Compilation error

[Tobias Burnus]

Dear Daniel,

Paul Richard Thomas wrote:
>> Is it ok to ask "user" questions here? I'm back at school doing research. I
>> have a piece of code that used to work and now refuses to compile. I'm using
>> GFortran 4.4.3.
...
>> Error: Internal procedure 'dp' is not allowed as an actual argument at (1)

It might have worked with some gfortran compiler. Passing internal 
procedures is something which Fortran up to 2003 does not allow, but 
Fortran 2008 does. There are some gotchas which make the implementation 
nonstraight forward - though as GCC's middle end supports it, the 
Fortran front-end implementation was trivial.

Since gfortran 4.6, it is officially supported by GCC (unless you use 
-std=f95/f2003). I think some old version of gfortran (4.1, 4.2, ...?) 
didn't diagnose it and, hence, also supported it.

Tobias