I guess you could do something like (couldn’t get Xcode’s clang to compile this, so it probably is buggy)

  static unsigned int __deferDepth = 0;

  #define RETURN return
  #define return ((__deferDepth == 0) ? RETURN : break do_return)

  #define DEFER(EXPR) \
    __label__ do_return; \
    for(int _tmp = 1; _tmp; _tmp = (do { \
      __deferDepth += 1; \
      EXPR; \
      __deferDepth -= 1; \
      break; \
      do_return: \
        RETURN; \
    }while(0);))

Nested DEFERs could get hairy, though (do you need a stack of __returnNotBreak values?), and there probably are issues if EXPR contains some nested loops with break or return.

Regardless, this isn’t C. Statement expressions (and __label_) are a gcc* extension, and if you’re willing to go there, __attribute__((cleanup)) seems the wiser route.