On Tue, Jan 24, 2023 at 12:04 AM David Gow davidgow@google.com wrote:
KUnit has several macros and functions intended for use from non-test code. These hooks, currently the kunit_get_current_test() and kunit_fail_current_test() macros, didn't work when CONFIG_KUNIT=m.
In order to support this case, the required functions and static data need to be available unconditionally, even when KUnit itself is not built-in. The new 'hooks.c' file is therefore always included, and has both the static key required for kunit_get_current_test(), and a function pointer to the real implementation of __kunit_fail_current_test(), which is populated when the KUnit module is loaded.
A new header, kunit/hooks-table.h, contains a table of all hooks, and is repeatedly included with different definitions of the KUNIT_HOOK() in order to automatically generate the needed function pointer tables. When
Perhaps I'm overlooking something and this is a dumb question.
Is there a reason we can't go with a less-clever approach? Like have a global struct? We could memset it to 0 to clear it instead of defining a macro to set individual variables to NULL?
i.e.
// hooks.h extern struct kunit_hook_table { __printf(3, 4) void (*fail_current_test)(const char*, int, const char*, ...); } kunit_hooks;
//hooks.c struct kunit_hook_table kunit_hooks;
// in test.c // here all the functions should be in scope for us to use static void kunit_set_hooks(void) { kunit_hooks.fail_current_test = __kunit_fail_current_test; ... }
static int __init kunit_init(void) { ... kunit_set_hooks(); ... }
static void __exit kunit_exit(void) { ... memset(&kunit_hooks, 0, sizeof(kunit_hooks)); }
KUnit is disabled, or the module is not loaded, these function pointers are all NULL. This shouldn't be a problem, as they're all used behind wrappers which check kunit_running and/or that the pointer is non-NULL.
This can then be extended for future features which require similar "hook" behaviour, such as static stubs: https://lore.kernel.org/all/20221208061841.2186447-1-davidgow@google.com/
Signed-off-by: David Gow davidgow@google.com