Hi, On Fri, 2020-06-05 at 09:25 -0600, Jeff Law wrote: > The LTO bytecode streams do not survive past any given package build. ie, > they > are used within the build, then discarded. They're not supposed to show up in > any installed libraries. > > Thus the fact that the two compilers use totally different LTO representations > (and always will) is a non-issue here.
One issue I am concerned about here is debuginfo quality. GCC produced pretty bad debuginfo with LTO in older versions. The EarlyDebug work did make it usable. And we needed some work on the DARF consumers to correctly process GCC 10 LTO produced DWARF (I actually have two small patches for elfutils pending so it correctly parses the cross CU- references GCC 10 LTO now produces). I don't know if anybody did any analysis on llvm LTO produced debuginfo. In the past it was observed that llvm doesn't do VTA (Var Tracking Assignments) that is default in GCC. And VTA is really important for debugging and performance/tracing tools like systemtap. So even without LTO I am concerned about the observability of llvm generated binaries. Cheers, Mark _______________________________________________ devel mailing list -- devel@lists.fedoraproject.org To unsubscribe send an email to devel-le...@lists.fedoraproject.org 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@lists.fedoraproject.org
