CsWin32 follow-up: ComReference family + typelib registration interop

[JeremyKuhne]

Context

Continues the CsWin32 struct-based COM interop migration started in #13872, converting the remaining hand-rolled COM in src/Tasks to the Windows.Win32 PInvoke / ComScope<T> / AgileComPointer<T> surface defined in src/Framework. This removes the last [ComImport] / [DllImport] COM declarations in the COM-reference resolution, type-library registration, and resource-zone paths.

Changes Made

ComReference resolution (net472-only, #if FEATURE_APPDOMAIN)

• ComReferenceInfo.cs : typeLibPointer is now AgileComPointer<ITypeLib> and attr is TLIBATTR; the type library loads through PInvoke.LoadTypeLibEx into a ComScope<ITypeLib> using the PInvoke.LOAD_TLB_AS_32BIT/_64BIT constants.
• ComReference.cs : GetTypeLibAttrForTypeLib / GetTypeAttrForTypeInfo / GetVarDescForVarIndex / GetFuncDescForDescIndex / GetTypeLibNameForITypeLib (QI to ITypeLib2 + VARIANT) / Ado27Installed take struct pointers; GetPathOfTypeLib inlines PInvoke.QueryPathOfRegTypeLib(out BSTR).
• ComDependencyWalker.cs : struct pointers throughout; IID comparisons via IUnknown/IDispatch.IID_Guid; GetCustData via VARIANT + VariantClear; drops the MarshalReleaseComObject delegate and the IFixedTypeInfo usage.
• TlbReference.cs / AxReference.cs / PiaReference.cs / AxTlbBaseReference.cs / IComReferenceResolver.cs / ResolveComReference.cs gated; the TYPELIBATTR alias is repointed to Windows.Win32.System.Com.TLIBATTR.
• IFixedTypeInfo.cs is retained as public API but is no longer used internally.

Type-library registration (net472-only)

• RegisterAssembly.cs / UnregisterAssembly.cs register and unregister the type library through PInvoke.RegisterTypeLib / UnRegisterTypeLib / LoadTypeLibEx / LoadRegTypeLib, with the pointer held in a using ComScope<ITypeLib>.

GenerateResource zone check

• Deletes the hand-rolled Interop.cs (IInternetSecurityManager and friends). IsDangerous now CoCreates the security manager via PInvoke.CoCreateInstance, caches it in an AgileComPointer<IInternetSecurityManager> behind a double-checked lock, and calls MapUrlToZone on a ComScope.

Inlining / dead-code removal

• Move.cs : MoveFileEx inlined as a #if FEATURE_WINDOWSINTEROP helper over PInvoke.MoveFileEx + MOVE_FILE_FLAGS.
• Exec.cs : AllDrivesMapped inlined over PInvoke.GetLogicalDrives.
• NativeMethods.cs : removes the now-dead RegisterTypeLib / UnregisterTypeLib / LoadTypeLibEx / LoadRegTypeLib / QueryPathOfRegTypeLib / REGKIND / MoveFileEx / MoveFileFlags / AllDrivesMapped wrappers and the duplicate IUnknown / IDispatch / ITypeInfo IID constants.

Framework plumbing

• NativeMethods.txt : adds ITypeLib2, IDispatch, IDispatchEx, IEnumVARIANT, IInternetSecurityManager, LoadTypeLibEx, LoadRegTypeLib, RegisterTypeLib, UnRegisterTypeLib, QueryPathOfRegTypeLib, LOAD_TLB_AS_32BIT, LOAD_TLB_AS_64BIT.
• IComIIDPolyfills.cs : ITypeLib / ITypeLib2 / ITypeInfo / ITypeComp IComIID partials.
• GeneratedInteropClsCompliance.cs : CLSCompliant(false) partials for the newly pulled interfaces (ITypeLib2, IDispatchEx, IEnumVARIANT, IServiceProvider) to keep warn-as-error happy on net10.

Tests

• The COM-reference tests are gated #if FEATURE_APPDOMAIN and drive the struct-based code through a CCW bridge: managed mocks implement the BCL System.Runtime.InteropServices.ComTypes.* interfaces and are handed to the SUT as interface pointers via Marshal.GetComInterfaceForObject. MockTypeLib throws COMException (not Assert) on out-of-range input; MockTypeInfo drops IFixedTypeInfo from its base list with a <remarks> explaining why it must not be reintroduced (shared IID 00020401, different ABI).

Skill docs

• cswin32-com / cswin32-interop SKILL.md document the CCW-mocking boundary rules, standalone PInvoke constants, and the CS3016 transitive-CLSCompliant gotcha, and are compressed for token efficiency.

ClickOnce ManifestUtil interop (follow-up commit)

• Deletes src/Tasks/ManifestUtil/NativeMethods.cs and moves its P/Invokes to the CsWin32 PInvoke surface (adding EnumResourceNames, SetDllDirectory, SfcIsFileProtected to NativeMethods.txt).
• EmbeddedManifestReader.cs — LoadLibraryEx / EnumResourceNames / FindResource / LoadResource / LockResource / SizeofResource / FreeLibrary via PInvoke. The EnumResourceNames callback is an unmanaged stdcall function pointer bridged from a managed delegate (works on .NET Framework and .NET Core). The native path is #if FEATURE_WINDOWSINTEROP with a no-op source-build fallback.
• ComImporter.cs — rewritten to use the struct-based ITypeLib/ITypeInfo directly (LoadTypeLibEx + ComScope<ITypeLib>) instead of marshalling back to an RCW; early-returns on !IsWindows and on load failure, with inverted conditions to flatten nesting.
• SecurityUtil.cs — clr.dll loading (SetDllDirectory / LoadLibraryEx / FreeLibrary) via PInvoke, nested inside the existing RUNTIME_TYPE_NETCORE gate.
• MetadataReader.cs — GetAssemblyIdentityFromFile is a CLR-internal mscorwks export (not in the Win32 metadata), so it is declared inline at its sole call site rather than CsWin32-generated.
• Windows-only call sites are guarded by NativeMethodsShared.IsWindows (a windows6.1 platform guard) to satisfy CA1416 without rippling [SupportedOSPlatform] onto cross-platform callers.

Testing

• Microsoft.Build.Framework and Microsoft.Build.Tasks build clean (0 errors, 0 warnings) on net472 and net10.0.
• The ManifestUtil conversion additionally builds clean under source build (-p:TargetFramework=netstandard2.0 -p:DotNetBuildSourceOnly=true).
• COM-reference, Move, Exec, and RegisterAssembly unit tests pass on net472; MetadataReader / SecurityUtil / AddToWin32Manifest tests pass on net472 and net10.0.

Notes

• No behavior change is intended. The COM-reference and type-library paths are net472-only (#if FEATURE_APPDOMAIN) and the Windows interop is gated #if FEATURE_WINDOWSINTEROP, so source-build (DotNetBuildSourceOnly=true) and non-Windows builds are unaffected by construction.
• IFixedTypeInfo is kept purely as a public-API compatibility surface even though it is now unused internally.

[github-actions]

🔍 Skill Validator Results

⚠️ Warnings or advisories found

Scope	Checked
Skills	2
Agents	0
Total	2
Severity	Count
---	---:
❌ Errors	0
⚠️ Warnings	2
ℹ️ Advisories	0

Summary

Level	Finding
ℹ️	Found 2 skill(s)
ℹ️	[cswin32-com] 📊 cswin32-com: 4,238 BPE tokens [chars/4: 4,095] (standard ~), 14 sections, 7 code blocks
ℹ️	[cswin32-com] ⚠ Skill is 4,238 BPE tokens (chars/4 estimate: 4,095) — approaching "comprehensive" range where gains diminish.
ℹ️	[cswin32-interop] 📊 cswin32-interop: 3,568 BPE tokens [chars/4: 3,337] (standard ~), 14 sections, 3 code blocks
ℹ️	[cswin32-interop] ⚠ Skill is 3,568 BPE tokens (chars/4 estimate: 3,337) — approaching "comprehensive" range where gains diminish.
ℹ️	✅ All checks passed (2 skill(s))

Full validator output

```text Found 2 skill(s) [cswin32-com] 📊 cswin32-com: 4,238 BPE tokens [chars/4: 4,095] (standard ~), 14 sections, 7 code blocks [cswin32-com] ⚠ Skill is 4,238 BPE tokens (chars/4 estimate: 4,095) — approaching "comprehensive" range where gains diminish. [cswin32-interop] 📊 cswin32-interop: 3,568 BPE tokens [chars/4: 3,337] (standard ~), 14 sections, 3 code blocks [cswin32-interop] ⚠ Skill is 3,568 BPE tokens (chars/4 estimate: 3,337) — approaching "comprehensive" range where gains diminish. ✅ All checks passed (2 skill(s)) ```

[Copilot]

Pull request overview

This PR continues the MSBuild src/Tasks COM interop migration to the CsWin32 struct-based pattern (Windows.Win32.PInvoke, ComScope<T>, AgileComPointer<T>), removing remaining [ComImport]/[DllImport] COM declarations from COM reference resolution, type library registration, and the GenerateResource zone check path (net472 / Windows-only as appropriate).

Changes:

• Migrates COM reference resolution and dependency walking to struct-based COM pointers (incl. TLIBATTR, VARIANT, BSTR) and removes legacy COM wrapper plumbing from NativeMethods.cs.
• Migrates type library registration/unregistration to CsWin32 (RegisterTypeLib / UnRegisterTypeLib / LoadTypeLibEx / LoadRegTypeLib) with ComScope<T> lifetimes.
• Replaces the hand-rolled urlmon COM interop for MOTW/zone checks in GenerateResource with CoCreateInstance + cached AgileComPointer<IInternetSecurityManager>, updates unit tests to drive struct-based COM via CCW bridging, and refreshes cswin32 skills docs.

Reviewed changes

Copilot reviewed 27 out of 27 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/Tasks/UnregisterAssembly.cs	Switches typelib unregistration to CsWin32 LoadTypeLibEx + UnRegisterTypeLib with ComScope<T>.
src/Tasks/RegisterAssembly.cs	Switches typelib registration to CsWin32 LoadTypeLibEx + RegisterTypeLib with ComScope<T>.
src/Tasks/ComReferenceInfo.cs	Stores typelibs as AgileComPointer<ITypeLib> and uses CsWin32 TLIBATTR/LoadTypeLibEx flags.
src/Tasks/ComReference.cs	Rewrites typelib/typeinfo helpers to pointer-based COM, VARIANT/VariantClear, and BSTR out params.
src/Tasks/ComDependencyWalker.cs	Converts dependency walker to struct-based COM pointers and removes Marshal.ReleaseComObject injection.
src/Tasks/ResolveComReference.cs	Updates dependency scanning and task-item metadata parsing for CsWin32 TLIBATTR shapes.
src/Tasks/TlbReference.cs	Bridges agile ITypeLib* back to an RCW for TypeLibConverter (BCL API constraint).
src/Tasks/PiaReference.cs	Updates PIA lookup callsites for TLIBATTR field types.
src/Tasks/AxReference.cs	Updates wrapper filename version handling for TLIBATTR field types.
src/Tasks/AxTlbBaseReference.cs	Gates COM reference code behind FEATURE_APPDOMAIN.
src/Tasks/IComReferenceResolver.cs	Gates COM reference resolver contract behind FEATURE_APPDOMAIN and swaps to CsWin32 TLIBATTR.
src/Tasks/GenerateResource.cs	Replaces urlmon COM interop with CoCreateInstance + cached AgileComPointer<IInternetSecurityManager>.
src/Tasks/Exec.cs	Inlines AllDrivesMapped using CsWin32 GetLogicalDrives.
src/Tasks/Move.cs	Inlines MoveFileEx helper over CsWin32 PInvoke.MoveFileEx with managed fallback.
src/Tasks/NativeMethods.cs	Removes dead COM/interop wrappers and clarifies StdOle identifier as LIBID, not IID.
src/Tasks/Microsoft.Build.Tasks.csproj	Removes Interop.cs from compilation.
src/Tasks/Interop.cs	Deleted legacy [ComImport] urlmon COM definitions.
src/Tasks.UnitTests/ResolveComReference_Tests.cs	Updates test expectations for CsWin32 TLIBATTR field types.
src/Tasks.UnitTests/MockTypeLib.cs	Adjusts mock behavior for CCW boundary (throws COMException on invalid input).
src/Tasks.UnitTests/MockTypeInfo.cs	Removes IFixedTypeInfo from mock to avoid IID/ABI ambiguity across CCW.
src/Tasks.UnitTests/ComReferenceWalker_Tests.cs	Switches tests to pass CCW pointers into struct-based walker (Marshal.GetComInterfaceForObject).
src/Tasks.UnitTests/ComReference_Tests.cs	Gates COM reference tests behind FEATURE_APPDOMAIN.
src/Framework/NativeMethods.txt	Adds COM interfaces/APIs/constants required for migrated paths.
src/Framework/Polyfills/IComIIDPolyfills.cs	Adds IComIID polyfills for additional generated COM structs.
src/Framework/Windows/Win32/GeneratedInteropClsCompliance.cs	Adds [CLSCompliant(false)] partials for new transitive COM interfaces.
.github/skills/cswin32-interop/SKILL.md	Documents CsWin32 constant-vs-enum flag behavior for LoadTypeLibEx flags.
.github/skills/cswin32-com/SKILL.md	Documents CCW-based testing boundary rules for struct-based COM and CLS compliance gotchas.

[JanProvaznik]

https://devdiv.visualstudio.com/DevDiv/_git/VS/pullrequest/746732 experimental insertion

passed

[JanProvaznik]

/review

[github-actions]

❌ Expert Code Review (command) failed. Please review the logs for details.

[JanProvaznik]

I read through it, seems good.

then I gave it to worflow reviewer locally

Here's the review of PR #13975 — "CsWin32 follow-up: ComReference family + typelib registration interop" (@JeremyKuhne, 32 files).

Verification (done during review)

 - ✅ Builds clean (0 warn / 0 err): net472, net10.0, netstandard2.0, and source-only (DotNetBuildSourceOnly=true, WINDOWSINTEROP off)
 - ✅ COM tests pass: ComReferenceWalker_Tests 13/13, ResolveComReference_Tests 21/21

Verdict: ✅ Approve with nits — no blocking issues

The hardest parts of this kind of migration are all handled correctly: COM ref-count balance (ComScope<T> disposal, AgileComPointer(takeOwnership:false) paired with GIT register/revoke = net-zero), BSTR/VARIANT freeing (using/VariantClear in finally), HRESULT→same-exception equivalence, the EnumResourceNames callback kept alive via GC.KeepAlive, and the IInternetSecurityManager double-checked lock (volatile + safe publication). The "no behavior change" claim holds; the FEATURE_APPDOMAIN ⟹ FEATURE_WINDOWSINTEROP gating is sound.

Findings (all Low / Nit — none block merge)

 - L1 ComImporter.cs — non-Windows early-return leaves Success == true with null ComClasses/TypeLib. Set Success = false (unreachable in practice, but inconsistent). Most worth fixing.
 - L2 UnregisterAssembly.cs — ReleaseTLibAttr moved out of a finally; lost null-attr guard + debug assert. Restore the finally. Most worth fixing.
 - L3 ComDependencyWalker.cs:219 — GetCustData COM error now swallowed (.Succeeded) instead of aborting the typelib; only differs on genuine errors.
 - L4 ComReferenceWalker_Tests — fault-injection assertion relaxed (Count <= 1 + type check); necessary for CCW boundary but slightly less precise.
 - L5 GenerateResource.IsDangerous — zone check additionally gated on FEATURE_WINDOWSINTEROP; fail-safe in the hypothetical net4x-source-only case, fragile coupling.
 - L6 ResolveComReference.cs — short→ushort/int→uint parse widening (actually a correctness improvement; downstream casts still truncate).
 - Nits: MockTypeLib.cs:247 stray brace formatting; over-broad fixed block in RegisterAssembly.cs; IFixedTypeInfo correctly retained for public-API compat but now dead.