[Trimming] Fix remaining trimming warnings related to XAML parsing

src/Controls/src/Core/BindablePropertyConverter.cs

@@ -1,6 +1,7 @@
 #nullable disable
 using System;
 using System.ComponentModel;
+using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using System.Linq;
 using System.Reflection;
@@ -23,6 +24,11 @@ public override bool CanConvertTo(ITypeDescriptorContext context, Type destinati
 
 		object IExtendedTypeConverter.ConvertFromInvariantString(string value, IServiceProvider serviceProvider)
 		{
+			if (!RuntimeFeature.IsXamlRuntimeParsingSupported)
+			{
+				throw new InvalidOperationException(RuntimeFeature.XamlRuntimeParsingNotSupportedErrorMessage);
+			}
+
 			if (string.IsNullOrWhiteSpace(value))
 				return null;
 			if (serviceProvider == null)
@@ -75,6 +81,11 @@ object IExtendedTypeConverter.ConvertFromInvariantString(string value, IServiceP
 
 		public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
 		{
+			if (!RuntimeFeature.IsXamlRuntimeParsingSupported)
+			{
+				throw new InvalidOperationException(RuntimeFeature.XamlRuntimeParsingNotSupportedErrorMessage);
+			}
+
 			var strValue = value?.ToString();
 
 			if (string.IsNullOrWhiteSpace(strValue))
@@ -90,10 +101,15 @@ public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo c
 				Application.Current?.FindMauiContext()?.CreateLogger<BindablePropertyConverter>()?.LogWarning($"Can't resolve {value}. Accepted syntax is Type.PropertyName.");
 				return null;
 			}
-			Type type = Type.GetType("Microsoft.Maui.Controls." + parts[0]);
+			Type type = GetControlType(parts[0]);
 			return ConvertFrom(type, parts[1], null);
+
+			[RequiresUnreferencedCode(TrimmerConstants.XamlRuntimeParsingNotSupportedWarning)]
+			static Type GetControlType(string typeName)
+				=> Type.GetType("Microsoft.Maui.Controls." + typeName);
 		}
 
+		[RequiresUnreferencedCode(TrimmerConstants.XamlRuntimeParsingNotSupportedWarning)]
 		BindableProperty ConvertFrom(Type type, string propertyName, IXmlLineInfo lineinfo)
 		{
 			string name = propertyName + "Property";

src/Controls/src/Core/TrimmerConstants.cs

@@ -7,5 +7,5 @@ class TrimmerConstants
 
 	internal const string NativeBindingService = "This method properly handles missing properties, and there is not a way to preserve them from this method.";
 
-	internal const string XamlLoadingTrimmerWarning = "Loading XAML at runtime might require types that cannot be statically analyzed. Make sure all of the required types are preserved.";
+	internal const string XamlRuntimeParsingNotSupportedWarning = "Loading XAML at runtime might require types and members that cannot be statically analyzed. Make sure all of the required types and members are preserved.";
 }

src/Controls/src/Xaml/ViewExtensions.cs

@@ -33,21 +33,21 @@ namespace Microsoft.Maui.Controls.Xaml
 {
 	public static class Extensions
 	{
-		[RequiresUnreferencedCode(TrimmerConstants.XamlLoadingTrimmerWarning)]
+		[RequiresUnreferencedCode(TrimmerConstants.XamlRuntimeParsingNotSupportedWarning)]
 		public static TXaml LoadFromXaml<TXaml>(this TXaml view, Type callingType)
 		{
 			XamlLoader.Load(view, callingType);
 			return view;
 		}
 
-		[RequiresUnreferencedCode(TrimmerConstants.XamlLoadingTrimmerWarning)]
+		[RequiresUnreferencedCode(TrimmerConstants.XamlRuntimeParsingNotSupportedWarning)]
 		public static TXaml LoadFromXaml<TXaml>(this TXaml view, string xaml)
 		{
 			XamlLoader.Load(view, xaml);
 			return view;
 		}
 
-		[RequiresUnreferencedCode(TrimmerConstants.XamlLoadingTrimmerWarning)]
+		[RequiresUnreferencedCode(TrimmerConstants.XamlRuntimeParsingNotSupportedWarning)]
 		internal static TXaml LoadFromXaml<TXaml>(this TXaml view, string xaml, Assembly rootAssembly)
 		{
 			XamlLoader.Load(view, xaml, rootAssembly);

src/Controls/src/Xaml/XamlParser.cs

@@ -28,6 +28,7 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Reflection;
 using System.Runtime.CompilerServices;
@@ -358,6 +359,18 @@ static void GatherXmlnsDefinitionAttributes()
 
 		public static Type GetElementType(XmlType xmlType, IXmlLineInfo xmlInfo, Assembly currentAssembly,
 			out XamlParseException exception)
+		{
+			if (!RuntimeFeature.IsXamlRuntimeParsingSupported)
+			{
+				throw new NotSupportedException(RuntimeFeature.XamlRuntimeParsingNotSupportedErrorMessage);
+			}
+
+			return GetElementTypeCore(xmlType, xmlInfo, currentAssembly, out exception);
+		}
+
+		[RequiresUnreferencedCode(TrimmerConstants.XamlRuntimeParsingNotSupportedWarning)]
+		private static Type GetElementTypeCore(XmlType xmlType, IXmlLineInfo xmlInfo, Assembly currentAssembly,
+			out XamlParseException exception)
 		{
 			bool hasRetriedNsSearch = false;
 

src/Core/src/RuntimeFeature.cs

@@ -22,6 +22,11 @@ internal static bool IsXamlRuntimeParsingSupported
 				? isEnabled
 				: IsXamlRuntimeParsingSupportedByDefault;
 
+		internal const string XamlRuntimeParsingNotSupportedErrorMessage = "XAML runtime parsing is not supported. " +
+			"Ensure all XAML resources are compiled using XamlC. Alternatively, enable parsing XAML resources at runtime by setting " +
+			"the MauiXamlRuntimeParsingSupport MSBuild property to true. Note: this feature is not trimming-safe and it might not " +
+			"behave as expected when the application is trimmed.";
+
 		internal static bool IsIVisualAssemblyScanningEnabled =>
 			AppContext.TryGetSwitch("Microsoft.Maui.RuntimeFeature.IsIVisualAssemblyScanningEnabled", out bool isEnabled)
 				? isEnabled

src/TestUtils/src/Microsoft.Maui.IntegrationTests/Utilities/BuildWarningsUtilities.cs

@@ -123,37 +123,6 @@ public static void AssertWarnings(this List<WarningsPerFile> actualWarnings, Lis
 		// IMPORTANT: Always store expected File information as a relative path to the repo ROOT
 		private static readonly List<WarningsPerFile> expectedNativeAOTWarnings = new()
 		{
-			new WarningsPerFile
-			{
-				File = "src/Controls/src/Xaml/XamlParser.cs",
-				WarningsPerCode = new List<WarningsPerCode>
-				{
-					new WarningsPerCode
-					{
-						Code = "IL2055",
-						Messages = new List<string>
-						{
-							"Microsoft.Maui.Controls.Xaml.XamlParser.GetElementType(XmlType,IXmlLineInfo,Assembly,XamlParseException&): Call to 'System.Type.MakeGenericType(Type[])' can not be statically analyzed. It's not possible to guarantee the availability of requirements of the generic type.",
-						}
-					},
-					new WarningsPerCode
-					{
-						Code = "IL3050",
-						Messages = new List<string>
-						{
-							"Microsoft.Maui.Controls.Xaml.XamlParser.GetElementType(XmlType,IXmlLineInfo,Assembly,XamlParseException&): Using member 'System.Type.MakeGenericType(Type[])' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. The native code for this instantiation might not be available at runtime.",
-						}
-					},
-					new WarningsPerCode
-					{
-						Code = "IL2057",
-						Messages = new List<string>
-						{
-							"Microsoft.Maui.Controls.Xaml.XamlParser.<>c__DisplayClass11_0.<GetElementType>b__0(ValueTuple`3<String,String,String>): Unrecognized value passed to the parameter 'typeName' of method 'System.Type.GetType(String)'. It's not possible to guarantee the availability of the target type.",
-						}
-					},
-				}
-			},
 			new WarningsPerFile
 			{
 				File = "src/Controls/src/Core/Xaml/TypeConversionExtensions.cs",
@@ -187,21 +156,6 @@ public static void AssertWarnings(this List<WarningsPerFile> actualWarnings, Lis
 				}
 			},
 			new WarningsPerFile
-			{
-				File = "src/Controls/src/Core/BindablePropertyConverter.cs",
-				WarningsPerCode = new List<WarningsPerCode>
-				{
-					new WarningsPerCode
-					{
-						Code = "IL2057",
-						Messages = new List<string>
-						{
-							"Microsoft.Maui.Controls.BindablePropertyConverter.ConvertFrom(ITypeDescriptorContext,CultureInfo,Object): Unrecognized value passed to the parameter 'typeName' of method 'System.Type.GetType(String)'. It's not possible to guarantee the availability of the target type.",
-						}
-					},
-				}
-			},
-			new WarningsPerFile
 			{
 				File = "src/Controls/src/Core/BindingExpression.cs",
 				WarningsPerCode = new List<WarningsPerCode>
@@ -263,21 +217,6 @@ public static void AssertWarnings(this List<WarningsPerFile> actualWarnings, Lis
 					},
 				}
 			},
-			new WarningsPerFile
-			{
-				File = "src/Core/src/Platform/ReflectionExtensions.cs",
-				WarningsPerCode = new List<WarningsPerCode>
-				{
-					new WarningsPerCode
-					{
-						Code = "IL2070",
-						Messages = new List<string>
-						{
-							"Microsoft.Maui.Platform.ReflectionExtensions.<>c.<GetFields>b__1_0(TypeInfo): 'this' argument does not satisfy 'DynamicallyAccessedMemberTypes.PublicFields', 'DynamicallyAccessedMemberTypes.NonPublicFields' in call to 'System.Reflection.TypeInfo.DeclaredFields.get'. The parameter 'i' of method 'Microsoft.Maui.Platform.ReflectionExtensions.<>c.<GetFields>b__1_0(TypeInfo)' does not have matching annotations. The source value must declare at least the same requirements as those declared on the target location it is assigned to.",
-						}
-					},
-				}
-			},
 		};
 
 		#region Utility methods for generating the list of expected warnings