[net11.0][NativeAOT] Hook _PrepareTrimConfiguration to fix IL3050 on Android

[sbomer]

Note

This PR was created with assistance from AI.

Port of #35071 to the net11.0 branch.

Summary

Add _PrepareTrimConfiguration to _MauiPrepareForILLink's BeforeTargets so that RuntimeHostConfigurationOption items (like IsHybridWebViewSupported) are added before the runtime's internal target snapshots them into _TrimmerFeatureSettings.

Problem

dotnet/runtime PR #124801 moved the RuntimeHostConfigurationOption → _TrimmerFeatureSettings conversion from PrepareForILLink into an earlier internal target (_PrepareTrimConfiguration). MAUI's _MauiPrepareForILLink hooks BeforeTargets="PrepareForILLink", which now fires after the snapshot. As a result, ILC never receives --feature flags for MAUI's feature switches on Android NativeAOT, causing spurious IL3050 warnings for HybridWebViewHandler.

This is the branch (net11.0, SDK 11.0.100-preview.3.26203.107) where the bug manifests — the .NET 11 SDK has _PrepareTrimConfiguration.

Fix

Remove PrepareForILLink from BeforeTargets (redundant — it's a transitive dependent of _PrepareTrimConfiguration) and add _PrepareTrimConfiguration instead. This ensures MAUI's RuntimeHostConfigurationOption items are present when the snapshot runs.

Temporary workaround using the internal target name. The runtime fix (dotnet/runtime#127253) renames this to the public PrepareTrimConfiguration. Once that flows, update to BeforeTargets="PrepareTrimConfiguration".

Workaround for dotnet/runtime#127017

cc @sbomer @simonrozsival

[github-actions]

🚀 Dogfood this PR with:

⚠️ WARNING: Do not do this without first carefully reviewing the code of this PR to satisfy yourself it is safe.

curl -fsSL https://github.com/dotnet/maui/main/eng/scripts/get-maui-pr.sh | bash -s -- 35094

Or

• Run remotely in PowerShell:

iex "& { $(irm https://github.com/dotnet/maui/main/eng/scripts/get-maui-pr.ps1) } 35094"

[Copilot]

Pull request overview

Updates MAUI’s build-transitive targets to ensure RuntimeHostConfigurationOption feature switches are applied early enough for Android NativeAOT trimming, avoiding spurious IL3050 warnings after dotnet/runtime moved the snapshotting logic earlier in the target graph.

Changes:

• Retarget _MauiPrepareForILLink to run before _PrepareTrimConfiguration (instead of PrepareForILLink) so feature switches are present when _TrimmerFeatureSettings is computed.

[Copilot]

Dropping PrepareForILLink from BeforeTargets makes this target rely on _PrepareTrimConfiguration being present/invoked to ensure the RuntimeHostConfigurationOption items are set before trimming. To keep the hook resilient across SDK/runtime target graph changes (and align with the original fix strategy), keep PrepareForILLink in the list as a fallback (and optionally add the future public PrepareTrimConfiguration name as well).

Suggested change

	<Target Name="_MauiPrepareForILLink" BeforeTargets="_PrepareTrimConfiguration;_GenerateRuntimeConfigurationFilesInputCache;XamlC">
	<Target Name="_MauiPrepareForILLink" BeforeTargets="PrepareForILLink;PrepareTrimConfiguration;_PrepareTrimConfiguration;_GenerateRuntimeConfigurationFilesInputCache;XamlC">

[Copilot]

This target now hooks an internal SDK target name (_PrepareTrimConfiguration) as a workaround. Please add a short XML comment on/above this target explaining the runtime issue/workaround and that it should be switched to PrepareTrimConfiguration once available, so future maintainers don’t remove or “clean up” the underscore target reference.

Suggested change

	<!--
	Intentionally hook the internal SDK target `_PrepareTrimConfiguration` as a workaround for
	the current runtime/SDK trimming issue. Do not remove or "clean up" the underscore target
	reference; switch this to `PrepareTrimConfiguration` once that public target is available.
	-->

[PureWeen]

/azp run maui-pr-uitests, maui-pr-devicetests

[azure-pipelines]

Azure Pipelines successfully started running 2 pipeline(s).

[MauiBot]

⚠️ Merge Conflict Detected — This PR has merge conflicts with its target branch. Please rebase onto the target branch and resolve the conflicts.

[jonathanpeppers]

Looks OK, I have the same question as:

• #35071 (comment)