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 abstract class CodeElement { 28*0957b409SSimon J. Gerraty 29*0957b409SSimon J. Gerraty internal int Address { get; set; } 30*0957b409SSimon J. Gerraty 31*0957b409SSimon J. Gerraty internal int LastLength { get; set; } 32*0957b409SSimon J. Gerraty 33*0957b409SSimon J. Gerraty // internal abstract int Length { get; } 34*0957b409SSimon J. Gerraty CodeElement()35*0957b409SSimon J. Gerraty internal CodeElement() 36*0957b409SSimon J. Gerraty { 37*0957b409SSimon J. Gerraty Address = -1; 38*0957b409SSimon J. Gerraty } 39*0957b409SSimon J. Gerraty SetJumpTarget(CodeElement target)40*0957b409SSimon J. Gerraty internal virtual void SetJumpTarget(CodeElement target) 41*0957b409SSimon J. Gerraty { 42*0957b409SSimon J. Gerraty throw new Exception("Code element accepts no target"); 43*0957b409SSimon J. Gerraty } 44*0957b409SSimon J. Gerraty GetLength(bool oneByteCode)45*0957b409SSimon J. Gerraty internal abstract int GetLength(bool oneByteCode); 46*0957b409SSimon J. Gerraty Encode(BlobWriter bw, bool oneByteCode)47*0957b409SSimon J. Gerraty internal abstract int Encode(BlobWriter bw, bool oneByteCode); 48*0957b409SSimon J. Gerraty EncodeOneByte(uint val, BlobWriter bw)49*0957b409SSimon J. Gerraty internal static int EncodeOneByte(uint val, BlobWriter bw) 50*0957b409SSimon J. Gerraty { 51*0957b409SSimon J. Gerraty if (val > 255) { 52*0957b409SSimon J. Gerraty throw new Exception(string.Format( 53*0957b409SSimon J. Gerraty "Cannot encode '{0}' over one byte", val)); 54*0957b409SSimon J. Gerraty } 55*0957b409SSimon J. Gerraty bw.Append((byte)val); 56*0957b409SSimon J. Gerraty return 1; 57*0957b409SSimon J. Gerraty } 58*0957b409SSimon J. Gerraty Encode7EUnsigned(uint val, BlobWriter bw)59*0957b409SSimon J. Gerraty internal static int Encode7EUnsigned(uint val, BlobWriter bw) 60*0957b409SSimon J. Gerraty { 61*0957b409SSimon J. Gerraty int len = 1; 62*0957b409SSimon J. Gerraty for (uint w = val; w >= 0x80; w >>= 7) { 63*0957b409SSimon J. Gerraty len ++; 64*0957b409SSimon J. Gerraty } 65*0957b409SSimon J. Gerraty if (bw != null) { 66*0957b409SSimon J. Gerraty for (int k = (len - 1) * 7; k >= 0; k -= 7) { 67*0957b409SSimon J. Gerraty int x = (int)(val >> k) & 0x7F; 68*0957b409SSimon J. Gerraty if (k > 0) { 69*0957b409SSimon J. Gerraty x |= 0x80; 70*0957b409SSimon J. Gerraty } 71*0957b409SSimon J. Gerraty bw.Append((byte)x); 72*0957b409SSimon J. Gerraty } 73*0957b409SSimon J. Gerraty } 74*0957b409SSimon J. Gerraty return len; 75*0957b409SSimon J. Gerraty } 76*0957b409SSimon J. Gerraty Encode7ESigned(int val, BlobWriter bw)77*0957b409SSimon J. Gerraty internal static int Encode7ESigned(int val, BlobWriter bw) 78*0957b409SSimon J. Gerraty { 79*0957b409SSimon J. Gerraty int len = 1; 80*0957b409SSimon J. Gerraty if (val < 0) { 81*0957b409SSimon J. Gerraty for (int w = val; w < -0x40; w >>= 7) { 82*0957b409SSimon J. Gerraty len ++; 83*0957b409SSimon J. Gerraty } 84*0957b409SSimon J. Gerraty } else { 85*0957b409SSimon J. Gerraty for (int w = val; w >= 0x40; w >>= 7) { 86*0957b409SSimon J. Gerraty len ++; 87*0957b409SSimon J. Gerraty } 88*0957b409SSimon J. Gerraty } 89*0957b409SSimon J. Gerraty if (bw != null) { 90*0957b409SSimon J. Gerraty for (int k = (len - 1) * 7; k >= 0; k -= 7) { 91*0957b409SSimon J. Gerraty int x = (int)(val >> k) & 0x7F; 92*0957b409SSimon J. Gerraty if (k > 0) { 93*0957b409SSimon J. Gerraty x |= 0x80; 94*0957b409SSimon J. Gerraty } 95*0957b409SSimon J. Gerraty bw.Append((byte)x); 96*0957b409SSimon J. Gerraty } 97*0957b409SSimon J. Gerraty } 98*0957b409SSimon J. Gerraty return len; 99*0957b409SSimon J. Gerraty } 100*0957b409SSimon J. Gerraty } 101