On Mon, Aug 7, 2023 at 9:55 AM Nathan Chancellor <nathan@xxxxxxxxxx> wrote: > > On Mon, Aug 07, 2023 at 09:50:32AM -0700, Nick Desaulniers wrote: > > I noticed Tom was sending patches where smatch was recommending > > annotating functions as static when no previous declaration existed. > > Surely the compiler could make such recommendations as well, I thought. > > > > Looks like -Wmissing-variable-declarations can make such > > recommendations. > > > > GCC just added support for this warning (gcc 14.1.0 will ship with > > support), and all versions of clang relevant to building the kernel > > support this flag. > > > > Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> > > Any idea how many instances of this there are? At least x86_64 defconfig > fails immediately with: $ make LLVM=1 -j128 W=1 allnoconfig 2>log.txt $ grep -r Wmissing-variable-declarations log.txt | sort -u | wc -l 140 Though that's not perfectly filtered due to overlapping output due to -j 128. > > In file included from scripts/mod/devicetable-offsets.c:3: > In file included from include/linux/mod_devicetable.h:14: > In file included from include/linux/uuid.h:11: > In file included from include/linux/string.h:20: > In file included from arch/x86/include/asm/string.h:5: > In file included from arch/x86/include/asm/string_64.h:6: > In file included from include/linux/jump_label.h:112: > In file included from arch/x86/include/asm/jump_label.h:7: > arch/x86/include/asm/asm.h:208:24: error: no previous extern declaration for non-static variable 'current_stack_pointer' [-Werror,-Wmissing-variable-declarations] > 208 | register unsigned long current_stack_pointer asm(_ASM_SP); > | ^ > arch/x86/include/asm/asm.h:208:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit > 208 | register unsigned long current_stack_pointer asm(_ASM_SP); > | ^ Hmm...I wonder if clang and gcc should ignore variables with register storage for this warning. > 1 error generated. > > > --- > > scripts/Makefile.extrawarn | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn > > index 40cd13eca82e..617739eb84e2 100644 > > --- a/scripts/Makefile.extrawarn > > +++ b/scripts/Makefile.extrawarn > > @@ -32,6 +32,7 @@ KBUILD_CFLAGS += $(call cc-option, -Wunused-but-set-variable) > > KBUILD_CFLAGS += $(call cc-option, -Wunused-const-variable) > > KBUILD_CFLAGS += $(call cc-option, -Wpacked-not-aligned) > > KBUILD_CFLAGS += $(call cc-option, -Wstringop-truncation) > > +KBUILD_CFLAGS += $(call cc-option, -Wmissing-varibale-declarations) > ^ variable > > # The following turn off the warnings enabled by -Wextra > > KBUILD_CFLAGS += -Wno-missing-field-initializers > > KBUILD_CFLAGS += -Wno-sign-compare > > > > --- > > base-commit: 52a93d39b17dc7eb98b6aa3edb93943248e03b2f > > change-id: 20230807-missing_proto-0cb90ec6454c > > > > Best regards, > > -- > > Nick Desaulniers <ndesaulniers@xxxxxxxxxx> > > -- Thanks, ~Nick Desaulniers
