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.

5 files changed, 18 insertions, 3 deletions

diff --git a/src/common/compat_libevent.c b/src/common/compat_libevent.c
index cc58883750..96fcec54d4 100644
--- a/src/common/compat_libevent.c
+++ b/src/common/compat_libevent.c
@@ -125,7 +125,7 @@ tor_event_free(struct event *ev)
 #endif
 
 /** Global event base for use by the main thread. */
-struct event_base *the_event_base = NULL;
+static struct event_base *the_event_base = NULL;
 
 /* This is what passes for version detection on OSX.  We set
  * MACOSX_KQUEUE_IS_BROKEN to true iff we're on a version of OSX before
diff --git a/src/common/crypto.h b/src/common/crypto.h
index ff38cca0da..f8fb0daa81 100644
--- a/src/common/crypto.h
+++ b/src/common/crypto.h
@@ -319,6 +319,11 @@ void crypto_add_spaces_to_fp(char *out, size_t outlen, const char *in);
 #ifdef CRYPTO_PRIVATE
 STATIC int crypto_force_rand_ssleay(void);
 STATIC int crypto_strongest_rand_raw(uint8_t *out, size_t out_len);
+
+#ifdef TOR_UNIT_TESTS
+extern int break_strongest_rng_syscall;
+extern int break_strongest_rng_fallback;
+#endif
 #endif
 
 #endif
diff --git a/src/common/log.c b/src/common/log.c
index 6c387c6244..e948ccfa04 100644
--- a/src/common/log.c
+++ b/src/common/log.c
@@ -270,7 +270,7 @@ log_tor_version(logfile_t *lf, int reset)
   return 0;
 }
 
-const char bug_suffix[] = " (on Tor " VERSION
+static const char bug_suffix[] = " (on Tor " VERSION
 #ifndef _MSC_VER
   " "
 #include "micro-revision.i"
diff --git a/src/common/tortls.c b/src/common/tortls.c
index 252da6295e..1cb6ca8777 100644
--- a/src/common/tortls.c
+++ b/src/common/tortls.c
@@ -562,7 +562,7 @@ MOCK_IMPL(STATIC X509 *,
 
 /** List of ciphers that servers should select from when we actually have
  * our choice of what cipher to use. */
-const char UNRESTRICTED_SERVER_CIPHER_LIST[] =
+static const char UNRESTRICTED_SERVER_CIPHER_LIST[] =
   /* This list is autogenerated with the gen_server_ciphers.py script;
    * don't hand-edit it. */
 #ifdef TLS1_TXT_ECDHE_RSA_WITH_AES_256_GCM_SHA384
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);