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Cmake include subdirectories8/1/2023 ![]() If you had to given such a phrase a meaning, here's what would make sense to me: Visual Studio, and possibly Code::Blocks). What CMake refers to as a target sometimes translates to what IDEs call projects (Ix. Each project can contain multiple targets (libraries, executables, etc.). Each buildsystem generated by CMake consists of one top-level project, possibly including other external or subdirectory projects. ![]() Also note that the word "project" is a quite overloaded term. I have not seen that phrase used in documentation. It therefore seems to me that CMake consider those headers to be external to the project, and does not track them in the dependsĪs far as I know, there is no official or useful definition of "external header" when it comes to CMake. I realized recently that the issue seemed to be that CMake considered those header files to be external to the project. What is an "external" header in CMake? (no such thing) How CMake configures the Code::Blocks IDE is a completely separate story. TL DR CMake and Makefiles have their own way of tracking header dependencies given include directories and source files. This question is vexing, as it is motivated by a specific behaviour of a specific IDE- Code::Blocks) and CMake, but then poses a question unrelated to that IDE and instead about Makefiles and CMake, assuming that they have done something wrong with CMake which led to a problem with Makefiles, which led to a problem with their IDE. In all the answers to this question, there is a whole lot of "how" (to get what you want), and precious little "why" (digging into the problem that motivated the question and what the asker may have misunderstood about the ways in which different types of tools like IDEs and build tools do / do not interact and share information with each other, and what information CMake passes / needs to pass to those tools). ![]() Where with "seems" I mean that, CMake could detect such header-files automatically if it wanted, because it parses project's C/C++ files anyway. set(AMENT_EXTENSIONS_ament_package $ PARENT_SCOPE)Īlternatively, when a CMake project uses add_subdirectory() it might be a sign that it has gotten too big and should be split into smaller projects.First add the directory to be included: target_include_directories(test PRIVATE $) You might be able to work around this setting that variable in the PARENT_SCOPE at the very end of the /CMakeLists.txt, though, it's possible other variables used by rclcpp_components_register_nodes() will need to be set in the parent scope too. Since this is a subdirectory, the call to ament_package() in the parent directory doesn't see the changed value. This appends to the CMake variable AMENT_EXTENSIONS_ament_package, presumably to register something to be called when ament_package() is called. It looks like rclcpp_components_register_nodes()calls _rclcpp_components_register_package_hook This is a macro that calls ament_register_extension(). This is probably because in CMake each call to add_subdirectory() creates a new scope, meaning CMake variables set in the subdirectory are not visible to the parent directory. If I take the contents of the subdirectories' CMakeLists.txt file to the main CMakeLists.txt and remove the call to add_subdirectory, everything works fine.
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