[bgen] Route output through IToolLog

[rolfbjarne]

Refactor bgen diagnostics and normal output to use an injected IToolLog while preserving standalone command-line behavior through ConsoleLog.

This adds BindingTouch.Run (string [] args, IToolLog log, CancellationToken cancellationToken) for in-process callers. It is preparatory work for #26590, which will pass the BGen MSBuild task as the logger when invoking bgen in-process.

This PR is stacked on #26614, which removes bgen's source compilation and subprocess execution support. The change preserves bgen warning/error formatting, verbosity handling, exit codes, unexpected-exception reporting, cancellation behavior, and help output. Focused tests cover ConsoleLog, injected normal/warning/error output, BI0000 errors, and cancellation.

🤖 Pull request created by Copilot

[Copilot]

🟡 Changes recommended

Four unresolved findings remain, including one critical process-termination issue and three moderate correctness or concurrency issues.

Get a fresh assessment by requesting another Copilot review.

Pull request overview

This pull request refactors bgen diagnostics and compiler execution around injected IToolLog, adding in-process BindingTouch.Run while preserving standalone CLI behavior.

Changes:

• Adds logger-aware execution with cancellation and custom HOME support.
• Routes diagnostics and compiler output through injected logging.
• Adds focused logging and cancellation tests.

Unresolved findings:

• Critical (3 votes) — src/bgen/Generator.cs:1252: invalid selectors can terminate the host process.
• Moderate (1 vote) — src/bgen/BindingTouch.cs:401: cancellation is not checked during generation.
• Moderate (1 vote) — src/bgen/BindingTouch.cs:126: global warning state is unsafe for concurrent runs.
• Moderate (1 vote) — src/bgen/error.cs:176: warning details may be promoted to MSBuild errors.

File summaries

File	Summary
tools/common/IToolLog.cs	Preserves standalone console routing.
tools/common/Driver.execution.cs	Adds cancellation-aware process execution.
tests/bgen/LoggingTests.cs	Tests logging, errors, and cancellation.
src/bgen/Nomenclator.cs	Routes nomenclator warnings through the logger.
src/bgen/Generator.cs	Uses injected logging for generator diagnostics.
src/bgen/error.cs	Routes diagnostics through IToolLog.
src/bgen/BindingTouch.cs	Adds in-process execution and cancellation handling.
src/bgen/AttributeManager.cs	Stores the diagnostic logger.

Review details

Suppressed comments (3)

src/bgen/BindingTouch.cs:402

• ⚠️ bug — The token is checked immediately before and after g.Go(), but not while generation runs. A cancellation requested during this synchronous traversal is therefore ignored until the entire generator finishes (and may then proceed to compilation), so the new in-process entry point cannot cancel promptly. Add cancellation checks within the generator's long-running traversal and cover cancellation during generation.

			g.Go ();
			ThrowIfCancellationRequested ();

src/bgen/BindingTouch.cs:126

• ❌ concurrency — Exposing Run for in-process callers makes concurrent invocations possible, but warning severity is still stored in the process-global ErrorHelper.warning_levels dictionary: Main3 clears it, option parsing mutates it, and BindingException constructors read it. Parallel MSBuild tasks can therefore overwrite or clear each other's --warnaserror/--nowarn settings (and race on the dictionary), producing incorrect diagnostics. Keep warning state in the per-run context/logger or serialize Run invocations.

	public static int Run (string [] args, IToolLog log, CancellationToken cancellationToken, string? customHome)

src/bgen/error.cs:177

• ⚠️ bug — For a warning (error == false), this still sends the stack trace through LogError. The injected MSBuild logger maps IToolLog.LogError(string) to Log.LogError, so a verbose bgen warning is promoted to an MSBuild error and can fail the build. Route warning details through log.Log while retaining LogError for actual errors.

			if (log.Verbosity > 2 && e.StackTrace is not null)
				log.LogError (e.StackTrace);

• Files reviewed: 8/8 changed files
• Comments generated: 1
• Review effort level: Lite

[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

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Pipeline on Agent
Hash: bdf0c1662bf58cb123f0e5ac84475b5e8ab685e7 [PR build]

[rolfbjarne]

Superseded by #26615, which contains the rebased changes on a new branch because updating this PR's published branch would require a prohibited force-push.