Thread: Compile error: Inheritance related?

My project was working fine, and all of a sudden i started getting this error:

Undefined first referenced
symbol in file
Creature type_info function Grass.o
Creature type_info node Grass.o
Creature virtual table world.o

ld: fatal: Symbol referencing errors. No output written to world
collect2: ld returned 1 exit status


World is the excecutable, and Grass IS-A Creature.

using g++ version 2.95.2

Any ideas? Thanks.

Sorry for the really long post.

Code:

//
// World
//
// 

#include <ezwin.h>
#include <assert.h>
#include <rect.h>
#include "Creature.h"
#include "Wanderer.h"
#include "Grass.h"
#include "linkedList.h"
#include "unorderedLinkedList.h"
using namespace std;
const double PI = 3.14159265;
unorderedLinkedList<Wanderer> wanderers;
linkedListIterator<Wanderer> wit; 
linkedListIterator<Wanderer> wit2;
unorderedLinkedList<Grass> grasses;
linkedListIterator<Grass> git;
linkedListIterator<Grass> git2; 
...
........................LOTS OF CODE........................
...
// MoveBox(): Move the box a little bit (gets called by timer)
//            This will animate the box.
double growgrass =0;
int LetThereBeLife() {
    growgrass++;
    Wanderer a;
    bool collided;
    bool grazing;
    for (wit = wanderers.begin(); wit != wanderers.end(); ++wit){
        collided=false;
        grazing=false;
        Wanderer temp = *wit;
        undrawWanderer(temp);
        a=temp.act(0);
        
        for (wit2 = wanderers.begin(); wit2 != wanderers.end(); ++wit2){
            if(*wit2 != a && collided==false)
                collided = collide(*wit2,a);
        }
        for (git2 = grasses.begin(); git2 != grasses.end(); ++git2){
            if(grazing==false)
                grazing = collide(*wit,*git2);
        }
        if(grazing){
            temp.act(-1);
        }
        
        if(collided){
            temp.act(2);
        }
        else{ 
            temp.act(1);
        }
        
        drawWanderer(temp);
        wanderers.deleteNode(temp);
        wanderers.insertLast(temp);     
    }
    Grass g;
    collided=false;
    for (git = grasses.begin(); git != grasses.end(); ++git){
        
        Grass temp = *git;
        undrawGrass(temp);
        g=temp.act(0);
        
        for (wit2 = wanderers.begin(); wit2 != wanderers.end(); ++wit2){
            if(collided==false)
                collided = collide(*wit2,*git);
        }
        if( collided){
           temp.act(2);
        }
        else{ 
            temp.act(1);
        }
        drawGrass(temp);
        
        temp.eat();
        grasses.deleteNode(temp);
        grasses.insertLast(temp); 
        cout<<temp.getScale()<<endl;
    
    }
    
    
 
  return 0;
}

Grass.h

Code:

#ifndef GRASS
#define GRASS
#include <iostream>

using namespace std;



class Grass : public Creature
{
public:
    Grass act(int);
    Grass(double,double,int,int,int,int);
    Grass();
    void setScale(double s);
    void eat();
private:
    Grass *simulation;
};
#endif

Grass.cpp

Code:

#include <iostream>
#include <cstdlib> 
#include "Creature.h"
#include "Grass.h"

using namespace std;

Grass Grass::act(int code){
    
    int x = rand()%20;
    int pm = rand()%2;
    int perc = rand()%100;
    // if(perc>50){
//         if(perc>25){
//             cout<<"cont right"<<endl;
//             pm = 0;
//         }else{
//             cout<<"cont left"<<endl;
//             pm = 1;
//         }
        
//     }
   switch(code){
        case 0:
            simulation= new Grass(xLoc,yLoc,orientation,worldx,worldy,ID);
            
            break;
        case 1:
            
            
            break;
        case 2:
            
            if(xSize>.01)
                xSize=xSize-.01;
            if(ySize>.01)
                ySize=ySize-.01;
            scale-=.01;
            break;
    }
   return *simulation;
}

Grass::Grass(double x,double y,int orient,int worldsizex, int worldsizey, int cID){
    yLoc = y;
    xLoc = x;
    walkSpeed=0;
    runSpeed=.01;
    maxAngle=20;
    xSize=.2;
    ySize=.2;
    orientation=orient;
    age=0;
    health=10;
    worldx=worldsizex;
    worldy=worldsizey;
    ID=cID;
}
Grass::Grass(){
}
void Grass::setScale(double s){
    if(xSize<1.5){
        scale+=s/1000;
        xSize+=s/1000;
        ySize+=s/1000;
    }
    
}

void Grass::eat(){
    setScale(getXSize()+2);
}

Creature.cpp

Code:

#include "Creature.h"
#include <iostream>
#include <math.h>

using namespace std;

const double PI = 3.14159265;

bool Creature::move(double x,double y){
    lastxLoc=xLoc;
    lastyLoc=yLoc;
    if(x>0 && x<worldx && y>0 && y<worldy){
        xLoc=x;
        yLoc=y;
        return true;
    }else
        return false;
}
void Creature::run(int angle){
    oldorientation = orientation;
  
    double xTemp;
    double yTemp;
    if(abs(angle-orientation)<maxAngle){
       
        yTemp=-1*sin(angle*PI/180)*runSpeed+yLoc;
        xTemp=cos(angle*PI/180)*runSpeed+xLoc;
        
        move(xTemp,yTemp);
            orientation = angle;
    }
    
        
    
}
void Creature::walk(int angle){
    oldorientation = orientation;
  
    double xTemp;
    double yTemp;
    if(abs(angle-orientation)<maxAngle){
       
        yTemp=-1*sin(angle*PI/180)*walkSpeed+yLoc;
        xTemp=cos(angle*PI/180)*walkSpeed+xLoc;
        
        move(xTemp,yTemp);
            orientation = angle;
    }
    
}
void Creature::die(){
    // undraw();
    
}

double Creature::getYLoc(){
    return yLoc;
}
double Creature::getXLoc(){
    return xLoc;
}
double Creature::getXSize(){
    return xSize;
}
double Creature::getYSize(){
    return ySize;
}
double Creature::getHealth(){
    return health;
}
int Creature::getID() const{
    return ID;
}
Creature::Creature(double x,double y,int orient,int worldsizex, int worldsizey, int cID){
    yLoc = y;
    xLoc = x;
    walkSpeed=2;
    runSpeed=4;
    maxAngle=10;
    xSize=3;
    ySize=3;
    orientation=90;
    age=0;
    health=100;
    worldx=worldsizex;
    worldy=worldsizey;
    ID=cID;
    //draw();
}
Creature::Creature(){
}
    

void Creature::setScale(double newscale){
    scale=newscale;
}
double Creature::getScale(){
    return scale;
}

bool Creature::operator == (const Creature c)const{
    return ID == c.getID();
}
bool Creature::operator != (const Creature c)const{
    return ID != c.getID();
}
int Creature::getOrientation(){
    return orientation;
}

Creature.h

Code:

#ifndef CREATURE
#define CREATURE

#include <iostream>
#include "linkedList.h"
#include "unorderedLinkedList.h"

using namespace std;


class Creature
{
public:

    bool operator == (const Creature c) const;
    bool operator != (const Creature c) const;
    bool move(double,double);
    void run(int angle);
    void walk(int angle);
    void die();
    double getYLoc();
    double getXLoc();
    double getXSize();
    double getYSize();
    int getID() const;
    double getHealth();
    int getOrientation();
    Creature(double,double,int,int,int,int);
    Creature();
    void setScale(double scale);
    double getScale();
    virtual void eat();

protected:
    double xLoc;
    double yLoc;
    double walkSpeed;
    double runSpeed;
    int maxAngle;
    double xSize;
    double ySize;
    int orientation;
    int oldorientation;
    int age;
    double health;
    int worldx;
    int worldy;
    double scale;
    int ID;
    double lastxLoc;
    double lastyLoc;

};

#endif

With multi-module code such as this, posting a .zip may be more in your interest -- because even though you took the time and pre-apologized for the long post, you are still missing several files that would allow others to attempt to build your project.

[edit]This isn't that old Borland stuff, is it?

Code:

#include <ezwin.h>

Try to rebuild, instead of build?

Originally Posted by blyrrh

yea, ezwin is some ancient graphics api, but we have to use it for this assignment. I would have zipped them but im new to UNIX and don't really know how.

I'm surprised to hear that it's possible to build a Borland EzWin app for Windows using gcc on UNIX.