Re: [avr-libc-dev] Can pgmspace.h __LPM_xxx__ macros become inlinefn's?

[E. Weddington]

Bill Somerville wrote:

<explanations>

Thanks for the explanations!

> > Wouldn't it be simpler to figure out what it is about the macros that
> > -pedantic doesn't like?
> >    
>
> The problem is that the used of a braced block in the middle of an
> expression is not leagal C or C++. The block is required so that
> automatic variables can be introduced for local storage (these are in
> fact optimised away).
>
>  

I was afraid it was that.

> inline in C++ and now C99 was introduced to get around this problem
> among others of which the most useful are the type safety of compiler
> checked arguments etc, the avoidance of multiple evaluation of complex
> arguments, and that the fn names are handled by the compiler which
> honours C/C++ scoping rules unlike the CPP which doesn't.
>
>  

Ok. So making this change makes a lot of sense.

The only issue I still see is when optimization is turned off. Currently 
the macros will put the code in the function no matter what the 
optimisation setting. It looks like using inline will not do this 
without using that always_inline function attribute. I would assume that 
if this change was made that it would be documented in the user manual 
about requiring optimisation.

Eric