add AlwaysGenerateExceptionVariableForCatchBlocks setting to avoid Ca…

…tch clauses without a variable; disable C#'s query expression translation
stark-lang · Jul 15, 2011 · f4d29b2 · f4d29b2
1 parent 7542cc7
commit f4d29b2
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Showing 7 changed files with 33 additions and 10 deletions.
diff --git a/ICSharpCode.Decompiler/Ast/AstMethodBodyBuilder.cs b/ICSharpCode.Decompiler/Ast/AstMethodBodyBuilder.cs
@@ -95,7 +95,7 @@ public BlockStatement CreateMethodBody(IEnumerable<ParameterDeclaration> paramet
 			context.CancellationToken.ThrowIfCancellationRequested();
 			ILBlock ilMethod = new ILBlock();
 			ILAstBuilder astBuilder = new ILAstBuilder();
-			ilMethod.Body = astBuilder.Build(methodDef, true);
+			ilMethod.Body = astBuilder.Build(methodDef, true, context);
 
 			context.CancellationToken.ThrowIfCancellationRequested();
 			ILAstOptimizer bodyGraph = new ILAstOptimizer();

diff --git a/ICSharpCode.Decompiler/DecompilerSettings.cs b/ICSharpCode.Decompiler/DecompilerSettings.cs
@@ -239,6 +239,21 @@ public bool IntroduceIncrementAndDecrement {
 				}
 			}
 		}
+
+		bool alwaysGenerateExceptionVariableForCatchBlocks = false;
+
+		/// <summary>
+		/// Gets/Sets whether to always generate exception variables in catch blocks
+		/// </summary>
+		public bool AlwaysGenerateExceptionVariableForCatchBlocks {
+			get { return alwaysGenerateExceptionVariableForCatchBlocks; }
+			set {
+				if (alwaysGenerateExceptionVariableForCatchBlocks != value) {
+					alwaysGenerateExceptionVariableForCatchBlocks = value;
+					OnPropertyChanged("AlwaysGenerateExceptionVariableForCatchBlocks");
+				}
+			}
+		}
 		#endregion
 
 		public event PropertyChangedEventHandler PropertyChanged;

diff --git a/ICSharpCode.Decompiler/ILAst/ILAstBuilder.cs b/ICSharpCode.Decompiler/ILAst/ILAstBuilder.cs
@@ -62,7 +62,7 @@ public static List<StackSlot> CloneStack(List<StackSlot> stack, int? popCount)
 
 		/// <summary> Immutable </summary>
 		class VariableSlot
-		{			
+		{
 			public readonly ByteCode[] StoredBy;    // One of those
 			public readonly bool       StoredByAll; // Overestimate which is useful for exceptional control flow.
 
@@ -224,10 +224,13 @@ public override string ToString()
 		// Virtual instructions to load exception on stack
 		Dictionary<ExceptionHandler, ByteCode> ldexceptions = new Dictionary<ExceptionHandler, ILAstBuilder.ByteCode>();
 
-		public List<ILNode> Build(MethodDefinition methodDef, bool optimize)
+		DecompilerContext context;
+
+		public List<ILNode> Build(MethodDefinition methodDef, bool optimize, DecompilerContext context)
 		{
 			this.methodDef = methodDef;
 			this.optimize = optimize;
+			this.context = context;
 
 			if (methodDef.Body.Instructions.Count == 0) return new List<ILNode>();
 
@@ -351,7 +354,7 @@ List<ByteCode> StackAnalysis(MethodDefinition methodDef)
 				if (!byteCode.Code.IsUnconditionalControlFlow()) {
 					if (exceptionHandlerStarts.Contains(byteCode.Next)) {
 						// Do not fall though down to exception handler
-						// It is invalid IL as per ECMA-335 §12.4.2.8.1, but some obfuscators produce it						
+						// It is invalid IL as per ECMA-335 §12.4.2.8.1, but some obfuscators produce it
 					} else {
 						branchTargets.Add(byteCode.Next);
 					}
@@ -711,7 +714,10 @@ List<ILNode> ConvertToAst(List<ByteCode> body, HashSet<ExceptionHandler> ehs)
 							    first.Arguments[0].Operand == ldexception.StoreTo[0])
 							{
 								// The exception is just poped - optimize it all away;
-								catchBlock.ExceptionVariable = null;
+								if (context.Settings.AlwaysGenerateExceptionVariableForCatchBlocks)
+									catchBlock.ExceptionVariable = new ILVariable() { Name = "ex_" + eh.HandlerStart.Offset.ToString("X2"), IsGenerated = true };
+								else
+									catchBlock.ExceptionVariable = null;
 								catchBlock.Body.RemoveAt(0);
 							} else {
 								catchBlock.ExceptionVariable = ldexception.StoreTo[0];
@@ -778,7 +784,7 @@ List<ILNode> ConvertToAst(List<ByteCode> body)
 					StackSlot slot = byteCode.StackBefore[i];
 					expr.Arguments.Add(new ILExpression(ILCode.Ldloc, slot.LoadFrom));
 				}
-
+				
 				// Store the result to temporary variable(s) if needed
 				if (byteCode.StoreTo == null || byteCode.StoreTo.Count == 0) {
 					ast.Add(expr);

diff --git a/ICSharpCode.Decompiler/ILAst/YieldReturnDecompiler.cs b/ICSharpCode.Decompiler/ILAst/YieldReturnDecompiler.cs
@@ -224,7 +224,7 @@ ILBlock CreateILAst(MethodDefinition method)
 
 			ILBlock ilMethod = new ILBlock();
 			ILAstBuilder astBuilder = new ILAstBuilder();
-			ilMethod.Body = astBuilder.Build(method, true);
+			ilMethod.Body = astBuilder.Build(method, true, context);
 			ILAstOptimizer optimizer = new ILAstOptimizer();
 			optimizer.Optimize(context, ilMethod, ILAstOptimizationStep.YieldReturn);
 			return ilMethod;

diff --git a/ILSpy.BamlDecompiler/ConnectMethodDecompiler.cs b/ILSpy.BamlDecompiler/ConnectMethodDecompiler.cs
@@ -56,9 +56,9 @@ public Dictionary<int, EventRegistration[]> DecompileEventMappings(string fullTy
 			// decompile method and optimize the switch
 			ILBlock ilMethod = new ILBlock();
 			ILAstBuilder astBuilder = new ILAstBuilder();
-			ilMethod.Body = astBuilder.Build(def, true);
 			ILAstOptimizer optimizer = new ILAstOptimizer();
 			var context = new DecompilerContext(type.Module) { CurrentMethod = def, CurrentType = type };
+			ilMethod.Body = astBuilder.Build(def, true, context);
 			optimizer.Optimize(context, ilMethod, ILAstOptimizationStep.RemoveRedundantCode3);
 
 			ILSwitch ilSwitch = ilMethod.Body.OfType<ILSwitch>().FirstOrDefault();

diff --git a/ILSpy/Languages/ILAstLanguage.cs b/ILSpy/Languages/ILAstLanguage.cs
@@ -53,10 +53,10 @@ public override void DecompileMethod(MethodDefinition method, ITextOutput output
 
 			ILAstBuilder astBuilder = new ILAstBuilder();
 			ILBlock ilMethod = new ILBlock();
-			ilMethod.Body = astBuilder.Build(method, inlineVariables);
+			DecompilerContext context = new DecompilerContext(method.Module) { CurrentType = method.DeclaringType, CurrentMethod = method };
+			ilMethod.Body = astBuilder.Build(method, inlineVariables, context);
 
 			if (abortBeforeStep != null) {
-				DecompilerContext context = new DecompilerContext(method.Module) { CurrentType = method.DeclaringType, CurrentMethod = method };
 				new ILAstOptimizer().Optimize(context, ilMethod, abortBeforeStep.Value);
 			}
 

diff --git a/ILSpy/VB/VBLanguage.cs b/ILSpy/VB/VBLanguage.cs
@@ -126,6 +126,8 @@ AstBuilder CreateAstBuilder(DecompilationOptions options, ModuleDefinition curre
 			if (isSingleMember)
 				settings.UsingDeclarations = false;
 			settings.IntroduceIncrementAndDecrement = false;
+			settings.QueryExpressions = false;
+			settings.AlwaysGenerateExceptionVariableForCatchBlocks = true;
 			return new AstBuilder(
 				new DecompilerContext(currentModule) {
 					CancellationToken = options.CancellationToken,