Request for approval: Allow Java's ELF symtab reader to use separate debuginfo files

Andrew John Hughes gnu_andrew at
Fri Jan 8 19:27:55 UTC 2010

2010/1/8 Kelly O'Hair <Kelly.Ohair at>:
> Andrew Haley wrote:
>> On 12/09/2009 03:36 PM, Andrew Haley wrote:
>>> This is
>>> The symptom is that jmap doesn't work because target libraries are
>>> stripped.
>>> The fix is to allow the symtab reader to use the separate debuginfo files
>>> that are available for all (AFAIK) GNU/Linux distributions.
>> This is now also
>> Webrev at
>> I have now checked several Linux distros, old and new, and although
>> they keep their debuginfo files in different places, this patch works
>> on all of them.
>> Is this OK?  And, if so, which repos should I push the patch to?
> I'm a little concerned about the impact this might have on hotspot
> as it will eventually get delivered into a jdk6 release (I assume).
> And jdk6 does builds on really old Linux systems, e.g.
> "Red Hat Enterprise Advanced Server 2.1 update 2".
> Can you think of anything that might be a problem with that?
> Either at compile time or runtime?

aph will be able to respond to this in more detail, but my
understanding of the patch is that it only tries separate debug files
if it doesn't find debuginfo in the binary itself.  If the builds om
RHEL AS 2.1 use non-stripped binaries, it won't even get that far
AFAICS.  And if they don't and /usr/lib/debug also doesn't exist, then
it will just fail as it always did.

So the only issue would be that the code relies on building against
something newer than it did previously.

> I still am a bit uncomfortable with that 1K block of bytes we are adding,
> but I'll resign from that debate, if this is the official way to do it.
> How many of these 1K blocks are floating around the system? :^(
> The change probably needs to go through one of the hotspot forests, maybe
> hotspot-rt?

I would have assumed hotspot-svc as it's serviceability-related.

> In the meantime, I will take this patch and apply it, and make sure
> hotspot still builds with the jdk6 and jdk7 Linux systems we have.

Thanks.  HotSpot patches go through JPRT so that should also give it
some build testing.

> -kto
>> Thanks.
>> Andrew.

Andrew :-)

Free Java Software Engineer
Red Hat, Inc. (

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