On 01/26/2017 02:54 PM, Arkady wrote:
> In my case this is
> 116: 0000000000003a30    49 FUNC    GLOBAL DEFAULT   11
> json_object_object_get_ex
> 
> Symlink to /usr/lib/x86_64-linux-gnu/libjson-c.so.2.0.0
> Package config
> 
> prefix=/usr
> exec_prefix=${prefix}
> libdir=${prefix}/lib/x86_64-linux-gnu
> includedir=${prefix}/include
> 
> Name: json-c
> Description: JSON implementation in C
> Version: 0.11.99
> Requires:
> Libs:  -L${libdir} -ljson-c
> Cflags: -I${includedir}/json-c

Hmm, ok. Let's try the following to see what command is being run to
link stapio - "make -n stapio". On my system, the output looks like (run
from the 'staprun' directory):

====
# make -n stapio
rm -f stapio
echo "  CCLD    " stapio;gcc -Wall -Wextra -Werror -Wunused -W
-Wformat=2  -g -O2 -fstack-protector-all -D_FORTIFY_SOURCE=2   -o stapio
stapio.o mainloop.o common.o ctl.o relay.o relay_old.o monitor.o
libstrfloctime.a -lpthread -ljson-c   -lpanel -lncurses -ltinfo
====

The above output makes sense:

  gcc {other options} -o stapio {bunch of .o files} {libraries} -ljson-c
{other libraries}

Hopefully we'll see something similar with your output.

I've also attached a small test program. For me it compiles/links
correctly with:

# gcc -o jsonc-test jsonc-test.c -ljson-c

Does it work for you?

> On Thu, Jan 26, 2017 at 10:40 PM, David Smith <dsmith@redhat.com> wrote:
>> On 01/26/2017 01:38 PM, Arkady wrote:
>>> On Thu, Jan 26, 2017 at 7:43 PM, David Smith <dsmith@redhat.com> wrote:
>>>> On 01/26/2017 05:17 AM, Arkady wrote:
>>>>> Hi,
>>>>>
>>>>> This thread is probably the closest to the problem I experience.
>>>>>
>>>>> I need --monitor support in the stap. I am trying to compile the 3.0 release
>>>>> On my Ubuntu 4.4.0-59-generic
>>>>>
>>>>> make[3]: Entering directory '/home/arkady/systemtap-3.0/staprun'
>>>>>   CCLD     stapio
>>>>> monitor.o: In function `comp_name':
>>>>> /home/arkady/systemtap-3.0/staprun/monitor.c:151: undefined reference
>>>>> to `json_object_object_get_ex'
>>>>> I have ./lib/x86_64-linux-gnu/libjson.a and the library contains
>>>>> json_object_object_get_ex
>>>>> ...................
>>>>>
>>>>> What am I missing?
>>>>
>>>> Am I correct in thinking that libjson is installed in your home
>>>> directory somewhere and isn't a system library? If so, that might be
>>>> your problem. We can probably pass more options to configure to add that
>>>> directory to the link search path.
>>>>
>>>> Another possibility is that the link is looking for a shared library
>>>> (.so) and you've got a static library (.a).
>>>>
>>>
>>> This is what I have
>>> /usr/lib/x86_64-linux-gnu/libjson-c.so
>>> /usr/lib/x86_64-linux-gnu/libjson-c.a
>>> /usr/lib/x86_64-linux-gnu/libjson-c.so.2
>>
>> So I was wrong about the library being installed in your home directory.
>>
>>> Can it be an order of the object files and libraries?
>>
>> I'd doubt it. I wonder if we've got a json-c version problem. Let's see
>> if your shared library has that symbol in it. When I run "readelf -Ws"
>> on mine, I see the following:
>>
>> ====
>> # readelf -Ws /lib64/libjson-c.so | fgrep json_object_object_get_ex
>>    115: 0000000000003790    49 FUNC    GLOBAL DEFAULT   11
>> json_object_object_get_ex
>> ====
>>
>> What does yours return?
>>
>> Also, what version of json-c do you have? I've got json-c-0.12-7.
>>
>> --
>> David Smith
>> dsmith@redhat.com
>> Red Hat
>> http://www.redhat.com
>> 256.217.0141 (direct)
>> 256.837.0057 (fax)


-- 
David Smith
dsmith@redhat.com
Red Hat
http://www.redhat.com
256.217.0141 (direct)
256.837.0057 (fax)