CsWin32 follow-up: polyfills, ValueStringBuilder, and additional interop migrations

[JeremyKuhne]

Builds on the initial CsWin32 migration with additional cleanup and migrations:

• Add ValueStringBuilder to Framework (adapted from runtime/WinForms/Touki/etc.) and use it in NodeLauncher to build the command line and environment block into pinnable buffers, replacing Marshal.StringToHGlobalUni.

• Add Polyfills/ for Framework: IComIID (and supporting helpers) gated by #if !NET so struct-based COM works on net472, plus Span.Replace and ReadOnlySpan.IndexOfAnyExcept polyfills.

• Unify RunningObjectTable on the CsWin32 struct-based COM path.

• LockCheck: use WIN32_ERROR locals/parameters and RM_APP_* enums; add a FILETIME.ToDateTime() helper and document the type-matching rule.

• Migrate additional P/Invokes to CsWin32: CommunicationsUtilities env vars; NodeLauncher CreateProcess; Utilities/LockCheck Restart Manager; UntrustedLocationCheck SHGetKnownFolderPath; Tasks CreateHardLink/MoveFileEx/GetLogicalDrives, GetFileVersion (mscoree), and BootstrapperUtil resource updater APIs.

• Remove dead crypt32/advapi32 P/Invokes and the unused CreateProcess declaration from Tasks/NativeMethods.

• Add unit tests for ValueStringBuilder, the SpanExtensions polyfill, and the FILETIME helpers.

[github-actions]

🔍 Skill Validator Results

✅ All checks passed

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

Summary

Level	Finding
ℹ️	Found 2 skill(s)
ℹ️	[cswin32-com] 📊 cswin32-com: 1,788 BPE tokens [chars/4: 1,702] (detailed ✓), 9 sections, 4 code blocks
ℹ️	[cswin32-interop] 📊 cswin32-interop: 2,351 BPE tokens [chars/4: 2,263] (detailed ✓), 13 sections, 3 code blocks
ℹ️	✅ All checks passed (2 skill(s))

Full validator output

```text Found 2 skill(s) [cswin32-com] 📊 cswin32-com: 1,788 BPE tokens [chars/4: 1,702] (detailed ✓), 9 sections, 4 code blocks [cswin32-interop] 📊 cswin32-interop: 2,351 BPE tokens [chars/4: 2,263] (detailed ✓), 13 sections, 3 code blocks ✅ All checks passed (2 skill(s)) ```

[Copilot]

Pull request overview

This PR is a follow-up to the initial CsWin32 migration, extending struct-based interop usage across MSBuild and adding supporting infrastructure (polyfills + ValueStringBuilder) to improve compatibility and reduce allocations in Windows interop-heavy paths.

Changes:

• Added ValueStringBuilder (Framework) and Span polyfills, plus unit tests for these helpers and FILETIME conversions.
• Migrated additional Win32 P/Invokes to CsWin32 (Restart Manager / ROT / CreateProcess / SHGetKnownFolderPath / env block APIs) and removed now-dead native interop declarations.
• Updated build/project wiring and documentation to reflect the new CsWin32 + COM polyfill approach across TFMs.

Reviewed changes

Copilot reviewed 26 out of 26 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
src/Utilities/LockCheck.cs	Migrates Restart Manager usage to CsWin32 and adds typed WIN32_ERROR/RM enums (but introduces a build break when FEATURE_WINDOWSINTEROP is off).
src/Tasks/NativeMethods.cs	Removes unused Win32 crypto/process interop and switches several Windows APIs to CsWin32.
src/Tasks/BootstrapperUtil/ResourceUpdater.cs	Ports bootstrapper resource updating to CsWin32 and adds an UpdateResource helper.
src/Tasks/BootstrapperUtil/NativeMethods.cs	Deletes legacy bootstrapper resource-update P/Invokes.
src/Tasks/AssemblyDependency/AssemblyInformation.cs	Migrates mscoree!GetFileVersion usage to CsWin32.
src/Framework/Windows/Win32/GeneratedInteropClsCompliance.cs	Adds CLS compliance suppressions for additional CsWin32 COM structs.
src/Framework/Windows/Win32/Foundation/FileTimeExtensions.cs	Adds FILETIME → DateTime helpers for local/UTC conversions.
src/Framework/Utilities/ValueStringBuilder.cs	Introduces pooled/stack-based string building for interop-friendly, pinnable buffers.
src/Framework/Polyfills/SpanExtensions.cs	Adds net472/netstandard Span API polyfills (Replace, IndexOfAnyExcept).
src/Framework/Polyfills/IComIIDPolyfills.cs	Adds net472/netstandard COM IID polyfills by attaching IComIID to CsWin32 COM structs via partials.
src/Framework/Polyfills/IComIID.cs	Adds the instance-based IComIID polyfill for non-.NET TFMs.
src/Framework/NativeMethods.txt	Updates CsWin32 inputs to generate additional APIs/types used by the migrations.
src/Framework/Microsoft.Build.Framework.csproj	Adjusts compile-item conditions to include COM helpers and the new polyfill structure correctly.
src/Framework/Framework/Windows/Win32/IComIID.cs	Removes the old location of the net472 IComIID polyfill (replaced by Polyfills/).
src/Framework/BackEnd/CommunicationsUtilities.cs	Migrates environment block retrieval/freeing to CsWin32.
src/Framework.UnitTests/ValueStringBuilder_Tests.cs	Adds unit tests for ValueStringBuilder.
src/Framework.UnitTests/SpanExtensions_Tests.cs	Adds unit tests for Span polyfills (non-.NET TFMs only).
src/Framework.UnitTests/FileTimeExtensions_Tests.cs	Adds unit tests for FILETIME extension helpers.
src/Build/Microsoft.Build.csproj	Removes a now-unneeded native interop source file from compilation.
src/Build/Instance/RunningObjectTable.cs	Switches ROT implementation to struct-based COM via CsWin32 and adds richer COM error details.
src/Build/BuildCheck/Checks/UntrustedLocationCheck.cs	Migrates SHGetKnownFolderPath to CsWin32 with a safe PWSTR free path.
src/Build/BackEnd/Components/Communications/NodeLauncher.cs	Uses ValueStringBuilder to build pinnable command line/env blocks and migrates CreateProcess to CsWin32.
src/Build.UnitTests/BackEnd/BuildRequest_Tests.cs	Updates Windows platform attributes to match revised minimum supported versions.
.github/skills/cswin32-interop/SKILL.md	Documents enum/type preference and FILETIME conversion helpers for interop work.
.github/skills/cswin32-com/SKILL.md	Documents COM struct usage, plus the new IComIID polyfill approach for non-.NET TFMs.
.editorconfig	Expands CLS compliance suppression scope to cover the new COM IID polyfill file.

[github-actions]

Review Summary: CsWin32 COM Interop Migration

This is a well-executed migration from manual P/Invoke to CsWin32-generated types. The PR correctly replaces BackendNativeMethods, Ole32 interop, Crypt32/Advapi32 dead P/Invokes, and Restart Manager manual types with their CsWin32 equivalents. The IComIID polyfill pattern for net472/netstandard2.0 is sound and follows the established winforms approach.

Strengths

• Correctness: The ValueStringBuilder + fixed pattern for CreateProcessW correctly provides a writable, null-terminated buffer — satisfying the Win32 API contract.
• Resource cleanup: ComScope<T> usage in RunningObjectTable properly manages COM pointer lifetimes for transient objects (monikers, IUnknown results).
• Environment block: The ValueStringBuilder-based approach eliminates Marshal.StringToHGlobalUni / Marshal.FreeHGlobal with a cleaner stack-first allocation pattern.
• MAKEINTRESOURCE: Correct (PCWSTR)(char*)intValue pattern for integer resource types.
• Behavioral equivalence on Unix: The CreateNoWindow = redirectStreams simplification preserves the original semantics since redirectStreams was only true when CREATENOWINDOW was set.

Concerns (see inline comments)

1. RunningObjectTable finalizer without IDisposable (medium) — Raw COM pointer released only via finalizer; risks crash-on-shutdown if COM is torn down first. Previous RCW had built-in shutdown protection.
2. ResourceUpdater silent return false (low) — Non-Windows path returns false without logging, which may confuse callers checking the return value.

No breaking changes detected

• CLI behavior unchanged
• No new warnings or errors introduced
• Public API surface unaffected
• All conditional compilation guards (#if FEATURE_WINDOWSINTEROP, #if !NET) correctly preserve behavior on all TFMs

Note

🔒 Integrity filter blocked 1 item

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• #13705 pull_request_read: has lower integrity than agent requires. The agent cannot read data with integrity below "approved".

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Generated by Expert Code Review (on open) for issue #13705 · ● 20.4M