RE: [Caml-list] Flexdll circular dependency fix uses system provided flexdll.h [was: opam-cross-windows]

[David Allsopp <dra-news@metastack.com>]

Michael Soegtrop wrote:
> > This isn't a great way - better is to override the detection of
> > FLEXDIR a few lines later (the FLEXDIR:= line):
> 
> > sed -I "s|FLEXDIR:=.*|FLEXDIR=|" config/Makefile
> 
> I thought about this, but I wonder if this would use the correct
> flexdll.h, but still the wrong flexlink. I thought it would be safer to
> point it to the right flexlink and derive the flexdll.h location from
> there.

If it's working correctly, each individual Makefile.nt selects flexlink based on the presence of flexdll/Makefile (e.g. https://github.com/ocaml/ocaml/blob/trunk/Makefile.nt#L24-L30). I think what's happened here is a piece of laziness/regression, because it's hard for config/Makefile to know what level it's been included at (the use of ROOTDIR, for example in https://github.com/ocaml/ocaml/blob/trunk/otherlibs/Makefile#L18, is not consistent across the entire build tree).

However, I was going to verify that it never picks up the wrong one by putting a dummy flexlink.exe into PATH which simply does `exit 2`.

> The mingw cross compiler + standard library builds fine, but then when I
> use it, it doesn't find pervasives, although the pervasives.cmx is in the
> folder ocamlc -config says it should be. I guess something went wrong with
> the flexlink process. Is there some way to see from ocamlc - config if
> flexlink support is there? Or is there another way to check if flexlink is
> the problem?

They should be identical, but possibly worth checking ocamlopt -config, rather than ocamlc -config. Being unable to find a .cmx is unlikely to be a flexlink problem (flexlink handles .o files, not .cmx).

Running ocamlopt -verbose allows you to see the flexlink command invocation and, IIRC, adding -ccopt -v should cause flexlink to display the commands it's running too.


David