CMake can't find include file from subfolder

Question

I want to add to my CMake project some subfolder which contains some additional functionality. MyProject is a shared library. Ideally it will be fine to just include files from subfolder and to compile all them together. But so far I've found a way only to include that as a static library that suits me too. So my files structure should look like the following:

MyProject
    src
        main.cpp
    include
        main.h
    CMakeLists.txt
    3dparty
        SomeFolder
           src
               file.cpp
           include
               file.h
           CMakeLists.txt

MyProject/CMakeLists.txt:

cmake_minimum_required(VERSION 2.8)
project(MyProject)
file(GLOB SRC . src/*.cpp)
file(GLOB INC . include/*.h)
set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/lib)
set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/bin)
add_library(${PROJECT_NAME} SHARED ${SRC} ${INC})
target_include_directories(${PROJECT_NAME} PUBLIC
  ${CMAKE_CURRENT_SOURCE_DIR}/include
)
add_subdirectory(3dparty/SomeFolder)

and 3dparty/SomeFolder/CMakeLists.txt:

project (SomeFolder)
file(GLOB SRC . src/*.cpp)
file(GLOB INC . include/*.h)
add_library(${PROJECT_NAME} STATIC ${SRC} ${INC})
target_include_directories(${PROJECT_NAME} PUBLIC
  ${CMAKE_CURRENT_SOURCE_DIR}/include
)

I can compile the project and I see that compiler produses SomeFolder.a so it looks good. But for some reason I can't include files from 3dparty/SomeFolder/include in main.*. So far I've tried:

#include "file.h"
#include "3dparty/SomeFolder/file.h"

but nothing works. I get error: 'file.h' file not found.

What I did wrong? How can I include files from subproject?

Arne J · Accepted Answer · 2019-08-11 13:03:11Z

1

Because you forgot to link the sublibrary to your main library. Usr target_link_libraries()

answered Aug 11, 2019 at 13:03

Arne J

4252 silver badges9 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

folibis Over a year ago

Ok, I've added target_link_libraries(${PROJECT_NAME} SomeFolder) to the main CMakeLists.txt and looks that that works. Is that possible to add somehow this line inside 3dparty/SomeFolder/CMakeLists.txt ? It would be nice to add subfolder with only one instruction only (add_subdirectory).

Arne J Over a year ago

No, and I believe you're making a few wrong assumptions here. add_subirectory() will do nothing for linking (as you experienced), and the arguments of target_link_libraries() are targets (executable or library), not directory paths. The normal way to link is just to specify the dependencies for each target with target_link_libraries(). If CMake can at some point uniquely identify one of the dependencies as another target, it will know what to do.

Collectives™ on Stack Overflow

CMake can't find include file from subfolder

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related