[dotnet-linker] Only override NSObjectProxyAttribute.LookupUnmanagedFunction when the type actually has any UnmanagedCallersOnly methods to look up.

[rolfbjarne]

Only override NSObjectProxyAttribute.LookupUnmanagedFunction when the type actually has any UnmanagedCallersOnly methods to look up. The method is now virtual instead of abstract, and the base implementation returns IntPtr.Zero, which is exactly what the generated override did for types without any such methods.

Copilot-Session: 6aeeddfd-3bd8-4129-ad90-7292860c4b66

[Copilot]

Pull request overview

This PR reduces the size of trimmable static registrar type map assemblies by only emitting NSObjectProxyAttribute.LookupUnmanagedFunction overrides for proxy types that actually need to resolve any UnmanagedCallersOnly trampolines. It does this by making LookupUnmanagedFunction virtual with a default IntPtr.Zero implementation, and then skipping override emission when there are no entry points to look up.

Changes:

• Make NSObjectProxyAttribute.LookupUnmanagedFunction virtual with a default implementation returning IntPtr.Zero.
• Update the trimmable registrar step to only generate LookupUnmanagedFunction when there are any UnmanagedCallersOnly entry points for the proxied type.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
tools/dotnet-linker/Steps/TrimmableRegistrarStep.cs	Only emits a LookupUnmanagedFunction override when UnmanagedCallersOnly trampolines exist for the proxy type.
src/ObjCRuntime/TypeMaps.cs	Changes LookupUnmanagedFunction from abstract to virtual, with a default IntPtr.Zero implementation to support skipping overrides.

[vs-mobiletools-engineering-service2]

⚠️ AppSizeTest expected files changed ⚠️

The AppSizeTest detected changes in the expected app size files.

To update the expected files, add a comment with the following command:

/apply-gist https://gist.github.com/vs-mobiletools-engineering-service2/6957d959a45ca8593060ebf74f17b36c

Updated files

• iOS-NativeAOT-TrimmableStatic-size.txt
• MacCatalyst-NativeAOT-TrimmableStatic-size.txt
• MacOSX-CoreCLR-Interpreter-size.txt
• MacOSX-CoreCLR-Interpreter-TrimmableStatic-size.txt
• MacOSX-NativeAOT-TrimmableStatic-size.txt
• TVOS-NativeAOT-size.txt
• TVOS-NativeAOT-TrimmableStatic-size.txt

Pipeline on Agent
Hash: d76b78b4819bcdd3154fc7d68397709d8a550241 [PR build]

[rolfbjarne]

/apply-gist https://gist.github.com/vs-mobiletools-engineering-service2/6957d959a45ca8593060ebf74f17b36c

[github-actions]

✅ Applied expected app size files from gist.

[vs-mobiletools-engineering-service2]

✅ API diff for current PR / commit

NET (empty diffs)

• iOS: vsdrops gist ( No breaking changes )
• tvOS: vsdrops gist ( No breaking changes )
• MacCatalyst: vsdrops gist ( No breaking changes )
• macOS: vsdrops gist ( No breaking changes )

✅ API diff vs stable

NET (empty diffs)

• iOS: vsdrops gist ( No breaking changes )
• tvOS: vsdrops gist ( No breaking changes )
• MacCatalyst: vsdrops gist ( No breaking changes )
• macOS: vsdrops gist ( No breaking changes )

ℹ️ Generator diff

Generator Diff: vsdrops (html) vsdrops (raw diff) gist (raw diff) - Please review changes)

Pipeline on Agent
Hash: 39a281bbc3ba47589012527f7e51be00ad026c64 [PR build]

[vs-mobiletools-engineering-service2]

🚀 [CI Build #39a281b] Test results 🚀

Test results

✅ All tests passed on VSTS: test results.

🎉 All 203 tests passed 🎉

Tests counts

✅ assembly-processing: All 1 tests passed. Html Report (VSDrops) Download
✅ cecil: All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (iOS): All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (MacCatalyst): All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (macOS): All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (Multiple platforms): All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (tvOS): All 1 tests passed. Html Report (VSDrops) Download
✅ framework: All 2 tests passed. Html Report (VSDrops) Download
✅ fsharp: All 4 tests passed. Html Report (VSDrops) Download
✅ generator: All 5 tests passed. Html Report (VSDrops) Download
✅ interdependent-binding-projects: All 4 tests passed. Html Report (VSDrops) Download
✅ introspection: All 4 tests passed. Html Report (VSDrops) Download
✅ linker (iOS): All 15 tests passed. Html Report (VSDrops) Download
✅ linker (MacCatalyst): All 15 tests passed. Html Report (VSDrops) Download
✅ linker (macOS): All 21 tests passed. Html Report (VSDrops) Download
✅ linker (tvOS): All 15 tests passed. Html Report (VSDrops) Download
✅ monotouch (iOS): All 19 tests passed. Html Report (VSDrops) Download
✅ monotouch (MacCatalyst): All 18 tests passed. Html Report (VSDrops) Download
✅ monotouch (macOS): All 19 tests passed. Html Report (VSDrops) Download
✅ monotouch (tvOS): All 19 tests passed. Html Report (VSDrops) Download
✅ msbuild: All 2 tests passed. Html Report (VSDrops) Download
✅ sharpie: All 1 tests passed. Html Report (VSDrops) Download
✅ windows: All 3 tests passed. Html Report (VSDrops) Download
✅ xcframework: All 4 tests passed. Html Report (VSDrops) Download
✅ xtro: All 1 tests passed. Html Report (VSDrops) Download

macOS tests

✅ Tests on macOS Monterey (12): All 5 tests passed. Html Report (VSDrops) Download
✅ Tests on macOS Ventura (13): All 5 tests passed. Html Report (VSDrops) Download
✅ Tests on macOS Sonoma (14): All 5 tests passed. [attempt 2] Html Report (VSDrops) Download
✅ Tests on macOS Sequoia (15): All 5 tests passed. Html Report (VSDrops) Download
✅ Tests on macOS Tahoe (26): All 5 tests passed. Html Report (VSDrops) Download

Linux Build Verification

✅ Linux build succeeded

Pipeline on Agent
Hash: 39a281bbc3ba47589012527f7e51be00ad026c64 [PR build]