C: inline without forcing?

[Danielle Church]

On Wed, Jun 2, 2021, 18:30 Segher Boessenkool <segher@kernel.crashing.org>
wrote:

> On Wed, Jun 02, 2021 at 12:22:58PM -0400, Danielle Church wrote:
> > On Wed, Jun 2, 2021 at 11:54 AM Segher Boessenkool
> > <segher@kernel.crashing.org> wrote:
> > > > Is there no way to get the code-emit behavior (inline the
> > > > function or emit a TU-external reference, don't emit standalone
> > > > definition) without the optimizer changes (more likely to inline the
> > > > function, even if it's a bad idea)?
> > >
> > > extern attribute((gnu_inline))
> >
> > Does ``extern inline attribute((gnu_inline))'' behave appreciably
> > differently than C99's bare ``inline''? They seem to have the same
> > effect from the documentation, though with reversed semantics for the
> > presence vs absence of the extern keyword.
>
> Neither GNU inline nor standard C inline is inclusive of the other.  A
> gnu_inline extern inline is never emitted as a standalone function.
>

Can you explain to me how that's different from C99 inline? I'm afraid I
don't understand, since a C99 declaration like

inline void foo() {
 ...
}

won't emit a standalone function either, no?

-Danielle

>