[Caml-list] OASIS and -no-alias-deps: the non-evil approach

[Caml-list] OASIS and -no-alias-deps: the non-evil approach

[Dario Teixeira]

Hi,

I still haven't given up on using -no-alias-deps with a OASIS/OCamlbuild build
system, despite a critical component -- OCamldep -- seemingly not supporting
-no-alias-deps in 4.02 [1].  I've made a small experiment which suggests it
should be possible anyway, but I'll need a bit of help from someone who's
more familiar with OASIS and OCamlbuild.

I'm using the same dummy library I've described before [2].  Basically, I 
have three actual code files (foo_a.ml, foo_b.ml, foo_c.ml), plus a foo.ml
which only declares module aliases.  Due to ocamldep's obliviousness to
-no-alias-deps, it infers that foo.ml depends on the 3 other modules, 
whereas each in turn also depends on foo.ml, resulting in a circular build.

The small experiment I made was to rename ocamldep and to replace it with
a small frontend that detects whether it's being called on foo.ml, in which
case it declares no dependencies.  Something like this:

let () = match Sys.argv with
  | [| "ocamldep.opt";  "-modules";  "src/foo.ml" |] ->
    print_endline "src/foo.ml:"
  | x ->
    Unix.execv "/home/dario/.opam/4.02.1/bin/ocamldep.opt.orig" x


Pure evil, but it works.  Now, my question is: would it be possible to achieve
the same result in plain OASIS/OCamlbuild, ie, without the evil?  I reckon
one would need to tag a certain file in such a way that any invocation of
ocamldep for that file should be replaced with a string.  Your thoughts?

Thanks in advance for your time + best regards,
Dario Teixeira

[1] https://sympa.inria.fr/sympa/arc/caml-list/2014-09/msg00078.html
[2] https://sympa.inria.fr/sympa/arc/caml-list/2014-12/msg00097.html