Re: [Caml-list] Interface(.mli) location

[Gabriel Scherer <gabriel.scherer@gmail.com>]

It is correct that ocamldep assumes that the .ml and .mli of a given
module are at the same place, but this is not the case for the rest of
the compilation chain, which is either concerned with single source
files (a .ml file or a .mli file) or with "compilation units" (a .cmo
and .cmi files passed together, independently of where their source
files were). In particular, all type-checking tools do look in -I
directories to find .cmi files for the dependencies of the module
being compiled (and at this stage they do not care for .mli files).

On Mon, Aug 8, 2016 at 6:09 PM,  <moosotc@gmail.com> wrote:
>
> It appears that .mli ought to always reside in the same directory
> corresponding .ml lives in. Here's a simple shell script to illustrate
> (probably a good idea to run inside freshly created temporary
> directory):
>
> #!/bin/sh
> set -x
> rm -fr a* d
>
> touch a.ml
> ocamldep a.ml
> ocamlc -c a.ml || echo no cookie 1
> ls
> rm -f a* *.cm*
>
> touch a.ml a.mli
> ocamldep a.ml
> ocamlc -c a.ml || echo no cookie 2 && ls
> ocamlc -c a.mli && ls
> ocamldep a.ml
> ocamlc -c a.ml || echo no cookie 3 && ls
> rm -f a*
>
> mkdir -p d
> touch a.ml d/a.mli
> ocamldep -I d a.ml
> ocamlc -I d -c a.ml
> ls
>
> Transcript:
> + rm -fr 'a*' d
> + touch a.ml
> + ocamldep a.ml
> a.cmo :
> a.cmx :
> + ocamlc -c a.ml
> + ls
> a.cmi
> a.cmo
> a.ml
> repro.sh
> + rm -f a.cmi a.cmo a.ml a.cmi a.cmo
> + touch a.ml a.mli
> + ocamldep a.ml
> a.cmo : a.cmi
> a.cmx : a.cmi
> + ocamlc -c a.ml
> File "a.ml", line 1:
> Error: Could not find the .cmi file for interface a.mli.
> + echo no cookie 2
> no cookie 2
> + ls
> a.ml
> a.mli
> repro.sh
> + ocamlc -c a.mli
> + ls
> a.cmi
> a.ml
> a.mli
> repro.sh
> + ocamldep a.ml
> a.cmo : a.cmi
> a.cmx : a.cmi
> + ocamlc -c a.ml
> + ls
> a.cmi
> a.cmo
> a.ml
> a.mli
> repro.sh
> + rm -f a.cmi a.cmo a.ml a.mli
> + mkdir -p d
> + touch a.ml d/a.mli
> + ocamldep -I d a.ml
> a.cmo :
> a.cmx :
> + ocamlc -I d -c a.ml
> + ls
> a.cmi
> a.cmo
> a.ml
> d
> repro.sh
>
> In essence: if one needs a variant build with some module providing the
> same interface but different implementations (in different directories)
> ocaml(c|opt|dep) will force this person to have the same (stable and
> unchanging) .mli in those implementation specific directories.
>
> Section 2.5 of the manual does not specify the relative file-system
> locations of interface/implementation files, but typing/typemod.ml, if I
> am reading it correctly, forces specific layout.
>
> So it would have been nice to either lift this restriction (i.e. have
> ocaml[c|opt|dep] look inside -I supplied directories or spell out the
> requirements in the documentation.
>
> --
> mailto:moosotc@gmail.com
>
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