MadCoder

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

void
invalid_code(void)
{
  void (^block)(void);
  if (rand() % 2) {
    block = ^{ printf("odd\n"); };
  } else {

MadCoder

__attribute__((warn_unused_result))
id my_func(int a, int b, int c);

#define my_func(a, b, c) \
    _Pragma("clang diagnostic push") \
    _Pragma("clang diagnostic error \"-Wunused-result\"") \
    my_func(a, b, c) \
    _Pragma("clang diagnostic pop")

MadCoder

@implementation MyClass

+ (instancetype)sharedInstanceWithError:(NSError **)error
{
    static _Atomic(MyClass *) sMyClass;
    MyClass *tmp = nil, *expected = nil;

#if defined(__i386__) || defined(__x86_64__) || defined(__arm__) || defined(__arm64__)
    // this assumes that this platform has consume ordering
    // for loads through dereferencing pointers, which both intel & arm have.

MadCoder

bool is_even(unsigned n)
{
    char buf[11];

    sprintf(buf, "%10u", n);
    switch (buf[9]) {
    case '0': return true;
    case '1': return false;
    default:  return is_even(buf[9]);
    }