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.codegen;
  27 
  28 import static jdk.nashorn.internal.runtime.arrays.ArrayIndex.getArrayIndex;
  29 import static jdk.nashorn.internal.runtime.arrays.ArrayIndex.isValidArrayIndex;
  30 
  31 import java.util.ArrayList;
  32 import java.util.List;
  33 import jdk.nashorn.internal.ir.Symbol;
  34 import jdk.nashorn.internal.runtime.AccessorProperty;
  35 import jdk.nashorn.internal.runtime.Property;
  36 import jdk.nashorn.internal.runtime.PropertyMap;
  37 
  38 /**
  39  * Class that creates PropertyMap sent to script object constructors.
  40  */
  41 public class MapCreator {
  42     /** Object structure for objects associated with this map */
  43     private final Class<?> structure;
  44 
  45     /** key set for object map */
  46     final List<String> keys;
  47 
  48     /** corresponding symbol set for object map */
  49     final List<Symbol> symbols;
  50 
  51     /**
  52      * Constructor
  53      *
  54      * @param structure structure to generate map for (a JO subclass)
  55      * @param keys      list of keys for map
  56      * @param symbols   list of symbols for map
  57      */
  58     MapCreator(final Class<?> structure, final List<String> keys, final List<Symbol> symbols) {
  59         this.structure = structure;
  60         this.keys      = keys;
  61         this.symbols   = symbols;
  62     }
  63 
  64     /**
  65      * Constructs a property map based on a set of fields.
  66      *
  67      * @param hasArguments does the created object have an "arguments" property
  68      * @param fieldCount    Number of fields in use.
  69      * @param fieldMaximum Number of fields available.
  70      *
  71      * @return New map populated with accessor properties.
  72      */
  73     PropertyMap makeFieldMap(final boolean hasArguments, final int fieldCount, final int fieldMaximum) {
  74         final List<Property> properties = new ArrayList<>();
  75         assert keys != null;
  76 
  77         for (int i = 0, length = keys.size(); i < length; i++) {
  78             final String key    = keys.get(i);
  79             final Symbol symbol = symbols.get(i);
  80 
  81             if (symbol != null && !isValidArrayIndex(getArrayIndex(key))) {
  82                 properties.add(new AccessorProperty(key, getPropertyFlags(symbol, hasArguments), structure, symbol.getFieldIndex()));
  83             }
  84         }
  85 
  86         return PropertyMap.newMap(properties, fieldCount, fieldMaximum, 0);
  87     }
  88 
  89     PropertyMap makeSpillMap(final boolean hasArguments) {
  90         final List<Property> properties = new ArrayList<>();
  91         int spillIndex = 0;
  92         assert keys != null;
  93 
  94         for (int i = 0, length = keys.size(); i < length; i++) {
  95             final String key    = keys.get(i);
  96             final Symbol symbol = symbols.get(i);
  97 
  98             if (symbol != null && !isValidArrayIndex(getArrayIndex(key))) {
  99                 properties.add(new AccessorProperty(key, getPropertyFlags(symbol, hasArguments), spillIndex++));
 100             }
 101         }
 102 
 103         return PropertyMap.newMap(properties, 0, 0, spillIndex);
 104     }
 105 
 106     /**
 107      * Compute property flags given local state of a field. May be overridden and extended,
 108      *
 109      * @param symbol       symbol to check
 110      * @param hasArguments does the created object have an "arguments" property
 111      *
 112      * @return flags to use for fields
 113      */
 114     protected int getPropertyFlags(final Symbol symbol, final boolean hasArguments) {
 115         int flags = 0;
 116 
 117         if (symbol.isParam()) {
 118             flags |= Property.IS_ALWAYS_OBJECT | Property.IS_PARAMETER;
 119         }
 120 
 121         if (hasArguments) {
 122             flags |= Property.IS_ALWAYS_OBJECT | Property.HAS_ARGUMENTS;
 123         }
 124 
 125         if (symbol.isScope()) {
 126             flags |= Property.NOT_CONFIGURABLE;
 127         }
 128 
 129         if (symbol.canBePrimitive()) {
 130             flags |= Property.CAN_BE_PRIMITIVE;
 131         }
 132 
 133         if (symbol.canBeUndefined()) {
 134             flags |= Property.CAN_BE_UNDEFINED;
 135         }
 136 
 137         if (symbol.isFunctionDeclaration()) {
 138             flags |= Property.IS_FUNCTION_DECLARATION;
 139         }
 140 
 141         return flags;
 142     }
 143 
 144 }