1 /*
   2  * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package jdk.nashorn.internal.runtime;
  27 
  28 import java.lang.module.ModuleDescriptor;
  29 import java.lang.module.ModuleDescriptor.Modifier;
  30 import java.security.CodeSource;
  31 import java.util.Objects;
  32 import java.util.Set;
  33 
  34 /**
  35  * Responsible for loading script generated classes.
  36  *
  37  */
  38 final class ScriptLoader extends NashornLoader {
  39     private static final String NASHORN_PKG_PREFIX = "jdk.nashorn.internal.";
  40 
  41     private volatile boolean structureAccessAdded;
  42     private final Context context;
  43     private final Module scriptModule;
  44 
  45     /*package-private*/ Context getContext() {
  46         return context;
  47     }
  48 
  49     /**
  50      * Constructor.
  51      */
  52     ScriptLoader(final Context context) {
  53         super(context.getStructLoader());
  54         this.context = context;
  55 
  56         // new scripts module, it's specific exports and read-edges
  57         scriptModule = createModule("jdk.scripting.nashorn.scripts");
  58 
  59         // specific exports from nashorn to new scripts module
  60         NASHORN_MODULE.addExports(OBJECTS_PKG, scriptModule);
  61         NASHORN_MODULE.addExports(RUNTIME_PKG, scriptModule);
  62         NASHORN_MODULE.addExports(RUNTIME_ARRAYS_PKG, scriptModule);
  63         NASHORN_MODULE.addExports(RUNTIME_LINKER_PKG, scriptModule);
  64         NASHORN_MODULE.addExports(SCRIPTS_PKG, scriptModule);
  65 
  66         // nashorn needs to read scripts module methods,fields
  67         NASHORN_MODULE.addReads(scriptModule);
  68     }
  69 
  70     private Module createModule(final String moduleName) {
  71         final Module structMod = context.getStructLoader().getModule();
  72         final ModuleDescriptor.Builder builder =
  73             ModuleDescriptor.newModule(moduleName, Set.of(Modifier.SYNTHETIC))
  74                     .requires("java.logging")
  75                     .requires(NASHORN_MODULE.getName())
  76                     .requires(structMod.getName())
  77                     .packages(Set.of(SCRIPTS_PKG));
  78 
  79         if (Context.javaSqlFound) {
  80             builder.requires("java.sql");
  81         }
  82 
  83         if (Context.javaSqlRowsetFound) {
  84             builder.requires("java.sql.rowset");
  85         }
  86 
  87         final ModuleDescriptor descriptor = builder.build();
  88 
  89         final Module mod = Context.createModuleTrusted(structMod.getLayer(), descriptor, this);
  90         loadModuleManipulator();
  91         return mod;
  92     }
  93 
  94     @Override
  95     protected Class<?> loadClass(final String name, final boolean resolve) throws ClassNotFoundException {
  96         checkPackageAccess(name);
  97         final Class<?> cl = super.loadClass(name, resolve);
  98         if (!structureAccessAdded) {
  99             final StructureLoader structLoader = context.getStructLoader();
 100             if (cl.getClassLoader() == structLoader) {
 101                 structureAccessAdded = true;
 102                 structLoader.addModuleExport(scriptModule);
 103             }
 104         }
 105         return cl;
 106     }
 107 
 108     @Override
 109     protected Class<?> findClass(final String name) throws ClassNotFoundException {
 110         final ClassLoader appLoader = context.getAppLoader();
 111 
 112         /*
 113          * If the appLoader is null, don't bother side-delegating to it!
 114          * Bootloader has been already attempted via parent loader
 115          * delegation from the "loadClass" method.
 116          *
 117          * Also, make sure that we don't delegate to the app loader
 118          * for nashorn's own classes or nashorn generated classes!
 119          */
 120         if (appLoader == null || name.startsWith(NASHORN_PKG_PREFIX)) {
 121             throw new ClassNotFoundException(name);
 122         }
 123 
 124         /*
 125          * This split-delegation is used so that caller loader
 126          * based resolutions of classes would work. For example,
 127          * java.sql.DriverManager uses caller's class loader to
 128          * get Driver instances. Without this split-delegation
 129          * a script class evaluating DriverManager.getDrivers()
 130          * will not get back any JDBC driver!
 131          */
 132         return appLoader.loadClass(name);
 133     }
 134 
 135     // package-private and private stuff below this point
 136 
 137     /**
 138      * Install a class for use by the Nashorn runtime
 139      *
 140      * @param name Binary name of class.
 141      * @param data Class data bytes.
 142      * @param cs CodeSource code source of the class bytes.
 143      *
 144      * @return Installed class.
 145      */
 146     synchronized Class<?> installClass(final String name, final byte[] data, final CodeSource cs) {
 147         return defineClass(name, data, 0, data.length, Objects.requireNonNull(cs));
 148     }
 149 }