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 static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.INVALID_PROGRAM_POINT;
  29 
  30 import jdk.nashorn.internal.codegen.types.Type;
  31 import jdk.nashorn.internal.ir.annotations.Immutable;
  32 import jdk.nashorn.internal.parser.TokenType;
  33 
  34 /**
  35  * IR base for accessing/indexing nodes.
  36  *
  37  * @see AccessNode
  38  * @see IndexNode
  39  */
  40 @Immutable
  41 public abstract class BaseNode extends Expression implements FunctionCall, Optimistic {
  42     private static final long serialVersionUID = 1L;
  43 
  44     /** Base Node. */
  45     protected final Expression base;
  46 
  47     private final boolean isFunction;
  48 
  49     /** Callsite type for this node, if overridden optimistically or conservatively depending on coercion */
  50     protected final Type type;
  51 
  52     /** Program point id */
  53     protected final int programPoint;
  54 
  55     /** Super property access. */
  56     private final boolean isSuper;
  57 
  58     /**
  59      * Constructor
  60      *
  61      * @param token  token
  62      * @param finish finish
  63      * @param base   base node
  64      * @param isFunction is this a function
  65      * @param isSuper is this a super property access
  66      */
  67     public BaseNode(final long token, final int finish, final Expression base, final boolean isFunction, final boolean isSuper) {
  68         super(token, base.getStart(), finish);
  69         this.base           = base;
  70         this.isFunction     = isFunction;
  71         this.type = null;
  72         this.programPoint   = INVALID_PROGRAM_POINT;
  73         this.isSuper        = isSuper;
  74     }
  75 
  76     /**
  77      * Copy constructor for immutable nodes
  78      * @param baseNode node to inherit from
  79      * @param base base
  80      * @param isFunction is this a function
  81      * @param callSiteType  the callsite type for this base node, either optimistic or conservative
  82      * @param programPoint  program point id
  83      * @param isSuper is this a super property access
  84      */
  85     protected BaseNode(final BaseNode baseNode, final Expression base, final boolean isFunction, final Type callSiteType, final int programPoint, final boolean isSuper) {
  86         super(baseNode);
  87         this.base           = base;
  88         this.isFunction     = isFunction;
  89         this.type = callSiteType;
  90         this.programPoint   = programPoint;
  91         this.isSuper        = isSuper;
  92     }
  93 
  94     /**
  95      * Get the base node for this access
  96      * @return the base node
  97      */
  98     public Expression getBase() {
  99         return base;
 100     }
 101 
 102     @Override
 103     public boolean isFunction() {
 104         return isFunction;
 105     }
 106 
 107     @Override
 108     public Type getType() {
 109         return type == null ? getMostPessimisticType() : type;
 110     }
 111 
 112     @Override
 113     public int getProgramPoint() {
 114         return programPoint;
 115     }
 116 
 117     @Override
 118     public Type getMostOptimisticType() {
 119         return Type.INT;
 120     }
 121 
 122     @Override
 123     public Type getMostPessimisticType() {
 124         return Type.OBJECT;
 125     }
 126 
 127     @Override
 128     public boolean canBeOptimistic() {
 129         return true;
 130     }
 131 
 132     /**
 133      * Return true if this node represents an index operation normally represented as {@link IndexNode}.
 134      * @return true if an index access.
 135      */
 136     public boolean isIndex() {
 137         return isTokenType(TokenType.LBRACKET);
 138     }
 139 
 140     /**
 141      * Mark this node as being the callee operand of a {@link CallNode}.
 142      * @return a base node identical to this one in all aspects except with its function flag set.
 143      */
 144     public abstract BaseNode setIsFunction();
 145 
 146     /**
 147      * @return {@code true} if a SuperProperty access.
 148      */
 149     public boolean isSuper() {
 150         return isSuper;
 151     }
 152 
 153     /**
 154      * Mark this node as being a SuperProperty access.
 155      *
 156      * @return  a base node identical to this one in all aspects except with its super flag set.
 157      */
 158     public abstract BaseNode setIsSuper();
 159 }