Fwd: [Caml-list] Using OCaml from C

[Tom Ridge <tom.j.ridge+caml@googlemail.com>]

Just to make a final report:

Following Gerd and Stephane, I used ocamlfind -verbose to print the
options ocamlfind was passing to cc. After tidying, my Makefile now
looks like:

--

SHELL=bash

OCAMLPATH=/home/tr61/.opam/4.00.1/lib


all:
  ocamlfind ocamlc -package core,str -linkpkg -thread -output-obj -o
modcaml.o pqueue.ml mod.ml
  ocamlc -c modwrap.c
  rm -f mod.a
  ar rcs mod.a modcaml.o modwrap.o
  cc -o prog main.c mod.a -L$(OCAMLPATH)/bin_prot
-L$(OCAMLPATH)/variantslib -L$(OCAMLPATH)/num -L$(OCAMLPATH)/sexplib
-L$(OCAMLPATH)/fieldslib -L$(OCAMLPATH)/oUnit -L$(OCAMLPATH)/pa_ounit
-L$(OCAMLPATH)/res -L$(OCAMLPATH)/core_kernel -L$(OCAMLPATH)/core
-L$(OCAMLPATH)/ocaml/threads -L$(OCAMLPATH)/ocaml -lcamlstr
-lcore_stubs -lrt -lcore_kernel_stubs -lnums -lbin_prot_stubs
-lbigarray -lthreads -lunix -lpthread -lunix -lcamlrun
-I$(OCAMLPATH)/ocaml -lm  -ldl -lcurses -lpthread

--

which is better (e.g. no need for -pthread argument to cc, no need for
-Xlinker --allow-multiple-definition), although a bit verbose (but the
options were determined automatically, so this is a big time win).

Thanks



On 10 September 2013 15:21, Stéphane Glondu <steph@glondu.net> wrote:
> Le 10/09/2013 15:30, David Allsopp a écrit :
>>> Your calls to cp, ar and your use of -custom look suspicious. But it is
>>> difficult to be more helpful without a concrete testcase.
>>
>> They're exactly as in the manual and are correct for compiling with ocamlc for static linking with C code. The cp and ar calls are necessary to set-up the static library (which should use libcamlrun.a as a starting point) - see #19.8 (the example in question), #19.7.4, #19.7.5 and #19.1.3 in the manual.
>
> Well, that doesn't make them more right.
>
> With the example of the manual, the following works and is much saner:
>
>   ocamlc -output-obj -o modcaml.o mod.ml
>   ocamlc -c modwrap.c
>   ar rcs mod.a modcaml.o modwrap.o
>   cc -o prog main.c mod.a -L`ocamlc -where` -lcamlrun -lm -ldl -lcurses
>
> Copying libcamlrun.a around and fiddling with it also works and avoids
> -L`ocamlc -where` -lcamlrun but it is just insane, as insane as
> embedding the C standard library and runtime into third-party static
> libraries.
>
>
> Cheers,
>
> --
> Stéphane
>
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