disas/libvixl: Suppress gcc 4.6.3 sign-compare warnings

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.maydell@linaro.org>
Message-id: 1452604204-27202-1-git-send-email-peter.maydell@linaro.org
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

diff --git a/disas/Makefile.objs b/disas/Makefile.objs
index 8dae4daec00f8139906cdab48a4478923587fcc9..abeba846617e91d7cb9ed7b3bf90d26f7681f790 100644 (file)
--- 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 e373cf02d3f1ea7cf0c2bc8d235a2f3e83ba3668..d1e801a1e92965f24869965c80b6097f5ee7a280 100644 (file)
--- 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)