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 * LPC2020NotesGDB
 * LPC2020NotesDWARF
 * LPC2020NotesBinutils
 * LPC2020NotesGlibc
 * LPC2020NotesCxxModules
 * LPC2020NotesSteering
 * LPC2020NotesLLVMGNU
 * [LPC2020NotesGDB]
 * [LPC2020NotesDWARF]
 * [LPC2020NotesBinutils]
 * [LPC2020NotesGlibc]
 * [LPC2020NotesCxxModules]
 * [LPC2020NotesSteering]
 * [LPC2020NotesLLVMGNU]

GNU Tools @ LPC 2020

We are unable to hold GNU Tools Cauldron in 2020, due to the current COVID-19 situation. However our friends at the Linux Plumbers Conference have generously offered to hold a GNU Tools track as part of their virtual meeting 24-28 August 2020.

  • Date: 24-28 August 2020.

    Five half-days of talks, provisionally 07:00-11:00 Pacific Time each day (16:00-20:00 Central European Time, 19:30-23:30 India Standard Time, 22:00-02:00 China Standard Time)
  • Location: Videoconference using BigBlueButton

  • Registration Fee: $50. See here for details on how to register.

  • Submission deadline: 31 July 2020. Note: Unlike traditional Cauldron, this has to be a hard deadline to give time to sort out logistics. See here for details of how to submit.

The use of half days makes the talks available during waking hours from the US West Coast (albeit quite early) to India (albeit rather late). Apologies to our East Asian/Australasian participants, since this will be quite late for you.

Slides, videos and notes

Slides and videos will be made available through the official LPC website after the conference.

These are notes taken live during the various BoFs

  • [LPC2020NotesGDB]
  • [LPC2020NotesDWARF]
  • [LPC2020NotesBinutils]
  • [LPC2020NotesGlibc]
  • [LPC2020NotesCxxModules]
  • [LPC2020NotesSteering]
  • [LPC2020NotesLLVMGNU]


70 attendees

FreeBSD support for gdbserver - who is working on this?

  • Andrew Burgess has been looking at this
  • John Baldwin is a big FreeBSD contributor

Discussion of having a "bare metal" gdbserver or gdbserver framework. What could we use?

  • OpenOCD, but that's a separate framework
  • Embecosm have a bare metail GDBserver framework, originally created from training
  • Kevin Buettner noted https://sourceware.org/rda/ - not been used much recently.

    • Pedro Alves had looked at this, coverage is pretty complete. Noted the challenges around licensing.
  • Can we split out a libgdbserver core of this.
    • do we start with multiple gdbservers and then try to find a unifying underlying library


79 attendees

Can we default to DWARF5 for GCC11?

  • smaller, fewer relocations
  • GNU extensions are now standardized


  • make it the default, see what breaks
  • GCC, elfutils, binutils and GDB testsuites


  • don't use location-review (breaks elfutils/binutils)
  • only small number of fixes needed for binutils
    • including one for ld
    • gas has issue with .debug_line (Mark Wielaard has patches)
  • Valgrind RPM/debugedit/DWZ need patches
  • GDB has DWARF5 issue with .debugnames section

Look into generating .debug_names

Considerations for DWARF64

  • cross section references > 32bit

    • mostly already supported, if not, easy to add
  • -fdwarf64/-fdwarf32
    • or -gdwarf32 or -gdwarf64
    • or -gdbdwarf=32/64
    • but all compute units need to agree!
  • Jakub Jelinek suggests would be good to enable so could test

Single file split DWARF

  • two debug_*.dwo sections in same object file
  • no separate .dwo file, although allowed by standard
  • -gsplit-dwarf=single
  • -SHF_EXCLUDE (ignored by link editor)
    • not standardized


  • negatives:
    • somewhat large overhead
    • can only reference full type directly]
    • not universally supported
  • Positives
    • makes dedup easier and earlier,
    • should naturally fit in early debug scheme, so would be natural for LTO

Mailing lists

  1. Abstract submissions, registration, administrivia questions: tools-cauldron-admin@googlegroups.com

  2. Announcements and discussions related to the conference: gcc@gcc.gnu.org

Track description

The purpose of this virtual meeting is to gather all GNU tools developers, discuss current/future work, coordinate efforts, exchange reports on ongoing efforts, discuss development plans for the next 12 months, developer tutorials and any other related discussions.

The format of the meeting will be different to accommodate its virtual nature, talks and discussions will be shorter to allow us to fit in as many speakers/discussions as possible. However we may not be able to include every proposal.

We are inviting every developer working in the GNU tool chain: GCC, GDB, binutils, runtimes, etc. In particular this is an opportunity for participation by members of the community who are not able to travel to our regular GNU Tools Cauldron. We will need talk abstracts to be submitted well in advance, so we can incorporate them within the LPC program.


If you intend to participate (whether or not you are presenting) you will need to also register for LPC, which costs $50. This helps to cover the administrative costs of the conference and will ensure the BigBlueButton platform does not become overloaded. You will need to have or create a Linux Foundation single sign-on (SSO) account.

The GNU Tools Fund can provide scholarships for students and unpaid community volunteer. We'll publish criteria shortly. Please send a request to tools-cauldron-admin@googlegroups.com. The deadline to submit a request is 31 July 2020.

Submitting talks/BoFs/tutorials

If you have a topic that you would like to present, please submit an abstract to tools-cauldron-admin@googlegroups.com describing what you plan to present. We are accepting four types of submissions:

  • Prepared presentations: demos, project reports, etc (max. 25 minutes, including questions).
  • Lightning talks (max 10 minutes, including questions).
  • BoFs: coordination meetings with other developers (30 minute slot).

  • Tutorials for developers (25 or possibly 55 minutes including questions). No user tutorials, please.

Note. We shall not be doing in-depth reviews of the presentations. Mainly we are looking for applicability and to decide scheduling. We are aware that there is less time available this year (20 hours in 1 track, rather than 48 hours in 3 tracks). If we are oversubscribed, the program committee will attempt to merge talks, convert talks to lightning talks or (for BoFs only) schedule outside the official hours. If necessary we may have to turn some proposals down this year.

Your submission should contain the following information:

  • Title:
  • Authors:
  • Abstract:

If you are submitting a BoF and willing for it to be scheduled outside the official hours, please indicate if you would prefer an earlier time (easier for Europeans, tougher on Americans) or later (easier for Americans, tougher on Europeans).

If your talk is accepted, you will need to create an account on the Indico website, which will allow you to upload your abstract, speaker details and in due course your slides. You will also need to register for the conference and will get one free speaker pass for each talk. By submitting a talk/!BoF/tutorial, you agree that your name, affiliation and abstract may appear on the LPC website, and that you may be videoed during your talk, with those videos being made public after the conference.

Organising committee

The organising committee is:

  • Jeremy Bennett, Embecosm
  • Joel Brobecker, Adacore
  • Sarah Cook, Embecosm (GNU Track GDPR Data Officer)
  • Matt Newsome, Red Hat

Program committee

The program committee is:

  • Jeremy Bennett
  • Joel Brobecker
  • David Edelsohn
  • Frank Ch. Eigler
  • Simon Marchi
  • Jose E Marchesi
  • Ulrich Weigand

Code of conduct

All participants are required to abide by the conference Code of Conduct.

GDPR compliance

The personal information the GNU track organisers hold on you is your name, email address and affiliation. This information will only be used to contact you about the arrangements for the GNU Tools track at LPC 2020, including a follow-up questionnaire after the event. The data is held securely on outsourced secure servers, including as messages within a Google Group where the data is encrypted. The data is only accessible by the organisers of the GNU Tools Track.

Please contact the Data Officer if you would like to know the information we hold on you, wish to have that information deleted, or for any other queries related to GDPR.

When you register for the LPC Conference, you will receive their GDPR declaration, which will cover all activities as an attendee/speaker.

Schedule and talk abstracts

The schedule and talk abstracts will appear on the LPC conference pages shortly after the deadline for submissions.

None: linuxplumbers2020 (last edited 2022-07-25 17:28:13 by tschwinge)