>> The patch titled >> Subject: scripts: checkpatch: check unused parameters for function-like macro >> has been added to the -mm mm-nonmm-unstable branch. Its filename is >> scripts-checkpatch-check-unused-parameters-for-function-like-macro.patch > > Conceptually I don't disagree but I wonder what the false > positive rate is. Hi Joe, If your concern is whether this script might produce inaccurate reports, I'm confident that the false positive rate is 0%. Xining, please correct me if I'm mistaken. Regarding the percentage of cases where a macro function might not utilize a parameter, it varies depending on the specific scenario. For the code below, if flush_dcache_page is implemented as a macro on those architecturs which have not dcache and doesn't cast its parameter to void, it will trigger a build warning. struct page *dst_page = sg_page(req->dst); for (i = 0; i < nr_pages; i++) flush_dcache_page(dst_page + i); If we perform the following action before invoking flush_dcache_page(), struct page *dst_page = sg_page(req->dst); xxx = dst_page; ... for (i = 0; i < nr_pages; i++) flush_dcache_page(dst_page + i); We won't have any issue. The coding style modification operates on the assumption of the worst-case scenario. Thanks Barry
