Fix (re)alloc of polymorphic arrays

        PR fortran/87625
        * trans-array.c (gfc_is_reallocatable_lhs): Detect allocatable
        polymorphic arrays.

        PR fortran/87625
        * gfortran.dg/realloc_on_assign_31.f90: New file.

From-SVN: r265283

gcc/fortran/ChangeLog

+2018-10-18  Tobias Burnus  <burnus@net-b.de>
+
+	PR fortran/87625
+	* trans-array.c (gfc_is_reallocatable_lhs): Detect allocatable
+	polymorphic arrays.
+
 2018-10-18  Paul Thomas  <pault@gcc.gnu.org>
 
 	PR fortran/58618

gcc/fortran/trans-array.c

@@ -9616,9 +9616,15 @@ gfc_is_reallocatable_lhs (gfc_expr *expr)
   if (sym->ts.type == BT_CLASS
       && !sym->attr.associate_var
       && CLASS_DATA (sym)->attr.allocatable
-      && expr->ref && expr->ref->type == REF_COMPONENT
-      && strcmp (expr->ref->u.c.component->name, "_data") == 0
-      && expr->ref->next == NULL)
+      && expr->ref
+      && ((expr->ref->type == REF_ARRAY && expr->ref->u.ar.type == AR_FULL
+	   && expr->ref->next == NULL)
+	  || (expr->ref->type == REF_COMPONENT
+	      && strcmp (expr->ref->u.c.component->name, "_data") == 0
+	      && (expr->ref->next == NULL
+		  || (expr->ref->next->type == REF_ARRAY
+		      && expr->ref->next->u.ar.type == AR_FULL
+		      && expr->ref->next->next == NULL)))))
     return true;
 
   /* An allocatable variable.  */

gcc/testsuite/ChangeLog

+2018-10-18  Tobias Burnus  <burnus@net-b.de>
+
+	PR fortran/87625
+	* gfortran.dg/realloc_on_assign_31.f90: New file.
+
 2018-10-18  David Malcolm  <dmalcolm@redhat.com>
 
 	PR tree-optimization/87562

gcc/testsuite/gfortran.dg/realloc_on_assign_31.f90

+! { dg-do run }
+!
+! PR fortran/87625
+!
+! Ensure that "var" gets allocated.
+!
+! Contributed by Tobias Burnus
+!
+program test
+   implicit none
+   type t
+     integer :: i
+   end type t
+   class(t), allocatable :: var(:)
+   call poly_init()
+   print *, var(:)%i
+   if (lbound(var, 1) /= 1 .and. ubound(var, 1) /= 2) call abort()
+   if (var(1)%i /= 11 .or. var(2)%i /= 12) call abort()
+   call poly_init2()
+   !print *, var(:)%i
+   if (lbound(var, 1) /= 1 .and. ubound(var, 1) /= 3) call abort()
+   if (var(1)%i /= 11 .or. var(2)%i /= 12 .or. var(3)%i /= 13) call abort()
+contains
+   subroutine poly_init()
+     !allocate(var(2))
+     var = [t :: t(11), t(12)]
+   end subroutine poly_init
+   subroutine poly_init2()
+     var = [t :: t(11), t(12), t(13)]
+   end subroutine poly_init2
+ end program test