| Message ID | 8ac93de3eef16c454a9cdd9770515ee7c5bd229a.1665492943.git.dsterba@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Enumerated bits in enum | expand |
diff --git a/fs/btrfs/misc.h b/fs/btrfs/misc.h index f9850edfd726..69826ccd6644 100644 --- a/fs/btrfs/misc.h +++ b/fs/btrfs/misc.h @@ -10,6 +10,14 @@ #define in_range(b, first, len) ((b) >= (first) && (b) < (first) + (len)) +/* + * Enumerate bits using enum autoincrement. Define the @name as the n-th bit. + */ +#define ENUM_BIT(name) \ + __ ## name ## _BIT, \ + name = (1U << __ ## name ## _BIT), \ + __ ## name ## _SEQ = __ ## name ## _BIT + static inline void cond_wake_up(struct wait_queue_head *wq) { /*
Define helper macro that can be used in enum {} to utilize the automatic increment to define all bits without directly defining the values or using additional linear bits. 1. capture the sequence value, N 2. use the value to define the given enum with N-th bit set 3. reset the sequence back to N Use for enums that do not require fixed values for symbolic names (like for on-disk structures): enum { ENUM_BIT(FIRST), ENUM_BIT(SECOND), ENUM_BIT(THIRD) }; Where the values would be 0x1, 0x2 and 0x4. Signed-off-by: David Sterba <dsterba@suse.com> --- fs/btrfs/misc.h | 8 ++++++++ 1 file changed, 8 insertions(+)