ILSpy/ICSharpCode.ILSpyX/Analyzers/Builtin/MemberOverridesAnalyzer.cs

// Copyright (c) 2026 Siegfried Pammer
//
// Permission is hereby granted, free of charge, to any person obtaining a copy of this
// software and associated documentation files (the "Software"), to deal in the Software
// without restriction, including without limitation the rights to use, copy, modify, merge,
// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
// to whom the Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all copies or
// substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
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using System.Collections.Generic;
using System.Composition;
using System.Diagnostics;

using ICSharpCode.Decompiler.TypeSystem;

namespace ICSharpCode.ILSpyX.Analyzers.Builtin
{
	/// <summary>
	/// Shows the base members overridden by a member; the dual of the "Overridden By" analysis.
	/// </summary>
	[ExportAnalyzer(Header = "Overrides", Order = 35)]
	[Shared]
	class MemberOverridesAnalyzer : IAnalyzer
	{
		public IEnumerable<ISymbol> Analyze(ISymbol analyzedSymbol, AnalyzerContext context)
		{
			Debug.Assert(analyzedSymbol is IMember);
			var member = (IMember)analyzedSymbol;
			// Walk the override chain member by member instead of collecting all
			// signature-equal base members: this stops at 'new virtual' shadow
			// boundaries, which hide any further base members from overriding.
			var visitedMembers = new HashSet<IMember>();
			while (member.IsOverride)
			{
				member = member.MemberDefinition;
				if (!visitedMembers.Add(member))
				{
					// abort if we seem to be in an infinite loop (cyclic inheritance)
					break;
				}
				var baseMember = InheritanceHelper.GetBaseMember(member);
				if (baseMember == null)
					break;
				yield return baseMember;
				member = baseMember;
			}
		}

		public bool Show(ISymbol? symbol)
		{
			switch (symbol?.SymbolKind)
			{
				case SymbolKind.Event:
				case SymbolKind.Indexer:
				case SymbolKind.Method:
				case SymbolKind.Property:
					return ((IMember)symbol).IsOverride;

				default:
					return false;
			}
		}
	}
}