modifying ocaml sources

modifying ocaml sources

[Tom Hirschowitz]

Hi all,

We are trying to modify the ocaml compiler in order to have it verify
the well foundedness of recursive module definitions, and have a
question for the long standing ocaml source hackers.

>From early experiments, it seems that the dependencies in the various
.depend files are insufficient. For example, try to modify the version
string, say "3.08.3", in stdlib/sys.cmo, and make the world. Launch
the new toplevel; nothing has changed. How do people deal with this
issue? In the cases we have, cleaning up the executables before making
the world again is enough. Is it in general? 

Thanks.

Re: [Caml-list] modifying ocaml sources

[Jacques Garrigue]

From: Tom Hirschowitz <tom.hirschowitz@ens-lyon.fr>

> We are trying to modify the ocaml compiler in order to have it verify
> the well foundedness of recursive module definitions, and have a
> question for the long standing ocaml source hackers.

Interesting endeavour.
Of course I hope that you can handle my pet case:
http://www.math.nagoya-u.ac.jp/~garrigue/papers/mixmod5.ml.txt

> >From early experiments, it seems that the dependencies in the various
> .depend files are insufficient. For example, try to modify the version
> string, say "3.08.3", in stdlib/sys.cmo, and make the world. Launch
> the new toplevel; nothing has changed. How do people deal with this
> issue? In the cases we have, cleaning up the executables before making
> the world again is enough. Is it in general? 

There are indeed a few things that are not redone automatically.
But of course make clean; make world should always solve the problem;
except when you have changed some internal data and you need to
bootstrap.

The kinds of problem I see frequently are:
* after modifying the standard library implementation, need to relink
  everything. Dirty workaround: touch utils/config.ml; this will force
  to relink the compilers, but not all tools.
* any change in the interface of a standard library module used
  somewhere in the compiler requires recompilation. Generally you're
  better off recompiling everything than trying to track the
  dependencies by hand.
* after changes in the compiler, ocamlbrowser compilation breaks
  sometimes. (cd otherlibs/labltk/browser; make clean) solves it.
  
The dependencies are not all that clever because:
* some cases are really cyclic (eg ./ocamlc and the standard library
  clearly depend on each other)
* having too many dependencies automatically enforced can be a pain.
  (For instance, on slow machines I sometimes disable the rule forcing
  ocamlc.opt and ocamlopt.opt to be recompiled from scratch everytime
  ocamlopt has changed.)

Jacques Garrigue