HotSpot 16 and OpenJDK6

[Joe Darcy]

Andrew John Hughes wrote:
> On 24 February 2010 00:28, Joe Darcy <Joe.Darcy at sun.com> wrote:
>   
>> Andrew John Hughes wrote:
>>     
>>> On 23 February 2010 20:10, Joseph D. Darcy <Joe.Darcy at sun.com> wrote:
>>>
>>>       
>>>> Hello.
>>>>
>>>> Andrew John Hughes wrote:
>>>>
>>>>         
>>>>> Here's the merge:
>>>>>
>>>>> http://cr.openjdk.java.net/~andrew/jdk6-hs16-merge/webrev.01/
>>>>>
>>>>> which now builds, thanks to this additional changeset from Daniel
>>>>> Daugherty in baseline:
>>>>> http://hg.openjdk.java.net/hsx/hsx16/baseline/rev/c9740f5ed5b4
>>>>>
>>>>>
>>>>>           
>>>> Good.
>>>>
>>>>
>>>>         
>>>>> It also includes an additional fix, also listed separately at:
>>>>>
>>>>> http://cr.openjdk.java.net/~andrew/jdk6-hs16-merge/webrev.02/
>>>>>
>>>>> which reverts an erroneous change from SIZE_FORMAT to %d in
>>>>>
>>>>> changeset:   734:dbbe28fc66b5
>>>>> user:        twisti
>>>>> date:        Fri Feb 27 03:35:40 2009 -0800
>>>>> summary:     6778669: Patch from Red Hat -- fixes compilation errors
>>>>>
>>>>> fixing the build on x86_64.  We'll need a bug ID for this reversion.
>>>>>
>>>>>
>>>>>           
>>>> The webrev generally looks good, but I have a few questions and comments
>>>> before this goes back.
>>>>
>>>> Do you know why webrev shows so many files with zero changes?  I assume
>>>> this
>>>> is an artifact of the merge.
>>>>
>>>>
>>>>         
>>> No, you're right that does seem strange.  All I did was a pull from
>>> hs16 and then a merge.  Perhaps this is some webrev oddity?
>>>
>>> If you look at
>>> http://mail.openjdk.java.net/pipermail/jdk6-dev/2010-February/001230.html
>>> I included a diff of the merged OpenJDK6 against the hs16 master
>>> (which includes Daniel's patch that is currently only in baseline).
>>> It actually makes the other questions below a bit clearer.
>>>
>>>       
>> Yes, that patch size is more manageable!
>>
>>     
>>>> In hotspot_version, what are the semantics of JDK_PREVIOUS_VERSION?
>>>>
>>>>
>>>>         
>>> I'm not sure.  It doesn't seem to do much.  Its only use is to set a
>>> default BOOTDIR AFAICS:
>>>
>>> # Find JDK used for javac compiles
>>>
>>> BOOTDIR=$(SLASH_JAVA)/re/j2se/$(PREVIOUS_JDK_VERSION)/latest/binaries/$(PLATFORM)
>>>
>>> (from hotspot/make/defs.make)
>>>
>>> We actually differ from hs16 by still using 1.5.0 rather than 1.6.0.
>>> 1.5.0 implicitly seems to make more sense to me, because 1.6.0 is the
>>> version being built.  But in practice, it doesn't seem to matter
>>> unless you're relying on the contents of a /java tree.
>>>
>>>       
>> I have a vague recollection of there being a particular reason why this was
>> upgraded to 1.6.0 so I'd prefer to see this kept as 1.6.0.
>>
>>     
>>>> In terms of fixing the %d vs SIZE_FORMAT in vmError.cpp, I've filed
>>>> 6929005
>>>> "Fix format specifier in vmError.cpp."  However, I notice that the JDK 7
>>>> master still has %d in this location.  I'll approve going back from %d ->
>>>> SIZE_FORMAT in OpenJDK 6 conditional on the review and approval of a
>>>> HotSpot
>>>> engineer.
>>>>
>>>>
>>>>         
>>> Interesting; I didn't check OpenJDK7 and indeed you're right.  Looking
>>> again at the diff, it seems that we don't apply part of the same
>>> changeset:
>>>
>>> --- ../hs16/src/share/vm/utilities/vmError.hpp  2010-01-13
>>> 14:35:26.651211783 +0000
>>> +++ hotspot/src/share/vm/utilities/vmError.hpp  2010-02-17
>>> 11:07:40.899854566 +0000
>>> @@ -50,7 +50,7 @@
>>>
>>>   // additional info for VM internal errors
>>>   const char * _filename;
>>> -  int          _lineno;
>>> +  size_t       _lineno;
>>>
>>>   // used by fatal error handler
>>>   int          _current_step;
>>>
>>> keeping the size_t rather than using int.  So I'll change the fix to
>>> be making vmError.hpp match hs16 and OpenJDK7, rather than changing
>>> vmError.cpp.
>>>
>>> The remaining diffs are typos and license fixups from the previous
>>> merge which need to go back to the main HotSpot tree.
>>>
>>>
>>>       
>> If vmError.hpp matches what is in JDK 7 and HS 16, I approve your merge of
>> HS 16 + Dan's fixes into OpenJDK 6.
>>
>>     
>
> Pushed.  I reused 6929005 as Fix HS16 merge issues in OpenJDK 6 to
> make vmError.hpp and JDK_PREVIOUS_VERSION match hs16.  You should
> probably update the bug itself to match :-)
>
>   

A fine use for that bug id; content of the bug adjusted accordingly :-)

-Joe