RE: [Caml-list] Forcing gcc/ocamlopt to link against specific versions of libc.so and libm.so

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

Микола Стрєбков wrote:
> Hi, David
> 
> On 24 січ. 2011, at 17:00, David Allsopp wrote:
> 
> > I'm working with OCaml 3.12.0 on FreeBSD 8.1 and need to produce native
> binaries which are compatible with FreeBSD 6.4. I have therefore installed
> the compat6x package. FreeBSD 8.1 has /lib/libm.so.5 and /lib/libc.so.7
> and the compat6x package gives me /usr/local/lib/compat/libm.so.4 and
> /usr/local/lib/compat/libc.so.6 as they're what shipped in FreeBSD 6.x
> >
> > My question therefore is twofold:
> >
> > 1. What do I have to pass to gcc to tell it to use the older libm.so.4
> and libc.so.6?
> 
> Look at the -nostartfiles, -nodefaultlibs and -nostdlib. Those options
> should allow you to pass exact libraries to linker.

Thanks for the confidence boost - I had looked at these switches but was
guessing/hoping that there was some other way of specifying versions of .so
files. I hacked OCaml's configure script to redefine
mathlib='/usr/local/lib/compat/libm.so.4' (there doesn't seem to be a way to
replace the default -lm via the command line to configure - but as it's an
easy patch, perhaps I'll open a feature request with the patch) and
configured OCaml with

	./configure -lib '-nodefaultlibs /usr/local/lib/compat/libc.so.6'

and OCaml seems to be working correctly (and ldd shows the resulting
executables are linked against the older versions).


David