**target_link_libraries(
                       native-lib
                       ${log-lib}
                       ${CMAKE_SOURCE_DIR}/libadd.a)**

#include <jni.h>
#include <string>
#include "../../../staticLib/files/add.hpp"

extern "C" JNIEXPORT jstring JNICALL
Java_com_example_oncall_myapplication_MainActivity_stringFromJNI(
        JNIEnv* env,
        jobject /* this */) {
    std::string hello = "Hello SUCESSS its 12";

    std::string hello1 = "Hello FAILED it is not 12";

    addition::my::work::abc     Obj;
    Obj.add(5,7);

    if(Obj.add(5,7) == 12)
    {
     return env->NewStringUTF(hello.c_str());
    }
    else
    {
    return env->NewStringUTF(hello1.c_str());
    }

}

Build command failed.
Error while executing process /home/oncall/Desktop/Android/Sdk/cmake/3.6.4111459/bin/cmake with arguments {--build /home/oncall/Bha/MyApplication3/app/.externalNativeBuild/cmake/debug/x86_64 --target native-lib}

ninja: error: '../../../../libadd.a', needed by '../../../../build/intermediates/cmake/debug/obj/x86_64/libnative-lib.so', missing and no known rule to make it