[Bug fortran/30902] gfortran produces wrong result with code using generic interface block

[burnus at gcc dot gnu dot org]

------- Comment #2 from burnus at gcc dot gnu dot org  2007-02-21 07:33 -------
(In reply to comment #0)
> The attached test code using a generic interface block produces wrong output
> when compiled with gfortran, and works fine with pgf90.

I think both compilers are right; or to be more precise: The program is
wrong/undefined.

If one removes the INTERFACE blocks and puts the subroutines into below a
CONTAINS in the main program, gfortran gives the following error:


      call adsorb(tsl, gamm, adwat, wsc, dime = ns, mode = 1)
                 1
Error: Type/rank mismatch in argument 'te' at (1)

The actual argument "tsl" is REAL, DIMENSION(10);
the dummy argument "te" is REAL, INTENT(IN)  :: gam, te

Analogously for gam(m) and adwat/adsor.

Thus: The compiler expects in the main program that it has to pass an array,
but the routine only accepts a single real.

What happens in your program is now highly platform and compiler dependent:
pgf90 seems to set all values to "0.5104298" (but I wouldn't rely on this
happening all the times), gfortran has seemingly "0.5104298" in adwat(10) only.
(The rest is uninitialized.) And ifort/g95 have for the whole array adwat(:)
uninitialized values.

By the way, NAG f95 detects the interface/procedure mismatch also for the
original program as the interface and the subroutines are in the same file.
This same-file error detection is also planed for gfortran.


-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |burnus at gcc dot gnu dot
                   |                            |org
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |INVALID


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30902