[dotnet-linker] Use [DynamicDependency] attributes instead of manual marking when preserving smart enum methods. by rolfbjarne · Pull Request #24934 · dotnet/macios

rolfbjarne · 2026-03-19T13:32:19Z

This makes it easier to move this code out of a custom linker step in the future.

Contributes towards #17693.

Copilot

Pull request overview

This PR updates the dotnet-linker integration to preserve smart-enum conversion methods by injecting [DynamicDependency] attributes instead of manually marking methods in a custom mark handler, supporting the longer-term goal of removing custom linker steps (issue #17693).

Changes:

Added a new PreserveSmartEnumConversionsStep that scans assemblies for BindAsAttribute usage and adds DynamicDependency attributes to keep GetConstant/GetValue.
Refactored the existing PreserveSmartEnumConversionsHandler to reuse shared preservation logic.
Extended AppBundleRewriter with a helper to add DynamicDependency attributes, and wired the new step into Xamarin.Shared.Sdk.targets behind a property toggle.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
tools/linker/MonoTouch.Tuner/PreserveSmartEnumConversions.cs	Refactors mark handler to delegate smart-enum detection/preservation to shared helper logic.
tools/dotnet-linker/PreserveSmartEnumConversionsStep.cs	Introduces a new pre-mark linker step that injects `DynamicDependency` attributes for smart-enum conversions.
tools/dotnet-linker/AppBundleRewriter.cs	Adds a `DynamicDependencyAttribute` ctor reference and a convenience method to attach the attribute based on type/module location.
dotnet/targets/Xamarin.Shared.Sdk.targets	Adds a property toggle and registers the new step conditionally, keeping the old handler as fallback.

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…marking when preserving smart enum methods. This makes it easier to move this code out of a custom linker step in the future. Contributes towards #17693.

Copilot

Pull request overview

This PR updates the dotnet-linker pipeline to preserve smart enum conversion methods by injecting DynamicDependency attributes (when enabled) instead of relying solely on manual marking in a custom mark handler, helping reduce reliance on custom linker steps (issue #17693).

Changes:

Introduces a new PreserveSmartEnumConversionsStep (an AssemblyModifierStep) that adds DynamicDependency attributes to root smart enum conversion methods.
Refactors the existing PreserveSmartEnumConversionsHandler to reuse shared preservation logic.
Extends AppBundleRewriter with helpers to add DynamicDependency attributes (including a guard to only add dependencies targeting trimmed assemblies) and wires the new step into Xamarin.Shared.Sdk.targets.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
tools/linker/MonoTouch.Tuner/PreserveSmartEnumConversions.cs	Refactors the mark handler to delegate logic to a shared preserver helper.
tools/dotnet-linker/PreserveSmartEnumConversionsStep.cs	Adds a new assembly-modifier step that preserves smart enum conversions via `DynamicDependency` attributes.
tools/dotnet-linker/PreserveProtocolsStep.cs	Adds clarifying comment about only processing linked assemblies.
tools/dotnet-linker/AppBundleRewriter.cs	Adds `DynamicDependency` ctor lookup + helper to apply dependency attributes (and trims-only guard).
dotnet/targets/Xamarin.Shared.Sdk.targets	Adds MSBuild switches and wires in the new step, keeping the legacy handler as fallback.

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

…dependency-attributes-preservesmartenumconversion

vs-mobiletools-engineering-service2 · 2026-03-25T18:09:53Z

✅ [PR Build #54cf0f6] Build passed (Detect API changes) ✅

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vs-mobiletools-engineering-service2 · 2026-03-25T18:22:16Z

✅ 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 )

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

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Hash: 54cf0f64c18cf2df463d82300d3bc263a54fcfa4 [PR build]

vs-mobiletools-engineering-service2 · 2026-03-25T18:51:19Z

✅ [CI Build #54cf0f6] Build passed (Build packages) ✅

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Hash: 54cf0f64c18cf2df463d82300d3bc263a54fcfa4 [PR build]

vs-mobiletools-engineering-service2 · 2026-03-25T19:19:19Z

✅ [CI Build #54cf0f6] Build passed (Build macOS tests) ✅

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Hash: 54cf0f64c18cf2df463d82300d3bc263a54fcfa4 [PR build]

vs-mobiletools-engineering-service2 · 2026-03-27T22:34:40Z

🚀 [CI Build #54cf0f6] Test results 🚀

Test results

✅ All tests passed on VSTS: test results.

🎉 All 156 tests passed 🎉

Tests counts

✅ 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 6 tests passed. Html Report (VSDrops) Download
✅ linker: All 44 tests passed. Html Report (VSDrops) Download
✅ monotouch (iOS): All 11 tests passed. Html Report (VSDrops) Download
✅ monotouch (MacCatalyst): All 15 tests passed. Html Report (VSDrops) Download
✅ monotouch (macOS): All 12 tests passed. Html Report (VSDrops) Download
✅ monotouch (tvOS): All 11 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. 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

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✅ Linux build succeeded

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Hash: 54cf0f64c18cf2df463d82300d3bc263a54fcfa4 [PR build]

rolfbjarne requested a review from Copilot March 19, 2026 13:32

Copilot AI reviewed Mar 19, 2026

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Comment thread tools/dotnet-linker/PreserveSmartEnumConversionsStep.cs Outdated

Comment thread tools/linker/MonoTouch.Tuner/PreserveSmartEnumConversions.cs Outdated

Comment thread tools/dotnet-linker/PreserveSmartEnumConversionsStep.cs