Thomas Huth <th...@redhat.com> writes:
> Different versions of GCC and Clang use different versions of the C standard. > This repeatedly caused problems already, e.g. with duplicated typedefs: > > https://lists.gnu.org/archive/html/qemu-devel/2018-11/msg05829.html > > or with for-loop variable initializers: > > https://lists.gnu.org/archive/html/qemu-devel/2019-01/msg00237.html > > To avoid these problems, we should enforce the C language version to the > same level for all compilers. Since our minimum compiler versions is > GCC v4.8, our best option is "gnu99" for C code right now ("gnu17" is not > available there yet, and "gnu11" is marked as "experimental"), and "gnu++98" > for the few C++ code that we have in the repository. > > Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com> > Reviewed-by: Richard Henderson <richard.hender...@linaro.org> > Signed-off-by: Thomas Huth <th...@redhat.com> > --- > configure | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/configure b/configure > index cf763d4..f0b5dcd 100755 > --- a/configure > +++ b/configure > @@ -107,6 +107,9 @@ update_cxxflags() { > -Wstrict-prototypes|-Wmissing-prototypes|-Wnested-externs|\ > -Wold-style-declaration|-Wold-style-definition|-Wredundant-decls) > ;; > + -std=gnu99) > + QEMU_CXXFLAGS=${QEMU_CXXFLAGS:+$QEMU_CXXFLAGS }"-std=gnu++98" > + ;; > *) > QEMU_CXXFLAGS=${QEMU_CXXFLAGS:+$QEMU_CXXFLAGS }$arg > ;; > @@ -585,7 +588,7 @@ ARFLAGS="${ARFLAGS-rv}" > # left shift of signed integers is well defined and has the expected > # 2s-complement style results. (Both clang and gcc agree that it > # provides these semantics.) > -QEMU_CFLAGS="-fno-strict-aliasing -fno-common -fwrapv $QEMU_CFLAGS" > +QEMU_CFLAGS="-fno-strict-aliasing -fno-common -fwrapv -std=gnu99 > $QEMU_CFLAGS" > QEMU_CFLAGS="-Wall -Wundef -Wwrite-strings -Wmissing-prototypes $QEMU_CFLAGS" > QEMU_CFLAGS="-Wstrict-prototypes -Wredundant-decls $QEMU_CFLAGS" > QEMU_CFLAGS="-D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE > $QEMU_CFLAGS" Reviewed-by: Alex Bennée <alex.ben...@linaro.org> -- Alex Bennée
