Changes/DebugInfoStandardization

Debug Info Standardization

Summary

Fedora 18 implemented Features/DwarfCompressor. As the format did not get widespread and the tool is not much maintained it became burden to make existing debugging tools compatible with Fedora.

Owner

• Name: Jan Kratochvil
• Email: jan.kratochvil@redhat.com

Current status

• Targeted release: Fedora 34
• Last updated: 2020-09-23
• FESCo issue: <will be assigned by the Wrangler>
• Tracker bug: <will be assigned by the Wrangler>
• Release notes tracker: <will be assigned by the Wrangler>

Detailed Description

The is a refresh of Fedora 18 Features/DebugTypesSections.

• .debug files contained in *-debuginfo.rpm are very big in general (debug/ has 82GB while all the other x86_64 Fedora distribution files are 75GB). There are various methods how to make the *-debuginfo.rpms smaller. Fedora 18 started using DWZ tool (from Features/DwarfCompressor) while Google implemented a similar but different approach called -fdebug-types-section.

The problem of existing Fedora DWZ saving is that almost nobody uses it (only Fedora/CentOS/RHEL and SuSE OSes) and so its support is missing in tools like LLDB and llvm-dwarfdump. Implementing support for DWZ is about 8x times more complicated (LoC count) than -fdebug-types-section.

• DWZ advantage: On the whole Fedora distro it saves 3.3% (5GB of the 157GB distribution size).
• Bulleted list item

Scope

• Proposal owners:

• Other developers: N/A (not a System Wide Change)

• Release engineering: #Releng issue number (a check of an impact with Release Engineering is needed)

• Policies and guidelines: N/A (not a System Wide Change)

• Trademark approval: N/A (not needed for this Change)

• Alignment with Objectives:

Upgrade/compatibility impact

N/A (not a System Wide Change)

How To Test

N/A (not a System Wide Change)

Dependencies

N/A (not a System Wide Change)

Contingency Plan

• Contingency mechanism: (What to do? Who will do it?) N/A (not a System Wide Change)
• Contingency deadline: N/A (not a System Wide Change)
• Blocks release? N/A (not a System Wide Change), Yes/No
• Blocks product? product

Documentation

N/A (not a System Wide Change)