llvm-gcc-4.2/gcc/testsuite/gcc.apple/block-blocks-test-1.c

/* APPLE LOCAL file 5932809 */
/* { dg-options "-fblocks" } */
/* { dg-do compile } */

__block  int X; /* { dg-error "__block attribute on \\'X\\' not allowed, only allowed on local variables" } */

int foo(__block int param) { /* { dg-error "__block attribute can be specified on variables only" } */
  __block int OK = 1;

  extern __block double extern_var; /* { dg-error "__block attribute on \\'extern_var\\' not allowed, only allowed on local variables" } */
  if (X) {
    static __block char * pch;	/* { dg-error "__block attribute on \\'pch\\' not allowed, only allowed on local variables" } */
  }
  return OK - 1;
}