Custom CMake library - What have I done wrong? - c++

Question

I am trying to install a custom library with CMake.
It consists of 2 'sub-libraries' and a main header file which includes the 'sub-libraries'.
I think it installs okay (The output looks like this:)
-- Configuring done
-- Generating done
-- Build files have been written to: /home/pi/Desktop/Projects/MaxLib/build
[ 20%] Building CXX object Geom/CMakeFiles/Geom.dir/Geom.cpp.o
[ 40%] Linking CXX shared library libGeom.so
[ 40%] Built target Geom
[ 60%] Building CXX object File/CMakeFiles/File.dir/File.cpp.o
[ 80%] Linking CXX shared library libFile.so
[ 80%] Built target File
[100%] Built target MaxLib
Install the project...
-- Install configuration: "Debug"
-- Installing: /usr/local/lib/libMaxLib.a
-- Installing: /usr/local/include/MaxLib.h
-- Installing: /usr/local/include/MaxLib/File.h
-- Installing: /usr/local/include/MaxLib/Geom.h
However, when I try to compile a program using it, I receive a number of "undefined reference to" errors. Where have I gone wrong?
The Main Header looks like:
#include "MaxLib/File.h"
#include "MaxLib/Geom.h"
It's CMakefile looks like this:
cmake_minimum_required(VERSION 3.5)
project(MaxLib)
add_library(${PROJECT_NAME}
"${CMAKE_CURRENT_SOURCE_DIR}/MaxLib.h"
)
add_subdirectory(File)
add_subdirectory(Geom)
target_link_libraries(${PROJECT_NAME} File)
target_link_libraries(${PROJECT_NAME} Geom)
# Install Library
install (TARGETS ${PROJECT_NAME}
LIBRARY DESTINATION lib)
# Install Main Header File
INSTALL(FILES "${CMAKE_CURRENT_SOURCE_DIR}/MaxLib.h" DESTINATION include) #
INSTALL(FILES ...) or install(DIRECTORY ...)
# Build list of header files to install from other directorys. Root == "."
set(HEADER_DIRS "File" "Geom")
## Add Source Files from the other directories
foreach(DIR ${HEADER_DIRS})
# Find all source files & append to list
if(DIR STREQUAL ".")
file(GLOB HEADER_FILES_IN_FOLDER *.h)
else()
file(GLOB HEADER_FILES_IN_FOLDER ${CMAKE_CURRENT_SOURCE_DIR}/${DIR}/*.h)
endif()
list(APPEND HEADER_FILES ${HEADER_FILES_IN_FOLDER})
endforeach()
# Install Header files
INSTALL(FILES ${HEADER_FILES} DESTINATION include/${PROJECT_NAME}) # INSTALL(FILES ...) or install(DIRECTORY ...)
target_compile_options(${PROJECT_NAME} PRIVATE -Wall -Wextra -Wpedantic -g)
set_target_properties(${PROJECT_NAME} PROPERTIES LINKER_LANGUAGE CXX)
The 'sub-libraries's CMakefiles look like this:
project(Geom)
add_library(${PROJECT_NAME} SHARED
${CMAKE_CURRENT_SOURCE_DIR}/Geom.cpp
)
target_include_directories(${PROJECT_NAME}
PUBLIC
${CMAKE_CURRENT_SOURCE_DIR}
)
I am trying to include the library like this:
#include <MaxLib.h>
And I am adding -lMaxLib to its makefile
Edit:
A basic program like this:
#include <MaxLib.h>
int main() {
float y1 = MaxLib::Geom::CleanAngle(7654);
}
Will produce the undefined reference error:
/usr/bin/ld: warning: libFile.so, needed by //usr/local/lib/libMaxLib.so, not found (try using -rpath or -rpath-link) // This shows when add_library marked SHARED
/usr/bin/ld: warning: libGeom.so, needed by //usr/local/lib/libMaxLib.so, not found (try using -rpath or -rpath-link) // This shows when add_library marked SHARED
/home/pi/Desktop/Projects/TestProgram/main.cpp:43: undefined reference to `MaxLib::Geom::CleanAngle(double)'