DECLARE_BLOCK
typedef DECLARE_BLOCK(int, fts_block,
typedef DECLARE_BLOCK(int, glob_b_block, const char*, int);
typedef DECLARE_BLOCK(int, select_block, const struct dirent *);
typedef DECLARE_BLOCK(int, dcomp_block, const struct dirent **,
typedef DECLARE_BLOCK(void, atexit_block, void);
typedef DECLARE_BLOCK(int, compar_block, const void *, const void *);
typedef DECLARE_BLOCK(int, heapsort_block, const void *, const void *);
#define DECLARE_CMP DECLARE_BLOCK(int, cmp, const void *, const void *)
typedef DECLARE_BLOCK(int, cmp_t, const void *, const void *);
typedef DECLARE_BLOCK(int, qsort_block, const void *, const void *);