On Thu, Sep 24, 2020 at 2:04 PM Stephen John Smoogen <smooge(a)gmail.com> wrote:
On Thu, 24 Sep 2020 at 13:44, Jan Kratochvil <jan.kratochvil(a)redhat.com> wrote:
>
> On Thu, 24 Sep 2020 19:16:32 +0200, Neal Gompa wrote:
> > Then that certainly means that Ubuntu uses this too, since they reuse
> > the dbgsym subpackage generation for the ddeb system they have now.
>
> I am not much familiar with Debian/Ubuntu but I cannot find any use of DWZ
> there:
>
https://packages.ubuntu.com/groovy/amd64/bluez-dbg/download
> llvm-dwarfdump -color=0
bluez-dbg_5.55-0ubuntu1_amd64/data/usr/lib/debug/.build-id/*/*.debug|grep
DW_TAG_partial_unit
>
> This debuginfo package has been built 2020-09-15.
>
> (Besides that this proposal is not based on whether Debian uses DWZ or not.)
The original language of the proposal said no other distribution used DWZ, and that the
format was not adopted and should be removed. So it comes across that it is based on
whether Debian, Ubuntu, etc use it.
```
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 debug
info.
....
Almost nobody uses existing Fedora DWZ (only Fedora/CentOS/RHEL and
SuSE OSes) and so its support is missing in tools like
[
https://lldb.llvm.org/ LLDB],
[[llvm-dwarfdumphttps://llvm.org/docs/CommandGuide/llvm-dwarfdump.html|llvm-dwarfdump]]
or binutils readelf. -fdebug-types-section is used internally by
Google (produced by clang). Debian does not store any debug info
archives. Ubuntu uses neither -fdebug-types-section nor DWZ.
```
For the record, the reason why it was hard to broaden adoption is that
the patch wasn't upstreamed into rpm itself until RPM 4.14's release:
https://rpm.org/wiki/Releases/4.14.0.html
That was only three years ago, and in the span of that time, it's gone
from only Fedora using it to almost everyone using it now.
Just stick to the following:
The tool is not easily maintained, and has become a burden to make existing debugging
tools, namely llvm, compatible with this method.
Also expect that cross-distribution support is going to be important. No distribution is
an island entire of itself; and few 'customers' use just one distribution. If a
lot of distributions have been using this because Fedora had been and it was easier to
work out things.. then work is going to be needed to get them to work together..
I do not feel that this is a valid premise either, since the reason
for no dwz support in LLDB is because nobody contributed it. I'm
slightly surprised that Red Hat's debuginfo engineers hadn't already
contributed support for it into LLDB. I wonder if the reason for that
was the mistaken impression that dwz wasn't broadly used.
--
真実はいつも一つ!/ Always, there's only one truth!