Fix DecimalConstantTransform.

ICSharpCode.Decompiler/Ast/Transforms/DecimalConstantTransform.cs

@@ -17,145 +17,42 @@
 // DEALINGS IN THE SOFTWARE.
 
 using System;
-using System.Collections.Generic;
-using System.Linq;
 using ICSharpCode.NRefactory.CSharp;
 using ICSharpCode.NRefactory.PatternMatching;
+using Mono.Cecil;
 
 namespace ICSharpCode.Decompiler.Ast.Transforms
 {
 	/// <summary>
-	/// Description of DecimalConstantTransform.
+	/// Transforms decimal constant fields.
 	/// </summary>
 	public class DecimalConstantTransform : DepthFirstAstVisitor<object, object>, IAstTransform
 	{
-		static readonly ICSharpCode.NRefactory.CSharp.Attribute decimalConstantAttribute = new ICSharpCode.NRefactory.CSharp.Attribute {
-			Type = new SimpleType("DecimalConstant"),
-			Arguments = { new Repeat(new AnyNode()) }
-		};
-		
-		static readonly FieldDeclaration decimalConstantPattern = new FieldDeclaration {
-			Attributes = {
-				new AttributeSection {
-					Attributes = {
-						decimalConstantAttribute
-					}
-				}
-			},
-			Modifiers = Modifiers.Any,
-			Variables = { new Repeat(new AnyNode()) },
-			ReturnType = new PrimitiveType("decimal")
-		};
-		
-		Expression ConstructExpression(string typeName, string member)
-		{
-			return new AssignmentExpression(
-				new MemberReferenceExpression(
-					new TypeReferenceExpression(new SimpleType(typeName)),
-					member
-				),
-				AssignmentOperatorType.Assign,
-				new AnyNode()
-			);
-		}
-		
-		class ClassInfo
-		{
-			public ClassInfo()
-			{
-				Fields = new List<string>();
-			}
-			
-			public List<string> Fields { get; private set; }
-			public TypeDeclaration Declaration { get; set; }
-		}
-		
-		Stack<ClassInfo> replaceableFields;
-		
-		public DecimalConstantTransform()
-		{
-		}
-		
-		void IAstTransform.Run(AstNode compilationUnit)
-		{
-			this.replaceableFields = new Stack<ClassInfo>();
-			compilationUnit.AcceptVisitor(this, null);
-		}
+		static readonly PrimitiveType decimalType = new PrimitiveType("decimal");
 		
 		public override object VisitFieldDeclaration(FieldDeclaration fieldDeclaration, object data)
 		{
-			base.VisitFieldDeclaration(fieldDeclaration, data);
-			
-			var match = decimalConstantPattern.Match(fieldDeclaration);
-			
-			if (match.Success) {
-				Modifiers pattern = Modifiers.Static | Modifiers.Readonly;
-				if ((fieldDeclaration.Modifiers & pattern) == pattern) {
-					replaceableFields.Peek().Fields.AddRange(fieldDeclaration.Variables.Select(v => v.Name));
-					fieldDeclaration.ReplaceWith(ReplaceFieldWithConstant);
-				}
-			}
-			
-			return null;
-		}
-		
-		AstNode ReplaceFieldWithConstant(AstNode node)
-		{
-			var old = node as FieldDeclaration;
-			var fd = new FieldDeclaration {
-				Modifiers = old.Modifiers & ~(Modifiers.Readonly | Modifiers.Static) | Modifiers.Const,
-				ReturnType = new PrimitiveType("decimal")
-			};
-			
-			var foundAttr = old.Attributes.SelectMany(section => section.Attributes)
-				.First(a => decimalConstantAttribute.IsMatch(a));
-			foundAttr.Remove();
-			foreach (var attr in old.Attributes.Where(section => section.Attributes.Count == 0))
-				attr.Remove();
-			
-			old.Attributes.MoveTo(fd.Attributes);
-			old.Variables.MoveTo(fd.Variables);
-			
-			fd.Variables.Single().Initializer = new PrimitiveExpression(CreateDecimalValue(foundAttr));
-			
-			return fd;
-		}
-		
-		object CreateDecimalValue(ICSharpCode.NRefactory.CSharp.Attribute foundAttr)
-		{
-			byte scale = (byte)((PrimitiveExpression)foundAttr.Arguments.ElementAt(0)).Value;
-			byte sign = (byte)((PrimitiveExpression)foundAttr.Arguments.ElementAt(1)).Value;
-			int high = (int)(uint)((PrimitiveExpression)foundAttr.Arguments.ElementAt(2)).Value;
-			int mid = (int)(uint)((PrimitiveExpression)foundAttr.Arguments.ElementAt(3)).Value;
-			int low = (int)(uint)((PrimitiveExpression)foundAttr.Arguments.ElementAt(4)).Value;
-			
-			return new Decimal(low, mid, high, sign == 1, scale);
-		}
-		
-		public override object VisitConstructorDeclaration(ConstructorDeclaration constructorDeclaration, object data)
-		{
-			if ((constructorDeclaration.Modifiers & Modifiers.Static) == Modifiers.Static && replaceableFields.Count > 0) {
-				var current = replaceableFields.Peek();
-				
-				foreach (var fieldName in current.Fields) {
-					var pattern = ConstructExpression(current.Declaration.Name, fieldName);
-					foreach (var expr in constructorDeclaration.Body
-					         .OfType<ExpressionStatement>()) {
-						if (pattern.IsMatch(expr.Expression))
-							expr.Remove();
+			const Modifiers staticReadOnly = Modifiers.Static | Modifiers.Readonly;
+			if ((fieldDeclaration.Modifiers & staticReadOnly) == staticReadOnly && decimalType.IsMatch(fieldDeclaration.ReturnType)) {
+				foreach (var attributeSection in fieldDeclaration.Attributes) {
+					foreach (var attribute in attributeSection.Attributes) {
+						TypeReference tr = attribute.Type.Annotation<TypeReference>();
+						if (tr != null && tr.Name == "DecimalConstantAttribute" && tr.Namespace == "System.Runtime.CompilerServices") {
+							attribute.Remove();
+							if (attributeSection.Attributes.Count == 0)
+								attributeSection.Remove();
+							fieldDeclaration.Modifiers = (fieldDeclaration.Modifiers & ~staticReadOnly) | Modifiers.Const;
+							return null;
+						}
 					}
 				}
 			}
-			
 			return null;
 		}
 		
-		public override object VisitTypeDeclaration(TypeDeclaration typeDeclaration, object data)
+		public void Run(AstNode compilationUnit)
 		{
-			replaceableFields.Push(new ClassInfo() { Declaration = typeDeclaration });
-			base.VisitTypeDeclaration(typeDeclaration, data);
-			replaceableFields.Pop();
-			return null;
+			compilationUnit.AcceptVisitor(this, null);
 		}
 	}
 }

ICSharpCode.Decompiler/Ast/Transforms/TransformationPipeline.cs

@@ -32,7 +32,6 @@ namespace ICSharpCode.Decompiler.Ast.Transforms
 		public static IAstTransform[] CreatePipeline(DecompilerContext context)
 		{
 			return new IAstTransform[] {
-				new DecimalConstantTransform(),
 				new PushNegation(),
 				new DelegateConstruction(context),
 				new PatternStatementTransform(context),
@@ -41,6 +40,7 @@ namespace ICSharpCode.Decompiler.Ast.Transforms
 				new AddCheckedBlocks(),
 				new DeclareVariables(context), // should run after most transforms that modify statements
 				new ConvertConstructorCallIntoInitializer(), // must run after DeclareVariables
+				new DecimalConstantTransform(),
 				new IntroduceUsingDeclarations(context),
 				new IntroduceExtensionMethods(context), // must run after IntroduceUsingDeclarations
 				new IntroduceQueryExpressions(context), // must run after IntroduceExtensionMethods