RFR: 8234535: Cross compilation fails due to missing CFLAGS for the BUILD_CC

[Erik Joelsson]

Will do.

/Erik

On 2019-11-26 01:05, christoph.goettschkes at microdoc.com wrote:
> Hi Erik,
>
> thanks for looking into this. I created a new webrev which includes the
> changeset and you as a reviewer:
>
> http://cr.openjdk.java.net/~cgo/8234535/webrev.02/
>
> Could you please sponsor this changeset and commit it into the repository
> for me?
>
> Thanks,
> Christoph
>
> Erik Joelsson <erik.joelsson at oracle.com> wrote on 2019-11-22 17:19:08:
>
>> From: Erik Joelsson <erik.joelsson at oracle.com>
>> To: christoph.goettschkes at microdoc.com, build-dev at openjdk.java.net
>> Date: 2019-11-22 17:19
>> Subject: Re: RFR: 8234535: Cross compilation fails due to missing
>> CFLAGS for the BUILD_CC
>>
>> Hello Christoph,
>>
>> On 2019-11-20 10:22, christoph.goettschkes at microdoc.com wrote:
>>> Hi,
>>>
>>> please review the following change.
>>>
>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8234535
>>> Webrev: https://cr.openjdk.java.net/~cgo/8234535/webrev.00/
>>>
>>> The removed lines are completely out of place and have no use at all.
> for
>>> the CC variable, for instance, the script does the following:
>>>
>>> CC_OLD="$CC"
>>> CC="$BUILD_CC"
>>> CC="$CC_OLD"
>>>
>>> without executing any function between those lines. I think that,
> while
>>> restructuring the build system, those lines have been copied to the
> wrong
>>> location. I copied them around the "FLAGS_SETUP_CFLAGS_CPU_DEP" call
> for
>>> the BUILD_CC, in order to make configure not use the target CFLAGS
> while
>>> discovering possible CFLAGS for the BUILD_CC, which was happening in
> our
>>> case.
>> Wow, I had not noticed that. Your fix looks correct.
>>> I am also not sure if the variable BUILD_CC_DISABLE_WARNING_PREFIX is
>>> actually used anywhere. I could not find any user and it might be
> possible
>>> to simply remove it.
>> It's used to override DISABLE_WARNING_PREFIX in buildjdk-spec.gmk so I
>> think it serves a purpose, even if we don't actually support different
>> toolchain types for cross and native compiler. If we ever will, then
>> this variable will be needed, so I think it should stay.
>>> I tried the change and compiled on an amd64 linux machine for amd64,
> and
>>> cross-compiled for linux on armv7 and linux on aarch64. I don't have
>>> access to other cross-compilation environments and would like to ask
>>> others to review and try out the change.
>> I applied the patch and tried a few of our configurations. Since we use
>> the same (or close to the same) compiler versions across architectures,
>> I don't actually see any difference in the generated spec files. The
>> reason you see this is the large version difference between your
> compilers.
>> Looks good, thanks for finding and fixing this!
>>
>> /Erik
>>
>>> Thanks,
>>> Christoph
>>>