kbuild: add all Clang-specific flags unconditionally

We do not support old Clang versions. Upgrade your clang version
if any of these flags is unsupported.

Let's add all flags inside ifdef CONFIG_CC_IS_CLANG unconditionally.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>

Makefile

@@ -731,15 +731,15 @@ stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
 KBUILD_CFLAGS += $(stackp-flags-y)
 
 ifdef CONFIG_CC_IS_CLANG
-KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
-KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
-KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
+KBUILD_CPPFLAGS += -Qunused-arguments
+KBUILD_CFLAGS += -Wno-format-invalid-specifier
+KBUILD_CFLAGS += -Wno-gnu
 # Quiet clang warning: comparison of unsigned expression < 0 is always false
-KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
+KBUILD_CFLAGS += -Wno-tautological-compare
 # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
 # source of a reference will be _MergedGlobals and not on of the whitelisted names.
 # See modpost pattern 2
-KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,)
+KBUILD_CFLAGS += -mno-global-merge
 else
 
 # These warnings generated too much noise in a regular build.

scripts/Makefile.extrawarn

@@ -67,11 +67,11 @@ KBUILD_CFLAGS += $(warning)
 else
 
 ifdef CONFIG_CC_IS_CLANG
-KBUILD_CFLAGS += $(call cc-disable-warning, initializer-overrides)
-KBUILD_CFLAGS += $(call cc-disable-warning, unused-value)
-KBUILD_CFLAGS += $(call cc-disable-warning, format)
-KBUILD_CFLAGS += $(call cc-disable-warning, sign-compare)
-KBUILD_CFLAGS += $(call cc-disable-warning, format-zero-length)
-KBUILD_CFLAGS += $(call cc-disable-warning, uninitialized)
+KBUILD_CFLAGS += -Wno-initializer-overrides
+KBUILD_CFLAGS += -Wno-unused-value
+KBUILD_CFLAGS += -Wno-format
+KBUILD_CFLAGS += -Wno-sign-compare
+KBUILD_CFLAGS += -Wno-format-zero-length
+KBUILD_CFLAGS += -Wno-uninitialized
 endif
 endif