Re: Problem Compiling gdbserver with musl

[Brian Wang <brian.wang.0721@gmail.com>]

On Fri, Oct 19, 2012 at 9:54 PM, John Spencer <maillist-musl@barfooze.de> wrote:
> On 10/19/2012 08:13 AM, Brian Wang wrote:
>>
>> Hello all,
>>
>> Is it possible to cross compile gdbserver with musl?  I tried it and
>> it failed complaining about some thread-db stuff:
>> --------------
>> thread-db.c: In function ‘find_one_thread’:
>> thread-db.c:292:7: error: format ‘%ld’ expects argument of type ‘long
>> int’, but argument 3 has type ‘thread_t’ [-Werror=format]
>> thread-db.c:315:6: error: ‘struct lwp_info’ has no member named ‘th’
>> thread-db.c: In function ‘attach_thread’:
>> thread-db.c:329:7: error: format ‘%ld’ expects argument of type ‘long
>> int’, but argument 3 has type ‘thread_t’ [-Werror=format]
>> thread-db.c:335:9: error: format ‘%ld’ expects argument of type ‘long
>> int’, but argument 2 has type ‘thread_t’ [-Werror=format]
>> thread-db.c:340:6: error: ‘struct lwp_info’ has no member named ‘th’
>> thread-db.c: In function ‘thread_db_get_tls_address’:
>> thread-db.c:513:47: error: ‘struct lwp_info’ has no member named ‘th’
>> thread-db.c: In function ‘dladdr_to_soname’:
>> thread-db.c:652:3: error: passing argument 1 of ‘dladdr’ discards
>> ‘const’ qualifier from pointer target type [-Werror]
>> In file included from thread-db.c:33:0:
>>
>> /opt/cross/arm-linux-musleabi/lib/gcc/arm-linux-musleabi/4.7.1/../../../../arm-linux-musleabi/include/dlfcn.h:30:5:
>> note: expected ‘void *’ but argument is of type ‘const void *’
>> thread-db.c: In function ‘try_thread_db_load_from_sdir’:
>> thread-db.c:708:30: error: ‘LIBTHREAD_DB_SO’ undeclared (first use in
>> this function)
>> thread-db.c:708:30: note: each undeclared identifier is reported only
>> once for each function it appears in
>> thread-db.c: In function ‘try_thread_db_load_from_dir’:
>> thread-db.c:719:29: error: ‘LIBTHREAD_DB_SO’ undeclared (first use in
>> this function)
>> thread-db.c: In function ‘thread_db_load_search’:
>> thread-db.c:748:41: error: ‘LIBTHREAD_DB_SEARCH_PATH’ undeclared
>> (first use in this function)
>> thread-db.c: In function ‘thread_db_handle_monitor_command’:
>> thread-db.c:971:7: error: ‘LIBTHREAD_DB_SEARCH_PATH’ undeclared (first
>> use in this function)
>> thread-db.c: In function ‘try_thread_db_load_from_sdir’:
>> thread-db.c:709:1: error: control reaches end of non-void function
>> [-Werror=return-type]
>> cc1: all warnings being treated as errors
>> --------------
>>
>
> hello brian, please forward your bug report to gdb mailing list.
> clearly gdb devs should check if these facilities are available before using
> them.
> we must raise awareness of such issues upstream.

I guess gdb development is somehow tightly coupled with glibc, which
supplies libthread_db.
I remember seeing similar issues reported:
http://sourceware.org/bugzilla/show_bug.cgi?id=13011

>
>
> as a temporary fix, you can either build gdb without gdbserver:
> https://github.com/rofl0r/sabotage/blob/master/pkg/gdb
>
> patches are here: https://github.com/rofl0r/sabotage/tree/master/KEEP
>
> before i ported sabotage to mips i had working patches for gdbserver to
> *compile* (did not test if it *works*) on x86 and amd64:
>
> https://github.com/rofl0r/sabotage/commit/02202d48d5062c62a3fa62deaf3bdc01d5b4423d
>
> the dlopen patch should not be necessary with current musl.

Thank you for the pointers. :-)

gdbserver+gdb now works for my ARM target, at least for single-thread program.


Brian

-- 
brian
------------------

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