nashorn/src/jdk/nashorn/internal/runtime/SetMethodCreator.java - edge/openjdk - Git at Google

 /*
  * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this
  * particular file as subject to the "Classpath" exception as provided
  * by Oracle in the LICENSE file that accompanied this code.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */

 package jdk.nashorn.internal.runtime;

 import static jdk.nashorn.internal.lookup.Lookup.MH;
 import static jdk.nashorn.internal.runtime.ECMAErrors.referenceError;
 import static jdk.nashorn.internal.runtime.JSType.getAccessorTypeIndex;
 import java.lang.invoke.MethodHandle;
 import java.lang.invoke.SwitchPoint;
 import jdk.internal.dynalink.CallSiteDescriptor;
 import jdk.internal.dynalink.linker.GuardedInvocation;
 import jdk.internal.dynalink.linker.LinkRequest;
 import jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor;
 import jdk.nashorn.internal.runtime.linker.NashornGuards;

 /**
  * Instances of this class are quite ephemeral; they only exist for the duration of an invocation of
  * {@link ScriptObject#findSetMethod(CallSiteDescriptor, jdk.internal.dynalink.linker.LinkRequest)} and
  * serve as the actual encapsulation of the algorithm for creating an appropriate property setter method.
  */
 final class SetMethodCreator {
     // See constructor parameters for description of fields
     private final ScriptObject       sobj;
     private final PropertyMap        map;
     private final FindProperty       find;
     private final CallSiteDescriptor desc;
     private final Class<?>           type;
     private final LinkRequest        request;

     /**
      * Creates a new property setter method creator.
      * @param sobj the object for which we're creating the property setter
      * @param find a result of a {@link ScriptObject#findProperty(String, boolean)} on the object for the property we
      * want to create a setter for. Can be null if the property does not yet exist on the object.
      * @param desc the descriptor of the call site that triggered the property setter lookup
      * @param request the link request
      */
     SetMethodCreator(final ScriptObject sobj, final FindProperty find, final CallSiteDescriptor desc, final LinkRequest request) {
         this.sobj    = sobj;
         this.map     = sobj.getMap();
         this.find    = find;
         this.desc    = desc;
         this.type    = desc.getMethodType().parameterType(1);
         this.request = request;

     }

     private String getName() {
         return desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);
     }

     private PropertyMap getMap() {
         return map;
     }

     /**
      * Creates the actual guarded invocation that represents the dynamic setter method for the property.
      * @return the actual guarded invocation that represents the dynamic setter method for the property.
      */
     GuardedInvocation createGuardedInvocation(final SwitchPoint builtinSwitchPoint) {
         return createSetMethod(builtinSwitchPoint).createGuardedInvocation();
     }

     /**
      * This class encapsulates the results of looking up a setter method; it's basically a triple of a method handle,
      * a Property object, and flags for invocation.
      *
      */
     private class SetMethod {
         private final MethodHandle methodHandle;
         private final Property property;

         /**
          * Creates a new lookup result.
          * @param methodHandle the actual method handle
          * @param property the property object. Can be null in case we're creating a new property in the global object.
          */
         SetMethod(final MethodHandle methodHandle, final Property property) {
             assert methodHandle != null;
             this.methodHandle = methodHandle;
             this.property     = property;
         }

         /**
          * Composes from its components an actual guarded invocation that represents the dynamic setter method for the property.
          * @return the composed guarded invocation that represents the dynamic setter method for the property.
          */
         GuardedInvocation createGuardedInvocation() {
             // getGuard() and getException() either both return null, or neither does. The reason for that is that now
             // getGuard returns a map guard that casts its argument to ScriptObject, and if that fails, we need to
             // relink on ClassCastException.
             final boolean explicitInstanceOfCheck = NashornGuards.explicitInstanceOfCheck(desc, request);
             return new GuardedInvocation(methodHandle, NashornGuards.getGuard(sobj, property, desc, explicitInstanceOfCheck),
                     (SwitchPoint)null, explicitInstanceOfCheck ? null : ClassCastException.class);
         }
     }

     private SetMethod createSetMethod(final SwitchPoint builtinSwitchPoint) {
         if (find != null) {
             return createExistingPropertySetter();
         }

         checkStrictCreateNewVariable();

         if (sobj.isScope()) {
             return createGlobalPropertySetter();
         }

         return createNewPropertySetter(builtinSwitchPoint);
     }

     private void checkStrictCreateNewVariable() {
         // In strict mode, assignment can not create a new variable.
         // See also ECMA Annex C item 4. ReferenceError is thrown.
         if (NashornCallSiteDescriptor.isScope(desc) && NashornCallSiteDescriptor.isStrict(desc)) {
             throw referenceError("not.defined", getName());
         }
     }

     private SetMethod createExistingPropertySetter() {
         final Property property = find.getProperty();
         final boolean isStrict  = NashornCallSiteDescriptor.isStrict(desc);
         final MethodHandle methodHandle;

         if (NashornCallSiteDescriptor.isDeclaration(desc)) {
             assert property.needsDeclaration();
             // This is a LET or CONST being declared. The property is already there but flagged as needing declaration.
             // We create a new PropertyMap with the flag removed. The map is installed with a fast compare-and-set
             // method if the pre-callsite map is stable (which should be the case for function scopes except for
             // non-strict functions containing eval() with var). Otherwise we have to use a slow setter that creates
             // a new PropertyMap on the fly.
             final PropertyMap oldMap = getMap();
             final Property newProperty = property.removeFlags(Property.NEEDS_DECLARATION);
             final PropertyMap newMap = oldMap.replaceProperty(property, newProperty);
             final MethodHandle fastSetter = find.replaceProperty(newProperty).getSetter(type, isStrict, request);
             final MethodHandle slowSetter = MH.insertArguments(ScriptObject.DECLARE_AND_SET, 1, getName()).asType(fastSetter.type());

             // cas map used as guard, if true that means we can do the set fast
             MethodHandle casMap = MH.insertArguments(ScriptObject.CAS_MAP, 1, oldMap, newMap);
             casMap = MH.dropArguments(casMap, 1, type);
             casMap = MH.asType(casMap, casMap.type().changeParameterType(0, Object.class));
             methodHandle = MH.guardWithTest(casMap, fastSetter, slowSetter);
         } else {
             methodHandle = find.getSetter(type, isStrict, request);
         }

         assert methodHandle != null;
         assert property     != null;

         final MethodHandle boundHandle;
         if (!(property instanceof UserAccessorProperty) && find.isInherited()) {
             boundHandle = ScriptObject.addProtoFilter(methodHandle, find.getProtoChainLength());
         } else {
             boundHandle = methodHandle;
         }
         return new SetMethod(boundHandle, property);
     }

     private SetMethod createGlobalPropertySetter() {
         final ScriptObject global = Context.getGlobal();
         return new SetMethod(MH.filterArguments(global.addSpill(type, getName()), 0, ScriptObject.GLOBALFILTER), null);
     }

     private SetMethod createNewPropertySetter(final SwitchPoint builtinSwitchPoint) {
         final SetMethod sm = map.getFreeFieldSlot() > -1 ? createNewFieldSetter(builtinSwitchPoint) : createNewSpillPropertySetter(builtinSwitchPoint);
         map.propertyAdded(sm.property, true);
         return sm;
     }

     private SetMethod createNewSetter(final Property property, final SwitchPoint builtinSwitchPoint) {
         property.setBuiltinSwitchPoint(builtinSwitchPoint);

         final PropertyMap oldMap   = getMap();
         final PropertyMap newMap   = getNewMap(property);
         final boolean     isStrict = NashornCallSiteDescriptor.isStrict(desc);
         final String      name     = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);

         //fast type specific setter
         final MethodHandle fastSetter = property.getSetter(type, newMap); //0 sobj, 1 value, slot folded for spill property already

         //slow setter, that calls ScriptObject.set with appropriate type and key name
         MethodHandle slowSetter = ScriptObject.SET_SLOW[getAccessorTypeIndex(type)];
         slowSetter = MH.insertArguments(slowSetter, 3, NashornCallSiteDescriptor.getFlags(desc));
         slowSetter = MH.insertArguments(slowSetter, 1, name);
         slowSetter = MH.asType(slowSetter, slowSetter.type().changeParameterType(0, Object.class));

         assert slowSetter.type().equals(fastSetter.type()) : "slow=" + slowSetter + " != fast=" + fastSetter;

         //cas map used as guard, if true that means we can do the set fast
         MethodHandle casMap = MH.insertArguments(ScriptObject.CAS_MAP, 1, oldMap, newMap);
         casMap = MH.dropArguments(casMap, 1, type);
         casMap = MH.asType(casMap, casMap.type().changeParameterType(0, Object.class));
         final MethodHandle casGuard = MH.guardWithTest(casMap, fastSetter, slowSetter);

         //outermost level needs an extendable check. if object can be extended, guard is true and
         //we can run the cas setter. The setter goes to "nop" VOID_RETURN if false or throws an
         //exception if we are in strict mode and object is not extensible
         MethodHandle extCheck = MH.insertArguments(ScriptObject.EXTENSION_CHECK, 1, isStrict, name);
         extCheck = MH.asType(extCheck, extCheck.type().changeParameterType(0, Object.class));
         extCheck = MH.dropArguments(extCheck, 1, type);

         MethodHandle nop = JSType.VOID_RETURN.methodHandle();
         nop = MH.dropArguments(nop, 0, Object.class, type);

         return new SetMethod(MH.asType(MH.guardWithTest(extCheck, casGuard, nop), fastSetter.type()), property);
     }

     private SetMethod createNewFieldSetter(final SwitchPoint builtinSwitchPoint) {
         return createNewSetter(new AccessorProperty(getName(), getFlags(sobj), sobj.getClass(), getMap().getFreeFieldSlot(), type), builtinSwitchPoint);
     }

     private SetMethod createNewSpillPropertySetter(final SwitchPoint builtinSwitchPoint) {
         return createNewSetter(new SpillProperty(getName(), getFlags(sobj), getMap().getFreeSpillSlot(), type), builtinSwitchPoint);
     }

     private PropertyMap getNewMap(final Property property) {
         return getMap().addProperty(property);
     }

     private static int getFlags(final ScriptObject scriptObject) {
         return scriptObject.useDualFields() ? Property.DUAL_FIELDS : 0;
     }
 }
	/*
	* Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package jdk.nashorn.internal.runtime;

	import static jdk.nashorn.internal.lookup.Lookup.MH;
	import static jdk.nashorn.internal.runtime.ECMAErrors.referenceError;
	import static jdk.nashorn.internal.runtime.JSType.getAccessorTypeIndex;
	import java.lang.invoke.MethodHandle;
	import java.lang.invoke.SwitchPoint;
	import jdk.internal.dynalink.CallSiteDescriptor;
	import jdk.internal.dynalink.linker.GuardedInvocation;
	import jdk.internal.dynalink.linker.LinkRequest;
	import jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor;
	import jdk.nashorn.internal.runtime.linker.NashornGuards;

	/**
	* Instances of this class are quite ephemeral; they only exist for the duration of an invocation of
	* {@link ScriptObject#findSetMethod(CallSiteDescriptor, jdk.internal.dynalink.linker.LinkRequest)} and
	* serve as the actual encapsulation of the algorithm for creating an appropriate property setter method.
	*/
	final class SetMethodCreator {
	// See constructor parameters for description of fields
	private final ScriptObject sobj;
	private final PropertyMap map;
	private final FindProperty find;
	private final CallSiteDescriptor desc;
	private final Class<?> type;
	private final LinkRequest request;

	/**
	* Creates a new property setter method creator.
	* @param sobj the object for which we're creating the property setter
	* @param find a result of a {@link ScriptObject#findProperty(String, boolean)} on the object for the property we
	* want to create a setter for. Can be null if the property does not yet exist on the object.
	* @param desc the descriptor of the call site that triggered the property setter lookup
	* @param request the link request
	*/
	SetMethodCreator(final ScriptObject sobj, final FindProperty find, final CallSiteDescriptor desc, final LinkRequest request) {
	this.sobj = sobj;
	this.map = sobj.getMap();
	this.find = find;
	this.desc = desc;
	this.type = desc.getMethodType().parameterType(1);
	this.request = request;

	}

	private String getName() {
	return desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);
	}

	private PropertyMap getMap() {
	return map;
	}

	/**
	* Creates the actual guarded invocation that represents the dynamic setter method for the property.
	* @return the actual guarded invocation that represents the dynamic setter method for the property.
	*/
	GuardedInvocation createGuardedInvocation(final SwitchPoint builtinSwitchPoint) {
	return createSetMethod(builtinSwitchPoint).createGuardedInvocation();
	}

	/**
	* This class encapsulates the results of looking up a setter method; it's basically a triple of a method handle,
	* a Property object, and flags for invocation.
	*
	*/
	private class SetMethod {
	private final MethodHandle methodHandle;
	private final Property property;

	/**
	* Creates a new lookup result.
	* @param methodHandle the actual method handle
	* @param property the property object. Can be null in case we're creating a new property in the global object.
	*/
	SetMethod(final MethodHandle methodHandle, final Property property) {
	assert methodHandle != null;
	this.methodHandle = methodHandle;
	this.property = property;
	}

	/**
	* Composes from its components an actual guarded invocation that represents the dynamic setter method for the property.
	* @return the composed guarded invocation that represents the dynamic setter method for the property.
	*/
	GuardedInvocation createGuardedInvocation() {
	// getGuard() and getException() either both return null, or neither does. The reason for that is that now
	// getGuard returns a map guard that casts its argument to ScriptObject, and if that fails, we need to
	// relink on ClassCastException.
	final boolean explicitInstanceOfCheck = NashornGuards.explicitInstanceOfCheck(desc, request);
	return new GuardedInvocation(methodHandle, NashornGuards.getGuard(sobj, property, desc, explicitInstanceOfCheck),
	(SwitchPoint)null, explicitInstanceOfCheck ? null : ClassCastException.class);
	}
	}

	private SetMethod createSetMethod(final SwitchPoint builtinSwitchPoint) {
	if (find != null) {
	return createExistingPropertySetter();
	}

	checkStrictCreateNewVariable();

	if (sobj.isScope()) {
	return createGlobalPropertySetter();
	}

	return createNewPropertySetter(builtinSwitchPoint);
	}

	private void checkStrictCreateNewVariable() {
	// In strict mode, assignment can not create a new variable.
	// See also ECMA Annex C item 4. ReferenceError is thrown.
	if (NashornCallSiteDescriptor.isScope(desc) && NashornCallSiteDescriptor.isStrict(desc)) {
	throw referenceError("not.defined", getName());
	}
	}

	private SetMethod createExistingPropertySetter() {
	final Property property = find.getProperty();
	final boolean isStrict = NashornCallSiteDescriptor.isStrict(desc);
	final MethodHandle methodHandle;

	if (NashornCallSiteDescriptor.isDeclaration(desc)) {
	assert property.needsDeclaration();
	// This is a LET or CONST being declared. The property is already there but flagged as needing declaration.
	// We create a new PropertyMap with the flag removed. The map is installed with a fast compare-and-set
	// method if the pre-callsite map is stable (which should be the case for function scopes except for
	// non-strict functions containing eval() with var). Otherwise we have to use a slow setter that creates
	// a new PropertyMap on the fly.
	final PropertyMap oldMap = getMap();
	final Property newProperty = property.removeFlags(Property.NEEDS_DECLARATION);
	final PropertyMap newMap = oldMap.replaceProperty(property, newProperty);
	final MethodHandle fastSetter = find.replaceProperty(newProperty).getSetter(type, isStrict, request);
	final MethodHandle slowSetter = MH.insertArguments(ScriptObject.DECLARE_AND_SET, 1, getName()).asType(fastSetter.type());

	// cas map used as guard, if true that means we can do the set fast
	MethodHandle casMap = MH.insertArguments(ScriptObject.CAS_MAP, 1, oldMap, newMap);
	casMap = MH.dropArguments(casMap, 1, type);
	casMap = MH.asType(casMap, casMap.type().changeParameterType(0, Object.class));
	methodHandle = MH.guardWithTest(casMap, fastSetter, slowSetter);
	} else {
	methodHandle = find.getSetter(type, isStrict, request);
	}

	assert methodHandle != null;
	assert property != null;

	final MethodHandle boundHandle;
	if (!(property instanceof UserAccessorProperty) && find.isInherited()) {
	boundHandle = ScriptObject.addProtoFilter(methodHandle, find.getProtoChainLength());
	} else {
	boundHandle = methodHandle;
	}
	return new SetMethod(boundHandle, property);
	}

	private SetMethod createGlobalPropertySetter() {
	final ScriptObject global = Context.getGlobal();
	return new SetMethod(MH.filterArguments(global.addSpill(type, getName()), 0, ScriptObject.GLOBALFILTER), null);
	}

	private SetMethod createNewPropertySetter(final SwitchPoint builtinSwitchPoint) {
	final SetMethod sm = map.getFreeFieldSlot() > -1 ? createNewFieldSetter(builtinSwitchPoint) : createNewSpillPropertySetter(builtinSwitchPoint);
	map.propertyAdded(sm.property, true);
	return sm;
	}

	private SetMethod createNewSetter(final Property property, final SwitchPoint builtinSwitchPoint) {
	property.setBuiltinSwitchPoint(builtinSwitchPoint);

	final PropertyMap oldMap = getMap();
	final PropertyMap newMap = getNewMap(property);
	final boolean isStrict = NashornCallSiteDescriptor.isStrict(desc);
	final String name = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);

	//fast type specific setter
	final MethodHandle fastSetter = property.getSetter(type, newMap); //0 sobj, 1 value, slot folded for spill property already

	//slow setter, that calls ScriptObject.set with appropriate type and key name
	MethodHandle slowSetter = ScriptObject.SET_SLOW[getAccessorTypeIndex(type)];
	slowSetter = MH.insertArguments(slowSetter, 3, NashornCallSiteDescriptor.getFlags(desc));
	slowSetter = MH.insertArguments(slowSetter, 1, name);
	slowSetter = MH.asType(slowSetter, slowSetter.type().changeParameterType(0, Object.class));

	assert slowSetter.type().equals(fastSetter.type()) : "slow=" + slowSetter + " != fast=" + fastSetter;

	//cas map used as guard, if true that means we can do the set fast
	MethodHandle casMap = MH.insertArguments(ScriptObject.CAS_MAP, 1, oldMap, newMap);
	casMap = MH.dropArguments(casMap, 1, type);
	casMap = MH.asType(casMap, casMap.type().changeParameterType(0, Object.class));
	final MethodHandle casGuard = MH.guardWithTest(casMap, fastSetter, slowSetter);

	//outermost level needs an extendable check. if object can be extended, guard is true and
	//we can run the cas setter. The setter goes to "nop" VOID_RETURN if false or throws an
	//exception if we are in strict mode and object is not extensible
	MethodHandle extCheck = MH.insertArguments(ScriptObject.EXTENSION_CHECK, 1, isStrict, name);
	extCheck = MH.asType(extCheck, extCheck.type().changeParameterType(0, Object.class));
	extCheck = MH.dropArguments(extCheck, 1, type);

	MethodHandle nop = JSType.VOID_RETURN.methodHandle();
	nop = MH.dropArguments(nop, 0, Object.class, type);

	return new SetMethod(MH.asType(MH.guardWithTest(extCheck, casGuard, nop), fastSetter.type()), property);
	}

	private SetMethod createNewFieldSetter(final SwitchPoint builtinSwitchPoint) {
	return createNewSetter(new AccessorProperty(getName(), getFlags(sobj), sobj.getClass(), getMap().getFreeFieldSlot(), type), builtinSwitchPoint);
	}

	private SetMethod createNewSpillPropertySetter(final SwitchPoint builtinSwitchPoint) {
	return createNewSetter(new SpillProperty(getName(), getFlags(sobj), getMap().getFreeSpillSlot(), type), builtinSwitchPoint);
	}

	private PropertyMap getNewMap(final Property property) {
	return getMap().addProperty(property);
	}

	private static int getFlags(final ScriptObject scriptObject) {
	return scriptObject.useDualFields() ? Property.DUAL_FIELDS : 0;
	}
	}