RFR: 8223553: Fix code constructs that do not compile with the Eclipse Java Compiler

[Langer, Christoph]

Hi Daniel,

I fully agree, @SuppressWarnings should be avoided wherever possible.

So, thanks for coming up with this alternative suggestion. It works and so I updated my webrev: http://cr.openjdk.java.net/~clanger/webrevs/8223553.1/  

Any reviews for the other 3 files?

Thanks
Christoph

> -----Original Message-----
> From: Daniel Fuchs <daniel.fuchs at oracle.com>
> Sent: Donnerstag, 9. Mai 2019 17:24
> To: Langer, Christoph <christoph.langer at sap.com>; core-libs-dev <core-libs-
> dev at openjdk.java.net>; net-dev <net-dev at openjdk.java.net>
> Cc: compiler-dev at openjdk.java.net
> Subject: Re: RFR: 8223553: Fix code constructs that do not compile with the
> Eclipse Java Compiler
> 
> Hi Christoph,
> 
> I'm only commenting on the HttpClient changes, I'll let
> others comment on the other changes...
> 
> http://cr.openjdk.java.net/~clanger/webrevs/8223553.0/src/java.net.http/s
> hare/classes/jdk/internal/net/http/ExchangeImpl.java.udiff.html
> 
> I have a profound dislike for using @SuppressedWarnings, unless
> it's the only alternative. My preference would be to introduce
> local variables, if that can make the compiler happy, until such time
> where the issue is actually resolved...
> 
> For instance, it seems that the following would work:
> 
>      // Use local variable assignments to keep other java compilers
>      // happy and avoid unchecked casts warnings
>      BiFunction<Http2Connection, Throwable, CompletableFuture<? extends
> ExchangeImpl<U>>>
>          factory = (h2c, t) -> createExchangeImpl(h2c, t, exchange,
> connection);
>      Function<CompletableFuture<? extends ExchangeImpl<U>>,
> CompletableFuture<? extends ExchangeImpl<U>>>
>          identity = (cf) -> cf;
>      return c2f.handle(factory).thenCompose(identity);
> 
> 
> best regards,
> 
> -- daniel
> 
> On 08/05/2019 09:02, Langer, Christoph wrote:
> > Hi,
> >
> > please review a small change that I'd like to see in OpenJDK to get rid
> > of compilation errors in the Eclipse IDE.
> >
> > It seems the root cause for the compilation errors is that javac would
> > sometimes widen capture variables and is hence able to compile the
> > places that I touch here. The EC4J compiler claims that it's following
> > the spec more strictly and bails out at these places. I had posted about
> > this on compiler-dev but got no reaction [0].
> >
> > So, as this seems to be some field of open work for the compiler/spec
> > folks, I'd like to get EC4J quiesced by introducing some slight
> > modifications to the original places which makes the code appeal a bit
> > less elegant and fluent but will get rid of the compile errors.
> >
> > Please review:
> >
> > Bug: https://bugs.openjdk.java.net/browse/JDK-8223553
> >
> > Webrev: http://cr.openjdk.java.net/~clanger/webrevs/8223553.0/
> >
> > The modification to
> >
> src/java.base/share/classes/java/util/concurrent/ConcurrentSkipListMap.jav
> a
> > belongs to JSR-166, so I don't know if it needs some special handling.
> >
> > Thanks & Best regards
> >
> > Christoph
> >
> > [0]
> > https://mail.openjdk.java.net/pipermail/compiler-dev/2019-
> March/013054.html
> >