Uplift status.c unit test coverage with new test cases and macros.

A new set of unit test cases are provided, as well as introducing
an alternative paradigm and macros to support it. Primarily, each test
case is given its own namespace, in order to isolate tests from each
other. We do this by in the usual fashion, by appending module and
submodule names to our symbols. New macros assist by reducing friction
for this and other tasks, like overriding a function in the global
namespace with one in the current namespace, or declaring integer
variables to assist tracking how many times a mock has been called.

A set of tests for a small-scale module has been included in this
commit, in order to highlight how the paradigm can be used. This
suite gives 100% coverage to status.c in test execution.

4 files changed, 14 insertions, 9 deletions

diff --git a/src/common/log.c b/src/common/log.c
index a837cf86a7..592dc2c5d4 100644
--- a/src/common/log.c
+++ b/src/common/log.c
@@ -147,9 +147,6 @@ static INLINE char *format_msg(char *buf, size_t buf_len,
            const char *suffix,
            const char *format, va_list ap, size_t *msg_len_out)
   CHECK_PRINTF(7,0);
-static void logv(int severity, log_domain_mask_t domain, const char *funcname,
-                 const char *suffix, const char *format, va_list ap)
-  CHECK_PRINTF(5,0);
 
 /** Name of the application: used to generate the message we write at the
  * start of each new log. */
@@ -336,9 +333,9 @@ format_msg(char *buf, size_t buf_len,
  * <b>severity</b>.  If provided, <b>funcname</b> is prepended to the
  * message.  The actual message is derived as from tor_snprintf(format,ap).
  */
-static void
-logv(int severity, log_domain_mask_t domain, const char *funcname,
-     const char *suffix, const char *format, va_list ap)
+MOCK_IMPL(STATIC void,
+logv,(int severity, log_domain_mask_t domain, const char *funcname,
+     const char *suffix, const char *format, va_list ap))
 {
   char buf[10024];
   size_t msg_len = 0;
diff --git a/src/common/torlog.h b/src/common/torlog.h
index d210c8b249..4493b251d2 100644
--- a/src/common/torlog.h
+++ b/src/common/torlog.h
@@ -13,6 +13,7 @@
 #ifndef TOR_TORLOG_H
 
 #include "compat.h"
+#include "testsupport.h"
 
 #ifdef HAVE_SYSLOG_H
 #include <syslog.h>
@@ -228,6 +229,12 @@ extern const char *log_fn_function_name_;
 
 #endif /* !GNUC */
 
+#ifdef LOG_PRIVATE
+MOCK_DECL(STATIC void, logv, (int severity, log_domain_mask_t domain,
+    const char *funcname, const char *suffix, const char *format,
+    va_list ap) CHECK_PRINTF(5,0));
+#endif
+
 # define TOR_TORLOG_H
 #endif
 
diff --git a/src/common/tortls.c b/src/common/tortls.c
index 5bf7cb304c..dbe8cdcef4 100644
--- a/src/common/tortls.c
+++ b/src/common/tortls.c
@@ -2579,8 +2579,8 @@ tor_tls_get_n_raw_bytes(tor_tls_t *tls, size_t *n_read, size_t *n_written)
 
 /** Return a ratio of the bytes that TLS has sent to the bytes that we've told
  * it to send. Used to track whether our TLS records are getting too tiny. */
-double
-tls_get_write_overhead_ratio(void)
+MOCK_IMPL(double,
+tls_get_write_overhead_ratio,(void))
 {
   if (total_bytes_written_over_tls == 0)
     return 1.0;
diff --git a/src/common/tortls.h b/src/common/tortls.h
index 49c488b365..a76ba3bc7a 100644
--- a/src/common/tortls.h
+++ b/src/common/tortls.h
@@ -13,6 +13,7 @@
 
 #include "crypto.h"
 #include "compat.h"
+#include "testsupport.h"
 
 /* Opaque structure to hold a TLS connection. */
 typedef struct tor_tls_t tor_tls_t;
@@ -95,7 +96,7 @@ void tor_tls_get_buffer_sizes(tor_tls_t *tls,
                               size_t *rbuf_capacity, size_t *rbuf_bytes,
                               size_t *wbuf_capacity, size_t *wbuf_bytes);
 
-double tls_get_write_overhead_ratio(void);
+MOCK_DECL(double, tls_get_write_overhead_ratio, (void));
 
 int tor_tls_used_v1_handshake(tor_tls_t *tls);
 int tor_tls_received_v3_certificate(tor_tls_t *tls);