Occasionally, I get one error message and many warnings.
The error message is utterly useless:
"Error error: ld returned 1 exit status collect2.exe"
The verbose build output is attached.
My code is huge, so I am not going to waste your (or my) time trying to attach it. Instead, I want to understand:
BuildOutput.txt (134 KB)
- What causes this message?
Errors in your code.
- How do I diagnose that cause?
Do not ignore the messages that come before the last one (that you show).
I.E. What do I look for that will help me understand the cause?
The messages that come before that one.
- How do I fix this problem?
Fix the errors that precede it.
I would appreciate a serious answer rather than a simplistic one. Here is the data:
There is only 1 error: "ld returned 1 exit status collect2.exe"
There are a number of warnings:
The two that are at the heart of the problem are (I believe) the "Undefined reference to 'vtable... messages. I have checked carefully to make sure that all abstract methods in parent classes have corresponding concrete methods in this class. I have made sure that every class has a destructor. Beyond that, I can find no information on how to determine what the "undefined references to vtable" are. I can find no utility program that can give me an answer to this question and I have had no success with any other sources.
The verbose output of the build is attached.
BuildVerboseOutput.txt (153 KB)
DualMotorRomeo.h:undefined reference to
vtable for DualMotorRomeo DualMotorRomeo.h:undefined reference tovtable for DualMotorRomeo
Are you adorning initialized object instances with PROGMEM that have virtual methods?
I am still struggling with cryptic output from gcc, Here is the complete error / warning list:
Severity Description File Line Column Category
Warning In function `DualMotorRomeo D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\CommandPattern3.cpp.o -1
Error error: ld returned 1 exit status collect2.exe
Warning undefined reference to `vtable for DualMotorRomeo D:\Users\Bob.ObigOne\Documents\Arduino\CommandPattern3\DualMotorRomeo.h 40
Warning undefined reference to `vtable for DualMotorRomeo D:\Users\Bob.ObigOne\Documents\Arduino\CommandPattern3\DualMotorRomeo.h 40
Here is the DualMotorRomeo.h code:
#ifndef _DUALMOTORROMEO_h
#define _DUALMOTORROMEO_h
#if defined(ARDUINO) && ARDUINO >= 100
#include "arduino.h"
#else
#include "WProgram.h"
#endif
#include "BJRobotOptions.h"
#include "AssertDiagnostic.h"
#include "PropulsionSystem.h"
#include "GenericDualMotor.h"
#include "MotorDefinition.h"
#include "MotorDefinitionRomeo.h"
class DualMotorRomeo : public GenericDualMotor {
public:
int _leftMotion;
int _leftSpeed;
bool _leftFlip;
int _rightMotion;
int _rightSpeed;
bool _rightFlip;
bool _validated;
MotorDefinitionRomeo *leftMotor;
MotorDefinitionRomeo *rightMotor;
BJRobotOptions::Settings *settings;
// Constructor
DualMotorRomeo(BJRobotOptions::Settings *s) : settings(s), GenericDualMotor(this, MT_ROMEO) {
_leftMotion = settings->motorPins.leftMotion;
_leftSpeed = settings->motorPins.leftSpeed;
_leftFlip = settings->motorPins.leftFlip;
_rightMotion = settings->motorPins.rightMotion;
_rightSpeed = settings->motorPins.rightSpeed;
_rightFlip = settings->motorPins.rightFlip;
};
// Destructor
~DualMotorRomeo() {};
virtual bool init();
// Show motor pin configurations
virtual void showMotorPins();
// Show motor diagnostics
virtual void diagnostics();
virtual void forward(int speed);
virtual void backward(int speed);
virtual void stop();
virtual void forwardLeft(int speed);
virtual void backwardLeft(int speed);
virtual void stopLeft();
virtual void forwardRight(int speed);
virtual void backwardRight(int speed);
virtual void stopRight();
virtual void turnLeft(int speed, int heading);
virtual void turnRight(int speed, int heading);
virtual void spinLeft(int speed, int heading);
virtual void spinRight(int speed, int heading);
};
#endif
#endif
The entire verbose build output is attached.
The critical questions is, "what references to vtable are undefined? Is there a Window's based too that can give me an answer to this?
BuildVerboseOutput.txt (31.7 KB)
Coding Badly might have a hint I guess 
#include "[color=red]a[/color]rduino.h" ??
Why do you have the implementation in the header file? Real programmers define classes in header files and implement the classes in source files.
Makes it a LOT easier to see the definition vs. the implementation.
Only the constructor code was included in the header file, as any "Real Programmer" (thank you, PAUL S) would be able to see. And a "Real Programmer" would actually answer my questions with useful answers instead of disparaging remarks.
In response to "Coding Badly", all PROGMEM references have been removed, so that is not the problem. It is a linking problem. There are two references not being resolved and I have been unable to spot them. I have been asking for any tools or diagnostics that could help me chase this problem down.
The last few lines of the output are:
"C:\Program Files (x86)\Arduino\hardware\tools\avr/bin/avr-gcc" -w -Os -Wl,--gc-sections,--relax -mmcu=atmega2560 -o "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560/CommandPattern3.ino.elf" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\CommandPattern3.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\Wire\Wire.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\Wire\utility\twi.c.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\BJMotionDetector\BJMotionDetector.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\LSM303\LSM303.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\TimerOne\TimerOne.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\VM_DBG\VM_DBG.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\ActiveObjectEngine.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\AssertDiagnostic.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\BJCompass.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\BJCompassBase.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\BJCompassHeading.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\BJCompassHMC5883L.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\BJCompassLSM303.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\BJRobotOptions.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\BJRobotSettings.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\Command.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\CommandClient.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\CommandCodes.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\CommandDispatcher.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\CommandMaker.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\CommandRequest.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\DemoClient.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\Detection.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\Dispatcher.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\DualMotorL298N.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\DualMotorL9110.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\DualMotorRomeo.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\DualMotorZumo.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\FreeMemoryDiagnostic.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\GenericClient.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\GenericDualMotor.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\GenericSingleMotor.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\HMC5883L.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\LineDetection.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\LinkedList.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\MaintainHeading.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\MotorDefinition.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\MotorDefinitionL298N.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\MotorDefinitionL9110.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\MotorDefinitionRomeo.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\MotorDefinitionZumo.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\NavigationClient.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\ObstacleDetection.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\OptionSettings.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\PropulsionSystem.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\RemoteControlClient.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560\SerialInputClient.cpp.o" "D:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560/core.a" "-LD:\Users\Bob.ObigOne\Documents\Arduino\TEMP_BUILD_FOLDER\CommandPattern3\mega_atmega2560" -lm
CommandPattern3.cpp.o:In function `DualMotorRomeo
DualMotorRomeo.h:undefined reference to `vtable for DualMotorRomeo
DualMotorRomeo.h:undefined reference to `vtable for DualMotorRomeo
collect2.exe*:error: ld returned 1 exit status
Error compiling for board Arduino/Genuino Mega w/ ATmega2560 (Mega 2560)
I guess the problem is not in your code but in the Arduino program files,
check this out:
