Add unit tests for the new used-to-be-signed check as introduced in [1]: Results before applying [1]: $ ./test-suite used-to-be-signed.c TEST used-to-be-signed (used-to-be-signed.c) error: actual error text does not match expected error text. error: see used-to-be-signed.c.error.* for further investigation. --- used-to-be-signed.c.error.expected 2025-09-23 00:50:07.079654644 +0900 +++ used-to-be-signed.c.error.got 2025-09-23 00:50:07.073654719 +0900 @@ -1,8 +0,0 @@ -used-to-be-signed.c:8:19: warning: unsigned value that used to be signed checked against zero? -used-to-be-signed.c:6:33: signed value source -used-to-be-signed.c:11:17: warning: unsigned value that used to be signed checked against zero? -used-to-be-signed.c:6:33: signed value source -used-to-be-signed.c:14:20: warning: unsigned value that used to be signed checked against zero? -used-to-be-signed.c:6:33: signed value source -used-to-be-signed.c:17:18: warning: unsigned value that used to be signed checked against zero? -used-to-be-signed.c:6:33: signed value source error: FAIL: test 'used-to-be-signed.c' failed KO: out of 1 tests, 0 passed, 1 failed ...and after: $ ./test-suite used-to-be-signed.c TEST used-to-be-signed (used-to-be-signed.c) OK: out of 1 tests, 1 passed, 0 failed [1] Warn about "unsigned value that used to be signed against zero" Link: https://lore.kernel.org/linux-sparse/20250921061337.3047616-1-mailhol@kernel.org/ Signed-off-by: Vincent Mailhol <mailhol@kernel.org> Signed-off-by: Chris Li <sparse@chrisli.org>