Extended Description

@​interface Face1

• (void)foo:(int)i attribute((unavailable));
  @​end
  @​interface Face0
• (void)foo:(float)i;
  @​end

void f(id i) {
[i foo:4.0f];
}

$ bin/clang -c test.m
test.m:9:6: error: 'foo:' is unavailable
[i foo:4.0f];
^
test.m:2:1: note: 'foo:' has been explicitly marked unavailable here

• (void)foo:(int)i attribute((unavailable));
  ^

This is incorrect, the float version of foo: is available. This is because the warning only looks at the first overload.

If the order of Face1 and Face0 is swapped, the warning goes away.