[Bug libfortran/18924] New: segfault in dot_product with missing interface information

[Thomas dot Koenig at online dot de]

This one is a bit tricky.  It passes two arrays
to a subroutine, where they are passed on to the
intrinsic function dot_product.  However, they
are passed old-style, without interface information.
dot_product expects to receive only new-style arrays,
and generates a segfault in the executed program.

This one can't be caught at compile time (at least not
without inter-procedural analysis) because it's
the caller who determines wether to pass an old-style
or a new-style array.

$ cat dot_product.f90
program main
  implicit none
  real, dimension(2) :: a, b
  real :: c
  a = 1.
  b = -2.3
  call foo(a,b,c)
  print *,c
end program main

subroutine foo(a,b,c)
  real, dimension(:), intent(in) :: a, b
  real, intent(out) :: c
  c = dot_product(a,b)
end subroutine foo
$ gfortran dot_product.f90 && ./a.out
Segmentation fault
$ gfortran -v
Reading specs from /home/zfkts/lib/gcc/ia64-unknown-linux-gnu/4.0.0/specs
Configured with: ../gcc-4.0-20041205/configure --prefix=/home/zfkts
--enable-languages=c,c++,f95 --disable-shared
Thread model: posix
gcc version 4.0.0 20041205 (experimental)

-- 
           Summary: segfault in dot_product with missing interface
                    information
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: libfortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: Thomas dot Koenig at online dot de
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18924