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 static jdk.nashorn.internal.codegen.CompilerConstants.staticCallNoLookup;
  29 import static jdk.nashorn.internal.codegen.CompilerConstants.virtualField;
  30 import static jdk.nashorn.internal.runtime.ScriptRuntime.UNDEFINED;
  31 
  32 import javax.script.ScriptException;
  33 import jdk.nashorn.api.scripting.NashornException;
  34 import jdk.nashorn.internal.codegen.CompilerConstants.Call;
  35 import jdk.nashorn.internal.codegen.CompilerConstants.FieldAccess;
  36 
  37 /**
  38  * Exception used to implement ECMAScript "throw" from scripts. The actual thrown
  39  * object from script need not be a Java exception and so it is wrapped as an
  40  * instance field called "thrown" here. This exception class is also used to
  41  * represent ECMA errors thrown from runtime code (for example, TypeError,
  42  * ReferenceError thrown from Nashorn engine runtime).
  43  */
  44 @SuppressWarnings("serial")
  45 public final class ECMAException extends NashornException {
  46     /**
  47      * Method handle pointing to the constructor {@link ECMAException#create(Object, String, int, int)},
  48      */
  49     public static final Call CREATE = staticCallNoLookup(ECMAException.class, "create", ECMAException.class, Object.class, String.class, int.class, int.class);
  50 
  51     /** Field handle to the{@link ECMAException#thrown} field, so that it can be accessed from generated code */
  52     public static final FieldAccess THROWN = virtualField(ECMAException.class, "thrown", Object.class);
  53 
  54     private static final String EXCEPTION_PROPERTY = "nashornException";
  55 
  56     /** Object thrown. */
  57     public final Object thrown;
  58     
  59     /**
  60      * Constructor. Called from the factory method 'create'.
  61      *
  62      * @param thrown    object to be thrown
  63      * @param fileName  script file name
  64      * @param line      line number of throw
  65      * @param column    column number of throw
  66      */
  67     private ECMAException(final Object thrown, final String fileName, final int line, final int column) {
  68         super(ScriptRuntime.safeToString(thrown), asThrowable(thrown), fileName, line, column);
  69         this.thrown = thrown;
  70         setExceptionToThrown();
  71     }
  72 
  73     /**
  74      * Constructor. This is called from the runtime code.
  75      *
  76      * @param thrown   object to be thrown
  77      * @param cause    Java exception that triggered this throw
  78      */
  79     public ECMAException(final Object thrown, final Throwable cause) {
  80         super(ScriptRuntime.safeToString(thrown), cause);
  81         this.thrown = thrown;
  82         setExceptionToThrown();
  83     }
  84 
  85     /**
  86      * Factory method to retrieve the underlying exception or create an exception.
  87      * This method is called from the generated code.
  88      *
  89      * @param thrown    object to be thrown
  90      * @param fileName  script file name
  91      * @param line      line number of throw
  92      * @param column    column number of throw
  93      * @return ECMAException object
  94      */
  95     public static ECMAException create(final Object thrown, final String fileName, final int line, final int column) {
  96         // If thrown object is an Error or sub-object like TypeError, then
  97         // an ECMAException object has been already initialized at constructor.
  98         if (thrown instanceof ScriptObject) {
  99             ScriptObject sobj = (ScriptObject)thrown;
 100             Object exception = getException(sobj);
 101             if (exception instanceof ECMAException) {
 102                 // copy over file name, line number and column number.
 103                 final ECMAException ee = (ECMAException)exception;
 104                 ee.setFileName(fileName);
 105                 ee.setLineNumber(line);
 106                 ee.setColumnNumber(column);
 107                 return ee;
 108             }
 109         }
 110 
 111         return new ECMAException(thrown, fileName, line, column);
 112     }
 113 
 114     /**
 115      * Get the thrown object
 116      * @return thrown object
 117      */
 118     @Override
 119     public Object getThrown() {
 120         return thrown;
 121     }
 122 
 123     @Override
 124     public String toString() {
 125         final StringBuilder sb = new StringBuilder();
 126         final String fileName = getFileName();
 127         final int line = getLineNumber();
 128         final int column = getColumnNumber();
 129 
 130         if (fileName != null) {
 131             sb.append(fileName);
 132             if (line >= 0) {
 133                 sb.append(':');
 134                 sb.append(line);
 135             }
 136             if (column >= 0) {
 137                 sb.append(':');
 138                 sb.append(column);
 139             }
 140             sb.append(' ');
 141         } else {
 142             sb.append("ECMAScript Exception: ");
 143         }
 144 
 145         sb.append(getMessage());
 146         return sb.toString();
 147     }
 148 
 149     /**
 150      * Get the {@link ECMAException}, i.e. the underlying Java object for the
 151      * JavaScript error object from a {@link ScriptObject} representing an error
 152      *
 153      * @param errObj the error object
 154      * @return a {@link ECMAException}
 155      */
 156     public static Object getException(final ScriptObject errObj) {
 157         return errObj.get(ECMAException.EXCEPTION_PROPERTY);
 158     }
 159 
 160     /**
 161      * Print the stack trace for a {@code ScriptObject} representing an error
 162      *
 163      * @param errObj the error object
 164      * @return undefined
 165      */
 166     public static Object printStackTrace(final ScriptObject errObj) {
 167         final Object exception = getException(errObj);
 168         if (exception instanceof Throwable) {
 169             ((Throwable)exception).printStackTrace(Context.getCurrentErr());
 170         } else {
 171             Context.err("<stack trace not available>");
 172         }
 173         return UNDEFINED;
 174     }
 175 
 176     /**
 177      * Get the line number for a {@code ScriptObject} representing an error
 178      *
 179      * @param errObj the error object
 180      * @return the line number, or undefined if wrapped exception is not a ParserException
 181      */
 182     public static Object getLineNumber(final ScriptObject errObj) {
 183         final Object e = getException(errObj);
 184         if (e instanceof NashornException) {
 185             return ((NashornException)e).getLineNumber();
 186         } else if (e instanceof ScriptException) {
 187             return ((ScriptException)e).getLineNumber();
 188         }
 189 
 190         return UNDEFINED;
 191     }
 192 
 193     /**
 194      * Get the column number for a {@code ScriptObject} representing an error
 195      *
 196      * @param errObj the error object
 197      * @return the column number, or undefined if wrapped exception is not a ParserException
 198      */
 199     public static Object getColumnNumber(final ScriptObject errObj) {
 200         final Object e = getException(errObj);
 201         if (e instanceof NashornException) {
 202             return ((NashornException)e).getColumnNumber();
 203         } else if (e instanceof ScriptException) {
 204             return ((ScriptException)e).getColumnNumber();
 205         }
 206 
 207         return UNDEFINED;
 208     }
 209 
 210     /**
 211      * Get the file name for a {@code ScriptObject} representing an error
 212      *
 213      * @param errObj the error object
 214      * @return the file name, or undefined if wrapped exception is not a ParserException
 215      */
 216     public static Object getFileName(final ScriptObject errObj) {
 217         final Object e = getException(errObj);
 218         if (e instanceof NashornException) {
 219             return ((NashornException)e).getFileName();
 220         } else if (e instanceof ScriptException) {
 221             return ((ScriptException)e).getFileName();
 222         }
 223 
 224         return UNDEFINED;
 225     }
 226 
 227     /**
 228      * Stateless string conversion for an error object
 229      *
 230      * @param errObj the error object
 231      * @return string representation of {@code errObj}
 232      */
 233     public static String safeToString(final ScriptObject errObj) {
 234         Object name = UNDEFINED;
 235         try {
 236             name = errObj.get("name");
 237         } catch (final Exception e) {
 238             //ignored
 239         }
 240 
 241         if (name == UNDEFINED) {
 242             name = "Error";
 243         } else {
 244             name = ScriptRuntime.safeToString(name);
 245         }
 246 
 247         Object msg = UNDEFINED;
 248         try {
 249             msg = errObj.get("message");
 250         } catch (final Exception e) {
 251             //ignored
 252         }
 253 
 254         if (msg == UNDEFINED) {
 255             msg = "";
 256         } else {
 257             msg = ScriptRuntime.safeToString(msg);
 258         }
 259 
 260         if (((String)name).isEmpty()) {
 261             return (String)msg;
 262         }
 263 
 264         if (((String)msg).isEmpty()) {
 265             return (String)name;
 266         }
 267 
 268         return name + ": " + msg;
 269     }
 270 
 271     private static Throwable asThrowable(final Object obj) {
 272         return (obj instanceof Throwable)? (Throwable)obj : null;
 273     }
 274 
 275     private void setExceptionToThrown() {
 276         /*
 277          * Nashorn extension: errorObject.nashornException
 278          * Expose this exception via "nashornException" property of on the
 279          * thrown object. This exception object can be used to print stack
 280          * trace and fileName, line number etc. from script code.
 281          */
 282 
 283         if (thrown instanceof ScriptObject) {
 284             final ScriptObject sobj = (ScriptObject)thrown;
 285             if (!sobj.has(EXCEPTION_PROPERTY)) {
 286                 sobj.addOwnProperty(EXCEPTION_PROPERTY, Property.NOT_ENUMERABLE, this);
 287             } else {
 288                 sobj.set(EXCEPTION_PROPERTY, this, false);
 289             }
 290         }
 291     }
 292 }