[Bug fortran/71936] ICE in wide_int_to_tree, at tree.c:1487

["gerhard dot steinmetz dot fortran at t-online dot de" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71936

--- Comment #2 from Gerhard Steinmetz <gerhard.steinmetz.fortran@t-online.de> ---

To get the whole picture it's necessary to take a look at four
analogous cases with "type" instead of "class". They compile without
an error (v6/v7), but occationally run for a long time (y3/y4).


$ cat y1.f90
program p
   type t
   end type
   type(t), allocatable :: x(:)
   allocate (x, mold=f())
   deallocate (x)
   allocate (x, source=f())
contains
   function f()
      type(t), allocatable :: f(:)
   end
end


$ cat y2.f90
program p
   type t
   end type
   type(t), allocatable :: x(:)
   allocate (x, mold=f())
   deallocate (x)
   allocate (x, source=f())
contains
   function f()
      type(t), pointer :: f(:)
   end
end


$ cat y3.f90
program p
   type t
   end type
   type(t), pointer :: x(:)
   allocate (x, mold=f())
   deallocate (x)
   allocate (x, source=f())
contains
   function f()
      type(t), allocatable :: f(:)
   end
end


$ cat y4.f90
program p
   type t
   end type
   type(t), pointer :: x(:)
   allocate (x, mold=f())
   deallocate (x)
   allocate (x, source=f())
contains
   function f()
      type(t), pointer :: f(:)
   end
end



$ gfortran-5 y4.f90
y4.f90:5:13:

    allocate (x, mold=f())
             1
Error: Array specification required in ALLOCATE statement at (1)
y4.f90:7:13:

    allocate (x, source=f())
             1
Error: Array specification required in ALLOCATE statement at (1)
$


$ gfortran-7-20160717 y4.f90
$
$ time timeout 100.0 a.out

real    1m40.002s
user    1m40.046s
sys     0m0.003s