[cmake-developers] Creating cdash subprojects: create_cdash_subprojects()

[Alexander Neundorf]

Hi,

I'd like to set up subprojects for KDE, but I think this is right now not 
feasible because it needs too much manual work:

when setting up subprojects for cdash, somebody has to write a Project.xml:
<Project name=”Tutorial”>
 <SubProject name=”Libs”>
 </SubProject>
 <SubProject name=”Exes”>
  <Dependency name=”Libs”/>
 </SubProject>
</Project>

This is too much manual work to be usable in KDE. Somebody (me initially) 
would have to go through each KDE module, figure out what subprojects there 
should be, how they depend on each other, and write that file. If something 
changes in the project, it has to be updated manually.
I don't feel like trying to do that.


Additionally , the following CMakelists.txt are required:
• Name targets same as subprojects, base target names on
  subproject names, or provide a look up mechanism to map
  from subproject name to target name
• Possibly add custom targets to aggregate existing targets
  into subprojects, using add_dependencies to say which
  existing targets the custom target depends on

This is IMO basically impossible for KDE to implement and keep current.


• Add LABELS target property to targets with a value of
  subproject name
• Add LABELS test property to tests with a value of
  subproject name

The items above should be really easy to do from within cmake.

To make all that much easier, I propose to add a new command to cmake, which 
will do more or less all that:

create_cdash_subprojects(PROJECTS p1 p2...)

This command will 
* generate a Project.xml with one cdash subproject for each listed project (as 
in defined with the project() command)
* Add a custom target for each of the listed projects, which depends on all 
the contained targets
* Set the LABELS property automatically on all targets and tests


How it should work:

The command takes the listed projects and search them in the cmMakefiles.
If it detects that one listed project is contained in another one which is 
also listed it reports an error.
Otherwise, it collects all the targets contained in the project.

After having done that, it knows which targets belong to which project, and it 
also knows which targets where not in any of the listed projects. These will 
be put into a separate cdash subprojects.

Now that it has all the targets, it needs to figure out the dependencies 
between the targets/projects. I think this is the most complicated step. With 
this information, it can then write a Projects.xml.

The next step is to add custom targets for each of the projects and let them 
depend on all contained targets. There shouldn't be major issues here ?

Finally, it will iterate over all targets and tests and assign the respective 
LABELS properties. Here I also wouldn't expect trouble.

With all that done, I think it should require more or less only one such 
create_cdash_subprojects() call per "parent project" (e.g. Paraview, or 
kdelibs, ...) and it should just work.

What's left to do is to adapt the ctest script accordingly, but this doesn't 
seem to be too much work.

Comments ?

Alex
Project.xml: