Clean up PEFile, move Pdb related types to DebugInfo namespace

ICSharpCode.Decompiler.PdbProvider.Cecil/MonoCecilDebugInfoProvider.cs

@@ -20,7 +20,7 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Reflection.Metadata.Ecma335;
 
-using ICSharpCode.Decompiler.Metadata;
+using ICSharpCode.Decompiler.DebugInfo;
 using ICSharpCode.Decompiler.Util;
 
 using Mono.Cecil;
@@ -43,7 +43,7 @@ namespace ICSharpCode.Decompiler.PdbProvider.Cecil
 			var method = this.module.LookupToken(MetadataTokens.GetToken(handle)) as Mono.Cecil.MethodDefinition;
 			if (method?.DebugInformation == null || !method.DebugInformation.HasSequencePoints)
 				return EmptyList<SequencePoint>.Instance;
-			return method.DebugInformation.SequencePoints.Select(point => new Metadata.SequencePoint {
+			return method.DebugInformation.SequencePoints.Select(point => new SequencePoint {
 				Offset = point.Offset,
 				StartLine = point.StartLine,
 				StartColumn = point.StartColumn,

ICSharpCode.Decompiler.Tests/Helpers/Tester.cs

@@ -348,8 +348,9 @@ namespace ICSharpCode.Decompiler.Tests.Helpers
 			var emitResult = compilation.Emit(peStream);
 			peStream.Position = 0;
 
-			var moduleDefinition = new PEFile("TestAssembly.dll", peStream, false, PEStreamOptions.PrefetchEntireImage);
+			var moduleDefinition = new PEFile("TestAssembly.dll", peStream, PEStreamOptions.PrefetchEntireImage);
-			var decompiler = new CSharpDecompiler(moduleDefinition, new DecompilerSettings());
+			var resolver = new UniversalAssemblyResolver("TestAssembly.dll", false, moduleDefinition.Reader.DetectTargetFrameworkId(), PEStreamOptions.PrefetchEntireImage);
+			var decompiler = new CSharpDecompiler(moduleDefinition, resolver, new DecompilerSettings());
 
 			return decompiler;
 		}
@@ -394,9 +395,11 @@ namespace ICSharpCode.Decompiler.Tests.Helpers
 		public static string DecompileCSharp(string assemblyFileName, DecompilerSettings settings = null)
 		{
 			using (var file = new FileStream(assemblyFileName, FileMode.Open, FileAccess.Read)) {
-				var module = new PEFile(assemblyFileName, file, false, PEStreamOptions.PrefetchEntireImage);
+				var module = new PEFile(assemblyFileName, file, PEStreamOptions.PrefetchEntireImage);
-				var typeSystem = new DecompilerTypeSystem(module);
+				var resolver = new UniversalAssemblyResolver(assemblyFileName, false,
-				CSharpDecompiler decompiler = new CSharpDecompiler(typeSystem, settings ?? new DecompilerSettings());
+					module.Reader.DetectTargetFrameworkId(), PEStreamOptions.PrefetchMetadata);
+				var typeSystem = new DecompilerTypeSystem(module, resolver);
+				CSharpDecompiler decompiler = new CSharpDecompiler(typeSystem, resolver, settings ?? new DecompilerSettings());
 				decompiler.AstTransforms.Insert(0, new RemoveEmbeddedAtttributes());
 				decompiler.AstTransforms.Insert(0, new RemoveCompilerAttribute());
 				decompiler.AstTransforms.Add(new EscapeInvalidIdentifiers());

ICSharpCode.Decompiler.Tests/RoundtripAssembly.cs

@@ -144,11 +144,12 @@ namespace ICSharpCode.Decompiler.Tests
 					Console.WriteLine($"Decompiling {fileToRoundtrip}...");
 					Stopwatch w = Stopwatch.StartNew();
 					using (var fileStream = new FileStream(file, FileMode.Open, FileAccess.Read)) {
-						PEFile module = new PEFile(file, fileStream, false, PEStreamOptions.PrefetchEntireImage);
+						PEFile module = new PEFile(file, fileStream, PEStreamOptions.PrefetchEntireImage);
-						UniversalAssemblyResolver resolver = (UniversalAssemblyResolver)module.AssemblyResolver;
+						UniversalAssemblyResolver resolver = new UniversalAssemblyResolver(file, false, module.Reader.DetectTargetFrameworkId(), PEStreamOptions.PrefetchMetadata);
 						resolver.AddSearchDirectory(inputDir);
 						resolver.RemoveSearchDirectory(".");
 						var decompiler = new TestProjectDecompiler(inputDir);
+						decompiler.AssemblyResolver = resolver;
 						// use a fixed GUID so that we can diff the output between different ILSpy runs without spurious changes
 						decompiler.ProjectGuid = Guid.Parse("{127C83E4-4587-4CF9-ADCA-799875F3DFE6}");
 						decompiler.DecompileProject(module, decompiledDir);

ICSharpCode.Decompiler/CSharp/CSharpDecompiler.cs

@@ -39,6 +39,8 @@ using System.Reflection.Metadata;
 using SRM = System.Reflection.Metadata;
 using ICSharpCode.Decompiler.Metadata;
 using System.Reflection.PortableExecutable;
+using ICSharpCode.Decompiler.Documentation;
+using ICSharpCode.Decompiler.DebugInfo;
 
 namespace ICSharpCode.Decompiler.CSharp
 {
@@ -179,6 +181,18 @@ namespace ICSharpCode.Decompiler.CSharp
 
 		public IDecompilerTypeSystem TypeSystem => typeSystem;
 
+		public IAssemblyResolver AssemblyResolver { get; }
+
+		/// <summary>
+		/// Gets or sets the optional provider for debug info.
+		/// </summary>
+		public IDebugInfoProvider DebugInfoProvider { get; set; }
+
+		/// <summary>
+		/// Gets or sets the optional provider for XML documentation strings.
+		/// </summary>
+		public IDocumentationProvider DocumentationProvider { get; set; }
+
 		/// <summary>
 		/// IL transforms.
 		/// </summary>
@@ -193,21 +207,20 @@ namespace ICSharpCode.Decompiler.CSharp
 			get { return astTransforms; }
 		}
 
-		public CSharpDecompiler(string fileName, DecompilerSettings settings)
+		public CSharpDecompiler(string fileName, IAssemblyResolver assemblyResolver, DecompilerSettings settings)
-			: this(LoadPEFile(fileName, settings), settings)
+			: this(LoadPEFile(fileName, settings), assemblyResolver, settings)
 		{
 		}
 
-		public CSharpDecompiler(Metadata.PEFile module, DecompilerSettings settings)
+		public CSharpDecompiler(PEFile module, IAssemblyResolver assemblyResolver, DecompilerSettings settings)
-			: this(new DecompilerTypeSystem(module, settings), settings)
+			: this(new DecompilerTypeSystem(module, assemblyResolver, settings), assemblyResolver, settings)
 		{
 		}
 
-		public CSharpDecompiler(DecompilerTypeSystem typeSystem, DecompilerSettings settings)
+		public CSharpDecompiler(DecompilerTypeSystem typeSystem, IAssemblyResolver assemblyResolver, DecompilerSettings settings)
 		{
-			if (typeSystem == null)
+			this.typeSystem = typeSystem ?? throw new ArgumentNullException(nameof(typeSystem));
-				throw new ArgumentNullException(nameof(typeSystem));
+			this.AssemblyResolver = assemblyResolver ?? throw new ArgumentNullException(nameof(assemblyResolver));
-			this.typeSystem = typeSystem;
 			this.settings = settings;
 		}
 
@@ -318,7 +331,6 @@ namespace ICSharpCode.Decompiler.CSharp
 			return new PEFile(
 				fileName,
 				new FileStream(fileName, FileMode.Open, FileAccess.Read),
-				settings.ThrowOnAssemblyResolveErrors,
 				options: settings.LoadInMemory ? PEStreamOptions.PrefetchEntireImage : PEStreamOptions.Default
 			);
 		}
@@ -436,7 +448,7 @@ namespace ICSharpCode.Decompiler.CSharp
 		{
 			var decompileRun = new DecompileRun(settings) { CancellationToken = CancellationToken };
 			RequiredNamespaceCollector.CollectNamespaces(function.Method, typeSystem, decompileRun.Namespaces);
-			return new ILTransformContext(function, typeSystem, settings) {
+			return new ILTransformContext(function, typeSystem, DebugInfoProvider, settings) {
 				CancellationToken = CancellationToken,
 				DecompileRun = decompileRun
 			};
@@ -887,10 +899,13 @@ namespace ICSharpCode.Decompiler.CSharp
 		{
 			try {
 				var specializingTypeSystem = typeSystem.GetSpecializingTypeSystem(decompilationContext);
-				var ilReader = new ILReader(specializingTypeSystem);
+				var ilReader = new ILReader(specializingTypeSystem) {
-				ilReader.UseDebugSymbols = settings.UseDebugSymbols;
+					UseDebugSymbols = settings.UseDebugSymbols,
+					DebugInfo = DebugInfoProvider
+				};
 				var methodDef = typeSystem.ModuleDefinition.Metadata.GetMethodDefinition((MethodDefinitionHandle)method.MetadataToken);
-				var function = ilReader.ReadIL(typeSystem.ModuleDefinition, (MethodDefinitionHandle)method.MetadataToken, typeSystem.ModuleDefinition.Reader.GetMethodBody(methodDef.RelativeVirtualAddress), CancellationToken);
+				var methodBody = typeSystem.ModuleDefinition.Reader.GetMethodBody(methodDef.RelativeVirtualAddress);
+				var function = ilReader.ReadIL(typeSystem.ModuleDefinition, (MethodDefinitionHandle)method.MetadataToken, methodBody, CancellationToken);
 				function.CheckInvariant(ILPhase.Normal);
 
 				if (entityDecl != null) {
@@ -911,7 +926,7 @@ namespace ICSharpCode.Decompiler.CSharp
 					localSettings.AlwaysCastTargetsOfExplicitInterfaceImplementationCalls = true;
 				}
 
-				var context = new ILTransformContext(function, specializingTypeSystem, localSettings) {
+				var context = new ILTransformContext(function, specializingTypeSystem, DebugInfoProvider, localSettings) {
 					CancellationToken = CancellationToken,
 					DecompileRun = decompileRun
 				};
@@ -1126,7 +1141,7 @@ namespace ICSharpCode.Decompiler.CSharp
 		/// 
 		/// This only works correctly when the nodes in the syntax tree have line/column information.
 		/// </summary>
-		public Dictionary<ILFunction, List<Metadata.SequencePoint>> CreateSequencePoints(SyntaxTree syntaxTree)
+		public Dictionary<ILFunction, List<DebugInfo.SequencePoint>> CreateSequencePoints(SyntaxTree syntaxTree)
 		{
 			SequencePointBuilder spb = new SequencePointBuilder();
 			syntaxTree.AcceptVisitor(spb);

ICSharpCode.Decompiler/CSharp/SequencePointBuilder.cs

@@ -56,7 +56,7 @@ namespace ICSharpCode.Decompiler.CSharp
 			}
 		}
 
-		readonly List<(ILFunction, Metadata.SequencePoint)> sequencePoints = new List<(ILFunction, Metadata.SequencePoint)>();
+		readonly List<(ILFunction, DebugInfo.SequencePoint)> sequencePoints = new List<(ILFunction, DebugInfo.SequencePoint)>();
 		readonly HashSet<ILInstruction> mappedInstructions = new HashSet<ILInstruction>();
 		
 		// Stack holding information for outer statements.
@@ -219,7 +219,7 @@ namespace ICSharpCode.Decompiler.CSharp
 				// use LongSet to deduplicate and merge the intervals
 				var longSet = new LongSet(current.Intervals.Select(i => new LongInterval(i.Start, i.End)));
 				Debug.Assert(!longSet.IsEmpty);
-				sequencePoints.Add((current.Function, new Metadata.SequencePoint {
+				sequencePoints.Add((current.Function, new DebugInfo.SequencePoint {
 					Offset = (int)longSet.Intervals[0].Start,
 					EndOffset = (int)longSet.Intervals[0].End,
 					StartLine = startLocation.Line,
@@ -277,18 +277,18 @@ namespace ICSharpCode.Decompiler.CSharp
 		/// <summary>
 		/// Called after the visitor is done to return the results.
 		/// </summary>
-		internal Dictionary<ILFunction, List<Metadata.SequencePoint>> GetSequencePoints()
+		internal Dictionary<ILFunction, List<DebugInfo.SequencePoint>> GetSequencePoints()
 		{
-			var dict = new Dictionary<ILFunction, List<Metadata.SequencePoint>>();
+			var dict = new Dictionary<ILFunction, List<DebugInfo.SequencePoint>>();
 			foreach (var (function, sequencePoint) in this.sequencePoints) {
 				if (!dict.TryGetValue(function, out var list)) {
-					dict.Add(function, list = new List<Metadata.SequencePoint>());
+					dict.Add(function, list = new List<DebugInfo.SequencePoint>());
 				}
 				list.Add(sequencePoint);
 			}
 			foreach (var (function, list) in dict.ToList()) {
 				// For each function, sort sequence points and fix overlaps+gaps
-				var newList = new List<Metadata.SequencePoint>();
+				var newList = new List<DebugInfo.SequencePoint>();
 				int pos = 0;
 				foreach (var sequencePoint in list.OrderBy(sp => sp.Offset).ThenBy(sp => sp.EndOffset)) {
 					if (sequencePoint.Offset < pos) {
@@ -305,7 +305,7 @@ namespace ICSharpCode.Decompiler.CSharp
 						}
 					} else if (sequencePoint.Offset > pos) {
 						// insert hidden sequence point in the gap.
-						var hidden = new Metadata.SequencePoint();
+						var hidden = new DebugInfo.SequencePoint();
 						hidden.Offset = pos;
 						hidden.EndOffset = sequencePoint.Offset;
 						hidden.SetHidden();
@@ -315,7 +315,7 @@ namespace ICSharpCode.Decompiler.CSharp
 					pos = sequencePoint.EndOffset;
 				}
 				if (pos < function.CodeSize) {
-					var hidden = new Metadata.SequencePoint();
+					var hidden = new DebugInfo.SequencePoint();
 					hidden.Offset = pos;
 					hidden.EndOffset = function.CodeSize;
 					hidden.SetHidden();

ICSharpCode.Decompiler/CSharp/WholeProjectDecompiler.cs

@@ -34,6 +34,7 @@ using System.Reflection.PortableExecutable;
 using System.Reflection.Metadata;
 using static ICSharpCode.Decompiler.Metadata.DotNetCorePathFinderExtensions;
 using static ICSharpCode.Decompiler.Metadata.MetadataExtensions;
+using ICSharpCode.Decompiler.Metadata;
 
 namespace ICSharpCode.Decompiler.CSharp
 {
@@ -56,6 +57,8 @@ namespace ICSharpCode.Decompiler.CSharp
 			}
 		}
 
+		public IAssemblyResolver AssemblyResolver { get; set; }
+
 		/// <summary>
 		/// The MSBuild ProjectGuid to use for the new project.
 		/// <c>null</c> to automatically generate a new GUID.
@@ -218,7 +221,7 @@ namespace ICSharpCode.Decompiler.CSharp
 					if (r.Name != "mscorlib") {
 						w.WriteStartElement("Reference");
 						w.WriteAttributeString("Include", r.Name);
-						var asm = module.AssemblyResolver.Resolve(r);
+						var asm = AssemblyResolver.Resolve(r);
 						if (!IsGacAssembly(r, asm)) {
 							if (asm != null) {
 								w.WriteElementString("HintPath", asm.FileName);
@@ -275,7 +278,7 @@ namespace ICSharpCode.Decompiler.CSharp
 
 		CSharpDecompiler CreateDecompiler(DecompilerTypeSystem ts)
 		{
-			var decompiler = new CSharpDecompiler(ts, settings);
+			var decompiler = new CSharpDecompiler(ts, AssemblyResolver, settings);
 			decompiler.AstTransforms.Add(new EscapeInvalidIdentifiers());
 			decompiler.AstTransforms.Add(new RemoveCLSCompliantAttribute());
 			return decompiler;
@@ -314,7 +317,7 @@ namespace ICSharpCode.Decompiler.CSharp
 						return Path.Combine(dir, file);
 					}
 				}, StringComparer.OrdinalIgnoreCase).ToList();
-			DecompilerTypeSystem ts = new DecompilerTypeSystem(module);
+			DecompilerTypeSystem ts = new DecompilerTypeSystem(module, AssemblyResolver);
 			Parallel.ForEach(
 				files,
 				new ParallelOptions {

ICSharpCode.Decompiler/DebugInfo/IDebugInfoProvider.cs

@@ -0,0 +1,19 @@
+using System;
+using System.Collections.Generic;
+using System.Reflection.Metadata;
+using System.Text;
+
+namespace ICSharpCode.Decompiler.DebugInfo
+{
+	public struct Variable
+	{
+		public string Name { get; set; }
+	}
+
+	public interface IDebugInfoProvider
+	{
+		IList<SequencePoint> GetSequencePoints(MethodDefinitionHandle method);
+		IList<Variable> GetVariables(MethodDefinitionHandle method);
+		bool TryGetName(MethodDefinitionHandle method, int index, out string name);
+	}
+}

ICSharpCode.Decompiler/DebugInfo/PortablePdbWriter.cs

@@ -17,7 +17,7 @@ using ICSharpCode.Decompiler.Metadata;
 using ICSharpCode.Decompiler.TypeSystem;
 using ICSharpCode.Decompiler.Util;
 
-namespace ICSharpCode.Decompiler.Pdb
+namespace ICSharpCode.Decompiler.DebugInfo
 {
 	public class PortablePdbWriter
 	{
@@ -39,7 +39,7 @@ namespace ICSharpCode.Decompiler.Pdb
 			var hasher = SHA256.Create();
 			var sequencePointBlobs = new Dictionary<MethodDefinitionHandle, (DocumentHandle Document, BlobHandle SequencePoints)>();
 			var importScopeBlobs = new Dictionary<MethodDefinitionHandle, (DocumentHandle Document, BlobHandle ImportScope)>();
-			var emptyList = new List<Metadata.SequencePoint>();
+			var emptyList = new List<SequencePoint>();
 
 			foreach (var handle in reader.GetTopLevelTypeDefinitions()) {
 				var type = reader.GetTypeDefinition(handle);
@@ -156,7 +156,7 @@ namespace ICSharpCode.Decompiler.Pdb
 			return metadata.GetOrAddBlob(writer);
 		}
 
-		static BlobHandle EncodeSequencePoints(MetadataBuilder metadata, int localSignatureRowId, List<Metadata.SequencePoint> sequencePoints)
+		static BlobHandle EncodeSequencePoints(MetadataBuilder metadata, int localSignatureRowId, List<SequencePoint> sequencePoints)
 		{
 			if (sequencePoints.Count == 0)
 				return default;

ICSharpCode.Decompiler/DebugInfo/SequencePoint.cs

@@ -18,7 +18,7 @@
 
 using System;
 
-namespace ICSharpCode.Decompiler.Metadata
+namespace ICSharpCode.Decompiler.DebugInfo
 {
 	/// <summary>
 	/// A sequence point read from a PDB file or produced by the decompiler.

ICSharpCode.Decompiler/Disassembler/MethodBodyDisassembler.cs

@@ -21,7 +21,7 @@ using System.Collections.Generic;
 using System.Reflection.Metadata;
 using System.Reflection.Metadata.Ecma335;
 using System.Threading;
-
+using ICSharpCode.Decompiler.DebugInfo;
 using ICSharpCode.Decompiler.IL;
 using ICSharpCode.Decompiler.Metadata;
 using ICSharpCode.Decompiler.Util;
@@ -51,7 +51,12 @@ namespace ICSharpCode.Decompiler.Disassembler
 		/// </summary>
 		public bool ShowMetadataTokens { get; set; }
 
-		IList<Metadata.SequencePoint> sequencePoints;
+		/// <summary>
+		/// Optional provider for sequence points.
+		/// </summary>
+		public IDebugInfoProvider DebugInfo { get; set; }
+
+		IList<DebugInfo.SequencePoint> sequencePoints;
 		int nextSequencePointIndex;
 
 		// cache info
@@ -68,7 +73,7 @@ namespace ICSharpCode.Decompiler.Disassembler
 
 		public virtual void Disassemble(PEFile module, MethodDefinitionHandle handle)
 		{
-			this.module = module;
+			this.module = module ?? throw new ArgumentNullException(nameof(module));
 			metadata = module.Metadata;
 			genericContext = new GenericContext(handle, module);
 			signatureDecoder = new DisassemblerSignatureProvider(module, output);
@@ -94,7 +99,7 @@ namespace ICSharpCode.Decompiler.Disassembler
 			DisassembleLocalsBlock(body);
 			output.WriteLine();
 
-			sequencePoints = module.DebugInfo?.GetSequencePoints(handle) ?? EmptyList<Metadata.SequencePoint>.Instance;
+			sequencePoints = DebugInfo?.GetSequencePoints(handle) ?? EmptyList<DebugInfo.SequencePoint>.Instance;
 			nextSequencePointIndex = 0;
 			if (DetectControlStructure && blob.Length > 0) {
 				blob.Reset();
@@ -278,7 +283,7 @@ namespace ICSharpCode.Decompiler.Disassembler
 		{
 			int offset = blob.Offset;
 			if (ShowSequencePoints && nextSequencePointIndex < sequencePoints?.Count) {
-				Metadata.SequencePoint sp = sequencePoints[nextSequencePointIndex];
+				var sp = sequencePoints[nextSequencePointIndex];
 				if (sp.Offset <= offset) {
 					output.Write("// sequence point: ");
 					if (sp.Offset != offset) {

ICSharpCode.Decompiler/Disassembler/ReflectionDisassembler.cs

@@ -27,6 +27,7 @@ using System.Threading;
 
 using ICSharpCode.Decompiler.Metadata;
 using ICSharpCode.Decompiler.IL;
+using ICSharpCode.Decompiler.DebugInfo;
 
 namespace ICSharpCode.Decompiler.Disassembler
 {
@@ -55,8 +56,15 @@ namespace ICSharpCode.Decompiler.Disassembler
 			set => methodBodyDisassembler.ShowMetadataTokens = value;
 		}
 
+		public IDebugInfoProvider DebugInfo {
+			get => methodBodyDisassembler.DebugInfo;
+			set => methodBodyDisassembler.DebugInfo = value;
+		}
+
 		public bool ExpandMemberDefinitions { get; set; } = false;
 
+		public IAssemblyResolver AssemblyResolver { get; set; }
+
 		public ReflectionDisassembler(ITextOutput output, CancellationToken cancellationToken)
 			: this(output, new MethodBodyDisassembler(output, cancellationToken), cancellationToken)
 		{
@@ -362,59 +370,61 @@ namespace ICSharpCode.Decompiler.Disassembler
 						output.Write(secdecl.Action.ToString());
 						break;
 				}
-				output.WriteLine(" = {");
+				if (AssemblyResolver == null) {
-				output.Indent();
+					output.Write(" = ");
-				var blob = metadata.GetBlobReader(secdecl.PermissionSet);
+					WriteBlob(secdecl.PermissionSet, metadata);
-				if ((char)blob.ReadByte() != '.') {
-					blob.Reset();
-					WriteXmlSecurityDeclaration(blob.ReadUTF8(blob.RemainingBytes));
 				} else {
-					string currentAssemblyName = null;
+					output.WriteLine(" = {");
-					string currentFullAssemblyName = null;
+					output.Indent();
-					if (metadata.IsAssembly) {
+					var blob = metadata.GetBlobReader(secdecl.PermissionSet);
-						currentAssemblyName = metadata.GetString(metadata.GetAssemblyDefinition().Name);
+					if ((char)blob.ReadByte() != '.') {
-						currentFullAssemblyName = metadata.GetFullAssemblyName();
+						blob.Reset();
-					}
+						WriteXmlSecurityDeclaration(blob.ReadUTF8(blob.RemainingBytes));
-					int count = blob.ReadCompressedInteger();
+					} else {
-					for (int i = 0; i < count; i++) {
+						string currentAssemblyName = null;
-						var typeName = blob.ReadSerializedString();
+						string currentFullAssemblyName = null;
-						string[] nameParts = typeName.Split(new[] { ", " }, StringSplitOptions.None);
+						if (metadata.IsAssembly) {
-						if (nameParts.Length < 2 || nameParts[1] == currentAssemblyName) {
+							currentAssemblyName = metadata.GetString(metadata.GetAssemblyDefinition().Name);
-							output.Write("class ");
+							currentFullAssemblyName = metadata.GetFullAssemblyName();
-							output.Write(DisassemblerHelpers.Escape(typeName + ", " + currentFullAssemblyName));
-						} else {
-							string[] typeNameParts = typeName.Split(new[] { ", " }, StringSplitOptions.None);
-							if (typeNameParts.Length < 2)
-								throw new NotImplementedException();
-							output.Write('[');
-							output.Write(typeNameParts[1]);
-							output.Write(']');
-							output.WriteReference(typeNameParts[0], null); // TODO : hyperlink!
 						}
-						output.Write(" = {");
+						int count = blob.ReadCompressedInteger();
-						blob.ReadCompressedInteger(); // ?
+						for (int i = 0; i < count; i++) {
-													  // The specification seems to be incorrect here, so I'm using the logic from Cecil instead.
+							var typeName = blob.ReadSerializedString();
-						int argCount = blob.ReadCompressedInteger();
+							string[] nameParts = typeName.Split(new[] { ", " }, StringSplitOptions.None);
-						if (argCount > 0) {
+							if (nameParts.Length < 2 || nameParts[1] == currentAssemblyName) {
-							output.WriteLine();
+								output.Write("class ");
-							output.Indent();
+								output.Write(DisassemblerHelpers.Escape(typeName + ", " + currentFullAssemblyName));
-
+							} else {
-							for (int j = 0; j < argCount; j++) {
+								output.Write('[');
-								WriteSecurityDeclarationArgument(module, ref blob);
+								output.Write(nameParts[1]);
+								output.Write(']');
+								output.WriteReference(nameParts[0], null); // TODO : hyperlink!
+							}
+							output.Write(" = {");
+							blob.ReadCompressedInteger(); // ?
+														  // The specification seems to be incorrect here, so I'm using the logic from Cecil instead.
+							int argCount = blob.ReadCompressedInteger();
+							if (argCount > 0) {
 								output.WriteLine();
+								output.Indent();
+
+								for (int j = 0; j < argCount; j++) {
+									WriteSecurityDeclarationArgument(module, ref blob);
+									output.WriteLine();
+								}
+
+								output.Unindent();
 							}
+							output.Write('}');
 
-							output.Unindent();
+							if (i + 1 < count)
+								output.Write(',');
+							output.WriteLine();
 						}
-						output.Write('}');
-
-						if (i + 1 < count)
-							output.Write(',');
-						output.WriteLine();
 					}
+					output.Unindent();
+					output.WriteLine("}");
 				}
-				output.Unindent();
-				output.WriteLine("}");
 			}
 		}
 
@@ -525,7 +535,7 @@ namespace ICSharpCode.Decompiler.Disassembler
 			PEFile containingModule = null;
 			// if we deal with an assembly-qualified name, resolve the assembly
 			if (nameParts.Length == 2)
-				containingModule = module.AssemblyResolver.Resolve(AssemblyNameReference.Parse(nameParts[1]));
+				containingModule = AssemblyResolver.Resolve(AssemblyNameReference.Parse(nameParts[1]));
 			if (containingModule != null) {
 				// try to find the type in the assembly
 				var handle = FindType(containingModule, typeNameParts);
@@ -539,7 +549,7 @@ namespace ICSharpCode.Decompiler.Disassembler
 				var handle = FindType(module, typeNameParts);
 				if (handle.IsNil) {
 					// otherwise try mscorlib
-					var mscorlib = module.AssemblyResolver.Resolve(AssemblyNameReference.Parse("mscorlib"));
+					var mscorlib = AssemblyResolver.Resolve(AssemblyNameReference.Parse("mscorlib"));
 					handle = FindType(mscorlib, typeNameParts);
 					if (handle.IsNil)
 						throw new NotImplementedException();
@@ -1352,27 +1362,27 @@ namespace ICSharpCode.Decompiler.Disassembler
 				output.Write(".custom ");
 				var attr = metadata.GetCustomAttribute(a);
 				attr.Constructor.WriteTo(module, output, GenericContext.Empty);
-				byte[] blob = metadata.GetBlobBytes(attr.Value);
+				if (!attr.Value.IsNil) {
-				if (blob.Length > 0) {
 					output.Write(" = ");
-					WriteBlob(blob);
+					WriteBlob(attr.Value, metadata);
 				}
 				output.WriteLine();
 			}
 		}
 
-		void WriteBlob(byte[] blob)
+		void WriteBlob(BlobHandle blob, MetadataReader metadata)
 		{
+			var reader = metadata.GetBlobReader(blob);
 			output.Write("(");
 			output.Indent();
 
-			for (int i = 0; i < blob.Length; i++) {
+			for (int i = 0; i < reader.Length; i++) {
-				if (i % 16 == 0 && i < blob.Length - 1) {
+				if (i % 16 == 0 && i < reader.Length - 1) {
 					output.WriteLine();
 				} else {
 					output.Write(' ');
 				}
-				output.Write(blob[i].ToString("x2"));
+				output.Write(reader.ReadByte().ToString("x2"));
 			}
 
 			output.WriteLine();
@@ -1484,10 +1494,9 @@ namespace ICSharpCode.Decompiler.Disassembler
 			OpenBlock(false);
 			WriteAttributes(module, asm.GetCustomAttributes());
 			WriteSecurityDeclarations(module, asm.GetDeclarativeSecurityAttributes());
-			var publicKey = metadata.GetBlobBytes(asm.PublicKey);
+			if (!asm.PublicKey.IsNil) {
-			if (publicKey.Length > 0) {
 				output.Write(".publickey = ");
-				WriteBlob(publicKey);
+				WriteBlob(asm.PublicKey, metadata);
 				output.WriteLine();
 			}
 			if (asm.HashAlgorithm != AssemblyHashAlgorithm.None) {
@@ -1518,7 +1527,7 @@ namespace ICSharpCode.Decompiler.Disassembler
 				OpenBlock(false);
 				if (!aref.PublicKeyOrToken.IsNil) {
 					output.Write(".publickeytoken = ");
-					WriteBlob(metadata.GetBlobBytes(aref.PublicKeyOrToken));
+					WriteBlob(aref.PublicKeyOrToken, metadata);
 					output.WriteLine();
 				}
 				if (aref.Version != null) {

ICSharpCode.Decompiler/Documentation/XmlDocumentationProvider.cs

@@ -23,9 +23,15 @@ using System.IO;
 using System.Runtime.Serialization;
 using System.Text;
 using System.Xml;
+using ICSharpCode.Decompiler.TypeSystem;
 
 namespace ICSharpCode.Decompiler.Documentation
 {
+	public interface IDocumentationProvider
+	{
+		string GetDocumentation(IEntity entity);
+	}
+
 	/// <summary>
 	/// Provides documentation from an .xml file (as generated by the Microsoft C# compiler).
 	/// </summary>
@@ -36,7 +42,7 @@ namespace ICSharpCode.Decompiler.Documentation
 	/// If the .xml file is changed, the index will automatically be recreated.
 	/// </remarks>
 	[Serializable]
-	public class XmlDocumentationProvider : IDeserializationCallback
+	public class XmlDocumentationProvider : IDeserializationCallback, IDocumentationProvider
 	{
 		#region Cache
 		sealed class XmlDocumentationCache
@@ -316,7 +322,17 @@ namespace ICSharpCode.Decompiler.Documentation
 				throw new ArgumentNullException("key");
 			return GetDocumentation(key, true);
 		}
-		
+
+		/// <summary>
+		/// Get the documentation for the specified member.
+		/// </summary>
+		public string GetDocumentation(IEntity entity)
+		{
+			if (entity == null)
+				throw new ArgumentNullException(nameof(entity));
+			return GetDocumentation(XmlDocKeyProvider.GetKey(entity));
+		}
+
 		string GetDocumentation(string key, bool allowReload)
 		{
 			int hashcode = GetHashCode(key);

ICSharpCode.Decompiler/ICSharpCode.Decompiler.csproj

@@ -306,7 +306,7 @@
     <Compile Include="IL\Instructions\LdFlda.cs" />
     <Compile Include="IL\Instructions\NullableInstructions.cs" />
     <Compile Include="IL\Instructions\StLoc.cs" />
-    <Compile Include="Metadata\SequencePoint.cs" />
+    <Compile Include="DebugInfo\SequencePoint.cs" />
     <Compile Include="IL\Instructions\CallIndirect.cs" />
     <Compile Include="IL\Instructions\DefaultValue.cs" />
     <Compile Include="IL\Transforms\DynamicCallSiteTransform.cs" />
@@ -342,7 +342,8 @@
     <Compile Include="IL\Transforms\StatementTransform.cs" />
     <Compile Include="IL\Transforms\TransformCollectionAndObjectInitializers.cs" />
     <Compile Include="Output\TextTokenWriter.cs" />
-    <Compile Include="Pdb\PortablePdbWriter.cs" />
+    <Compile Include="DebugInfo\IDebugInfoProvider.cs" />
+    <Compile Include="DebugInfo\PortablePdbWriter.cs" />
     <Compile Include="SRMExtensions.cs" />
     <Compile Include="SRMHacks.cs" />
     <Compile Include="TypeSystem\ApplyAttributeTypeVisitor.cs" />

ICSharpCode.Decompiler/IL/ControlFlow/YieldReturnDecompiler.cs

@@ -384,9 +384,11 @@ namespace ICSharpCode.Decompiler.IL.ControlFlow
 					)
 				);
 			}
-			var il = new ILReader(typeSystem).ReadIL(typeSystem.ModuleDefinition, method, typeSystem.ModuleDefinition.Reader.GetMethodBody(methodDef.RelativeVirtualAddress), context.CancellationToken);
+			var body = typeSystem.ModuleDefinition.Reader.GetMethodBody(methodDef.RelativeVirtualAddress);
+			var il = context.CreateILReader(typeSystem)
+				.ReadIL(typeSystem.ModuleDefinition, method, body, context.CancellationToken);
 			il.RunTransforms(CSharpDecompiler.EarlyILTransforms(true),
-				new ILTransformContext(il, typeSystem, context.Settings) {
+				new ILTransformContext(il, typeSystem, context.DebugInfo, context.Settings) {
 					CancellationToken = context.CancellationToken,
 					DecompileRun = context.DecompileRun
 				});

ICSharpCode.Decompiler/IL/ILReader.cs

@@ -40,6 +40,7 @@ namespace ICSharpCode.Decompiler.IL
 		readonly IDecompilerTypeSystem typeSystem;
 
 		public bool UseDebugSymbols { get; set; }
+		public DebugInfo.IDebugInfoProvider DebugInfo { get; set; }
 		public List<string> Warnings { get; } = new List<string>();
 
 		public ILReader(IDecompilerTypeSystem typeSystem)
@@ -53,7 +54,6 @@ namespace ICSharpCode.Decompiler.IL
 		MetadataReader metadata;
 		IMethod method;
 		MethodBodyBlock body;
-		Metadata.IDebugInfoProvider debugInfo;
 		StackType methodReturnStackType;
 		BlobReader reader;
 		ImmutableStack<ILVariable> currentStack;
@@ -79,7 +79,6 @@ namespace ICSharpCode.Decompiler.IL
 			var methodDefinition = metadata.GetMethodDefinition(methodDefinitionHandle);
 			this.body = body;
 			this.reader = body.GetILReader();
-			this.debugInfo = module.DebugInfo;
 			this.currentStack = ImmutableStack<ILVariable>.Empty;
 			this.unionFind = new UnionFind<ILVariable>();
 			this.stackMismatchPairs = new List<(ILVariable, ILVariable)>();
@@ -177,7 +176,7 @@ namespace ICSharpCode.Decompiler.IL
 				kind = VariableKind.Local;
 			}
 			ILVariable ilVar = new ILVariable(kind, type, index);
-			if (!UseDebugSymbols || debugInfo == null || !debugInfo.TryGetName((MethodDefinitionHandle)method.MetadataToken, index, out string name)) {
+			if (!UseDebugSymbols || DebugInfo == null || !DebugInfo.TryGetName((MethodDefinitionHandle)method.MetadataToken, index, out string name)) {
 				ilVar.Name = "V_" + index;
 				ilVar.HasGeneratedName = true;
 			} else if (string.IsNullOrWhiteSpace(name)) {
@@ -410,7 +409,8 @@ namespace ICSharpCode.Decompiler.IL
 		/// <summary>
 		/// Debugging helper: writes the decoded instruction stream interleaved with the inferred evaluation stack layout.
 		/// </summary>
-		public void WriteTypedIL(Metadata.PEFile module, MethodDefinitionHandle method, MethodBodyBlock body, ITextOutput output, CancellationToken cancellationToken = default(CancellationToken))
+		public void WriteTypedIL(Metadata.PEFile module,
+			MethodDefinitionHandle method, MethodBodyBlock body, ITextOutput output, CancellationToken cancellationToken = default)
 		{
 			Init(module, method, body);
 			ReadInstructions(cancellationToken);

ICSharpCode.Decompiler/IL/Transforms/DelegateConstruction.cs

@@ -145,8 +145,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 			if (!methodDefinition.HasBody())
 				return null;
 			var localTypeSystem = context.TypeSystem.GetSpecializingTypeSystem(targetMethod.Substitution);
-			var ilReader = new ILReader(localTypeSystem);
+			var ilReader = context.CreateILReader(localTypeSystem);
-			ilReader.UseDebugSymbols = context.Settings.UseDebugSymbols;
 			var function = ilReader.ReadIL(context.TypeSystem.ModuleDefinition, (MethodDefinitionHandle)targetMethod.MetadataToken, context.TypeSystem.ModuleDefinition.Reader.GetMethodBody(methodDefinition.RelativeVirtualAddress), context.CancellationToken);
 			function.DelegateType = value.Method.DeclaringType;
 			function.CheckInvariant(ILPhase.Normal);
@@ -156,7 +155,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 				v.Name = contextPrefix + v.Name;
 			}
 
-			var nestedContext = new ILTransformContext(function, localTypeSystem, context.Settings) {
+			var nestedContext = new ILTransformContext(function, localTypeSystem, context.DebugInfo, context.Settings) {
 				CancellationToken = context.CancellationToken,
 				DecompileRun = context.DecompileRun
 			};

ICSharpCode.Decompiler/IL/Transforms/IILTransform.cs

@@ -22,6 +22,7 @@ using System.Collections.Immutable;
 using System.Diagnostics;
 using System.Threading;
 using ICSharpCode.Decompiler.CSharp.TypeSystem;
+using ICSharpCode.Decompiler.DebugInfo;
 using ICSharpCode.Decompiler.TypeSystem;
 using ICSharpCode.Decompiler.Util;
 
@@ -42,6 +43,7 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 	{
 		public ILFunction Function { get; }
 		public IDecompilerTypeSystem TypeSystem { get; }
+		public IDebugInfoProvider DebugInfo { get; }
 		public DecompilerSettings Settings { get; }
 		public CancellationToken CancellationToken { get; set; }
 		public Stepper Stepper { get; set; }
@@ -49,11 +51,12 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 		internal DecompileRun DecompileRun { get; set; }
 		internal ResolvedUsingScope UsingScope => DecompileRun.UsingScope.Resolve(TypeSystem.Compilation);
 
-		public ILTransformContext(ILFunction function, IDecompilerTypeSystem typeSystem, DecompilerSettings settings = null)
+		public ILTransformContext(ILFunction function, IDecompilerTypeSystem typeSystem, IDebugInfoProvider debugInfo, DecompilerSettings settings = null)
 		{
 			this.Function = function ?? throw new ArgumentNullException(nameof(function));
 			this.TypeSystem = typeSystem ?? throw new ArgumentNullException(nameof(typeSystem));
 			this.Settings = settings ?? new DecompilerSettings();
+			this.DebugInfo = debugInfo;
 			Stepper = new Stepper();
 		}
 
@@ -61,12 +64,23 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 		{
 			this.Function = context.Function;
 			this.TypeSystem = context.TypeSystem;
+			this.DebugInfo = context.DebugInfo;
 			this.Settings = context.Settings;
 			this.DecompileRun = context.DecompileRun;
 			this.CancellationToken = context.CancellationToken;
 			this.Stepper = context.Stepper;
 		}
 
+		public ILReader CreateILReader(IDecompilerTypeSystem typeSystem = null)
+		{
+			if (typeSystem == null)
+				typeSystem = this.TypeSystem;
+			return new ILReader(typeSystem) {
+				UseDebugSymbols = Settings.UseDebugSymbols,
+				DebugInfo = DebugInfo
+			};
+		}
+
 		/// <summary>
 		/// Call this method immediately before performing a transform step.
 		/// Unlike <c>context.Stepper.Step()</c>, calls to this method are only compiled in debug builds.

ICSharpCode.Decompiler/IL/Transforms/ProxyCallReplacer.cs

@@ -31,20 +31,14 @@ namespace ICSharpCode.Decompiler.IL.Transforms
 				return;
 			// partially copied from CSharpDecompiler
 			var specializingTypeSystem = context.TypeSystem.GetSpecializingTypeSystem(inst.Method.Substitution);
-			var ilReader = new ILReader(specializingTypeSystem);
+			var ilReader = context.CreateILReader(specializingTypeSystem);
-			System.Threading.CancellationToken cancellationToken = new System.Threading.CancellationToken();
+			var body = module.Reader.GetMethodBody(methodDef.RelativeVirtualAddress);
-			var proxyFunction = ilReader.ReadIL(module, handle, module.Reader.GetMethodBody(methodDef.RelativeVirtualAddress), cancellationToken);
+			var proxyFunction = ilReader.ReadIL(module, handle, body, context.CancellationToken);
-			var transformContext = new ILTransformContext(proxyFunction, specializingTypeSystem, context.Settings) {
+			var transformContext = new ILTransformContext(proxyFunction, specializingTypeSystem, context.DebugInfo, context.Settings) {
-				CancellationToken = cancellationToken,
+				CancellationToken = context.CancellationToken,
 				DecompileRun = context.DecompileRun
 			};
-			foreach (var transform in CSharp.CSharpDecompiler.GetILTransforms()) {
+			proxyFunction.RunTransforms(CSharp.CSharpDecompiler.EarlyILTransforms(), transformContext);
-				if (transform.GetType() != typeof(ProxyCallReplacer)) { // don't call itself on itself
-					cancellationToken.ThrowIfCancellationRequested();
-					transform.Run(proxyFunction, transformContext);
-				}
-			}
-
 			if (!(proxyFunction.Body is BlockContainer blockContainer))
 				return;
 			if (blockContainer.Blocks.Count != 1)

ICSharpCode.Decompiler/Metadata/Dom.cs

@@ -15,23 +15,6 @@ using ICSharpCode.Decompiler.Util;
 
 namespace ICSharpCode.Decompiler.Metadata
 {
-	public interface IAssemblyDocumentationResolver
-	{
-		XmlDocumentationProvider GetProvider();
-	}
-
-	public struct Variable
-	{
-		public string Name { get; set; }
-	}
-
-	public interface IDebugInfoProvider
-	{
-		IList<SequencePoint> GetSequencePoints(MethodDefinitionHandle method);
-		IList<Variable> GetVariables(MethodDefinitionHandle method);
-		bool TryGetName(MethodDefinitionHandle method, int index, out string name);
-	}
-
 	public enum TargetRuntime
 	{
 		Unknown,

ICSharpCode.Decompiler/Metadata/MetadataResolver.cs

@@ -40,18 +40,18 @@ namespace ICSharpCode.Decompiler.Metadata
 		readonly IAssemblyResolver assemblyResolver;
 		readonly Dictionary<IAssemblyReference, PEFile> loadedModules;
 
-		public SimpleMetadataResolveContext(PEFile mainModule)
+		public SimpleMetadataResolveContext(PEFile mainModule, IAssemblyResolver assemblyResolver)
 		{
-			this.mainModule = mainModule;
+			this.mainModule = mainModule ?? throw new ArgumentNullException(nameof(mainModule));
-			this.assemblyResolver = mainModule.AssemblyResolver;
+			this.assemblyResolver = assemblyResolver ?? throw new ArgumentNullException(nameof(assemblyResolver));
 			this.loadedModules = new Dictionary<IAssemblyReference, PEFile>();
 		}
 
-		public SimpleMetadataResolveContext(PEFile mainModule, IMetadataResolveContext parentContext)
+		public SimpleMetadataResolveContext(PEFile mainModule, SimpleMetadataResolveContext parentContext)
 		{
-			this.mainModule = mainModule;
+			this.mainModule = mainModule ?? throw new ArgumentNullException(nameof(mainModule));
-			this.assemblyResolver = mainModule.AssemblyResolver;
+			this.assemblyResolver = parentContext.assemblyResolver;
-			this.loadedModules = parentContext is SimpleMetadataResolveContext simple ? simple.loadedModules : new Dictionary<IAssemblyReference, PEFile>();
+			this.loadedModules = parentContext.loadedModules;
 		}
 
 		public PEFile CurrentModule => mainModule;

ICSharpCode.Decompiler/Metadata/PEFile.cs

@@ -33,24 +33,17 @@ namespace ICSharpCode.Decompiler.Metadata
 		public string FileName { get; }
 		public PEReader Reader { get; }
 		public MetadataReader Metadata { get; }
-		public IAssemblyResolver AssemblyResolver { get; }
-		public IAssemblyDocumentationResolver DocumentationResolver { get; set; }
-		public IDebugInfoProvider DebugInfo { get; set; }
 
-		public PEFile(string fileName, Stream stream, bool throwOnResolveError = false, PEStreamOptions options = PEStreamOptions.Default)
+		public PEFile(string fileName, Stream stream, PEStreamOptions options = PEStreamOptions.Default)
+			: this(fileName, new PEReader(stream, options))
 		{
-			this.FileName = fileName;
-			this.Reader = new PEReader(stream, options);
-			this.Metadata = Reader.GetMetadataReader();
-			this.AssemblyResolver = new UniversalAssemblyResolver(fileName, throwOnResolveError, Reader.DetectTargetFrameworkId(), options);
 		}
 
-		public PEFile(string fileName, Stream stream, IAssemblyResolver assemblyResolver, PEStreamOptions options = PEStreamOptions.Default)
+		public PEFile(string fileName, PEReader reader)
 		{
-			this.FileName = fileName;
+			this.FileName = fileName ?? throw new ArgumentNullException(nameof(fileName));
-			this.Reader = new PEReader(stream, options);
+			this.Reader = reader ?? throw new ArgumentNullException(nameof(reader));
-			this.Metadata = Reader.GetMetadataReader();
+			this.Metadata = reader.GetMetadataReader();
-			this.AssemblyResolver = assemblyResolver;
 		}
 
 		public bool IsAssembly => Metadata.IsAssembly;

ICSharpCode.Decompiler/Metadata/UniversalAssemblyResolver.cs

@@ -90,7 +90,7 @@ namespace ICSharpCode.Decompiler.Metadata
 					throw new AssemblyResolutionException(name);
 				return null;
 			}
-			return new PEFile(file, new FileStream(file, FileMode.Open, FileAccess.Read), this, options);
+			return new PEFile(file, new FileStream(file, FileMode.Open, FileAccess.Read), options);
 		}
 
 		public string FindAssemblyFile(IAssemblyReference name)

ICSharpCode.Decompiler/TypeSystem/DecompilerTypeSystem.cs

@@ -26,6 +26,7 @@ using ICSharpCode.Decompiler.Util;
 using static ICSharpCode.Decompiler.Metadata.MetadataExtensions;
 using System.Diagnostics;
 using System.Collections.Immutable;
+using ICSharpCode.Decompiler.Metadata;
 
 namespace ICSharpCode.Decompiler.TypeSystem
 {
@@ -77,18 +78,21 @@ namespace ICSharpCode.Decompiler.TypeSystem
 	{
 		readonly Metadata.PEFile moduleDefinition;
 		readonly ICompilation compilation;
+		readonly IAssemblyResolver assemblyResolver;
 		readonly TypeSystemOptions typeSystemOptions;
 		readonly MetadataAssembly mainAssembly;
 
-		public DecompilerTypeSystem(Metadata.PEFile moduleDefinition) : this(moduleDefinition, new DecompilerSettings())
+		public DecompilerTypeSystem(Metadata.PEFile moduleDefinition, IAssemblyResolver assemblyResolver)
+			: this(moduleDefinition, assemblyResolver, new DecompilerSettings())
 		{
 		}
 
-		public DecompilerTypeSystem(Metadata.PEFile moduleDefinition, DecompilerSettings settings)
+		public DecompilerTypeSystem(PEFile moduleDefinition, IAssemblyResolver assemblyResolver, DecompilerSettings settings)
 		{
 			if (settings == null)
 				throw new ArgumentNullException(nameof(settings));
-			this.moduleDefinition = moduleDefinition;
+			this.moduleDefinition = moduleDefinition ?? throw new ArgumentNullException(nameof(moduleDefinition));
+			this.assemblyResolver = assemblyResolver ?? throw new ArgumentNullException(nameof(assemblyResolver));
 			typeSystemOptions = TypeSystemOptions.None;
 			if (settings.Dynamic)
 				typeSystemOptions |= TypeSystemOptions.Dynamic;
@@ -106,7 +110,7 @@ namespace ICSharpCode.Decompiler.TypeSystem
 				var asmRef = assemblyReferenceQueue.Dequeue();
 				if (!processedAssemblyReferences.Add(asmRef))
 					continue;
-				var asm = moduleDefinition.AssemblyResolver.Resolve(asmRef);
+				var asm = assemblyResolver.Resolve(asmRef);
 				if (asm != null) {
 					referencedAssemblies.Add(asm.WithOptions(typeSystemOptions));
 					var metadata = asm.Metadata;

ICSharpCode.Decompiler/TypeSystem/IAssembly.cs

@@ -18,6 +18,7 @@
 
 using System.Collections.Generic;
 using System.Reflection.Metadata;
+using ICSharpCode.Decompiler.Metadata;
 
 namespace ICSharpCode.Decompiler.TypeSystem
 {
@@ -65,6 +66,11 @@ namespace ICSharpCode.Decompiler.TypeSystem
 	/// </summary>
 	public interface IAssembly : ICompilationProvider
 	{
+		/// <summary>
+		/// Gets the underlying metadata file. May return null, if the IAssembly was not created from a PE file.
+		/// </summary>
+		PEFile PEFile { get; }
+
 		/// <summary>
 		/// Gets whether this assembly is the main assembly of the compilation.
 		/// </summary>

ICSharpCode.Decompiler/TypeSystem/Implementation/DefaultUnresolvedAssembly.cs

@@ -329,6 +329,8 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 				this.AssemblyAttributes = unresolved.AssemblyAttributes.CreateResolvedAttributes(context);
 				this.ModuleAttributes = unresolved.ModuleAttributes.CreateResolvedAttributes(context);
 			}
+
+			public Metadata.PEFile PEFile => null;
 			
 			public IUnresolvedAssembly UnresolvedAssembly {
 				get { return unresolvedAssembly; }

ICSharpCode.Decompiler/TypeSystem/MetadataAssembly.cs

@@ -38,7 +38,6 @@ namespace ICSharpCode.Decompiler.TypeSystem
 	public class MetadataAssembly : IAssembly
 	{
 		public ICompilation Compilation { get; }
-		public readonly Metadata.PEFile PEFile;
 		internal readonly MetadataReader metadata;
 		readonly TypeSystemOptions options;
 		internal readonly TypeProvider TypeProvider;
@@ -86,6 +85,8 @@ namespace ICSharpCode.Decompiler.TypeSystem
 		public TypeSystemOptions TypeSystemOptions => options;
 
 		#region IAssembly interface
+		public PEFile PEFile { get; }
+
 		public bool IsMainAssembly => this == Compilation.MainAssembly;
 
 		public string AssemblyName { get; }

ILSpy.BamlDecompiler.Tests/BamlTestRunner.cs

@@ -114,13 +114,13 @@ namespace ILSpy.BamlDecompiler.Tests
 		{
 			using (var fileStream = new FileStream(asmPath, FileMode.Open, FileAccess.Read)) {
 				var module = new PEFile(asmPath, fileStream);
-				var resolver = (UniversalAssemblyResolver)module.AssemblyResolver;
+				var resolver = new UniversalAssemblyResolver(asmPath, false, module.Reader.DetectTargetFrameworkId());
 				resolver.RemoveSearchDirectory(".");
 				resolver.AddSearchDirectory(Path.GetDirectoryName(asmPath));
 				var res = module.Resources.First();
 				Stream bamlStream = LoadBaml(res, name + ".baml");
 				Assert.IsNotNull(bamlStream);
-				XDocument document = BamlResourceEntryNode.LoadIntoDocument(module, bamlStream, CancellationToken.None);
+				XDocument document = BamlResourceEntryNode.LoadIntoDocument(module, resolver, bamlStream, CancellationToken.None);
 
 				XamlIsEqual(File.ReadAllText(sourcePath), document.ToString());
 			}

ILSpy.BamlDecompiler/BamlResourceEntryNode.cs

@@ -50,30 +50,32 @@ namespace ILSpy.BamlDecompiler
 		{
 			var asm = this.Ancestors().OfType<AssemblyTreeNode>().FirstOrDefault().LoadedAssembly;
 			Data.Position = 0;
-			XDocument xamlDocument = LoadIntoDocument(asm.GetPEFileOrNull(), Data, cancellationToken);
+			XDocument xamlDocument = LoadIntoDocument(asm.GetPEFileOrNull(), asm.GetAssemblyResolver(), Data, cancellationToken);
 			output.Write(xamlDocument.ToString());
 			return true;
 		}
 
-		internal static XDocument LoadIntoDocument(PEFile module, Stream stream, CancellationToken cancellationToken)
+		internal static XDocument LoadIntoDocument(PEFile module, IAssemblyResolver assemblyResolver,
+			Stream stream, CancellationToken cancellationToken)
 		{
 			cancellationToken.ThrowIfCancellationRequested();
 			XDocument xamlDocument;
-			using (XmlBamlReader reader = new XmlBamlReader(stream, new NRTypeResolver(module))) {
+			using (XmlBamlReader reader = new XmlBamlReader(stream, new NRTypeResolver(module, assemblyResolver))) {
 				xamlDocument = XDocument.Load(reader);
-				ConvertConnectionIds(xamlDocument, module, cancellationToken);
+				ConvertConnectionIds(xamlDocument, module, assemblyResolver, cancellationToken);
 				ConvertToEmptyElements(xamlDocument.Root);
 				MoveNamespacesToRoot(xamlDocument, reader.XmlnsDefinitions);
 				return xamlDocument;
 			}
 		}
 
-		static void ConvertConnectionIds(XDocument xamlDocument, PEFile asm, CancellationToken cancellationToken)
+		static void ConvertConnectionIds(XDocument xamlDocument, PEFile asm, IAssemblyResolver assemblyResolver,
+			CancellationToken cancellationToken)
 		{
 			var attr = xamlDocument.Root.Attribute(XName.Get("Class", XmlBamlReader.XWPFNamespace));
 			if (attr != null) {
 				string fullTypeName = attr.Value;
-				var mappings = new ConnectMethodDecompiler().DecompileEventMappings(asm, fullTypeName, cancellationToken);
+				var mappings = new ConnectMethodDecompiler().DecompileEventMappings(asm, assemblyResolver, fullTypeName, cancellationToken);
 				RemoveConnectionIds(xamlDocument.Root, mappings);
 			}
 		}

ILSpy.BamlDecompiler/BamlResourceNodeFactory.cs

@@ -36,7 +36,7 @@ namespace ILSpy.BamlDecompiler
 
 		public string WriteResourceToFile(LoadedAssembly assembly, string fileName, Stream stream, DecompilationOptions options)
 		{
-			var document = BamlResourceEntryNode.LoadIntoDocument(assembly.GetPEFileOrNull(), stream, options.CancellationToken);
+			var document = BamlResourceEntryNode.LoadIntoDocument(assembly.GetPEFileOrNull(), assembly.GetAssemblyResolver(), stream, options.CancellationToken);
 			fileName = Path.ChangeExtension(fileName, ".xaml");
 			document.Save(Path.Combine(options.SaveAsProjectDirectory, fileName));
 			return fileName;

ILSpy.BamlDecompiler/CecilTypeResolver.cs

@@ -4,6 +4,7 @@
 using System;
 using ICSharpCode.Decompiler.Metadata;
 using ICSharpCode.Decompiler.TypeSystem;
+using ICSharpCode.ILSpy;
 using Ricciolo.StylesExplorer.MarkupReflection;
 
 namespace ILSpy.BamlDecompiler
@@ -17,10 +18,10 @@ namespace ILSpy.BamlDecompiler
 		readonly DecompilerTypeSystem typeSystem;
 		readonly ICompilation compilation;
 	
-		public NRTypeResolver(PEFile module)
+		public NRTypeResolver(PEFile module, IAssemblyResolver resolver)
 		{
-			this.module = module;
+			this.module = module ?? throw new ArgumentNullException(nameof(module));
-			this.typeSystem = new DecompilerTypeSystem(module);
+			this.typeSystem = new DecompilerTypeSystem(module, resolver);
 			this.compilation = typeSystem.Compilation;
 		}
 		

ILSpy.BamlDecompiler/ConnectMethodDecompiler.cs

@@ -9,9 +9,11 @@ using System.Threading;
 using ICSharpCode.Decompiler.CSharp;
 using ICSharpCode.Decompiler.IL;
 using ICSharpCode.Decompiler.IL.Transforms;
+using ICSharpCode.Decompiler.Metadata;
 using ICSharpCode.Decompiler.TypeSystem;
 using ICSharpCode.Decompiler.TypeSystem.Implementation;
 using ICSharpCode.Decompiler.Util;
+using ICSharpCode.ILSpy;
 using Metadata = ICSharpCode.Decompiler.Metadata;
 
 namespace ILSpy.BamlDecompiler
@@ -29,11 +31,11 @@ namespace ILSpy.BamlDecompiler
 	/// </summary>
 	sealed class ConnectMethodDecompiler
 	{
-		public List<(LongSet, EventRegistration[])> DecompileEventMappings(Metadata.PEFile module,
+		public List<(LongSet, EventRegistration[])> DecompileEventMappings(Metadata.PEFile module, IAssemblyResolver assemblyResolver,
 			string fullTypeName, CancellationToken cancellationToken)
 		{
 			var result = new List<(LongSet, EventRegistration[])>();
-			var typeSystem = new DecompilerTypeSystem(module);
+			var typeSystem = new DecompilerTypeSystem(module, assemblyResolver);
 
 			var typeDefinition = typeSystem.Compilation.FindType(new FullTypeName(fullTypeName)).GetDefinition();
 			if (typeDefinition == null)
@@ -58,7 +60,7 @@ namespace ILSpy.BamlDecompiler
 			var function = ilReader.ReadIL(module, (MethodDefinitionHandle)method.MetadataToken,
 				module.Reader.GetMethodBody(metadataEntry.RelativeVirtualAddress), cancellationToken);
 
-			var context = new ILTransformContext(function, typeSystem) {
+			var context = new ILTransformContext(function, typeSystem, null) {
 				CancellationToken = cancellationToken
 			};
 			function.RunTransforms(CSharpDecompiler.GetILTransforms(), context);

ILSpy/DebugInfo/DiaSymNativeDebugInfoProvider.cs

@@ -25,6 +25,7 @@ using System.Reflection.Metadata;
 using System.Reflection.Metadata.Ecma335;
 using System.Text;
 using System.Threading.Tasks;
+using ICSharpCode.Decompiler.DebugInfo;
 using ICSharpCode.Decompiler.Metadata;
 using ICSharpCode.Decompiler.Util;
 using Microsoft.DiaSymReader;
@@ -48,12 +49,12 @@ namespace ICSharpCode.ILSpy.DebugInfo
 			this.reader = SymUnmanagedReaderFactory.CreateReader<ISymUnmanagedReader5>(stream, this);
 		}
 
-		public IList<Decompiler.Metadata.SequencePoint> GetSequencePoints(MethodDefinitionHandle handle)
+		public IList<Decompiler.DebugInfo.SequencePoint> GetSequencePoints(MethodDefinitionHandle handle)
 		{
 			var method = reader.GetMethod(MetadataTokens.GetToken(handle));
 			if (method == null || method.GetSequencePointCount(out int count) != 0)
-				return Empty<Decompiler.Metadata.SequencePoint>.Array;
+				return Empty<Decompiler.DebugInfo.SequencePoint>.Array;
-			var sequencePoints = new Decompiler.Metadata.SequencePoint[count];
+			var sequencePoints = new Decompiler.DebugInfo.SequencePoint[count];
 			var points = method.GetSequencePoints();
 			int i = 0;
 			var buffer = new char[1024];
@@ -64,7 +65,7 @@ namespace ICSharpCode.ILSpy.DebugInfo
 				} else {
 					url = "";
 				}
-				sequencePoints[i] = new Decompiler.Metadata.SequencePoint() {
+				sequencePoints[i] = new Decompiler.DebugInfo.SequencePoint() {
 					Offset = point.Offset,
 					StartLine = point.StartLine,
 					StartColumn = point.StartColumn,

ILSpy/DebugInfo/PortableDebugInfoProvider.cs

@@ -19,6 +19,7 @@
 using System;
 using System.Collections.Generic;
 using System.Reflection.Metadata;
+using ICSharpCode.Decompiler.DebugInfo;
 using ICSharpCode.Decompiler.Metadata;
 
 namespace ICSharpCode.ILSpy.DebugInfo
@@ -34,11 +35,11 @@ namespace ICSharpCode.ILSpy.DebugInfo
 			this.provider = provider;
 		}
 
-		public IList<Decompiler.Metadata.SequencePoint> GetSequencePoints(MethodDefinitionHandle method)
+		public IList<Decompiler.DebugInfo.SequencePoint> GetSequencePoints(MethodDefinitionHandle method)
 		{
 			var metadata = provider.GetMetadataReader();
 			var debugInfo = metadata.GetMethodDebugInformation(method);
-			var sequencePoints = new List<Decompiler.Metadata.SequencePoint>();
+			var sequencePoints = new List<Decompiler.DebugInfo.SequencePoint>();
 
 			foreach (var point in debugInfo.GetSequencePoints()) {
 				string documentFileName;
@@ -50,7 +51,7 @@ namespace ICSharpCode.ILSpy.DebugInfo
 					documentFileName = "";
 				}
 
-				sequencePoints.Add(new Decompiler.Metadata.SequencePoint() {
+				sequencePoints.Add(new Decompiler.DebugInfo.SequencePoint() {
 					Offset = point.Offset,
 					StartLine = point.StartLine,
 					StartColumn = point.StartColumn,

ILSpy/ILSpy.csproj

@@ -120,6 +120,7 @@
     <Compile Include="GacInterop.cs" />
     <Compile Include="GuessFileType.cs" />
     <Compile Include="ContextMenuEntry.cs" />
+    <Compile Include="Languages\CSharpLanguage.cs" />
     <Compile Include="Languages\CSharpLexer.cs" />
     <Compile Include="Languages\CSharpHighlightingTokenWriter.cs" />
     <Compile Include="ILSpySettings.cs" />
@@ -135,6 +136,7 @@
     <Compile Include="Languages\Language.cs" />
     <Compile Include="Languages\Languages.cs" />
     <Compile Include="LoadedAssembly.cs" />
+    <Compile Include="LoadedAssemblyExtensions.cs" />
     <Compile Include="LoadedNugetPackage.cs" />
     <Compile Include="NativeMethods.cs" />
     <Compile Include="NavigationHistory.cs" />

ILSpy/Languages/CSharpLanguage.cs

@@ -110,9 +110,9 @@ namespace ICSharpCode.ILSpy
 			}
 		}
 
-		CSharpDecompiler CreateDecompiler(Decompiler.Metadata.PEFile module, DecompilationOptions options)
+		CSharpDecompiler CreateDecompiler(PEFile module, DecompilationOptions options)
 		{
-			CSharpDecompiler decompiler = new CSharpDecompiler(module, options.DecompilerSettings);
+			CSharpDecompiler decompiler = new CSharpDecompiler(module, module.GetAssemblyResolver(), options.DecompilerSettings);
 			decompiler.CancellationToken = options.CancellationToken;
 			while (decompiler.AstTransforms.Count > transformCount)
 				decompiler.AstTransforms.RemoveAt(decompiler.AstTransforms.Count - 1);
@@ -129,19 +129,19 @@ namespace ICSharpCode.ILSpy
 			syntaxTree.AcceptVisitor(new CSharpOutputVisitor(tokenWriter, settings.CSharpFormattingOptions));
 		}
 
-		public override void DecompileMethod(Decompiler.Metadata.MethodDefinition method, ITextOutput output, DecompilationOptions options)
+		public override void DecompileMethod(IMethod method, ITextOutput output, DecompilationOptions options)
 		{
-			AddReferenceWarningMessage(method.Module, output);
+			PEFile assembly = method.ParentAssembly.PEFile;
-			var md = method.Module.Metadata.GetMethodDefinition(method.Handle);
+			AddReferenceWarningMessage(assembly, output);
-			WriteCommentLine(output, TypeToString(new Entity(method.Module, md.GetDeclaringType()), includeNamespace: true));
+			WriteCommentLine(output, TypeToString(method.DeclaringType, includeNamespace: true));
-			CSharpDecompiler decompiler = CreateDecompiler(method.Module, options);
+			CSharpDecompiler decompiler = CreateDecompiler(assembly, options);
-			var methodDefinition = decompiler.TypeSystem.ResolveAsMethod(method.Handle);
+			var methodDefinition = decompiler.TypeSystem.ResolveAsMethod(method.MetadataToken);
 			if (methodDefinition.IsConstructor && methodDefinition.DeclaringType.IsReferenceType != false) {
 				var members = CollectFieldsAndCtors(methodDefinition.DeclaringTypeDefinition, methodDefinition.IsStatic);
 				decompiler.AstTransforms.Add(new SelectCtorTransform(methodDefinition));
 				WriteCode(output, options.DecompilerSettings, decompiler.Decompile(members), decompiler.TypeSystem);
 			} else {
-				WriteCode(output, options.DecompilerSettings, decompiler.Decompile(method.Handle), decompiler.TypeSystem);
+				WriteCode(output, options.DecompilerSettings, decompiler.Decompile(method.MetadataToken), decompiler.TypeSystem);
 			}
 		}
 
@@ -196,28 +196,26 @@ namespace ICSharpCode.ILSpy
 			}
 		}
 
-		public override void DecompileProperty(Decompiler.Metadata.PropertyDefinition property, ITextOutput output, DecompilationOptions options)
+		public override void DecompileProperty(IProperty property, ITextOutput output, DecompilationOptions options)
 		{
-			AddReferenceWarningMessage(property.Module, output);
+			PEFile assembly = property.ParentAssembly.PEFile;
-			CSharpDecompiler decompiler = CreateDecompiler(property.Module, options);
+			AddReferenceWarningMessage(assembly, output);
-			var metadata = property.Module.Metadata;
+			CSharpDecompiler decompiler = CreateDecompiler(assembly, options);
-			var accessorHandle = metadata.GetPropertyDefinition(property.Handle).GetAccessors().GetAny();
+			WriteCommentLine(output, TypeToString(property.DeclaringType, includeNamespace: true));
-			WriteCommentLine(output, TypeToString(new Decompiler.Metadata.TypeDefinition(property.Module, metadata.GetMethodDefinition(accessorHandle).GetDeclaringType()), includeNamespace: true));
+			WriteCode(output, options.DecompilerSettings, decompiler.Decompile(property.MetadataToken), decompiler.TypeSystem);
-			WriteCode(output, options.DecompilerSettings, decompiler.Decompile(property.Handle), decompiler.TypeSystem);
 		}
 
-		public override void DecompileField(Decompiler.Metadata.FieldDefinition field, ITextOutput output, DecompilationOptions options)
+		public override void DecompileField(IField field, ITextOutput output, DecompilationOptions options)
 		{
-			AddReferenceWarningMessage(field.Module, output);
+			PEFile assembly = field.ParentAssembly.PEFile;
-			var fd = field.Module.Metadata.GetFieldDefinition(field.Handle);
+			AddReferenceWarningMessage(assembly, output);
-			WriteCommentLine(output, TypeToString(new Decompiler.Metadata.TypeDefinition(field.Module, fd.GetDeclaringType()), includeNamespace: true));
+			WriteCommentLine(output, TypeToString(field.DeclaringType, includeNamespace: true));
-			CSharpDecompiler decompiler = CreateDecompiler(field.Module, options);
+			CSharpDecompiler decompiler = CreateDecompiler(assembly, options);
-			var fieldDefinition = decompiler.TypeSystem.ResolveAsField(field.Handle);
+			if (field.IsConst) {
-			if (fd.HasFlag(FieldAttributes.Literal)) {
+				WriteCode(output, options.DecompilerSettings, decompiler.Decompile(field.MetadataToken), decompiler.TypeSystem);
-				WriteCode(output, options.DecompilerSettings, decompiler.Decompile(field.Handle), decompiler.TypeSystem);
 			} else {
-				var members = CollectFieldsAndCtors(fieldDefinition.DeclaringTypeDefinition, fieldDefinition.IsStatic);
+				var members = CollectFieldsAndCtors(field.DeclaringTypeDefinition, field.IsStatic);
-				decompiler.AstTransforms.Add(new SelectFieldTransform(fieldDefinition));
+				decompiler.AstTransforms.Add(new SelectFieldTransform(field));
 				WriteCode(output, options.DecompilerSettings, decompiler.Decompile(members), decompiler.TypeSystem);
 			}
 		}
@@ -266,25 +264,25 @@ namespace ICSharpCode.ILSpy
 			}
 		}
 
-		public override void DecompileEvent(Decompiler.Metadata.EventDefinition ev, ITextOutput output, DecompilationOptions options)
+		public override void DecompileEvent(IEvent @event, ITextOutput output, DecompilationOptions options)
 		{
-			AddReferenceWarningMessage(ev.Module, output);
+			PEFile assembly = @event.ParentAssembly.PEFile;
-			var metadata = ev.Module.Metadata;
+			AddReferenceWarningMessage(assembly, output);
-			var accessorHandle = metadata.GetEventDefinition(ev.Handle).GetAccessors().GetAny();
+			base.WriteCommentLine(output, TypeToString(@event.DeclaringType, includeNamespace: true));
-			base.WriteCommentLine(output, TypeToString(new Decompiler.Metadata.TypeDefinition(ev.Module, metadata.GetMethodDefinition(accessorHandle).GetDeclaringType()), includeNamespace: true));
+			CSharpDecompiler decompiler = CreateDecompiler(assembly, options);
-			CSharpDecompiler decompiler = CreateDecompiler(ev.Module, options);
+			WriteCode(output, options.DecompilerSettings, decompiler.Decompile(@event.MetadataToken), decompiler.TypeSystem);
-			WriteCode(output, options.DecompilerSettings, decompiler.Decompile(ev.Handle), decompiler.TypeSystem);
 		}
 
-		public override void DecompileType(Decompiler.Metadata.TypeDefinition type, ITextOutput output, DecompilationOptions options)
+		public override void DecompileType(ITypeDefinition type, ITextOutput output, DecompilationOptions options)
 		{
-			AddReferenceWarningMessage(type.Module, output);
+			PEFile assembly = type.ParentAssembly.PEFile;
+			AddReferenceWarningMessage(assembly, output);
 			WriteCommentLine(output, TypeToString(type, includeNamespace: true));
-			CSharpDecompiler decompiler = CreateDecompiler(type.Module, options);
+			CSharpDecompiler decompiler = CreateDecompiler(assembly, options);
-			WriteCode(output, options.DecompilerSettings, decompiler.Decompile(type.Handle), decompiler.TypeSystem);
+			WriteCode(output, options.DecompilerSettings, decompiler.Decompile(type.MetadataToken), decompiler.TypeSystem);
 		}
 
-		void AddReferenceWarningMessage(Decompiler.Metadata.PEFile assembly, ITextOutput output)
+		void AddReferenceWarningMessage(PEFile assembly, ITextOutput output)
 		{
 			var loadedAssembly = MainWindow.Instance.CurrentAssemblyList.GetAssemblies().FirstOrDefault(la => la.GetPEFileOrNull() == assembly);
 			if (loadedAssembly == null || !loadedAssembly.LoadedAssemblyReferencesInfo.HasErrors)
@@ -320,7 +318,7 @@ namespace ICSharpCode.ILSpy
 
 		public override void DecompileAssembly(LoadedAssembly assembly, ITextOutput output, DecompilationOptions options)
 		{
-			var module = assembly.GetPEFileAsync().Result;
+			var module = assembly.GetPEFileOrNull();
 			if (options.FullDecompilation && options.SaveAsProjectDirectory != null) {
 				var decompiler = new ILSpyWholeProjectDecompiler(assembly, options);
 				decompiler.DecompileProject(module, options.SaveAsProjectDirectory, new TextOutputWriter(output), options.CancellationToken);
@@ -328,23 +326,24 @@ namespace ICSharpCode.ILSpy
 				AddReferenceWarningMessage(module, output);
 				output.WriteLine();
 				base.DecompileAssembly(assembly, output, options);
-				var metadata = module.Metadata;
+				IAssemblyResolver assemblyResolver = assembly.GetAssemblyResolver();
-				
+				var typeSystem = new DecompilerTypeSystem(module, assemblyResolver, options.DecompilerSettings);
-				if (metadata.TypeDefinitions.Count > 0) {
+				var globalType = typeSystem.MainAssembly.TypeDefinitions.FirstOrDefault();
+				if (globalType != null) {
 					output.Write("// Global type: ");
-					var globalType = metadata.TypeDefinitions.First();
+					output.WriteReference(globalType.FullName, globalType);
-					output.WriteReference(globalType.GetFullTypeName(metadata).ToString(), new Decompiler.Metadata.TypeDefinition(module, globalType));
 					output.WriteLine();
 				}
+				var metadata = module.Metadata;
 				var corHeader = module.Reader.PEHeaders.CorHeader;
 				var entrypointHandle = MetadataTokenHelpers.EntityHandleOrNil(corHeader.EntryPointTokenOrRelativeVirtualAddress);
 				if (!entrypointHandle.IsNil && entrypointHandle.Kind == HandleKind.MethodDefinition) {
-					var entrypoint = metadata.GetMethodDefinition((MethodDefinitionHandle)entrypointHandle);
+					var entrypoint = typeSystem.ResolveAsMethod(entrypointHandle);
-					output.Write("// Entry point: ");
+					if (entrypoint != null) {
-					string name = entrypoint.GetDeclaringType().GetFullTypeName(metadata) + "." + metadata.GetString(entrypoint.Name);
+						output.Write("// Entry point: ");
-					var entrypointEntity = new Decompiler.Metadata.MethodDefinition(module, (MethodDefinitionHandle)entrypointHandle);
+						output.WriteReference(entrypoint.DeclaringType.FullName + "." + entrypoint.Name, entrypoint);
-					output.WriteReference(name, entrypointEntity);
+						output.WriteLine();
-					output.WriteLine();
+					}
 				}
 				output.WriteLine("// Architecture: " + GetPlatformDisplayName(module));
 				if ((corHeader.Flags & System.Reflection.PortableExecutable.CorFlags.ILOnly) == 0) {
@@ -358,7 +357,7 @@ namespace ICSharpCode.ILSpy
 
 				// don't automatically load additional assemblies when an assembly node is selected in the tree view
 				using (options.FullDecompilation ? null : LoadedAssembly.DisableAssemblyLoad()) {
-					CSharpDecompiler decompiler = new CSharpDecompiler(module, options.DecompilerSettings);
+					CSharpDecompiler decompiler = new CSharpDecompiler(typeSystem, assemblyResolver, options.DecompilerSettings);
 					decompiler.CancellationToken = options.CancellationToken;
 					SyntaxTree st;
 					if (options.FullDecompilation) {
@@ -405,82 +404,35 @@ namespace ICSharpCode.ILSpy
 			}
 		}
 
-		public override string TypeToString(Entity type, Decompiler.Metadata.GenericContext genericContext = null, bool includeNamespace = true)
+		public override string TypeToString(IType type, bool includeNamespace)
 		{
-			if (type.Handle.IsNil)
+			if (type == null)
 				throw new ArgumentNullException(nameof(type));
-			var metadata = type.Module.Metadata;
+			TypeSystemAstBuilder builder = new TypeSystemAstBuilder();
-			ConvertTypeOptions convertTypeOptions = ConvertTypeOptions.IncludeTypeParameterDefinitions;
+			AstType astType = builder.ConvertType(type);
-			if (includeNamespace)
+			StringWriter w = new StringWriter();
-				convertTypeOptions |= ConvertTypeOptions.IncludeNamespace;
-			//if (includeTypeName)
-			//	convertTypeOptions |= ConvertTypeOptions.IncludeOuterTypeName;
-			var builder = new AstTypeBuilder(convertTypeOptions);
-			AstType astType;
-			switch (type.Handle.Kind) {
-				case HandleKind.TypeReference:
-					astType = builder.GetTypeFromReference(metadata, (TypeReferenceHandle)type.Handle, 0);
-					return TypeToString(astType, metadata, null);
-				case HandleKind.TypeDefinition:
-					var td = metadata.GetTypeDefinition((TypeDefinitionHandle)type.Handle);
-					var genericParams = td.GetGenericParameters();
-
-					var buffer = new System.Text.StringBuilder();
-
-					var name = td.GetFullTypeName(metadata);
-
-					if (includeNamespace)
-						buffer.Append(name.ToString());
-					else
-						buffer.Append(name.Name);
-
-					if (genericParams.Count > 0) {
-						buffer.Append('<');
-						int i = 0;
-						foreach (var h in genericParams) {
-							var gp = metadata.GetGenericParameter(h);
-							if (i > 0)
-								buffer.Append(", ");
-							buffer.Append(metadata.GetString(gp.Name));
-							i++;
-						}
-						buffer.Append('>');
-					}
 
-					return buffer.ToString();
+			astType.AcceptVisitor(new CSharpOutputVisitor(w, FormattingOptionsFactory.CreateAllman()));
-				case HandleKind.TypeSpecification:
+			return w.ToString();
-					var ts = metadata.GetTypeSpecification((TypeSpecificationHandle)type.Handle);
-					astType = builder.GetTypeFromSpecification(metadata, genericContext ?? GenericContext.Empty, (TypeSpecificationHandle)type.Handle, 0);
-					return TypeToString(astType, metadata, ts.GetCustomAttributes());
-				default:
-					throw new NotSupportedException();
-			}
 		}
 
-		public override string FieldToString(Decompiler.Metadata.FieldDefinition field, bool includeTypeName, bool includeNamespace)
+		public override string FieldToString(IField field, bool includeTypeName, bool includeNamespace)
 		{
-			if (field.Handle.IsNil)
+			if (field == null)
 				throw new ArgumentNullException(nameof(field));
-			ConvertTypeOptions convertTypeOptions = ConvertTypeOptions.IncludeTypeParameterDefinitions;
+
-			if (includeNamespace)
+			string simple = field.Name + " : " + TypeToString(field.Type, includeNamespace);
-				convertTypeOptions |= ConvertTypeOptions.IncludeNamespace;
-			if (includeTypeName)
-				convertTypeOptions |= ConvertTypeOptions.IncludeOuterTypeName;
-			var metadata = field.Module.Metadata;
-			var fd = metadata.GetFieldDefinition(field.Handle);
-			AstType fieldType = fd.DecodeSignature(new AstTypeBuilder(convertTypeOptions), new GenericContext(fd.GetDeclaringType(), field.Module));
-			string simple = metadata.GetString(fd.Name) + " : " + TypeToString(fieldType, metadata, fd.GetCustomAttributes());
 			if (!includeTypeName)
 				return simple;
-			var typeName = fd.GetDeclaringType().GetFullTypeName(metadata);
+			var typeName = field.DeclaringTypeDefinition.FullTypeName;
 			if (!includeNamespace)
 				return typeName.Name + "." + simple;
 			return typeName + "." + simple;
 		}
-
+		/*
-		public override string PropertyToString(Decompiler.Metadata.PropertyDefinition property, bool includeTypeName, bool includeNamespace, bool? isIndexer = null)
+		public override string PropertyToString(IProperty property, bool includeTypeName, bool includeNamespace, bool? isIndexer = null)
 		{
-			if (property.IsNil)
+			if (property == null)
 				throw new ArgumentNullException(nameof(property));
 			ConvertTypeOptions convertTypeOptions = ConvertTypeOptions.IncludeTypeParameterDefinitions;
 			if (includeNamespace)
@@ -699,43 +651,18 @@ namespace ICSharpCode.ILSpy
 			buffer.Append(" : ");
 			buffer.Append(TypeToString(signature, metadata, returnTypeAttributes));
 			return buffer.ToString();
-		}
+		}*/
 
-		public override bool ShowMember(IMetadataEntity member)
+		public override bool ShowMember(IEntity member)
 		{
-			return showAllMembers || !CSharpDecompiler.MemberIsHidden(member.Module, member.Handle, new DecompilationOptions().DecompilerSettings);
+			PEFile assembly = member.ParentAssembly.PEFile;
+			return showAllMembers || !CSharpDecompiler.MemberIsHidden(assembly, member.MetadataToken, new DecompilationOptions().DecompilerSettings);
 		}
 
-		public override string GetTooltip(Entity entity)
+		public override string GetTooltip(IEntity entity)
 		{
-			var decompilerTypeSystem = new DecompilerTypeSystem(entity.Module);
-			ISymbol symbol;
-			switch (entity.Handle.Kind) {
-				case HandleKind.MethodDefinition:
-					symbol = decompilerTypeSystem.ResolveAsMethod(entity.Handle);
-					if (symbol == null) return base.GetTooltip(entity);
-					break;
-				case HandleKind.PropertyDefinition:
-					symbol = decompilerTypeSystem.ResolveAsProperty(entity.Handle);
-					if (symbol == null) return base.GetTooltip(entity);
-					break;
-				case HandleKind.EventDefinition:
-					symbol = decompilerTypeSystem.ResolveAsEvent(entity.Handle);
-					if (symbol == null) return base.GetTooltip(entity);
-					break;
-				case HandleKind.FieldDefinition:
-					symbol = decompilerTypeSystem.ResolveAsField(entity.Handle);
-					if (symbol == null) return base.GetTooltip(entity);
-					break;
-				case HandleKind.TypeDefinition:
-					symbol = decompilerTypeSystem.ResolveAsType(entity.Handle).GetDefinition();
-					if (symbol == null) return base.GetTooltip(entity);
-					break;
-				default:
-					return base.GetTooltip(entity);
-			}
 			var flags = ConversionFlags.All & ~ConversionFlags.ShowBody;
-			return new CSharpAmbience() { ConversionFlags = flags }.ConvertSymbol(symbol);
+			return new CSharpAmbience() { ConversionFlags = flags }.ConvertSymbol(entity);
 		}
 
 		public override CodeMappingInfo GetCodeMappingInfo(PEFile module, EntityHandle member)

ILSpy/LoadedAssembly.cs

@@ -21,9 +21,11 @@ using System.Collections.Generic;
 using System.IO;
 using System.Reflection.Metadata;
 using System.Reflection.PortableExecutable;
+using System.Runtime.CompilerServices;
 using System.Threading;
 using System.Threading.Tasks;
 using ICSharpCode.Decompiler;
+using ICSharpCode.Decompiler.DebugInfo;
 using ICSharpCode.Decompiler.Metadata;
 using ICSharpCode.Decompiler.TypeSystem;
 using ICSharpCode.Decompiler.TypeSystem.Implementation;
@@ -39,6 +41,8 @@ namespace ICSharpCode.ILSpy
 	/// </summary>
 	public sealed class LoadedAssembly
 	{
+		internal static readonly ConditionalWeakTable<PEFile, LoadedAssembly> loadedAssemblies = new ConditionalWeakTable<PEFile, LoadedAssembly>();
+
 		readonly Task<PEFile> assemblyTask;
 		readonly AssemblyList assemblyList;
 		readonly string fileName;
@@ -65,6 +69,8 @@ namespace ICSharpCode.ILSpy
 
 		public ReferenceLoadInfo LoadedAssemblyReferencesInfo { get; } = new ReferenceLoadInfo();
 
+		IDebugInfoProvider debugInfoProvider;
+
 		/// <summary>
 		/// Gets the Cecil ModuleDefinition.
 		/// </summary>
@@ -87,12 +93,20 @@ namespace ICSharpCode.ILSpy
 			}
 		}
 
-		public ICompilation GetTypeSystem()
+		ICompilation typeSystem;
+
+		/// <summary>
+		/// Gets a type system containing all types from this assembly + primitve types from mscorlib.
+		/// Returns null in case of load errors.
+		/// </summary>
+		public ICompilation GetTypeSystemOrNull()
 		{
+			if (typeSystem != null)
+				return typeSystem;
 			var module = GetPEFileOrNull();
 			if (module == null)
 				return null;
-			return new SimpleCompilation(module, MinimalCorlib.Instance);
+			return typeSystem = new SimpleCompilation(module, MinimalCorlib.Instance);
 		}
 
 		public AssemblyList AssemblyList => assemblyList;
@@ -129,12 +143,12 @@ namespace ICSharpCode.ILSpy
 			if (stream != null)
 			{
 				// Read the module from a precrafted stream
-				module = new PEFile(fileName, stream, new MyAssemblyResolver(this), PEStreamOptions.Default);
+				module = new PEFile(fileName, stream);
 			}
 			else
 			{
 				// Read the module from disk (by default)
-				module = new PEFile(fileName, new FileStream(fileName, FileMode.Open, FileAccess.Read), new MyAssemblyResolver(this), PEStreamOptions.PrefetchEntireImage);
+				module = new PEFile(fileName, new FileStream(fileName, FileMode.Open, FileAccess.Read), PEStreamOptions.PrefetchEntireImage);
 			}
 
 			if (DecompilerSettingsPanel.CurrentDecompilerSettings.UseDebugSymbols) {
@@ -146,6 +160,9 @@ namespace ICSharpCode.ILSpy
 					// ignore any errors during symbol loading
 				}
 			}
+			lock (loadedAssemblies) {
+				loadedAssemblies.Add(module, this);
+			}
 			return module;
 		}
 		
@@ -154,13 +171,13 @@ namespace ICSharpCode.ILSpy
 			var reader = module.Reader;
 			// try to open portable pdb file/embedded pdb info:
 			if (reader.TryOpenAssociatedPortablePdb(fileName, OpenStream, out var provider, out var pdbFileName)) {
-				module.DebugInfo = new PortableDebugInfoProvider(pdbFileName, provider);
+				debugInfoProvider = new PortableDebugInfoProvider(pdbFileName, provider);
 			} else {
 				// search for pdb in same directory as dll
 				string pdbDirectory = Path.GetDirectoryName(fileName);
 				pdbFileName = Path.Combine(pdbDirectory, Path.GetFileNameWithoutExtension(fileName) + ".pdb");
 				if (File.Exists(pdbFileName)) {
-					module.DebugInfo = new DiaSymNativeDebugInfoProvider(module, pdbFileName, OpenStream(pdbFileName));
+					debugInfoProvider = new DiaSymNativeDebugInfoProvider(module, pdbFileName, OpenStream(pdbFileName));
 					return;
 				}
 
@@ -222,6 +239,16 @@ namespace ICSharpCode.ILSpy
 		{
 			return new MyAssemblyResolver(this);
 		}
+
+		/// <summary>
+		/// Returns the debug info for this assembly. Returns null in case of load errors or no debug info is available.
+		/// </summary>
+		public IDebugInfoProvider GetDebugInfoOrNull()
+		{
+			if (GetPEFileOrNull() == null)
+				return null;
+			return debugInfoProvider;
+		}
 		
 		public LoadedAssembly LookupReferencedAssembly(Decompiler.Metadata.IAssemblyReference reference)
 		{

ILSpy/LoadedAssemblyExtensions.cs

@@ -0,0 +1,25 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Runtime.CompilerServices;
+using System.Text;
+using System.Threading.Tasks;
+using ICSharpCode.Decompiler.Metadata;
+
+namespace ICSharpCode.ILSpy
+{
+	public static class LoadedAssemblyExtensions
+	{
+		public static IAssemblyResolver GetAssemblyResolver(this PEFile file)
+		{
+			if (file == null)
+				throw new ArgumentNullException(nameof(file));
+			LoadedAssembly loadedAssembly;
+			lock (LoadedAssembly.loadedAssemblies) {
+				if (!LoadedAssembly.loadedAssemblies.TryGetValue(file, out loadedAssembly))
+					throw new ArgumentException("The specified file is not associated with a LoadedAssembly!");
+			}
+			return loadedAssembly.GetAssemblyResolver();
+		}
+	}
+}

ILSpy/SearchPane.cs

@@ -217,7 +217,7 @@ namespace ICSharpCode.ILSpy
 				try {
 					var searcher = GetSearchStrategy(searchMode, searchTerm);
 					foreach (var loadedAssembly in assemblies) {
-						var typeSystem = loadedAssembly.GetTypeSystem();
+						var typeSystem = loadedAssembly.GetTypeSystemOrNull();
 						if (typeSystem == null)
 							continue;
 						CancellationToken cancellationToken = cts.Token;

ILSpy/TreeNodes/Analyzer/ScopedWhereUsedAnalyzer.cs

@@ -233,7 +233,7 @@ namespace ICSharpCode.ILSpy.TreeNodes.Analyzer
 
 		IEnumerable<T> FindReferencesInAssembly(Decompiler.Metadata.PEFile module, CancellationToken ct)
 		{
-			IDecompilerTypeSystem ts = provideTypeSystem ? new DecompilerTypeSystem(module) : null;
+			IDecompilerTypeSystem ts = provideTypeSystem ? new DecompilerTypeSystem(module, module.GetAssemblyResolver()) : null;
 			var metadata = module.Metadata;
 			foreach (var type in TreeTraversal.PreOrder(metadata.TypeDefinitions, t => metadata.GetTypeDefinition(t).GetNestedTypes())) {
 				ct.ThrowIfCancellationRequested();
@@ -247,7 +247,7 @@ namespace ICSharpCode.ILSpy.TreeNodes.Analyzer
 
 		IEnumerable<T> FindReferencesInTypeScope(CancellationToken ct)
 		{
-			IDecompilerTypeSystem ts = provideTypeSystem ? new DecompilerTypeSystem(assemblyScope) : null;
+			IDecompilerTypeSystem ts = provideTypeSystem ? new DecompilerTypeSystem(assemblyScope, assemblyScope.GetAssemblyResolver()) : null;
 			foreach (var type in TreeTraversal.PreOrder(typeScopeHandle, t => assemblyScope.Metadata.GetTypeDefinition(t).GetNestedTypes())) {
 				ct.ThrowIfCancellationRequested();
 				var codeMappingInfo = language.GetCodeMappingInfo(assemblyScope, type);
@@ -260,7 +260,7 @@ namespace ICSharpCode.ILSpy.TreeNodes.Analyzer
 
 		IEnumerable<T> FindReferencesInEnclosingTypeScope(CancellationToken ct)
 		{
-			IDecompilerTypeSystem ts = provideTypeSystem ? new DecompilerTypeSystem(assemblyScope) : null;
+			IDecompilerTypeSystem ts = provideTypeSystem ? new DecompilerTypeSystem(assemblyScope, assemblyScope.GetAssemblyResolver()) : null;
 			var codeMappingInfo = language.GetCodeMappingInfo(assemblyScope, typeScope.GetDeclaringType());
 			foreach (var type in TreeTraversal.PreOrder(typeScope.GetDeclaringType(), t => assemblyScope.Metadata.GetTypeDefinition(t).GetNestedTypes())) {
 				ct.ThrowIfCancellationRequested();

ILSpy/TreeNodes/AssemblyTreeNode.cs

@@ -135,7 +135,7 @@ namespace ICSharpCode.ILSpy.TreeNodes
 				// if we crashed on loading, then we don't have any children
 				return;
 			}
-			typeSystem = new SimpleCompilation(module, MinimalCorlib.Instance);
+			typeSystem = LoadedAssembly.GetTypeSystemOrNull();
 			var assembly = (MetadataAssembly)typeSystem.MainAssembly;
 			var metadata = module.Metadata;
 

ILSpy/TreeNodes/BaseTypesEntryNode.cs

@@ -65,16 +65,16 @@ namespace ICSharpCode.ILSpy.TreeNodes
 
 		protected override void LoadChildren()
 		{
-			DecompilerTypeSystem typeSystem = new DecompilerTypeSystem(module);
+			DecompilerTypeSystem typeSystem = new DecompilerTypeSystem(module, module.GetAssemblyResolver());
 			var t = typeSystem.ResolveAsType(handle).GetDefinition();
 			if (t != null) {
-				BaseTypesTreeNode.AddBaseTypes(this.Children, ((MetadataAssembly)t.ParentAssembly).PEFile, t);
+				BaseTypesTreeNode.AddBaseTypes(this.Children, t.ParentAssembly.PEFile, t);
 			}
 		}
 
 		public override void ActivateItem(System.Windows.RoutedEventArgs e)
 		{
-			DecompilerTypeSystem typeSystem = new DecompilerTypeSystem(module);
+			DecompilerTypeSystem typeSystem = new DecompilerTypeSystem(module, module.GetAssemblyResolver());
 			var t = typeSystem.ResolveAsType(handle).GetDefinition();
 			e.Handled = ActivateItem(this, t);
 		}
@@ -98,7 +98,7 @@ namespace ICSharpCode.ILSpy.TreeNodes
 
 		IEntity IMemberTreeNode.Member {
 			get {
-				DecompilerTypeSystem typeSystem = new DecompilerTypeSystem(module);
+				DecompilerTypeSystem typeSystem = new DecompilerTypeSystem(module, module.GetAssemblyResolver());
 				var t = typeSystem.ResolveAsType(handle).GetDefinition();
 				return t;
 			}

ILSpy/TreeNodes/GeneratePdbContextMenuEntry.cs

@@ -7,7 +7,7 @@ using System.Text;
 using System.Threading.Tasks;
 using ICSharpCode.Decompiler;
 using ICSharpCode.Decompiler.CSharp;
-using ICSharpCode.Decompiler.Pdb;
+using ICSharpCode.Decompiler.DebugInfo;
 using ICSharpCode.ILSpy.TextView;
 using Microsoft.Win32;
 
@@ -33,7 +33,7 @@ namespace ICSharpCode.ILSpy.TreeNodes
 				using (FileStream stream = new FileStream(fileName, FileMode.OpenOrCreate, FileAccess.Write)) {
 					try {
 						var file = assembly.GetPEFileOrNull();
-						var decompiler = new CSharpDecompiler(file, options.DecompilerSettings);
+						var decompiler = new CSharpDecompiler(file, assembly.GetAssemblyResolver(), options.DecompilerSettings);
 						PortablePdbWriter.WritePdb(file, decompiler, options.DecompilerSettings, stream);
 					} catch (OperationCanceledException) {
 						output.WriteLine();