Re: FFI on OS X?

[Hans Aberg]

On 3 Mar 2011, at 00:03, Ludovic Courtès wrote:

>>>> scheme@(guile-user)> (define libm (dynamic-link "/usr/lib/libm.dylib"))
>>>> ERROR: In procedure dynamic-link: file: "/usr/lib/libm.dylib",
>>>> message: "file not found"
>>> 
>>> You should omit the extension, which will be automatically inferred by
>>> Guile (actually ltdl) depending on the system:
>>> 
>>> (dynamic-link "/usr/lib/libm")
>>> 
>>> or:
>>> 
>>> (dynamic-link "libm")
>> 
>> None of those work - I checked and rechecked that. Making a soft link ending 
>> on ".so", and it works fine. I have seen this before in the Bessel function 
>> example.
> 
> Right.  There’s this insightful test started by you last year:
> 
>  http://lists.gnu.org/archive/html/bug-libtool/2010-02/msg00000.html
> 
> The crux is that on older MacOS X versions ‘.dylib’ are shared libraries
> (not dlopenable), whereas ‘.so’ are “bundles” (dlopenable).  That’s why
> lt_dlopenext (which is what ‘dynamic-link’ uses) doesn’t try to open
> ‘.dylib’ files.

The shared libraries (not dynamically loadable, except as when starting up the 
program like some web browser plugins) were on the PPC platform (XCOFF and PEF 
I think it was).

Now (Mac OS 10.5 and later), all is loadable. Haven't seen any .so files, 
except as coming from GNU/Linux.

> May I recommend switching to GNU/Linux?  :-)

You can always try:-), but Mac OS X 10.5 Intel and later is certified UNIX, and 
the only parts in the UNIX standard recognizing file name extensions is 'make' 
and ".c" (I checked on the standardization list).

Hans