On Wed, Oct 19, 2022 at 11:30:59AM +0200, Florian Weimer wrote: > I'm going to push a branch to dist-git for very few packages (so far gcc > and redhat-rpm-config) which will be used by COPR builds to port Fedora > to C99 and later language standards. > > GCC 14 is expected to reject certain constructs that were removed from C > in C99: If we're changing defaults, could we make -fPIC the default and have -fno-pic be an explicit choice? Finding every place in the OCaml toolchain that passes flags to the compiler is very tedious, I had another bug filed about it only a few days ago. This would all go away if -fPIC was simply the default. AIUI on x86-64 because of rip-relative addressing there's no serious penalty. Rich. > * implicit function declarations > * implicit ints > * implicit conversion between pointers and int > (that may not have been in C89 even; details still pending) > > It's possible to build with -std=gnu89 or -std=c89 to re-enable these > constructs, or fix the sources not to use them. Implicit function > declarations in particular have wasted countless programmer hours due to > difficult-to-track-down ABI mismatches, so it's definitely desirable to > cause them to fail the build. > > We have tooling that identifies these constructs if GCC is used, even if > they are used in configure check. Unexpected failures in configure > checks can be tricky because if the package is well-written, the end > result is still a consistent build with some expected failures missing, > corresponding testsuite bits disabled etc. > > We will contribute fixes upstream and to rawhide, either by fixing the > sources or switch to C89 mode where it is unlikely source changes will > be acceptable to upstream. The c99-port dist-git branch will only be > used for our support tooling that should not be used by production > builds in the rawhide buildroot. As this is necessarily a > cross-distribution effort, there will be some tracking mechanism to > record and share patches for which no active upstream exists anymore. > > C++ packages are only affected in so far as they use the C compiler in > configure checks: these constructs haven't been part of C++ for a long, > long time and may not have been implemented in G++, ever. > > I hope to submit a formal Fedora 40 change proposal after some initial > experiments. > > Thanks, > Florian > _______________________________________________ > devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx > To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: https://lists.fedoraproject.org/archives/list/devel@xxxxxxxxxxxxxxxxxxxxxxx > Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-p2v converts physical machines to virtual machines. Boot with a live CD or over the network (PXE) and turn machines into KVM guests. http://libguestfs.org/virt-v2v _______________________________________________ devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@xxxxxxxxxxxxxxxxxxxxxxx Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
