Merge remote-tracking branch 'upstream/main' into DUsRecordsCompiledT…

…oStrings
abonie · Jul 30, 2026 · Jun 21, 2026 · Jun 21, 2026 · Jun 21, 2026 · Jun 21, 2026
commit 2ccd69d9c09a341e94d0dc7686d1912bb4087ea5
@@ -143,6 +143,7 @@
 * Debug: rework conditional erasure, fix stepping over literals ([PR #19897](https://github.com/dotnet/fsharp/pull/19897))
 * Debug: fix if and match condition sequence points ([PR #19932](https://github.com/dotnet/fsharp/pull/19932))
 * Under `--reflectionfree`, discriminated unions, records and anonymous records now get a [generated `ToString`](../../reflectionfree-printing.md) (rendering each field like `Option` does) instead of falling back to the namespace-qualified type name. ([PR #19976](https://github.com/dotnet/fsharp/pull/19976))
+* Support common types of `NotNullIfNotNullAttribute` usage. If a method parameter is marked with `NotNullIfNotNullAttribute`, the compiler will now honor this attribute and mark the return type as non-null. ([PR #19977](https://github.com/dotnet/fsharp/pull/19977))
 * Checker: recover on checking language version ([PR ##19970](https://github.com/dotnet/fsharp/pull/19970))
 * Implied argument names for function-to-delegate coercions now fall back to the delegate's `Invoke` parameter names when the function has no recoverable names (e.g. a partial application like `System.Func<int, int>((+) 1)`), instead of synthetic `delegateArg0`, `delegateArg1`, … names. ([PR #20001](https://github.com/dotnet/fsharp/pull/20001))
 * Add internal `ResetCompilerGeneratedNameState` to `CompilerGlobalState` name generators so warm-checker re-compilation can produce fresh-process-identical generated names. ([PR #20017](https://github.com/dotnet/fsharp/pull/20017))