Handle Mono generated implicit delegate caching

Zhentar · Jul 9, 2017 · f7d28dd · f7d28dd
1 parent a9a9ad4
commit f7d28dd
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Showing 2 changed files with 13 additions and 4 deletions.
diff --git a/ICSharpCode.Decompiler/Ast/AstBuilder.cs b/ICSharpCode.Decompiler/Ast/AstBuilder.cs
@@ -94,6 +94,8 @@ public static bool MemberIsHidden(MemberReference member, DecompilerSettings set
 			FieldDefinition field = member as FieldDefinition;
 			if (field != null) {
 				if (field.IsCompilerGenerated()) {
+					if (IsDelegateMethodCacheField(field))
+						return true;
 					if (settings.AnonymousMethods && IsAnonymousMethodCacheField(field))
 						return true;
 					if (settings.AutomaticProperties && IsAutomaticPropertyBackingField(field))
@@ -124,6 +126,11 @@ static bool IsAnonymousMethodCacheField(FieldDefinition field)
 			return field.Name.StartsWith("CS$<>", StringComparison.Ordinal) || field.Name.StartsWith("<>f__am", StringComparison.Ordinal);
 		}
 
+		static bool IsDelegateMethodCacheField(FieldDefinition field)
+		{
+			return field.Name.StartsWith("<>f__mg", StringComparison.Ordinal);
+		}
+
 		static bool IsClosureType(TypeDefinition type)
 		{
 			return type.HasGeneratedName() && type.IsCompilerGenerated() && (type.Name.Contains("DisplayClass") || type.Name.Contains("AnonStorey"));

diff --git a/ICSharpCode.Decompiler/ILAst/PeepholeTransform.cs b/ICSharpCode.Decompiler/ILAst/PeepholeTransform.cs
@@ -198,10 +198,12 @@ void CachedDelegateInitializationWithField(ILBlock block, ref int i)
 				return;
 			if (newObj.Arguments[1].Code != ILCode.Ldftn)
 				return;
-			MethodDefinition anonymousMethod = ((MethodReference)newObj.Arguments[1].Operand).ResolveWithinSameModule(); // method is defined in current assembly
-			if (!Ast.Transforms.DelegateConstruction.IsAnonymousMethod(context, anonymousMethod))
-				return;
-
+			if (!field.IsCompilerGenerated()) //If it's a compiler generated field, it's a cached delegate initialization, whether or not the method is anonymous (Mono caches method group implicit delegates)
+			{
+				MethodDefinition anonymousMethod = ((MethodReference)newObj.Arguments[1].Operand).ResolveWithinSameModule(); // method is defined in current assembly
+				if (!Ast.Transforms.DelegateConstruction.IsAnonymousMethod(context, anonymousMethod))
+					return;
+			}
 			ILNode followingNode = block.Body.ElementAtOrDefault(i + 1);
 			if (followingNode != null && followingNode.GetSelfAndChildrenRecursive<ILExpression>().Count(
 				e => e.Code == ILCode.Ldsfld && ((FieldReference)e.Operand).ResolveWithinSameModule() == field) == 1)