Fortran: Extend cylic type detection for deallocate [PR116669]

Using cycles in derived/class types lead to the compiler doing a endless
recursion in several locations, when the cycle was not immediate.
An immediate cyclic dependency is present in, for example T T::comp.
Cylcic dependencies of the form T T2::comp; T2 T::comp2; are now
detected and the recursive bit in the derived type's attr is set.

gcc/fortran/ChangeLog:

	PR fortran/116669

	* class.cc (gfc_find_derived_vtab): Use attr to determine cyclic
	type dependendies.
	* expr.cc (gfc_has_default_initializer): Prevent endless
	recursion by storing already visited derived types.
	* resolve.cc (resolve_cyclic_derived_type): Determine if a type
	is used in its hierarchy in a cyclic way.
	(resolve_fl_derived0): Call resolve_cyclic_derived_type.
	(resolve_fl_derived): Ensure vtab is generated when cyclic
	derived types have allocatable components.
	* trans-array.cc (structure_alloc_comps): Prevent endless loop
	for derived type cycles.
	* trans-expr.cc (gfc_get_ultimate_alloc_ptr_comps_caf_token):
	Off topic, just prevent memory leaks.

gcc/testsuite/ChangeLog:

	* gfortran.dg/class_array_15.f03: Freeing more memory.
	* gfortran.dg/recursive_alloc_comp_6.f90: New test.

1 files changed, 8 insertions, 2 deletions

diff --git a/gcc/fortran/trans-expr.cc b/gcc/fortran/trans-expr.cc
index bc24105..bef49d3 100644
--- a/gcc/fortran/trans-expr.cc
+++ b/gcc/fortran/trans-expr.cc
@@ -165,7 +165,10 @@ gfc_get_ultimate_alloc_ptr_comps_caf_token (gfc_se *outerse, gfc_expr *expr)
     }
 
   if (last_caf_ref == NULL)
-    return NULL_TREE;
+    {
+      gfc_free_expr (caf_expr);
+      return NULL_TREE;
+    }
 
   tree comp = last_caf_ref->u.c.component->caf_token
 		? gfc_comp_caf_token (last_caf_ref->u.c.component)
@@ -174,7 +177,10 @@ gfc_get_ultimate_alloc_ptr_comps_caf_token (gfc_se *outerse, gfc_expr *expr)
   gfc_se se;
   bool comp_ref = !last_caf_ref->u.c.component->attr.dimension;
   if (comp == NULL_TREE && comp_ref)
-    return NULL_TREE;
+    {
+      gfc_free_expr (caf_expr);
+      return NULL_TREE;
+    }
   gfc_init_se (&se, outerse);
   gfc_free_ref_list (last_caf_ref->next);
   last_caf_ref->next = NULL;