Support params keyword on non-array collections

.github/workflows/build-frontends.yml

@@ -21,7 +21,7 @@ jobs:
 
     - uses: actions/setup-dotnet@v4
       with:
-        dotnet-version: '8.0.x'
+        dotnet-version: '9.0.x'
         dotnet-quality: 'ga'
 
     - name: Install dependencies

.github/workflows/codeql-analysis.yml

@@ -37,7 +37,7 @@ jobs:
 
     - uses: actions/setup-dotnet@v4
       with:
-        dotnet-version: '8.0.x'
+        dotnet-version: '9.0.x'
         dotnet-quality: 'ga'
 
     - name: Build

ICSharpCode.Decompiler.TestRunner/ICSharpCode.Decompiler.TestRunner.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net8.0</TargetFramework>
+    <TargetFramework>net9.0</TargetFramework>
     <Nullable>enable</Nullable>
   </PropertyGroup>
 

ICSharpCode.Decompiler.Tests/Helpers/Tester.cs

@@ -104,9 +104,9 @@ static Tester()
 			TesterPath = Path.GetDirectoryName(typeof(Tester).Assembly.Location);
 			TestCasePath = Path.Combine(TesterPath, "../../../../TestCases");
 #if DEBUG
-			testRunnerBasePath = Path.Combine(TesterPath, "../../../../../ICSharpCode.Decompiler.TestRunner/bin/Debug/net8.0");
+			testRunnerBasePath = Path.Combine(TesterPath, "../../../../../ICSharpCode.Decompiler.TestRunner/bin/Debug/net9.0");
 #else
-			testRunnerBasePath = Path.Combine(TesterPath, "../../../../../ICSharpCode.Decompiler.TestRunner/bin/Release/net8.0");
+			testRunnerBasePath = Path.Combine(TesterPath, "../../../../../ICSharpCode.Decompiler.TestRunner/bin/Release/net9.0");
 #endif
 			// To parse: <Project><ItemGroup><PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="4.8.0-3.final" />
 			packagesPropsFile = Path.Combine(TesterPath, "../../../../../Directory.Packages.props");
@@ -276,8 +276,8 @@ private static string ReplacePrivImplDetails(string il)
 		}
 
 		static readonly string coreRefAsmPath = new DotNetCorePathFinder(TargetFrameworkIdentifier.NET,
-			new Version(8, 0), "Microsoft.NETCore.App")
-				.GetReferenceAssemblyPath(".NETCoreApp,Version=v8.0");
+			new Version(9, 0), "Microsoft.NETCore.App")
+				.GetReferenceAssemblyPath(".NETCoreApp,Version=v9.0");
 
 		public static readonly string RefAsmPath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ProgramFilesX86),
 			@"Reference Assemblies\Microsoft\Framework\.NETFramework\v4.7.2");
@@ -313,11 +313,9 @@ private static string ReplacePrivImplDetails(string il)
 				"Microsoft.VisualBasic.dll",
 			};
 
-		const string targetFrameworkAttributeSnippet = @"
-
-[assembly: System.Runtime.Versioning.TargetFramework("".NETCoreApp,Version=v8.0"", FrameworkDisplayName = """")]
-
-";
+		const string targetFrameworkAttributeSnippet = """
+			[assembly: System.Runtime.Versioning.TargetFramework(".NETCoreApp,Version=v9.0", FrameworkDisplayName = "")]
+			""";
 
 		static readonly Lazy<string> targetFrameworkAttributeSnippetFile = new Lazy<string>(GetTargetFrameworkAttributeSnippetFile);
 
@@ -391,6 +389,7 @@ public static List<string> GetPreprocessorSymbols(CompilerOptions flags)
 					preprocessorSymbols.Add("NET60");
 					preprocessorSymbols.Add("NET70");
 					preprocessorSymbols.Add("NET80");
+					preprocessorSymbols.Add("NET90");
 				}
 				preprocessorSymbols.Add("ROSLYN");
 				preprocessorSymbols.Add("CS60");
@@ -421,6 +420,7 @@ public static List<string> GetPreprocessorSymbols(CompilerOptions flags)
 					preprocessorSymbols.Add("CS100");
 					preprocessorSymbols.Add("CS110");
 					preprocessorSymbols.Add("CS120");
+					preprocessorSymbols.Add("CS130");
 				}
 			}
 			else if ((flags & CompilerOptions.UseMcsMask) != 0)
@@ -639,7 +639,7 @@ internal static DecompilerSettings GetSettings(CompilerOptions cscOptions)
 					CompilerOptions.UseRoslyn1_3_2 => CSharp.LanguageVersion.CSharp6,
 					CompilerOptions.UseRoslyn2_10_0 => CSharp.LanguageVersion.CSharp7_3,
 					CompilerOptions.UseRoslyn3_11_0 => CSharp.LanguageVersion.CSharp9_0,
-					_ => cscOptions.HasFlag(CompilerOptions.Preview) ? CSharp.LanguageVersion.Latest : CSharp.LanguageVersion.CSharp12_0,
+					_ => cscOptions.HasFlag(CompilerOptions.Preview) ? CSharp.LanguageVersion.Latest : CSharp.LanguageVersion.CSharp13_0,
 				};
 				DecompilerSettings settings = new(langVersion) {
 					// Never use file-scoped namespaces

ICSharpCode.Decompiler.Tests/ICSharpCode.Decompiler.Tests.csproj

@@ -8,6 +8,7 @@
 
   <PropertyGroup>
     <TargetFramework>net8.0-windows</TargetFramework>
+    <LangVersion>13</LangVersion>
     <RuntimeIdentifier Condition="$(IsWindowsX64) == true">win-x64</RuntimeIdentifier>
     <RuntimeIdentifier Condition="$(IsWindowsARM64) == true">win-arm64</RuntimeIdentifier>
 
@@ -17,7 +18,7 @@
     <AllowUnsafeBlocks>True</AllowUnsafeBlocks>
 
     <NoWarn>1701;1702;1705,67,169,1058,728,1720,649,168,251,660,661,675;1998;162;8632;626;8618;8714;8602;8981</NoWarn>
-    <DefineConstants>ROSLYN;ROSLYN2;ROSLYN3;ROSLYN4;NET60;CS60;CS70;CS71;CS72;CS73;CS80;CS90;CS100;CS110;CS120</DefineConstants>
+    <DefineConstants>ROSLYN;ROSLYN2;ROSLYN3;ROSLYN4;NET60;CS60;CS70;CS71;CS72;CS73;CS80;CS90;CS100;CS110;CS120;CS130</DefineConstants>
 
     <GenerateAssemblyVersionAttribute>False</GenerateAssemblyVersionAttribute>
     <GenerateAssemblyFileVersionAttribute>False</GenerateAssemblyFileVersionAttribute>
@@ -141,6 +142,7 @@
     <Compile Include="TestCases\Pretty\PointerArithmetic.cs" />
     <Compile Include="TestCases\Pretty\Issue3439.cs" />
     <Compile Include="TestCases\Pretty\Issue3442.cs" />
+    <Compile Include="TestCases\Pretty\ParamsCollections.cs" />
     <None Include="TestCases\VBPretty\VBAutomaticEvents.vb" />
     <Compile Include="TestCases\VBPretty\VBAutomaticEvents.cs" />
     <Compile Include="TestCases\VBPretty\VBNonGenericForEach.cs" />

ICSharpCode.Decompiler.Tests/PrettyTestRunner.cs

@@ -598,6 +598,12 @@ public async Task ConstantsTests([ValueSource(nameof(defaultOptions))] CompilerO
 			await RunForLibrary(cscOptions: cscOptions);
 		}
 
+		[Test]
+		public async Task ParamsCollections([ValueSource(nameof(roslyn4OrNewerOptions))] CompilerOptions cscOptions)
+		{
+			await RunForLibrary(cscOptions: cscOptions);
+		}
+
 		[Test]
 		public async Task Issue1080([ValueSource(nameof(roslynOnlyOptions))] CompilerOptions cscOptions)
 		{

ICSharpCode.Decompiler.Tests/TestCases/Pretty/ParamsCollections.cs

@@ -0,0 +1,21 @@
+using System;
+using System.Collections.Generic;
+
+namespace ICSharpCode.Decompiler.Tests.TestCases.Pretty
+{
+	public static class ParamsCollections
+	{
+		public static void ParamsEnumerable(params IEnumerable<int> values)
+		{
+		}
+		public static void ParamsList(params List<int> values)
+		{
+		}
+		public static void ParamsReadOnlySpan(params ReadOnlySpan<int> values)
+		{
+		}
+		public static void ParamsSpan(params Span<int> values)
+		{
+		}
+	}
+}

ICSharpCode.Decompiler/CSharp/CSharpLanguageVersion.cs

@@ -35,7 +35,8 @@ public enum LanguageVersion
 		CSharp10_0 = 1000,
 		CSharp11_0 = 1100,
 		CSharp12_0 = 1200,
-		Preview = 1100,
+		CSharp13_0 = 1300,
+		Preview = 1300,
 		Latest = 0x7FFFFFFF
 	}
 }

ICSharpCode.Decompiler/CSharp/Transforms/EscapeInvalidIdentifiers.cs

@@ -166,6 +166,7 @@ public class RemoveEmbeddedAttributes : DepthFirstAstVisitor, IAstTransform
 			"System.Runtime.CompilerServices.NullableAttribute",
 			"System.Runtime.CompilerServices.NullableContextAttribute",
 			"System.Runtime.CompilerServices.NativeIntegerAttribute",
+			"System.Runtime.CompilerServices.ParamCollectionAttribute",
 			"System.Runtime.CompilerServices.RefSafetyRulesAttribute",
 			"System.Runtime.CompilerServices.ScopedRefAttribute",
 			"System.Runtime.CompilerServices.RequiresLocationAttribute",

ICSharpCode.Decompiler/DecompilerSettings.cs

@@ -165,10 +165,16 @@ public void SetLanguageVersion(CSharp.LanguageVersion languageVersion)
 				refReadOnlyParameters = false;
 				usePrimaryConstructorSyntaxForNonRecordTypes = false;
 			}
+			if (languageVersion < CSharp.LanguageVersion.CSharp13_0)
+			{
+				paramsCollections = false;
+			}
 		}
 
 		public CSharp.LanguageVersion GetMinimumRequiredVersion()
 		{
+			if (paramsCollections)
+				return CSharp.LanguageVersion.CSharp13_0;
 			if (refReadOnlyParameters || usePrimaryConstructorSyntaxForNonRecordTypes)
 				return CSharp.LanguageVersion.CSharp12_0;
 			if (scopedRef || requiredMembers || numericIntPtr || utf8StringLiterals || unsignedRightShift || checkedOperators)
@@ -848,6 +854,24 @@ public bool ForEachWithGetEnumeratorExtension {
 			}
 		}
 
+		bool paramsCollections = true;
+
+		/// <summary>
+		/// Support params collections.
+		/// </summary>
+		[Category("C# 13.0 / VS 2022.12")]
+		[Description("DecompilerSettings.DecompileParamsCollections")]
+		public bool ParamsCollections {
+			get { return paramsCollections; }
+			set {
+				if (paramsCollections != value)
+				{
+					paramsCollections = value;
+					OnPropertyChanged();
+				}
+			}
+		}
+
 		bool lockStatement = true;
 
 		/// <summary>

ICSharpCode.Decompiler/TypeSystem/DecompilerTypeSystem.cs

@@ -138,12 +138,19 @@ public enum TypeSystemOptions
 		/// </summary>
 		RefReadOnlyParameters = 0x10000,
 		/// <summary>
+		/// If this option is active, [ParamCollectionAttribute] on parameters is removed
+		/// and parameters are marked as params.
+		/// Otherwise, the attribute is preserved but the parameters are not marked
+		/// as if it was a normal parameter without any attributes.
+		/// </summary>
+		ParamsCollections = 0x20000,
+		/// <summary>
 		/// Default settings: typical options for the decompiler, with all C# languages features enabled.
 		/// </summary>
 		Default = Dynamic | Tuple | ExtensionMethods | DecimalConstants | ReadOnlyStructsAndParameters
 			| RefStructs | UnmanagedConstraints | NullabilityAnnotations | ReadOnlyMethods
 			| NativeIntegers | FunctionPointers | ScopedRef | NativeIntegersWithoutAttribute
-			| RefReadOnlyParameters
+			| RefReadOnlyParameters | ParamsCollections
 	}
 
 	/// <summary>
@@ -185,6 +192,8 @@ public static TypeSystemOptions GetOptions(DecompilerSettings settings)
 				typeSystemOptions |= TypeSystemOptions.NativeIntegersWithoutAttribute;
 			if (settings.RefReadOnlyParameters)
 				typeSystemOptions |= TypeSystemOptions.RefReadOnlyParameters;
+			if (settings.ParamsCollections)
+				typeSystemOptions |= TypeSystemOptions.ParamsCollections;
 			return typeSystemOptions;
 		}
 

ICSharpCode.Decompiler/TypeSystem/Implementation/AttributeListBuilder.cs

@@ -258,6 +258,9 @@ internal bool IgnoreAttribute(TopLevelTypeName attributeType, SymbolKind target)
 						case "RequiresLocationAttribute":
 							return (options & TypeSystemOptions.RefReadOnlyParameters) != 0
 								&& (target == SymbolKind.Parameter);
+						case "ParamCollectionAttribute":
+							return (options & TypeSystemOptions.ParamsCollections) != 0
+								&& (target == SymbolKind.Parameter);
 						default:
 							return false;
 					}

ICSharpCode.Decompiler/TypeSystem/Implementation/KnownAttributes.cs

@@ -87,6 +87,7 @@ public enum KnownAttribute
 
 		// Parameter attributes:
 		ParamArray,
+		ParamCollection,
 		In,
 		Out,
 		Optional,
@@ -166,6 +167,7 @@ public static class KnownAttributes
 			new TopLevelTypeName("System.Runtime.CompilerServices", nameof(IndexerNameAttribute)),
 			// Parameter attributes:
 			new TopLevelTypeName("System", nameof(ParamArrayAttribute)),
+			new TopLevelTypeName("System.Runtime.CompilerServices", "ParamCollectionAttribute"),
 			new TopLevelTypeName("System.Runtime.InteropServices", nameof(InAttribute)),
 			new TopLevelTypeName("System.Runtime.InteropServices", nameof(OutAttribute)),
 			new TopLevelTypeName("System.Runtime.InteropServices", nameof(OptionalAttribute)),

ICSharpCode.Decompiler/TypeSystem/Implementation/MetadataParameter.cs

@@ -125,6 +125,12 @@ public LifetimeAnnotation Lifetime {
 
 				var metadata = module.metadata;
 				var parameterDef = metadata.GetParameter(handle);
+				if ((module.TypeSystemOptions & TypeSystemOptions.ParamsCollections) != 0
+					&& parameterDef.GetCustomAttributes().HasKnownAttribute(metadata, KnownAttribute.ParamCollection))
+				{
+					// params collections are implicitly scoped
+					return default;
+				}
 				if (parameterDef.GetCustomAttributes().HasKnownAttribute(metadata, KnownAttribute.ScopedRef))
 				{
 					return new LifetimeAnnotation { ScopedRef = true };
@@ -135,11 +141,17 @@ public LifetimeAnnotation Lifetime {
 
 		public bool IsParams {
 			get {
-				if (Type.Kind != TypeKind.Array)
-					return false;
 				var metadata = module.metadata;
 				var parameterDef = metadata.GetParameter(handle);
-				return parameterDef.GetCustomAttributes().HasKnownAttribute(metadata, KnownAttribute.ParamArray);
+				if (Type.Kind == TypeKind.Array)
+				{
+					return parameterDef.GetCustomAttributes().HasKnownAttribute(metadata, KnownAttribute.ParamArray);
+				}
+				if (module.TypeSystemOptions.HasFlag(TypeSystemOptions.ParamsCollections))
+				{
+					return parameterDef.GetCustomAttributes().HasKnownAttribute(metadata, KnownAttribute.ParamCollection);
+				}
+				return false;
 			}
 		}
 

ILSpy/Languages/CSharpLanguage.cs

@@ -116,6 +116,7 @@ public override IReadOnlyList<LanguageVersion> LanguageVersions {
 						new LanguageVersion(Decompiler.CSharp.LanguageVersion.CSharp10_0.ToString(), "C# 10.0 / VS 2022"),
 						new LanguageVersion(Decompiler.CSharp.LanguageVersion.CSharp11_0.ToString(), "C# 11.0 / VS 2022.4"),
 						new LanguageVersion(Decompiler.CSharp.LanguageVersion.CSharp12_0.ToString(), "C# 12.0 / VS 2022.8"),
+						new LanguageVersion(Decompiler.CSharp.LanguageVersion.CSharp13_0.ToString(), "C# 13.0 / VS 2022.12"),
 					};
 				}
 				return versions;

ILSpy/Properties/Resources.resx

@@ -324,6 +324,9 @@ Are you sure you want to continue?</value>
   <data name="DecompilerSettings.DecompileForEachWithGetEnumeratorExtension" xml:space="preserve">
     <value>Decompile foreach statements with GetEnumerator extension methods</value>
   </data>
+  <data name="DecompilerSettings.DecompileParamsCollections" xml:space="preserve">
+    <value>Decompile params collections</value>
+  </data>
   <data name="DecompilerSettings.DecompileUseOfTheDynamicType" xml:space="preserve">
     <value>Decompile use of the 'dynamic' type</value>
   </data>

ILSpy/Properties/Resources.zh-Hans.resx

@@ -312,6 +312,9 @@
   <data name="DecompilerSettings.DecompileForEachWithGetEnumeratorExtension" xml:space="preserve">
     <value>反编译使用 GetEnumerator 扩展方法的 foreach 语句</value>
   </data>
+  <data name="DecompilerSettings.DecompileParamsCollections" xml:space="preserve">
+    <value />
+  </data>
   <data name="DecompilerSettings.DecompileUseOfTheDynamicType" xml:space="preserve">
     <value>反编译 dynamic 类型</value>
   </data>

README.md

@@ -48,11 +48,11 @@ How to build
 - Make sure Windows PowerShell (at least version) 5.0 or [PowerShell](https://github.com/PowerShell/PowerShell) 7+ is installed.
 - Clone the ILSpy repository using git.
 - Execute `git submodule update --init --recursive` to download the ILSpy-Tests submodule (used by some test cases).
-- Install Visual Studio (documented version: 17.8). You can install the necessary components in one of 3 ways:
+- Install Visual Studio (documented version: 17.12). You can install the necessary components in one of 3 ways:
   - Follow Microsoft's instructions for [importing a configuration](https://docs.microsoft.com/en-us/visualstudio/install/import-export-installation-configurations?view=vs-2022#import-a-configuration), and import the .vsconfig file located at the root of the solution.
   - Alternatively, you can open the ILSpy solution (ILSpy.sln) and Visual Studio will [prompt you to install the missing components](https://docs.microsoft.com/en-us/visualstudio/install/import-export-installation-configurations?view=vs-2022#automatically-install-missing-components).
   - Finally, you can manually install the necessary components via the Visual Studio Installer. The workloads/components are as follows:
-    - Workload ".NET Desktop Development". This workload includes the .NET Framework 4.8 SDK and the .NET Framework 4.7.2 targeting pack, as well as the [.NET 8.0 SDK](https://dotnet.microsoft.com/download/dotnet/8.0) (ILSpy.csproj targets .NET 8.0, but we have net472 projects too). _Note: The optional components of this workload are not required for ILSpy_
+    - Workload ".NET Desktop Development". This workload includes the .NET Framework 4.8 SDK and the .NET Framework 4.7.2 targeting pack, as well as the [.NET 9.0 SDK](https://dotnet.microsoft.com/download/dotnet/9.0) (ILSpy.csproj targets .NET 8.0, but we have net472 projects too). _Note: The optional components of this workload are not required for ILSpy_
     - Workload "Visual Studio extension development" (ILSpy.sln contains a VS extension project) _Note: The optional components of this workload are not required for ILSpy_
     - Individual Component "MSVC v143 - VS 2022 C++ x64/x86 build tools" (or similar)
       - _The VC++ toolset is optional_; if present it is used for `editbin.exe` to modify the stack size used by ILSpy.exe from 1MB to 16MB, because the decompiler makes heavy use of recursion, where small stack sizes lead to problems in very complex methods.
@@ -66,12 +66,12 @@ How to build
       - ILSpy.AddIn.slnf: for the Visual Studio plugin
 
 **Note:** Visual Studio includes a version of the .NET SDK that is managed by the Visual Studio installer - once you update, it may get upgraded too.
-Please note that ILSpy is only compatible with the .NET 8.0 SDK and Visual Studio will refuse to load some projects in the solution (and unit tests will fail). 
-If this problem occurs, please manually install the .NET 8.0 SDK from [here](https://dotnet.microsoft.com/download/dotnet/8.0).
+Please note that ILSpy is only compatible with the .NET 9.0 SDK and Visual Studio will refuse to load some projects in the solution (and unit tests will fail). 
+If this problem occurs, please manually install the .NET 9.0 SDK from [here](https://dotnet.microsoft.com/download/dotnet/9.0).
 
 #### Unix / Mac:
 
-- Make sure [.NET 8.0 SDK](https://dotnet.microsoft.com/download/dotnet/8.0) is installed.
+- Make sure [.NET 9.0 SDK](https://dotnet.microsoft.com/download/dotnet/9.0) is installed.
 - Make sure [PowerShell](https://github.com/PowerShell/PowerShell) is installed (formerly known as PowerShell Core)
 - Clone the repository using git.
 - Execute `git submodule update --init --recursive` to download the ILSpy-Tests submodule (used by some test cases).

global.json

@@ -1,6 +1,6 @@
 {
   "sdk": {
-    "version": "8.0.100",
+    "version": "9.0.100",
     "rollForward": "major",
     "allowPrerelease": true
   }