[v1,0/2] kunit: add macro to allow conditionally exposing static symbols to tests

Message

Rae Moar Nov. 2, 2022, 5:59 p.m. UTC

Currently in order to test a static function, tests must be included in the
same translation unit as the function. However, this can cause issues with
including implementation and test code in the same file. As an alternative,
the first patch in this series creates a macro that will set a function to
be static or not depending on whether CONFIG_KUNIT is enabled. This allows
the function to be visible during testing and static otherwise.

As an example, the current status quo to test static functions is:

=== test.c ===

static void test_case(struct kunit *test)
{
  KUNIT_EXPECT_EQ(test, my_func_to_test(), 2);
}

Then the tests are included in the implementation file as a workaround to
the issue of testing static functions:

=== implementation.c ===

static int my_func_to_test() {...}
...
#include "test.c"

Instead, the function could be defined with this new macro:

=== implementation.c ===

VISIBLE_IF_KUNIT int my_func_to_test() {...}

The first patch also creates a macro that will export a symbol into a kunit
testing namespace only if CONFIG_KUNIT is enabled. This follows the logic
above and allows symbols to be conditionally exported based on the testing
status.

The second patch in the series updates the policy_unpack test in AppArmor
to show an example of how to use both of these macros in order to address
the issue of testing static functions.

Rae Moar (2):
  kunit: add macro to allow conditionally exposing static symbols to
    tests
  apparmor: test: make static symbols visible during kunit testing

 include/kunit/visibility.h                | 32 ++++++++++
 security/apparmor/Kconfig                 |  4 +-
 security/apparmor/Makefile                |  2 +
 security/apparmor/include/policy_unpack.h | 50 ++++++++++++++++
 security/apparmor/policy_unpack.c         | 72 +++++++----------------
 security/apparmor/policy_unpack_test.c    |  5 ++
 6 files changed, 112 insertions(+), 53 deletions(-)
 create mode 100644 include/kunit/visibility.h


base-commit: 11e76194937b506caf1b49512c42d5c2588681d7

Comments

John Johansen Nov. 22, 2022, 6:13 a.m. UTC | #1

sorry for the delay on this

On 11/2/22 10:59, Rae Moar wrote:
> Currently in order to test a static function, tests must be included in the
> same translation unit as the function. However, this can cause issues with
> including implementation and test code in the same file. As an alternative,

And the issue is? An ugly include of C file that only happens if kunit is
built. Also that you can't make the kunit code a module but is that really
an issue?
  
> the first patch in this series creates a macro that will set a function to
> be static or not depending on whether CONFIG_KUNIT is enabled. This allows
> the function to be visible during testing and static otherwise.
> 
> As an example, the current status quo to test static functions is:
> 
> === test.c ===
> 
> static void test_case(struct kunit *test)
> {
>    KUNIT_EXPECT_EQ(test, my_func_to_test(), 2);
> }
> 
> Then the tests are included in the implementation file as a workaround to
> the issue of testing static functions:
> 
> === implementation.c ===
> 
> static int my_func_to_test() {...}
> ...
> #include "test.c"
> 
> Instead, the function could be defined with this new macro:
> 
> === implementation.c ===
> 
> VISIBLE_IF_KUNIT int my_func_to_test() {...}
> 
> The first patch also creates a macro that will export a symbol into a kunit
> testing namespace only if CONFIG_KUNIT is enabled. This follows the logic
> above and allows symbols to be conditionally exported based on the testing
> status.
> 
> The second patch in the series updates the policy_unpack test in AppArmor
> to show an example of how to use both of these macros in order to address
> the issue of testing static functions.
> 
> Rae Moar (2):
>    kunit: add macro to allow conditionally exposing static symbols to
>      tests
>    apparmor: test: make static symbols visible during kunit testing
> 
>   include/kunit/visibility.h                | 32 ++++++++++
>   security/apparmor/Kconfig                 |  4 +-
>   security/apparmor/Makefile                |  2 +
>   security/apparmor/include/policy_unpack.h | 50 ++++++++++++++++
>   security/apparmor/policy_unpack.c         | 72 +++++++----------------
>   security/apparmor/policy_unpack_test.c    |  5 ++
>   6 files changed, 112 insertions(+), 53 deletions(-)
>   create mode 100644 include/kunit/visibility.h
> 
> 
> base-commit: 11e76194937b506caf1b49512c42d5c2588681d7