So what I would do for the warning in IplParameterBlock is the following
(if I got the comments right):
- Remove IplBlockFcp from IplParameterBlock
- Keep IPLBlockPV and, in its declaration, use
struct IPLBlockPVComp components[0];
Now for the IplBlockFcp struct declaration, it does not seem to be used
anywhere now.
I could either keep it as it was before (with the variable-size array)
or remove it entirely.
I guess this is more a question for the maintainers, what is your
preference here?
Daniele
On 10/27/2020 7:38 AM, Cornelia Huck wrote:
On Tue, 27 Oct 2020 12:26:21 +0100
Thomas Huth <th...@redhat.com> wrote:
On 26/10/2020 16.12, Paolo Bonzini wrote:
On 26/10/20 16:03, Daniele Buono wrote:
Hi Paolo,
I reorganized UASStatus to put uas_iu at the end and it works fine.
Unfortunately, this uncovered another part of the code with a similar
issue (variable sized type not at the end of the struct), here:
In file included from ../qemu-cfi-v3/target/s390x/diag.c:21:
../qemu-cfi-v3/hw/s390x/ipl.h:161:23: error: field 'iplb' with variable
sized type 'IplParameterBlock' (aka 'union IplParameterBlock') not at
the end of a struct or class is a GNU extension
[-Werror,-Wgnu-variable-sized-type-not-at-end]
IplParameterBlock iplb;
^
../qemu-cfi-v3/hw/s390x/ipl.h:162:23: error: field 'iplb_pv' with
variable sized type 'IplParameterBlock' (aka 'union IplParameterBlock')
not at the end of a struct or class is a GNU extension
[-Werror,-Wgnu-variable-sized-type-not-at-end]
IplParameterBlock iplb_pv;
My understanding is that each of these IplParameterBlock may contain
either a IPLBlockPV or a IplBlockFcp, which both end with a variable
sized field (an array).
Adding maintainers of s390x to see if they have a suggested solution to
avoid disabling the warning.
This one seems okay because the union constrains the size to 4K. If
"[0]" is enough to shut up the compiler, I'd say do that.
The "IplBlockFcp fcp" part seems to be completely unused, so I think you
could even remove that IplBlockFcp struct. For IPLBlockPV I agree with
Paolo, it's likely easiest to use [0] for that struct.
The fcp block had probably been added for completeness' sake, but we do
not support list-directed IPL anyway. Not sure if we actually want it,
as we use a different mechanism for IPLing from SCSI devices. So yes,
maybe we should just drop it.
