Reduce size of *.debug files in debuginfo packages in Fedora 18 using DWARF Compressor dwz.
- Name: Jakub Jelinek
- Email: firstname.lastname@example.org
- Targeted release: Releases/18
- Last updated: 2012-07-18
- Percentage of completion: 100%
The dwz tool http://sourceware.org/git/?p=dwz.git;a=summary can rewrite .debug_* sections, either in binaries/shared libraries, or their *.debug split files, into equivalent, but smaller, DWARF. The tool with -m option also attempts to optimize also several *.debug files at once, by moving common .debug_* data into a single new ET_REL *.debug file and using DWARF extensions refer to that from the *.debug files. The rpm and redhat-rpm-config packages have been tweaked to invoke this tool by default during find-debuginfo.sh.
Benefit to Fedora
Smaller debuginfo files.
All packages should be rebuilt with the new tool as well as rpm changes hit dist-f18.
How To Test
GDB testsuite, perhaps some tool to analyze whether the non-compressed and compressed debuginfos contain equivalent info.
Users shouldn't notice this, except that debuginfo files will be smaller, and newer DWARF consumers will be needed (gdb, valgrind, dwarves, prelink, elfutils, systemtap).
All packages need to be rebuilt.
Worst case we stop using the compressor.
http://www.dwarfstd.org/ShowIssue.php?issue=120604.1&type=open and dwz manual page.
Fedora 18 debuginfo has been post-processed by a DWARF compressor tool to reduce size of the *.debug files.