[U-Boot] [PATCH 1/4] Kbuild: support W=[N, ]err for passing '-Werror' to the compiler

[Masahiro Yamada]

Hi Daniel,


2018-01-26 2:21 GMT+09:00 Daniel Schwierzeck <daniel.schwierzeck at gmail.com>:
> Extend the Kbuild's W=N option with an optional 'err' value. This
> will pass -Werror to the compiler to treat all warnings as errors.
> This is useful to enforce a zero-warnings policy.
>
> The 'err' value can also be combined with the numerical values
> like this:
>
>     make W=1
>     make W=err
>     make W=1,err
>
> Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck at gmail.com>
> ---
>
>  scripts/Makefile.extrawarn | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn
> index 1d3a570594..d8d93b7fe1 100644
> --- a/scripts/Makefile.extrawarn
> +++ b/scripts/Makefile.extrawarn
> @@ -48,9 +48,12 @@ warning-3 += -Wswitch-default
>  warning-3 += $(call cc-option, -Wpacked-bitfield-compat)
>  warning-3 += $(call cc-option, -Wvla)
>
> +warning-err := -Werror
> +
>  warning := $(warning-$(findstring 1, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
>  warning += $(warning-$(findstring 2, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
>  warning += $(warning-$(findstring 3, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
> +warning += $(warning-$(findstring err, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
>
>  ifeq ("$(strip $(warning))","")
>          $(error W=$(KBUILD_ENABLE_EXTRA_GCC_CHECKS) is unknown)
> --
> 2.16.1


I saw a similar patch before in linux-kbuild ML.


Kbuild provides a way to specify user-specific options.
See the following lines in the top-level Makefile:


  # Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
  KBUILD_CPPFLAGS += $(KCPPFLAGS)
  KBUILD_AFLAGS += $(KAFLAGS)
  KBUILD_CFLAGS += $(KCFLAGS)



"make W=err" is a shorthand of "make KCFLAGS=-Werror", right?

I tend to hesitate to add another way
to do the same thing...



-- 
Best Regards
Masahiro Yamada