introduce a reset function

For multi-run tests (benchmarks), we introduce a `reset` function. By
default, between each run of a test, the initialization will be called
at startup, and the cleanup will be called at finish. A benchmark may
wish to set up multi-run state at the beginning of the invocation (in
initialization), and keep a steady state through all test runs. Users
can now add a `reset` function so that initialization occurs only at the
beginning of all runs.

clar.c

@@ -202,6 +202,7 @@ struct clar_func {
 struct clar_suite {
 	const char *name;
 	struct clar_func initialize;
+	struct clar_func reset;
 	struct clar_func cleanup;
 	const struct clar_func *tests;
 	size_t test_count;
@@ -328,6 +329,7 @@ clar_run_test(
 	const struct clar_suite *suite,
 	const struct clar_func *test,
 	const struct clar_func *initialize,
+	const struct clar_func *reset,
 	const struct clar_func *cleanup)
 {
 	int runs = test->runs, i = 0;
@@ -353,6 +355,17 @@ clar_run_test(
 			struct clar_counter start, end;
 			double elapsed;
 
+			if (i > 0 && reset->ptr != NULL) {
+				reset->ptr();
+			} else if (i > 0) {
+				if (_clar.local_cleanup != NULL)
+					_clar.local_cleanup(_clar.local_cleanup_payload);
+				if (cleanup->ptr != NULL)
+					cleanup->ptr();
+				if (initialize->ptr != NULL)
+					initialize->ptr();
+			}
+
 			clar_counter_now(&start);
 			test->ptr();
 			clar_counter_now(&end);
@@ -481,7 +494,7 @@ clar_run_suite(const struct clar_suite *suite, const char *filter)
 
 		_clar.last_report = report;
 
-		clar_run_test(suite, &test[i], &suite->initialize, &suite->cleanup);
+		clar_run_test(suite, &test[i], &suite->initialize, &suite->reset, &suite->cleanup);
 
 		if (_clar.exit_on_error && _clar.total_errors)
 			return;

generate.py

@@ -32,6 +32,9 @@ def render(self):
             for initializer in self.module.initializers:
                 out += "extern %s;\n" % initializer['declaration']
 
+            if self.module.reset:
+                out += "extern %s;\n" % self.module.reset['declaration']
+
             if self.module.cleanup:
                 out += "extern %s;\n" % self.module.cleanup['declaration']
 
@@ -63,12 +66,14 @@ def render(self):
     {
         "${clean_name}",
     ${initialize},
+    ${reset},
     ${cleanup},
         ${cb_ptr}, ${cb_count}, ${enabled}
     }"""
                 ).substitute(
                     clean_name = name,
                     initialize = self._render_callback(initializer),
+                    reset = self._render_callback(self.module.reset),
                     cleanup = self._render_callback(self.module.cleanup),
                     cb_ptr = "_%s_cb_%s" % (self.module.app_name, self.module.name),
                     cb_count = len(self.module.callbacks),
@@ -109,6 +114,7 @@ def parse(self, contents):
 
         self.callbacks = []
         self.initializers = []
+        self.reset = None
         self.cleanup = None
 
         for (declaration, symbol, short_name, options) in regex.findall(contents):
@@ -156,6 +162,8 @@ def parse(self, contents):
 
             if short_name.startswith('initialize'):
                 self.initializers.append(data)
+            elif short_name == 'reset':
+                self.reset = data
             elif short_name == 'cleanup':
                 self.cleanup = data
             else: