[Caml-list] Annoying compiler magic

[Caml-list] Annoying compiler magic

[Jonathan Roewen]

Hi,

I'm trying to make a custom stdlib.cma, and I'm running into a few
problems when linking.

Even when external references to a bunch of C functions are removed
from stdlib implementation, the compiler still manages to link in
those external references.

Things like caml_sys_open, caml_output_value, caml_ml_seek_out, etc., etc.

Where the hell are these coming from? Are they built into the compiler
itself? As I can't find anything to explain it.

Jonathan

Re: [Caml-list] Annoying compiler magic

[Eric Cooper]

On Sun, Nov 13, 2005 at 11:00:21AM +1300, Jonathan Roewen wrote:
> Where the hell are these coming from? Are they built into the compiler
> itself? As I can't find anything to explain it.

grep is your friend.

$ grep -r caml_sys_open .
./stdlib/pervasives.ml:external open_desc: string -> open_flag list ->
int -> int = "caml_sys_open"
./stdlib/filename.ml:external open_desc: string -> open_flag list ->
int -> int = "caml_sys_open"
./otherlibs/threads/pervasives.ml:external open_desc: string ->
open_flag list -> int -> int = "caml_sys_open"
./byterun/sys.c:CAMLprim value caml_sys_open(value path, value vflags,
value vperm)

-- 
Eric Cooper             e c c @ c m u . e d u

Re: [Caml-list] Annoying compiler magic

[Jonathan Roewen]

> grep is your friend.
>
> $ grep -r caml_sys_open .
> ./stdlib/pervasives.ml:external open_desc: string -> open_flag list ->
> int -> int = "caml_sys_open"
> ./stdlib/filename.ml:external open_desc: string -> open_flag list ->
> int -> int = "caml_sys_open"

Both of these instances are commented out, and replaced by functions
which raise an exception.

> ./otherlibs/threads/pervasives.ml:external open_desc: string ->
> open_flag list -> int -> int = "caml_sys_open"

> ./byterun/sys.c:CAMLprim value caml_sys_open(value path, value vflags,
> value vperm)

My custom runtime also removes this function.

This is a -custom- environment. The question is, why is the compiler
adding references to these symbols when my code (stdlib.cma &
libcamlrun.a) does NOT reference these.

Jonathan

Re: [Caml-list] Annoying compiler magic

[Jonathan Roewen]

> This is a -custom- environment. The question is, why is the compiler
> adding references to these symbols when my code (stdlib.cma &
> libcamlrun.a) does NOT reference these.

You guys make life fun ;-) (Yes, note the sarcasm). So you define
these external functions INTO the compiler itself... an interesting
design...

Looks like I'll have to figure out how to break up the build system to
build JUST the ocamlc compiler and nothing else; use system tools for
everything else.

Is this to ensure your particular implementation of stdlib is
guaranteed to work? As I noticed an interesting error when trying to
build a custom compiler the naive way:

Error while linking ../../stdlib/stdlib.cma(Pervasives):
The external function `caml_ml_input' is not available

Anyways, I assume you did it like this for a good reason.

Jonathan =)