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Message-ID: <23da162e-1018-9bfa-bc5c-ec09eba9428b@isovalent.com>
Date:   Thu, 18 Aug 2022 17:40:04 +0100
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Subject: Re: [PATCH 3/3] tools/build: Display logical OR of a feature flavors
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To:     Roberto Sassu <roberto.sassu@huaweicloud.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>
Cc:     peterz@infradead.org, mingo@redhat.com, mark.rutland@arm.com,
        alexander.shishkin@linux.intel.com, jolsa@kernel.org,
        namhyung@kernel.org, linux-perf-users@vger.kernel.org,
        bpf@vger.kernel.org, linux-kernel@vger.kernel.org,
        Roberto Sassu <roberto.sassu@huawei.com>
References: <20220818120957.319995-1-roberto.sassu@huaweicloud.com>
 <20220818120957.319995-3-roberto.sassu@huaweicloud.com>
 <Yv46EW6KbUe9zjur@kernel.org>
 <71544d2970e246e1f0d5f5ec065ea2437df58cd9.camel@huaweicloud.com>
From:   Quentin Monnet <quentin@isovalent.com>
In-Reply-To: <71544d2970e246e1f0d5f5ec065ea2437df58cd9.camel@huaweicloud.com>
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On 18/08/2022 14:25, Roberto Sassu wrote:
> On Thu, 2022-08-18 at 10:09 -0300, Arnaldo Carvalho de Melo wrote:
>> Em Thu, Aug 18, 2022 at 02:09:57PM +0200, 
>> roberto.sassu@huaweicloud.com escreveu:
>>> From: Roberto Sassu <roberto.sassu@huawei.com>
>>>
>>> Sometimes, features are simply different flavors of another
>>> feature, to
>>> properly detect the exact dependencies needed by different Linux
>>> distributions.
>>>
>>> For example, libbfd has three flavors: libbfd if the distro does
>>> not
>>> require any additional dependency; libbfd-liberty if it requires
>>> libiberty;
>>> libbfd-liberty-z if it requires libiberty and libz.
>>>
>>> It might not be clear to the user whether a feature has been
>>> successfully
>>> detected or not, given that some of its flavors will be set to OFF,
>>> others
>>> to ON.
>>>
>>> Instead, display only the feature main flavor if not in verbose
>>> mode
>>> (VF != 1), and set it to ON if at least one of its flavors has been
>>> successfully detected (logical OR), OFF otherwise. Omit the other
>>> flavors.
>>>
>>> Accomplish that by declaring a FEATURE_GROUP_MEMBERS-<feature main
>>> flavor>
>>> variable, with the list of the other flavors as variable value. For
>>> now, do
>>> it just for libbfd.
>>>
>>> In verbose mode, of if no group is defined for a feature, show the
>>> feature
>>> detection result as before.
>>
>> Looks cool, tested and added this to the commit log message here in
>> my
>> local branch, that will go public after further tests for the other
>> csets in it:
>>
>> Committer testing:
>>
>> Collecting the output from:
>>
>>   $ make -C tools/bpf/bpftool/ clean
>>   $ make -C tools/bpf/bpftool/ |& grep "Auto-detecting system
>> features" -A10
>>
>>   $ diff -u before after
>>   --- before    2022-08-18 10:06:40.422086966 -0300
>>   +++ after     2022-08-18 10:07:59.202138282 -0300
>>   @@ -1,6 +1,4 @@
>>    Auto-detecting system features:
>>    ...                                  libbfd: [ on  ]
>>   -...                          libbfd-liberty: [ on  ]
>>   -...                        libbfd-liberty-z: [ on  ]
>>    ...                                  libcap: [ on  ]
>>    ...                         clang-bpf-co-re: [ on  ]
>>   $
>>
>> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
>>
>> Thanks for working on this!
> 
> Thanks for testing and for adapting/pushing the other patches!
> 
> Roberto
> 

Tested locally for bpftool and I also observe "libbfd: [ on  ]" only.
This looks much better, thank you Roberto for following up on this!

Quentin