Re: [xml] Generating a correct xml2-config for use with --libs

[Gary Pennington <Gary Pennington sun com>]

Igor Zlatkovic wrote:

> Good Morning, 
>
>  
>
> > Let me be clear, you should only link your application with 
> > -lsocket if 
> > your application needs access to a member of libsocket. Otherwise you 
> > are creating a completely unneccessary dependancy on a 
> > library that your 
> > application doesn't directly depend on.
> >    
>
> I was wondering... Why does Sun linker create that dependence?
That's the default behaviour for the linker. See below.

> The way you want to have it is the only way possible on Windows. I
> cannot successfully compile a shared object without resolving all
> dependences. But, my linker has a switch which makes it ignore all
> libraries specified on the command line if the program being linked uses
> no symbols from these libraries.
>
> Isn't Sun's linker able to do the same, means create a dependence to
> libsocket.so if and only if your program actually used something in
> libsocket.so? Treat -lsocket merely as a hint for where to look for
> symbols, not as an instruction to create a dependence in any case? Isn't
> that possible?
It is possible, but it's not default. The default behaviour is to create 
dependancies for all supplied libraries. You can get the behaviour you 
describe by specifying the -z ignore option to the linker, which 
suppresses the dependency recording of unused shared objects.

> Don't get me wrong, I am not taking sides here. We don't use the same
> makefile, so I am neutral on the topic. I am just surprised about Sun's
> compiler package.
No need to be surprised, it seems like the linker (MSVC?) you describe 
and the Sun linker have the same behaviour.

The reason I wanted to clean up the xml2-config script is simply because 
I want to help those people who aren't knowledgeable about all the 
options which their compilation system supports. Sure, knowledgeable 
people can use "-z ignore" and thus remain unaffected by the (in the 
case of Solaris and dynamic linking) redundant library specifications in 
xml2-config. However, that's not much help to the vast majority of 
application developers who don't know all the linker flags on all the 
platforms they develop on.

Gary