[Caml-list] 4.04 linker woes

[Caml-list] 4.04 linker woes

[Christoph Höger]

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Dear all,

today I attempted to migrate my stack towards 4.04.0 - unfortunately
ppx_monadic is not yet available for that language version. I attempted
to build it myself, but to no avail:

Error: Required module `Compplugin' is unavailable

This error is newly introduced into 4.04.0 (and does not exist in the
HEAD version). Compplugin should be provided by compilerlibs.common, so
I assume I need to fix the build system somehow.

Does anyone have any idea how to fix this?

regards,

Christoph
-- 
Christoph Höger

Technische Universität Berlin
Fakultät IV - Elektrotechnik und Informatik
Übersetzerbau und Programmiersprachen

Sekr. TEL12-2, Ernst-Reuter-Platz 7, 10587 Berlin

Tel.: +49 (30) 314-24890
E-Mail: christoph.hoeger@tu-berlin.de


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Re: [Caml-list] 4.04 linker woes

[Gabriel Scherer]

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Compplugin is a module from the compiler distribution that indeed is new in
4.04.0. It is not included in ocamlcommon.cma. It is part of
ocamlbytecomp.cma, but not of ocamloptcomp.cma, and I believe that the
latter omission is a bug (as Optcompile depends on it), so maybe it should
really be in ocamlcommon.cma.

This looks like an upstream bug (in the OCaml distribution). Could you open
a Mantis issue?

As a workaround, you may be able to link to the compplugin module
separately, it is installed in the $(ocamlfind query compiler-libs)
directory.

On Mon, Nov 7, 2016 at 3:10 PM, Christoph Höger <
christoph.hoeger@tu-berlin.de> wrote:

> Dear all,
>
> today I attempted to migrate my stack towards 4.04.0 - unfortunately
> ppx_monadic is not yet available for that language version. I attempted
> to build it myself, but to no avail:
>
> Error: Required module `Compplugin' is unavailable
>
> This error is newly introduced into 4.04.0 (and does not exist in the
> HEAD version). Compplugin should be provided by compilerlibs.common, so
> I assume I need to fix the build system somehow.
>
> Does anyone have any idea how to fix this?
>
> regards,
>
> Christoph
> --
> Christoph Höger
>
> Technische Universität Berlin
> Fakultät IV - Elektrotechnik und Informatik
> Übersetzerbau und Programmiersprachen
>
> Sekr. TEL12-2, Ernst-Reuter-Platz 7, 10587 Berlin
>
> Tel.: +49 (30) 314-24890
> E-Mail: christoph.hoeger@tu-berlin.de
>
>

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Re: [Caml-list] 4.04 linker woes

[Christoph Höger]

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I am going to give the workaround a try tomorrow.

Regarding the bug, are you sure about that?
When I load the common libs in utop, the module is loaded.

utop # #require "compiler-libs.common";;
─( 21:39:56 )─< command 1
>────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────{
counter: 0 }─utop # #typeof "Compplugin";;
module Compplugin : sig val load : string -> unit end


So if the module is not part of the common library, how do I reproduce
the actual bug?

Am 07.11.2016 um 21:30 schrieb Gabriel Scherer:
> Compplugin is a module from the compiler distribution that indeed is new
> in 4.04.0. It is not included in ocamlcommon.cma. It is part of
> ocamlbytecomp.cma, but not of ocamloptcomp.cma, and I believe that the
> latter omission is a bug (as Optcompile depends on it), so maybe it
> should really be in ocamlcommon.cma.
> 
> This looks like an upstream bug (in the OCaml distribution). Could you
> open a Mantis issue?
> 
> As a workaround, you may be able to link to the compplugin module
> separately, it is installed in the $(ocamlfind query compiler-libs)
> directory.
> 
> On Mon, Nov 7, 2016 at 3:10 PM, Christoph Höger
> <christoph.hoeger@tu-berlin.de <mailto:christoph.hoeger@tu-berlin.de>>
> wrote:
> 
>     Dear all,
> 
>     today I attempted to migrate my stack towards 4.04.0 - unfortunately
>     ppx_monadic is not yet available for that language version. I attempted
>     to build it myself, but to no avail:
> 
>     Error: Required module `Compplugin' is unavailable
> 
>     This error is newly introduced into 4.04.0 (and does not exist in the
>     HEAD version). Compplugin should be provided by compilerlibs.common, so
>     I assume I need to fix the build system somehow.
> 
>     Does anyone have any idea how to fix this?
> 
>     regards,
> 
>     Christoph
>     --
>     Christoph Höger
> 
>     Technische Universität Berlin
>     Fakultät IV - Elektrotechnik und Informatik
>     Übersetzerbau und Programmiersprachen
> 
>     Sekr. TEL12-2, Ernst-Reuter-Platz 7, 10587 Berlin
> 
>     Tel.: +49 (30) 314-24890 <tel:%2B49%20%2830%29%20314-24890>
>     E-Mail: christoph.hoeger@tu-berlin.de
>     <mailto:christoph.hoeger@tu-berlin.de>
> 
> 


-- 
Christoph Höger

Technische Universität Berlin
Fakultät IV - Elektrotechnik und Informatik
Übersetzerbau und Programmiersprachen

Sekr. TEL12-2, Ernst-Reuter-Platz 7, 10587 Berlin

Tel.: +49 (30) 314-24890
E-Mail: christoph.hoeger@tu-berlin.de


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Re: [Caml-list] 4.04 linker woes

[Gabriel Scherer]

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I am not sure (I haven't tested the failing build).

I use
  ocamlobjinfo $(ocamlfind query compiler-libs.common)/ocamlcommon.cma
to see what is present in the archive.

One possible explanation for the behavior of utop is that requiring the
package adds the compiler-libs location to the include path, and therefore
lets utop find the package when you ask for it. But the compilation of a
binary that uses this module would still fail at link-time. (On the other
hand, I'm not sure why a binary would need this module.)

In the example below, using compiler-libs.bytecomp instead of
compiler-libs.common fixes linking. (compiler-libs.optcomp also fails.)

$ echo "let _ = Compplugin.load" > test.ml
$ ocamlfind ocamlc -package compiler-libs.common -linkpkg test.ml
findlib: [WARNING] Interface topdirs.cmi occurs in several directories: ...
File "test.ml", line 1:
Error: Required module `Compplugin' is unavailable
$ ocamlfind ocamlc -package compiler-libs.bytecomp -linkpkg test.ml
findlib: [WARNING] Interface topdirs.cmi occurs in several directories: ...
$


On Mon, Nov 7, 2016 at 3:46 PM, Christoph Höger <
christoph.hoeger@tu-berlin.de> wrote:

> I am going to give the workaround a try tomorrow.
>
> Regarding the bug, are you sure about that?
> When I load the common libs in utop, the module is loaded.
>
> utop # #require "compiler-libs.common";;
> ─( 21:39:56 )─< command 1
> >───────────────────────────────────────────────────────────
> ────────────────────────────────────────────────────────────
> ────────────────────────────────────────────────────────────
> ────────────────────────────────────────────────────────────
> ─────────────────────────────────────{
> counter: 0 }─utop # #typeof "Compplugin";;
> module Compplugin : sig val load : string -> unit end
>
>
> So if the module is not part of the common library, how do I reproduce
> the actual bug?
>
> Am 07.11.2016 um 21:30 schrieb Gabriel Scherer:
> > Compplugin is a module from the compiler distribution that indeed is new
> > in 4.04.0. It is not included in ocamlcommon.cma. It is part of
> > ocamlbytecomp.cma, but not of ocamloptcomp.cma, and I believe that the
> > latter omission is a bug (as Optcompile depends on it), so maybe it
> > should really be in ocamlcommon.cma.
> >
> > This looks like an upstream bug (in the OCaml distribution). Could you
> > open a Mantis issue?
> >
> > As a workaround, you may be able to link to the compplugin module
> > separately, it is installed in the $(ocamlfind query compiler-libs)
> > directory.
> >
> > On Mon, Nov 7, 2016 at 3:10 PM, Christoph Höger
> > <christoph.hoeger@tu-berlin.de <mailto:christoph.hoeger@tu-berlin.de>>
> > wrote:
> >
> >     Dear all,
> >
> >     today I attempted to migrate my stack towards 4.04.0 - unfortunately
> >     ppx_monadic is not yet available for that language version. I
> attempted
> >     to build it myself, but to no avail:
> >
> >     Error: Required module `Compplugin' is unavailable
> >
> >     This error is newly introduced into 4.04.0 (and does not exist in the
> >     HEAD version). Compplugin should be provided by compilerlibs.common,
> so
> >     I assume I need to fix the build system somehow.
> >
> >     Does anyone have any idea how to fix this?
> >
> >     regards,
> >
> >     Christoph
> >     --
> >     Christoph Höger
> >
> >     Technische Universität Berlin
> >     Fakultät IV - Elektrotechnik und Informatik
> >     Übersetzerbau und Programmiersprachen
> >
> >     Sekr. TEL12-2, Ernst-Reuter-Platz 7, 10587 Berlin
> >
> >     Tel.: +49 (30) 314-24890 <tel:%2B49%20%2830%29%20314-24890>
> >     E-Mail: christoph.hoeger@tu-berlin.de
> >     <mailto:christoph.hoeger@tu-berlin.de>
> >
> >
>
>
> --
> Christoph Höger
>
> Technische Universität Berlin
> Fakultät IV - Elektrotechnik und Informatik
> Übersetzerbau und Programmiersprachen
>
> Sekr. TEL12-2, Ernst-Reuter-Platz 7, 10587 Berlin
>
> Tel.: +49 (30) 314-24890
> E-Mail: christoph.hoeger@tu-berlin.de
>
>

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Re: [Caml-list] 4.04 linker woes

[Alain Frisch]

On 07/11/2016 21:30, Gabriel Scherer wrote:
> Compplugin is a module from the compiler distribution that indeed is new
> in 4.04.0. It is not included in ocamlcommon.cma. It is part of
> ocamlbytecomp.cma, but not of ocamloptcomp.cma, and I believe that the
> latter omission is a bug (as Optcompile depends on it), so maybe it
> should really be in ocamlcommon.cma.

ocamlopt now includes ocamlbytecomp.cma. The reason is that the copy of 
Dynlink which is now included in ocamlopt relies on many modules found 
in this library.   This is not ideal, as this will force linking 
unneeded modules in ocamlopt (well, -linkall is not currently used, but 
to make ocamlc/ocamlopt work well with plugins, it probably should).

I guess the fix is to add ocamlbytecomp wherever ocamloptcomp is required.

> As a workaround, you may be able to link to the compplugin module
> separately, it is installed in the $(ocamlfind query compiler-libs)
> directory.

Compplugin depends on Compdynlink (which depends on many modules in 
ocamlbytecomp.cma); it cannot simply be linked separately, I think.


-- Alain

Re: [Caml-list] 4.04 linker woes

[Jeremie Dimino]

On Mon, Nov 7, 2016 at 9:21 PM, Gabriel Scherer
<gabriel.scherer@gmail.com> wrote:
> One possible explanation for the behavior of utop is that requiring the
> package adds the compiler-libs location to the include path, and therefore
> lets utop find the package when you ask for it. But the compilation of a
> binary that uses this module would still fail at link-time. (On the other
> hand, I'm not sure why a binary would need this module.)

That's correct. utop already has compiler-libs.bytecomp linked in, so
the only effect of [#require "compiler-libs.{common,bytecomp}"] is
[#directory "+compiler-libs"].

-- 
Jeremie