Hi Pasha,
when in dir a run rootcint like this:
rootcint -f adict.cxx -c -I../b A.h LinkDef.h
I know this is not documented, but it is the same a the cint
arguments (see cint -?).
Cheers, Fons.
>
> Hello,
>
> there is a certain problem with rootcint handling of classes it considers
> "not defined". To see what the problem is lets assume that we deal with a
> large software system with source codes residing in many directories
> (a/ and b/ in this example). Suppose sources of class A are located in
> directory a/ :
>
> -------------------------------- A.h
> class A : public TObject {
> B b;
> ClassDef(A,1)
> };
> --------------------
>
> with class B being described in directory b/ .
>
> Now, we use the following linkdef.h:
> -------------------------------------------------- linkdef.h
> #ifdef __CINT__
> #pragma link off all globals
> #pragma link off all functions
> #pragma link off all classes
> #pragma link C++ class A;
> #pragma link C++ class B;
> #endif
> --------------------------------------------------
> then we `cd' into directory a/ and try to create CINT dictionary:
>
> >cd a
> >rootcint -f a_cint.cc -c linkdef.h A.h
>
> This generates diagnostics:
>
> Class B: Streamer() not declared
> Class B: ShowMembers() not declared
>
> which is fine, however (and this is not fine at all!) A::Streamer method
> generated by rootcint *does not* contain call to B::Streamer:
> ----------------------------------------------
> void A::Streamer(TBuffer &R__b)
> {
> // Stream an object of class A. ***** call to B::Streamer is missing here
>
> TObject::Streamer(R__b);
> }
> ----------------------------------------------
> The example above shows that there is an implicit assumption that there
> is *only one* CINT dictionary for the whole system...
> If I want (and it seems to be a pretty reasonable solution) to have a CINT
> dictionary per subdirectory, then to generate CINT dictionary for the files
> in directory a/ it
> is necessary for rootcint to read include files from directory b/.
> Therefore, the generated for a/ CINT dictionary will include B::Streamer.
> However the same function B::Streamer would also be contained in the dictionary
> generated for directory b/ and we end up with having multiple definitions of the
> same function and a lot of linker warnings...
>
> One of the ways to resolve this problem is to generate Class::Streamer etc
> functions assuming that *all* the classes involved if not defined on the input
> stream have their dictionaries generated elsewhere.
> I remind that in most of the cases (if not in 100%) correct generation
> of the A::Streamer method *does not* require the definition of the class B to
> be available. To do it it is quite enough to know only the name of the
> class (B in this case).
>
> Any comments ? Regards, Pasha
--
Org: CERN, European Laboratory for Particle Physics.
Mail: 1211 Geneve 23, Switzerland Phone: +41 22 7679248
E-Mail: Fons.Rademakers@cern.ch Fax: +41 22 7677910
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