RFR: 8016780: (xs) README-builds.html misses crucial requirement on bootstrap JDK

[Jonathan Gibbons]

The only problem with using N is that you don't know whether you have 
broken building with N-1. Therefore the general recommendation for most 
people should be to always use N-1.  I think Stuart is just searching 
for ways to make people aware that using N-1 is "the right thing to do".

-- Jon


On 06/17/2013 10:04 PM, David Holmes wrote:
> I thought the only rule was "must be buildable by N-1", not that you 
> must not try to use N!
>
> Can the problem preventing a build using JDK8 as the boot JDK not be 
> corrected? I'm assuming it is one of the more unusual parts of the 
> build where we mess with bootclasspath etc?
>
> David
>
> On 18/06/2013 10:21 AM, Stuart Marks wrote:
>> On 6/17/13 4:02 PM, Kelly O'Hair wrote:
>>> Rule #1 Nobody reads the README
>>> Rule #2 When things go wrong, blame the README
>>>
>>> I of course have no objection to the change, however, I'm not
>>> convinced it will
>>> help much the next time someone runs into this. :^(
>>
>> Hi Kelly! You still read this stuff here? :-)
>>
>> Yeah, I have no illusions that changing the README will prevent many, if
>> any, future occurrences of this problem. However, we had an internal
>> discussion on this incident where the N-1 rule was asserted. There was
>> no dispute about the rule, but I went off to find where it was
>> documented, and found only the fairly weak statement in the README. So,
>> at the very least, that ought to be fixed.
>>
>> A stronger step would be to modify configure to check the version of the
>> boot JDK and to complain if it doesn't match N-1. Or perhaps even N-1
>> and update >= 7. What do you think? I was considering filing an RFE.
>>
>> A restriction in configure would probably be more effective at
>> preventing these kinds of errors.
>>
>> s'marks