[cmake-developers] CMP0022 documentation is outdated

[Alan W. Irwin]

I have a software project with a dated CMake-based build system that
specifically set CMP0022 to OLD.  So while updating that build system
I naturally consulted the latest CMP0022 documentation, e.g.,
<https://cmake.org/cmake/help/git-stage/policy/CMP0022.html>, and
discovered that documentation was outdated, e.g.,
lots of historical references to CMake-2.8 which are likely no
longer needed, and the following recommendation

Warning-free future-compatible code which works with CMake 2.8.7
onwards can be written by using the LINK_PRIVATE and LINK_PUBLIC
keywords of target_link_libraries().

(The obvious problem with that advice is that LINK_PRIVATE and
LINK_PUBLIC are now deprecated themselves!)

IF cmake-4 is coming soon and presuming that CMP0022 OLD behaviour
will no longer be supported by that version of cmake, then you may not
want to do anything about this outdated documentation since it will
be removed with cmake-4.

But otherwise for current needs like mine (updating an old build system
that specifically set CMP0022 to OLD) a complete rewrite would
be a good idea with the emphasis on simplifying down to one
or two sentences such as

Support for CMP0022 OLD behaviour is scheduled for removal with
cmake-4 [if that decision has indeed already been made] so do not set
this policy to OLD for new build systems.  But if you need to know
details about CMP0022 OLD behaviour in order to upgrade an old build
system that currently requires the OLD version of this policy, see the
target_link_libraries() documentation.

Alan
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Alan W. Irwin

Astronomical research affiliation with Department of Physics and Astronomy,
University of Victoria (astrowww.phys.uvic.ca).

Programming affiliations with the FreeEOS equation-of-state
implementation for stellar interiors (freeeos.sf.net); the Time
Ephemerides project (timeephem.sf.net); PLplot scientific plotting
software package (plplot.sf.net); the libLASi project
(unifont.org/lasi); the Loads of Linux Links project (loll.sf.net);
and the Linux Brochure Project (lbproject.sf.net).
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Linux-powered Science
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