Implement infra to support marshalling blittable generics (equivalent to .NET 5 support)

DllImportGenerator/DllImportGenerator.Test/ManualTypeMarshallingAnalyzerTests.cs

@@ -140,7 +140,6 @@ struct T
 }
 ";
  await VerifyCS.VerifyAnalyzerAsync(source,
- VerifyCS.Diagnostic(BlittableTypeMustBeBlittableRule).WithSpan(4, 2, 4, 15).WithArguments("S"),
  VerifyCS.Diagnostic(BlittableTypeMustBeBlittableRule).WithSpan(10, 2, 10, 15).WithArguments("T"));
  }
 
@@ -243,7 +242,7 @@ public Native(S s)
  public S ToManaged() => new S();
 }";
  await VerifyCS.VerifyAnalyzerAsync(source,
- VerifyCS.Diagnostic(NativeTypeMustBeBlittableRule).WithSpan(11, 1, 20, 2).WithArguments("Native", "S"));
+ VerifyCS.Diagnostic(NativeTypeMustHaveRequiredShapeRule).WithSpan(11, 1, 20, 2).WithArguments("Native", "S"));
  }
 
  [Fact]
@@ -837,64 +836,6 @@ public Native(S s)
 }";
  await VerifyCS.VerifyAnalyzerAsync(source);
  }
-
- public static IEnumerable<object[]> GenericTypeWithGenericFieldMarkedBlittable_ReportsDiagnostic_TestData {
- get
- {
- yield return new object[]
- {
- @"
-using System.Runtime.InteropServices;
-
-[BlittableType]
-struct S<T>
-{
- public T t;
-}"
- };
- yield return new object[]
- {
- @"
-using System.Runtime.InteropServices;
-
-[BlittableType]
-struct S<T> where T : class
-{
- public T t;
-}"
- };
- yield return new object[]
- {
- @"
-using System.Runtime.InteropServices;
-
-[BlittableType]
-struct S<T> where T : struct
-{
- public T t;
-}"
- };
- yield return new object[]
- {
- @"
-using System.Runtime.InteropServices;
-
-[BlittableType]
-struct S<T> where T : unmanaged
-{
- public T t;
-}"
- };
- }
- }
-
- [MemberData(nameof(GenericTypeWithGenericFieldMarkedBlittable_ReportsDiagnostic_TestData))]
- [Theory]
- public async Task GenericTypeWithGenericFieldMarkedBlittable_ReportsDiagnostic(string source)
- {
- await VerifyCS.VerifyAnalyzerAsync(source,
- VerifyCS.Diagnostic(BlittableTypeMustBeBlittableRule).WithSpan(4, 2, 4, 15).WithArguments("S<T>"));
- }
 
  [Fact]
  public async Task ValueTypeContainingPointerBlittableType_DoesNotReportDiagnostic()
@@ -967,6 +908,141 @@ public async Task BlittableTypeContainingFunctionPointer_DoesNotReportDiagnostic
 unsafe struct S
 {
  private delegate*<int> ptr;
+}";
+ await VerifyCS.VerifyAnalyzerAsync(source);
+ }
+
+ [Fact]
+ public async Task BlittableGenericTypeInBlittableType_DoesNotReportDiagnostic()
+ {
+
+ var source = @"
+using System.Runtime.InteropServices;
+
+[BlittableType]
+struct G<T>
+{
+ T fld;
+}
+
+[BlittableType]
+unsafe struct S
+{
+ private G<int> field;
+}";
+ await VerifyCS.VerifyAnalyzerAsync(source);
+ }
+
+ [Fact]
+ public async Task NonBlittableGenericTypeInBlittableType_ReportsDiagnostic()
+ {
+ var source = @"
+using System.Runtime.InteropServices;
+
+[BlittableType]
+struct G<T>
+{
+ T fld;
+}
+
+[BlittableType]
+unsafe struct S
+{
+ private G<string> field;
+}";
+ await VerifyCS.VerifyAnalyzerAsync(source,
+ VerifyCS.Diagnostic(BlittableTypeMustBeBlittableRule).WithSpan(10, 2, 10, 15).WithArguments("S"));
+ }
+
+ [Fact]
+ public async Task BlittableGenericTypeTypeParameterReferenceType_ReportsDiagnostic()
+ {
+ var source = @"
+using System.Runtime.InteropServices;
+
+[BlittableType]
+struct G<T> where T : class
+{
+ T fld;
+}";
+ await VerifyCS.VerifyAnalyzerAsync(source,
+ VerifyCS.Diagnostic(BlittableTypeMustBeBlittableRule).WithSpan(4, 2, 4, 15).WithArguments("G<T>"));
+ }
+
+ [Fact]
+ public async Task BlittableGenericTypeContainingGenericType_DoesNotReportDiagnostic()
+ {
+ var source = @"
+using System.Runtime.InteropServices;
+
+[BlittableType]
+struct G<T>
+{
+ T fld;
+}
+
+[BlittableType]
+struct F<T>
+{
+ G<T> fld;
+}
+";
+ await VerifyCS.VerifyAnalyzerAsync(source);
+ }
+
+ [Fact]
+ public async Task BlittableNestedGenericType_DoesNotReportDiagnostic()
+ {
+ var source = @"
+using System.Runtime.InteropServices;
+
+struct C<T>
+{
+ [BlittableType]
+ public struct G
+ {
+ T fld;
+ }
+}
+
+[BlittableType]
+struct S
+{
+ C<int>.G g;
+}
+";
+ await VerifyCS.VerifyAnalyzerAsync(source);
+ }
+
+ [Fact]
+ public async Task BlittableNestedGenericTypeWithReferenceTypeGenericParameter_DoesNotReportDiagnostic()
+ {
+ var source = @"
+using System.Runtime.InteropServices;
+
+struct C<T> where T : class
+{
+ [BlittableType]
+ struct G
+ {
+ T fld;
+ }
+}
+";
+ await VerifyCS.VerifyAnalyzerAsync(source,
+ VerifyCS.Diagnostic(BlittableTypeMustBeBlittableRule).WithSpan(6, 6, 6, 19).WithArguments("C<T>.G"));
+ }
+
+ [Fact]
+ public async Task BlittableGenericTypeWithReferenceTypeParameterNotUsedInFieldType_DoesNotReportDiagnostic()
+ {
+ var source = @"
+using System.Runtime.InteropServices;
+
+[BlittableType]
+struct G<T, U> where U : class
+{
+ T fld;
 }";
  await VerifyCS.VerifyAnalyzerAsync(source);
  }

DllImportGenerator/DllImportGenerator/ManualTypeMarshallingAnalyzer.cs

@@ -12,7 +12,7 @@ namespace Microsoft.Interop
  [DiagnosticAnalyzer(LanguageNames.CSharp)]
  public class ManualTypeMarshallingAnalyzer : DiagnosticAnalyzer
  {
- private const string Category = "Interoperability";
+ private const string Category = "Usage";
  public readonly static DiagnosticDescriptor BlittableTypeMustBeBlittableRule =
  new DiagnosticDescriptor(
  "INTEROPGEN001",
@@ -159,7 +159,13 @@ nativeMarshallingAttribute is not null &&
  marshalUsingAttribute is not null &&
  spanOfByte is not null)
  {
- var perCompilationAnalyzer = new PerCompilationAnalyzer(generatedMarshallingAttribute, blittableTypeAttribute, nativeMarshallingAttribute, marshalUsingAttribute, spanOfByte);
+ var perCompilationAnalyzer = new PerCompilationAnalyzer(
+ generatedMarshallingAttribute,
+ blittableTypeAttribute,
+ nativeMarshallingAttribute,
+ marshalUsingAttribute,
+ spanOfByte,
+ context.Compilation.GetTypeByMetadataName(TypeNames.System_Runtime_InteropServices_StructLayoutAttribute)!);
  context.RegisterSymbolAction(context => perCompilationAnalyzer.AnalyzeTypeDefinition(context), SymbolKind.NamedType);
  context.RegisterSymbolAction(context => perCompilationAnalyzer.AnalyzeElement(context), SymbolKind.Parameter, SymbolKind.Field);
  context.RegisterSymbolAction(context => perCompilationAnalyzer.AnalyzeReturnType(context), SymbolKind.Method);
@@ -172,19 +178,22 @@ class PerCompilationAnalyzer
  private readonly INamedTypeSymbol BlittableTypeAttribute;
  private readonly INamedTypeSymbol NativeMarshallingAttribute;
  private readonly INamedTypeSymbol MarshalUsingAttribute;
- private readonly ITypeSymbol SpanOfByte;
+ private readonly INamedTypeSymbol SpanOfByte;
+ private readonly INamedTypeSymbol StructLayoutAttribute;
 
  public PerCompilationAnalyzer(INamedTypeSymbol generatedMarshallingAttribute,
  INamedTypeSymbol blittableTypeAttribute,
  INamedTypeSymbol nativeMarshallingAttribute,
  INamedTypeSymbol marshalUsingAttribute,
- INamedTypeSymbol spanOfByte)
+ INamedTypeSymbol spanOfByte,
+ INamedTypeSymbol structLayoutAttribute)
  {
  GeneratedMarshallingAttribute = generatedMarshallingAttribute;
  BlittableTypeAttribute = blittableTypeAttribute;
  NativeMarshallingAttribute = nativeMarshallingAttribute;
  MarshalUsingAttribute = marshalUsingAttribute;
  SpanOfByte = spanOfByte;
+ StructLayoutAttribute = structLayoutAttribute;
  }
 
  public void AnalyzeTypeDefinition(SymbolAnalysisContext context)
@@ -211,11 +220,11 @@ public void AnalyzeTypeDefinition(SymbolAnalysisContext context)
  }
  }
 
- if (blittableTypeAttributeData is not null && nativeMarshallingAttributeData is not null)
+ if (HasMultipleMarshallingAttributes(blittableTypeAttributeData, nativeMarshallingAttributeData))
  {
- context.ReportDiagnostic(Diagnostic.Create(CannotHaveMultipleMarshallingAttributesRule, blittableTypeAttributeData.ApplicationSyntaxReference!.GetSyntax().GetLocation(), type.ToDisplayString()));
+ context.ReportDiagnostic(Diagnostic.Create(CannotHaveMultipleMarshallingAttributesRule, blittableTypeAttributeData!.ApplicationSyntaxReference!.GetSyntax().GetLocation(), type.ToDisplayString()));
  }
- else if (blittableTypeAttributeData is not null && !type.HasOnlyBlittableFields())
+ else if (blittableTypeAttributeData is not null && (!type.HasOnlyBlittableFields() || type.IsAutoLayout(StructLayoutAttribute)))
  {
  context.ReportDiagnostic(Diagnostic.Create(BlittableTypeMustBeBlittableRule, blittableTypeAttributeData.ApplicationSyntaxReference!.GetSyntax().GetLocation(), type.ToDisplayString()));
  }
@@ -225,6 +234,17 @@ public void AnalyzeTypeDefinition(SymbolAnalysisContext context)
  }
  }
 
+ private bool HasMultipleMarshallingAttributes(AttributeData? blittableTypeAttributeData, AttributeData? nativeMarshallingAttributeData)
+ {
+ return (blittableTypeAttributeData, nativeMarshallingAttributeData) switch
+ {
+ (null, null) => false,
+ (not null, null) => false,
+ (null, not null) => false,
+ _ => true
+ };
+ }
+
  public void AnalyzeElement(SymbolAnalysisContext context)
  {
  AttributeData? attrData = context.Symbol.GetAttributes().FirstOrDefault(attr => SymbolEqualityComparer.Default.Equals(MarshalUsingAttribute, attr.AttributeClass));

DllImportGenerator/DllImportGenerator/Resources.resx

@@ -124,7 +124,7 @@
  <value>Type '{0}' is marked with 'BlittableTypeAttribute' but is not blittable.</value>
  </data>
  <data name="CannotHaveMultipleMarshallingAttributesDescription" xml:space="preserve">
- <value>The 'BlittableTypeAttribute' and 'NativeMarshallingAttributes' are mutually exclusive.</value>
+ <value>The 'BlittableTypeAttribute' and 'NativeMarshallingAttribute' attributes are mutually exclusive.</value>
  </data>
  <data name="CannotHaveMultipleMarshallingAttributesMessage" xml:space="preserve">
  <value>Type '{0}' is marked with 'BlittableTypeAttribute' and 'NativeMarshallingAttribute'. A type can only have one of these two attributes.</value>
@@ -183,4 +183,4 @@
  <data name="ValuePropertyMustHaveSetterMessage" xml:space="preserve">
  <value>The 'Value' property on the native type '{0}' must have a setter.</value>
  </data>
-</root>
+</root>

DllImportGenerator/DllImportGenerator/TypeNames.cs

@@ -15,5 +15,7 @@ static class TypeNames
  public const string MarshalUsingAttribute = "System.Runtime.InteropServices.MarshalUsingAttribute";
 
  public const string System_Span = "System.Span`1";
+
+ public const string System_Runtime_InteropServices_StructLayoutAttribute = "System.Runtime.InteropServices.StructLayoutAttribute";
  }
 }