Re-enable IntroduceUsingDeclarations

ICSharpCode.Decompiler/CSharp/CSharpDecompiler.cs

@@ -18,6 +18,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Linq;
 using System.Text;
 using System.Threading;
@@ -36,8 +37,22 @@ namespace ICSharpCode.Decompiler.CSharp
 	public class CSharpDecompiler
 	{
 		readonly DecompilerTypeSystem typeSystem;
-		TypeSystemAstBuilder typeSystemAstBuilder;
-		List<IAstTransform> astTransforms;
+		List<IAstTransform> astTransforms = new List<IAstTransform> {
+			//new PushNegation(),
+			//new DelegateConstruction(context),
+			//new PatternStatementTransform(context),
+			new ReplaceMethodCallsWithOperators(),
+			new IntroduceUnsafeModifier(),
+			new AddCheckedBlocks(),
+			//new DeclareVariables(context), // should run after most transforms that modify statements
+			new ConvertConstructorCallIntoInitializer(), // must run after DeclareVariables
+			//new DecimalConstantTransform(),
+			new IntroduceUsingDeclarations(),
+			//new IntroduceExtensionMethods(context), // must run after IntroduceUsingDeclarations
+			//new IntroduceQueryExpressions(context), // must run after IntroduceExtensionMethods
+			//new CombineQueryExpressions(context),
+			//new FlattenSwitchBlocks(),
+		};
 
 		public CancellationToken CancellationToken { get; set; }
 
@@ -58,38 +73,27 @@ namespace ICSharpCode.Decompiler.CSharp
 			if (typeSystem == null)
 				throw new ArgumentNullException("typeSystem");
 			this.typeSystem = typeSystem;
-
-			astTransforms = new List<IAstTransform> {
-				//new PushNegation(),
-				//new DelegateConstruction(context),
-				//new PatternStatementTransform(context),
-				new ReplaceMethodCallsWithOperators(),
-				new IntroduceUnsafeModifier(),
-				new AddCheckedBlocks(),
-				//new DeclareVariables(context), // should run after most transforms that modify statements
-				new ConvertConstructorCallIntoInitializer(typeSystem), // must run after DeclareVariables
-				//new DecimalConstantTransform(),
-				//new IntroduceUsingDeclarations(context),
-				//new IntroduceExtensionMethods(context), // must run after IntroduceUsingDeclarations
-				//new IntroduceQueryExpressions(context), // must run after IntroduceExtensionMethods
-				//new CombineQueryExpressions(context),
-				//new FlattenSwitchBlocks(),
-			};
-
-			typeSystemAstBuilder = new TypeSystemAstBuilder();
+		}
+		
+		TypeSystemAstBuilder CreateAstBuilder(ITypeResolveContext decompilationContext)
+		{
+			var typeSystemAstBuilder = new TypeSystemAstBuilder();
 			typeSystemAstBuilder.AlwaysUseShortTypeNames = true;
-			typeSystemAstBuilder.AddAnnotations = true;
+			typeSystemAstBuilder.AddResolveResultAnnotations = true;
+			return typeSystemAstBuilder;
 		}
 		
-		void RunTransforms(AstNode rootNode)
+		void RunTransforms(AstNode rootNode, ITypeResolveContext decompilationContext)
 		{
+			var context = new TransformContext(typeSystem, decompilationContext);
 			foreach (var transform in astTransforms)
-				transform.Run(rootNode);
+				transform.Run(rootNode, context);
 			rootNode.AcceptVisitor(new InsertParenthesesVisitor { InsertParenthesesForReadability = true });
 		}
 		
 		public SyntaxTree DecompileWholeModuleAsSingleFile()
 		{
+			var decompilationContext = new SimpleTypeResolveContext(typeSystem.MainAssembly);
 			SyntaxTree syntaxTree = new SyntaxTree();
 			foreach (var g in typeSystem.Compilation.MainAssembly.TopLevelTypeDefinitions.GroupBy(t => t.Namespace)) {
 				AstNode groupNode;
@@ -104,11 +108,11 @@ namespace ICSharpCode.Decompiler.CSharp
 				foreach (var typeDef in g) {
 					if (typeDef.Name == "<Module>" && typeDef.Members.Count == 0)
 						continue;
-					var typeDecl = DoDecompile(typeDef);
+					var typeDecl = DoDecompile(typeDef, decompilationContext.WithCurrentTypeDefinition(typeDef));
 					groupNode.AddChild(typeDecl, SyntaxTree.MemberRole);
 				}
 			}
-			RunTransforms(syntaxTree);
+			RunTransforms(syntaxTree, decompilationContext);
 			return syntaxTree;
 		}
 		
@@ -116,16 +120,19 @@ namespace ICSharpCode.Decompiler.CSharp
 		{
 			if (typeDefinition == null)
 				throw new ArgumentNullException("typeDefinition");
-			ITypeDefinition typeDef = typeSystem.GetType(typeDefinition).GetDefinition();
+			ITypeDefinition typeDef = typeSystem.Resolve(typeDefinition).GetDefinition();
 			if (typeDef == null)
 				throw new InvalidOperationException("Could not find type definition in NR type system");
-			var decl = DoDecompile(typeDef);
-			RunTransforms(decl);
+			var decompilationContext = new SimpleTypeResolveContext(typeDef);
+			var decl = DoDecompile(typeDef, decompilationContext);
+			RunTransforms(decl, decompilationContext);
 			return decl;
 		}
 		
-		EntityDeclaration DoDecompile(ITypeDefinition typeDef)
+		EntityDeclaration DoDecompile(ITypeDefinition typeDef, ITypeResolveContext decompilationContext)
 		{
+			Debug.Assert(decompilationContext.CurrentTypeDefinition == typeDef);
+			var typeSystemAstBuilder = CreateAstBuilder(decompilationContext);
 			var entityDecl = typeSystemAstBuilder.ConvertEntity(typeDef);
 			var typeDecl = entityDecl as TypeDeclaration;
 			if (typeDecl == null) {
@@ -135,7 +142,7 @@ namespace ICSharpCode.Decompiler.CSharp
 			foreach (var method in typeDef.Methods) {
 				var methodDef = typeSystem.GetCecil(method) as MethodDefinition;
 				if (methodDef != null) {
-					var memberDecl = DoDecompile(methodDef, method);
+					var memberDecl = DoDecompile(methodDef, method, decompilationContext.WithCurrentMember(method));
 					typeDecl.Members.Add(memberDecl);
 				}
 			}
@@ -146,16 +153,19 @@ namespace ICSharpCode.Decompiler.CSharp
 		{
 			if (methodDefinition == null)
 				throw new ArgumentNullException("methodDefinition");
-			var method = typeSystem.GetMethod(methodDefinition);
+			var method = typeSystem.Resolve(methodDefinition);
 			if (method == null)
 				throw new InvalidOperationException("Could not find method in NR type system");
-			var decl = DoDecompile(methodDefinition, method);
-			RunTransforms(decl);
+			var decompilationContext = new SimpleTypeResolveContext(method);
+			var decl = DoDecompile(methodDefinition, method, decompilationContext);
+			RunTransforms(decl, decompilationContext);
 			return decl;
 		}
 
-		EntityDeclaration DoDecompile(MethodDefinition methodDefinition, IMethod method)
+		EntityDeclaration DoDecompile(MethodDefinition methodDefinition, IMethod method, ITypeResolveContext decompilationContext)
 		{
+			Debug.Assert(decompilationContext.CurrentMember == method);
+			var typeSystemAstBuilder = CreateAstBuilder(decompilationContext);
 			var entityDecl = typeSystemAstBuilder.ConvertEntity(method);
 			if (methodDefinition.HasBody) {
 				var ilReader = new ILReader(typeSystem);
@@ -163,7 +173,7 @@ namespace ICSharpCode.Decompiler.CSharp
 				function.CheckInvariant();
 				function.Body = function.Body.AcceptVisitor(new TransformingVisitor());
 				function.CheckInvariant();
-				var statementBuilder = new StatementBuilder(method);
+				var statementBuilder = new StatementBuilder(decompilationContext);
 				var body = statementBuilder.ConvertAsBlock(function.Body);
 				
 				// insert variables at start of body

ICSharpCode.Decompiler/CSharp/ExpressionBuilder.cs

@@ -17,6 +17,7 @@
 // DEALINGS IN THE SOFTWARE.
 
 using System.Diagnostics;
+using ICSharpCode.NRefactory.CSharp.TypeSystem;
 using ExpressionType = System.Linq.Expressions.ExpressionType;
 using ICSharpCode.NRefactory.CSharp.Refactoring;
 using ICSharpCode.NRefactory.CSharp.Resolver;
@@ -41,12 +42,14 @@ namespace ICSharpCode.Decompiler.CSharp
 		internal readonly CSharpResolver resolver;
 		internal readonly TypeSystemAstBuilder astBuilder;
 		
-		public ExpressionBuilder(ICompilation compilation)
+		public ExpressionBuilder(ITypeResolveContext decompilationContext)
 		{
-			Debug.Assert(compilation != null);
-			this.compilation = compilation;
-			this.resolver = new CSharpResolver(compilation);
+			Debug.Assert(decompilationContext != null);
+			this.compilation = decompilationContext.Compilation;
+			this.resolver = new CSharpResolver(new CSharpTypeResolveContext(compilation.MainAssembly, null, decompilationContext.CurrentTypeDefinition, decompilationContext.CurrentMember));
 			this.astBuilder = new TypeSystemAstBuilder(resolver);
+			this.astBuilder.AlwaysUseShortTypeNames = true;
+			this.astBuilder.AddResolveResultAnnotations = true;
 		}
 
 		public AstType ConvertType(IType type)
@@ -145,7 +148,7 @@ namespace ICSharpCode.Decompiler.CSharp
 		{
 			return new NullReferenceExpression()
 				.WithILInstruction(inst)
-				.WithRR(new ConstantResolveResult(SpecialType.UnknownType, null));
+				.WithRR(new ConstantResolveResult(SpecialType.NullType, null));
 		}
 		
 		protected internal override TranslatedExpression VisitLogicNot(LogicNot inst)

ICSharpCode.Decompiler/CSharp/StatementBuilder.cs

@@ -16,6 +16,7 @@
 // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 // DEALINGS IN THE SOFTWARE.
 
+using System.Diagnostics;
 using ICSharpCode.Decompiler.IL;
 using ICSharpCode.NRefactory.CSharp;
 using ICSharpCode.NRefactory.TypeSystem;
@@ -32,10 +33,11 @@ namespace ICSharpCode.Decompiler.CSharp
 		readonly ExpressionBuilder exprBuilder;
 		readonly IMethod currentMethod;
 		
-		public StatementBuilder(IMethod method)
+		public StatementBuilder(ITypeResolveContext decompilationContext)
 		{
-			this.exprBuilder = new ExpressionBuilder(method.Compilation);
-			this.currentMethod = method;
+			Debug.Assert(decompilationContext != null && decompilationContext.CurrentMember is IMethod);
+			this.exprBuilder = new ExpressionBuilder(decompilationContext);
+			this.currentMethod = (IMethod)decompilationContext.CurrentMember;
 		}
 		
 		public Statement Convert(ILInstruction inst)

ICSharpCode.Decompiler/CSharp/Transforms/AddCheckedBlocks.cs

@@ -234,12 +234,12 @@ namespace ICSharpCode.Decompiler.CSharp.Transforms
 		}
 		#endregion
 		
-		public void Run(AstNode node)
+		public void Run(AstNode node, TransformContext context)
 		{
 			BlockStatement block = node as BlockStatement;
 			if (block == null) {
 				for (AstNode child = node.FirstChild; child != null; child = child.NextSibling) {
-					Run(child);
+					Run(child, context);
 				}
 			} else {
 				Result r = GetResultFromBlock(block);

ICSharpCode.Decompiler/CSharp/Transforms/ConvertConstructorCallIntoInitializer.cs

@@ -18,6 +18,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Linq;
 using ICSharpCode.NRefactory.CSharp;
 using ICSharpCode.NRefactory.PatternMatching;
@@ -30,17 +31,31 @@ namespace ICSharpCode.Decompiler.CSharp.Transforms
 	/// <summary>
 	/// If the first element of a constructor is a chained constructor call, convert it into a constructor initializer.
 	/// </summary>
-	public class ConvertConstructorCallIntoInitializer : DepthFirstAstVisitor, IAstTransform
+	public class ConvertConstructorCallIntoInitializer : IAstTransform
 	{
-		readonly DecompilerTypeSystem typeSystem;
-
-		public ConvertConstructorCallIntoInitializer(DecompilerTypeSystem typeSystem)
+		public void Run(AstNode node, TransformContext context)
 		{
-			if (typeSystem == null)
-				throw new ArgumentNullException("typeSystem");
-			this.typeSystem = typeSystem;
+			var visitor = new ConvertConstructorCallIntoInitializerVisitor(context);
+			
+			// If we're viewing some set of members (fields are direct children of SyntaxTree),
+			// we also need to handle those:
+			visitor.HandleInstanceFieldInitializers(node.Children);
+			visitor.HandleStaticFieldInitializers(node.Children);
+			
+			node.AcceptVisitor(visitor);
 		}
-
+	}
+	
+	sealed class ConvertConstructorCallIntoInitializerVisitor : DepthFirstAstVisitor
+	{
+		readonly TransformContext context;
+		
+		public ConvertConstructorCallIntoInitializerVisitor(TransformContext context)
+		{
+			Debug.Assert(context != null);
+			this.context = context;
+		}
+		
 		public override void VisitConstructorDeclaration(ConstructorDeclaration constructorDeclaration)
 		{
 			ExpressionStatement stmt = constructorDeclaration.Body.Statements.FirstOrDefault() as ExpressionStatement;
@@ -96,7 +111,7 @@ namespace ICSharpCode.Decompiler.CSharp.Transforms
 			HandleStaticFieldInitializers(typeDeclaration.Members);
 		}
 		
-		void HandleInstanceFieldInitializers(IEnumerable<AstNode> members)
+		internal void HandleInstanceFieldInitializers(IEnumerable<AstNode> members)
 		{
 			var instanceCtors = members.OfType<ConstructorDeclaration>().Where(c => (c.Modifiers & Modifiers.Static) == 0).ToArray();
 			var instanceCtorsNotChainingWithThis = instanceCtors.Where(ctor => !thisCallPattern.IsMatch(ctor.Body.Statements.FirstOrDefault())).ToArray();
@@ -150,13 +165,13 @@ namespace ICSharpCode.Decompiler.CSharp.Transforms
 			}
 		}
 		
-		void HandleStaticFieldInitializers(IEnumerable<AstNode> members)
+		internal void HandleStaticFieldInitializers(IEnumerable<AstNode> members)
 		{
 			// Translate static constructor into field initializers if the class is BeforeFieldInit
 			var staticCtor = members.OfType<ConstructorDeclaration>().FirstOrDefault(c => (c.Modifiers & Modifiers.Static) == Modifiers.Static);
 			if (staticCtor != null) {
 				IMethod ctorMethod = staticCtor.GetSymbol() as IMethod;
-				MethodDefinition ctorMethodDef = typeSystem.GetCecil(ctorMethod) as MethodDefinition;
+				MethodDefinition ctorMethodDef = context.TypeSystem.GetCecil(ctorMethod) as MethodDefinition;
 				if (ctorMethodDef != null && ctorMethodDef.DeclaringType.IsBeforeFieldInit) {
 					while (true) {
 						ExpressionStatement es = staticCtor.Body.Statements.FirstOrDefault() as ExpressionStatement;
@@ -179,15 +194,5 @@ namespace ICSharpCode.Decompiler.CSharp.Transforms
 				}
 			}
 		}
-		
-		public void Run(AstNode node)
-		{
-			// If we're viewing some set of members (fields are direct children of CompilationUnit),
-			// we also need to handle those:
-			HandleInstanceFieldInitializers(node.Children);
-			HandleStaticFieldInitializers(node.Children);
-			
-			node.AcceptVisitor(this);
-		}
 	}
 }

ICSharpCode.Decompiler/CSharp/Transforms/IAstTransform.cs

@@ -25,6 +25,6 @@ namespace ICSharpCode.Decompiler.CSharp.Transforms
 {
 	public interface IAstTransform
 	{
-		void Run(AstNode rootNode);
+		void Run(AstNode rootNode, TransformContext context);
 	}
 }

ICSharpCode.Decompiler/CSharp/Transforms/IntroduceUnsafeModifier.cs

@@ -27,7 +27,7 @@ namespace ICSharpCode.Decompiler.CSharp.Transforms
 		
 		sealed class PointerArithmetic {}
 		
-		public void Run(AstNode compilationUnit)
+		public void Run(AstNode compilationUnit, TransformContext context)
 		{
 			compilationUnit.AcceptVisitor(this);
 		}

ICSharpCode.Decompiler/CSharp/Transforms/IntroduceUsingDeclarations.cs

@@ -20,7 +20,7 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using ICSharpCode.NRefactory.CSharp;
-using Mono.Cecil;
+using ICSharpCode.NRefactory.Semantics;
 
 namespace ICSharpCode.Decompiler.CSharp.Transforms
 {
@@ -29,25 +29,18 @@ namespace ICSharpCode.Decompiler.CSharp.Transforms
 	/// </summary>
 	public class IntroduceUsingDeclarations : IAstTransform
 	{
-		DecompilerContext context;
+		public bool FullyQualifyAmbiguousTypeNames = true;
 		
-		public IntroduceUsingDeclarations(DecompilerContext context)
+		public void Run(AstNode compilationUnit, TransformContext context)
 		{
-			this.context = context;
-		}
-		
-		public void Run(AstNode compilationUnit)
-		{
-			if (!context.Settings.UsingDeclarations)
-				return;
-			
 			// First determine all the namespaces that need to be imported:
-			compilationUnit.AcceptVisitor(new FindRequiredImports(this), null);
+			var requiredImports = new FindRequiredImports(context);
+			compilationUnit.AcceptVisitor(requiredImports);
 			
-			importedNamespaces.Add("System"); // always import System, even when not necessary
+			requiredImports.ImportedNamespaces.Add("System"); // always import System, even when not necessary
 			
 			// Now add using declarations for those namespaces:
-			foreach (string ns in importedNamespaces.OrderByDescending(n => n)) {
+			foreach (string ns in requiredImports.ImportedNamespaces.OrderByDescending(n => n)) {
 				// we go backwards (OrderByDescending) through the list of namespaces because we insert them backwards
 				// (always inserting at the start of the list)
 				string[] parts = ns.Split('.');
@@ -58,9 +51,10 @@ namespace ICSharpCode.Decompiler.CSharp.Transforms
 				compilationUnit.InsertChildAfter(null, new UsingDeclaration { Import = nsType }, SyntaxTree.MemberRole);
 			}
 			
-			if (!context.Settings.FullyQualifyAmbiguousTypeNames)
+			if (!FullyQualifyAmbiguousTypeNames)
 				return;
-			
+
+			/*
 			FindAmbiguousTypeNames(context.CurrentModule, internalsVisible: true);
 			foreach (AssemblyNameReference r in context.CurrentModule.AssemblyReferences) {
 				AssemblyDefinition d = context.CurrentModule.AssemblyResolver.Resolve(r);
@@ -69,25 +63,24 @@ namespace ICSharpCode.Decompiler.CSharp.Transforms
 			}
 			
 			// verify that the SimpleTypes refer to the correct type (no ambiguities)
-			compilationUnit.AcceptVisitor(new FullyQualifyAmbiguousTypeNamesVisitor(this), null);
+			compilationUnit.AcceptVisitor(new FullyQualifyAmbiguousTypeNamesVisitor(this), null);*/
 		}
 		
-		readonly HashSet<string> declaredNamespaces = new HashSet<string>() { string.Empty };
-		readonly HashSet<string> importedNamespaces = new HashSet<string>();
 		
 		// Note that we store type names with `n suffix, so we automatically disambiguate based on number of type parameters.
-		readonly HashSet<string> availableTypeNames = new HashSet<string>();
-		readonly HashSet<string> ambiguousTypeNames = new HashSet<string>();
+		//readonly HashSet<string> availableTypeNames = new HashSet<string>();
+		//readonly HashSet<string> ambiguousTypeNames = new HashSet<string>();
 		
-		sealed class FindRequiredImports : DepthFirstAstVisitor<object, object>
+		sealed class FindRequiredImports : DepthFirstAstVisitor
 		{
-			readonly IntroduceUsingDeclarations transform;
 			string currentNamespace;
+
+			public readonly HashSet<string> DeclaredNamespaces = new HashSet<string>() { string.Empty };
+			public readonly HashSet<string> ImportedNamespaces = new HashSet<string>();
 			
-			public FindRequiredImports(IntroduceUsingDeclarations transform)
+			public FindRequiredImports(TransformContext context)
 			{
-				this.transform = transform;
-				this.currentNamespace = transform.context.CurrentType != null ? transform.context.CurrentType.Namespace : string.Empty;
+				this.currentNamespace = context.DecompiledTypeDefinition != null ? context.DecompiledTypeDefinition.Namespace : string.Empty;
 			}
 			
 			bool IsParentOfCurrentNamespace(string ns)
@@ -103,28 +96,28 @@ namespace ICSharpCode.Decompiler.CSharp.Transforms
 				return false;
 			}
 			
-			public override object VisitSimpleType(SimpleType simpleType, object data)
+			public override void VisitSimpleType(SimpleType simpleType)
 			{
-				TypeReference tr = simpleType.Annotation<TypeReference>();
-				if (tr != null && !IsParentOfCurrentNamespace(tr.Namespace)) {
-					transform.importedNamespaces.Add(tr.Namespace);
+				var trr = simpleType.Annotation<TypeResolveResult>();
+				if (trr != null && !IsParentOfCurrentNamespace(trr.Type.Namespace)) {
+					ImportedNamespaces.Add(trr.Type.Namespace);
 				}
-				return base.VisitSimpleType(simpleType, data); // also visit type arguments
+				base.VisitSimpleType(simpleType); // also visit type arguments
 			}
 			
-			public override object VisitNamespaceDeclaration(NamespaceDeclaration namespaceDeclaration, object data)
+			public override void VisitNamespaceDeclaration(NamespaceDeclaration namespaceDeclaration)
 			{
 				string oldNamespace = currentNamespace;
-				foreach (Identifier ident in namespaceDeclaration.Identifiers) {
-					currentNamespace = NamespaceDeclaration.BuildQualifiedName(currentNamespace, ident.Name);
-					transform.declaredNamespaces.Add(currentNamespace);
+				foreach (string ident in namespaceDeclaration.Identifiers) {
+					currentNamespace = NamespaceDeclaration.BuildQualifiedName(currentNamespace, ident);
+					DeclaredNamespaces.Add(currentNamespace);
 				}
-				base.VisitNamespaceDeclaration(namespaceDeclaration, data);
+				base.VisitNamespaceDeclaration(namespaceDeclaration);
 				currentNamespace = oldNamespace;
-				return null;
 			}
 		}
 		
+		/*
 		void FindAmbiguousTypeNames(ModuleDefinition module, bool internalsVisible)
 		{
 			foreach (TypeDefinition type in module.Types) {
@@ -355,6 +348,6 @@ namespace ICSharpCode.Decompiler.CSharp.Transforms
 					return false;
 				return transform.ambiguousTypeNames.Contains(name);
 			}
-		}
+		}*/
 	}
 }

ICSharpCode.Decompiler/CSharp/Transforms/ReplaceMethodCallsWithOperators.cs

@@ -345,7 +345,7 @@ namespace ICSharpCode.Decompiler.CSharp.Transforms
 			}
 		}
 		
-		void IAstTransform.Run(AstNode node)
+		void IAstTransform.Run(AstNode node, TransformContext context)
 		{
 			node.AcceptVisitor(this);
 		}

ICSharpCode.Decompiler/CSharp/Transforms/TransformContext.cs

@@ -0,0 +1,53 @@
+// Copyright (c) 2014 Daniel Grunwald
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this
+// software and associated documentation files (the "Software"), to deal in the Software
+// without restriction, including without limitation the rights to use, copy, modify, merge,
+// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
+// to whom the Software is furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all copies or
+// substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
+// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+
+using System;
+using ICSharpCode.NRefactory.CSharp.Resolver;
+using ICSharpCode.NRefactory.TypeSystem;
+
+namespace ICSharpCode.Decompiler.CSharp.Transforms
+{
+	/// <summary>
+	/// Parameters for IAstTransform.
+	/// </summary>
+	public class TransformContext
+	{
+		public readonly DecompilerTypeSystem TypeSystem;
+		readonly ITypeResolveContext decompilationContext;
+		
+		/// <summary>
+		/// Returns the member that is being decompiled; or null if a whole type or assembly is being decompiled.
+		/// </summary>
+		public IMember DecompiledMember {
+			get { return decompilationContext.CurrentMember; }
+		}
+		
+		/// <summary>
+		/// Returns the type definition that is being decompiled; or null if an assembly is being decompiled.
+		/// </summary>
+		public ITypeDefinition DecompiledTypeDefinition {
+			get { return decompilationContext.CurrentTypeDefinition; }
+		}
+		
+		internal TransformContext(DecompilerTypeSystem typeSystem, ITypeResolveContext decompilationContext)
+		{
+			this.TypeSystem = typeSystem;
+			this.decompilationContext = decompilationContext;
+		}
+	}
+}

ICSharpCode.Decompiler/CSharp/TranslatedExpression.cs

@@ -194,7 +194,7 @@ namespace ICSharpCode.Decompiler.CSharp
 			} else if (Type.Kind == TypeKind.Pointer) {
 				var nullRef = new NullReferenceExpression()
 					.WithoutILInstruction()
-					.WithRR(new ConstantResolveResult(this.Type, null));
+					.WithRR(new ConstantResolveResult(SpecialType.NullType, null));
 				return new BinaryOperatorExpression(Expression, BinaryOperatorType.InEquality, nullRef.Expression)
 					.WithoutILInstruction()
 					.WithRR(new OperatorResolveResult(boolType, System.Linq.Expressions.ExpressionType.NotEqual,

ICSharpCode.Decompiler/DecompilerTypeSystem.cs

@@ -56,13 +56,15 @@ namespace ICSharpCode.Decompiler
 			context = new SimpleTypeResolveContext(compilation.MainAssembly);
 		}
 
-		public ICompilation Compilation
-		{
+		public ICompilation Compilation {
 			get { return compilation; }
 		}
+		
+		public IAssembly MainAssembly {
+			get { return compilation.MainAssembly; }
+		}
 
-		public ModuleDefinition ModuleDefinition
-		{
+		public ModuleDefinition ModuleDefinition {
 			get { return moduleDefinition; }
 		}
 
@@ -113,7 +115,7 @@ namespace ICSharpCode.Decompiler
 		/// <summary>
 		/// Retrieves a type definition for a type defined in the compilation's main assembly.
 		/// </summary>
-		public IType GetType(TypeReference typeReference)
+		public IType Resolve(TypeReference typeReference)
 		{
 			if (typeReference == null)
 				return SpecialType.UnknownType;
@@ -125,7 +127,7 @@ namespace ICSharpCode.Decompiler
 		#endregion
 
 		#region Resolve Field
-		public IField GetField(FieldReference fieldReference)
+		public IField Resolve(FieldReference fieldReference)
 		{
 			if (fieldReference == null)
 				throw new ArgumentNullException("fieldReference");
@@ -135,7 +137,7 @@ namespace ICSharpCode.Decompiler
 					field = FindNonGenericField(fieldReference);
 					if (fieldReference.DeclaringType.IsGenericInstance) {
 						var git = (GenericInstanceType)fieldReference.DeclaringType;
-						var typeArguments = git.GenericArguments.SelectArray(GetType);
+						var typeArguments = git.GenericArguments.SelectArray(Resolve);
 						field = (IField)field.Specialize(new TypeParameterSubstitution(typeArguments, null));
 					}
 					fieldLookupCache.Add(fieldReference, field);
@@ -146,7 +148,7 @@ namespace ICSharpCode.Decompiler
 
 		IField FindNonGenericField(FieldReference fieldReference)
 		{
-			ITypeDefinition typeDef = GetType(fieldReference.DeclaringType).GetDefinition();
+			ITypeDefinition typeDef = Resolve(fieldReference.DeclaringType).GetDefinition();
 			if (typeDef == null)
 				return CreateFakeField(fieldReference);
 			foreach (IField field in typeDef.Fields)
@@ -157,7 +159,7 @@ namespace ICSharpCode.Decompiler
 
 		IField CreateFakeField(FieldReference fieldReference)
 		{
-			var declaringType = GetType(fieldReference.DeclaringType);
+			var declaringType = Resolve(fieldReference.DeclaringType);
 			var f = new DefaultUnresolvedField();
 			f.Name = fieldReference.Name;
 			f.ReturnType = typeReferenceCecilLoader.ReadTypeReference(fieldReference.FieldType);
@@ -182,7 +184,7 @@ namespace ICSharpCode.Decompiler
 		#endregion
 
 		#region Resolve Method
-		public IMethod GetMethod(MethodReference methodReference)
+		public IMethod Resolve(MethodReference methodReference)
 		{
 			if (methodReference == null)
 				throw new ArgumentNullException("methodReference");
@@ -195,11 +197,11 @@ namespace ICSharpCode.Decompiler
 						IList<IType> methodTypeArguments = null;
 						if (methodReference.IsGenericInstance) {
 							var gim = ((GenericInstanceMethod)methodReference);
-							methodTypeArguments = gim.GenericArguments.SelectArray(GetType);
+							methodTypeArguments = gim.GenericArguments.SelectArray(Resolve);
 						}
 						if (methodReference.DeclaringType.IsGenericInstance) {
 							var git = (GenericInstanceType)methodReference.DeclaringType;
-							classTypeArguments = git.GenericArguments.SelectArray(GetType);
+							classTypeArguments = git.GenericArguments.SelectArray(Resolve);
 						}
 						method = method.Specialize(new TypeParameterSubstitution(classTypeArguments, methodTypeArguments));
 					}
@@ -211,7 +213,7 @@ namespace ICSharpCode.Decompiler
 
 		IMethod FindNonGenericMethod(MethodReference methodReference)
 		{
-			ITypeDefinition typeDef = GetType(methodReference.DeclaringType).GetDefinition();
+			ITypeDefinition typeDef = Resolve(methodReference.DeclaringType).GetDefinition();
 			if (typeDef == null)
 				return CreateFakeMethod(methodReference);
 			IEnumerable<IMethod> methods;
@@ -227,7 +229,7 @@ namespace ICSharpCode.Decompiler
 				if (GetCecil(method) == methodReference)
 					return method;
 			}
-			var parameterTypes = methodReference.Parameters.SelectArray(p => GetType(p.ParameterType));
+			var parameterTypes = methodReference.Parameters.SelectArray(p => Resolve(p.ParameterType));
 			foreach (var method in methods) {
 				if (CompareSignatures(method.Parameters, parameterTypes))
 					return method;

ICSharpCode.Decompiler/ICSharpCode.Decompiler.csproj

@@ -63,6 +63,8 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="CSharp\Annotations.cs" />
+    <Compile Include="CSharp\Transforms\IntroduceUsingDeclarations.cs" />
+    <Compile Include="CSharp\Transforms\TransformContext.cs" />
     <Compile Include="CSharp\TranslatedExpression.cs" />
     <Compile Include="CSharp\CSharpDecompiler.cs" />
     <Compile Include="CSharp\ExpressionBuilder.cs" />

ICSharpCode.Decompiler/IL/BlockBuilder.cs

@@ -72,7 +72,7 @@ namespace ICSharpCode.Decompiler.IL
 					tryInstructionList.Add(tryCatch);
 				}
 
-				var variable = new ILVariable(VariableKind.Exception, typeSystem.GetType(eh.CatchType), handlerBlock.ILRange.Start);
+				var variable = new ILVariable(VariableKind.Exception, typeSystem.Resolve(eh.CatchType), handlerBlock.ILRange.Start);
 				variable.Name = "ex";
 				handlerBlock.EntryPoint.Instructions.Add(new LdLoc(variable));
 				

ICSharpCode.Decompiler/IL/ILReader.cs

@@ -93,21 +93,21 @@ namespace ICSharpCode.Decompiler.IL
 		{
 			var token = ReadMetadataToken(ref reader);
 			var typeReference = body.LookupToken(token) as TypeReference;
-			return typeSystem.GetType(typeReference);
+			return typeSystem.Resolve(typeReference);
 		}
 
 		IMethod ReadAndDecodeMethodReference()
 		{
 			var token = ReadMetadataToken(ref reader);
 			var methodReference = body.LookupToken(token) as MethodReference;
-			return typeSystem.GetMethod(methodReference);
+			return typeSystem.Resolve(methodReference);
 		}
 
 		IField ReadAndDecodeFieldReference()
 		{
 			var token = ReadMetadataToken(ref reader);
 			var fieldReference = body.LookupToken(token) as FieldReference;
-			return typeSystem.GetField(fieldReference);
+			return typeSystem.Resolve(fieldReference);
 		}
 
 		void InitParameterVariables()
@@ -123,7 +123,7 @@ namespace ICSharpCode.Decompiler.IL
 
 		ILVariable CreateILVariable(Cil.VariableDefinition v)
 		{
-			var ilVar = new ILVariable(VariableKind.Local, typeSystem.GetType(v.VariableType), v.Index);
+			var ilVar = new ILVariable(VariableKind.Local, typeSystem.Resolve(v.VariableType), v.Index);
 			if (string.IsNullOrEmpty(v.Name))
 				ilVar.Name = "V_" + v.Index;
 			else
@@ -134,7 +134,7 @@ namespace ICSharpCode.Decompiler.IL
 		ILVariable CreateILVariable(ParameterDefinition p)
 		{
 			var variableKind = p.Index == -1 ? VariableKind.This : VariableKind.Parameter;
-			var ilVar = new ILVariable(variableKind, typeSystem.GetType(p.ParameterType), p.Index);
+			var ilVar = new ILVariable(variableKind, typeSystem.Resolve(p.ParameterType), p.Index);
 			ilVar.StoreCount = 1; // count the initial store when the method is called with an argument
 			if (variableKind == VariableKind.This)
 				ilVar.Name = "this";

NRefactory/ICSharpCode.NRefactory.CSharp/OutputVisitor/CSharpAmbience.cs

@@ -171,7 +171,7 @@ namespace ICSharpCode.NRefactory.CSharp
 		TypeSystemAstBuilder CreateAstBuilder()
 		{
 			TypeSystemAstBuilder astBuilder = new TypeSystemAstBuilder();
-			astBuilder.AddAnnotations = true;
+			astBuilder.AddTypeReferenceAnnotations = true;
 			astBuilder.ShowModifiers = (ConversionFlags & ConversionFlags.ShowModifiers) == ConversionFlags.ShowModifiers;
 			astBuilder.ShowAccessibility = (ConversionFlags & ConversionFlags.ShowAccessibility) == ConversionFlags.ShowAccessibility;
 			astBuilder.AlwaysUseShortTypeNames = (ConversionFlags & ConversionFlags.UseFullyQualifiedTypeNames) != ConversionFlags.UseFullyQualifiedTypeNames;

NRefactory/ICSharpCode.NRefactory.CSharp/Refactoring/TypeSystemAstBuilder.cs

@@ -77,7 +77,13 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 		/// Specifies whether the ast builder should add annotations to type references.
 		/// The default value is <c>false</c>.
 		/// </summary>
-		public bool AddAnnotations { get; set; }
+		public bool AddTypeReferenceAnnotations { get; set; }
+		
+		/// <summary>
+		/// Specifies whether the ast builder should add ResolveResult annotations to AST nodes.
+		/// The default value is <c>false</c>.
+		/// </summary>
+		public bool AddResolveResultAnnotations { get; set; }
 		
 		/// <summary>
 		/// Controls the accessibility modifiers are shown.
@@ -159,8 +165,10 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 			if (type == null)
 				throw new ArgumentNullException("type");
 			AstType astType = ConvertTypeHelper(type);
-			if (AddAnnotations)
+			if (AddTypeReferenceAnnotations)
 				astType.AddAnnotation(type);
+			if (AddResolveResultAnnotations)
+				astType.AddAnnotation(new TypeResolveResult(type));
 			return astType;
 		}
 		
@@ -417,7 +425,10 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 			}
 			
 			if (rr is TypeOfResolveResult) {
-				return new TypeOfExpression(ConvertType(rr.Type));
+				var expr = new TypeOfExpression(ConvertType(rr.Type));
+				if (AddResolveResultAnnotations)
+					expr.AddAnnotation(rr);
+				return expr;
 			} else if (rr is ArrayCreateResolveResult) {
 				ArrayCreateResolveResult acrr = (ArrayCreateResolveResult)rr;
 				ArrayCreateExpression ace = new ArrayCreateExpression();
@@ -438,6 +449,8 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 					initializer.Elements.AddRange(acrr.InitializerElements.Select(ConvertConstantValue));
 					ace.Initializer = initializer;
 				}
+				if (AddResolveResultAnnotations)
+					ace.AddAnnotation(rr);
 				return ace;
 			} else if (rr.IsCompileTimeConstant) {
 				return ConvertConstantValue(rr.Type, rr.ConstantValue);
@@ -451,10 +464,17 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 			if (type == null)
 				throw new ArgumentNullException("type");
 			if (constantValue == null) {
-				if (type.IsReferenceType == true)
-					return new NullReferenceExpression();
-				else
-					return new DefaultValueExpression(ConvertType(type));
+				if (type.IsReferenceType == true) {
+					var expr = new NullReferenceExpression();
+					if (AddResolveResultAnnotations)
+						expr.AddAnnotation(new ConstantResolveResult(SpecialType.NullType, null));
+					return expr;
+				} else {
+					var expr = new DefaultValueExpression(ConvertType(type));
+					if (AddResolveResultAnnotations)
+						expr.AddAnnotation(new ConstantResolveResult(type, null));
+					return expr;
+				}
 			} else if (type.Kind == TypeKind.Enum) {
 				return ConvertEnumValue(type, (long)CSharpPrimitiveCast.Cast(TypeCode.Int64, constantValue, false));
 			} else {