Fully qualify ambiguous type names.

ICSharpCode.Decompiler/Ast/AstBuilder.cs

@@ -31,7 +31,7 @@ namespace ICSharpCode.Decompiler.Ast
 	
 	public class AstBuilder
 	{
-		DecompilerContext context = new DecompilerContext();
+		DecompilerContext context;
 		CompilationUnit astCompileUnit = new CompilationUnit();
 		Dictionary<string, NamespaceDeclaration> astNamespaces = new Dictionary<string, NamespaceDeclaration>();
 		bool transformationsHaveRun;

ICSharpCode.Decompiler/Ast/DecompilerContext.cs

@@ -10,11 +10,19 @@ namespace ICSharpCode.Decompiler
 {
 	public class DecompilerContext
 	{
+		public ModuleDefinition CurrentModule;
 		public CancellationToken CancellationToken;
 		public TypeDefinition CurrentType;
 		public MethodDefinition CurrentMethod;
 		public DecompilerSettings Settings = new DecompilerSettings();
 		
+		public DecompilerContext(ModuleDefinition currentModule)
+		{
+			if (currentModule == null)
+				throw new ArgumentNullException("currentModule");
+			this.CurrentModule = currentModule;
+		}
+		
 		/// <summary>
 		/// Used to pass variable names from a method to its anonymous methods.
 		/// </summary>

ICSharpCode.Decompiler/Ast/Transforms/IntroduceUsingDeclarations.cs

@@ -44,10 +44,22 @@ namespace ICSharpCode.Decompiler.Ast.Transforms
 				compilationUnit.InsertChildAfter(null, new UsingDeclaration { Import = nsType }, CompilationUnit.MemberRole);
 			}
 			
-			// TODO: verify that the SimpleTypes refer to the correct type (no ambiguities)
+			FindAmbiguousTypeNames(context.CurrentModule, internalsVisible: true);
+			foreach (AssemblyNameReference r in context.CurrentModule.AssemblyReferences) {
+				AssemblyDefinition d = context.CurrentModule.AssemblyResolver.Resolve(r);
+				if (d != null)
+					FindAmbiguousTypeNames(d.MainModule, internalsVisible: false);
+			}
+			
+			// verify that the SimpleTypes refer to the correct type (no ambiguities)
+			FullyQualifyAmbiguousTypeNames(compilationUnit);
 		}
 		
+		readonly HashSet<string> declaredNamespaces = new HashSet<string>() { string.Empty };
 		readonly HashSet<string> importedNamespaces = new HashSet<string>();
+		
+		readonly HashSet<string> availableTypeNames = new HashSet<string>();
+		readonly HashSet<string> ambiguousTypeNames = new HashSet<string>();
 		string currentNamespace;
 		
 		bool IsParentOfCurrentNamespace(string ns)
@@ -77,10 +89,49 @@ namespace ICSharpCode.Decompiler.Ast.Transforms
 			string oldNamespace = currentNamespace;
 			foreach (Identifier ident in namespaceDeclaration.Identifiers) {
 				currentNamespace = NamespaceDeclaration.BuildQualifiedName(currentNamespace, ident.Name);
+				declaredNamespaces.Add(currentNamespace);
 			}
 			base.VisitNamespaceDeclaration(namespaceDeclaration, data);
 			currentNamespace = oldNamespace;
 			return null;
 		}
+		
+		void FindAmbiguousTypeNames(ModuleDefinition module, bool internalsVisible)
+		{
+			foreach (TypeDefinition type in module.Types) {
+				if (internalsVisible || type.IsPublic) {
+					if (importedNamespaces.Contains(type.Namespace) || declaredNamespaces.Contains(type.Namespace)) {
+						if (!availableTypeNames.Add(type.Name))
+							ambiguousTypeNames.Add(type.Name);
+					}
+				}
+			}
+		}
+		
+		void FullyQualifyAmbiguousTypeNames(AstNode compilationUnit)
+		{
+			foreach (SimpleType simpleType in compilationUnit.Descendants.OfType<SimpleType>()) {
+				TypeReference tr = simpleType.Annotation<TypeReference>();
+				if (tr != null && ambiguousTypeNames.Contains(tr.Name)) {
+					AstType ns;
+					if (string.IsNullOrEmpty(tr.Namespace)) {
+						ns = new SimpleType("global");
+					} else {
+						string[] parts = tr.Namespace.Split('.');
+						ns = new SimpleType(parts[0]);
+						for (int i = 1; i < parts.Length; i++) {
+							ns = new MemberType { Target = ns, MemberName = parts[i] };
+						}
+					}
+					MemberType mt = new MemberType();
+					mt.Target = ns;
+					mt.IsDoubleColon = string.IsNullOrEmpty(tr.Namespace);
+					mt.MemberName = simpleType.Identifier;
+					mt.CopyAnnotationsFrom(simpleType);
+					simpleType.TypeArguments.MoveTo(mt.TypeArguments);
+					simpleType.ReplaceWith(mt);
+				}
+			}
+		}
 	}
 }

ICSharpCode.Decompiler/Tests/DecompilerTestBase.cs

@@ -35,7 +35,7 @@ namespace ICSharpCode.Decompiler.Tests
 		static string RoundtripCode(string code)
 		{
 			AssemblyDefinition assembly = Compile(code);
-			AstBuilder decompiler = new AstBuilder(new DecompilerContext());
+			AstBuilder decompiler = new AstBuilder(new DecompilerContext(assembly.MainModule));
 			decompiler.AddAssembly(assembly);
 			new Helpers.RemoveCompilerAttribute().Run(decompiler.CompilationUnit);
 			StringWriter output = new StringWriter();

ICSharpCode.Decompiler/Tests/TestRunner.cs

@@ -98,7 +98,7 @@ namespace ICSharpCode.Decompiler.Tests
 		{
 			string code = File.ReadAllText(fileName);
 			AssemblyDefinition assembly = Compile(code);
-			AstBuilder decompiler = new AstBuilder(new DecompilerContext());
+			AstBuilder decompiler = new AstBuilder(new DecompilerContext(assembly.MainModule));
 			decompiler.AddAssembly(assembly);
 			new Helpers.RemoveCompilerAttribute().Run(decompiler.CompilationUnit);
 			StringWriter output = new StringWriter();

ILSpy/CSharpLanguage.cs

@@ -51,8 +51,9 @@ namespace ICSharpCode.ILSpy
 		#if DEBUG
 		internal static IEnumerable<CSharpLanguage> GetDebugLanguages()
 		{
+			DecompilerContext context = new DecompilerContext(ModuleDefinition.CreateModule("dummy", ModuleKind.Dll));
 			string lastTransformName = "no transforms";
-			foreach (Type _transformType in TransformationPipeline.CreatePipeline(new DecompilerContext()).Select(v => v.GetType()).Distinct()) {
+			foreach (Type _transformType in TransformationPipeline.CreatePipeline(context).Select(v => v.GetType()).Distinct()) {
 				Type transformType = _transformType; // copy for lambda
 				yield return new CSharpLanguage {
 					transformAbortCondition = v => transformType.IsInstanceOfType(v),
@@ -83,7 +84,7 @@ namespace ICSharpCode.ILSpy
 		public override void DecompileMethod(MethodDefinition method, ITextOutput output, DecompilationOptions options)
 		{
 			WriteCommentLine(output, TypeToString(method.DeclaringType, includeNamespace: true));
-			AstBuilder codeDomBuilder = CreateAstBuilder(options, method.DeclaringType);
+			AstBuilder codeDomBuilder = CreateAstBuilder(options, currentType: method.DeclaringType);
 			codeDomBuilder.AddMethod(method);
 			codeDomBuilder.RunTransformations(transformAbortCondition);
 			codeDomBuilder.GenerateCode(output);
@@ -92,7 +93,7 @@ namespace ICSharpCode.ILSpy
 		public override void DecompileProperty(PropertyDefinition property, ITextOutput output, DecompilationOptions options)
 		{
 			WriteCommentLine(output, TypeToString(property.DeclaringType, includeNamespace: true));
-			AstBuilder codeDomBuilder = CreateAstBuilder(options, property.DeclaringType);
+			AstBuilder codeDomBuilder = CreateAstBuilder(options, currentType: property.DeclaringType);
 			codeDomBuilder.AddProperty(property);
 			codeDomBuilder.RunTransformations(transformAbortCondition);
 			codeDomBuilder.GenerateCode(output);
@@ -101,7 +102,7 @@ namespace ICSharpCode.ILSpy
 		public override void DecompileField(FieldDefinition field, ITextOutput output, DecompilationOptions options)
 		{
 			WriteCommentLine(output, TypeToString(field.DeclaringType, includeNamespace: true));
-			AstBuilder codeDomBuilder = CreateAstBuilder(options, field.DeclaringType);
+			AstBuilder codeDomBuilder = CreateAstBuilder(options, currentType: field.DeclaringType);
 			codeDomBuilder.AddField(field);
 			codeDomBuilder.RunTransformations(transformAbortCondition);
 			codeDomBuilder.GenerateCode(output);
@@ -110,7 +111,7 @@ namespace ICSharpCode.ILSpy
 		public override void DecompileEvent(EventDefinition ev, ITextOutput output, DecompilationOptions options)
 		{
 			WriteCommentLine(output, TypeToString(ev.DeclaringType, includeNamespace: true));
-			AstBuilder codeDomBuilder = CreateAstBuilder(options, ev.DeclaringType);
+			AstBuilder codeDomBuilder = CreateAstBuilder(options, currentType: ev.DeclaringType);
 			codeDomBuilder.AddEvent(ev);
 			codeDomBuilder.RunTransformations(transformAbortCondition);
 			codeDomBuilder.GenerateCode(output);
@@ -118,7 +119,7 @@ namespace ICSharpCode.ILSpy
 		
 		public override void DecompileType(TypeDefinition type, ITextOutput output, DecompilationOptions options)
 		{
-			AstBuilder codeDomBuilder = CreateAstBuilder(options, type);
+			AstBuilder codeDomBuilder = CreateAstBuilder(options, currentType: type);
 			codeDomBuilder.AddType(type);
 			codeDomBuilder.RunTransformations(transformAbortCondition);
 			codeDomBuilder.GenerateCode(output);
@@ -133,7 +134,7 @@ namespace ICSharpCode.ILSpy
 				WriteProjectFile(new TextOutputWriter(output), files, assembly.MainModule);
 			} else {
 				base.DecompileAssembly(assembly, fileName, output, options);
-				AstBuilder codeDomBuilder = CreateAstBuilder(options, currentType: null);
+				AstBuilder codeDomBuilder = CreateAstBuilder(options, currentModule: assembly.MainModule);
 				codeDomBuilder.AddAssembly(assembly, onlyAssemblyLevel: !options.FullDecompilation);
 				codeDomBuilder.RunTransformations(transformAbortCondition);
 				codeDomBuilder.GenerateCode(output);
@@ -296,7 +297,7 @@ namespace ICSharpCode.ILSpy
 				new ParallelOptions { MaxDegreeOfParallelism = Environment.ProcessorCount },
 				delegate (IGrouping<string, TypeDefinition> file) {
 					using (StreamWriter w = new StreamWriter(Path.Combine(options.SaveAsProjectDirectory, file.Key))) {
-						AstBuilder codeDomBuilder = CreateAstBuilder(options, null);
+						AstBuilder codeDomBuilder = CreateAstBuilder(options, currentModule: assembly.MainModule);
 						foreach (TypeDefinition type in file) {
 							codeDomBuilder.AddType(type);
 						}
@@ -383,10 +384,12 @@ namespace ICSharpCode.ILSpy
 		}
 		#endregion
 		
-		AstBuilder CreateAstBuilder(DecompilationOptions options, TypeDefinition currentType)
+		AstBuilder CreateAstBuilder(DecompilationOptions options, ModuleDefinition currentModule = null, TypeDefinition currentType = null)
 		{
+			if (currentModule == null)
+				currentModule = currentType.Module;
 			return new AstBuilder(
-				new DecompilerContext {
+				new DecompilerContext(currentModule) {
 					CancellationToken = options.CancellationToken,
 					CurrentType = currentType,
 					Settings = options.DecompilerSettings

ILSpy/ILAstLanguage.cs

@@ -56,7 +56,7 @@ namespace ICSharpCode.ILSpy
 			ilMethod.Body = astBuilder.Build(method, inlineVariables);
 			
 			if (abortBeforeStep != null) {
-				DecompilerContext context = new DecompilerContext { CurrentType = method.DeclaringType, CurrentMethod = method };
+				DecompilerContext context = new DecompilerContext(method.Module) { CurrentType = method.DeclaringType, CurrentMethod = method };
 				new ILAstOptimizer().Optimize(context, ilMethod, abortBeforeStep.Value);
 			}