编译体积力时遇到的小报错

[Joann]

在学习用openfoam做自航的时候想尝试用体积力模型替代桨模型产生的推力，这需要引入体积力模型。
在编译时有遇到一点小问题，关于未定义引用，请问要怎么正确引用，解决这个报错提示使得编译成功？
首先这是wmake出现的提示:

/usr/bin/ld.bfd: /home/dyfluid/OpenFOAM/OpenFOAM-7/platforms/linux64GccDPInt32Opt/applications/solvers/multiphase/waveProp/waveProp.o: in function `main.cold':
waveProp.C:(.text.unlikely+0x49d): undefined reference to `Foam::functionObjects::forces::~forces()'
/usr/bin/ld.bfd: /home/dyfluid/OpenFOAM/OpenFOAM-7/platforms/linux64GccDPInt32Opt/applications/solvers/multiphase/waveProp/waveProp.o: in function `main':
waveProp.C:(.text.startup+0x8bc9): undefined reference to `Foam::functionObjects::forces::forces(Foam::word const&, Foam::objectRegistry const&, Foam::dictionary const&)'
/usr/bin/ld.bfd: waveProp.C:(.text.startup+0x8bed): undefined reference to `Foam::functionObjects::forces::calcForcesMoment()'
/usr/bin/ld.bfd: waveProp.C:(.text.startup+0x8bfc): undefined reference to `Foam::functionObjects::forces::forceEff() const'
/usr/bin/ld.bfd: waveProp.C:(.text.startup+0xa444): undefined reference to `Foam::functionObjects::forces::~forces()'
collect2: error: ld returned 1 exit status
make: *** [/home/dyfluid/OpenFOAM/OpenFOAM-7/wmake/makefiles/general:142: /home/dyfluid/OpenFOAM/OpenFOAM-7/platforms/linux64GccDPInt32Opt/bin/waveProp] Error 1

对应文件bodyForce.H中定义体积力的部分：

// Define the (cylindrical) region for the body force from dictionary values
const scalar yProp (readScalar(bodyForceDict.lookup("yProp")));
const scalar zProp (readScalar(bodyForceDict.lookup("zProp")));
const scalar xPropmin (readScalar(bodyForceDict.lookup("xPropmin")));
const scalar xPropmax (readScalar(bodyForceDict.lookup("xPropmax")));
const scalar tipRadius (readScalar(bodyForceDict.lookup("tipRadius")));
const scalar hubRadius (readScalar(bodyForceDict.lookup("hubRadius")));

Foam::functionObjects::forces F
 (
   "forces",
    mesh,
    dragForceDict
 );
F.calcForcesMoment();//这里未定义引用，该如何修改？
vector force =F.forceEff();//这里未定义引用，该如何修改？
scalar drag = force.x();//这里未定义，该如何修改？
Info << "Thrust = " << drag << endl;
scalar thrust = 1.1*drag; //Considering 10% more