Problem 2348

Dear all,

following a suggestion by a colleague of yours (here https://bugzilla-geant4.kek.jp/show_bug.cgi?id=2347) I am working on replacing my crude Geant4 output suppression via stream failbits with a more appropriate solution.

As I understand, the best way to achieve my goal (having full control over terminal output) is to derive from G4UIsession and to overload the Receive*() methods. This is what I do (abbreviated):

    class G4LoggingDestination : public G4UIsession {
    public:
        G4int G4LoggingDestination::ReceiveG4cout(const G4String& msg) {
            MY_LOGGER << msg;
            return 0;
        }
    };

In order to activate this I attach this class to the UI session in the RunManager's constructor (abbreviated):

    class RunManager : public G4RunManager {
    public:
        RunManager() {
            auto* my_logger = new G4LoggingDestination();
            G4UImanager* ui_g4 = G4UImanager::GetUIpointer();
            ui_g4->SetCoutDestination(my_logger);
        }
    };

and do the same for possible WorkerRunManager in their constructor.

This approach seems to work fine for most output, however, there are two bits that don't respect the G4UIsession cout target:

* At construction of the run manager, the Geant4 version is printed to plain std::cout:

**************************************************************
 Geant4 version Name: geant4-10-07-patch-01 [MT]   (5-February-2021)
  << in Multi-threaded mode >> 
[...]
**************************************************************

I'm not sure if this can be changed, i.e. if the G4cout stream is already present.

* During InitializePhysics() of the RunManagerKernel, so at a much later stage, there is one tiny bit of information that uses the G4cout stream but does not seem to respect the UIsession target - I always get this printed directly to the terminal and not to my own logger instance. This comes from the Dump() method of  the class G4DeexPrecoParameters in source/processes/hadronic/models/de_excitation/management/src/G4DeexPrecoParameters.cc

=======================================================================
======       Pre-compound/De-excitation Physics Parameters     ========
=======================================================================
Type of pre-compound inverse x-section              3
[...]
=======================================================================

Is there a way to fix this?

All the best,
Simon