On 10/20/17 12:12, Paolo Bonzini wrote:
> GCC 4.9 and newer stopped warning for missing braces around the
> "universal" C zero initializer {0}. One such initializer sneaked
s/sneaked/snuck/
Hmmm, no, wait, both forms are valid!
https://en.wiktionary.org/wiki/sneaked
https://en.wiktionary.org/wiki/snuck
The irregular form snuck originated by analogy with struck for the
past of strike. Snuck was originally limited to a few dialects, but
is now very widespread (especially in American English) and is
recognized by most dictionaries. The word is now one of the best
examples of irregularization of a regular verb, along with dove.
> into scsi/qemu-pr-helper.c and is breaking the build with such
> older GCC versions.
>
> Detect the lack of support for the idiom, and disable the warning
> in that case.
>
> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
> ---
> Of course it's always possible to use "memset", but {0}
> is neater in my opinion.
Strongly agree.
>
> configure | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/configure b/configure
> index 7766e74125..0b2d595c6e 100755
> --- a/configure
> +++ b/configure
> @@ -1651,6 +1651,19 @@ EOF
> fi
> fi
>
> +# Disable -Wmissing-braces on older compilers that warn even for
> +# the "universal" C zero initializer {0}.
> +cat > $TMPC << EOF
> +struct {
> + int a[2];
> +} x = {0};
> +EOF
> +if compile_object "-Werror" "" ; then
> + :
> +else
Is this an established idiom for the configure script, in place of:
if ! compile_object "-Werror" "" ; then
?
Looks good to me otherwise.
Thanks!
Laszlo
> + QEMU_CFLAGS="$QEMU_CFLAGS -Wno-missing-braces"
> +fi
> +
> # Workaround for http://gcc.gnu.org/PR55489. Happens with -fPIE/-fPIC and
> # large functions that use global variables. The bug is in all releases of
> # GCC, but it became particularly acute in 4.6.x and 4.7.x. It is fixed in
>
