On 2018-05-10 15:12, David Holmes wrote:
Hi Erik,
cc'ing Kumar as he is nominally the owner of the jvm.cfg files.
On 11/05/2018 3:38 AM, Erik Joelsson wrote:
I took a further look at the jvm.cfg generation and reworked it
completely. This change removes all the predefined jvm.cfg files and
replaces them with a simple generation script. This should produce
the same files as before JDK-8202683 for any configuration Oracle
builds officially and zero. For special jvm variant combinations, it
will stay closer to the official ones. See bug comments for details.
Bug: https://bugs.openjdk.java.net/browse/JDK-8202920
Webrev: http://cr.openjdk.java.net/~erikj/8202920/webrev.01/
I'm not sure of the details here. You no longer alias any flags for
VMs not present, but list them as "ignore". IIUC that means the
default VM will be selected - so as long as the default VM is the one
previously aliased to then it is equivalent. I also thought that the
first line in the file defined the default VM and so had to be a known
VM - with these changes a client-only build, for example, will have a
first entry of "-server ignore".
I wasn't sure about the ordering and default, but if the first one
matters, then I need to rework this a bit. In particular the order is
now reversed for windows x86 (if that is something we would want to
preserve). Inserting the KNOWN should also be moved last as you point out.
There is always some debate as to whether a non-present VM should be
ignored or cause an error. For the minimal VM builds we used to do for
SE Embedded it was chosen to ignore them and just use the Minimal VM.
This isn't necessarily what everyone would want.
For that part, this change is not changing behavior for any
configuration that we really care about. (Note that you need to compare
to the behavior previous to Shipilev's change which did indeed move
things around.) All the static jvm.cfg files should be equivalent as
none of them had ALIAS in them anymore (since your change way back in
JDK 8). There will only be a difference if you explicitly build a non
standard combination, like only client or only minimal. In those cases,
the old generation logic would kick in and generate aliases. Do we want
to keep aliases in those cases? Does it really matter?
/Erik
David
/Erik
