CMake examples targets

[bendudson]

If BOUT_BUILD_EXAMPLES is Off, add the examples subdirectory but with the EXCLUDE_FROM_ALL option. That enables examples to be built after the library is built, and specific examples can be built by using the --target argument to cmake.

[ZedThree]

Ah sorry, I think my earlier comment was misleading -- you can build individual examples with --target but you would still need to configure with BOUT_BUILD_EXAMPLES=on.

[dschwoerer]

LGTM 👍

[bendudson]

I think this may be a little more complicated than I initially thought. There are I think three scenarios to cover:

1. BOUT-dev is being included as a sub-module of a model, so we just want the library and are not interested in examples
2. We are first compiling the library, then later may want to compile one or more examples (I think this should be the default)
3. We want to build executables for all examples. I don't think this will happen often, but should be an option at least for testing if all examples can build

Previously the BOUT_BUILD_EXAMPLES switch chose between (1) and (3); this PR changes it to choosing between (2) and (3).

What about:
BOUT_CONFIGURE_EXAMPLES is On by default, and adds the examples to the cmake build. Turning it Off also turns BOUT_BUILD_EXAMPLES to Off. This switches between (1) and (2 or 3)
BOUT_BUILD_EXAMPLES is Off by default. It controls whether EXCLUDE_FROM_ALL is used when adding the examples. It switches between (2) and (3)
?

[ZedThree]

An alternative: `BOUT_BUILD_EXAMPLES` configures them with `EXCLUDE_FROM_ALL`, and we add a target `build-all-examples`? We do a similar thing with the tests, and this feels like perhaps the easiest thing to do from the user point of view.

…

On Sat, 2 Oct 2021, 01:22 Ben Dudson, ***@***.***> wrote: I think this may be a little more complicated than I initially thought. There are I think three scenarios to cover: 1. BOUT-dev is being included as a sub-module of a model, so we just want the library and are not interested in examples 2. We are first compiling the library, then later may want to compile one or more examples (I think this should be the default) 3. We want to build executables for all examples. I don't think this will happen often, but should be an option at least for testing if all examples can build Previously the BOUT_BUILD_EXAMPLES switch chose between (1) and (3); this PR changes it to choosing between (2) and (3). What about: BOUT_CONFIGURE_EXAMPLES is On by default, and adds the examples to the cmake build. Turning it Off also turns BOUT_BUILD_EXAMPLES to Off. This switches between (1) and (2 or 3) BOUT_BUILD_EXAMPLES is Off by default. It controls whether EXCLUDE_FROM_ALL is used when adding the examples. It switches between (2) and (3) ? — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#2429 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AALLAXT2NLMIYI36WYA7SB3UEZGEZANCNFSM5EFSJ6XQ> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>.