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.ir;
  27 
  28 import jdk.nashorn.internal.ir.annotations.Immutable;
  29 import jdk.nashorn.internal.ir.visitor.NodeVisitor;
  30 
  31 /**
  32  * IR representation of a catch clause.
  33  */
  34 @Immutable
  35 public final class CatchNode extends Statement {
  36     private static final long serialVersionUID = 1L;
  37 
  38     /** Exception identifier or pattern. */
  39     private final Expression exception;
  40 
  41     /** Exception condition. */
  42     private final Expression exceptionCondition;
  43 
  44     /** Catch body. */
  45     private final Block body;
  46 
  47     private final boolean isSyntheticRethrow;
  48 
  49     /**
  50      * Constructors
  51      *
  52      * @param lineNumber         lineNumber
  53      * @param token              token
  54      * @param finish             finish
  55      * @param exception          variable name or pattern of exception
  56      * @param exceptionCondition exception condition
  57      * @param body               catch body
  58      * @param isSyntheticRethrow true if this node is a synthetically generated rethrow node.
  59      */
  60     public CatchNode(final int lineNumber, final long token, final int finish, final Expression exception,
  61             final Expression exceptionCondition, final Block body, final boolean isSyntheticRethrow) {
  62         super(lineNumber, token, finish);
  63         if (exception instanceof IdentNode) {
  64             this.exception = ((IdentNode) exception == null) ? null : ((IdentNode) exception).setIsInitializedHere();
  65         } else {
  66             this.exception = exception;
  67         }
  68 
  69         this.exceptionCondition = exceptionCondition;
  70         this.body = body;
  71         this.isSyntheticRethrow = isSyntheticRethrow;
  72     }
  73 
  74     private CatchNode(final CatchNode catchNode, final Expression exception, final Expression exceptionCondition,
  75             final Block body, final boolean isSyntheticRethrow) {
  76         super(catchNode);
  77         this.exception          = exception;
  78         this.exceptionCondition = exceptionCondition;
  79         this.body               = body;
  80         this.isSyntheticRethrow = isSyntheticRethrow;
  81     }
  82 
  83     /**
  84      * Assist in IR navigation.
  85      * @param visitor IR navigating visitor.
  86      */
  87     @Override
  88     public Node accept(final NodeVisitor<? extends LexicalContext> visitor) {
  89         if (visitor.enterCatchNode(this)) {
  90             return visitor.leaveCatchNode(
  91                     setException((Expression) exception.accept(visitor)).
  92                             setExceptionCondition(exceptionCondition == null ? null : (Expression) exceptionCondition.accept(visitor)).
  93                             setBody((Block) body.accept(visitor)));
  94         }

  95         return this;
  96     }
  97 
  98     @Override
  99     public boolean isTerminal() {
 100         return body.isTerminal();
 101     }
 102 
 103     @Override
 104     public void toString(final StringBuilder sb, final boolean printTypes) {
 105         sb.append(" catch (");
 106         exception.toString(sb, printTypes);
 107 
 108         if (exceptionCondition != null) {
 109             sb.append(" if ");
 110             exceptionCondition.toString(sb, printTypes);
 111         }
 112         sb.append(')');
 113     }
 114 
 115     /**
 116      * Get the identifier representing the exception thrown
 117      * @return the exception identifier
 118      */
 119     public IdentNode getException() {
 120         //Fixme :http://www.ecma-international.org/ecma-262/6.0/
 121         //for now, only parsing is supported
 122         if (exception instanceof IdentNode) {
 123             return (IdentNode) exception;
 124         } else {
 125             return null;
 126         }
 127     }
 128 
 129     /**
 130      * Get the exception condition for this catch block
 131      * @return the exception condition
 132      */
 133     public Expression getExceptionCondition() {
 134         return exceptionCondition;
 135     }
 136 
 137     /**
 138      * Reset the exception condition for this catch block
 139      * @param exceptionCondition the new exception condition
 140      * @return new or same CatchNode
 141      */
 142     public CatchNode setExceptionCondition(final Expression exceptionCondition) {
 143         if (this.exceptionCondition == exceptionCondition) {
 144             return this;
 145         }
 146         return new CatchNode(this, exception, exceptionCondition, body, isSyntheticRethrow);
 147     }
 148 
 149     /**
 150      * Get the body for this catch block
 151      * @return the catch block body
 152      */
 153     public Block getBody() {
 154         return body;
 155     }
 156 
 157     /**
 158      * Resets the exception of a catch block
 159      * @param exception new exception
 160      * @return new catch node if changed, same otherwise
 161      */
 162     public CatchNode setException(final Expression exception) {
 163         if (this.exception == exception) {
 164             return this;
 165         }
 166         return new CatchNode(this, exception, exceptionCondition, body, isSyntheticRethrow);
 167     }
 168 
 169     private CatchNode setBody(final Block body) {
 170         if (this.body == body) {
 171             return this;
 172         }
 173         return new CatchNode(this, exception, exceptionCondition, body, isSyntheticRethrow);
 174     }
 175 
 176     /**
 177      * Is this catch block a non-JavaScript constructor, for example created as
 178      * part of the rethrow mechanism of a finally block in Lower? Then we just
 179      * pass the exception on and need not unwrap whatever is in the ECMAException
 180      * object catch symbol
 181      * @return true if a finally synthetic rethrow
 182      */
 183     public boolean isSyntheticRethrow() {
 184         return isSyntheticRethrow;
 185     }
 186 }
--- EOF ---