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.api.scripting;
  27 
  28 import static jdk.nashorn.internal.runtime.ScriptRuntime.UNDEFINED;
  29 
  30 import java.lang.invoke.MethodHandle;
  31 import jdk.internal.dynalink.beans.StaticClass;
  32 import jdk.internal.dynalink.linker.LinkerServices;
  33 import jdk.nashorn.internal.runtime.Context;
  34 import jdk.nashorn.internal.runtime.ScriptFunction;
  35 import jdk.nashorn.internal.runtime.ScriptObject;
  36 import jdk.nashorn.internal.runtime.ScriptRuntime;
  37 import jdk.nashorn.internal.runtime.linker.Bootstrap;
  38 
  39 /**
  40  * Utilities that are to be called from script code.
  41  */
  42 public final class ScriptUtils {
  43     private ScriptUtils() {}
  44 
  45     /**
  46      * Returns AST as JSON compatible string. This is used to
  47      * implement "parse" function in resources/parse.js script.
  48      *
  49      * @param code code to be parsed
  50      * @param name name of the code source (used for location)
  51      * @param includeLoc tells whether to include location information for nodes or not
  52      * @return JSON string representation of AST of the supplied code
  53      */
  54     public static String parse(final String code, final String name, final boolean includeLoc) {
  55         return ScriptRuntime.parse(code, name, includeLoc);
  56     }
  57 
  58     /**
  59      * Method which converts javascript types to java types for the
  60      * String.format method (jrunscript function sprintf).
  61      *
  62      * @param format a format string
  63      * @param args arguments referenced by the format specifiers in format
  64      * @return a formatted string
  65      */
  66     public static String format(final String format, final Object[] args) {
  67         return Formatter.format(format, args);
  68     }
  69 
  70     /**
  71      * Create a wrapper function that calls {@code func} synchronized on {@code sync} or, if that is undefined,
  72      * {@code self}. Used to implement "sync" function in resources/mozilla_compat.js.
  73      *
  74      * @param func the function to wrap
  75      * @param sync the object to synchronize on
  76      * @return a synchronizing wrapper function
  77      */
  78     public static Object makeSynchronizedFunction(final Object func, final Object sync) {
  79         return func instanceof ScriptFunction?
  80             ((ScriptFunction)func).makeSynchronizedFunction(sync) : UNDEFINED;
  81     }
  82 
  83     /**
  84      * Make a script object mirror on given object if needed.
  85      *
  86      * @param obj object to be wrapped
  87      * @return wrapped object
  88      */
  89     public static Object wrap(final Object obj) {
  90         if (obj instanceof ScriptObject) {
  91             return ScriptObjectMirror.wrap(obj, Context.getGlobal());
  92         }
  93 
  94         return obj;
  95     }
  96 
  97     /**
  98      * Unwrap a script object mirror if needed.
  99      *
 100      * @param obj object to be unwrapped
 101      * @return unwrapped object
 102      */
 103     public static Object unwrap(final Object obj) {
 104         if (obj instanceof ScriptObjectMirror) {
 105             return ScriptObjectMirror.unwrap(obj, Context.getGlobal());
 106         }
 107 
 108         return obj;
 109     }
 110 
 111     /**
 112      * Wrap an array of object to script object mirrors if needed.
 113      *
 114      * @param args array to be unwrapped
 115      * @return wrapped array
 116      */
 117     public static Object[] wrapArray(final Object[] args) {
 118         if (args == null || args.length == 0) {
 119             return args;
 120         }
 121 
 122         return ScriptObjectMirror.wrapArray(args, Context.getGlobal());
 123     }
 124 
 125     /**
 126      * Unwrap an array of script object mirrors if needed.
 127      *
 128      * @param args array to be unwrapped
 129      * @return unwrapped array
 130      */
 131     public static Object[] unwrapArray(final Object[] args) {
 132         if (args == null || args.length == 0) {
 133             return args;
 134         }
 135 
 136         return ScriptObjectMirror.unwrapArray(args, Context.getGlobal());
 137     }
 138 
 139     /**
 140      * Convert the given object to the given type.
 141      *
 142      * @param obj object to be converted
 143      * @param type destination type to convert to
 144      * @return converted object
 145      */
 146     public static Object convert(final Object obj, final Object type) {
 147         if (obj == null) {
 148             return null;
 149         }
 150 
 151         final Class<?> clazz;
 152         if (type instanceof Class) {
 153             clazz = (Class<?>)type;
 154         } else if (type instanceof StaticClass) {
 155             clazz = ((StaticClass)type).getRepresentedClass();
 156         } else {
 157             throw new IllegalArgumentException("type expected");
 158         }
 159 
 160         final LinkerServices linker = Bootstrap.getLinkerServices();
 161         final MethodHandle converter = linker.getTypeConverter(obj.getClass(),  clazz);
 162         if (converter == null) {
 163             // no supported conversion!
 164             throw new UnsupportedOperationException("conversion not supported");
 165         }
 166 
 167         try {
 168             return converter.invoke(obj);
 169         } catch (final RuntimeException | Error e) {
 170             throw e;
 171         } catch (final Throwable t) {
 172             throw new RuntimeException(t);
 173         }
 174     }
 175 }