Peter Maydell <peter.mayd...@linaro.org> writes: > The VIXL code includes some equality comparisons between signed > and unsigned types. Modern gcc and clang do not complain about > these, but older versions of gcc such as gcc 4.6.3 do. Since > libvixl is an upstream library, the simplest approach is to > suppress the warnings by applying -Wno-sign-compare to the > relevant files. > > (GCC 4.6 is not quite yet irrelevant for us; it is the gcc > shipped with Ubuntu Precise, for example, which is an LTS > release not yet out of its support period.) > > Signed-off-by: Peter Maydell <peter.mayd...@linaro.org> > --- > I had mistakenly thought these warnings only happened with > the totally ancient mingw gcc, but it turns out they're a > bit more widespread. In particular this is causing our > Travis builds to fail: > https://travis-ci.org/qemu/qemu/jobs/101813358 > > If somebody could review this then I'll apply it to master > as a buildfix.
Reviewed-by: Alex Bennée <alex.ben...@linaro.org> > --- > disas/Makefile.objs | 5 ++++- > disas/libvixl/Makefile.objs | 4 +++- > 2 files changed, 7 insertions(+), 2 deletions(-) > > diff --git a/disas/Makefile.objs b/disas/Makefile.objs > index 8dae4da..abeba84 100644 > --- a/disas/Makefile.objs > +++ b/disas/Makefile.objs > @@ -4,7 +4,10 @@ common-obj-$(CONFIG_ARM_DIS) += arm.o > common-obj-$(CONFIG_ARM_A64_DIS) += arm-a64.o > common-obj-$(CONFIG_ARM_A64_DIS) += libvixl/ > libvixldir = $(SRC_PATH)/disas/libvixl > -arm-a64.o-cflags := -I$(libvixldir) > +# The -Wno-sign-compare is needed only for gcc 4.6, which complains about > +# some signed-unsigned equality comparisons in libvixl which later gcc > +# versions do not. > +arm-a64.o-cflags := -I$(libvixldir) -Wno-sign-compare > common-obj-$(CONFIG_CRIS_DIS) += cris.o > common-obj-$(CONFIG_HPPA_DIS) += hppa.o > common-obj-$(CONFIG_I386_DIS) += i386.o > diff --git a/disas/libvixl/Makefile.objs b/disas/libvixl/Makefile.objs > index e373cf0..d1e801a 100644 > --- a/disas/libvixl/Makefile.objs > +++ b/disas/libvixl/Makefile.objs > @@ -4,6 +4,8 @@ libvixl_OBJS = vixl/utils.o \ > vixl/a64/decoder-a64.o \ > vixl/a64/disasm-a64.o > > -$(addprefix $(obj)/,$(libvixl_OBJS)): QEMU_CFLAGS := > -I$(SRC_PATH)/disas/libvixl $(QEMU_CFLAGS) > +# The -Wno-sign-compare is needed only for gcc 4.6, which complains about > +# some signed-unsigned equality comparisons which later gcc versions do not. > +$(addprefix $(obj)/,$(libvixl_OBJS)): QEMU_CFLAGS := > -I$(SRC_PATH)/disas/libvixl -Wno-sign-compare $(QEMU_CFLAGS) > > common-obj-$(CONFIG_ARM_A64_DIS) += $(libvixl_OBJS) -- Alex Bennée
