Fix #661: Emit ".data" IL directives for fields with associated data

ICSharpCode.Decompiler/Disassembler/ReflectionDisassembler.cs

@@ -1112,7 +1112,7 @@ namespace ICSharpCode.Decompiler.Disassembler
 			var fieldName = metadata.GetString(fieldDefinition.Name);
 			output.Write(DisassemblerHelpers.Escape(fieldName));
 			if (fieldDefinition.HasFlag(FieldAttributes.HasFieldRVA)) {
-				output.Write(" at I_{0:x8}", fieldDefinition.GetRelativeVirtualAddress());
+				output.Write(" at D_{0:X8}", fieldDefinition.GetRelativeVirtualAddress());
 			}
 
 			var defaultValue = fieldDefinition.GetDefaultValue();
@@ -1127,6 +1127,20 @@ namespace ICSharpCode.Decompiler.Disassembler
 				WriteAttributes(module, fieldDefinition.GetCustomAttributes());
 				output.MarkFoldEnd();
 			}
+			if (fieldDefinition.HasFlag(FieldAttributes.HasFieldRVA)) {
+				BlobReader initVal;
+				try {
+					initVal = fieldDefinition.GetInitialValue(module.Reader, null);
+				} catch (BadImageFormatException ex) {
+					initVal = default;
+					output.WriteLine("// .data D_{0:X8} = {1}", fieldDefinition.GetRelativeVirtualAddress(), ex.Message);
+				}
+				if (initVal.Length > 0) {
+					output.Write(".data D_{0:X8} = bytearray ", fieldDefinition.GetRelativeVirtualAddress());
+					WriteBlob(initVal);
+					output.WriteLine();
+				}
+			}
 		}
 		#endregion
 

ICSharpCode.Decompiler/SRMExtensions.cs

@@ -386,23 +386,25 @@ namespace ICSharpCode.Decompiler
 
 		sealed class FieldValueSizeDecoder : ISignatureTypeProvider<int, GenericContext>
 		{
-			MetadataModule module;
+			readonly MetadataModule module;
+			// This is the same as Cecil does, but probably not a good idea.
+			static readonly int pointerSize = IntPtr.Size;
 
-			public FieldValueSizeDecoder(ICompilation typeSystem)
+			public FieldValueSizeDecoder(ICompilation typeSystem = null)
 			{
-				this.module = (MetadataModule)typeSystem.MainModule;
+				this.module = (MetadataModule)typeSystem?.MainModule;
 			}
 
 			public int GetArrayType(int elementType, ArrayShape shape) => GetPrimitiveType(PrimitiveTypeCode.Object);
 			public int GetSZArrayType(int elementType) => GetPrimitiveType(PrimitiveTypeCode.Object);
-			public int GetByReferenceType(int elementType) => GetPointerType(elementType);
-			public int GetFunctionPointerType(MethodSignature<int> signature) => GetPrimitiveType(PrimitiveTypeCode.IntPtr);
+			public int GetByReferenceType(int elementType) => pointerSize;
+			public int GetFunctionPointerType(MethodSignature<int> signature) => pointerSize;
 			public int GetGenericInstantiation(int genericType, ImmutableArray<int> typeArguments) => genericType;
 			public int GetGenericMethodParameter(GenericContext genericContext, int index) => 0;
 			public int GetGenericTypeParameter(GenericContext genericContext, int index) => 0;
 			public int GetModifiedType(int modifier, int unmodifiedType, bool isRequired) => unmodifiedType;
 			public int GetPinnedType(int elementType) => elementType;
-			public int GetPointerType(int elementType) => GetPrimitiveType(PrimitiveTypeCode.IntPtr);
+			public int GetPointerType(int elementType) => pointerSize;
 
 			public int GetPrimitiveType(PrimitiveTypeCode typeCode) 
 			{
@@ -425,8 +427,7 @@ namespace ICSharpCode.Decompiler
 						return 8;
 					case PrimitiveTypeCode.IntPtr:
 					case PrimitiveTypeCode.UIntPtr:
-						// This is the same as Cecil does, but probably not a good idea.
-						return IntPtr.Size;
+						return pointerSize;
 					default:
 						return 0;
 				}
@@ -440,7 +441,7 @@ namespace ICSharpCode.Decompiler
 
 			public int GetTypeFromReference(MetadataReader reader, TypeReferenceHandle handle, byte rawTypeKind)
 			{
-				var typeDef = module.ResolveType(handle, new GenericContext()).GetDefinition();
+				var typeDef = module?.ResolveType(handle, new GenericContext()).GetDefinition();
 				if (typeDef == null || typeDef.MetadataToken.IsNil)
 					return 0;
 				reader = typeDef.ParentModule.PEFile.Metadata;