Message-ID: <53B71E83.3010005@suse.cz>
Date: Fri, 04 Jul 2014 23:37:07 +0200
From: Michal Marek <mmarek@suse.cz>
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To: Randy Dunlap <rdunlap@infradead.org>, Sam Ravnborg <sam@ravnborg.org>
CC: "J. Bruce Fields" <bfields@fieldses.org>, linux-kbuild@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: relative objtree change broke tar builds?
References: <20140617223854.GC6168@fieldses.org> <53A15684.9000002@suse.cz> <20140618122029.GA17790@fieldses.org> <53A18712.6030907@suse.cz> <20140618131452.GB17790@fieldses.org> <53A1B72E.7030907@infradead.org> <53A1ECD0.2030001@suse.cz> <20140618195259.GA21939@ravnborg.org> <53A200DD.3060004@infradead.org>
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Dne 18.6.2014 23:13, Randy Dunlap napsal(a):
> On 06/18/14 12:52, Sam Ravnborg wrote:
>> On Wed, Jun 18, 2014 at 09:47:28PM +0200, Michal Marek wrote:
>>> Dne 18.6.2014 17:58, Randy Dunlap napsal(a):
>>>> On 06/18/14 06:14, J. Bruce Fields wrote:
>>>>> On Wed, Jun 18, 2014 at 02:33:22PM +0200, Michal Marek wrote:
>>>>>> Dne 18.6.2014 14:20, J. Bruce Fields napsal(a):
>>>>>>> On Wed, Jun 18, 2014 at 11:06:12AM +0200, Michal Marek wrote:
>>>>>>>> Dne 18.6.2014 00:38, J. Bruce Fields napsal(a):
>>>>>>>>> The changelog there says
>>>>>>>>>
>>>>>>>>> 	The main Makefile sets its working directory to the object tree
>>>>>>>>> 	and never changes it again. Therefore, we can use '.' instead of
>>>>>>>>> 	the absolute path.
>>>>>>>>>
>>>>>>>>> But the main Makefile also exports objtree, and a quick grep suggests
>>>>>>>>> lots of other uses outside the main Makefile.
>>>>>>>>
>>>>>>>> Do you have examples? Besides your report, I'm only aware of make
>>>>>>>> deb-pkg and make *docs. What else?
>>>>>>>
>>>>>>> I haven't looked.
>>>>>>>
>>>>>>> I only note that grep finds 47 files referencing that variable, and
>>>>>>> absent some argument that the remaining ones are correct, I'd be
>>>>>>> inclined to revert.
>>>>>>
>>>>>> Do these 47 files change the working directory before referencing the
>>>>>> variable?
>>>>>
>>>>> Sorry, I'm not volunteering to check.
>>>>>
>>>>> Note also that other variables are defined in terms of objtree, and they
>>>>> may be exported or passed to other scripts.
>>>>
>>>>
>>>> I'll note one side effect that I really dislike:
>>>> If not in silent mode, scripts/mkmakefile tells me that the it is
>>>> generating ./Makefile.  I want to see the real path there instead of '.'.
>>>
>>> The idea is that one should be able to compare as much as possible
>>> between the build of /usr/src/linux-<version_a> built in
>>> /usr/src/linux-<version_a>/build and /usr/src/linux-<version_b> built in
>>> /usr/src/linux-<version_b>/build. One can now even compare the build log
>>> with -j1, although that was not the primary goal. So if the changed
>>> message is considered problematic, I can change it to show the full path
>>> again, like
>>>
>>> diff --git a/scripts/mkmakefile b/scripts/mkmakefile
>>> index 84af27b..9d291f5 100644
>>> --- a/scripts/mkmakefile
>>> +++ b/scripts/mkmakefile
>>> @@ -18,7 +18,7 @@ then
>>>         exit 0
>>>  fi
>>>  if [ "${quiet}" != "silent_" ]; then
>>> -       echo "  GEN     $2/Makefile"
>>> +       echo "  GEN     $(cd $2 && /bin/pwd)/Makefile"
>>>  fi
>>>
>>>  cat << EOF > $2/Makefile
>>>
>>> Opinions?
>> I agree with Randy - the full path is more informative.
>>
>> 	Sam
> 
> Yes, just '.' discards some very useful information.

With commit c2e28dc9 ("kbuild: Print the name of the build directory"),
it now prints the full path at the beginning of each make invocation. So
I think it is not necessary to repeat the full path a few lines later,
do you agree?

Thanks,
Michal
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