Re: [PATCH v3 2/2] kbuild: rename KBUILD_ENABLE_EXTRA_GCC_CHECKS to KBUILD_EXTRA_WARN

[Sedat Dilek]

On Tue, Sep 3, 2019 at 11:50 PM Nick Desaulniers
<ndesaulniers@xxxxxxxxxx> wrote:
>
> On Sat, Aug 31, 2019 at 9:26 AM Masahiro Yamada
> <yamada.masahiro@xxxxxxxxxxxxx> wrote:
> >
> > KBUILD_ENABLE_EXTRA_GCC_CHECKS started as a switch to add extra warning
> > options for GCC, but now it is a historical misnomer since we use it
> > also for Clang, DTC, and even kernel-doc.
>
> Thanks for the patch!
> Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
>

Thanks for the patch.
I like the backward compatibility and am OK with pointing to 'make
--help' for the documentation part (KISS - Keep It Simple and
Short/Stupid).

Reviewed-by: Sedat Dilek <sedat.dilek@xxxxxxxxx>

- Sedat -

> >
> > Rename it to more sensible, and shorter KBUILD_EXTRA_WARN.
> >
> > For the backward compatibility, KBUILD_ENABLE_EXTRA_GCC_CHECKS is still
> > supported (but not advertised in the documentation).
> >
> > I also fixed up 'make help', and updated the documentation.
> >
> > Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
> > ---
> >
> > Changes in v3:
> >   - new patch
> >
> > Changes in v2: None
> >
> >  Documentation/kbuild/kbuild.rst | 14 +++++++++-----
> >  Makefile                        |  2 +-
> >  scripts/Makefile.build          |  2 +-
> >  scripts/Makefile.extrawarn      | 13 +++++++++----
> >  scripts/Makefile.lib            |  4 ++--
> >  scripts/genksyms/Makefile       |  2 +-
> >  6 files changed, 23 insertions(+), 14 deletions(-)
> >
> > diff --git a/Documentation/kbuild/kbuild.rst b/Documentation/kbuild/kbuild.rst
> > index 62f9d86c082c..f1e5dce86af7 100644
> > --- a/Documentation/kbuild/kbuild.rst
> > +++ b/Documentation/kbuild/kbuild.rst
> > @@ -105,6 +105,15 @@ The output directory can also be specified using "O=...".
> >
> >  Setting "O=..." takes precedence over KBUILD_OUTPUT.
> >
> > +KBUILD_EXTRA_WARN
> > +-----------------
> > +Specify the extra build checks. The same value can be assigned by passing
> > +W=... from the command line.
> > +
> > +See `make help` for the list of the supported values.
> > +
> > +Setting "W=..." takes precedence over KBUILD_EXTRA_WARN.
> > +
> >  KBUILD_DEBARCH
> >  --------------
> >  For the deb-pkg target, allows overriding the normal heuristics deployed by
> > @@ -241,11 +250,6 @@ To get all available archs you can also specify all. E.g.::
> >
> >      $ make ALLSOURCE_ARCHS=all tags
> >
> > -KBUILD_ENABLE_EXTRA_GCC_CHECKS
> > -------------------------------
> > -If enabled over the make command line with "W=1", it turns on additional
> > -gcc -W... options for more extensive build-time checking.
> > -
> >  KBUILD_BUILD_TIMESTAMP
> >  ----------------------
> >  Setting this to a date string overrides the timestamp used in the
> > diff --git a/Makefile b/Makefile
> > index 06e1e21c0f45..016d72eb3ddf 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -1538,7 +1538,7 @@ help:
> >         @echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK (sparse by default)'
> >         @echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
> >         @echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
> > -       @echo  '  make W=n   [targets] Enable extra gcc checks, n=1,2,3 where'
> > +       @echo  '  make W=n   [targets] Enable extra checks, n=1,2,3 where'
> >         @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'
> > diff --git a/scripts/Makefile.build b/scripts/Makefile.build
> > index 2a21ca86b720..f72aba64d611 100644
> > --- a/scripts/Makefile.build
> > +++ b/scripts/Makefile.build
> > @@ -85,7 +85,7 @@ else ifeq ($(KBUILD_CHECKSRC),2)
> >          cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
> >  endif
> >
> > -ifneq ($(KBUILD_ENABLE_EXTRA_GCC_CHECKS),)
> > +ifneq ($(KBUILD_EXTRA_WARN),)
> >    cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $<
> >  endif
> >
> > diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn
> > index d226c5fb13e2..53eb7e0c6a5a 100644
> > --- a/scripts/Makefile.extrawarn
> > +++ b/scripts/Makefile.extrawarn
> > @@ -8,14 +8,19 @@
> >
> >  KBUILD_CFLAGS += $(call cc-disable-warning, packed-not-aligned)
> >
> > +# backward compatibility
> > +KBUILD_EXTRA_WARN ?= $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)
> > +
> >  ifeq ("$(origin W)", "command line")
> > -  export KBUILD_ENABLE_EXTRA_GCC_CHECKS := $(W)
> > +  KBUILD_EXTRA_WARN := $(W)
> >  endif
> >
> > +export KBUILD_EXTRA_WARN
> > +
> >  #
> >  # W=1 - warnings which may be relevant and do not occur too often
> >  #
> > -ifneq ($(findstring 1, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)),)
> > +ifneq ($(findstring 1, $(KBUILD_EXTRA_WARN)),)
> >
> >  KBUILD_CFLAGS += -Wextra -Wunused -Wno-unused-parameter
> >  KBUILD_CFLAGS += -Wmissing-declarations
> > @@ -48,7 +53,7 @@ endif
> >  #
> >  # W=2 - warnings which occur quite often but may still be relevant
> >  #
> > -ifneq ($(findstring 2, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)),)
> > +ifneq ($(findstring 2, $(KBUILD_EXTRA_WARN)),)
> >
> >  KBUILD_CFLAGS += -Wcast-align
> >  KBUILD_CFLAGS += -Wdisabled-optimization
> > @@ -65,7 +70,7 @@ endif
> >  #
> >  # W=3 - more obscure warnings, can most likely be ignored
> >  #
> > -ifneq ($(findstring 3, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)),)
> > +ifneq ($(findstring 3, $(KBUILD_EXTRA_WARN)),)
> >
> >  KBUILD_CFLAGS += -Wbad-function-cast
> >  KBUILD_CFLAGS += -Wcast-qual
> > diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
> > index 7ab17712ab24..df83967268ba 100644
> > --- a/scripts/Makefile.lib
> > +++ b/scripts/Makefile.lib
> > @@ -248,7 +248,7 @@ quiet_cmd_gzip = GZIP    $@
> >  DTC ?= $(objtree)/scripts/dtc/dtc
> >
> >  # Disable noisy checks by default
> > -ifeq ($(findstring 1,$(KBUILD_ENABLE_EXTRA_GCC_CHECKS)),)
> > +ifeq ($(findstring 1,$(KBUILD_EXTRA_WARN)),)
> >  DTC_FLAGS += -Wno-unit_address_vs_reg \
> >         -Wno-unit_address_format \
> >         -Wno-avoid_unnecessary_addr_size \
> > @@ -259,7 +259,7 @@ DTC_FLAGS += -Wno-unit_address_vs_reg \
> >         -Wno-pci_device_reg
> >  endif
> >
> > -ifneq ($(findstring 2,$(KBUILD_ENABLE_EXTRA_GCC_CHECKS)),)
> > +ifneq ($(findstring 2,$(KBUILD_EXTRA_WARN)),)
> >  DTC_FLAGS += -Wnode_name_chars_strict \
> >         -Wproperty_name_chars_strict
> >  endif
> > diff --git a/scripts/genksyms/Makefile b/scripts/genksyms/Makefile
> > index baf44ed0a93a..78629f515e78 100644
> > --- a/scripts/genksyms/Makefile
> > +++ b/scripts/genksyms/Makefile
> > @@ -12,7 +12,7 @@ genksyms-objs := genksyms.o parse.tab.o lex.lex.o
> >  #
> >  # Just in case, run "$(YACC) --version" without suppressing stderr
> >  # so that 'bison: not found' will be displayed if it is missing.
> > -ifeq ($(findstring 1,$(KBUILD_ENABLE_EXTRA_GCC_CHECKS)),)
> > +ifeq ($(findstring 1,$(KBUILD_EXTRA_WARN)),)
> >
> >  quiet_cmd_bison_no_warn = $(quiet_cmd_bison)
> >        cmd_bison_no_warn = $(YACC) --version >/dev/null; \
> > --
> > 2.17.1
> >
>
>
> --
> Thanks,
> ~Nick Desaulniers