Command producing several targets at once

[Sébastien Hinderer]

Dear all,

OCaml's parser generator, ocamlyacc, produces two files simultaneously.
For example, the command

ocamlyacc parsermly

will produce both parser.ml (the code of the parser) and parser.mli (the
interface of the parsing module, descrbing which symbols it exports).

I am wondering what's the best way to let make know about this.

>From what I understand, a rule like

parser.mli parser.ml: parser.mly
           ocaplyacc $<

does nos say exactly this but is rather an abbreviation for

parser.mli: parser.mly
            ocamlyacc $<

parser.ml: parser.mly
            ocamlyacc $<

which is not what I'd like to express

I have been told that one way to make things work could be the two
following rules:

parser.mli parser.ml: parser.mly
           ocamlyacc $<

parser.mli: parser.ml

Is this the commonly used way to achieve the expected result?

I find it a bit tricky because "parser.mli: parser.ml" looks like a hack
to me, there is no real dependency.

Even if that is what is commonly used, I am wondering how this would
generalize to a command that would produce n files where n>2.

Many thanks for any comment,

Sébastien.