[TrimmableTypeMap] Build pipeline: targets, stubs, manifest integration, feature switches by simonrozsival · Pull Request #11036 · dotnet/android

simonrozsival · 2026-03-27T11:25:12Z

Summary

Build pipeline changes for the trimmable typemap feature. This PR stacks on PRs #11032, #11033, #11034, and #11035 — it includes their changes via a merge commit and adds the build infrastructure on top.

PR 4 commit changes (11 files, +492/-77):

New files

GenerateEmptyTypemapStub.cs — MSBuild task generating empty LLVM IR typemap stubs (typemap.{abi}.ll) per ABI. The native toolchain compiles these into the symbols libmonodroid.so expects.
ApplicationRegistration.Trimmable.java — Empty registerApplications() for the trimmable path (Application/Instrumentation types are activated via Runtime.registerNatives() + UCO wrappers).
Trimmable.CoreCLR.xml — ILLink preserve descriptor ensuring JNIEnvInit.Initialize survives trimming (native entry point from host.cc).

Rewritten targets

Trimmable.targets — Major rewrite:
- New _GenerateTrimmableTypeMap target runs after CoreCompile (uses @(ReferencePath))
- _GenerateJavaStubs becomes the orchestration target (copies JCW files, manifest, ApplicationRegistration.java, acw-map.txt)
- _PrepareNativeAssemblySources generates empty typemap LLVM stubs via GenerateEmptyTypemapStub
- _RemoveRegisterAttribute overridden as no-op (trimmable path needs [Register] at runtime)
- Removed _CollectPerAssemblyAcwMaps and _MergeAcwMaps (merged acw-map now written directly by the task)
Trimmable.CoreCLR.targets — Major rewrite:
- _AddTrimmableTypeMapToLinker adds TypeMap DLLs to ILLink
- _ConfigureTrimmableTypeMapForLinker passes --typemap-entry-assembly
- _AddTrimmableTypeMapAssembliesToStore adds per-ABI TypeMap DLLs to assembly store (tries linked/ first, falls back to untrimmed)

Feature switches

MonoVM.targets / NativeAOT.targets — Add Microsoft.Android.Runtime.RuntimeFeature.TrimmableTypeMap=false feature switch (trimmable path is CoreCLR-only for now)

Modified tasks

GenerateTrimmableTypeMap.cs — Added 14 manifest/config properties, ManifestConfig construction, merged acw-map.txt output, AdditionalProviderSources output
TrimmableTypeMapGenerator.cs — Added manifest generation, assembly manifest scanning, acw-map writing
TrimmableTypeMapTypes.cs — Added ManifestConfig record, AdditionalProviderSources to result
GenerateNativeApplicationConfigSources.cs — Gracefully handle trimmed JNIEnvInit tokens when TargetsCLR (use token 0 for missing tokens)

Dependencies

Depends on (merge first):

[TrimmableTypeMap] Fix JniNameToJavaName #11032 (PR 1a: JniSignatureHelper fix)
[TrimmableTypeMap] Fix NativeCallbackName and DeclaringType derivation from Connector #11033 (PR 1b: NativeCallbackName + DeclaringType)
[TrimmableTypeMap] Extract TrimmableTypeMapGenerator from MSBuild task #11034 (PR 2: Extract TrimmableTypeMapGenerator)
[TrimmableTypeMap] Assembly-level manifest attribute scanning #11035 (PR 3: Assembly-level scanning + manifest)

…or $ to . JniNameToJavaName was only replacing '/' with '.' but JNI also uses '$' for inner/nested classes. Java source uses '.' for both package and inner class separators. Before: android/view/View$OnClickListener → android.view.View$OnClickListener After: android/view/View$OnClickListener → android.view.View.OnClickListener Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

…n from Connector NativeCallbackName was previously set to a simple "n_{managedName}" which produced incorrect names like "n_OnCreate" instead of the correct "n_OnCreate_Landroid_os_Bundle_" that the JNI native method expects. The new GetNativeCallbackName() derives the correct name from the [Register] Connector field (e.g. "GetOnCreate_Landroid_os_Bundle_Handler" → "n_OnCreate_Landroid_os_Bundle_"). Similarly, AddMarshalMethod was not populating DeclaringTypeName and DeclaringAssemblyName for interface implementation methods. The new ParseConnectorDeclaringType() extracts these from the Connector's type qualifier (after the colon). Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Extract the core generation pipeline (scan → typemaps → JCW → acw-map) from GenerateTrimmableTypeMap into a standalone TrimmableTypeMapGenerator class that takes Action<string> for logging, keeping the TrimmableTypeMap project free of Microsoft.Build.* dependencies. The MSBuild task becomes a thin adapter. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

The per-assembly acw-map files are consumed by existing targets. Keep GeneratePerAssemblyAcwMaps in the task (it uses MSBuild types like MemoryStreamPool and Files) rather than moving the merged acw-map.txt logic to the generator, which is PR 4 work. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

- Restore GetJavaInteropAssemblyPaths (MonoAndroidHelper.IsMonoAndroidAssembly) filtering to match main's behavior — removing the filter is a build pipeline change that belongs in a later PR. - Add ArgumentNullException checks to TrimmableTypeMapGenerator.Execute(). Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

…d.Tests Move incremental build, parsing, and empty-input tests to TrimmableTypeMapGeneratorTests (xUnit, uses TestFixtures.dll). Keep MSBuild-specific tests (error handling, Mono.Android integration) in GenerateTrimmableTypeMapTests. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

The scanner needs all assemblies — not just those with HasMonoAndroidReference. Framework JCW pre-compilation is tracked by #10792; until then we generate JCWs for everything. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

This is MSBuild input parsing, not core generator logic. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Add scanning for assembly-level attributes ([Application], [Activity], [Service], [BroadcastReceiver], [ContentProvider], permissions, etc.) and wire them into the manifest generator via Generate(XDocument?) overload. Replace ManifestModel.cs with individual Scanner/ record types for better composability. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

… types Add assembly-level manifest attribute scanning to the TrimmableTypeMap scanner: - AssemblyIndex.ScanAssemblyAttributes(): parses 9 assembly-level attribute types (UsesPermission, UsesLibrary, UsesFeature, UsesConfiguration, Permission, PermissionGroup, PermissionTree, MetaData, Property) - JavaPeerScanner.ScanAssemblyManifestInfo(): aggregates attributes across assemblies - JavaPeerScanner.ToComponentInfo()/HasPublicParameterlessCtor(): attaches component info to scanned peers - ManifestGenerator.Generate(XDocument?): new overload accepting pre-loaded template - ManifestGenerator.CreateDefaultManifest(): extracted from LoadOrCreateManifest - Replace ManifestModel.cs (105-line flat class) with 12 focused record types - Update JavaPeerInfo.ComponentAttribute doc comment Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

…r-class', 'origin/dev/simonrozsival/fix-native-callback-name', 'origin/dev/simonrozsival/extract-trimmable-typemap-generator' and 'origin/dev/simonrozsival/scanner-manifest-attributes' into dev/simonrozsival/trimmable-typemap-build-pipeline-v2

- Update TrimmableTypeMapGenerator.Execute() with manifest generation, assembly manifest scanning, acw-map writing, and new optional parameters - Add ManifestConfig record to TrimmableTypeMapTypes.cs - Update TrimmableTypeMapResult with AdditionalProviderSources - Update GenerateTrimmableTypeMap MSBuild task with manifest/config properties - Create GenerateEmptyTypemapStub task for LLVM IR native typemap stubs - Create ApplicationRegistration.Trimmable.java (empty registerApplications) - Create Trimmable.CoreCLR.xml preserve list for JNIEnvInit.Initialize - Rewrite Trimmable.targets with full build pipeline (separate generation and _GenerateJavaStubs targets, native stub generation, manifest handling) - Rewrite Trimmable.CoreCLR.targets with ILLink integration and per-ABI assembly store support - Add TrimmableTypeMap=false feature switch to MonoVM and NativeAOT targets - Handle trimmed JNIEnvInit tokens in GenerateNativeApplicationConfigSources Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Copilot

Pull request overview

This PR wires the TrimmableTypeMap feature into the .NET for Android build pipeline, adding CoreCLR linker/store integration, generating required Java/native stubs, and expanding the typemap generator to emit manifest + merged acw-map outputs.

Changes:

Reworks trimmable typemap MSBuild targets to generate typemap assemblies/JCWs post-compile, integrate with ILLink, and populate assembly-store inputs.
Adds new build-time stubs and preserve config (LLVM IR typemap stubs, empty ApplicationRegistration for trimmable path, ILLink root descriptor).
Extends the TrimmableTypeMap generator/scanner to support manifest generation inputs and updated JNI/override naming behavior, with corresponding test updates.

Reviewed changes

Copilot reviewed 36 out of 36 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Scanner/OverrideDetectionTests.cs	Updates expected native callback name derivation from Connector.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/TypeMapModelBuilderTests.cs	Adjusts expectations for generated wrapper members.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/TypeMapAssemblyGeneratorTests.cs	Aligns proxy type wrapper expectations with generator output.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/TrimmableTypeMapGeneratorTests.cs	Adds direct unit tests for the core generator pipeline and incremental behavior.
tests/Microsoft.Android.Sdk.TrimmableTypeMap.Tests/Generator/JcwJavaSourceGeneratorTests.cs	Updates JNI name conversion and native method naming assertions.
src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/Tasks/GenerateTrimmableTypeMapTests.cs	Refactors MSBuild-task tests to match new outputs/behavior.
src/Xamarin.Android.Build.Tasks/Tasks/GenerateTrimmableTypeMap.cs	Converts MSBuild task into adapter delegating to TrimmableTypeMapGenerator, adds manifest/acw-map integration inputs/outputs.
src/Xamarin.Android.Build.Tasks/Tasks/GenerateNativeApplicationConfigSources.cs	Allows CoreCLR trimmable path to proceed when JNIEnvInit tokens are trimmed (token=0 fallback).
src/Xamarin.Android.Build.Tasks/Tasks/GenerateEmptyTypemapStub.cs	New task generating per-ABI empty LLVM IR typemap stubs.
src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.TypeMap.Trimmable.targets	Major build pipeline rewrite for trimmable typemap generation, stub copying, and native-stub prep.
src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.TypeMap.Trimmable.CoreCLR.targets	Adds ILLink and assembly-store integration for typemap assemblies under CoreCLR.
src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.NativeAOT.targets	Disables TrimmableTypeMap runtime feature for NativeAOT.
src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.MonoVM.targets	Disables TrimmableTypeMap runtime feature for MonoVM.
src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/ApplicationRegistration.Trimmable.java	Adds trimmable-path ApplicationRegistration stub with empty registerApplications().
src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/PreserveLists/Trimmable.CoreCLR.xml	Adds ILLink root descriptor to preserve JNIEnvInit.Initialize.
src/Microsoft.Android.Sdk.TrimmableTypeMap/TrimmableTypeMapTypes.cs	Introduces result/config records for manifest + provider sources.
src/Microsoft.Android.Sdk.TrimmableTypeMap/TrimmableTypeMapGenerator.cs	Implements end-to-end generator (scan → typemap → JCW → manifest/acw-map outputs).
src/Microsoft.Android.Sdk.TrimmableTypeMap/NullableExtensions.cs	Adds NRT-friendly string helpers for netstandard2.0.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Generator/ManifestGenerator.cs	Adds Generate overload accepting pre-loaded manifest template and refactors default creation.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Generator/ManifestModel.cs	Removes old manifest model types (replaced by scanner records).
src/Microsoft.Android.Sdk.TrimmableTypeMap/Generator/JniSignatureHelper.cs	Fixes nested-class JNI name conversion for Java source output.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/JavaPeerScanner.cs	Adds manifest scanning, component attribute capture, and correct native callback/declaring-type derivation.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/JavaPeerInfo.cs	Updates component attribute documentation and usage.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/AssemblyIndex.cs	Expands attribute decoding to capture component properties, intent-filters, metadata, and assembly-level manifest info.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/AssemblyManifestInfo.cs	Adds aggregated assembly-level manifest data model.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/ComponentInfo.cs	Adds component kind + data model for manifest generation.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/IntentFilterInfo.cs	Adds intent-filter data model used by manifest generation.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/MetaDataInfo.cs	Adds metadata data model used by manifest generation.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/PermissionInfo.cs	Adds permission data model used by manifest generation.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/PermissionGroupInfo.cs	Adds permission-group data model used by manifest generation.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/PermissionTreeInfo.cs	Adds permission-tree data model used by manifest generation.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/UsesPermissionInfo.cs	Adds uses-permission data model used by manifest generation.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/UsesFeatureInfo.cs	Adds uses-feature data model used by manifest generation.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/UsesLibraryInfo.cs	Adds uses-library data model used by manifest generation.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/UsesConfigurationInfo.cs	Adds uses-configuration data model used by manifest generation.
src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/PropertyInfo.cs	Adds manifest property data model used by manifest generation.

Copilot · 2026-03-27T11:29:49Z

src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/AssemblyIndex.cs

+			} else if (attrName == "IntentFilterAttribute") {
+				attrInfo ??= new TypeAttributeInfo ("IntentFilterAttribute");
+				attrInfo.IntentFilters.Add (ParseIntentFilterAttribute (ca));
+			} else if (attrName == "MetaDataAttribute") {
+				attrInfo ??= new TypeAttributeInfo ("MetaDataAttribute");
+				attrInfo.MetaData.Add (ParseMetaDataAttribute (ca));


IntentFilterAttribute / MetaDataAttribute can initialize attrInfo with a TypeAttributeInfo whose AttributeName is not a component attribute. If those attributes appear before [Activity]/[Service]/…, later component parsing won’t create the correct TypeAttributeInfo subtype (e.g., ApplicationAttributeInfo), and ToComponentInfo() won’t recognize the component kind, so manifest generation may silently drop component data/intent-filters/metadata. Consider keeping component-kind separate from intent-filter/metadata collection (e.g., always create the component TypeAttributeInfo via CreateTypeAttributeInfo() when a component attribute is encountered, and store intent-filters/metadata on a separate structure or on a type-info object that doesn’t overwrite the component attribute identity).

Copilot · 2026-03-27T11:29:49Z

...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 Outputs as typemaps.%(Identity).ll, but GenerateEmptyTypemapStub writes files named typemap.{abi}.ll. This output mismatch breaks MSBuild incremental up-to-date checks (the target will look for non-existent outputs and rerun every build). Update the Outputs pattern (and/or the generated filename) so they match exactly.

Suggested change

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

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

Copilot · 2026-03-27T11:29:49Z

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

+		var generator = CreateGenerator ();
+		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 argument. The repo guidance is to avoid ! even in tests; prefer a nullable local (e.g., IReadOnlyList<string>? assemblyPaths = null) and pass that, or otherwise structure the test so it doesn’t require !.

…e enable - Fix ParseAttributes: collect IntentFilter/MetaData in local lists and attach after the loop to avoid creating attrInfo with wrong AttributeName when [IntentFilter] appears before [Activity] - Remove redundant #nullable enable from 13 files (project has <Nullable>enable) Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

…into dev/simonrozsival/trimmable-typemap-build-pipeline-v2

…/simonrozsival/trimmable-typemap-build-pipeline-v2

- Remove redundant #nullable enable from 6 Generator files and task file - Convert string.IsNullOrEmpty to IsNullOrEmpty extension in task Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

simonrozsival and others added 12 commits March 27, 2026 10:17

Move ParseTargetFrameworkVersion to GenerateTrimmableTypeMap task

68f2409

This is MSBuild input parsing, not core generator logic. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Copilot AI review requested due to automatic review settings March 27, 2026 11:25

simonrozsival requested a review from jonathanpeppers as a code owner March 27, 2026 11:25

Copilot started reviewing on behalf of simonrozsival March 27, 2026 11:25 View session

simonrozsival mentioned this pull request Mar 27, 2026

[TrimmableTypeMap] Root manifest-referenced types as unconditional #11016

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Copilot AI reviewed Mar 27, 2026

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simonrozsival mentioned this pull request Mar 27, 2026

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

Draft

simonrozsival marked this pull request as draft March 27, 2026 11:44

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

simonrozsival and others added 5 commits March 27, 2026 13:04

Address review fixes

1183f9d

Merge branch 'dev/simonrozsival/extract-trimmable-typemap-generator' …

1f2243c

…into dev/simonrozsival/trimmable-typemap-build-pipeline-v2

Merge branch 'dev/simonrozsival/scanner-manifest-attributes' into dev…

c6188dd

…/simonrozsival/trimmable-typemap-build-pipeline-v2

Address review: remove #nullable enable, use IsNullOrEmpty extension

db8fc87

- Remove redundant #nullable enable from 6 Generator files and task file - Convert string.IsNullOrEmpty to IsNullOrEmpty extension in task Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

simonrozsival mentioned this pull request Mar 30, 2026

[TrimmableTypeMap] Run full on-device test suite with trimmable type map #11054

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[TrimmableTypeMap] Build pipeline: targets, stubs, manifest integration, feature switches#11036

[TrimmableTypeMap] Build pipeline: targets, stubs, manifest integration, feature switches#11036
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	Outputs="@(_BuildTargetAbis->'$(_NativeAssemblySourceDir)typemaps.%(Identity).ll')">
	Outputs="@(_BuildTargetAbis->'$(_NativeAssemblySourceDir)typemap.%(Identity).ll')">

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simonrozsival commented Mar 27, 2026

Summary

New files

Rewritten targets

Feature switches

Modified tasks

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