Thread: undefined reference to function in class error

Yea for some reason I keep getting this error.

ERROR

Code:

main.o: In function `Render()':
main.cpp:(.text+0xa0): undefined reference to `CControllerFunc::buttonstatus(int
)'
collect2: ld returned 1 exit status
make: *** [gui_class_tut.elf] Error 1

Here's all the files.

main.cpp

Code:

#include <pspdisplay.h>
#include <pspkernel.h>
#include <pspdebug.h>
#include <pspctrl.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
//#include "main.h"
#include "controller.h"
//#include "menu.h"

CControllerFunc CController;

//#include "menu.h"
//Define module info for this program.
PSP_MODULE_INFO("BLADECONTROLLERTUT", 0, 1, 1);
//Define dprint as pspDebugScreenPrintf.
#define dprint	pspDebugScreenPrintf 
//Define done integer.
int done = 0;
//Define variable called pad with controller data type.
//Define exit_callback function.
int exit_callback(int arg1, int arg2, void *common)
{
	done = 1;
	return 0;
}
//Define CallbackThread function.
int CallbackThread(SceSize args, void *argp)
{
	int cbid;
	cbid = sceKernelCreateCallback("Exit Callback", exit_callback, NULL);
	sceKernelRegisterExitCallback(cbid);
	sceKernelSleepThreadCB();
	return 0;
}
//Define Render function. Contains main code
void Render(){
//Reads the controller buffer.
sceCtrlReadBufferPositive(&CController.pad, 1);
dprint("-STATUS-\t\t-BUTTON-\n\n");
if(CController.buttonstatus(PSP_CTRL_CROSS)){
	dprint("-DOWN-\t\t-CROSS-\n\n");
	} else {
	dprint("- UP -\t\t-CROSS-\n\n");
	}
}
//Define SetupCallbacks function
int SetupCallbacks(void)
{
	int thid = 0;
	thid = sceKernelCreateThread("update_thread", CallbackThread, 0x11, 0xFA0, 0, 0);
	if(thid >= 0)
	{
		sceKernelStartThread(thid, 0, 0);
	}
	return thid;
}
//Define main function
int main(void)
{
	pspDebugScreenInit();//Intialize debug screen mode.
	SetupCallbacks();
	sceCtrlSetSamplingCycle(0);//Set controller sampling cycle
	sceCtrlSetSamplingMode(1);//Set controller sampling mode
	pspDebugScreenSetTextColor(0x82DCFD00);//Set debug text color
	while(!done){//While the program isn't done
		sceDisplayWaitVblankStart();//Wait until the screen is done clearing
		Render();//Render
		pspDebugScreenClear();//Clear the screen
	}
	sceKernelExitGame();//Exit game
	return 0;//Return 0 since main is an int type
}

controller.cpp

Code:

#include "controller.h"

int CControllerFunc::buttonstatus(int Button)
{

	if(pad.Buttons & Button){
	pressed = 1;
	} else {
	pressed = 0;
	}
	return pressed;

}

controller.h

Code:

#ifndef CONTROLLER_H
#define CONTROLLER_H

class CControllerFunc
{

public:

	CControllerFunc();
	~CControllerFunc();
	int buttonstatus(int Button);
	SceCtrlData pad;

private:

	int pressed;
	
	
};

//Constructor of CControllerFunc

CControllerFunc::CControllerFunc()
{
pressed = 0;
}

//Deconstructor of CControllerFunc - Takes no action

CControllerFunc::~CControllerFunc()
{


}
#endif

Any ideas? Thanks for everything

You have to compile and link controller.cpp along with main.cpp so that the function definition is compiled and linked.

Originally Posted by Daved

You have to compile and link controller.cpp along with main.cpp so that the function definition is compiled and linked.

Well controller.h is included into main.cpp, so wouldn't that work? If not give me an example.

Each source file (cpp file) must be compiled, and then after each source file is compiled, they are all linked together. If you have a makefile, you must add controller.cpp to the makefile. If you have a project, then you must add controller.cpp to the project. If you build on the command line, then you must add controller.cpp to the command line.

If you have trouble, tell us what compiler and/or IDE you are using and show the commands (if any) you are using to build the program.

Originally Posted by Daved

Each source file (cpp file) must be compiled, and then after each source file is compiled, they are all linked together. If you have a makefile, you must add controller.cpp to the makefile. If you have a project, then you must add controller.cpp to the project. If you build on the command line, then you must add controller.cpp to the command line.

If you have trouble, tell us what compiler and/or IDE you are using and show the commands (if any) you are using to build the program.

Yea, I am using a make file, and I am using Cygwin, because this a linux based compiler and this is what's in it :

Code:

TARGET = gui_class_tut
OBJS = main.o

INCDIR = 
CFLAGS = -O2 -G0 -Wall
CXXFLAGS = $(CFLAGS) -fno-exceptions -fno-rtti
ASFLAGS = $(CFLAGS)

LIBDIR =
LDFLAGS =

EXTRA_TARGETS = EBOOT.PBP
PSP_EBOOT_TITLE = GUI Class Tut
PSPSDK=$(shell psp-config --pspsdk-path)
include $(PSPSDK)/lib/build.mak

It's been awhile since I've even looked at a makefile, but it looks like something is missing. You will need to add controller.o to the OBJS, but I don't see where it specifies all the source files. Maybe in build.mak?

Originally Posted by Daved

It's been awhile since I've even looked at a makefile, but it looks like something is missing. You will need to add controller.o to the OBJS, but I don't see where it specifies all the source files. Maybe in build.mak?

build.mak is just part of the sdk itself. Lemme see if adding it to the OBJS works.

Ok, now I changed the make file to

Code:

TARGET = gui_class_tut
OBJS = main.o
OBJS = controller.o

INCDIR = 
CFLAGS = -O2 -G0 -Wall
CXXFLAGS = $(CFLAGS) -fno-exceptions -fno-rtti
ASFLAGS = $(CFLAGS)

LIBDIR =
LDFLAGS =

EXTRA_TARGETS = EBOOT.PBP
PSP_EBOOT_TITLE = GUI Class Tut
PSPSDK=$(shell psp-config --pspsdk-path)
include $(PSPSDK)/lib/build.mak

but now I get this error

Code:

In function `_main': undefined reference to `main'
collect2: ld returned 1 exit status

This seems..........ridiculous

I would think it should be one definition of OBJS:

Code:

OBJS = main.o controller.o

Originally Posted by Daved

I would think it should be one definition of OBJS:

Code:

OBJS = main.o controller.o

That works better, but I still get alot of errors

Code:

controller.o: In function `CControllerFunc::CControllerFunc()':
controller.cpp:(.text+0x0): multiple definition of `CControllerFunc::CController
Func()'
main.o:main.cpp:(.text+0x0): first defined here
controller.o: In function `CControllerFunc::CControllerFunc()':
controller.cpp:(.text+0x8): multiple definition of `CControllerFunc::CController
Func()'
main.o:main.cpp:(.text+0x8): first defined here
controller.o: In function `CControllerFunc::~CControllerFunc()':
controller.cpp:(.text+0x10): multiple definition of `CControllerFunc::~CControll
erFunc()'
main.o:main.cpp:(.text+0x10): first defined here
controller.o: In function `CControllerFunc::~CControllerFunc()':
controller.cpp:(.text+0x18): multiple definition of `CControllerFunc::~CControll
erFunc()'
main.o:main.cpp:(.text+0x18): first defined here
collect2: ld returned 1 exit status
make: *** [gui_class_tut.elf] Error 1

Since both controller.cpp and main.cpp are including controller.h, the compiler compiles the functions in controller.h both times, and you get errors in the linking because they are defined multiple times. So the definitions for those functions (CControllerFunc::CControllerFunc() and CControllerFunc::~CControllerFunc()) in your header file should go in the controller.cpp file instead, or they should be moved inside the class declaration to be inlined.

Originally Posted by Daved

Since both controller.cpp and main.cpp are including controller.h, the compiler compiles the functions in controller.h both times, and you get errors in the linking because they are defined multiple times. So the definitions for those functions (CControllerFunc::CControllerFunc() and CControllerFunc::~CControllerFunc()) in your header file should go in the controller.cpp file instead, or they should be moved inside the class declaration to be inlined.

That would beat the point of the header file. I don't wanna do that.
There another alternative?

That doesn't beat the point of the header file, since the class declaration would still go in the header and the class method definitions would go in the source file.

An alternative is to make the method definitions inline. You can do that by moving the definition inside the class declaration (instead of ending the constructor declaration with a semi-colon replace that with the block of code for the method itself).