Share MakeGeneric.. and Expression.Call (dotnet/linker#2758)

Moves the intrinsic handling of `MakeGenericType`, `MakeGenericMethod` and `Expression.Call` into the shared code.

Other changes:
* Some small refactorings on the shared type system and value system.
* Expose generic parameters on type system proxies
* Fix a bug in analyzer when we're recording patterns, the values must be cloned (as they can mutate during analysis after the record is taken)
* Fix some problems in Nullable<T> handling in MakeGenericType - specifically if we don't know what the T is going to be, we now return just Nullable<> known type (but unknown T).
* Add couple new tests - update existing ones (mainly due to limitation in the analyzer)

Co-authored-by: Sven Boemer <[email protected]>

Commit migrated from dotnet/linker@bf4d43b

Author: vitek-karas

src/tools/illink/src/ILLink.RoslynAnalyzer/DynamicallyAccessedMembersAnalyzer.cs

@@ -42,6 +42,8 @@ static ImmutableArray<DiagnosticDescriptor> GetSupportedDiagnostics ()
 			diagDescriptorsArrayBuilder.Add (DiagnosticDescriptors.GetDiagnosticDescriptor (DiagnosticId.DynamicallyAccessedMembersMismatchOnImplicitThisBetweenOverrides));
 			diagDescriptorsArrayBuilder.Add (DiagnosticDescriptors.GetDiagnosticDescriptor (DiagnosticId.DynamicallyAccessedMembersConflictsBetweenPropertyAndAccessor));
 			diagDescriptorsArrayBuilder.Add (DiagnosticDescriptors.GetDiagnosticDescriptor (DiagnosticId.PropertyAccessorParameterInLinqExpressionsCannotBeStaticallyDetermined));
+			diagDescriptorsArrayBuilder.Add (DiagnosticDescriptors.GetDiagnosticDescriptor (DiagnosticId.MakeGenericType));
+			diagDescriptorsArrayBuilder.Add (DiagnosticDescriptors.GetDiagnosticDescriptor (DiagnosticId.MakeGenericMethod));
 			return diagDescriptorsArrayBuilder.ToImmutable ();
 
 			void AddRange (DiagnosticId first, DiagnosticId last)

src/tools/illink/src/ILLink.RoslynAnalyzer/TrimAnalysis/GenericParameterProxy.cs

@@ -9,6 +9,11 @@ internal readonly partial struct GenericParameterProxy
 	{
 		public GenericParameterProxy (ITypeParameterSymbol typeParameterSymbol) => TypeParameterSymbol = typeParameterSymbol;
 
+		internal partial bool HasDefaultConstructorConstraint () =>
+			TypeParameterSymbol.HasConstructorConstraint |
+			TypeParameterSymbol.HasValueTypeConstraint |
+			TypeParameterSymbol.HasUnmanagedTypeConstraint;
+
 		public readonly ITypeParameterSymbol TypeParameterSymbol;
 
 		public override string ToString () => TypeParameterSymbol.ToString ();

src/tools/illink/src/ILLink.RoslynAnalyzer/TrimAnalysis/GenericParameterValue.cs

@@ -17,11 +17,6 @@ partial record GenericParameterValue
 	{
 		public GenericParameterValue (ITypeParameterSymbol typeParameterSymbol) => GenericParameter = new (typeParameterSymbol);
 
-		public partial bool HasDefaultConstructorConstraint () =>
-			GenericParameter.TypeParameterSymbol.HasConstructorConstraint |
-			GenericParameter.TypeParameterSymbol.HasValueTypeConstraint |
-			GenericParameter.TypeParameterSymbol.HasUnmanagedTypeConstraint;
-
 		public override DynamicallyAccessedMemberTypes DynamicallyAccessedMemberTypes => GenericParameter.TypeParameterSymbol.GetDynamicallyAccessedMemberTypes ();
 
 		public override IEnumerable<string> GetDiagnosticArgumentsForAnnotationMismatch ()

src/tools/illink/src/ILLink.RoslynAnalyzer/TrimAnalysis/MethodProxy.cs

@@ -1,6 +1,7 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved.
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
+using System.Collections.Immutable;
 using ILLink.RoslynAnalyzer;
 using Microsoft.CodeAnalysis;
 
@@ -29,6 +30,19 @@ internal partial bool HasParameterOfType (int parameterIndex, string fullTypeNam
 
 		internal partial bool HasGenericParametersCount (int genericParameterCount) => Method.TypeParameters.Length == genericParameterCount;
 
+		internal partial ImmutableArray<GenericParameterProxy> GetGenericParameters ()
+		{
+			if (Method.TypeParameters.IsEmpty)
+				return ImmutableArray<GenericParameterProxy>.Empty;
+
+			var builder = ImmutableArray.CreateBuilder<GenericParameterProxy> (Method.TypeParameters.Length);
+			foreach (var typeParameter in Method.TypeParameters) {
+				builder.Add (new GenericParameterProxy (typeParameter));
+			}
+
+			return builder.ToImmutableArray ();
+		}
+
 		internal partial bool IsStatic () => Method.IsStatic;
 
 		internal partial bool ReturnsVoid () => Method.ReturnType.SpecialType == SpecialType.System_Void;

src/tools/illink/src/ILLink.RoslynAnalyzer/TrimAnalysis/TrimAnalysisAssignmentPattern.cs

@@ -12,11 +12,19 @@
 
 namespace ILLink.RoslynAnalyzer.TrimAnalysis
 {
-	public readonly record struct TrimAnalysisAssignmentPattern (
-		MultiValue Source,
-		MultiValue Target,
-		IOperation Operation)
+	public readonly record struct TrimAnalysisAssignmentPattern
 	{
+		public MultiValue Source { init; get; }
+		public MultiValue Target { init; get; }
+		public IOperation Operation { init; get; }
+
+		public TrimAnalysisAssignmentPattern (MultiValue source, MultiValue target, IOperation operation)
+		{
+			Source = source.Clone ();
+			Target = target.Clone ();
+			Operation = operation;
+		}
+
 		public TrimAnalysisAssignmentPattern Merge (ValueSetLattice<SingleValue> lattice, TrimAnalysisAssignmentPattern other)
 		{
 			Debug.Assert (Operation == other.Operation);

src/tools/illink/src/ILLink.RoslynAnalyzer/TrimAnalysis/TrimAnalysisMethodCallPattern.cs

@@ -13,13 +13,36 @@
 
 namespace ILLink.RoslynAnalyzer.TrimAnalysis
 {
-	public readonly record struct TrimAnalysisMethodCallPattern (
-		IMethodSymbol CalledMethod,
-		MultiValue Instance,
-		ImmutableArray<MultiValue> Arguments,
-		IOperation Operation,
-		ISymbol OwningSymbol)
+	public readonly record struct TrimAnalysisMethodCallPattern
 	{
+		public IMethodSymbol CalledMethod { init; get; }
+		public MultiValue Instance { init; get; }
+		public ImmutableArray<MultiValue> Arguments { init; get; }
+		public IOperation Operation { init; get; }
+		public ISymbol OwningSymbol { init; get; }
+
+		public TrimAnalysisMethodCallPattern (
+			IMethodSymbol calledMethod,
+			MultiValue instance,
+			ImmutableArray<MultiValue> arguments,
+			IOperation operation,
+			ISymbol owningSymbol)
+		{
+			CalledMethod = calledMethod;
+			Instance = instance.Clone ();
+			if (arguments.IsEmpty) {
+				Arguments = ImmutableArray<MultiValue>.Empty;
+			} else {
+				var builder = ImmutableArray.CreateBuilder<MultiValue> ();
+				foreach (var argument in arguments) {
+					builder.Add (argument.Clone ());
+				}
+				Arguments = builder.ToImmutableArray ();
+			}
+			Operation = operation;
+			OwningSymbol = owningSymbol;
+		}
+
 		public TrimAnalysisMethodCallPattern Merge (ValueSetLattice<SingleValue> lattice, TrimAnalysisMethodCallPattern other)
 		{
 			Debug.Assert (Operation == other.Operation);

src/tools/illink/src/ILLink.RoslynAnalyzer/TrimAnalysis/TrimAnalysisVisitor.cs

@@ -191,6 +191,7 @@ public override void HandleAssignment (MultiValue source, MultiValue target, IOp
 			// TODO: consider not tracking patterns unless the target is something
 			// annotated with DAMT.
 			TrimAnalysisPatterns.Add (
+				// This will copy the values if necessary
 				new TrimAnalysisAssignmentPattern (source, target, operation),
 				isReturnValue: false
 			);
@@ -264,6 +265,7 @@ public override MultiValue HandleMethodCall (IMethodSymbol calledMethod, MultiVa
 				}
 			}
 
+			// This will copy the values if necessary
 			TrimAnalysisPatterns.Add (new TrimAnalysisMethodCallPattern (
 				calledMethod,
 				instance,

src/tools/illink/src/ILLink.RoslynAnalyzer/TrimAnalysis/TypeProxy.cs

@@ -1,6 +1,7 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved.
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
+using System.Collections.Immutable;
 using ILLink.RoslynAnalyzer;
 using Microsoft.CodeAnalysis;
 
@@ -10,6 +11,20 @@ internal readonly partial struct TypeProxy
 	{
 		public TypeProxy (ITypeSymbol type) => Type = type;
 
+		internal partial ImmutableArray<GenericParameterProxy> GetGenericParameters ()
+		{
+			if (Type is not INamedTypeSymbol namedType ||
+				namedType.TypeParameters.IsEmpty)
+				return ImmutableArray<GenericParameterProxy>.Empty;
+
+			var builder = ImmutableArray.CreateBuilder<GenericParameterProxy> (namedType.TypeParameters.Length);
+			foreach (var typeParameter in namedType.TypeParameters) {
+				builder.Add (new GenericParameterProxy (typeParameter));
+			}
+
+			return builder.ToImmutableArray ();
+		}
+
 		public readonly ITypeSymbol Type;
 
 		public string Name { get => Type.MetadataName; }

src/tools/illink/src/ILLink.Shared/TrimAnalysis/GenericParameterValue.cs

@@ -12,7 +12,5 @@ namespace ILLink.Shared.TrimAnalysis
 	sealed partial record GenericParameterValue : ValueWithDynamicallyAccessedMembers
 	{
 		public readonly GenericParameterProxy GenericParameter;
-
-		public partial bool HasDefaultConstructorConstraint ();
 	}
 }