[PATCH] PR fortran/78500 -- Yet another NULL pointer dereference

[Janus Weil]

Hi Steve,

> Regression tested on x86_64-*-freebsd.  OK to commit?

the patch is certainly ok.

Just my usual request for a meaningful test-case name: This one could
be class_result_4.f90. (I don't want to be pedantic about this, but in
a growing testsuite of 4000+ files, I really think it makes sense to
have meaningful names. It does have various advantages and, to be
honest, I don't see any disadvantage).

Thanks for the patch,
Janus



> 2016-11-23  Steven G. Kargl  <kargl@gcc.gnu.org>
>
>         PR fortran/78500
>         * expr.c (gfc_check_vardef_contextm): YANPD
>         * interface.c (matching_typebound_op): Ditto.
>
> 2016-11-23  Steven G. Kargl  <kargl@gcc.gnu.org>
>
>         PR fortran/78500
>         * gfortran.dg/pr78500.f90: New test.
>
>
> Index: gcc/fortran/expr.c
> ===================================================================
> --- gcc/fortran/expr.c  (revision 242789)
> +++ gcc/fortran/expr.c  (working copy)
> @@ -5291,7 +5291,8 @@ gfc_check_vardef_context (gfc_expr* e, b
>       component.  Note that (normal) assignment to procedure pointers is not
>       possible.  */
>    check_intentin = !own_scope;
> -  ptr_component = (sym->ts.type == BT_CLASS && CLASS_DATA (sym))
> +  ptr_component = (sym->ts.type == BT_CLASS && sym->ts.u.derived
> +                  && CLASS_DATA (sym))
>                   ? CLASS_DATA (sym)->attr.class_pointer : sym->attr.pointer;
>    for (ref = e->ref; ref && check_intentin; ref = ref->next)
>      {
> Index: gcc/fortran/interface.c
> ===================================================================
> --- gcc/fortran/interface.c     (revision 242789)
> +++ gcc/fortran/interface.c     (working copy)
> @@ -3885,7 +3885,7 @@ matching_typebound_op (gfc_expr** tb_bas
>
>         if (base->expr->ts.type == BT_CLASS)
>           {
> -           if (CLASS_DATA (base->expr) == NULL
> +           if (!base->expr->ts.u.derived || CLASS_DATA (base->expr) == NULL
>                 || !gfc_expr_attr (base->expr).class_ok)
>               continue;
>             derived = CLASS_DATA (base->expr)->ts.u.derived;
> Index: gcc/testsuite/gfortran.dg/pr78500.f90
> ===================================================================
> --- gcc/testsuite/gfortran.dg/pr78500.f90       (nonexistent)
> +++ gcc/testsuite/gfortran.dg/pr78500.f90       (working copy)
> @@ -0,0 +1,5 @@
> +! { dg-do compile }
> +class(t) function f() ! { dg-error "must be dummy, allocatable or pointer" }
> +   f = 1              ! { dg-error "variable must not be polymorphic" }
> +end
> +
>
> --
> Steve