[CMake] BOOL type

[Miguel A. Figueroa-Villanueva]

On Dec 18, 2007 11:14 AM, Mike Jackson wrote:
> On Dec 18, 2007, at 10:07 AM, James Bigler wrote:
> > On Dec 18, 2007, at 7:48 AM, Bill Hoffman wrote:
> >> James Bigler wrote:
> >>
> >>> I also agree that trying to maintain backwards compatibility to
> >>> the detriment of the future can become a hinderance.  I just had
> >>> a collegue who was extreemly frustrated for several hours with
> >>> why his build didn't work, only to discover that he should have
> >>> been using ADD_SUBDIRECTORIES instead of SUBDIRS.  There was no
> >>> warning from CMake stating that he shouldn't be using it (I would
> >>> argue that CMake should warn about the use of SUBDIRS).
> >> That would be lots of warnings!  SUBDIRS was the only way to do
> >> things for a long time.  CMake itself still uses them so it can be
> >> bootstrapped with older versions of CMake.  SUBDIRS still works,
> >> it just works different.  The behavior of both are documented.
> >
> > "The ADD_SUBDIRECTORY command should be used instead of SUBDIRS
> > although SUBDIRS will still work."
> >
> > There isn't a mention in the docs that SUBDIRS behaves differently
> > to ADD_SUBDIRECTORIES in the man page, just that it should work.
> >
> > Part of the problem with my collegue is that he was copying code
> > from another part of the build system.  He was new to cmake and
> > hadn't read the whole man page.  He just assumed the one way he
> > found to traverse subdirectories was the one to use.  It's really
> > confusing to have two ways to do basically the same thing with only
> > subtle differences.
> >
> > I guess my argument is that changing syntax shouldn't be shied away
> > from, but it would be nice to have a way to flush out old code.
>
>
> Would it be possible to emit a warning when commands like subdirs are
> used? The warning is built into cmake and emits every time cmake is
> run? This would help motivate people to move to the newer commands?
>
> I know this has ramifications that I am not thinking of..

Bill basically answered this... It's too many warnings! So, how about
only reporting the warning on the first time it encounters the
deprecated command? Or having a CMAKE_SUPPRESS_DEPRECATION_COMMENTS
(or something variable) and make sure that in the message there is a
note. The message would be something like the following. Ideally it
would be an automatically generated message to avoid duplicity in the
help strings.

-----------
WARNING: SUBDIRS is a deprecated command! Use the add_subdirectory()
command instead.

For more information use: cmake --help-command ADD_SUBDIRECTORIES or
whatever else you feel like...

If you would like to supress these deprecation warnings, put:
SET(CMAKE_SUPPRESS_DEPRECATION_COMMENTS TRUE) on your root
CMakeLists.txt file.
-----------

Just my two cents.
--Miguel