Minor refactoring in MarshallingAttributeInfoParser (#67325)

src/libraries/System.Runtime.InteropServices/gen/Microsoft.Interop.SourceGeneration/ManualTypeMarshallingHelper.cs

@@ -75,6 +75,29 @@ public static (bool hasAttribute, ITypeSymbol? managedType, CustomTypeMarshaller
             return (true, managedType, new CustomTypeMarshallerData(kind, direction, features, bufferSize));
         }
 
+        /// <summary>
+        /// Get the supported <see cref="CustomTypeMarshallerPinning"/> for a marshaller type
+        /// </summary>
+        /// <param name="marshallerType">The marshaller type.</param>
+        /// <param name="managedType">The mananged type that would be marshalled.</param>
+        /// <returns>Supported <see cref="CustomTypeMarshallerPinning"/></returns>
+        public static CustomTypeMarshallerPinning GetMarshallerPinningFeatures(ITypeSymbol marshallerType, ITypeSymbol? managedType)
+        {
+            CustomTypeMarshallerPinning pinning = CustomTypeMarshallerPinning.None;
+
+            if (FindGetPinnableReference(marshallerType) is not null)
+            {
+                pinning |= CustomTypeMarshallerPinning.NativeType;
+            }
+
+            if (managedType is not null && FindGetPinnableReference(managedType) is not null)
+            {
+                pinning |= CustomTypeMarshallerPinning.ManagedType;
+            }
+
+            return pinning;
+        }
+
         /// <summary>
         /// Resolve a non-<see cref="INamedTypeSymbol"/> <paramref name="managedType"/> to the correct managed type if <paramref name="marshallerType"/> is generic and <paramref name="managedType"/> is using any placeholder types.
         /// </summary>

src/libraries/System.Runtime.InteropServices/gen/Microsoft.Interop.SourceGeneration/MarshallingAttributeInfo.cs

@@ -536,62 +536,29 @@ private CountInfo CreateCountInfo(AttributeData marshalUsingData, ImmutableHashS
                 }
             }
 
-            if (!isArrayType)
+            if (isArrayType)
             {
-                return new MarshalAsInfo(unmanagedType, _defaultInfo.CharEncoding);
-            }
-
-            if (type is not IArrayTypeSymbol { ElementType: ITypeSymbol elementType })
-            {
-                _diagnostics.ReportConfigurationNotSupported(attrData, nameof(UnmanagedType), unmanagedType.ToString());
-                return NoMarshallingInfo.Instance;
-            }
-
-            MarshallingInfo elementMarshallingInfo = NoMarshallingInfo.Instance;
-            if (elementUnmanagedType != (UnmanagedType)SizeAndParamIndexInfo.UnspecifiedConstSize)
-            {
-                elementMarshallingInfo = new MarshalAsInfo(elementUnmanagedType, _defaultInfo.CharEncoding);
-            }
-            else
-            {
-                maxIndirectionDepthUsed = 1;
-                elementMarshallingInfo = GetMarshallingInfo(elementType, new Dictionary<int, AttributeData>(), 1, ImmutableHashSet<string>.Empty, ref maxIndirectionDepthUsed);
-            }
-
-            INamedTypeSymbol? arrayMarshaller;
+                if (type is not IArrayTypeSymbol { ElementType: ITypeSymbol elementType })
+                {
+                    _diagnostics.ReportConfigurationNotSupported(attrData, nameof(UnmanagedType), unmanagedType.ToString());
+                    return NoMarshallingInfo.Instance;
+                }
 
-            if (elementType is IPointerTypeSymbol { PointedAtType: ITypeSymbol pointedAt })
-            {
-                arrayMarshaller = _compilation.GetTypeByMetadataName(TypeNames.System_Runtime_InteropServices_GeneratedMarshalling_PtrArrayMarshaller_Metadata)?.Construct(pointedAt);
-            }
-            else
-            {
-                arrayMarshaller = _compilation.GetTypeByMetadataName(TypeNames.System_Runtime_InteropServices_GeneratedMarshalling_ArrayMarshaller_Metadata)?.Construct(elementType);
-            }
+                MarshallingInfo elementMarshallingInfo = NoMarshallingInfo.Instance;
+                if (elementUnmanagedType != (UnmanagedType)SizeAndParamIndexInfo.UnspecifiedConstSize)
+                {
+                    elementMarshallingInfo = new MarshalAsInfo(elementUnmanagedType, _defaultInfo.CharEncoding);
+                }
+                else
+                {
+                    maxIndirectionDepthUsed = 1;
+                    elementMarshallingInfo = GetMarshallingInfo(elementType, new Dictionary<int, AttributeData>(), 1, ImmutableHashSet<string>.Empty, ref maxIndirectionDepthUsed);
+                }
 
-            if (arrayMarshaller is null)
-            {
-                // If the array marshaler type is not available, then we cannot marshal arrays but indicate it is missing.
-                return new MissingSupportCollectionMarshallingInfo(arraySizeInfo, elementMarshallingInfo);
+                return CreateArrayMarshallingInfo(elementType, arraySizeInfo, elementMarshallingInfo);
             }
 
-            var (_, _, customTypeMarshallerData) = ManualTypeMarshallingHelper.GetMarshallerShapeInfo(arrayMarshaller);
-
-            Debug.Assert(customTypeMarshallerData is not null);
-
-            ITypeSymbol? nativeValueType = ManualTypeMarshallingHelper.FindToNativeValueMethod(arrayMarshaller)?.ReturnType;
-
-            return new NativeLinearCollectionMarshallingInfo(
-                NativeMarshallingType: ManagedTypeInfo.CreateTypeInfoForTypeSymbol(arrayMarshaller),
-                NativeValueType: nativeValueType is not null ? ManagedTypeInfo.CreateTypeInfoForTypeSymbol(nativeValueType) : null,
-                Direction: customTypeMarshallerData.Value.Direction,
-                MarshallingFeatures: customTypeMarshallerData.Value.Features,
-                PinningFeatures: CustomTypeMarshallerPinning.NativeType,
-                UseDefaultMarshalling: true,
-                BufferSize: customTypeMarshallerData.Value.BufferSize,
-                ElementCountInfo: arraySizeInfo,
-                ElementType: ManagedTypeInfo.CreateTypeInfoForTypeSymbol(elementType),
-                ElementMarshallingInfo: elementMarshallingInfo);
+            return new MarshalAsInfo(unmanagedType, _defaultInfo.CharEncoding);
         }
 
         private MarshallingInfo CreateNativeMarshallingInfo(
@@ -605,8 +572,6 @@ private CountInfo CreateCountInfo(AttributeData marshalUsingData, ImmutableHashS
             ImmutableHashSet<string> inspectedElements,
             ref int maxIndirectionDepthUsed)
         {
-            INamedTypeSymbol readOnlySpanOfT = _compilation.GetTypeByMetadataName(TypeNames.System_ReadOnlySpan_Metadata)!;
-
             if (nativeType.IsUnboundGenericType)
             {
                 if (isMarshalUsingAttribute)
@@ -639,31 +604,21 @@ private CountInfo CreateCountInfo(AttributeData marshalUsingData, ImmutableHashS
                 return NoMarshallingInfo.Instance;
             }
 
-            CustomTypeMarshallerPinning pinning = CustomTypeMarshallerPinning.None;
-
-            if (!isMarshalUsingAttribute && ManualTypeMarshallingHelper.FindGetPinnableReference(type) is not null)
-            {
-                pinning |= CustomTypeMarshallerPinning.ManagedType;
-            }
-
-            if (ManualTypeMarshallingHelper.FindGetPinnableReference(nativeType) is not null)
-            {
-                pinning |= CustomTypeMarshallerPinning.NativeType;
-            }
-
-            IMethodSymbol? toNativeValueMethod = ManualTypeMarshallingHelper.FindToNativeValueMethod(nativeType);
-
             if (customTypeMarshallerData.Value.Kind == CustomTypeMarshallerKind.LinearCollection)
             {
+                INamedTypeSymbol readOnlySpanOfT = _compilation.GetTypeByMetadataName(TypeNames.System_ReadOnlySpan_Metadata)!;
                 if (!ManualTypeMarshallingHelper.TryGetElementTypeFromLinearCollectionMarshaller(nativeType, readOnlySpanOfT, out ITypeSymbol elementType))
                 {
                     _diagnostics.ReportInvalidMarshallingAttributeInfo(attrData, nameof(SR.CollectionNativeTypeMustHaveRequiredShapeMessage), nativeType.ToDisplayString());
                     return NoMarshallingInfo.Instance;
                 }
 
+                CustomTypeMarshallerPinning pinning = ManualTypeMarshallingHelper.GetMarshallerPinningFeatures(nativeType, isMarshalUsingAttribute ? null : type);
+                IMethodSymbol? toNativeValueMethod = ManualTypeMarshallingHelper.FindToNativeValueMethod(nativeType);
+                ManagedTypeInfo? nativeValueType = toNativeValueMethod is not null ? ManagedTypeInfo.CreateTypeInfoForTypeSymbol(toNativeValueMethod.ReturnType) : null;
                 return new NativeLinearCollectionMarshallingInfo(
                     ManagedTypeInfo.CreateTypeInfoForTypeSymbol(nativeType),
-                    toNativeValueMethod is not null ? ManagedTypeInfo.CreateTypeInfoForTypeSymbol(toNativeValueMethod.ReturnType) : null,
+                    nativeValueType,
                     customTypeMarshallerData.Value.Direction,
                     customTypeMarshallerData.Value.Features,
                     pinning,
@@ -674,14 +629,31 @@ private CountInfo CreateCountInfo(AttributeData marshalUsingData, ImmutableHashS
                     GetMarshallingInfo(elementType, useSiteAttributes, indirectionLevel + 1, inspectedElements, ref maxIndirectionDepthUsed));
             }
 
+            return CreateNativeMarshallingInfoForValue(
+                type,
+                nativeType,
+                attrData,
+                customTypeMarshallerData.Value,
+                allowPinningManagedType: !isMarshalUsingAttribute,
+                useDefaultMarshalling: !isMarshalUsingAttribute);
+        }
+
+        private MarshallingInfo CreateNativeMarshallingInfoForValue(
+            ITypeSymbol type,
+            INamedTypeSymbol nativeType,
+            AttributeData attrData,
+            CustomTypeMarshallerData customTypeMarshallerData,
+            bool allowPinningManagedType,
+            bool useDefaultMarshalling)
+        {
             ManagedTypeInfo? bufferElementTypeInfo = null;
-            if (customTypeMarshallerData.Value.Features.HasFlag(CustomTypeMarshallerFeatures.CallerAllocatedBuffer))
+            if (customTypeMarshallerData.Features.HasFlag(CustomTypeMarshallerFeatures.CallerAllocatedBuffer))
             {
                 ITypeSymbol? bufferElementType = null;
                 INamedTypeSymbol spanOfT = _compilation.GetTypeByMetadataName(TypeNames.System_Span_Metadata)!;
                 foreach (IMethodSymbol ctor in nativeType.Constructors)
                 {
-                    if (ManualTypeMarshallingHelper.IsCallerAllocatedSpanConstructor(ctor, type, spanOfT, customTypeMarshallerData.Value.Kind, out bufferElementType))
+                    if (ManualTypeMarshallingHelper.IsCallerAllocatedSpanConstructor(ctor, type, spanOfT, customTypeMarshallerData.Kind, out bufferElementType))
                         break;
                 }
 
@@ -694,15 +666,20 @@ private CountInfo CreateCountInfo(AttributeData marshalUsingData, ImmutableHashS
                 bufferElementTypeInfo = ManagedTypeInfo.CreateTypeInfoForTypeSymbol(bufferElementType);
             }
 
+            CustomTypeMarshallerPinning pinning = ManualTypeMarshallingHelper.GetMarshallerPinningFeatures(nativeType, allowPinningManagedType ? type : null);
+
+            IMethodSymbol? toNativeValueMethod = ManualTypeMarshallingHelper.FindToNativeValueMethod(nativeType);
+            ManagedTypeInfo? nativeValueType = toNativeValueMethod is not null ? ManagedTypeInfo.CreateTypeInfoForTypeSymbol(toNativeValueMethod.ReturnType) : null;
+
             return new NativeMarshallingAttributeInfo(
                 ManagedTypeInfo.CreateTypeInfoForTypeSymbol(nativeType),
-                toNativeValueMethod is not null ? ManagedTypeInfo.CreateTypeInfoForTypeSymbol(toNativeValueMethod.ReturnType) : null,
-                customTypeMarshallerData.Value.Direction,
-                customTypeMarshallerData.Value.Features,
+                nativeValueType,
+                customTypeMarshallerData.Direction,
+                customTypeMarshallerData.Features,
                 pinning,
-                UseDefaultMarshalling: !isMarshalUsingAttribute,
+                useDefaultMarshalling,
                 bufferElementTypeInfo,
-                customTypeMarshallerData.Value.BufferSize);
+                customTypeMarshallerData.BufferSize);
         }
 
         private bool TryCreateTypeBasedMarshallingInfo(
@@ -743,38 +720,8 @@ private CountInfo CreateCountInfo(AttributeData marshalUsingData, ImmutableHashS
 
             if (type is IArrayTypeSymbol { ElementType: ITypeSymbol elementType })
             {
-                INamedTypeSymbol? arrayMarshaller;
-
-                if (elementType is IPointerTypeSymbol { PointedAtType: ITypeSymbol pointedAt })
-                {
-                    arrayMarshaller = _compilation.GetTypeByMetadataName(TypeNames.System_Runtime_InteropServices_GeneratedMarshalling_PtrArrayMarshaller_Metadata)?.Construct(pointedAt);
-                }
-                else
-                {
-                    arrayMarshaller = _compilation.GetTypeByMetadataName(TypeNames.System_Runtime_InteropServices_GeneratedMarshalling_ArrayMarshaller_Metadata)?.Construct(elementType);
-                }
-
-                if (arrayMarshaller is null)
-                {
-                    // If the array marshaler type is not available, then we cannot marshal arrays but indicate it is missing.
-                    marshallingInfo = new MissingSupportCollectionMarshallingInfo(parsedCountInfo, GetMarshallingInfo(elementType, useSiteAttributes, indirectionLevel + 1, inspectedElements, ref maxIndirectionDepthUsed));
-                    return true;
-                }
-
-                var (_, _, customTypeMarshallerData) = ManualTypeMarshallingHelper.GetMarshallerShapeInfo(arrayMarshaller);
-                ITypeSymbol? valuePropertyType = ManualTypeMarshallingHelper.FindToNativeValueMethod(arrayMarshaller)?.ReturnType;
-
-                marshallingInfo = new NativeLinearCollectionMarshallingInfo(
-                    NativeMarshallingType: ManagedTypeInfo.CreateTypeInfoForTypeSymbol(arrayMarshaller),
-                    NativeValueType: valuePropertyType is not null ? ManagedTypeInfo.CreateTypeInfoForTypeSymbol(valuePropertyType) : null,
-                    Direction: CustomTypeMarshallerDirection.Ref,
-                    MarshallingFeatures: CustomTypeMarshallerFeatures.TwoStageMarshalling | CustomTypeMarshallerFeatures.UnmanagedResources | CustomTypeMarshallerFeatures.CallerAllocatedBuffer,
-                    PinningFeatures: CustomTypeMarshallerPinning.NativeType,
-                    UseDefaultMarshalling: true,
-                    customTypeMarshallerData.Value.BufferSize,
-                    ElementCountInfo: parsedCountInfo,
-                    ElementType: ManagedTypeInfo.CreateTypeInfoForTypeSymbol(elementType),
-                    ElementMarshallingInfo: GetMarshallingInfo(elementType, useSiteAttributes, indirectionLevel + 1, inspectedElements, ref maxIndirectionDepthUsed));
+                MarshallingInfo elementMarshallingInfo = GetMarshallingInfo(elementType, useSiteAttributes, indirectionLevel + 1, inspectedElements, ref maxIndirectionDepthUsed);
+                marshallingInfo = CreateArrayMarshallingInfo(elementType, parsedCountInfo, elementMarshallingInfo);
                 return true;
             }
 
@@ -820,6 +767,45 @@ private CountInfo CreateCountInfo(AttributeData marshalUsingData, ImmutableHashS
             return false;
         }
 
+        private MarshallingInfo CreateArrayMarshallingInfo(
+            ITypeSymbol elementType,
+            CountInfo countInfo,
+            MarshallingInfo elementMarshallingInfo)
+        {
+            INamedTypeSymbol? arrayMarshaller;
+            if (elementType is IPointerTypeSymbol { PointedAtType: ITypeSymbol pointedAt })
+            {
+                arrayMarshaller = _compilation.GetTypeByMetadataName(TypeNames.System_Runtime_InteropServices_GeneratedMarshalling_PtrArrayMarshaller_Metadata)?.Construct(pointedAt);
+            }
+            else
+            {
+                arrayMarshaller = _compilation.GetTypeByMetadataName(TypeNames.System_Runtime_InteropServices_GeneratedMarshalling_ArrayMarshaller_Metadata)?.Construct(elementType);
+            }
+
+            if (arrayMarshaller is null)
+            {
+                // If the array marshaler type is not available, then we cannot marshal arrays but indicate it is missing.
+                return new MissingSupportCollectionMarshallingInfo(countInfo, elementMarshallingInfo);
+            }
+
+            var (_, _, customTypeMarshallerData) = ManualTypeMarshallingHelper.GetMarshallerShapeInfo(arrayMarshaller);
+            Debug.Assert(customTypeMarshallerData is not null);
+
+            ITypeSymbol? nativeValueType = ManualTypeMarshallingHelper.FindToNativeValueMethod(arrayMarshaller)?.ReturnType;
+
+            return new NativeLinearCollectionMarshallingInfo(
+                NativeMarshallingType: ManagedTypeInfo.CreateTypeInfoForTypeSymbol(arrayMarshaller),
+                NativeValueType: nativeValueType is not null ? ManagedTypeInfo.CreateTypeInfoForTypeSymbol(nativeValueType) : null,
+                Direction: customTypeMarshallerData.Value.Direction,
+                MarshallingFeatures: customTypeMarshallerData.Value.Features,
+                PinningFeatures: CustomTypeMarshallerPinning.NativeType,
+                UseDefaultMarshalling: true,
+                customTypeMarshallerData.Value.BufferSize,
+                ElementCountInfo: countInfo,
+                ElementType: ManagedTypeInfo.CreateTypeInfoForTypeSymbol(elementType),
+                ElementMarshallingInfo: elementMarshallingInfo);
+        }
+
         private MarshallingInfo GetBlittableMarshallingInfo(ITypeSymbol type)
         {
             if (type.TypeKind is TypeKind.Enum or TypeKind.Pointer or TypeKind.FunctionPointer