xref: /freebsd/contrib/bearssl/T0/OpcodeConst.cs (revision f7c32ed617858bcd22f8d1b03199099d50125721)
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 }
96