Generate trim annotations for [NotifyDataErrorInfo] properties

src/CommunityToolkit.Mvvm.SourceGenerators/ComponentModel/Models/PropertyInfo.cs

@@ -20,6 +20,7 @@ namespace CommunityToolkit.Mvvm.SourceGenerators.ComponentModel.Models;
 /// <param name="IsOldPropertyValueDirectlyReferenced">Whether the old property value is being directly referenced.</param>
 /// <param name="IsReferenceTypeOrUnconstraindTypeParameter">Indicates whether the property is of a reference type or an unconstrained type parameter.</param>
 /// <param name="IncludeMemberNotNullOnSetAccessor">Indicates whether to include nullability annotations on the setter.</param>
+/// <param name="IncludeRequiresUnreferencedCodeOnSetAccessor">Indicates whether to annotate the setter as requiring unreferenced code.</param>
 /// <param name="ForwardedAttributes">The sequence of forwarded attributes for the generated property.</param>
 internal sealed record PropertyInfo(
     string TypeNameWithNullabilityAnnotations,
@@ -33,4 +34,5 @@ internal sealed record PropertyInfo(
     bool IsOldPropertyValueDirectlyReferenced,
     bool IsReferenceTypeOrUnconstraindTypeParameter,
     bool IncludeMemberNotNullOnSetAccessor,
+    bool IncludeRequiresUnreferencedCodeOnSetAccessor,
     EquatableArray<AttributeInfo> ForwardedAttributes);

src/CommunityToolkit.Mvvm.SourceGenerators/ComponentModel/ObservablePropertyGenerator.Execute.cs

@@ -297,6 +297,13 @@ public static bool TryGetInfo(
 
             token.ThrowIfCancellationRequested();
 
+            // We should generate [RequiresUnreferencedCode] on the setter if [NotifyDataErrorInfo] was used and the attribute is available
+            bool includeRequiresUnreferencedCodeOnSetAccessor =
+                notifyDataErrorInfo &&
+                semanticModel.Compilation.HasAccessibleTypeWithMetadataName("System.Diagnostics.CodeAnalysis.RequiresUnreferencedCodeAttribute");
+
+            token.ThrowIfCancellationRequested();
+
             // Prepare the effective property changing/changed names. For the property changing names,
             // there are two possible cases: if the mode is disabled, then there are no names to report
             // at all. If the mode is enabled, then the list is just the same as for property changed.
@@ -321,6 +328,7 @@ public static bool TryGetInfo(
                 isOldPropertyValueDirectlyReferenced,
                 isReferenceTypeOrUnconstraindTypeParameter,
                 includeMemberNotNullOnSetAccessor,
+                includeRequiresUnreferencedCodeOnSetAccessor,
                 forwardedAttributes.ToImmutable());
 
             diagnostics = builder.ToImmutable();
@@ -1044,6 +1052,19 @@ public static MemberDeclarationSyntax GetPropertySyntax(PropertyInfo propertyInf
                             AttributeArgument(LiteralExpression(SyntaxKind.StringLiteralExpression, Literal(propertyInfo.FieldName)))))));
             }
 
+            // Add the [RequiresUnreferencedCode] attribute if needed:
+            //
+            // [RequiresUnreferencedCode("The type of the current instance cannot be statically discovered.")]
+            // <SET_ACCESSOR>
+            if (propertyInfo.IncludeRequiresUnreferencedCodeOnSetAccessor)
+            {
+                setAccessor = setAccessor.AddAttributeLists(
+                    AttributeList(SingletonSeparatedList(
+                        Attribute(IdentifierName("global::System.Diagnostics.CodeAnalysis.RequiresUnreferencedCode"))
+                        .AddArgumentListArguments(
+                            AttributeArgument(LiteralExpression(SyntaxKind.StringLiteralExpression, Literal("The type of the current instance cannot be statically discovered.")))))));
+            }
+
             // Construct the generated property as follows:
             //
             // /// <inheritdoc cref="<FIELD_NAME>"/>