[CMake] emulating `make check' behaviour

[Scott Amort]

Hello,

I am attempting to emulate the autotools `make check' behaviour in my
CMake project.  I currently have a testing framework setup and working
using ENABLE_TESTING() and CTest, however, it has two drawbacks (from my
perspective, anyways ;-) ).

1) Testing executables are compiled at the same time as the project
(i.e. when `make' is executed).  I would prefer these to only compile
when explicitly requested with `make test'.

2) `make test' only executes ctest with no dependencies on the testing
executables (i.e. if I make a change to the testing code, I need to
rerun `make' and then `make test').

I enquired about this a little while back, and it was suggested to use
ctest with --build-and-test, however, I can't seem to find any
documentation on what this actually does.  It appears to be independent
of the CMake build process, however, so it is likely not the solution I
am after.

Does anyone have any suggestions on how to proceed?  My current idea is
to create an optional subproject that is the testing executable(s) and
link that to an ADD_CUSTOM_TARGET, however, I don't think it is possible
to selectively compile projects with this command.  If anyone could
offer some assistance, it would be greatly appreciated.

Best,
Scott