[Buildroot] [PATCH v6 18/28] package/cmake: Fix for using -O in top-level make

Thomas Petazzoni thomas.petazzoni at bootlin.com
Thu Mar 19 14:00:18 UTC 2020


On Thu, 19 Mar 2020 15:53:23 +0200
Asaf Kahlon <asafka7 at gmail.com> wrote:

> > Requiring make > 4.0 on the host system is too strict, especially
> > considering that the issue we have here only happens in very specific
> > conditions: ccache support enabled, and passing of custom -O flags that
> > are only useful for top-level parallel build, which is itself an
> > experimental feature.  
> 
> Just as a side note - the problem isn't related to ccache. We
> reproduced it with -O and top-level parallel build.

Sorry, I mixed things up, and thought it was ccache related.

> In addition, if you have any suggestion how to address that case -
> I'll be more than happy to help.

I don't have any really good suggestion. But it's really a corner case:
only happens with make 4.1 if I understand correctly, and only when you
pass some variants of the -O option.

The "make -Orecurse" option, which is the most relevant for top-level
parallel build, does not exhibit the issue.

So essentially I simply wouldn't fix the problem. If you really want to
fix it, maybe we can have some fancy logic in the main Makefile to
detect that one of the problematic -O option is passed, and the make
version is not appropriate, and then error out.

Thomas
-- 
Thomas Petazzoni, CTO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com


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