[dotnet-linker] Use [DynamicDependency] attributes instead of manual marking when preserving smart enum methods.

[rolfbjarne]

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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[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.

[vs-mobiletools-engineering-service2]

🔥 [CI Build #9cfacc0] Test results 🔥

Test results

❌ Tests failed on VSTS: test results

0 tests crashed, 12 tests failed, 144 tests passed.

Failures

❌ linker tests

1 tests failed, 43 tests passed.

Failed tests

• link all/iOS - simulator/Release: LaunchFailure

Html Report (VSDrops) Download

❌ monotouch tests (tvOS)

11 tests failed, 0 tests passed.

Failed tests

• monotouch-test/tvOS - simulator/Debug: BuildFailure
• monotouch-test/tvOS - simulator/Debug (LinkSdk): BuildFailure
• monotouch-test/tvOS - simulator/Debug (static registrar): BuildFailure
• monotouch-test/tvOS - simulator/Release (all optimizations): BuildFailure
• monotouch-test/tvOS - simulator/Debug (ARM64): BuildFailure
• monotouch-test/tvOS - simulator/Release (NativeAOT, ARM64): BuildFailure
• monotouch-test/tvOS - simulator/Debug (managed static registrar): BuildFailure
• monotouch-test/tvOS - simulator/Release (managed static registrar, all optimizations): BuildFailure
• monotouch-test/tvOS - simulator/Release (NativeAOT, x64): BuildFailure
• monotouch-test/tvOS - simulator/Debug (interpreter): BuildFailure
• monotouch-test/tvOS - simulator/Release (interpreter): BuildFailure

Html Report (VSDrops) Download

Successes

✅ 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
✅ 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
✅ 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

Linux Build Verification

✅ Linux build succeeded

Pipeline on Agent
Hash: 9cfacc05e341669a97a6ff423c28cfb2fbc49ffd [PR build]

[vs-mobiletools-engineering-service2]

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

Pipeline on Agent
Hash: 54cf0f64c18cf2df463d82300d3bc263a54fcfa4 [PR build]

[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: 54cf0f64c18cf2df463d82300d3bc263a54fcfa4 [PR build]

[vs-mobiletools-engineering-service2]

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

Pipeline on Agent
Hash: 54cf0f64c18cf2df463d82300d3bc263a54fcfa4 [PR build]

[vs-mobiletools-engineering-service2]

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

Pipeline on Agent
Hash: 54cf0f64c18cf2df463d82300d3bc263a54fcfa4 [PR build]