#include <stdio.h>
#include <stdbool.h>

int SmallerOf(int x, int y);

void TestCase(void)

{
    int x, y, actual;

    x = 3;
    y = 4;
    actual = 3;
    int expected = SmallerOf(x, y);
    if (actual == expected)
    {
        printf("PASS");
    }
    else
    {
        printf("FAIL");
    }
}

Having an error with linker having a linker error message 2019. I tried to see if my linker under properties looking at something different or a certain file. It seems like everything is good and I a just look. What could be the cause of this when I haven't touched the linker directories? thank you

I have looked at properties and it seems to be fine and not sure what this error message means.

CodePudding user response：

This is a (forward) declaration of a function:

int SmallerOf(int x, int y);

It makes a promise to the compiler that there will be a definition of the function later, so the compiler will not complain when you call it in your code - even if the compiler have even not seen the actual function definition yet.

When linking your final program, it will however not find this definition, hence you get a linker error. In order to fix the problem, provide a definition of the function too. Example:

int SmallerOf(int x, int y) {
    return x < y ? x : y;
}

Your final program also needs a definition of the int main(void) or int main(int, char**) function in order to know where to start execution of the program.