[build] make TrimMode=full function like NativeAOT

[jonathanpeppers]

Context: dotnet/android#8805
Context: xamarin/xamarin-macios#20354

In .NET 9, we want .NET MAUI applications to be able to use the TrimMode=full option to remove unused code from the application:

<PropertyGroup Condition="'$(Configuration)' == 'Release'">
  <TrimMode>full</TrimMode>
</PropertyGroup>

With all the trimming work done to support NativeAOT, we should toggle the same options when TrimMode=full is used:

• MauiStrictXamlCompilation=true
• MauiXamlRuntimeParsingSupport=false
• MauiShellSearchResultsRendererDisplayMemberNameSupported=false
• MauiQueryPropertyAttributeSupport=false
• MauiImplicitCastOperatorsUsageViaReflectionSupport=false

With these set, the dotnet new maui project template should have zero trimmer warnings when TrimMode=full is used. Developers can also adjust these settings and respond to trimmer warnings in their own code.

I also updated RunOnAndroid and RunOniOS tests to verify that project templates launch successfully with TrimMode=full.

[jonathanpeppers]

@simonrozsival it seems like this found a single warning:

src\Controls\src\Core\StyleSheets\StylePropertyAttribute.cs(24,4): error IL2069: Microsoft.Maui.Controls.StyleSheets.StylePropertyAttribute.StylePropertyAttribute(String, Type, String): value stored in field 'Microsoft.Maui.Controls.StyleSheets.StylePropertyAttribute.<TargetType>k__BackingField' does not satisfy 'DynamicallyAccessedMemberTypes.PublicFields', 'DynamicallyAccessedMemberTypes.NonPublicFields' requirements. The parameter 'targetType' of method 'Microsoft.Maui.Controls.StyleSheets.StylePropertyAttribute.StylePropertyAttribute(String, Type, String)' 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.

Is this different behavior than NativeAOT?

[jonathanpeppers]

I guess maui-blazor apps have trimmer warnings (but iOS only?):

ILLink error IL2072: Microsoft.AspNetCore.Components.CascadingParameterState.FindCascadingParameters(ComponentState, Boolean&): 'componentType' argument does not satisfy 'DynamicallyAccessedMemberTypes.All' in call to 'Microsoft.AspNetCore.Components.CascadingParameterState.GetCascadingParameterInfos(Type)'. The return value of method 'System.Object.GetType()' 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.
ILLink error IL2072: Microsoft.AspNetCore.Components.ComponentFactory.PerformPropertyInjection(IServiceProvider, IComponent): 'componentType' argument does not satisfy 'DynamicallyAccessedMemberTypes.All' in call to 'Microsoft.AspNetCore.Components.ComponentFactory.GetComponentTypeInfo(Type)'. The return value of method 'System.Object.GetType()' 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.
ILLink error IL2026: Microsoft.AspNetCore.Components.WebView.IpcCommon.Serialize(String, Object[]): Using member 'System.Text.Json.JsonSerializer.Serialize<TValue>(TValue, JsonSerializerOptions)' which has 'RequiresUnreferencedCodeAttribute' can break functionality when trimming application code. JSON serialization and deserialization might require types that cannot be statically analyzed. Use the overload that takes a JsonTypeInfo or JsonSerializerContext, or make sure all of the required types are preserved.
ILLink error IL2026: Microsoft.AspNetCore.Components.WebView.IpcCommon.TryDeserialize<T>(String, T&, ArraySegment`1&): Using member 'System.Text.Json.JsonSerializer.Deserialize(ReadOnlySpan<Char>, Type, JsonSerializerOptions)' which has 'RequiresUnreferencedCodeAttribute' can break functionality when trimming application code. JSON serialization and deserialization might require types that cannot be statically analyzed. Use the overload that takes a JsonTypeInfo or JsonSerializerContext, or make sure all of the required types are preserved.
ILLink error IL2067: Microsoft.AspNetCore.Components.WebView.Services.WebViewRenderer.AddRootComponent(Type, String): 'componentType' argument does not satisfy 'DynamicallyAccessedMemberTypes.All' in call to 'Microsoft.AspNetCore.Components.RenderTree.WebRenderer.AddRootComponent(Type, String)'. The parameter 'componentType' of method 'Microsoft.AspNetCore.Components.WebView.Services.WebViewRenderer.AddRootComponent(Type, String)' 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.
ILLink error IL2111: Microsoft.JSInterop.Infrastructure.DotNetDispatcher.GetCachedMethodInfo(IDotNetObjectReference, String): Method 'Microsoft.JSInterop.Infrastructure.DotNetDispatcher.<GetCachedMethodInfo>g__ScanTypeForCallableMethods|16_0(Type)' with parameters or return value with `DynamicallyAccessedMembersAttribute` is accessed via reflection. Trimmer can't guarantee availability of the requirements of the method.
ILLink error IL2065: Microsoft.JSInterop.Infrastructure.DotNetDispatcher.ScanAssemblyForCallableMethods(DotNetDispatcher.AssemblyKey): Value passed to implicit 'this' parameter of method 'System.Type.GetMethods(BindingFlags)' can not be statically determined and may not meet 'DynamicallyAccessedMembersAttribute' requirements.
ILLink error IL2121: Microsoft.JSInterop.Infrastructure.DotNetDispatcher.ScanAssemblyForCallableMethods(DotNetDispatcher.AssemblyKey): Unused 'UnconditionalSuppressMessageAttribute' for warning 'IL2072'. Consider removing the unused warning suppression.
ILLink error IL2121: Microsoft.JSInterop.Infrastructure.DotNetDispatcher.ScanAssemblyForCallableMethods(DotNetDispatcher.AssemblyKey): Unused 'UnconditionalSuppressMessageAttribute' for warning 'IL2075'. Consider removing the unused warning suppression.
ILLink error IL2121: Microsoft.JSInterop.JSRuntime.EndInvokeJS(Int64, Boolean, Utf8JsonReader&): Unused 'UnconditionalSuppressMessageAttribute' for warning 'IL2072'. Consider removing the unused warning suppression.

Android somehow passes:

I will probably exclude maui-blazor for now.

[simonrozsival]

It is weird that we didn't see the StylePropertyAttribute warning before. I'll need to investigate this a bit more and see if it's intentional or if it is a bug in one of the analyzers.

[simonrozsival]

We should look into the Blazor warnings separately, these warnings are coming from a different repository (https://github.com/dotnet/aspnetcore).