[TrimmableTypeMap] Root manifest-referenced types as unconditional by simonrozsival · Pull Request #11037 · dotnet/android

simonrozsival · 2026-03-27T11:31:18Z

Summary

Parses the user's AndroidManifest.xml template for activity, service, receiver, and provider elements with android:name attributes. Marks matching scanned Java peer types as IsUnconditional = true so the ILLink TypeMap step preserves them even if no managed code references them directly.

Replaces #11016 (closed — depended on old PR shape).

Changes (4 files, +197/-3)

JavaPeerInfo.IsUnconditional: init → set (must be mutated after scanning when the manifest references a type)
TrimmableTypeMapGenerator:
- Added optional Action<string>? warn callback for warning-level messages
- RootManifestReferencedTypes(allPeers, manifestTemplatePath) — loads and parses the manifest XML
- RootManifestReferencedTypes(allPeers, XDocument) — internal for direct testing; builds a lookup by Java dot-name, then marks matching peers as unconditional
- Called between scanning and typemap generation in Execute()
GenerateTrimmableTypeMap task: passes msg => Log.LogWarning(msg) as the warn callback
4 new xUnit tests:
- RootManifestReferencedTypes_RootsMatchingPeers — verifies matching type gets rooted
- RootManifestReferencedTypes_WarnsForUnresolvedTypes — verifies warning for unknown types
- RootManifestReferencedTypes_SkipsAlreadyUnconditional — no-op for already-rooted
- RootManifestReferencedTypes_EmptyManifest_NoChanges — empty manifest doesn't affect peers

Dependencies

Stacked on #11036 (PR 4: build pipeline), which includes #11032, #11033, #11034, #11035.

Copilot

Pull request overview

This PR improves the TrimmableTypeMap pipeline so Android components referenced only from a user-provided AndroidManifest.xml template are treated as unconditionally preserved, preventing them from being trimmed when there are no direct managed references.

Changes:

Parse the manifest template for component declarations and mark matching scanned JavaPeerInfo entries as IsUnconditional.
Integrate trimmable typemap generation more deeply into the MSBuild pipeline (targets + runtime host config), including generation of native typemap stub .ll sources.
Expand scanning/generator models for manifest-related metadata and update tests for the updated JNI/native-callback naming behavior.

Reviewed changes

Copilot reviewed 36 out of 36 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Scanner/OverrideDetectionTests.cs	Updates expected derived native callback name for override detection.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/TypeMapModelBuilderTests.cs	Adjusts expectations for generated wrapper surface.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/TypeMapAssemblyGeneratorTests.cs	Adjusts expectations for generated wrapper surface.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/TrimmableTypeMapGeneratorTests.cs	Adds direct generator tests, including manifest rooting scenarios.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/JcwJavaSourceGeneratorTests.cs	Updates JNI name conversion and generated native method naming expectations.
src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/Tasks/GenerateTrimmableTypeMapTests.cs	Refactors MSBuild task tests to the new adapter behavior and outputs.
src/Xamarin.Android.Build.Tasks/Tasks/GenerateTrimmableTypeMap.cs	Makes the task a thin adapter over `TrimmableTypeMapGenerator` and passes manifest/acw-map parameters.
src/Xamarin.Android.Build.Tasks/Tasks/GenerateNativeApplicationConfigSources.cs	Allows missing `JNIEnvInit` tokens in the CoreCLR/trimmable path by using token 0.
src/Xamarin.Android.Build.Tasks/Tasks/GenerateEmptyTypemapStub.cs	New task to generate empty LLVM IR typemap stubs per ABI.
src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.TypeMap.Trimmable.targets	Wires typemap generation target, JCW copying, manifest/acw-map handling, and native stub generation.
src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.TypeMap.Trimmable.CoreCLR.targets	Hooks generated TypeMap assemblies into ILLink and assembly store for CoreCLR builds.
src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.NativeAOT.targets	Adds runtime feature flag defaulting trimmable typemap off for NativeAOT.
src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.MonoVM.targets	Adds runtime feature flag defaulting trimmable typemap off for MonoVM.
src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/ApplicationRegistration.Trimmable.java	Adds a trimmable-path ApplicationRegistration stub with empty registration.
src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/PreserveLists/Trimmable.CoreCLR.xml	Adds an ILLink descriptor to preserve `Android.Runtime.JNIEnvInit.Initialize`.
src/Microsoft.Android.Sdk.TrimmableTypeMap/TrimmableTypeMapTypes.cs	Adds shared result/config records (`TrimmableTypeMapResult`, `ManifestConfig`).
src/Microsoft.Android.Sdk.TrimmableTypeMap/TrimmableTypeMapGenerator.cs	Implements manifest-rooting + orchestrates scan → typemap → JCW → manifest/acw-map.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/UsesPermissionInfo.cs	New manifest model record for assembly-level uses-permission.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/UsesLibraryInfo.cs	New manifest model record for assembly-level uses-library.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/UsesFeatureInfo.cs	New manifest model record for assembly-level uses-feature.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/UsesConfigurationInfo.cs	New manifest model record for assembly-level uses-configuration.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/PropertyInfo.cs	New manifest model record for assembly-level property entries.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/PermissionTreeInfo.cs	New manifest model record for permission-tree.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/PermissionInfo.cs	New manifest model record for permission.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/PermissionGroupInfo.cs	New manifest model record for permission-group.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/MetaDataInfo.cs	New/updated model for metadata entries (type + assembly level).
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/JavaPeerScanner.cs	Captures component attribute data + improves native callback name derivation and declaring type parsing.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/JavaPeerInfo.cs	Makes `IsUnconditional` mutable post-scan; documents component attribute storage.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/IntentFilterInfo.cs	New model for intent-filter data.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/ComponentInfo.cs	New model for component attributes and related intent filters/metadata.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/AssemblyManifestInfo.cs	New model to aggregate assembly-level manifest attributes across assemblies.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/AssemblyIndex.cs	Adds decoding/parsing for assembly-level manifest attributes + richer type attribute capture.
src/Microsoft.Android.Sdk.TrimmableTypeMap/NullableExtensions.cs	Adds NRT-friendly string helper extensions for netstandard2.0.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Generator/ManifestModel.cs	Removes the old manifest model types (superseded by Scanner/ record types).
src/Microsoft.Android.Sdk.TrimmableTypeMap/Generator/ManifestGenerator.cs	Refactors manifest generation to accept a pre-loaded template document.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Generator/JniSignatureHelper.cs	Fixes JNI name → Java name conversion for nested types (`$` → `.`) in Java source contexts.

Copilot · 2026-03-27T11:34:54Z

src/Microsoft.Android.Sdk.TrimmableTypeMap/TrimmableTypeMapGenerator.cs

+
+		// Write merged acw-map.txt if requested
+		if (!acwMapOutputPath.IsNullOrEmpty ()) {
+			Directory.CreateDirectory (Path.GetDirectoryName (acwMapOutputPath));


Directory.CreateDirectory (Path.GetDirectoryName (acwMapOutputPath)) can throw because Path.GetDirectoryName() returns null when acwMapOutputPath has no directory component (e.g., just acw-map.txt). Guard against null (or use the current directory) before calling CreateDirectory.

Suggested change

Directory.CreateDirectory (Path.GetDirectoryName (acwMapOutputPath));

var acwDirectory = Path.GetDirectoryName (acwMapOutputPath);

if (!string.IsNullOrEmpty (acwDirectory)) {

Directory.CreateDirectory (acwDirectory);

}

Copilot · 2026-03-27T11:34:54Z

src/Microsoft.Android.Sdk.TrimmableTypeMap/TrimmableTypeMapGenerator.cs

+		var peersByDotName = new Dictionary<string, List<JavaPeerInfo>> (StringComparer.Ordinal);
+		foreach (var peer in allPeers) {
+			var dotName = peer.JavaName.Replace ('/', '.').Replace ('$', '.');
+			if (!peersByDotName.TryGetValue (dotName, out var list)) {
+				list = [];
+				peersByDotName [dotName] = list;
+			}
+			list.Add (peer);
+		}


RootManifestReferencedTypes builds its lookup key by converting peer.JavaName with .Replace ('$', '.'), but Android manifest class names for nested types use $ (e.g., com.example.Outer$Inner), so those will never match and won't be rooted. Also, manifest android:name commonly supports relative names (e.g., .MyActivity or MyActivity), which won't match the current dictionary keys either. Normalize android:name values (resolve relative names using the manifest package attribute) and avoid converting $ to . for manifest matching.

Copilot · 2026-03-27T11:34:55Z

tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/TrimmableTypeMapGeneratorTests.cs

+		Assert.Throws<ArgumentNullException> (() => generator.Execute (
+			null!, Path.Combine (testDir, "out"), Path.Combine (testDir, "java"),
+			new Version (11, 0), new HashSet<string> ()));


This test uses the null-forgiving operator (null!) to pass a null value. Repository guidance prefers avoiding ! even in tests; consider using a nullable local variable (or an explicit cast) so the test still passes null without the null-forgiving operator.

Copilot · 2026-03-27T11:34:55Z

...id.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.TypeMap.Trimmable.targets

+  <Target Name="_PrepareNativeAssemblySources"
+      Condition=" '$(_AndroidRuntime)' != 'NativeAOT' "
+      Inputs="@(_BuildTargetAbis)"
+      Outputs="@(_BuildTargetAbis->'$(_NativeAssemblySourceDir)typemaps.%(Identity).ll')">


_PrepareNativeAssemblySources declares its Outputs as typemaps.%(Identity).ll, but GenerateEmptyTypemapStub actually writes typemap.{abi}.ll (no trailing 's'). This mismatch breaks MSBuild incremental tracking for the target and can cause it to rerun unnecessarily or appear out-of-date forever. Update the Outputs transform to match the generated file name(s).

Suggested change

Outputs="@(_BuildTargetAbis->'$(_NativeAssemblySourceDir)typemaps.%(Identity).ll')">

Outputs="@(_BuildTargetAbis->'$(_NativeAssemblySourceDir)typemap.%(Identity).ll')">

Copilot · 2026-03-27T11:34:55Z

...id.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.TypeMap.Trimmable.targets

+  <Target Name="_GenerateTrimmableTypeMap"
+      Condition=" '$(_AndroidTypeMapImplementation)' == 'trimmable' and '@(ReferencePath->Count())' != '0' "
+      AfterTargets="CoreCompile"
+      Inputs="@(ReferencePath);$(IntermediateOutputPath)$(TargetFileName);$(_AndroidManifestAbs)"
+      Outputs="$(_TypeMapOutputDirectory)$(_TypeMapAssemblyName).dll">
+
+    <ItemGroup>
+      <_TypeMapInputAssemblies Include="@(ReferencePath)" />
+      <_TypeMapInputAssemblies Include="@(ResolvedAssemblies)" />
+      <_TypeMapInputAssemblies Include="@(ResolvedFrameworkAssemblies)" />
+      <_TypeMapInputAssemblies Include="$(IntermediateOutputPath)$(TargetFileName)"
+          Condition="Exists('$(IntermediateOutputPath)$(TargetFileName)')" />
+    </ItemGroup>

    <GenerateTrimmableTypeMap
-        ResolvedAssemblies="@(_ResolvedAssemblies)"
+        ResolvedAssemblies="@(_TypeMapInputAssemblies)"
        OutputDirectory="$(_TypeMapOutputDirectory)"
        JavaSourceOutputDirectory="$(_TypeMapJavaOutputDirectory)"
-        AcwMapDirectory="$(_PerAssemblyAcwMapDirectory)"
-        TargetFrameworkVersion="$(TargetFrameworkVersion)">
+        AcwMapDirectory="$(_TypeMapBaseOutputDir)acw-maps/"
+        TargetFrameworkVersion="$(TargetFrameworkVersion)"
+        ManifestTemplate="$(_AndroidManifestAbs)"
+        MergedAndroidManifestOutput="$(_TypeMapBaseOutputDir)AndroidManifest.xml"
+        PackageName="$(_AndroidPackage)"
+        ApplicationLabel="$(_ApplicationLabel)"
+        VersionCode="$(_AndroidVersionCode)"
+        VersionName="$(_AndroidVersionName)"
+        AndroidApiLevel="$(_AndroidApiLevel)"
+        SupportedOSPlatformVersion="$(SupportedOSPlatformVersion)"
+        AndroidRuntime="$(_AndroidRuntime)"
+        Debug="$(AndroidIncludeDebugSymbols)"
+        NeedsInternet="$(AndroidNeedsInternetPermission)"
+        EmbedAssemblies="$(EmbedAssembliesIntoApk)"
+        ManifestPlaceholders="$(AndroidManifestPlaceholders)"
+        CheckedBuild="$(_AndroidCheckedBuild)"
+        ApplicationJavaClass="$(AndroidApplicationJavaClass)"
+        AcwMapOutputFile="$(IntermediateOutputPath)acw-map.txt">


_GenerateTrimmableTypeMap has an Inputs/Outputs incremental definition, but the task output is also affected by many property values passed to GenerateTrimmableTypeMap (e.g., _ApplicationLabel, _AndroidVersionCode, AndroidNeedsInternetPermission, AndroidManifestPlaceholders, etc.). If any of these change without changing @(ReferencePath)/manifest template, MSBuild can skip the target and leave a stale merged manifest/acw-map in the intermediate output. Consider including these properties in Inputs (or removing the Inputs/Outputs incremental gating / splitting manifest generation into its own target with correct inputs).

Parse the user's AndroidManifest.xml template for activity, service, receiver, and provider elements with android:name attributes. Mark matching scanned Java peer types as IsUnconditional = true so the ILLink TypeMap step preserves them even if no managed code references them directly. Changes: - JavaPeerInfo.IsUnconditional: init → set (must be mutated after scanning) - TrimmableTypeMapGenerator: add warn callback, RootManifestReferencedTypes() called between scanning and typemap generation - GenerateTrimmableTypeMap task: pass Log.LogWarning as warn callback - 4 new xUnit tests covering rooting, unresolved warnings, already-unconditional skip, and empty manifest Replaces #11016 (closed — depended on old PR shape with TaskLoggingHelper). Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

- Fix RootManifestReferencedTypes to resolve relative android:name values (.MyActivity, MyActivity) using manifest package attribute - Keep $ separator in peer lookup keys so nested types (Outer$Inner) match correctly against manifest class names - Guard Path.GetDirectoryName against null return for acw-map path - Fix pre-existing compilation error: load XDocument from template path before passing to ManifestGenerator.Generate - Add tests for relative name resolution and nested type matching Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

simonrozsival requested a review from jonathanpeppers as a code owner March 27, 2026 11:31

Copilot AI review requested due to automatic review settings March 27, 2026 11:31

Copilot started reviewing on behalf of simonrozsival March 27, 2026 11:31 View session

Copilot AI reviewed Mar 27, 2026

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simonrozsival marked this pull request as draft March 27, 2026 11:45

simonrozsival added copilot `copilot-cli` or other AIs were used to author this trimmable-type-map labels Mar 27, 2026

simonrozsival changed the base branch from main to dev/simonrozsival/trimmable-typemap-build-pipeline-v2 March 30, 2026 16:10

simonrozsival force-pushed the dev/simonrozsival/trimmable-typemap-build-pipeline-v2 branch from db8fc87 to 6500aa5 Compare March 31, 2026 15:09

simonrozsival force-pushed the dev/simonrozsival/root-manifest-referenced-types branch from 590d41d to ff7258a Compare March 31, 2026 15:55

simonrozsival and others added 2 commits March 31, 2026 18:17

simonrozsival force-pushed the dev/simonrozsival/root-manifest-referenced-types branch from e1819e1 to c504fa1 Compare March 31, 2026 16:17

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[TrimmableTypeMap] Root manifest-referenced types as unconditional#11037

[TrimmableTypeMap] Root manifest-referenced types as unconditional#11037
simonrozsival wants to merge 2 commits intodev/simonrozsival/trimmable-typemap-build-pipeline-v2from
dev/simonrozsival/root-manifest-referenced-types

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-			Directory.CreateDirectory (Path.GetDirectoryName (acwMapOutputPath));
+			var acwDirectory = Path.GetDirectoryName (acwMapOutputPath);
+			if (!string.IsNullOrEmpty (acwDirectory)) {
+				Directory.CreateDirectory (acwDirectory);
+			}

	Outputs="@(_BuildTargetAbis->'$(_NativeAssemblySourceDir)typemaps.%(Identity).ll')">
	Outputs="@(_BuildTargetAbis->'$(_NativeAssemblySourceDir)typemap.%(Identity).ll')">

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simonrozsival commented Mar 27, 2026

Summary

Changes (4 files, +197/-3)

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