[Bug fortran/69834] Collision in derived type hashes

["pault at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69834

--- Comment #8 from Paul Thomas <pault at gcc dot gnu.org> ---
(In reply to Dominique d'Humieres from comment #6)
> > Created attachment 37791 [details]
> >   --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=37791&action=edit
> > Better Patch
> 
> Withe patch applied to my working tree (many patches) fixes the PR but I see
> several regressions at run time
> 
> FAIL: gfortran.dg/allocate_with_source_(7|8).f08   *  execution test
> FAIL: gfortran.dg/unlimited_polymorphic_zzz.f03   *  execution test
> 
> with zzz in (1, 5, 6, 14, 17, 18, 20, 22). AFAICT it "fixes"
> 
> FAIL: gfortran.dg/finalize_21.f90   -O   scan-tree-dump original "static
> struct __vtype__STAR __vtab__STAR = {._hash=0, ._size=., ._extends=0B,
> ._def_init=0B, ._copy=0B, ._final=0B};"

Dominique,

I just applied the patch posted here to another tree on another machine and it
regtests fine.

Could you please send me the tree dump for one of the failing cases, especially
unlimited_polymorphic_1.f03 if that is amongst them?

It would be good if you could confirm that it is only cases of intrinsic types
that cause the failures. I had a lot of trouble with those. Try this testcase
and send me the tree dump as well:

  type a
    integer :: a = 99
  end type
  type, extends (a) :: b
    real :: b = 1.0
  end type

  class(*), allocatable :: star
  real(8) :: x = 3.14152
  character(4) :: chr = "abcd"

  allocate (star, mold = b())
  select type (star)
    type is (a)
      print *, "a = ", star%a
    type is (b)
      print *, "b = ", star%a, star%b
    class default
      print *, "FAILURE"
  end select

  deallocate (star)
  allocate (star, source = x)
  select type (star)
    type is (real(8))
      print *, "x = ", star
    class default
      print *, "FAILURE on REAL(8)"
  end select

  deallocate (star)
  allocate (star, source = chr)
  select type (star)
    type is (character(*))
      print *, "chr = ", star
    class default
      print *, "FAILURE on CHARACTER(*)"
  end select
end

Thanks

Paul