When i execute make i am getting following error : -

$make

/bin/bash ./libtool  --tag=CXX   --mode=link g++  -g -O2 -std=c++0x -O3 -Wall -Wextra -Wno-missing-field-initializers -g3   -o src/poll src/poll.o src/sample_nfc.la -lwiringPi
libtool: link: g++ -g -O2 -std=c++0x -O3 -Wall -Wextra -Wno-missing-field-initializers -g3 -o src/.libs/poll src/poll.o  src/.libs/sample_nfc.so -lwiringPi
/usr/lib/gcc/x86_64-linux-gnu/5/../../../../lib/libwiringPi.so: undefined reference to `pthread_create'
/usr/lib/gcc/x86_64-linux-gnu/5/../../../../lib/libwiringPi.so: undefined reference to `shm_open'
/usr/lib/gcc/x86_64-linux-gnu/5/../../../../lib/libwiringPi.so: undefined reference to `crypt'
/usr/lib/gcc/x86_64-linux-gnu/5/../../../../lib/libwiringPi.so: undefined reference to `pthread_join'
/usr/lib/gcc/x86_64-linux-gnu/5/../../../../lib/libwiringPi.so: undefined reference to `pthread_cancel'