Re: [Caml-list] Re: Conditional BuildDepends in OASIS

[Dario Teixeira <darioteixeira@yahoo.com>]

Hi,

> Having pgocaml.batteries and pgocaml.extlib is the best solution,

> depending on a flag is perfect. Congrat to have find it yourself ;-)
> (don't forget to CC me directly if you want a quicker response, I am a
> little bit overloaded and don't spend much time reading caml-list).
> 
> Concerning FindlibParent that complains about non-existing pgocaml, you
> should use FindlibContainers rather than FindlibParent.

Thank you Sylvain and Anil for your suggestions!

Using FindlibContainers does solve the virtual package problem, but
in the meantime I've run into a perplexing issue involving Camlp4.
Here's the relevant fragment from the _oasis file:

BuildTools:             ocamlbuild, camlp4o

Flag "batteries"
  Description: Use Batteries
  Default: true

Library "pgocaml_batteries"
  Build$:               flag(batteries)
  Install$:             flag(batteries)
  Path:                 src
  Modules:              PGOCaml
  BuildDepends:         calendar, csv, pcre, batteries, camlp4.macro
  FindlibContainers:    pgocaml
  Findlibname:          batteries
  ByteOpt+:             -ppopt -DUSE_BATTERIES
  NativeOpt+:           -ppopt -DUSE_BATTERIES

Library "pa_pgocaml_batteries"
  Build$:               flag(batteries)
  Install$:             flag(batteries)
  Path:                 src
  Modules:              Pa_pgsql
  BuildDepends:         pgocaml.batteries, camlp4.macro, camlp4.quotations.o, camlp4.extend
  FindlibContainers:    pgocaml.batteries
  FindlibName:          syntax
  ByteOpt+:             -ppopt -DUSE_BATTERIES
  NativeOpt+:           -ppopt -DUSE_BATTERIES

The problem occurs during the compilation of pa_pgocaml_batteries.
OCamlbuild issues the command below to determine dependencies,
which is manifestly wrong, since there is a "-syntax camlp4o" missing.

ocamlfind ocamldep -package pcre -package extlib -package csv -package camlp4.quotations.o -package camlp4.macro -package camlp4.extend -package calendar -package batteries -modules src/pa_pgsql.ml > src/pa_pgsql.ml.depends

What I find perplexing is that the compilation of pgocaml_batteries had succeeded,
so the required "-syntax camlp4o" must have had been given then, though at first
glance I can see no applicable difference in their declarations.

Any idea on what's going on?

Thanks again for your time!
Cheers,
Dario