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
25using System;
26
27class CodeElementJump : CodeElement {
28
29	uint jumpType;
30	CodeElement target;
31
32	internal CodeElementJump(uint jumpType)
33	{
34		this.jumpType = jumpType;
35	}
36
37	/* obsolete
38	internal override int Length {
39		get {
40			int len = Encode7EUnsigned(jumpType, null);
41			int joff = JumpOff;
42			if (joff == Int32.MinValue) {
43				len ++;
44			} else {
45				len += Encode7ESigned(joff, null);
46			}
47			return len;
48		}
49	}
50	*/
51
52	internal override int GetLength(bool oneByteCode)
53	{
54		int len = oneByteCode ? 1 : Encode7EUnsigned(jumpType, null);
55		int joff = JumpOff;
56		if (joff == Int32.MinValue) {
57			len ++;
58		} else {
59			len += Encode7ESigned(joff, null);
60		}
61		return len;
62	}
63
64	internal override void SetJumpTarget(CodeElement target)
65	{
66		this.target = target;
67	}
68
69	int JumpOff {
70		get {
71			if (target == null || Address < 0 || target.Address < 0)
72			{
73				return Int32.MinValue;
74			} else {
75				return target.Address - (Address + LastLength);
76			}
77		}
78	}
79
80	internal override int Encode(BlobWriter bw, bool oneByteCode)
81	{
82		if (bw == null) {
83			return GetLength(oneByteCode);
84		}
85		int len;
86		if (oneByteCode) {
87			len = EncodeOneByte(jumpType, bw);
88		} else {
89			len = Encode7EUnsigned(jumpType, bw);
90		}
91		int joff = JumpOff;
92		if (joff == Int32.MinValue) {
93			throw new Exception("Unresolved addresses");
94		}
95		return len + Encode7ESigned(joff, bw);
96	}
97}
98