We ICEd on this testcase in do_warn_double_promotion because an invalid
conversion had produced an error result type and accessing that via
TYPE_MAIN_VARIANT crashes. Fixed in an obvious way.
Bootstrapped/regtested on x86_64-linux, ok for trunk?
2017-02-15 Marek Polacek <pola...@redhat.com>
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.
diff --git gcc/c-family/c-warn.c gcc/c-family/c-warn.c
index 3c9077c..09c5760 100644
--- gcc/c-family/c-warn.c
+++ 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;
diff --git gcc/testsuite/gcc.dg/dfp/pr79515.c gcc/testsuite/gcc.dg/dfp/pr79515.c
index e69de29..6f6f09c 100644
--- gcc/testsuite/gcc.dg/dfp/pr79515.c
+++ gcc/testsuite/gcc.dg/dfp/pr79515.c
@@ -0,0 +1,13 @@
+/* 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++;
+}
Marek
