I have been trying to solve this issue for more than two days, but still no luck.

I have no idea what is wrong, I need just to set up a simple NDK project, but it has already taken a tremendous amount of time.

The problem is that I am getting

error: undefined reference to 'firpm(unsigned int, std::vector<double, std::allocator<double> > const&, std::vector<double, std::allocator<double> > const&, std::vector<double, std::allocator<double> > const&, double, int)'
Here is my root CMakeLists

# Cmake Minimum Version
cmake_minimum_required(VERSION 3.4.1)
project(EcgProcessing)
# Add nested cmake files
include(libs/CMakeLists.txt)

include_directories(${CMAKE_CURRENT_SOURCE_DIR})

# ECG Audio Processor library
add_library(ecg-signal-processor-demodulator SHARED
demodulator.cpp)
add_library(ecg-signal-processor-qrsdetection SHARED
qrsdetection.cpp)
# Link

target_link_libraries(
firpm_d
log
android
ecg-signal-processor-demodulator
ecg-signal-processor-qrsdetection)

And in the libs directory

# Cmake Minimum Version
cmake_minimum_required(VERSION 3.4.1)
set(LIBS_DIRECTORY ${CMAKE_CURRENT_LIST_DIR})
#include_directories(${CMAKE_CURRENT_SOURCE_DIR}/Eigen/)
MACRO(ADD_SUBLIB libname source_ext)
#Compute required sources
set(sublib_path "${LIBS_DIRECTORY}/${libname}")
file(GLOB_RECURSE sublib_sources "${sublib_path}/src/*.${source_ext}")
#Create library
IF( sublib_sources )
ADD_LIBRARY(${libname} SHARED ${sublib_sources})
ENDIF()
#add this library's header folder to the global include set
INCLUDE_DIRECTORIES("${sublib_path}/include")
INCLUDE_DIRECTORIES("${sublib_path}/")
link_directories(${sublib_path})
ENDMACRO(ADD_SUBLIB)

ADD_SUBLIB(firpm_d "cpp")
ADD_SUBLIB(eigen "cpp")
It starts to compile the project, however ends up with the error.

What can cause this error, I have no idea what to try else.

Here is source code, so you can see it all structured. https://github.com/DurianOdour/EcgProcessor

I would be grateful for any help