Re: don't configure libobjc on Darwin

[Geoffrey Keating <geoffk at apple dot com>]

First, I'd like to disclaim all true knowledge.  I don't know enough 
objc to be able to test any of these statements; they're just how I 
think things work.

On Saturday, February 15, 2003, at 05:34  PM, Nicola Pero wrote:

> > The Apple compiler has for a long time had a local patch to libobjc to
> > build but not install it.  This patch prevents both building and
> > installation on Darwin.  (I believe that if you did actually try to
> > use the GNU libobjc with the Darwin compiler, you'd discover that
> > it didn't work anyway---but haven't checked).
> I'm confused.  Can you explain why this patch is a good idea, in your
> opinion ?
If you try to actually build and install FSF GCC on Darwin, you get a 
non-working objc compiler, because it will default to the NEXT runtime 
but will be installed with the GNU one in $prefix/lib masking the NEXT 
one in /usr/lib.

> What's wrong with using the GNU ObjC runtime on Darwin ?
Nothing, it's just not the default.  From Apple's point of view, we 
would rather than when the compiler is configured with --prefix=/usr, 
that libobjc.a in /usr/lib is not replaced with GNU libobjc, though.

> I would have thought that one reason to install the FSF GCC ObjC 
> compiler
> on Darwin was precisely to get the GNU ObjC runtime ... in case you 
> want
> (or need) to use that instead of the Apple one (for example, for 
> copyright
> reasons).  There should be a command line switch to switch between the 
> two
> runtimes anyway.
Right, but you have to pick the runtime that's actually on your system, 
right?  You can't say "gcc -fgnu-runtime foo.m -o foo -lobjc" if -lobjc 
is the NEXT runtime.

I wouldn't object to a patch that let you say --enable-gnu-objc-runtime 
(or whatever) and would both build the GNU runtime and change the 
default, if anyone wants to write one.