计算BasicBlock，并且计算是否属于loop中。支持const cache策略
walon
parent
3f8f97207e
commit
3094532eaa
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@ -0,0 +1,300 @@
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using dnlib.DotNet;
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using dnlib.DotNet.Emit;
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using System;
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using System.Collections.Generic;
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using System.Linq;
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using System.Runtime.Remoting.Messaging;
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using System.Text;
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using System.Threading.Tasks;
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namespace Obfuz.Emit
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{
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public static class LoopDetector
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{
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}
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public class BasicBlock
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{
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public readonly List<Instruction> instructions = new List<Instruction>();
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public readonly List<BasicBlock> inBlocks = new List<BasicBlock>();
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public readonly List<BasicBlock> outBlocks = new List<BasicBlock>();
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public bool inLoop;
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public void AddTargetBasicBlock(BasicBlock target)
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{
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if (!outBlocks.Contains(target))
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{
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outBlocks.Add(target);
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}
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if (!target.inBlocks.Contains(this))
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{
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target.inBlocks.Add(this);
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}
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}
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}
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public class BasicBlockCollection
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{
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private readonly MethodDef _method;
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private readonly List<BasicBlock> _blocks = new List<BasicBlock>();
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private readonly Dictionary<Instruction, BasicBlock> _inst2BlockMap = new Dictionary<Instruction, BasicBlock>();
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public IList<BasicBlock> Blocks => _blocks;
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public BasicBlockCollection(MethodDef method)
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{
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_method = method;
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HashSet<Instruction> splitPoints = BuildSplitPoint(method);
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BuildBasicBlocks(method, splitPoints);
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BuildInOutGraph(method);
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var loopBlocks = FindLoopBlocks(_blocks);
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foreach (var block in loopBlocks)
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{
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block.inLoop = true;
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}
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}
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public BasicBlock GetBasicBlockByInstruction(Instruction inst)
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{
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return _inst2BlockMap[inst];
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}
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private HashSet<Instruction> BuildSplitPoint(MethodDef method)
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{
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var insts = method.Body.Instructions;
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var splitPoints = new HashSet<Instruction>();
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foreach (ExceptionHandler eh in method.Body.ExceptionHandlers)
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{
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if (eh.TryStart != null)
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{
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splitPoints.Add(eh.TryStart);
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}
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if (eh.TryEnd != null)
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{
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splitPoints.Add(eh.TryEnd);
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}
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if (eh.HandlerStart != null)
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{
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splitPoints.Add(eh.HandlerStart);
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}
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if (eh.HandlerEnd != null)
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{
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splitPoints.Add(eh.HandlerEnd);
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}
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if (eh.FilterStart != null)
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{
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splitPoints.Add(eh.FilterStart);
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}
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}
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for (int i = 0, n = insts.Count; i < n; i++)
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{
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Instruction curInst = insts[i];
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Instruction nextInst = i + 1 < n ? insts[i + 1] : null;
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switch (curInst.OpCode.FlowControl)
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{
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case FlowControl.Branch:
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{
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if (nextInst != null)
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{
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splitPoints.Add(nextInst);
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}
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break;
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}
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case FlowControl.Cond_Branch:
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{
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if (nextInst != null)
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{
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splitPoints.Add(nextInst);
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}
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if (curInst.Operand is Instruction targetInst)
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{
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splitPoints.Add(targetInst);
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}
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else if (curInst.Operand is Instruction[] targetInsts)
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{
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foreach (var target in targetInsts)
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{
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splitPoints.Add(target);
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}
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}
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break;
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}
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case FlowControl.Return:
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{
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if (nextInst != null)
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{
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splitPoints.Add(nextInst);
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}
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break;
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}
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case FlowControl.Throw:
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{
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if (nextInst != null)
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{
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splitPoints.Add(nextInst);
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}
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break;
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}
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}
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}
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return splitPoints;
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}
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private void BuildBasicBlocks(MethodDef method, HashSet<Instruction> splitPoints)
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{
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var insts = method.Body.Instructions;
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BasicBlock curBlock = new BasicBlock();
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foreach (Instruction inst in insts)
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{
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if (splitPoints.Contains(inst) && curBlock.instructions.Count > 0)
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{
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_blocks.Add(curBlock);
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curBlock = new BasicBlock();
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}
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curBlock.instructions.Add(inst);
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_inst2BlockMap.Add(inst, curBlock);
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}
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if (curBlock.instructions.Count > 0)
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{
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_blocks.Add(curBlock);
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}
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}
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private void BuildInOutGraph(MethodDef method)
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{
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var insts = method.Body.Instructions;
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for (int i = 0, n = _blocks.Count; i < n; i++)
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{
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BasicBlock curBlock = _blocks[i];
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BasicBlock nextBlock = i + 1 < n ? _blocks[i + 1] : null;
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Instruction lastInst = curBlock.instructions.Last();
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switch (lastInst.OpCode.FlowControl)
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{
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case FlowControl.Branch:
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{
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Instruction targetInst = (Instruction)lastInst.Operand;
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BasicBlock targetBlock = GetBasicBlockByInstruction(targetInst);
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curBlock.AddTargetBasicBlock(targetBlock);
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break;
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}
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case FlowControl.Cond_Branch:
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{
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if (lastInst.Operand is Instruction targetInst)
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{
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BasicBlock targetBlock = GetBasicBlockByInstruction(targetInst);
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curBlock.AddTargetBasicBlock(targetBlock);
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}
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else if (lastInst.Operand is Instruction[] targetInsts)
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{
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foreach (var target in targetInsts)
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{
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BasicBlock targetBlock = GetBasicBlockByInstruction(target);
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curBlock.AddTargetBasicBlock(targetBlock);
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}
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}
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else
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{
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throw new Exception("Invalid operand type for conditional branch");
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}
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if (nextBlock != null)
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{
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curBlock.AddTargetBasicBlock(nextBlock);
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}
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break;
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}
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case FlowControl.Return:
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case FlowControl.Throw:
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{
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break;
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}
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}
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}
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}
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private static HashSet<BasicBlock> FindLoopBlocks(List<BasicBlock> allBlocks)
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{
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// Tarjan算法找强连通分量
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var sccList = FindStronglyConnectedComponents(allBlocks);
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// 筛选有效循环
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var loopBlocks = new HashSet<BasicBlock>();
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foreach (var scc in sccList)
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{
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// 有效循环需满足以下条件之一：
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// 1. 分量包含多个块
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// 2. 单个块有自环（跳转自己）
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if (scc.Count > 1 ||
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(scc.Count == 1 && scc[0].outBlocks.Contains(scc[0])))
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{
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foreach (var block in scc)
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{
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loopBlocks.Add(block);
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}
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}
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}
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return loopBlocks;
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}
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private static List<List<BasicBlock>> FindStronglyConnectedComponents(List<BasicBlock> allBlocks)
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{
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int index = 0;
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var stack = new Stack<BasicBlock>();
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var indexes = new Dictionary<BasicBlock, int>();
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var lowLinks = new Dictionary<BasicBlock, int>();
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var onStack = new HashSet<BasicBlock>();
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var sccList = new List<List<BasicBlock>>();
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foreach (var block in allBlocks.Where(b => !indexes.ContainsKey(b)))
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{
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StrongConnect(block);
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}
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return sccList;
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void StrongConnect(BasicBlock v)
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{
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indexes[v] = index;
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lowLinks[v] = index;
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index++;
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stack.Push(v);
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onStack.Add(v);
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foreach (var w in v.outBlocks)
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{
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if (!indexes.ContainsKey(w))
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{
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StrongConnect(w);
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lowLinks[v] = System.Math.Min(lowLinks[v], lowLinks[w]);
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}
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else if (onStack.Contains(w))
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{
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lowLinks[v] = System.Math.Min(lowLinks[v], indexes[w]);
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}
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}
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if (lowLinks[v] == indexes[v])
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{
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var scc = new List<BasicBlock>();
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BasicBlock w;
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do
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{
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w = stack.Pop();
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onStack.Remove(w);
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scc.Add(w);
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} while (!w.Equals(v));
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sccList.Add(scc);
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}
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}
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}
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}
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}
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@ -0,0 +1,80 @@
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using dnlib.DotNet.Emit;
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using dnlib.DotNet;
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using System.Collections.Generic;
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using System.Linq;
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using Obfuz.Emit;
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namespace Obfuz.ObfusPasses
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{
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public abstract class BasicBlockObfuscationPassBase : ObfuscationPassBase
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{
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protected abstract bool NeedObfuscateMethod(MethodDef method);
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public override void Process(ObfuscationPassContext ctx)
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{
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foreach (ModuleDef mod in ctx.toObfuscatedModules)
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{
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// ToArray to avoid modify list exception
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foreach (TypeDef type in mod.GetTypes().ToArray())
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{
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if (type.Name.StartsWith("$Obfuz$"))
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{
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continue;
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}
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// ToArray to avoid modify list exception
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foreach (MethodDef method in type.Methods.ToArray())
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{
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if (!method.HasBody || method.Name.StartsWith("$Obfuz$") || !NeedObfuscateMethod(method))
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{
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continue;
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}
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// TODO if isGeneratedBy Obfuscator, continue
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ObfuscateData(method);
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}
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}
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}
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}
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protected abstract bool TryObfuscateInstruction(MethodDef callingMethod, Instruction inst, BasicBlock block, int instructionIndex,
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List<Instruction> outputInstructions, List<Instruction> totalFinalInstructions);
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private void ObfuscateData(MethodDef method)
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{
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BasicBlockCollection bbc = new BasicBlockCollection(method);
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IList<Instruction> instructions = method.Body.Instructions;
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var outputInstructions = new List<Instruction>();
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var totalFinalInstructions = new List<Instruction>();
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for (int i = 0; i < instructions.Count; i++)
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{
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Instruction inst = instructions[i];
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BasicBlock block = bbc.GetBasicBlockByInstruction(inst);
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outputInstructions.Clear();
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if (TryObfuscateInstruction(method, inst, block, i, outputInstructions, totalFinalInstructions))
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{
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// current instruction may be the target of control flow instruction, so we can't remove it directly.
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// we replace it with nop now, then remove it in CleanUpInstructionPass
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inst.OpCode = outputInstructions[0].OpCode;
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inst.Operand = outputInstructions[0].Operand;
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totalFinalInstructions.Add(inst);
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for (int k = 1; k < outputInstructions.Count; k++)
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{
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totalFinalInstructions.Add(outputInstructions[k]);
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}
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}
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else
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{
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totalFinalInstructions.Add(inst);
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}
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}
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instructions.Clear();
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foreach (var obInst in totalFinalInstructions)
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{
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instructions.Add(obInst);
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}
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}
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}
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}
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@ -1,5 +1,6 @@
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using dnlib.DotNet;
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using dnlib.DotNet.Emit;
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using Obfuz.Emit;
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using Obfuz.ObfusPasses.ConstObfus.Policies;
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using Obfuz.Settings;
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using System;
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@ -13,7 +14,7 @@ using UnityEngine.Assertions;
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namespace Obfuz.ObfusPasses.ConstObfus
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{
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public class ConstObfusPass : InstructionObfuscationPassBase
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public class ConstObfusPass : BasicBlockObfuscationPassBase
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{
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private readonly string _configFile;
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private IObfuscationPolicy _dataObfuscatorPolicy;
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return _dataObfuscatorPolicy.NeedObfuscateMethod(method);
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}
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protected override bool TryObfuscateInstruction(MethodDef method, Instruction inst, IList<Instruction> instructions, int instructionIndex,
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protected override bool TryObfuscateInstruction(MethodDef method, Instruction inst, BasicBlock block, int instructionIndex,
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List<Instruction> outputInstructions, List<Instruction> totalFinalInstructions)
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{
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bool currentInLoop = false;
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bool currentInLoop = block.inLoop;
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ConstCachePolicy constCachePolicy = _dataObfuscatorPolicy.GetMethodConstCachePolicy(method);
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switch (inst.OpCode.OperandType)
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{
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@ -127,7 +128,7 @@ namespace Obfuz.ObfusPasses.ConstObfus
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{
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if (((IMethod)inst.Operand).FullName == "System.Void System.Runtime.CompilerServices.RuntimeHelpers::InitializeArray(System.Array,System.RuntimeFieldHandle)")
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{
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Instruction prevInst = instructions[instructionIndex - 1];
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Instruction prevInst = block.instructions[instructionIndex - 1];
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if (prevInst.OpCode.Code == Code.Ldtoken)
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{
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IField rvaField = (IField)prevInst.Operand;
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