Add include directories from sub_directory to main application. How?

[bogong]

Hello all!

My project have some libraries that defined with 'qt_add_library'. This libraries have some includes. How to automatically add library 'target_include_directories' to main application from this libraries CMakeLists.txt?

Application (qt_add_executable)
|-- Library 1 (qt_add_library)
|-- Library 2 (qt_add_library)
|-- Library ...

Or is there option to declare global variable within required include directories?

The global goal to make possible adding libraries just by using 'add_subdirectory'.

[bogong]

Totally got forgotten about CMake 'CACHE INTERNAL' parameter when setting variable:

set(${LIB_PREFIX}_DIR_INCLUDES /dir1 /dir2 /dir3 CACHE INTERNAL "")

And in the main application just add it to target includes:

add_subdirectory(/Lib1 ${DIR_BUILD_LIBRARIES}/Library_1)
add_subdirectory(/lib2 ${DIR_BUILD_LIBRARIES}/Library_2)

...

target_include_directories(target
	PRIVATE
		${LIB1_PREFIX_DIR_INCLUDES}
		${LIB2_PREFIX_DIR_INCLUDES}
)

[Christian Ehrlicher]

Use the correct target_include_directories() call for your library instead your hack.

[bogong]

@Christian-Ehrlicher What is correct call? Examples?

Something like this:

target_include_directories(target
	PRIVATE
		$<TARGET_PROPERTY:Library_1,INTERFACE_INCLUDE_DIRECTORIES>
		$<TARGET_PROPERTY:Library_2,INTERFACE_INCLUDE_DIRECTORIES>
)

[Christian Ehrlicher]

Define the correct include dirs for you libraries with target_include_directories and simply link them to your executable. Then cmake is doing the rest for you automatically.

[bogong]

@Christian-Ehrlicher What is 'correct'?

[Christian Ehrlicher]

@bogong said in Add include directories from sub_directory to main application. How?:

What is 'correct'?

See https://cmake.org/cmake/help/latest/command/target_include_directories.html on how to use target_include_directories() and properly set the include dirs for your libraries. Nothing more to do.