re PR fortran/85603 (ICE with character array substring assignment)

2018-09-22  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/85603
	* trans-array.c (gfc_alloc_allocatable_for_assignment): Test
	the charlen backend_decl before using the VAR_P macro.

2018-09-22  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/85603
	* gfortran.dg/deferred_character_23.f90 : New test.

From-SVN: r264502

gcc/fortran/ChangeLog

+2018-09-22  Paul Thomas  <pault@gcc.gnu.org>
+
+	PR fortran/85603
+	* trans-array.c (gfc_alloc_allocatable_for_assignment): Test
+	the charlen backend_decl before using the VAR_P macro.
+
 2018-09-21  Paul Thomas  <pault@gcc.gnu.org>
 
 	PR fortran/77325

gcc/fortran/trans-array.c

@@ -9950,7 +9950,8 @@ gfc_alloc_allocatable_for_assignment (gfc_loopinfo *loop,
     {
       if (expr2->ts.deferred)
 	{
-	  if (VAR_P (expr2->ts.u.cl->backend_decl))
+	  if (expr2->ts.u.cl->backend_decl
+	      && VAR_P (expr2->ts.u.cl->backend_decl))
 	    tmp = expr2->ts.u.cl->backend_decl;
 	  else
 	    tmp = rss->info->string_length;

gcc/testsuite/ChangeLog

+2018-09-22  Paul Thomas  <pault@gcc.gnu.org>
+
+	PR fortran/85603
+	* gfortran.dg/deferred_character_23.f90 : New test.
+
 2018-09-21  Jeff Law  <law@redhat.com>
 
 	* gcc.dg/tree-ssa/vrp113.c: Disable EVRP.

gcc/testsuite/gfortran.dg/deferred_character_23.f90

+! { dg-do run }
+!
+! Tests the fix for PR85603.
+!
+! Contributed by Walt Spector  <w6ws@earthlink.net>
+!
+program strlen_bug
+  implicit none
+
+  character(:), allocatable :: strings(:)
+  integer :: maxlen
+
+  strings = [ character(32) ::  &
+      'short',  &
+      'somewhat longer' ]
+  maxlen = maxval (len_trim (strings))
+  if (maxlen .ne. 15) stop 1
+  strings = strings(:)(:maxlen) ! Used to ICE
+  if (any (strings .ne. ['short          ','somewhat longer'])) stop 2
+
+  deallocate (strings)          ! To check for memory leaks
+end program