0957b409a9
Disabled by default, used by loader and sbin/veriexec Reviewed by: emaste Sponsored by: Juniper Networks Differential Revision: D16334
101 lines
2.5 KiB
C#
101 lines
2.5 KiB
C#
/*
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* Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
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*
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* Permission is hereby granted, free of charge, to any person obtaining
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* a copy of this software and associated documentation files (the
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* "Software"), to deal in the Software without restriction, including
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* without limitation the rights to use, copy, modify, merge, publish,
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* distribute, sublicense, and/or sell copies of the Software, and to
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* permit persons to whom the Software is furnished to do so, subject to
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* the following conditions:
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*
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* The above copyright notice and this permission notice shall be
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* included in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*/
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using System;
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abstract class CodeElement {
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internal int Address { get; set; }
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internal int LastLength { get; set; }
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// internal abstract int Length { get; }
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internal CodeElement()
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{
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Address = -1;
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}
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internal virtual void SetJumpTarget(CodeElement target)
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{
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throw new Exception("Code element accepts no target");
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}
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internal abstract int GetLength(bool oneByteCode);
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internal abstract int Encode(BlobWriter bw, bool oneByteCode);
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internal static int EncodeOneByte(uint val, BlobWriter bw)
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{
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if (val > 255) {
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throw new Exception(string.Format(
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"Cannot encode '{0}' over one byte", val));
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}
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bw.Append((byte)val);
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return 1;
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}
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internal static int Encode7EUnsigned(uint val, BlobWriter bw)
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{
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int len = 1;
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for (uint w = val; w >= 0x80; w >>= 7) {
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len ++;
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}
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if (bw != null) {
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for (int k = (len - 1) * 7; k >= 0; k -= 7) {
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int x = (int)(val >> k) & 0x7F;
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if (k > 0) {
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x |= 0x80;
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}
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bw.Append((byte)x);
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}
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}
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return len;
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}
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internal static int Encode7ESigned(int val, BlobWriter bw)
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{
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int len = 1;
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if (val < 0) {
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for (int w = val; w < -0x40; w >>= 7) {
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len ++;
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}
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} else {
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for (int w = val; w >= 0x40; w >>= 7) {
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len ++;
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}
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}
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if (bw != null) {
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for (int k = (len - 1) * 7; k >= 0; k -= 7) {
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int x = (int)(val >> k) & 0x7F;
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if (k > 0) {
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x |= 0x80;
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}
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bw.Append((byte)x);
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}
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}
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return len;
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}
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}
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