Re: [Qemu-devel] [PATCH] Annotate questionable fallthroughs

[Kevin Wolf <kwolf@redhat.com>]

Am 20.01.2013 16:54, schrieb Blue Swirl:
> Recent Clang compilers have preliminary support for finding
> unannotated fallthrough cases in switch statements with
> compiler flag -Wimplicit-fallthrough. The support is incomplete,
> it's only possible to annotate the case in C++ but not in C, so it
> wouldn't be useful to enable the flag for QEMU yet.
> 
> Mark cases which don't have a comment about fall through with
> a comment. In legitimate fall through cases the comment can be
> edited later to mark the case for future readers.
> 
> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

> diff --git a/hw/ide/core.c b/hw/ide/core.c
> index 14ad079..0457c65 100644
> --- a/hw/ide/core.c
> +++ b/hw/ide/core.c
> @@ -1151,6 +1151,7 @@ void ide_exec_cmd(IDEBus *bus, uint32_t val)
>          break;
>      case WIN_VERIFY_EXT:
>  	lba48 = 1;
> +        /* XXX: questionable fallthrough */
>      case WIN_VERIFY:
>      case WIN_VERIFY_ONCE:
>          /* do sector number check ? */
> @@ -1160,6 +1161,7 @@ void ide_exec_cmd(IDEBus *bus, uint32_t val)
>          break;
>      case WIN_READ_EXT:
>  	lba48 = 1;
> +        /* XXX: questionable fallthrough */
>      case WIN_READ:
>      case WIN_READ_ONCE:
>          if (s->drive_kind == IDE_CD) {
> @@ -1175,6 +1177,7 @@ void ide_exec_cmd(IDEBus *bus, uint32_t val)
>          break;
>      case WIN_WRITE_EXT:
>  	lba48 = 1;
> +        /* XXX: questionable fallthrough */
>      case WIN_WRITE:
>      case WIN_WRITE_ONCE:
>      case CFA_WRITE_SECT_WO_ERASE:
> @@ -1191,6 +1194,7 @@ void ide_exec_cmd(IDEBus *bus, uint32_t val)
>          break;
>      case WIN_MULTREAD_EXT:
>  	lba48 = 1;
> +        /* XXX: questionable fallthrough */
>      case WIN_MULTREAD:
>          if (!s->bs) {
>              goto abort_cmd;
> @@ -1204,6 +1208,7 @@ void ide_exec_cmd(IDEBus *bus, uint32_t val)
>          break;
>      case WIN_MULTWRITE_EXT:
>  	lba48 = 1;
> +        /* XXX: questionable fallthrough */
>      case WIN_MULTWRITE:
>      case CFA_WRITE_MULTI_WO_ERASE:
>          if (!s->bs) {
> @@ -1224,6 +1229,7 @@ void ide_exec_cmd(IDEBus *bus, uint32_t val)
>          break;
>      case WIN_READDMA_EXT:
>  	lba48 = 1;
> +        /* XXX: questionable fallthrough */
>      case WIN_READDMA:
>      case WIN_READDMA_ONCE:
>          if (!s->bs) {
> @@ -1234,6 +1240,7 @@ void ide_exec_cmd(IDEBus *bus, uint32_t val)
>          break;
>      case WIN_WRITEDMA_EXT:
>  	lba48 = 1;
> +        /* XXX: questionable fallthrough */
>      case WIN_WRITEDMA:
>      case WIN_WRITEDMA_ONCE:
>          if (!s->bs) {
> @@ -1245,6 +1252,7 @@ void ide_exec_cmd(IDEBus *bus, uint32_t val)
>          break;
>      case WIN_READ_NATIVE_MAX_EXT:
>  	lba48 = 1;
> +        /* XXX: questionable fallthrough */
>      case WIN_READ_NATIVE_MAX:
>  	ide_cmd_lba48_transform(s, lba48);
>          ide_set_sector(s, s->nb_sectors - 1);

All IDE cases are clearly intentional.

Kevin