Error while LoadLibrary a c-shared .so in CentOS

I have created a C application and built it as a C-Shared library .so. The C application contains reference to ZMQ library. To generate the shared library I tried following steps:

1) I wrote a C application ZMQInterface.c with a header file ZMQInterface.h

2) Built the application as C-shared library

[varun@localhost zmqproj]$  gcc -c -Wall -Werror -I/usr/local/include/ -L/usr/local/lib -lzmq -fpic ZMQInterface.c
[varun@localhost zmqproj]$  gcc -shared -o ZMQInterface.so ZMQInterface.o

The shared library ZMQInterface.so was generated successfully

When I tried to load it in MATLAB using loadlibrary() I am getting the following error. I have attached the files (zmqproj.zip)

>> [status,warn] = loadlibrary('ZMQInterface.so','ZMQInterface.h');
Error loading library intermediate output follows.
The actual error is at the end of this output.
*********

Type '' was not found.  Defaulting to type error.

Found on line 11 of input from line 5 of file /home/varun/zmqproj/ZMQInterface.h

Type 'char(visibility("default")))Ptrs_recv(voidPtr' was not found.  Defaulting to type voidPtr.

Found on line 11 of input from line 5 of file /home/varun/zmqproj/ZMQInterface.h

Type '' was not found.  Defaulting to type error.

Found on line 12 of input from line 6 of file /home/varun/zmqproj/ZMQInterface.h

Failed to parse type '( visibility (" default "))) void * create_socket_context ( void' original input '( visibility (" default "))) void * create_socket_context ( void '
Found on line 12 of input from line 6 of file /home/varun/zmqproj/ZMQInterface.h
Error parsing argument for function __attribute__ function may be invalid.

Type '' was not found.  Defaulting to type error.

Found on line 13 of input from line 7 of file /home/varun/zmqproj/ZMQInterface.h

Type 'int(visibility("default")))voidPtrcreate_socket_subscriber(voidPtr' was not found.  Defaulting to type voidPtr.

Found on line 13 of input from line 7 of file /home/varun/zmqproj/ZMQInterface.h
*********
Error using loadlibrary
Building ZMQInterface_thunk_glnxa64 failed.  Compiler output is:
/usr/bin/gcc -I"/usr/local/MATLAB/R2017a/extern/include" -fexceptions -fPIC -fno-omit-frame-pointer -pthread -I"/home/varun/zmqproj"
-I"/home/varun/zmqproj" "ZMQInterface_thunk_glnxa64.c" -o "ZMQInterface_thunk_glnxa64.so" -Wl,-E -shared
ZMQInterface_thunk_glnxa64.c: In function ‘voidPtrThunk’:
ZMQInterface_thunk_glnxa64.c:38:14: error: expected expression before ‘)’ token
  return (( (*)(void * ))fcn)(p0);
              ^
ZMQInterface_thunk_glnxa64.c:38:25: error: expected ‘)’ before ‘fcn’
  return (( (*)(void * ))fcn)(p0);
                         ^
ZMQInterface_thunk_glnxa64.c: At top level:
ZMQInterface_thunk_glnxa64.c:42:30: error: expected declaration specifiers or ‘...’ before string constant
 EXPORT_EXTERN_C  (visibility("default")))void*create_socket_context(voidThunk(void fcn(),const char *callstack,int stacksize)
                              ^

Try 2 :

Then I tried removing the __attribute__ ((visibility ("default"))) then compiled and loaded. But I am getting following error then

                              Error using loadlibrary
There was an error loading the library "/home/varun/zmqproj/ZMQInterface.so"

Missing symbol 'zmq_connect' required by '/home/varun/zmqproj/ZMQInterface.so'
Missing symbol 'zmq_ctx_new' required by '/home/varun/zmqproj/ZMQInterface.so'
Missing symbol 'zmq_recv' required by '/home/varun/zmqproj/ZMQInterface.so'
Missing symbol 'zmq_send' required by '/home/varun/zmqproj/ZMQInterface.so'
Missing symbol 'zmq_socket' required by '/home/varun/zmqproj/ZMQInterface.so'

Caused by:
    Error using loaddefinedlibrary

    Missing symbol 'zmq_connect' required by '/home/varun/zmqproj/ZMQInterface.so'
    Missing symbol 'zmq_ctx_new' required by '/home/varun/zmqproj/ZMQInterface.so'
    Missing symbol 'zmq_recv' required by '/home/varun/zmqproj/ZMQInterface.so'
    Missing symbol 'zmq_send' required by '/home/varun/zmqproj/ZMQInterface.so'
    Missing symbol 'zmq_socket' required by '/home/varun/zmqproj/ZMQInterface.so'
    

Could any one help me to know the actual cause for this issue ?

Execution Environment :

OS - CentOS 7 64 bit

gcc version - gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-36)

MATLAB 2017a