re PR c/79515 (ICE: tree check: expected class 'type', have 'exceptional'…

re PR c/79515 (ICE: tree check: expected class 'type', have 'exceptional' (error_mark) in do_warn_double_promotion, at c-family/c-warn.c:1867)

	PR c/79515
	* c-warn.c (do_warn_double_promotion): Don't warn if an invalid
	conversion has occured.

	* gcc.dg/dfp/pr79515.c: New.

From-SVN: r245485

gcc/c-family/ChangeLog

+2017-02-15  Marek Polacek  <polacek@redhat.com>
+
+	PR c/79515
+	* c-warn.c (do_warn_double_promotion): Don't warn if an invalid
+	conversion has occured.
+
 2017-01-24  David Malcolm  <dmalcolm@redhat.com>
 
 	* c-common.c (c_common_reswords): Add "__RTL".

gcc/c-family/c-warn.c

@@ -1864,6 +1864,9 @@ do_warn_double_promotion (tree result_type, tree type1, tree type2,
      warn about it.  */
   if (c_inhibit_evaluation_warnings)
     return;
+  /* If an invalid conversion has occured, don't warn.  */
+  if (result_type == error_mark_node)
+    return;
   if (TYPE_MAIN_VARIANT (result_type) != double_type_node
       && TYPE_MAIN_VARIANT (result_type) != complex_double_type_node)
     return;

gcc/testsuite/ChangeLog

+2017-02-15  Marek Polacek  <polacek@redhat.com>
+
+	PR c/79515
+	* gcc.dg/dfp/pr79515.c: New.
+
 2017-02-15  David Edelsohn  <dje.gcc@gmail.com>
 
 	* g++.dg/cpp0x/pr79296.C: Move dg-do compile directive first.

gcc/testsuite/gcc.dg/dfp/pr79515.c

+/* PR c/79515 */
+/* { dg-do compile } */
+/* { dg-options "-Wdouble-promotion" } */
+
+extern _Decimal64 x;
+extern int i;
+
+void
+foo (void)
+{
+  if (x <= 2.0) /* { dg-error "mix operands" } */
+    i++;
+}