C Makefile collect2: error: - c

Question

Processor.c
#include<time.h>
#include<stdio.h>
#include<pthread.h>
#include<semaphore.h>
#include<string.h>
#include<stdlib.h>
#include<malloc.h>
#include<unistd.h>
#include"Process_struct.h"
sem_t empty;//semaphores
#define MAX_PROCS 5
#define EXIT 1
#define TRUE 1
char outbaseStr [100];
int numProcessors;
FILE *outLog=NULL;
FILE *file=NULL;
FILE *outFile=NULL;
FILE *temp=NULL;
pthread_t producer;//Producer Thread ID
pthread_t consumer[MAX_PROCS];//consumer thread ID
int main(int argc, char *argv[])
{
/* Initialize Data */
initializeData();
printf("argc equals %d\n", argc);
int num_processors=atoi(argv[2]);
int case_num=atoi(argv[3]);
char filename;
char *outfilename=argv[1];
printf("outfilename equals %s\n", outfilename);
printf("num_processors equals %d\n\n", num_processors);
switch(case_num)
{
case 1:
//printf("case 1\n");
/* Reading in from the text */
file = fopen("temp.txt", "wr");
/* fopen returns 0, the NULL pointer, on failure */
if(file==0||file==NULL)
{
printf("Error: couldn't open the file\n");
exit(EXIT);
}
/*****************************************************************************/
//write to temp
int length=argc-4;
for(int i=0;i<length;i++)
{
if(i%2==0)
{
//printf("%d ", atoi(argv[i+3]));
fprintf(file, "%d ", atoi(argv[i+4]));
}
else
{
//printf("%d\n", atoi(argv[i+3]));
fprintf(file,"%d\n", atoi(argv[i+4]));
}
}
/*****************************************************************************/
fclose(file);
file = fopen("temp.txt", "r");
/* Create the producer thread */
pthread_create(&producer, NULL, get_request, (void *)file);
break;
case 2:
//char filename[100];
//filename=argv[3];
//printf("usage: %s filename\n", argv[3]);
/* Reading in from the text */
file = fopen(argv[4], "r");
/* fopen returns 0, the NULL pointer, on failure */
if(file==0||file==NULL)
{
printf("Error: couldn't open the file\n");
exit(EXIT);
}
/* Create the producer thread */
pthread_create(&producer, NULL, get_request, (void *)file);
break;
default:
printf("Error: should be either case 1 or case 2\n");
exit(EXIT);
break;
}
pthread_join(producer, NULL);
//displayQ();
// Create the consumer threads
for(int i=0;i<num_processors;i++)
{
sprintf(outbaseStr, "%s.%ld", outfilename, (long)(i+1));
//printf("outbaseStr equals %s\n", outbaseStr);
outLog=fopen(outbaseStr, "w");
if(outLog==NULL)
{
printf("Error: couldn't open the file\n");
exit(EXIT);
}
pthread_create(&consumer[i], NULL, processor, (void *)outLog);
}
for(int i=0;i<num_processors;i++)
{
pthread_join(consumer[i], NULL);
}
//printf("\nfclose\n");
close((FILE *)file);
//fclose((FILE *)file);
if(case_num==1)
{
if(remove("temp.txt")!=0)
{
printf("error deleting file");
}
else
{
//printf("success deleting file");
}
}
}
Process_struct.c
#include<time.h>
#include<stdio.h>
#include<pthread.h>
#include<semaphore.h>
#include<string.h>
#include<stdlib.h>
#include<malloc.h>
#include<unistd.h>
#include"Process_struct.h"
sem_t empty;//semaphores
#define MAX_PROCS 5
#define EXIT 1
#define TRUE 1
char outbaseStr [100];
int numProcessors;
FILE *outLog=NULL;
FILE *file=NULL;
FILE *outFile=NULL;
FILE *temp=NULL;
pthread_t producer;//Producer Thread ID
pthread_t consumer[MAX_PROCS];//consumer thread ID
void initializeData()
{
//printf("initializeData\n");
//Create the empty semaphore and initialize it
sem_init(&empty, 0, MAX_PROCS);
// pthread_attr_init(attr);
}
void *get_request(void *argv)//this produces a queue
{
prcmd_t *process;
//printf("get_request\n");
if(file==NULL)
{
printf("\nwe have a file null error\n");
}
while(!feof(file))
{
process=(prcmd_t *)malloc(sizeof(prcmd_t));
fscanf(file, "%d %d", &process->owner, &process->burst_time);
if(process->owner!=0||process->burst_time!=0)
{
//printf("%d %d\n", process->owner, process->burst_time);
if(add_queue(process)==-1)
{
printf("failure from add_queue");
}
}
}
//printf("this is the end of get_request\n");
}
void *processor(void *argv)//this consumes a queue
{
prcmd_t *process;
// process=(prcmd_t *)malloc(sizeof(prcmd_t));
process=pr_head;
int sleep_time=process->burst_time;
//printf("\nprocessor\n");
while(TRUE)
{
if(get_number_request()>0)
{
if(remove_queue(&process)==0)
{
fprintf(outLog, "\n->Process with id %d and it %d de-equeue by thread \n", process->owner, process->burst_time);
clock_t start=clock();
sleep(process->burst_time);
clock_t end=clock();
fprintf(outLog, "\nSlept for %d seconds\n", sleep_time);
}
}
close((FILE *)outLog);
//fclose((FILE *)outLog);
//printf("the end of the processor\n");
//displayQ();
return NULL;
}
}
int get_number_request()
{
return pending_request;
}
void displayQ()
{
printf("\n\nthis is the beginning of displayQ\n");
prcmd_t *process=pr_head;
do
{
printf("%d %d\n", process->owner, process->burst_time);
process=process->next;
}while(process!=NULL);
printf("\nthe end of displayQ\n\n");
}
int add_queue(prcmd_t *node)
{
prcmd_t *temp;
temp=node;
pthread_mutex_lock(&prmutex);
//printf("add_queue\n");
//printf("%d %d\n", temp->owner, temp->burst_time);
/* adding a linkedlist to a queue */
if(pr_head==NULL)//then pr_tail==NULL
{
//printf("pr_head==NULL\n");
temp->next=NULL;
pr_head=temp;
pr_tail=temp;
}
else
{
//printf("pr_head!=NULL\n");
temp->next=NULL;
pr_tail->next=temp;
pr_tail=temp;
}
pending_request++;
pthread_mutex_unlock(&prmutex);
//printf("add_queue success\n");
return(0);
}
int remove_queue(prcmd_t **node)
{
//printf("\nremove_queue/enqueue\n");
pthread_mutex_lock(&prmutex);
prcmd_t *temp;
// printf("this is the end of remove_queue/enqueue and is returning 0\n");
if(pr_head==NULL)
{
//printf("pr_head==NULL");
pr_head = pr_tail = NULL; // Reset everything to empty queue
pthread_mutex_unlock(&prmutex);
//printf("this is the end of remove_queue/enqueue and is returning -1\n");
return(-1);
}
else
{
//printf("pr_head!=NULL\n");
temp=pr_head;
temp->next=pr_head->next;
pr_head=temp->next;
pending_request--;
pthread_mutex_unlock(&prmutex);
//printf("this is the end of remove_queue/enqueue and is returning 0\n");
return(0);
}
}
Process_struct.h
GNU nano 2.2.6 File: Process_struct.h
#include<time.h>
#include<stdio.h>
#include<pthread.h>
#include<semaphore.h>
#include<string.h>
#include<stdlib.h>
#include<malloc.h>
#include<unistd.h>
typedef struct pr_struct
{
int owner;
int burst_time;
struct pr_struct *next;
} prcmd_t;
void displayQ();//this displays the queue
void initializeData();//initializes the data for the program
void *get_request(void *args);//to be calls as a thread to enqueue input reques$
void *processor(void *args);//which removes a request from the process request $
int get_number_request();//returns the number of request
int add_queue(prcmd_t *);//adds a node at the end of the request queue
int remove_queue(prcmd_t **);//removes a node for the queue
#define MAX_PROCS 5
#define EXIT 1
#define TRUE 1
This is the error I have:
/tmp/ccvDJUQI.o:(.bss+0x0): multiple definition of `outLog'
/tmp/cc4RWdZ4.o:(.bss+0x0): first defined here
/tmp/ccvDJUQI.o:(.bss+0x8): multiple definition of `file'
/tmp/cc4RWdZ4.o:(.bss+0x8): first defined here
/tmp/ccvDJUQI.o:(.bss+0x10): multiple definition of `outFile'
/tmp/cc4RWdZ4.o:(.bss+0x10): first defined here
/tmp/ccvDJUQI.o:(.bss+0x18): multiple definition of `temp'
/tmp/cc4RWdZ4.o:(.bss+0x18): first defined here
collect2: error: ld returned 1 exit status
make: *** [Multiprocessor] Error 1
Whenever I go to run my make file this is the error I get. I don't understand where the error would be so I can't find it and change it. I was hoping someone could tell me what collect2: error: ld returned 1 exit status means and where the error would be at.

Answer 1

From your comment, it looks like you're trying to compile header files
gcc Processor.c Process_struct.h Process_struct.c -o Multiprocessor -std=c99 -lm -lpthread
A header file is included in a .c file and not compiled separately. Your command line should more look like
gcc Processor.c Process_struct.c -o Multiprocessor -std=c99 -lm -lpthread
Another source of this kind of errors, is when you define variables in a header file and include the header file in multiple source files, e.g. in Process_struct.h
FILE *file = NULL;
char temp[] = "/tmp";
When you include this header file in Processor.c and Process_struct.c, you define these variables in both sources and as a consequence get multiple defined variables.
To fix this, you must not define, but only declare the variables in the header file. You can then define them in one source file, e.g.
Process_struct.h:
extern FILE *file;
extern char temp[];
and in Process_struct.c:
FILE *file = NULL;
char temp[] = "/tmp";
Yet another source of multiple definitions is just that, you have defined the same variable in multiple places. This means when you have
Processor.c:
FILE *file = NULL;
char temp[] = "/tmp";
Process_struct.c:
FILE *file = NULL;
char temp[] = "/tmp";
you will get this error. The fix for this depends on your intention. If these variables are local to the file (independent from each other) narrow their scope to the file by prefixing with static
static FILE *file = NULL;
static char temp[] = "/tmp";
However, if you want to share the variables between these two sources, you must keep one definition and make the other one a declaration only. Better yet, move the declaration to a header file and keep the definition in only one source file, as in the second part above.
In any case, you should structure your makefile a bit differently. Use the built-in rules as much as possible, see Using Implicit Rules. E.g.
CFLAGS = -std=c99 -pthread
LDLIBS = -lm -lpthread
OBJS = Processor.o Process_struct.o
Multiprocessor: $(OBJS)
$(CC) $(CFLAGS) -o $# $(OBJS) $(LDLIBS)

Answer 2

For all user looking for an answer to collect2: error: ld returned 1 exit status, remember that it is helpful to make all the variables in your header file a STATIC variable. That's what made my error go away so to all other users that could be the answer to your error.