Re: [PATCH] selftests: Add support for argc and argv.

[Kees Cook <keescook@chromium.org>]

On Wed, Mar 04, 2020 at 05:52:04PM +0900, Kuniyuki Iwashima wrote:
> Currently tests are often written in C and shell script. In many cases, the
> script passes some arguments to the C program. However, the helper
> functions do not support arguments, so many tests are written without
> helper functions.
> 
> This patch allows us to handle argc and argv in each tests and makes it
> easier to write tests flexibly with helper functions.
> 
> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>

Interesting! Do you have an example that uses this? I wonder if it might
make sense instead to allow extending the struct __test_metadata with
test-specific options so that individual tests don't have to re-parse
argv every time (the main test running could instead do it once and set
variables in struct __test_metadata (or somewhere else).

-Kees

> ---
>  tools/testing/selftests/kselftest_harness.h | 30 ++++++++++++---------
>  1 file changed, 18 insertions(+), 12 deletions(-)
> 
> diff --git a/tools/testing/selftests/kselftest_harness.h b/tools/testing/selftests/kselftest_harness.h
> index 5336b26506ab..75bee67b87fa 100644
> --- a/tools/testing/selftests/kselftest_harness.h
> +++ b/tools/testing/selftests/kselftest_harness.h
> @@ -167,7 +167,8 @@
>  #define TEST_SIGNAL(test_name, signal) __TEST_IMPL(test_name, signal)
>  
>  #define __TEST_IMPL(test_name, _signal) \
> -	static void test_name(struct __test_metadata *_metadata); \
> +	static void test_name(struct __test_metadata *_metadata, \
> +		int argc, char **argv); \
>  	static struct __test_metadata _##test_name##_object = \
>  		{ .name = "global." #test_name, \
>  		  .fn = &test_name, .termsig = _signal, \
> @@ -177,7 +178,9 @@
>  		__register_test(&_##test_name##_object); \
>  	} \
>  	static void test_name( \
> -		struct __test_metadata __attribute__((unused)) *_metadata)
> +		struct __test_metadata __attribute__((unused)) *_metadata, \
> +		int __attribute__((unused)) argc, \
> +		char __attribute__((unused)) **argv)
>  
>  /**
>   * FIXTURE_DATA(datatype_name) - Wraps the struct name so we have one less
> @@ -293,9 +296,11 @@
>  #define __TEST_F_IMPL(fixture_name, test_name, signal, tmout) \
>  	static void fixture_name##_##test_name( \
>  		struct __test_metadata *_metadata, \
> -		FIXTURE_DATA(fixture_name) *self); \
> +		FIXTURE_DATA(fixture_name) *self, \
> +		int argc, char **argv); \
>  	static inline void wrapper_##fixture_name##_##test_name( \
> -		struct __test_metadata *_metadata) \
> +		struct __test_metadata *_metadata, \
> +		int argc, char **argv) \
>  	{ \
>  		/* fixture data is alloced, setup, and torn down per call. */ \
>  		FIXTURE_DATA(fixture_name) self; \
> @@ -304,7 +309,7 @@
>  		/* Let setup failure terminate early. */ \
>  		if (!_metadata->passed) \
>  			return; \
> -		fixture_name##_##test_name(_metadata, &self); \
> +		fixture_name##_##test_name(_metadata, &self, argc, argv); \
>  		fixture_name##_teardown(_metadata, &self); \
>  	} \
>  	static struct __test_metadata \
> @@ -321,7 +326,9 @@
>  	} \
>  	static void fixture_name##_##test_name( \
>  		struct __test_metadata __attribute__((unused)) *_metadata, \
> -		FIXTURE_DATA(fixture_name) __attribute__((unused)) *self)
> +		FIXTURE_DATA(fixture_name) __attribute__((unused)) *self, \
> +		int __attribute__ ((unused)) argc, \
> +		char __attribute__ ((unused)) **argv)
>  
>  /**
>   * TEST_HARNESS_MAIN - Simple wrapper to run the test harness
> @@ -634,7 +641,7 @@
>  /* Contains all the information for test execution and status checking. */
>  struct __test_metadata {
>  	const char *name;
> -	void (*fn)(struct __test_metadata *);
> +	void (*fn)(struct __test_metadata *, int, char **);
>  	int termsig;
>  	int passed;
>  	int trigger; /* extra handler after the evaluation */
> @@ -695,7 +702,7 @@ static inline int __bail(int for_realz, bool no_print, __u8 step)
>  	return 0;
>  }
>  
> -void __run_test(struct __test_metadata *t)
> +void __run_test(struct __test_metadata *t, int argc, char **argv)
>  {
>  	pid_t child_pid;
>  	int status;
> @@ -709,7 +716,7 @@ void __run_test(struct __test_metadata *t)
>  		printf("ERROR SPAWNING TEST CHILD\n");
>  		t->passed = 0;
>  	} else if (child_pid == 0) {
> -		t->fn(t);
> +		t->fn(t, argc, argv);
>  		/* return the step that failed or 0 */
>  		_exit(t->passed ? 0 : t->step);
>  	} else {
> @@ -755,8 +762,7 @@ void __run_test(struct __test_metadata *t)
>  	alarm(0);
>  }
>  
> -static int test_harness_run(int __attribute__((unused)) argc,
> -			    char __attribute__((unused)) **argv)
> +static int test_harness_run(int argc, char **argv)
>  {
>  	struct __test_metadata *t;
>  	int ret = 0;
> @@ -768,7 +774,7 @@ static int test_harness_run(int __attribute__((unused)) argc,
>  	       __test_count, __fixture_count + 1);
>  	for (t = __test_list; t; t = t->next) {
>  		count++;
> -		__run_test(t);
> +		__run_test(t, argc, argv);
>  		if (t->passed)
>  			pass_count++;
>  		else
> -- 
> 2.17.2 (Apple Git-113)
> 

-- 
Kees Cook