BUILD_BUG_ON(!__builtin_constant_p(feature)) breaks bcc trace tool

[Arnd Bergmann]

On Tue, Jan 24, 2017 at 7:15 AM, Michael Ellerman <mpe at ellerman.id.au> wrote:

> Hmm, in fact it seems because we don't define
> CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING and CONFIG_OPTIMIZE_INLINING, we
> get:
>
> #define inline          inline          __attribute__((always_inline)) notrace
>
> So in fact every inline function is marked always_inline all the time,
> which seems dubious.
>
> But still, it seems clang is ignoring always_inline.

I think the problem is that __builtin_constant_p() is usually false on
clang, at least for arguments
that are not constant pointers.

    Arnd