[Bug web/98875] DWARF5 as default causes perf probe to hang
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98875 Mark Wielaard changed: What|Removed |Added Resolution|--- |FIXED Status|ASSIGNED|RESOLVED --- Comment #6 from Mark Wielaard --- Hopefully https://gcc.gnu.org/gcc-11/changes.html now lists the DWARF5 requirements correctly. gcc-wwwdocs commit 80dc53f6b38d697b169fad9ce3b8787ce1c6768c (HEAD -> master, origin/master, origin/HEAD) Author: Mark Wielaard Date: Fri Feb 19 18:02:19 2021 +0100 Document the GCC11 change to DWARF5 default. * gcc-11/changes.html (General Improvements): Add a section on the DWARF version 5 default.
[Bug web/98875] DWARF5 as default causes perf probe to hang
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98875 --- Comment #5 from Mark Wielaard --- https://gcc.gnu.org/pipermail/gcc-patches/2021-February/565587.html
[Bug web/98875] DWARF5 as default causes perf probe to hang
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98875 Mark Wielaard changed: What|Removed |Added Ever confirmed|0 |1 Assignee|unassigned at gcc dot gnu.org |mark at gcc dot gnu.org Status|UNCONFIRMED |ASSIGNED Last reconfirmed||2021-02-19 Component|debug |web --- Comment #4 from Mark Wielaard --- (In reply to Paul Clarke from comment #3) > The IBM Advance Toolchain supports SLES 15, where the latest version of > libdw is 0.168. We'll work around the issue by reverting the commit for the > version of GCC included with the Advance Toolchain. Yes, that is probably reasonable when targetting a distro that is so old that it doesn't have any tooling to support DWARF5. Still you might want to request that the perf tool be fixed to simply skip the DWARF5 data instead of going into an infinite loop. That bug could trigger for any DWARF that old perf/libdw doesn't know about and it really should just skip it. The fix for that really is just a oneliner. > I didn't see any update to the GCC documentation regarding the disruptive > nature of the change causing the problem other than "[DWARF] Version 5 > requires GDB 8.0 or higher". > > Should there be something about libdw as well? Anything else? You are right. I'll submit an update for the GCC 11 Release Notes to document things.
