Add Analyzer rule to prohibit `typeof(T).ToString()`

Common.ruleset

@@ -22,6 +22,12 @@
 		<!-- Don't call this.GetType(), use typeof operator (or replace subtype check with better encapsulation) -->
 		<Rule Id="BHI1101" Action="Error" />
 
+		<!-- Don't call typeof(T).Name, use nameof operator -->
+		<Rule Id="BHI1102" Action="Error" />
+
+		<!-- Don't call typeof(T).ToString(), use nameof operator or typeof(T).FullName -->
+		<Rule Id="BHI1103" Action="Error" />
+
 		<!-- Throw NotImplementedException from methods/props marked [FeatureNotImplemented] -->
 		<Rule Id="BHI3300" Action="Error" />
 	</Rules>

ExternalProjects/BizHawk.Analyzer/UseNameofOperatorAnalyzer.cs

@@ -0,0 +1,69 @@
+namespace BizHawk.Analyzers;
+
+using System.Collections.Immutable;
+
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Diagnostics;
+
+[DiagnosticAnalyzer(LanguageNames.CSharp)]
+public sealed class UseNameofOperatorAnalyzer : DiagnosticAnalyzer
+{
+	private static readonly DiagnosticDescriptor DiagNoToStringOnType = new(
+		id: "BHI1103",
+		title: "Don't call typeof(T).ToString(), use nameof operator or typeof(T).FullName",
+		messageFormat: "Replace typeof({0}){1} with either nameof({0}) or typeof({0}).FullName",
+		category: "Usage",
+		defaultSeverity: DiagnosticSeverity.Warning,
+		isEnabledByDefault: true);
+
+	private static readonly DiagnosticDescriptor DiagUseNameof = new(
+		id: "BHI1102",
+		title: "Don't call typeof(T).Name, use nameof operator",
+		messageFormat: "Replace typeof({0}).Name with nameof({0})",
+		category: "Usage",
+		defaultSeverity: DiagnosticSeverity.Error,
+		isEnabledByDefault: true);
+
+	public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics { get; } = ImmutableArray.Create(DiagNoToStringOnType, DiagUseNameof);
+
+	public override void Initialize(AnalysisContext context)
+	{
+		context.ConfigureGeneratedCodeAnalysis(GeneratedCodeAnalysisFlags.None);
+		context.EnableConcurrentExecution();
+		ISymbol? memberInfoDotNameSym = null;
+		ISymbol? typeDotToStringSym = null;
+		context.RegisterSyntaxNodeAction(
+			snac =>
+			{
+				memberInfoDotNameSym ??= snac.Compilation.GetTypeByMetadataName("System.Reflection.MemberInfo")!.GetMembers("Name")[0];
+				typeDotToStringSym ??= snac.Compilation.GetTypeByMetadataName("System.Type")!.GetMembers("ToString")[0];
+				var toes = (TypeOfExpressionSyntax) snac.Node;
+				switch (toes.Parent)
+				{
+					case BinaryExpressionSyntax bes:
+						if ((ReferenceEquals(toes, bes.Left) ? bes.Right : bes.Left) is LiteralExpressionSyntax { Token.RawKind: (int) SyntaxKind.StringLiteralToken })
+						{
+							snac.ReportDiagnostic(Diagnostic.Create(DiagNoToStringOnType, toes.GetLocation(), toes.Type.GetText(), " in string concatenation"));
+						}
+						break;
+					case InterpolationSyntax:
+						snac.ReportDiagnostic(Diagnostic.Create(DiagNoToStringOnType, toes.GetLocation(), toes.Type.GetText(), " in string interpolation"));
+						break;
+					case MemberAccessExpressionSyntax maes1:
+						var accessed = snac.SemanticModel.GetSymbolInfo(maes1.Name).Symbol;
+						if (memberInfoDotNameSym.Matches(accessed))
+						{
+							snac.ReportDiagnostic(Diagnostic.Create(DiagUseNameof, maes1.GetLocation(), toes.Type.GetText()));
+						}
+						else if (typeDotToStringSym.Matches(accessed))
+						{
+							snac.ReportDiagnostic(Diagnostic.Create(DiagNoToStringOnType, maes1.GetLocation(), toes.Type.GetText(), ".ToString()"));
+						}
+						break;
+				}
+			},
+			SyntaxKind.TypeOfExpression);
+	}
+}

src/BizHawk.Client.EmuHawk/tools/ToolManager.cs

@@ -131,7 +131,7 @@ namespace BizHawk.Client.EmuHawk
 			if (newTool is Form form) form.Owner = _owner;
 			ServiceInjector.UpdateServices(_emulator.ServiceProvider, newTool);
 			SetBaseProperties(newTool);
-			var toolTypeName = typeof(T).ToString();
+			var toolTypeName = typeof(T).FullName!;
 			// auto settings
 			if (newTool is IToolFormAutoConfig autoConfigTool)
 			{

src/BizHawk.Emulation.Cores/Computers/AmstradCPC/Hardware/Datacorder/DatacorderDevice.cs

@@ -347,9 +347,7 @@ namespace BizHawk.Emulation.Cores.Computers.AmstradCPC
 				catch (Exception ex)
 				{
 					// exception during operation
-					var e = ex;
-					throw new Exception(typeof(DatacorderDevice).ToString() +
-					"\n\nTape image file has a valid CDT header, but threw an exception whilst data was being parsed.\n\n" + e.ToString());
+					throw new Exception($"{nameof(DatacorderDevice)}\n\nTape image file has a valid CDT header, but threw an exception whilst data was being parsed.\n\n{ex}", ex);
 				}
 			}
 		}

src/BizHawk.Emulation.Cores/Computers/AmstradCPC/Hardware/Disk/NECUPD765.FDD.cs

@@ -775,8 +775,7 @@ namespace BizHawk.Emulation.Cores.Computers.AmstradCPC
 
 				if (!found)
 				{
-					throw new Exception(typeof(DriveState).ToString() +
-						"\n\nDisk image file could not be parsed. Potentially an unknown format.");
+					throw new Exception($"{nameof(DriveState)}\n\nDisk image file could not be parsed. Potentially an unknown format.");
 				}
 			}
 

src/BizHawk.Emulation.Cores/Computers/AmstradCPC/Media/MediaConverter.cs

@@ -24,34 +24,25 @@ namespace BizHawk.Emulation.Cores.Computers.AmstradCPC
 		/// </summary>
 		public virtual bool IsWriter => false;
 
-		protected abstract Type SelfType { get; }
+		protected abstract string SelfTypeName { get; }
 
 		/// <summary>
 		/// Serialization method
 		/// </summary>
 		public virtual void Read(byte[] data)
-		{
-			throw new NotImplementedException(SelfType +
-				"Read operation is not implemented for this converter");
-		}
+			=> throw new NotImplementedException($"Read operation is not implemented for {SelfTypeName}");
 
 		/// <summary>
 		/// DeSerialization method
 		/// </summary>
 		public virtual void Write(byte[] data)
-		{
-			throw new NotImplementedException(SelfType +
-				"Write operation is not implemented for this converter");
-		}
+			=> throw new NotImplementedException($"Write operation is not implemented for {SelfTypeName}");
 
 		/// <summary>
 		/// Serializer does a quick check, returns TRUE if file is detected as this type
 		/// </summary>
 		public virtual bool CheckType(byte[] data)
-		{
-			throw new NotImplementedException(SelfType.ToString() +
-				"Check type operation is not implemented for this converter");
-		}
+			=> throw new NotImplementedException($"Check type operation is not implemented for {SelfTypeName}");
 
 		/// <summary>
 		/// Converts an int32 value into a byte array

src/BizHawk.Emulation.Cores/Computers/AmstradCPC/Media/Tape/CDT/CdtConverter.cs

@@ -26,8 +26,8 @@ namespace BizHawk.Emulation.Cores.Computers.AmstradCPC
 		/// </summary>
 		public override bool IsWriter => false;
 
-		protected override Type SelfType
-			=> typeof(CdtConverter);
+		protected override string SelfTypeName
+			=> nameof(CdtConverter);
 
 		/// <summary>
 		/// Working list of generated tape data blocks
@@ -167,8 +167,7 @@ namespace BizHawk.Emulation.Cores.Computers.AmstradCPC
 			if (ident != "ZXTape!" || eotm != 0x1A)
 			{
 				// this is not a valid TZX format file
-				throw new Exception(typeof(CdtConverter) +
-					"This is not a valid TZX format file");
+				throw new Exception($"{nameof(CdtConverter)}: This is not a valid TZX format file");
 			}
 
 			// iterate through each block

src/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Hardware/Datacorder/DatacorderDevice.cs

@@ -311,9 +311,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 				catch (Exception ex)
 				{
 					// exception during operation
-					var e = ex;
-					throw new Exception(typeof(DatacorderDevice).ToString() +
-					"\n\nTape image file has a valid TZX header, but threw an exception whilst data was being parsed.\n\n" + e.ToString());
+					throw new Exception($"{nameof(DatacorderDevice)}\n\nTape image file has a valid TZX header, but threw an exception whilst data was being parsed.\n\n{ex}", ex);
 				}
 			}
 
@@ -331,9 +329,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 				catch (Exception ex)
 				{
 					// exception during operation
-					var e = ex;
-					throw new Exception(typeof(DatacorderDevice).ToString() +
-					"\n\nTape image file has a valid PZX header, but threw an exception whilst data was being parsed.\n\n" + e.ToString());
+					throw new Exception($"{nameof(DatacorderDevice)}\n\nTape image file has a valid PZX header, but threw an exception whilst data was being parsed.\n\n{ex}", ex);
 				}
 			}
 
@@ -351,9 +347,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 				catch (Exception ex)
 				{
 					// exception during operation
-					var e = ex;
-					throw new Exception(typeof(DatacorderDevice).ToString() +
-					"\n\nTape image file has a valid CSW header, but threw an exception whilst data was being parsed.\n\n" + e.ToString());
+					throw new Exception($"{nameof(DatacorderDevice)}\n\nTape image file has a valid CSW header, but threw an exception whilst data was being parsed.\n\n{ex}", ex);
 				}
 			}
 
@@ -371,9 +365,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 				catch (Exception ex)
 				{
 					// exception during operation
-					var e = ex;
-					throw new Exception(typeof(DatacorderDevice).ToString() +
-					"\n\nTape image file has a valid WAV header, but threw an exception whilst data was being parsed.\n\n" + e.ToString());
+					throw new Exception($"{nameof(DatacorderDevice)}\n\nTape image file has a valid WAV header, but threw an exception whilst data was being parsed.\n\n{ex}", ex);
 				}
 			}
 
@@ -390,9 +382,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 				catch (Exception ex)
 				{
 					// exception during operation
-					var e = ex;
-					throw new Exception(typeof(DatacorderDevice).ToString() +
-					"\n\nAn exception was thrown whilst data from this tape image was being parsed as TAP.\n\n" + e.ToString());
+					throw new Exception($"{nameof(DatacorderDevice)}\n\nAn exception was thrown whilst data from this tape image was being parsed as TAP.\n\n{ex}", ex);
 				}
 			}
 		}

src/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Hardware/Disk/NECUPD765.FDD.cs

@@ -776,8 +776,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 
 				if (!found)
 				{
-					throw new Exception(typeof(DriveState).ToString() +
-						"\n\nDisk image file could not be parsed. Potentially an unknown format.");
+					throw new Exception($"{nameof(DriveState)}\n\nDisk image file could not be parsed. Potentially an unknown format.");
 				}
 			}
 

src/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Media/MediaConverter.cs

@@ -26,34 +26,25 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 		/// </summary>
 		public virtual bool IsWriter => false;
 
-		protected abstract Type SelfType { get; }
+		protected abstract string SelfTypeName { get; }
 
 		/// <summary>
 		/// Serialization method
 		/// </summary>
 		public virtual void Read(byte[] data)
-		{
-			throw new NotImplementedException(SelfType.ToString() +
-				"Read operation is not implemented for this converter");
-		}
+			=> throw new NotImplementedException($"Read operation is not implemented for {SelfTypeName}");
 
 		/// <summary>
 		/// DeSerialization method
 		/// </summary>
 		public virtual void Write(byte[] data)
-		{
-			throw new NotImplementedException(SelfType.ToString() +
-				"Write operation is not implemented for this converter");
-		}
+			=> throw new NotImplementedException($"Write operation is not implemented for {SelfTypeName}");
 
 		/// <summary>
 		/// Serializer does a quick check, returns TRUE if file is detected as this type
 		/// </summary>
 		public virtual bool CheckType(byte[] data)
-		{
-			throw new NotImplementedException(SelfType.ToString() +
-				"Check type operation is not implemented for this converter");
-		}
+			=> throw new NotImplementedException($"Check type operation is not implemented for {SelfTypeName}");
 
 		/// <summary>
 		/// Converts an int32 value into a byte array

src/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Media/Tape/CSW/CswConverter.cs

@@ -32,8 +32,8 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 		/// </summary>
 		public override bool IsWriter => false;
 
-		protected override Type SelfType
-			=> typeof(CswConverter);
+		protected override string SelfTypeName
+			=> nameof(CswConverter);
 
 		private readonly DatacorderDevice _datacorder;
 
@@ -83,15 +83,13 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 			if (ident.ToUpper() != "COMPRESSED SQUARE WAVE")
 			{
 				// this is not a valid CSW format file
-				throw new Exception(typeof(CswConverter).ToString() +
-					"This is not a valid CSW format file");
+				throw new Exception($"{nameof(CswConverter)}: This is not a valid CSW format file");
 			}
 
 			if (data[0x16] != 0x1a)
 			{
 				// invalid terminator code
-				throw new Exception(typeof(CswConverter).ToString() +
-					"This image reports as a CSW but has an invalid terminator code");
+				throw new Exception($"{nameof(CswConverter)}: This image reports as a CSW but has an invalid terminator code");
 			}
 
 			_position = 0;
@@ -185,13 +183,11 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 				if (compressionType == 1)
 					Array.Copy(data, _position, cswDataUncompressed, 0, cswDataUncompressed.Length);
 				else
-					throw new Exception(typeof(CswConverter).ToString() +
-					"CSW Format unknown compression type");
+					throw new Exception($"{nameof(CswConverter)}: CSW Format unknown compression type");
 			}
 			else
 			{
-				throw new Exception(typeof(CswConverter).ToString() +
-					"CSW Format Version " + majorVer + "." + minorVer + " is not currently supported");
+				throw new Exception($"{nameof(CswConverter)}: CSW Format Version {majorVer}.{minorVer} is not currently supported");
 			}
 
 			// create the single tape block

src/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Media/Tape/PZX/PzxConverter.cs

@@ -27,8 +27,8 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 		/// </summary>
 		public override bool IsWriter => false;
 
-		protected override Type SelfType
-			=> typeof(PzxConverter);
+		protected override string SelfTypeName
+			=> nameof(PzxConverter);
 
 		/// <summary>
 		/// Working list of generated tape data blocks
@@ -99,8 +99,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 			if (ident.ToUpper() != "PZXT")
 			{
 				// this is not a valid TZX format file
-				throw new Exception(typeof(PzxConverter).ToString() +
-					"This is not a valid PZX format file");
+				throw new Exception($"{nameof(PzxConverter)}: This is not a valid PZX format file");
 			}
 
 			_position = 0;

src/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Media/Tape/TAP/TapConverter.cs

@@ -27,8 +27,8 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 		/// </summary>
 		public override bool IsWriter => false;
 
-		protected override Type SelfType
-			=> typeof(TapConverter);
+		protected override string SelfTypeName
+			=> nameof(TapConverter);
 
 		private readonly DatacorderDevice _datacorder;
 

src/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Media/Tape/TZX/TzxConverter.cs

@@ -26,8 +26,8 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 		/// </summary>
 		public override bool IsWriter => false;
 
-		protected override Type SelfType
-			=> typeof(TzxConverter);
+		protected override string SelfTypeName
+			=> nameof(TzxConverter);
 
 		/// <summary>
 		/// Working list of generated tape data blocks
@@ -205,8 +205,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 			if (ident != "ZXTape!" || eotm != 0x1A)
 			{
 				// this is not a valid TZX format file
-				throw new Exception(typeof(TzxConverter) +
-					"This is not a valid TZX format file");
+				throw new Exception($"{nameof(TzxConverter)}: This is not a valid TZX format file");
 			}
 
 			// iterate through each block

src/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Media/Tape/WAV/WavConverter.cs

@@ -28,8 +28,8 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 		/// </summary>
 		public override bool IsWriter => false;
 
-		protected override Type SelfType
-			=> typeof(WavConverter);
+		protected override string SelfTypeName
+			=> nameof(WavConverter);
 
 		/// <summary>
 		/// Position counter
@@ -77,8 +77,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 			if (ident.ToUpper() != "WAVE")
 			{
 				// this is not a valid TZX format file
-				throw new Exception(typeof(WavConverter).ToString() +
-					"This is not a valid WAV format file");
+				throw new Exception($"{nameof(WavConverter)}: This is not a valid WAV format file");
 			}
 
 			//_position = 0;

src/BizHawk.Emulation.Cores/Consoles/Nintendo/QuickNES/QuickNES.cs

@@ -293,7 +293,7 @@ namespace BizHawk.Emulation.Cores.Consoles.Nintendo.QuickNES
 		private void CheckDisposed()
 		{
 			if (Context == IntPtr.Zero)
-				throw new ObjectDisposedException(typeof(QuickNES).Name);
+				throw new ObjectDisposedException(nameof(QuickNES));
 		}
 
 		// Fix some incorrect ines header entries that QuickNES uses to load games.

src/BizHawk.Emulation.Cores/Consoles/Sega/gpgx64/GenDbgHlp.cs

@@ -49,7 +49,7 @@ namespace BizHawk.Emulation.Cores.Consoles.Sega.gpgx
 
 		public void SaveState(int statenum)
 		{
-			if (disposed) throw new ObjectDisposedException(typeof(GenDbgHlp).ToString());
+			if (disposed) throw new ObjectDisposedException(nameof(GenDbgHlp));
 
 			data[statenum] ??= new byte[length];
 
@@ -60,7 +60,7 @@ namespace BizHawk.Emulation.Cores.Consoles.Sega.gpgx
 
 		public unsafe void Cmp(int statex, int statey)
 		{
-			if (disposed) throw new ObjectDisposedException(typeof(GenDbgHlp).ToString());
+			if (disposed) throw new ObjectDisposedException(nameof(GenDbgHlp));
 			List<Tuple<int, int>> bads = new List<Tuple<int, int>>();
 
 			byte[] x = data[statex];
@@ -134,7 +134,7 @@ namespace BizHawk.Emulation.Cores.Consoles.Sega.gpgx
 
 		public List<Symbol> Find(IntPtr addr, int length)
 		{
-			if (disposed) throw new ObjectDisposedException(typeof(GenDbgHlp).ToString());
+			if (disposed) throw new ObjectDisposedException(nameof(GenDbgHlp));
 			Symbol min = new Symbol { addr = addr };
 			Symbol max = new Symbol { addr = addr + length };