Re: [avr-gcc-list] assembler macros

[E. Weddington]

Jamie Lawson wrote:

> On Mon, 8 Nov 2004, Johannes Bauer wrote:
>
>  
>
> > Jamie Lawson wrote:
> >
> >    
> >
> > > #define _NOP() do { __asm__ __volatile__ ("nop") } while (0)
> > >
> > > What does the "do while(0)" do?
> > >      
> > The "do while(0)" thing is frequently being using in macros to open a
> > new scope. Usually it's only used when more than one instruction should
> > be execute. Imagine:
> >
> >    
>
> Ahh yes, I see. Thanks.
>
>  
>
> > However, in your code, I do not see why you would get an error. Line 100
> > is the macro-line, I guess? Should the macro maybe read
> >
> > #define _NOP() do { __asm__ __volatile__ ("nop"); } while (0)
> >
> > instead of
> >
> > #define _NOP() do { __asm__ __volatile__ ("nop") } while (0)
> >    
>
> You are correct here. It compiles without complaint with your fix.
>
>  
Would you be willing to open a bug report on this at the avr-libc project?:
<http://savannah.nongnu.org/projects/avr-libc/>

Also, FYI, the name of the project is *avr-libc*, not avr-glibc.

Eric