On Tue, Jun 07, 2016 at 05:23:34PM +0200, Jakub Jelinek wrote:
> Marek has recently added code to set TREE_USED bits on the elements of
> TREE_VEC referenced in SIZEOF_EXPR.
> But, as the testcase shows, it can be used on various parameter/argument
> packs, some of them have types as elements, others decls.
> And IMHO we want to set TREE_USED only on the decls listed in those,
> for types TREE_USED should be a property of the type regardless of whether
> the type is mentioned in sizeof... or not, otherwise we suddenly stop
> diagnosing any unused vars with those types.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk/6.2/5.5?
>
> 2016-06-07 Jakub Jelinek <ja...@redhat.com>
>
> PR c++/71442
> * pt.c (tsubst_copy): Only set TREE_USED on DECLs.
>
> * g++.dg/cpp0x/Wunused-variable-1.C: New test.
Richi pointed in the PR that I've screwed up the testcase, it doesn't FAIL
with unpatched compiler.
Here is the same patch with slightly adjusted testcase that does fail
with unpatched trunk, 6.1 or 5.4. Bootstrapped/regtested again on
x86_64-linux and i686-linux, ok for trunk/6.2/5.5?
2016-06-08 Jakub Jelinek <ja...@redhat.com>
PR c++/71442
* pt.c (tsubst_copy): Only set TREE_USED on DECLs.
* g++.dg/cpp0x/Wunused-variable-1.C: New test.
--- gcc/cp/pt.c.jj 2016-06-01 14:17:12.000000000 +0200
+++ gcc/cp/pt.c 2016-06-07 14:29:16.608041125 +0200
@@ -14160,7 +14160,8 @@ tsubst_copy (tree t, tree args, tsubst_f
len = TREE_VEC_LENGTH (expanded);
/* Set TREE_USED for the benefit of -Wunused. */
for (int i = 0; i < len; i++)
- TREE_USED (TREE_VEC_ELT (expanded, i)) = true;
+ if (DECL_P (TREE_VEC_ELT (expanded, i)))
+ TREE_USED (TREE_VEC_ELT (expanded, i)) = true;
}
if (expanded == error_mark_node)
--- gcc/testsuite/g++.dg/cpp0x/Wunused-variable-1.C.jj 2016-06-07
14:31:15.514486508 +0200
+++ gcc/testsuite/g++.dg/cpp0x/Wunused-variable-1.C 2016-06-07
14:32:13.526730026 +0200
@@ -0,0 +1,37 @@
+// PR c++/71442
+// { dg-do compile { target c++11 } }
+// { dg-options "-Wunused-variable" }
+
+struct C
+{
+ template<typename... Ts>
+ int operator()(Ts &&...)
+ {
+ return sizeof...(Ts);
+ }
+};
+
+int
+foo ()
+{
+ C {} (1, 1L, 1LL, 1.0);
+}
+
+template<int N>
+void
+bar ()
+{
+ char a; // { dg-warning "unused variable" }
+ short b; // { dg-warning "unused variable" }
+ int c; // { dg-warning "unused variable" }
+ long d; // { dg-warning "unused variable" }
+ long long e; // { dg-warning "unused variable" }
+ float f; // { dg-warning "unused variable" }
+ double g; // { dg-warning "unused variable" }
+}
+
+void
+baz ()
+{
+ bar <0> ();
+}
Jakub
