[Bug fortran/45304] New: Functions/subroutines without arguments always treated like varargs

[jakub at gcc dot gnu dot org]

In:
subroutine foo (i, j)
  integer :: i, j, k, l
  k = i
  l = j
  i = i * 10
  i = i + j
  call baz (i)
  i = i + j
end subroutine
subroutine bar (i, j)
  integer :: i, j, k, l
  k = i
  l = j
  i = i * 10
  i = i + j
  call baz (i)
  i = i + j
end subroutine
subroutine fn ()
end subroutine fn
program entryval
  interface bar
    subroutine bar (i, j)
      integer :: i, j
    end subroutine
  end interface
  integer :: i
  i = 6
  call foo (i, 7)
  i = 8
  call bar (i, 7)
  i = 10
  call foo (i, 7)
  i = 12
  call bar (i, 7)
  call fn ()
end
the calls to MAIN__, fn_ and baz_ are all treated like varargs call (on
x86_64-linux that means movl $0, %eax or xorl %eax, %eax has to precede each
such call).  The patch I'm going to attach fixes at least the callq MAIN__ case
(and should decrease memory consumption by sharing the terminating list nodes).

Unfortunately using if (!typelist) typelist = void_list_node; in
gfc_get_function_type unconditionally isn't right, while it would fix the fn_
case (in -fwhole-file mode we know it has no arguments), for baz_ case which is
external the function really has some arguments, but we don't know them in
gfc_get_function_type.  Is there any way to differentiate between the two cases
(when we know the subroutine/function has no arguments and is defined in the
current TU, or when it is unknown)?
Or better yet, can't we for the really extern decls make up the formal
parameters from the call?  As in, shouldn't:
subroutine foo (i)
  integer :: i
end subroutine foo
program nn
  integer :: i
  real :: f
  call foo (i)
  call foo (f)
  call bar (i)
  call bar (f)
end

warn not just about the argument mismatch to foo, but also about bar?


-- 
           Summary: Functions/subroutines without arguments always treated
                    like varargs
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: jakub at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45304