How to add new source file in CMakeLists.txt?

Question

I am creating a demo to read and write files through android NDK. I am using CMake and have CMakeLists.txt in my project with following content:

    # For more information about using CMake with Android Studio, read the
    # documentation: https://d.android.com/studio/projects/add-native-code.html

    # Sets the minimum version of CMake required to build the native library.

    cmake_minimum_required(VERSION 3.4.1)

    # Creates and names a library, sets it as either STATIC
    # or SHARED, and provides the relative paths to its source code.
    # You can define multiple libraries, and CMake builds them for you.
    # Gradle automatically packages shared libraries with your APK.

    add_library( # Sets the name of the library.
            native-lib

            # Sets the library as a shared library.
            SHARED

            # Provides a relative path to your source file(s).
            src/main/cpp/native-lib.cpp)

    # Searches for a specified prebuilt library and stores the path as a
    # variable. Because CMake includes system libraries in the search path by
    # default, you only need to specify the name of the public NDK library
    # you want to add. CMake verifies that the library exists before
    # completing its build.

    find_library( # Sets the name of the path variable.
            log-lib

            # Specifies the name of the NDK library that
            # you want CMake to locate.
            log)

    # Specifies libraries CMake should link to your target library. You
    # can link multiple libraries, such as libraries you define in this
    # build script, prebuilt third-party libraries, or system libraries.

    target_link_libraries( # Specifies the target library.
            native-lib

            # Links the target library to the log library
            # included in the NDK.
            ${log-lib})

I have created a new utility.cpp and utility.h file in the same folder where native-lib.cpp saved. I am able to include utility.h in native-lib.cpp . When I run the program I got an error undefined reference to function {fun} where {fun} is a function written in utility.cpp .

Please suggest how can I build both the source files in my project.

Answer 1

Just add the cpp to your CMakeLists

add_library( # Sets the name of the library.
        native-lib

        # Sets the library as a shared library.
        SHARED

        # Provides a relative path to your source file(s).
        src/main/cpp/native-lib.cpp
        src/main/cpp/utility.cpp
)

Answer 2

Replace

src/main/cpp/native-lib.cpp)

with

src/main/cpp/utility.cpp
src/main/cpp/native-lib.cpp)

if utility is in src/main/cpp/