On ecj and @Override annotations for interface methods

[Joseph D. Darcy]

Mark Wielaard wrote:
> Hi Andrew,
>
> On Thu, 2008-09-18 at 11:28 +0100, Andrew John Hughes wrote:
>   
>> Does anyone recall why we stopped using 1.6, other than, as a target, it gives
>> little benefits?  Lillian made this commit:
>>
>> 2008-05-20  Lillian Angel  <langel at redhat.com>
>>
>> 	* Makefile.am: Updated JAVAC calls so ecj wrapper script is used.
>>         * Makefile.in: Regenerated.
>> 	* aclocal.m4: Likewise.
>> 	* configure: Likewise.
>> 	* javac.in: Updated to use source 1.6 instead of 1.5.
>>
>> which I don't know the reasoning behind (it also changed the behaviour so
>> that javac.in was always used in ecj builds, slowing things down if the
>> system ecj was native).  mjw then reverted us back to 1.5:
>>
>> 2008-05-25  Mark Wielaard  <mark at klomp.org>
>>
>> 	* Makefile.am: Use -source 1.5 whenever possible.
>>         * Makefile.in: Regenerated.
>> 	* javac.in: Use -1.5.
>>
>> Debian stable's version would be too old (3.2.1) but we don't support this
>> fully anyway, and stable will soon change to lenny, which I presume
>> will have a newer version.
>>     
>
> See:
> http://mail.openjdk.java.net/pipermail/distro-pkg-dev/2008-May/001990.html
>
> Change was indeed made to keep bootstrapping on "older" platforms
> working.
>
> Another issue is that although -target 1.6 looks like it is supported by
> the free VMs, because they just ignore the bigger major number, there is
> no public documentation about the class file format changes. 

The class file format changes for JDK 6 are documented in JSR 202, 
"Java(TM) Class File Specification Update":
http://www.jcp.org/en/jsr/detail?id=202

-Joe