
@@ -108,6 +108,20 @@ ObjectGroup::maybePreliminaryObjects()
return maybePreliminaryObjectsDontCheckGeneration();
}
+inline UnboxedLayout*
+ObjectGroup::maybeUnboxedLayout()
+{
+ maybeSweep(nullptr);
+ return maybeUnboxedLayoutDontCheckGeneration();
+}
+
+inline UnboxedLayout&
+ObjectGroup::unboxedLayout()
+{
+ maybeSweep(nullptr);
+ return unboxedLayoutDontCheckGeneration();
+}
+
} // namespace js
#endif /* vm_ObjectGroup_inl_h */
diff --git a/js/src/vm/ObjectGroup.cpp b/js/src/vm/ObjectGroup.cpp
index 91070b3f6..95fcada94 100644
--- a/js/src/vm/ObjectGroup.cpp
+++ b/js/src/vm/ObjectGroup.cpp
@@ -18,10 +18,11 @@
#include "vm/ArrayObject.h"
#include "vm/Shape.h"
#include "vm/TaggedProto.h"
+#include "vm/UnboxedObject.h"
#include "jsobjinlines.h"
-#include "vm/NativeObject-inl.h"
+#include "vm/UnboxedObject-inl.h"
using namespace js;
@@ -55,6 +56,7 @@ ObjectGroup::finalize(FreeOp* fop)
if (newScriptDontCheckGeneration())
newScriptDontCheckGeneration()->clear();
fop->delete_(newScriptDontCheckGeneration());
+ fop->delete_(maybeUnboxedLayoutDontCheckGeneration());
if (maybePreliminaryObjectsDontCheckGeneration())
maybePreliminaryObjectsDontCheckGeneration()->clear();
fop->delete_(maybePreliminaryObjectsDontCheckGeneration());
@@ -81,6 +83,8 @@ ObjectGroup::sizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const
size_t n = 0;
if (TypeNewScript* newScript = newScriptDontCheckGeneration())
n += newScript->sizeOfIncludingThis(mallocSizeOf);
+ if (UnboxedLayout* layout = maybeUnboxedLayoutDontCheckGeneration())
+ n += layout->sizeOfIncludingThis(mallocSizeOf);
return n;
}
@@ -529,7 +533,8 @@ ObjectGroup::defaultNewGroup(ExclusiveContext* cx, const Class* clasp,
if (p) {
ObjectGroup* group = p->group;
MOZ_ASSERT_IF(clasp, group->clasp() == clasp);
- MOZ_ASSERT_IF(!clasp, group->clasp() == &PlainObject::class_);
+ MOZ_ASSERT_IF(!clasp, group->clasp() == &PlainObject::class_ ||
+ group->clasp() == &UnboxedPlainObject::class_);
MOZ_ASSERT(group->proto() == proto);
return group;
}
@@ -969,6 +974,46 @@ js::CombinePlainObjectPropertyTypes(ExclusiveContext* cx, JSObject* newObj,
}
}
}
+ } else if (newObj->is<UnboxedPlainObject>()) {
+ const UnboxedLayout& layout = newObj->as<UnboxedPlainObject>().layout();
+ const int32_t* traceList = layout.traceList();
+ if (!traceList)
+ return true;
+
+ uint8_t* newData = newObj->as<UnboxedPlainObject>().data();
+ uint8_t* oldData = oldObj->as<UnboxedPlainObject>().data();
+
+ for (; *traceList != -1; traceList++) {}
+ traceList++;
+ for (; *traceList != -1; traceList++) {
+ JSObject* newInnerObj = *reinterpret_cast<JSObject**>(newData + *traceList);
+ JSObject* oldInnerObj = *reinterpret_cast<JSObject**>(oldData + *traceList);
+
+ if (!newInnerObj || !oldInnerObj || SameGroup(oldInnerObj, newInnerObj))
+ continue;
+
+ if (!GiveObjectGroup(cx, newInnerObj, oldInnerObj))
+ return false;
+
+ if (SameGroup(oldInnerObj, newInnerObj))
+ continue;
+
+ if (!GiveObjectGroup(cx, oldInnerObj, newInnerObj))
+ return false;
+
+ if (SameGroup(oldInnerObj, newInnerObj)) {
+ for (size_t i = 1; i < ncompare; i++) {
+ if (compare[i].isObject() && SameGroup(&compare[i].toObject(), newObj)) {
+ uint8_t* otherData = compare[i].toObject().as<UnboxedPlainObject>().data();
+ JSObject* otherInnerObj = *reinterpret_cast<JSObject**>(otherData + *traceList);
+ if (otherInnerObj && !SameGroup(otherInnerObj, newInnerObj)) {
+ if (!GiveObjectGroup(cx, otherInnerObj, newInnerObj))
+ return false;
+ }
+ }
+ }
+ }
+ }
}
return true;
@@ -1192,6 +1237,12 @@ ObjectGroup::newPlainObject(ExclusiveContext* cx, IdValuePair* properties, size_
RootedObjectGroup group(cx, p->value().group);
+ // Watch for existing groups which now use an unboxed layout.
+ if (group->maybeUnboxedLayout()) {
+ MOZ_ASSERT(group->unboxedLayout().properties().length() == nproperties);
+ return UnboxedPlainObject::createWithProperties(cx, group, newKind, properties);
+ }
+
// Update property types according to the properties we are about to add.
// Do this before we do anything which can GC, which might move or remove
// this table entry.
diff --git a/js/src/vm/ObjectGroup.h b/js/src/vm/ObjectGroup.h
index 0b6eaee51..553cb8366 100644
--- a/js/src/vm/ObjectGroup.h
+++ b/js/src/vm/ObjectGroup.h
@@ -20,6 +20,7 @@
namespace js {
class TypeDescr;
+class UnboxedLayout;
class PreliminaryObjectArrayWithTemplate;
class TypeNewScript;
@@ -153,6 +154,16 @@ class ObjectGroup : public gc::TenuredCell
// For some plain objects, the addendum stores a PreliminaryObjectArrayWithTemplate.
Addendum_PreliminaryObjects,
+ // When objects in this group have an unboxed representation, the
+ // addendum stores an UnboxedLayout (which might have a TypeNewScript
+ // as well, if the group is also constructed using 'new').
+ Addendum_UnboxedLayout,
+
+ // If this group is used by objects that have been converted from an
+ // unboxed representation and/or have the same allocation kind as such
+ // objects, the addendum points to that unboxed group.
+ Addendum_OriginalUnboxedGroup,
+
// When used by typed objects, the addendum stores a TypeDescr.
Addendum_TypeDescr
};
@@ -174,6 +185,7 @@ class ObjectGroup : public gc::TenuredCell
return nullptr;
}
+ TypeNewScript* anyNewScript();
void detachNewScript(bool writeBarrier, ObjectGroup* replacement);
ObjectGroupFlags flagsDontCheckGeneration() const {
@@ -213,6 +225,34 @@ class ObjectGroup : public gc::TenuredCell
maybePreliminaryObjectsDontCheckGeneration();
}
+ inline UnboxedLayout* maybeUnboxedLayout();
+ inline UnboxedLayout& unboxedLayout();
+
+ UnboxedLayout* maybeUnboxedLayoutDontCheckGeneration() const {
+ if (addendumKind() == Addendum_UnboxedLayout)
+ return reinterpret_cast<UnboxedLayout*>(addendum_);
+ return nullptr;
+ }
+
+ UnboxedLayout& unboxedLayoutDontCheckGeneration() const {
+ MOZ_ASSERT(addendumKind() == Addendum_UnboxedLayout);
+ return *maybeUnboxedLayoutDontCheckGeneration();
+ }
+
+ void setUnboxedLayout(UnboxedLayout* layout) {
+ setAddendum(Addendum_UnboxedLayout, layout);
+ }
+
+ ObjectGroup* maybeOriginalUnboxedGroup() const {
+ if (addendumKind() == Addendum_OriginalUnboxedGroup)
+ return reinterpret_cast<ObjectGroup*>(addendum_);
+ return nullptr;
+ }
+
+ void setOriginalUnboxedGroup(ObjectGroup* group) {
+ setAddendum(Addendum_OriginalUnboxedGroup, group);
+ }
+
TypeDescr* maybeTypeDescr() {
// Note: there is no need to sweep when accessing the type descriptor
// of an object, as it is strongly held and immutable.
@@ -273,8 +313,9 @@ class ObjectGroup : public gc::TenuredCell
* that can be read out of that property in actual JS objects. In native
* objects, property types account for plain data properties (those with a
* slot and no getter or setter hook) and dense elements. In typed objects
- * property types account for object and value properties and elements in
- * the object.
+ * and unboxed objects, property types account for object and value
+ * properties and elements in the object, and expando properties in unboxed
+ * objects.
*
* For accesses on these properties, the correspondence is as follows:
*
@@ -297,9 +338,10 @@ class ObjectGroup : public gc::TenuredCell
* 2. Array lengths are special cased by the compiler and VM and are not
* reflected in property types.
*
- * 3. In typed objects, the initial values of properties (null pointers and
- * undefined values) are not reflected in the property types. These
- * values are always possible when reading the property.
+ * 3. In typed objects (but not unboxed objects), the initial values of
+ * properties (null pointers and undefined values) are not reflected in
+ * the property types. These values are always possible when reading the
+ * property.
*
* We establish these by using write barriers on calls to setProperty and
* defineProperty which are on native properties, and on any jitcode which
@@ -413,6 +455,12 @@ class ObjectGroup : public gc::TenuredCell
return &flags_;
}
+ // Get the bit pattern stored in an object's addendum when it has an
+ // original unboxed group.
+ static inline int32_t addendumOriginalUnboxedGroupValue() {
+ return Addendum_OriginalUnboxedGroup << OBJECT_FLAG_ADDENDUM_SHIFT;
+ }
+
inline uint32_t basePropertyCount();
private:
@@ -463,8 +511,8 @@ class ObjectGroup : public gc::TenuredCell
NewObjectKind newKind,
NewArrayKind arrayKind = NewArrayKind::Normal);
- // Create a PlainObject with the specified properties and a group specialized
- // for those properties.
+ // Create a PlainObject or UnboxedPlainObject with the specified properties
+ // and a group specialized for those properties.
static JSObject* newPlainObject(ExclusiveContext* cx,
IdValuePair* properties, size_t nproperties,
NewObjectKind newKind);
diff --git a/js/src/vm/ReceiverGuard.cpp b/js/src/vm/ReceiverGuard.cpp
index e95e8a208..e37bf8ee5 100644
--- a/js/src/vm/ReceiverGuard.cpp
+++ b/js/src/vm/ReceiverGuard.cpp
@@ -15,7 +15,11 @@ ReceiverGuard::ReceiverGuard(JSObject* obj)
: group(nullptr), shape(nullptr)
{
if (obj) {
- if (obj->is<TypedObject>()) {
+ if (obj->is<UnboxedPlainObject>()) {
+ group = obj->group();
+ if (UnboxedExpandoObject* expando = obj->as<UnboxedPlainObject>().maybeExpando())
+ shape = expando->lastProperty();
+ } else if (obj->is<TypedObject>()) {
group = obj->group();
} else {
shape = obj->maybeShape();
@@ -28,7 +32,9 @@ ReceiverGuard::ReceiverGuard(ObjectGroup* group, Shape* shape)
{
if (group) {
const Class* clasp = group->clasp();
- if (IsTypedObjectClass(clasp)) {
+ if (clasp == &UnboxedPlainObject::class_) {
+ // Keep both group and shape.
+ } else if (IsTypedObjectClass(clasp)) {
this->shape = nullptr;
} else {
this->group = nullptr;
@@ -39,6 +45,10 @@ ReceiverGuard::ReceiverGuard(ObjectGroup* group, Shape* shape)
/* static */ int32_t
HeapReceiverGuard::keyBits(JSObject* obj)
{
+ if (obj->is<UnboxedPlainObject>()) {
+ // Both the group and shape need to be guarded for unboxed plain objects.
+ return obj->as<UnboxedPlainObject>().maybeExpando() ? 0 : 1;
+ }
if (obj->is<TypedObject>()) {
// Only the group needs to be guarded for typed objects.
return 2;
diff --git a/js/src/vm/TypeInference-inl.h b/js/src/vm/TypeInference-inl.h
index 2af252cea..da47fa898 100644
--- a/js/src/vm/TypeInference-inl.h
+++ b/js/src/vm/TypeInference-inl.h
@@ -23,6 +23,7 @@
#include "vm/SharedArrayObject.h"
#include "vm/StringObject.h"
#include "vm/TypedArrayObject.h"
+#include "vm/UnboxedObject.h"
#include "jscntxtinlines.h"
@@ -284,6 +285,10 @@ TypeIdString(jsid id)
*/
struct AutoEnterAnalysis
{
+ // For use when initializing an UnboxedLayout. The UniquePtr's destructor
+ // must run when GC is not suppressed.
+ UniquePtr<UnboxedLayout> unboxedLayoutToCleanUp;
+
// Prevent GC activity in the middle of analysis.
gc::AutoSuppressGC suppressGC;
diff --git a/js/src/vm/TypeInference.cpp b/js/src/vm/TypeInference.cpp
index 2b1fa0e3b..39206539b 100644
--- a/js/src/vm/TypeInference.cpp
+++ b/js/src/vm/TypeInference.cpp
@@ -35,6 +35,7 @@
#include "vm/Opcodes.h"
#include "vm/Shape.h"
#include "vm/Time.h"
+#include "vm/UnboxedObject.h"
#include "jsatominlines.h"
#include "jsscriptinlines.h"
@@ -296,6 +297,9 @@ js::ObjectGroupHasProperty(JSContext* cx, ObjectGroup* group, jsid id, const Val
return true;
}
}
+ JSObject* obj = &value.toObject();
+ if (!obj->hasLazyGroup() && obj->group()->maybeOriginalUnboxedGroup())
+ return true;
}
if (!types->hasType(type)) {
@@ -1944,6 +1948,33 @@ class ConstraintDataFreezeObjectForTypedArrayData
}
};
+// Constraint which triggers recompilation if an unboxed object in some group
+// is converted to a native object.
+class ConstraintDataFreezeObjectForUnboxedConvertedToNative
+{
+ public:
+ ConstraintDataFreezeObjectForUnboxedConvertedToNative()
+ {}
+
+ const char* kind() { return "freezeObjectForUnboxedConvertedToNative"; }
+
+ bool invalidateOnNewType(TypeSet::Type type) { return false; }
+ bool invalidateOnNewPropertyState(TypeSet* property) { return false; }
+ bool invalidateOnNewObjectState(ObjectGroup* group) {
+ return group->unboxedLayout().nativeGroup() != nullptr;
+ }
+
+ bool constraintHolds(JSContext* cx,
+ const HeapTypeSetKey& property, TemporaryTypeSet* expected)
+ {
+ return !invalidateOnNewObjectState(property.object()->maybeGroup());
+ }
+
+ bool shouldSweep() { return false; }
+
+ JSCompartment* maybeCompartment() { return nullptr; }
+};
+
} /* anonymous namespace */
void
@@ -2478,6 +2509,8 @@ TemporaryTypeSet::propertyNeedsBarrier(CompilerConstraintList* constraints, jsid
bool
js::ClassCanHaveExtraProperties(const Class* clasp)
{
+ if (clasp == &UnboxedPlainObject::class_)
+ return false;
return clasp->getResolve()
|| clasp->getOpsLookupProperty()
|| clasp->getOpsGetProperty()
@@ -2768,6 +2801,15 @@ js::AddTypePropertyId(ExclusiveContext* cx, ObjectGroup* group, JSObject* obj, j
// from acquiring the fully initialized group.
if (group->newScript() && group->newScript()->initializedGroup())
AddTypePropertyId(cx, group->newScript()->initializedGroup(), nullptr, id, type);
+
+ // Maintain equivalent type information for unboxed object groups and their
+ // corresponding native group. Since type sets might contain the unboxed
+ // group but not the native group, this ensures optimizations based on the
+ // unboxed group are valid for the native group.
+ if (group->maybeUnboxedLayout() && group->maybeUnboxedLayout()->nativeGroup())
+ AddTypePropertyId(cx, group->maybeUnboxedLayout()->nativeGroup(), nullptr, id, type);
+ if (ObjectGroup* unboxedGroup = group->maybeOriginalUnboxedGroup())
+ AddTypePropertyId(cx, unboxedGroup, nullptr, id, type);
}
void
@@ -2839,6 +2881,12 @@ ObjectGroup::setFlags(ExclusiveContext* cx, ObjectGroupFlags flags)
// acquired properties analysis.
if (newScript() && newScript()->initializedGroup())
newScript()->initializedGroup()->setFlags(cx, flags);
+
+ // Propagate flag changes between unboxed and corresponding native groups.
+ if (maybeUnboxedLayout() && maybeUnboxedLayout()->nativeGroup())
+ maybeUnboxedLayout()->nativeGroup()->setFlags(cx, flags);
+ if (ObjectGroup* unboxedGroup = maybeOriginalUnboxedGroup())
+ unboxedGroup->setFlags(cx, flags);
}
void
@@ -2871,6 +2919,23 @@ ObjectGroup::markUnknown(ExclusiveContext* cx)
prop->types.setNonDataProperty(cx);
}
}
+
+ if (ObjectGroup* unboxedGroup = maybeOriginalUnboxedGroup())
+ MarkObjectGroupUnknownProperties(cx, unboxedGroup);
+ if (maybeUnboxedLayout() && maybeUnboxedLayout()->nativeGroup())
+ MarkObjectGroupUnknownProperties(cx, maybeUnboxedLayout()->nativeGroup());
+ if (ObjectGroup* unboxedGroup = maybeOriginalUnboxedGroup())
+ MarkObjectGroupUnknownProperties(cx, unboxedGroup);
+}
+
+TypeNewScript*
+ObjectGroup::anyNewScript()
+{
+ if (newScript())
+ return newScript();
+ if (maybeUnboxedLayout())
+ return unboxedLayout().newScript();
+ return nullptr;
}
void
@@ -2880,7 +2945,7 @@ ObjectGroup::detachNewScript(bool writeBarrier, ObjectGroup* replacement)
// analyzed, remove it from the newObjectGroups table so that it will not be
// produced by calling 'new' on the associated function anymore.
// The TypeNewScript is not actually destroyed.
- TypeNewScript* newScript = this->newScript();
+ TypeNewScript* newScript = anyNewScript();
MOZ_ASSERT(newScript);
if (newScript->analyzed()) {
@@ -2899,7 +2964,10 @@ ObjectGroup::detachNewScript(bool writeBarrier, ObjectGroup* replacement)
MOZ_ASSERT(!replacement);
}
- setAddendum(Addendum_None, nullptr, writeBarrier);
+ if (this->newScript())
+ setAddendum(Addendum_None, nullptr, writeBarrier);
+ else
+ unboxedLayout().setNewScript(nullptr, writeBarrier);
}
void
@@ -2910,7 +2978,7 @@ ObjectGroup::maybeClearNewScriptOnOOM()
if (!isMarked())
return;
- TypeNewScript* newScript = this->newScript();
+ TypeNewScript* newScript = anyNewScript();
if (!newScript)
return;
@@ -2925,7 +2993,7 @@ ObjectGroup::maybeClearNewScriptOnOOM()
void
ObjectGroup::clearNewScript(ExclusiveContext* cx, ObjectGroup* replacement /* = nullptr*/)
{
- TypeNewScript* newScript = this->newScript();
+ TypeNewScript* newScript = anyNewScript();
if (!newScript)
return;
@@ -3390,6 +3458,22 @@ PreliminaryObjectArray::sweep()
for (size_t i = 0; i < COUNT; i++) {
JSObject** ptr = &objects[i];
if (*ptr && IsAboutToBeFinalizedUnbarriered(ptr)) {
+ // Before we clear this reference, change the object's group to the
+ // Object.prototype group. This is done to ensure JSObject::finalize
+ // sees a NativeObject Class even if we change the current group's
+ // Class to one of the unboxed object classes in the meantime. If
+ // the compartment's global is dead, we don't do anything as the
+ // group's Class is not going to change in that case.
+ JSObject* obj = *ptr;
+ GlobalObject* global = obj->compartment()->unsafeUnbarrieredMaybeGlobal();
+ if (global && !obj->isSingleton()) {
+ JSObject* objectProto = GetBuiltinPrototypePure(global, JSProto_Object);
+ obj->setGroup(objectProto->groupRaw());
+ MOZ_ASSERT(obj->is<NativeObject>());
+ MOZ_ASSERT(obj->getClass() == objectProto->getClass());
+ MOZ_ASSERT(!obj->getClass()->hasFinalize());
+ }
+
*ptr = nullptr;
}
}
@@ -3489,11 +3573,16 @@ PreliminaryObjectArrayWithTemplate::maybeAnalyze(ExclusiveContext* cx, ObjectGro
}
}
- // Since the preliminary objects still reflect the template object's
- // properties, and all objects in the future will be created with those
- // properties, the properties can be marked as definitive for objects in
- // the group.
- group->addDefiniteProperties(cx, shape());
+ if (group->maybeUnboxedLayout())
+ return;
+
+ if (shape()) {
+ // We weren't able to use an unboxed layout, but since the preliminary
+ // objects still reflect the template object's properties, and all
+ // objects in the future will be created with those properties, the
+ // properties can be marked as definite for objects in the group.
+ group->addDefiniteProperties(cx, shape());
+ }
}
/////////////////////////////////////////////////////////////////////
@@ -3507,6 +3596,7 @@ TypeNewScript::make(JSContext* cx, ObjectGroup* group, JSFunction* fun)
{
MOZ_ASSERT(cx->zone()->types.activeAnalysis);
MOZ_ASSERT(!group->newScript());
+ MOZ_ASSERT(!group->maybeUnboxedLayout());
// rollbackPartiallyInitializedObjects expects function_ to be
// canonicalized.
@@ -3814,6 +3904,27 @@ TypeNewScript::maybeAnalyze(JSContext* cx, ObjectGroup* group, bool* regenerate,
js_delete(preliminaryObjects);
preliminaryObjects = nullptr;
+ if (group->maybeUnboxedLayout()) {
+ // An unboxed layout was constructed for the group, and this has already
+ // been hooked into it.
+ MOZ_ASSERT(group->unboxedLayout().newScript() == this);
+ destroyNewScript.group = nullptr;
+
+ // Clear out the template object, which is not used for TypeNewScripts
+ // with an unboxed layout. Currently it is a mutant object with a
+ // non-native group and native shape, so make it safe for GC by changing
+ // its group to the default for its prototype.
+ AutoEnterOOMUnsafeRegion oomUnsafe;
+ ObjectGroup* plainGroup = ObjectGroup::defaultNewGroup(cx, &PlainObject::class_,
+ group->proto());
+ if (!plainGroup)
+ oomUnsafe.crash("TypeNewScript::maybeAnalyze");
+ templateObject_->setGroup(plainGroup);
+ templateObject_ = nullptr;
+
+ return true;
+ }
+
if (prefixShape->slotSpan() == templateObject()->slotSpan()) {
// The definite properties analysis found exactly the properties that
// are held in common by the preliminary objects. No further analysis
@@ -3927,6 +4038,12 @@ TypeNewScript::rollbackPartiallyInitializedObjects(JSContext* cx, ObjectGroup* g
continue;
}
+ if (thisv.toObject().is<UnboxedPlainObject>()) {
+ AutoEnterOOMUnsafeRegion oomUnsafe;
+ if (!UnboxedPlainObject::convertToNative(cx, &thisv.toObject()))
+ oomUnsafe.crash("rollbackPartiallyInitializedObjects");
+ }
+
// Found a matching frame.
RootedPlainObject obj(cx, &thisv.toObject().as<PlainObject>());
@@ -4120,6 +4237,12 @@ ConstraintTypeSet::sweep(Zone* zone, AutoClearTypeInferenceStateOnOOM& oom)
// Object sets containing objects with unknown properties might
// not be complete. Mark the type set as unknown, which it will
// be treated as during Ion compilation.
+ //
+ // Note that we don't have to do this when the type set might
+ // be missing the native group corresponding to an unboxed
+ // object group. In this case, the native group points to the
+ // unboxed object group via its addendum, so as long as objects
+ // with either group exist, neither group will be finalized.
flags |= TYPE_FLAG_ANYOBJECT;
clearObjects();
objectCount = 0;
@@ -4203,6 +4326,21 @@ ObjectGroup::sweep(AutoClearTypeInferenceStateOnOOM* oom)
Maybe<AutoClearTypeInferenceStateOnOOM> fallbackOOM;
EnsureHasAutoClearTypeInferenceStateOnOOM(oom, zone(), fallbackOOM);
+ if (maybeUnboxedLayout()) {
+ // Remove unboxed layouts that are about to be finalized from the
+ // compartment wide list while we are still on the main thread.
+ ObjectGroup* group = this;
+ if (IsAboutToBeFinalizedUnbarriered(&group))
+ unboxedLayout().detachFromCompartment();
+
+ if (unboxedLayout().newScript())
+ unboxedLayout().newScript()->sweep();
+
+ // Discard constructor code to avoid holding onto ExecutablePools.
+ if (zone()->isGCCompacting())
+ unboxedLayout().setConstructorCode(nullptr);
+ }
+
if (maybePreliminaryObjects())
maybePreliminaryObjects()->sweep();
diff --git a/js/src/vm/UnboxedObject-inl.h b/js/src/vm/UnboxedObject-inl.h
new file mode 100644
index 000000000..c1468a5b1
--- /dev/null
+++ b/js/src/vm/UnboxedObject-inl.h
@@ -0,0 +1,177 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef vm_UnboxedObject_inl_h
+#define vm_UnboxedObject_inl_h
+
+#include "vm/UnboxedObject.h"
+
+#include "gc/StoreBuffer-inl.h"
+#include "vm/ArrayObject-inl.h"
+#include "vm/NativeObject-inl.h"
+
+namespace js {
+
+static inline Value
+GetUnboxedValue(uint8_t* p, JSValueType type, bool maybeUninitialized)
+{
+ switch (type) {
+ case JSVAL_TYPE_BOOLEAN:
+ return BooleanValue(*p != 0);
+
+ case JSVAL_TYPE_INT32:
+ return Int32Value(*reinterpret_cast<int32_t*>(p));
+
+ case JSVAL_TYPE_DOUBLE: {
+ // During unboxed plain object creation, non-GC thing properties are
+ // left uninitialized. This is normally fine, since the properties will
+ // be filled in shortly, but if they are read before that happens we
+ // need to make sure that doubles are canonical.
+ double d = *reinterpret_cast<double*>(p);
+ if (maybeUninitialized)
+ return DoubleValue(JS::CanonicalizeNaN(d));
+ return DoubleValue(d);
+ }
+
+ case JSVAL_TYPE_STRING:
+ return StringValue(*reinterpret_cast<JSString**>(p));
+
+ case JSVAL_TYPE_OBJECT:
+ return ObjectOrNullValue(*reinterpret_cast<JSObject**>(p));
+
+ default:
+ MOZ_CRASH("Invalid type for unboxed value");
+ }
+}
+
+static inline void
+SetUnboxedValueNoTypeChange(JSObject* unboxedObject,
+ uint8_t* p, JSValueType type, const Value& v,
+ bool preBarrier)
+{
+ switch (type) {
+ case JSVAL_TYPE_BOOLEAN:
+ *p = v.toBoolean();
+ return;
+
+ case JSVAL_TYPE_INT32:
+ *reinterpret_cast<int32_t*>(p) = v.toInt32();
+ return;
+
+ case JSVAL_TYPE_DOUBLE:
+ *reinterpret_cast<double*>(p) = v.toNumber();
+ return;
+
+ case JSVAL_TYPE_STRING: {
+ MOZ_ASSERT(!IsInsideNursery(v.toString()));
+ JSString** np = reinterpret_cast<JSString**>(p);
+ if (preBarrier)
+ JSString::writeBarrierPre(*np);
+ *np = v.toString();
+ return;
+ }
+
+ case JSVAL_TYPE_OBJECT: {
+ JSObject** np = reinterpret_cast<JSObject**>(p);
+
+ // Manually trigger post barriers on the whole object. If we treat
+ // the pointer as a HeapPtrObject we will get confused later if the
+ // object is converted to its native representation.
+ JSObject* obj = v.toObjectOrNull();
+ if (IsInsideNursery(obj) && !IsInsideNursery(unboxedObject)) {
+ JSRuntime* rt = unboxedObject->runtimeFromMainThread();
+ rt->gc.storeBuffer.putWholeCell(unboxedObject);
+ }
+
+ if (preBarrier)
+ JSObject::writeBarrierPre(*np);
+ *np = obj;
+ return;
+ }
+
+ default:
+ MOZ_CRASH("Invalid type for unboxed value");
+ }
+}
+
+static inline bool
+SetUnboxedValue(ExclusiveContext* cx, JSObject* unboxedObject, jsid id,
+ uint8_t* p, JSValueType type, const Value& v, bool preBarrier)
+{
+ switch (type) {
+ case JSVAL_TYPE_BOOLEAN:
+ if (v.isBoolean()) {
+ *p = v.toBoolean();
+ return true;
+ }
+ return false;
+
+ case JSVAL_TYPE_INT32:
+ if (v.isInt32()) {
+ *reinterpret_cast<int32_t*>(p) = v.toInt32();
+ return true;
+ }
+ return false;
+
+ case JSVAL_TYPE_DOUBLE:
+ if (v.isNumber()) {
+ *reinterpret_cast<double*>(p) = v.toNumber();
+ return true;
+ }
+ return false;
+
+ case JSVAL_TYPE_STRING:
+ if (v.isString()) {
+ MOZ_ASSERT(!IsInsideNursery(v.toString()));
+ JSString** np = reinterpret_cast<JSString**>(p);
+ if (preBarrier)
+ JSString::writeBarrierPre(*np);
+ *np = v.toString();
+ return true;
+ }
+ return false;
+
+ case JSVAL_TYPE_OBJECT:
+ if (v.isObjectOrNull()) {
+ JSObject** np = reinterpret_cast<JSObject**>(p);
+
+ // Update property types when writing object properties. Types for
+ // other properties were captured when the unboxed layout was
+ // created.
+ AddTypePropertyId(cx, unboxedObject, id, v);
+
+ // As above, trigger post barriers on the whole object.
+ JSObject* obj = v.toObjectOrNull();
+ if (IsInsideNursery(v.toObjectOrNull()) && !IsInsideNursery(unboxedObject)) {
+ JSRuntime* rt = unboxedObject->runtimeFromMainThread();
+ rt->gc.storeBuffer.putWholeCell(unboxedObject);
+ }
+
+ if (preBarrier)
+ JSObject::writeBarrierPre(*np);
+ *np = obj;
+ return true;
+ }
+ return false;
+
+ default:
+ MOZ_CRASH("Invalid type for unboxed value");
+ }
+}
+
+/////////////////////////////////////////////////////////////////////
+// UnboxedPlainObject
+/////////////////////////////////////////////////////////////////////
+
+inline const UnboxedLayout&
+UnboxedPlainObject::layout() const
+{
+ return group()->unboxedLayout();
+}
+
+} // namespace js
+
+#endif // vm_UnboxedObject_inl_h
diff --git a/js/src/vm/UnboxedObject.cpp b/js/src/vm/UnboxedObject.cpp
new file mode 100644
index 000000000..2e017ca3b
--- /dev/null
+++ b/js/src/vm/UnboxedObject.cpp
@@ -0,0 +1,946 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "vm/UnboxedObject-inl.h"
+
+#include "jit/BaselineIC.h"
+#include "jit/ExecutableAllocator.h"
+#include "jit/JitCommon.h"
+#include "jit/Linker.h"
+
+#include "jsobjinlines.h"
+
+#include "gc/Nursery-inl.h"
+#include "jit/MacroAssembler-inl.h"
+#include "vm/Shape-inl.h"
+
+using mozilla::ArrayLength;
+using mozilla::DebugOnly;
+using mozilla::PodCopy;
+
+using namespace js;
+
+/////////////////////////////////////////////////////////////////////
+// UnboxedLayout
+/////////////////////////////////////////////////////////////////////
+
+void
+UnboxedLayout::trace(JSTracer* trc)
+{
+ for (size_t i = 0; i < properties_.length(); i++)
+ TraceManuallyBarrieredEdge(trc, &properties_[i].name, "unboxed_layout_name");
+
+ if (newScript())
+ newScript()->trace(trc);
+
+ TraceNullableEdge(trc, &nativeGroup_, "unboxed_layout_nativeGroup");
+ TraceNullableEdge(trc, &nativeShape_, "unboxed_layout_nativeShape");
+ TraceNullableEdge(trc, &allocationScript_, "unboxed_layout_allocationScript");
+ TraceNullableEdge(trc, &replacementGroup_, "unboxed_layout_replacementGroup");
+ TraceNullableEdge(trc, &constructorCode_, "unboxed_layout_constructorCode");
+}
+
+size_t
+UnboxedLayout::sizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf)
+{
+ return mallocSizeOf(this)
+ + properties_.sizeOfExcludingThis(mallocSizeOf)
+ + (newScript() ? newScript()->sizeOfIncludingThis(mallocSizeOf) : 0)
+ + mallocSizeOf(traceList());
+}
+
+void
+UnboxedLayout::setNewScript(TypeNewScript* newScript, bool writeBarrier /* = true */)
+{
+ if (newScript_ && writeBarrier)
+ TypeNewScript::writeBarrierPre(newScript_);
+ newScript_ = newScript;
+}
+
+// Constructor code returns a 0x1 value to indicate the constructor code should
+// be cleared.
+static const uintptr_t CLEAR_CONSTRUCTOR_CODE_TOKEN = 0x1;
+
+/* static */ bool
+UnboxedLayout::makeConstructorCode(JSContext* cx, HandleObjectGroup group)
+{
+ gc::AutoSuppressGC suppress(cx);
+
+ using namespace jit;
+
+ if (!cx->compartment()->ensureJitCompartmentExists(cx))
+ return false;
+
+ UnboxedLayout& layout = group->unboxedLayout();
+ MOZ_ASSERT(!layout.constructorCode());
+
+ UnboxedPlainObject* templateObject = UnboxedPlainObject::create(cx, group, TenuredObject);
+ if (!templateObject)
+ return false;
+
+ JitContext jitContext(cx, nullptr);
+
+ MacroAssembler masm;
+
+ Register propertiesReg, newKindReg;
+#ifdef JS_CODEGEN_X86
+ propertiesReg = eax;
+ newKindReg = ecx;
+ masm.loadPtr(Address(masm.getStackPointer(), sizeof(void*)), propertiesReg);
+ masm.loadPtr(Address(masm.getStackPointer(), 2 * sizeof(void*)), newKindReg);
+#else
+ propertiesReg = IntArgReg0;
+ newKindReg = IntArgReg1;
+#endif
+
+#ifdef JS_CODEGEN_ARM64
+ // ARM64 communicates stack address via sp, but uses a pseudo-sp for addressing.
+ masm.initStackPtr();
+#endif
+
+ MOZ_ASSERT(propertiesReg.volatile_());
+ MOZ_ASSERT(newKindReg.volatile_());
+
+ AllocatableGeneralRegisterSet regs(GeneralRegisterSet::All());
+ regs.take(propertiesReg);
+ regs.take(newKindReg);
+ Register object = regs.takeAny(), scratch1 = regs.takeAny(), scratch2 = regs.takeAny();
+
+ LiveGeneralRegisterSet savedNonVolatileRegisters = SavedNonVolatileRegisters(regs);
+ masm.PushRegsInMask(savedNonVolatileRegisters);
+
+ // The scratch double register might be used by MacroAssembler methods.
+ if (ScratchDoubleReg.volatile_())
+ masm.push(ScratchDoubleReg);
+
+ Label failure, tenuredObject, allocated;
+ masm.branch32(Assembler::NotEqual, newKindReg, Imm32(GenericObject), &tenuredObject);
+ masm.branchTest32(Assembler::NonZero, AbsoluteAddress(group->addressOfFlags()),
+ Imm32(OBJECT_FLAG_PRE_TENURE), &tenuredObject);
+
+ // Allocate an object in the nursery
+ masm.createGCObject(object, scratch1, templateObject, gc::DefaultHeap, &failure,
+ /* initFixedSlots = */ false);
+
+ masm.jump(&allocated);
+ masm.bind(&tenuredObject);
+
+ // Allocate an object in the tenured heap.
+ masm.createGCObject(object, scratch1, templateObject, gc::TenuredHeap, &failure,
+ /* initFixedSlots = */ false);
+
+ // If any of the properties being stored are in the nursery, add a store
+ // buffer entry for the new object.
+ Label postBarrier;
+ for (size_t i = 0; i < layout.properties().length(); i++) {
+ const UnboxedLayout::Property& property = layout.properties()[i];
+ if (property.type == JSVAL_TYPE_OBJECT) {
+ Address valueAddress(propertiesReg, i * sizeof(IdValuePair) + offsetof(IdValuePair, value));
+ Label notObject;
+ masm.branchTestObject(Assembler::NotEqual, valueAddress, &notObject);
+ Register valueObject = masm.extractObject(valueAddress, scratch1);
+ masm.branchPtrInNurseryChunk(Assembler::Equal, valueObject, scratch2, &postBarrier);
+ masm.bind(&notObject);
+ }
+ }
+
+ masm.jump(&allocated);
+ masm.bind(&postBarrier);
+
+ LiveGeneralRegisterSet liveVolatileRegisters;
+ liveVolatileRegisters.add(propertiesReg);
+ if (object.volatile_())
+ liveVolatileRegisters.add(object);
+ masm.PushRegsInMask(liveVolatileRegisters);
+
+ masm.mov(ImmPtr(cx->runtime()), scratch1);
+ masm.setupUnalignedABICall(scratch2);
+ masm.passABIArg(scratch1);
+ masm.passABIArg(object);
+ masm.callWithABI(JS_FUNC_TO_DATA_PTR(void*, PostWriteBarrier));
+
+ masm.PopRegsInMask(liveVolatileRegisters);
+
+ masm.bind(&allocated);
+
+ ValueOperand valueOperand;
+#ifdef JS_NUNBOX32
+ valueOperand = ValueOperand(scratch1, scratch2);
+#else
+ valueOperand = ValueOperand(scratch1);
+#endif
+
+ Label failureStoreOther, failureStoreObject;
+
+ for (size_t i = 0; i < layout.properties().length(); i++) {
+ const UnboxedLayout::Property& property = layout.properties()[i];
+ Address valueAddress(propertiesReg, i * sizeof(IdValuePair) + offsetof(IdValuePair, value));
+ Address targetAddress(object, UnboxedPlainObject::offsetOfData() + property.offset);
+
+ masm.loadValue(valueAddress, valueOperand);
+
+ if (property.type == JSVAL_TYPE_OBJECT) {
+ HeapTypeSet* types = group->maybeGetProperty(IdToTypeId(NameToId(property.name)));
+
+ Label notObject;
+ masm.branchTestObject(Assembler::NotEqual, valueOperand,
+ types->mightBeMIRType(MIRType::Null) ? &notObject : &failureStoreObject);
+
+ Register payloadReg = masm.extractObject(valueOperand, scratch1);
+
+ if (!types->hasType(TypeSet::AnyObjectType())) {
+ Register scratch = (payloadReg == scratch1) ? scratch2 : scratch1;
+ masm.guardObjectType(payloadReg, types, scratch, &failureStoreObject);
+ }
+
+ masm.storeUnboxedProperty(targetAddress, JSVAL_TYPE_OBJECT,
+ TypedOrValueRegister(MIRType::Object,
+ AnyRegister(payloadReg)), nullptr);
+
+ if (notObject.used()) {
+ Label done;
+ masm.jump(&done);
+ masm.bind(&notObject);
+ masm.branchTestNull(Assembler::NotEqual, valueOperand, &failureStoreOther);
+ masm.storeUnboxedProperty(targetAddress, JSVAL_TYPE_OBJECT, NullValue(), nullptr);
+ masm.bind(&done);
+ }
+ } else {
+ masm.storeUnboxedProperty(targetAddress, property.type,
+ ConstantOrRegister(valueOperand), &failureStoreOther);
+ }
+ }
+
+ Label done;
+ masm.bind(&done);
+
+ if (object != ReturnReg)
+ masm.movePtr(object, ReturnReg);
+
+ // Restore non-volatile registers which were saved on entry.
+ if (ScratchDoubleReg.volatile_())
+ masm.pop(ScratchDoubleReg);
+ masm.PopRegsInMask(savedNonVolatileRegisters);
+
+ masm.abiret();
+
+ masm.bind(&failureStoreOther);
+
+ // There was a failure while storing a value which cannot be stored at all
+ // in the unboxed object. Initialize the object so it is safe for GC and
+ // return null.
+ masm.initUnboxedObjectContents(object, templateObject);
+
+ masm.bind(&failure);
+
+ masm.movePtr(ImmWord(0), object);
+ masm.jump(&done);
+
+ masm.bind(&failureStoreObject);
+
+ // There was a failure while storing a value to an object slot of the
+ // unboxed object. If the value is storable, the failure occurred due to
+ // incomplete type information in the object, so return a token to trigger
+ // regeneration of the jitcode after a new object is created in the VM.
+ {
+ Label isObject;
+ masm.branchTestObject(Assembler::Equal, valueOperand, &isObject);
+ masm.branchTestNull(Assembler::NotEqual, valueOperand, &failureStoreOther);
+ masm.bind(&isObject);
+ }
+
+ // Initialize the object so it is safe for GC.
+ masm.initUnboxedObjectContents(object, templateObject);
+
+ masm.movePtr(ImmWord(CLEAR_CONSTRUCTOR_CODE_TOKEN), object);
+ masm.jump(&done);
+
+ Linker linker(masm);
+ AutoFlushICache afc("UnboxedObject");
+ JitCode* code = linker.newCode<NoGC>(cx, OTHER_CODE);
+ if (!code)
+ return false;
+
+ layout.setConstructorCode(code);
+ return true;
+}
+
+void
+UnboxedLayout::detachFromCompartment()
+{
+ if (isInList())
+ remove();
+}
+
+/////////////////////////////////////////////////////////////////////
+// UnboxedPlainObject
+/////////////////////////////////////////////////////////////////////
+
+bool
+UnboxedPlainObject::setValue(ExclusiveContext* cx, const UnboxedLayout::Property& property,
+ const Value& v)
+{
+ uint8_t* p = &data_[property.offset];
+ return SetUnboxedValue(cx, this, NameToId(property.name), p, property.type, v,
+ /* preBarrier = */ true);
+}
+
+Value
+UnboxedPlainObject::getValue(const UnboxedLayout::Property& property,
+ bool maybeUninitialized /* = false */)
+{
+ uint8_t* p = &data_[property.offset];
+ return GetUnboxedValue(p, property.type, maybeUninitialized);
+}
+
+void
+UnboxedPlainObject::trace(JSTracer* trc, JSObject* obj)
+{
+ if (obj->as<UnboxedPlainObject>().expando_) {
+ TraceManuallyBarrieredEdge(trc,
+ reinterpret_cast<NativeObject**>(&obj->as<UnboxedPlainObject>().expando_),
+ "unboxed_expando");
+ }
+
+ const UnboxedLayout& layout = obj->as<UnboxedPlainObject>().layoutDontCheckGeneration();
+ const int32_t* list = layout.traceList();
+ if (!list)
+ return;
+
+ uint8_t* data = obj->as<UnboxedPlainObject>().data();
+ while (*list != -1) {
+ GCPtrString* heap = reinterpret_cast<GCPtrString*>(data + *list);
+ TraceEdge(trc, heap, "unboxed_string");
+ list++;
+ }
+ list++;
+ while (*list != -1) {
+ GCPtrObject* heap = reinterpret_cast<GCPtrObject*>(data + *list);
+ TraceNullableEdge(trc, heap, "unboxed_object");
+ list++;
+ }
+
+ // Unboxed objects don't have Values to trace.
+ MOZ_ASSERT(*(list + 1) == -1);
+}
+
+/* static */ UnboxedExpandoObject*
+UnboxedPlainObject::ensureExpando(JSContext* cx, Handle<UnboxedPlainObject*> obj)
+{
+ if (obj->expando_)
+ return obj->expando_;
+
+ UnboxedExpandoObject* expando =
+ NewObjectWithGivenProto<UnboxedExpandoObject>(cx, nullptr, gc::AllocKind::OBJECT4);
+ if (!expando)
+ return nullptr;
+
+ // Don't track property types for expando objects. This allows Baseline
+ // and Ion AddSlot ICs to guard on the unboxed group without guarding on
+ // the expando group.
+ MarkObjectGroupUnknownProperties(cx, expando->group());
+
+ // If the expando is tenured then the original object must also be tenured.
+ // Otherwise barriers triggered on the original object for writes to the
+ // expando (as can happen in the JIT) won't see the tenured->nursery edge.
+ // See WholeCellEdges::mark.
+ MOZ_ASSERT_IF(!IsInsideNursery(expando), !IsInsideNursery(obj));
+
+ // As with setValue(), we need to manually trigger post barriers on the
+ // whole object. If we treat the field as a GCPtrObject and later
+ // convert the object to its native representation, we will end up with a
+ // corrupted store buffer entry.
+ if (IsInsideNursery(expando) && !IsInsideNursery(obj))
+ cx->runtime()->gc.storeBuffer.putWholeCell(obj);
+
+ obj->expando_ = expando;
+ return expando;
+}
+
+bool
+UnboxedPlainObject::containsUnboxedOrExpandoProperty(ExclusiveContext* cx, jsid id) const
+{
+ if (layout().lookup(id))
+ return true;
+
+ if (maybeExpando() && maybeExpando()->containsShapeOrElement(cx, id))
+ return true;
+
+ return false;
+}
+
+static bool
+PropagatePropertyTypes(JSContext* cx, jsid id, ObjectGroup* oldGroup, ObjectGroup* newGroup)
+{
+ HeapTypeSet* typeProperty = oldGroup->maybeGetProperty(id);
+ TypeSet::TypeList types;
+ if (!typeProperty->enumerateTypes(&types)) {
+ ReportOutOfMemory(cx);
+ return false;
+ }
+ for (size_t j = 0; j < types.length(); j++)
+ AddTypePropertyId(cx, newGroup, nullptr, id, types[j]);
+ return true;
+}
+
+static PlainObject*
+MakeReplacementTemplateObject(JSContext* cx, HandleObjectGroup group, const UnboxedLayout &layout)
+{
+ PlainObject* obj = NewObjectWithGroup<PlainObject>(cx, group, layout.getAllocKind(),
+ TenuredObject);
+ if (!obj)
+ return nullptr;
+
+ for (size_t i = 0; i < layout.properties().length(); i++) {
+ const UnboxedLayout::Property& property = layout.properties()[i];
+ if (!obj->addDataProperty(cx, NameToId(property.name), i, JSPROP_ENUMERATE))
+ return nullptr;
+ MOZ_ASSERT(obj->slotSpan() == i + 1);
+ MOZ_ASSERT(!obj->inDictionaryMode());
+ }
+
+ return obj;
+}
+
+/* static */ bool
+UnboxedLayout::makeNativeGroup(JSContext* cx, ObjectGroup* group)
+{
+ AutoEnterAnalysis enter(cx);
+
+ UnboxedLayout& layout = group->unboxedLayout();
+ Rooted<TaggedProto> proto(cx, group->proto());
+
+ MOZ_ASSERT(!layout.nativeGroup());
+
+ RootedObjectGroup replacementGroup(cx);
+
+ // Immediately clear any new script on the group. This is done by replacing
+ // the existing new script with one for a replacement default new group.
+ // This is done so that the size of the replacment group's objects is the
+ // same as that for the unboxed group, so that we do not see polymorphic
+ // slot accesses later on for sites that see converted objects from this
+ // group and objects that were allocated using the replacement new group.
+ if (layout.newScript()) {
+ replacementGroup = ObjectGroupCompartment::makeGroup(cx, &PlainObject::class_, proto);
+ if (!replacementGroup)
+ return false;
+
+ PlainObject* templateObject = MakeReplacementTemplateObject(cx, replacementGroup, layout);
+ if (!templateObject)
+ return false;
+
+ TypeNewScript* replacementNewScript =
+ TypeNewScript::makeNativeVersion(cx, layout.newScript(), templateObject);
+ if (!replacementNewScript)
+ return false;
+
+ replacementGroup->setNewScript(replacementNewScript);
+ gc::TraceTypeNewScript(replacementGroup);
+
+ group->clearNewScript(cx, replacementGroup);
+ }
+
+ // Similarly, if this group is keyed to an allocation site, replace its
+ // entry with a new group that has no unboxed layout.
+ if (layout.allocationScript()) {
+ RootedScript script(cx, layout.allocationScript());
+ jsbytecode* pc = layout.allocationPc();
+
+ replacementGroup = ObjectGroupCompartment::makeGroup(cx, &PlainObject::class_, proto);
+ if (!replacementGroup)
+ return false;
+
+ PlainObject* templateObject = &script->getObject(pc)->as<PlainObject>();
+ replacementGroup->addDefiniteProperties(cx, templateObject->lastProperty());
+
+ cx->compartment()->objectGroups.replaceAllocationSiteGroup(script, pc, JSProto_Object,
+ replacementGroup);
+
+ // Clear any baseline information at this opcode which might use the old group.
+ if (script->hasBaselineScript()) {
+ jit::ICEntry& entry = script->baselineScript()->icEntryFromPCOffset(script->pcToOffset(pc));
+ jit::ICFallbackStub* fallback = entry.fallbackStub();
+ for (jit::ICStubIterator iter = fallback->beginChain(); !iter.atEnd(); iter++)
+ iter.unlink(cx);
+ if (fallback->isNewObject_Fallback())
+ fallback->toNewObject_Fallback()->setTemplateObject(nullptr);
+ else if (fallback->isNewArray_Fallback())
+ fallback->toNewArray_Fallback()->setTemplateGroup(replacementGroup);
+ }
+ }
+
+ size_t nfixed = gc::GetGCKindSlots(layout.getAllocKind());
+
+ RootedShape shape(cx, EmptyShape::getInitialShape(cx, &PlainObject::class_, proto, nfixed, 0));
+ if (!shape)
+ return false;
+
+ // Add shapes for each property, if this is for a plain object.
+ for (size_t i = 0; i < layout.properties().length(); i++) {
+ const UnboxedLayout::Property& property = layout.properties()[i];
+
+ Rooted<StackShape> child(cx, StackShape(shape->base()->unowned(), NameToId(property.name),
+ i, JSPROP_ENUMERATE, 0));
+ shape = cx->zone()->propertyTree.getChild(cx, shape, child);
+ if (!shape)
+ return false;
+ }
+
+ ObjectGroup* nativeGroup =
+ ObjectGroupCompartment::makeGroup(cx, &PlainObject::class_, proto,
+ group->flags() & OBJECT_FLAG_DYNAMIC_MASK);
+ if (!nativeGroup)
+ return false;
+
+ // No sense propagating if we don't know what we started with.
+ if (!group->unknownProperties()) {
+ // Propagate all property types from the old group to the new group.
+ for (size_t i = 0; i < layout.properties().length(); i++) {
+ const UnboxedLayout::Property& property = layout.properties()[i];
+ jsid id = NameToId(property.name);
+ if (!PropagatePropertyTypes(cx, id, group, nativeGroup))
+ return false;
+
+ // If we are OOM we may not be able to propagate properties.
+ if (nativeGroup->unknownProperties())
+ break;
+
+ HeapTypeSet* nativeProperty = nativeGroup->maybeGetProperty(id);
+ if (nativeProperty && nativeProperty->canSetDefinite(i))
+ nativeProperty->setDefinite(i);
+ }
+ } else {
+ // If we skip, though, the new group had better agree.
+ MOZ_ASSERT(nativeGroup->unknownProperties());
+ }
+
+ layout.nativeGroup_ = nativeGroup;
+ layout.nativeShape_ = shape;
+ layout.replacementGroup_ = replacementGroup;
+
+ nativeGroup->setOriginalUnboxedGroup(group);
+
+ group->markStateChange(cx);
+
+ return true;
+}
+
+/* static */ bool
+UnboxedPlainObject::convertToNative(JSContext* cx, JSObject* obj)
+{
+ const UnboxedLayout& layout = obj->as<UnboxedPlainObject>().layout();
+ UnboxedExpandoObject* expando = obj->as<UnboxedPlainObject>().maybeExpando();
+
+ if (!layout.nativeGroup()) {
+ if (!UnboxedLayout::makeNativeGroup(cx, obj->group()))
+ return false;
+
+ // makeNativeGroup can reentrantly invoke this method.
+ if (obj->is<PlainObject>())
+ return true;
+ }
+
+ AutoValueVector values(cx);
+ for (size_t i = 0; i < layout.properties().length(); i++) {
+ // We might be reading properties off the object which have not been
+ // initialized yet. Make sure any double values we read here are
+ // canonicalized.
+ if (!values.append(obj->as<UnboxedPlainObject>().getValue(layout.properties()[i], true)))
+ return false;
+ }
+
+ // We are eliminating the expando edge with the conversion, so trigger a
+ // pre barrier.
+ JSObject::writeBarrierPre(expando);
+
+ // Additionally trigger a post barrier on the expando itself. Whole cell
+ // store buffer entries can be added on the original unboxed object for
+ // writes to the expando (see WholeCellEdges::trace), so after conversion
+ // we need to make sure the expando itself will still be traced.
+ if (expando && !IsInsideNursery(expando))
+ cx->runtime()->gc.storeBuffer.putWholeCell(expando);
+
+ obj->setGroup(layout.nativeGroup());
+ obj->as<PlainObject>().setLastPropertyMakeNative(cx, layout.nativeShape());
+
+ for (size_t i = 0; i < values.length(); i++)
+ obj->as<PlainObject>().initSlotUnchecked(i, values[i]);
+
+ if (expando) {
+ // Add properties from the expando object to the object, in order.
+ // Suppress GC here, so that callers don't need to worry about this
+ // method collecting. The stuff below can only fail due to OOM, in
+ // which case the object will not have been completely filled back in.
+ gc::AutoSuppressGC suppress(cx);
+
+ Vector<jsid> ids(cx);
+ for (Shape::Range<NoGC> r(expando->lastProperty()); !r.empty(); r.popFront()) {
+ if (!ids.append(r.front().propid()))
+ return false;
+ }
+ for (size_t i = 0; i < expando->getDenseInitializedLength(); i++) {
+ if (!expando->getDenseElement(i).isMagic(JS_ELEMENTS_HOLE)) {
+ if (!ids.append(INT_TO_JSID(i)))
+ return false;
+ }
+ }
+ ::Reverse(ids.begin(), ids.end());
+
+ RootedPlainObject nobj(cx, &obj->as<PlainObject>());
+ Rooted<UnboxedExpandoObject*> nexpando(cx, expando);
+ RootedId id(cx);
+ Rooted<PropertyDescriptor> desc(cx);
+ for (size_t i = 0; i < ids.length(); i++) {
+ id = ids[i];
+ if (!GetOwnPropertyDescriptor(cx, nexpando, id, &desc))
+ return false;
+ ObjectOpResult result;
+ if (!DefineProperty(cx, nobj, id, desc, result))
+ return false;
+ MOZ_ASSERT(result.ok());
+ }
+ }
+
+ return true;
+}
+
+/* static */
+UnboxedPlainObject*
+UnboxedPlainObject::create(ExclusiveContext* cx, HandleObjectGroup group, NewObjectKind newKind)
+{
+ AutoSetNewObjectMetadata metadata(cx);
+
+ MOZ_ASSERT(group->clasp() == &class_);
+ gc::AllocKind allocKind = group->unboxedLayout().getAllocKind();
+
+ UnboxedPlainObject* res =
+ NewObjectWithGroup<UnboxedPlainObject>(cx, group, allocKind, newKind);
+ if (!res)
+ return nullptr;
+
+ // Overwrite the dummy shape which was written to the object's expando field.
+ res->initExpando();
+
+ // Initialize reference fields of the object. All fields in the object will
+ // be overwritten shortly, but references need to be safe for the GC.
+ const int32_t* list = res->layout().traceList();
+ if (list) {
+ uint8_t* data = res->data();
+ while (*list != -1) {
+ GCPtrString* heap = reinterpret_cast<GCPtrString*>(data + *list);
+ heap->init(cx->names().empty);
+ list++;
+ }
+ list++;
+ while (*list != -1) {
+ GCPtrObject* heap = reinterpret_cast<GCPtrObject*>(data + *list);
+ heap->init(nullptr);
+ list++;
+ }
+ // Unboxed objects don't have Values to initialize.
+ MOZ_ASSERT(*(list + 1) == -1);
+ }
+
+ return res;
+}
+
+/* static */ JSObject*
+UnboxedPlainObject::createWithProperties(ExclusiveContext* cx, HandleObjectGroup group,
+ NewObjectKind newKind, IdValuePair* properties)
+{
+ MOZ_ASSERT(newKind == GenericObject || newKind == TenuredObject);
+
+ UnboxedLayout& layout = group->unboxedLayout();
+
+ if (layout.constructorCode()) {
+ MOZ_ASSERT(cx->isJSContext());
+
+ typedef JSObject* (*ConstructorCodeSignature)(IdValuePair*, NewObjectKind);
+ ConstructorCodeSignature function =
+ reinterpret_cast<ConstructorCodeSignature>(layout.constructorCode()->raw());
+
+ JSObject* obj;
+ {
+ JS::AutoSuppressGCAnalysis nogc;
+ obj = reinterpret_cast<JSObject*>(CALL_GENERATED_2(function, properties, newKind));
+ }
+ if (obj > reinterpret_cast<JSObject*>(CLEAR_CONSTRUCTOR_CODE_TOKEN))
+ return obj;
+
+ if (obj == reinterpret_cast<JSObject*>(CLEAR_CONSTRUCTOR_CODE_TOKEN))
+ layout.setConstructorCode(nullptr);
+ }
+
+ UnboxedPlainObject* obj = UnboxedPlainObject::create(cx, group, newKind);
+ if (!obj)
+ return nullptr;
+
+ for (size_t i = 0; i < layout.properties().length(); i++) {
+ if (!obj->setValue(cx, layout.properties()[i], properties[i].value))
+ return NewPlainObjectWithProperties(cx, properties, layout.properties().length(), newKind);
+ }
+
+#ifndef JS_CODEGEN_NONE
+ if (cx->isJSContext() &&
+ !group->unknownProperties() &&
+ !layout.constructorCode() &&
+ cx->asJSContext()->runtime()->jitSupportsFloatingPoint &&
+ jit::CanLikelyAllocateMoreExecutableMemory())
+ {
+ if (!UnboxedLayout::makeConstructorCode(cx->asJSContext(), group))
+ return nullptr;
+ }
+#endif
+
+ return obj;
+}
+
+/* static */ bool
+UnboxedPlainObject::obj_lookupProperty(JSContext* cx, HandleObject obj,
+ HandleId id, MutableHandleObject objp,
+ MutableHandleShape propp)
+{
+ if (obj->as<UnboxedPlainObject>().containsUnboxedOrExpandoProperty(cx, id)) {
+ MarkNonNativePropertyFound<CanGC>(propp);
+ objp.set(obj);
+ return true;
+ }
+
+ RootedObject proto(cx, obj->staticPrototype());
+ if (!proto) {
+ objp.set(nullptr);
+ propp.set(nullptr);
+ return true;
+ }
+
+ return LookupProperty(cx, proto, id, objp, propp);
+}
+
+/* static */ bool
+UnboxedPlainObject::obj_defineProperty(JSContext* cx, HandleObject obj, HandleId id,
+ Handle<PropertyDescriptor> desc,
+ ObjectOpResult& result)
+{
+ const UnboxedLayout& layout = obj->as<UnboxedPlainObject>().layout();
+
+ if (const UnboxedLayout::Property* property = layout.lookup(id)) {
+ if (!desc.getter() && !desc.setter() && desc.attributes() == JSPROP_ENUMERATE) {
+ // This define is equivalent to setting an existing property.
+ if (obj->as<UnboxedPlainObject>().setValue(cx, *property, desc.value()))
+ return result.succeed();
+ }
+
+ // Trying to incompatibly redefine an existing property requires the
+ // object to be converted to a native object.
+ if (!convertToNative(cx, obj))
+ return false;
+
+ return DefineProperty(cx, obj, id, desc, result);
+ }
+
+ // Define the property on the expando object.
+ Rooted<UnboxedExpandoObject*> expando(cx, ensureExpando(cx, obj.as<UnboxedPlainObject>()));
+ if (!expando)
+ return false;
+
+ // Update property types on the unboxed object as well.
+ AddTypePropertyId(cx, obj, id, desc.value());
+
+ return DefineProperty(cx, expando, id, desc, result);
+}
+
+/* static */ bool
+UnboxedPlainObject::obj_hasProperty(JSContext* cx, HandleObject obj, HandleId id, bool* foundp)
+{
+ if (obj->as<UnboxedPlainObject>().containsUnboxedOrExpandoProperty(cx, id)) {
+ *foundp = true;
+ return true;
+ }
+
+ RootedObject proto(cx, obj->staticPrototype());
+ if (!proto) {
+ *foundp = false;
+ return true;
+ }
+
+ return HasProperty(cx, proto, id, foundp);
+}
+
+/* static */ bool
+UnboxedPlainObject::obj_getProperty(JSContext* cx, HandleObject obj, HandleValue receiver,
+ HandleId id, MutableHandleValue vp)
+{
+ const UnboxedLayout& layout = obj->as<UnboxedPlainObject>().layout();
+
+ if (const UnboxedLayout::Property* property = layout.lookup(id)) {
+ vp.set(obj->as<UnboxedPlainObject>().getValue(*property));
+ return true;
+ }
+
+ if (UnboxedExpandoObject* expando = obj->as<UnboxedPlainObject>().maybeExpando()) {
+ if (expando->containsShapeOrElement(cx, id)) {
+ RootedObject nexpando(cx, expando);
+ return GetProperty(cx, nexpando, receiver, id, vp);
+ }
+ }
+
+ RootedObject proto(cx, obj->staticPrototype());
+ if (!proto) {
+ vp.setUndefined();
+ return true;
+ }
+
+ return GetProperty(cx, proto, receiver, id, vp);
+}
+
+/* static */ bool
+UnboxedPlainObject::obj_setProperty(JSContext* cx, HandleObject obj, HandleId id, HandleValue v,
+ HandleValue receiver, ObjectOpResult& result)
+{
+ const UnboxedLayout& layout = obj->as<UnboxedPlainObject>().layout();
+
+ if (const UnboxedLayout::Property* property = layout.lookup(id)) {
+ if (receiver.isObject() && obj == &receiver.toObject()) {
+ if (obj->as<UnboxedPlainObject>().setValue(cx, *property, v))
+ return result.succeed();
+
+ if (!convertToNative(cx, obj))
+ return false;
+ return SetProperty(cx, obj, id, v, receiver, result);
+ }
+
+ return SetPropertyByDefining(cx, id, v, receiver, result);
+ }
+
+ if (UnboxedExpandoObject* expando = obj->as<UnboxedPlainObject>().maybeExpando()) {
+ if (expando->containsShapeOrElement(cx, id)) {
+ // Update property types on the unboxed object as well.
+ AddTypePropertyId(cx, obj, id, v);
+
+ RootedObject nexpando(cx, expando);
+ return SetProperty(cx, nexpando, id, v, receiver, result);
+ }
+ }
+
+ return SetPropertyOnProto(cx, obj, id, v, receiver, result);
+}
+
+/* static */ bool
+UnboxedPlainObject::obj_getOwnPropertyDescriptor(JSContext* cx, HandleObject obj, HandleId id,
+ MutableHandle<PropertyDescriptor> desc)
+{
+ const UnboxedLayout& layout = obj->as<UnboxedPlainObject>().layout();
+
+ if (const UnboxedLayout::Property* property = layout.lookup(id)) {
+ desc.value().set(obj->as<UnboxedPlainObject>().getValue(*property));
+ desc.setAttributes(JSPROP_ENUMERATE);
+ desc.object().set(obj);
+ return true;
+ }
+
+ if (UnboxedExpandoObject* expando = obj->as<UnboxedPlainObject>().maybeExpando()) {
+ if (expando->containsShapeOrElement(cx, id)) {
+ RootedObject nexpando(cx, expando);
+ if (!GetOwnPropertyDescriptor(cx, nexpando, id, desc))
+ return false;
+ if (desc.object() == nexpando)
+ desc.object().set(obj);
+ return true;
+ }
+ }
+
+ desc.object().set(nullptr);
+ return true;
+}
+
+/* static */ bool
+UnboxedPlainObject::obj_deleteProperty(JSContext* cx, HandleObject obj, HandleId id,
+ ObjectOpResult& result)
+{
+ if (!convertToNative(cx, obj))
+ return false;
+ return DeleteProperty(cx, obj, id, result);
+}
+
+/* static */ bool
+UnboxedPlainObject::obj_enumerate(JSContext* cx, HandleObject obj, AutoIdVector& properties,
+ bool enumerableOnly)
+{
+ // Ignore expando properties here, they are special-cased by the property
+ // enumeration code.
+
+ const UnboxedLayout::PropertyVector& unboxed = obj->as<UnboxedPlainObject>().layout().properties();
+ for (size_t i = 0; i < unboxed.length(); i++) {
+ if (!properties.append(NameToId(unboxed[i].name)))
+ return false;
+ }
+
+ return true;
+}
+
+const Class UnboxedExpandoObject::class_ = {
+ "UnboxedExpandoObject",
+ 0
+};
+
+static const ClassOps UnboxedPlainObjectClassOps = {
+ nullptr, /* addProperty */
+ nullptr, /* delProperty */
+ nullptr, /* getProperty */
+ nullptr, /* setProperty */
+ nullptr, /* enumerate */
+ nullptr, /* resolve */
+ nullptr, /* mayResolve */
+ nullptr, /* finalize */
+ nullptr, /* call */
+ nullptr, /* hasInstance */
+ nullptr, /* construct */
+ UnboxedPlainObject::trace,
+};
+
+static const ObjectOps UnboxedPlainObjectObjectOps = {
+ UnboxedPlainObject::obj_lookupProperty,
+ UnboxedPlainObject::obj_defineProperty,
+ UnboxedPlainObject::obj_hasProperty,
+ UnboxedPlainObject::obj_getProperty,
+ UnboxedPlainObject::obj_setProperty,
+ UnboxedPlainObject::obj_getOwnPropertyDescriptor,
+ UnboxedPlainObject::obj_deleteProperty,
+ nullptr, /* getElements */
+ UnboxedPlainObject::obj_enumerate,
+ nullptr /* funToString */
+};
+
+const Class UnboxedPlainObject::class_ = {
+ js_Object_str,
+ Class::NON_NATIVE |
+ JSCLASS_HAS_CACHED_PROTO(JSProto_Object) |
+ JSCLASS_DELAY_METADATA_BUILDER,
+ &UnboxedPlainObjectClassOps,
+ JS_NULL_CLASS_SPEC,
+ JS_NULL_CLASS_EXT,
+ &UnboxedPlainObjectObjectOps
+};
+
+/////////////////////////////////////////////////////////////////////
+// API
+/////////////////////////////////////////////////////////////////////
+
+static inline Value
+NextValue(Handle<GCVector<Value>> values, size_t* valueCursor)
+{
+ return values[(*valueCursor)++];
+}
+
+void
+UnboxedPlainObject::fillAfterConvert(ExclusiveContext* cx,
+ Handle<GCVector<Value>> values, size_t* valueCursor)
+{
+ initExpando();
+ memset(data(), 0, layout().size());
+ for (size_t i = 0; i < layout().properties().length(); i++)
+ JS_ALWAYS_TRUE(setValue(cx, layout().properties()[i], NextValue(values, valueCursor)));
+}
diff --git a/js/src/vm/UnboxedObject.h b/js/src/vm/UnboxedObject.h
new file mode 100644
index 000000000..ba66434bc
--- /dev/null
+++ b/js/src/vm/UnboxedObject.h
@@ -0,0 +1,319 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef vm_UnboxedObject_h
+#define vm_UnboxedObject_h
+
+#include "jsgc.h"
+#include "jsobj.h"
+
+#include "vm/Runtime.h"
+#include "vm/TypeInference.h"
+
+namespace js {
+
+// Memory required for an unboxed value of a given type. Returns zero for types
+// which can't be used for unboxed objects.
+static inline size_t
+UnboxedTypeSize(JSValueType type)
+{
+ switch (type) {
+ case JSVAL_TYPE_BOOLEAN: return 1;
+ case JSVAL_TYPE_INT32: return 4;
+ case JSVAL_TYPE_DOUBLE: return 8;
+ case JSVAL_TYPE_STRING: return sizeof(void*);
+ case JSVAL_TYPE_OBJECT: return sizeof(void*);
+ default: return 0;
+ }
+}
+
+static inline bool
+UnboxedTypeNeedsPreBarrier(JSValueType type)
+{
+ return type == JSVAL_TYPE_STRING || type == JSVAL_TYPE_OBJECT;
+}
+
+static inline bool
+UnboxedTypeNeedsPostBarrier(JSValueType type)
+{
+ return type == JSVAL_TYPE_OBJECT;
+}
+
+// Class tracking information specific to unboxed objects.
+class UnboxedLayout : public mozilla::LinkedListElement<UnboxedLayout>
+{
+ public:
+ struct Property {
+ PropertyName* name;
+ uint32_t offset;
+ JSValueType type;
+
+ Property()
+ : name(nullptr), offset(UINT32_MAX), type(JSVAL_TYPE_MAGIC)
+ {}
+ };
+
+ typedef Vector<Property, 0, SystemAllocPolicy> PropertyVector;
+
+ private:
+ // If objects in this group have ever been converted to native objects,
+ // these store the corresponding native group and initial shape for such
+ // objects. Type information for this object is reflected in nativeGroup.
+ GCPtrObjectGroup nativeGroup_;
+ GCPtrShape nativeShape_;
+
+ // Any script/pc which the associated group is created for.
+ GCPtrScript allocationScript_;
+ jsbytecode* allocationPc_;
+
+ // If nativeGroup is set and this object originally had a TypeNewScript or
+ // was keyed to an allocation site, this points to the group which replaced
+ // this one. This link is only needed to keep the replacement group from
+ // being GC'ed. If it were GC'ed and a new one regenerated later, that new
+ // group might have a different allocation kind from this group.
+ GCPtrObjectGroup replacementGroup_;
+
+ // The following members are only used for unboxed plain objects.
+
+ // All properties on objects with this layout, in enumeration order.
+ PropertyVector properties_;
+
+ // Byte size of the data for objects with this layout.
+ size_t size_;
+
+ // Any 'new' script information associated with this layout.
+ TypeNewScript* newScript_;
+
+ // List for use in tracing objects with this layout. This has the same
+ // structure as the trace list on a TypeDescr.
+ int32_t* traceList_;
+
+ // If this layout has been used to construct script or JSON constant
+ // objects, this code might be filled in to more quickly fill in objects
+ // from an array of values.
+ GCPtrJitCode constructorCode_;
+
+ public:
+ UnboxedLayout()
+ : nativeGroup_(nullptr), nativeShape_(nullptr),
+ allocationScript_(nullptr), allocationPc_(nullptr), replacementGroup_(nullptr),
+ size_(0), newScript_(nullptr), traceList_(nullptr), constructorCode_(nullptr)
+ {}
+
+ bool initProperties(const PropertyVector& properties, size_t size) {
+ size_ = size;
+ return properties_.appendAll(properties);
+ }
+
+ ~UnboxedLayout() {
+ if (newScript_)
+ newScript_->clear();
+ js_delete(newScript_);
+ js_free(traceList_);
+
+ nativeGroup_.init(nullptr);
+ nativeShape_.init(nullptr);
+ replacementGroup_.init(nullptr);
+ constructorCode_.init(nullptr);
+ }
+
+ void detachFromCompartment();
+
+ const PropertyVector& properties() const {
+ return properties_;
+ }
+
+ TypeNewScript* newScript() const {
+ return newScript_;
+ }
+
+ void setNewScript(TypeNewScript* newScript, bool writeBarrier = true);
+
+ JSScript* allocationScript() const {
+ return allocationScript_;
+ }
+
+ jsbytecode* allocationPc() const {
+ return allocationPc_;
+ }
+
+ void setAllocationSite(JSScript* script, jsbytecode* pc) {
+ allocationScript_ = script;
+ allocationPc_ = pc;
+ }
+
+ const int32_t* traceList() const {
+ return traceList_;
+ }
+
+ void setTraceList(int32_t* traceList) {
+ traceList_ = traceList;
+ }
+
+ const Property* lookup(JSAtom* atom) const {
+ for (size_t i = 0; i < properties_.length(); i++) {
+ if (properties_[i].name == atom)
+ return &properties_[i];
+ }
+ return nullptr;
+ }
+
+ const Property* lookup(jsid id) const {
+ if (JSID_IS_STRING(id))
+ return lookup(JSID_TO_ATOM(id));
+ return nullptr;
+ }
+
+ size_t size() const {
+ return size_;
+ }
+
+ ObjectGroup* nativeGroup() const {
+ return nativeGroup_;
+ }
+
+ Shape* nativeShape() const {
+ return nativeShape_;
+ }
+
+ jit::JitCode* constructorCode() const {
+ return constructorCode_;
+ }
+
+ void setConstructorCode(jit::JitCode* code) {
+ constructorCode_ = code;
+ }
+
+ inline gc::AllocKind getAllocKind() const;
+
+ void trace(JSTracer* trc);
+
+ size_t sizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf);
+
+ static bool makeNativeGroup(JSContext* cx, ObjectGroup* group);
+ static bool makeConstructorCode(JSContext* cx, HandleObjectGroup group);
+};
+
+// Class for expando objects holding extra properties given to an unboxed plain
+// object. These objects behave identically to normal native plain objects, and
+// have a separate Class to distinguish them for memory usage reporting.
+class UnboxedExpandoObject : public NativeObject
+{
+ public:
+ static const Class class_;
+};
+
+// Class for a plain object using an unboxed representation. The physical
+// layout of these objects is identical to that of an InlineTypedObject, though
+// these objects use an UnboxedLayout instead of a TypeDescr to keep track of
+// how their properties are stored.
+class UnboxedPlainObject : public JSObject
+{
+ // Optional object which stores extra properties on this object. This is
+ // not automatically barriered to avoid problems if the object is converted
+ // to a native. See ensureExpando().
+ UnboxedExpandoObject* expando_;
+
+ // Start of the inline data, which immediately follows the group and extra properties.
+ uint8_t data_[1];
+
+ public:
+ static const Class class_;
+
+ static bool obj_lookupProperty(JSContext* cx, HandleObject obj,
+ HandleId id, MutableHandleObject objp,
+ MutableHandleShape propp);
+
+ static bool obj_defineProperty(JSContext* cx, HandleObject obj, HandleId id,
+ Handle<PropertyDescriptor> desc,
+ ObjectOpResult& result);
+
+ static bool obj_hasProperty(JSContext* cx, HandleObject obj, HandleId id, bool* foundp);
+
+ static bool obj_getProperty(JSContext* cx, HandleObject obj, HandleValue receiver,
+ HandleId id, MutableHandleValue vp);
+
+ static bool obj_setProperty(JSContext* cx, HandleObject obj, HandleId id, HandleValue v,
+ HandleValue receiver, ObjectOpResult& result);
+
+ static bool obj_getOwnPropertyDescriptor(JSContext* cx, HandleObject obj, HandleId id,
+ MutableHandle<PropertyDescriptor> desc);
+
+ static bool obj_deleteProperty(JSContext* cx, HandleObject obj, HandleId id,
+ ObjectOpResult& result);
+
+ static bool obj_enumerate(JSContext* cx, HandleObject obj, AutoIdVector& properties,
+ bool enumerableOnly);
+ static bool obj_watch(JSContext* cx, HandleObject obj, HandleId id, HandleObject callable);
+
+ inline const UnboxedLayout& layout() const;
+
+ const UnboxedLayout& layoutDontCheckGeneration() const {
+ return group()->unboxedLayoutDontCheckGeneration();
+ }
+
+ uint8_t* data() {
+ return &data_[0];
+ }
+
+ UnboxedExpandoObject* maybeExpando() const {
+ return expando_;
+ }
+
+ void initExpando() {
+ expando_ = nullptr;
+ }
+
+ // For use during GC.
+ JSObject** addressOfExpando() {
+ return reinterpret_cast<JSObject**>(&expando_);
+ }
+
+ bool containsUnboxedOrExpandoProperty(ExclusiveContext* cx, jsid id) const;
+
+ static UnboxedExpandoObject* ensureExpando(JSContext* cx, Handle<UnboxedPlainObject*> obj);
+
+ bool setValue(ExclusiveContext* cx, const UnboxedLayout::Property& property, const Value& v);
+ Value getValue(const UnboxedLayout::Property& property, bool maybeUninitialized = false);
+
+ static bool convertToNative(JSContext* cx, JSObject* obj);
+ static UnboxedPlainObject* create(ExclusiveContext* cx, HandleObjectGroup group,
+ NewObjectKind newKind);
+ static JSObject* createWithProperties(ExclusiveContext* cx, HandleObjectGroup group,
+ NewObjectKind newKind, IdValuePair* properties);
+
+ void fillAfterConvert(ExclusiveContext* cx,
+ Handle<GCVector<Value>> values, size_t* valueCursor);
+
+ static void trace(JSTracer* trc, JSObject* object);
+
+ static size_t offsetOfExpando() {
+ return offsetof(UnboxedPlainObject, expando_);
+ }
+
+ static size_t offsetOfData() {
+ return offsetof(UnboxedPlainObject, data_[0]);
+ }
+};
+
+inline gc::AllocKind
+UnboxedLayout::getAllocKind() const
+{
+ MOZ_ASSERT(size());
+ return gc::GetGCObjectKindForBytes(UnboxedPlainObject::offsetOfData() + size());
+}
+
+} // namespace js
+
+namespace JS {
+
+template <>
+struct DeletePolicy<js::UnboxedLayout> : public js::GCManagedDeletePolicy<js::UnboxedLayout>
+{};
+
+} /* namespace JS */
+
+#endif /* vm_UnboxedObject_h */