[Fortran,pr60322] was: [Patch 1/2, Fortran, pr60322] [OOP] Incorrect bounds on polymorphic dummy array

Hi all,

I have worked on the comments Mikael gave me. I am now checking for
class_pointer in the way he pointed out.

Furthermore did I *join the two parts* of the patch into this one, because
keeping both in sync was no benefit but only tedious and did not prove to be
reviewed faster.

Paul, Dominique: I have addressed the LOC issue that came up lately. Or rather
the patch addressed it already. I feel like this is not tested very well, not
the loc() call nor the sizeof() call as given in the 57305 second's download.
Unfortunately, is that download not runable. I would love to see a test similar
to that download, but couldn't come up with one, that satisfied me. Given that
the patch's review will last some days, I still have enough time to come up
with something beautiful which I will add then.

Bootstraps and regtests ok on x86_64-linux-gnu/F20.

Regards,
	Andre

On Tue, 24 Mar 2015 11:13:27 +0100
Paul Richard Thomas <paul.richard.thomas@gmail.com> wrote:

> Dear Andre,
> 
> Dominique pointed out to me that the 'loc' patch causes a ICE in the
> testsuite. It seems that 'loc' should provide the address of the class
> container in some places and the address of the data in others. I will
> put my thinking cap on tonight :-)
> 
> Cheers
> 
> Paul
> 
> On 23 March 2015 at 13:43, Andre Vehreschild <vehre@gmx.de> wrote:
> > Hi Mikael,
> >
> > thanks for looking at the patch. Please note, that Paul has sent an
> > addendum to the patches for 60322, which I deliberately have attached.
> >
> >>  26/02/2015 18:17, Andre Vehreschild a écrit :
> >> > This first patch is only preparatory and does not change any of the
> >> > semantics of gfortran at all.
> >> Sure?
> >
> > With the counterexample you found below, this of course is a wrong
> > statement.
> >
> >> > diff --git a/gcc/fortran/expr.c b/gcc/fortran/expr.c
> >> > index ab6f7a5..d28cf77 100644
> >> > --- a/gcc/fortran/expr.c
> >> > +++ b/gcc/fortran/expr.c
> >> > @@ -4059,10 +4060,10 @@ gfc_lval_expr_from_sym (gfc_symbol *sym)
> >> >    lval->symtree = gfc_find_symtree (sym->ns->sym_root, sym->name);
> >> >
> >> >    /* It will always be a full array.  */
> >> > -  lval->rank = sym->as ? sym->as->rank : 0;
> >> > +  as = sym->as;
> >> > +  lval->rank = as ? as->rank : 0;
> >> >    if (lval->rank)
> >> > -    gfc_add_full_array_ref (lval, sym->ts.type == BT_CLASS ?
> >> > -                       CLASS_DATA (sym)->as : sym->as);
> >> > +    gfc_add_full_array_ref (lval, as);
> >>
> >> This is a change of semantics.  Or do you know that sym->ts.type !=
> >> BT_CLASS?
> >
> > You are completely right. I have made a mistake here. I have to tell the
> > truth, I never ran a regtest with only part 1 of the patches applied. The
> > second part of the patch will correct this, by setting the variable as
> > depending on whether type == BT_CLASS or not. Sorry for the mistake.
> >
> >> > diff --git a/gcc/fortran/trans-decl.c b/gcc/fortran/trans-decl.c
> >> > index 3664824..e571a17 100644
> >> > --- a/gcc/fortran/trans-decl.c
> >> > +++ b/gcc/fortran/trans-decl.c
> >> > @@ -1013,16 +1017,24 @@ gfc_build_dummy_array_decl (gfc_symbol * sym,
> >> > tree dummy) tree decl;
> >> >    tree type;
> >> >    gfc_array_spec *as;
> >> > +  symbol_attribute *array_attr;
> >> >    char *name;
> >> >    gfc_packed packed;
> >> >    int n;
> >> >    bool known_size;
> >> >
> >> > -  if (sym->attr.pointer || sym->attr.allocatable
> >> > -      || (sym->as && sym->as->type == AS_ASSUMED_RANK))
> >> > +  /* Use the array as and attr.  */
> >> > +  as = sym->as;
> >> > +  array_attr = &sym->attr;
> >> > +
> >> > +  /* The pointer attribute is always set on a _data component, therefore
> >> > check
> >> > +     the sym's attribute only.  */
> >> > +  if (sym->attr.pointer || array_attr->allocatable
> >> > +      || (as && as->type == AS_ASSUMED_RANK))
> >> >      return dummy;
> >> >
> >> Any reason to sometimes use array_attr, sometimes not, like here?
> >> By the way, the comment is misleading: for classes, there is the
> >> class_pointer attribute (and it is a pain, I know).
> >
> > Yes, and a good one. Array_attr is sometimes sym->attr and sometimes
> > CLASS_DATA(sym)->attr aka sym->ts.u.derived->components->attr. In the later
> > case .pointer is always set to 1 in the _data component's attr. I.e., the
> > above if, would always yield true for a class_array, which is not intended,
> > but rather destructive. I know about the class_pointer attribute, but I
> > figured, that it is not relevant here. Any idea how to formulate the
> > comment better, to reflect what I just explained?
> >
> > Regards,
> >         Andre
> > --
> > Andre Vehreschild * Email: vehre ad gmx dot de
> >
> >
> > ---------- Forwarded message ----------
> > From: Paul Richard Thomas <paul.richard.thomas@gmail.com>
> > To: Andre Vehreschild <vehre@gmx.de>, Dominique Dhumieres
> > <dominiq@lps.ens.fr> Cc:
> > Date: Sun, 22 Mar 2015 21:20:20 +0100
> > Subject: Bug in intrinsic LOC for scalar class objects
> > Dear Andre and Dominique,
> >
> > I have found that LOC is returning the address of the class container
> > rather than the _data component for class scalars. See the source
> > below, which you will recognise! A fix is attached.
> >
> > Note that the scalar allocate fails with MOLD= and so I substituted SOURCE=.
> >
> > Cheers
> >
> > Paul
> >
> >     class(*), allocatable :: a(:), e ! Change 'e' to an array and
> > second memcpy works correctly
> >                                      ! Problem is with loc(e), which
> > returns the address of the
> >                                      ! class container.
> >     allocate (e, source = 99.0)
> >     allocate (a(2), source = [1.0, 2.0])
> >     call add_element_poly (a,e)
> >     select type (a)
> >       type is (real)
> >         print *, a
> >     end select
> >
> > contains
> >
> >     subroutine add_element_poly(a,e)
> >       use iso_c_binding
> >       class(*),allocatable,intent(inout),target :: a(:)
> >       class(*),intent(in),target :: e
> >       class(*),allocatable,target :: tmp(:)
> >       type(c_ptr) :: dummy
> >
> >       interface
> >         function memcpy(dest,src,n) bind(C,name="memcpy") result(res)
> >           import
> >           type(c_ptr) :: res
> >           integer(c_intptr_t),value :: dest
> >           integer(c_intptr_t),value :: src
> >           integer(c_size_t),value :: n
> >         end function
> >       end interface
> >
> >       if (.not.allocated(a)) then
> >         allocate(a(1), source=e)
> >       else
> >         allocate(tmp(size(a)),source=a)
> >         deallocate(a)
> >         allocate(a(size(tmp)+1),source=e) ! mold gives a segfault
> >         dummy = memcpy(loc(a(1)),loc(tmp),sizeof(tmp))
> >         dummy = memcpy(loc(a(size(tmp)+1)),loc(e),sizeof(e))
> >       end if
> >     end subroutine
> > end
> >
> 
> 
>

[Fortran,pr60322] was: [Patch 1/2, Fortran, pr60322] [OOP] Incorrect bounds on polymorphic dummy array

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