Re: [Caml-list] building and using a library in a subdirectory

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

> I don't (yet) need dynamic linking; my current main aim with the .mllib setup is to specify the package dependencies for each plugin in its > own section of the _tags file, and not have a long list of every plugin's dependencies in the main module.

Well, that doesn't quite work: you need to have the ocamlfind packages
passed to the command linking the final executable.

I suppose changing
  <**/puz.*>: ...
to
  <**/puz.*> or <file.*>: ...
could work, as this line seems to pass all the libraries flags.


On Tue, Sep 22, 2015 at 8:52 AM, Martin DeMello <martindemello@gmail.com> wrote:
> Thanks, I didn't realise that. Replacing Puz_plugin.read with Puz.read
> compiled, but didn't link:
>
> + ocamlfind ocamlopt -linkpkg -g -thread -package core_kernel
> plugins/puz/puz_types.cmx plugins/puz/puz_utils.cmx plugins/puz/puz_bin.cmx
> plugins/puz/puz_match.cmx types.cmx xword.cmx plugins/puz/puz.cmx file.cmx
> -o file.native
> File "_none_", line 1:
> Error: No implementations provided for the following modules:
>          Bitstring referenced from plugins/puz/puz_bin.cmx
>          Run_mikmatch_pcre referenced from plugins/puz/puz_match.cmx
>          Str referenced from plugins/puz/puz.cmx
>          Pcre referenced from plugins/puz/puz_match.cmx
> Command exited with code 2.
>
> I don't (yet) need dynamic linking; my current main aim with the .mllib
> setup is to specify the package dependencies for each plugin in its own
> section of the _tags file, and not have a long list of every plugin's
> dependencies in the main module.
>
> martin
>
> On Mon, Sep 21, 2015 at 11:45 PM, Gabriel Scherer
> <gabriel.scherer@gmail.com> wrote:
>>
>> A .cma or .cmxa archive does not pack its sub-modules under a common
>> module name: the module name Puz_plugin that you use does not refer to
>> anything. Accessing any of the constituent modules directly (eg.
>> Puz_match.foo) should work -- although it may not go through the .cmxa
>> but directly refer to the compilation unit.
>>
>> Note that if "_plugin" is intended to refer to dynamic linking, you
>> may want to use a .mldylib file instead of .mllib, to be used to
>> generate a .cmxs file: .cmxa is not suitable for dynamic linking
>> (while, at the bytecode level, .cma work for both static and dynamic
>> linking).
>>
>> On Tue, Sep 22, 2015 at 8:23 AM, Martin DeMello <martindemello@gmail.com>
>> wrote:
>> > If I have my project set up like this:
>> >
>> > .
>> > ├── file.ml
>> > ├── plugins
>> > │   └── puz
>> > │       ├── puz_bin.ml
>> > │       ├── puz_match.ml
>> > │       ├── puz.ml
>> > │       ├── puz_plugin.mllib
>> > │       ├── puz_types.ml
>> > │       └── puz_utils.ml
>> > └── _tags
>> >
>> > $ cat plugins/puz/puz_plugin.mllib
>> > Puz Puz_bin Puz_match
>> >
>> > This works:
>> >
>> > $ ocamlbuild -use-ocamlfind plugins/puz/puz_plugin.cmxa
>> > Finished, 22 targets (3 cached) in 00:00:03.
>> >
>> > My _tags file:
>> > ------------------------------------------------
>> > $ cat _tags
>> > true: thread,debug
>> > true: package(core_kernel)
>> >
>> > "plugins/puz": include
>> >
>> > <gui.*>: package(labltk)
>> > <**/puz.*>: package(unix), package(str), package(core_kernel),
>> > package(bitstring), package(mikmatch_pcre)
>> > <**/*_bin.*>: package(bitstring.syntax), syntax(bitstring)
>> > <**/*_match.*>: package(mikmatch_pcre), syntax(camlp4o)
>> > ------------------------------------------------
>> >
>> > But I can't figure out how to use this library in my main program. This
>> > is a
>> > minimal example of what I'm trying to do, not working of course:
>> >
>> > $ cat file.ml
>> > open Core_kernel.Std
>> >
>> > let read fname =
>> >   let data = In_channel.read_all fname in
>> >   Puz_plugin.read data
>> >
>> > $ ocamlbuild -use-ocamlfind file.native
>> > + ocamlfind ocamlc -c -g -thread -package core_kernel -I plugins/puz -o
>> > file.cmo file.ml
>> > File "file.ml", line 5, characters 2-17:
>> > Error: Unbound module Puz_plugin
>> >
>> > martin
>
>