RFR (M): Enable OpenJDK builds on Windows with MinGW/MSYS

Fri Mar 9 17:58:13 UTC 2012

On Thu, Mar 8, 2012 at 8:58 PM, Kelly O'Hair <kelly.ohair at oracle.com> wrote:
>
> On Mar 8, 2012, at 9:39 AM, Volker Simonis wrote:
>
>> Hi,
>>
>> please review the following changes which make it possible to use MinGW/MSYS as
>> underlying build environment for Windows. Because the changes touch several
>> repositories I prepared three webrevs, all relative to
>> http://hg.openjdk.java.net/jdk8/build
>>
>> For the main repository:
>> http://cr.openjdk.java.net/~simonis/MinGW_MSYS.v1/
>
> I had originally purged all mention of MKS from this README because we wanted to stop
> using it in favor of CYGWIN, and only maintain one way to build on Windows.
> That never happened internally, many kept using MKS because it was so much faster.
> So as much as I hate seeing the MKS instructions being added, I understand why you felt
> compelled to add them, and see no obvious inaccuracies
>
> We didn't  have any plans to continue to support MKS with the new build infrastructure work.
> It creates a complication that we wanted to avoid, but at the same time we are running into
> the "CYGWIN is too slow, especially on 64bit Windows" problem.
> So we will need to discuss this on the build-infra-dev alias.
>
> Since this change is just README, and I see nothing wrong with regards to your changes,
> it seems ok, with the caveat that if we end up really abandoning MKS, we may need to purge
> the MKS references.  I just don't know what will happen here right now.
>
>>
>> For the HotSpot repository:
>> http://cr.openjdk.java.net/~simonis/MinGW_MSYS_hotspot.v1/
>
> Seems fine. This change could probably proceed regardless of the others I think.
> But someone from the hotspot team may need to help here.... or maybe I could do it...
>
> Was the /option to -option a style issue, or was it required somehow? Just curious, I have
> no objection to making it consistent.
>

Yes, it is required because MinGW tries to be smart when calling
non-MinGW executables and
interprets slash-options as paths (e.g. "/I" may end up as "I:\")
See http://mingw.org/wiki/Posix_path_conversion for more information.

> Also, the quotes on the paths..  any particular reason why?
>

This was very tricky to get right on all three environments and the
quoted version basically just worked.
The problem again is MinGWs automatic path conversion: if you give the
top-level make something like
ALT_BOOTDIR=C:/Java/jdk1.7.0_02 it implicitly converts it into
ALT_BOOTDIR=/c/Java/jdk1.7.0_02
for the next recursive make call. Later, when nmake will be called, it
converts it back into C:/Java/jdk1.7.0_02
which fools nmake. But if the path is quoted, all works well.

>>
>> For the JDK repository
>> http://cr.openjdk.java.net/~simonis/MinGW_MSYS_jdk.v1/
>
> Seems fine but unfortunately, we have other closed repos that might be impacted here.
> The cpio change concerns me, not that I'm in love with cpio, I tried to get rid of it
> a long time ago, but it was so much faster than tar for some reason.
> So I'll need to make sure the entire Oracle JDK build process is ok with these changes
> before this could go in.
>

I didn't realized any performance problems and tar is already used in
some places
for copying files so I thought it will be ok. Hope your internal repos
work fine with
the change, otherwise please let me know.

> Right now I'm not so concerned about using MinGW/MSYS as making sure the existing
> builds are not broken. But I am looking forward to using MinGW/MSYS soon.
>
> I may need to enlist someone to do some image comparisons and double check that the
> end result has not changed too.
>

Absolutely. Please keep me informed if you encounter any problems.

>>
>> Please be so kind and also create three bug ids for the corresponding changes.
>
> Created:
> 7152336: Enable builds on Windows with MinGW/MSYS
>
> I think we can use the same CR for all repos. Unless you really want 3 CRs.
>

That's your playground:) I'm happy either way.

>>
>> The changes are minimal in the sense that I did "just enough" changes to be able
>> to build on Windows with either one of the three Unix emulation environments
>> (MKS, Cygwin, MinGW/MSYS).
>>
>> The main benefits of the new MinGW/MSYS based Windows build are:
>> - no problems with make - one can simply use the make tool which comes with
>>   MinGW/MSYS
>> - with the current MinGW/MSYS version the build is known to succeed, while
>>   the newest Cygwin 1.7.10 version is known to break the OpenJDK build (see:
>>   http://old.nabble.com/Is-anyone-able-to-build-on-Win-7-td33196055.html)
>> - speed - the MinGW/MSYS build times are comparable to the MKS build times
>>   and is at least 50% faster than the Cygwin build times (see numbers below)
>
> That 50% faster is great news.
>
>>
>> The changes are intentionally against the old, "traditional" build system to fix
>> the mentioned Cygwin problems and simplify the Windows build just now. I don't
>> expect any problems in adapting the "new" build infrastructure to MinGW/MSYS as
>> well in a follow-up step.
>>
>> More information on each change can be found in the corresponding webrevs.
>>
>> Timing results for the different build environments (MKS ver. 9.4, Cygwin
>> ver. 1.7.9, MinGW/MSYS 1.0.17) for a full JDK 8 product build on a freshly
>> booted, dual core i7 notebook with 8GB RAM, HDD and 64-bit Windows 7: </p>
>>
>> MKS
>> -- Build times ----------
>> Target all_product_build
>> Start 2012-02-29 19:19:26
>> End   2012-02-29 20:07:44
>> 00:03:10 corba
>> 00:03:44 hotspot
>> 00:00:30 jaxp
>> 00:00:37 jaxws
>> 00:39:39 jdk
>> 00:00:36 langtools
>> 00:48:18 TOTAL
>> -------------------------
>>
>> MinGW/MSYS
>> -- Build times ----------
>> Target all_product_build
>> Start 2012-02-29 18:16:31
>> End   2012-02-29 19:10:59
>> 00:02:57 corba
>> 00:03:04 hotspot
>> 00:00:32 jaxp
>> 00:00:40 jaxws
>> 00:46:36 jdk
>> 00:00:36 langtools
>> 00:54:28 TOTAL
>> -------------------------
>>
>> Cygwin
>> -- Build times ----------
>> Target all_product_build
>> Start 2012-02-29 14:36:50
>> End   2012-02-29 16:05:50
>> 00:05:47 corba
>> 00:03:24 hotspot
>> 00:00:33 jaxp
>> 00:00:43 jaxws
>> 01:17:45 jdk
>> 00:00:39 langtools
>> 01:29:00 TOTAL
>> -------------------------
>>
>
> Excellent details.  Thanks.
>
> I'll definitely work with you to get these changes integrated.
>
>
> -kto
>
>> Regards,
>> Volker
>