https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80598
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |jakub at gcc dot gnu.org,
| |jason at gcc dot gnu.org
--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Started with r245643.
I wonder if we couldn't do something like following, still set TREE_USED on
where we've previously called mark_used but not really do the rest.
--- gcc/cp/semantics.c.jj 2018-03-06 21:40:35.717360176 +0100
+++ gcc/cp/semantics.c 2018-03-07 18:31:35.782132830 +0100
@@ -3740,10 +3740,15 @@ finish_id_expression (tree id_expression
But only mark it if it's a complete postfix-expression; in a call,
ADL might select a different function, and we'll call mark_used in
build_over_call. */
- if (done
- && !really_overloaded_fn (decl)
- && !mark_used (first_fn))
- return error_mark_node;
+ if (!really_overloaded_fn (decl))
+ {
+ if (done && !mark_used (first_fn))
+ return error_mark_node;
+ /* Otherwise in templates mark first_fn as potentially used
+ for the benefit of -Wunused, see PR80598. */
+ else if (!done && processing_template_decl)
+ TREE_USED (first_fn) = 1;
+ }
if (!template_arg_p
&& TREE_CODE (first_fn) == FUNCTION_DECL
--- gcc/testsuite/g++.dg/warn/Wunused-function4.C.jj 2018-03-07
18:34:30.463176743 +0100
+++ gcc/testsuite/g++.dg/warn/Wunused-function4.C 2018-03-07
18:33:20.484159148 +0100
@@ -0,0 +1,21 @@
+// PR c++/80598
+// { dg-do compile }
+// { dg-options "-Wunused-function" }
+
+static void
+foo () // { dg-bogus "defined but not used" }
+{
+}
+
+static void
+bar () // { dg-warning "defined but not used" }
+{
+}
+
+template <class T>
+int
+baz (T x)
+{
+ foo ();
+ return 0;
+}
