C++ Header Files and Dependency Management in CMake

Code
1

When creating targets in CMake using the add_executable or add_library commands, do I need to explicitly specify header files in order to create the dependency tree for automatic build triggering, or does CMake handle this automatically?

For example, consider the following CMake configuration:

cmake_minimum_required(VERSION 3.10)
project(ExampleProject)

add_executable(ExampleApp main.cpp utils.cpp)
# Should I list the headers here too?
# target_sources(ExampleApp PRIVATE main.cpp utils.cpp utils.h)

In this example, main.cpp includes utils.h. If I modify utils.h, will CMake automatically detect this change and trigger a rebuild of ExampleApp, or do I need to specify utils.h in the add_executable command or another command to ensure the dependency is tracked?

2

CMake manage automatically such dependencies. Moreover, for the most common compilers, CMake relies on the compiler itself to discover these dependencies.

3

Yeah, I see that gnu compilers support dependency discovery (-MD ) whereas with Fortran CMake does the scanning of dependencies. So the header files are completely ignored? or are they useful for IDEs?

4

Header files, as specified as part of add_library() or add_executable() commands, are not compilable files so are ignored for the compilation step but, as you suggest, will be shown in the IDEs.