configure - gcc >4.6 needed for JDK9 build

[Volker Simonis]

On Wed, Jan 25, 2017 at 8:13 PM, Kim Barrett <kim.barrett at oracle.com> wrote:
>> On Jan 24, 2017, at 7:34 PM, David Holmes <david.holmes at oracle.com> wrote:
>>
>> Hi Kim,
>>
>> On 25/01/2017 7:25 AM, Kim Barrett wrote:
>>>> On Jan 23, 2017, at 5:34 AM, Mike Burton <mikeb at mycosystems.co.uk> wrote:
>>>>
>>>> Hello,
>>>>
>>>> I ran an OpenJDK Hack Day session on Saturday, at which some people got stuck on lost a fair bit of time, failing to build JDK9. Then we found that updating gcc from 4.6 to 4.8 fixed it.
>>>> Could the `configure` script be updated (by running get-source.sh) so as to check for minimum required gcc version?
>>>>
>>>> Best Regards
>>>>
>>>> Mike Burton
>>>
>>> I don’t think there is supposed to be a requirement for gcc > 4.6 in JDK 9.  I’m pretty
>>> sure there are folks still building with older versions.  It would be helpful to know the
>>> details of the platform and the error messages that led to the conclusion that something
>>> more recent was required.
>>
>> We may have "accidentally" moved on to gcc 4.8+. Even the ppc builds, which are still listed as using 4.1.2 on the wiki:
>>
>> https://wiki.openjdk.java.net/display/Build/Supported+Build+Platforms
>>
>> are now using 4.8.5:
>>
>> http://cr.openjdk.java.net/~simonis/ppc-aix-port/ (look at a build log)
>>
>> So some breakage with earlier versions may have crept in. I thought I recalled a few issues but can't see any bug reports.
>
> The PPC build from SAP was the one I was thinking of as still being around.
> And it does seem they’ve moved on too, which is useful to know.
> So yes, entirely possible something crept in if there isn’t frequent testing.
>

You're right. I've updated
https://wiki.openjdk.java.net/display/Build/Supported+Build+Platforms
to match our current settings.

Thanks,
Volker