NDEBUG-like macro

[Bernd Schmidt]

On Wed, 15 Apr 1998, Mark Mitchell wrote: 
>   In private email, Jeff and I have been discussing the following
>   proposal:
> 
>   o Add a configuration option --enable-checking to enable additional,
>     possibly costly, consistency checks in the compiler.

>   The motivation for this is the disturbingly common situation in
> which I find that bugs are triggered by using, say, DECL_INITIAL on a
> tree node that is not a DECL.  In general, the use of a macro that
> pulls something out of a tagged union when the tag doesn't match.  It
> would be nice if we could blow up when we did this wrong.

The tree and rtl structures are terribly overloaded. Some of that checking
could be done at compile-time instead of at run-time, by introducing new
types. For example, it might be possible to distinguish between trees that
describe expressions and those that describe types instead of calling both
simply a "tree".
Of course such a change would require a lot more work.

Bernd