List header files as target dependencies

[schuhschuh]

While header files are not required to be in the list of source files of a library or executable target because these are no actual compilation units, CMake IDE generators will not link them in the project files such as Xcode or Visual Studio. Weakly related issue: #4.

[ghisvail]

Should be solved with appropriate usage of source_group.

[ghisvail]

And an example of how it is used: https://github.com/arrayfire/arrayfire/blob/devel/src/backend/opencl/CMakeLists.txt

[schuhschuh]

That's another thing. Yes, it's nice to define source groups, but adding a file to a source group does not add it automatically also to the list of files of a build target. You still have to add the header files to the list of source files that a target depends on. Another reason for doing this is that the target otherwise will not be rebuild when the header file is modified.

When you look at the example you posted, you will see that they pass both lists of header files and source files to the add_library command.

[schuhschuh]

BTW I am not sure how valuable source groups are actually in this scenario because source files are already grouped by modules (i.e., separate libraries). Visual Studio, for example, will then have a list of Common module source files in "includes" and "sources" (or so) folders of the Common library target. The same for other modules. Not sure how it is for Xcode or whether source_groups are even used by the respective generator. The command was mainly introduced for Visual Studio as the documentation also states. Source groups would make a lot more sense when source files of all modules would be linked into a single library target.