[Bug fortran/28378] New: Intrinsic extensions should be deselectable via command line

["anlauf at gmx dot de" <gcc-bugzilla at gcc dot gnu dot org>]

Hi,

gfortran has the nasty behavior to fail on completely legal code
that uses subroutines or functions with whose name equals an extension.
g77 had flags to "hide" extensions, but there is no (no documented?)
way to do this with gfortran.

Example:

program gfcbug37
  a = second (1.0)
  print *, a
end program gfcbug37

function second (minute)
  real minute
  second = 60 * minute
end function second

leads to:

 In file gfcbug37.f90:2

  a = second (1.0)
     1
Error: Too many arguments in call to 'second' at (1)

I can compile this with gfortran by adding -std=f95 to the
command line for this particular example, but this is not
possible for most other code, in particular legacy code
that is essentially Fortran 77.

If there are flags similar to g77's they should be documented.

An alternative to g77's -f*-intrinsics-* options are those
provided by IBM's xlf:

         -qextern=<name1>[:<name2>[: ... [:<namen>]]]
                Allows user-written procedures to be called instead
                of XL Fortran intrinsics. The suboption is a list
                of procedure names separated by colons. The
                procedure names are treated as if they appear in an
                EXTERNAL statement in each compilation unit being
                compiled.


-- 
           Summary: Intrinsic extensions should be deselectable via command
                    line
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: anlauf at gmx dot de
  GCC host triplet: i686-pc-cygwin


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28378