Weird clang behavior

funkyClang.c

// https://twitter.com/zneakr/status/1164651753993715712
/*  So @zneakr tweeted about this weird behavior and I decided to tinker with his example. In order to optimize, clang
    assigns fun_ptr to leak_all_my_secrets no matter what. This leads to "I have 9 toes" being printed no matter the
    result of the if statement. Super weird behavior from clang and I just wanted to make a note of it :)
    
    To reproduce this result:
    clang funkyClang.c -O1 -o funkyClang; ./funkyClang
*/

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

static void (*fun_ptr)(void);

void leak_all_my_secrets () {
	printf("I have 9 toes\n");
}

int main() {
	if ((random() % 1000000) == 12321) {
		fun_ptr = leak_all_my_secrets;
	}
	fun_ptr();
}