path: root/scripts/Kbuild.include
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authorMichal Marek <mmarek@suse.cz>2011-05-02 12:51:15 +0200
committerMichal Marek <mmarek@suse.cz>2011-05-03 10:50:54 +0200
commit8417da6f2128008c431c7d130af6cd3d9079922e (patch)
tree79bfdaadfc1548826651b9b0378e70e60cdc7720 /scripts/Kbuild.include
parentbffd2020a972a188750e5cf4b9566950dfdf25a2 (diff)
kbuild: Fix passing -Wno-* options to gcc 4.4+
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>
Diffstat (limited to 'scripts/Kbuild.include')
1 files changed, 5 insertions, 0 deletions
diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index fae2d8d8cb0..c034dd7161a 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -118,6 +118,11 @@ cc-option-yn = $(call try-run,\
cc-option-align = $(subst -functions=0,,\
$(call cc-option,-falign-functions=0,-malign-functions=0))
+# cc-disable-warning
+# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
+cc-disable-warning = $(call try-run,\
+ $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip $(1)) -c -xc /dev/null -o "$$TMP",-Wno-$(strip $(1)))
# cc-version
# Usage gcc-ver := $(call cc-version)
cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))