modules/tool-classfile/src/main/java/net/multiphasicapps/classfile/ClassVersion.java

   1 // -*- Mode: Java; indent-tabs-mode: t; tab-width: 4 -*-
   2 // ---------------------------------------------------------------------------
   3 // SquirrelJME
   4 //     Copyright (C) Stephanie Gawroriski <xer@multiphasicapps.net>
   5 // ---------------------------------------------------------------------------
   6 // SquirrelJME is under the GNU General Public License v3+, or later.
   7 // See license.mkd for licensing and copyright information.
   8 // ---------------------------------------------------------------------------
   9
  10 package net.multiphasicapps.classfile;
  11
  12 /**
  13  * This represents the class version that a class may be.
  14  *
  15  * @since 2016/06/29
  16  */
  17 public enum ClassVersion
  18 {
  19         /** CLDC 1.0 (JSR 30). */
  20         CLDC_1((45 << 16) + 3, (47 << 16) - 1, false, false, false),
  21
  22         /** CLDC 1.1 (JSR 139). */
  23         CLDC_1_1((47 << 16), (51 << 16) - 1, true, false, false),
  24
  25         /** CLDC 8 (aka Java 7). */
  26         CLDC_8((51 << 16), (52 << 16), true, false, true),
  27
  28         /* End. */
  29         ;
  30
  31         /** The minimum supported version. */
  32         public static final ClassVersion MIN_VERSION = ClassVersion.CLDC_1;
  33
  34         /** The maximum supported version. */
  35         public static final ClassVersion MAX_VERSION = ClassVersion.CLDC_8;
  36
  37         /** The version ID. */
  38         protected final int version;
  39
  40         /** The maximum range of the version. */
  41         protected final int maxversion;
  42
  43         /** Has floating point support? */
  44         protected final boolean hasfloat;
  45
  46         /** Supports invokedynamic? */
  47         protected final boolean hasinvokedynamic;
  48
  49         /** Use StackMapTable? */
  50         protected final boolean usestackmaptable;
  51
  52         /**
  53          * Initializes the version data.
  54          *
  55          * @param __vid The version ID.
  56          * @param __vmx The max version identifier.
  57          * @param __float Is floating point supported?
  58          * @param __hasid Has invoke dynamic support?
  59          * @param __usesmt Should the StackMapTable attribute be used?
  60          * @since 2016/03/13
  61          */
  62         ClassVersion(int __vid, int __vmx, boolean __float, boolean __hasid,
  63                 boolean __usesmt)
  64         {
  65                 // Set
  66                 this.version = __vid;
  67                 this.maxversion = __vmx;
  68                 this.hasfloat = __float;
  69                 this.hasinvokedynamic = __hasid;
  70                 this.usestackmaptable = __usesmt;
  71         }
  72
  73         /**
  74          * Returns {@code true} if floating point is supported by the virtual
  75          * machine.
  76          *
  77          * @return {@code true} if it is.
  78          * @since 2016/03/13
  79          */
  80         public boolean hasFloatingPoint()
  81         {
  82                 return this.hasfloat;
  83         }
  84
  85         /**
  86          * Returns {@code true} if invokedynamic is supported by the virtual
  87          * machine.
  88          *
  89          * @return {@code true} if it is.
  90          * @since 2016/03/15
  91          */
  92         public boolean hasInvokeDynamic()
  93         {
  94                 return this.hasinvokedynamic;
  95         }
  96
  97         /**
  98          * Should the new StackMapTable attribute be used when veryifying the byte
  99          * code of a class?
 100          *
 101          * @return {@code true} if the "StackMapTable" attribute should be parsed
 102          * instead of "StackMap".
 103          * @since 2016/03/20
 104          */
 105         public boolean useStackMapTable()
 106         {
 107                 return this.usestackmaptable;
 108         }
 109
 110         /**
 111          * Finds the best matching version with the given ID.
 112          *
 113          * @param __vid The version ID to get a match for.
 114          * @return The matching class version or {@code null} if not found.
 115          * @since 2016/03/13
 116          */
 117         public static ClassVersion findVersion(int __vid)
 118         {
 119                 // Go through all versions, find the best
 120                 ClassVersion best = null;
 121                 for (ClassVersion v : ClassVersion.values())
 122                         if (__vid >= v.version && __vid <= v.maxversion)
 123                                 if (best == null || v.version > best.version)
 124                                         best = v;
 125
 126                 // Use the best (if any)
 127                 return best;
 128         }
 129 }
 130