Add -Wmissing-variable-declarations, with attendant fixes

This is a big-ish patch, but it's very straightforward.  Under this
clang warning, we're not actually allowed to have a global variable
without a previous extern declaration for it.  The cases where we
violated this rule fall into three roughly equal groups:
  * Stuff that should have been static.
  * Stuff that was global but where the extern was local to some
    other C file.
  * Stuff that was only global when built for the unit tests, that
    needed a conditional extern in the headers.

The first two were IMO genuine problems; the last is a wart of how
we build tests.

1 files changed, 8 insertions, 0 deletions

diff --git a/src/or/channeltls.h b/src/or/channeltls.h
index a4d9c7a095..8b5863a461 100644
--- a/src/or/channeltls.h
+++ b/src/or/channeltls.h
@@ -52,6 +52,14 @@ void channel_tls_update_marks(or_connection_t *conn);
 /* Cleanup at shutdown */
 void channel_tls_free_all(void);
 
+extern uint64_t stats_n_authorize_cells_processed;
+extern uint64_t stats_n_authenticate_cells_processed;
+extern uint64_t stats_n_versions_cells_processed;
+extern uint64_t stats_n_netinfo_cells_processed;
+extern uint64_t stats_n_vpadding_cells_processed;
+extern uint64_t stats_n_certs_cells_processed;
+extern uint64_t stats_n_auth_challenge_cells_processed;
+
 #ifdef CHANNELTLS_PRIVATE
 STATIC void channel_tls_process_certs_cell(var_cell_t *cell,
                                            channel_tls_t *tlschan);