RFC: Only enable NIO2 by default when building with IcedTea

[Andrew John Hughes]

2009/2/10 Mark Wielaard <mark at klomp.org>:
> Hi Andrew,
>
> On Tue, 2009-02-10 at 19:07 +0000, Andrew John Hughes wrote:
>> It appears that some older versions of ecj fail when building the
>> NIO2 code:
>>
>> 1. ERROR in ../../../src/share/classes/org/classpath/icedtea/java/nio/file/spi/AbstractPath.java (at line 276)
>>    public final WatchKey register(WatchService watcher, WatchEvent.Kind<?>... events)
>>         throws IOException
>>                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>> Name clash: The method register(WatchService, WatchEvent.Kind<?>...) of type AbstractPath has the same erasure as register(WatchService, WatchEvent.Kind<?>...) of type Watchable but does not override it
>> ----------
>
> I can confirm this bug against Eclipse Java Compiler 0.793_R33x, 3.3.2.
>
>> The attached patch sets the NIO2 default based on whether with_icedtea is enabled.  So this works,
>> and to be consistent with the rest of the autotools macro, it switches the values used from true/false
>> to yes/no.
>>
>> Okay to commit?
>>
>> ChangeLog:
>>
>> 2009-02-10  Andrew John Hughes  <ahughes at redhat.com>
>>
>>       * Makefile.am:
>>       Only build NIO2 by default if building with
>>       IcedTea.  Fix with_icedtea/with_openjdk to use
>>       yes/no rather than true/false.
>
> The attached patch is for configure.ac, not for Makefile.am.
> I am slightly confused by why this works.
> Are you counting on the fact that if --with-icedtea is given the
> provided javac will not be based on ecj and so not have the bug?

--with-icedtea uses ICEDTEA_HOME/bin/javac so yeah but...

> Wouldn't it be more correct to disable nio2 by default and/or add a
> compiler configure check to see if these kind of constructs can be
> compiled?

...I'd prefer this.  But given I can't duplicate this myself, someone
else needs to write the test... ;)
>
> Cheers,
>
> Mark
>
>
-- 
Andrew :-)

Free Java Software Engineer
Red Hat, Inc. (http://www.redhat.com)

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