1 files changed, 73 insertions, 0 deletions
diff --git a/src/Java/sun/repackage/ClassDefiner.java b/src/Java/sun/repackage/ClassDefiner.java
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+++ b/src/Java/sun/repackage/ClassDefiner.java
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+/*
+ * Copyright (c) 2001, 2011, 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 sun.repackage;
+
+import java.security.AccessController;
+import java.security.PrivilegedAction;
+
+/** Utility class which assists in calling Unsafe.defineClass() by
+    creating a new class loader which delegates to the one needed in
+    order for proper resolution of the given bytecodes to occur. */
+
+class ClassDefiner {
+    static final Unsafe unsafe = Unsafe.getUnsafe();
+
+    /** <P> We define generated code into a new class loader which
+      delegates to the defining loader of the target class. It is
+      necessary for the VM to be able to resolve references to the
+      target class from the generated bytecodes, which could not occur
+      if the generated code was loaded into the bootstrap class
+      loader. </P>
+
+      <P> There are two primary reasons for creating a new loader
+      instead of defining these bytecodes directly into the defining
+      loader of the target class: first, it avoids any possible
+      security risk of having these bytecodes in the same loader.
+      Second, it allows the generated bytecodes to be unloaded earlier
+      than would otherwise be possible, decreasing run-time
+      footprint. </P>
+    */
+    static Class<?> defineClass(String name, byte[] bytes, int off, int len,
+                                final ClassLoader parentClassLoader)
+    {
+        ClassLoader newLoader = AccessController.doPrivileged(
+            new PrivilegedAction<ClassLoader>() {
+                public ClassLoader run() {
+                        return new DelegatingClassLoader(parentClassLoader);
+                    }
+                });
+        return unsafe.defineClass(name, bytes, off, len, newLoader, null);
+    }
+}
+
+
+// NOTE: this class's name and presence are known to the virtual
+// machine as of the fix for 4474172.
+class DelegatingClassLoader extends ClassLoader {
+    DelegatingClassLoader(ClassLoader parent) {
+        super(parent);
+    }
+}