On Tue, Oct 16, 2018 at 10:52:26AM +1100, Finn Thain wrote:
True enough. We agree that this #ifdef is undesirable. And yet when I
tried it, I found an unexpected readability benefit to your suggestion:
#ifdef CONFIG_SCSI_ESP_PIO
u8 __iomem *fifo_reg;
int send_cmd_error;
u32 send_cmd_residual;
#endif
This grouping does help convey the purpose of these struct members, even
though the #ifdef is meant for the compiler not for the human reader.
So maybe it makes sense to group these definitions (they are all the same
size):
/* These are used by esp_scsi_send_pio_cmd() */
u8 __iomem *fifo_reg;
int send_cmd_error;
u32 send_cmd_residual;
I like the grouping, and in fact the ifdef sounds fine to me as well.
Do static checkers really complain about this? I think the validity of an
extern can't be known until the final linkage is done.
None that I know of does, and as said before this patterns is very
common all over the kernel.
