kbuild: Disable -Wunused-but-set-variable for gcc 4.6.0

[ upstream commit af0e5d565d2fffcd97d1e2d89669d627cc04e8b8 ]

Disable the new -Wunused-but-set-variable that was added in gcc 4.6.0
It produces more false positives than useful warnings.

This can still be enabled using W=1

[AK: dropped W=1 support in backport]
Signed-off-by: Dave Jones <davej@redhat.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Tested-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

diff --git a/Makefile b/Makefile
index 5ade8188d821b95cc0d168eae0885d1282b357a5..1d483a72822586f9a707e1444247569840adfe37 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -546,6 +546,9 @@ ifndef CONFIG_CC_STACKPROTECTOR
 KBUILD_CFLAGS += $(call cc-option, -fno-stack-protector)
 endif
 
+# This warning generated too much noise in a regular build.
+KBUILD_CFLAGS += $(call cc-option, -Wno-unused-but-set-variable)
+
 ifdef CONFIG_FRAME_POINTER
 KBUILD_CFLAGS  += -fno-omit-frame-pointer -fno-optimize-sibling-calls
 else