Re: new classes

From: Axel Naumann <Axel.Naumann_at_cern.ch>
Date: Sat, 01 Jul 2006 21:29:35 +0200

Hi Mario,

have a look at the Makefile in test, where libEvent is build from Event.cxx and the dictionary generated on Event.h. You'll need

gcc `root-config --cflags` -c MyClass.cxx
rootcint -f MyClassDict.cxx -c -p MyClass.h MyClassLinkdef.h
gcc `root-config --cflags` -c MyClassDict.cxx

ld `root-config --ldflags` `root-config --glibs` MyClass.o MyClassDict.o -o test

MyClassLinkdef.h contains
#ifdef __CINT__

#pragma link off all globals;
#pragma link off all classes;
#pragma link off all functions;

#pragma link C++ class TMyClass;
#endif

There's no contradiction between a script and a set of command line parameters: you can always call

root -l -b -q "MySteeringScript.C(\"whats the question\",42)"

where MySteeringScript.C contains e.g.

void MySteeringScript(const char sentence, int number) {   if (gSystem->CompileMacro("MyClass.C"))     gSystem->ProcessLine(Form("myfunc(\"%s\", %d);", sentence, number); }

That way you don't have to write a build system, but can immediately work on code. The build system you're going to come up with is most probably not the one used when your code goes into production - it's just for prototyping.

> Also what do I have to do to be able to just add #include "MyEvent.h"
> and then just use the object in any code segment? What kind of
> compilation does that have to be? Is ACLiC compiled .so file enough (if
> it's in LD_LIBRARY_PATH) or do I have to do something else?

The .so file will be enough. Again, in ACLiC you don't have to care, you just load the lib before you use it.

Cheers, Axel.

> On Jul 1, 2006, at 2:47 AM, Axel Naumann wrote:
> 
> 

>> Hi Mario,
>>
>>
>> I'm positive that the total time of you reading the part on ACLiC in
>>
>> chapter 7 is less than me copying its content into an email and you
>>
>> reading this email. So why don't you read the users guide, chapter 7.
>>
>>
>> As I'm a nice guy (sometimes :-), I even gave you the way to compile
>>
>> your code with root - you probably didn't realize it, though: the ".L
>>
>> ..+" compiles it.
>>
>>
>> If you have to use GCC (trust me, you don't, but you seem not be the
>>
>> listening kind of guy :-) then look at root-config, which returns the
>>
>> flags you'll need to pass to GCC. And you can check rootcint to build
>>
>> the dict, which you then need to compile and link into a library,
>>
>> together with your compiled code.
>>
>>
>> Or you just read ch7 and use ACLiC.
>>
>>
>> Cheers, Axel.
>>
>>
>> Mario Kadastik wrote:
>>
>>>> root [0] .L MyEvent.cxx+
>>>>
>>>>
>>>> root [1] .L MyTreeCreator.cxx+
>>>>
>>>>
>>>> root [2] createTree()
>>>>
>>>>
>>>>
>>>> would be an example. Move your main into a CreateTree() func in
>>>>
>>>>
>>>> MyTreeCreator.cxx, and you're done.
>>>>
>>>>
>>>
>>> ok, thanks for the response and I will take a look into it with testing
>>>
>>> as well, but just to spare time at this moment can you also tell me what
>>>
>>> do I have to do to actually compile a working binary with the new class
>>>
>>> and my test code? Seems the g++ commands I used didn't quite do the
>>>
>>> trick. I probably have to incorporate the dictionary, but have no
>>> idea how.
>>>
>>>
>>>
>>> --------------------------------
>>>
>>>
>>> Mario Kadastik
>>>
>>>
>>> CMS experiment
>>>
>>>
>>> mario.kadastik_at_cern.ch <mailto:mario.kadastik_at_cern.ch>
>>>
>>>
>>>
>>> "Physics is like sex, sure it may give some practical results, but
>>>
>>> that's not why we do it"
>>>
>>>
>>> --- Richard P. Feynman
>>>
>>>
>>>
>>>
>>

> 
> --------------------------------
> 
> Mario Kadastik
> 
> CMS experiment
> 
> mario.kadastik_at_cern.ch <mailto:mario.kadastik_at_cern.ch>
> 
> 
> "Physics is like sex, sure it may give some practical results, but
> that's not why we do it"
> 
>     --- Richard P. Feynman
> 
> 
> 

Received on Sat Jul 01 2006 - 21:29:47 MEST