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  }