Messages in this thread | | | From | Arnd Bergmann <> | Date | Fri, 1 May 2020 09:54:19 +0200 | Subject | Re: [PATCH 13/15] scsi: sas: avoid gcc-10 zero-length-bounds warning |
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On Fri, May 1, 2020 at 9:48 AM John Garry <john.garry@huawei.com> wrote: > On 30/04/2020 22:30, Arnd Bergmann wrote:
> > This should really be a flexible-array member, but the structure > > already has such a member, swapping it out with sense_data[] would > > cause many more warnings elsewhere. > > > > > Hi Arnd, > > If we really prefer flexible-array members over zero-length array > members, then could we have a union of flexible-array members? I'm not > sure if that's a good idea TBH (or even permitted), as these structures > are defined by the SAS spec and good practice to keep as consistent as > possible, but just wondering.
gcc does not allow flexible-array members inside of a union, or more than one flexible-array member at the end of a structure.
I found one hack that would work, but I think it's too ugly and likely not well-defined either:
struct ssp_response_iu { ... struct { u8 dummy[0]; /* a struct must have at least one non-flexible member */ u8 resp_data[]; /* allowed here because it's at the one of a struct */ }; u8 sense_data[]; } __attribute__ ((packed));
> Apart from that: > > Reviewed-by: John Garry <john.garry@huawei.com>
Thanks!
Arnd
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