Re: [RFC][PATCH] tree-wide: Remove __inline__ and __inline usage

[Linus Torvalds]

On Tue, Nov 6, 2018 at 2:02 AM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
> Therefore I'm proposing to run:
>
>   git grep -l "\<__inline\(\|__\)\>" | while read file
>   do
>         sed -i -e 's/\<__inline\(\|__\)\>/inline/g' $file
>   done
>
> On your current tree, and apply the below fixup patch on top of that
> result.

So I started doing this, and in fact fixed up a few more issues by
hand on top of your patch, but then realized hat it's somewhat
dangerous and possibly broken.

For the uapi header files in particular, __inline__ may actually be
required. Depending on use, and compiler settings, "inline" can be a
word reserved for the user, and shouldn't be used by system headers.

Now, several uapi headers obviously *do* use "inline", and I think in
this day and age that's fine, but I don't actually want to break
possible valid uses.

So I'd argue that we don't actually want to get rid of "__inline__" at
all, because we may need it.

But we *could* get rid of these two lines in include/linux/compiler_types.h

  #define __inline__ inline
  #define __inline   inline

and just say that "inline" for the kernel means "always_inline", but
if you use __inline__ or __inline then you get the "raw" compiler
inlining.

Then people can decide to get rid of __inline__ on a case-by-case basis.

                 Linus