Commit 5c84d76a authored Oct 01, 2021 by Jan de Mooij

Bug 1733075 part 1 - Add HasEnumerable ObjectFlag. r=iain

This gives us the ability to check whether an object has only non-enumerable
properties in constant time. Prototype objects typically don't have enumerable
properties.

Differential Revision: https://phabricator.services.mozilla.com/D127054

parent 7897dc69

js/src/vm/JSObject.cpp

+3 −0

Original line number	Diff line number	Diff line
		@@ -2947,6 +2947,9 @@ void JSObject::dump(js::GenericPrinter& out) const {
		if (nobj->isIndexed()) {
		out.put(" indexed");
		}
		if (nobj->hasEnumerableProperty()) {
		out.put(" has_enumerable");
		}
		if (nobj->is<PlainObject>() &&
		nobj->as<PlainObject>().hasNonWritableOrAccessorPropExclProto()) {
		out.put(" has_non_writable_or_accessor_prop_excl_proto");

js/src/vm/NativeObject.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -823,6 +823,10 @@ class NativeObject : public JSObject {
		return hasFlag(ObjectFlag::HasInterestingSymbol);
		}

		bool hasEnumerableProperty() const {
		return hasFlag(ObjectFlag::HasEnumerable);
		}

		static bool setHadGetterSetterChange(JSContext* cx, HandleNativeObject obj) {
		return setFlag(cx, obj, ObjectFlag::HadGetterSetterChange);
		}

js/src/vm/ObjectFlags-inl.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -31,6 +31,10 @@ GetObjectFlagsForNewProperty(const JSClass* clasp, ObjectFlags flags, jsid id,
		flags.setFlag(ObjectFlag::HasNonWritableOrAccessorPropExclProto);
		}

		if (propFlags.enumerable()) {
		flags.setFlag(ObjectFlag::HasEnumerable);
		}

		return flags;
		}

js/src/vm/ObjectFlags.h

+7 −1

Original line number	Diff line number	Diff line
		@@ -22,7 +22,13 @@ enum class ObjectFlag : uint16_t {
		NotExtensible = 1 << 1,
		Indexed = 1 << 2,
		HasInterestingSymbol = 1 << 3,
		// (1 << 4) is unused.

		// If set, the shape's property map may contain an enumerable property. This
		// only accounts for (own) shape properties: if the flag is not set, the
		// object may still have (enumerable) dense elements, typed array elements, or
		// a JSClass enumeration hook.
		HasEnumerable = 1 << 4,

		FrozenElements = 1 << 5, // See ObjectElements::FROZEN comment.

		// If set, the shape teleporting optimization can no longer be used for