build and install annotation files

[madroach]

Hi,
it would be nice if oasis was able to build and install annotation files.
Is this sensible default behaviour? Do we need a knob to turn it off?

[kit-ty-kate]

Maybe you can put it in an AlphaFeature but I think it good like that. This PR is really nice ! I'm all for it.

[avsm]

+1 for cmt/cmti files -- there should be no real downside except for this not being available on earlier OCaml revisions (3.12.1).

[gildor478]

.cmti ?

[madroach]

ocamlc -bin-annot -c intf.mli will produce intf.cmi and intf.cmti

[avsm]

There's a dot missing in the "cmti" string above

[gildor478]

The .annot is only available since 3.11.0, but I suppose this is totally fine and OASIS needs > 3.11 anyway.

Also, I would like to have at least one test for this PR!

[madroach]

I don't know how the tests work.
Could you provide a simple test case with two modules A and B which are linked with Pack: true into a library C. this should then produce {a,b,c}.cmt.
I implemented and tested against 24 janestreet libraries: core, async, ...
at least core is packing its submodules into a core.cmo before building the library core.cma.

[gildor478]

You can create a _oasis + required files in test/data/TestOCamlbuild/annot (several directories already exist) and then create a test to check your expectation in test/TestOCamlbuild.ml.

For example, you can look at:
https://github.com/ocaml/oasis/blob/master/test/TestOCamlbuild.ml#L175

Thanks

[madroach]

Turns out the existing tests already cover the cases I planned to test. So I ended up just adding the annotation files to files expected to be installed by the current tests. On OpenBSD I now get the following test results:

Ran: 231 tests in: 179.82 seconds.
FAILED: Cases: 231 Tried: 231 Errors: 0 Failures: 22 Skip:  6 Todo: 0 Timeouts: 0.
..
Ran: 2 tests in: 0.17 seconds.
OK

The test logs are here: ftp://gmerlin.de/pub/oasis/

Also I found the builtin bin_annot and annot tags in ocamlbuild and enabled them instead of adding custom -annot and -bin-annot flags. Problem is that ocamlbuild is not yet using -bin-annot when packing (http://caml.inria.fr/mantis/view.php?id=6599).
Oasis seems to be fault tolerant enough. Running the tests with an unpatched ocamlbuild will just tell me differences: -lib/ocaml/packedlib/packedlib.cmt. This means that oasis did successfully install all the rest and just skipped the missing packetlib.cmt, doesn't it?

[gildor478]

The test suite fails at the point of packedlib.cmt.

Not a big deal.

Can you just remove this specific files and add a comment so that I can re-add it with the right logic when ocamlbuild will be released with the patch ?