[CMake] Upper or lower case for package variables in FindXXX.cmake files?

[Alexander Neundorf]

On Friday 27 February 2009, Philip Lowman wrote:
> On Fri, Feb 27, 2009 at 1:13 PM, Matt Williams <lists at milliams.com> wrote:
...
> > There is no indication in the readme.txt which is preferred though I have
> > been
> > assuming the mixed case version. Based on bits and pieces I guess I am
> > right
> > (for example,the "DOXYGEN_FIND_QUIETLY, but it should have been
> > Doxygen_FIND_QUIETLY" comment in FindDoxygen.cmake).
>
> I have wondered the same thing for many a moon.
>
> The arguments to find_package, i.e. EXACT, QUIET, COMPONENTS, version
> number, etc. cause variables such as Doxygen_FIND_QUIETLY,
> Boost_COMPONENTS, and OpenSceneGraph_FIND_VERSION to be generated by CMake.
>  These are based directly off of the name of the find module filename so
> they will generally appear to be mixed case if that is the name of the
> module.
>
> Macros like FindPackageHandleStandardArgs seem to make everything upper
> case (i.e DOXYGEN_FOUND, OPENSCENEGRAPH_FOUND, etc.).
>
> Not sure what the answer is.  It's almost as if input variables are
> encouraged to be the case of the module and output variables are encouraged
> to be uppercase always.

Currently it is like this:
the variables which are set in a module, are all-upper case. The variables 
provided by cmake to the module, are exact-case.
The issue with changing the recommendation to use exact-case for everything is 
that most early cmake modules used all-upper-case, and so to stay consistent 
we should keep it like this for variables defined by modules.

Alex