[Bug fortran/108434] [12/13 Regression] ICE in class_allocatable, at fortran/expr.cc:5000

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108434

--- Comment #7 from anlauf at gcc dot gnu.org ---
(In reply to anlauf from comment #6)
> There is another potential issue (see comment#1) which might be related
> to this one or not.  Keeping this PR open until the finalization work
> reaches the next stage...

The variant from comment#1 first hits a NULL pointer dereference fixed by:

diff --git a/gcc/fortran/class.cc b/gcc/fortran/class.cc
index bffc0ffff3a..0436db82020 100644
--- a/gcc/fortran/class.cc
+++ b/gcc/fortran/class.cc
@@ -940,7 +940,7 @@ comp_is_finalizable (gfc_component *comp)
               || (comp->ts.u.derived->f2k_derived
                   && comp->ts.u.derived->f2k_derived->finalizers)))
     return true;
-  else if (comp->ts.type == BT_CLASS && CLASS_DATA (comp)
+  else if (comp->ts.type == BT_CLASS && comp->attr.class_ok && CLASS_DATA
(comp)
            && CLASS_DATA (comp)->attr.allocatable)
     return true;
   else

but afterwards generates a traceback in generate_finalization_wrapper:

pr108434-aa.f90:8:35:

    8 |      class(c), allocatable :: a(2) ! { dg-error "must have a deferred
shape" }
      |                                   1
Error: Allocatable component of structure at (1) must have a deferred shape
f951: internal compiler error: in generate_finalization_wrapper, at
fortran/class.cc:1714
0x8e10e1 generate_finalization_wrapper
        ../../gcc-trunk/gcc/fortran/class.cc:1714
0x8e4396 gfc_find_derived_vtab(gfc_symbol*)
        ../../gcc-trunk/gcc/fortran/class.cc:2618
0x9abfb8 resolve_fl_derived
        ../../gcc-trunk/gcc/fortran/resolve.cc:15482
0x9ad0af resolve_symbol
        ../../gcc-trunk/gcc/fortran/resolve.cc:15867
0x9d78d8 do_traverse_symtree
        ../../gcc-trunk/gcc/fortran/symbol.cc:4196
0x9d7996 gfc_traverse_ns(gfc_namespace*, void (*)(gfc_symbol*))
        ../../gcc-trunk/gcc/fortran/symbol.cc:4221
0x9b1f95 resolve_types
        ../../gcc-trunk/gcc/fortran/resolve.cc:17830
0x9b2446 gfc_resolve(gfc_namespace*)
        ../../gcc-trunk/gcc/fortran/resolve.cc:17945
0x97f916 resolve_all_program_units
        ../../gcc-trunk/gcc/fortran/parse.cc:6655
0x980112 gfc_parse_file()
        ../../gcc-trunk/gcc/fortran/parse.cc:6911
0x9e779f gfc_be_parse_file
        ../../gcc-trunk/gcc/fortran/f95-lang.cc:229