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 * (a) the Software, and
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 * (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
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package com.oracle.truffle.js.runtime.builtins;

import com.oracle.truffle.api.CompilerAsserts;
import com.oracle.truffle.api.object.DynamicObject;
import com.oracle.truffle.api.object.Shape;
import com.oracle.truffle.js.runtime.JSContext;
import com.oracle.truffle.js.runtime.JSRealm;
import com.oracle.truffle.js.runtime.objects.JSDynamicObject;
import com.oracle.truffle.js.runtime.objects.JSObject;
import com.oracle.truffle.js.runtime.objects.JSObjectUtil;
import com.oracle.truffle.js.runtime.objects.JSShape;

public final class JSGlobal extends JSNonProxy {

    public static final String CLASS_NAME = "global";
    public static final String EVAL_NAME = "eval";

    public static final JSGlobal INSTANCE = new JSGlobal();

    private JSGlobal() {
    }

    public static DynamicObject create(JSRealm realm, DynamicObject objectPrototype) {
        CompilerAsserts.neverPartOfCompilation();
        JSContext context = realm.getContext();
        JSObjectFactory factory = context.getGlobalObjectFactory();
        DynamicObject global = new JSGlobalObject(factory.getShape(realm));
        factory.initProto(global, objectPrototype);

        JSObjectUtil.putToStringTag(global, CLASS_NAME);
        return global;
    }

    public static Shape makeGlobalObjectShape(JSContext context, DynamicObject objectPrototype) {
        // keep a separate shape tree for the global object in order not to pollute user objects
        boolean singleContext = !context.isMultiContext();
        Shape globalObjectShape = JSShape.newBuilder(context, JSGlobal.INSTANCE, singleContext ? objectPrototype : null).propertyAssumptions(singleContext).singleContextAssumption(
                        singleContext ? context.getSingleRealmAssumption() : null).build();
        if (singleContext) {
            globalObjectShape = Shape.newBuilder(globalObjectShape).addConstantProperty(JSObject.HIDDEN_PROTO, objectPrototype, 0).build();
        }
        return globalObjectShape;
    }

    public static DynamicObject createGlobalScope(JSContext context) {
        CompilerAsserts.neverPartOfCompilation();
        return new JSGlobalObject(context.getGlobalScopeShape());
    }

    public static boolean isJSGlobalObject(Object obj) {
        return JSDynamicObject.isJSDynamicObject(obj) && isJSGlobalObject((DynamicObject) obj);
    }

    public static boolean isJSGlobalObject(DynamicObject obj) {
        return isInstance(obj, INSTANCE);
    }

    @Override
    public String getClassName(DynamicObject object) {
        return CLASS_NAME;
    }
}