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, 10 insertions, 0 deletions

diff --git a/src/common/tortls.h b/src/common/tortls.h
index 1a59c67df3..b6ab2ec8f5 100644
--- a/src/common/tortls.h
+++ b/src/common/tortls.h
@@ -164,8 +164,18 @@ STATIC int tor_tls_context_init_one(tor_tls_context_t **ppcontext,
                                     int is_client);
 STATIC void tls_log_errors(tor_tls_t *tls, int severity, int domain,
                            const char *doing);
+
+#ifdef TOR_UNIT_TESTS
+extern int tor_tls_object_ex_data_index;
+extern tor_tls_context_t *server_tls_context;
+extern tor_tls_context_t *client_tls_context;
+extern uint16_t v2_cipher_list[];
+extern uint64_t total_bytes_written_over_tls;
+extern uint64_t total_bytes_written_by_tls;
 #endif
 
+#endif /* endif TORTLS_PRIVATE */
+
 const char *tor_tls_err_to_string(int err);
 void tor_tls_get_state_description(tor_tls_t *tls, char *buf, size_t sz);