Re: Two questions about bundles

[Peter Cooper]

On 2008-08-28 22:43:01 +0200 David Chisnall <theraven@sucs.org> wrote:


> > I'm looking at using bundles for a non-gui tool. A curious thing is  
> > that I 
> > get a lot of superfluous libraries automatically linked.
>
> These are not superfluous.

Thanks for your response!

I'm not sure I agree with you though - the dependency on a run-time 
linked gnustep-gui means that in a non-gui tool I get exceptions from 
GSFontEnumerator etc when I load the bundle and enumerate classes and 
methods (the class enumeration happens in code I don't control, at 
least officially). In a non-GUI tool doing certain kinds of 
introspection, it is very irritating.

Thanks for the list of the library functions. I've come across most of 
them at some level of detail in the past ;-).

My question is how do I restrict them to a minimum list using 
GNUstep-make. I've hand-linked the bundle down to the following

        linux-gate.so.1 =>  (0xb7f07000)
        libc.so.6 => /lib/tls/i686/cmov/libc.so.6 (0xb7d53000)
        /lib/ld-linux.so.2 (0xb7f08000)

And a custom library and it still works (for my needs) - no problems 
using gnustep-base objects and methods (they're linked after all in 
the code I'm using to load the bundle, and are quite available at 
truntime to the code actually i the bundle).

...

> GNUstep AppKit implementation.  Possibly superfluous for a tool, but  
> it 
> contains things like NSImage and the NSAttributedString additions,  
> and so 
> it's sometimes useful.

I think a google search will show you people with corner-case problems 
with this.


> Failing to understand the output from ldd, which is not entirely your 
>  fault, 

Thanks ;-) I suspect I understand it well enough for my purposes, 
though.

> and is more to do with the fact that the UNIX linker is  monumentally 
> stupid. 
>   While you would expect to only link against the  libraries you use, 
> and have 
> the routines they use exposed to you (as  it worked in VMS, Multics, 
> and 
> pretty much any real OS), this is not  what happens on UNIX.  
> Instead, every 
> library you use and every  library it uses (and so on) is linked 
> directly 
> against your program,  and pollutes your namespace.  The output from 
> ldd 
> lists every library  you use, and every library it uses.  It's not 
> unusual 
> for this to be  a really long list even for fairly simple programs.

Again, this is output from ldd against a bundle. Not an "executable" 
or at least not standalone. It is due to be runtime linked into 
something which has these libraries (although there's some hand-waving 
social-contract stuff about who will link to what which is needed in 
commercial distribution environments I think: normally that's easy to 
regulate).

For bundles and frameworks it doesn't have to be this way, at least as 
far as I understand: it seems to me to potentially being a misfeature 
at link time using GNUstep-make for bundles; they certainly work after 
having a manual link with far fewer libraries on my particular 
platform, and in my particular case that's a real win.

Thanks again for your views

Peter