re PR fortran/70853 (ICE on pointing to null, in gfc_add_block_to_block, at fortran/trans.c:1599)

2019-12-18  Harald Anlauf  <anlauf@gmx.de>

	PR fortran/70853
	* trans-expr.c (gfc_trans_pointer_assignment): Reject bounds
	remapping if pointer target is NULL().

	PR fortran/70853
	* gfortran.dg/pr70853.f90: New test.

From-SVN: r279527

gcc/fortran/ChangeLog

+2019-12-18  Harald Anlauf  <anlauf@gmx.de>
+
+	PR fortran/70853
+	* trans-expr.c (gfc_trans_pointer_assignment): Reject bounds
+	remapping if pointer target is NULL().
+
 2019-12-12  Harald Anlauf  <anlauf@gmx.de>
 
 	PR fortran/92898

gcc/fortran/trans-expr.c

@@ -9218,6 +9218,13 @@ gfc_trans_pointer_assignment (gfc_expr * expr1, gfc_expr * expr2)
 	  break;
       rank_remap = (remap && remap->u.ar.end[0]);
 
+      if (remap && expr2->expr_type == EXPR_NULL)
+	{
+	  gfc_error ("If bounds remapping is specified at %L, "
+		     "the pointer target shall not be NULL", &expr1->where);
+	  return NULL_TREE;
+	}
+
       gfc_init_se (&lse, NULL);
       if (remap)
 	lse.descriptor_only = 1;

gcc/testsuite/ChangeLog

+2019-12-18  Harald Anlauf  <anlauf@gmx.de>
+
+	PR fortran/70853
+	* gfortran.dg/pr70853.f90: New test.
+
 2019-12-18  Martin Jambor  <mjambor@suse.cz>
 
 	PR ipa/92971

gcc/testsuite/gfortran.dg/pr70853.f90

+! { dg-do compile }
+! PR fortran/70853
+! Contributed by Gerhard Steinmetz
+program p
+   real, pointer :: z(:)
+   z(1:2) => null() ! { dg-error "pointer target shall not be NULL" }
+   z(2:1) => null() ! { dg-error "pointer target shall not be NULL" }
+end