Add Analyzer to enforce exception type for default switch branches

Common.ruleset

@@ -12,6 +12,9 @@
 
 		<!-- Verbatim interpolated strings should begin $@, not @$ -->
 		<Rule Id="BHI1004" Action="Error" />
+
+		<!-- Default branch of switch expression should throw InvalidOperationException/SwitchExpressionException or not throw -->
+		<Rule Id="BHI1005" Action="Error" />
 	</Rules>
 	<Rules AnalyzerId="DocumentationAnalyzers" RuleNamespace="DocumentationAnalyzers.StyleRules">
 		<!-- Place text in paragraphs -->

ExternalProjects/BizHawk.Analyzer/HawkSourceAnalyzer.cs

@@ -1,5 +1,6 @@
 namespace BizHawk.Analyzers;
 
+using System;
 using System.Collections.Immutable;
 
 using Microsoft.CodeAnalysis;
@@ -10,6 +11,10 @@ using Microsoft.CodeAnalysis.Diagnostics;
 [DiagnosticAnalyzer(LanguageNames.CSharp)]
 public class HawkSourceAnalyzer : DiagnosticAnalyzer
 {
+	private const string ERR_MSG_SWITCH_THROWS_UNKNOWN = "Indeterminable exception type in default switch branch, should be InvalidOperationException/SwitchExpressionException";
+
+	private const string ERR_MSG_SWITCH_THROWS_WRONG_TYPE = "Incorrect exception type in default switch branch, should be InvalidOperationException/SwitchExpressionException";
+
 	private static readonly DiagnosticDescriptor DiagInterpStringIsDollarAt = new(
 		id: "BHI1004",
 		title: "Verbatim interpolated strings should begin $@, not @$",
@@ -42,11 +47,20 @@ public class HawkSourceAnalyzer : DiagnosticAnalyzer
 		defaultSeverity: DiagnosticSeverity.Error,
 		isEnabledByDefault: true);
 
+	private static readonly DiagnosticDescriptor DiagSwitchShouldThrowIOE = new(
+		id: "BHI1005",
+		title: "Default branch of switch expression should throw InvalidOperationException/SwitchExpressionException or not throw",
+		messageFormat: "{0}",
+		category: "Usage",
+		defaultSeverity: DiagnosticSeverity.Error,
+		isEnabledByDefault: true);
+
 	public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics { get; } = ImmutableArray.Create(
 		DiagInterpStringIsDollarAt,
 		DiagNoAnonClasses,
 		DiagNoAnonDelegates,
-		DiagNoQueryExpression);
+		DiagNoQueryExpression,
+		DiagSwitchShouldThrowIOE);
 
 	public override void Initialize(AnalysisContext context)
 	{
@@ -69,11 +83,37 @@ public class HawkSourceAnalyzer : DiagnosticAnalyzer
 					case QueryExpressionSyntax:
 						snac.ReportDiagnostic(Diagnostic.Create(DiagNoQueryExpression, snac.Node.GetLocation()));
 						break;
+					case SwitchExpressionArmSyntax { WhenClause: null, Pattern: DiscardPatternSyntax, Expression: ThrowExpressionSyntax tes }:
+						if (tes.Expression is ObjectCreationExpressionSyntax oces)
+						{
+							// to resolve edge-cases involving aliases, you're supposed to use `snac.SemanticModel.GetTypeInfo(oces.Type).ConvertedType?.Name`, but I couldn't get it to work
+							if (((oces.Type as IdentifierNameSyntax)?.Identifier)?.ToString() is "SwitchExpressionException" or nameof(InvalidOperationException))
+							{
+								// correct usage, do not flag
+							}
+							else
+							{
+								snac.ReportDiagnostic(Diagnostic.Create(DiagSwitchShouldThrowIOE, tes.GetLocation(), ERR_MSG_SWITCH_THROWS_WRONG_TYPE));
+							}
+						}
+						else
+						{
+							// code reads `throw <something weird>`
+							snac.ReportDiagnostic(Diagnostic.Create(
+								DiagSwitchShouldThrowIOE,
+								tes.GetLocation(),
+								DiagnosticSeverity.Warning,
+								additionalLocations: null,
+								properties: null,
+								ERR_MSG_SWITCH_THROWS_UNKNOWN));
+						}
+						break;
 				}
 			},
 			SyntaxKind.AnonymousObjectCreationExpression,
 			SyntaxKind.AnonymousMethodExpression,
 			SyntaxKind.InterpolatedStringExpression,
-			SyntaxKind.QueryExpression);
+			SyntaxKind.QueryExpression,
+			SyntaxKind.SwitchExpressionArm);
 	}
 }

src/BizHawk.Bizware.DirectX/IGL_SlimDX9.cs

@@ -257,7 +257,7 @@ namespace BizHawk.Bizware.DirectX
 				BlendEquationMode.Max => BlendOperation.Maximum,
 				BlendEquationMode.Min => BlendOperation.Minimum,
 				BlendEquationMode.FuncReverseSubtract => BlendOperation.ReverseSubtract,
-				_ => throw new ArgumentOutOfRangeException()
+				_ => throw new InvalidOperationException()
 			};
 		}
 
@@ -284,7 +284,7 @@ namespace BizHawk.Bizware.DirectX
 			BlendingFactorSrc.Src1Color => throw new NotSupportedException(),
 			BlendingFactorSrc.OneMinusSrc1Color => throw new NotSupportedException(),
 			BlendingFactorSrc.OneMinusSrc1Alpha => throw new NotSupportedException(),
-			_ => throw new ArgumentOutOfRangeException()
+			_ => throw new InvalidOperationException()
 		};
 
 		public void SetBlendState(IBlendState rsBlend)

src/BizHawk.Client.Common/Api/BizHawkSystemIdToCoreSystemEnumConverter.cs

@@ -65,7 +65,7 @@ namespace BizHawk.Client.Common
 				VSystemID.Raw.SGB => CoreSystem.SuperGameBoy,
 				VSystemID.Raw.UZE => CoreSystem.UzeBox,
 				VSystemID.Raw.PCFX => CoreSystem.PcFx,
-				_ => throw new IndexOutOfRangeException($"{value} is missing in convert list")
+				_ => throw new InvalidOperationException($"{value} is missing in convert list")
 			};
 		}
 
@@ -131,7 +131,7 @@ namespace BizHawk.Client.Common
 				CoreSystem.ZXSpectrum => VSystemID.Raw.ZXSpectrum,
 				CoreSystem.AmstradCPC => VSystemID.Raw.AmstradCPC,
 				CoreSystem.Odyssey2 => VSystemID.Raw.O2,
-				_ => throw new IndexOutOfRangeException($"{value} is missing in convert list")
+				_ => throw new InvalidOperationException($"{value} is missing in convert list")
 			};
 		}
 

src/BizHawk.Client.Common/Api/DisplaySurfaceID.cs

@@ -14,6 +14,7 @@ namespace BizHawk.Client.Common
 	/// <remarks>should probably centralise these enum extensions and not-extensions somewhere... --yoshi</remarks>
 	public static class DisplaySurfaceIDParser
 	{
+#pragma warning disable BHI1005 // switching on string, possibly from user input, ArgumentException is correct here
 		[return: NotNullIfNotNull("str")]
 		public static DisplaySurfaceID? Parse(string? str) => str?.ToLowerInvariant() switch
 		{
@@ -24,12 +25,13 @@ namespace BizHawk.Client.Common
 			"native" => DisplaySurfaceID.Client,
 			_ => throw new ArgumentException(message: $"{str} is not the name of a display surface", paramName: nameof(str))
 		};
+#pragma warning restore BHI1005
 
 		public static string GetName(this DisplaySurfaceID surfaceID) => surfaceID switch
 		{
 			DisplaySurfaceID.EmuCore => "emucore",
 			DisplaySurfaceID.Client => "client",
-			_ => throw new ArgumentException(message: "not a valid enum member", paramName: nameof(surfaceID))
+			_ => throw new InvalidOperationException()
 		};
 	}
 }

src/BizHawk.Client.Common/DisplayManager/DisplayManagerBase.cs

@@ -1023,7 +1023,7 @@ namespace BizHawk.Client.Common
 			{
 				DisplaySurfaceID.EmuCore => (GameExtraPadding.Left + _currEmuWidth + GameExtraPadding.Right, GameExtraPadding.Top + _currEmuHeight + GameExtraPadding.Bottom),
 				DisplaySurfaceID.Client => (currNativeWidth, currNativeHeight),
-				_ => throw new ArgumentException(message: "not a valid enum member", paramName: nameof(surfaceID))
+				_ => throw new InvalidOperationException()
 			};
 
 			IDisplaySurface ret = sdss.AllocateSurface(width, height, clear);

src/BizHawk.Client.EmuHawk/DialogControllerWinFormsExtensions.cs

@@ -43,7 +43,7 @@ namespace BizHawk.Client.EmuHawk
 						EMsgBoxIcon.Question => MessageBoxIcon.Question,
 						EMsgBoxIcon.Warning => MessageBoxIcon.Warning,
 						EMsgBoxIcon.Info => MessageBoxIcon.Information,
-						_ => throw new ArgumentException(message: "not a valid enum member", paramName: nameof(icon))
+						_ => throw new InvalidOperationException()
 					});
 	}
 }

src/BizHawk.Client.EmuHawk/Input/Input.cs

@@ -51,7 +51,7 @@ namespace BizHawk.Client.EmuHawk
 				EHostInputMethod.OpenTK => new OpenTKInputAdapter(),
 				_ when OSTailoredCode.IsUnixHost => new OpenTKInputAdapter(),
 				EHostInputMethod.DirectInput => new DirectInputAdapter(),
-				_ => throw new Exception()
+				_ => throw new InvalidOperationException()
 			};
 			Console.WriteLine($"Using {Adapter.Desc} for host input (keyboard + gamepads)");
 			Adapter.UpdateConfig(_currentConfig);

src/BizHawk.Client.EmuHawk/tools/Watch/RamWatch.cs

@@ -774,7 +774,7 @@ namespace BizHawk.Client.EmuHawk
 			{
 				WatchSize.DWord => WatchSize.Word,
 				WatchSize.Word => WatchSize.Byte,
-				_ => throw new Exception()
+				_ => throw new InvalidOperationException()
 			};
 			var a = Watch.GenerateWatch(ab.Domain, ab.Address, newSize, ab.Type, ab.BigEndian, ab.Notes);
 			var b = Watch.GenerateWatch(ab.Domain, ab.Address + (int) newSize, newSize, ab.Type, ab.BigEndian, ab.Notes);

src/BizHawk.Common/OSTailoredCode.cs

@@ -72,7 +72,7 @@ namespace BizHawk.Common
 			DistinctOS.Linux => new UnixMonoLLManager(),
 			DistinctOS.macOS => new UnixMonoLLManager(),
 			DistinctOS.Windows => new WindowsLLManager(),
-			_ => throw new ArgumentOutOfRangeException()
+			_ => throw new InvalidOperationException()
 		});
 
 		public static ILinkedLibManager LinkedLibManager => _LinkedLibManager.Value;

src/BizHawk.Emulation.Cores/Consoles/Nintendo/BSNES/BsnesCore.IDebuggable.cs

@@ -152,7 +152,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.BSNES
 			{
 				0x20 or 0xfc => 3,
 				0x22 => 4,
-				_ => throw new ArgumentOutOfRangeException()
+				_ => throw new InvalidOperationException()
 			};
 		}
 	}

src/BizHawk.Emulation.Cores/Consoles/Nintendo/Gameboy/GBColors.cs

@@ -214,7 +214,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.Gameboy
 				ColorType.vbabgbold => OldVBAColor,
 				ColorType.gba => GBAColor,
 				ColorType.libretrogbc => LibretroGBCColor,
-				_ => throw new ArgumentOutOfRangeException(nameof(c)),
+				_ => throw new InvalidOperationException()
 			};
 
 			int i = 0;

src/BizHawk.Emulation.Cores/Consoles/Nintendo/NDS/NDSDisassembler.cs

@@ -37,7 +37,7 @@ namespace BizHawk.Emulation.Cores.Consoles.Nintendo.NDS
 				"ARM v5 (Thumb)" => LibMelonDS.TraceMask.ARM9_THUMB,
 				"ARM v4" => LibMelonDS.TraceMask.ARM7_ARM,
 				"ARM v4 (Thumb)" => LibMelonDS.TraceMask.ARM7_THUMB,
-				_ => throw new Exception("Invalid CPU mode?"),
+				_ => throw new InvalidOperationException("Invalid CPU mode?")
 			};
 
 			if (Cpu.Length == 14)

src/BizHawk.Emulation.Cores/Consoles/Nintendo/SNES/SNESGraphicsDecoder.cs

@@ -68,7 +68,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.SNES
 				ScreenSize.ABAB_64x32 => new Dimensions(2, 1),
 				ScreenSize.AABB_32x64 => new Dimensions(1, 2),
 				ScreenSize.ABCD_64x64 => new Dimensions(2, 2),
-				_ => throw new Exception()
+				_ => throw new InvalidOperationException()
 			};
 		}
 

src/BizHawk.Emulation.Cores/vpads_schemata/PSXSchema.cs

@@ -63,7 +63,7 @@ namespace BizHawk.Emulation.Cores
 						"guncon" => NymaGunCon(num),
 						"justifier" => NymaKonamiJustifier(num),
 						"dancepad" => NymaDancePad(num),
-						_ => throw new NotSupportedException($"device {device} is not supported"),
+						_ => throw new InvalidOperationException($"device {device} is not supported")
 					};
 				}