[Cmake] Removing a cache entry? Multiple MACRO definitions?

[Amitha Perera]

On Fri 02 Jan 2004, Andy Cedilnik wrote:
> I had a similar idea. Something like a global variable which reruns all
> the try compiles, so then you do:
> 
> cmake -DCMAKE_RERUN_TRY_COMPILES=1 .
> 
> which will ignore values in the cache.

That is a good thing to have on all the CHECK* macros.

> Also, I think it may work if you set HAVE_STDLIB to be HAVE_STDLIB, but
> I am not sure.

This may be a workaround. I'll check.

However, it seems that deleting a variable from the cache is a missing
feature. Following existing syntax, perhaps

  SET( VAR CACHE TYPE "doc string )

should delete the variable from the cache, while

  SET( VAR "" CACHE TYPE "doc string )

will have the current behaviour of setting the cache entry to an empty string.

Amitha.