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* RE: Portability of applications written in OCAML
@ 2000-02-21 19:02 Don Syme
  0 siblings, 0 replies; 12+ messages in thread
From: Don Syme @ 2000-02-21 19:02 UTC (permalink / raw)
  To: 'caml-list@pauillac.inria.fr'


Under Windows, I would ideally I'd like to package up binary distributions
in the same way I would any other kind of application, e.g. using a "do it
all for you" packager like InstallShield.  Has anyone had experience of
doing this with Caml applications?  

Thanks,
Don


-----Original Message-----
From: Xavier Leroy [mailto:Xavier.Leroy@inria.fr]
Sent: 21 February 2000 17:04
To: caml-redistribution@pauillac.inria.fr
Subject: Re: Portability of applications written in OCAML


Claude Marche asks:

>One idea could be distributing bytecode: is it true the any bytecode
>can be executed on any architecture and OS as soon as the right
>ocamlrun is used? (Even under non unix OSs like Microsoft-Windows or
>Mac-OS?) 

For MacOS, there are some problems with end-of-line being represented
by different control characters in MacOS and in Unix and Windows.  So,
newlines in program output are broken.

For MacOS and Windows, there is also the fact that file path names are
represented differently.  So, if your program manipulates file names,
even though the Filename module, the bytecode may not work well under
a different OS.

I think the easiest way to distribute an OCaml application is as
sources, plus binaries for a couple of popular architectures
(typically, Linux/Intel and Windows).  Novice users can pick the
binaries, and experienced users should have no problems installing
OCaml for compiling your application.

Gerd Stolpmann wrote:
> My suggestion: Every modern operating system can link libraries
dynamically.
> This is also possible for the parts of the OCaml libraries written in C
> which need to be available in the runtime system.

Right, I have been considering dynamic loading of C libraries as an
alternative to -custom.  This would allow, among other benefits,
dynamic loading of Caml libraries that contain some C code.

There are some portability issues with old or exotic versions of Unix,
but I think it can be made to work under, say, Linux, Solaris,
Digital/Tru64 Unix, and Windows.  There are some issues still to be
resolved, however, such as how to build shared C libraries in a
portable fashion, perhaps by using the GNU libtool package.

> - Only libraries needed for the application are loaded into memory;
>   the memory footprints become much smaller

Yes and no, because static linking under C is able to remove members
of the .a archive that are not referenced, while dynamic loading
typically loads everything.  But memory footprint of code is not much
of an issue these days.

- Xavier Leroy



^ permalink raw reply	[flat|nested] 12+ messages in thread
* Portability of applications written in OCAML
@ 2000-02-15 13:01 Claude Marche
  2000-02-16 13:09 ` Jean-Francois Monin
                   ` (2 more replies)
  0 siblings, 3 replies; 12+ messages in thread
From: Claude Marche @ 2000-02-15 13:01 UTC (permalink / raw)
  To: caml-list


Bonjour,

[long message, english translation follows]

J'ai des remarques et des questions à propos de la façon dont on peut
distribuer une application écrite en Objective CAML, et sur la
portabilité à laquelle on peut s'attendre.

Voici mon problème : supposons que l'on ait programmé une application
en ocaml, que l'on a envie de distribuer (gratuitement) sur le
Web, comment doit-on procéder pour la distribuer ? Supposons que cette
application n'ait en elle-meme rien à voir avec CAML, et que l'on
souhaite atteindre un public qui a priori ne connait pas ce langage,
et ne dispose pas du compilateur ni de l'interpréteur.

Pour distribuer, on peut proposer a priori les sources, et aussi des
exécutables (compilés avec ocamlopt pour que ça aille
vite). Proposer les sources pose un problème car une personne
intéressée par cette application devra au préalable installer ocaml
sur son ordinateur, et cela rebuterait je pense une grande partie des
personnes intéressées au départ. Proposer des binaires contourne ce
problème mais on entre dans de multiples problemes de configuration,
car l'exécutable ne pourra fonctionner que sur la bonne architecture,
avec la bonne version du bon OS, sans oublier les problèmes de
versions de bibliothèques dynamiques (curses/ncurses, libc/glibc,
etc.) 

Le juste milieu me semble être d'utiliser le bytecode : Est-ce que
c'est vrai qu'il est possible d'executer n'importe quel bytecode sur
n'importe quel archi et OS à partir du moment où on a le ocamlrun
approprié pour cette architecture et cet OS ? (Meme sous des OS non
unix comme Microsoft-Windows ou Mac-OS ?) Si oui, un utilisateur
potentiel de l'application n'aurait pas besoin d'installer tout ocaml
mais seulement une version de ocamlrun appropriée pour sa combinaison
architecture/OS. Cela permettrait a cet utilisateur potentiel de
facilement essayer l'application qui l'interesse, et s'il la trouve
utile pour lui, il sera alors motivé pour faire l'effort d'installer
ocaml pour compiler une version en code natif de cette application
pour son archi et son OS.

Pour que cela fonctionne, il faudrait qu'il existe quelque part sur le
Web une sorte d'archive de versions de ocamlrun, permettant de choisir
son architecture, son OS, la version ocaml requise, peut-etre aussi
certaines variantes de bibliotheques comme libc 5 ou 6, glibc.

Je pense qu'il y a potentiellement un nombre non negligeable
d'applications concernées, il suffit de se promener un peu sur la «
bosse » : HeVeA, GeneWeb, Bibtex2html, et bien d'autres.

Il y a néanmoins un problème ennuyeux: dès qu'une application devient
un peu conséquente, il arrive que l'on commence à utiliser des
bibliothèques comme unix, str, nums, threads, qui nécessitent une
compilation en -custom. Si j'ai bien compris, les binaires obtenus
contiennent le code natif de l'interpréteur de bytecode lui-même, et
ne sont plus portables. Est-il techniquement possible de changer cela
en utilisant un ocamlrun linké avec ces bibliothèques ?

Pour résumer mon propos, voici donc les questions que je me pose :

1) Un fichier de bytecode est-il exécutable par ocamlrun sur n'importe
   quelle combinaison d'une architecture et d'un OS ? Y compris OS non
   unix ?

2) Est-il possible de fabriquer des versions d'ocamlrun contenant en
   plus des bibliothèques linkées habituellement avec -custom : unix,
   str, nums, threads ; et par conséquent pourraient exécuter des
   bytecode portables utilisant ces bibliotheques ?

Si ceci est techniquement faisable, cela m'intéresserait de connaitre
les personnes intéressées par l'utiliser, pour distribuer leur propre
application sous forme de bytecode portable. De plus, pour constituer
cette archive de binaires ocamlrun, il faudrait la participation du
plus grand nombre de personnes possible afin de couvrir largement les
combinaisons d'architectures et d'OS. Personnellement j'ai accès à des
PC sous Linux (Distribution Redhat en général) et des SPARC sous
Solaris 2.7, mais c'est tout.

Toutes remarques, toutes suggestions et tous commentaires sont les
bienvenus. Mon but est de pouvoir distribuer le plus largement
possible une application écrite en Ocaml, en évitant des remarques du
genre « cette application m'intéresse mais je ne peux pas compiler le
Ocaml et vous ne fournissez pas un binaire adapté à ma configuration
», et je serais heureux d'entendre toute suggestion permettant
d'atteindre ce but.

[English translation]

I have a few remarks and questions about how one may distribute an
application written in Objective CAML, and how much portability one
may expect.

Here is my problem: suppose one has written an application in ocaml,
and wants to distribute it (freely) on the Web, how should he proceed?
Suppose that the application itself has nothing to do with CAML, and
one wants to reach people that do not know a priori this langage, so
do not have caml installed on their computer.

Distribution could be achieve by making the source files available,
and also some binary executables (compiled with ocamlopt for
efficiency). Installing from source is not nice because anyone
interested must first install ocaml on his computer, and I think that
many people in that case would not do it, and will better try to find
another application doing the same thing but easier to install.
Distributing binaries is not nice also, because one may encounter many
configuration problems, the program will run only for the right
architecture, the right version of the right OS, not to mention
problems with versions of dynamic libraries (curses/ncurses,
libc/glibc, etc.)

One idea could be distributing bytecode: is it true the any bytecode
can be executed on any architecture and OS as soon as the right
ocamlrun is used? (Even under non unix OSs like Microsoft-Windows or
Mac-OS?) If yes, anyone interested in using the application would
need only to install the suitable ocamlrun for its architecture/OS
combination.  It would allow any potentially interested user to try
the application, and in case he finds it suitable for its need, he
would be motivated to install ocaml for compiling from the sources and
getting a faster application.

For this to work, a kind of archive of various versions of ocamlrun
should exist somewhere on the web, allowing to choose the right
architecture/OS, also the right ocaml version, the right libraries
like libc 5 or 6 or glibc.

I think there is a significant number of applications that could be
interested in being distributed like this, like the ones that are on
the ``hump'': HeVeA, GeneWeb, Bibtex2html, and many others.

Nevertheless, there is a problem for applications that use other
libraries like unix, str, nums, threads, that need to be compiled in
-custom mode. If I understand well, binaries compiled with -custom
contain the native code of the interpreter itself, so are not portable
anymore. Techically speaking, is it possible to build an ocamlrun
interpreter that contains those libraries statically linked?

So to conclude, I would like to know two things:

1) Can a bytecode file be run using any ocamlrun version, on any
   combination of architecture and OS? Even a non-unix OS?

2) Is it possible to build an ocamlrun interpreter containing also
   some librairies usually linked with -custom: unix, str, nums,
   threads ; hence being able to run portable bytecode files using
   such libraries ? 

If this is technically feasible, I would like to know people who are
interested in using this for distribution of their own application in
bytecode form. Moreover, for building this archive of ocamlrun
binaries, many people are needed to cover a wide range of
architecture/OS combinations. I have access myself to PCs under Linux
(Redhat distribution) and SPARC/Solaris 2.7, that's all.

Any comments, remarks and suggestions will be welcome. My goal is be
able to distribute as widely as possible an application written in
Ocaml, avoiding remarks like ``I'm interested in this application but
I cannot compile Ocaml sources, and you do not offer a suitable binary
for my configuration », and I would be glad to hear any suggestion for
achieving this goal.

- Claude



-- 
| Claude Marché           | mailto:Claude.Marche@lri.fr |
| LRI - Bât. 490          | http://www.lri.fr/~marche/  |
| Université de Paris-Sud | phoneto: +33 1 69 15 64 85  |
| F-91405 ORSAY Cedex     | faxto: +33 1 69 15 65 86    |



^ permalink raw reply	[flat|nested] 12+ messages in thread
end of thread, other threads:[~2000-02-24 17:43 UTC | newest]

Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2000-02-21 19:02 Portability of applications written in OCAML Don Syme
  -- strict thread matches above, loose matches on Subject: below --
2000-02-15 13:01 Claude Marche
2000-02-16 13:09 ` Jean-Francois Monin
2000-02-16 14:08   ` Claude Marche
2000-02-16 14:28     ` Jean-Francois Monin
2000-02-18  9:18     ` Patrick Goldbronn - SYSCO
2000-02-16 22:49 ` Gerd Stolpmann
2000-02-18  9:36   ` Xavier Leroy
2000-02-21 20:45     ` skaller
2000-02-22  8:13     ` Sven LUTHER
2000-02-22  9:21       ` Xavier Leroy
2000-02-17  8:05 ` skaller

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