Warnings find bugs PERIOD. Although most are not useful, I've found quite a number of real issues from compiling with gcc8.
If you want to _actually_ be helpful fix these: https://people.freebsd.org/~mmacy/gcc8logs/GENERIC-NODEBUG.log https://people.freebsd.org/~mmacy/gcc8logs/GENERIC.log On Wed, May 23, 2018 at 9:42 PM, Gleb Smirnoff <gleb...@freebsd.org> wrote: > Let me repeat again. The warning is a false positive, and thus assignment > isn't useful. I'm not worried about a single instruction, more about > polluting the code. > > If the warning was escalated to build error, and we did carry about > building with gcc8, in this case the assignment should be added with > a comment /* pacify gcc */. > > On Wed, May 23, 2018 at 03:59:33PM -0700, Matthew Macy wrote: > M> On Wed, May 23, 2018 at 3:57 PM, Gleb Smirnoff <gleb...@freebsd.org> wrote: > M> > The initialization isn't useful. > M> > M> It silences a gcc warning. So yes it is. It's this exchange which is not > useful. > M> > M> -M > M> > M> > M> > On Wed, May 23, 2018 at 03:52:42PM -0700, Matthew Macy wrote: > M> > M> Talk to the gcc devs. The warning is useful even if there are false > positives. > M> > M> > M> > M> On Wed, May 23, 2018 at 3:27 PM, Gleb Smirnoff <gleb...@freebsd.org> > wrote: > M> > M> > Hi, > M> > M> > > M> > M> > On Sat, May 19, 2018 at 05:10:52AM +0000, Matt Macy wrote: > M> > M> > M> Author: mmacy > M> > M> > M> Date: Sat May 19 05:10:51 2018 > M> > M> > M> New Revision: 333860 > M> > M> > M> URL: https://svnweb.freebsd.org/changeset/base/333860 > M> > M> > M> > M> > M> > M> Log: > M> > M> > M> sendfile: annotate unused value and ensure that npages is > actually initialized > M> > M> > M> > M> > M> > M> Modified: > M> > M> > M> head/sys/kern/kern_sendfile.c > M> > M> > M> > M> > M> > M> Modified: head/sys/kern/kern_sendfile.c > M> > M> > M> > ============================================================================== > M> > M> > M> --- head/sys/kern/kern_sendfile.c Sat May 19 05:09:10 2018 > (r333859) > M> > M> > M> +++ head/sys/kern/kern_sendfile.c Sat May 19 05:10:51 2018 > (r333860) > M> > M> > M> @@ -341,7 +341,7 @@ sendfile_swapin(vm_object_t obj, struct > sf_io *sfio, o > M> > M> > M> } > M> > M> > M> > M> > M> > M> for (int i = 0; i < npages;) { > M> > M> > M> - int j, a, count, rv; > M> > M> > M> + int j, a, count, rv __unused; > M> > M> > M> > M> > M> > M> /* Skip valid pages. */ > M> > M> > M> if (vm_page_is_valid(pa[i], vmoff(i, off) & > PAGE_MASK, > M> > M> > M> @@ -688,6 +688,7 @@ retry_space: > M> > M> > M> if (space == 0) { > M> > M> > M> sfio = NULL; > M> > M> > M> nios = 0; > M> > M> > M> + npages = 0; > M> > M> > M> goto prepend_header; > M> > M> > M> } > M> > M> > M> hdr_uio = NULL; > M> > M> > > M> > M> > This initialization is redundant and a compiler warning if exists > is wrong. > M> > M> > > M> > M> > If we jump down to prepend_header with nios == 0, we won't ever use > npages. > M> > M> > > M> > M> > -- > M> > M> > Gleb Smirnoff > M> > > M> > -- > M> > Gleb Smirnoff > > -- > Gleb Smirnoff _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"