Quest for ml_gdk_cairo_create

I finally found where ml_gdk_cairo_create is defined.  Its definition
was cunningly hidden from Google search by token-pasting.

Within cairo.1.2.0/src/ml_cairo_lablgtk.c, in the source code I obtained
from opam source, there is the line

wML_1(gdk_cairo_create, GdkDrawable_val, Val_cairo_t)

wML_1 is defined in cairo.1.2.0/src/ml_cairo_wrappers.h, and
token-pastes "ml_" onto the start of "gdk_cairo_create"
to produce ml_gdk_cairo_create

What remains to be explained is why the compiled code doesn't seem to
end up in opam's cairo library.

Any ideas?

-- hendrik

On Sat, Jul 11, 2015 at 10:48:37PM -0400, Hendrik Boom [email protected] [ocaml_beginners] wrote:
> On Sun, Jul 12, 2015 at 08:07:04AM +0900, Gabriel Scherer [email protected] [ocaml_beginners] wrote:
> > When building an executable you should pass the flag -linkpkg to ocamlfind.
> 
> Yes, that helps a lot.  Thanks.  I'm left with one undefined symbol:
> 
> hendrik@notlookedfor:~/dv/fun/group/toy/cairo_toy$ ocamlfind ocamlopt -package cairo -package lablgtk2 -linkpkg toy_maker.mli toy_maker.ml my_interactor.ml demo_toy.ml -o runme
> toy_maker.o: In function `camlToy_maker__redraw_1030':
> (.text+0x102): undefined reference to `ml_gdk_cairo_create'
> collect2: error: ld returned 1 exit status
> File "caml_startup", line 1:
> Error: Error during linking
> hendrik@notlookedfor:~/dv/fun/group/toy/cairo_toy$ 
> 
> 
> Now presumably this is the symbol referenced in cairo_lablgtk.ml:
> 
> external create           : [> `drawable] Gobject.obj -> Cairo.t = "ml_gdk_cairo_create"
> 
> and I'd guess there should be C code around somewhere interfacing this module to 
> the actual gdk or cairo libraries.  And a shared or unshared binary library 
> somewhere defining it.  But a google search didn't find it, and 
> presumably there's some proper way to track it down.
> 
> -- hendrik
> 
> > 
> > On Sun, Jul 12, 2015 at 7:54 AM, Hendrik Boom [email protected]
> > [ocaml_beginners] <[email protected]> wrote:
> > 
> > > On Sat, Jul 04, 2015 at 10:29:22AM -0400, Hendrik Boom
> > > [email protected] [ocaml_beginners] wrote:
> > > > On Sat, Jul 04, 2015 at 06:19:02AM +0000, Gage Peterson
> > > [email protected] [ocaml_beginners] wrote:
> > > > > Use opam. It will work out much better. Also I don't think you should
> > > ever
> > > > > have to run it from root.
> > > >
> > > > Running it from root was a mistake.  And the way it affected the
> > > > results was a clue that the Debian-installed packages weren't even
> > > > being seen.  THough first I misinterpreted the clue.
> > > >
> > > > I'll try opam.  That should work.
> > > >
> > > > Will report back.
> > >
> > > OK.  Did
> > >    opam install lablgtk
> > > and
> > >    opam install cairo
> > >
> > > Now I get
> > >
> > > hendrik@notlookedfor:~/dv/fun/group/toy/cairo_toy$ ocamlfind ocamlopt
> > > -package cairo -package lablgtk2 toy_maker.mli toy_maker.ml
> > > my_interactor.ml demo_toy.ml -o runme
> > > File "demo_toy.ml", line 1:
> > > Error: No implementations provided for the following modules:
> > >          GMain referenced from toy_maker.cmx, my_interactor.cmx
> > >          GPack referenced from toy_maker.cmx
> > >          GWindow referenced from toy_maker.cmx
> > >          GBin referenced from toy_maker.cmx
> > >          Cairo referenced from my_interactor.cmx
> > >          GMisc referenced from toy_maker.cmx
> > > hendrik@notlookedfor:~/dv/fun/group/toy/cairo_toy$
> > >
> > >
> > > Can I conclude that I'm now getting as far as the linker?
> > >
> > > How do I go abbout getting it to actually *find* these modules?
> > >
> > > -- hendrik
> > >
> > >
> > > ------------------------------------
> > > Posted by: Hendrik Boom <[email protected]>
> > > ------------------------------------
> > >
> > > Archives up to December 31, 2011 are also downloadable at
> > > http://www.connettivo.net/cntprojects/ocaml_beginners
> > > The archives of the very official ocaml list (the seniors' one) can be
> > > found at http://caml.inria.fr
> > > Attachments are banned and you're asked to be polite, avoid flames etc.
> > > ------------------------------------
> > >
> > > Yahoo Groups Links
> > >
> > >
> > >
> > >
> 
> 
> ------------------------------------
> Posted by: Hendrik Boom <[email protected]>
> ------------------------------------
> 
> Archives up to December 31, 2011 are also downloadable at http://www.connettivo.net/cntprojects/ocaml_beginners
> The archives of the very official ocaml list (the seniors' one) can be found at http://caml.inria.fr
> Attachments are banned and you're asked to be polite, avoid flames etc.
> ------------------------------------
> 
> Yahoo Groups Links
> 
> 
>