_ Git - BearSSL/blob - T0/OpcodeConst.cs

   1 /*
   2  * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining
   5  * a copy of this software and associated documentation files (the
   6  * "Software"), to deal in the Software without restriction, including
   7  * without limitation the rights to use, copy, modify, merge, publish,
   8  * distribute, sublicense, and/or sell copies of the Software, and to
   9  * permit persons to whom the Software is furnished to do so, subject to
  10  * the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be
  13  * included in all copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  16  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  18  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  19  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  20  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  22  * SOFTWARE.
  23  */
  24
  25 using System;
  26 using System.Collections.Generic;
  27
  28 class OpcodeConst : Opcode {
  29
  30         TValue val;
  31
  32         internal OpcodeConst(TValue val)
  33         {
  34                 this.val = val;
  35         }
  36
  37         internal override void Run(CPU cpu)
  38         {
  39                 cpu.Push(val);
  40         }
  41
  42         internal override Word GetReference(T0Comp ctx)
  43         {
  44                 TPointerXT xt = val.ptr as TPointerXT;
  45                 if (xt == null) {
  46                         return null;
  47                 }
  48                 xt.Resolve(ctx);
  49                 return xt.Target;
  50         }
  51
  52         internal override ConstData GetDataBlock(T0Comp ctx)
  53         {
  54                 TPointerBlob bp = val.ptr as TPointerBlob;
  55                 return bp == null ? null : bp.Blob;
  56         }
  57
  58         internal override CodeElement ToCodeElement()
  59         {
  60                 if (val.ptr == null) {
  61                         return new CodeElementUIntInt(1, val.Int);
  62                 }
  63                 TPointerXT xt = val.ptr as TPointerXT;
  64                 if (xt != null) {
  65                         if (val.x != 0) {
  66                                 throw new Exception(
  67                                         "Cannot compile XT: non-zero offset");
  68                         }
  69                         return new CodeElementUIntInt(1, xt.Target.Slot);
  70                 }
  71                 TPointerBlob bp = val.ptr as TPointerBlob;
  72                 if (bp != null) {
  73                         return new CodeElementUIntInt(1,
  74                                 val.x + bp.Blob.Address);
  75                 }
  76                 TPointerExpr cx = val.ptr as TPointerExpr;
  77                 if (cx != null) {
  78                         return new CodeElementUIntExpr(1, cx, val.x);
  79                 }
  80                 throw new Exception(String.Format(
  81                         "Cannot embed constant (type = {0})",
  82                         val.ptr.GetType().FullName));
  83         }
  84
  85         internal override int StackAction {
  86                 get {
  87                         return 1;
  88                 }
  89         }
  90
  91         public override string ToString()
  92         {
  93                 return "const " + val.ToString();
  94         }
  95 }