[jdk19] RFR: 8290417: CDS cannot archive lamda proxy with useImplMethodHandle

[David Holmes]

On Mon, 18 Jul 2022 03:15:02 GMT, Ioi Lam <iklam at openjdk.org> wrote:

> Since the impact of this bug can be big, and the fix is simple and low risk (just avoids doing optimizations), I'd like to put this into JDK 19 before RDP2 (Jul 21).
> 
> CDS cannot handle Lambda proxy classes that are generated in the useImplMethodHandle mode. This could happen with classfiles generated by JDK 8 or JDK 11 that access protected methods in a base class from a different package. E.g.,
> 
> 
> class pkg1.Base {
>     protected void doit(String s) {
>         System.out.println(s);
>     }
> }
> class pkg2.Child  extends pkg1.Base {
>     void test() {
>         Optional<String> opt = Optional.of("foo");
>         opt.ifPresent(this::doit);
>     }
> }
> 
> 
> More details of useImplMethodHandle can be found here: https://github.com/openjdk/jdk/blob/522b65743ca10fcba0a27d25b8fa11319999e228/src/java.base/share/classes/java/lang/invoke/InnerClassLambdaMetafactory.java#L183-L191
> 
> More details about the condition that triggers the error can be found in the test file Child.jcod.

Looks good!

Thanks.

test/hotspot/jtreg/runtime/cds/appcds/LambdaWithUseImplMethodHandle.java line 28:

> 26:  * @test
> 27:  * @bug 8290417
> 28:  * @summary CDS cannot archive lamda proxy with useImplMethodHandle

typo: lamda -> lambda

test/hotspot/jtreg/runtime/cds/appcds/dynamicArchive/DynamicLambdaWithUseImplMethodHandle.java line 28:

> 26:  * @test
> 27:  * @bug 8290417
> 28:  * @summary CDS cannot archive lamda proxy with useImplMethodHandle

typo: lamda -> lambda

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

Marked as reviewed by dholmes (Reviewer).

PR: https://git.openjdk.org/jdk19/pull/146