basic asm and memory clobbers - Proposed solution

[Bernd Schmidt]

On 12/17/2015 02:41 AM, David Wohlferd wrote:

> So how about:
>
> - Update the basic asm docs to describe basic asm's current (and
> historical) semantics (ie clobber nothing).
> - Emphasize how that might be different from users' expectations or the
> behavior of other compilers.
> - Warn that this could change in future versions of gcc.  To avoid
> impacts from this change, use extended.
> - Mention -Wonly-top-basic-asm as a way to locate affected statements.

Sounds like a pretty reasonable plan.

> What's your take on making -Wonly-top-basic-asm a default (either now or
> v7)?  Is making it a non-default a waste of time because no one will
> ever see it?  Or is making it a default too aggressive? What about
> adding it to -Wall?

Depends if anyone has one in system headers I guess. We could try to add 
it to -Wall.


Bernd