Linker error with kissfft function (language: C/C++)

Question

I'm trying to do a simple FFT with the kiss_fft library, but I keep getting a linkage error and was hoping somebody could shed light on the situation. Here's my code (which I hope is correct as far as the usage of kiss_fft goes):

#include<stdlib.h>
#include<stdio.h>
#include "kiss_fft.h"

#define SIZE 1024

int main () {
    double samples[SIZE];
    int i;

    for (i = 0; i < SIZE; i++) {       // initialize samples to randomish values
        samples[i] = (float)(rand() % 50) * .5;
    }

    kiss_fft_cfg cfg = kiss_fft_alloc(SIZE, 0, 0, 0);
    kiss_fft_cpx fft_in[SIZE];
    kiss_fft_cpx fft_out[SIZE];

    for (i = 0; i < SIZE; i++) {
        fft_in[i].r = samples[i];
        fft_in[i].i = 0;
        fft_out[i].r = 0;
        fft_out[i].i = 0;
    }

    kiss_fft(cfg,fft_in,fft_out);

    free(cfg);
}

And here's the error that I'm getting:

Undefined symbols for architecture x86_64:
  "_kiss_fft", referenced from:
      _main in FFT_standalone-712deb.o
  "_kiss_fft_alloc", referenced from:
      _main in FFT_standalone-712deb.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

According to kissFFT's readme document, the only thing I have to include is the kiss_fft header and I should be okay. Other than that, the program itself is not involved at all, and I'm not sure what could be the problem. C is also not my preferred language, so I could be doing something very wrong. Any ideas?