[Fortran, Patch, PR70842, v1] [4.9/5/6/7 Regression] internal compiler error with character members within a polymorphic pointer

[Andre Vehreschild <vehre at gmx dot de>]

Hi all,

attached patch fixes the ICE and the wrong char array length mentioned
in comment #3 of the PR. The issue was that getting the _len component
is valid online for unlimited polymorphic pointers. But here this was
tried for polymorphic entity, which had to fail.

Bootstrapped and regtests ok on trunk, gcc-6-branch, gcc-5-branch,
gcc-4_9-branch. Ok for trunk and one week later for the other branches?

Regards,
	Andre
-- 
Andre Vehreschild * Email: vehre ad gmx dot de

Attachment: pr70842_1.clog
Description: Text document

diff --git a/gcc/fortran/simplify.c b/gcc/fortran/simplify.c
index 95a8d10..e3f4d50 100644
--- a/gcc/fortran/simplify.c
+++ b/gcc/fortran/simplify.c
@@ -3816,8 +3816,11 @@ gfc_simplify_len (gfc_expr *e, gfc_expr *kind)
     }
   else if (e->expr_type == EXPR_VARIABLE && e->ts.type == BT_CHARACTER
 	   && e->symtree->n.sym
+	   && e->symtree->n.sym->ts.type != BT_DERIVED
 	   && e->symtree->n.sym->assoc && e->symtree->n.sym->assoc->target
-	   && e->symtree->n.sym->assoc->target->ts.type == BT_DERIVED)
+	   && e->symtree->n.sym->assoc->target->ts.type == BT_DERIVED
+	   && e->symtree->n.sym->assoc->target->symtree->n.sym
+	   && UNLIMITED_POLY (e->symtree->n.sym->assoc->target->symtree->n.sym))
     /* The expression in assoc->target points to a ref to the _data component
        of the unlimited polymorphic entity.  To get the _len component the last
        _data ref needs to be stripped and a ref to the _len component added.  */
diff --git a/gcc/testsuite/gfortran.dg/select_type_35.f03 b/gcc/testsuite/gfortran.dg/select_type_35.f03
new file mode 100644
index 0000000..92d2f27
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/select_type_35.f03
@@ -0,0 +1,41 @@
+! { dg-do run }
+!
+! Contributed by Nathanael Huebbe
+! Check fix for PR/70842
+
+program foo
+
+  TYPE, ABSTRACT :: t_Intermediate
+  END TYPE t_Intermediate
+
+  type, extends(t_Intermediate) :: t_Foo
+    character(:), allocatable :: string
+  end type t_Foo
+
+  class(t_Foo), allocatable :: obj
+
+  allocate(obj)
+  obj%string = "blabarfoo"
+
+  call bar(obj)
+
+  deallocate(obj)
+contains
+  subroutine bar(me)
+    class(t_Intermediate), target :: me
+
+    class(*), pointer :: alias
+
+    select type(me)
+      type is(t_Foo)
+      if (len(me%string) /= 9) call abort()
+    end select
+
+    alias => me
+    select type(alias)
+      type is(t_Foo)
+        if (len(alias%string) /= 9) call abort()
+    end select
+  end subroutine bar
+end program foo
+