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From:   Masahiro Yamada <masahiroy@kernel.org>
Date:   Fri, 16 Apr 2021 14:57:12 +0900
Message-ID: <CAK7LNARTEhRtmFtCEA9JM9fqWmu2wcxPoGCJC4U8eofJibNUPQ@mail.gmail.com>
Subject: Re: [PATCH v2] kconfig: redo fake deps at include/config/*.h
To:     Alexey Dobriyan <adobriyan@gmail.com>
Cc:     Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>
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On Fri, Apr 16, 2021 at 2:36 AM Alexey Dobriyan <adobriyan@gmail.com> wrote=
:
>
> Make include/config/foo/bar.h fake deps files generation simpler.
>
> * delete .h suffix
>         those aren't header files, shorten filenames,
>
> * delete tolower()
>         Linux filesystems can deal with both upper and lowercase
>         filenames very well,
>
> * put everything in 1 directory
>         Presumably 'mkdir -p' split is from dark times when filesystems
>         handled huge directories badly, disks were round adding to
>         seek times.
>
>         x86_64 allmodconfig lists 12364 files in include/config.
>
>         ../obj/include/config/
>         =E2=94=9C=E2=94=80=E2=94=80 104_QUAD_8
>         =E2=94=9C=E2=94=80=E2=94=80 60XX_WDT
>         =E2=94=9C=E2=94=80=E2=94=80 64BIT
>                 ...
>         =E2=94=9C=E2=94=80=E2=94=80 ZSWAP_DEFAULT_ON
>         =E2=94=9C=E2=94=80=E2=94=80 ZSWAP_ZPOOL_DEFAULT
>         =E2=94=94=E2=94=80=E2=94=80 ZSWAP_ZPOOL_DEFAULT_ZBUD
>
>         0 directories, 12364 files
>
> Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
> ---
>
>  include/linux/compiler-version.h |    2 +-
>  init/Kconfig                     |    2 +-
>  kernel/gen_kheaders.sh           |    2 +-
>  scripts/Makefile.build           |    4 ++--
>  scripts/basic/fixdep.c           |   39 ++++----------------------------=
-------
>  scripts/kconfig/confdata.c       |   15 +++++----------
>  6 files changed, 14 insertions(+), 50 deletions(-)
>
> --- a/include/linux/compiler-version.h
> +++ b/include/linux/compiler-version.h
> @@ -9,6 +9,6 @@
>   * This header exists to force full rebuild when the compiler is upgrade=
d.
>   *
>   * When fixdep scans this, it will find this string "CONFIG_CC_VERSION_T=
EXT"
> - * and add dependency on include/config/cc/version/text.h, which is touc=
hed
> + * and add dependency on include/config/CC_VERSION_TEXT, which is touche=
d
>   * by Kconfig when the version string from the compiler changes.
>   */
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -21,7 +21,7 @@ config CC_VERSION_TEXT
>
>           - Ensure full rebuild when the compiler is updated
>             include/linux/compiler-version.h contains this option in the =
comment
> -           line so fixdep adds include/config/cc/version/text.h into the
> +           line so fixdep adds include/config/CC_VERSION_TEXT into the
>             auto-generated dependency. When the compiler is updated, sync=
config
>             will touch it and then every file will be rebuilt.
>
> --- a/kernel/gen_kheaders.sh
> +++ b/kernel/gen_kheaders.sh
> @@ -36,7 +36,7 @@ all_dirs=3D"$all_dirs $dir_list"
>  #
>  # When Kconfig regenerates include/generated/autoconf.h, its timestamp i=
s
>  # updated, but the contents might be still the same. When any CONFIG opt=
ion is
> -# changed, Kconfig touches the corresponding timestamp file include/conf=
ig/*.h.
> +# changed, Kconfig touches the corresponding timestamp file include/conf=
ig/*.
>  # Hence, the md5sum detects the configuration change anyway. We do not n=
eed to
>  # check include/generated/autoconf.h explicitly.
>  #
> --- a/scripts/Makefile.build
> +++ b/scripts/Makefile.build
> @@ -238,8 +238,8 @@ endif # CONFIG_STACK_VALIDATION
>
>  # Rebuild all objects when objtool changes, or is enabled/disabled.
>  objtool_dep =3D $(objtool_obj)                                   \
> -             $(wildcard include/config/orc/unwinder.h          \
> -                        include/config/stack/validation.h)
> +             $(wildcard include/config/ORC_UNWINDER            \
> +                        include/config/STACK_VALIDATION)
>
>  ifdef CONFIG_TRIM_UNUSED_KSYMS
>  cmd_gen_ksymdeps =3D \
> --- a/scripts/basic/fixdep.c
> +++ b/scripts/basic/fixdep.c
> @@ -34,7 +34,7 @@
>   * the config symbols are rebuilt.
>   *
>   * So if the user changes his CONFIG_HIS_DRIVER option, only the objects
> - * which depend on "include/config/his/driver.h" will be rebuilt,
> + * which depend on "include/config/HIS_DRIVER" will be rebuilt,
>   * so most likely only his driver ;-)
>   *
>   * The idea above dates, by the way, back to Michael E Chastain, AFAIK.
> @@ -74,7 +74,7 @@
>   *
>   * and then basically copies the .<target>.d file to stdout, in the
>   * process filtering out the dependency on autoconf.h and adding
> - * dependencies on include/config/my/option.h for every
> + * dependencies on include/config/MY_OPTION for every
>   * CONFIG_MY_OPTION encountered in any of the prerequisites.
>   *
>   * We don't even try to really parse the header files, but
> @@ -124,38 +124,6 @@ static void xprintf(const char *format, ...)
>         va_end(ap);
>  }
>
> -static void xputchar(int c)
> -{
> -       int ret;
> -
> -       ret =3D putchar(c);
> -       if (ret =3D=3D EOF) {
> -               perror("fixdep");
> -               exit(1);
> -       }
> -}
> -


Applied to linux-kbuild.

I just found one more minor thing to fix up.

fixdep no longer calls putchar(), so I squashed the following:


diff --git a/scripts/basic/fixdep.c b/scripts/basic/fixdep.c
index 5bee6a80992f..44e887cff49b 100644
--- a/scripts/basic/fixdep.c
+++ b/scripts/basic/fixdep.c
@@ -107,8 +107,8 @@ static void usage(void)

 /*
  * In the intended usage of this program, the stdout is redirected to .*.c=
md
- * files. The return value of printf() and putchar() must be checked to ca=
tch
- * any error, e.g. "No space left on device".
+ * files. The return value of printf() must be checked to catch any error,
+ * e.g. "No space left on device".
  */
 static void xprintf(const char *format, ...)
 {


--=20
Best Regards
Masahiro Yamada