How do I correctly create dependencies between targets in CMake?

I am trying to use CMake to set up some simple dependencies between a C++ project and the libraries that it uses.

The set up is as follows

• Project
  • Dependency

Project itself contains source files that include headers from Dependency and when the executable is built it needs to be linked against Dependency's static library.

So far I can get this to work, but I have to specify the include directories of Dependency in the CMakeLists.txt file for Project manually. I wan开发者_如何转开发t this to be pulled out automatically, and I have explored the option of using the find_package() command to do so with limited success and making things much more complicated.

All I want to do is have Dependency built before Project and have Project link against the library and have its include directories. Is there a simple concise way of achieving this?

My current CMake files:

Project, file CMakeLists.txt:

cmake_minimum_required (VERSION 2.6)
project (Project)
include_directories ("${PROJECT_SOURCE_DIR}/Project")
add_subdirectory (Dependency)
add_executable (Project main.cpp)
target_link_libraries (Project Dependency)
add_dependencies(Project Dependency)

Dependency, file CMakeLists.txt:

project(Dependency)
add_library(Dependency SomethingToCompile.cpp)
target_link_libraries(Dependency)

Since CMake 2.8.11 you can use target_include_directories. Just simply add in your DEPENDENCY project this function and fill in include directories you want to see in the main project. CMake will care the rest.

PROJECT, CMakeLists.txt:

cmake_minimum_required (VERSION 2.8.11)
project (Project)
include_directories (Project)
add_subdirectory (Dependency)
add_executable (Project main.cpp)
target_link_libraries (Project Dependency)

DEPENDENCY, CMakeLists.txt

project (Dependency)
add_library (Dependency SomethingToCompile.cpp)
target_include_directories (Dependency PUBLIC include)

It is not exactly clear what you want to do, and why Project and Dependency have to be build separately.

My first though on your example would be

1. In PROJECT's CMakeLists.txt:

   • Remove add_dependencies(Project Dependency) There is no need to specify dependency, target_link_libraries() already does that.

2. In DEPENDENCY's CMakeLists.txt:

   • Remove project(Dependency) It builds a library, so why to have own project?
   • Remove target_link_libraries(Dependency) Because it does nothing