C# ILBlock类代码示例

		public static void RunStep1(DecompilerContext context, ILBlock method)
		{
			if (!context.Settings.AsyncAwait)
				return; // abort if async decompilation is disabled
			var yrd = new AsyncDecompiler();
			yrd.context = context;
			if (!yrd.MatchTaskCreationPattern(method))
				return;
			#if DEBUG
			if (Debugger.IsAttached) {
				yrd.Run();
			} else {
				#endif
				try {
					yrd.Run();
				} catch (SymbolicAnalysisFailedException) {
					return;
				}
				#if DEBUG
			}
			#endif
			context.CurrentMethodIsAsync = true;
			
			method.Body.Clear();
			method.EntryGoto = null;
			method.Body.AddRange(yrd.newTopLevelBody);
			ILAstOptimizer.RemoveRedundantCode(method);
		}

        public ILBlockTranslator(AssemblyTranslator translator, DecompilerContext context, MethodReference methodReference, MethodDefinition methodDefinition, ILBlock ilb, IEnumerable<ILVariable> parameters, IEnumerable<ILVariable> allVariables)
        {
            Translator = translator;
            Context = context;
            ThisMethodReference = methodReference;
            ThisMethod = methodDefinition;
            Block = ilb;

            SpecialIdentifiers = new JSIL.SpecialIdentifiers(TypeSystem);

            if (methodReference.HasThis)
                Variables.Add("this", JSThisParameter.New(methodReference.DeclaringType, methodReference));

            foreach (var parameter in parameters) {
                if ((parameter.Name == "this") && (parameter.OriginalParameter.Index == -1))
                    continue;

                ParameterNames.Add(parameter.Name);
                Variables.Add(parameter.Name, new JSParameter(parameter.Name, parameter.Type, methodReference));
            }

            foreach (var variable in allVariables) {
                var v = JSVariable.New(variable, methodReference);
                if (Variables.ContainsKey(v.Identifier)) {
                    v = new JSVariable(variable.OriginalVariable.Name, variable.Type, methodReference);
                    RenamedVariables[variable] = v;
                    Variables.Add(v.Identifier, v);
                } else {
                    Variables.Add(v.Identifier, v);
                }
            }
        }

		public static void Run(DecompilerContext context, ILBlock method, List<ILNode> list_ILNode, Func<ILBlock, ILInlining> getILInlining)
		{
			if (!context.Settings.YieldReturn)
				return; // abort if enumerator decompilation is disabled
			var yrd = new YieldReturnDecompiler();
			yrd.context = context;
			if (!yrd.MatchEnumeratorCreationPattern(method))
				return;
			yrd.enumeratorType = yrd.enumeratorCtor.DeclaringType;
			#if DEBUG && CRASH_IN_DEBUG_MODE
			if (Debugger.IsAttached) {
				yrd.Run();
			} else {
				#endif
				try {
					yrd.Run();
				} catch (SymbolicAnalysisFailedException) {
					return;
				}
				#if DEBUG && CRASH_IN_DEBUG_MODE
			}
			#endif
			method.Body.Clear();
			method.EntryGoto = null;
			method.Body.AddRange(yrd.newBody);//TODO: Make sure that the removed ILRanges from Clear() above is saved in the new body
			
			// Repeat the inlining/copy propagation optimization because the conversion of field access
			// to local variables can open up additional inlining possibilities.
			var inlining = getILInlining(method);
			inlining.InlineAllVariables();
			inlining.CopyPropagation(list_ILNode);
		}

        public BlockStatement CreateMethodBody()
        {
            if (methodDef.Body == null) return null;

            context.CancellationToken.ThrowIfCancellationRequested();
            ILBlock ilMethod = new ILBlock();
            ILAstBuilder astBuilder = new ILAstBuilder();
            ilMethod.Body = astBuilder.Build(methodDef, true);

            context.CancellationToken.ThrowIfCancellationRequested();
            ILAstOptimizer bodyGraph = new ILAstOptimizer();
            bodyGraph.Optimize(context, ilMethod);
            context.CancellationToken.ThrowIfCancellationRequested();

            NameVariables.AssignNamesToVariables(methodDef.Parameters.Select(p => p.Name), astBuilder.Variables, ilMethod);

            context.CancellationToken.ThrowIfCancellationRequested();
            Ast.BlockStatement astBlock = TransformBlock(ilMethod);
            CommentStatement.ReplaceAll(astBlock); // convert CommentStatements to Comments
            foreach (ILVariable v in localVariablesToDefine) {
                DeclareVariableInSmallestScope.DeclareVariable(astBlock, AstBuilder.ConvertType(v.Type), v.Name);
            }

            return astBlock;
        }

    protected override ILBlock VisitBlock(ILBlock block)
    {
        currentScope++;

        var result = base.VisitBlock(block);

        currentScope--;

        if (block.Body.Count == 0)
            return result;

        var toOffset = block.LastILOffset();

        if (toOffset < 0)
            return result;

        foreach (var start in starts.Where(kvp => kvp.Key.Item2 == currentScope + 1).ToList())
        {
            starts.Remove(start.Key);

            List<ILExpression> args;
            if (block.Body.Last().Match(ILCode.Ret, out args) && args.Count == 1 && args[0].MatchLdloc(start.Key.Item1))
                continue; // Returning the variable

            UsingRanges.Add(new ILRange { From = start.Value, To = toOffset });
        }

        return result;
    }

		public void RemoveGotos(ILBlock method)
		{
			// Build the navigation data
			parent[method] = null;
			foreach (ILNode node in method.GetSelfAndChildrenRecursive<ILNode>()) {
				ILNode previousChild = null;
				foreach (ILNode child in node.GetChildren()) {
					if (parent.ContainsKey(child))
						throw new Exception("The following expression is linked from several locations: " + child.ToString());
					parent[child] = node;
					if (previousChild != null)
						nextSibling[previousChild] = child;
					previousChild = child;
				}
				if (previousChild != null)
					nextSibling[previousChild] = null;
			}
			
			// Simplify gotos
			bool modified;
			do {
				modified = false;
				foreach (ILExpression gotoExpr in method.GetSelfAndChildrenRecursive<ILExpression>(e => e.Code == ILCode.Br || e.Code == ILCode.Leave)) {
					modified |= TrySimplifyGoto(gotoExpr);
				}
			} while(modified);
			
			RemoveRedundantCode(method);
		}

		public static void Run(DecompilerContext context, ILBlock method)
		{
			if (!context.Settings.YieldReturn)
				return; // abort if enumerator decompilation is disabled
			var yrd = new YieldReturnDecompiler();
			yrd.context = context;
			if (!yrd.MatchEnumeratorCreationPattern(method))
				return;
			yrd.enumeratorType = yrd.enumeratorCtor.DeclaringType;
			#if DEBUG
			if (Debugger.IsAttached) {
				yrd.Run();
			} else {
				#endif
				try {
					yrd.Run();
				} catch (YieldAnalysisFailedException) {
					return;
				}
				#if DEBUG
			}
			#endif
			method.Body.Clear();
			method.EntryGoto = null;
			method.Body.AddRange(yrd.newBody);
		}

		public static void Run(DecompilerContext context, ILBlock method)
		{
			if (!context.Settings.YieldReturn)
				return; // abort if enumerator decompilation is disabled
			var yrd = new YieldReturnDecompiler();
			yrd.context = context;
			if (!yrd.MatchEnumeratorCreationPattern(method))
				return;
			yrd.enumeratorType = yrd.enumeratorCtor.DeclaringType;
			#if DEBUG
			if (Debugger.IsAttached) {
				yrd.Run();
			} else {
				#endif
				try {
					yrd.Run();
				} catch (SymbolicAnalysisFailedException) {
					return;
				}
				#if DEBUG
			}
			#endif
			method.Body.Clear();
			method.EntryGoto = null;
			method.Body.AddRange(yrd.newBody);
			
			// Repeat the inlining/copy propagation optimization because the conversion of field access
			// to local variables can open up additional inlining possibilities.
			ILInlining inlining = new ILInlining(method);
			inlining.InlineAllVariables();
			inlining.CopyPropagation();
		}

        public void Optimize(ILBlock method)
        {
            foreach(ILBlock block in method.GetSelfAndChildrenRecursive<ILBlock>().ToList()) {
                SplitToMovableBlocks(block);
            }

            foreach(ILBlock block in method.GetSelfAndChildrenRecursive<ILBlock>().Where(b => !(b is ILMoveableBlock)).ToList()) {
                ControlFlowGraph graph;
                graph = BuildGraph(block.Body, block.EntryPoint);
                graph.ComputeDominance();
                graph.ComputeDominanceFrontier();
                block.Body = FindLoops(new HashSet<ControlFlowNode>(graph.Nodes.Skip(3)), graph.EntryPoint, true);
            }

            foreach(ILBlock block in method.GetSelfAndChildrenRecursive<ILBlock>().Where(b => !(b is ILMoveableBlock)).ToList()) {
                ControlFlowGraph graph;
                graph = BuildGraph(block.Body, block.EntryPoint);
                graph.ComputeDominance();
                graph.ComputeDominanceFrontier();
                block.Body = FindConditions(new HashSet<ControlFlowNode>(graph.Nodes.Skip(3)), graph.EntryPoint);
            }

            // OrderNodes(method);
            FlattenNestedMovableBlocks(method);
            SimpleGotoRemoval(method);
            RemoveDeadLabels(method);
        }

		public BlockStatement CreateMethodBody()
		{
			if (methodDef.Body == null) return null;
			
			context.CancellationToken.ThrowIfCancellationRequested();
			ILBlock ilMethod = new ILBlock();
			ILAstBuilder astBuilder = new ILAstBuilder();
			ilMethod.Body = astBuilder.Build(methodDef, true);
			
			context.CancellationToken.ThrowIfCancellationRequested();
			ILAstOptimizer bodyGraph = new ILAstOptimizer();
			bodyGraph.Optimize(context, ilMethod);
			context.CancellationToken.ThrowIfCancellationRequested();
			
			var allVariables = ilMethod.GetSelfAndChildrenRecursive<ILExpression>().Select(e => e.Operand as ILVariable).Where(v => v != null && !v.IsGenerated).Distinct();
			NameVariables.AssignNamesToVariables(methodDef.Parameters.Select(p => p.Name), allVariables, ilMethod);
			
			context.CancellationToken.ThrowIfCancellationRequested();
			Ast.BlockStatement astBlock = TransformBlock(ilMethod);
			CommentStatement.ReplaceAll(astBlock); // convert CommentStatements to Comments
			foreach (ILVariable v in localVariablesToDefine) {
				DeclareVariableInSmallestScope.DeclareVariable(astBlock, AstBuilder.ConvertType(v.Type), v.Name);
			}
			
			return astBlock;
		}

		public override void DecompileMethod(MethodDefinition method, ITextOutput output, DecompilationOptions options)
		{
			if (!method.HasBody) {
				return;
			}
			
			ILAstBuilder astBuilder = new ILAstBuilder();
			ILBlock ilMethod = new ILBlock();
			ilMethod.Body = astBuilder.Build(method, inlineVariables);
			
			if (abortBeforeStep != null) {
				DecompilerContext context = new DecompilerContext(method.Module) { CurrentType = method.DeclaringType, CurrentMethod = method };
				new ILAstOptimizer().Optimize(context, ilMethod, abortBeforeStep.Value);
			}
			
			var allVariables = ilMethod.GetSelfAndChildrenRecursive<ILExpression>().Select(e => e.Operand as ILVariable)
				.Where(v => v != null && !v.IsParameter).Distinct();
			foreach (ILVariable v in allVariables) {
				output.WriteDefinition(v.Name, v);
				if (v.Type != null) {
					output.Write(" : ");
					if (v.IsPinned)
						output.Write("pinned ");
					v.Type.WriteTo(output, ILNameSyntax.ShortTypeName);
				}
				output.WriteLine();
			}
			output.WriteLine();
			
			foreach (ILNode node in ilMethod.Body) {
				node.WriteTo(output);
				output.WriteLine();
			}
		}

		public override void DecompileMethod(MethodDef method, ITextOutput output, DecompilationOptions options)
		{
			WriteComment(output, "Method: ");
			output.WriteDefinition(IdentifierEscaper.Escape(method.FullName), method, TextTokenType.Comment, false);
			output.WriteLine();

			if (!method.HasBody) {
				return;
			}
			
			StartKeywordBlock(output, ".body", method);

			ILAstBuilder astBuilder = new ILAstBuilder();
			ILBlock ilMethod = new ILBlock();
			DecompilerContext context = new DecompilerContext(method.Module) { CurrentType = method.DeclaringType, CurrentMethod = method };
			ilMethod.Body = astBuilder.Build(method, inlineVariables, context);
			
			if (abortBeforeStep != null) {
				new ILAstOptimizer().Optimize(context, ilMethod, abortBeforeStep.Value);
			}
			
			if (context.CurrentMethodIsAsync) {
				output.Write("async", TextTokenType.Keyword);
				output.Write('/', TextTokenType.Operator);
				output.WriteLine("await", TextTokenType.Keyword);
			}
			
			var allVariables = ilMethod.GetSelfAndChildrenRecursive<ILExpression>().Select(e => e.Operand as ILVariable)
				.Where(v => v != null && !v.IsParameter).Distinct();
			foreach (ILVariable v in allVariables) {
				output.WriteDefinition(IdentifierEscaper.Escape(v.Name), v, v.IsParameter ? TextTokenType.Parameter : TextTokenType.Local);
				if (v.Type != null) {
					output.WriteSpace();
					output.Write(':', TextTokenType.Operator);
					output.WriteSpace();
					if (v.IsPinned) {
						output.Write("pinned", TextTokenType.Keyword);
						output.WriteSpace();
					}
					v.Type.WriteTo(output, ILNameSyntax.ShortTypeName);
				}
				if (v.IsGenerated) {
					output.WriteSpace();
					output.Write('[', TextTokenType.Operator);
					output.Write("generated", TextTokenType.Keyword);
					output.Write(']', TextTokenType.Operator);
				}
				output.WriteLine();
			}
			
			var memberMapping = new MemberMapping(method);
			foreach (ILNode node in ilMethod.Body) {
				node.WriteTo(output, memberMapping);
				if (!node.WritesNewLine)
					output.WriteLine();
			}
			output.AddDebugSymbols(memberMapping);
			EndKeywordBlock(output);
		}

 public static void AssignNamesToVariables(IEnumerable<string> existingNames, IEnumerable<ILVariable> variables, ILBlock methodBody)
 {
     NameVariables nv = new NameVariables();
     nv.AddExistingNames(existingNames);
     foreach (ILVariable varDef in variables) {
         nv.AssignNameToVariable(varDef, methodBody.GetSelfAndChildrenRecursive<ILExpression>());
     }
 }

		/// <summary>
		/// Inlines the stloc instruction at block.Body[pos] into the next instruction, if possible.
		/// </summary>
		public static bool InlineIfPossible(ILBlock block, int pos, ILBlock method)
		{
			if (InlineIfPossible((ILExpression)block.Body[pos], block.Body.ElementAtOrDefault(pos+1), method)) {
				block.Body.RemoveAt(pos);
				return true;
			}
			return false;
		}

		Ast.BlockStatement TransformBlock(ILBlock block)
		{
			Ast.BlockStatement astBlock = new BlockStatement();
			if (block != null) {
				foreach(ILNode node in block.GetChildren()) {
					astBlock.AddRange(TransformNode(node));
				}
			}
			return astBlock;
		}