Re: Ping: [PATCH 1/9] build: use if_changed more consistently (and correctly) for prelink*.o

[Jan Beulich <jbeulich@xxxxxxxx>]

On 22.09.2020 11:24, Julien Grall wrote:
> On 22/09/2020 09:28, Jan Beulich wrote:
>> On 21.09.2020 13:39, Julien Grall wrote:
>>> On 21/09/2020 11:17, Jan Beulich wrote:
>>>> On 14.09.2020 12:15, Jan Beulich wrote:
>>>>> Switch to $(call if_changed,ld) where possible; presumably not doing so
>>>>> in e321576f4047 ("xen/build: start using if_changed") right away was an
>>>>> oversight, as it did for Arm in (just) one case. It failed to add
>>>>> prelink.o to $(targets), though, causing - judging from the observed
>>>>> behavior on x86 - undue rebuilds of the final binary (because of
>>>>> prelink.o getting rebuild for $(cmd_prelink.o) being empty, in turn
>>>>> because of .prelink.o.cmd not getting read) during "make install-xen".
>>>>>
>>>>> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
>>>>> ---
>>>>>    xen/arch/arm/Makefile |  4 +++-
>>>>>    xen/arch/x86/Makefile | 18 ++++++++++--------
>>>>>    2 files changed, 13 insertions(+), 9 deletions(-)
>>>>
>>>> May I ask for an Arm-side ack (or otherwise) here, please?
>>>
>>> Acked-by: Julien Grall <jgrall@xxxxxxxxxx>
>>
>> Thanks. On the Arm side this is actually addressing a (minor) bug,
> 
> Just to confirm, the bug is: Xen will be rebuilt when it is not 
> necessary, right?

Yes. When building as non-root but installing as root, this would
typically involve an owner change of some of the involved files.
That's how I did notice the issue on x86 (after switching to
if_changed) in the first place.

Jan