Extra Objects¶
It’s possible to specify native object files to be packaged with OCaml
libraries or linked into OCaml executables. Do this by using the
extra_objects
field of the library
or executable
stanzas.
For example:
(executable
(public_name main)
(extra_objects foo bar))
(rule
(targets foo.o bar.o)
(deps foo.c bar.c)
(action (run ocamlopt %{deps})))
This example builds an executable which is linked against a pair of native
object files, foo.o
and bar.o
. The extra_objects
field takes a list
of object names, which correspond to the object file names with their path and
extension omitted (in contrast, (rule)
manipulates file names, so the
extension needs to be provided).
In this example, the sources corresponding to the objects (foo.c
and
bar.c
) are assumed to be present in the same directory as the OCaml source
code, and a custom rule
is used to compile the C source code into object
files using ocamlopt
. This is not necessary; one can instead compile foreign
object files manually and place them next to the OCaml source code.