Re: [AD] make cmake guess the CMAKE_INSTALL_PREFIX

[Peter Wang <novalazy@xxxxxxxxxx>]

On 2008-09-23, Thomas Fjellstrom <tfjellstrom@xxxxxxxxxx> wrote:
> On Tuesday 23 September 2008, Peter Wang wrote:
> > On 2008-09-23, Thomas Fjellstrom <tfjellstrom@xxxxxxxxxx> wrote:
> > > Should we make cmake guess the CMAKE_INSTALL_PREFIX to go along with
> > > guessing MINGDIR? I think it'd be really handy to set
> > > CMAKE_INSTALL_PREFIX to MINGDIR instead of letting cmake pick something
> > > like "C:\Program Files\ALLEGRO".
> >
> > It should be doing that already.
> >
> >     # ... detect MINGDIR here
> >
> >     # Install to MINGDIR
> >     if(INSTALL_PREFIX STREQUAL "")
> >         set(CMAKE_INSTALL_PREFIX ${MINGDIR})
> >     else(INSTALL_PREFIX STREQUAL "")
> >         set(CMAKE_INSTALL_PREFIX ${INSTALL_PREFIX})
> >     endif(INSTALL_PREFIX STREQUAL "")
> >
> > Peter
> >
> 
> Yeah, saw that, but for some reason it doesn't seem to be working. Which is 
> odd since it sets INSTALL_PREFIX to "" closer to the top of the file. maybe 
> cmake-gui sets some things it shouldn't?

Tip for debugging: cut out the relevant sections of code into a test
file, then run cmake -P testfile.  Use MESSAGE("${VAR}") to print.

> And I think we should be setting a bunch of the non windows WANT_ options to 
> "off" or "no" or whatever if its building on win32.

Ideally, I'd like us to move away from assuming that some libraries are
only available on certain platforms.  There's no particular reason you
shouldn't be able to build the X11 port on Windows (more likely, OS X),
and the Direct3D driver on Unix (with Wine).  Of course, it would be a
lot of work and we'll probably never get there.

Configuration is much slower on Windows than on Linux so avoiding
unnecessary checks could be worthwhile.  But WANT_X11, WANT_ALSA and
WANT_OSS are the only options that I see that don't apply to Windows.
We *could* avoid a few of the check_include_files, check_function_exists
calls, but that seems to go against the whole point of checking for
things at configuration time.

Peter