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