mnj/lua/Expdesc.java

   1 /*  $Header: //info.ravenbrook.com/project/jili/version/1.1/code/mnj/lua/Expdesc.java#1 $
   2  * Copyright (c) 2006 Nokia Corporation and/or its subsidiary(-ies).
   3  * All rights reserved.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining
   6  * a copy of this software and associated documentation files (the
   7  * "Software"), to deal in the Software without restriction, including
   8  * without limitation the rights to use, copy, modify, merge, publish,
   9  * distribute, sublicense, and/or sell copies of the Software, and to
  10  * permit persons to whom the Software is furnished to do so, subject
  11  * to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be
  14  * included in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  17  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  18  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  19  * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
  20  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
  21  * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  22  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25 package mnj.lua;
  26
  27 /** Equivalent to struct expdesc. */
  28 final class Expdesc
  29 {
  30
  31   static final int VVOID = 0;           // no value
  32   static final int VNIL = 1;
  33   static final int VTRUE = 2;
  34   static final int VFALSE = 3;
  35   static final int VK = 4;              // info = index into 'k'
  36   static final int VKNUM = 5;           // nval = numerical value
  37   static final int VLOCAL = 6;          // info = local register
  38   static final int VUPVAL = 7;          // info = index into 'upvalues'
  39   static final int VGLOBAL = 8;         // info = index of table;
  40                                         // aux = index of global name in 'k'
  41   static final int VINDEXED = 9;        // info = table register
  42                                         // aux = index register (or 'k')
  43   static final int VJMP = 10;           // info = instruction pc
  44   static final int VRELOCABLE = 11;     // info = instruction pc
  45   static final int VNONRELOC = 12;      // info = result register
  46   static final int VCALL = 13;          // info = instruction pc
  47   static final int VVARARG = 14;        // info = instruction pc
  48
  49   int k;        // one of V* enums above
  50   int info;
  51   int aux;
  52   double nval;
  53   int t;
  54   int f;
  55
  56   Expdesc()
  57   {
  58   }
  59
  60   Expdesc(int k, int i)
  61   {
  62     init(k, i);
  63   }
  64
  65   /** Equivalent to init_exp from lparser.c */
  66   void init(int kind, int i)
  67   {
  68     this.t = FuncState.NO_JUMP;
  69     this.f = FuncState.NO_JUMP;
  70     this.k = kind;
  71     this.info = i;
  72   }
  73
  74   void init(Expdesc e)
  75   {
  76     // Must initialise all members of this.
  77     this.k = e.k;
  78     this.info = e.info;
  79     this.aux = e.aux;
  80     this.nval = e.nval;
  81     this.t = e.t;
  82     this.f = e.f;
  83   }
  84
  85   int kind()
  86   {
  87     return k;
  88   }
  89
  90   void setKind(int kind)
  91   {
  92     this.k = kind;
  93   }
  94
  95   int info()
  96   {
  97     return info;
  98   }
  99
 100   void setInfo(int i)
 101   {
 102     this.info = i;
 103   }
 104
 105   int aux()
 106   {
 107     return aux;
 108   }
 109
 110   double nval()
 111   {
 112     return nval;
 113   }
 114
 115   void setNval(double d)
 116   {
 117     this.nval = d;
 118   }
 119
 120   /** Equivalent to hasmultret from lparser.c */
 121   boolean hasmultret()
 122   {
 123     return k == VCALL || k == VVARARG;
 124   }
 125
 126   /** Equivalent to hasjumps from lcode.c. */
 127   boolean hasjumps()
 128   {
 129     return t != f;
 130   }
 131
 132   void nonreloc(int i)
 133   {
 134     k = VNONRELOC;
 135     info = i;
 136   }
 137
 138   void reloc(int i)
 139   {
 140     k = VRELOCABLE;
 141     info = i;
 142   }
 143
 144   void upval(int i)
 145   {
 146     k = VUPVAL;
 147     info = i;
 148   }
 149 }