[PATCH v2] Documentation: KUnit: Update the instructions on how to test static functions

[Arthur Grillo]

Now that we have the VISIBLE_IF_KUNIT and EXPORT_SYMBOL_IF_KUNIT macros,
update the instructions to stop recommending including .c files.

Signed-off-by: Arthur Grillo <arthurgrillo@xxxxxxxxxx>
---
Changes in v2:
- Fix #if condition
- Link to v1: https://lore.kernel.org/r/20240108-kunit-doc-export-v1-1-119368df0d96@xxxxxxxxxx
---
 Documentation/dev-tools/kunit/usage.rst | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/Documentation/dev-tools/kunit/usage.rst b/Documentation/dev-tools/kunit/usage.rst
index c27e1646ecd9..f095c6bb76ff 100644
--- a/Documentation/dev-tools/kunit/usage.rst
+++ b/Documentation/dev-tools/kunit/usage.rst
@@ -671,19 +671,22 @@ Testing Static Functions
 ------------------------
 
 If we do not want to expose functions or variables for testing, one option is to
-conditionally ``#include`` the test file at the end of your .c file. For
-example:
+conditionally export the used symbol.
 
 .. code-block:: c
 
 	/* In my_file.c */
 
-	static int do_interesting_thing();
+	VISIBLE_IF_KUNIT int do_interesting_thing();
+	EXPORT_SYMBOL_IF_KUNIT(do_interesting_thing);
 
-	#ifdef CONFIG_MY_KUNIT_TEST
-	#include "my_kunit_test.c"
+	/* In my_file.h */
+
+	#if IS_ENABLED(CONFIG_KUNIT)
+		int do_interesting_thing(void);
 	#endif
 
+
 Injecting Test-Only Code
 ------------------------
 

---
base-commit: eeb8e8d9f124f279e80ae679f4ba6e822ce4f95f
change-id: 20240108-kunit-doc-export-eec1f910ab67

Best regards,
-- 
Arthur Grillo <arthurgrillo@xxxxxxxxxx>