[vtkusers] build with all modules except XYZ

[Ben Boeckel]

On Mon, Nov 16, 2015 at 09:19:05 +0000, Nico Schlömer wrote:
> I'd like to build VTK with all modules except a specific one. What's the
> CMake configuration for this? I've tried
> ```
> -DVTK_BUILD_ALL_MODULES=ON \
> -DModule_vtkIOXdmf3=OFF \
> ```
> to no avail:
> ```
> 
> --  * vtkIOXdmf3, requested by VTK_BUILD_ALL_MODULES.
> 
> ```

There's no shorthand for this. You'll have to get the list of modules
from CMake (or scraping module.cmake files, or using find/replace on the
CMakeCache.txt) and turn all but that one. Lots belong to groups, so
turning on the groups should reduce the number of explicit module flags
you'll need to give.

It'd be nice if the module flags were tristate:

  - ON: build the module
  - OFF: don't build the module
  - DEFAULT: build if required by another module

and then error if an ON module requires an OFF module (and if testing is
enabled, possibly turning of the test modules that require it if that's
all there is). But that's not the way it currently is implemented :( .

--Ben