twister: Skip scanning non-ztest tests in Twister

Twister scans C-files to find testcases that are implemented
using ZTest framework. Also runs scanning of Elf files
after building. Skip scanning files if it is not required.

Signed-off-by: Grzegorz Chwierut <grzegorz.chwierut@nordicsemi.no>

scripts/pylib/twister/twisterlib/runner.py

@@ -660,6 +660,7 @@ class ProjectBuilder(FilterBuilder):
                     self.instance.add_missing_case_status("blocked", self.instance.reason)
                     pipeline.put({"op": "report", "test": self.instance})
                 else:
+                    if self.instance.testsuite.harness in ['ztest', 'test']:
                         logger.debug(f"Determine test cases for test instance: {self.instance.name}")
                         try:
                             self.determine_testcases(results)
@@ -669,6 +670,8 @@ class ProjectBuilder(FilterBuilder):
                             self.instance.status = "error"
                             self.instance.reason = str(e)
                             pipeline.put({"op": "report", "test": self.instance})
+                    else:
+                        pipeline.put({"op": "gather_metrics", "test": self.instance})
 
         elif op == "gather_metrics":
             ret = self.gather_metrics(self.instance)

scripts/pylib/twister/twisterlib/testplan.py

@@ -542,12 +542,19 @@ class TestPlan:
                 try:
                     parsed_data = TwisterConfigParser(suite_yaml_path, self.suite_schema)
                     parsed_data.load()
-                    subcases, ztest_suite_names = scan_testsuite_path(suite_path)
+                    subcases = None
+                    ztest_suite_names = None
 
                     for name in parsed_data.scenarios.keys():
                         suite_dict = parsed_data.get_scenario(name)
                         suite = TestSuite(root, suite_path, name, data=suite_dict, detailed_test_id=self.options.detailed_test_id)
+                        if suite.harness in ['ztest', 'test']:
+                            if subcases is None:
+                                # scan it only once per testsuite
+                                subcases, ztest_suite_names = scan_testsuite_path(suite_path)
                             suite.add_subcases(suite_dict, subcases, ztest_suite_names)
+                        else:
+                            suite.add_subcases(suite_dict)
                         if testsuite_filter:
                             scenario = os.path.basename(suite.name)
                             if suite.name and (suite.name in testsuite_filter or scenario in testsuite_filter):

scripts/pylib/twister/twisterlib/testsuite.py

@@ -423,20 +423,21 @@ class TestSuite(DisablePyTestCollectionMixin):
         if self.harness == 'console' and not self.harness_config:
             raise Exception('Harness config error: console harness defined without a configuration.')
 
-    def add_subcases(self, data, parsed_subcases, suite_names):
+    def add_subcases(self, data, parsed_subcases=None, suite_names=None):
         testcases = data.get("testcases", [])
         if testcases:
             for tc in testcases:
                 self.add_testcase(name=f"{self.id}.{tc}")
+        else:
+            if not parsed_subcases:
+                self.add_testcase(self.id, freeform=True)
             else:
                 # only add each testcase once
                 for sub in set(parsed_subcases):
                     name = "{}.{}".format(self.id, sub)
                     self.add_testcase(name)
 
-            if not parsed_subcases:
-                self.add_testcase(self.id, freeform=True)
-
+        if suite_names:
             self.ztest_suite_names = suite_names
 
     def add_testcase(self, name, freeform=False):

scripts/tests/twister/test_runner.py

@@ -1504,6 +1504,7 @@ def test_projectbuilder_process(
     instance_mock.run = instance_run
     instance_mock.handler = mock.Mock()
     instance_mock.handler.ready = instance_handler_ready
+    instance_mock.testsuite.harness = 'test'
     env_mock = mock.Mock()
 
     pb = ProjectBuilder(instance_mock, env_mock, mocked_jobserver)