Re: annoying new gcc 4.6.0 warnings.

From: David Daney
Date: Thu Apr 21 2011 - 16:37:46 EST


On 04/21/2011 01:27 PM, Dave Jones wrote:
On Thu, Apr 21, 2011 at 10:08:36PM +0200, Sam Ravnborg wrote:

> My gcc (4.3.2) barfed over -Wno-unused-but-set-variable.
> So your patch needs to check if the option is supported.

I don't have a gcc older than 4.4.0. Can you try this ?

Dave
--

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

Signed-off-by: Dave Jones<davej@xxxxxxxxxx>

diff --git a/Makefile b/Makefile
index b967b96..29e16f2 100644
--- a/Makefile
+++ b/Makefile
@@ -559,6 +559,8 @@ ifndef CONFIG_CC_STACKPROTECTOR
KBUILD_CFLAGS += $(call cc-option, -fno-stack-protector)
endif

+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
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index d5f925a..30627ab 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -79,6 +79,7 @@ KBUILD_EXTRA_WARNINGS += -Wpointer-arith
KBUILD_EXTRA_WARNINGS += -Wredundant-decls
KBUILD_EXTRA_WARNINGS += -Wshadow
KBUILD_EXTRA_WARNINGS += -Wswitch-default
+KBUILD_EXTRA_WARNINGS += -Wunused-but-set-variable

Well I didn't test it, but presumably if you need the $(call cc-option, -Wno-unused-but-set-variable), you would need similar here.

David Daney
--
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