--- old/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/objects/annotations/SpecializedFunction.java 2020-04-15 18:49:16.000000000 +0530 +++ /dev/null 2020-04-15 18:49:16.000000000 +0530 @@ -1,228 +0,0 @@ -/* - * Copyright (c) 2010, 2015, 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.objects.annotations; - -import java.lang.annotation.ElementType; -import java.lang.annotation.Retention; -import java.lang.annotation.RetentionPolicy; -import java.lang.annotation.Target; -import java.lang.invoke.MethodHandle; -import jdk.dynalink.CallSiteDescriptor; -import jdk.dynalink.linker.LinkRequest; -import jdk.nashorn.internal.runtime.ScriptFunction; -import jdk.nashorn.internal.runtime.UnwarrantedOptimismException; - -/** - * The SpecializedFunction annotation is used to flag more type specific - * functions than the standard one in the native objects. - */ -@Retention(RetentionPolicy.RUNTIME) -@Target(ElementType.METHOD) -public @interface SpecializedFunction { - - /** - * Functionality for testing if we are allowed to link a specialized - * function the first time we encounter it. Then the guard will handle the - * rest of the invocations. - * - * This is the same for all callsites in Nashorn; the first time a callsite is - * linked, we have to manually check that the linkage is OK. Even if we add - * a guard and it fails upon the first try, this is not good enough. - * (Symmetrical to how it works everywhere else in the Nashorn runtime.) - * - * Here we abstract out a few of the most common link guard checks. - */ - public static abstract class LinkLogic { - /** - * Empty link logic instance - this is the default. - * "no special linking or runtime guard behavior" - */ - public static final LinkLogic EMPTY_INSTANCE = new Empty(); - - /** Empty link logic class - allow all linking, no guards. */ - private static final class Empty extends LinkLogic { - @Override - public boolean canLink(final Object self, final CallSiteDescriptor desc, final LinkRequest request) { - return true; - } - - @Override - public boolean isEmpty() { - return true; - } - } - - /** - * Get the class representing the empty link logic. - * - * @return class representing empty link logic - */ - public static Class getEmptyLinkLogicClass() { - return Empty.class; - } - - /** - * Should this callsite relink when an exception is thrown? - * - * @return the relink exception, or {@code null} if none - */ - public Class getRelinkException() { - return null; - } - - /** - * Is this link logic class empty - i.e., no special linking logic - * supplied? - * - * @param clazz class to check - * - * @return {@code true} if this link logic is empty - */ - public static boolean isEmpty(final Class clazz) { - return clazz == Empty.class; - } - - /** - * Is this link logic instance empty - i.e., no special linking logic - * supplied? - * - * @return {@code true} if this link logic instance is empty - */ - public boolean isEmpty() { - return false; - } - - /** - * Given a callsite, can we link this method based on the receiver and - * parameters? - * - * @param self receiver - * @param desc callsite descriptor - * @param request link request - * - * @return {@code true} if we can link this callsite at this time - */ - public abstract boolean canLink(final Object self, final CallSiteDescriptor desc, final LinkRequest request); - - /** - * Given a callsite, do we require an extra guard for specialization to - * go through? - * - * @param self receiver - * - * @return {@code true} if a guard is to be woven into the callsite - */ - public boolean needsGuard(final Object self) { - return true; - } - - /** - * Given a callsite, and optional arguments, do we need an extra guard - * for specialization to go through? This guard can be a function of - * the arguments too. - * - * @param self receiver - * @param args arguments - * - * @return {@code true} if a guard is to be woven into the callsite - */ - public boolean needsGuard(final Object self, final Object... args) { - return true; - } - - /** - * Given a callsite, and optional arguments, return any extra guard we - * might need for specialization as a method handle. - * - * @return methodhandle for guard, or null if no guard is needed - */ - public MethodHandle getGuard() { - return null; - } - - /** - * Check, given a link request and a receiver, if this specialization - * fits This is used by the linker in {@link ScriptFunction} to figure - * out if an optimistic builtin can be linked when first discovered - * - * @param self receiver - * @param desc callsite descriptor - * @param request link request - * - * @return {@code true} if we can link, {@code false} otherwise - that - * means we have to pick a non specialized target - */ - public boolean checkLinkable(final Object self, final CallSiteDescriptor desc, final LinkRequest request) { - // check the link guard, if it says we can link, go ahead - return canLink(self, desc, request); - } - } - - /** - * Name override for return value polymorphism, for example we can't have - * pop(V)I and pop(V)D in the same Java class, so they need to be named, - * e.g., popInt(V)I and popDouble(V)D for disambiguation, however, their - * names still need to resolve to "pop" to JavaScript so we can still - * specialize on return values and so that the linker can find them. - * - * @return name, "" means no override, use the Java function name, e.g. - * "push" - */ - String name() default ""; - - /** - * Return the guard for this specialized function. The default is no guard. - * - * @return guard - */ - Class linkLogic() default LinkLogic.Empty.class; - - /** - * @return whether this is a specialized constructor. - */ - boolean isConstructor() default false; - - /** - * Can this function throw {@link UnwarrantedOptimismException}s? This works - * just like the normal functions, but we need the function to be - * immutable/non-state modifying, as we can't generate continuations for - * native code. Luckily a lot of the methods we want to specialize have this - * property. - * - * @return whether this function can throw {@link UnwarrantedOptimismException}. - */ - boolean isOptimistic() default false; - - /** - * Is it safe to convert non-numeric arguments to numbers for this function's primitive numeric parameters? - * This is true for many built-in functions which expect numeric arguments, but not for those that - * expect generic arguments and just have specializations with numeric params to avoid boxing overhead. - * The default value is {@code true} because that is by far the most common case. - * - * @return true if it is safe to convert arguments to numbers - */ - boolean convertsNumericArgs() default true; -}