Re: How can I tell if Fortran compiler is GNU ?

[Noah Misch]

On Sat, Jan 23, 2010 at 02:22:45AM +0000, Dr. David Kirkby wrote:
> If using AC_PROG_CC and the compiler is the gcc, the variable GCC is set to 
> "yes".
>
> Likewise, if using AC_PROG_F77 and the Fortran 77 compiler is g77, then 
> the variable G77 is set to "yes".
>
> If however I call AC_PROG_FC, is there any simple way of knowing if that  
> compiler is a GNU compiler? The configure script shows:

You could use $ac_cv_fc_compiler_gnu for that, but

> What I am trying to do is test the C, C++ and Fortran compilers, to 
> ensure they are either
>
> 1) All GNU compilers   OR
> 2) All non-GNU compilers
>
> What I want is to avoid a mixture of the two. I would imagine trying to 
> mix object files from the Sun Fortran compiler and the GNU C++ compiler 
> is likely to end in tears.

the more Autoconfish approach would test making an executable using objects from
all three compilers and accept the combination if this works.