Hi, I tested this patch with clang 7 on master. - On unpatched master I can't reproduce errors with make check-world in: src/backend/access/heap/heapam.c src/backend/utils/cache/relcache.c (IIRC I triggered this one in a pg previous version) src/backend/utils/misc/guc.c
- I have a hard to reproduce one not in this patched: src/backend/storage/ipc/shm_mq.c line 727 About the changes - in src/fe_utils/print.c line memset(header_done, false, col_count * sizeof(bool)); is redundant and should be remove not guarded with if (hearder_done), header_done is either null or already zeroed, it's pg_malloc0 ed. In all cases but one patched version shortcut an undefined no ops but in src/backend/access/transam/clog.c memcmp 0 bytes return 0 thus current change modifies code path, before with nsubxids == 0 if branch was taken now it's not. Could wait more often while taking lock, no idea if it's relevant. Regards Didier On Thu, Jun 6, 2019 at 11:36 AM Peter Eisentraut <peter.eisentr...@2ndquadrant.com> wrote: > > On 2019-06-05 21:30, Robert Haas wrote: > > On Mon, Jun 3, 2019 at 3:22 PM Peter Eisentraut > > <peter.eisentr...@2ndquadrant.com> wrote: > >> After many years of trying, it seems the -fsanitize=undefined checking > >> in gcc is now working somewhat reliably. Attached is a patch that fixes > >> all errors of the kind > > > > Is this as of some particular gcc version? > > I used gcc-8. > > The option has existed in gcc for quite some time, but in previous > releases it always tended to hang or get confused somewhere. > > -- > Peter Eisentraut http://www.2ndQuadrant.com/ > PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services > >
