Adding a new objective function to DAFoam

[chairmanmao256]

Dear He Ping:
I'm here again. I'd like to add a new objective function to DAFoam and I do it in the following steps:

   1. Write `DAObjFuncMyObj.H` and `DAObjFuncMyObj.C` to define my own objective function.
   2. Add `DAObjFuncMyObj.C` to `dafoam-2.2.9/src/adjoint/Make/files`
   3. Compile the entire DAFoam

However, the compilation is aborted due to error. The error message is:

cc1plus: warning: command line option ‘-Wstrict-prototypes’ is valid for C/ObjC but not for C++
In file included from ../adjoint/lnInclude/DAResidual.H:19,
                 from ../adjoint/lnInclude/DAObjFunc.H:22,
                 from ../adjoint/lnInclude/DASolver.H:27,
                 from DASolvers.H:16,
                 from pyDASolvers.cpp:714:
DASolvers.H: In member function ‘double Foam::DASolvers::getObjFuncValue(Foam::word)’:
../include/DAMacroFunctions.H:101:17: error: request for member ‘getValue’ in ‘((Foam::DASolvers*)this)->Foam::DASolvers::DASolverPtr_.Foam::autoPtr<Foam::DASolver>::operator->()->Foam::DASolver::getObjFuncValue(Foam::word(objFuncName))’, which is of non-class type ‘Foam::scalar’ {aka ‘double’}
  101 |     valA = valB.getValue();
      |                 ^~~~~~~~
../include/DAMacroFunctions.H:101:17: note: in definition of macro ‘assignValueCheckAD’
  101 |     valA = valB.getValue();
      |                 ^~~~~~~~
DASolvers.H: In member function ‘double Foam::DASolvers::getPrevPrimalSolTime()’:
../include/DAMacroFunctions.H:101:17: error: request for member ‘getValue’ in ‘((Foam::DASolvers*)this)->Foam::DASolvers::DASolverPtr_.Foam::autoPtr<Foam::DASolver>::operator->()->Foam::DASolver::getPrevPrimalSolTime()’, which is of non-class type ‘Foam::scalar’ {aka ‘double’}
  101 |     valA = valB.getValue();
      |                 ^~~~~~~~
../include/DAMacroFunctions.H:101:17: note: in definition of macro ‘assignValueCheckAD’
  101 |     valA = valB.getValue();
      |                 ^~~~~~~~
DASolvers.H: In member function ‘double Foam::DASolvers::getTimeInstanceObjFunc(Foam::label, Foam::word)’:
../include/DAMacroFunctions.H:101:17: error: request for member ‘getValue’ in ‘((Foam::DASolvers*)this)->Foam::DASolvers::DASolverPtr_.Foam::autoPtr<Foam::DASolver>::operator->()->Foam::DASolver::getTimeInstanceObjFunc(((Foam::label)instanceI), Foam::word(objFuncName))’, which is of non-class type ‘Foam::scalar’ {aka ‘double’}
  101 |     valA = valB.getValue();
      |                 ^~~~~~~~
../include/DAMacroFunctions.H:101:17: note: in definition of macro ‘assignValueCheckAD’
  101 |     valA = valB.getValue();
      |                 ^~~~~~~~
error: command 'mpicc' failed with exit status 1
./Allmake: line 20: cd: src/utilities/coloring: No such file or directory
./Allmake: line 21: cd: src/utilities/postProcessing: No such file or directory

The error might have something to do with the AD version of the code. It seems that the steps I followed to add a new objective function are incomplete or wrong. Looking forward to your reply!
Thank you!

[chairmanmao256]

Problem fixed! I've rewritten the expression of the objective function and converted the result to scalar type. And then everything works. Thus the steps I followed to add a new objective function might be correct.