8040655: When processing a RewriteException debug object, the return value has already been reset to null. We need to catch this value before that

Reviewed-by: attila, lagergren

nashorn/src/jdk/nashorn/internal/objects/NativeArray.java

@@ -712,7 +712,6 @@ public final class NativeArray extends ScriptObject {
         return new NativeArray(list.toArray());
     }
 
-    @SuppressWarnings("null")
     private static void concatToList(final ArrayList<Object> list, final Object obj) {
         final boolean isScriptArray = isArray(obj);
         final boolean isScriptObject = isScriptArray || obj instanceof ScriptObject;

nashorn/src/jdk/nashorn/internal/objects/NativeDebug.java

@@ -39,9 +39,9 @@ import jdk.nashorn.internal.runtime.Context;
 import jdk.nashorn.internal.runtime.JSType;
 import jdk.nashorn.internal.runtime.PropertyListeners;
 import jdk.nashorn.internal.runtime.PropertyMap;
-import jdk.nashorn.internal.runtime.RuntimeEvent;
 import jdk.nashorn.internal.runtime.ScriptFunction;
 import jdk.nashorn.internal.runtime.ScriptObject;
+import jdk.nashorn.internal.runtime.events.RuntimeEvent;
 import jdk.nashorn.internal.runtime.linker.LinkerCallSite;
 
 /**

nashorn/src/jdk/nashorn/internal/runtime/CompiledFunction.java

@@ -41,6 +41,7 @@ import java.util.logging.Level;
 import jdk.nashorn.internal.codegen.types.ArrayType;
 import jdk.nashorn.internal.codegen.types.Type;
 import jdk.nashorn.internal.ir.FunctionNode;
+import jdk.nashorn.internal.runtime.events.RecompilationEvent;
 import jdk.nashorn.internal.runtime.linker.Bootstrap;
 
 /**
@@ -576,7 +577,7 @@ final class CompiledFunction {
 
         final FunctionNode fn = oldOptimismInfo.recompile(callSiteType, re);
         if (LOG.isEnabled()) {
-            LOG.info(new RuntimeEvent<>(Level.INFO, re), "\tRewriteException ", re.getMessageShort());
+            LOG.info(new RecompilationEvent(Level.INFO, re, re.getReturnValueNonDestructive()), "\tRewriteException ", re.getMessageShort());
         }
 
         // It didn't necessarily recompile, e.g. for an outer invocation of a recursive function if we already

nashorn/src/jdk/nashorn/internal/runtime/Context.java

@@ -64,6 +64,7 @@ import jdk.nashorn.internal.ir.debug.ASTWriter;
 import jdk.nashorn.internal.ir.debug.PrintVisitor;
 import jdk.nashorn.internal.objects.Global;
 import jdk.nashorn.internal.parser.Parser;
+import jdk.nashorn.internal.runtime.events.RuntimeEvent;
 import jdk.nashorn.internal.runtime.options.Options;
 
 /**

nashorn/src/jdk/nashorn/internal/runtime/DebugLogger.java

@@ -30,7 +30,7 @@ import java.util.logging.Level;
 import java.util.logging.Logger;
 
 import jdk.nashorn.internal.objects.Global;
-import jdk.nashorn.internal.runtime.RuntimeEvent;
+import jdk.nashorn.internal.runtime.events.RuntimeEvent;
 import jdk.nashorn.internal.runtime.options.Options;
 
 /**

nashorn/src/jdk/nashorn/internal/runtime/Property.java

@@ -100,6 +100,7 @@ public abstract class Property {
     /** Property field number or spill slot. */
     private final int slot;
 
+    /** SwitchPoint that is invalidated when property is changed, optional */
     protected SwitchPoint changeCallback;
 
     /**
@@ -173,6 +174,12 @@ public abstract class Property {
         return propFlags;
     }
 
+    /**
+     * Set the change callback for this property, i.e. a SwitchPoint
+     * that will be invalidated when the value of the property is
+     * changed
+     * @param sp SwitchPoint to use for change callback
+     */
     public final void setChangeCallback(final SwitchPoint sp) {
         this.changeCallback = sp;
     }

nashorn/src/jdk/nashorn/internal/runtime/RewriteException.java

@@ -167,7 +167,7 @@ public class RewriteException extends Exception {
         return getUOE().getReturnValueDestructive();
     }
 
-    private Object getReturnValueNonDestructive() {
+    Object getReturnValueNonDestructive() {
         return getUOE().getReturnValueNonDestructive();
     }
 

nashorn/src/jdk/nashorn/internal/runtime/ScriptObject.java

@@ -2246,7 +2246,6 @@ public abstract class ScriptObject implements PropertyAccess {
      * @param request the link request
      * @return GuardedInvocation to be invoked at call site.
      */
-    @SuppressWarnings("null")
     public GuardedInvocation noSuchProperty(final CallSiteDescriptor desc, final LinkRequest request) {
         final String       name        = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);
         final FindProperty find        = findProperty(NO_SUCH_PROPERTY_NAME, true);

nashorn/src/jdk/nashorn/internal/runtime/events/RecompilationEvent.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright (c) 2010, 2014, 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.events;
+
+import java.util.logging.Level;
+
+import jdk.nashorn.internal.runtime.RecompilableScriptFunctionData;
+import jdk.nashorn.internal.runtime.RewriteException;
+
+/**
+ * Subclass of runtime event for {@link RewriteException}. In order not
+ * to leak memory, RewriteExceptions get their return value destroyed
+ * and nulled out during recompilation. If we are running with event
+ * logging enabled, we need to retain the returnValue, hence the extra
+ * field
+ */
+public final class RecompilationEvent extends RuntimeEvent<RewriteException> {
+
+    private final Object returnValue;
+
+    /**
+     * Constructor
+     *
+     * @param level            logging level
+     * @param rewriteException rewriteException wrapped by this RuntimEvent
+     * @param returnValue      rewriteException return value - as we don't want to make
+     *     {@link RewriteException#getReturnValueNonDestructive()} public, we pass it as
+     *     an extra parameter, rather than querying the getter from another package.
+     */
+    public RecompilationEvent(final Level level, final RewriteException rewriteException, final Object returnValue) {
+        super(level, rewriteException);
+        assert RecompilableScriptFunctionData.getLogger().isEnabled() :
+            "Unit test/instrumentation purpose only: RecompilationEvent instances should not be created without '--log=recompile', or we will leak memory in the general case";
+        this.returnValue = returnValue;
+    }
+
+    /**
+     * Get the preserved return value for the RewriteException
+     * @return return value
+     */
+    public Object getReturnValue() {
+        return returnValue;
+    }
+}

nashorn/src/jdk/nashorn/internal/runtime/events/RuntimeEvent.java

@@ -23,7 +23,7 @@
  * questions.
  */
 
-package jdk.nashorn.internal.runtime;
+package jdk.nashorn.internal.runtime.events;
 
 import java.util.logging.Level;
 
@@ -46,6 +46,7 @@ public class RuntimeEvent<T> {
 
     /**
      * Constructor
+     *
      * @param level  log level for runtime event to create
      * @param object object to wrap
      */
@@ -58,7 +59,7 @@ public class RuntimeEvent<T> {
      * Return the value wrapped in this runtime event
      * @return value
      */
-    public T getValue() {
+    public final T getValue() {
         return value;
     }
 

nashorn/src/jdk/nashorn/internal/runtime/linker/JavaAdapterClassLoader.java

@@ -39,14 +39,13 @@ import jdk.internal.dynalink.beans.StaticClass;
  * "class loader", it does not, in fact, extend {@code ClassLoader}, but rather uses them internally. Instances of this
  * class are normally created by {@link JavaAdapterBytecodeGenerator}.
  */
-@SuppressWarnings("javadoc")
 final class JavaAdapterClassLoader {
     private static final AccessControlContext CREATE_LOADER_ACC_CTXT = ClassAndLoader.createPermAccCtxt("createClassLoader");
 
     private final String className;
     private final byte[] classBytes;
 
-    JavaAdapterClassLoader(String className, byte[] classBytes) {
+    JavaAdapterClassLoader(final String className, final byte[] classBytes) {
         this.className = className.replace('/', '.');
         this.classBytes = classBytes;
     }

nashorn/test/script/basic/relink_index_getter.js

@@ -22,7 +22,7 @@
  */
 
 /**
- * relinkIndexGetter: after call site was linked for array, make sure it
+ * relink_index_getter: after call site was linked for array, make sure it
  * gets correctly relinked for boolean.
  *
  * @test

nashorn/test/script/trusted/event_queue.js

@@ -35,7 +35,7 @@ print(Debug);
 print();
 
 var forName       = java.lang.Class["forName(String)"];
-var RuntimeEvent  = forName("jdk.nashorn.internal.runtime.RuntimeEvent").static;
+var RuntimeEvent  = forName("jdk.nashorn.internal.runtime.events.RuntimeEvent").static;
 var getValue      = RuntimeEvent.class.getMethod("getValue"); 
 var getValueClass = RuntimeEvent.class.getMethod("getValueClass"); 
 

nashorn/test/script/trusted/event_queue.js.EXPECTED

@@ -1,6 +1,6 @@
 [object Debug]
 
-[JavaClass jdk.nashorn.internal.runtime.RuntimeEvent]
+[JavaClass jdk.nashorn.internal.runtime.events.RuntimeEvent]
 [JavaClass jdk.nashorn.internal.runtime.RewriteException]
 
 4.840000000000001
@@ -10,24 +10,24 @@ Done with 2 in the event queue
 events = true
 events.length = 2
 event #0
-	event class=class jdk.nashorn.internal.runtime.RuntimeEvent
+	event class=class jdk.nashorn.internal.runtime.events.RecompilationEvent
 	valueClass in event=class jdk.nashorn.internal.runtime.RewriteException
 	class of value=class jdk.nashorn.internal.runtime.RewriteException
 	return type=double
 event #1
-	event class=class jdk.nashorn.internal.runtime.RuntimeEvent
+	event class=class jdk.nashorn.internal.runtime.events.RecompilationEvent
 	valueClass in event=class jdk.nashorn.internal.runtime.RewriteException
 	class of value=class jdk.nashorn.internal.runtime.RewriteException
 	return type=double
 
-in loop last class = class jdk.nashorn.internal.runtime.RuntimeEvent
+in loop last class = class jdk.nashorn.internal.runtime.events.RecompilationEvent
 in loop last value class = class jdk.nashorn.internal.runtime.RewriteException
 in loop rex class = class jdk.nashorn.internal.runtime.RewriteException
 in loop rex return type = double
 
 true
 
-last class = class jdk.nashorn.internal.runtime.RuntimeEvent
+last class = class jdk.nashorn.internal.runtime.events.RecompilationEvent
 last value class = class jdk.nashorn.internal.runtime.RewriteException
 rex class = class jdk.nashorn.internal.runtime.RewriteException
 rex return type = object