[CMake] --enable-* with cmake

[Brandon Van Every]

On 8/8/07, Philip Lowman <philip at yhbt.com> wrote:
>
> In defense of the original post,
>
> --enable-foo is much more readable than -DENABLE_FOO or -DUSE_FOO.

No it isn't, and it's not much of a defense.  "Slightly more readable"
I'd accept.  Let's refrain from religious hyperbole when contemplating
feature requests.  The reality is any time you learn a new tool, you
have to do things a new way.

> I love CMake, but there have been times when I wished that
>
> --enable-foo would simply be a shortcut to set a boolean variable
> ENABLE_FOO to true.

Some would say that's not nice because you don't get exactly what's on
the command line.    By the logic of exactitude, --enable-foo should
define enable-foo to true.  And if I wanted ENABLE_FOO, then I'd put
--ENABLE_FOO on the command line.  Or I could put -DENABLE_FOO,
couldn't I?  ;p  My point is that --enable-foo is an Autoconf
convention, nothing more.  It's mainly about making an Autoconf
migration crowd happy.

Should we make 'em happy?  I don't know.  On the one hand, the
Autoconf crowd routinely complains about command line features.  CMake
isn't as oriented to the command line, maybe it could use work there.
On the other hand, I believe that people who actually have to get
projects done, learn what they need to learn and get on with it.  It's
one thing to play with a new tool and make complaints about it.  It's
another to know for fact that you have to port your build to several
platforms including MSVC, and know that CMake is a far better tool for
the job.  My point is, we don't need to convert people who already
know for fact that they need CMake's capabilities.

Maybe there's a 3rd class of users I haven't considered.  People who
have been handed the job of doing a CMake build, but who didn't
originally make the decision, and who don't spend their time on more
than one platform.  So they see CMake through "Linux only" eyes for
instance, because that's the part of the build they're personally
responsible for.  There's also a "Windows only" crowd who sees CMake
primarily in terms of how MSVC support could be improved.

So maybe it's worth keeping these kinds of people happy, even though
they raise what I personally would call "superficial objections."  If
their requests aren't a lot of work and don't do any harm.  It would
increase the body count of people who speak positively of CMake.


Cheers,
Brandon Van Every