From: Andrew Hughes <gnu.andrew@redhat.com>
To: Jeff Law <law@redhat.com>
Cc: Andrew Haley <aph@redhat.com>, Matthias Klose <doko@ubuntu.com>,
Tom Tromey <tom@tromey.com>,
Uros Bizjak <ubizjak@gmail.com>,
gcc-patches@gcc.gnu.org, java-patches@gcc.gnu.org
Subject: Re: [PATCH, libjava/classpath]: Fix overriding recipe for target 'gjdoc' build warning
Date: Thu, 20 Aug 2015 16:03:00 -0000 [thread overview]
Message-ID: <1092027746.13351972.1440086614051.JavaMail.zimbra@redhat.com> (raw)
In-Reply-To: <55D5F681.5060809@redhat.com>
----- Original Message -----
> On 08/20/2015 09:27 AM, Andrew Haley wrote:
> > On 08/20/2015 03:57 PM, Andrew Hughes wrote:
> >> ----- Original Message -----
> >>> On 20/08/15 09:24, Matthias Klose wrote:
> >>>> On 08/20/2015 06:36 AM, Tom Tromey wrote:
> >>>>> Andrew> No, it isn't. It's still a necessity for initial bootstrapping
> >>>>> of
> >>>>> Andrew> OpenJDK/IcedTea.
> >>>>>
> >>>>> Andrew Haley said the opposite here:
> >>>>>
> >>>>> https://gcc.gnu.org/ml/gcc-patches/2015-08/msg00537.html
> >>>>
> >>>> if you need bootstrapping OpenJDK 6 or OpenJDK 7, then having gcj
> >>>> available for the target platform is required. Starting with OpenJDK
> >>>> 8 you should be able to cross build OpenJDK 8 with an OpenJDK 8
> >>>> available on the cross platform. It might be possible to cross
> >>>> build older OpenJDK versions, but this usually is painful.
> >>>
> >>> Sure, but we don't need GCJ going forward. I don't think that there
> >>> are any new platforms to which OpenJDK has not been ported which will
> >>> require GCJ to bootstrap. And even if there are, anybody who needs to
> >>> do that can (and, indeed, should) use an earlier version of GCJ. It's
> >>> not going to go away; it will always be in the GCC repos. And because
> >>> newer versions of GCC may break GCJ (and maybe OpenJDK) it makes more
> >>> sense to use an old GCC/GCJ for the bootstrapping of an old OpenJDK.
> >>
> >> I don't see how we don't at present. How else do you solve the
> >> chicken-and-egg situation of needing a JDK to build a JDK? I don't
> >> see crossing your fingers and hoping there's a binary around
> >> somewhere as a very sustainable system.
> >
> > That's what we do with GCC, binutils, etc: we bootstrap.
> Right. So the question is there some reason why OpenJDK can't be used
> to bootstrap itself? Ie, is there a fundamental reason why Andrew needs
> to drop back down to GCJ and start the bootstrapping process from scratch.
>
> ISTM that ideally the previous version of OpenJDK would be used to
> bootstrap the new version of OpenJDK.
>
> Which leaves the question of how to deal with new platforms, but it
> sounds like there's a cross-compilation process starting with OpenJDK 8
> which ought to solve that problem.
>
The issue is that we're still supporting a version of OpenJDK/IcedTea where
there is no previous version (6). Once that goes, gcj could go too. This
is still just a little too soon.
>
> >
> >> From a personal point of view, I need gcj to make sure each new
> >> IcedTea 1.x and 2.x release bootstraps.
> >
> > Sure, but all that does is test that the GCJ bootstrap still works.
> > And it's probably the only serious use of GCJ left.
> And how much value is there in that in the real world?
>
I do know it's been used recently on Gentoo to bootstrap IcedTea on
non-x86 archs.
That's where it comes unstuck. How do you get a JDK built when there are
no JDK binaries for your architecture?
> >
> > It's not a sudden whim: it's something we've been discussing for years.
> > The only reason GCJ is still alive is that I committed to keep it
> > going while we still needed it boot bootstrap OpenJDK. Maintaining
> > GCJ in GCC is a significant cost, and GCJ has reached the end of its
> > natural life. Classpath is substantially unmaintained, and GCJ
> > doesn't support any recent versions of Java.
> Right. I think we last discuss this in 2013 and there was still some
> benefit in keeping GCJ building, but that benefit is dwindling over time.
>
>
> There's an ongoing cost to every GCC developer to keep GCJ functional as
> changes in the core compiler happen. Furthermore, there's a round-trip
> cost for every patch under development by every developer in the
> boostrap & testing cycles.
>
> Given the marginal benefit to GCC and OpenJDK and the fairly high cost,
> we'd really prefer to drop GCJ.
>
I'm not against this long-term, just not immediately. Deprecating it now
and removing it in the next release cycle (7?) would probably be enough,
but we need a little more time to wind down dependencies. I don't see us
needing it in a GCC released in 2017.
>
> Jeff
>
>
--
Andrew :)
Senior Free Java Software Engineer
Red Hat, Inc. (http://www.redhat.com)
PGP Key: ed25519/35964222 (hkp://keys.gnupg.net)
Fingerprint = 5132 579D D154 0ED2 3E04 C5A0 CFDA 0F9B 3596 4222
PGP Key: rsa4096/248BDC07 (hkp://keys.gnupg.net)
Fingerprint = EC5A 1F5E C0AD 1D15 8F1F 8F91 3B96 A578 248B DC07
next prev parent reply other threads:[~2015-08-20 16:03 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-07 11:22 Uros Bizjak
2015-08-11 18:03 ` Uros Bizjak
2015-08-11 18:54 ` Jeff Law
2015-08-11 19:24 ` Andrew Haley
2015-08-11 19:34 ` Jeff Law
2015-08-12 2:48 ` Tom Tromey
2015-08-12 14:44 ` Jeff Law
2015-08-12 14:57 ` Andrew Haley
2015-08-12 16:23 ` Ian Lance Taylor
2015-08-12 16:21 ` Tom Tromey
2015-08-12 16:24 ` Ian Lance Taylor
2015-08-12 16:47 ` Jeff Law
2015-08-12 16:59 ` Ian Lance Taylor
2015-08-13 10:00 ` Richard Biener
2015-08-13 21:31 ` Jeff Law
2015-08-14 7:44 ` Richard Biener
2015-08-14 9:24 ` Andrew Haley
2015-08-20 2:35 ` Andrew Hughes
2015-08-20 4:37 ` Tom Tromey
2015-08-20 8:24 ` Matthias Klose
2015-08-20 8:32 ` Andrew Haley
2015-08-20 14:57 ` Andrew Hughes
2015-08-20 15:27 ` Andrew Haley
2015-08-20 15:47 ` Jeff Law
2015-08-20 16:03 ` Andrew Hughes [this message]
2015-08-20 16:08 ` Andrew Haley
2015-08-20 16:26 ` Andrew Hughes
2015-08-20 16:38 ` Richard Biener
2015-08-20 16:39 ` Andrew Haley
2015-08-20 17:35 ` Jeff Law
2015-08-20 17:39 ` Andrew Hughes
2015-08-20 15:52 ` Andrew Hughes
2015-08-20 16:34 ` Richard Biener
2015-08-20 16:59 ` Andrew Hughes
2015-08-20 17:35 ` Andrew Hughes
2015-08-20 18:05 ` Richard Biener
2015-08-20 21:06 ` Joseph Myers
2015-08-20 22:32 ` Andrew Hughes
2015-08-24 16:39 ` Jeff Law
2015-08-20 14:58 ` Andrew Hughes
2015-08-20 2:48 ` Andrew Hughes
2015-08-20 6:20 ` Uros Bizjak
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1092027746.13351972.1440086614051.JavaMail.zimbra@redhat.com \
--to=gnu.andrew@redhat.com \
--cc=aph@redhat.com \
--cc=doko@ubuntu.com \
--cc=gcc-patches@gcc.gnu.org \
--cc=java-patches@gcc.gnu.org \
--cc=law@redhat.com \
--cc=tom@tromey.com \
--cc=ubizjak@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).