xref: /freebsd/contrib/bearssl/T0/CodeElementJump.cs (revision 2aaf9152a852aba9eb2036b95f4948ee77988826)
1*0957b409SSimon J. Gerraty /*
2*0957b409SSimon J. Gerraty  * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
3*0957b409SSimon J. Gerraty  *
4*0957b409SSimon J. Gerraty  * Permission is hereby granted, free of charge, to any person obtaining
5*0957b409SSimon J. Gerraty  * a copy of this software and associated documentation files (the
6*0957b409SSimon J. Gerraty  * "Software"), to deal in the Software without restriction, including
7*0957b409SSimon J. Gerraty  * without limitation the rights to use, copy, modify, merge, publish,
8*0957b409SSimon J. Gerraty  * distribute, sublicense, and/or sell copies of the Software, and to
9*0957b409SSimon J. Gerraty  * permit persons to whom the Software is furnished to do so, subject to
10*0957b409SSimon J. Gerraty  * the following conditions:
11*0957b409SSimon J. Gerraty  *
12*0957b409SSimon J. Gerraty  * The above copyright notice and this permission notice shall be
13*0957b409SSimon J. Gerraty  * included in all copies or substantial portions of the Software.
14*0957b409SSimon J. Gerraty  *
15*0957b409SSimon J. Gerraty  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16*0957b409SSimon J. Gerraty  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17*0957b409SSimon J. Gerraty  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18*0957b409SSimon J. Gerraty  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19*0957b409SSimon J. Gerraty  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20*0957b409SSimon J. Gerraty  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21*0957b409SSimon J. Gerraty  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22*0957b409SSimon J. Gerraty  * SOFTWARE.
23*0957b409SSimon J. Gerraty  */
24*0957b409SSimon J. Gerraty 
25*0957b409SSimon J. Gerraty using System;
26*0957b409SSimon J. Gerraty 
27*0957b409SSimon J. Gerraty class CodeElementJump : CodeElement {
28*0957b409SSimon J. Gerraty 
29*0957b409SSimon J. Gerraty 	uint jumpType;
30*0957b409SSimon J. Gerraty 	CodeElement target;
31*0957b409SSimon J. Gerraty 
CodeElementJump(uint jumpType)32*0957b409SSimon J. Gerraty 	internal CodeElementJump(uint jumpType)
33*0957b409SSimon J. Gerraty 	{
34*0957b409SSimon J. Gerraty 		this.jumpType = jumpType;
35*0957b409SSimon J. Gerraty 	}
36*0957b409SSimon J. Gerraty 
37*0957b409SSimon J. Gerraty 	/* obsolete
38*0957b409SSimon J. Gerraty 	internal override int Length {
39*0957b409SSimon J. Gerraty 		get {
40*0957b409SSimon J. Gerraty 			int len = Encode7EUnsigned(jumpType, null);
41*0957b409SSimon J. Gerraty 			int joff = JumpOff;
42*0957b409SSimon J. Gerraty 			if (joff == Int32.MinValue) {
43*0957b409SSimon J. Gerraty 				len ++;
44*0957b409SSimon J. Gerraty 			} else {
45*0957b409SSimon J. Gerraty 				len += Encode7ESigned(joff, null);
46*0957b409SSimon J. Gerraty 			}
47*0957b409SSimon J. Gerraty 			return len;
48*0957b409SSimon J. Gerraty 		}
49*0957b409SSimon J. Gerraty 	}
50*0957b409SSimon J. Gerraty 	*/
51*0957b409SSimon J. Gerraty 
GetLength(bool oneByteCode)52*0957b409SSimon J. Gerraty 	internal override int GetLength(bool oneByteCode)
53*0957b409SSimon J. Gerraty 	{
54*0957b409SSimon J. Gerraty 		int len = oneByteCode ? 1 : Encode7EUnsigned(jumpType, null);
55*0957b409SSimon J. Gerraty 		int joff = JumpOff;
56*0957b409SSimon J. Gerraty 		if (joff == Int32.MinValue) {
57*0957b409SSimon J. Gerraty 			len ++;
58*0957b409SSimon J. Gerraty 		} else {
59*0957b409SSimon J. Gerraty 			len += Encode7ESigned(joff, null);
60*0957b409SSimon J. Gerraty 		}
61*0957b409SSimon J. Gerraty 		return len;
62*0957b409SSimon J. Gerraty 	}
63*0957b409SSimon J. Gerraty 
SetJumpTarget(CodeElement target)64*0957b409SSimon J. Gerraty 	internal override void SetJumpTarget(CodeElement target)
65*0957b409SSimon J. Gerraty 	{
66*0957b409SSimon J. Gerraty 		this.target = target;
67*0957b409SSimon J. Gerraty 	}
68*0957b409SSimon J. Gerraty 
69*0957b409SSimon J. Gerraty 	int JumpOff {
70*0957b409SSimon J. Gerraty 		get {
71*0957b409SSimon J. Gerraty 			if (target == null || Address < 0 || target.Address < 0)
72*0957b409SSimon J. Gerraty 			{
73*0957b409SSimon J. Gerraty 				return Int32.MinValue;
74*0957b409SSimon J. Gerraty 			} else {
75*0957b409SSimon J. Gerraty 				return target.Address - (Address + LastLength);
76*0957b409SSimon J. Gerraty 			}
77*0957b409SSimon J. Gerraty 		}
78*0957b409SSimon J. Gerraty 	}
79*0957b409SSimon J. Gerraty 
Encode(BlobWriter bw, bool oneByteCode)80*0957b409SSimon J. Gerraty 	internal override int Encode(BlobWriter bw, bool oneByteCode)
81*0957b409SSimon J. Gerraty 	{
82*0957b409SSimon J. Gerraty 		if (bw == null) {
83*0957b409SSimon J. Gerraty 			return GetLength(oneByteCode);
84*0957b409SSimon J. Gerraty 		}
85*0957b409SSimon J. Gerraty 		int len;
86*0957b409SSimon J. Gerraty 		if (oneByteCode) {
87*0957b409SSimon J. Gerraty 			len = EncodeOneByte(jumpType, bw);
88*0957b409SSimon J. Gerraty 		} else {
89*0957b409SSimon J. Gerraty 			len = Encode7EUnsigned(jumpType, bw);
90*0957b409SSimon J. Gerraty 		}
91*0957b409SSimon J. Gerraty 		int joff = JumpOff;
92*0957b409SSimon J. Gerraty 		if (joff == Int32.MinValue) {
93*0957b409SSimon J. Gerraty 			throw new Exception("Unresolved addresses");
94*0957b409SSimon J. Gerraty 		}
95*0957b409SSimon J. Gerraty 		return len + Encode7ESigned(joff, bw);
96*0957b409SSimon J. Gerraty 	}
97*0957b409SSimon J. Gerraty }
98