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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.nodes.access;

import com.oracle.truffle.api.Assumption;
import com.oracle.truffle.api.dsl.Cached;
import com.oracle.truffle.api.dsl.Specialization;
import com.oracle.truffle.api.object.DynamicObject;
import com.oracle.truffle.api.object.Property;
import com.oracle.truffle.api.object.Shape;
import com.oracle.truffle.api.profiles.BranchProfile;
import com.oracle.truffle.api.utilities.NeverValidAssumption;
import com.oracle.truffle.js.lang.JavaScriptLanguage;
import com.oracle.truffle.js.nodes.JavaScriptBaseNode;
import com.oracle.truffle.js.runtime.Errors;
import com.oracle.truffle.js.runtime.objects.Dead;
import com.oracle.truffle.js.runtime.objects.JSDynamicObject;
import com.oracle.truffle.js.runtime.objects.JSProperty;
import com.oracle.truffle.js.runtime.objects.JSShape;

Checks if a scope binding is present and guards against TDZ and const assignment.
/**
 * Checks if a scope binding is present and guards against TDZ and const assignment.
 */
public abstract class GlobalScopeLookupNode extends JavaScriptBaseNode {
    final String varName;
    final boolean write;

    GlobalScopeLookupNode(String varName, boolean write) {
        this.varName = varName;
        this.write = write;
    }

    public static GlobalScopeLookupNode create(String varName, boolean write) {
        return GlobalScopeLookupNodeGen.create(varName, write);
    }

    public abstract boolean execute(Object scope);

    @SuppressWarnings("unused")
    @Specialization(assumptions = {"assumption"})
    static boolean doAbsent(DynamicObject scope,
                    @Cached("getAbsentPropertyAssumption(scope.getShape())") Assumption assumption) {
        return false;
    }

    @SuppressWarnings("unused")
    @Specialization(guards = {"scope.getShape() == cachedShape"}, assumptions = {"cachedShape.getValidAssumption()"}, limit = "cacheLimit", replaces = "doAbsent")
    final boolean doCached(DynamicObject scope,
                    @Cached("scope.getShape()") Shape cachedShape,
                    @Cached("cachedShape.hasProperty(varName)") boolean exists,
                    @Cached("isDead(cachedShape)") boolean dead,
                    @Cached("isConstAssignment(cachedShape)") boolean constAssignment,
                    @Cached("getPropertyCacheLimit()") int cacheLimit) {
        assert !exists || dead == (JSDynamicObject.getOrNull(scope, varName) == Dead.instance());
        if (dead) {
            throw Errors.createReferenceErrorNotDefined(JavaScriptLanguage.getCurrentJSRealm().getContext(), varName, this);
        }
        if (constAssignment) {
            throw Errors.createTypeErrorConstReassignment(varName, scope, this);
        }
        return exists;
    }

    protected int getPropertyCacheLimit() {
        return JavaScriptLanguage.getCurrentJSRealm().getContext().getPropertyCacheLimit();
    }

    @Specialization(replaces = "doCached")
    final boolean doUncached(DynamicObject scope,
                    @Cached("create()") BranchProfile errorBranch) {
        Property property = scope.getShape().getProperty(varName);
        if (property != null) {
            if (JSDynamicObject.getOrNull(scope, varName) == Dead.instance()) {
                errorBranch.enter();
                throw Errors.createReferenceErrorNotDefined(JavaScriptLanguage.getCurrentJSRealm().getContext(), varName, this);
            } else if (write && JSProperty.isConst(property)) {
                errorBranch.enter();
                throw Errors.createTypeErrorConstReassignment(varName, scope, this);
            }
            return true;
        }
        return false;
    }

    final boolean isDead(Shape shape) {
        Property property = shape.getProperty(varName);
        return property != null && property.getLocation().isDeclared();
    }

    final boolean isConstAssignment(Shape shape) {
        if (write) {
            Property property = shape.getProperty(varName);
            return property != null && JSProperty.isConst(property);
        }
        return false;
    }

    final Assumption getAbsentPropertyAssumption(Shape shape) {
        Property property = shape.getProperty(varName);
        if (property == null) {
            return JSShape.getPropertyAssumption(shape, varName);
        }
        return NeverValidAssumption.INSTANCE;
    }
}