Cmake include_directories()
c++, cmake, include
Solution
Quoting the documentation for `include_directories`:
The include directories are added to the directory property INCLUDE_DIRECTORIES for the current CMakeLists file. They are also added to the target property INCLUDE_DIRECTORIES for each target in the current CMakeLists file. The target property values are the ones used by the generators.
The `INCLUDE_DIRECTORIES` directory property is inherited to all subdirectories and all targets in the directory.
- Specifying `${CMAKE_CURRENT_SOURCE_DIR}` for `include_directories` is redundant as relative paths are interpreted as relative to this directory by default. You should throw it out to increase readability.
- Specifying an include directory in both a subdirectory and its parent is redundant. You should avoid this and settle on one location.
- Use `get_property` and `message` to double-check that all directories and targets end up with the correct entries in their `INCLUDE_DIRECTORIES` property.
- If you are free to require CMake 2.8.11 as a minimum requirement, consider abandoning `include_directories` completely and use `target_include_directories` instead. This has the advantage that include dependencies get resolved on a per-target basis exclusively which is usually the more desirable behavior.
Problem
This is my project tree: ``` project | + src | + external | | + foo | | | + include | | | | - foo.hpp | | | + src | | | | - foo.cpp | | | | - CMakeLists.txt | | | - CMakeLists.txt | | + CMakeLists.txt | + src | | - main.cpp | - CMakeLists.txt ``` foo.cpp includes foo.hpp: ``` // foo.cpp #include "foo.hpp" ``` Now the problem is that including the directory in the top CMake successfully find foo.hpp, but if I include in the subproject it doesn't. Any reason for it? (directories are included before the executable is compiled). ``` // project/CMakeLists.txt include_directories(external/foo/include) //OK add_subdirectory(external) add_executable(main main.cpp) target_link_libraries(main foo) // project/external/CMakeLists.txt add_subdirectory(foo) // project/external/foo/CMakeLists.txt include_directories(include) // NOT WORKING add_subdirectory(src) // project/external/foo/src/CMakeLists.txt add_library(foo foo.cpp) ```