[CMake] cmake 2.6.2 RC 5

[Bill Hoffman]

Alan W. Irwin wrote:
> On 2008-09-22 16:44-0400 Bill Hoffman wrote:
> 
>> [...]this bug is a bit of a corner case.  Most projects just enable 
>> all the languages as the top of the project.  In this case, no one 
>> could have a project that depends on this working because it never 
>> worked. However, I will try to get to it soon.
> 
> Thanks, Bill, for giving this bug #4772 fix a "soon" priority since it does
> directly impact PLplot users.
> 
> ENABLE_LANGUAGE is a necessity for PLplot since we have multiple optional
> language bindings.  (If we put, e.g., Fortran in our PROJECT statement, we
> would exclude all our users that don't have a Fortran compiler available
> even if they didn't care about those particular language bindings for
> PLplot.)
> 
> As a result of this bug I have had to recommend to our PLplot users that
> they should not use build types (which depend on the compiler flags that 
> are
> not correctly set as a result of this ENABLE_LANGUAGE bug) and instead
> specify compiler flags directly using, e.g.,
> 
> FC='gfortran -g'
> 
> I look forward to your bug fix which should make build types work properly
> for the first time on the Linux platform for PLplot (and all other projects
> that use ENABLE_LANGUAGE).
> 

Another approach might be to use enable_language(languageName OPTIONAL).

Would this work:

enable_language(Fortran OPTIONAL)
project(myproject C CXX)

It would always test for fortran, and enable it if they have it.  If 
they do not have it, then you can just turn off that binding.  It won't 
be an error not to have it.  If they do have it you can offer the 
binding option for Fortran.

-Bill