[Click] element_provides and element_requires

[Eddie Kohler]

I agree with Bart, Nele; it sounds like you have not put
#include "trains_tcb.hh"
in the top of trains_CDM.cc.

Eddie


Bart Braem wrote:
> Nele,
> 
> On Friday 06 July 2007 09:55, Nele Gheysens wrote:
>> Eddie, you asked my which linker errors appeared. But I cannot reproduce
>> these linker errors anymore after performing a make distclean. 
> 
> (This is always a good thing to do when you have strange errors, even better 
> Makefiles like the ones used in Click can't avoid linking leftovers.)
> 
>> End of file trains_CDM.cc:
>>
>> CLICK_ENDDECLS
>> ELEMENT_REQUIRES(sctp_Trains_TCB)
>> ELEMENT_REQUIRES(sctp_Trains_Timer )
>> ELEMENT_REQUIRES(sctp_Trains_Link)
>> EXPORT_ELEMENT(Trains_CDM)
>>
>> When I compile this, I get the following error:
>>
>> ../elements/local/trains/trains_CDM.cc:98: error:
>> `get_databuffer_length' undeclared (first use this function)
>> (and so on for some other functions)
>>  
>>
>> where get_databuffer_length()  (and the other functions the compiler is
>> complaining about) is a funcion provided bij trains_tcb.cc.
>> If I put a mistake in de file trains_tcb.cc or trains_tcb.hh, the
>> compiler doesn't complain. So I believe that this file isn't compiled.
>> But I don't understand why.
> 
> Did you include trains_tcb.hh in trains_CDM.cc? I think ELEMENT_REQUIRES does 
> not do any source file includes, so you must make the functions visible 
> yourself by including the right headers.
> (Perhaps you did this, but then I completely don't understand why the compiler 
> does not complain about mistakes in those files.)
> 
> Bart
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> click mailing list
> click at amsterdam.lcs.mit.edu
> https://amsterdam.lcs.mit.edu/mailman/listinfo/click