kbuild: Fix passing -Wno-* options to gcc 4.4+
[ upstream commit 8417da6f2128008c431c7d130af6cd3d9079922e ]
Starting with 4.4, gcc will happily accept -Wno-<anything> in the
cc-option test and complain later when compiling a file that has some
other warning. This rather unexpected behavior is intentional as per
http://gcc.gnu.org/PR28322, so work around it by testing for support of
the opposite option (without the no-). Introduce a new Makefile function
cc-disable-warning that does this and update two uses of cc-option in
the toplevel Makefile.
Reported-and-tested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
diff --git a/Makefile b/Makefile
index a0d3cd1..02ddd86 100644
--- a/Makefile
+++ b/Makefile
@@ -548,7 +548,7 @@
endif
# This warning generated too much noise in a regular build.
-KBUILD_CFLAGS += $(call cc-option, -Wno-unused-but-set-variable)
+KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
ifdef CONFIG_FRAME_POINTER
KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
@@ -583,7 +583,7 @@
KBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)
# disable pointer signed / unsigned warnings in gcc 4.0
-KBUILD_CFLAGS += $(call cc-option,-Wno-pointer-sign,)
+KBUILD_CFLAGS += $(call cc-disable-warning, pointer-sign)
# disable invalid "can't wrap" optimizations for signed / pointers
KBUILD_CFLAGS += $(call cc-option,-fno-strict-overflow)