CODEWITHSUNDEEP
c++nachos
Jeremy
Jeremy

Reputation: 21

expected initializer before ‘*’ token in nachos experiments

here's the definition of class Alarm:(I've made some changes to the question)

//Alarm.h
#pragma once
#include "system.h"
#include "list.h"
//#include "../machine/timer.h"
//void timerhandler(int dummy);

void check(int which);

class Alarm
{
public:         
    Alarm();
    ~Alarm();
    void Pause(int howLong);
    List *queue;
    //Timer *timer;
    int waiters;
    void CheckIfDue();          // Check if an interrupt is supposed
                                // to occur now
    static void new_instance();
    static Alarm *instance;
};

the declaration of the alm is in a file named system.cc.

//system.cc
#include "copyright.h"
#include "system.h"

...

Alarm *alm;

the error occurs in system.h,in which i've declared Alarm.h.

//system.h
#include "copyright.h"
#include "utility.h"
#include "thread.h"
#include "scheduler.h"
#include "interrupt.h"
#include "stats.h"
#include "timer.h"
#include "Alarm.h"

// Initialization and cleanup routines
extern void Initialize(int argc, char **argv);  // Initialization,
                        // called before anything else
extern void Cleanup();              // Cleanup, called when
                        // Nachos is done.


extern Thread *currentThread;           // the thread holding the CPU
extern Thread *threadToBeDestroyed;         // the thread that just finished
extern Scheduler *scheduler;            // the ready list
extern Interrupt *interrupt;            // interrupt status
extern Statistics *stats;           // performance metrics
extern Timer *timer;                // the hardware alarm clock
extern Alarm *alm;

33 extern Alarm *alm;
../threads/system.h:33: error：expected initializer before ‘*’ token

it seems wherever i put the code "extern Alarm *alarm;",the error occurs.

Upvotes: 0

Views: 211

Answers (1)

Jeremy
Jeremy

Reputation: 21

i've found the reason. it seems to be caused by header files containing each other(system.h&Alarm.h). The error is disappeared once i put the "extern Alarm *alarm" in Alarm.cc. But I still haven't find out more details about the error. I would be appreciate if you can give me some ideas.

Upvotes: 0

Related Questions