Re: [PULL 00/14] Block layer patches

[Peter Maydell]

On Mon, 22 Jan 2024 at 11:15, Kevin Wolf <kwolf@redhat.com> wrote:
>
> Am 20.01.2024 um 18:21 hat Peter Maydell geschrieben:
> > Got some compile failures on this one; looks like the compiler
> > on our s390 box didn't like this:
> >
> > https://gitlab.com/qemu-project/qemu/-/jobs/5973441293
> > https://gitlab.com/qemu-project/qemu/-/jobs/5973441291
> > https://gitlab.com/qemu-project/qemu/-/jobs/5973441330
> >
> > In file included from ../include/qemu/host-utils.h:33,
> > from ../include/qemu/bitops.h:16,
> > from ../include/qemu/timer.h:4,
> > from ../include/block/aio.h:24,
> > from ../include/block/aio-wait.h:28,
> > from ../include/block/block-io.h:27,
> > from ../block/blklogwrites.c:15:
> > ../block/blklogwrites.c: In function ‘blk_log_writes_co_do_log’:
> > ../include/qemu/bswap.h:148:36: error: left shift count >= width of
> > type [-Werror=shift-count-overflow]
> > 148 | ((((_x) & 0x00000000000000ffU) << 56) | \
> > | ^~
> > ../block/blklogwrites.c:409:27: note: in expansion of macro ‘const_le64’
> > 409 | .nr_entries = const_le64(0),
> > | ^~~~~~~~~~
> > ../include/qemu/bswap.h:149:36: error: left shift count >= width of
> > type [-Werror=shift-count-overflow]
> > 149 | (((_x) & 0x000000000000ff00U) << 40) | \
> > | ^~
> > ../block/blklogwrites.c:409:27: note: in expansion of macro ‘const_le64’
> > 409 | .nr_entries = const_le64(0),
> > | ^~~~~~~~~~
> > cc1: all warnings being treated as errors
>
> Looks like const_le64() introduced in commit 845d80a8 is buggy. I wonder
> why we even added it when there is no user of it (this blklogwrites one
> is the first one, so it exposes the error).
>
> Of course, 0 is just as good as const_le64(0), so I'll just change it to
> that for now. But I suppose const_le64() should either be fixed (and
> used by something) or removed.

Using ULL as the suffix on the constants in the macro should
be sufficient to fix the problem, I suspect.

-- PMM