Re: [Caml-list] Can this OMakefile be simplified?

[Aleksey Nogin <nogin@metaprl.org>]

On 28.03.2007 01:28, Joel Reymont wrote:

> I found this OMakefile in the sqlite3 bindings for OCaml. I'm trying to 
> package my translator as a set of C bindings and I wonder if this 
> Omakefile can be made simpler.
[...]
> ###########################################
> 
> SubstVersion(output, input) =
>    # should use fsubst, but it doesn't seem to be
>    # working properly in 0.9.2.
>    $(output) : $(input)
>        sed "s%@VERSION@%$(VERSION)%g" < $< > $@

I wonder what the problem was here - I would imagine it is fixed now. In 
any case, a lot of this version mangling stuff is probably specific to 
how the sqlite3 build environment is set up.

A lot of the code below can be simplified using some of the features of 
the more recent versions of OMake.

> ###########################################
> OCamlLibraryExt(name, files, cfiles) =
>    OFILES   = $(addsuffix $(EXT_OBJ), $(cfiles))
>    CMOFILES = $(addsuffix .cmo, $(files))
>    CMXFILES = $(addsuffix .cmx, $(files))
>    CMIFILES = $(addsuffix .cmi, $(files))
>    CLIB      = $(file $(name)$(EXT_LIB))
>    BYTELIB   = $(file $(name).cma)
>    NATIVELIB = $(file $(name).cmxa)
>    STUBLIB   = lib$(name)_stubs
>    # Create C library to contain all the object files...
>    StaticCLibrary($(STUBLIB), $(cfiles))
>    # Link commands
>    # TODO: Doesn't work with ddls...
>    $(BYTELIB): $(CMOFILES) $(STUBLIB)$(EXT_LIB)
>         $(OCAMLFIND) $(OCAMLLINK) $(OCAMLFLAGS) $(OCAMLCFLAGS) \
>                 $(OCAML_LIB_FLAGS) -a -custom -cclib -l$(name)_stubs \
>                 -o $@ $(OCamlLinkSort $(CMOFILES))
> 
>    $(NATIVELIB) $(CLIB): $(CMXFILES) $(STUBLIB)$(EXT_LIB)
>         $(OCAMLFIND) $(OCAMLOPTLINK) $(OCAMLFLAGS) $(OCAMLOPTFLAGS) \
>                 $(OCAML_LIB_FLAGS) -a -cclib -l$(name)_stubs -o \
>                 $(NATIVELIB) $(OCamlLinkSort $(CMXFILES))
> 
>    # Add to targets
>    if $(NATIVE_ENABLED)
>         library: $(NATIVELIB)
> 
>    if $(BYTE_ENABLED)
>         library: $(BYTELIB)

The above can be significantly simplified, using something like the code 
below (untested).

OCamlLibraryExt(name, files, cfiles) =
    STUBLIB     = lib$(name)_stubs
    STUBLIB_BIN = $(StaticCLibrary $(STUBLIB), $(cfiles))

    OCAMLCFLAGS += -custom
    OCAML_LIB_FLAGS += -cclib -l$(STUBLIB)

    LIB_FILES = $(OCamlLibrary $(name), $(files))
    $(LIB_FILES): $(STUBLIB_BIN)

    library: $(LIB_FILES)

    return $(LIB_FILES)

The "return" line is option - it is only needed if somebody wants to 
know with files just got their build rules defined (can be very helpful, 
as the usage of the StaticCLibrary and OCamlLibrary functions above 
demonstrates).

> # Program with tag for executables
> OCamlProgramExt(tag, name, sources) =
>    OCamlProgram($(name), $(sources))
> 
>    if $(NATIVE_ENABLED)
>         $(tag) : $(name).opt
> 
>    if $(BYTE_ENABLED)
>         $(tag) : $(name).run

The above is IMO unnecessary. The function can be defined as

OCamlProgramExt(tag, name, sources) =
    $(tag): $(OCamlProgram $(name), $(sources))

but it is better to simply inline the corresponding code.

> OCAMLLIBDIR = $(shell ocamlfind printconf stdlib)

OCAMLLIBDIR = $(shell $(OCAMLC) -where)

might be a slightly better idea (it's nice not to rely on having 
ocamlfind installed).

Aleksey