Re: bootstrap problem with union Lisp_Object

[Ken Raeburn]

On Dec 7, 2005, at 23:54, Richard M. Stallman wrote:
>     If people think this is a good idea, I could start changing those
>     macros that use eassert (XSET, XCONS, XVECTOR, ...) to have GCC  
> and
>     non-GCC versions, with the GCC versions using statement  
> expressions
>     (inline functions wouldn't preserve the file and line number) and
>     temporary variables, and error out if ENABLE_CHECKING is  
> defined but
>     GCC isn't used.  Should be straightforward, about a dozen  
> places or
>     so to change I think.
>
> Is this really necessary now?  I hope not.

No, but without such a thing -- or some other approach like replacing  
some of these macros with functions -- the ENABLE_CHECKING version of  
these macros will evaluate arguments more than once.  As far as I  
know, most if not all of the actual uses are cases where this doesn't  
cause much trouble except perhaps for performance.

Ken