On Friday, August 25, 2017 12:30:11 PM Warner Losh wrote: > On Fri, Aug 25, 2017 at 12:27 PM, Ed Maste <ema...@freebsd.org> wrote: > > > On 25 August 2017 at 14:07, Ryan Libby <rli...@gmail.com> wrote: > > > On Wed, Aug 23, 2017 at 4:30 PM, John Baldwin <j...@freebsd.org> wrote: > > >> Author: jhb > > >> Date: Wed Aug 23 23:30:25 2017 > > >> New Revision: 322824 > > >> URL: https://svnweb.freebsd.org/changeset/base/322824 > > >> > > >> Log: > > >> Improve the coverage of debug symbols for MK_DEBUG_FILES. > > >> > > ... > > > This causes llvm to emit hundreds of new warnings [1] for > > > "DWARF2 only supports one section per compilation unit" > > > > > > Are these expected? Are they a concern? Should we silence them? > > > Is this an upstream llvm bug [2]? > > > > I'm not sure they were "expected" but I guess are an unsurprising > > consequence of building more things with debug. In any case they're > > not a concern. > > > > It is an llvm bug (the warning really ought not be emitted for empty > > sections), but upstream is probably not too concerned as (most? all) > > other platforms are not using dwarf2. > > > > The right answer for us is likely to just stop defaulting to dwarf2 > > (and specifying it via CFLAGS for kernel if necessary). > > > > What's the status of kicking gdb out of the tree? If we kick it out, we can > stop doing dwarf2 and move to something more modern. Last time this issue > came up, that was the decision, pending a few issues with the gdb port > which I think John Baldwin is getting close to reaching closure on.
gdb is mostly disabled in-tree, but there is no in-tree replacement for the kgdb stack trace from /usr/sbin/crashinfo if the gdb port is not installed, and there won't be until lldb grows some kernel support. OTOH, for most platforms /usr/bin/gdb is now disabled (hidden in /usr/libexec) so isn't relevant for userland binaries certainly. The kernel probably doesn't benefit much from DWARF > 2 (except perhaps for .dwo files if we decide to use those at some point) as the other things added since DWARF2 are largely about handling C++ features like r-value references, etc. -- John Baldwin _______________________________________________ freebsd-toolchain@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-toolchain To unsubscribe, send any mail to "freebsd-toolchain-unsubscr...@freebsd.org"
