cmake: Move runtime output artifacts to ${PROJECT_BINARY_DIR}

[hebasto]

From IRC:

12:32 < sipa> With cmake, the build artefacts seem to end up in build/src/, while I'd expect them in build/.

Implemented in this PR.

On Windows, this also simplifies running examples, because the DLL must resides either in the same folder where the executable is or somewhere in PATH.

[real-or-random]

Hm, I don't know. This seems a bit arbitrary.

If we now deviate from putting the artifacts in their respective source directory anyway, and setting the artifact path is just setting a variable, would it make sense to also just put anything in ${PROJECT_BINARY_DIR} (or in a dedicated subdir of that)?

[hebasto]

Hm, I don't know. This seems a bit arbitrary.

Agree. But adding each path for every configuration to PATH, which is the case for multi-config, is really annoying.

If we now deviate from putting the artifacts in their respective source directory anyway, and setting the artifact path is just setting a variable, would it make sense to also just put anything in ${PROJECT_BINARY_DIR} (or in a dedicated subdir of that)?

Like ${PROJECT_BINARY_DIR}/out? Or ${PROJECT_BINARY_DIR}/bin?

[real-or-random]

Agree. But adding each path for every configuration to PATH, which is the case for multi-config, is really annoying.

Indeed. It's also annoying for devs on Windows (though noone uses Windows right now...)

Like ${PROJECT_BINARY_DIR}/out? Or ${PROJECT_BINARY_DIR}/bin?

Yeah, I had something like this in mind. out is probably a bit nicer because bin looks wrong for .so etc. Just not convinced it's worth it. Having a subdir is a cheap and feels tiny bit cleaner because it avoids name collisions with existing files (e.g., what if we have a binary examples). Though in that case, autotools would break anyway... I guess there's no clear right or wrong here, but if we want to move all artifacts to a single location, then ${PROJECT_BINARY_DIR} is probably good enough, and then it matches the autotools behavior at least. As discussed in IRC, we don't care much and should do whatever makes things easier.

[hebasto]

... if we want to move all artifacts to a single location, then ${PROJECT_BINARY_DIR} is probably good enough, and then it matches the autotools behavior at least.

Done.

The PR description has been updated (friendly ping @sipa :D ).

[hebasto]

Converted to draft for now.

[theuni]

Rather than setting the PATH in CI, can we set it in CMake for make check?

[real-or-random]

Rather than setting the PATH in CI, can we set it in CMake for make check?

I think this makes sense, and then Concept NACK on moving the binaries

[hebasto]

@theuni @real-or-random

Rather than setting the PATH in CI, can we set it in CMake for make check?

Implemented in #1290.

Closing in favour of #1290.