| Message ID | 20220408084607.106468-1-ydroneaud@opteya.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [PATCHv1] kbuild: support W=e to make build abort in case of warning | expand |
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
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
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..
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.)
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.
På lø. 09. april 2022 kl. 10.47 +0000 skrev Masahiro Yamada: > 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. If I set CONFIG_WERROR=y on the make command line, I could have the same result, don't I? make CONFIG_WERROR=1 ... no matter if in-tree or for external kernel modules. Kind regards, Nicolas
On Thu, Apr 14, 2022 at 10:19 PM Nicolas Schier <nicolas@fjasle.eu> wrote: > > På lø. 09. april 2022 kl. 10.47 +0000 skrev Masahiro Yamada: > > 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. > > If I set CONFIG_WERROR=y on the make command line, I could have the > same result, don't I? > > make CONFIG_WERROR=1 ... > > no matter if in-tree or for external kernel modules. Yes. If you can change the kernel configuration, you can enable CONFIG_WERROR. To build external modules against the read-only /lib/modules/$(uname -r)/build/, it is not so feasible to change the .config file, though. > > Kind regards, > Nicolas
On Fri, Apr 15, 2022 at 12:15:40AM +0900 Masahiro Yamada wrote: > On Thu, Apr 14, 2022 at 10:19 PM Nicolas Schier <nicolas@fjasle.eu> wrote: > > > > På lø. 09. april 2022 kl. 10.47 +0000 skrev Masahiro Yamada: > > > 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. > > > > If I set CONFIG_WERROR=y on the make command line, I could have the > > same result, don't I? > > > > make CONFIG_WERROR=1 ... > > > > no matter if in-tree or for external kernel modules. > > Yes. > > If you can change the kernel configuration, > you can enable CONFIG_WERROR. > > To build external modules against the read-only > /lib/modules/$(uname -r)/build/, > it is not so feasible to change the .config file, though. hm, I wanted to point out something different. When I build an external module against a read-only kbuild-tree, I _can_ change kconfig values by specifying them on the make command line, just as I can add 'W=e': make -C /lib/modules/$(uname -r)/build M=~+ CONFIG_SAMPLE_KOBJECT=m CONFIG_WERROR=y Thus, I suspect, that this is the very same as if I'd run make -C /lib/modules/$(uname -r)/build M=~+ CONFIG_SAMPLE_KOBJECT=m W=e So, "W=e" is actually just a shortcut for "CONFIG_WERROR=1". Or have I missed something? Kind regards, Nicolas
On Thu, Apr 14, 2022 at 07:51:46PM +0200 Nicolas Schier wrote: > On Fri, Apr 15, 2022 at 12:15:40AM +0900 Masahiro Yamada wrote: > > On Thu, Apr 14, 2022 at 10:19 PM Nicolas Schier <nicolas@fjasle.eu> wrote: > > > > > > På lø. 09. april 2022 kl. 10.47 +0000 skrev Masahiro Yamada: > > > > 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. > > > > > > If I set CONFIG_WERROR=y on the make command line, I could have the > > > same result, don't I? > > > > > > make CONFIG_WERROR=1 ... > > > > > > no matter if in-tree or for external kernel modules. > > > > Yes. > > > > If you can change the kernel configuration, > > you can enable CONFIG_WERROR. > > > > To build external modules against the read-only > > /lib/modules/$(uname -r)/build/, > > it is not so feasible to change the .config file, though. > > hm, I wanted to point out something different. When I build an external module > against a read-only kbuild-tree, I _can_ change kconfig values by specifying > them on the make command line, just as I can add 'W=e': > > make -C /lib/modules/$(uname -r)/build M=~+ CONFIG_SAMPLE_KOBJECT=m CONFIG_WERROR=y > > Thus, I suspect, that this is the very same as if I'd run > > make -C /lib/modules/$(uname -r)/build M=~+ CONFIG_SAMPLE_KOBJECT=m W=e > > So, "W=e" is actually just a shortcut for "CONFIG_WERROR=1". Or have I missed > something? > > Kind regards, > Nicolas oh, sorry. Yann wrote it already in his commit message, please excuse the noise. Kind regards, Nicolas
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 >
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
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/