RE: [ROOT] filling tree with objects

From: Philippe Canal (pcanal@fnal.gov)
Date: Mon Jul 07 2003 - 14:56:04 MEST 

Hi Paul,

Your problem is probably that you are using a static library.  
When using a shared library, the dictionary is automatically loaded.
On the other hand when using a static library you have to force the linking of the dictionary.  For this you have 3 methods:
	- add the dictionary object file to the link line
	- Explicitly ask for a symbol from the dictionary on the link line -uXXXX
	- add to the main and/or a function that is for sure linked in a reference to something in
		the dictionary file.

Cheers,
Philippe.

-----Original Message-----
From: Paul Balm [mailto:r45@nikhef.nl]
Sent: Monday, July 07, 2003 2:43 AM
To: Philippe Canal
Cc: p.balm@nikhef.nl; roottalk@pcroot.cern.ch
Subject: Re: [ROOT] filling tree with objects


Hi Philippe,

I think now my dictionary generation actually did succeed: I see messages like "generating rootcint dictionary" and "compiling dictionary" etc., and they're not followed by errors.
But when I run my program I have a new problem:

Error in <BuildRealData>: Can not find any ShowMembers function for recocert::V0!

It seems that the ShowMembers method was generated correctly and included in my library too:

diemen-clued0:/work/diemen-clued0/balm/recocert/p1403 >nm lib/Linux2.4-KCC_4_0/librecocert.a  | grep ShowMembers
         U ShowMembers__7TCanvasFR16TMemberInspectorPc
00000628 t GenericShowMembers__4ROOTFPCcPvR16TMemberInspectorPcb
00000c50 t GetShowMembersWrapper__6TClassFv
         U ShowMembers__7TObjectFR16TMemberInspectorPc
000003bc T ShowMembers__Q2_8recocert2V0FR16TMemberInspectorPc

Do you know what may be the problem here?
Thanks-

Paul

Philippe Canal wrote:

Hi Paul,

I am surprised that your dictionary generation succeeded.  I would expect that you need to have (in that order):

class V0 : public TObject {
(...)
ClassDef(V0,1);
};
....
#ifdef __MAKECINT__
#pragma link C++ namespace recocert;
#pragma link C++ class recocert::V0+;
#endif

__AND__ 

have either an empty linkdef file or at least a linkdef file with NO 'pragma link off'

Cheers,
Philippe.


-----Original Message-----
From: Paul Balm [mailto:r45@nikhef.nl]
Sent: Thursday, July 03, 2003 10:42 AM
To: Philippe Canal
Cc: roottalk@pcroot.cern.ch
Subject: Re: [ROOT] filling tree with objects


Hi Philippe,

In the header file that defines the V0 class, I (now) have:

#pragma link C++ namespace recocert;
#pragma link C++ class recocert::V0+;

and later on:

class V0 : public TObject {
(...)
};

When I run the program, it says:

Error in <TTree::Bronch>: Cannot find class:recocert::V0

So I think the answer to your question is yes, but...

Thanks-

Paul


Philippe Canal wrote:

  
Hi Paul,

This should work.

Did you create a dictionary for the namespace recocert?
	#pragma link C++ namespace recocert;


Cheers,
Philippe.

-----Original Message-----
From: owner-roottalk@pcroot.cern.ch
[mailto:owner-roottalk@pcroot.cern.ch]On Behalf Of Paul Balm
Sent: Wednesday, July 02, 2003 8:07 AM
To: roottalk@pcroot.cern.ch
Subject: [ROOT] filling tree with objects


Hello,

I'm trying to fill a TTree with objects of a class "V0", declared in a
namespace "recocert". I do this:

TTree* _mytree = new TTree("V0tree","secondary vertices");
V0* _myV0 = new V0();

_mytree->Branch("V0s", "recocert::V0",&_myV0);

This gives me an error message:

Error in <TTree::Bronch>: Cannot find class:recocert::V0

At first I was creating the branch like this:

_mytree->Branch("V0s", "V0",&_myV0);

(i.e. omitting the "recocert::"), this gave me the same error message,
but, without "recocert::".

In the same file where I create the tree and the branch, I have "using
namespace recocert;"

Any idea what the problem is here? Is this just not supported? Are there
ways to work around it?

I'm using this root version:
/D0/ups/root/Linux-2-4/v3_05_00bKCC_4_0-exception-opt-thread
On Red Hat 7.1.

Thanks!

Paul

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