kunit: Support skipped tests

The kunit_mark_skipped() macro marks the current test as "skipped", with
the provided reason. The kunit_skip() macro will mark the test as
skipped, and abort the test.

The TAP specification supports this "SKIP directive" as a comment after
the "ok" / "not ok" for a test. See the "Directives" section of the TAP
spec for details:
https://testanything.org/tap-specification.html#directives

The 'success' field for KUnit tests is replaced with a kunit_status
enum, which can be SUCCESS, FAILURE, or SKIPPED, combined with a
'status_comment' containing information on why a test was skipped.

A new 'kunit_status' test suite is added to test this.

Signed-off-by: David Gow <davidgow@google.com>
Tested-by: Marco Elver <elver@google.com>
Reviewed-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

1 files changed, 67 insertions, 6 deletions

diff --git a/include/kunit/test.h b/include/kunit/test.h
index e79ac81f5fca..35b0aed9b739 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -97,6 +97,9 @@ struct kunit;
 /* Maximum size of parameter description string. */
 #define KUNIT_PARAM_DESC_SIZE 128
 
+/* Maximum size of a status comment. */
+#define KUNIT_STATUS_COMMENT_SIZE 256
+
 /*
  * TAP specifies subtest stream indentation of 4 spaces, 8 spaces for a
  * sub-subtest.  See the "Subtests" section in
@@ -106,6 +109,18 @@ struct kunit;
 #define KUNIT_SUBSUBTEST_INDENT		"        "
 
 /**
+ * enum kunit_status - Type of result for a test or test suite
+ * @KUNIT_SUCCESS: Denotes the test suite has not failed nor been skipped
+ * @KUNIT_FAILURE: Denotes the test has failed.
+ * @KUNIT_SKIPPED: Denotes the test has been skipped.
+ */
+enum kunit_status {
+	KUNIT_SUCCESS,
+	KUNIT_FAILURE,
+	KUNIT_SKIPPED,
+};
+
+/**
  * struct kunit_case - represents an individual test case.
  *
  * @run_case: the function representing the actual test case.
@@ -148,13 +163,20 @@ struct kunit_case {
 	const void* (*generate_params)(const void *prev, char *desc);
 
 	/* private: internal use only. */
-	bool success;
+	enum kunit_status status;
 	char *log;
 };
 
-static inline char *kunit_status_to_string(bool status)
+static inline char *kunit_status_to_ok_not_ok(enum kunit_status status)
 {
-	return status ? "ok" : "not ok";
+	switch (status) {
+	case KUNIT_SKIPPED:
+	case KUNIT_SUCCESS:
+		return "ok";
+	case KUNIT_FAILURE:
+		return "not ok";
+	}
+	return "invalid";
 }
 
 /**
@@ -212,6 +234,7 @@ struct kunit_suite {
 	struct kunit_case *test_cases;
 
 	/* private: internal use only */
+	char status_comment[KUNIT_STATUS_COMMENT_SIZE];
 	struct dentry *debugfs;
 	char *log;
 };
@@ -245,19 +268,21 @@ struct kunit {
 	 * be read after the test case finishes once all threads associated
 	 * with the test case have terminated.
 	 */
-	bool success; /* Read only after test_case finishes! */
 	spinlock_t lock; /* Guards all mutable test state. */
+	enum kunit_status status; /* Read only after test_case finishes! */
 	/*
 	 * Because resources is a list that may be updated multiple times (with
 	 * new resources) from any thread associated with a test case, we must
 	 * protect it with some type of lock.
 	 */
 	struct list_head resources; /* Protected by lock. */
+
+	char status_comment[KUNIT_STATUS_COMMENT_SIZE];
 };
 
 static inline void kunit_set_failure(struct kunit *test)
 {
-	WRITE_ONCE(test->success, false);
+	WRITE_ONCE(test->status, KUNIT_FAILURE);
 }
 
 void kunit_init_test(struct kunit *test, const char *name, char *log);
@@ -348,7 +373,7 @@ static inline int kunit_run_all_tests(void)
 #define kunit_suite_for_each_test_case(suite, test_case)		\
 	for (test_case = suite->test_cases; test_case->run_case; test_case++)
 
-bool kunit_suite_has_succeeded(struct kunit_suite *suite);
+enum kunit_status kunit_suite_has_succeeded(struct kunit_suite *suite);
 
 /*
  * Like kunit_alloc_resource() below, but returns the struct kunit_resource
@@ -640,6 +665,42 @@ void kunit_cleanup(struct kunit *test);
 
 void __printf(2, 3) kunit_log_append(char *log, const char *fmt, ...);
 
+/**
+ * kunit_mark_skipped() - Marks @test_or_suite as skipped
+ *
+ * @test_or_suite: The test context object.
+ * @fmt:  A printk() style format string.
+ *
+ * Marks the test as skipped. @fmt is given output as the test status
+ * comment, typically the reason the test was skipped.
+ *
+ * Test execution continues after kunit_mark_skipped() is called.
+ */
+#define kunit_mark_skipped(test_or_suite, fmt, ...)			\
+	do {								\
+		WRITE_ONCE((test_or_suite)->status, KUNIT_SKIPPED);	\
+		scnprintf((test_or_suite)->status_comment,		\
+			  KUNIT_STATUS_COMMENT_SIZE,			\
+			  fmt, ##__VA_ARGS__);				\
+	} while (0)
+
+/**
+ * kunit_skip() - Marks @test_or_suite as skipped
+ *
+ * @test_or_suite: The test context object.
+ * @fmt:  A printk() style format string.
+ *
+ * Skips the test. @fmt is given output as the test status
+ * comment, typically the reason the test was skipped.
+ *
+ * Test execution is halted after kunit_skip() is called.
+ */
+#define kunit_skip(test_or_suite, fmt, ...)				\
+	do {								\
+		kunit_mark_skipped((test_or_suite), fmt, ##__VA_ARGS__);\
+		kunit_try_catch_throw(&((test_or_suite)->try_catch));	\
+	} while (0)
+
 /*
  * printk and log to per-test or per-suite log buffer.  Logging only done
  * if CONFIG_KUNIT_DEBUGFS is 'y'; if it is 'n', no log is allocated/used.