RFC: Add CMAKE_ON and CMAKE_OFF to cmake.mk

[tcberner]

Summary

Lot's of ports pass a list of -DFOO:BOOL=OFF -DBAR:BOOL=ON to CMAKE_ARGS, which is both tedious to write and read.

The options framework provides a nicer interface <opt>_CMAKE_ON and <opt>_CMAKE_OFF where on can just pass FOO and BAR -- making it shorter and more readable.

So

CMAKE_ARGS=	-DFOO:BOOL=TRUE \
		-DBAR:BOOL=FALSE \
		[other args]

could now be written as

CMAKE_ON=	FOO
CMAKE_OFF=	BAR
CMAKE_ARGS=	[other args]

The attached diff extends cmake.mk with this behaviour.

• As an example the ports devel/cmake-gui and devel/cmake-doc are included too.

[antoine]

There are already _CMAKE_BOOL and _CMAKE_BOOL_OFF helpers doing this.

[tcberner]

In D13636#285045, @antoine wrote:

There are already _CMAKE_BOOL and _CMAKE_BOOL_OFF helpers doing this.

Hm, really?

[antoine]

https://www.freebsd.org/doc/en_US.ISO8859-1/books/porters-handbook/makefile-options.html#options-cmake_bool

[tcberner]

In D13636#285048, @antoine wrote:

https://www.freebsd.org/doc/en_US.ISO8859-1/books/porters-handbook/makefile-options.html#options-cmake_bool

Yes, that I know off :) -- but this here is for use outside of options -- maybe, I was describing it poorly, sorry.

[rakuco]

Personally I don't see a huge improvement here, nor do I see why boolean CMake variables should be treated differently from the rest, but no objections if you feel like adding this.

Mk/Uses/cmake.mk

28

-D<var>:BOOL=TRUE.

29

And likewise here.

devel/cmake-gui/Makefile

28–29

Probably a good time to sort this list too.

[tcberner]

They could be treated differently to reduce unnecessary typing -- but I see what you mean.

[mat]

Mk/Uses/cmake.mk

95–97

For new code, we try to prefix local variables with an _, so _bool_kind would be nice here.

devel/cmake-doc/Makefile

25

What about a:

CMAKE_STR=   CMAKE_DOC_DIR="${DOCSDIR_REL}"

[adridg]

I like it, since it pulls all of the boolean handling into something that looks consistent in the Makefile. It will need some PHB work, later, to give it some nice docs.

Mk/Uses/cmake.mk

29

Actually -D<var>:BOOL=OFF , or =ON

devel/cmake-doc/Makefile

25

Not sure if facetious .. there's no other support already for string options, string options themselves are fairly uncommon, the amount of typing saved is lower .. and there's less consistency to be gained here. IOW, I think this is pushing things too far.

[tcberner]

• Rename internal variable to _bool_kind
• Fix comment
• Order variables in cmake-gui

[rakuco]

no objections

[tcberner]

Added entry to CHANGES.