RFR: 8155591: Misleading warning when not overriding close method in interface extending AutoCloseable [v3]

[ExE Boss]

On Wed, 5 Nov 2025 18:23:27 GMT, Archie Cobbs <acobbs at openjdk.org> wrote:

>> The compiler generates a warning if you declare a `close()` method that throws any supertype of `InterruptedException` in a class or interface extending `AutoCloseable`. This is because suppressed `InterruptedException`'s are likely to lead to misbehavior at runtime.
>> 
>> However, this feature also generates a warning due to `AutoCloseable.close()` itself, if you simply inherit it. For example:
>> 
>> $ cat MyClass.java
>> public interface MyClass extends AutoCloseable {
>> }
>> $ javac -Xlint:try MyClass.java
>> MyClass.java:1: warning: [try] auto-closeable resource MyClass has a member method close() that could throw InterruptedException
>> public interface MyClass extends AutoCloseable {
>>        ^
>> 1 warning
>> 
>> The warning is not useful because `AutoCloseable.close()` is abstract and so it's going to be some other class' job to deal with the throws clause.
>> 
>> This change prevents `AutoCloseable.close()` itself from triggering the warning in a class declaration. We preserve the existing behavior in which a warning is generated at the use site (i.e., at the try-with-resources statement).
>
> Archie Cobbs has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains five additional commits since the last revision:
> 
>  - Add more regression test variants.
>  - Fix missed warning when close() method implemented in superclass.
>  - Merge branch 'master' into JDK-8155591
>  - Merge branch 'master' into JDK-8155591 to get recent build fixes.
>  - Don't warn about AutoCloseable.close() itself throwing InterruptedException.

test/langtools/tools/javac/TryWithResources/InterruptedExceptionTest2.java line 92:

> 90: }
> 91: 
> 92: abstract class InterruptedExceptionTest_C10 extends WithClose implements AutoCloseable { // warning here

What about the case when `WithClose` is replaced with an `abstract class` with an `abstract void close()` method declaration?

abstract class WithAbstractClose {
	public abstract void close() throws Exception;
}

abstract class InterruptedExceptionTest_C11
	extends WithAbstractClose
	implements AutoCloseable {
}

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/27062#discussion_r2496525853