>From gcc documentation: -Wimplicit-fallthrough=0 disables the warning altogether. -Wimplicit-fallthrough=1 matches .* regular expression, any comment is used as fallthrough comment. -Wimplicit-fallthrough=2 case insensitively matches .*falls?[ \t-]*thr(ough|u).* regular expression. -Wimplicit-fallthrough=3 case sensitively matches one of the following regular expressions: -fallthrough @fallthrough@ lint -fallthrough[ \t]* [ \t.!]*(ELSE,? |INTENTIONAL(LY)? )? FALL(S | |-)?THR(OUGH|U)[ \t.!]*(-[^\n\r]*)? [ \t.!]*(Else,? |Intentional(ly)? )? Fall((s | |-)[Tt]|t)hr(ough|u)[ \t.!]*(-[^\n\r]*)? [ \t.!]*([Ee]lse,? |[Ii]ntentional(ly)? )? fall(s | |-)?thr(ough|u)[ \t.!]*(-[^\n\r]*)? -Wimplicit-fallthrough=4 case sensitively matches one of the following regular expressions: -fallthrough @fallthrough@ lint -fallthrough[ \t]* [ \t]*FALLTHR(OUGH|U)[ \t]* -Wimplicit-fallthrough=5 doesn’t recognize any comments as fallthrough comments, only attributes disable the warning.
In particular the default value of 3 does not match the comments like /* falls through to do foobar */ generating suprious warnings on properly annotated code. Signed-off-by: Michal Suchanek <msucha...@suse.de> --- Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Makefile b/Makefile index f125625efd60..641ec413c2a6 100644 --- 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,) +KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough=2,) # Variable Length Arrays (VLAs) should not be used anywhere in the kernel KBUILD_CFLAGS += -Wvla -- 2.22.0
