On Fri, Nov 27, 2020 at 11:05 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> As for the cc1plus cost, I got a similar result.
>
> Running scripts/gcc-plugin.sh directly
> took me 0.5 sec, which is a fourth
> of the allmodconfig run-time.
>
> Actually, I did not know this shell script
> was so expensive to run...

So it turns out that one reason it's so expensive to run is that it
does a *lot* more than it claims to do.

It says "we need a c++ compiler that supports the designated
initializer GNU extension", but then it actually includes a header
file from hell, rather than just test designated initializers.

This patch makes the cc1plus overhead go down a lot. That said, I'm
doubtful we really want gcc plugins at all, considering that the only
real users have all apparently migrated to clang builtin functionality
instead.

        Linus