VS code problems suggestion in C - c

Question

I am writing a HW for school, where I should implement a circular buffer and I ran into 2 things. VS Code says that:
too few arguments in function call [8,21]
expected a ';' [9,5]
But I'am quite sure, I have not made any mistake so far. I also don't know how to compile it, GCC won't take that. Makefile provided by school throws some error, but none regarding this issue.
I've got C/C++ extension form Microsoft [v1.2.2]. Are errors/problems handled by that one?
Here is the code queue.c:
#include "queue.h"
// TODO - your code
queue_t* create_queue(int capacity){
queue_t * q;
q->capacity = capacity;
q->count = 0;
q->arr = malloc(capacity*sizeof(int));
if(q->arr == NULL){
fprintf(stderr, "ERROR: cannot alocate enough memory!\n"); // here is the er#1
}
q->arr_end =(int*)q->arr + capacity * sizeof(int);
return q; // er#2 occurs here
}
And here queue.h
#ifndef __QUEUE_H__
#define __QUEUE_H__
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
/* Queue structure which holds all necessary data */
typedef struct {
// TODO - Include your data structure here
int capacity; // the max # of elemetns, that can be stored
int count; // # of elements in Q
int * arr; // the array itself
int * arr_end; // pointer to the end of arr (ie: *(arr+int*len))
int * read; // position to read from; ie: HEAD
int * write; // position to write form; ie: TAIL
} queue_t;
/* creates a new queue with a given size */
queue_t* create_queue(int capacity);
// ...
#endif /* __QUEUE_H__ */
Output of the GCC for gcc queue.c
/usr/bin/ld: /usr/lib/gcc/x86_64-linux-gnu/9/../../../x86_64-linux-gnu/Scrt1.o: in function `_start':
(.text+0x24): undefined reference to `main'
collect2: error: ld returned 1 exit status
And this is the main.c as is from school:
#include "stdio.h"
#include "stdlib.h"
#include "string.h"
#include "queue.h"
/* allocate new integer with value a and add it to the queue */
void add(int a, queue_t *queue)
{
int *p = (int*)malloc(sizeof(int));
*p = a;
bool ret = push_to_queue(queue, (void*)p);
if (!ret) {
// free memory on failure
free(p);
}
}
/* print the int value on pointer p */
void print_int(void *p)
{
if (p != NULL) {
printf("%d\n", *((int*)p));
} else {
printf("NULL\n");
}
}
/* pop from the queue, print and free the element */
void pop(queue_t *queue)
{
void *p = pop_from_queue(queue);
print_int(p);
free(p);
}
/* get i-th element and print it (do not remove them) */
void get(int idx, queue_t *queue)
{
print_int(get_from_queue(queue, idx));
}
/*
* TEST PROGRAM
* - reads commands from stdin and executes them in the queue
*/
int main(int argc, char *argv[])
{
int n;
/* the tested queue */
queue_t *queue;
// read the size of the queue
scanf("%d", &n);
// create queue
queue = create_queue(n);
while (true) {
char s[2];
// read one command
int ret = scanf("%1s", s);
if (ret != 1) {
break;
}
// add command
if (s[0] == 'a') {
int a;
// read the argument of the command
ret = scanf("%d", &a);
if (ret != 1) {
break;
}
add(a, queue);
// remove command
} else if (s[0] == 'r') {
pop(queue);
// get command
} else if (s[0] == 'g') {
int a;
// read the argument of the command
ret = scanf("%d", &a);
if (ret != 1) {
break;
}
get(a, queue);
}
}
// remove rest of the elements in the queue
while (get_queue_size(queue)) {
void *p = pop_from_queue(queue);
free(p);
}
// free memory
delete_queue(queue);
queue = NULL;
// return 0 on succes
return 0;
}

Answer 1

You forget to reserve space for the queue:
queue_t * q = malloc(sizeof *q);
if (q != NULL)
{
q->capacity = capacity;
...
Also
q->arr_end =(int*)q->arr + capacity * sizeof(int);
here you want (assuming that you want a pointer to the last element):
q->arr_end = q->arr + capacity - 1;
pointer arithmetic is done in terms of elements (not bytes)
Regarding your compile error, it seems that you forget to include the unit containing main, try with
gcc main.c queue.c