why is it showing undefined reference to `add'?

Question

I have written a code that just basically add two numbers. file is the self made header file named xoxo.h

extern int add(int r,int m);

This is my second file that contains the function defination of the function add.The name is run.c

#include "xoxo.h"
int add (int i,int f) {
  return (i+f);
}

This is my main file tester.c

#include "xoxo.h"
#include <stdio.h>
void main() {
  printf("%d",add(1,2));
}

The error is shown as

PS C:\Users\HOME\Desktop\New folder> gcc tester.c C:\Users\HOME\AppData\Local\Temp\ccBwWXFk.o:tester.c:(.text+0x1e): undefined reference to `add' collect2.exe: error: ld returned 1 exit status

plz help

You need to compile all of the `.c` files and link them together. `gcc tester.c run.c -o tester.exe` is one way to do that. — Retired Ninja, May 30 '22 at 20:15
Welcome to Stack Overflow. What source are you using to learn C? It should have already explained this to you. — Karl Knechtel, May 30 '22 at 20:16

score 2 · Answer 1 · answered May 30 '22 at 20:15

2

When you compile the application, you need to provide run.c as well, otherwise the application cannot find the implementation of add.

Run gcc tester.c run.c instead.

answered May 30 '22 at 20:15

Daniel Trugman

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why is it showing undefined reference to `add'?

1 Answers1