RFR: 8261006: 'super' qualified method references cannot occur in a static context

[Vicente Romero]

On Thu, 24 Jun 2021 05:19:58 GMT, Srikanth Adayapalam <sadayapalam at openjdk.org> wrote:

>> Please review this PR, currently javac is accepting code like:
>> 
>> 
>> import java.util.function.Supplier;
>> 
>> public class MethodReferenceInConstructorInvocation {
>>     interface Bar {
>>         default String getString() { return ""; }
>>     }
>> 
>>     static class Foo implements Bar {
>>         public Foo() {  this(Bar.super::getString);  }
>>         public Foo(Supplier<String> sString) {}
>>     }
>> }
>> 
>> 
>> but the spec states in `15.13 Method Reference Expressions`:
>> 
>> If a method reference expression has the form super :: [TypeArguments] Identifier
>> or TypeName . super :: [TypeArguments] Identifier, it is a compile-time error if
>> the expression occurs in a static context (§8.1.3).
>> 
>> and a constructor invocation is a static context. So method references of this form, qualified by `super`, should be rejected by the compiler if they appear in a static context.
>> 
>> TIA
>
> Also this test case:
> 
> 
> import java.util.function.Supplier;
> 
> public class X {
> 
>     interface Feature {
>         default String getString() {
>             return "Hello World";
>         }
>     }
> 
>     private static class Broken implements Feature {
>         private final String sString;
> 
>         public Broken() {
>             this(Feature.super.getString());
>         }
> 
>         public Broken(String sString) {
>             this.sString = sString;
>         }
>     }
> }
> 
> 
> compiles both with JDK16 and your patch. 
> 
> Should we actually compile it ???

@sadayapalam, thanks for your comments, I have uploaded another iteration of the patch

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

PR: https://git.openjdk.java.net/jdk/pull/4376