http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54372
Dodji Seketeli <dodji at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |ASSIGNED
--- Comment #3 from Dodji Seketeli <dodji at gcc dot gnu.org> 2012-09-20
11:27:19 UTC ---
The 'unused' attribute is applied to its appertaining entity only at
instantiation time. As a result, TREE_USED is not set on the entity before
instantiation.
But then maybe_warn_unused_local_typedefs checks for TREE_USED at compile time,
and wrongly emits the warning.
I am testing this patch that tests for the syntactic presence of the unused
attribute:
diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index 6de2f1c..36c4aa6 100644
--- a/gcc/c-family/c-common.c
+++ b/gcc/c-family/c-common.c
@@ -10899,7 +10899,8 @@ maybe_warn_unused_local_typedefs (void)
&& errorcount == unused_local_typedefs_warn_count)
{
FOR_EACH_VEC_ELT (tree, l->local_typedefs, i, decl)
- if (!TREE_USED (decl))
+ if (!TREE_USED (decl)
+ && !lookup_attribute_spec (get_identifier ("unused")))
warning_at (DECL_SOURCE_LOCATION (decl),
OPT_Wunused_local_typedefs,
"typedef %qD locally defined but not used", decl);
