[Bug fortran/32317] New: No warning on bad arguments with explicit interface

["terry at chem dot gu dot se" <gcc-bugzilla at gcc dot gnu dot org>]

Even when an explicit interface is known, no warnings are generated when array
argument bounds (available to the compiler) don't match.  Consider the
following:

module mod
implicit none

contains

subroutine a(n,v)
integer,intent(in)::n
real,dimension(n),intent(in)::v
write(*,*)v
end subroutine a

subroutine b
real,dimension(5)::v
v=0
call a(8,v(1:4))
end subroutine b

end module mod

When b is being compiled the interface to a is known, yet no warnings are
generated of the obvious mismatch in the arguments (run.f90 just calls b):

$ gfortran -Wall -W -c --std=f2003 --pedantic -fbounds-check -O case.f90
$ gfortran -Wall -W --std=f2003 --pedantic -fbounds-check -O run.f90 case.o
$ ./a.out 
   0.000000       0.000000       0.000000       0.000000       0.000000      
0.000000     -1.1411260E-37  1.5604860E-41 -5.1655852E-38  1.5604860E-41
-6.3728095E-38  1.5604860E-41   0.000000       0.000000      5.8804453E-39  
0.000000      4.2038954E-45   0.000000      5.8809218E-39   0.000000    
-6.3728095E-38  1.5604860E-41 -8.5373851E-38  1.5604860E-41  5.8801398E-39

While this construct is probably legal as a hang-on from crappy old fortran, I
can't think of a situation when giving explicit bounds like this where simply
overrunning would be the desired effect.  A warning would be nice.

(I was going to also complain that -fbouns-check didn't come up with anything,
but then I saw PR 27989.)


-- 
           Summary: No warning on bad arguments with explicit interface
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: terry at chem dot gu dot se
  GCC host triplet: x86_64-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32317