compiler info in kernel identification string

Andriy Gapon avg at
Fri Nov 16 10:59:31 UTC 2012

on 16/11/2012 12:54 Daniel Braniss said the following:
>> This is starting to turn into a bikeshed, but anyway...
>> on 16/11/2012 12:00 Daniel Braniss said the following:
>>> the question as to what compiler was used to compile the kernel is a bit of an
>>> oxymoron, since the kernel is made up of many different modules, which get 
>>> compiled
>>> either by different compilers, or different compiler flags.
>> The canonical way to compile a kernel is to use buildkernel and compile modules
> this does not guarantee uniformity, just look at the output it produces and 
> you will see
> different compilers/assemblers/scripts/flags

Different flags specified in the build infrastructure are OK.

>> along with the kernel.  Other configurations are supported too, of course.
>>> since the compiler does 'sign' the modules it compiles (and clang will/should
>>> do it soon: some tool like
>>> file(1) could be modified to provide it, or config -x (8) ...
>> The key word in your note about clang is 'soon' as in 'not yet'.
> Dimitry wrote that he will handle it :-)

Right. 'will' is not 'did'.

>> Besides, when I see a bug report with a dmesg *I* want to immediately know what
>> compiler was used there.
> today it's clang vs. gcc -- transition time --, but again it's only part of 
> the story,
> and soon it will only be noise.

Different kernel toolchains are here to stay.
And it's not just clang vs gcc, but also different toolchains for embedded
world, etc.

Andriy Gapon

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