Re: [Caml-list] Segmentationfault on 64bit when called from C

[Georg Martius <georg.martius@web.de>]

On Tuesday 31 July 2012 14:59:14 Gerd Stolpmann wrote:
> Just a rough guess: The frametable is not initialized. Quite funny that
> it crashes so quickly. (Maybe more is not initialized, maybe the heap
> register, so it crashes at the first allocation.)
> 
> You cannot just link Ocaml code without adding the frametable. This is a
> description of how the stack and the CPU registers are used at runtime.
> If it is missing the OCaml runtime thinks that the Ocaml code is C code,
> and applies the wrong conventions.
> 
> The -shared switch generates a library that is prepared to be loaded
> with Dynlink. Dynlink registers the frametable.
> 
> You should consider using -output-obj to create a library that can be
> loaded without such tricks (see section 18.7.5 of the Ocaml manual).
ocamlopt -output-obj -o camlcode.o interface.c m1.ml
gcc -fPIC -g -Wall  -c -I/usr/local/lib/ocaml interface.c
gcc -fPIC -o test main.c camlcode.o  interface.o -L/usr/local/lib/ocaml -lunix 
-lm -lasmrun -ldl

works, but 
ocamlopt -o libmytest.so -output-obj  interface.c m1.ml
gcc -Wall main.c  -lmytest -o test
does not! Is it clear why it doesn't work?

So I get away with static linking for now.

Thanks!
  Georg

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