[pacman-dev] Pacman split debug info symbol path

[Dave Reisner]

On Mar 29, 2014 1:52 PM, "Steven Noonan" <steven at uplinklabs.net> wrote:
>
> On Sat, Mar 29, 2014 at 10:41 AM, Dave Reisner <d at falconindy.com> wrote:
> > On Mar 29, 2014 1:36 PM, "Steven Noonan" <steven at uplinklabs.net> wrote:
> >>
> >> Hi folks,
> >>
> >> I think the directory Pacman is using for the split-out debug symbols
> >> is incorrect. This appears to be needed:
> >
> > Why do you think this? What are the symptoms you're seeing? I use debug
> > packages all the time and they work as expected.
>
> I've seen tools complain they can't find debug symbols or simply not show
any.
>
> What tools have you used successfully? perf, gdb, and oprofile all
> seem to look in the 'debug-id' directory, not in 'debug_id'...

gdb and valgrind, mostly. I've not seen either complain about missing
symbols.

> >>
> >> commit 61ed104abf95ac38e7d317c760807f308ea90555
> >> Author: Steven Noonan <steven at uplinklabs.net>
> >> Date:   Wed Feb 12 05:44:16 2014 -0800
> >>
> >>     makepkg: use dash instead of underscore in /usr/lib/debug/.build-id
> >>
> >>     Signed-off-by: Steven Noonan <steven at uplinklabs.net>
> >>
> >> diff --git a/scripts/makepkg.sh.in b/scripts/makepkg.sh.in
> >> index 027fcc3..7e663af 100644
> >> --- a/scripts/makepkg.sh.in
> >> +++ b/scripts/makepkg.sh.in
> >> @@ -1525,7 +1525,7 @@ strip_file() {
> >>
> >>                 # has this file already been stripped
> >>                 if [[ -n "$bid" ]]; then
> >> -                       if [[ -f
> >> "$dbgdir/.build_id/${bid:0:2}/${bid:2}.debug" ]]; then
> >> +                       if [[ -f
> >> "$dbgdir/.build-id/${bid:0:2}/${bid:2}.debug" ]]; then
> >>                                 return
> >>                         fi
> >>                 elif [[ -f "$dbgdir/$binary.debug" ]]; then
> >> @@ -1546,15 +1546,15 @@ strip_file() {
> >>
> >>                 if [[ -n "$bid" ]]; then
> >>                         local target
> >> -                       mkdir -p "$dbgdir/.build_id/${bid:0:2}"
> >> +                       mkdir -p "$dbgdir/.build-id/${bid:0:2}"
> >>
> >>                         target="../../../../../${binary#./}"
> >>                         target="${target/..\/..\/usr\/lib\/}"
> >>                         target="${target/..\/usr\/}"
> >> -                       ln -s "$target"
> > "$dbgdir/.build_id/${bid:0:2}/${bid:2}"
> >> +                       ln -s "$target"
> > "$dbgdir/.build-id/${bid:0:2}/${bid:2}"
> >>
> >>                         target="../../${binary#./}.debug"
> >> -                       ln -s "$target"
> >> "$dbgdir/.build_id/${bid:0:2}/${bid:2}.debug"
> >> +                       ln -s "$target"
> >> "$dbgdir/.build-id/${bid:0:2}/${bid:2}.debug"
> >>                 fi
> >>         fi
> >>
> >> To justify this change, I can't find any tools that actually look in
> >> 'build_id' (with an underscore) when searching for symbols.
> >>
> >> For example, perf does this (lines 101, 105):
> >>
> >>
> >
https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/tree/tools/perf/util/build-id.c#n92
> >>
> >> GDB also looks in '.build-id' (lines 83, 102):
> >>
> >>
> >
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=blob;f=gdb/build-id.c;h=491900b3e545c72325a54fc79847b8872fa63aae;hb=HEAD#l73
> >>
> >> OProfile, same issue (lines 93, 104):
> >>
> >>
> >
http://sourceforge.net/p/oprofile/oprofile/ci/master/tree/libutil++/bfd_support.cpp
> >>
> >> I noticed tool breakage back when I submitted the kernel module
> >> split+debug patch, but kept the patch to myself because I figured I
> >> must have been missing the rationale for the difference, but I've been
> >> so far unable to find any.
> >>
> >> - Steven
> >>
> >
>