Who contributed to .NET on May 17, 2026?

4 developers shipped this update, including ToddGrun, wtgodbe, tannergooding, and Copilot.

What were the notable .NET updates?

Fix TryGetAttributeName nameLocation to include parameter name, Delete unused WBF_NoBarrier_CheckNotHeapInDebug and CORINFO_HELP_ASSIGN_REF_ENSURE_NONHEAP (#128230), and Use deterministic pre-step for re-quarantine detection to bypass DIFC filtering.

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The Wire · Showcase

ROSLYN FIXES RAZOR DIRECTIVE SPANS, RUNTIME ELIMINATES DEAD GC CODE

By RepoJournal · Filed 06:03 UTC on May 17, 2026 · About .NET

4 people shipped this

ToddGrun @ToddGrun 1 cited

wtgodbe @wtgodbe 1 cited

tannergooding @tannergooding 1 cited

Copilot @Copilot 1 cited

Roslyn's completion engine now correctly reports attribute parameter locations in Razor directives, fixing a precision bug that cascaded into performance work across webtools.

The Roslyn team closed a long-standing span computation bug where directive attributes like @bind-value:format were reported as only @bind-value, omitting the colon and parameter portion [1]. This fix extracts from a larger effort to reduce webtools dependence during completion for measurable performance gains. In parallel, the runtime team is aggressively pruning dead code paths: they deleted the unused WBF_NoBarrier_CheckNotHeapInDebug write barrier form and its associated JIT helper, which were never emitted by the garbage collector [2]. On the JIT side, folding optimizations for double not/neg operations moved earlier in the pipeline, eliminating trivially unnecessary nodes and showing measurable throughput improvements in SPMI benchmarks [4]. The cDAC work continues reshaping allocation-heavy APIs like GetHeapSegments into callback-based EnumerateHeapSegments to reduce native heap pressure [5]. ASP.NET Core shipped a critical fix to the quarantine workflow where external contributor PRs were silently filtered by DIFC integrity checks, causing re-quarantine detection to fail and tests to be incorrectly unquarantined [3].

Action items

→ Validate Razor directive completion spans in your tooling integration tests dotnet/roslyn [plan]
→ Review ASP.NET Core quarantine workflow changes if you maintain test infrastructure dotnet/aspnetcore [monitor]
→ Update cDAC consumers to use EnumerateHeapSegments callback pattern dotnet/runtime [plan]

References

[1] Fix TryGetAttributeName nameLocation to include parameter name ↗ dotnet/roslyn
[2] Delete unused WBF_NoBarrier_CheckNotHeapInDebug and CORINFO_HELP_ASSIGN_REF_ENSURE_NONHEAP (#128230) dotnet/runtime
[3] Use deterministic pre-step for re-quarantine detection to bypass DIFC filtering ↗ dotnet/aspnetcore
[4] Move the folding of double not/neg to gtFoldExpr ↗ dotnet/runtime
[5] [cDAC] Reshape DacDbi API GetHeapSegments to EnumerateHeapSegments and implement in cDAC ↗ dotnet/runtime

Quick answers

What shipped in .NET on May 17, 2026?: Roslyn's completion engine now correctly reports attribute parameter locations in Razor directives, fixing a precision bug that cascaded into performance work across webtools. In total, 10 commits and 9 pull requests landed.
Who contributed to .NET on May 17, 2026?: 4 developers shipped this update, including ToddGrun, wtgodbe, tannergooding, and Copilot.
What were the notable .NET updates?: Fix TryGetAttributeName nameLocation to include parameter name, Delete unused WBF_NoBarrier_CheckNotHeapInDebug and CORINFO_HELP_ASSIGN_REF_ENSURE_NONHEAP (#128230), and Use deterministic pre-step for re-quarantine detection to bypass DIFC filtering.

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