Re: VirtualBox-6.0.6 fails build under 8.99.39

[Chavdar Ivanov <ci4ic4%gmail.com@localhost>]

Hi,

Forget about this thread - replacing 'asm' with '__asm' in cpufunc.h
solves the problem, as was indeed mentioned above. VirtualBox
extensions compile ok.

On Fri, 31 May 2019 at 08:11, Chavdar Ivanov <ci4ic4%gmail.com@localhost> wrote:
>
> On Fri, 31 May 2019 at 02:07, Joerg Sonnenberger <joerg%bec.de@localhost> wrote:
> >
> > On Thu, May 30, 2019 at 09:32:24PM +0100, Chavdar Ivanov wrote:
> > > error: 'asm' undeclared (first use in this function)
> > >   asm volatile ("pause");
> > >   ^~~
> > > ...............
> > >
> > > (I had to revert to the original cpufunc.h as the cvs update was failing).
> > >
> > > What is the solution here - should I continue to locally modify
> > > cpufunc.h from the NetBSD src/sys/arch/x86/include/ ? What is the
> > > purpose of having 'asm volatile' if __asm__ does the job (and volatile
> > > is a NOP anyway, according to the gcc manual, it is considered
> > > volatile without the keyword)?
> >
> > volatile is *not* a nop. It prevents the statement from being optimised
> > away as having no side effects.
>
> Yes. I meant I saw discussions stating that the compiler treats all
> basic asm blocks as having the volatile keyword anyway.
>
> Perhaps it may depend on the gcc version as well.
>
> The query was about what is the right thing to do - should VirtualBox
> change the gcc command line ( it uses '-std=c99', as I understand it
> this is the reasxon it does not work ), should cpufunc.h be modified
> to allow for such treatment, or should I simply maintain a second copy
> of cpufunc.h to put in place only when building VirtualBox extensions
> ( which is what I do now, kinda stupid ).
>
> >
> > Joerg
>
>
>
> --
> ----



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