Pending Character-related work - Character-warnings

[Ulf Zibis]

Jonathan, Kelly,

thanks for your short but excellent descriptive explanation.
It mainly reflects how I understood the build process in general.
Can you briefly answer my questions below?

Am 01.07.2010 18:13, schrieb Kelly O'Hair:
>
> On Jul 1, 2010, at 7:56 AM, Jonathan Gibbons wrote:
>
>> On 07/01/2010 01:32 AM, Ulf Zibis wrote:
>>> Am 01.07.2010 09:38, schrieb Martin Buchholz:
>>>> On Wed, Jun 30, 2010 at 23:49, Ulf Zibis<Ulf.Zibis at gmx.de>  wrote:
>>>>> Am 30.06.2010 19:50, schrieb Martin Buchholz:
>>>>>> On Wed, Jun 30, 2010 at 01:22, Ulf Zibis<Ulf.Zibis at gmx.de>    wrote:
>>>>>>
>>>>>>> Am 29.06.2010 02:29, schrieb Martin Buchholz:
>>>>>>>> I tried to do that, but Character.java is one of those classes
>>>>>>>> that needs to be compilable by the bootstrap JDK,
>>>>>>>> so this change ist leider nicht moeglich.
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>> I think, there should be a note about this in the sources of those
>>>>>>> classes.
>>>>>>>
>>>>>> Such a note is likely to become obsolete soon.
>>>>>>
>>>>> How do you mean that? Will the build procedure change soon. Then 
>>>>> it would be
>>>>> anyway appropriate to update to new "style".
>>>> In jdk8, the bootstrap jdk will be at least jdk7.
>>>
>>> It would make me wonder if there wont come new language extensions.
>>> I was thinking about a comment (in all bootstrap compiled classes) 
>>> which couldn't become obsolete like:
>>> "Don't use latest language extensions in this class. It's one of 
>>> those which must be compilable by the bootstrap JDK while building 
>>> this JDK. Add @suppressWarnings if appropriate."
>>>
>>> Anyway, couldn't we use the latest existing JDK-7 build for 
>>> bootstrap? Then we could update the sources 2 weeks later.
>>> ... or use 2 versions for bootstrap and library as said before.
>>>
>>> -Ulf
>>>
>>>
>>
>> Ulf,
>>
>> I suggest you go read blogs by Kelly (http://blogs.sun.com/kto/) and 
>> myself (http://blogs.sun.com/jjg/) on the process of building the 
>> JDK. The boot JDK is always the latest available FCS product (i.e JDK 
>> 6 for JDK 7), but the first thing done in the build is to build a 
>> hybrid javac that runs on the boot JDK and which understands the 
>> latest language.  Therefore, with the exception of javac and related 
>> tools that are used during the bootstrap (e.g. javah) most of the 
>> JDK, and all the code in the jdk/ repo can be built with the latest 
>> language features.

I understand this, that all classes in jdk7/tl are compiled by source=7 
level.
Is that correct?
In particular, why should j.l.Character then be compilable by source=6 
level, as Martin said?
If so, is it thinkable to have 2 versions, one for the bootstrap and one 
for the final JDK7 library, so the latter would be "clean" for the 
source=7 level?

-Ulf


>>
>> There may however be historical reasons why some classes still get 
>> special treatment; those would need to be examined on a case by case 
>> basis.
>>
>
> I think some of the source generation tools may require a 'dumbing 
> down' of the source, I forget the exact details.
>
> The jdk/make/tools/src tools are supposed to be built with the BOOT 
> jdk (jdk6), and in general are small utility tools
> that need to be run before the jdk7 image exists, but are not 
> technically part of the jdk7 image.
> So like langtools, they need to be BOOT jdk flavored sources, or have 
> a way to run with a BOOT jdk.
>
> -kto
>
>> -- Jon
>>
>
>
>