Re: [PATCH] tools: Fix math.h breakage

[Matthew Wilcox <willy@infradead.org>]

On Tue, Nov 30, 2021 at 04:39:00PM +0200, Andy Shevchenko wrote:
> On Tue, Nov 30, 2021 at 02:13:16PM +0000, Matthew Wilcox (Oracle) wrote:
> > Commit 98e1385ef24b broke the radix tree test suite in two different ways;
> > first by including math.h which didn't exist in the tools directory, and
> > second by removing an implicit include of spinlock.h before lockdep.h.
> > Fix both issues.
> 
> Sorry for that and thank you for the fix.
> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> 
> I'm wondering if there is a way of not copying kernel headers manually,
> otherwise we always will have such breakages.

It's not necessarily that these are _copies_ of kernel headers, so much as
they're ways of mocking kernel interfaces when building userspace code.
We could separate out pieces and include them from each direction, but
that has its own problems, and doesn't necessarily solve these kinds of
problems either.

I think the only way to prevent these kinds of breakages is to make sure
the build bots are also building things.