kbuild: support W=e to make build abort in case of warning

[PATCHv1] kbuild: support W=e to make build abort in case of warning

Posted by Yann Droneaud 4 years, 1 month ago

When developing new code/feature, CONFIG_WERROR is most
often turned off, especially for people using make W=12 to
get more warnings.

In such case, turning on -Werror temporarily would require
switching on CONFIG_WERROR in the configuration, building,
then switching off CONFIG_WERROR.

For this use case, this patch introduces a new 'e' modifier
to W= as a short hand for KCFLAGS+=-Werror" so that -Werror
got added to the kernel (built-in) and modules' CFLAGS.

Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
---
 Makefile                   |  1 +
 scripts/Makefile.extrawarn | 13 +++++++++++--
 2 files changed, 12 insertions(+), 2 deletions(-)

Changes since v0[0]:

 - rebase on top of commit 64a91907c896 ("kbuild: refactor scripts/Makefile.extrawarn")
 - document use case after commit 3fe617ccafd6 ("Enable '-Werror' by default for all kernel builds")

[0] https://lore.kernel.org/all/1422803720-14723-1-git-send-email-ydroneaud@opteya.com/

diff --git a/Makefile b/Makefile
index 8c7de9a72ea2..6dc621af18d1 100644
--- a/Makefile
+++ b/Makefile
@@ -1649,6 +1649,7 @@ help:
 	@echo  '		1: warnings which may be relevant and do not occur too often'
 	@echo  '		2: warnings which occur quite often but may still be relevant'
 	@echo  '		3: more obscure warnings, can most likely be ignored'
+	@echo  '		e: warnings are being treated as errors'
 	@echo  '		Multiple levels can be combined with W=12 or W=123'
 	@echo  ''
 	@echo  'Execute "make" or "make all" to build all targets marked with [*] '
diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn
index 650d0b8ceec3..f5f0d6f09053 100644
--- a/scripts/Makefile.extrawarn
+++ b/scripts/Makefile.extrawarn
@@ -2,8 +2,8 @@
 # ==========================================================================
 # make W=... settings
 #
-# There are three warning groups enabled by W=1, W=2, W=3.
-# They are independent, and can be combined like W=12 or W=123.
+# There are four warning groups enabled by W=1, W=2, W=3, and W=e
+# They are independent, and can be combined like W=12 or W=123e.
 # ==========================================================================
 
 KBUILD_CFLAGS += $(call cc-disable-warning, packed-not-aligned)
@@ -94,3 +94,12 @@ KBUILD_CFLAGS += $(call cc-option, -Wpacked-bitfield-compat)
 KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN3
 
 endif
+
+#
+# W=e - error out on warnings
+#
+ifneq ($(findstring e, $(KBUILD_EXTRA_WARN)),)
+
+KBUILD_CFLAGS += -Werror
+
+endif
-- 
2.32.0

Re: [PATCHv1] kbuild: support W=e to make build abort in case of warning

Posted by Masahiro Yamada 4 years ago

On Fri, Apr 8, 2022 at 5:46 PM Yann Droneaud <ydroneaud@opteya.com> wrote:
>
> When developing new code/feature, CONFIG_WERROR is most
> often turned off, especially for people using make W=12 to
> get more warnings.
>
> In such case, turning on -Werror temporarily would require
> switching on CONFIG_WERROR in the configuration, building,
> then switching off CONFIG_WERROR.
>
> For this use case, this patch introduces a new 'e' modifier
> to W= as a short hand for KCFLAGS+=-Werror" so that -Werror
> got added to the kernel (built-in) and modules' CFLAGS.
>
> Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
> ---


Applied to linux-kbuild.
Thanks.

>  Makefile                   |  1 +
>  scripts/Makefile.extrawarn | 13 +++++++++++--
>  2 files changed, 12 insertions(+), 2 deletions(-)
>
> Changes since v0[0]:
>
>  - rebase on top of commit 64a91907c896 ("kbuild: refactor scripts/Makefile.extrawarn")
>  - document use case after commit 3fe617ccafd6 ("Enable '-Werror' by default for all kernel builds")
>
> [0] https://lore.kernel.org/all/1422803720-14723-1-git-send-email-ydroneaud@opteya.com/
>
> diff --git a/Makefile b/Makefile
> index 8c7de9a72ea2..6dc621af18d1 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -1649,6 +1649,7 @@ help:
>         @echo  '                1: warnings which may be relevant and do not occur too often'
>         @echo  '                2: warnings which occur quite often but may still be relevant'
>         @echo  '                3: more obscure warnings, can most likely be ignored'
> +       @echo  '                e: warnings are being treated as errors'
>         @echo  '                Multiple levels can be combined with W=12 or W=123'
>         @echo  ''
>         @echo  'Execute "make" or "make all" to build all targets marked with [*] '
> diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn
> index 650d0b8ceec3..f5f0d6f09053 100644
> --- a/scripts/Makefile.extrawarn
> +++ b/scripts/Makefile.extrawarn
> @@ -2,8 +2,8 @@
>  # ==========================================================================
>  # make W=... settings
>  #
> -# There are three warning groups enabled by W=1, W=2, W=3.
> -# They are independent, and can be combined like W=12 or W=123.
> +# There are four warning groups enabled by W=1, W=2, W=3, and W=e
> +# They are independent, and can be combined like W=12 or W=123e.
>  # ==========================================================================
>
>  KBUILD_CFLAGS += $(call cc-disable-warning, packed-not-aligned)
> @@ -94,3 +94,12 @@ KBUILD_CFLAGS += $(call cc-option, -Wpacked-bitfield-compat)
>  KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN3
>
>  endif
> +
> +#
> +# W=e - error out on warnings
> +#
> +ifneq ($(findstring e, $(KBUILD_EXTRA_WARN)),)
> +
> +KBUILD_CFLAGS += -Werror
> +
> +endif
> --
> 2.32.0
>


-- 
Best Regards
Masahiro Yamada

Re: [PATCHv1] kbuild: support W=e to make build abort in case of warning

Posted by Masahiro Yamada 4 years, 1 month ago

On Fri, Apr 8, 2022 at 5:46 PM Yann Droneaud <ydroneaud@opteya.com> wrote:
>
> When developing new code/feature, CONFIG_WERROR is most
> often turned off, especially for people using make W=12 to
> get more warnings.
>
> In such case, turning on -Werror temporarily would require
> switching on CONFIG_WERROR in the configuration, building,
> then switching off CONFIG_WERROR.
>
> For this use case, this patch introduces a new 'e' modifier
> to W= as a short hand for KCFLAGS+=-Werror" so that -Werror
> got added to the kernel (built-in) and modules' CFLAGS.
>
> Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
> ---
>  Makefile                   |  1 +
>  scripts/Makefile.extrawarn | 13 +++++++++++--
>  2 files changed, 12 insertions(+), 2 deletions(-)
>
> Changes since v0[0]:
>
>  - rebase on top of commit 64a91907c896 ("kbuild: refactor scripts/Makefile.extrawarn")
>  - document use case after commit 3fe617ccafd6 ("Enable '-Werror' by default for all kernel builds")
>
> [0] https://lore.kernel.org/all/1422803720-14723-1-git-send-email-ydroneaud@opteya.com/


I remembered the previous submission, I liked it, but I had lost it.

It seems already 7 years ago, (before I became the Kbuild maintainer).
Thanks for coming back to this.


I like this, but I will wait some time for review comments.









> diff --git a/Makefile b/Makefile
> index 8c7de9a72ea2..6dc621af18d1 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -1649,6 +1649,7 @@ help:
>         @echo  '                1: warnings which may be relevant and do not occur too often'
>         @echo  '                2: warnings which occur quite often but may still be relevant'
>         @echo  '                3: more obscure warnings, can most likely be ignored'
> +       @echo  '                e: warnings are being treated as errors'
>         @echo  '                Multiple levels can be combined with W=12 or W=123'
>         @echo  ''
>         @echo  'Execute "make" or "make all" to build all targets marked with [*] '
> diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn
> index 650d0b8ceec3..f5f0d6f09053 100644
> --- a/scripts/Makefile.extrawarn
> +++ b/scripts/Makefile.extrawarn
> @@ -2,8 +2,8 @@
>  # ==========================================================================
>  # make W=... settings
>  #
> -# There are three warning groups enabled by W=1, W=2, W=3.
> -# They are independent, and can be combined like W=12 or W=123.
> +# There are four warning groups enabled by W=1, W=2, W=3, and W=e
> +# They are independent, and can be combined like W=12 or W=123e.
>  # ==========================================================================
>
>  KBUILD_CFLAGS += $(call cc-disable-warning, packed-not-aligned)
> @@ -94,3 +94,12 @@ KBUILD_CFLAGS += $(call cc-option, -Wpacked-bitfield-compat)
>  KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN3
>
>  endif
> +
> +#
> +# W=e - error out on warnings
> +#
> +ifneq ($(findstring e, $(KBUILD_EXTRA_WARN)),)
> +
> +KBUILD_CFLAGS += -Werror
> +
> +endif
> --
> 2.32.0
>


--
Best Regards
Masahiro Yamada

Re: [PATCHv1] kbuild: support W=e to make build abort in case of warning

Posted by Nick Desaulniers 4 years, 1 month ago

On Fri, Apr 8, 2022 at 4:06 AM Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> On Fri, Apr 8, 2022 at 5:46 PM Yann Droneaud <ydroneaud@opteya.com> wrote:
> >
> > When developing new code/feature, CONFIG_WERROR is most
> > often turned off, especially for people using make W=12 to
> > get more warnings.
> >
> > In such case, turning on -Werror temporarily would require
> > switching on CONFIG_WERROR in the configuration, building,
> > then switching off CONFIG_WERROR.
> >
> > For this use case, this patch introduces a new 'e' modifier
> > to W= as a short hand for KCFLAGS+=-Werror" so that -Werror
> > got added to the kernel (built-in) and modules' CFLAGS.
> >
> > Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
> > ---
> >  Makefile                   |  1 +
> >  scripts/Makefile.extrawarn | 13 +++++++++++--
> >  2 files changed, 12 insertions(+), 2 deletions(-)
> >
> > Changes since v0[0]:
> >
> >  - rebase on top of commit 64a91907c896 ("kbuild: refactor scripts/Makefile.extrawarn")
> >  - document use case after commit 3fe617ccafd6 ("Enable '-Werror' by default for all kernel builds")
> >
> > [0] https://lore.kernel.org/all/1422803720-14723-1-git-send-email-ydroneaud@opteya.com/
>
>
> I remembered the previous submission, I liked it, but I had lost it.
>
> It seems already 7 years ago, (before I became the Kbuild maintainer).
> Thanks for coming back to this.
>
>
> I like this, but I will wait some time for review comments.

Dunno, this seems pretty simple:

$ ./scripts/config -e WERROR
$ make ... W=12
-- 
Thanks,
~Nick Desaulniers

Re: [PATCHv1] kbuild: support W=e to make build abort in case of warning

Posted by Randy Dunlap 4 years, 1 month ago


On 4/8/22 13:29, Nick Desaulniers wrote:
> On Fri, Apr 8, 2022 at 4:06 AM Masahiro Yamada <masahiroy@kernel.org> wrote:
>>
>> On Fri, Apr 8, 2022 at 5:46 PM Yann Droneaud <ydroneaud@opteya.com> wrote:
>>>
>>> When developing new code/feature, CONFIG_WERROR is most
>>> often turned off, especially for people using make W=12 to
>>> get more warnings.
>>>
>>> In such case, turning on -Werror temporarily would require
>>> switching on CONFIG_WERROR in the configuration, building,
>>> then switching off CONFIG_WERROR.
>>>
>>> For this use case, this patch introduces a new 'e' modifier
>>> to W= as a short hand for KCFLAGS+=-Werror" so that -Werror
>>> got added to the kernel (built-in) and modules' CFLAGS.
>>>
>>> Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
>>> ---
>>>  Makefile                   |  1 +
>>>  scripts/Makefile.extrawarn | 13 +++++++++++--
>>>  2 files changed, 12 insertions(+), 2 deletions(-)
>>>
>>> Changes since v0[0]:
>>>
>>>  - rebase on top of commit 64a91907c896 ("kbuild: refactor scripts/Makefile.extrawarn")
>>>  - document use case after commit 3fe617ccafd6 ("Enable '-Werror' by default for all kernel builds")
>>>
>>> [0] https://lore.kernel.org/all/1422803720-14723-1-git-send-email-ydroneaud@opteya.com/
>>
>>
>> I remembered the previous submission, I liked it, but I had lost it.
>>
>> It seems already 7 years ago, (before I became the Kbuild maintainer).
>> Thanks for coming back to this.
>>
>>
>> I like this, but I will wait some time for review comments.
> 
> Dunno, this seems pretty simple:
> 
> $ ./scripts/config -e WERROR
> $ make ... W=12

Yeah, that's about what I was thinking too..

-- 
~Randy

Re: [PATCHv1] kbuild: support W=e to make build abort in case of warning

Posted by Masahiro Yamada 4 years, 1 month ago

On Sat, Apr 9, 2022 at 5:36 AM Randy Dunlap <rdunlap@infradead.org> wrote:
>
>
>
> On 4/8/22 13:29, Nick Desaulniers wrote:
> > On Fri, Apr 8, 2022 at 4:06 AM Masahiro Yamada <masahiroy@kernel.org> wrote:
> >>
> >> On Fri, Apr 8, 2022 at 5:46 PM Yann Droneaud <ydroneaud@opteya.com> wrote:
> >>>
> >>> When developing new code/feature, CONFIG_WERROR is most
> >>> often turned off, especially for people using make W=12 to
> >>> get more warnings.
> >>>
> >>> In such case, turning on -Werror temporarily would require
> >>> switching on CONFIG_WERROR in the configuration, building,
> >>> then switching off CONFIG_WERROR.
> >>>
> >>> For this use case, this patch introduces a new 'e' modifier
> >>> to W= as a short hand for KCFLAGS+=-Werror" so that -Werror
> >>> got added to the kernel (built-in) and modules' CFLAGS.
> >>>
> >>> Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
> >>> ---
> >>>  Makefile                   |  1 +
> >>>  scripts/Makefile.extrawarn | 13 +++++++++++--
> >>>  2 files changed, 12 insertions(+), 2 deletions(-)
> >>>
> >>> Changes since v0[0]:
> >>>
> >>>  - rebase on top of commit 64a91907c896 ("kbuild: refactor scripts/Makefile.extrawarn")
> >>>  - document use case after commit 3fe617ccafd6 ("Enable '-Werror' by default for all kernel builds")
> >>>
> >>> [0] https://lore.kernel.org/all/1422803720-14723-1-git-send-email-ydroneaud@opteya.com/
> >>
> >>
> >> I remembered the previous submission, I liked it, but I had lost it.
> >>
> >> It seems already 7 years ago, (before I became the Kbuild maintainer).
> >> Thanks for coming back to this.
> >>
> >>
> >> I like this, but I will wait some time for review comments.
> >
> > Dunno, this seems pretty simple:
> >
> > $ ./scripts/config -e WERROR
> > $ make ... W=12
>
> Yeah, that's about what I was thinking too..



But, you cannot change the .config
when you build external modules.

"make W=e" might be useful for people who strive to
keep their downstream modules warning-free.


W=e is the same pattern.
I do not see much downside.



(BTW, I do not like CONFIG_WERROR.)






-- 
Best Regards
Masahiro Yamada

Re: [PATCHv1] kbuild: support W=e to make build abort in case of warning

Posted by Randy Dunlap 4 years, 1 month ago


On 4/8/22 18:47, Masahiro Yamada wrote:
> On Sat, Apr 9, 2022 at 5:36 AM Randy Dunlap <rdunlap@infradead.org> wrote:
>>
>>
>>
>> On 4/8/22 13:29, Nick Desaulniers wrote:
>>> On Fri, Apr 8, 2022 at 4:06 AM Masahiro Yamada <masahiroy@kernel.org> wrote:
>>>>
>>>> On Fri, Apr 8, 2022 at 5:46 PM Yann Droneaud <ydroneaud@opteya.com> wrote:
>>>>>
>>>>> When developing new code/feature, CONFIG_WERROR is most
>>>>> often turned off, especially for people using make W=12 to
>>>>> get more warnings.
>>>>>
>>>>> In such case, turning on -Werror temporarily would require
>>>>> switching on CONFIG_WERROR in the configuration, building,
>>>>> then switching off CONFIG_WERROR.
>>>>>
>>>>> For this use case, this patch introduces a new 'e' modifier
>>>>> to W= as a short hand for KCFLAGS+=-Werror" so that -Werror
>>>>> got added to the kernel (built-in) and modules' CFLAGS.
>>>>>
>>>>> Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
>>>>> ---
>>>>>  Makefile                   |  1 +
>>>>>  scripts/Makefile.extrawarn | 13 +++++++++++--
>>>>>  2 files changed, 12 insertions(+), 2 deletions(-)
>>>>>
>>>>> Changes since v0[0]:
>>>>>
>>>>>  - rebase on top of commit 64a91907c896 ("kbuild: refactor scripts/Makefile.extrawarn")
>>>>>  - document use case after commit 3fe617ccafd6 ("Enable '-Werror' by default for all kernel builds")
>>>>>
>>>>> [0] https://lore.kernel.org/all/1422803720-14723-1-git-send-email-ydroneaud@opteya.com/
>>>>
>>>>
>>>> I remembered the previous submission, I liked it, but I had lost it.
>>>>
>>>> It seems already 7 years ago, (before I became the Kbuild maintainer).
>>>> Thanks for coming back to this.
>>>>
>>>>
>>>> I like this, but I will wait some time for review comments.
>>>
>>> Dunno, this seems pretty simple:
>>>
>>> $ ./scripts/config -e WERROR
>>> $ make ... W=12
>>
>> Yeah, that's about what I was thinking too..
> 
> 
> 
> But, you cannot change the .config
> when you build external modules.
> 
> "make W=e" might be useful for people who strive to
> keep their downstream modules warning-free.
> 
> 
> W=e is the same pattern.
> I do not see much downside.
> 

Well, I don't see much downside either.

> 
> 
> (BTW, I do not like CONFIG_WERROR.)

Yeah, I disable it most of the time, but I am pretty good
at searching for errors & warnings. Apparently some people
are not.

-- 
~Randy