On Wed, May 4, 2022 at 4:35 PM Daniel Latypov dlatypov@google.com wrote:
On Thu, Mar 17, 2022 at 9:13 PM David Gow davidgow@google.com wrote:
+#define kunit_activate_static_stub(test, real_fn_addr, replacement_addr) do { \
typecheck(typeof(real_fn_addr), replacement_addr); \We can't call this macro in the same scope for functions w/ different signatures.
E.g. if we add this func to the example test static void other_func(void) {} then trying to call kunit_activate_static_stub() on it in the same test case, we get
./include/linux/typecheck.h:10:14: error: conflicting types for ‘__dummy’; have ‘void(void)’ 10 | ({ type __dummy; \ | ^~~~~~~ ./include/kunit/static_stub.h:99:9: note: in expansion of macro ‘typecheck’ 99 | typecheck(typeof(real_fn_addr), replacement_addr); \ | ^~~~~~~~~ lib/kunit/example-test.c:64:9: note: in expansion of macro ‘kunit_activate_static_stub’ 64 | kunit_activate_static_stub(test, other_func, other_func); | ^~~~~~~~~~~~~~~~~~~~~~~~~~ ./include/linux/typecheck.h:10:14: note: previous declaration of ‘__dummy’ with type ‘int(int)’ 10 | ({ type __dummy; \ | ^~~~~~~ ./include/kunit/static_stub.h:99:9: note: in expansion of macro ‘typecheck’ 99 | typecheck(typeof(real_fn_addr), replacement_addr); \ | ^~~~~~~~~ lib/kunit/example-test.c:62:9: note: in expansion of macro ‘kunit_activate_static_stub’ 62 | kunit_activate_static_stub(test, add_one, subtract_one); | ^~~~~~~~~~~~~~~~~~~~~~~~~~
Afaict, the problem is that GCC thinks we're declaring a *function* called __dummy, not a variable. So it bleeds across the scope boundary of do-while unlike normal variables.
Yeah, I ran into that problem too. I posted a fix to gerrit. I have been meaning to share it here.
There's the typecheck_fn macro, but it doesn't work either.
That's weird. It worked for me.