Caml with main in C + .cmxa

Caml with main in C + .cmxa

[Florent Monnier]

Hi,

I'm compiling the beginning of a small app written in OCaml but with the main 
which boot the app in C.
The OCaml app should also use a .cmxa lib, which is a binding to a C lib.

Without the .cmxa binding, compiling works good with this:

% ocamlopt -c  app.ml
% ocamlopt -output-obj -o mlobj.o  unix.cmxa  app.cmx
% gcc main.c  -o myapp.opt  mlobj.o \
        -I'/usr/local/lib/ocaml' \
        -L/usr/local/lib/ocaml \
        -lunix -lasmrun  -lm -ldl


But now I'm trying to figure out how to compile with the .cmxa
which is the binding to ImageMagick  (hump ~contrib:487)

To compile C code without caml pieces with the libMagick is done this way:
gcc `Magick-config --cflags --cppflags` app.c `Magick-config --ldflags --libs`

So here is my attempt to mix all together:

% ocamlopt -c  -I +libMagick  magick.cmxa   app.ml
% ocamlopt -output-obj -o mlobj.o unix.cmxa -I +libMagick magick.cmxa  app.cmx
(untill there, no error messages)

% gcc `Magick-config --cflags --cppflags`  main.c  -o myapp.opt  mlobj.o \
        -I'/usr/local/lib/ocaml' \
        -L/usr/local/lib/ocaml \
        -lunix -lasmrun  -lm -ldl \
        `Magick-config --ldflags --libs`

and then with this last command, I get about 200 errors like this:
--------------------
mlobj.o: In function `camlMagick__scale_1177':
: undefined reference to `fun_scaleimage'

mlobj.o: In function `camlMagick__sharpen_1136':
: undefined reference to `fun_sharpenimage'

mlobj.o: In function `camlMagick__blur_channel_1193':
: undefined reference to `fun_blurimagechannel'
--------------------

'fun_scaleimage' and the others are the names of the functions in
the C file of the OCaml-libMagick binding.



So what is the error I have done?
What should I correct to get the app compliled?


-- 
Thanks in advance
Florent Monnier

Re: [Caml-list] Caml with main in C + .cmxa

[Florent Monnier]

> > % ocamlopt -c  -I +libMagick  magick.cmxa   app.ml
> > % ocamlopt -output-obj -o mlobj.o unix.cmxa -I +libMagick magick.cmxa \
> >       app.cmx
> > (untill there, no error messages) 
> >
> > % gcc `Magick-config --cflags --cppflags`  main.c  -o myapp.opt  mlobj.o \
> >         -I'/usr/local/lib/ocaml' \
> >         -L/usr/local/lib/ocaml \
> >         -lunix -lasmrun  -lm -ldl \
> >         `Magick-config --ldflags --libs`
> >
> > and then with this last command, I get about 200 errors like this:
> > [...]

Indeed, the solution was to give the stubs of the binding to gcc:

% ls /usr/local/lib/ocaml/libMagick/
dllmagick_stubs.so  libmagick_stubs.a  magick.a  magick.cma  magick.cmi  
magick.cmxa  magick.mli

% gcc \
        `Magick-config --cflags --cppflags` \
        main.c  -o myapp.opt  mlobj.o \
        -I'/usr/local/lib/ocaml' \
        -L/usr/local/lib/ocaml \
        -lunix -lasmrun  -lm -ldl \
        `Magick-config --ldflags --libs` \
        -L/usr/local/lib/ocaml/libMagick  \
        -lmagick_stubs


++ Thanks a lot to Jonathan and Rabih for your help !

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