Re: [patch] Fix for gdb.threads/staticthreads.exp failure on Linux

[Doug Evans <dje at google dot com>]

On Thu, Jul 16, 2009 at 12:48 PM, Paul Pluzhnikov<ppluzhnikov@google.com> wrote:
> On Wed, Jul 15, 2009 at 6:25 PM, Doug Evans<dje@google.com> wrote:
>
>> I like the patch. If thread enumeration fails during
>> try_thread_db_load_1 we ignore it and leave gdb to try again later.
>> When we get to this point we've already verified libthread_db is
>> (mostly) happy.
>> I kinda wonder, though, if that works then maybe gdb shouldn't do
>> thread enumeration at all here.
>
> There is the 'attach' scenario under which (I believe) we *should* do
> thread enumeration here.

Right.  But for "run", that's my question.

>> I think a comment needs to be added to your patch, probably to the
>> call site of thread_db_find_new_threads_silently, that thoroughly
>> explains what's going on (assuming that's still the best solution).
>
> Added.
>
>> btw, the reason for the 1 known failure is, I'm guessing, because gdb
>> was built with the same toolchain that uses the older glibc, but the
>> test was run using a native toolchain that uses a newer glibc and the
>> mismatch is sufficient to trigger the failure. ?At least that explains
>> things in my sandbox. ?If I rebuild gdb with native gcc, or set
>> libthread-db-search-path to find the newer glibc, the kfail goes away.
>
> When gdb is built with native toolchain (glibc-2.7) and the test is built
> with the same, then there is no failure.
>
> When gdb is built with native toolchain, but the test is built against
> glibc-2.3.6, I see one KFAIL.
>
> When both gdb and the test are built against glibc-2.3.6, I see this:
>
> FAIL: gdb.threads/staticthreads.exp: running to main in runto
> FAIL: gdb.threads/staticthreads.exp: Continue to main's call of sem_post
> FAIL: gdb.threads/staticthreads.exp: handle SIG32 helps
>
> # of expected passes ? ? ? ? ? ?6
> # of unexpected failures ? ? ? ?3
> # of known failures ? ? ? ? ? ? 1
>
> When gdb is built against glibc-2.3.6, but test with glibc-2.7, I see
> one KFAIL.

That's what I see too.

> I've retested attached patch under all four combinations above, which
> results in:
>
> gdb-glibc-2.7 ? test-glibc-2.7: ? no failures
> gdb-glibc-2.7 ? test-glibc-2.3.6: KFAIL:
> gdb.threads/staticthreads.exp: info threads (PRMS: gdb/1328)
> gdb-glibc-2.3.6 test-glibc-2.3.6: no failures
> gdb-glibc-2.3.6 test-glibc-2.7: ? KFAIL:
> gdb.threads/staticthreads.exp: info threads (PRMS: gdb/1328)
>
> and checked this in.

Thanks.
I tweaked the comment a bit.