Re: [jamboost] Re: Re: Re: bjamv2: linking exe with whole list of system libs

From: Toon Knapen (toon.knapen_at_[hidden])
Date: 2004-08-24 08:58:24

Vladimir Prus wrote:

>>However what do you mean with _messy_ order-sensitivity. Why do you
>>think it is messy ?
> 
> 
> I generally believe that non-obvious order sensitivity is bad. If "-la -lb"
> means something different from "-lb -la", it's non-obvious

I can not agree with you here. Actually I find the library-order 
sensitivity a good thing. First of all the order allows the linker to 
optimise the search operations for finding definitions. OTOH this makes 
that developers should be aware of the dependencies between the 
libraries which is also a good thing: this forces developers to avoid 
circular dependencies.

> I've seen a lot
> of folks type
> 
> gcc -o hello -lm hello.o
> 
> and then wonder why math function are not found. 

But users should learn first about using the tool (from the 
documentation e.g.) instead of trying a tool and complain that it does 
not work as _they_ expect.

> Yes, the order sensitivity
> can be handy when one library wants to override symbols from the other.
> That is, if two libraries define function 'userinit', then the first
> definition is used. But such cases are not common and could be solved with
> explicit mechanisms. 

I never considered this a feature of the order-dependency, I also find 
this kind of use 'dirty'.

> Anyway, that's just philosophical ideas of mine, so
> don't take them too seriously.

I was just curious about your opinion. In our company I find it very 
important that developers know what the different development tools 
actually do and how these tools work (and eventually how a computer 
works): I think it improves code-quality.