Cannot find a header with 'include_directories' in CMake

Here is the folder hierarchy of a c++ project:

 1. FolderA 1. file1.h/cpp 2. CMakeLists.txt (CmakeA) 2. FolderB 1. file2.h/cpp 2. CMakeLists.txt (CmakeB) 3. main.cpp 4. CMakeLists.txt (CmakeAll) 

CmakeA:

file(GLOB FolderA_FILES *.cpp *.h *.hpp) # add component add_library(FolderA ${FolderA_FILES}) include_directories(../FolderB) target_link_libraries(FolderA FolderB) 

CMakeB:

file(GLOB FolderB_FILES *.cpp *.h *.hpp) # add component add_library(FolderB ${FolderB_FILES}) 

CMakeAll:

cmake_minimum_required(VERSION 2.8) #add smirk dependency set(Smirk_DIR /usr/local CACHE PATH "Directory where Smirk has been installed (e.g. /usr/local).") include(${Smirk_DIR}/cmake/smirk.cmake) smirk_project(operatingTableProject) file(GLOB smirk_operatingTableProject_FILES *.cpp *.h *.hpp) add_executable(smirk_operatingTableProject ${smirk_operatingTableProject_FILES}) # install directives install( TARGETS smirk_operatingTableProject RUNTIME DESTINATION bin ) #add FolderB dependency add_subdirectory(FolderB) target_link_libraries(smirk_operatingTableProject FolderB) #add FolderA dependency add_subdirectory(FolderA) target_link_libraries(smirk_operatingTableProject FolderA) 

In the file1.h I include file2.h. The problem is wherever I include in the main.cpp FolderA/file1.h I got a compilation issue:

file2.h: No such file or directory (in file1.h) 

But if I comment out the include in the main.cpp, it works. Also, If I include file2.h in file1.cpp it works so the main problem is wherever I include a header file from a subdirectory in another header file from other subdirectory and one of them is included in the main file.

Any help would be appreciated.

1 Answer

Command include_directories affects only on local scope: being issued in FolderA it affects only on the compilation of FolderA library. You need to issue that command in top-level CMakeLists.txt for compile main.cpp.

Alternatively, you may use command target_include_directories with PUBLIC option in FolderA:

target_include_directories(FolderA PUBLIC ../FolderB) 

so include directories will be propagated to any target which is linked with that library.