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.
