re PR fortran/78592 (ICE in gfc_find_specific_dtio_proc, at fortran/interface.c:4939)

2016-11-30  Janus Weil  <janus@gcc.gnu.org>

	PR fortran/78592
	* interface.c (gfc_find_specific_dtio_proc): Rearrange code to avoid
	dereferencing a null pointer.

2016-11-30  Janus Weil  <janus@gcc.gnu.org>

	PR fortran/78592
	* gfortran.dg/dtio_18.f90: New test case.

From-SVN: r243005

gcc/fortran/ChangeLog

 2016-11-30  Janus Weil  <janus@gcc.gnu.org>
 
+	PR fortran/78592
+	* interface.c (gfc_find_specific_dtio_proc): Rearrange code to avoid
+	dereferencing a null pointer.
+
+2016-11-30  Janus Weil  <janus@gcc.gnu.org>
+
 	PR fortran/78573
 	* decl.c (build_struct): On error, return directly and do not build
 	class symbol.

gcc/fortran/interface.c

@@ -4933,15 +4933,15 @@ gfc_find_specific_dtio_proc (gfc_symbol *derived, bool write, bool formatted)
 	  && tb_io_st->n.sym
 	  && tb_io_st->n.sym->generic)
 	{
-	  gfc_interface *intr;
-	  for (intr = tb_io_st->n.sym->generic; intr; intr = intr->next)
+	  for (gfc_interface *intr = tb_io_st->n.sym->generic;
+	       intr && intr->sym && intr->sym->formal;
+	       intr = intr->next)
 	    {
 	      gfc_symbol *fsym = intr->sym->formal->sym;
-	      if (intr->sym && intr->sym->formal
-		  && ((fsym->ts.type == BT_CLASS
-		      && CLASS_DATA (fsym)->ts.u.derived == extended)
-		    || (fsym->ts.type == BT_DERIVED
-			&& fsym->ts.u.derived == extended)))
+	      if ((fsym->ts.type == BT_CLASS
+		   && CLASS_DATA (fsym)->ts.u.derived == extended)
+		  || (fsym->ts.type == BT_DERIVED
+		      && fsym->ts.u.derived == extended))
 		{
 		  dtio_sub = intr->sym;
 		  break;

gcc/testsuite/ChangeLog

+2016-11-30  Janus Weil  <janus@gcc.gnu.org>
+
+	PR fortran/78592
+	* gfortran.dg/dtio_18.f90: New test case.
+
 2016-11-30  Martin Liska  <mliska@suse.cz>
 
 	PR sanitizer/78541

gcc/testsuite/gfortran.dg/dtio_18.f90

+! { dg-do compile }
+!
+! PR 78592: [7 Regression] ICE in gfc_find_specific_dtio_proc, at fortran/interface.c:4939
+!
+! Contributed by Gerhard Steinmetz <gerhard.steinmetz.fortran@t-online.de>
+
+program p
+   type t
+   end type
+   type(t) :: z
+   interface write(formatted)
+      module procedure wf    ! { dg-error "is neither function nor subroutine" }
+   end interface
+   print *, z
+end