Makefile: Convert -Wimplicit-fallthrough=3 to just -Wimplicit-fallthrough for clang

A compilation -Wimplicit-fallthrough warning was enabled by commit
a035d552a93b ("Makefile: Globally enable fall-through warning")

Even though clang 10.0.0 does not currently support this warning without
a patch, clang currently does not support a value for this option.

Link: https://bugs.llvm.org/show_bug.cgi?id=39382
The gcc default for this warning is 3 so removing the =3 has no effect
for gcc and enables the warning for patched versions of clang.

Also remove the =3 from an existing use in a parisc Makefile:
arch/parisc/math-emu/Makefile

Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-and-tested-by: Nathan Chancellor <natechancellor@gmail.com>
Cc: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/Makefile b/Makefile
index 02aff718a11d63142062902d962f85ba7994ce9e..18a237743a02ecf58a89960e7aa84b3dca384b2a 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -846,7 +846,7 @@ NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
 KBUILD_CFLAGS += -Wdeclaration-after-statement
 
 # Warn about unmarked fall-throughs in switch statement.
-KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough=3,)
+KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough,)
 
 # Variable Length Arrays (VLAs) should not be used anywhere in the kernel
 KBUILD_CFLAGS += -Wvla

diff --git a/arch/parisc/math-emu/Makefile b/arch/parisc/math-emu/Makefile
index 55c1396580a4b051c2b2efa6bbf9173a4966d152..3747a0cbd3b8fc1b150e67fb067c3994149119e1 100644 (file)
--- a/arch/parisc/math-emu/Makefile
+++ b/arch/parisc/math-emu/Makefile
@@ -18,4 +18,4 @@ obj-y  := frnd.o driver.o decode_exc.o fpudispatch.o denormal.o \
 # other very old or stripped-down PA-RISC CPUs -- not currently supported
 
 obj-$(CONFIG_MATH_EMULATION)   += unimplemented-math-emulation.o
-CFLAGS_REMOVE_fpudispatch.o    = -Wimplicit-fallthrough=3
+CFLAGS_REMOVE_fpudispatch.o    = -Wimplicit-fallthrough