Extended Description

If the linker places a zero-length function at the same address as another function, function pointer equality may be broken.

$ cat addr-taken.c

#include <stdio.h> void f1() { __builtin_unreachable(); } void f2() { __builtin_unreachable(); } int main() { printf("%p %p\n", &f1, &f2); }

$ clang -Os addr-taken.c
$ ./a.out
0x400510 0x400510